A low-density three-dimensional carbon fiber composite material product and production method thereof

Abstract

A low-density three-dimensional carbon fiber composite material product and a production method thereof, comprising the following steps: S1, obtaining an epoxy resin foam material that can be cured and foamed in sections; S2, subjecting the foam material to a section-by-section foaming and section-by-section curing to obtain a foamed embryo; S3, wrapping a carbon fiber prepreg cloth sheet on the outer surface of the foamed embryo, and coating and fixing it to form a preform; S4, placing the preform into a full-size mold for two-stage foaming and two-stage curing, during which the foamed embryo expands internally and is hot molded; S5, exhausting or cooling to eliminate the internal expansion force to obtain a finished product. The method of the present invention can prepare a three-dimensional carbon fiber product with excellent performance and good appearance, and the yield is greatly improved, with a basic 100% yield for simple parts and a 90% yield for complex parts.

Description

Technical Field

[0001] The invention belongs to the technical field of carbon fiber composite material products, and in particular relates to a production method of a low-density three-dimensional carbon fiber composite material product. Background Art

[0002] The preparation methods of three-dimensional carbon fiber composite products mainly include the hollow blowing bag method and the foaming internal expansion support method. Chinese patent documents CN113370557A, CN108127938A, CN103331899A and CN101298188A use the hollow blowing bag method to prepare tubular three-dimensional carbon fiber products with low texture requirements and relatively simple structure, such as carbon fiber exhaust pipes, bicycle support frames, missile shells, simple luggage, air intake wind knives and other products. The hollow blowing bag method is currently the main production process for three-dimensional carbon fiber products. The advantage is that the product molding process is simple; however, since the interior of the product is hollow, it requires multiple layers of carbon fiber for support, and angled plying is required in some parts. The finished product can often only be sprayed with colored paint, and transparent 3K texture carbon fiber products cannot be produced.

[0003] Chinese patent documents CN202111356815.X, CN202011259797.9, etc. use the foaming internal expansion support method to prepare three-dimensional carbon fiber. Its advantage is that it can realize three-dimensional transparent 3K texture carbon fiber parts with few layers or even single layer of carbon fiber; its disadvantage is that when manufacturing larger and wider carbon fiber composite products (such as Tesla modle3 large tail wing, Tank 300 Cyber ​​Edition modified car super large tail wing, etc.), due to the problem of uniformity of foaming support, there are often a lot of product defects such as grain distortion, yarn separation, yarn insertion, bottom exposure, glue accumulation and lack of materials, deformation and shaking due to wind resistance, etc., and the yield rate of single process products drops sharply with the complexity and large-scale of the shape.

[0004] Due to the above-mentioned shortcomings of the foaming internal expansion support method, when manufacturing large carbon fiber composite products, the A-side shell is often made by silicone molding and then composited. This process is currently the most advanced technology for manufacturing 3K-textured three-dimensional carbon fiber products, but it requires more than 10 processes, 7 of which cannot be automated. Summary of the invention

[0005] The purpose of the present invention is to provide a low-density three-dimensional carbon fiber composite material product and a production method thereof to solve the above-mentioned technical problems existing in the prior art.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention provides a method for producing a low-density three-dimensional carbon fiber composite product, which is characterized in that it comprises the following steps: S1, obtaining an epoxy resin foaming material that can be cured and foamed in stages; S2, subjecting the foaming material to one-stage foaming and one-stage curing to obtain a foaming embryo; S3, wrapping a carbon fiber prepreg cloth sheet on the outer surface of the foaming embryo, and wrapping and fixing it to form a preform; S4, placing the preform in a full-size mold for two-stage foaming and two-stage curing, during which the foaming embryo expands internally and is hot molded; S5, exhausting or cooling to eliminate the internal expansion force to obtain the low-density three-dimensional carbon fiber composite product.

[0008] More specifically, the present invention provides a method for producing a low-density three-dimensional carbon fiber composite material product, characterized in that it comprises the following steps:

[0009] S1, preparing an epoxy resin foam material having a clay-like state at 35-60° C. and having two-stage curing and two-stage foaming functions;

[0010] S2, filling the epoxy resin foaming material in a proportionally reduced jig at 30-40°C to form a blank; cooling to below 25°C and moving it into a foaming mold; then maintaining the mold pressure at a temperature of 80-110°C and a pressure of 1-5MPa for 5-30min to perform the first foaming and curing; cooling to below 80°C (preferably 40-55°C) to obtain a density of 0.1-0.25g / cm 3 A foamed embryo having a product shape;

[0011] S3, wrapping the carbon fiber prepreg cloth sheet on the outer surface of the foamed preform, bonding and fixing at 20 to 50° C. (preferably 25 to 35° C.) (including vacuum preforming process and manual kneading) to form a preform;

[0012] S4, placing the preform into a full-size mold, and performing molding for 5 to 60 minutes at a temperature of 120 to 180° C., a pressure of 2.0 to 8.0 MPa, and staged exhaust, to obtain a low-density three-dimensional carbon fiber composite material product with a low-density foam as the core and a three-dimensional carbon fiber reinforcement base as the facade;

[0013] The epoxy resin foam material has a Tg of 100-150°C after two-stage foaming and curing, the first foaming temperature is 80-110°C, preferably 100-110°C; the first foaming volume expansion ratio is 2-12 times, and the first curing reaction crosslinking degree is less than 60%; the second foaming curing temperature is 120-180°C, preferably 120-160°C;

[0014] The preparation method of the carbon fiber prepreg cloth sheet is as follows: impregnate the carbon fiber cloth in the prepreg material, pre-impregnate at a temperature of 55-75°C, cool to 20-30°C, and cut into sheets with a designed pattern; commercially available products can also be purchased, such as Zhongfu Shenying's SYT45 carbon fiber prepreg cloth, Guangwei Composites' WP-3011 carbon fiber prepreg cloth, etc.; the prepreg material is an epoxy resin curing material, and its curing agent and accelerator should be consistent with the curing agent and accelerator of the epoxy resin foaming material, so that the prepreg material and the primary embryo can be completely combined with each other; the mass fraction of the epoxy resin in the carbon fiber prepreg material is 38%-45%, and the resin viscosity at 65°C is 10000-50000cP.

[0015] Furthermore, in the step (S2), the foamed embryo is a foam composite in which the continuous phase is an epoxy resin or a modified epoxy resin with a crosslinking degree of 30% to 60%, and the dispersed phase is microbubbles and inorganic fillers; its overall size should be 200 to 800 μm smaller than the overall size of the preform, and the Shore C hardness at 30°C is 45 to 90, preferably 60 to 85; because the foamed embryo is an incompletely cured body and has post-curing activity, the surface will become sticky at 20 to 40°C, and can be bonded to the resin in the prepreg, thereby well bonding the carbon fiber prepreg cloth.

[0016] Furthermore, in the step (S4), the free expansion ratio of the volume of the preform is 1.05 to 1.5 times, and the Tg of the molded body is ≥110°C; at a temperature of 120 to 180°C, in the preform, the semi-crosslinked epoxy resin of the foamed embryo and the epoxy resin of the prepreg can be fused and cured together, and have a good composite effect; at this time, the high-temperature foaming agent inside the foamed embryo begins to release inert gas or expand due to heat, so that the carbon fiber cloth fits well on the inner surface of the mold, which not only ensures the texture of the carbon fiber, but also eliminates the problems of glue accumulation and material shortage caused by uneven force.

[0017] The present invention provides a method for producing a low-density three-dimensional carbon fiber composite product. Commercially available epoxy resin foaming materials can be used as long as they meet the application conditions of the present invention.

[0018] But more preferably, the present invention provides an epoxy resin foaming material, comprising the following raw materials by mass fraction: solid epoxy resin 10% to 30%, liquid epoxy resin 10% to 40%, modified epoxy resin 0 to 15%, active diluent 0 to 15%, active coupling agent 0 to 5%, nucleating agent 5 to 20%, filler 0 to 10%, high temperature foaming agent 1% to 3%, high temperature curing agent 2% to 8%, high temperature accelerator 1% to 4%, low temperature foaming agent 1% to 6%, low temperature curing agent 10% to 20%;

[0019] The solid epoxy resin is one or more of bisphenol A epoxy resin or hydrogenated bisphenol A epoxy resin, with a glass transition temperature Tg of 12 to 105° C. and an epoxy value of 0.08 to 0.38 eq / 100 g, such as E-35, E-31, E-20, E-14, and E-10;

[0020] The liquid epoxy resin refers to one or more of bisphenol A epoxy resin (e.g., E51, E44, AG-80, TED-85), bisphenol F epoxy resin (e.g., YDF-161, YDF162), and phenolic epoxy resin (e.g., F-44, F-51) with an epoxy value of 0.38 to 1.0 eq / 100 g;

[0021] The modified epoxy resin is one or more of silicone modified epoxy resin, polyurethane modified epoxy resin, and hydroxyl-terminated liquid nitrile rubber modified epoxy resin, such as EPU-133L, EPSI-3266 and EPP-175 produced by Luhe Hi-Tech;

[0022] The active diluent is one or more of allyl glycidyl ether (AGE), n-butyl glycidyl ether (BGE), phenyl glycidyl ether (PGE), and epoxybenzene;

[0023] The active coupling agent is one or more of an aminosilane coupling agent, an epoxysilane coupling agent, and an acryloxysilane coupling agent; preferably an aminosilane coupling agent; the aminosilane coupling agent includes γ-aminopropyltrimethoxysilane (brand A-1110), γ-aminopropyltriethoxysilane (brand KH550), N-β (aminoethyl)-γ-aminopropyltrimethoxysilane (brand A-1120), N-β (aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl)-γ-aminopropyltriethoxysilane, N-β (aminoethyl)-γ-aminopropylmethyldiethoxysilane, anilinomethyltriethoxysilane, anilinomethyltrimethoxysilane, γ-aminoethylaminoethylaminopropyltrimethoxysilane (brand A-1130), and more preferably KH550;

[0024] The nucleating agent is a silicate, carbonate or metal oxide powder with a diameter of 20 to 500 nanometers; such as one or more of calcium carbonate, precipitated barium sulfate, aluminum hydroxide powder, microsilica powder, montmorillonite, etc., more preferably stearate-modified hydrophobic nano calcium carbonate, titanate-modified hydrophobic nano calcium carbonate;

[0025] The filler is one or more of nano carbon black, color paste, nano clay, and PVC powder;

[0026] The high-temperature foaming agent is a foaming agent that can release gas or thermally expand at a foaming temperature of 120 to 180 degrees, such as one or more of rubber microspheres, bis(2-hydroxyethyl)hydrazide foaming agents (OBSH), and modified high-temperature ADC;

[0027] The high temperature curing agent is one or more of dicyandiamide, diaminodiphenyl sulfone, and boron trifluoride-monoethylamine;

[0028] The high temperature accelerator is an organic urea accelerator; the preferred organic urea accelerator is one or more of 3-phenyl-1,1-dimethylurea (e.g., Evonik UR300 from Germany), N,N''-(4-methyl-1,3-phenylene)bis[N',N'-dimethylurea (e.g., Evonik UR500 from Germany), 3-(4-chlorophenyl)-1,1-dimethylurea, 3-p-anisyl-1,1-dimethylurea, complex high-tech dicyandiamide curing accelerator 5050 or dicyandiamide accelerator 5200;

[0029] The low-temperature foaming agent is a physical or chemical foaming agent with a foaming temperature of 80 to 120° C., such as one or more of water, 2,2'-azobisisobutyronitrile, sodium bicarbonate powder, modified low-temperature azodicarbonamide (modified low-temperature ADC), etc.;

[0030] The low-temperature curing agent is a polyether-modified polyamine, such as Huntsman's polyoxypropylene diamine D400 and polyoxypropylene triamine T403; polyoxypropylene diamine D400 is a bifunctional primary amine with an average molecular weight of 400 to 500, with propane oxide as the basic repeating chain segment in the main chain structure, and the primary amine group is connected to the second carbon atom of the end group of the aliphatic polyether main chain; polyoxypropylene triamine T403 is a trifunctional primary amine with an average molecular weight of 400 to 500, with propane oxide as the basic repeating chain segment in the main chain structure, and the primary amine group is connected to the second carbon atom of the end group of the aliphatic polyether main chain;

[0031] Preferably, the preparation method of the epoxy resin foam material of the present invention comprises the following steps: adding the solid epoxy resin, liquid epoxy resin, modified epoxy resin, active diluent, active coupling agent, nucleating agent and filler into an insulated kettle according to mass fractions, heating, and stirring and dispersing at 70-90°C for 10-80 minutes; then cooling to 55-65°C, adding the high-temperature foaming agent, high-temperature curing agent, high-temperature accelerator, low-temperature foaming agent and low-temperature curing agent; and then grinding at a rotation speed of 50-500rpm for 10-60min to obtain a clay-like epoxy resin foam material at 35-60°C.

[0032] The epoxy resin foaming material provided by the present invention has basically stable chemical properties in the range of 15 to 60°C, and its viscosity gradually decreases from about 500,000 centipoise (cP) to about 50,000 cP. As the temperature rises, the surface hydroxyl groups are freely exposed and the hand feels sticky. Specifically, it is solid below 15°C, asphalt-like semi-solid between 15 and 35°C, and clay-like plastic body at 35 to 60°C. Its viscosity drops to about 15,000 cP in the range of 60 to 75°C. Starting from about 75°C, the low-temperature curing agent begins to initially cross-link with the epoxy resin, so that the viscosity of the foaming agent begins to rise. After keeping warm at about 100°C for 20 to 30 minutes, the viscosity can reach about 200,000 cP. At this time, the low-temperature foaming agent begins to react and releases gas to allow the entire viscous semi-cross-linked epoxy resin body to foam and expand. At the first foaming temperature of 80-120°C, under the action of a highly active low-temperature curing agent (such as polyether-modified polyamine), nearly 30-60% of the active functional groups of the epoxy resin participate in the reaction, and more than 99% of the low-temperature foaming agent releases inert gas for foaming, and a foaming embryo can be prepared at this time. The foaming embryo is a solid elastomer at room temperature, has no reactivity and foaming properties below 100°C, but at above 120°C, the remaining 40% of the active functional groups can be secondary cured under a low-activity curing system, and a small amount of high-temperature foaming agent also foams in the secondary curing and provides internal expansion force.

[0033] The second object of the present invention is to provide a low-density three-dimensional carbon fiber composite material product produced by the production method of the low-density three-dimensional carbon fiber composite material product.

[0034] The low-density three-dimensional carbon fiber composite material product of the present invention is used for automobile accessories, such as automobile tail wings and exhaust pipes.

[0035] Compared with the prior art, the innovations of the present invention are mainly as follows:

[0036] The method of the present invention can prepare three-dimensional complex carbon fiber transparent 3K texture performance parts with a length of 2 meters, a width of 0.3 meters, and a thickness of 0.3 meters in one molding, and the product yield can reach 95%. The subsequent 100°C baking performance is stable and the appearance is good.

[0037] At present, the technology of using foam to prepare three-dimensional carbon fiber products on the market is to make a complete foam body, and then use the foam body as support to prepare carbon fiber products. Because the foam body has no secondary curing activity and secondary self-expansion force, it often has phenomena such as collapse, blistering, surface undulation, and loss of prepreg resin. The defective rate reaches more than 10%, and the defective rate of carbon fiber products with complex structures can reach 90%. This is also an important reason why carbon fiber products are expensive and cannot be standardized for mass production. By adopting the method of the present invention, the yield of three-dimensional carbon fiber products is greatly improved, with simple parts basically having a 100% yield and complex parts having a 90% yield.

[0038] The method of the present invention adopts low-temperature curing and low-temperature foaming to solve the basic requirement that the primary embryo can be used to make a preform. Then, through secondary curing, the primary embryo with a Tg of only about 110° C. and the prepreg resin are fully bonded, cross-linked and cured at 120-180° C., so that the secondary curing has good adhesion.

[0039] Moreover, the secondary curing of the present invention is accompanied by slight secondary foaming. If rubber microspheres are used as secondary foaming bodies, the foamed embryo can be tightly bonded to the prepreg. When the temperature is cooled to below 110°C, the gas inside the rubber microspheres cools and shrinks, and the internal expansion force is eliminated. If OBSH or high-temperature AC foaming is used, the excess internal stress can be eliminated by exhausting multiple times during the molding process. Finally, a three-dimensional carbon fiber product with good thermal stability and good appearance can be prepared. DETAILED DESCRIPTION

[0040] Those skilled in the art should realize that the present embodiment is only used to illustrate the present invention, but not to limit the present invention.

[0041] The raw materials involved in the embodiments of the present invention are all commercially available products.

[0042] Example 1

[0043] A method for producing a low-density three-dimensional carbon fiber composite material product comprises the following steps:

[0044] S1, preparing an epoxy resin foam material having a clay-like state at 35-60° C. and having two-stage curing and two-stage foaming functions;

[0045] The epoxy resin foaming material is homemade, including the following raw materials in parts by weight: solid epoxy resin (bisphenol A epoxy resin E-20) 20%, liquid epoxy resin (bisphenol A epoxy resin E44) 38%, modified epoxy resin (complex high-tech EPU-133L) 3%, active diluent (allyl glycidyl ether AGE) 10%, active coupling agent (KH550) 1%, nucleating agent (titanate modified hydrophobic nano calcium carbonate) 5%, filler (nano carbon black powder) 2%, high temperature foaming agent (rubber microsphere) 3%, high temperature curing agent (dicyandiamide) 5%, high temperature accelerator (German Evonik UR300) 1%, low temperature foaming agent (2,2'-azobisisobutyronitrile) 2%, low temperature curing agent (polyoxypropylene triamine T403) 10%;

[0046] The solid epoxy resin, liquid epoxy resin, modified epoxy resin, active diluent, active coupling agent, nucleating agent and filler are added to an insulated kettle according to their mass fractions, heated, and stirred and dispersed at 80° C. for 60 minutes; then cooled to 55° C., and the high-temperature foaming agent, high-temperature curing agent, high-temperature accelerator, low-temperature foaming agent and low-temperature curing agent are added; then ground at a speed of 200 rpm for 30 minutes to obtain a clay-like epoxy resin foaming material at 35-60° C.

[0047] S2, filling the epoxy resin foaming material in a proportionally reduced jig at 30°C to form a blank; after cooling to 20°C, moving it into a foaming mold; then maintaining the mold pressing at a temperature of 110°C and a pressure of 3MPa for 10 minutes to perform the first foaming and curing; cooling to 40°C to obtain a density of 0.15g / cm 3 A foamed embryo having the shape of a product.

[0048] S3, wrapping the outer surface of the foamed preform A with SYT45 carbon fiber cloth, bonding and fixing at 35° C. (including vacuum preforming process and manual kneading) to form a preform.

[0049] S4, placing the preform into a full-size mold, and performing molding for 30 minutes at a temperature of 150°C, a pressure of 5.0 MPa, and staged exhaust, to obtain a low-density three-dimensional carbon fiber composite product with a low-density foam as the core and a three-dimensional carbon fiber reinforcement base as the facade.

[0050] Example 2

[0051] A method for producing a low-density three-dimensional carbon fiber composite material product comprises the following steps:

[0052] S1, preparing an epoxy resin foam material having a clay-like state at 35-60° C. and having two-stage curing and two-stage foaming functions;

[0053] The epoxy resin foaming material is homemade, and includes the following raw materials in parts by weight: solid epoxy resin (bisphenol A epoxy resin E-20) 30%, liquid epoxy resin (bisphenol A epoxy resin E44) 30%, active coupling agent (N-β (aminoethyl) -γ-aminopropyltrimethoxysilane A-1120) 3%, nucleating agent (titanate modified hydrophobic nano calcium carbonate) 8%, high temperature foaming agent (rubber microsphere) 3%, high temperature curing agent (dicyandiamide) 4%, high temperature accelerator (German Evonik UR500) 1%, water 6%, low temperature curing agent (polyoxypropylene diamine D400) 15%;

[0054] The solid epoxy resin, liquid epoxy resin, modified epoxy resin, active diluent, active coupling agent, nucleating agent and filler are added to an insulated kettle according to their mass fractions, heated, and stirred and dispersed at 80° C. for 60 minutes; then cooled to 50° C., and the high-temperature foaming agent, high-temperature curing agent, high-temperature accelerator, low-temperature foaming agent and low-temperature curing agent are added; then ground at a speed of 50 rpm for 30 minutes to obtain a clay-like epoxy resin foaming material at 35-60° C.

[0055] S2, filling the epoxy resin foaming material in a proportionally reduced jig at 30°C to form a blank; after cooling to 20°C, moving it into a foaming mold; then maintaining the mold pressure at a temperature of 100°C and a pressure of 1MPa for 30 minutes to perform the first foaming and curing; cooling to 40°C to obtain a density of 0.25g / cm 3 A foamed embryo having the shape of a product.

[0056] S3, wrapping the WP-3011 carbon fiber cloth on the outer surface of the foamed preform A, bonding and fixing at 35° C. (including vacuum preforming process and manual kneading) to form a preform.

[0057] S4, placing the preform into a full-size mold, and performing molding for 30 minutes at a temperature of 180°C, a pressure of 5.0 MPa, and staged exhaust, to obtain a low-density three-dimensional carbon fiber composite product with a low-density foam as the core and a three-dimensional carbon fiber reinforcement base as the facade.

[0058] Example 3

[0059] A method for producing a low-density three-dimensional carbon fiber composite material product comprises the following steps:

[0060] S1, preparing an epoxy resin foam material having a clay-like state at 35-60° C. and having two-stage curing and two-stage foaming functions;

[0061] The epoxy resin foaming material is homemade, and includes the following raw materials in parts by mass: solid epoxy resin (bisphenol A epoxy resin E-10) 10%, AG-80 liquid epoxy resin 30%, EPSI-3266 liquid silicone modified epoxy resin 10%, active diluent (epoxybenzene) 3%, active coupling agent (γ-aminopropyltrimethoxysilane A-1110) 5%, nucleating agent (aluminum hydroxide powder) 5%, filler (SG-2 type PVC resin powder) 9%, high temperature foaming agent (OBSH foaming agent) 2%, high temperature curing agent (diaminodiphenyl sulfone) 3%, high temperature accelerator (3-(4-chlorophenyl)-1,1-dimethylurea) 1%, 3-(4-chlorophenyl)-1,1-dimethylurea) 1%, low temperature modified AC foaming agent foaming at 100-120°C 6%, low temperature curing agent (polyoxypropylene diamine D400) 5%, low temperature curing agent (polyoxypropylene triamine T403) 10%;

[0062] The solid epoxy resin, liquid epoxy resin, modified epoxy resin, active diluent, active coupling agent, nucleating agent and filler are added to an insulated kettle according to their mass fractions, heated, and stirred and dispersed at 80° C. for 60 minutes; then cooled to 60° C., and the high-temperature foaming agent, high-temperature curing agent, high-temperature accelerator, low-temperature foaming agent and low-temperature curing agent are added; then ground at a speed of 100 rpm for 30 minutes to obtain a clay-like epoxy resin foaming material at 35 to 60° C.

[0063] S2, filling the epoxy resin foaming material in a proportionally reduced jig at 30°C to form a blank; after cooling to 20°C, moving it into a foaming mold; then maintaining the mold pressure at a temperature of 110°C and a pressure of 3MPa for 30 minutes to perform the first foaming and curing; cooling to 40°C to obtain a density of 0.10g / cm 3 A foamed embryo having the shape of a product.

[0064] S3, Toray's 3K carbon fiber cloth was impregnated with epoxy resin at a temperature of 65°C (the formula was 40% E-10 resin, 30% AG-80 resin, 10% EPSI-3266 resin, 13% diaminodiphenyl sulfone, 2% 3-(4-chlorophenyl)-1,1-dimethylurea, and 5% fumed silica; the viscosity was about 15,000 cps at 65°C) to prepare a 3K carbon fiber cloth with a gram weight of 195-210 g / cm 2 , a prepreg with a resin content of 40% to 42%, and then wrapping the prepreg on the outer surface of the foaming embryo A, bonding and fixing at 35°C (including vacuum preforming process and manual kneading) to form a preform.

[0065] S4, placing the preform into a full-size mold, and performing molding for 30 minutes at a temperature of 165°C, a pressure of 3.0 MPa, and staged exhaust, to obtain a low-density three-dimensional carbon fiber composite product with a low-density foam as the core and a three-dimensional carbon fiber reinforcement base as the facade.

[0066] Example 4

[0067] A method for producing a low-density three-dimensional carbon fiber composite material product comprises the following steps:

[0068] S1, preparing an epoxy resin foam material having a clay-like state at 35-60° C. and having two-stage curing and two-stage foaming functions;

[0069] The epoxy resin foaming material is homemade, and includes the following raw materials in parts by weight: solid epoxy resin (bisphenol A epoxy resin E-31) 30%, YDF-161 liquid epoxy resin 10%, EPP-175 modified epoxy resin 10%, active coupling agent (KH550) 5%, nucleating agent (stearate modified hydrophobic nano calcium carbonate) 10%, filler (SG-2 type PVC resin powder) 10%, high temperature foaming agent (high temperature AC foaming agent) 2%, high temperature curing agent (boron trifluoride-monoethylamine) 5%, high temperature accelerator (3-p-anisyl-1,1-dimethylurea) 1%, low temperature foaming agent (sodium bicarbonate) 5%, low temperature curing agent (polyoxypropylene diamine D400) 7%, low temperature curing agent (polyoxypropylene triamine T403) 5%;

[0070] The solid epoxy resin, liquid epoxy resin, modified epoxy resin, active diluent, active coupling agent, nucleating agent and filler are added to an insulated kettle according to their mass fractions, heated, and stirred and dispersed at 80° C. for 60 minutes; then cooled to 50° C., and the high-temperature foaming agent, high-temperature curing agent, high-temperature accelerator, low-temperature foaming agent and low-temperature curing agent are added; then ground at a speed of 50 rpm for 30 minutes to obtain a clay-like epoxy resin foaming material at 35-60° C.

[0071] S2, filling the epoxy resin foaming material in a proportionally reduced jig at 30°C to form a blank; after cooling to 20°C, moving it into a foaming mold; then maintaining the mold pressure at a temperature of 80°C and a pressure of 5MPa for 30 minutes to perform the first foaming and curing; cooling to 40°C to obtain a density of 0.12g / cm 3 A foamed embryo having the shape of a product.

[0072] S3, wrapping the outer surface of the foamed preform A with SYT-45 carbon fiber cloth, bonding and fixing at 35° C. (including vacuum preforming process and manual kneading) to form a preform.

[0073] S4, placing the preform into a full-size mold, and performing molding for 30 minutes at a temperature of 170°C, a pressure of 1.0 MPa, and staged exhaust, to obtain a low-density three-dimensional carbon fiber composite product with a low-density foam as the core and a three-dimensional carbon fiber reinforcement base as the facade.

[0074] Example 5

[0075] A method for producing a low-density three-dimensional carbon fiber composite material product comprises the following steps:

[0076] S1, preparing an epoxy resin foam material having a clay-like state at 35-60° C. and having two-stage curing and two-stage foaming functions;

[0077] The epoxy resin foaming material is homemade, including the following raw materials in parts by weight: solid epoxy resin (bisphenol A epoxy resin E-35) 30%, F-44 liquid epoxy resin 10%, EPU-133L modified epoxy resin 10%, nucleating agent (microsilica powder) 20%, filler (nano carbon black) 2%, high temperature foaming agent (rubber microsphere) 3%, high temperature curing agent (dicyandiamide) 5%, high temperature accelerator (5200) 1%, high temperature accelerator (5050) 1%, low temperature foaming agent (2,2'-azobisisobutyronitrile) 2%, low temperature curing agent (polyoxypropylene diamine D400) 8%, low temperature curing agent (polyoxypropylene triamine T403) 8%;

[0078] The solid epoxy resin, liquid epoxy resin, modified epoxy resin, active diluent, active coupling agent, nucleating agent and filler are added to an insulated kettle according to their mass fractions, heated, and stirred and dispersed at 70° C. for 30 minutes; then cooled to 50° C., and the high-temperature foaming agent, high-temperature curing agent, high-temperature accelerator, low-temperature foaming agent and low-temperature curing agent are added; then ground at a speed of 50 rpm for 30 minutes to obtain a clay-like epoxy resin foaming material at 35-60° C.

[0079] S2, filling the epoxy resin foaming material in a proportionally reduced jig at 30°C to form a blank; after cooling to 20°C, moving it into a foaming mold; then maintaining the mold pressure at a temperature of 80°C and a pressure of 5MPa for 30 minutes to perform the first foaming and curing; cooling to 40°C to obtain a density of 0.18g / cm 3 A foamed embryo having the shape of a product.

[0080] S3, wrapping the outer surface of the foamed preform A with SYT-45 carbon fiber cloth, bonding and fixing at 35° C. (including vacuum preforming process and manual kneading) to form a preform.

[0081] S4, placing the preform into a full-size mold, and performing molding for 20 minutes at a temperature of 145°C, a pressure of 2.5 MPa, and staged exhaust, to obtain a low-density three-dimensional carbon fiber composite product with a low-density foam as the core and a three-dimensional carbon fiber reinforcement base as the facade.

[0082] Example 6

[0083] A method for producing a low-density three-dimensional carbon fiber composite material product comprises the following steps:

[0084] S1, preparing an epoxy resin foam material having a clay-like state at 35-60° C. and having two-stage curing and two-stage foaming functions;

[0085] The epoxy resin foaming material is homemade, including the following raw materials in parts by weight: solid epoxy resin (bisphenol A epoxy resin E-20) 20%, TED-85 liquid epoxy resin 15%, EPSI-3266 modified epoxy resin 15%, active diluent (epoxybenzene) 10%, active coupling agent (KH550) 2%, nucleating agent (nano-montmorillonite) 5%, filler (SG-2 type PVC resin powder) 5%, high temperature foaming agent (rubber microsphere) 3%, high temperature curing agent (dicyandiamide) 5%, high temperature accelerator (5200) 1%, high temperature accelerator (5050) 1%, low temperature foaming agent (2,2'-azobisisobutyronitrile) 2%, low temperature curing agent (polyoxypropylene diamine D400) 10%, low temperature curing agent (polyoxypropylene triamine T403) 6%;

[0086] The solid epoxy resin, liquid epoxy resin, modified epoxy resin, active diluent, active coupling agent, nucleating agent and filler are added to an insulated kettle according to their mass fractions, heated, and stirred and dispersed at 70° C. for 30 minutes; then cooled to 50° C., and the high-temperature foaming agent, high-temperature curing agent, high-temperature accelerator, low-temperature foaming agent and low-temperature curing agent are added; then ground at a speed of 50 rpm for 30 minutes to obtain a clay-like epoxy resin foaming material at 35-60° C.

[0087] S2, filling the epoxy resin foaming material in a proportionally reduced jig at 30°C to form a blank; after cooling to 20°C, moving it into a foaming mold; then maintaining the mold pressure at a temperature of 80°C and a pressure of 5MPa for 30 minutes to perform the first foaming and curing; cooling to 40°C to obtain a density of 0.18g / cm 3 A foamed embryo having the shape of a product.

[0088] S3, wrapping the outer surface of the foamed preform A with SYT-45 carbon fiber cloth, bonding and fixing at 35° C. (including vacuum preforming process and manual kneading) to form a preform.

[0089] S4, placing the preform into a full-size mold, and performing molding for 20 minutes at a temperature of 180°C, a pressure of 2.5 MPa, and staged exhaust, to obtain a low-density three-dimensional carbon fiber composite product with a low-density foam as the core and a three-dimensional carbon fiber reinforcement base as the facade.

[0090] The test results of the Great Wall Tank 300 Cyber ​​Edition super-large carbon fiber tail wing prepared in Examples 1-6 and the finished products of a competitor's brand are compared in Table 1.

[0091] Table 1 Test results of Examples 1-6

[0092] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparison sample Performance requirements Coating adhesion (cross-cut method) GB / T9286-1988 ISO 2049:2013 100% no shedding 100% no shedding 100% no shedding 100% no shedding 100% no shedding 100% no shedding 82% no shedding 100% no shedding Stone chip impact resistance ISO 20567-1:2017 2 2 2 2 2 2 4 ≤4 High pressure washdown resistant ISO 16925:2014 100% no shedding 100% no shedding 100% no shedding 100% no shedding 100% no shedding 100% no shedding 92% no shedding 100% no shedding Flexural strength (MPa) GB / T 9341-2008 105 122 108 92 88 111 93 60-120 Flexural modulus (MPa) GB / T 9341-2008 1703 1421 2300 1600 1812 1710 618 ≥1000 <![CDATA[Izod impact (J / m at 23 °C 2 ) ASTM D256 - 2002]]> 800 710 1010 650 736 910 392 ≥500 TABER wear resistance GB / T 1768-2006 ISO 7784-1:1997 ISO7784-2:1997 No yarn out No yarn out No yarn out No yarn out No yarn out No yarn out No yarn out No yarn out <![CDATA[Product density (g / cm 3 )]]> 0.41 0.52 0.36 0.34 0.45 0.46 0.47 ≤0.5 The wind resistance simulation force at both ends is calculated based on the product structure. The tail force at 120km / h 1420 1680 1071 1040 1339 1320 779 ≥1000 Appearance Slightly disordered, no bulges or depressions Slightly disordered, no bulges or depressions Slightly disordered, 2 bulges, 1 dent No obvious streaks, bulges or depressions No obvious streaks, bulges or depressions No obvious streaks, bulges or depressions More random lines, depressions, and bulges No obvious streaks, bulges or depressions

[0093] Note: The carbon fiber product of the car rear wing is mainly considered to avoid wind shaking, high-pressure water gun washing and gravel impact when driving at high speed, and no cracks will appear. The overall appearance of the product is good.

[0094] As can be seen from Table 1, the method of the present invention can prepare three-dimensional carbon fiber products with excellent performance, and the yield of three-dimensional carbon fiber products is greatly improved. The yield of simple parts is basically 100%, and the yield of complex parts can reach 90%. In particular, in Example 5, polyurethane-modified epoxy resin is used as toughness modification, micro-silica powder with low oil absorption rate is used as filler, and rubber microspheres are used as high-temperature foaming body. The product effect is the most stable, and the physical properties all meet customer requirements. At present, 1,000 products are produced using this technology, and only 26 need to be reworked. This is the first time in the field of large-scale appearance performance carbon fiber parts processing.

[0095] In Example 2, due to the use of a completely rigid formula and water as a foaming agent, there are more pores, resulting in slight irregular lines; however, the physical properties can meet the modification requirements, especially the good effect in the wind resistance test; it needs to be treated with a color paint, and the anti-shake effect is good. In Example 3, the product has good mechanical properties and good toughness. The product also has good supporting force at a lower density, but because the PVC powder may degrade and volatilize HCl during molding, there are more product defects.

[0096] The comparison column uses a one-time foaming process for polyurethane foam. It is a T300 rear wing produced by a company in Shenzhen. After the product was installed, it shook violently at a speed of 90km / h, and a large number of bulges appeared during the painting process. The product strength was extremely poor and could not meet the standards.

Claims

1. A method for producing a low-density three-dimensional carbon fiber composite material product, characterized in that: The following steps are involved: S1, preparing an epoxy resin foam material having a clay-like state at 35-60° C. and having two-stage curing and two-stage foaming functions; S2, filling the epoxy resin foaming material in a proportionally reduced jig at 30-40°C to form a blank; after cooling to below 25°C, moving it into a foaming mold; then maintaining the mold pressure at a temperature of 80-110°C and a pressure of 1-5MPa for 5-30min to perform the first foaming and curing; cooling to below 80°C to obtain a density of 0.1-0.25g / cm 3 A foamed embryo having a product shape; S3, wrapping the carbon fiber prepreg cloth sheet on the outer surface of the foamed preform, bonding and fixing at 20-50° C. to form a preform; S4, placing the preform into a full-size mold, and performing molding for 5 to 60 minutes at a temperature of 120 to 180° C., a pressure of 2.0 to 8.0 MPa, and staged exhaust, to obtain a low-density three-dimensional carbon fiber composite material product; The epoxy resin foaming material comprises the following raw materials in mass fraction: 10% to 30% solid epoxy resin, 10% to 40% liquid epoxy resin, 0% to 15% modified epoxy resin, 0% to 15% active diluent, 0% to 5% active coupling agent, 5% to 20% nucleating agent, 0% to 10% filler, 1% to 3% high-temperature foaming agent, 2% to 8% high-temperature curing agent, 1% to 4% high-temperature accelerator, 1% to 6% low-temperature foaming agent, and 10% to 20% low-temperature curing agent; the epoxy resin foaming material has a Tg of 100 to 150° C. after two-stage foaming and curing, and the first foaming temperature is 80 to 110° C.; the first foaming volume expansion ratio is 2 to 12 times, and the reaction crosslinking degree of the first curing is less than 60%; the second foaming and curing temperature is 120 to 180° C.; The prepreg of the carbon fiber prepreg cloth is an epoxy resin curing material, the mass fraction of the epoxy resin in the prepreg is 38% to 45%, and the viscosity of the epoxy resin at 65° C. is 10,000 to 50,000 cP.

2. The method for producing a low-density three-dimensional carbon fiber composite material product according to claim 1, characterized in that: The preparation method of the carbon fiber prepreg cloth sheet is as follows: impregnating the carbon fiber cloth in the prepreg material, pre-impregnating at a temperature of 55-75° C., cooling to 20-30° C., and cutting into sheets with a designed pattern.

3. The method for producing a low-density three-dimensional carbon fiber composite material product according to claim 1, characterized in that: In the step S2, the foamed embryo is a foam composite in which the continuous phase is an epoxy resin or a modified epoxy resin with a crosslinking degree of 30% to 60%, and the dispersed phase is microbubbles and inorganic fillers; its overall size should be 200 to 800 μm smaller than the overall size of the preform, and the Shore C hardness at 30°C is 45 to 90; in the step S4, the volume free expansion ratio of the preform is 1.05 to 1.5 times, and the Tg of the molded body is ≥110°C.

4. The method for producing a low-density three-dimensional carbon fiber composite material product according to claim 1, characterized in that: The solid epoxy resin is one or more of bisphenol A epoxy resin or hydrogenated bisphenol A epoxy resin, and its glass transition temperature Tg is 12 to 105°C, and the epoxy value is 0.08 to 0.38 eq / 100g; the liquid epoxy resin refers to one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, and phenolic epoxy resin with an epoxy value of 0.38 to 1.0 eq / 100g; the modified epoxy resin is one or more of silicone modified epoxy resin, polyurethane modified epoxy resin, and terminal hydroxyl liquid nitrile rubber modified epoxy resin.

5. The method for producing a low-density three-dimensional carbon fiber composite material product according to claim 1, characterized in that: The active diluent is one or more of allyl glycidyl ether, n-butyl glycidyl ether, phenyl glycidyl ether, and epoxybenzene; the active coupling agent is one or more of aminosilane coupling agent, epoxysilane coupling agent, and acryloxysilane coupling agent; the nucleating agent is a silicate, carbonate, or metal oxide powder with a diameter of 20 to 500 nanometers; the filler is one or more of nano carbon black, color paste, nano clay, and PVC powder.

6. The method for producing a low-density three-dimensional carbon fiber composite material product according to claim 1, characterized in that: The high-temperature foaming agent is a foaming agent that can release gas or thermally expand at a foaming temperature of 120 to 180°C; the high-temperature curing agent is one or more of dicyandiamide, diaminodiphenyl sulfone, and boron trifluoride-monoethylamine; the high-temperature accelerator is an organic urea accelerator; the low-temperature foaming agent is one or more of physical or chemical foaming agents with a foaming temperature of 80 to 120°C; and the low-temperature curing agent is a polyether-modified polyamine.

7. The method for producing a low-density three-dimensional carbon fiber composite material product according to claim 6, characterized in that: The organic urea accelerator is one or more of 3-phenyl-1,1-dimethyl urea, N,N''-(4-methyl-1,3-phenylene)bis[N',N'-dimethyl urea, 3-(4-chlorophenyl)-1,1-dimethyl urea, 3-p-anisyl-1,1-dimethyl urea, complex high-tech dicyandiamide curing accelerator 5050 or dicyandiamide accelerator 5200.

8. The method for producing a low-density three-dimensional carbon fiber composite material product according to claim 1, characterized in that: The preparation method of the epoxy resin foaming material comprises the following steps: adding the solid epoxy resin, liquid epoxy resin, modified epoxy resin, active diluent, active coupling agent, nucleating agent and filler into an insulation kettle according to mass fractions, heating, and stirring and dispersing at 70-90° C. for 10-80 minutes; then cooling to 55-65° C., adding the high-temperature foaming agent, high-temperature curing agent, high-temperature accelerator, low-temperature foaming agent and low-temperature curing agent; and then grinding at a rotation speed of 50-500 rpm for 10-60 minutes to obtain a clay-like epoxy resin foaming material at 35-60° C.

9. A low-density three-dimensional carbon fiber composite material product obtained according to the production method of a low-density three-dimensional carbon fiber composite material product according to any one of claims 1 to 8.

10. The low-density three-dimensional carbon fiber composite material product according to claim 9, characterized in that: Used in automotive accessories.