• 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:
    FIBER DOPE SOLUTION, METHOD FOR PRODUCING A FIBER DOPE SOLUTION, PRODUCT, AND, FIBER The invention relates to a process for preparing a composition comprising 10 to 45% by weight of total solids of lignin, polyacrylonitrile or a copolymer of polyacrylonitrile, and a solvent to form a dope containing polyacrylonitrile and based on lignin and the resulting products. The dope can be processed to produce fibers, including precursor, oxidized and carbonized fibers. Oxidized fibers are of value for their flame resistant properties and carbonized fibers are suitable for use in applications requiring high strength fibers, or to be used to form composite materials.
    公开号:BR112012028938B1
    申请号:R112012028938-1
    申请日:2011-06-07
    公开日:2020-10-13
    发明作者:Carole W. Herriott；Paul J. Bissett
    申请人:Weyerhaeuser Nr Company；
    IPC主号:
    专利说明:

    FIELD OF THE INVENTION
    The invention relates to the preparation of a polyacrylonitrile (PAN) or dope based on PAN copolymer for fiber preparation comprising polyacrylonitrile (PAN) or PAN copolymers, and a solvent that also contains lignin. The dope can be processed to produce fibers, such as solution or wet spinning. The fibers can be further processed to form products, such as oxidized or carbonized fibers. Carbonized fibers are of value for their flame resistant properties and carbonized fibers are suitable for use in applications requiring high strength fibers, or to be used to form composite materials. DESCRIPTION OF THE DRAWINGS
    The foregoing aspects and many of the accompanying advantages of this invention will be readily appreciated as they become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings.
    Figure 1 is a table showing properties of “green” (precursor), oxidized and carbonized fibers.
    Figure 2 is a graph showing the relationship of lignin content, solids content and viscosity of the solution with respect to PAN 1 and PAN 2.
    Figure 3 is a graph showing the observed versus predicted viscosities for PAN4 at 50 ° C.
    Figure 4 shows viscosity as a function of solids and lignin for PAN4.
    Figure 5 shows the viscosity of PAN4 and PAN4 with lignin, as measured over time. DETAILED DESCRIPTION
    For the past 30 years, PAN or PAN copolymers have been the industry standard for precursor fibers used for the production of heat-treated carbon fibers and fibers. Carbon fibers are highly valued for their low weight, high strength, hardness and resistance to fatigue.
    As used here, "PAN" refers to a polyacrylonitrile homopolymer, having a molecular weight ranging from about 50,000 to 500,000 and an intrinsic viscosity from 1 to 4.
    As used herein, a "PAN copolymer" refers to a polyacrylonitrile copolymer and a comonomer such as vinyl acetate, methyl acrylate, methyl methacrylate or methylitaconate, to provide a copolymer such as PAN-vinyl acetate, PAN-methyl acrylate or PAN-methyl methacrylate. The molecular weights of PAN copolymers can vary from about 50,000 to 500,000.
    A solvent is used to dissolve the PAN or PAN copolymer and create a spinning dope. The solvents used are DMF (dimethylformamide), DMAA or DMAc (dimethylacetamide) and DMSO (dimethylsulfoxide). A viscose solution, although considered for use as a solvent for some chemicals, is not used with PAN or PAN copolymer.
    Additional components can be added in the polymerization process to produce the PAN. For example, persons of ordinary skill in the art are familiar with agents that facilitate the cyclization of acrylamide, including species containing carboxylic acid, such as vinyl carboxylic acids. Non-limiting examples of carboxylic acids that can be included in dopes described here include acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, isocrotonic acid, itaconic acid, maleic acid, mesaconic acid, citraconic acid, p-vinyl benzoic acid and m -benzoic vinyl, and its alkaline and ammonium salts. Carboxylic acid-containing species can be added to the dopes described here in amounts up to and including 1%.
    The PAN or PAN copolymer dope is then spun into a fiber.
    Various methods of spinning dopes within fibers are known in the art. Solution or wet spinning and dry jet spinning are exemplary methods that can be employed in methods of the present invention to produce the fibers described herein. Additional information regarding spinning techniques is found in the Examples below.
    Solution or wet wiring is well known in the art. In solution or wet spinning, the polymer to be produced in a fiber is dissolved in a solvent to create a viscous spinning dope. The dope is typically passed through a filter and, through a multi-hole spinner, into a coagulation bath. The dope leaving the spinner produces fibers like dope coagulants. Dope coagulation occurs as a result of the codification of water, the anti-solvent, inside the fibers and solvent outside the fibers. The fibers typically pass into a solvent drawing bath, in which the fibers are drawn and, as a result, drawn to a smaller diameter. The residual solvent is removed in a series of washing steps. The fiber is then dried. The resulting fiber can be further stretched to a smaller diameter, if desired.
    In wet spinning with a dry jet, the viscous polymeric dope is extruded in fiber form by a spinner inside and through an air gap and then into a coagulation bath, in which the polymeric dope is coagulated within a fiber . The passage through the air gap is under some tension and the pull of gravity, which creates some orientation of the polymeric molecules in the longitudinal direction of the fiber. The coagulation bath also extracts the solvent from the dope. The tension is applied to the fiber when it leaves the coagulation bath. This stretches the fiber, which improves the degree of orientation of the polymeric molecules in the longitudinal direction of the fiber. The fiber will pass through washing steps to remove residual solvent and is then dried.
    As used herein, the solids content of the dope solution is the material, other than the solvent, that is in the solution. The weight of the solids in solution is the total weight of the solution minus the weight of the solvent.
    The content of solids in the dope is a determining factor in the rate of fiber production. Increasing the solids content of the dope can increase the rate of fiber production. However, viscosity becomes a limiting factor for fiber production, as the viscosity exceeds the process design limits for pressure and pumping capacity. The dope solids content and the dope viscosity are also related. When the solids content of the dope is increased, the viscosity of the dope is increased. There is a tension between increased production due to increased solids in the dope and decreased production, because the increased solids content of the dope makes the dope too viscous.
    The viscosity of the PAN dope or PAN copolymer is also a determining factor in the propensity for fiber formation. A fiber will not be formed if the viscosity of the PAN or PAN copolymer is too low, but it will undoubtedly extrude into droplets or staple fibers. There is a lower viscosity limit before the PAN or PAN copolymer forms fibers. This is typically around 20 poises.
    The viscosity of the PAN dope or PAN copolymer must be quite high to form fibers, but low enough to flow through the spinner or extrusion head, at rates that provide a good production rate. The solids content of the PAN dope or PAN copolymer must be high enough to provide a flow rate that provides a good production rate. The solids content and viscosity of the dope must be balanced to provide a good production rate.
    In one embodiment, the maximum viscosity is 1500 poises at 20 to 80 ° C. In another embodiment, the maximum viscosity is 1000 to 20 to 80 ° C.
    The viscosity of the PAN dope or PAN copolymer is also dependent on the other polymer that is used and any additives that may be used. Viscosity is also dependent on the dope temperature. When the temperature is increased, the viscosity is decreased.
    Raising the temperature of the dope solution has been a method of increasing solids because the higher temperature decreases the viscosity. Again, there is a dilemma because the increase in temperature increases the energy costs of the process and the cost of the fiber product. There is also a maximum temperature at which the dope can be heated before other reactions can occur in the dope.
    A process and product has been developed that reduces the need for higher temperatures to keep the dope viscosity within a usable range, thereby lowering the cost of the process and the resulting product. The reduction in viscosity and temperature reduces the need for more robust equipment, required for higher viscosity and higher temperatures. The new process and product also reduces the raw material cost of the product.
    It has been found that the addition of lignin to the PAN dope or PAN copolymer decreases the viscosity of the dope and allows the solids content of the dope to be increased. It has also been found that the maximum amount of lignin that can be added to the PAN or PAN copolymer dope is 45% by weight of the solids content. The dope solids content is the total weight of the dope minus the weight of the solvent. The solids content of the dope would include PAN or PAN copolymer, any additives and lignin and the weight of the solids content of the dope would be the total weight of these elements. The weight of lignin in the dope would be 10 to 45% of this total weight.
    Lignin is a common by-product of the pulp and paper industry, separated from trees by hydrolytic degradation in chemical pulping processes, which consistently produce well-defined lignin. Kraft lignin or sulfate, is obtained by the kraft pulping process, and sulfite lignin (lignin sulfates or lignin sulfates) is obtained by the sulfite pulping process. The physical and chemical properties of lignin depend on its plant source and processing conditions. Lignosulfates, which are hydrophilic, can be dissolved in water, and kraft lignins, which are hydrophobic, cannot be dissolved in water. Industrial wood pulping processes were seen as a potential source of cheap lignin-based precursor materials, having well-defined, consistent compositions, even though lignin may vary in molecular weight and chemical homogeneity, because of differences in the types and ratios of intermonomeric units and connections.
    Lignin is one of the biopolymers found in plants.
    The plant cell walls are mainly composed of three biopolymers: cellulose, hemicellulose and lignin. Cellulose is a relatively simple polymer of D-glucose molecules, linked together, mainly with glycosidic bonds. Hemicelluloses are branched polymers of xylose, arabinose, galactose, mannose and glucose. Hemicellulose polymers attach to bundles of cellulose fibrils to form microfibrils and crosslink with lignin, creating a complex web of bonds that increase the structural stability of the cell wall. Lignin is a complex, three-dimensional biopolymer found in all vascular plants, being responsible for a quarter to a third of the dry mass of wood in gymnosperms and angiosperms. Lignins are formed from
    Dehydrogenative enzyme-mediated free radical polymerization of cinnamyl alcohol based precursors (Formula 1). The dominant intermonomeric unit bond is the arylglycerol-β-O-4 aryl ether bond. The β-O-4 bond is responsible for 48 - 60% of the total interunit bonds in 5 lignin (Braun et al., Carbon, 43: 385-394 (2005)). FORMULA 1

    Lignins can be grouped into three broad classes: white or coniferous wood (gymnosperm), hardwood (dicotyledonous angiosperm) and grass or annual plant (monocotyledonous angiosperm). The 10 hardwood lignins are often characterized as being derived from coniferyl alcohol or guaiacylpropane monomer (4-hydroxy-3-methoxyphenylpropane) (Formula 2). Hardwood lignins contain polymers of 3,5-dimethoxy-4-hydroxyphenylpropane monomers (Formula 3) in addition to guaiacylpropane monomers. Grass lignins contain 15 polymers of both of these monomers, plus 4-hydroxyphenylpropane monomers (Formula 4). Hardwood lignins are much more heterogeneous in structure from species to species than hardwood lignins when isolated by similar procedures. FORMULAS 2, 3 AND 4

    (4)
    Typical white woods that can be used are pine, spruce, larch, Douglas fir, spruce, pseudotsuga, Canadian pine, cedar and juniper. Typical hardwoods that can be used are aspen, linden tree, beech, birch, canada poplar, gomiferous tree, maple, ash, pine nut, elm and eucalyptus.
    In the wood pulping process, most of the lignin and hemicellulose in the wood is separated from the cellulose in the digester by the sulfate or sulfite cooking liquor. The chemicals in the cooking liquor react with hemicellulose and lignin and cause them to become a solution. The materials leaving the pulp digester are black liquor containing lignin and hemicellulose and pulp fibers containing cellulose and residual lignin and hemicellulose. This residual material is removed in the later bleaching stages.
    Lignin can be purified by black liquor using a process designed to preferably precipitate lignin using a series of acidic treatments, as is known in the art. The process lignin
    Kraft is generally isolated by precipitation of black liquor acid from a kraft pulping process at a pH below the pKa of the phenolic groups.
    Depending on the conditions under which the lignin is precipitated, the precipitated lignin may be in the form of free acid lignin or a lignin salt.
    If the lignin is precipitated at a high pH, such as about 9.5 to 10, the lignin is obtained in the form of a salt. If this lignin is then processed by washing and acidification at a low pH, such as about 2 to 5, and still washed in order to be substantially free of salt and ash-forming ingredients, the free acid lignin, known as lignin "A" is obtained. A monovalent lignin salt, such as an alkali metal salt or an ammonium salt, is soluble in water, while free acid lignin and polyvalent metal salts of lignin are insoluble in water. The lignin suitable for the present invention is not soluble in water. Exemplary methods for separating lignin from black liquor and a liquid / sludge containing lignin have been described in WO 2006/031175 and WO 2006/038863, respectively. Partially purified lignin can be purchased from a number of commercial suppliers, such as Westvaco, Inc. (SWKL-Indulin AT ™) and Repap (Organosolv lignin-Alcell ™). Solvent extraction methods can also be used to generate lignin from a variety of sources.
    Lignin can also be prepared from other types of biomass, including grasses, and consistent batches of materials rich in lignin, recovered from waste materials from fermentation and biorefinery beverage processes. The absolute and relative amounts of lignin in a lignin supply stock may vary. Large-scale manufacturing processes typically offer an inexpensive source of precursors or lignin-based feed stock, which can be used directly in the process of the invention, or pretreated with enzymes or chemicals to facilitate lignin purification and recovery of a bulky, raw feed stock. Enzymes, for example, can be used to degrade lignin, reducing its molecular weight to a preferred range, or to reduce the amount of intermolecular crosslinking. Chemicals can also be used to alter selected side chains or components of lignin-based materials, or to facilitate the hydrolysis of intramolecular or intermolecular bonds between subunits or chains, respectively. Enzymatic or chemical treatments are typically designed to improve the physical or chemical characteristics of the resulting product, to increase homogeneity, obtain a desirable solubility in preferred solvents, select a preferred molecular weight range or facilitate fiber reliability.
    In one embodiment, the lignin feed stock is characterized as having a total ash content of less than 0.2% by weight. In addition, in this embodiment, kraft lignins can have an average molecular weight between 1,000 and 30,000 and potentially greater for other sources of lignin. An embodiment of the invention includes a process in which the lignin supplied to the process is selected from the group consisting of purified lignin, precipitated from black liquor and lignin / cellulose residues prepared from bio-refuse waste or fermented beverage preparation. Lignin can be prepared from white wood or hardwood materials. Another embodiment of the invention includes a process in which the lignin is black liquor and is prepared from a white wood fiber source. Another embodiment of the invention includes a process in which the lignin is black liquor and is prepared by a process comprising the steps of: (a) filtering; (b) acidification of the black liquor to precipitate the lignin; (c) centrifuging or filtering the acidified black liquor to separate the lignin precipitate from the black liquor; (d) washing the lignin to remove foreign material, such as ash, (e) optional filtration to separate the lignin from the washing water, (f) additional washing and filtering steps if necessary and (g) drying the lignin.
    There have been attempts to produce carbon fibers based on lignin and lignin fractions, but these attempts have so far been limited by the inability to produce filaments with desirable chemical and physical receptive properties for the subsequent processing required to convert the precursor fiber to a fiber heat treated or carbon fiber. These attempts have not produced long flexible fibers of small diameter and good raw strength. In these attempts, lignin was tried as the main and, frequently, only element of the fiber production and the fiber thus produced was rigid and brittle. Fusion spinning, in which the lignin was heated to a molten and extruded state, was experimented with. Often white wood lignin charred and hardwood lignin was not easily stabilized, so the fiber melted or had voids that reduced strength. It is understood that melt spinning was not the way to produce lignin-containing fibers. It is understood that lignin should not be the main ingredient in fiber. She was supposed to be an adjunct to another chemical.
    The understanding was reached that there was synergy in the combination of lignin with a PAN-based dope or copolymer of
    PAN. Lignin had very poor fiber properties alone. The dope based on PAN and PAN copolymer produced good fiber, but had production limitations. A fiber was found to have good properties and could increase the production rate of precursor fibers, using PAN and PAN copolymer dopes.
    In dope production the lignin fraction is 10 to 45% of the total weight of the solids in the dope, that is, the total weight of the lignin, the PAN and PAN copolymers and any other additives. The solvent should be one that is a solvent for both lignin and PAN or a copolymer of
    PAN. Some of these solvents are DMF, DMAA or DMAc and DMSO. The total solids of the solution can be from 10 to 35% by weight. The actual total solids content will depend on the amount of lignin in the mixture. A higher ratio of lignin to PAN or PAN copolymer in the mixture will allow a higher total solids content in the solution. The purpose is to keep the viscosity of the solution in the range of 20 to 1500 poises at a temperature of 20 ° C to 80 ° C, while keeping the total solids content as high as possible.
    Typically, the lignin and the PAN or PAN copolymer are added to the solvent and the solution is mixed. The solution is de-trimmed before fiber spinning to obtain good reliability and to reduce the possibility of voids in the fiber. The PAN-based dope or copolymer of
    PAN containing lignin can be spun in precursor fibers by solvent or wet spinning or wet spinning with dry jet, as described above.
    The fibers are coagulated, stretched, washed, filtered and dried as described above.
    The precursor fibers, oxidized and carbonized, described here, can be characterized by a variety of analytical techniques. Among them are chemical content, degree of polymerization, X-ray diffraction, fiber diameter, tensile strength, birefringence, crystallinity index, TGA and
    DSC. The techniques for measuring these properties are well known in the art and several methods are described in the Examples section below.
    A typical precursor fiber comprising 10 to 45% by weight of lignin and still comprising polyacrylonitrile or polyacrylonitrile copolymer could have a total stretch of 7 to 15 times, a denier of 0.6 to 4.5, a diameter of 8 to 25 microns , a tensile strength of 30 to 100 ksi (2109 to 7030 kg / cm2), a traction module of 0.6 to 20 Msi (42184 to 1.406138 kg / cm2) and an elongation of 8 to 18%.
    Carbon fibers, which have been prepared from a variety of precursor materials, including rayon, tar (oil or coal) and
    PAN, are highly valued for their strength, hardness, fatigue resistance and low weight. Carbon fiber composite materials can be found in aerospace materials, sports equipment, marine products and products for the automotive industry, among many other applications. Carbon fibers can be made by treating the fibers up to 2,000 ° C, in an inert atmosphere, while maintaining a fibrous structure.
    In one embodiment, the temperature is from 600 to 2000 ° C. A typical carbonized fiber comprises a reaction product of lignin and polyacrylonitrile or polyacrylonitrile copolymer and could have a diameter of 5 to 20 microns, a tensile strength of 80 to 400 ksi (5624 to 28122 kg / cm2), a traction module from 7 to 30 Msi (492148 kg / cm2 to 2109207 kg / cm) and an elongation of 0.8 to 1.4%.
    Before carbonization, the precursor fibers are first stabilized by oxidation, heating them to 200 - 3000 ° C for 60 to 180 minutes, in the presence of air, to facilitate intra and inter molecular crosslinking, to produce thermally stabilized fibers, which prevent contraction, melting and casting in carbonization. A typical oxidized fiber comprises a lignin and polyacrylonitrile reaction product or polyacrylonitrile copolymer and could have a diameter of 6 to 22 microns, a tensile strength of 10 to 30 ksi (703 to 2109 kgcm2) and an elongation of 3 to 20 %.
    Methods for producing PAN precursor fibers and oxidized and carbonized fibers from PAN precursor fibers are known. THE
    US Patent No. 5,804,108 is exemplary.
    In the heating process for both oxidation and carbonization there may be a reaction product of lignin and PAN or PAN copolymer at the oxidation and carbonization temperatures.
    Any method discussed here can employ any lignin / PAN fiber or lignin / PAN copolymer described here. EXAMPLES
    The following materials were used in the Examples listed, unless otherwise noted.
    Polyacrylonitrile (PAN): PAN 1, PAN 2, PAN3 and PAN 4 were supplied by Sterling Fibers, Inc. (Pace, Florida). PAN 1 and PAN 2 are precursor grade of carbon fiber; PAN 3 and PAN 4 are textile grade. Table 1. PAN polymers and copolymers

    Lignin. White wood kraft lignin was used as produced by acid precipitation of the black pulp liquor predominantly from a fiber source of the fir wood species. Example 1: Preparation of Characterization of “Crude” Fibers (Precursor)
    Mixed solutions or "dopes" of lignin and PAN or PAN copolymer were prepared by weight / weight mixtures of the component materials and solvent. The standard method of preparation for the mixtures was to prepare a lignin solution of known solids content by dissolving a determined amount of the lignin in the solvent. Then the correct aliquot of the known lignin / solvent solution was weighed before and additional solvent was then weighed and added to the sample. A specified amount of the desired PAN or PAN copolymer was then added to the sample in the amount necessary to achieve the desired lignin / PAN or PAN lignin / copolymer ratio and total solids. The prepared sample was then mixed using a Silverson Series L5M-5 high shear laboratory mixer. PAN, lignin / PAN or PAN lignin / copolymer solutions were allowed to settle, typically overnight, and then deaerated before fiber spinning. Deaeration of the dopes was completed using a standard laboratory vacuum pump, producing approximately 30 inches (76 cm) of Hg vacuum.
    Fiber spinning was accomplished using a laboratory solution spinning line. For those skilled in the art, the complexity of the solution spinning process is well understood. The general process of solution spinning is well documented in the literature and the fiber spinning associated with this work follows the typical fiber processing. The exact conditions for shaping and drawing fibers have been modified in response to observed spinning conditions, fiber performance and processing attributes. The technology associated with fiber based on solution spinning acrylic can be found in references such as: Acrylic Fiber Technology and Application, 1995, edited by James C. Mason, New York, Marcei Decker, Inc.
    In general, the prepared dope was spun through a spinner with between 30 and 1000 holes, with each hole between 45 and 75 microns. The fibers were then coagulated in a bath of 40% dimethylacetamide (DMAc) and 60% water (weight / weight basis). The subsequent bath was a solvent stretching bath with a solvent concentration of 20% DMAc and 80% water (weight / weight basis). The fibers were then washed in water at room temperature, followed by a heated water bath of 80 - 90 ° C, which was followed by a hot stretch bath close to the boiling temperature (~ 90 ° C). The fibers were then dried and stretched using a series of four electrically heated rollers.
    The mechanical properties of raw precursor fibers (single tow) were measured using the modified ASTM D 7269 standard (modifications follow). An Instron 4400R frame using Blue HÍ112 software version 2.19 was used in conjunction with a 100N load element. The test dimensions were a gauge length of 250 mm and standard wire geometry with a test speed of 125.00 mm / minute. Rectangular pneumatic clamps were used with a test speed of 125.00 mm / minute. Rectangular pneumatic fasteners were used with ■ ■% pressure at 40 psi (2812 kg / cm). The fiber samples were first conditioned for 24 hours at 50% RH and 22 ° C. Approximately 1 - 2 meters of fiber yarn / tow length was removed from the spool before starting the test procedure. Each specimen was rolled as close as possible inside the upper and lower fasteners and held in place, taking care not to twist the wire. After the test was completed, the replica was considered “good” if the wire break did not occur within 10 mm of each fastener, otherwise the repetition was rejected. Ten "good" repetitions were used to report the calculations. 5 Modifications of the ASTM D7269 procedure are provided below:
    Section 6.1.1 - Rectangular fasteners are used, not the Bollard style
    Section 7.3.3 - After the required amount of wire has been removed, the sample was not cut to individual segment lengths, but tested with a continuous wire, with the post-tested areas pulled out of the test range before a new one. test. Table 2. Properties of “raw” fibers (precursors) produced from spinning in lignin and PAN solution in dimethylacetamide:
    The properties of these "raw" fibers demonstrate that lignin can be incorporated to produce fibers of attractive mechanical and physical properties for consideration as precursor fibers for the production of, for example, commercial oxidized and / or carbonized fibers. Example 2: Preparation and Properties of Oxidized and Carbonized Fibers
    The fibers as prepared in Example 1 were oxidized and carbonized to produce fibers that can be used, e.g. eg as flame retardant fibers or carbon fibers.
    The precursor fiber (PAN 3) was oxidized to a maximum temperature of 300 ° C for approximately 2 hours. The properties of the 25 filaments after oxidation are shown in Figure 1.
    The carbonized fiber was produced by first oxidizing the fiber first as summarized above and then carbonizing it in a continuous process, passing the fiber first through low temperature carbonization at 600 ° C and then subsequently through high temperature carbonization at 1200 ° C. All carbonization was carried out under nitrogen.
    The properties of carbonized fibers are also shown in Figure 1.
    The tensile strength of the oxidized and carbonized fiber (in kg / cm2), the stress at peak tension (%) and the modulus (Mpsi) were determined using an MTS Alliance RT / 5 tester following the ASTM standard method D3379. Example 3: Lignin Concentration Affects Solution Viscosity
    Lignin has a low degree of polymerization and produces low viscosity solutions when dissolved in a compatible organic solvent and in solids levels in excess of 50% when heated. Lignin, when mixed with a mixture of synthetic polymer or synthetic copolymer (PAN, PAN copolymers), substantially reduces the viscosity of the resulting solution or the fiber dope solution, when compared at equivalent level and temperature of solids in solution (see Table 3). Table 3. Viscosities of Various Solutions Containing Lignin / PAN

    The ratio of lignin content to the viscosity of the resulting solution is dependent on the total solids that are prepared, which is illustrated in Figure 2. In Fig. 2 the 50% lignin plot has a viscosity that is below the gel viscosity. Example 4: Generation of an Experimentally Determined Surface Viscosity Response Model
    A model can be used for a preliminary determination of the amount of lignin, PAN or PAN copolymer and total solids needed to obtain the desired viscosity at a given temperature. The model is based on actual viscosity observations for given amounts of lignin, PAN or PAN copolymer and total solids.
    Several series of observations may be necessary to obtain observations that aim at viscosity.
    A dope solution of lignin and PAN or PAN copolymer consists of a mixture of three components: polymer, lignin and solvent. The weight of the oven-dried polymer or copolymer (P), the weight of the oven-dried lignin (L) and the weight of the solvent (S) required to obtain a fixed solids fraction and a fixed lignin fraction are calculated: Fraction of Solids = (P + L) / (P + L + S) Fraction of Lignin = L / (P + L + S)
    In this example, a viscosity of 45 poise and a dope temperature of 50 ° C were used for the target dope conditions.
    Other target values can be chosen. The data set for determining the response surface used n (30 or more) {S, L, V} triple data. The data set was then used to fit a model to the viscosity data. The model coefficients were used to predict the viscosity in all (S, L) pairs in the relevant region of interest, to produce the response surface for S, L and V.
    Viscosity, V, is modeled as a function of Lignin, L, and Solids, S. One model is:

    The purpose of the model is to obtain a smoothing function that: (1) fits the observed data well; (2) has sufficient degrees of freedom for error; and (3) allow a smooth surface to be drawn into selected pairs {S, L}.
    The projection for the Latent Structure (PLS) was selected as the method for model adjustment, since it typically fits the data very appropriately.
    FIGURE 3 shows observed viscosities vs. predicted for
    PAN 4 at 50 ° C. There are 31 points and the model has 15 parameters, so there is 16 degrees of freedom for error. The r-value is 0.97, so the model and data are in respectable agreement.
    The coefficients of the adjusted model were then used to estimate the viscosity in all pairs {S, L} across the ranges 0.12 <S <0.2 and 0. l <L <0.5. The resulting viscosity surface is shown in Figure 4, where the viscosity values over 60 poise and under 30 poise were truncated, leaving only the values in the vicinity of the target viscosity, 45 poise.
    FIGURE 4 demonstrates that the response surface for solutions containing lignin and PAN can be greatly exaggerated and the region of acceptable viscosity to obtain good fiber reliability can be limited, which demonstrates the value of this modeling approach in order to increase the likelihood of successful dope properties for fiber production. Example 5: Stability of Lignin / PAN Solutions
    FIGURE 5 shows the viscosity of PAN 4 and lignin with
    PAN 4, as measured over time. The lignin and PAN solutions exhibit good viscosity stability over time and there is no evident effect on viscosity stability due to the lignin content in the prepared polymeric solution.
    Although illustrative embodiments have been illustrated and described, we note that several changes can be made to them, without deviating from the spirit and scope of the invention.
    权利要求:
    Claims (17)
    [0001]
    1. Fiber dope solution, characterized by the fact that it comprises lignin, and polyacrylonitrile or polyacrylonitrile copolymer, in an organic solvent that dissolves both lignin and polyacrylonitrile or polyacrylonitrile copolymer, where the solution has a solids content of 10 at 35% of the total weight of the solution, where the lignin is 5 to 45% of the total solids weight of the solution and where the solution has a viscosity of 20 to 1500 poise, at a temperature of 20 ° C to 80 ° C .
    [0002]
    2. Fiber dope solution according to claim 1, characterized in that it has a viscosity of 20 to 1000 poise at a temperature of 20 ° C to 80 ° C.
    [0003]
    3. Fiber dope solution according to claim 1, characterized by the fact that it has a viscosity of 20 to 500 poises, at a temperature of 20 ° C to 80 ° C.
    [0004]
    4. Fiber dope solution according to claim 1, characterized in that it has a viscosity of 20 to 100 poises, at a temperature of 20 ° C to 80 ° C.
    [0005]
    5. Fiber dope solution according to claim 1, characterized in that the lignin is 10 to 45% of the total solids weight of the solution.
    [0006]
    6. Fiber dope solution according to claim 1, characterized in that the lignin is 30 to 45% of the total solids weight of the solution.
    [0007]
    7. Method for producing a fiber dope solution, the method characterized by the fact that it comprises combining lignin, polyacrylonitrile or polyacrylonitrile copolymer and an organic solvent that dissolves both lignin and polyacrylonitrile or polyacrylonitrile copolymer to produce a dope solution fiber having a viscosity of 20 to 1500 poises at a temperature of 20 ° C to 80 ° C, where the total solids in the solution is 10 to 35% of the total weight of the solution and where the weight of the lignin in the solution is 5 to 45% by weight of solids in the solution.
    [0008]
    8. Method according to claim 7, characterized in that it further comprises forming a fiber of the dope by spinning, coagulating and extracting the solvent to form a fiber, where the spinning is spinning in solution.
    [0009]
    9. Method according to claim 7, characterized in that it further comprises forming a fiber of the dope by spinning, coagulating and extracting the solvent to form a fiber, in which the spinning is wet spinning with a dry jet.
    [0010]
    Method according to claim 8 or 9, characterized in that it also comprises stretching the fiber to decrease the diameter of the fiber and still increase the molecular orientation.
    [0011]
    Method according to claim 10, characterized in that it further comprises washing the fiber to remove residual solvent from the fiber.
    [0012]
    Method according to claim 8 or 9, characterized in that it further comprises heating the fiber in an air atmosphere at a temperature in the range of 200 to 300 ° C.
    [0013]
    13. Method according to claim 12, characterized in that it further comprises carbonizing the fiber in an inert atmosphere at a temperature of 600 to 2,000 ° C.
    [0014]
    14. Product, characterized by the fact that it is obtained by the process as defined in claim 12 or 13.
    [0015]
    15. Fiber, characterized by the fact that it comprises 10 to 45% by weight of total solids lignin and also comprises polyacrylonitrile or polyacrylonitrile copolymer, in which the fiber exhibits one or more of the following properties: (a) a total stretch of 7x at 15x; (b) a 0.6 to 4.5 denier; (c) a diameter of 8 microns to 25 microns; (d) a tensile strength of 30 to 100 ksi (2109 to 7030 kg / cm2); (e) a tensile modulus, also known as a Young modulus, from 0.60 Msi to 20 Msi (42184 to 1,406,138 kg / cm2); or (f) an 8% to 18% elongation.
    [0016]
    16. Oxidized fiber, characterized by the fact that it comprises a reaction product of a fiber that comprises from 10 to 45% by weight of lignin, and polyacrylonitrile or polyacrylonitrile copolymer, heated to 200 to 300 ° C for 60 to 180 minutes to oxidize the fiber, wherein the oxidized fiber exhibits one or more of the following properties: (a) a diameter of 6 to 22 microns; (b) a tensile strength of 10 to 30 ksi (703 to 2109 kg / cm2); or (c) an elongation of 3 to 20%.
    [0017]
    17. Carbonized fiber, characterized by the fact that it comprises a reaction product of a fiber comprising 10 to 45% by weight of lignin, and polyacrylonitrile or polyacrylonitrile copolymer, at carbonization temperatures until the fiber is carbonized; wherein the carbonized fiber exhibits one or more of the following properties: (a) a diameter of 5 to 20 microns; (b) a tensile strength of 80 to 400 ksi (5624 to 18122 kg / cm2); (c) a module of 7 to 30 Msi (492148 to 2,109,207 kg / cm2); or (d) an elongation of 0.8 to 1.4%.
    类似技术:
    公开号 | 公开日 | 专利标题
    BR112012028938B1|2020-10-13|fiber dope solution, method to produce a fiber dope solution, product, and, fiber
    JP6744268B2|2020-08-19|Method for producing lignin-containing precursor fibers and also carbon fibers
    EP2925918B1|2021-07-07|Thermally reactive thermoplastic intermediate product and method of manufacturing thereof
    JP2013542276A|2013-11-21|Thermoplastic lignin for carbon fiber manufacture
    US20220033529A1|2022-02-03|Regenerated cellulosic fibres spun from an aqueous alkaline spindope
    JPH06220213A|1994-08-09|Lignocellulose molding and its preparation
    BR112020017780A2|2020-12-22|CELLULOSE PULP AND LYOCELL BODY WITH REDUCED CELLULOSE CONTENT
    BR112013029571B1|2021-09-28|METHOD FOR THE PRODUCTION OF A PRECURSOR FIBER CONTAINING LIGNIN AND PRECURSOR FIBER FOR THE PRODUCTION OF CARBON FIBERS
    同族专利:
    公开号 | 公开日
    WO2012003070A1|2012-01-05|
    CN103080390A|2013-05-01|
    JP5698839B2|2015-04-08|
    DE112011102202T5|2013-06-27|
    CN103080390B|2015-09-02|
    US9133568B2|2015-09-15|
    DE112011102202B4|2019-09-12|
    US20120003471A1|2012-01-05|
    BR112012028938A2|2016-07-26|
    US20140302315A1|2014-10-09|
    US8771832B2|2014-07-08|
    JP2013532238A|2013-08-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    GB1111299A|1964-10-10|1968-04-24|Nippon Kayaku Kk|Method of producing carbonized material|
    BE757620A|1969-10-17|1971-04-16|Bayer Ag|CARBON FIBER PREPARATION PROCESS|
    JPH0223982B2|1984-03-30|1990-05-28|Nippon Koku Denshi Kogyo Kk|
    JPH04223982A|1990-12-27|1992-08-13|Hitachi Building Syst Eng & Service Co Ltd|Calling device at group-controlled elevator stop|
    EP0752024B1|1994-03-24|1998-12-16|The Procter & Gamble Company|Heat treated high lignin content cellulosic fibers|
    US5804108A|1996-10-31|1998-09-08|Wilkinson; Kenneth|Process for the preparation of carbon fiber|
    JP4223982B2|2004-03-25|2009-02-12|株式会社東芝|Non-aqueous electrolyte battery|
    SE0402201D0|2004-09-14|2004-09-14|Stfi Packforsk Ab|Method for separating lignin from black liquor|
    SE0402437D0|2004-10-07|2004-10-07|Stfi Packforsk Ab|Method for separating lignin from a lignin containing liquid / slurry|
    ES2326455B2|2007-11-27|2010-02-26|Universidad De Sevilla|PROCEDURE FOR THE MANUFACTURING IN AMBIENT TEMPERATURE OF MICRO AND NANOFIBERS OF LIGNINA AND OTHER RESINOSUS COMPOUNDS.|
    JP2009197358A|2008-02-21|2009-09-03|Toray Ind Inc|Flame resistant polymer fiber bundle and method for producing flame resistant fiber bundle|JP5068057B2|2006-10-19|2012-11-07|三菱電機株式会社|Semiconductor device|
    EP2524980A1|2011-05-18|2012-11-21|Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.|Method for producing precursor fibres and carbon fibres containing lignine|
    DE102011080548A1|2011-08-05|2013-02-07|Sgl Carbon Se|Precursor fibers based on renewable raw materials|
    EP2644758B1|2012-03-29|2014-12-10|Honda R&D EuropeGmbH|Stabilization of lignin carbon fibers with crosslinkers|
    US9340425B2|2012-10-09|2016-05-17|Iowa State University Research Foundation, Inc.|Process of making carbon fibers from compositions including esterified lignin and poly|
    SE537712C2|2012-11-13|2015-10-06|Stora Enso Oyj|Thermally reactive thermoplastic intermediate comprising conifers lignin and process for the preparation thereof.|
    US9771669B2|2013-11-08|2017-09-26|Georgia Tech Research Corporation|Use, stabilization and carbonization of polyacrylonitrile/carbon composite fibers|
    CN103614806A|2013-11-25|2014-03-05|常熟市金羽纤维制品厂|Activated carbon fiber cotton|
    RU2016129461A|2013-12-23|2018-01-30|Стора Энсо Ойй|CONDUCTING CARBON POWDER, METHOD FOR ITS PRODUCTION AND METHOD FOR ITS APPLICATION|
    CN103774276B|2014-01-13|2016-05-04|东华大学|Adopt physical blending to prepare the method for lignin/polyacrylonitrile blended melt spun fibre|
    CN103993382B|2014-05-30|2016-06-08|东华大学|A kind of method improving polyacrylonitrile fibre pre-oxidation speed by physical blending|
    US9453129B2|2014-06-23|2016-09-27|Ut-Battelle, Llc|Polymer blend compositions and methods of preparation|
    CN104389068A|2014-09-15|2015-03-04|荣成炭谷有限公司|Preparation method for novel decorative material|
    CN104269526A|2014-09-19|2015-01-07|易高环保能源研究院有限公司|Preparation of polyacrylonitrile/lignin carbon nanofiber electrode for sodium ion battery|
    CN104466140B|2014-12-31|2017-02-01|南开大学|Method for preparing nano tin/carbon composite nanofibers through electrospinning technology|
    CN104945573B|2015-06-15|2018-05-01|中国科学院宁波材料技术与工程研究所|The preparation method of the preparation method and lignin-base carbon fiber of lignin and acrylonitrile copolymer|
    US9815985B2|2015-07-14|2017-11-14|Ut-Battelle, Llc|High performance lignin-acrylonitrile polymer blend materials|
    RU2604620C1|2015-07-15|2016-12-10|Федеральное государственное бюджетное учреждение науки Институт высокомолекулярных соединений Российской академии наук|Method of composite fibrous adsorbent producing|
    BR102015025429A2|2015-10-05|2018-03-20|Laboratorios Quimicos E Metrologicos Quimlab Ltda|Composition of polyacrylonitrile / lignin blends for the production of carbon fiber precursor fiber|
    SE539261C2|2015-10-08|2017-06-07|Stora Enso Oyj|A process for the manufacture of a lignin shaped body|
    CN105887238A|2016-05-23|2016-08-24|太和县蓝翎养殖有限公司|Flame-retardant artificial wig fibers containing peacock feather|
    RU2621758C1|2016-06-21|2017-06-07|Федеральное государственное бюджетное образовательное учреждение высшего образования "Санкт-Петербургский государственный университет промышленных технологий и дизайна" |Production process of composite fiber based on hydrolysis lignin with polyacrylonitril|
    WO2018237111A1|2017-06-21|2018-12-27|Ut-Battelle, Llc|Shape memory polymer blend materials|
    CN107326477A|2017-08-28|2017-11-07|德阳力久云智知识产权运营有限公司|A kind of lignin-base is combined carbon fiber and preparation method thereof|
    CN108043249B|2017-12-18|2021-01-08|中国科学院山西煤炭化学研究所|Method for preparing hollow fiber membrane from lignin modified polyacrylonitrile|
    US10633770B2|2018-01-04|2020-04-28|North Carolina State University|Coagulation map for fiber spinning|
    CN108997632A|2018-06-25|2018-12-14|广东格瑞新材料股份有限公司|A kind of weather-proof PE composition and preparation method thereof|
    CN108691024A|2018-06-29|2018-10-23|百事基材料（青岛）股份有限公司|Modified acrylic fibres and preparation method thereof containing plant extracts|
    CN109545570B|2018-11-29|2020-07-03|青岛大学|Preparation method of lignin-based carbon fiber electrode rich in mesoporous structure, product and application thereof|
    CN109576824A|2018-11-30|2019-04-05|中国科学院山西煤炭化学研究所|A kind of preparation method of polyacrylonitrile-radical hollow mesoporous carbon fiber|
    法律状态:
    2018-04-10| B06F| Objections, documents and/or translations needed after an examination request according art. 34 industrial property law|
    2019-02-26| B06T| Formal requirements before examination|
    2019-12-31| B07A| Technical examination (opinion): publication of technical examination (opinion)|
    2020-05-05| B09A| Decision: intention to grant|
    2020-10-13| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 07/06/2011, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    US12/828,054|US8771832B2|2010-06-30|2010-06-30|Lignin/polyacrylonitrile-containing dopes, fibers, and methods of making same|
    US12/828054|2010-06-30|
    PCT/US2011/039484|WO2012003070A1|2010-06-30|2011-06-07|Lignin/polyacrylonitrile-containing dopes, fibers, and methods of making same|
    [返回顶部]