Spinneret housing for use in producing polymeric fibers and method of use thereof - Patents.com

Abstract

The present disclosure relates to a spinneret housing for use in the production of polymeric fibers, such as polymeric large tow fibers typically used in the production of carbon fibers. The present disclosure also relates to a system including a spinneret housing, and a method for producing polymeric fibers using such a system. The produced polymeric fibers are useful in the production of carbon fibers, which are utilized as structural components in composite materials relevant to many sectors, particularly the aerospace, marine, and automotive industries.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 252,673, filed October 06, 2021, and incorporated herein by reference.

[0002] The present disclosure relates to a spinneret housing for use in producing polymeric fibers, such as polymeric large tow fibers typically used in the production of carbon fibers. The present disclosure also relates to a system including a spinneret housing, and a method for producing polymeric fibers using such a system. The produced polymeric fibers are useful in the production of carbon fibers, which are utilized as structural components in composite materials relevant to many sectors, particularly the aerospace, marine, and automotive industries. [Background technology]

[0003] Carbon fibers have been used in a wide variety of applications due to their desirable properties, such as high strength and stiffness, high chemical resistance, and low thermal expansion. For example, carbon fibers can be molded into structural parts that combine high strength and stiffness while weighing significantly less than metal components of comparable properties. Carbon fibers are increasingly being used as structural components in composite materials, especially for aerospace, marine, and automotive applications. In particular, composite materials have been developed in which carbon fibers act as reinforcing materials in a resin or ceramic matrix.

[0004] Acrylonitrile-derived carbon fibers are generally produced by a series of manufacturing processes or stages including polymerization, spinning, drawing and / or washing, oxidation, and carbonization. Polyacrylonitrile (PAN) polymer is currently the most widely used precursor of carbon fibers. During the polymerization stage, acrylonitrile (AN), optionally with one or more comonomers, is converted into PAN polymer. The PAN polymer is then spun, drawn and / or washed, oxidized, and carbonized to produce carbon fibers.

[0005] Since over 90% of carbon fibers are derived from PAN polymers, it is important to identify controllable parameters of polymer properties that affect downstream processes for faster production, lower cost, and / or easier manufacturing of carbon fibers, especially large tow carbon fibers.

[0006] In the spinning and coagulation process, the polymer dope is extruded through a spinneret into a coagulation bath where the polymer coagulates to form a fiber tow or fiber bundle. The volume of the fiber bundle decreases continuously along the coagulation bath, from which the spent coagulant is squeezed. This solvent-rich liquid tends to recirculate to the fiber coagulation zone, which is essentially the first few inches from the spinneret face. Due to the geometry of the coagulation bath and the submerged spinneret pack, the laminar coagulant flow around the spinneret is not uniform, and therefore the backflow rate of the spent coagulant also varies, which leads to non-uniform solvent concentration around the spinneret. Such concentration gradients around the coagulation zone cause variability in filament formation.

[0007] Thus, there is a continuing need for apparatus and methods for producing polymeric fibers that can reduce or eliminate concentration gradients that appear around the coagulation zone during the coagulation process, thereby reducing or eliminating variability in filament formation, especially for large tow fibers. Summary of the Invention

[0008] This objective, and other objectives that will become apparent from the following detailed description, are accomplished in whole or in part by the apparatus, methods and / or processes disclosed herein.

[0009] In a first aspect, the present disclosure provides a spinneret housing having a body adapted to typically removably secure a spinneret or spinneret assembly, the body comprising: a flanged cylindrical wall extending from the body, the flange projecting radially inwardly at a distal portion of said wall; a cylindrical tube surrounding the body, the cylindrical tube being coaxial with the flanged cylindrical wall and having a diameter greater than that of the flanged cylindrical wall; a cowl extending from a cylindrical tube surrounding the body, the cowl extending beyond a distal end of the flanged cylindrical wall; The present invention relates to a spinneret housing comprising:

[0010] In a second aspect, the present disclosure provides a system for producing polymer fibers, comprising: a) a spinneret housing as described herein; b) a polymer dope supply line; c) a spinneret or spinneret assembly, typically for large tow applications; d) a coagulation bath containing a coagulation liquid; The present invention relates to a system comprising:

[0011] In a third aspect, the present disclosure provides a method for making a polymer fiber, comprising: a') providing a system as described herein; b') spinning a polymer dope fed to a spinneret or spinneret assembly through a polymer dope feed line into a coagulation bath; The present invention relates to a method comprising the steps of:

[0012] In a fourth aspect, the present disclosure relates to one or more polymeric fibers produced as described herein.

[0013] In a fifth aspect, the present disclosure provides a method for producing carbon fibers, comprising: (i) providing a polymer fiber as described herein or making a polymer fiber according to the methods described herein; (ii) producing carbon fibers by oxidizing the polymer fibers produced in step (i) to form stabilized carbon fiber precursor fibers, and then carbonizing the stabilized carbon fiber precursor fibers; The present invention relates to a method comprising the steps of:

[0014] In a sixth aspect, the present disclosure relates to a composite material comprising carbon fibers and a matrix resin produced according to the methods described herein. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a front perspective view of one embodiment of a spinneret housing described herein. [Diagram 2] FIG. 2 is a rear perspective view of one embodiment of a spinneret housing described herein. [Diagram 3] FIG. 2 is an exploded view of one embodiment of a spinneret housing as described herein. [Figure 4] 1 shows filament diameters, including standard deviations, determined for white fiber tows produced with and without one embodiment of a spinneret housing described herein. [Diagram 5] 1 illustrates the circularity, including standard deviation, determined for white fiber tows produced with and without one embodiment of a spinneret housing described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] As used herein, the terms "a," "an," or "the" mean "one or more" or "at least one," and can be used interchangeably, unless otherwise stated.

[0017] As used herein, the term "and / or" used in a phrase of the form "A and / or B" means A only, B only, or A and B together.

[0018] As used herein, the term "comprises" includes "consists essentially of" and "consists of." The term "comprising" includes "consisting essentially of" and "consisting of." "Comprising" is synonymous with "including," "containing," or "characterized by," and is intended to be inclusive or open-ended and does not exclude additional, unrecited components or steps. The transitional phrase "consisting essentially of" includes the specified materials or steps as well as those that do not essentially affect the basic characteristics or function of the described composition, process, method, or article. The transitional phrase "consisting of" excludes any components, steps, or ingredients not specified.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] As used herein, unless otherwise specified, the term "about" or "approximately" refers to an acceptable error for a particular value as determined by one of ordinary skill in the art, which depends in part on how the value is measured or determined. In certain embodiments, the term "about" or "approximately" refers to within 1, 2, 3, or 4 standard deviations. In certain embodiments, the term "about" or "approximately" refers to within 50%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.05% of a given value or range.

[0021] It will also be understood that any numerical ranges described herein are intended to include all subranges subsumed therein. For example, the range "1 to 10" is intended to include all subranges between (and including) the recited minimum of 1 and the recited maximum of 10, i.e., ranges having a minimum of 1 or more and a maximum of 10 or less. The disclosed numerical ranges are continuous, and therefore include all values ​​between the minimum and maximum values. Unless otherwise indicated, the various numerical ranges specified in this application are approximations.

[0022] The terms and phrases used herein, such as "invention," "present invention," "instant invention," and similar terms and phrases, are non-limiting and are not intended to limit the inventive subject matter to any single embodiment, but rather encompass all possible embodiments described.

[0023] In a first aspect, the present disclosure provides a spinneret housing having a body adapted to typically removably secure a spinneret or spinneret assembly, the body comprising: a flanged cylindrical wall extending from the body, the flange projecting radially inwardly at a distal portion of said wall; a cylindrical tube surrounding the body, the cylindrical tube being coaxial with the flanged cylindrical wall and having a diameter greater than that of the flanged cylindrical wall; a cowl extending from a cylindrical tube surrounding the body, the cowl extending beyond a distal end of the flanged cylindrical wall; The present invention relates to a spinneret housing comprising:

[0024] An exemplary embodiment of a spinneret housing is shown in Figures 1 and 2 as spinneret housing 100. Spinneret housing 100 includes a body 101 including a hollow interior shaped to receive and / or secure a spinneret or spinneret assembly, and a back cover 102. The spinneret or spinneret assembly can be permanently or removably, typically removably, secured to the spinneret housing. Body 101 also includes a flanged cylindrical wall 104 extending therefrom, with flange 103 projecting radially inward at a distal portion of said wall. A cylindrical tube 105 surrounds the body. A cowl 106 extends from the cylindrical tube surrounding the body and extends beyond the distal end of the flanged cylindrical wall.

[0025] 2, the cylindrical tube 105 is coaxial with the flanged cylindrical wall and has a larger diameter than the flanged cylindrical wall. The cylindrical tube 105 and body 101 are such that there are one or more openings 107 that allow the coagulation liquid to flow through and around the spinneret or spinneret assembly.

[0026] During spinning and coagulation, the volume of the fiber bundle extruded through the spinneret is continuously reduced along the coagulation bath from which the spent coagulant is squeezed. This solvent-rich liquid tends to recirculate to the fiber coagulation zone, which is essentially the first few inches from the spinneret face. Due to the geometry of the coagulation bath and the submerged spinneret pack, the laminar coagulant flow around the spinneret is not uniform, so the backflow rate of the spent coagulant also varies, which leads to non-uniform solvent concentration around the spinneret. Such concentration gradients around the coagulation zone cause filament formation variability. The presence of the cowl 106 serves to eliminate the formation of concentration gradients around the coagulation zone, thereby reducing or eliminating filament formation variability. In cases where the dope and coagulation bath temperatures are different, the cowl of the spinneret housing also reduces temperature non-uniformity of the coagulation bath around the spinneret through its insulating effect.

[0027] The shape of the cowl is not particularly limited, so long as it extends beyond the distal end of the flanged cylindrical wall (typically approximately at the location of the spinneret face). In one embodiment, the cowl has a cylindrical shape, a frusto-conical shape, or a combination thereof. In one embodiment, the cowl has a frusto-conical shape.

[0028] As will be understood by those skilled in the art, a "frustum of a cone" refers to a truncated cone. In other words, a "frustum of a cone" refers to a shape resulting from a portion of a cone that is between one or two planes (typically parallel planes) that cut the cone. A frustum of a cone may be symmetrical or asymmetrical. If the frustum of a cone is symmetrical, the cone from which the shape originates is a right cone, i.e., it has an apex on an axis that runs vertically through the center of the cone's base, which is usually circular. In this case, the angle that the side of the frustum of a cone makes with the base is the same throughout the shape. If the frustum of a cone is asymmetrical, the cone from which the shape originates is an oblique cone, i.e., it has an apex that is not on an axis that runs vertically through the center of the cone's base. In this case, the angle that the side of the frustum of a cone makes with the base is not the same throughout the shape.

[0029] The cowl may be a combination of cylindrical and conical shapes. In such a configuration, for example, the cowl may initially extend from the body as a cylindrical shape and then transition to a frusto-conical shape.

[0030] The dimensions of the cowl are not particularly limited. However, in some embodiments, the length of the cowl, measured from the face of the flanged cylindrical wall to the distal opening, is 10-100 mm, typically 15-40 mm. In some embodiments, the diameter of the distal opening of the cowl is 100-200 mm, typically 150-190 mm, more typically 160-190 mm.

[0031] The spinneret housing may be a combination of two or more parts secured together. The combination of two or more parts may be secured together in a permanent manner. However, it is advantageous that the combination of two or more parts is secured together so that the parts can be separated when desired, for example, for maintenance, repair, or replacement of one or more parts, or for removal or replacement of the spinneret. As shown in FIG. 3, an exemplary spinneret housing 200 may be a combination of a body 201 with a hollow interior shaped to receive and / or secure a spinneret or spinneret assembly 300, and a back cover 202. The body 201 also includes a flanged cylindrical wall 203 extending from the body, with a flange 204 projecting radially inward at a distal portion of said wall. A cylindrical tube 205 surrounds the body. A cowl 206 extends from the cylindrical tube surrounding the body and extends beyond the distal end of the flanged cylindrical wall.

[0032] The cowl may be a permanent extension of the cylindrical tube as shown in Figure 3, or may be removable as shown in Figure 2. In one embodiment, the cowl is removable. Any means known to those skilled in the art may be used to removably attach the cowl to the cylindrical tube, such as screws, clips, magnets, etc.

[0033] The spinneret housing can be manufactured from materials known to those skilled in the art. Exemplary materials include, but are not limited to, metals such as iron, cast iron, copper, brass, aluminum, titanium, carbon steel, stainless steel, and alloys thereof; and polymers such as thermosetting and thermoplastic resins. Exemplary thermosetting resins include, but are not limited to, epoxy resins, oxetanes, vinyl ester resins, cyanate ester resins, isocyanate modified epoxy resins, phenolic resins, furan resins, benzoxazines, formaldehyde condensation resins (such as urea, melamine, or phenol), polyesters, acrylics, hybrids, blends, and combinations thereof. Exemplary thermoplastic polymers include, but are not limited to, acrylonitrile butadiene styrene (ABS), polypropylene, polystyrene, polyvinyl chloride, polylactic acid, polyamides (PA), such as aliphatic polyamides and semi-aromatic polyamides; polyimides (PI), polyaryletherketones (PAEK), polyamide-imides (PAI), polyarylene sulfides (PAS), such as polyphenylene sulfide (PPS); polyarylethersulfones (PAES), polyetheretherketones (PEEK), fluoropolymers (FP), such as polyvinylidene fluoride; polycarbonates, and combinations thereof.

[0034] In a second aspect, the present disclosure provides a system for producing polymer fibers, comprising: a) a spinneret housing as described herein; b) a polymer dope supply line; c) a spinneret or spinneret assembly, typically for large tow applications; d) a coagulation bath containing a coagulation liquid; The present invention relates to a system comprising:

[0035] The systems described herein are typically used for spinning a polymer dope, or "spin dope," into a coagulation bath to produce polymer fibers. The spinneret or spinneret assembly is connected to a polymer dope supply line that functions to convey the polymer dope from a polymer dope source, such as a storage tank, to the spinneret through the action of one or more pumps. The polymer fibers are coagulated in a coagulation bath containing a coagulation liquid.

[0036] In one embodiment, the spinneret or spinneret assembly is secured, typically removably, within a spinneret housing.

[0037] In one embodiment, the polymer dope supply line is connected to the inlet of the spinneret.

[0038] In a third aspect, the present disclosure provides a method for making a polymer fiber, comprising: a') providing a system as described herein; b') spinning a polymer dope fed to a spinneret or spinneret assembly through a polymer dope feed line into a coagulation bath; The present invention relates to a method comprising the steps of:

[0039] During the manufacture of polymer fibers, such as those suitable for producing carbon fibers in a downstream process, a polymer solution (i.e., spin "dope") is typically spun into a coagulation bath. The spin dope can have a polymer concentration of at least 10% by weight, typically about 16% to about 28% by weight, and more typically about 19% to about 24% by weight, based on the total weight of the solution. The dope is filtered and extruded through holes in a spinneret (typically made of metal) into a liquid coagulation bath for the polymer to form filaments. The spinneret holes determine the desired filament count of the fiber (e.g., 3,000 holes for 3K carbon fiber). In one embodiment, the spinneret is for large tow fibers, typically for 24K to 50K fibers.

[0040] The coagulation liquid used in the method is a mixture of a solvent and a non-solvent. Water or alcohol is typically used as the non-solvent. Suitable solvents include those described herein. In one embodiment, dimethylsulfoxide, dimethylformamide, dimethylacetamide, or a mixture thereof is used as the solvent. In another embodiment, dimethylsulfoxide is used as the solvent. The ratio of solvent to non-solvent and bath temperature are not particularly limited and can be adjusted according to known methods to achieve a desired coagulation rate of the extruded nascent filament in the coagulation. However, the coagulation bath typically contains 40% to 85% by weight of one or more solvents, the remainder being a non-solvent such as water or alcohol. In one embodiment, the coagulation bath contains 40% to 70% by weight of one or more solvents, the remainder being a non-solvent. In another embodiment, the coagulation bath contains 50% to 85% by weight of one or more solvents, the remainder being a non-solvent.

[0041] Typically, the temperature of the coagulation bath is between 0° C. and 80° C. In one embodiment, the temperature of the coagulation bath is between 30° C. and 80° C. In another embodiment, the temperature of the coagulation bath is between 0° C. and 20° C.

[0042] To examine fiber tows, a digital microscope is used to take a cross-sectional image of the tow, and then image analysis software is used to determine the filament diameter and corresponding distribution. This distribution data is then analyzed using statistical analysis software such as JMP to determine the filament variability. Filament circularity is determined by analyzing the cross-sectional shape of the filament using image analysis software. Filament circularity is typically normalized to have a value in the range of 0 to 1. A filament circularity of 1 is considered to be the ideal case of a circle.

[0043] In one embodiment, the variation in filament diameter and / or circularity is reduced by 5-50%, typically 10-40%, more typically 20-25% compared to the variation in filament diameter and / or circularity obtained with a process without a spinneret housing.

[0044] In a fourth aspect, the present disclosure relates to one or more polymeric fibers produced as described herein.

[0045] In one embodiment, the filament diameter is from 1 to 50 μm, typically from 7 to 25 μm, more typically from 9 to 20 μm, and even more typically from 10 to 16 μm.

[0046] In one embodiment, the variation in filament diameter is less than 2.1, typically less than 2.

[0047] In one embodiment, the circularity of the filament is from 0.75 to 1, typically from 0.75 to 0.85.

[0048] In one embodiment, the filament has a circularity variation of less than 0.07.

[0049] In a fifth aspect, the present disclosure provides a method for producing carbon fibers, comprising: (i) providing a polymer fiber as described herein or making a polymer fiber according to the methods described herein; (ii) producing carbon fibers by oxidizing the polymer fibers produced in step (i) to form stabilized carbon fiber precursor fibers, and then carbonizing the stabilized carbon fiber precursor fibers; The present invention relates to a method comprising the steps of:

[0050] The polymer fibers described herein or produced according to the methods described herein can be oxidized to form stabilized carbon fiber precursor fibers, which are then carbonized to produce carbon fibers.

[0051] During the oxidation stage, the polymeric fibers are passed under tension through one or more specialized ovens, each having a temperature of 150-300° C., typically 200-280° C., more typically 220-270° C. Each oven is supplied with heated air. The polymeric fibers are conveyed through the one or more ovens at a speed of 4-100 fpm, typically 30-75 fpm, more typically 50-70 fpm.

[0052] During the oxidation process, oxygen molecules from the air combine with the fibers and initiate cross-linking of the polymer chains, which increases the fiber density to 1.3 g / cm 3 ~1.4g / cm 3 In the oxidation process, the tension applied to the fiber controls the stretching or shrinking of the fiber with a draw ratio usually between 0.8 and 1.35, typically between 1.0 and 1.2. When the draw ratio is 1, there is no stretching. When the draw ratio is greater than 1, the fiber is stretched by the applied tension. Such oxidized fibers, typically PAN fibers, have an infusible ladder-type aromatic molecular structure and are ready for the carbonization process.

[0053] Carbonization results in the crystallization of the carbon molecules, resulting in finished carbon fibers having a carbon content of greater than 90 percent. Carbonization of the oxidized or stabilized carbon fiber precursor fibers is carried out in one or more specially designed furnaces in an inert (oxygen-free) atmosphere, typically a nitrogen atmosphere. The oxidized carbon fiber precursor fibers are passed through one or more ovens, each heated to a temperature between 300° C. and 1650° C., typically between 1100° C. and 1450° C.

[0054] Adhesion between the matrix resin and the carbon fibers is an important criterion in carbon fiber reinforced polymer composites, so during the manufacture of carbon fibers, surface treatments can be performed after oxidation and carbonization to enhance this adhesion.

[0055] Surface treatment can include pulling the carbonized fibers through an electrolytic bath containing an electrolyte, such as ammonium bicarbonate or sodium hypochlorite. The chemicals in the electrolytic bath etch or roughen the surface of the fibers, thereby increasing the surface area available for interfacial fiber / matrix bonding and adding reactive chemical groups.

[0056] The carbon fibers can then be subjected to a sizing process in which a size coating (e.g., an epoxy-based coating) is applied to the fibers. The sizing process can be carried out by passing the fibers through a size bath containing a liquid coating material. The sizing process protects the carbon fibers during handling and processing into intermediate forms, such as dry fabrics and prepregs. The sizing process also reduces fuzz, improves processability, and holds the filaments together in individual tows to increase the interfacial shear strength between the fiber and the matrix resin.

[0057] After sizing, the coated carbon fibers are dried and then wound onto a bobbin.

[0058] Those skilled in the art will understand that processing conditions (such as spinning solution and coagulation bath composition, total bath volume, drawing, temperature, and filament speed) may be varied to obtain filaments of desired structure and denier without departing from the spirit of the present disclosure.

[0059] In a sixth aspect, the present disclosure relates to a composite material comprising carbon fibers and a matrix resin produced according to the methods described herein.

[0060] In a number of liquid-molding processes, composites can be produced by molding a preform containing carbon fibers produced according to the methods described herein and infusing the preform with a thermosetting resin. Liquid molding processes that can be used include, but are not limited to, vacuum impregnation (VARTM), where a vacuum-induced pressure differential is used to infuse the preform with resin. Another method is re-transfer molding (RTM), where the preform is pressure-injected with resin in a closed mold. A third method is resin film infusion (RFI), where a semi-solid resin is placed under or over the preform, appropriate tooling is placed on the part, the part is bagged, and then the part is melted in an autoclave to infuse the preform with resin.

[0061] The matrix resin for impregnating or infusing the preforms described herein is a curable resin. In this disclosure, "curing" or "cure" refers to the solidification of a polymeric material by chemical cross-linking of polymer chains. The term "curable" in reference to a composition means that the composition can be subjected to conditions that cause the composition to harden or become thermoset. The matrix resin is typically a hardenable or thermosetting resin that contains one or more uncured thermosetting or thermoplastic resins. Suitable thermosetting resins include, but are not limited to, epoxy resins, oxetanes, imides (such as polyimides or bismaleimides), vinyl ester resins, cyanate ester resins, isocyanate modified epoxy resins, phenolic resins, furan resins, benzoxazines, formaldehyde condensation resins (such as urea, melamine, or phenol), polyesters, acrylics, hybrids, blends, and combinations thereof. Suitable thermoplastics include, but are not limited to, polyolefins, fluoropolymers, perfluorosulfonic acids, polyamide-imides, polyamides, polyesters, polyketones, polyphenylene sulfides, polyvinylidene chloride, sulfone polymers, hybrids, blends, and combinations thereof.

[0062] Suitable epoxy resins include glycidyl derivatives of aromatic diamines, aromatic monoprimary amines, aminophenols, polyhydric phenols, polyhydric alcohols, polycarboxylic acids, and non-glycidyl resins produced by peroxidation of olefinic double bonds. Examples of suitable epoxy resins include polyglycidyl ethers of bisphenols such as bisphenol A, bisphenol F, bisphenol S, bisphenol K, and bisphenol Z; polyglycidyl ethers of cresols and phenolic novolacs, glycidyl ethers of phenol-aldehyde adducts, glycidyl ethers of aliphatic dialkyl, diglycidyl ethers, diethylene glycol diglycidyl ethers, aromatic epoxy resins, aliphatic polyglycidyl ethers, epoxidized olefins, brominated resins, aromatic glycidyl amines, heterocyclic glycidyl imides and amides, glycidyl ethers, fluorinated epoxy resins, or combinations thereof.

[0063] Specific examples are the tetraglycidyl derivative of 4,4'-diaminodiphenylmethane (TGDDM), resorcinol diglycidyl ether, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, bromobisphenol F diglycidyl ether, the tetraglycidyl derivative of diaminodiphenylmethane, trihydroxyphenylmethane triglycidyl ether, polyglycidyl ether of phenol-formaldehyde novolac, polyglycidyl ether of o-cresol novolac or the tetraglycidyl ether of tetraphenylethane.

[0064] Suitable oxetane compounds, which are compounds containing at least one oxetano group per molecule, include, for example, compounds such as 3-ethyl-3[[(3-ethyloxetan-3-yl)methoxy]methyl]oxetane, oxetane-3-methanol, 3,3-bis-(hydroxymethyl)oxetane, 3-butyl-3-methyloxetane, 3-methyl-3-oxetanemethanol, 3,3-dipropyloxetane, and 3-ethyl-3-(hydroxymethyl)oxetane.

[0065] The curable matrix resin may optionally contain one or more additives such as curing agents, curing catalysts, comonomers, rheology control agents, tackifiers, inorganic or organic fillers, thermoplastic and / or elastomeric polymers as reinforcing agents, stabilizers, inhibitors, pigments, dyes, flame retardants, reactive diluents, UV absorbers and other additives known to those skilled in the art to improve the properties of the matrix resin before and / or after curing.

[0066] Examples of suitable curing agents include, but are not limited to, aromatic, aliphatic and cycloaliphatic amines or guanidine derivatives. Suitable aromatic amines include 4,4'-diaminodiphenylsulfone (4,4'-DDS), and 3,3'-diaminodiphenylsulfone (3,3'-DDS), 1,3-diaminobenzene, 1,4-diaminobenzene, 4,4'-diammodiphenylmethane, benzenediamine (BDA); suitable aliphatic amines include ethylenediamine (EDA), 4,4'-methylenebis(2,6-diethylaniline) (M-DEA), m-xylylenediamine (mXDA), diethylenetriamine (DETA), triethylenetetramine (TETA), trioxatridecanediamine (TTDA), polyoxypropylenediamines, and further homologues, diaminosilane ... cycloaliphatic amines such as cyclohexane (DACH), isophorone diamine (IPDA), 4,4' diaminodicyclohexylmethane (PACM), bisaminopropylpiperazine (BAPP), N-aminoethylpiperazine (N-AEP); other suitable curing agents include anhydrides, typically polycarboxylic acid anhydrides, such as nadic anhydride, methylnadic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylene-tetrahydrophthalic anhydride, pyromellitic dianhydride, chlorendic anhydride, and trimellitic anhydride.

[0067] Still other hardeners are Lewis acid:Lewis base complexes. Suitable Lewis acid:base complexes include, for example, BCl 3 : Amine complex, BF3 amine complexes, e.g. BF 3 : Monoethylamine, BF 3 : Propylamine, BF 3 : Isopropylamine, BF 3 : Benzylamine, BF 3 : Chlorobenzylamine, BF 3: Trimethylamine, BF 3 : Pyridine, BF 3 :THF, AlCl 3 :THF, AlCl 3 : Acetonitrile, and ZnCl 2 :THF and other complexes.

[0068] Additional curing agents are polyamides, polyamines, amidoamines, polyamidoamines, polycycloaliphatics, polyetheramides, imidazoles, dicyandiamide, substituted ureas and urones, hydrazines and silicones.

[0069] Urea-based hardeners range from materials available under the tradename DYHARD (sold by Alzchem), and urea derivatives such as those sold as UR200, UR300, UR400, UR600, UR700, etc. Uron accelerators include, for example, 4,4-methylenediphenylenebis(N,N-dimethylurea) (available from Onmicure as U52M), etc.

[0070] When present, the total weight of the curing agent is in the range of 1% to 60% by weight of the resin composition. Typically, the curing agent is present in the range of 15% to 50% by weight, more typically in the range of 20% to 30% by weight.

[0071] Suitable toughening agents may include, but are not limited to, homopolymers or copolymers, either alone or in combination, of polyamides, copolyamides, polyimides, aramids, polyketones, polyetherimides (PEI), polyetherketones (PEK), polyetherketoneketones (PEKK), polyetheretherketones (PEEK), polyethersulfones (PES), polyetherethersulfones (PEES), polyesters, polyurethanes, polysulfones, polysulfides, polyphenylene oxides (PPOs) and modified PPOs, poly(ethylene oxide) (PEOs) and polypropylene oxides, polystyrenes, polybutadienes, polyacrylates, polystyrenes, polymethacrylates, polyacrylics, polyphenylsulfones, high performance hydrocarbon polymers, liquid crystal polymers, elastomers, segmented elastomers, and core-shell particles.

[0072] The reinforcing particles or agents, when present, may range from 0.1 wt% to 30 wt% of the resin composition. In one embodiment, the reinforcing particles or agents may be present in the range of 10 wt% to 25 wt%. In another embodiment, the reinforcing particles or agents may be present in the range of 0.1 to 10 wt%. Suitable reinforcing particles or agents include, for example, Virantage VW10200FRP, VW10300FP, and VW10700FRP from Solvay, BASF Ultrason E2020 and Sumikaexcel 5003P from Sumitomo Chemical.

[0073] The reinforcing particles or agents may be in the form of particles having a diameter greater than 20 microns to prevent incorporation into the fibrous layer. The size of the reinforcing particles or agents may be selected so as not to be filtered by the fibrous reinforcement. Optionally, the composition may also include inorganic ceramic particles, microspheres, microballoons, and clays.

[0074] The resin composition may contain conductive particles as described in, for example, WO 2013 / 141916, WO 2015 / 130368, and WO 2016 / 048885.

[0075] Molds for resin infusion can be two-component sealed or vacuum-bag sealed single-sided. After the matrix resin is injected into the mold, the mold is heated to harden the resin.

[0076] During heating, the resin reacts with itself to form crosslinks in the matrix of the composite. After the initial heating, the resin gels. Upon gelling, the resin no longer flows but rather behaves as a solid. After gelling, the temperature or cure may be increased to a final temperature to complete the cure. The final cure temperature will vary depending on the nature and properties of the thermoset resin selected.

[0077] Thus, in a preferred method, the composite material is heated to a first temperature suitable for gelling the matrix resin, and then the temperature is increased to a second temperature and held briefly at the second temperature to complete the cure.

[0078] Thus, the composite material described herein may be cured to provide the composite material.

[0079] The apparatus, systems, methods and processes according to the present disclosure are further illustrated by the following non-limiting examples.

[0080] Example 1. Spinning of polymer dope A polymer dope containing a polyacrylonitrile-based polymer was wet-spun into a coagulation bath containing 50 / 50 DMSO / water using a 50K spinneret attached to four different spinneret housings. The four different spinneret housings differed in the dimensions of the frustoconical cowl, i.e., cowl length, cowl opening diameter, cowl top angle, and cowl bottom angle. For comparison, the same polymer dope containing a polyacrylonitrile-based polymer was wet-spun into a coagulation bath containing 50 / 50 DMSO / water using a 50K spinneret without a spinneret housing. Tows of white fibers produced with and without the spinneret housing were collected. The dimensions of the spinneret housing of the present invention are summarized below.

[0081] [Table 1]

[0082] Filament diameter and circularity, including filament diameter and circularity variation, of fiber tows with and without the Design 2 spinneret housing were measured.

[0083] 4 shows the filament diameters, including standard deviations, determined for white fiber tows produced with and without the spinneret housing of Design 2. It is clear that the filament diameters of the white fiber tows produced with the spinneret housing of the present invention are less variable, i.e., more uniform, than the filament diameters of the white fiber tows produced without the spinneret housing of the present invention.

[0084] 5 shows the circularity determined for white fiber tows produced with and without the spinneret housing of Design 2. The circularity of the white fiber tows produced with the spinneret housing of the present invention is less variable, i.e., more uniform, than the circularity of the white fiber tows produced without the spinneret housing.

Claims

1. 1. A spinneret housing having a body adapted to typically removably secure a spinneret or spinneret assembly, said body comprising: a flanged cylindrical wall extending from the body, the flange projecting radially inward at a distal portion of the wall; a cylindrical tube surrounding the body, the cylindrical tube being coaxial with the flanged cylindrical wall and having a diameter greater than that of the flanged cylindrical wall; a cowl extending from a cylindrical tube surrounding the body, the cowl extending beyond a distal end of the flanged cylindrical wall; A spinneret housing comprising:

2. The spinneret housing of claim 1 , wherein the cowl has a cylindrical shape, a frusto-conical shape, or a combination thereof.

3. The spinneret housing of claim 1 , wherein the cowl has a frustoconical shape.

4. 4. The spinneret housing of claim 3, wherein the frustoconical shape is symmetrical or asymmetrical.

5. 2. The spinneret housing of claim 1, wherein the length of the cowl, measured from the face of the flanged cylindrical wall to the distal opening, is 10 to 100 mm, typically 15 to 40 mm.

6. 10. The spinneret housing of claim 1, wherein the diameter of the distal opening of the cowl is from 100 to 200 mm, typically from 150 to 190 mm, more typically from 160 to 190 mm.

7. 10. The spinneret housing of claim 1, wherein the spinneret housing is a combination of two or more parts that are fastened together, typically removably.

8. The spinneret housing of claim 1 , wherein the cowl is removable.

9. 1. A system for producing polymer fibers, comprising: a) a spinneret housing according to claim 1; b) a polymer dope supply line; c) a spinneret or spinneret assembly, typically for large tow applications; d) a coagulation bath containing a coagulation liquid; A system comprising:

10. 10. The system of claim 9, wherein the spinneret or spinneret assembly is typically removably secured within the spinneret housing.

11. The system of claim 9 , wherein the polymer dope supply line is connected to an inlet of the spinneret.

12. 1. A method for producing polymer fibers, comprising: a') providing a system according to claim 9; b') spinning a polymer dope fed to a spinneret or spinneret assembly through a polymer dope feed line into a coagulation bath; A method comprising:

13. The method of claim 12, wherein the variation in filament diameter and / or roundness is reduced by 5 to 50%, typically 10 to 40%, more typically 20 to 25% compared to the variation in filament diameter and / or roundness obtained by a method without the spinneret housing.

14. 13. One or more polymeric fibers produced by the method of claim 12.

15. One or more polymer fibers according to claim 14, having a filament diameter of 1 to 50 μm, typically 7 to 25 μm, more typically 9 to 20 μm, and even more typically 10 to 16 μm.

16. One or more polymer fibers as described in claim 14, having a filament diameter variation of less than 2.1, typically less than 2.

17. One or more polymer fibers according to claim 14, having a filament circularity of 0.75 to 1, typically 0.75 to 0.

85.

18. One or more polymer fibers as described in claim 14, having a filament circularity variation of less than 0.

07.

19. A method for producing carbon fibers, comprising: (i) providing a polymer fiber according to claim 14 or producing a polymer fiber according to the method of claim 12; (ii) producing carbon fibers by oxidizing the polymer fibers produced in step (i) to form stabilized carbon fiber precursor fibers, and then carbonizing the stabilized carbon fiber precursor fibers; Methods including:

20. 20. Carbon fiber produced by the method of claim 19.

21. 20. A composite material comprising carbon fibers produced according to the method of claim 19 and a matrix resin.

22. 22. A composite article obtained by curing the composite material of claim 21.

Images