High-toughness high-temperature curing epoxy resin prepreg for automatic fiber placement and preparation method of high-toughness high-temperature curing epoxy resin prepreg

Abstract

The invention discloses a high-toughness high-temperature curing epoxy resin prepreg for automatic fiber placement and a preparation method of the high-toughness high-temperature curing epoxy resin prepreg, and belongs to the technical field of resin-based composite materials. The whole high-toughness high-temperature curing epoxy resin prepreg for automatic fiber placement is of a layer structure and is formed by sequentially compounding a high-viscosity surface layer adhesive film, a high-toughness high-temperature curing epoxy resin layer adhesive film and a reinforced fiber layer by adopting a hot melt adhesive film method. According to the high-toughness high-temperature cured epoxy resin prepreg, the toughness is greatly improved, the long storage period can be guaranteed, the viscidity maintaining time is long, the outstanding comprehensive performance is achieved, and the manufacturability use requirement of automatic fiber placement prepreg can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of resin-based composite materials, in particular to a high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement and a preparation method thereof. Background Art

[0002] Resin-based composite materials have important properties required by modern aircraft, such as high specific strength, specific modulus, dimensional stability, excellent corrosion resistance, wear resistance, dielectric properties, electrical insulation properties, and other properties and characteristics. Therefore, they have been widely used in aerospace, military, rail transportation, wind power and other fields.

[0003] As an important category of resin-based composite materials, thermosetting resin-based composite materials include epoxy resin, phenolic resin, bismaleimide resin, cyanate resin and polyimide resin according to different resin systems. According to different molding methods, they can be divided into prepreg compression molding, winding molding, pultrusion molding and liquid molding.

[0004] Epoxy resin-based carbon fiber prepreg, a thermosetting resin-based composite material, is manufactured using prepreg compression molding technology. Its low curing temperature, good processability, and low cost make it widely used in primary load-bearing structures in aviation. High-toughness, medium-modulus, high-strength carbon fiber prepregs are widely used in the primary load-bearing structures of foreign civil aircraft. In terms of civil aviation materials, epoxy resin-based carbon fiber prepregs are primarily used in primary load-bearing structures such as the fuselage and wings of aircraft. Approximately 50% of the Boeing 787's fuselage structure is made of composite materials, 45% of which are carbon fiber composites. The key indicator of its composite material is the compressive strength after impact (CAI), which is used to characterize the composite material's ability to resist low-speed impact damage. Therefore, the toughening modification of high-temperature curing epoxy resins has always been a hot research topic in China and abroad.

[0005] To improve the toughness of epoxy resins, extensive scientific research has been conducted, yielding significant results. Currently, research on toughening epoxy resins has achieved remarkable results. The main approaches include: adding dispersed phases such as rubber elastomers, thermoplastic resins, or liquid crystal polymers to the epoxy matrix; using thermosetting resins to continuously penetrate the epoxy resin network to form interpenetrating or semi-interpenetrating networks; and curing the epoxy resin with a curing agent containing "flexible segments," introducing flexible segments into the crosslinked network to improve the flexibility of the network molecules. Specifically, Professor Yi Xiaosu proposed "interlaminar off-site toughening" (described in patent application number CN200610099381.9, entitled "A Toughened Composite Laminate and Its Preparation Method") for toughening epoxy resin-based prepregs. This method involves placing a thermoplastic resin in the form of a film or powder between two carbon fiber layers impregnated with a low-viscosity resin matrix. This method specifically improves the interlaminar toughness of the composite, thereby significantly increasing the composite's CAI. For example, when preparing prepregs, low-area-density organic thermoplastic fiber mesh or non-woven fabric is used for interlayer toughening or toughening particle layers (such as those disclosed in patent documents with publication numbers CN117264370A and CN112677602A). For example, patent document CN115109389A discloses an epoxy resin for interlayer toughening prepregs with micron particles and a preparation method thereof. The epoxy resin matrix modified with a thermoplastic resin is added with micron toughening particles to toughen the epoxy resin-based composite material. During the prepreg molding stage, the micron-sized toughening particles are evenly distributed on the fiber surface. During the composite molding stage, the micron-sized toughening particles are located on the fiber surface. During the curing process, the thermoplastic particles are in a highly active state and can be tightly combined with the inorganic toughening particles between layers. When the fibers are subjected to external forces in the longitudinal direction, the highly tightly combined inorganic toughening particles with the thermoplastic toughening particles can resist the external forces, thereby achieving interlayer toughening.

[0006] However, all of the above existing technologies have certain drawbacks. Among them, modifying epoxy resin with rubber or polyurethane elastomers is a traditional toughening method. This modification often results in a significant increase in impact strength, but the corresponding cured product suffers from a decrease in heat resistance and modulus. Furthermore, the use of various interlayer "intercalation" or "toughening" methods can compromise the prepreg's viscosity and other processability, affect the control of the composite's single-layer thickness, and hinder engineering applications. Toughening with thermoplastic resin nanoparticles, due to the presence of active groups such as amines or impurities in thermoplastic resins, can shorten the prepreg's shelf life, thus hindering the fabrication of large composite parts.

[0007] Currently, the manufacturing of various structural components and large parts in various aerospace vehicles, such as large aircraft and launch vehicles, has been automated. Among them, Automatic Fiber Placement (AFP) is one of the fastest-growing automated composite material manufacturing technologies in recent years. It uses unidirectional prepreg tows with relatively narrow widths (3.000, 3.175, 6.000, 6.350, and 12.700 mm) as raw materials and automatically places them on the mold surface. However, this requires the prepreg tape to have good adhesion and adhesion life (process life). Currently, prepregs prepared using existing technologies cannot meet the high damage tolerance requirements of composite materials used in civil aerospace, military aviation, and unmanned aerial vehicles. The modulus, toughness, and heat resistance of most products do not meet the requirements, making it difficult to guarantee the processability and lifespan of prepregs when using AFP to produce large parts. Furthermore, most cannot guarantee a long storage period and maintain adhesion for a short time, making them unsuitable for the processability requirements of AFP prepregs.

[0008] Based on this, how to develop high-toughness, high-temperature curing epoxy prepreg while taking into account other properties, and at the same time ensure that it meets the processability and life requirements when used in automatic fiber placement molding technology to prepare large parts, is an issue that we urgently need to solve. Summary of the Invention

[0009] The present invention aims to provide a high-toughness, high-temperature-curing epoxy resin prepreg for automated fiber placement. This high-toughness, high-temperature-curing epoxy resin prepreg not only significantly improves toughness but also ensures a long shelf life and maintains its tackiness for a long time. It exhibits outstanding overall performance and meets the processability requirements of automated fiber placement prepregs. The present invention also provides a method for preparing the high-toughness, high-temperature-curing epoxy resin prepreg for automated fiber placement.

[0010] The first aspect of the present invention provides a high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement, which has a layered structure and is composed of a high-viscosity surface layer film, a high-toughness, high-temperature curing epoxy resin layer film and a reinforcing fiber layer composited in sequence using a hot melt film method.

[0011] Based on the above technical solution, the high-viscosity surface layer film is composed of the following components in parts by weight:

[0012] Epoxy resin A 80-100 parts;

[0013] 2-20 parts of film-forming agent;

[0014] Toughener A 1-10 parts;

[0015] Curing agent A 5-20 parts;

[0016] in,

[0017] The epoxy value of the epoxy resin A is 0.1 to 0.35.

[0018] Based on the above technical solution, the epoxy resin A is one or a combination of any two or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and novolac epoxy resin;

[0019] The room temperature viscosity of the epoxy resin A is 100 Pa﹒ S to 500 Pa﹒ S.

[0020] Based on the above technical solution, the film-forming agent is one or a combination of any two or more of polysulfone ether, polysulfone, polyimide ether, polyketone ether, polyphenylene ether, polyaryletherketone and carboxyl nitrile rubber, random nitrile rubber, and polybutadiene rubber.

[0021] Based on the above technical solution, the toughening agent A is ultrafine powder rubber.

[0022] Based on the above technical solution, the curing agent A is ultrafine dicyandiamide, 3,3'-diaminodiphenyl sulfone (3,3'-DDS) or 4,4'-diaminodiphenyl sulfone (4,4'-DDS).

[0023] Based on the above technical solution, the high-toughness high-temperature curing epoxy resin layer film is composed of the following components in parts by weight:

[0024] Epoxy resin B 60-100 parts;

[0025] Toughener B 20-50 parts;

[0026] Curing agent B 18-50 parts;

[0027] in,

[0028] The epoxy value of the epoxy resin B is 0.4 to 0.85.

[0029] Based on the above technical solution, the epoxy resin B is one or a combination of any two or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, novolac epoxy resin, naphthalene epoxy resin, biphenyl resin, glycidylamine multifunctional epoxy resin, and glycidylester multifunctional epoxy resin.

[0030] Based on the above technical solution, the curing agent B is nadic anhydride, methyl nadic anhydride, hydrogenated methyl nadic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylene glycol ditrimellitic anhydride, polysebacic anhydride, 3,3'-diaminodiphenyl sulfone (3,3'-DDS), 4,4'-diaminodiphenyl sulfone (4,4'-DDS), diaminodiphenylmethane, m-phenylenediamine, diaminodiphenyl ether, benzyldiamine, o-phenylenediamine, p-phenylenediamine, p-phenylenediamine, 9,9-bis(3-chlorophenyl)benzene, 9,9-bis(3-amino-4-hydroxyphenyl)benzene, dicyandiamide, phenolic resin, bismaleimide resin, cyanate resin, one or a combination of any two or more substances.

[0031] Based on the above technical solution, the toughening agent B is an ultrafine powder toughening agent, and the ultrafine powder toughening agent is one or a combination of any two or more substances selected from rubber particles, ultrafine thermoplastic resin powder, phenoxy resin powder, core-shell particles, carbon nanotubes, ultrafine powder rubber, and silica.

[0032] Based on the above technical solution, the material of the reinforcing fiber layer is E glass fiber or its fabric, S glass fiber or its fabric, quartz fiber or its fabric, aramid fiber or its fabric, LCP fiber or its fabric, polyimide fiber or its fabric, basalt fiber or its fabric, polyethylene fiber or its fabric, PBO fiber or its fabric, plant fiber or its fabric, T300 grade fiber or its fabric, T400 grade fiber or its fabric, T700 grade fiber or its fabric, T800 grade fiber or its fabric, T1100 grade fiber or its fabric, high modulus fiber or its fabric, or a combination of any two or more substances.

[0033] A second aspect of the present invention provides a method for preparing a high-toughness, high-temperature-cured epoxy resin prepreg for automatic fiber placement, which is used to prepare the above-mentioned high-toughness, high-temperature-cured epoxy resin prepreg for automatic fiber placement, and the method comprises the following steps:

[0034] S1 Preparation of high-adhesion surface film

[0035] At room temperature, 80 to 100 parts by weight of epoxy resin A and 2 to 20 parts by weight of a film-forming agent are weighed and mixed, and the temperature is raised to 120 to 180° C. and kept at this temperature for 0.8 to 1.2 hours to melt-mix.

[0036] After the melt mixing is completed, the temperature is lowered to below 70-90°C, and 1-10 parts by weight of toughening agent A and 5-20 parts by weight of curing agent A are added simultaneously, stirred evenly, and then ground to obtain a resin mixture for the surface layer film;

[0037] Prepare a film from the resin mixture of the surface film, controlling the film thickness to 5-100 μm and the surface density to 5-25 g / m2 , thus obtaining the highly adhesive surface layer film;

[0038] S2 Preparation of high toughness high temperature curing epoxy resin layer film

[0039] Weigh 60-100 parts by weight of epoxy resin B and 20-50 parts by weight of toughening agent B at room temperature and stir them together. While stirring, heat them to 150-170°C and keep them warm for 1-2 hours to melt mix them.

[0040] After the melt mixing is completed, the temperature is lowered to below 70°C to 90°C, 18 to 50 parts by weight of curing agent B is added, stirred evenly, and then ground to obtain a resin mixture of a high-toughness epoxy resin layer film;

[0041] Taking the resin mixture of the high-toughness epoxy resin layer film to prepare a film, that is, obtaining the high-toughness high-temperature curing epoxy resin layer film;

[0042] S3 composite molding

[0043] The reinforcing fiber and the prepared high-toughness, high-temperature curing epoxy resin layer film are placed in a hot melt film prepreg device for a single layer lamination, so that the low-viscosity epoxy resin of the high-toughness, high-temperature curing epoxy resin layer film penetrates into the fiber surface of the reinforcing fiber, and the ultrafine toughening agent particles of the high-toughness, high-temperature curing epoxy resin layer film are retained on the fiber layer surface of the reinforcing fiber, thereby obtaining a prepreg fiber with a high-toughness, high-temperature curing epoxy resin layer film; wherein the primary lamination temperature is 90-110°C, and the primary lamination gap is 0.1-0.5mm;

[0044] The prepared high-viscosity surface layer adhesive film and pre-impregnated fiber are taken to the hot melt adhesive film pre-impregnation equipment for secondary lamination and compounding. The secondary compounding temperature is 60-80°C, and the gap of the secondary compounding is 0.3-0.6mm. After compounding, the pre-impregnated fiber is cut into pieces according to size to obtain the high-toughness high-temperature curing epoxy resin prepreg for automatic fiber placement.

[0045] Compared with the prior art, the present invention has the following beneficial effects: the prepreg of the present invention is composed of a high-viscosity surface layer film, a high-toughness high-temperature curing epoxy resin layer film and a reinforcing fiber layer, which are compounded in sequence by a hot-melt film method, wherein the high-viscosity surface layer film ensures the surface viscosity of the prepreg, so that the processability of the prepreg is good. At the same time, the epoxy resin A of the high-viscosity surface layer film is a long-chain molecule with a low epoxy value and low activity, which ensures the process life of the prepreg. The epoxy resin B of the high-toughness high-temperature curing epoxy resin layer film has a high epoxy value and low viscosity. During the prepreg process, the low-viscosity resin penetrates into the interior of the reinforcing fiber and reaches the surface of the fiber filaments, and the particulate toughening agent remains on the surface of the fiber layer. When preparing the composite material, the particles between the layers absorb energy when impacted and do not expand the cracks. The post-impact compressive strength (CAI) is good, and its overall comprehensive performance such as toughness, modulus and heat resistance is outstanding. It is suitable for the automated manufacturing of large composite parts for various aerospace vehicles such as civil aviation and launch vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0047] Figure 1 This is a performance test table of the corresponding prepregs of Examples 1-5 and Comparative Examples 1-2.

[0048] Figure 2 This is a composite material performance test table of the corresponding prepregs of Examples 1-5 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0049] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0050] The present invention provides a high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement. The prepreg has a layered structure and is formed by sequentially compounding a high-viscosity surface layer adhesive film, a high-toughness, high-temperature curing epoxy resin layer adhesive film, and a reinforcing fiber layer using a hot melt adhesive film method. The thickness of the high-viscosity surface layer adhesive film is 5 to 100 μm, and the unit area weight is 5 to 25 g / m 2 The thickness of the high-toughness high-temperature curing epoxy resin film is 5 to 100 μm, and the weight per unit area is 30 to 300 g / m 2 , the prepreg resin content of the overall prepreg is 30-60%.

[0051] When used, the high-adhesion surface layer film is composed of the following components in parts by weight:

[0052]

[0053] in,

[0054] The epoxy value of the epoxy resin A is 0.1 to 0.35.

[0055] When used, the epoxy resin A is one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and novolac epoxy resin, or a combination of any two or more thereof; the epoxy resin A has a high viscosity, with a room temperature viscosity of 100 to 500 Pa﹒s.

[0056] When used, the film-forming agent is one or a combination of any two or more of polysulfone ether, polysulfone, polyimide ether, polyketone ether, polyphenylene ether, polyaryletherketone, carboxyl nitrile rubber, random nitrile rubber, and polybutadiene rubber.

[0057] When used, the toughening agent A is ultrafine powder rubber. Specifically, the ultrafine powder rubber can be VP-501E, VP-5011, VP-501S or VP-401.

[0058] When used, the curing agent A is superfine dicyandiamide, 3,3'-diaminodiphenyl sulfone (3,3'-DDS) or 4,4'-diaminodiphenyl sulfone (4,4'-DDS).

[0059] When used, the high-toughness, high-temperature curing epoxy resin film is composed of the following components in parts by weight:

[0060] Epoxy resin B 60-100 parts;

[0061] Toughener B 20-50 parts;

[0062] Curing agent B 18-50 parts;

[0063] in,

[0064] The epoxy value of the epoxy resin is 0.4 to 0.85.

[0065] When used, the epoxy resin B is one or a combination of any two or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, novolac epoxy resin, naphthalene epoxy resin, biphenyl resin, glycidylamine multifunctional epoxy resin, and glycidylester multifunctional epoxy resin.

[0066] When used, the curing agent B is nadic anhydride, methyl nadic anhydride, hydrogenated methyl nadic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylene glycol trimellitic anhydride, polysebacic anhydride, 3,3'-diaminodiphenyl sulfone (3,3'-DDS), 4,4'-diaminodiphenyl sulfone (4,4'-DDS), diaminodiphenylmethane, m-phenylenediamine, diaminodiphenyl ether, benzyldiamine, o-phenylenediamine, p-phenylenediamine, p-phenylenediamine, 9,9-bis(3-chlorophenyl)benzene, 9,9-bis(3-amino-4-hydroxyphenyl)benzene, dicyandiamide, phenolic resin, bismaleimide resin, cyanate resin, one or a combination of any two or more substances.

[0067] When used, the toughening agent B is an ultrafine powder toughening agent, and the ultrafine powder toughening agent is rubber particles, ultrafine thermoplastic resin (such as PES, PES-C, PEK-C, PSF, PEI, PEK, PEEK, PPO, PEK-C, PC, PI, PA66, PA12, etc.) powder, phenoxy resin powder, core-shell particles, carbon nanotubes, ultrafine powder rubber (such as VP-501E, VP-5011, VP-501S or VP-401), silica, one or a combination of any two or more substances.

[0068] When used, the material of the reinforcing fiber layer is E glass fiber or its fabric, S glass fiber or its fabric, quartz fiber or its fabric, aramid fiber or its fabric, LCP fiber or its fabric, polyimide fiber or its fabric, basalt fiber or its fabric, polyethylene fiber or its fabric, PBO fiber or its fabric, plant fiber or its fabric, T300 grade fiber or its fabric, T400 grade fiber or its fabric, T700 grade fiber or its fabric, T800 grade fiber or its fabric, T1100 grade fiber or its fabric, high modulus fiber (M40J, etc.) or its fabric, or a combination of any two or more substances.

[0069] At the same time, an embodiment of the present invention also provides a method for preparing the above-mentioned high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement, which comprises the following steps:

[0070] S1 Preparation of high-adhesion surface film

[0071] S11: 80-100 parts by weight of epoxy resin A and 2-20 parts by weight of film-forming agent are weighed and mixed at room temperature. During the mixing, the temperature is raised to 120-180° C. and kept at this temperature for 0.8-1.2 hours to melt-mix.

[0072] In this step S11, epoxy resin A and film-forming agent can be placed in a planetary disperser for stirring and melting. During the specific operation, the heating temperature can be selected from 120°C, 150°C, 180°C, etc., preferably 150°C, and the insulation time can be 0.8h, 1h, 1.2h, etc., preferably 1h.

[0073] S12 After the melt mixing is completed, the temperature is lowered to below 70-90° C., and 1-10 parts by weight of toughening agent A and 5-20 parts by weight of curing agent A are simultaneously added, stirred evenly, and then ground to obtain a resin mixture for the surface layer film;

[0074] In step S12, a three-roller grinder may be used for grinding, and grinding may be performed 3-4 times to ensure the grinding effect.

[0075] S13 takes the resin mixture of the surface layer film to prepare a film, controls the film thickness to be 5 to 100 μm, and the surface density to be 5 to 25 g / m 2 , thus obtaining the highly adhesive surface layer film;

[0076] S2 Preparation of high toughness high temperature curing epoxy resin layer film

[0077] S21: Weigh 60-100 parts by weight of epoxy resin B and 20-50 parts by weight of toughening agent B at room temperature, mix and stir, raise the temperature to 150-170° C. and keep the temperature for 1-2 hours to melt and mix;

[0078] In this step S21, epoxy resin B and toughening agent B can be placed in a planetary disperser for stirring and melting. During the specific operation, protective gas such as nitrogen can be introduced as needed when heating. The heating temperature can be selected from 150°C, 160°C, 170°C, etc., preferably 160°C, and the holding time can be 1h, 1.5h, 2h, etc., preferably 1.5h.

[0079] After the melt mixing is completed in step S22, the temperature is lowered to below 70° C. to 90° C., 18 to 50 parts by weight of curing agent B is added, stirred evenly, and then ground to obtain a resin mixture of a high-toughness epoxy resin layer film;

[0080] In step S22, the grinding can be performed using a three-roll mill, and the grinding can be performed 3-4 times to ensure the grinding effect. In the specific operation, the cooling temperature can be 70°C, 80°C, 90°C, etc., preferably 80°C.

[0081] S23: preparing a film from the resin mixture of the high-toughness epoxy resin layer film, thereby obtaining the high-toughness high-temperature curing epoxy resin layer film;

[0082] S3 composite molding

[0083] S31 takes the reinforcing fiber and the prepared high-toughness, high-temperature curing epoxy resin layer film to the hot melt adhesive film prepreg equipment for a stacking compound, so that the low-viscosity epoxy resin of the high-toughness, high-temperature curing epoxy resin layer film penetrates into the fiber surface of the reinforcing fiber, and the ultrafine toughening agent particles of the high-toughness, high-temperature curing epoxy resin layer film are retained on the fiber layer surface of the reinforcing fiber, thereby obtaining a prepreg fiber with a high-toughness, high-temperature curing epoxy resin layer film; wherein, the one-time compounding temperature is 90~110℃, and the one-time compounding gap is 0.1~0.5mm; in this step, the hot melt adhesive film prepreg equipment is a hot melt adhesive film prepreg machine.

[0084] S32 takes the prepared high-viscosity surface layer adhesive film and pre-impregnated fiber to the hot melt adhesive film pre-impregnation equipment for secondary lamination and compounding. The secondary compounding temperature is 60-80°C, and the gap of the secondary compounding is 0.3-0.6mm. After compounding, it is cut according to size to obtain the high-toughness high-temperature curing epoxy resin prepreg for automatic fiber placement.

[0085] The above is the entire content of the present invention. For better understanding and implementation thereof, it will be further explained and illustrated below in conjunction with specific embodiments and comparative examples.

[0086] Example 1

[0087] A high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement is prepared by the following steps:

[0088] S1 Preparation of high-adhesion surface film

[0089] At room temperature, 100 parts by weight of epoxy resin A and 5 parts by weight of film-forming agent were weighed and poured into a planetary disperser for mixing and stirring. During stirring, the temperature was raised to 150°C and kept warm for 1 hour for melt mixing; wherein epoxy resin A is a mixture of 70 parts by weight of epoxy resin E-44 and 30 parts by weight of epoxy resin E-12, and the film-forming agent is polysulfone ether.

[0090] After the melt mixing is completed, the temperature is lowered to below 80°C, and 5 parts by weight of toughening agent A and 10 parts by weight of curing agent A are added simultaneously, stirred evenly, and then ground to obtain a resin mixture for the surface layer film; wherein the toughening agent A is VP-5011 and the curing agent A is ultrafine dicyandiamide.

[0091] The resin mixture of the surface layer film was prepared by a three-roll mill to control the film thickness to 40 μm and the surface density to 8 g / m 2 , and the high-viscosity surface layer film is obtained.

[0092] S2 Preparation of high toughness high temperature curing epoxy resin layer film

[0093] 100 parts by weight of epoxy resin B and 30 parts by weight of toughening agent B were weighed at room temperature; 100 parts by weight of epoxy resin B and 5 parts by weight of toughening agent B were mixed and stirred, and the temperature was raised to 150° C. during stirring and kept warm for 1 hour for melt mixing; wherein the epoxy resin B is a mixture of 50 parts by weight of bisphenol A type epoxy resin E-51, 30 parts by weight of trifunctional low-viscosity epoxy S-510, and 20 parts by weight of trifunctional epoxy resin AFG-90, and the toughening agent B is polyethersulfone.

[0094] After the melt mixing is completed, the temperature is lowered to below 80° C., and the remaining weight parts of toughening agent B and 40 weight parts of curing agent B are added, stirred evenly and then ground to obtain a resin mixture of a high-toughness epoxy resin layer film; wherein the curing agent B is ultrafine 4,4'-diaminodiphenyl sulfone (DDS).

[0095] Prepare a film from the resin mixture of the high-toughness epoxy resin layer, and control the film surface density to 64g / m 2 , thus obtaining the high-toughness, high-temperature curing epoxy resin layer film;

[0096] S3 composite molding

[0097] The reinforcing fiber and the prepared high-toughness, high-temperature curing epoxy resin layer film are placed in a hot melt film prepreg machine for a stacking and compounding process, so that the low-viscosity epoxy resin of the high-toughness, high-temperature curing epoxy resin layer film penetrates into the fiber surface of the reinforcing fiber, and the ultrafine toughening agent particles of the high-toughness, high-temperature curing epoxy resin layer film are retained on the fiber layer surface of the reinforcing fiber, thereby obtaining a prepreg fiber with a high-toughness, high-temperature curing epoxy resin layer film; wherein, the primary compounding temperature is 98°C, and the primary compounding gap (the hot roller gap of the hot melt film prepreg machine, the same below) is 0.2mm; wherein the reinforcing fiber is a high-strength medium modulus carbon fiber (CCF800S).

[0098] The prepared high-viscosity surface layer adhesive film and pre-impregnated fiber are taken to the hot melt adhesive film pre-impregnation equipment for secondary lamination. The secondary compounding temperature is 80 ° C, and the gap of the secondary compounding is 0.3 mm. After compounding, it is cut according to size to obtain a high-toughness high-temperature curing epoxy resin prepreg with a width of 6.350 ± 0.127 mm for automatic fiber placement.

[0099] The prepregs prepared above were laid using an automatic fiber placement machine to test mechanical properties. After assembly and packaging, they entered the autoclave composite material molding process, specifically: the laminated blanks were placed in a vacuum bag with a vacuum degree of not less than 0,085 MPa, and heated to 135°C±5°C at a heating rate of 1°C / min to 2°C / min, kept warm for 60 minutes, and then continued to heat to 180°C±5°C. They were kept warm at 180°C±5°C for 120 minutes to 150 minutes and cured to obtain a laminate.

[0100] The laminate was cut with a laser cutting machine to obtain specimens for testing mechanical properties. Mechanical properties were tested on a universal tensile testing machine according to the specified test method to obtain the corresponding mechanical properties data. The glass transition temperature of the composite laminate specimens was tested with a DMA tester at a heating rate of 5°C / min. The combustion performance of the composite laminate was tested using a vertical combustion instrument. Finally, the physical properties test results of the prepreg are shown in the attached figure. Figure 1 , the test results of the composite materials are attached Figure 2 .

[0101] Example 2

[0102] A high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement is prepared by the following steps:

[0103] S1 Preparation of high-adhesion surface film

[0104] At room temperature, 100 parts by weight of epoxy resin A and 5 parts by weight of film-forming agent were weighed and poured into a planetary disperser for mixing and stirring. During stirring, the temperature was raised to 150°C and kept warm for 1 hour for melt mixing; wherein epoxy resin A is a mixture of 60 parts by weight of epoxy resin E-51 and 40 parts by weight of epoxy resin E-20, and the film-forming agent is polysulfone ether.

[0105] After the melt mixing is completed, the temperature is lowered to below 80°C, and 5 parts by weight of toughening agent A and 15 parts by weight of curing agent A are added simultaneously, stirred evenly, and then ground to obtain a resin mixture for the surface layer film; wherein the toughening agent A is VP-501S and the curing agent A is ultrafine 3,3'-diaminodiphenyl sulfone.

[0106] The resin mixture of the surface layer film was prepared by a three-roll mill to control the film thickness to 50 μm and the surface density to 10 g / m 2 , and the high-viscosity surface layer film is obtained.

[0107] S2 Preparation of high toughness high temperature curing epoxy resin layer film

[0108] At room temperature, 100 parts by weight of epoxy resin B and 30 parts by weight of toughener B were weighed, and 100 parts by weight of epoxy resin B and 5 parts by weight of toughener B were mixed and stirred. During stirring, the temperature was raised to 150° C. and kept warm for 1 hour for melt mixing; wherein the epoxy resin B is a mixture of 50 parts by weight of bisphenol A type epoxy resin E-51, 30 parts by weight of trifunctional low-viscosity epoxy S-510, and 20 parts by weight of tetrafunctional epoxy resin AG-80, and the toughener B is polyethersulfone.

[0109] After the melt mixing is completed, the temperature is lowered to below 80° C., and the remaining weight parts of toughening agent B and 38 weight parts of curing agent B are added, stirred evenly and then ground to obtain a resin mixture of a high-toughness epoxy resin layer film; wherein the curing agent B is ultrafine 4,4'-diaminodiphenyl sulfone (DDS).

[0110] Prepare a film from the resin mixture of the high-toughness epoxy resin layer, and control the film surface density to 62g / m 2 , thus obtaining the high-toughness, high-temperature curing epoxy resin layer film;

[0111] S3 composite molding

[0112] The reinforcing fiber and the prepared high-toughness, high-temperature curing epoxy resin layer film are placed in a hot melt film prepreg machine for a stacking and compounding process, so that the low-viscosity epoxy resin of the high-toughness, high-temperature curing epoxy resin layer film penetrates into the fiber surface of the reinforcing fiber, and the ultrafine toughening agent particles of the high-toughness, high-temperature curing epoxy resin layer film are retained on the fiber layer surface of the reinforcing fiber, thereby obtaining a prepreg fiber with a high-toughness, high-temperature curing epoxy resin layer film; wherein, the primary compounding temperature is 98°C, and the primary compounding gap (the hot roller gap of the hot melt film prepreg machine, the same below) is 0.2mm; wherein the reinforcing fiber is a high-strength medium modulus carbon fiber (CCF800S).

[0113] The prepared high-viscosity surface layer adhesive film and pre-impregnated fiber are taken to the hot melt adhesive film pre-impregnation equipment for secondary lamination. The secondary compounding temperature is 80 ° C, and the gap of the secondary compounding is 0.3 mm. After compounding, it is cut according to size to obtain a high-toughness high-temperature curing epoxy resin prepreg with a width of 6.350 ± 0.127 mm for automatic fiber placement.

[0114] The performance test of the prepared prepreg was carried out in the same manner as in Example 1. The physical performance test results of the final test are shown in the attached Figure 1 , the test results of the composite materials are attached Figure 2 .

[0115] Example 3

[0116] A high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement is prepared by the following steps:

[0117] S1 Preparation of high-adhesion surface film

[0118] At room temperature, 100 parts by weight of epoxy resin A and 5 parts by weight of film-forming agent were weighed and poured into a planetary disperser for mixing and stirring. During stirring, the temperature was raised to 150°C and kept warm for 1 hour for melt mixing; wherein epoxy resin A is a mixture of 60 parts by weight of epoxy resin E-51 and 40 parts by weight of epoxy resin E-20, and the film-forming agent is polyaryletherketone (PEK-C).

[0119] After the melt mixing is completed, the temperature is lowered to below 80°C, and 5 parts by weight of toughening agent A and 15 parts by weight of curing agent A are added simultaneously, stirred evenly, and then ground to obtain a resin mixture for the surface layer film; wherein the toughening agent A is VP-401 and the curing agent A is ultrafine 4,4'-diaminodiphenyl sulfone.

[0120] The resin mixture of the surface layer film was prepared by a three-roll mill to control the film thickness to 50 μm and the surface density to 8 g / m 2 , and the high-viscosity surface layer film is obtained.

[0121] S2 Preparation of high toughness high temperature curing epoxy resin layer film

[0122] At room temperature, 100 parts by weight of epoxy resin B and 30 parts by weight of toughening agent B were weighed, and 100 parts by weight of epoxy resin B and 15 parts by weight of toughening agent B were mixed and stirred. During stirring, the temperature was raised to 150° C. and kept warm for 1 hour for melt mixing; wherein the epoxy resin B is a mixture of 30 parts by weight of bisphenol A type epoxy resin E-51, 50 parts by weight of trifunctional low-viscosity epoxy resin S-510, and 20 parts by weight of tetrafunctional epoxy resin AG-80, and the toughening agent B is polyethersulfone.

[0123] After the melt mixing is completed, the temperature is lowered to below 80° C., and the remaining weight parts of toughening agent B and 32 weight parts of curing agent B are added, stirred evenly and then ground to obtain a resin mixture of a high-toughness epoxy resin layer film; wherein the curing agent B is ultrafine 4,4'-diaminodiphenyl sulfone (DDS).

[0124] Prepare a film from the resin mixture of the high-toughness epoxy resin layer, and control the film surface density to 64g / m 2 , thus obtaining the high-toughness, high-temperature curing epoxy resin layer film;

[0125] S3 composite molding

[0126] The reinforcing fiber and the prepared high-toughness, high-temperature curing epoxy resin layer film are placed in a hot melt film prepreg machine for a stacking and compounding process, so that the low-viscosity epoxy resin of the high-toughness, high-temperature curing epoxy resin layer film penetrates into the fiber surface of the reinforcing fiber, and the ultrafine toughening agent particles of the high-toughness, high-temperature curing epoxy resin layer film are retained on the fiber layer surface of the reinforcing fiber, thereby obtaining a prepreg fiber with a high-toughness, high-temperature curing epoxy resin layer film; wherein, the primary compounding temperature is 98°C, and the primary compounding gap (the hot roller gap of the hot melt film prepreg machine, the same below) is 0.2mm; wherein the reinforcing fiber is a high-strength medium modulus carbon fiber (CCF800S).

[0127] The prepared high-viscosity surface layer adhesive film and pre-impregnated fiber are taken to the hot melt adhesive film pre-impregnation equipment for secondary lamination. The secondary compounding temperature is 80 ° C, and the gap of the secondary compounding is 0.3 mm. After compounding, it is cut according to size to obtain a high-toughness high-temperature curing epoxy resin prepreg with a width of 6.350 ± 0.127 mm for automatic fiber placement.

[0128] The performance test of the prepared prepreg was carried out in the same manner as in Example 1. The physical performance test results of the final test are shown in the attached Figure 1 , the test results of the composite materials are attached Figure 2 .

[0129] Example 4

[0130] A high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement is prepared by the following steps:

[0131] S1 Preparation of high-adhesion surface film

[0132] At room temperature, 100 parts by weight of epoxy resin A and 5 parts by weight of film-forming agent were weighed and poured into a planetary disperser for mixing and stirring. During stirring, the temperature was raised to 150°C and kept warm for 1 hour for melt mixing; wherein epoxy resin A is a mixture of 70 parts by weight of epoxy resin E-44 and 30 parts by weight of epoxy resin E-20, and the film-forming agent is polyarylethersulfone (PES-C).

[0133] After the melt mixing is completed, the temperature is lowered to below 80°C, and 5 parts by weight of toughening agent A and 8 parts by weight of curing agent A are added simultaneously, stirred evenly, and then ground to obtain a resin mixture for the surface layer film; wherein the toughening agent A is VP-501E and the curing agent A is ultrafine dicyandiamide.

[0134] The resin mixture of the surface layer film was prepared by a three-roll mill to control the film thickness to 40 μm and the surface density to 8 g / m 2 , and the high-viscosity surface layer film is obtained.

[0135] S2 Preparation of high toughness high temperature curing epoxy resin layer film

[0136] 100 parts by weight of epoxy resin B and 30 parts by weight of toughener B were weighed at room temperature, 100 parts by weight of epoxy resin B and 15 parts by weight of toughener B were taken and mixed and stirred, and the temperature was raised to 150° C. during stirring and kept warm for 1 hour for melt mixing; wherein the epoxy resin B is a mixture of 30 parts by weight of bisphenol A type epoxy resin E-51, 50 parts by weight of trifunctional low-viscosity epoxy resin S-510, and 20 parts by weight of tetrafunctional epoxy resin AG-80, and the toughener B is polyethersulfone (5003P, Sumitomo, Japan).

[0137] After the melt mixing is completed, the temperature is lowered to below 80° C., and the remaining weight parts of toughening agent B and 32 weight parts of curing agent B are added, stirred evenly and then ground to obtain a resin mixture of a high-toughness epoxy resin layer film; wherein the curing agent B is ultrafine 4,4'-diaminodiphenyl sulfone (DDS).

[0138] Prepare a film from the resin mixture of the high-toughness epoxy resin layer, and control the film surface density to 64g / m 2 , thus obtaining the high-toughness, high-temperature curing epoxy resin layer film;

[0139] S3 composite molding

[0140] The reinforcing fiber and the prepared high-toughness, high-temperature curing epoxy resin layer film are placed in a hot melt film prepreg machine for a stacking and compounding process, so that the low-viscosity epoxy resin of the high-toughness, high-temperature curing epoxy resin layer film penetrates into the fiber surface of the reinforcing fiber, and the ultrafine toughening agent particles of the high-toughness, high-temperature curing epoxy resin layer film are retained on the fiber layer surface of the reinforcing fiber, thereby obtaining a prepreg fiber with a high-toughness, high-temperature curing epoxy resin layer film; wherein, the primary compounding temperature is 98°C, and the primary compounding gap (the hot roller gap of the hot melt film prepreg machine, the same below) is 0.2mm; wherein the reinforcing fiber is a high-strength medium modulus carbon fiber (CCF800S).

[0141] The prepared high-viscosity surface layer adhesive film and pre-impregnated fiber are taken to the hot melt adhesive film pre-impregnation equipment for secondary lamination. The secondary compounding temperature is 80 ° C, and the gap of the secondary compounding is 0.3 mm. After compounding, it is cut according to size to obtain a high-toughness high-temperature curing epoxy resin prepreg with a width of 6.350 ± 0.127 mm for automatic fiber placement.

[0142] The performance test of the prepared prepreg was carried out in the same manner as in Example 1. The physical performance test results of the final test are shown in the attached Figure 1 , the test results of the composite materials are attached Figure 2 .

[0143] Example 5

[0144] A high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement is prepared by the following steps:

[0145] S1 Preparation of high-adhesion surface film

[0146] At room temperature, 100 parts by weight of epoxy resin A and 5 parts by weight of film-forming agent were weighed and poured into a planetary disperser for mixing and stirring. During stirring, the temperature was raised to 150°C and kept warm for 1 hour for melt mixing; wherein the epoxy resin A was a mixture of 70 parts by weight of epoxy resin E-44 and 30 parts by weight of epoxy resin F-44, and the film-forming agent was carboxyl nitrile rubber.

[0147] After the melt mixing is completed, the temperature is lowered to below 80°C, and 5 parts by weight of toughening agent A and 8 parts by weight of curing agent A are added simultaneously, stirred evenly, and then ground to obtain a resin mixture for the surface layer film; wherein the toughening agent A is VP-501E and the curing agent A is ultrafine dicyandiamide.

[0148] The resin mixture of the surface layer film was prepared by a three-roll mill to control the film thickness to 40 μm and the surface density to 8 g / m 2 , and the high-viscosity surface layer film is obtained.

[0149] S2 Preparation of high toughness high temperature curing epoxy resin layer film

[0150] 100 parts by weight of epoxy resin B and 30 parts by weight of toughening agent B were weighed at room temperature, and 100 parts by weight of epoxy resin B and 15 parts by weight of toughening agent B were mixed and stirred. During stirring, the temperature was raised to 150° C. and kept warm for 1 hour for melt mixing; wherein the epoxy resin B is a mixture of 40 parts by weight of bisphenol A type epoxy resin E-54, 40 parts by weight of epoxy resin TDE-85, and 20 parts by weight of tetrafunctional epoxy resin AG-80, and the toughening agent B is polyethersulfone (5003P, Sumitomo, Japan).

[0151] After the melt mixing is completed, the temperature is lowered to below 80° C., and the remaining weight parts of toughening agent B and 32 weight parts of curing agent B are added, stirred evenly and then ground to obtain a resin mixture of a high-toughness epoxy resin layer film; wherein the curing agent B is ultrafine 4,4'-diaminodiphenyl sulfone (DDS).

[0152] Prepare a film from the resin mixture of the high-toughness epoxy resin layer, and control the film surface density to 64g / m 2 , thus obtaining the high-toughness, high-temperature curing epoxy resin layer film;

[0153] S3 composite molding

[0154] The reinforcing fiber and the prepared high-toughness, high-temperature curing epoxy resin layer film are placed in a hot melt film prepreg machine for a stacking and compounding process, so that the low-viscosity epoxy resin of the high-toughness, high-temperature curing epoxy resin layer film penetrates into the fiber surface of the reinforcing fiber, and the ultrafine toughening agent particles of the high-toughness, high-temperature curing epoxy resin layer film are retained on the fiber layer surface of the reinforcing fiber, thereby obtaining a prepreg fiber with a high-toughness, high-temperature curing epoxy resin layer film; wherein, the primary compounding temperature is 98°C, and the primary compounding gap (the hot roller gap of the hot melt film prepreg machine, the same below) is 0.2mm; wherein the reinforcing fiber is a high-strength medium modulus carbon fiber (CCF800S).

[0155] The prepared high-viscosity surface layer adhesive film and pre-impregnated fiber are taken to the hot melt adhesive film pre-impregnation equipment for secondary lamination. The secondary compounding temperature is 80 ° C, and the gap of the secondary compounding is 0.3 mm. After compounding, it is cut according to size to obtain a high-toughness high-temperature curing epoxy resin prepreg with a width of 6.350 ± 0.127 mm for automatic fiber placement.

[0156] The performance test of the prepared prepreg was carried out in the same manner as in Example 1. The physical performance test results of the final test are shown in the attached Figure 1 , the test results of the composite materials are attached Figure 2 .

[0157] Comparative Example 1

[0158] A conventional toughened high-temperature curing epoxy resin prepreg is prepared by the following steps:

[0159] Weigh bisphenol A epoxy resin E-51, bisphenol A epoxy resin E-20, trifunctional low-viscosity epoxy S-510, tetrafunctional epoxy resin AG-80, and toughening agent polyethersulfone (5003P, Sumitomo, Japan) into a planetary disperser, heat and stir, raise the temperature to 150°C, keep warm for 2 hours to melt the toughening agent polyethersulfone, mix evenly, cool to below 80°C, add the curing agent ultrafine 4,4'-diaminodiphenyl sulfone (DDS), and stir evenly. Grind the mixture 3-4 times on a three-roll mill to obtain a resin mixture for the high-toughness epoxy resin layer film. The weight ratio of the above components is:

[0160] Epoxy resin E-51:E-20:S-510:AG-80=30:20:30:20

[0161] Polyethersulfone (5003P, Sumitomo, Japan): 30

[0162] DDS: 31

[0163] Film preparation: The film was prepared using a film preparation device. The coating temperature was 68°C to control the film layer. The surface density was 72g / m 2 .

[0164] Prepreg preparation: In the impregnation machine of the hot melt adhesive film prepreg machine, high-strength medium-modulus carbon fiber CCF800S and adhesive film are selected for compounding. The compounding temperature is 110°C and the gap between the hot rollers is 0.40mm to obtain a high-toughness, high-temperature cured epoxy resin carbon fiber prepreg.

[0165] The prepreg was cut into widths using a slitting machine to obtain conventional toughened high-temperature curing epoxy resin prepregs with a width of 6.350±0.127 mm.

[0166] The performance test of the prepared prepreg was carried out in the same manner as in Example 1. The physical performance test results of the final test are shown in the attached Figure 1 , the test results of the composite materials are attached Figure 2 .

[0167] Comparative Example 2

[0168] A conventional toughened high-temperature curing epoxy resin prepreg is prepared by the following steps:

[0169] Weigh bisphenol A epoxy resin E-54, bisphenol A epoxy resin E-12, trifunctional low-viscosity epoxy AFG-90, epoxy resin F-51, and toughening agent polyethersulfone (5003P, Sumitomo, Japan) into a planetary disperser, heat and stir, raise the temperature to 150°C, hold for 2 hours to melt the toughening agent polyethersulfone, mix thoroughly, cool to below 80°C, add curing agent dicyandiamide, and stir thoroughly. Grind the mixture 3-4 times on a three-roll mill to obtain a resin mixture for a high-toughness epoxy resin film. The weight ratio of the above components is:

[0170] Epoxy resin E-51:E-20:S-510:AG-80=30:20:30:20

[0171] Polyethersulfone (5003P, Sumitomo, Japan): 30

[0172] Dicyandiamide: 8

[0173] Film preparation: The film was prepared using a film preparation device. The coating temperature was 68°C to control the film layer. The surface density was 72g / m 2 .

[0174] Prepreg preparation: In the impregnation machine of the hot melt adhesive film prepreg machine, high-strength medium-modulus carbon fiber CCF800S and adhesive film are selected for compounding. The compounding temperature is 110°C and the gap between the hot rollers is 0.40mm to obtain a high-toughness, high-temperature cured epoxy resin carbon fiber prepreg.

[0175] The prepreg was cut into widths using a slitting machine to obtain conventional toughened high-temperature curing epoxy resin prepregs with a width of 6.350±0.127 mm.

[0176] The performance test of the prepared prepreg was carried out in the same manner as in Example 1. The physical performance test results of the final test are shown in the attached Figure 1 , the test results of the composite materials are attached Figure 2 .

[0177] Based on Example 1-Example 5, Comparative Example 1-Comparative Example 2, and the attached Figure 1 and attached Figure 2 It can be seen that:

[0178] The corresponding products of Examples 1-5 implemented using the technical solution of the present invention have comprehensive physical properties that meet the requirements of use, especially their better viscosity, which is more adaptable to the use of automatic wire placement technology. At the same time, the comprehensive mechanical properties of their materials are far higher than those of conventional products, especially their post-impact compressive strength and glass transition temperature Tg are far greater than those of conventional products, which proves that their overall comprehensive performance such as toughness, modulus and heat resistance is outstanding, and they are suitable for the automated manufacturing of large composite materials for various aerospace vehicles such as civil aviation and launch vehicles.

[0179] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement, characterized in that: The overall structure is a layered structure, which is composed of a high-viscosity surface layer film, a high-toughness high-temperature curing epoxy resin layer film and a reinforcing fiber layer composited in sequence using a hot melt film method.

2. The high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement according to claim 1, characterized in that: The high-viscosity surface layer adhesive film is composed of the following components in parts by weight: in, The epoxy value of the epoxy resin A is 0.1 to 0.

35.

3. The high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement according to claim 2, characterized in that: The epoxy resin A is one or a combination of any two or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and novolac epoxy resin; The room temperature viscosity of the epoxy resin A is 100-500 Pa﹒s.

4. The high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement according to claim 2, characterized in that: The film-forming agent is one or a combination of any two or more of polysulfone ether, polysulfone, polyimide ether, polyketone ether, polyphenylene ether, polyaryletherketone, carboxyl nitrile rubber, random nitrile rubber, and polybutadiene rubber.

5. The high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement according to claim 2, characterized in that: The toughening agent A is ultrafine powder rubber.

6. The high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement according to claim 2, characterized in that: The curing agent A is superfine dicyandiamide, 3,3'-diaminodiphenyl sulfone or 4,4'-diaminodiphenyl sulfone.

7. The high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement according to claim 1, characterized in that: The high-toughness, high-temperature curing epoxy resin layer film is composed of the following components in parts by weight: Epoxy resin B 60-100 parts; Toughener B 20-50 parts; Curing agent B 18-50 parts; in, The epoxy value of the epoxy resin B is 0.4 to 0.

85.

8. The high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement according to claim 7, characterized in that: The epoxy resin B is one or a combination of any two or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, novolac epoxy resin, naphthalene epoxy resin, biphenyl resin, glycidylamine multifunctional epoxy resin, and glycidylester multifunctional epoxy resin.

9. The high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement according to claim 7, characterized in that: The curing agent B is nadic anhydride, methyl nadic anhydride, hydrogenated methyl nadic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylene glycol trimellitic anhydride, polysebacic anhydride, 3,3'-diaminodiphenyl sulfone (3,3'-DDS), 4,4'-diaminodiphenyl sulfone (4,4'-DDS), diaminodiphenylmethane, m-phenylenediamine, diaminodiphenyl ether, benzyldiamine, o-phenylenediamine, p-phenylenediamine, p-phenylenediamine, 9,9-bis(3-chlorophenyl)benzene, 9,9-bis(3-amino-4-hydroxyphenyl)benzene, dicyandiamide, phenolic resin, bismaleimide resin, cyanate ester resin, or a combination of any two or more substances.

10. The high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement according to claim 7, characterized in that: The toughening agent B is an ultrafine powder toughening agent, which is one or a combination of any two or more of rubber particles, ultrafine thermoplastic resin powder, phenoxy resin powder, core-shell particles, carbon nanotubes, ultrafine powder rubber, and silicon dioxide.

11. The high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement according to claim 1, characterized in that: The material of the reinforcing fiber layer is one or a combination of any two or more of E glass fiber or its fabric, S glass fiber or its fabric, quartz fiber or its fabric, aramid fiber or its fabric, LCP fiber or its fabric, polyimide fiber or its fabric, basalt fiber or its fabric, polyethylene fiber or its fabric, PBO fiber or its fabric, plant fiber or its fabric, T300 grade fiber or its fabric, T400 grade fiber or its fabric, T700 grade fiber or its fabric, T800 grade fiber or its fabric, T1100 grade fiber or its fabric, and high modulus fiber or its fabric.

12. A method for preparing high-toughness, high-temperature curing epoxy resin prepreg for automatic fiber placement, characterized in that: The following steps are involved: S1 Preparation of high-adhesion surface film At room temperature, 80 to 100 parts by weight of epoxy resin A and 2 to 20 parts by weight of a film-forming agent are weighed and mixed, and the temperature is raised to 120 to 180° C. and kept at this temperature for 0.8 to 1.2 hours to melt-mix. After the melt mixing is completed, the temperature is lowered to below 70-90°C, and 1-10 parts by weight of toughening agent A and 5-20 parts by weight of curing agent A are added simultaneously, stirred evenly, and then ground to obtain a resin mixture for the surface layer film; Prepare a film from the resin mixture of the surface film, controlling the film thickness to 5-100 μm and the surface density to 5-25 g / m 2 , thus obtaining the highly adhesive surface layer film; S2 Preparation of high toughness high temperature curing epoxy resin layer film Weigh 60-100 parts by weight of epoxy resin B and 20-50 parts by weight of toughening agent B at room temperature and stir them together. While stirring, heat them to 150-170°C and keep them warm for 1-2 hours to melt mix them. After the melt mixing is completed, the temperature is lowered to below 70°C to 90°C, 18 to 50 parts by weight of curing agent B is added, stirred evenly, and then ground to obtain a resin mixture of a high-toughness epoxy resin layer film; Taking the resin mixture of the high-toughness epoxy resin layer film to prepare a film, that is, obtaining the high-toughness high-temperature curing epoxy resin layer film; S3 composite molding The reinforcing fiber and the prepared high-toughness, high-temperature curing epoxy resin layer film are placed in a hot melt film prepreg device for a single layer lamination, so that the low-viscosity epoxy resin of the high-toughness, high-temperature curing epoxy resin layer film penetrates into the fiber surface of the reinforcing fiber, and the ultrafine toughening agent particles of the high-toughness, high-temperature curing epoxy resin layer film are retained on the fiber layer surface of the reinforcing fiber, thereby obtaining a prepreg fiber with a high-toughness, high-temperature curing epoxy resin layer film; wherein the primary lamination temperature is 90-110°C, and the primary lamination gap is 0.1-0.5mm; The prepared high-viscosity surface layer adhesive film and pre-impregnated fiber are taken to the hot melt adhesive film pre-impregnation equipment for secondary lamination and compounding. The secondary compounding temperature is 60-80°C, and the gap of the secondary compounding is 0.3-0.6mm. After compounding, the pre-impregnated fiber is cut into pieces according to size to obtain the high-toughness high-temperature curing epoxy resin prepreg for automatic fiber placement.

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