专利摘要:
A ceramic precursor composition having a trimodal particle size distribution comprising: (a) a first inorganic particulate material having a coarse particle size distribution; (b) a second particulate mineral material having a particle size distribution that is thinner than (a); (c) a third inorganic particulate having a d50 less than or equal to about 5 μm and (d) a pore forming agent in an amount suitable for obtaining a ceramic having a porosity of at least about 50%.
公开号:FR3036114A1
申请号:FR1600770
申请日:2016-05-12
公开日:2016-11-18
发明作者:Pascual Garcia-Perez；Jean-Paul Giraud；Gilles Gasgnier；Marcia Sofia Gomes-Correia；Magdalena Gonzalez-Castro；Jean-Andre Alary
申请人:Imerys SA；
IPC主号:

专利说明:

[0001] TECHNICAL FIELD The present application relates to a ceramic precursor composition suitable for sintering a material of a ceramic structure, for example a ceramic honeycomb structure, a ceramic material or structure, for example a ceramic structure. honeycomb composition obtainable by sintering the ceramic precursor composition, a process for preparing the ceramic precursor composition and the ceramic material or structure, for example ceramic honeycomb structure, a filter diesel particulate comprising the ceramic structure, a diesel particulate filter, a gasoline particle filter comprising the ceramic structure, a vehicle comprising the diesel particulate filter, the diesel particulate filter or the diesel particulate filter. 20 gasoline particles, an SCR catalyst system comprising the material or structure Ceramic. BACKGROUND [0002] Ceramic structures, particularly ceramic honeycomb structures, are known in the art for the manufacture of liquid and gaseous fluid filters. The most relevant application today is the use of such ceramic structures as a particulate filter for the removal of fine particles from the vehicle diesel engine exhaust (diesel particles), since these fine particles have been shown to have a deleterious influence on human health. A brief overview of the ceramic materials known for this application is given in the article by J. Adler, Int. J. Appl. Ceram. Technol. 2005, 2 (6), p429-439, to which reference may be made for all purposes. Several ceramic materials have been described for the manufacture of ceramic honeycomb filters suitable for this specific application. Thus, for example, honeycombs made of mullite and tialite ceramic materials have been used to make diesel particulate filters. Mullite is a mineral silicate containing aluminum and silicon of varying composition between the two defined phases [3A1203 * 2Si02] (so-called "stoichiometric" mullite or "mullite 3: 2") and [2A1203 * 1SiO2] ( the so-called "mullite 2: 1"). The material is known to have a high melting point, refractory properties and quite good mechanical properties. Tialite is an aluminum titanate of formula [Al2Ti205]. The material is known to have a high thermal shock resistance, a small thermal expansion and a high melting point. Because of these properties, tialite has traditionally been a material of choice for the manufacture of honeycomb structures. For example, US-A-20070063398 discloses porous bodies for use as a particulate filter comprising greater than 90% tialite. Also US-A20100230870 discloses ceramic bodies suitable for use as a particulate filter having an aluminum titanate content of greater than 90% by weight. It has also been attempted to combine the good properties of mullite and tialite by providing ceramic materials comprising both phases.
[0002] WO-A-2009/076985 discloses a ceramic honeycomb structure comprising a mullite mineral phase and a tialite mineral phase. The examples describe a variety of ceramic structures typically comprising at least about 65 volume percent mullite and less than 15 volume percent tialite. WO-A-2014/053281 discloses a ceramic material providing desirable strength in combination with excellent thermal shock resistance which comprises a relatively small amount of a tialite phase in combination with a certain amount of mullite. As noted in the documents mentioned above, much has been focused on the relative amounts of tialite and mullite in ceramic structures and how this affects properties, such as strength, resistance to thermal shock and thermal expansion.
[0003] It is also known to coat porous ceramic structures with SCR (Selective Catalytic Reduction) catalysts. An example of such a structure is described in US-A-2013136662 using ammonia as a reducing agent in the conversion of NOx gas to N2 and water. The filtration efficiency of these ceramic structures depends on the physical and thermomechanical properties (eg, wall thickness, density, porosity, pore size, etc.) of the filter. High porosity is desirable, but it is still a challenge to prepare ceramic structures having both high porosity and good thermomechanical properties. SUMMARY OF THE INVENTION In a first aspect, there is provided a ceramic precursor composition having at least one trimodal particle size distribution, the ceramic precursor composition comprising: (a) a first inorganic particulate material having a coarse particle size distribution; (b) a second particulate mineral material having a particle size distribution that is thinner than (a); (c) a third inorganic particulate having a d50 of less than or equal to about 5 μm and optionally having a particle size distribution which is thinner than (b) and (d) one or at least one pore forming agent, for example in an amount suitable for obtaining a ceramic material having a porosity of at least about 50% (calculated on the basis of the total volume of the mineral phases and the pore space of the ceramic material). In a second aspect, there is provided a method for making a ceramic material or structure having a tialite content of at least about 50% by weight and a porosity of at least about 50%, the process comprising: (i) procuring, preparing or obtaining a ceramic precursor having at least one trimodal granulometry and having a composition comprising: (a) a first inorganic particulate material having a coarse particle size distribution, (b) a second inorganic particulate material having a particle size distribution which is finer (a), (c) a third mineral particulate matter having a d50 of less than or equal to about 5 μm and optionally a particle size distribution which is finer than (b), (d) a at least one pore-forming agent in an amount suitable for obtaining a ceramic material having a porosity of at least about 50%, (ii) forming a raw ceramic material to from the precursor ceramic composition, and (iii) sintering the raw ceramic material.
[0004] According to a third facet there is provided a ceramic material or structure having a tialite content of at least about 50% by weight based on the total weight of the material of the ceramic structure and a porosity of at least about 50%. the ceramic material or structure being obtained by a process comprising: (i) providing, preparing or obtaining a ceramic precursor having at least one trimodal particle size and having a composition comprising: (a) a first mineral particulate material having a coarse granulometric distribution, (b) a second mineral particulate having a particle size distribution which is finer than (a), (c) a third mineral particulate having a d50 of less than or equal to about 5 μm and optionally having a particle size distribution which is thinner than (b), and (d) one or at least one pore forming agent in an amount suitable for obtaining a material or ceramic having a porosity of at least about 50%, (ii) forming a material of a green ceramic structure from the ceramic precursor composition, and (iii) sintering the ceramic material or structure raw, for example at a temperature higher than 1400 ° C.
[0005] According to a fourth facet there is provided a ceramic structure according to the third facet in the form of a ceramic honeycomb structure. According to a fifth facet, there is provided a diesel particulate filter comprising or made of the ceramic honeycomb structure according to the fourth facet, or obtainable by certain embodiments of the method according to the second facet.
[0006] According to a sixth facet, there is provided a selective diesel particle filter comprising or made from the ceramic honeycomb structure according to the fourth facet, or obtainable by certain embodiments of the method according to the invention. second facet. According to a seventh facet, there is provided a gasoline particle filter comprising or made from the ceramic honeycomb structure following the fourth facet, or obtainable by certain embodiments of the process following the second facet.
[0007] According to an eighth facet, there is provided a vehicle having a diesel engine and a filtration system comprising: (i) the fifth-facet diesel particulate filter or (ii) the sixth diesel selective particle filter after the sixth facet. According to a ninth facet, there is provided a vehicle having a gasoline engine and a filtration system comprising the gasoline particle filter following the seventh facet. According to a tenth facet, there is provided an SCR catalyst system comprising a ceramic material or structure following the third or fourth facet and an SCR catalyst optionally coated on a surface of the ceramic material or structure. DETAILED DESCRIPTION OF THE INVENTION It has been surprisingly found that certain ceramic structures having both high porosity and good thermomechanical properties can be prepared by sintering from, for example, a ceramic precursor composition having minus a trimodal particle size distribution in combination with a blowing agent. Without wishing to be bound by theory, it is believed that the trimodal particle size distribution results in a tighter packing of the particulate materials to give a denser ceramic having sufficient wall strength to support a very porous structure.
[0008] The porosity of ceramic materials and structures, for example a ceramic honeycomb, is calculated on the basis of the total volume of the mineral phases and the pore space. The "total volume of mineral phases" of a ceramic material or structure means the total volume of the material or structure without the pore volume, i.e. only the solid phases. "Total volume of mineral phases and pore space" refers to the apparent volume of the ceramic material or structure, i.e., including solid phases and pore volume. Porosity can be determined by any suitable method. In some embodiments, the porosity is determined by mercury diffusion, as measured using a Mercury-Pascal Scientific Thermo201 porosimeter, with a 130 degree contact angle, or by any other measurement method that gives a result. equivalent. Quantities of tialite, mullite and other mineral phases can be measured in the ceramic material or structure, for example in the honeycomb ceramic structure, using the qualitative X-ray diffraction (Ka-ray radiation). Cu, 40 KV, 30 mA, Rietveld analysis with a 15% by weight Si standard) or by any other measurement method which gives an equivalent result. As will be understood by those skilled in the art, in the X-ray diffraction method, the sample is milled. After grinding, the powder is homogenized and then placed in the sample holder of the X-ray diffractometer. The powder is pressed into the sample holder and if powder is removed, it is removed to ensure a flat surface. . After placing the sample holder containing the sample in the X-ray diffractometer, the measurement is started. Typical measurement conditions are a step width of 0.030 °, a measurement time of 7 seconds per step and a measuring range of 29 from 10 to 60 °. The diffraction pattern obtained is used for the quantification of the different phases of which the sample material consists, using appropriate software capable of refining Rietveld. A suitable diffractometer is a SIEMENS D5000, and a suitable Rietveld software is the BRUKER AXS DIFRACPlus TOPAS. The amount of each mineral phase in the ceramic material or structure, for example in the honeycomb ceramic structure, is expressed as a percentage by weight relative to the total weight of the mineral phases.
[0009] Unless otherwise indicated, the particle size properties referred to herein, for example for inorganic particulate matter, for example inorganic starting materials or blowing agent, are as measured by the well-known conventional method employed. in the technique of laser light scattering, using a Malvern Mastersize 2000 machine as available from Malvern Instruments Ltd (or by other methods which provide substantially the same result). In the laser light scattering technique, the particle size of powders, suspensions and emulsions can be measured using diffraction of a laser beam on the basis of an application of the Mie theory. Such a machine provides measurements and plot of the cumulative percentage by volume of particles having a certain size, what is referred to in the art as the "equivalent spherical diameter" (dse), smaller than values. dse data The average particle size d50 is the value determined in this way of the particle size for which there is 50% by volume of the particles which have an equivalent spherical diameter smaller than the d50 value. We must understand in the same way the du and d90.
[0010] Unless otherwise indicated in each case, the lower and upper limits of a range are dso values. In the case of colloidal titania, the particle size is measured using transmission electron microscopy. Unless indicated otherwise, the size of the constituents present in the ceramic material or structure, for example in the honeycomb structure in particulate form, may be measured by image analysis.
[0011] The ceramic precursor composition which is suitable for sintering to form a ceramic structure has at least one trimodal particle size distribution and comprises (a) a first inorganic particulate material having a coarse particle size distribution; (b) a second particulate mineral material having a particle size distribution that is thinner than (a); (c) a third inorganic particulate having a d50 of less than or equal to about 5 μm and optionally having a particle size distribution which is finer than (b) and (d) one or at least one porogen.
[0012] By "trimodal" it is meant that the ceramic precursor composition comprises at least three constituents of inorganic particulate material which each have a singular particle size distribution (e.g., d50) relative to other mineral particulates of the ceramic precursor composition. . In some embodiments, the ceramic precursor composition has a trimodal particle size distribution. In some embodiments, the ceramic precursor composition has a tetramodal particle size distribution or a pentamodal particle size distribution or a hexamodal particle size distribution. The first inorganic particulate material has a relatively coarse particle size distribution, i.e., with respect to the at least two other inorganic particulates of the ceramic precursor composition.
[0013] The second mineral particulate material has a particle size distribution which is thinner than that of the first inorganic particulate material, for example a d50 which is smaller than the d50 of the first mineral particulate material.
[0014] The third mineral particulate matter has a d50 less than or equal to about 5 μm. In some embodiments, the third mineral particulate is thinner than the second mineral particulate, i.e., it has a d50 that is smaller than the d50 of the second mineral particulate matter.
[0015] In some embodiments, the first inorganic particulate matter has a d50 of from about 20 μm to about 80 μm, for example from about 20 μm to about 60 μm, or from about 20 μm to about 40 μm; and / or the second mineral particulate material has a d50 of from about 1.0 μm to about 20 μm, or from about 1.0 μm to less than about 20 μm, or about 1.0 μm to about about 15 μm, or about 1.0 μm to about 10 μm; and / or the third mineral particulate matter has a d50 less than or equal to about 5 μm and / or a finer particle size distribution than the second mineral particulate matter. In some embodiments, the first inorganic particulate has a d50 of about 20 μm to about 80 μm, the second mineral particulate has a d50 of about 1.0 μm to about 20 μm, or about 1 μm. 0 pm to less than 20 pm, and the third mineral particulate matter has a d50 less than or equal to about 5 pm and / or a finer particle size distribution than the second inorganic particulate matter. In some embodiments, the first inorganic particulate has a d50 of from about 20 μm to about 40 μm, the second mineral particulate matter has a d50 of from about 1.0 μm to about 10 μm, and the third material mineral particulate has a d50 less than or equal to about 5pm and / or a particle size distribution finer than the second mineral particulate matter.
[0016] In some embodiments, the first inorganic particulate has a d50 of from about 20 microns to about 35 microns, for example from about 20 microns to about 30 microns, or from about 20 microns to about 25 microns. or from about 25 pm to about 35 pm, or from about 30 pm to about 40 pm, or from about 30 pm to about 35 pm. In such embodiments, the first mineral particulate may have a d90 of from about 10 μm to about 60 μm, for example from about 35 μm to about 55 μm, or from about 30 μm to about 30 μm. 40 μm, or from about 45 μm to about 55 μm, or from about 55 μm to about 75 μm. By definition the d90 is always bigger than the d50. In addition or alternatively, the first mineral particulate may have a d10 of from about 10 μm to about 25 μm, for example from about 15 μm to about 25 μm, or from about 10 μm to about 20 μm, or from about 15 pm to about 25 pm. By definition the d10 is always smaller than the dm.
[0017] In some embodiments, the first mineral particulate has a d50 of from about 20 μm to about 30 μm, a d90 of from about 30 μm to about 40 μm, and a d10 of from about 10 μm to about 20 pm. In some embodiments, the first inorganic particulate matter has a d50 ranging from about 30 μm to about 40 μm, a d90 ranging from about 40% to about 60 μm, and a d10 ranging from about 15 μm to about 40 μm. 25 pm. In some embodiments, the second mineral particulate matter has a d50 of from about 2 μm to about 20 μm, for example from about 2 μm to less than about 20 μm, or from about 2 μm to about 14 μm. or about 2 μm to about 8 μm, or about 3 μm to about 6 μm, or about 5 μm to about 9 μm, or about 3.5 μm to about 5 μm. or from about 6.5 pm to about 8 pm. In such embodiments, the second mineral particulate may have a d90 of from about 5 μm to about 15 μm, for example from about 5 μm to about 10 μm, or from about 10 μm to about 10 μm. 15 pm. In addition or alternatively, the second mineral particulate may have a d10 of from about 0.5 μm to 5 μm, for example from about 1 μm to about 3 μm, or from about 3 μm to about 5 μm. . In some embodiments, the second inorganic particulate matter has a d50 ranging from about 6.5 to about 8 μm, a d90 ranging from about 10 μm to about 15 μm, and a d10 ranging from about 3 μm to about 10 μm. about 5 pm. In some embodiments, the second inorganic particulate matter has a d50 ranging from about 3 μm to about 6 μm, a d90 ranging from about 5 μm to about 10 μm, and a d10 ranging from about 1 μm to about 10 μm. 3pm. In some embodiments, the third inorganic particulate matter has a d50 less than or equal to about 5 μm, for example less than or equal to 4.5 μm, for example less than or equal to about 4 μm, for example less than or equal to about 3.5 μm, or less than or equal to about 3 μm, or less than or equal to about 2.5 μm, or less than or equal to about 2 μm, or less than or equal to about 1.5 μm, or less or less than about 1 μm, or less than or equal to about 0.5 μm, or less than or equal to about 0.25 μm. In some embodiments, the third mineral particulate matter has a d50 of at least about 0.05 μm, for example at least about 0.075 μm, or at least about 0.1 μm. In such embodiments, the third mineral particulate material may have a d90 of from about 0.25 μm to about 10 μm, for example from about 0.5 μm to about 7.5 μm, or about 0.5 pm to about 5 pm, or about 0.5 pm to about 2.5 pm, or about 0.5 pm to about 0.5 pm to about 2 pm, or about 0 pm 5 μm to about 1.5 μm, or about 0.5 μm to about 1 μm. In addition or alternatively, the third mineral particulate may have a d10 of from about 0.025 μm to about 5 μm, for example from about 0.025 μm to about 2.5 μm, or from about 0.04 μm to about 1.5 μm, or about 0.025 μm to about 1.0 μm, or about 0.025 μm to about 0.5 μm, or about 0.025 μm to about 0.25 μm, or about 0.025 μm to about 0.15 μm, or about 0.025 μm to about 0.1 μm, or about 0.025 μm to about 0.075 μm. In some embodiments, the third inorganic particulate material has a d50 less than or equal to about 5 μm, a d90 ranging from about 0.5 μm to about 2.5 μm and a d10 ranging from about 0.025 μm to about 0.15 pm.
[0018] In some embodiments, the third mineral particulate matter has a d50 less than or equal to about 2 μm, a d90 ranging from about 0.5 to about 2.5 μm and a d10 ranging from about 0.025 μm to about 0. , 15 pm.
[0019] In some embodiments, the third mineral particulate matter has a d50 less than or equal to about 0.5 μm, a d90 ranging from about 0.5 μm to about 1.5 μm and a d10 ranging from about 0.025 μm to about 1.0 μm. In some embodiments, the third inorganic particulate material has a d50 of from about 0.5 μm to about 1.5 μm, for example from about 0.5 μm to about 1 μm. In some embodiments, the third inorganic particulate material has a d50 of from about 1 μm to about 3 μm, for example from about 1.5 μm to about 2.5 μm. In some embodiments, the third inorganic particulate material has a d50 of from about 0.75 μm to about 2.25 μm, for example from about 1 μm to about 2 μm. Mineral particulates, for example solid inorganic compounds, suitable for use as raw materials in ceramic precursor compositions (aluminosilicate, alumina, titania, tialite, mullite, chamotte, etc.) can be used in the form of powders, suspensions, dispersions and the like. Corresponding formulations are commercially available and known to those skilled in the art. For example, powdered andalusite is commercially available under the trade name Kerphalite (Damrec), powdered alumina and alumina dispersions can be obtained from Evonik GmbH or at Nabaltec, and titanium oxide powder and titanium oxide dispersions are available from Cristal Global.
[0020] In some embodiments, the first inorganic particulate material comprises or is selected from tialite, one or more tialite-forming precursor compounds or compositions, mullite, and one or more mullite-forming precursor compounds or compositions and or the second mineral particulate comprises or is selected from tialite, one or more tialite-forming precursor compounds or compositions, mullite and one or more mullite-forming precursor compounds or compositions and / or the third mineral particulate matter is a precursor compound or composition forming tialite. In some embodiments, the first inorganic particulate material comprises or is selected from tialite, one or more tialite-forming precursor compounds or compositions, mullite, and one or more mullite-forming precursor compounds or compositions; the second mineral particulate 20 comprises or is selected from tialite, one or more tialite-forming precursor compounds or compositions, mullite and one or more mullite-forming precursor compounds or compositions, and the third mineral particulate material is a compound or a precursor composition forming tialite. In some embodiments, the first inorganic particulate comprises tialite and up to about 10% by weight of a Zr-containing mineral phase and / or one or more Zr-containing mineral phase compounds or compositions by relative to the total weight of the first inorganic particulate, for example up to about 8% by weight, or up to about 7% by weight, or up to about 6% by weight, or up to about 30% % by weight, or up to about 4% by weight, or up to about 3% by weight, or up to about 2% by weight, or up to about 1% by weight, or up to about 0% , 5% by weight, or up to about 0.25% by weight of a Zr-containing mineral phase and / or one or more Zr-containing compounds or mineral-forming compositions. In addition or alternatively, the first mineral particulate may comprise up to about 5% by weight of an alkaline earth metal-containing mineral phase and / or mineral phase-forming compounds or compositions containing a mineral phase containing a alkaline earth metal with respect to the total weight of the first inorganic particulate, for example up to about 4% by weight, or up to about 3% by weight, or up to about 2% by weight, or up to about at about 1% by weight, or up to about 0.5% by weight of a mineral phase containing alkaline earth metal or one or more compounds or compositions forming an alkaline earth metal-containing mineral phase .
[0021] In such embodiments, the first inorganic particulate may comprise at least about 80% by weight of tialite, based on the total weight of the first inorganic particulate, for example from about 80% by weight to about 100% by weight, or about 80% to about 99% by weight, or about 85% by weight to about 95% by weight, or about 90% by weight to about 95% by weight, or at least about 91% by weight, or at least about 92% by weight. In some embodiments, the first mineral particulate is substantially free of Zr-containing mineral phase and / or one or more Zr-containing mineral-containing compounds or compositions and / or the first mineral particulate material is substantially and an alkaline earth metal-containing inorganic phase and / or one or more alkaline earth-metal containing compounds or compositions.
[0022] As used herein, the term "substantially free" refers to the total absence or almost complete absence of a specific compound or composition or a specific mineral phase. For example, when it is said that the ceramic composition is substantially free of a mineral phase containing Zr and / or one or more Zr-containing mineral phase compounds or compositions, or although there is no such mineral phase or inorganic phase forming compounds or compositions in the first mineral particulate matter, or there are only traces thereof. One skilled in the art will understand that a trace is an amount that can be detected by the XRD method described above, but which is not quantifiable and which, if present, would not adversely affect the properties of the ceramic precursor composition. In some embodiments, the first inorganic particulate comprises mullite and up to about 5% by weight of a Zr-containing mineral phase and / or one or more Zr-containing mineral phase compounds or compositions by relative to the total weight of the first inorganic particulate, for example up to about 4% by weight, or up to about 3% by weight, or up to about 2% by weight, or up to about 1% by weight, or up to about 0.5% by weight, or up to about 0.25% by weight of a mineral phase containing Zr and / or one or more compounds or compositions forming a mineral phase containing Zr.
[0023] In addition or alternatively, the first inorganic particulate material may comprise up to about 2.5% by weight of an alkaline earth metal-containing mineral phase and / or inorganic phase-forming compounds or compositions containing alkaline earth metal with respect to the total weight of the first inorganic particulate, for example up to about 2% by weight, or up to about 1.5% by weight, or up to about 1% by weight, or up to about 0.5% by weight, or up to about 0.25% by weight of an alkaline earth metal-containing mineral phase and / or one or more inorganic phase-forming compounds or compositions containing an alkaline earth metal. In such embodiments, the first inorganic particulate material is substantially free of a mineral phase containing Zr and / or one or more Zr-containing mineral phase-forming compounds or compositions and / or the former. The inorganic particulate material is substantially free of an alkaline earth metal-containing inorganic phase and / or one or more alkaline earth-metal-containing inorganic phase-forming compounds or compositions. In such embodiments, the first inorganic particulate may comprise at least about 90% by weight mullite, based on the total weight of the first inorganic particulate, for example from about 95% by weight to about 100% by weight, or from about 95% by weight to about 99% by weight, or from about 95% by weight to about 98% by weight, or from about 95% by weight to about 97% by weight or at least about 95% by weight of mullite or at least about 96% by weight of mullite.
[0024] In some embodiments, the first inorganic particulate material is selected from tialite, one or more tialite-forming precursor compounds or compositions, mullite, and one or more mullite-forming precursor compounds or compositions. In some embodiments, the first mineral particulate is tialite, mullite, or a mixture of tialite and mullite. In some embodiments, the first inorganic particulate material is selected from mullite, tialite, aluminosilicate, titania and alumina. In some embodiments, the first mineral particulate is tialite. In some embodiments, the first inorganic particulate is a mixture of tialite and mullite, for example in a mullite tialite to weight ratio of about 1: 5 to about 1:10. In some embodiments, the first inorganic particulate is a mullite-forming precursor composition, comprising for example at least about 50% by weight of alumina and less than about 50% by weight of silica, for example at least about 75% by weight of alumina and less than about 25% by weight of silica. In such embodiments, the mullite-forming precursor composition may have a range of about 40 microns to about 80 microns, for example, about 50 microns to about 70 microns or about 55 microns to about 50 microns. 65 pm. In some embodiments, the second mineral particulate material is selected from tialite, one or more tialite-forming precursor compounds or compositions, mullite, and or more mullite-forming precursor compounds or compositions. In some embodiments, the second mineral particulate is mullite, tialite, or a mixture of mullite and tialite. In some embodiments, the second inorganic particulate material is selected from mullite, tialite, aluminosilicate, titania and alumina. In some embodiments, the second mineral particulate is mullite. In some embodiments, the second mineral particulate is tialite. In some embodiments, the second inorganic particulate is a mixture of tialite and mullite, for example, a mullite tialite to weight ratio of about 5: 1 to about 1: 5, e.g. 4: 1 to about 1: 4, or about 3: 1 to about 1: 3, or about 2: 1 to about 1: 2.
[0025] In some embodiments, the second inorganic particulate material comprises at least about 90% by weight mullite, for example at least about 95% by weight mullite, or at least about 99% by weight mullite, or at least about essential 100% by weight of mullite. In some embodiments, for example in embodiments where the first inorganic particulate is a mullite-forming precursor composition, the second inorganic particulate is a tialite precursor composition comprising at least about 90% by weight titanium oxide and up to about 5% by weight of an alkaline earth metal-containing inorganic phase, such as, for example, magnesium oxide. In some embodiments, the second inorganic particulate is a tialite precursor composition comprising at least about 95% by weight titanium oxide, or up to about 99% by weight titanium and up to about 5% by weight. Magnesium oxide, for example up to about 1% by weight of magnesium oxide. In some embodiments, the second inorganic particulate material has the same chemical composition as the first inorganic particulate material, thus differing only in particle size distribution. In some embodiments, the first inorganic particulate is tialite and the second inorganic particulate is mullite. In some embodiments, the first inorganic particulate is tialite and the second mineral particulate is a mixture of tialite and mullite as described above. In some embodiments, the first inorganic particulate is a mixture of tialite and mullite as described above, and the second mineral particulate is mullite or a mixture of tialite and mullite as described above. In some embodiments, the first mineral particulate is mullite and the second mineral particulate is tialite.
[0026] In some embodiments, the third inorganic particulate is a composition comprising titanium oxide, alumina, optionally an alkaline earth metal-containing mineral phase and / or one or more precursor compounds or compositions forming an inorganic phase containing an alkaline earth metal and optionally a mineral phase containing Zr and / or one or more compounds or compositions forming a mineral phase containing Zr. In some embodiments, the third mineral particulate 3036114 is substantially free of a mineral phase containing Zr and / or one or more Zr-containing mineral phase compounds or compositions.
[0027] In some embodiments, the third inorganic particulate material comprises at least about 90% by weight of alumina and / or titanium oxide, based on the total weight of the third mineral particulate matter, for example at least about 92% by weight. % by weight of alumina and / or titanium oxide, or at least about 94% by weight of alumina and / or titanium oxide, or at least about 95% by weight of alumina and / or of titanium oxide, or at least 96% by weight of alumina and / or titanium oxide, or at least 97% by weight of alumina and / or titanium oxide, or at least 98% by weight of alumina and / or titanium oxide, or at least 99% by weight of alumina and / or titanium oxide. In some embodiments, the third mineral particulate comprises up to about 5% by weight of an inorganic phase comprising an alkaline earth metal and / or one or more inorganic metal-containing compounds or compositions forming an alkali metal earth, based on the total weight of the third mineral particulate, for example up to about 4% by weight, or up to about 3% by weight, or up to about 2% by weight, or up to about about 1% by weight of an alkaline earth metal-containing inorganic phase and / or alkaline earth metal containing compounds or compositions forming an inorganic phase. In some embodiments, the third mineral particulate material is substantially free of an alkaline earth metal-containing mineral phase and / or one or more alkaline earth-metal-containing inorganic phase-forming compounds or compositions.
[0028] The aluminosilicate may be selected from one or more of andalusite, cyanite, sillimanite, mullite, molochite, hydrous candite clay such as kaolin, halloysite or plastic clay or anhydrous (calcined) candite clay such as completely calcined meta-kaolin or kaolin. The titanium oxide may be selected from one or more of rutile, anatase, brookite. Aluminum titanate can be selected from alumina and titania precursors, sintered aluminum titanate or molten aluminum titanate.
[0029] The Zr-containing mineral phase and / or one or more Zr-containing mineral-containing compounds or compositions can be selected from one or more of ZrO 2 and zirconium titanate, for example, Ti, Zr-xOl, in which x is from 0.1 to 0.9, for example being greater than about 0.5. In some embodiments, the Zr-containing mineral phase and / or one or more Zr-containing mineral phase-forming compounds or compositions is a mixture of ZrO 2 and zirconium titanate. The alkaline earth metal-containing inorganic phase and / or one or more alkaline earth metal-containing inorganic phase-forming compounds or compositions may be selected from one or more of an M oxide, a M carbonate, or of a M titanate, M being Mg, Ca or Ba, preferably Mg.
[0030] The alumina may be selected from one or more of fused alumina (eg, corundum), sintered alumina, calcined alumina, reactive or semi-reactive alumina, and bauxite.
[0031] In all of the above embodiments comprising the use of alumina (Al 2 O 3), titania (TiO 2) and zirconium oxide (ZrO 2), alumina, titania and / or or the zirconium oxide may be replaced in whole or in part by precursor compounds of alumina, titania and / or zirconium oxide. By the term "alumina precursor compound" is meant compounds which may comprise one or more additional constituents of alumina (Al) and oxygen (O), additional components which are removed when the precursor compound alumina is subjected to sintering conditions, the additional components being volatile under sintering conditions. Thus, although the precursor compound of alumina may have a total formula other than Al 2 O 3, only one component having a formula Al 2 O 3 (or its reaction product with other solid phases) remains after sintering. The amount of an alumina precursor compound present in the ceramic precursor composition or in an extrudable mixture prepared therefrom, or in a honeycomb net structure can be easily calculated to represent a precise equivalent of alumina (Al 2 O 3). The terms "titanium oxide precursor compound" and "zirconium oxide precursor compound" should be understood in a similar manner. Examples of precursor alumina compounds include, but are not limited to, aluminum salts, such as aluminum phosphates and aluminum sulfates, or aluminum hydroxides such as boehmite (A10 (OH) and gibbsite (Al (OH) 3) The additional hydrogen and oxygen components present in these compounds are released during sintering in the form of water, usually the precursor compounds of the alumina. reagents in solid phase reactions occurring under sintering conditions than alumina (A1203) itself.
[0032] When used, the aluminosilicate and in part the alumina may be considered as the main mullite forming components of the ceramic precursor composition. During the primary mullitization, the aluminosilicate decomposes and mullite is formed. In the secondary mullitization, excess silica of the aluminosilicate reacts with the remaining alumina, again forming mullite. As described below, the ceramic precursor composition can be sintered at a suitably high temperature, so that substantially all of the aluminosilicate and alumina is consumed in the primary and secondary mullitization stages.
[0033] In some embodiments, the third inorganic particulate is a composition comprising from about 40% by weight to about 60% by weight of titanium oxide, from about 40% by weight to about 60% by weight of alumina, from about 0% by weight up to about 5% by weight of a mineral phase containing an alkaline earth metal and / or one or more compounds or compositions forming an alkaline earth metal-containing mineral phase and from about 0% by weight to about 5% by weight of a mineral phase containing Zr and / or one or more compounds or compositions forming a mineral phase containing a Zr-containing mineral phase based on total weight of the third mineral particulate matter.
[0034] The relative amounts of the first, second and third mineral particulates may be selected so that, after sintering the ceramic precursor composition at a temperature higher than 1400 ° C, or higher than about 1500 ° C, there is obtained a ceramic material or structure, for example a ceramic honeycomb structure, according to the third aspect of the present invention, or obtainable by the method according to the second aspect of the present invention. In some embodiments, the ceramic precursor composition comprises from about 20% by weight to about 60% by weight of the first inorganic particulate, from about 15% by weight to about 50% by weight of the second material. mineral particulate, and from about 15% by weight to about 50% by weight of the third inorganic particulate matter based on the combined total weight of the first, second, and third mineral particulates. If the ceramic precursor composition has a tetramodal particle size distribution, the amounts disclosed herein would be based on the combined total weight of the first, second, third and fourth mineral particulate matter. In some embodiments, the ceramic precursor composition comprises from about 25% by weight to about 55% by weight of the first inorganic particulate, for example from about 25% by weight to about 55% by weight, or about 25% by weight to about 50% by weight, or about 30% by weight to about 45% by weight, or about 35% by weight to about 45% by weight, or about 5% by weight. From about 30% by weight to about 40% by weight, or from about 30% by weight to about 35% by weight, or from about 35% by weight to about 40% by weight, based on the combined total weight of the former, second and third mineral particulates.
[0035] In some embodiments, the ceramic precursor composition comprises from about 20% by weight to about 45% by weight of the second inorganic particulate, for example from about 20% by weight to about 40% by weight, or about 20% by weight to about 35% by weight, or about 25% by weight to about 40% by weight, or about 25% by weight to about 35% by weight, or about 30% by weight. from about 30% by weight to about 40% by weight, or from about 30% by weight to about 35% by weight, based on the combined total weight of the first, second, and third mineral particulates. In some embodiments, the ceramic precursor composition comprises from about 20% by weight to about 45% by weight of the third mineral particulate, for example from about 20% by weight to about 40% by weight, or from about 20% by weight to about 35% by weight, or from about 25% by weight to about 40% by weight, or from about 25% by weight to about 35% by weight, or about 30% by weight. from about 40 wt.%, or from about 30 wt.% to about 35 wt.%, or from about 25 wt.% to about 30 wt.%, based on the combined total weight of the first, second and third mineral particulate matter.
[0036] In some embodiments, the ceramic precursor composition comprises from about 25% by weight to about 40% by weight of a first inorganic particulate, from about 25% by weight to about 40% by weight of the composition. the second mineral particulate, and from about 25% by weight to about 35% by weight of the third mineral particulate, based on the combined total weight of the first, second, and third mineral particulates. In some embodiments, the ceramic precursor composition comprises from about 30% by weight to about 40% by weight of the first inorganic particulate, from about 30% by weight to about 40% by weight of the second material. mineral particulate, and from about 25% by weight to about 35% by weight of the third mineral particulate, based on the combined total weight of the first, second, and third mineral particulates. In some embodiments, the ceramic precursor composition comprises from about 40% by weight to about 60% by weight of the first inorganic particulate, from about 15% by weight to about 35% by weight of the second material. mineral particulate, and from about 15% by weight to about 35% by weight of the third mineral particulate, based on the combined total weight of the first, second, and third mineral particulates. In some embodiments, the ceramic precursor composition comprises from about 45% by weight to about 55% by weight of the first inorganic particulate, from about 15% by weight to about 35% by weight of the second. mineral particulate matter, and from about 15% by weight to about 30% by weight of the third mineral particulate matter, based on the combined total weight of the first, second and third mineral particulate matter. In some embodiments, the ceramic precursor composition comprises from about 45% by weight to about 55% by weight of the first inorganic particulate, from about 15% by weight to about 25% by weight of the second material. mineral particulate, and from about 25% by weight to about 30% by weight of the third mineral particulate, based on the combined total weight of the first, second, and third mineral particulates. In some embodiments, the ceramic precursor composition comprises from about 45% by weight to about 55% by weight of the first inorganic particulate, from about 15% by weight to about 25% by weight of the second material. mineral particulate, and from about 15% by weight to about 25% by weight of the third mineral particulate, based on the combined total weight of the first, second, and third mineral particulates. In some embodiments, the weight ratio of the first inorganic particulate to the third inorganic particulate is not greater than about 3: 1, for example not greater than about 2.5: 1, or no larger than about 2: 1. In addition or alternatively, in some embodiments, the weight ratio of the first inorganic particulate to the second mineral particulate is not greater than about 3: 1, for example not greater than about 2.5: 1, or not greater than about 2: 1, or not greater than about 1.5: 1. In addition or alternatively, in some embodiments, the weight ratio of the second inorganic particulate to the third mineral particulate is from about 0.5: 1 to about 2: 1, e.g. , 75: 1 to about 1.5: 1.
[0037] As described above, the ceramic precursor composition further comprises a blowing agent. A porogen is a species that induces and enhances the creation of porosity in the ceramic structure obtained from the ceramic precursor composition. The blowing agent may be a mixture of blowing agents. In some embodiments, the blowing agent is present in an amount suitable for obtaining (for example, by passing through the furnace or sintering of the ceramic precursor composition), a ceramic material or structure having a porosity of at least about 50%, e.g. at least about 55%, or at least about 60%, or at least about 65%, or at least about 70%, or at least about 75%. %. In general, the porosity of the material or the ceramic structure obtained therefrom, for example by passing through the oven or by sintering, is greater the greater the amount of pore-forming agent in the precursor composition of the ceramic is bigger. In some embodiments, the blowing agent is present in an amount suitable for obtaining a ceramic material or structure having a porosity of from about 50% to about 75%, or from about 55% to about 70%, or from about 55% to about 65%, or from about 60% to about 70%, or from about 60% to about 65%.
[0038] In some embodiments, the ceramic precursor composition comprises from about 10% by weight to about 90% by weight of blowing agent relative to the combined total weight of the first, second, and third mineral particulates. Thus, for example, if the ceramic precursor composition consists entirely of the first, second and third mineral raw materials and 50% by weight of blowing agent relative to the combined total weight of the first, second and third In the case of inorganic particulates, the weight ratio of the total combined weight of the first, second and third mineral particulate matter to the weight of the blowing agent would be 1: 1. If the ceramic precursor composition has a tetramodal particle size distribution, the amounts thus described would relate to the combined total weight of the first, second, third and fourth mineral particulate matter. Similarly, if the ceramic precursor composition has a pentamodal particle size distribution, the amounts described would relate to the combined total weight of the first, second, third, and fourth mineral particulate matter. This principle applies to any constituent in terms of an amount in relation to the total amount of mineral particulate matter.
[0039] In certain embodiments, the ceramic precursor composition comprises from about 20% by weight to pore-forming agent, for example about 80% by weight, or about 80% by weight, or about 85% by weight of about 30% by weight of about 40% by weight of about 45% by weight to about 80% by weight, or about 45% by weight to about 75% by weight, or about 50% by weight. weight at about 80% by weight, or about 50% by weight to about 75% by weight, or about 50% by weight to about 70% by weight, or about 50% by weight at about 65% by weight % by weight, or from about 55% by weight to about 70% by weight, or from about 60% by weight to about 70% by weight, based on the combined total weight of the first, second and third mineral particulates. Suitable blowing agents include graphite or other forms of carbon, cellulose and cellulose derivatives, starch, organic polymers, plastics and mixtures thereof. In some embodiments, the blowing agent comprises starch or is starch. In some embodiments, the blowing agent comprises a plastics material or is a plastics material, for example a polymer microsphere, for example an acrylate copolymer, such as, for example, a methyl methacrylate copolymer, for example for example, a copolymer of methyl methacrylate and an alkylene glycol dimethacrylate (for example a copolymer of methyl methacrylate and ethylene glycol dimethacrylate). In some embodiments, the blowing agent has a d50 of from about 20 to about 50 μm, for example from about 20 to about 45 μm, or for example from about 20 to about 40 μm, or about 20 to about 35 pm. In such embodiments, the blowing agent may have a density of about 1.0 to 2.5 g / cm 3.
[0040] The ceramic precursor composition may further comprise a binding agent or a plurality of binding agents, an adjuvant or a plurality of adjuvants and / or a solvent. Binders and adjuvants that can be used in the present invention are all commercially available from various sources known to those skilled in the art. The function of the binder is to provide sufficient mechanical stability of the green structure in the operating stages prior to heating or sintering. The additional adjuvants give the raw material, i.e., the ceramic precursor composition, advantageous properties in the extrusion stage (eg plasticizers, slip agents, lubricants, and the like). like). In some embodiments, the ceramic precursor composition (or the extrudable blend of the resulting green structure) comprises one or more binding agents selected from the group consisting of methyl cellulose, hydroxymethylpropyl cellulose, polyvinyl butyrals, emulsified acrylates, polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylics, starch, silicone binders, polyacrylates, silicates, polyethylene imine, lignosulphonates and alginates. Binders may be present in a total amount of from about 0.5 wt.% To about 20 wt.%, For example from about 0.5 wt.% To about 15 wt.%, Or from about 2 wt.% To about 10 wt.%, Or up to about 5 wt.%, Based on the combined total weight of the first, second and third mineral particulate matter. In another embodiment, the ceramic precursor composition (or extrudable mixture or green structure thereof) comprises one or more adjuvants (eg, plasticizers and lubricants) selected from the group consisting of polyethylene glycols. (PEGs), glycerol, ethylene glycol, octyl phthalates, ammonium stearates, wax emulsions, oleic acid, Manhattan fish oil, stearic acid, wax , palmitic acid, linoleic acid, myristic acid and lauric acid.
[0041] The adjuvants may be present in a total amount of from about 0.5% by weight to about 40% by weight, for example from about 0.5% by weight to about 35% by weight, or about 5% by weight. from about 10% by weight to about 30% by weight, or from about 10% by weight to about 30% by weight, or from about 20% by weight to about 30% by weight, based on the combined total amount of the first second and third mineral particulates.
[0042] The ceramic precursor composition may be combined with a solvent. The solvent may be an organic or aqueous liquid agent In some embodiments, the solvent is water. The solvent, for example water, may be present in an amount of from about 1% by weight to about 100% by weight, based on the combined total weight of the first, second and third mineral particulates, for example from about 5% by weight to about 90% by weight, or from about 25% by weight to about 75% by weight, or from about 35% by weight to about 65% by weight, or about 40 wt.% To about 60 wt.%, Or about 45 wt.% To about 55 wt.%, Based on the combined total weight of the first, second and third mineral particulates.
[0043] In another embodiment, the ceramic precursor composition (or the extrudable mixture or the honeycomb green structure formed therefrom) comprises one or more inorganic binders. A suitable inorganic binder may be selected from the group including, but not limited to, one or more of bentonite, aluminum phosphate, boehmite, sodium silicates, boron silicates, or mixtures thereof. The inorganic binders may be present in a total amount of up to about 10% by weight, for example, from about 0.1% by weight to about 10% by weight, or about 0.5% by weight. to about 5.0% by weight, or about 1.0% by weight to about 3.0% by weight, based on the combined total weight of the first, second, and third mineral particulates. In some embodiments, the third mineral particulate material is at least partly binder in the ceramic precursor composition. Without wishing to be bound by theory, it is believed that the relatively small particle size of the third mineral particulate allows particles, eg, titanium oxide and alumina precursors, to participate in a binding process or during the baking / sintering of the ceramic precursor composition. This can increase the stability of the ceramic structure at higher temperatures than ceramic structures prepared without the relatively fine third particulate mineral material which is described herein. The ceramic precursor composition may include minerals other than the first, second, and third mineral particulates and any other mineral-based additives described herein. In some embodiments, the ceramic precursor composition does not contain any mineral additive other than the first, second, and third mineral particulates disclosed herein. In certain embodiments in which the ceramic precursor composition has a tetramodal particle size distribution and comprises the first, second, third and fourth mineral particulate matter, the ceramic precursor composition does not comprise any mineral additives other than the first, second and second third and fourth mineral particulates.
[0044] Ceramic Structures The ceramic materials and structures of the present invention have a tialite content of at least about 50% by weight, based on the total weight of the ceramic material and a porosity of at least about 50% (calculated on the base of the total volume of the mineral phases and the pore space of the ceramic material). The ceramic material or structure is obtained or prepared by a process comprising: (i) providing, preparing or obtaining a ceramic precursor having at least one trimodal particle size and having a composition comprising: (a) a first particulate material mineral having a coarse particle size distribution; (b) a second mineral particulate having a particle size distribution which is thinner (a); (c) a third mineral particulate having a d50 less than or equal to about 5 μm and optionally a particle size distribution that is thinner than (b); (D) one or at least one pore forming agent in an amount suitable for obtaining a ceramic material having a porosity of at least about 50%, (ii) forming a green ceramic material from the ceramic precursor composition, and (Iii) sintering the raw ceramic material. In some embodiments, the ceramic precursor composition has a composition as described above. That is, the ceramic precursor composition may have a composition according to each of the embodiments of the first facet of the present invention. The preparation of the ceramic precursor composition (optionally in combination with a binder or binding agents, a mineral binder or inorganic binders and / or an adjuvant or adjuvants) is carried out by the technical methods known in the art. (For example, as described in Extrusion in Ceramics, F.
[0045] 30 Hândle, 2007, Springer). For example, the constituents of the ceramic precursor composition can be mixed in a conventional kneading machine with the addition of an appropriate amount of a suitable liquid phase, as required (normally water) to a slurry. or to a suitable paste for subsequent processing for example by extrusion. In some embodiments, the ceramic precursor composition is prepared as an extrudable blend. In addition, conventional extrusion equipment (such as, for example, a screw extruder) and dies may be used, for example for the extrusion of honeycomb structures known in the art. A summary of the technology can be found in the handbook of W. Kollenberg (ed.), Technische Keramik, Vulkan edition, Essen, Germany, 2004, to which reference will be made.
[0046] For extruded parts, the size and shape of the green structures (eg, honeycomb raw structures, based on their diameter) can be determined by selecting extruder dies of desired dimensions and shapes. . After the extrusion, the extruded mass can be cut into pieces, for example into monolithic pieces of suitable length or to obtain, for example, green honeycomb structures of a desired size. Suitable cutting means for this stage (such as wire knives) are known to those skilled in the art. The green structure (optionally extruded) formed from the ceramic precursor composition, for example the honeycomb green structure, can be dried by methods known in the art (eg microwave drying, drying). by hot air) before sintering.
[0047] The dried green structure is then heated to prepare ceramic materials and structures. In general, any furnace or cullet which is suitable for subjecting the heated objects to a predetermined temperature and / or controlled heating may be used and any cooling cycle is suitable for the process according to the invention. invention. Steps can be taken to control the temperature during heating and cooling. Steps can also be taken to control the gaseous atmosphere in the furnace or cullet, for example to control the oxygen content. In some embodiments, the heating is conducted under an atmosphere having a reduced oxygen content (i.e., less than the oxygen content of the air, which is about 21%). This can increase the homogenous combustion of the blowing agent during heating (eg at temperatures between about 180 ° C and 600 ° C) and, in turn, increase the thermal parameters of the ceramic material or structure. having the porosity advantageously large. In some embodiments, the oxygen content of the atmosphere in the furnace or cullet is less than about 10% by volume, for example less than about 5% by volume, OR less than about 2% by volume. An atmosphere having a reduced oxygen content can be obtained, for example by introducing a suitable amount of an inert gas, for example nitrogen and / or argon or by introducing a recirculated exhaust gas (for example a mixture air and exhaust gas from the furnace or cullet). In some embodiments, the green honeycomb structure can be plugged before sintering. In other embodiments, the capping may be performed after sintering. Other details of the capping operation will be described below. When the green structure comprises the binder organic compound and / or organic builders, the structure is usually heated to a temperature in the range of about 150 ° C to about 400 ° C, for example about 200 ° C. C at about 400 ° C, or about 200 ° C to about 300 ° C, before the structure is brought to the final sintering temperature, and the temperature is maintained for a time sufficient to remove organic binders and adjuvants at using a combustion (for example, between one and three hours).
[0048] The pre-sintered ceramic structure can be sintered at a temperature higher than about 1400 ° C, for example at a temperature of up to about 1700 ° C, or about 1450 ° C to 1650 ° C or about 1450 ° C. C. and 1600 ° C, or between about 1450 ° C and 1550 ° C, or between about 1475 ° C and 1525 ° C, or at a temperature of about 1500 ° C. In some embodiments, the method comprises the steps of: (i) (1) procuring, preparing, or obtaining an extrudable mixture of the ceramic precursor composition, (i) (2) extruding the mixture to form a structure for example, a green honeycomb structure, (i) (3) drying the green ceramic structure, and (ii) sintering the green ceramic structure, for example at a temperature higher than 1400 ° C.
[0049] The sintering may be carried out for a suitable period of time at a suitable temperature so that the ceramic material or structure comprises at least about 50% by weight of tialite and has a porosity of at least about 50% (calculated relative to the total volume of the mineral phases and the pore space of the ceramic material). In some embodiments, the ceramic material or structure has a porosity of at least about 55%, for example greater than or equal to about 60% or greater than or equal to 61%, or greater than or equal to about 62%, or greater than or equal to about 63%, or greater than or equal to about 64%, or greater than or equal to about 65%. In some embodiments, the ceramic material or structure has a porosity of from about 50% to about 75%, for example from about 55% to about 70%, or from about 60% to about 70%, or about 60% to about 65%. In such embodiments, the ceramic material or structure may have a tialite content of at least about 55% by weight, or at least about 60% by weight, or at least about 65% by weight. % by weight, or at least about 70% by weight, or at least about 75% by weight, or at least about 80% by weight. In some embodiments, the ceramic material or structure has a tialite content of from about 60% by weight to about 100% by weight, for example from about 60% by weight to about 90% by weight, or from from about 65% by weight to about 85% by weight, or from about 70% by weight to about 80% by weight, or from about 70% by weight to about 75% by weight. In some embodiments, the ceramic material or structure has a porosity of at least about 60% and a content of greater than or equal to 60% by weight, for example greater than or equal to about 65% by weight, or from about 65% by weight, or about 85% by weight, or about 70% by weight, or about 80% by weight, or from about 70% by weight to about 75% by weight . In some embodiments, the ceramic material or structure comprises from about 0% by weight to about 40% by weight of mullite, for example from about 10% by weight to about 40% by weight of mullite, or from from about 20% by weight to about 35% by weight of mullite, or from about 20% by weight to about 30% by weight of mullite, or from about 25 to 30% by weight of mullite.
[0050] In some embodiments, the total weight of the ceramic phases, for example the total weight of the mineral phases, the ceramic structure, or at least the mineral phases, at least about 80% of the total weight of the ceramic phase, may be the total weight of the mineral phases. or at least about 85% of the material or about 90% by weight or at least one or more of the ceramic material or structure, less 92% of the total weight of the inorganic phases, minus about 94%, or at least about 96%, or about 97, or at least about 98%, or at least about 99% of the total weight of the mineral phases, or about 98.5% by weight of the mineral phases, or about 98.0% by weight of the mineral phases, or up to about 97.5% by weight of the mineral phases, or up to about 97.0% by weight of the mineral phases, or up to about 96.5% by weight of the mineral phases, or up to about 96.0% by weight of the mineral phases, or up to about 95, 5% by weight of the mineral phases, or up to about 95.0% by weight of the mineral phases.
[0051] In some embodiments, the ceramic material or structure comprises up to about 5.0% by weight of a Zr-containing mineral phase, for example from about 0.1% by weight to about 5.0%. by weight of a Zr-containing mineral phase, or from about 0.1% by weight to about 3.5% by weight of a Zr-containing mineral phase, or from about 0.5% by weight to about about 2.0% by weight of a mineral phase containing Zr. In some embodiments, the Zr-containing mineral phase comprises Zr0 (e.g., zirconia). In some embodiments, the Zr-containing mineral phase comprises zirconium titanate. In some embodiments, the Zr-containing mineral phase comprises ZrO and zirconium titanate. In some embodiments, the zirconium titanate has the chemical formula Tix Zr1.02, x being from 0.1 to about 0.9, for example being greater than about 0.5. In some embodiments, the Zr-containing mineral phase comprises a mixture of ZrO 2 and Tix Zr1.02. In some embodiments, the ceramic material or structure is substantially free of a Zr-containing mineral phase, for example, free of ZrO 2.
[0052] In addition or alternatively, the material or ceramic may further comprise about 0 wt. Of a mineral phase containing a 3.0% alkaline earth metal, for example about 0.5 to 2 wt. 5% of about 1.0 to 2.5% by weight, or about 30% by weight, or about 1.0 to 2.0% of metal-containing mineral Advantageously, the mineral phase by weight, or 1.0 to 2.0% by weight of an alkaline earth phase. The alkaline earth metal-containing material is a mineral phase containing Mg, for example MgO.
[0053] In some embodiments, the ceramic material or structure comprises one or more alumina mineral phases and / or titanium oxide mineral phases and / or an amorphous phase. The alumina may be present in an amount of up to about 10% by weight, for example about 2 to 8% by weight, or about 4 to 6% by weight. The titanium oxide may be present in an amount of up to about 5% by weight, for example up to about 3% by weight or up to about 2% by weight, or up to about 1% by weight. The amorphous phase may comprise, consist essentially or consist of a vitreous silica phase which may be formed at sintering temperatures of from about 1400 ° C to 1600 ° C. The amorphous phase may be present in an amount of up to about 5% by weight, for example up to about 3% by weight, or up to about 2% by weight, or up to about 1% by weight. % in weight. In some embodiments, the ceramic composition is substantially free of alumina mineral phase and / or titanium oxide and / or amorphous phase inorganic phase. In one embodiment, the amount of iron in the ceramic composition or ceramic honeycomb structure, measured as Fe 2 O 3, is less than 5% by weight, and perhaps smaller, for example, than about 2% by weight, or for example less than about 1% by weight, or for example less than about 0.75% by weight, or for example less than about 0.50% by weight. or, for example, smaller than about 0.25% by weight. The structure may be substantially iron free, as can be obtained using, for example, starting materials which are substantially free of iron. The iron content, measured as Fe 2 O 3, can be measured by X-ray fluorescence. In one embodiment, the amount of strontium, measured as SrO, is smaller than about 2% by weight, and for example smaller. that about 1% by weight, or for example less than about 0.75% by weight, or for example less than about 0.50% by weight, or for example less than about 0.25% by weight in weight. The structure can be substantially strontium-free as can be achieved, for example, by using starting materials which are substantially free of strontium. The strontium content, measured as SrO 2, can be measured by X-ray fluorescence.
[0054] In one embodiment, the amount of chromium, measured as Cr 2 O 3, is smaller than about 2% by weight, and for example smaller than about 1% by weight, or for example smaller than about 0, 75% by weight, or for example less than about 0.50% by weight, or for example less than about 0.25% by weight. The structure may be substantially free of chromium as may be obtained, for example, using starting materials which are substantially free of chromium. The chromium content, measured as Cr 2 O 3, can be measured by X-ray fluorescence. In one embodiment, the amount of tungsten, measured in W 2 O 3, is smaller than about 2% by weight, and for example smaller about 1% by weight, or for example smaller than about 0.75% by weight, or for example less than about 0.50% by weight, or for example less than about 0, 25% by weight. The structure may be substantially free of tungsten as can be obtained, for example, by using starting materials which are substantially free of tungsten. The strontium content, measured in W203, can be measured by X-ray fluorescence.
[0055] In one embodiment, the amount of yttrium oxide, measured as Y 2 O 3, is smaller than about 2.5% by weight, and, for example, less than about 1.5% by weight, or for example smaller than about 1% by weight, or for example smaller than about 0.50% by weight, or for example in the range of about 0.3 to 0.4% by weight. Any yttrium oxide present may be from yttria stabilized zirconia which in some embodiments may be used as a source of zirconia. The structure may be substantially free of yttrium oxide as may be obtained, for example, using starting materials which are substantially free of yttrium oxide. The yttrium oxide content, measured in Y 2 O 3, can be measured by X-ray fluorescence.
[0056] In one embodiment, the amount of rare earth metals, measured in Ln203, (Ln representing any one or more of the lanthanide elements La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), is smaller than about 2% by weight, and for example smaller than about 1% by weight, or for example smaller than about 0.75% in peas, or for example smaller than about 0.50% by weight, or for example smaller than about 0.25% by weight. The structure may be substantially free of rare earth metals as may be obtained, for example, using starting materials that are substantially free of rare earth metals. The rare earth metal content, measured in Ln203, can be measured by X-ray fluorescence. In some embodiments, the ceramic composition has a pore size (d50) of about 5.0 microns to about 25 microns. 0 μm, for example from about 5.0 μm to about 20.0 μm, for example from about 7.5 μm to about 20.0 μm, or from about 10.0 μm to about 20.0 μm. or from about 10.0 μm to about 15.0 μm, or from about 12.0 μm to about 15.0 μm. The pore size can be determined by mercury porosimetry using a mercury porosimeter of the Pascal 140 series of Thermo Scientific (Thermo Fisher). The software used is S.O.L.I.D. S / W, version 1.3.3 of Thermo Scientific. For this measurement, a sample weight of 1.0 g +/- 0.5 g is normally used. In some embodiments, the ceramic material or structure has a porosity of at least about 55%, for example at least about 60%, a tialite content of greater than or equal to 60% by weight, for example greater than or about 65% by weight, or about 65% by weight to about 85% by weight, or about 70% by weight to about 80% by weight, or about 70% by weight to about 75% by weight % by weight, and a pore size of from about 10.0 μm to about 30.0 μm, for example from about 10.0 to about 25.0 μm, or from about 10.0 μm to about 20.0 μm. 0 μm, or about 10.0 μm to about 15 μm, or about 12.0 μm to about 15.0 μm.
[0057] In certain embodiments, the ceramic composition, for example the ceramic honeycomb structure, has good mechanical and thermomechanical properties at high temperatures.
[0058] In some embodiments, the ceramic material or structure, the honeycomb ceramic structure, of any of the embodiments mentioned above, has a lower thermal expansion coefficient (CDT) or equal to about 4.0 x 10-6oc-1, as measured at 800 ° C by dilatometry according to DIN 51045 using a Netzch dilatometer - model DIL 402 C, and a sample length of 25 mm + / - 2 mm. In some embodiments, the CDT may be less than or equal to about 3.0 x 10-6 ° C, for example less than or equal to about 2.5 x 10-6001, or less than or equal to about 2.0 x 10 -6oc-1, or less than or equal to about 1.75 x 10-6oc-1, or less than or equal to about 1.5 x 10-6oc-1. In some embodiments, the CDT 20 is at least about 0.75 x 10-6 ° C, for example at least about 1.0 x 10 -6oc-1, or at least about 1.25 x 10-6 ° C-1. The thermal resistance parameter (PRT) of the material 25 or of the ceramic structure, for example of the ceramic honeycomb structure, is determined according to the following equation: PRT = [MOR / (CDT x modulus Young)] (1) MOR is the modulus of rupture (MOR), also referred to as mechanical strength of the ceramic material or structure, for example honeycomb ceramic structure, and measured by a flexural strength measurement by a 3-point curvature test at room temperature. In the test method a test specimen is supported on two supports and is loaded with a load roller with a carrier. The press equipment was Mecmesin Multites 2.5-d (AFG2500N), Mecmesin LTC. The Young's modulus according to DIN EN 10 843-2: 2007 is determined using Pundit Lab + ultrasound equipment available from Proceq. The test specimen is a honeycomb sample cut to dimensions of 55 mm x 55 mm +/- 10 mm, length 50 mm +/- 5 mm. Measurement is made in the direction of the longitudinal cells (by transducers of 250 KHz with a diameter of 33 mm) with a resolution greater than 0.1 ps. In some embodiments, the ceramic material or structure, for example the ceramic honeycomb structure, of any of the above embodiments has a mechanical strength (MOR) of at least 0.5 MPa, for example at least about 0.6 MPa, or at least about 0.7 MPa, or at least about 0.8 MPa, greater than 0.8 MPa. In some embodiments, the MOR ranges from about 0.5 MPa to about 2.5 MPa, for example from about 1.0 MPa to about 1.0 MPa, or from about 1.5 MPa to about 2 MPa. , 0 MPa. In such embodiments, the ceramic material or structure, for example the ceramic honeycomb structure, may have a porosity of at least about 55%, for example greater than or equal to about 60%, or greater than or equal to about 61%, or greater than or equal to about 62%, or greater than or equal to about 3036114 52%, or greater than or equal to about 64%, or greater than or equal to about 65%. In some embodiments, the ceramic material or structure may have a porosity of from about 50% to about 75%, for example from about 55% to about 70%, or from about 60% to about 70% or from about 60% to about 65%. In some embodiments, the ceramic material or structure, for example the honeycomb ceramic structure, of any of the above embodiments has a Young's modulus which is not more than greater than about 10 GPa, being, for example not larger than about 8.0 GPa, or not greater than about 6.0 GPa. In some embodiments, the Young's modulus is from about 3.0 to about 7.0 GPa, for example from about 4.0 to about 6.0 GPa. The thermal resistance parameter (PRT) of the ceramic material or structure, for example the ceramic honeycomb structure, is determined according to the following equation: PRT = [MOR / (CDT x modulus) Young)] (1) In some embodiments, the ceramic material or structure, for example the ceramic honeycomb structure, of any of the above embodiments, has a PRT of at least at least about 60 ° C, for example at least about 80 ° C, or at least about 100 ° C, or at least about 125 ° C, or at least about 150 ° C, or at least about at least about 200 ° C, or at least about 250 ° C, or at least about 300 ° C, or at least about 350 ° C. In some embodiments, the PRT 3036114 53 is not greater than about 550 ° C, for example not greater than about 450 ° C, or not greater than about 400 ° C. In such embodiments, the ceramic material or structure, for example the ceramic honeycomb structure, may have a porosity of at least about 55%, for example greater than or equal to about 60%, or greater than or equal to about 61%, or greater than or equal to about 62%, or greater than or equal to about 63%, greater than or equal to about 64%, or greater than or equal to about 65%. In some embodiments, the ceramic material or structure has a porosity of from about 50% to about 75%, for example from about 55% to about 70%, or from about 60% to about 70%, or from about 60% to about 65%. In some embodiments, the ceramic material or structure, for example the ceramic honeycomb structure, of any of the above embodiments, has an absolute density (skeleton) of about 3.0 to about 4.0 g / cm3, for example from about 3.3 to about 3.7 g / cm3. The density of the skeleton can be measured by a picnometer (Accupic - Micrometrics). In addition or alternatively, the ceramic material or structure, for example the ceramic honeycomb structure, of any of the above embodiments has a bulk density of about 1.0. at about 1.5 g / cm3, for example from about 1.1 to about 1.4 g / cm3, or from about 1.2 to about 1.3 g / cm3. In such embodiments, the ceramic material or structure, for example the ceramic honeycomb structure, may have a porosity of at least about 55%, for example greater than or equal to about 60%, or greater than or equal to about 61%, or greater than or equal to about 62%, or greater than or equal to about 63%, or greater than or equal to about 64%, or greater than or equal to about 65%. In some embodiments, the ceramic material or structure has a porosity of at least about 50% to about 75%, for example, about 55% to about 70%, or about 60% to about 70%. or from about 60% to about 65%.
[0059] In some embodiments, the ceramic material or structure, for example the ceramic honeycomb structure, has: (i) a MOR of about 1.0 MPa to about 2.5 MPa, for example about 1.0 MPa to about 2.0 MPa; and / or (ii) a Young's modulus smaller than about 10 GPa, for example from about 3.5 GPa to about 6.0 GPa; and / or (iii) a PRT of at least about 100 ° C, for example from about 120 ° C to about 400 ° C; and / or (iv) a CDT of about 0.5 x 10-60-u-1 to about 3.5 x -60-100C; and / or (v) a porosity of from about 55% to about 70%, e.g. from about 60 to about 70%; and optionally (vi) an absolute density (backbone) of from about 3.0 to about 4.0 g / cm3, for example from about 3.3 to about 3.7 g / cm3.
[0060] In certain embodiments, the ceramic material or structure, for example the ceramic honeycomb structure, has: (i) a MOR of from about 0.8 MPa to about 2.5 MPa, e.g. about 1.0 MPa to about 2.5 MPa, for example, about 1.0 MPa to about 2.0 MPa; and / or (ii) a Young's modulus smaller than about 10 GPa, for example from about 2.5 GPa to about 6.0 GPa, or from about 3.5 GPa to about 6.0 GPa; and / or (iii) a PRT of at least about 100 ° C, for example from about 120 ° C to about 400 ° C; and / or (iv) a CDT of from about 0.5 x 10-6oc-1 to about 3.5 x 10-60; and / or (v) a porosity of from about 55% to about 70%, for example from about 60% to about 70%; and optionally (vi) an absolute density of from about 3.0 to about 4.0 g / cc, for example from about 3.3 to about 3.7 g / cc. Ceramic Honeycomb Structures: In the honeycomb ceramic structures described in the above embodiments, the optimum pore diameter is between 5 and 30 μm, or between 10 and 25 μm. Depending on the intended use of the ceramic honeycombs, particularly with regard to the question of whether the honeycomb is impregnated with catalyst, the values mentioned if the ceramic structure next, for example one above may vary. For impregnated structures, the range is usually between 10 and 25 μm before impregnation, for example between 15 and 25 μm, or between 20 and 20 μm before impregnation. The catalyst material deposited in the pore space will give a reduction in the original diameter of the pores. The honeycomb structure according to the invention can typically comprise a plurality of side-by-side cells in a longitudinal direction, which are separated by porous partitions and plugged alternately (for example as a chessboard). . In one embodiment, the cells of the honeycomb structure are arranged in a repeating pattern. The cells may be square, circular, rectangular, octagonal, polygonal, or any other shape or combination of shapes that is suitable for arranging in a repeating pattern.
[0061] Optionally, the opening surface at one end face of the honeycomb structural body may be different from an opening face at its other end face. Thus, for example, the honeycomb structure body may have a large block of through-hole holes clogged to provide a relatively large amount of opening area on its side. the gas inlet and a group of small volume through-holes clogged to provide a relatively small sum of opening area on its gas outlet side. In some embodiments, the cells of the honeycomb structure are arranged asymmetrically, for example being arranged like the structures described in WO-A-2011/117385, to which reference may be made. The average cell density of the honeycomb structure according to the invention is not limited. The honeycomb ceramic structure may have a cell density of between 6 and 2,000 cells per square inch (0.9 to 311 cells / cm 2) or between 50 and 100 cells per square inch (7.8 to 155 cells / cm 2), or between 100 and 400 cells per square inch (15.5 to 62.0 cells / cm 2). The thickness of the partition separating adjacent cells in the present invention is not limited. The thickness of the partition can range from 100 to 500 microns, or from 200 to 450 microns. In addition, the outer peripheral wall of the structure is preferably thicker than the bulkheads, and its thickness may be between 100 and 700 microns, or between 200 and 400 microns. The outer peripheral wall may be not only a wall formed integrally with the partition at the time of formation, but also a wall coated with a cementum formed by grinding an outer periphery to a shape determined in advance. In some embodiments, the ceramic honeycomb structure has a modular form in which a series of ceramic honeycomb structures are prepared according to the present invention and then combined to form a nest ceramic structure. bees composite. The honeycomb structure series can be combined in the green state before sintering or, alternatively, the members of the series can be individually sintered and then combined. In some embodiments, the composite honeycomb ceramic structure may comprise a series of ceramic honeycomb structures prepared in accordance with the present invention and honeycomb ceramic structures that are not in accordance with the present invention. the present invention. For use as a diesel particulate filter (DPF), a diesel particulate filter (S-FPD), also known as a selective catalytic reduction filter (FSRC), or a gasoline particulate filter (FPE) ), the ceramic honeycomb structures according to the present invention, or the raw honeycomb ceramic structures according to the present invention, can be further treated by plugging, that is, by closing certain open structures of the honeycomb in positions defined in advance by additional ceramic mass. The capping operations thus include the preparation of an appropriate capping mass, the application of the capping compound at the desired positions of the ceramic or raw honeycomb structure, and the subjugation of the structure. in honeycomb clogged at an additional sintering step, or sintering the single-stage green honeycomb structure, the clogging mass being converted into a ceramic clogging mass having suitable properties for to be used in a diesel particulate filter, in a diesel particulate filter or in a gasoline particle filter. It is not necessary that the capping ceramic mass has the same composition as the ceramic mass of the honeycomb body. In general, the methods and capping materials known to those skilled in the art for capping honeycombs according to the present invention can be applied. In an exemplary operation, about 50% of the input cells are plugged on one side of the honeycomb piece and on the opposite side 50% more of the cells are plugged so that, in use, the exhaust gases are forced to pass through walls of the honeycomb structure.
[0062] The plugged ceramic honeycomb structure can then be fixed in a box which is suitable for mounting the structure in the exhaust line of a diesel engine or a gasoline engine, for example in the engine. diesel or the gasoline engine of a vehicle (eg, automobile, truck, van, motorcycle, excavator, tractor, bulldozer, dump truck, and the like).
[0063] In such systems, the ceramic material or structure serves as a filter (i.e. similar or the same as its typical function in a diesel particulate filter). The SCR catalyst can be coated on an exhaust gas inlet of the filter. A coating of other materials may be applied to the outlet of the filter exhaust, for example an aluminum oxide layer and a precious metal catalyst layer formed on the surface of the oxide layer. aluminum, as described in US-A-2013136662, to which reference will be made. Other SCR coatings, including those suitable for reducing NOx emissions for a post-treatment diesel engine exhaust, include vanadium oxide (vanadium oxide (V)), Fe zeolite, and / or Cu zeolite. These and other systems are described in such publications as Urea-SCR Technology for NOx after treatment of Diesel Exhaust, I. Nova and E. Tronconi, Springer).
[0064] Preferably, in the ceramic composition: the blowing agent is present in an amount suitable for obtaining a ceramic material having a porosity of at least about 50% (calculated on the basis of the total volume of the mineral phases and the pore space of the ceramic material); the first inorganic particulate material has a range of from about 20 microns to about 80 microns, for example, from about 20 microns to about 40 microns and / or the second particulate mineral matter having a d50 ranging from about 1 micron to 0 pm to about 20 pm, or less than about 20 pm, or about 1.0 pm to about 10 pm and / or 3036114 - the third mineral particulate has a finer particle size distribution than the second inorganic particulate matter, the first inorganic particulate is selected from tialite, one or more tialite-forming precursor compounds or compositions, mullite and one or more mullite-forming precursor compounds or compositions and / or the second mineral particulate material is selected From tialite, one or more tialite-forming precursor compounds or compositions, mullite and one or more precursor compounds or compositions forming mullite and / or - the third me inorganic particulate material is a compound 15 or a precursor composition forming the tialite. the third mineral particulate is a composition comprising from about 40% by weight to about 60% by weight of titanium oxide, from about 40% by weight to about 60% by weight of alumina, from about 0% by weight up to about 5% by weight of an alkaline earth metal-containing inorganic phase and / or alkaline earth metal-containing inorganic phase-forming compounds or compositions and from about 0% by weight to about about 5% by weight of a Zr-containing mineral phase and / or one or more Zr-containing mineral phase-forming compounds or compositions based on the total weight of the third mineral particulate matter; the ceramic precursor composition comprises from about 20% by weight to about 60% by weight of the first inorganic particulate matter, from about 15% by weight to about 50% of the second particulate mineral matter and about 15% by weight. from about 50% by weight of the third mineral particulate matter to the combined total weight of the first, second and third mineral particulate matter; the weight ratio of the first inorganic particulate to the third mineral particulate 5 is not greater than about 3: 1; the ceramic precursor composition comprises from about 10% by weight to about 90% by weight of a blowing agent, based on the combined combined weight of the first, second and third mineral particulate matter; the blowing agent has a d50 of from about 20 μm to about 50 μm; the ceramic precursor composition comprises (i) one or more binding agents; and / or (ii) one or more adjuvants and / or (iii) a solvent, for example water. Preferably, in the process for making a ceramic material or structure having a tialite content of at least about 50% by weight and a porosity of at least about 50%, the ceramic precursor composition has a composition according to the invention. 'invention. Preferably, the process comprises the steps of: (i) (1) procuring, preparing, or obtaining an extrudable mixture of the ceramic precursor composition, (i) (2) extruding the mixture to form a green ceramic structure, for example, a green honeycomb structure, (i) (3) drying the green ceramic structure, and (ii) sintering the green ceramic structure, for example at a temperature higher than 1400 ° C; the green or sintered ceramic structure is in the form of a honeycomb, the method further comprising plugging the green or sintered honeycomb structure. Preferably the ceramic material or structure has a porosity of at least about 55%, or at least about 60%, or greater than 60% - a tialite content of greater than or equal to 65% by weight.
[0065] Preferably the structure is in the form of a honeycomb structure. Preferably the ceramic material or structure has: (i) a MOR of from about 0.8 MPa to about 2.5 MPa, for example from about 1.0 MPa to about 2.5 MPa, e.g. about 1.0 MPa to about 2.0 MPa; and / or - (ii) a Young's modulus of less than about 10 GPa, for example from about 2.5 GPa to about 6.0 GPa, for example from about 3.5 GPa to about 6.0 GPa; and / or (iii) a PRT of at least about 100 ° C, for example from about 120 ° C to about 500 ° C, for example from about 120 ° C to about 400 ° C; and / or - (iv) a CDT of about 0.5x106 ° C to about 3.5x106 ° C '; and / or (v) a porosity of from about 55% to about 70%, for example from about 60% to about 70%, and optionally - (vi) an absolute density (backbone) of about 3, 0 to about 4.0 g / cm 3, for example about 3.3 to about 3.7 g / cm 3.
[0066] Preferably the diesel particulate filter comprises or is made of the honeycomb ceramic structure according to the invention.
[0067] The present invention is further described in the following non-limiting examples. EXAMPLES A series of ceramic pieces were obtained from the ceramic precursor compositions described in Tables 1-7. The composition analysis and thermomechanical properties were determined by the methods described above. Tables 1 to 6: Samples were extruded and baked at 1500 ° C for 2 hours. Table 7: Samples were extruded and baked at 1525 ° C for 2 hours. In each case, the oxygen content of the furnace atmosphere was 5% by volume. Coarse powder AT = titanate alumina powder having a d50 of about 24 μm (chemical composition comprising 92% TiO 2 / Al 2 O 3, about 5% ZrO 2 and about 2% MgO). Coarse powder M = mullite powder having a d50 of about 60 μm (chemical composition comprising about 98% Al 2 O 3 / SiO 2). Precursor coarse powder M = mullite powder having a d50 of about 60 μm (chemical composition comprising about 80% Al 2 O 3/20% SiO 2).
[0068] Intermediate powder AT = alumina and titanate powder having a d50 of about 4.3 μm (chemical composition as for coarse powder AT).
[0069] Precursor precursor powder AT = powder having a d50 of about 17 μm (chemical composition comprising about 99% A1203 / 1% MgO).
[0070] Intermediate powder M = mullite powder having a d50 of about 7.2 μm (chemical composition comprising about 100% Al 2 O 3 / SiO 2). Precursor fine powder AT 1 = precursor mixture of alumina and titanate having a d50 of about 0.12 μm and a d90 of about 0.65 μm (chemical composition comprising about 98% TiO 2 / Al 2 O 3). AT 2 precursor fine powder = precursor mixture of alumina and titanate having a d50 of about 0.12 μm and a d90 of about 1.2 μm (chemical composition comprising about 98% TiO 2 / Al 2 O 3 and about 1, 9% MgO).
[0071] Precursor fine powder AT 3 = Precursor mixture of alumina and titanate having a d50 of about 0.9 μm (chemical composition comprising about 98% TiO 2 / Al 2 O 3 and about 1.9% MgO).
[0072] Precursor fine powder AT 4 = Precursor mixture of alumina and titanate having a d50 of about 3.8 μm (chemical composition comprising about 98% TiO 2 / Al 2 O 3 and about 1.9% MgO).
[0073] Precursor fine powder AT 5 = Precursor mixture of alumina and titanate having a d50 of about 2.1 μm (chemical composition comprising about 98% TiO 2 / Al 2 O 3 and about 1.9% MgO).
[0074] Precursor fine powder AT 6 = powder having a dso of about 3 μm (chemical composition comprising about 95% Al 2 O 3/5% ZrO 2).
[0075] Table Formulation (wt.%) Cl C2 Coarse Powder AT 39% 39% Powder 31% 31% Intermediate M Precursor Fine Powder AT 2 30% 30% Total Mineral Solid 100% 100% Starch 64% 0% Polymer Microspheres 0 % 51% Total foaming agent 64% 51% Plasticizers 24% 16% Lubricants 4% 4% Water 46% 28% Total organic materials 28% 20% Total 238% 199% Cl C2 Size of 12 7 pores (microns) Porosity (% ) Table 2. Formulation (% by weight) C3 Cl C4 Coarse powder AT Powder 39% 39% 39% intermediate M Precursor fine powder AT 2 31% 31% 31% 30% 30% 30% Total mineral solids 100% 100% 100% Starch 43% 64% 79% Total foaming agent 43% 64% 79% Plasticizers Lubricants Water 19% 24% 28% 3% 4% 5% 56% 46% 86% Total organic matter 22% 28% 33% Total 220% 238% 299% Pore size (microns) C3 Cl C4 Porosity (%) 10 12 12 57 63 64 3036114 67 Table 3. Formulation (% by weight) C5 C2 C6 C7 Coarse powder AT 39% 39% 3% 3% Coarse Powder M Intermediate powder M Intermediate powder AT Precursor fine powder AT 1 Precursor fine powder AT 2 0% 0% 30% 31% 30% 31% 0% 0% 37% 0% 30% 0% 0% 37% 31% 0% 31% 0% 30% 0% Total Mineral Solid 100% 100% 100% 100% Polymer Microspheres 50% 51% 50% 51% Total Blowing Agent 50% 51% 50% 51% Plasticizers Lubricants Water 16% 16% 21% 21 % 2% 4% 5% 5% 36% 28% 32% 32% Materials 18% 20% 26% 26% total organic Total 204% 199% 208% 209% Dimensions of C5 C2 C6 C7 pores (microns) Porosity (% ) Table 4. Formulation (% by weight) Cl C8 C9 C10 Cll Coarse powder AT 39% 44% 49% 45% 50% Intermediate powder M Precursor fine powder AT 2 31% 26% 22% 31% 31% 30% 30% 29% 24% 19% Total mineral solids 100% 100% 100% 100% 100% Starch 64% 63% 63% 64% 64% Total blowing agent 64% 63% 63% 64% 64% Plasticizers Lubricants Water 24% 24% 25% 25% 25% 4% 5% 5% 5% 5% 46% 48% 49% 50% 51% Total organic matter 28% 29% 30% 30% 30% Total 238% 240% 242% 244% 245% Dimensions of Cl C8 C9 C10 Cil Pore (microns) Porosity (%) 12 12 13 13 12 63 63 64 64 65 3036114 69 Table 5. Formulation (% by weight) Cl C12 C13 C14 Coarse powder AT 39% 39% 39% 39% Powder 31% 31% 31% 31% intermediate M Precursor fine powder AT 2 30% 0% 0% 0% Fine precursor powder AT 3 0% 30% 0% 0% Precursor fine powder AT 4 0% 0% 30% 0% Precursor Fine Powder AT 5 0% 0% 0% 30% Total Mineral Solids 100% 100% 100% 100% Starch 64% 64% 64% 64% Total Blowing Agent 64% 64% 64% 64% Plasticizers 24% 24% 25% 24% Lubricants 4% 4% 5% 4% Water 46% 48% 50% 50% Materials 28% 28% 30% 28% Total Organic Total 238% 240% 244% 242 % Cl C12 C13 C14 Dimensions of 12 12 12 12 pores (microns) Porosity (%) 63 63 62 62 3036114 Table 6. Formulation (% by weight) C12 C15 C16 Coarse powder AT 39% 39% 20% 12% 29% 38 % 10% 24% 29% Intermediate powder M Intermediate powder T Precursor fine powder 3 31% 0% 30% Solid ores total 1 00% 100% 100% Starch 64% 62% 61% Total foaming agent 64% 62% 61% Plasticizers 24% 18% 17% Lubricants 4% 4% 4% Water 48% 42% 41% Organic materials 28% 22% 21 % total Total 240% 226% 223% C12 C15 C16 Dimensions of 12 13 pores (microns) 12 Porosity (%) 63 58 56 CDT (0-800 ° C) 1.5 1 (* 10-6 ° C-1) 3 MOR (MPa) 2 1.7 1.5 Elastic modulus 4.9 4 (Gpa) 5 PRT (° C) 130 230 370 3036114 71 Table 7. Formulation (% by weight) C17 C18 C19 C20 C21 C22 Precursor coarse powder M 31% 31% 31% 31 % 31% 31% Intermediate Precursor Powder AT 36% 36% 36% 36% 36% 36% Fine Precursor Powder AT 6 33% 33% 33% 33% 33% 33% Solids total ores 100% 100% 100% 100% 100% 100% Starch 58% 44% 49% 54% 39% 35% Graphite 0% 22% 15% 7% 13% 6% Total Blowing Agent 58% 66% 63% 61% 52% 41% Plasticizers 17% 20% 18% 17% 16% 16% Lubricants 4% 4% 4% 4% 4% 3% Water 40% 47% 42% 41% 39% 36% Total Organic Matter 21% 24% 21% 21% 20% 19% Total 220% 236% 227% 223% 211% 196% C17 C18 C19 C20 C21 C22 Di 18 20 19 19 17 17 pores (microns) Porosity (%) 62 55 59 63 64 61 CDT (0-800 ° C) (* 10-6 ° C-1) 2.0 0.8 1.3 2.0 2.0 1.7 MoR (MPa) 0.8 1.2 1.1 0.9 1.0 1.1 Elastic module 2.7 3.0 3.0 2.7 2.8 3.0 PRT (° C) 148 500 282 167 179 216 5

权利要求:
Claims (25)
[0001]
REVENDICATIONS1. A ceramic precursor composition having at least one trimodal particle size distribution, the ceramic precursor composition comprising: (a) a first inorganic particulate material having a coarse particle size distribution; (b) a second inorganic particulate having a particle size distribution which is thinner than (a); (c) a third mineral particulate having a d50 of less than or equal to about 5 μm and optionally having a particle size distribution that is thinner than (b) and (d) one or at least one pore-forming agent, for example, an amount suitable for obtaining a ceramic material having a porosity of at least about 50% (calculated on the basis of the total volume of the mineral phases and the pore space of the ceramic material).
[0002]
Ceramic precursor composition according to claim 1, wherein the blowing agent is present in an amount suitable for obtaining a ceramic material having a porosity of at least about 50% (calculated on the basis of the total volume of the mineral phases and the pore space of the ceramic material). 3036114 73
[0003]
3. The ceramic precursor composition of claim 1 wherein: the first inorganic particulate has a d50 of from about 20 microns to about 80 microns, for example, from about 20 microns to about 40 microns and / or the second mineral particulate matter at a d50 of from about 1.0 μm to about 20 μm, or less than about 20 μm, or from about 1.0 μm to about 10 μm and / or the third mineral particulate matter has a distribution granulometric finer than the second mineral particulate matter.
[0004]
4. A ceramic precursor composition according to any one of the preceding claims wherein: the first inorganic particulate is selected from tialite, one or more tialite-forming precursor compounds or compositions, mullite and one or more compounds or compositions mullite-forming precursors and / or the second mineral particulate material is selected from tialite, one or more tialite-forming precursor compounds or compositions, mullite, and one or more mullite-forming precursor compounds or compositions and / or the third mineral particulate is a precursor compound or composition forming tialite.
[0005]
A ceramic precursor composition according to any one of the preceding claims, wherein the third inorganic particulate is a composition comprising from about 40% by weight to about 60% by weight of titanium oxide, from about 40% by weight. from about 0% by weight to about 5% by weight of an alkaline earth metal-containing mineral phase and / or compounds or compositions an alkaline earth metal-containing inorganic phase and from about 0% by weight to about 5% by weight of a Zr-containing mineral phase and / or one or more Zr-containing mineral phase-forming compounds or compositions with respect to to the total weight of the third mineral particulate matter.
[0006]
A ceramic precursor composition as claimed in any one of the preceding claims, wherein the ceramic precursor composition comprises from about 20% by weight to about 60% by weight of the first inorganic particulate matter, about 15% by weight at about 50% of the second mineral particulate matter and from about 15% by weight to about 50% by weight of the third mineral particulate matter based on the combined total weight of the first, second and third mineral particulate matter.
[0007]
The ceramic precursor composition of claim 5 wherein the weight ratio of the first inorganic particulate to the third mineral particulate is not greater than about 3: 1.
[0008]
A ceramic precursor composition as claimed in any one of the preceding claims, wherein the ceramic precursor composition comprises from about 10% by weight to about 90% by weight of a blowing agent, based on the total combined weight of the blowing agent. first, second and third mineral particulate matter. 3036114 75
[0009]
A ceramic precursor composition according to any one of the preceding claims, wherein the blowing agent has a d50 of from about 20 μm to about 50 μm. 5
[0010]
The ceramic precursor composition according to any one of the preceding claims, further comprising: (i) one or more binding agents; and / or (ii) one or more adjuvants and / or (iii) a solvent, for example water.
[0011]
11. A process for making a ceramic material or structure having a tialite content of at least about 50% by weight and a porosity of at least about 50%, the process comprising: (i) procuring, preparing or obtaining a ceramic precursor having at least one trimodal granulometry and having a composition comprising: (a) a first inorganic particulate having a coarse particle size distribution; (b) a second inorganic particulate having a particle size distribution which is finer (a) (c) a third inorganic particulate having a d50 of less than or equal to about 5 μm and optionally a particle size distribution which is finer than (b) ); (d) one or at least one pore forming agent in an amount suitable for obtaining a ceramic material having a porosity of at least about 50%; (ii) forming a green ceramic material from the ceramic precursor composition, and (iii) sintering the green ceramic material. 3036114 76
[0012]
The method of claim 11, wherein the ceramic precursor composition has a composition according to any one of claims 2 to 10.
[0013]
13. A process according to claim 11 or 12, comprising the steps of: (i) (1) procuring, preparing or obtaining an extrudable mixture of the ceramic precursor composition, (i) (2) extruding the mixture to form a green ceramic structure, for example a green honeycomb structure, (i) (3) drying the green ceramic structure, and (ii) sintering the green ceramic structure, for example at a temperature higher than 1400 ° vs.
[0014]
14. A process according to any one of claims 11 to 13, wherein the green or sintered ceramic structure is in the form of a honeycomb, further comprising butchering the green honeycomb structure or sintered.
[0015]
15. Ceramic material or structure having a tialite content of at least about 50% by weight based on the total weight of the material of the ceramic structure and a porosity of at least about 50%, the ceramic material or structure being obtained by a process comprising: (i) providing, preparing or obtaining a ceramic precursor having at least one trimodal granulometry and having a composition comprising: (a) a first mineral particulate material having a coarse particle size distribution, 3036114 b) a second mineral particulate having a particle size distribution which is thinner than (a), (c) a third mineral particulate having a d50 of less than or equal to about 5 μm and optionally having a particle size distribution which is thinner than (b), and (d) one or at least one pore forming agent in an amount suitable for obtaining a material or ceramic having a porosity at least about 50%, (ii) forming a material of a green ceramic structure from the ceramic precursor composition, and (iii) sintering the raw ceramic material or structure, for example at a higher temperature. high than 140000.
[0016]
The ceramic material or structure of claim 15 having a porosity of at least about 55%, or at least about 60%, or greater than 60%.
[0017]
17. The ceramic material or structure of claim 15 or 16 having a tialite content of greater than or equal to 65% by weight. 25
[0018]
18. A ceramic material or structure according to any one of claims 15 to 17 in the form of a honeycomb structure. 30
[0019]
The ceramic material or structure of any one of claims 15 to 18 having: (i) a MOR of from about 0.8 MPa to about 2.5 MPa, for example from about 1.0 MPa to about 2, MPa, for example from about 1.0 MPa to about 2.0 MPa; and / or (ii) a Young's modulus of less than about 10 GPa, for example from about 2.5 GPa to about 6.0 GPa, for example from about 3.5 GPa to about 6, 0 GPa; and / or (iii) a PRT of at least about 100 ° C, for example from about 120 ° C to about 500 ° C, for example from about 120 ° C to about 400 ° C; and / or (iv) a CDT of about 0.5x106 ° C to about 3.5x106 ° C; and / or (v) a porosity of from about 55% to about 70%, for example from about 60% to about 70%, and optionally (vi) an absolute density (skeleton) of about 3.0 to about 4.0 g / cc, for example about 3.3 to about 3.7 g / cc.
[0020]
20. A diesel particulate filter made of the honeycomb ceramic structure of claim 18 or 19 or obtainable by the process of claims 13 or 14.
[0021]
21. A diesel particulate filter comprising or of ceramic honeycomb structure according to claim 18 or 19 or obtainable by the process of claims 13 or 14.
[0022]
22. A fuel particle filter comprising or a ceramic honeycomb structure according to claim 18 or 19 or obtainable by the process according to claims 13 or 14.
[0023]
23. A vehicle having a diesel engine and a filtration system comprising the diesel particulate filter of claim 20 or the diesel particulate filter of claim 21. 3036114
[0024]
24. A vehicle having a gasoline engine and a filtration system comprising the gasoline particle filter of claim 22.
[0025]
25. SCR catalyst system comprising a ceramic material or structure according to any one of claims 15 to 19 and an SCR catalyst optionally coated on a surface of the ceramic material or structure.

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法律状态:
2017-05-25| PLFP| Fee payment|Year of fee payment: 2 |

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2018-05-25| PLFP| Fee payment|Year of fee payment: 3 |

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2019-05-27| PLFP| Fee payment|Year of fee payment: 4 |

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2021-02-12| ST| Notification of lapse|Effective date: 20210105 |

优先权:

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申请号 | 申请日 | 专利标题

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EP15305733|2015-05-15|

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