• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to an aircraft tire whose tread comprises a rubber composition based on at least a first diene elastomer, a reinforcing filler and a crosslinking system, which first diene elastomer comprises ethylene units and diene units. comprising a carbon-carbon double bond, which units are statistically distributed within the first diene elastomer, the ethylene units representing at least 50 mol% of all the monomer units of the first diene elastomer. Such a tire has a greatly improved landing performance, especially with respect to the very high speed wear resistance.
    公开号:FR3024154A1
    申请号:FR1457054
    申请日:2014-07-22
    公开日:2016-01-29
    发明作者:Da Silva José-Carlos Araujo；Mathilde Abad；Aurelie Triguel
    申请人:Michelin Recherche et Technique SA Switzerland ；Compagnie Generale des Etablissements Michelin SCA；Michelin Recherche et Technique SA France；
    IPC主号:
    专利说明:

    [0001] The present invention relates to tires for equipping aircraft.
    [0002] As is known, an aircraft tire must withstand high pressure, load and speed conditions. In addition it must also meet the requirements of resistance to wear and endurance. Endurance means the ability of the tire to withstand over time the cyclic stresses to which it is subjected. When the tread of an aircraft tire is worn, marking the end of a first life of use, the tire is retreaded, that is to say that the worn tread is replaced by a new tread to allow a second life of use. Improved wear resistance allows for more landings per life of use. An improved endurance allows to increase the number of lives of use of the same tire. It is known to use, in aircraft tire treads, rubber compositions based on natural rubber and carbon black, these two main elements making it possible to obtain compositions having properties compatible with the conditions of the invention. use of an airplane tire. In addition to these main elements, these compositions comprise the usual additives of this type of compositions such as a vulcanization system and protective agents. Such aircraft tire tread compositions have been used for many years and have mechanical properties to withstand the very particular wear conditions of aircraft tires. Indeed, these tires are subject to very large temperature and speed variations, especially at landing where they must go from a zero speed to a very high speed, causing considerable heating and wear.
    [0003] It is therefore always interesting for aircraft tire manufacturers to find more efficient and more resistant solutions, in particular more resistant to the extreme wear conditions caused by landing aircraft. A study (SK Clark "Touchdown Dynamics", Precision Measurement Company, Ann Arbor, Mt. NASA, Langley Research Center, Computational Modeling of Tires, pages 9-19, published August 1995) described the stresses on airframe tires in Canada. the landing and proposed a method of evaluating the performance of the aircraft tires during these requests. In their research, the Applicants have found that a particular composition of tire treads for aircraft can improve the properties of aircraft tires, particularly for the landing phase of these tires. Accordingly, the invention relates to an aircraft tire whose tread comprises a rubber composition based on at least a first diene elastomer, a reinforcing filler and a crosslinking system, which first elastomer diene comprises ethylene units and diene units comprising a carbon-carbon double bond, which units are statistically distributed within the first diene elastomer, the ethylene units representing at least 50 mol% of all the monomer units of the first diene elastomer .
    [0004] I. DETAILED DESCRIPTION OF THE INVENTION By the term "composition-based" is meant a composition comprising the mixture and / or the reaction product of the various constituents used, some of these basic constituents being capable of or intended to react with each other, at least in part, during the various phases of manufacture of the composition, in particular during its crosslinking or vulcanization. By the expression "part by weight per hundred parts by weight of elastomer" (or phr), is meant within the meaning of the present invention, the part by mass per hundred parts of elastomer.
    [0005] In the present description, unless expressly indicated otherwise, all the percentages (%) indicated are percentages (%) by mass. On the other hand, any range of values designated by the expression "between a and h" represents the range of values from more than a to less than b (i.e. terminals a and b excluded) while any range of values referred to as "from a to h" means the range of values from a to b (i.e., including the strict limits a and b). Generally speaking, a tire comprises a tread intended to come into contact with the ground via a running surface and connected via two sidewalls to two beads intended to provide a connection. between the tire and the rim on which it is mounted. In the following, the circumferential, axial and radial directions respectively designate a direction tangent to the running surface of the tire in the direction of rotation of the tire, a direction parallel to the axis of rotation of the tire and a direction perpendicular to the tire. axis of rotation of the tire. By "radially inner, respectively radially outer" is meant "closer or more distant from the axis of rotation of the tire". By "axially inner, respectively axially outer" is meant "closer or farther from the equatorial plane 40 of the tire", the equatorial plane of the tire being the plane passing through the middle of the running surface of the tire. pneumatic and perpendicular to the axis of rotation of the tire. A radial tire more particularly comprises a reinforcement, comprising a crown reinforcement, radially inner to the tread, and a carcass reinforcement, radially inner to the crown reinforcement. The carcass reinforcement of an aircraft tire generally comprises a plurality of carcass layers extending between the two beads and distributed between a first and a second family. The first family consists of carcass layers, wound in each bead, from the inside to the outside of the tire, around a circumferential reinforcing element, called a bead wire, to form a reversal whose end 15 is generally radially external to the most radially outer point of the bead wire. The upturn is the carcass layer portion between the most radially inner point of the carcass layer and its end. The carcass layers of the first family are the carcass layers closest to the inner cavity of the tire and therefore the most axially inner, in the flanks.
    [0006] The second family consists of carcass layers extending in each bead from the outside to the inside of the tire, to a generally radially inner end at the most radially outer point of the bead wire. The carcass layers of the second family are the carcass layers closest to the outer surface of the tire and therefore the outermost axially in the flanks. Usually, the carcass layers of the second family are positioned, all along their length, outside the carcass layers of the first family, that is to say, they envelop, in particular, the reversals of carcass layers of the first family. Each carcass layer of the first and second families consists of reinforcing elements parallel to each other, forming, with the circumferential direction, an angle of between 80 ° and 100 °.
    [0007] The reinforcing elements of the carcass layers are most often cables consisting of textile filament yarns, preferably of aliphatic polyamide or aromatic polyamide, and characterized by their mechanical properties in extension. The textile reinforcing elements are pulled over an initial length of 400 mm at a nominal speed of 200 mm / min. All results are an average of 10 40 measurements. P10-3401 3024154 4 In use, an aircraft tire is subjected to a combination of load and pressure inducing a high bending rate, typically greater than 30% (eg 32% or 35%). The bending rate of a tire is, by definition, its radial deformation, or its radial height variation, as it moves from an unloaded inflated state to a statically loaded inflated state under pressure conditions. and charging as defined, for example, by the standard of the Tire and Rim Association or TRA. It is defined by the ratio of the variation of the radial height of the tire to half of the difference between the outside diameter of the tire, measured statically in an unfilled state inflated to the reference pressure, and the maximum diameter of the rim. , measured on the rim flange. The TRA standard defines in particular the crushing of an aircraft tire by its crushed radius, that is to say by the distance between the axis of the wheel of the tire and the plane of the ground with which the tire is in contact under the conditions of pressure and reference load.
    [0008] An aircraft tire is also subjected to a high inflation pressure, typically greater than 9 bar. This high pressure level involves a large number of carcass layers, because the carcass reinforcement is dimensioned to ensure the resistance of the tire at this pressure level with a high safety factor. By way of example, the carcass reinforcement of a tire whose working pressure, as recommended by the TRA standard, is equal to 15 bars, must be dimensioned to withstand a pressure equal to 60 bars, assuming a safety factor of 4. With textile materials commonly used for reinforcing elements, such as aliphatic polyamides or aromatic polyamides, the carcass reinforcement may, for example, comprise at least 5 carcass layers.
    [0009] In use, the mechanical stresses of rolling induce bending cycles in the beads of the tire, which roll up on the rim flanges. These bending cycles in particular generate, in the carcass layer portions in the rim flexion zone, curvature variations combined with variations in elongation of the carcass layer reinforcing elements. These variations in elongation or deformations, in particular in the most axially outer carcass layers, may have negative minimum values, corresponding to compression. This compression is likely to induce a fatigue failure of the reinforcing elements and therefore premature degradation of the tire.
    [0010] Thus, the aircraft tire according to the invention is preferably an aircraft tire which is subjected during its use to a combination of load and pressure inducing a bending rate greater than 30.
    [0011] Likewise, the aircraft tire according to the invention is preferably an aircraft tire comprising in addition to the tread, an internal structure comprising a plurality of carcass layers extending between the two beads and distributed between a first and a second family, the first family consisting of carcass layers, wound in each bead from the inside to the outside of the tire and the second family being constituted by carcass layers. extending in each bead from the outside to the inside of the tire. The tread composition of the aircraft tires according to the invention comprises a first diene elastomer which comprises ethylene units and diene units having a carbon-carbon double bond, which units are statistically distributed within the first diene elastomer, the ethylene units representing at least 50 mol% of all the monomer units of the first diene elastomer.
    [0012] According to a preferred embodiment of the invention, the first diene elastomer comprises the following units UA, UB, UC and UD, which units UA, UB, UC and UD are statistically distributed within the first diene elastomer, UA). CH2-CH2- at a molar percentage of m% UB) at a molar percentage of n% UC) R1 at a molar percentage of 0% I -CH2-C-R2 CH2 (CH2) 12 in a molar percentage of the same or different, denoting a hydrogen atom, a methyl radical or a phenyl radical which may or may not be substituted in the ortho position, meta or para by a methyl radical, 40 - m> _50 - 0 <o + p 25 P10-3401 3024154 6 - n + o> 0 - m, n, o and p being numbers ranging from 0 to 100 - percentages respective moles of m, n, o, and p being calculated on the basis of the sum of m + n + o + p which is equal to 100. According to a particular embodiment of the invention, the first Diene atomomer contains statistically distributed units UE within the first diene elastomer: 5 10 EU) CH2-C H2 according to a molar percentage of q% / - CH CH-CH2-CH2 - o + p + q 10 15 - q> The respective molar percentages of m, n, o, p and q being calculated on the basis of the sum of m + n + o + p + q which is equal to 100. While the unit UD pattern forms a bivalent hydrocarbon ring with 6 carbon atoms of 1,2-cyclohexane type, the unit unit unit EU forms a divalent hydrocarbon ring with 6 carbon atoms of 1,4-cyclohexane type. According to another embodiment of the invention, the first diene elastomer contains UF units statistically distributed within the first diene elastomer, 25 UF) -CH 2 -CH- in a molar percentage of r 1, R 3 -R 3 denoting a radical. alkyl having 1 to 4 carbon atoms or an aryl radical, preferably 25, preferably 10, - the respective molar percentages of m, n, o, p and r being calculated on the base of the sum of m + n + o + p + r which is equal to 100.
    [0013] According to this particular embodiment of the invention, the first diene elastomer may comprise q% of statistically distributed units UE within the first diene elastomer, in which case the respective molar percentages of m, n, o, p, q and r are calculated on the basis of the sum of m + n + o + p + q + r which is equal to 100.
    [0014] It is understood that the first diene elastomer may consist of a mixture of elastomers which contain the units UA, UB, UC, UD, EU and UF according to the respective mole percentages m, n, o, p , q and r as defined above and which differ from each other by their macrostructure or their microstructure, in particular by the respective molar ratio of the units UA, UB, UC, UD, UE and UF.
    [0015] According to any of the embodiments of the invention, preferably the first diene elastomer does not contain a UF unit. According to one embodiment of the invention, at least one of the two molar percentages p and q is preferably different from 0. In other words, preferably the first diene elastomer contains at least one of the units which are a bivalent hydrocarbon ring with 6 carbon atoms of 1,2-cyclohexane type and a divalent hydrocarbon ring with 6 carbon atoms of 1,4-cyclohexane type. More preferably, p is strictly greater than 0.
    [0016] According to one embodiment of the invention, the first diene elastomer has at least one of the following criteria, and preferably all: m> 65 - n + o + p + q> 15, more preferably 20 - 10 p + q 2 20 - 1 n / (o + p + q) - when q is not zero, 20 / q 1 According to another preferred embodiment of the invention, the first diene elastomer contains as monomeric units only the units UA, UB, UC, UD and EU 25 according to their respective molar percentage m, n, o, p and q, preferably all different from 0. According to another preferred embodiment of the invention, the first diene elastomer contains as monomeric units only the units UA, UB, UC and UD according to their respective molar percentage m, n, o and p, preferably all different from 0. According to any of the embodiments of the invention, the UB units present in the polymer according to the invention preferably have the trans-tion represented by the following formula: ## STR1 ## According to any one of the embodiments of the invention, the first diene elastomer preferably has a number-average molecular weight (Mn) of at least 40 60 000 g / mol and at most 1 500 000 g / mol. The starting diene polymer useful for the purposes of the invention preferably has a polydispersity index Ip equal to Mw / Mn (Mw P10-3401 being the weight-average molar mass) of between 1.20 and 3. 00. The values of Mn, Mw and lp are measured according to the method described in paragraph 11.1. The first diene elastomer can be obtained according to various synthetic methods known to those skilled in the art, in particular according to the target values of m, n, o, p, q and r. Generally, the first diene elastomer may be prepared by copolymerization of at least one conjugated diene monomer and ethylene and according to known synthetic methods, in particular in the presence of a catalyst system comprising a metallocene complex. Catalyst systems based on metallocene complexes, which catalytic systems are described in EP 1 092 731 A1, EP 1 554 321 A1, EP 1 656 400 A1, EP 1 829 901 A1, EP 1, are described. 954 705 A1, EP 1 957 506 A1, on behalf of the Applicants. As conjugated diene monomer is suitable in particular a conjugated diene having from 4 to 12 carbon atoms. 1,3-Butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1-aryl-1,3-butadiene and 1,3-pentadiene may be mentioned. In a preferred aspect, the diene monomer is 1,3-butadiene or 2-methyl-1,3-butadiene, more preferably 1,3-butadiene, in which case R 1 and R 2 are each hydrogen.
    [0017] Thus, according to some of these synthetic methods, the first diene elastomer can be obtained by copolymerization of at least one conjugated diene monomer and ethylene, in the presence of a catalyst system comprising a metallocene lanthanide complex with ligands. fluorenyl type ansa. The metallocene complexes described in documents EP 1 092 731 A1, EP 1 554 321 A1 and EP 1 954 705 A1 can be cited as such.
    [0018] The first diene elastomer which contains UF units according to a particular embodiment of the invention can be obtained by copolymerization of at least one conjugated diene monomer and two olefins, such as ethylene and an alpha-olefin, into presence of a catalyst system comprising a metallocene lanthanide complex with ansa cyclopentadienyl-fluorenyl ligands. As alpha-olefin monomer suitable for example an alpha-olefin having 3 to 18 carbon atoms, preferably having 3 to 6 carbon atoms. There may be mentioned propylene, butene, pentene, hexene or a mixture of these compounds. As a termonomer associated with at least one conjugated diene monomer and ethylene, there may also be mentioned a styrene derivative.
    [0019] Catalyst systems based on metallocene complexes may be those described in EP 1 092 731 A1, EP 1 656 400 A1, EP 1 829 901 A1, EP 1 957 506 A1, in the name of the Applicants. The first diene elastomer may be prepared in accordance with the above-mentioned documents, by adapting the polymerization conditions by means known to those skilled in the art, so as to achieve average molecular weight values P10-3401 3024154 9 (Mn) of at least 60,000 g / mol. By way of illustration, the polymerization time can be significantly increased so that the conversion to monomer is greater, thus leading to the obtaining of molar masses of at least 60,000 g / mol. By way of illustration, during the preparation of the catalytic systems according to the documents cited above, the stoichiometry of the alkylating agent with respect to the metallocene complex (s) is decreased, so as to reduce the chain transfer reactions and to obtain molar masses of at least 60 000 g / mol. According to a first variant of the invention, the rubber composition further comprises a second elastomer, preferably diene, that is to say comprising diene monomeric units. According to any one of the embodiments of the first variant of the invention, the level of the second elastomer is preferably less than 50 phr. The second elastomer may be a "substantially unsaturated" or "essentially saturated" diene elastomer. The term "essentially unsaturated" is generally understood to mean a diene elastomer derived at least in part from conjugated diene monomers having a degree of units or units of diene origin (conjugated dienes) which is greater than 15% (mol%), which units of diene origin have a carbon-carbon double bond; Thus, diene elastomers such as butyl rubbers or copolymers of dienes and alpha-olefins of the EPDM type do not fall within the above definition and may in particular be referred to as "substantially saturated" diene elastomers ( low or very low diene origin, always less than 15%). In the category of "essentially unsaturated" diene elastomers, the term "highly unsaturated" diene elastomer is particularly understood to mean a diene elastomer having a content of units of diene origin (conjugated dienes) which is greater than 50%. Given these definitions, the second diene elastomer that may be used in the compositions in accordance with the invention may be: (a) - any homopolymer of a conjugated diene monomer, especially any homopolymer obtained by polymerization of a diene monomer conjugate having from 4 to 12 carbon atoms; (b) - any copolymer obtained by copolymerization of one or more conjugated dienes with each other or with one or more vinyl aromatic compounds having from 8 to 20 carbon atoms; (C) - a ternary copolymer obtained by copolymerization of ethylene, an α-olefin having 3 to 6 carbon atoms with a non-conjugated diene monomer having from 6 to 12 carbon atoms, such as, for example, elastomers obtained with from ethylene, propylene with a non-conjugated diene monomer of the aforementioned type such as in particular 1,4-hexadiene, ethylidene norbornene, dicyclopentadiene.
    [0020] The second elastomer is preferably a highly unsaturated diene elastomer selected from the group consisting of polybutadienes, polyisoprenes, butadiene copolymers, isoprene copolymers and mixtures of these elastomers, or a copolymer ternary obtained by copolymerization of ethylene, an α-olefin having 3 to 6 carbon atoms with a non-conjugated diene monomer having 6 to 12 carbon atoms, in particular an EPDM. According to a second variant of the invention, the first diene elastomer is the only elastomer of the rubber composition. The reinforcing filler, known for its ability to reinforce a rubber composition that can be used for the manufacture of tires, may be a carbon black, a reinforcing inorganic filler such as silica with which a coupling agent is associated in known manner, or still a mixture of these two types of load. Such a reinforcing filler typically consists of nanoparticles whose average size (in mass) is less than one micrometer, generally less than 500 nm, most often between 20 and 200 nm, in particular and more preferably between 20 and 150 nm.
    [0021] The carbon black has a BET surface area preferably of at least 90 m 2 / g, more preferably at least 100 m 2 / g. As such are suitable black conventionally used in tires or their treads (so-called pneumatic grade black). Among these, the reinforcing carbon blacks of the 100, 200, 300 series (ASTM grade), such as, for example, the N115, N134, N234 and N375 blacks, will be mentioned more particularly. The carbon blacks can be used in the isolated state, as commercially available, or in any other form, for example as a carrier for some of the rubber additives used. The BET specific surface area of the carbon blacks is measured according to the D6556-10 standard [multipoint method (at least 5 points). 30 - gas: nitrogen - relative pressure range P / PO: 0.1 to 0.3]. According to one embodiment of the invention, the reinforcing filler also comprises a reinforcing inorganic filler. By "reinforcing inorganic filler" is to be understood herein any inorganic or mineral filler, whatever its color and origin (natural or synthetic), also called "white" filler, "clear" filler or even "non-filler" filler. as opposed to carbon black, capable of reinforcing on its own, without any other means than an intermediate coupling agent, a rubber composition intended for the manufacture of pneumatic tires, in other words able to replace, in its reinforcement function, a conventional carbon black of pneumatic grade; such a charge is generally characterized, in a known manner, by the presence of hydroxyl groups (-OH) on its surface. Suitable reinforcing inorganic fillers are in particular mineral fillers of the siliceous type, preferably silica (SiO 2). The silica used may be any reinforcing silica known to those skilled in the art, in particular any precipitated or fumed silica having a BET surface and a CTAB specific surface both less than 450 m 2 / g, preferably from 30 to 400 m 2 / g, especially between 60 and 300 m2 / g. The physical state under which the reinforcing inorganic filler is present is indifferent, whether in the form of powder, microbeads, granules or beads. Of course, the term "reinforcing inorganic filler" also refers to mixtures of different reinforcing inorganic fillers, in particular highly dispersible silicas as described above. In the present specification, with respect to silica, the BET surface area is determined in a known manner by gas adsorption using the Brunauer-Emmett-Teller method described in "The Journal of the American Chemical Society". Flight. 60, page 309, February 1938, more precisely according to the French standard NF ISO 9277 of December 1996 (multipoint volumetric method (5 points) - gas: nitrogen - degassing: 1 hour at 160 ° C - relative pressure range p / po: 0.05 at 0.17). The CTAB specific surface is the external surface 20 determined according to the French standard NF T 45-007 of November 1987 (method B). In order to couple the reinforcing inorganic filler to the diene elastomer, an at least bifunctional coupling agent (or bonding agent) is well known to provide a sufficient chemical and / or physical connection between the filler and the diene elastomer. inorganic (surface of its particles) and the diene elastomer. In particular, organosilanes or at least bifunctional polyorganosiloxanes are used. Particularly suitable, but not limited to, polysulfide silanes having the following general formula (I): (I) Z - A - Sx - A - Z, wherein: - x is an integer of 2 to 8 (preferably 2 to 5); the symbols A, identical or different, represent a divalent hydrocarbon radical (preferably a C1-C18 alkylene group or a C6-C12 arylene group, more particularly a C1-C10 alkylene, especially C1-C4 alkylene, in particular especially propylene); the symbols Z, which are identical or different, correspond to one of the following three formulas: in which: the radicals R1, substituted or unsubstituted, identical or different from each other; represent a C 1 -C 18 alkyl, C 5 -C 18 cycloalkyl or C 6 -C 18 aryl group (preferably C 1 -C 6 alkyl, cyclohexyl or phenyl groups, especially C 1 -C 4 alkyl groups, more particularly methyl and / or ethyl). the radicals R2, substituted or unsubstituted, which are identical to or different from one another, represent a C1-C18 alkoxyl or a C5-C18 cycloalkoxyl group (preferably a group chosen from C1-C8 alkoxyls and C5-C8 cycloalkoxyls, plus preferably still another group chosen from C 1 -C 4 alkoxyls, in particular methoxyl and ethoxyl). By way of examples of polysulphide silanes, mention may be made more particularly of bis (C 1 -C 4) alkoxy (C 1 -C 4) alkylsilylalkyl (C 1 -C 4) polysulfides (especially disulfides, trisulphides or tetrasulfides), as polysulfides of bis (3-trimethoxysilylpropyl) or bis (3-triethoxysilylpropyl). Among these compounds, bis (3-triethoxysilylpropyl) tetrasulfide, abbreviated to TESPT, of formula [(C2H50) 3Si (CH2) 352) 2 or bis (triethoxysilylpropyl) disulfide, abbreviated to TESPD, is preferably used. formula [(C2H50) 3Si (CH2) 35] 2. By way of examples of other organosilanes, mention may be made, for example, of silanes bearing at least one thiol function (-SH) (called mercaptosilanes) and / or of at least one blocked thiol group, as described for example in patents or patent applications US 6,849,754, WO 99/09036, WO 2006/023815, WO 2007/098080, WO 2010/072685 and WO 2008/055986. The content of coupling agent is advantageously less than 12 phr, it being understood that it is generally desirable to use as little as possible. Typically the level of coupling agent is 0.5% to 15% by weight based on the amount of inorganic filler. Its level is preferably between 0.5 and 9 phr, more preferably in a range from 3 to 9 phr. This level is easily adjusted by those skilled in the art according to the level of inorganic filler used in the composition.
    [0022] According to a preferred embodiment of the invention, the reinforcing filler is 100% by weight of a carbon black. According to another embodiment of the invention, the level of reinforcing filler is in a range from 20 to 70 phr, preferably from 25 to 50 phr. These reinforcing charge rate ranges can be applied to any of the embodiments of the invention. The crosslinking system may be based on either sulfur or sulfur and / or peroxide donors and / or bismaleimides. The crosslinking system is preferably a vulcanization system, i.e., a sulfur (or sulfur donor) and a primary vulcanization accelerator system. To this base vulcanization system are added, incorporated during the first non-productive phase and / or during the productive phase as described later, various known secondary accelerators or vulcanization activators such as zinc oxide, stearic acid or equivalent compounds, guanidine derivatives (in particular diphenylguanidine), or known vulcanization retarders. Sulfur is used at a preferential rate of between 0.5 and 12 phr, in particular between 1 and 10 phr. The primary vulcanization accelerator is used at a preferred level of between 0.5 and 10 phr, more preferably between 0.5 and 5.0 phr.
    [0023] The rubber composition may also comprise all or part of the usual additives commonly used in elastomer compositions intended to constitute treads, such as, for example, plasticizers, pigments, protective agents such as anti-ozone waxes, chemical antiozonants, anti-oxidants, anti-fatigue agents. According to a preferred embodiment of the invention, the rubber composition contains from 0 to 20 phr of a liquid plasticizer, preferably it is devoid of any liquid plasticizer.
    [0024] A plasticizer is considered liquid when, at 23 ° C, it has the capacity to eventually take the shape of its container, this definition being given in contrast to plasticizing resins which are inherently solid at room temperature. As liquid plasticizer, mention may be made of vegetable oils, mineral oils, ethers, esters, phosphates and sulphonates plasticizers and mixtures thereof. The rubber composition according to the invention can be manufactured in suitable mixers, using two successive preparation phases according to a general procedure well known to those skilled in the art: a first thermomechanical working or mixing phase (sometimes qualified of "non-productive" phase) at a high temperature, up to a maximum temperature of between 130 ° C and 200 ° C, preferably between 145 ° C and 185 ° C, followed by a second phase of mechanical work (sometimes referred to as a "productive" phase) at a lower temperature, typically below 120 ° C, for example between 60 ° C and 100 ° C, a finishing phase during which the chemical crosslinking agent is incorporated, in particular the vulcanization system. The rubber composition according to the invention can be either in the green state (before crosslinking or vulcanization), or in the fired state (after crosslinking or vulcanization), can be a semi-finished product that can be used in a tire, especially in a tire tread band 40. The aforementioned features of the present invention, as well as others, will be better understood on reading the following description of several embodiments of the invention, given by way of non-limiting illustration.
    [0025] II. EXAMPLES OF THE INVENTION: II.1-Measurements and Tests Used: 11.1-a) Size Exclusion Chromatography Size Exclusion Chromatography (SEC) is used.
    [0026] The SEC makes it possible to separate the macromolecules in solution according to their size through columns filled with a porous gel. The macromolecules are separated according to their hydrodynamic volume, the larger ones being eluted first. Without being an absolute method, the SEC allows to apprehend the distribution of the molar masses of a polymer. From commercial standard products, the various average molar masses (Mn) and weight (Mw) can be determined and the polymolecularity index (Ip = Mw / Mn) calculated via a calibration called MOORE. Preparation of the polymer: There is no particular treatment of the polymer sample before analysis. This is simply solubilized in (tetrahydrofuran + 1% vol diisopropylamine + 1% vol triethylamine + 1% vol distilled water) or in chloroform at a concentration of about 1 g / I. Then the solution is filtered on 0.45um porosity filter before injection. SEC analysis: The equipment used is a "WATERS alliance" chromatograph. The elution solvent is tetrahydrofuran + 1% vol. of diisopropylamine + 1% vol. triethylamine or chloroform depending on the solvent used for dissolving the polymer. The flow rate is 0.7 ml / min, the system temperature 35 ° C and the analysis time 90 min. A set of four WATERS columns in series, trade names "STYRAGEL HMW7", "STYRAGEL HMW6E" and two "STYRAGEL HT6E" are used. The injected volume of the solution of the polymer sample is 100 μl. The detector is a "WATERS 2410" differential refractometer and the chromatographic data exploitation software is the "WATERS EMPOWER" system. The average molar masses calculated relate to a calibration curve made from commercial standard polystyrene "PSS READY CAL-KIT". 11.1-b) Mass Loss This test is used to determine the mass loss of an aircraft tire tread composition specimen when subjected to an abrasion test on a high-speed abrasive tester. The high speed abrasion test is carried out according to the principle described in the article by S. K.
    [0027] 40 Clark "Touchdown Dynamics", Precision Measurement Company, Ann Arbor, NASA Mt, Langley Research Center, Computational Modeling of Tires pages 9-19 published August, 1995. P10-3401 3024154 The tread material rubs on a surface such as as a Norton Vulcan A30S-BF42 disk. The linear velocity during contact is 70 m / s with an average contact pressure of 15 to 20 bar. The device is designed to scrub until a power of 10 to 20 MJ / m2 of contact area is exhausted.
    [0028] The elements of the constant energy tribometry device according to the S.K. Clark article mentioned above are a motor, a clutch, a turntable and a sample holder. The performance is evaluated on the basis of mass loss according to the following formula: Performance mass loss = loss of control mass / loss of mass sample. The results are expressed in base 100. A performance for the sample greater than 100 is considered better than the control. 11.1-c) Rheometry The measurements are carried out at 150 ° C. with an oscillating chamber rheometer according to DIN 53529 - Part 3 (June 1983). The evolution of the rheometric torque, ACouple (in dN.m), as a function of time describes the evolution of the stiffening of the composition as a result of the vulcanization reaction. The measurements are processed according to DIN 53529 - Part 2 (March 1983): T0 is the induction time, that is to say the time required for the beginning of the vulcanization reaction; Ta (eg T99) is the time required to reach a conversion of a%, i.e., a% (eg 99%) of the difference between the minimum and maximum torque. The conversion rate constant denoted by K (expressed in min-1), of order 1, calculated between 30% and 80% conversion, which makes it possible to evaluate the kinetics of vulcanization, is also measured.
    [0029] II.2-Preparation of the compositions: The compositions, in this case Cl and T1, the formulation of which is shown in Table I, are prepared in the following manner: It is introduced into an internal mixer (final filling rate: about 70% by volume), whose initial tank temperature is about 80 ° C, successively the diene elastomers, the reinforcing filler, as well as the various other ingredients with the exception of the vulcanization system. Thermomechanical work (non-productive phase) is then carried out in one step, which lasts a total of about 3 to 4 minutes, until a maximum temperature of "fall" of 165 ° C is reached. The mixture thus obtained is recovered, cooled, and sulfur and a sulfenamide accelerator are incorporated on a mixer (homo-finisher) at 70 ° C, mixing the whole (productive phase) for a suitable time (for example ten minutes). The compositions thus obtained are then calendered either in the form of plates (thickness 2 to 3 mm) or thin sheets of rubber for measuring their physical or mechanical properties, or extruded in the form of a tire tread 40 then are vulcanized. The compositions C1 and T1 are identical, except for the nature of the elastomer and the level of sulfur. The composition C1 which contains the El elastomer is intended to be used as an aircraft tire tread according to the invention, the composition T1 which contains natural rubber is a conventional composition used as an air tire tread for an airplane. . El elastomer is synthesized by copolymerization of ethylene and 1,3-butadiene comprising 71 mol% of ethylene unit, the complement to 100% consisting of 1,3-butadiene units, distributed in the form of units. UA, UB, UC and UD according to the molar percentages given in Table II. It is prepared according to a polymerization method according to Example 4-2 of Patent EP 1 954 705 B1 in the name of the Applicants. The polymerization time was adjusted to obtain a molar mass Mn = 153,000 g / mol with a polydispersity index equal to 1.9.
    [0030] The difference in the chemical structure of the C1 and T1 elastomers induces a different behavior of the compositions Cl and T1 with respect to the vulcanization, which has led to the adjustment of the sulfur content according to the composition to be vulcanized to obtain faster cooking kinetics and cooking time acceptable to those skilled in the art. The speed constants K, the values of To, T90 and T99 of the compositions Cl and T1 are shown in Table I. II.3. Bake properties of the rubber compositions: The result of this test which appears in Table I shows that the mass loss performance of the composition C1 is doubled compared to the control T1 in a high speed abrasion test, recognized as a specific laboratory descriptor of the extreme conditions of landing on ground. Thus, the aircraft tire according to the invention which has the tread composition C1 is twice as strong to withstand extreme landing conditions as the aircraft tire whose tread consists of a composition conventionally used to 30 natural rubber base. In summary, the tire according to the invention has a greatly improved landing performance, especially with regard to the very high speed wear resistance.
    [0031] Table I Composition T1 Cl NR (1) 100 El 100 Elastomer Carbon Black (2) 30 Antioxidant (3) 1.5 1.5 Stearic Acid (4) 2.5 2.5 Oxide Zinc (5) 3 3 Accelerator (6) 2.0 2.0 Sulfur 0.8 1.5 Performance mass loss (%) 100 180 Rheometry K (min-1) 0.41 0.18 TB (min) 6 9 T90 (min) 12 22 T99 (min) 17 34 (1) Natural rubber (2) N234 according to ASTM D-1765 5 (3) N-1,3-dimethylbutyl-N-phenylparaphenylenediamine "Santoflex 6-PPD" of the Flexsys company (4) Stearin "Pristerene 4931" from Uniqema (5) Industrial grade zinc oxide from Umicore (6) N-cyclohexyl-2-benzothiazyl sulfenamide "Santocure CBS" from Flexsys 10 Table 11 Pattern UA 71 Pattern UB 8 Pattern UC 14 Pattern UD 7 15 Table III Composition T1 Cl Performance Mass Loss (%) 100 180 P10-3401
    权利要求:
    Claims (21)
    [0001]
    REVENDICATIONS1. Aircraft tire whose tread comprises a rubber composition based on at least one first diene elastomer, a reinforcing filler and a crosslinking system, which first diene elastomer comprises ethylene units and diene units comprising a carbon double bond carbon, which units are statistically distributed within the first diene elastomer, the ethylene units representing at least 50 mol% of all the monomer units of the first diene elastomer.
    [0002]
    2. A tire according to claim 1 wherein the first diene elastomer comprises the following units UA, UB, UC and UD statistically distributed within the first diene elastomer, UA) -CH2-CH2- according to a molar percentage of m% UB). a molar percentage of n% UC) according to a molar percentage of o% R 1 I -CH 2 -C C 2 R 2 II CH 2 UD) CH 2 -Cl-12 in a molar percentage of p% CH 2 CH 2 CH 2 CH 2 And R 1 and R 2, which may be identical or different, denoting a hydrogen atom, a methyl radical or a phenyl radical which may or may not be substituted in the ortho, meta or para position with a methyl radical; m.sup.-50 -0 <o + p N + o> 0 - m, n, o and p being numbers from 0 to 100 - the respective mole percentages of m, n, o, and p being calculated on the basis of the sum of m + n + o + p which is equal to 100.
    [0003]
    3. A tire according to claim 2 wherein the first diene elastomer contains units UE statistically distributed within the first diene elastomer, UE) CH2-C H2 in a molar percentage of q% / CH CH-CH2-CH2 - o + p + q 10 - q> _0 15 - the respective molar percentages of m, n, o, p and q being calculated on the basis of the sum of m + n + o + p + q which is equal to 100.
    [0004]
    The tire of claim 2 or 3 wherein the first diene elastomer contains UF units statistically distributed within the first diene elastomer. 10 UF) -CH 2 -CH - according to a molar percentage of R 1 - R 3 denoting an alkyl radical having 1 to 4 carbon atoms or an aryl radical, - 0 <r <25. the respective molar percentages of m, n, o, p, q and r being calculated on the basis of the sum of m + n + o + p + q + r which is equal to 100.
    [0005]
    The tire of claim 4 wherein r is 0.
    [0006]
    Tire according to any one of claims 2 to 5, wherein at least one of the two molar percentages p and q is other than 0.
    [0007]
    A tire according to any one of claims 2 to 6, wherein p is strictly greater than 0. P10-3401 3024154
    [0008]
    8. The tire according to claim 2, wherein the first diene elastomer has at least one of the following criteria, and more preferably all more preferably 20 ^ 10 p + q 2 ^ 1 n / (o + p + q) when q is not zero, 20 / q 1 10
    [0009]
    Pneumatic tire according to any one of claims 3 to 8, in which the first diene elastomer contains, as monomeric units, only the units UA, UB, UC, UD and EU according to their respective molar percentage m, n, o, p and q, preferably all different from 0. 15
    [0010]
    A tire according to claim 2 or any one of claims 4 to 8 wherein the first diene elastomer contains as monomeric units only the units UA, UB, UC and UD according to their respective molar percentage m, n, o and p, preferably all different from 0. 20
    [0011]
    11. A tire according to any one of claims 1 to 10 wherein R1 and R2 are identical and denote a hydrogen atom.
    [0012]
    12. A tire according to any one of claims 1 to 11 wherein the rubber composition comprises a second elastomer, preferably diene.
    [0013]
    The tire of claim 12 wherein the second elastomer is a highly unsaturated diene elastomer selected from the group consisting of polybutadienes, polyisoprenes, butadiene copolymers, isoprene copolymers and mixtures of these elastomers.
    [0014]
    Tire according to claim 12, in which the second elastomer is a ternary copolymer obtained by copolymerization of ethylene, of an α-olefin having 3 to 6 carbon atoms with a non-conjugated diene monomer having from 6 to 12 carbon atoms. .
    [0015]
    15. A tire according to any one of claims 1 to 11 wherein the first diene elastomer is the only elastomer of the rubber composition.
    [0016]
    16. A tire according to any of claims 1 to 15 wherein the reinforcing filler comprises a carbon black. P10-3401 25 30 35 3024154 21
    [0017]
    17. A tire according to claim 16 wherein the reinforcing filler is made of 100% by weight of a carbon black.
    [0018]
    18. A tire according to any one of claims 1 to 16 wherein the reinforcing filler comprises an inorganic filler, preferably a silica.
    [0019]
    19. A tire according to any one of claims 1 to 18 wherein the reinforcing filler content is 20 to 70 phr, preferably 25 to 50 phr. 10
    [0020]
    20. A tire according to any one of claims 1 to 19 wherein the rubber composition contains 0 to 20 phr of a liquid plasticizer.
    [0021]
    The tire of claim 20 wherein the level of liquid plasticizer is 0. P10-3401
    类似技术:
    公开号 | 公开日 | 专利标题
    EP3172061B1|2020-02-12|Tire for airplane
    EP3172062B1|2018-09-12|Aircraft tyre
    EP3478759B1|2020-08-05|Rubber composition comprising an epoxidized resin and a specific amine hardener
    EP3328663A1|2018-06-06|Aircraft tyre
    EP3592573B1|2021-06-30|Tyre having a composition comprising an ethylene-rich elastomer, a peroxide and a polyfunctional acrylate derivative
    EP3592808B1|2021-06-02|Tyre having a composition comprising an ethylene-rich elastomer, a peroxide and a zinc acrylate
    EP3377339B1|2019-11-13|Tread for an aircraft tyre
    EP3083813B1|2018-11-07|Latex composition comprising a polyphenylene ether resin as plastisizer
    WO2017103386A1|2017-06-22|Tyre, the tread of which comprises a rubber composition comprising a low specific surface area silica and a low glass transition temperature diene elastomer
    FR3023844A1|2016-01-22|RUBBER COMPOSITION
    FR3060589A1|2018-06-22|RUBBER COMPOSITION COMPRISING A SPECIFIC RUBBER POWDER
    WO2019115955A1|2019-06-20|Aircraft tire
    EP3233997A1|2017-10-25|Reinforced rubber composition for a tyre
    WO2015059151A1|2015-04-30|Aircraft tire having a rolling thread that includes an elastomer silicone composition
    EP3558701A1|2019-10-30|Rubber composition comprising a specific hydrocarbon resin
    EP3377338B1|2020-01-01|Tread for pneumatic aviation tire
    EP3609723A1|2020-02-19|Rubber composition comprising a specific hydrocarbon resin
    WO2018115621A1|2018-06-28|Rubber composition comprising a specific hydrocarbon resin
    FR3090660A1|2020-06-26|Tire tread
    WO2021064317A1|2021-04-08|Rubber composition for a large-sized tire
    FR3090662A1|2020-06-26|Tire tread
    同族专利:
    公开号 | 公开日
    BR112017000784B1|2021-04-13|
    CN106536218A|2017-03-22|
    FR3024154B1|2016-07-22|
    EP3172061A1|2017-05-31|
    WO2016012259A1|2016-01-28|
    CN106536218B|2018-12-11|
    US20170198114A1|2017-07-13|
    BR112017000784A2|2019-02-05|
    EP3172061B1|2020-02-12|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4801641A|1986-06-17|1989-01-31|Bridgestone Corporation|Rubber compositions and pneumatic tires using the same|
    FR2893028B1|2005-11-09|2008-02-15|Michelin Soc Tech|METALOCENE COMPLEX BOROHYDRIDE OF LANTHANIDE, INCORPORATING CATALYTIC SYSTEM, POLYMERIZATION METHOD USING THE SAME, AND ETHYLENE / BUTADIENE COPOLYMER OBTAINED BY THIS PROCESS|
    FR2962371B1|2010-07-07|2014-03-21|Michelin Soc Tech|TOP REINFORCEMENT FOR AIR TIRE|
    JP5731217B2|2011-02-04|2015-06-10|株式会社ブリヂストン|Copolymer, rubber composition, crosslinked rubber composition, and tire|
    FR2973385B1|2011-04-01|2014-08-22|Michelin Soc Tech|PNEUMATIC RUBBER COMPOSITION COMPRISING AZOSILANE COUPLING AGENT.|
    FR2975999B1|2011-06-01|2014-07-04|Michelin Soc Tech|TIRE HAVING TREAD BAND COMPRISING THERMO-EXPANDABLE RUBBER COMPOSITION REDUCING ROLLING NOISE|
    CN103781837B|2011-08-26|2015-11-25|横滨橡胶株式会社|Rubber composition for tire tread|
    FR2981937B1|2011-10-28|2013-11-08|Michelin Soc Tech|ELASTOMERIC COMPOSITION HAVING VERY GOOD DISPERSION OF THE LOAD IN THE ELASTOMERIC MATRIX|
    US9212275B2|2012-09-26|2015-12-15|The Goodyear Tire & Rubber Company|Tire with tread comprised of functionalized elastomer and pre-treated silica|
    US20140135424A1|2012-11-15|2014-05-15|The Goodyear Tire & Rubber Company|Rubber composition and tire with component comprised of polyisoprene rubber and soybean oil|
    JP2014105237A|2012-11-26|2014-06-09|Sumitomo Rubber Ind Ltd|Rubber composition for tread and pneumatic tire|
    JP2014105320A|2012-11-29|2014-06-09|Sumitomo Rubber Ind Ltd|Rubber composition for base tread and pneumatic tire|FR3044009B1|2015-11-19|2017-12-08|Michelin & Cie|TIRE TREAD FOR TIRE AIRCRAFT|
    FR3067355A1|2017-06-08|2018-12-14|Compagnie Generale Des Etablissements Michelin|RUBBER COMPOSITION|
    FR3085683B1|2018-09-11|2020-10-23|Michelin & Cie|PNEUMATIC|
    FR3085684B1|2018-09-11|2021-06-04|Michelin & Cie|RUBBER COMPOSITION|
    FR3087443B3|2018-10-23|2020-10-23|Michelin & Cie|RUBBER COMPOSITION|
    FR3099766B1|2019-08-07|2021-07-30|Michelin & Cie|Ethylene-rich diene block polymer having a statistical block and a polyethylene block.|
    法律状态:
    2015-06-26| PLFP| Fee payment|Year of fee payment: 2 |
    2016-01-29| PLSC| Search report ready|Effective date: 20160129 |
    2016-07-21| PLFP| Fee payment|Year of fee payment: 3 |
    2017-07-24| PLFP| Fee payment|Year of fee payment: 4 |
    2018-07-25| PLFP| Fee payment|Year of fee payment: 5 |
    2020-04-10| ST| Notification of lapse|Effective date: 20200306 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1457054A|FR3024154B1|2014-07-22|2014-07-22|PNEUMATIC FOR AIRCRAFT|FR1457054A| FR3024154B1|2014-07-22|2014-07-22|PNEUMATIC FOR AIRCRAFT|
    CN201580039632.1A| CN106536218B|2014-07-22|2015-07-09|Aero tyre|
    PCT/EP2015/065757| WO2016012259A1|2014-07-22|2015-07-09|Aircraft tyre|
    US15/327,958| US20170198114A1|2014-07-22|2015-07-09|Aircraft tire|
    EP15736826.7A| EP3172061B1|2014-07-22|2015-07-09|Tire for airplane|
    BR112017000784-3A| BR112017000784B1|2014-07-22|2015-07-09|AIRPLANE PNEUMATIC|
    [返回顶部]