Epoxy resin composition as well as preparation method and application thereof

Abstract

The invention relates to an epoxy resin composition as well as a preparation method and application thereof. The epoxy resin composition comprises the following components in parts by weight: 35-80 parts of liquid epoxy resin, 30-70 parts of solid resin, 20-50 parts of a phenolic curing agent and 1-8 parts of a latent curing agent, the solid resin comprises solid epoxy resin; the softening point of the phenolic aldehyde curing agent is 60-90 DEG C. The epoxy resin composition provided by the invention has the characteristics of good flame retardant property, excellent mechanical property and long storage time by screening and compounding the components.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and particularly relates to an epoxy resin composition, a preparation method thereof, and an application thereof. Background Art

[0002] At present, hot-melt flame-retardant epoxy resin prepregs are generally divided into two types: halogenated flame-retardant epoxy resin prepregs and non-halogenated flame-retardant epoxy resin prepregs. Halogenated flame-retardant epoxy resin prepregs generally use brominated epoxy resins, which have relatively high flame-retardant efficiency and good mechanical properties. However, such halogenated flame-retardant epoxy resin prepregs usually have a relatively large smoke emission during combustion and are not suitable for occasions with relatively high requirements for smoke density, such as the rail transit field. At the same time, they are also restricted from being used in products with requirements for halogen content. Non-halogenated flame-retardant epoxy resin prepregs generally need to add a large amount of inorganic or organic additive flame retardants to meet the requirements of EN45545, FAR25.853, and UL94V0 for flame-retardant performance. However, their mechanical properties will deteriorate due to the addition of additive flame retardants.

[0003] CN114302907A provides a resin composition, which contains an epoxy resin, a curing agent, and an inorganic filler; the inorganic filler includes: magnesium hydroxide treated with silica, and the magnesium hydroxide treated with silica is magnesium hydroxide surface-treated with silica; and aluminum hydroxide. Although the resin composition obtains better flame-retardant performance due to the addition of the inorganic filler, its mechanical properties cannot be guaranteed.

[0004] Epoxy resin prepregs have wide applications in the composite material industry. The preparation methods are divided into hot-melt method and solvent method, and the hot-melt method is the most commonly used preparation method. Phenolic curing agents have good flame retardancy, but generally have relatively high softening points. When preparing prepregs by the hot-melt method, since phenolic curing agents and epoxy resins are generally mixed at relatively high temperatures, phenolic curing agents and epoxy resins are prone to react, resulting in a shorter normal-temperature storage life of the system, and the prepregs will lose their tackiness in a relatively short time. Therefore, on the premise of ensuring a relatively long storage time of the prepregs, it is an urgent problem to apply phenolic curing agents to prepregs.

[0005] Due to the problems that existing non-halogenated flame-retardant epoxy resin prepregs generally have poor mechanical properties due to the use of additive flame retardants, and the use of phenolic curing agents results in a shorter storage time, it is urgent to design an epoxy resin composition containing phenolic curing agents with good flame-retardant performance, excellent mechanical properties, and long storage time. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide an epoxy resin composition, a preparation method and an application thereof. Through the screening and compounding of each component, the epoxy resin composition has the characteristics of good flame retardancy, excellent mechanical properties and long storage time.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides an epoxy resin composition, which comprises the following components in parts by weight:

[0009]

[0010] The solid resin includes solid epoxy resin; the softening point of the phenolic curing agent is 60-90 °C.

[0011] Through the compounding of each component, the epoxy resin composition provided by the present invention has good flame retardancy and mechanical properties. In addition, by limiting the softening point of the phenolic curing agent, the epoxy resin composition has a long storage time.

[0012] In the epoxy resin composition, the liquid epoxy resin is 35-80 parts by weight, for example, it can be 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight or 80 parts by weight, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0013] In the present invention, the dosage of the liquid epoxy resin needs to be controlled within a suitable range. If the dosage is too small, the epoxy resin composition will be too dry at room temperature, which is not conducive to impregnation. And the prepreg is required to be soft and sticky at room temperature, and the epoxy resin composition being too dry is not conducive to operation at room temperature. If the dosage of the liquid epoxy resin is too large, the viscosity of the epoxy resin composition will be too low, and at the same time, the proportion of the flame retardant component will decrease, resulting in poor flame retardancy of the epoxy resin composition.

[0014] The solid resin is 30-70 parts by weight, for example, it can be 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight or 70 parts by weight, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0015] The phenolic curing agent is 20 - 50 parts by weight, for example, it can be 20 parts by weight, 22 parts by weight, 25 parts by weight, 28 parts by weight, 30 parts by weight, 32 parts by weight, 35 parts by weight, 38 parts by weight, 40 parts by weight, 42 parts by weight, 45 parts by weight, 48 parts by weight or 50 parts by weight, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the said range.

[0016] The latent curing agent is 1 - 8 parts by weight, for example, it can be 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, 5 parts by weight, 5.5 parts by weight, 6 parts by weight, 6.5 parts by weight, 7 parts by weight, 7.5 parts by weight, etc., as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the said range.

[0017] The softening point of the phenolic curing agent is 60 - 90 °C, for example, it can be 60 °C, 62 °C, 65 °C, 68 °C, 70 °C, 75 °C, 80 °C, 85 °C, 88 °C or 90 °C, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the said range.

[0018] The following are the preferred technical solutions of the present invention, but do not limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0019] As a preferred technical solution, the viscosity of the epoxy resin composition at 70 °C is 12000 - 24000 cPs, for example, it can be 13000 cPs, 14000 cPs, 15000 cPs, 16000 cPs, 17000 cPs, 18000 cPs, 19000 cPs, 20000 cPs, 21000 cPs, 22000 cPs, 23000 cPs, etc.

[0020] Preferably, the liquid epoxy resin includes liquid bisphenol A epoxy resin and / or liquid bisphenol F epoxy resin.

[0021] Preferably, the epoxy equivalent of the liquid epoxy resin is 150 - 210, for example, it can be 155, 160, 165, 170, 175, 180, 185, 190, 195, 200 or 205, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the said range.

[0022] Preferably, the solid epoxy resin includes any one or a combination of at least two of solid bisphenol A epoxy resin, DOPO epoxy resin, or phenolic epoxy resin.

[0023] In the present invention, the DOPO epoxy resin can be obtained through the prior art. Exemplarily, the DOPO epoxy resin can be selected from YEP-570 of Guangdong Guangshan New Materials Co., Ltd.

[0024] Preferably, the epoxy equivalent of the solid epoxy resin is 250 - 2500, for example, it can be 300, 350, 400, 450, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, etc.

[0025] Preferably, the solid resin further includes a thermoplastic resin.

[0026] Preferably, the thermoplastic resin includes any one or a combination of at least two of phenoxy resin, polysulfone, polyamide-imide, or polyether ether ketone.

[0027] Preferably, the weight average molecular weight of the phenoxy resin is 50000 - 80000, for example, it can be 52000, 54000, 56000, 58000, 60000, 62000, 64000, 66000, 68000, 70000, 72000, 74000, 76000, 78000, etc.

[0028] Preferably, the mass percentage content of the thermoplastic resin in the solid resin is 1 - 6%, for example, it can be 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, etc.

[0029] Preferably, the phenolic curing agent includes any one or a combination of at least two of phenol-formaldehyde type phenolic resin, o-cresol novolak resin, XYLOK phenolic resin, or trifunctional phenol phenolic resin.

[0030] In the present invention, the phenolic curing agent can be obtained through the prior art. For example, the phenol-formaldehyde type phenolic resin can be selected from PFNH9080L of Hunan Jiashengde Materials Technology Co., Ltd.; the o-cresol novolak resin can be selected from PFNH9880L of Hunan Jiashengde Materials Technology Co., Ltd.; the XYLOK phenolic resin can be selected from PNH9780L of Hunan Jiashengde Materials Technology Co., Ltd.; the trifunctional phenol phenolic resin can be selected from TPNH9750L of Hunan Jiashengde Materials Technology Co., Ltd.

[0031] Preferably, the latent curing agent includes dicyandiamide curing agent.

[0032] Preferably, the epoxy resin composition further includes 1 - 10 parts by weight of a promoter, for example, it can be 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight or 10 parts by weight, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the scope.

[0033] Preferably, the promoter includes a modified urea promoter, such as any one or a combination of at least two of dichlorophenyl dimethylurea, phenyl dimethylurea, tolyl bisdimethylurea, p-chlorophenyl dimethylurea, 1,1-dimethyl-3-(3-trifluoromethylphenyl)urea or methylene diphenyl dimethylurea.

[0034] Preferably, the epoxy resin composition further includes 0.2 - 1 part by weight of an antifoaming agent, for example, it can be 0.25 part by weight, 0.3 part by weight, 0.35 part by weight, 0.4 part by weight, 0.45 part by weight, 0.5 part by weight, 0.55 part by weight, 0.6 part by weight, 0.65 part by weight, 0.7 part by weight, 0.75 part by weight, 0.8 part by weight, 0.85 part by weight, 0.9 part by weight, 0.95 part by weight, etc.

[0035] Preferably, the antifoaming agent includes a silicone-based antifoaming agent and / or a non-silicone-containing antifoaming agent.

[0036] In a second aspect, the present invention provides a method for preparing the epoxy resin composition as described in the first aspect, and the preparation method includes:

[0037] Mixing the liquid epoxy resin, solid resin, phenolic curing agent and latent curing agent uniformly to obtain the epoxy resin composition.

[0038] Preferably, the mixed materials further include a promoter and / or an antifoaming agent.

[0039] Preferably, the mixing method includes the following steps:

[0040] (1) Divide the solid resin into two parts and the liquid epoxy resin into two parts; perform a first mixing on the first part of the liquid epoxy resin and the first part of the solid resin to obtain a first mixture; perform a second mixing on the first mixture and the second part of the solid resin to obtain an epoxy resin intermediate;

[0041] Perform a third mixing on the second part of the liquid epoxy resin, the latent curing agent, optionally the promoter and optionally the antifoaming agent to obtain a curing agent slurry;

[0042] (2) Mix the epoxy resin intermediate with the phenolic curing agent for a fourth time to obtain a second mixture; mix the second mixture with the curing agent slurry for a fifth time to obtain the epoxy resin composition.

[0043] The preparation method of the epoxy resin composition provided by the present invention belongs to the hot melt method. The solid resin is divided into two parts, which can be divided according to the weight of the solid resin or according to the type of the solid resin (when the type of the solid resin is more than one). Exemplarily, when divided according to the weight of the solid resin, the two parts of the solid resin obtained have the same type, and the masses of the two parts of the solid resin can be the same or different; when divided according to the type of the solid resin, the two parts of the solid resin obtained have different types, and the masses of the two parts of the solid resin can be the same or different.

[0044] The liquid epoxy resin is divided into two parts, which can be divided according to the weight of the liquid epoxy resin or according to the type of the liquid epoxy resin (when the type of the liquid epoxy resin is more than one). Exemplarily, when divided according to the weight of the liquid epoxy resin, the two parts of the liquid epoxy resin obtained have the same type, and the masses of the two parts of the liquid epoxy resin can be the same or different; when divided according to the type of the liquid epoxy resin, the two parts of the liquid epoxy resin obtained have different types, and the masses of the two parts of the liquid epoxy resin can be the same or different.

[0045] Preferably, the mass ratio of the first part of the solid resin to the second part of the solid resin is 1:(4 - 50), for example, it can be 1:6, 1:8, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45 or 1:50, etc.

[0046] Preferably, the mass ratio of the first part of the liquid epoxy resin to the second part of the liquid epoxy resin is (2 - 10):1, for example, it can be 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, etc.

[0047] Preferably, the temperature of the first mixing is 120 - 160 °C, for example, it can be 125 °C, 130 °C, 135 °C, 140 °C, 145 °C, 150 °C or 155 °C, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0048] Preferably, the time for the first mixing is 1 - 4 h. For example, it can be 1 h, 1.1 h, 1.2 h, 1.3 h, 1.4 h, 1.5 h, 1.6 h, 1.7 h, 1.8 h, 1.9 h, 2 h, 2.5 h, 3 h, 3.5 h, or 4 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0049] Preferably, the temperature for the second mixing is 110 - 140 °C. For example, it can be 110 °C, 112 °C, 115 °C, 120 °C, 121 °C, 122 °C, 123 °C, 124 °C, 125 °C, 126 °C, 127 °C, 128 °C, 129 °C, 130 °C, 135 °C, or 140 °C, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0050] Preferably, the time for the second mixing is 1 - 4 h. For example, it can be 1 h, 1.2 h, 1.5 h, 1.8 h, 2 h, 2.2 h, 2.5 h, 2.8 h, 3 h, 3.2 h, 3.4 h, 3.6 h, 3.8 h, or 4 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0051] Preferably, the viscosity of the epoxy resin intermediate at 70 °C is 4000 - 9000 cPs. For example, it can be 4500 cPs, 5000 cPs, 5500 cPs, 6000 cPs, 6500 cPs, 7000 cPs, 7500 cPs, 8000 cPs, 8500 cPs, etc.

[0052] Preferably, the temperature for the third mixing is 20 - 40 °C. For example, it can be 22 °C, 24 °C, 26 °C, 28 °C, 30 °C, 32 °C, 34 °C, 36 °C, 38 °C, etc.

[0053] Preferably, the viscosity of the curing agent slurry at 50 °C is 1400 - 3500 cPs. For example, it can be 1500 cPs, 1600 cPs, 1800 cPs, 2000 cPs, 2200 cPs, 2400 cPs, 2600 cPs, 2800 cPs, 3000 cPs, 3200 cPs, 3400 cPs, etc.

[0054] Preferably, the temperature of the fourth mixing is 70 - 90°C, for example, it can be 70°C, 72°C, 74°C, 76°C, 78°C, 80°C, 82°C, 84°C, 86°C, 88°C or 90°C, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range.

[0055] Preferably, the time of the fourth mixing is 1 - 2 h, for example, it can be 1 h, 1.1 h, 1.2 h, 1.3 h, 1.4 h, 1.5 h, 1.6 h, 1.7 h, 1.8 h, 1.9 h or 2 h, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range.

[0056] Preferably, the temperature of the fifth mixing is 50 - 80°C, for example, it can be 50°C, 52°C, 55°C, 58°C, 60°C, 62°C, 65°C, 68°C, 70°C, 72°C, 75°C or 78°C, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range.

[0057] Preferably, the time of the fifth mixing is 5 - 20 min, for example, it can be 5 min, 6 min, 7 min, 8 min, 10 min, 12 min, 14 min, 16 min, 18 min or 20 min, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range.

[0058] In a third aspect, the present invention provides a prepreg, which includes a reinforcing material and an epoxy resin composition as described in the first aspect attached thereto after impregnation and drying.

[0059] Preferably, the reinforcing material includes any one of carbon fiber, glass fiber, aramid fiber or basalt fiber.

[0060] In a fourth aspect, the present invention provides a laminate, which includes at least one prepreg as described in the third aspect.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] The epoxy resin composition provided by the present invention has the characteristics of good flame retardancy, excellent mechanical properties and long storage time through the screening and compounding of each component. The prepreg prepared by using the epoxy resin composition provided by the present invention has a tensile strength of 66-78 MPa, a tensile modulus of 3120-3300 MPa, a fracture elongation of 2.8-3.5%, a flexural strength of 125-140 MPa, a flexural modulus of 3000-3200 MPa, and an impact strength of 20-30 kJ / m 2 . The storage time of the epoxy resin composition provided by the present invention at room temperature is 22-28 days, and the glass transition temperature is 115-126 °C. The laminate prepared by using the epoxy resin composition provided by the present invention has good flame retardancy. Detailed Embodiments

[0063] To facilitate the understanding of the present invention, the following examples are listed. Those skilled in the art should understand that the examples are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0064] The sources of some components in the examples and comparative examples are as follows:

[0065] (1) Liquid epoxy resin:

[0066] a. Liquid bisphenol A epoxy resin: NPEL-128 purchased from Kunshan Nan Ya, with an epoxy equivalent of 186;

[0067] b. Liquid bisphenol F epoxy resin: NPEF-170 purchased from Kunshan Nan Ya, with an epoxy equivalent of 170;

[0068] (2) Solid resin:

[0069] a. DOPO epoxy resin: YEP-570 purchased from Guangdong Guangshan, with an epoxy equivalent of 310;

[0070] b. Solid bisphenol A epoxy resin: NPES-601 from Kunshan Nan Ya, with an epoxy equivalent of 455; NPES-609 from Kunshan Nan Ya, with an epoxy equivalent of 2500;

[0071] c. Phenoxy resin: YP-50H purchased from Gabriel in the United States, with a weight average molecular weight of 52000;

[0072] (3) Dicyandiamide curing agent: ECURE 20 purchased from Shanghai Moman Chemical Co., Ltd.;

[0073] (4) Accelerator: DYHARD UR200, DYHARD UR300, DYHARDUR500 purchased from Shanghai Moman Chemical Co., Ltd.;

[0074] (5) o-Cresol novolac resin:

[0075] a. PFNH9880L purchased from Hunan Jiashengde Material Technology Co., Ltd., with a softening point of 75 - 85°C;

[0076] b. PFNH9880M purchased from Hunan Jiashengde Material Technology Co., Ltd., with a softening point of 95 - 105°C;

[0077] (6) XYLOK phenolic resin: PNH9780L purchased from Hunan Jiashengde Material Technology Co., Ltd., with a softening point of 70 - 75°C;

[0078] (7) Phenol - formaldehyde type phenolic resin: PFNH9080L purchased from Hunan Jiashengde Material Technology Co., Ltd., with a softening point of 75 - 85°C;

[0079] (8) Defoamer: BYKA - 530 purchased from BYK - Chemie;

[0080] (9) Carbon fiber woven cloth: 24K T300 purchased from Zhongfu Shenying, with a thickness of about 0.4 mm.

[0081] In the following examples and comparative examples, the viscosities and gel times of the corresponding substances in the examples and comparative examples were tested according to the following methods respectively:

[0082] (1) Viscosity: Measured using a Brookfield CAP2000 + cone - plate viscometer;

[0083] (2) Gel time: Using a CT - 2 type gel time tester produced by Lin'an Fengyuan, the time when the epoxy resin composition breaks during wire drawing is measured, which is the gel time.

[0084] Example 1

[0085] An epoxy resin composition, the epoxy resin composition comprises the following components by weight:

[0086]

[0087]

[0088] The preparation method of the epoxy resin composition comprises the following steps:

[0089] (1) Take 50 parts by weight of liquid bisphenol A epoxy resin NPEL - 128 and mix it with phenoxy resin YP - 50H, stir at 140°C for 1.5 h, and after the phenoxy resin YP - 50H is completely dissolved, obtain the first mixture;

[0090] The first mixture, DOPO epoxy resin YEP-570, and solid bisphenol A epoxy resin NPES-601 were stirred at 120 °C for 1 h until completely dissolved, filtered and placed in a container to obtain an epoxy resin intermediate; the viscosity of the epoxy resin intermediate was 6300 cPs at 70 °C;

[0091] At room temperature, the remaining liquid bisphenol A epoxy resin NPEL-128, dicyandiamide curing agent ECURE 20, accelerator DYHARD UR200, and defoamer BYKA-530 were stirred evenly in a planetary mixer, and after passing through a three-roll mill, a curing agent slurry was prepared for standby. The viscosity of the curing agent slurry was 2200 cPs at 50 °C;

[0092] (2) The epoxy resin intermediate was heated to 78 °C, and o-cresol novolac resin PFNH9880L was added, and stirred in a planetary mixer for 1.5 h until the o-cresol novolac resin PFNH9880L was completely dissolved to obtain a second mixture;

[0093] The second mixture was mixed with the curing agent slurry at room temperature, stirred at 70 °C for 10 min to obtain the epoxy resin composition, which was poured out and stored in a -18 °C cold storage; the viscosity of the epoxy resin composition was 14500 cPs at 70 °C, and the gel time was 580 s at 120 °C;

[0094] A prepreg and a laminate comprising the epoxy resin composition, and its preparation method is as follows:

[0095] The epoxy resin composition was impregnated with Zhongfu Shenying 24K T300 carbon fiber woven fabric at 65 °C, and the resin content was controlled to be 38% to obtain the prepreg;

[0096] Five sheets of the prepreg were laminated, and the laminated thickness was about 1.9 mm, and cured at 140 °C for 1 h using a hot press to obtain the laminate.

[0097] Example 2

[0098] An epoxy resin composition, the epoxy resin composition comprises the following components by weight:

[0099]

[0100] The preparation method of the epoxy resin composition comprises the following steps:

[0101] (1) Take 45 parts by weight of liquid bisphenol F epoxy resin NPEF-170 and mix it with phenoxy resin YP-50H. Stir at 140 °C for 1.5 h. After the phenoxy resin YP-50H is completely dissolved, add solid bisphenol A epoxy resin NPES-609 and stir for 1 h until completely dissolved to obtain the first mixture;

[0102] Mix the first mixture, DOPO epoxy resin YEP-570, and solid bisphenol A epoxy resin NPES-601, stir at 120 °C for 1 h until completely dissolved, filter and put it into a container to obtain an epoxy resin intermediate. The viscosity of the epoxy resin intermediate at 70 °C is 6850 cPs;

[0103] At room temperature, mix the remaining liquid bisphenol F epoxy resin NPEF-170, dicyandiamide curing agent ECURE20, accelerator DYHARD UR300, and defoaming agent BYKA-530 in a planetary mixer until evenly mixed, and then pass through a three-roll mill to prepare a curing agent slurry for standby. The viscosity of the curing agent slurry at 50 °C is 2050 cPs;

[0104] (2) Heat the epoxy resin intermediate to 75 °C, add phenol-formaldehyde type phenolic resin PFNH9080L, and stir in a planetary mixer for 1.5 h until the phenol-formaldehyde type phenolic resin PFNH9080L is completely dissolved to obtain the second mixture;

[0105] Mix the second mixture with the curing agent slurry at room temperature, stir at 72 °C for 10 min to obtain the epoxy resin composition, pour it out and store it in a -18 °C cold storage; the viscosity of the epoxy resin composition at 70 °C is 14900 cPs, and the gel time at 120 °C is 625 s;

[0106] A prepreg and a laminate containing the epoxy resin composition, and its preparation method is as follows:

[0107] Impregnate the epoxy resin composition with Zhongfu Shenying 24K T300 carbon fiber woven fabric at 65 °C, and control the resin content to be 40% to obtain the prepreg;

[0108] Stack 5 pieces of the prepreg, with the stack thickness of about 2.2 mm, and cure it at 140 °C for 1 h using a hot press to obtain the laminate.

[0109] Example 3

[0110] An epoxy resin composition, the epoxy resin composition includes the following components by weight:

[0111]

[0112]

[0113] The preparation method of the epoxy resin composition comprises the following steps:

[0114] (1) Take 40 parts by weight of liquid bisphenol A epoxy resin NPEL-128 and mix it with phenoxy resin YP-50H, stir at 140 °C for 1.5 h. After the phenoxy resin YP-50H is completely dissolved, add solid bisphenol A epoxy resin NPES-609 and continue stirring for 2.5 h to obtain a first mixture;

[0115] Mix the first mixture, DOPO epoxy resin YEP-570 and solid bisphenol A epoxy resin NPES-601, stir at 120 °C for 1 h until completely dissolved, filter and put it into a container to make an epoxy resin intermediate. The viscosity of the epoxy resin intermediate is 7300 cPs at 70 °C;

[0116] At room temperature, mix the remaining liquid bisphenol A epoxy resin NPEL-128, dicyandiamide curing agent ECURE 20, accelerator DYHARD UR500 and defoaming agent BYKA-530 evenly in a planetary mixer, and after passing through a three-roll mill, make a curing agent slurry for standby. The viscosity of the curing agent slurry is 1450 cPs at 50 °C;

[0117] (2) At 79 °C, mix the epoxy resin intermediate with XYLOK phenolic resin PNH9780L, stir in a planetary mixer for 1.5 h until the XYLOK phenolic resin PNH9780L is completely dissolved to obtain a second mixture;

[0118] Mix the second mixture with the curing agent slurry at room temperature, stir at 70 °C for 10 min to obtain the epoxy resin composition, pour it out and store it in a cold storage at -18 °C; the viscosity of the epoxy resin composition is 15200 cPs at 70 °C, and the gel time is 646 s at 120 °C;

[0119] A prepreg and a laminate comprising the epoxy resin composition, and its preparation method is:

[0120] Impregnate the epoxy resin composition and Zhongfu Shenying 24K T300 carbon fiber woven cloth at 65 °C, control the resin content to be 42% to obtain the prepreg;

[0121] Stack 5 pieces of the prepreg, the stack thickness is about 2.0 mm, and cure it at 130 °C for 2 h using a hot press to obtain the laminate.

[0122] Example 4

[0123] An epoxy resin composition, the epoxy resin composition comprising the following components by weight:

[0124]

[0125] The preparation method of the epoxy resin composition comprises the following steps:

[0126] (1) Take 37 parts by weight of liquid bisphenol A epoxy resin NPEL-128 and solid bisphenol A epoxy resin NPES-609, mix them, stir at 140 °C for 1 h, and wait for the solid bisphenol A epoxy resin NPES-609 to completely dissolve to obtain a first mixture;

[0127] Mix the first mixture with DOPO epoxy resin YEP-570, stir at 120 °C for 1 h until completely dissolved, filter and put it into a container to make an epoxy resin intermediate. The viscosity of the epoxy resin intermediate is 8900 cPs at 70 °C;

[0128] At room temperature, the remaining liquid bisphenol A epoxy resin NPEL-128, dicyandiamide curing agent ECURE 20, accelerator DYHARD UR500 and defoaming agent BYKA-530 are stirred evenly in a planetary mixer, and then passed through a three-roll mill to make a curing agent slurry for standby. The viscosity of the curing agent slurry is 3450 cPs at 50 °C;

[0129] (2) At 77 °C, mix the epoxy resin intermediate with XYLOK phenolic resin PNH9780L, stir in a planetary mixer for 1.5 h until the XYLOK phenolic resin PNH9780L is completely dissolved to obtain a second mixture;

[0130] Mix the second mixture with the curing agent slurry, stir at 72 °C for 10 min to obtain the epoxy resin composition, pour it out and store it in a cold storage at -18 °C; the viscosity of the epoxy resin composition is 15800 cPs at 70 °C, and the gel time is 670 s at 120 °C;

[0131] A prepreg and a laminate comprising the epoxy resin composition, and its preparation method is:

[0132] The epoxy resin composition is impregnated with Zhongfu Shenying 24K T300 carbon fiber woven fabric at 65 °C, and the resin content is controlled to be 40% to obtain the prepreg;

[0133] Stack 5 pieces of the prepreg, the stacking thickness is about 1.9 mm, and use a hot press to cure at 135 °C for 1.5 h to obtain the laminate.

[0134] Comparative Example 1

[0135] An epoxy resin composition and its preparation method, which is different from Example 1 in that the o-cresol novolac resin PFNH9880L is replaced with an equal mass of o-cresol novolac resin PFNH9880M, and the preparation method of the epoxy resin composition is as follows:

[0136] (1) Take 50 parts by weight of liquid bisphenol A epoxy resin NPEL-128 and mix it with phenoxy resin YP-50H, stir at 140 °C for 1.5 h. After the phenoxy resin YP-50H is completely dissolved, cool down to 120 °C, add DOPO epoxy resin YEP-570 and solid bisphenol A epoxy resin NPES-601, stir for 1 h until completely dissolved, add o-cresol novolac resin PFNH9880M, and stir in a planetary mixer at 120 °C for 1.5 h until the o-cresol novolac resin PFNH9880M is completely dissolved, filter and put it into a container to make an epoxy resin intermediate, whose viscosity at 70 °C is 23300 cPs;

[0137] At room temperature, mix the remaining liquid bisphenol A epoxy resin NPEL-128, dicyandiamide curing agent ECURE 20, accelerator DYHARD UR200 and defoaming agent BYKA-530 evenly in a planetary mixer, and after passing through a three-roll mill, make a curing agent slurry for standby, whose viscosity at 50 °C is 2200 cPs;

[0138] (2) Heat the epoxy resin intermediate to 70 °C, then add the curing agent slurry at room temperature, stir for 10 min to obtain the epoxy resin composition, pour it out and store it in a -18 °C cold storage; the viscosity of the epoxy resin composition at 70 °C is 15400 cPs, and the gel time at 120 °C is 620 s;

[0139] A prepreg and a laminate containing the epoxy resin composition, and its preparation method is the same as that of Example 1.

[0140] Comparative Example 2

[0141] An epoxy resin composition, the epoxy resin composition comprises the following components by weight:

[0142]

[0143] (1) Take 40 parts by weight of liquid bisphenol A epoxy resin NPEL-128 and mix it with phenoxy resin YP-50H, stir at 140 °C for 1.5 h. After the phenoxy resin YP-50H is completely dissolved, obtain a first mixture;

[0144] Mix the first mixture with solid bisphenol A epoxy resin NPES-601, stir at 120 °C for 1 h until completely dissolved, then add DOPO epoxy resin YEP-570, stir for 1 h until completely dissolved, add aluminum hydroxide and magnesium hydroxide, stir evenly, filter and put into a container to prepare an epoxy resin intermediate with a viscosity of 42200 cPs at 70 °C;

[0145] At room temperature, mix the remaining liquid bisphenol A epoxy resin NPEL-128, dicyandiamide curing agent ECURE 20, accelerator DYHARD UR200 and defoaming agent BYKA-530 evenly in a planetary mixer, and after passing through a three-roll mill, prepare a curing agent slurry for standby with a viscosity of 2050 cPs at 50 °C;

[0146] (2) Heat the epoxy resin intermediate to 85 °C, then add the curing agent slurry at room temperature, stir for 10 min to obtain the epoxy resin composition, pour out and store it in a -18 °C cold storage; the viscosity of the epoxy resin composition is 25760 cPs at 70 °C and the gel time is 826 s at 120 °C;

[0147] A prepreg and a laminate containing the epoxy resin composition are prepared in the same manner as in Example 1.

[0148] Performance testing

[0149] (1) Tensile strength: Test according to GB / T 2567;

[0150] (2) Tensile modulus: Test according to GB / T 2567;

[0151] (3) Elongation at break: Test according to GB / T 2567;

[0152] (4) Flexural strength: Test according to GB / T 2567;

[0153] (5) Flexural modulus: Test according to GB / T 2567;

[0154] (6) Impact strength: Test according to GB / T 2567;

[0155] (7) Storage time: Store at room temperature of 25 °C, use a Brookfield CAP2000+ cone-plate viscometer to test the viscosity, and the time when the viscosity doubles is the storage time;

[0156] (8) Tg: Test according to ASTM E1640;

[0157] (9) Flame retardancy test: Test according to UL94, EN45545-2, FAR25.853;

[0158] The prepregs provided in Examples 1-4 and Comparative Examples 1-2 were subjected to performance tests according to the above (1)-(6), and the epoxy resin compositions provided in Examples 1-4 and Comparative Examples 1-2 were tested according to the above (7)-(8). The test results are shown in Table 1; the laminates provided in Examples 1-4 and Comparative Examples 1-2 were subjected to performance tests according to (9), and the test results are shown in Table 2.

[0159] Table 1

[0160]

[0161]

[0162] It can be seen from the data in Table 1 that the epoxy resin compositions provided in Examples 1-4 have a longer storage time, and the prepregs prepared using the epoxy resin compositions provided in Examples 1-4 have good mechanical properties.

[0163] In Comparative Example 1, due to the use of a phenolic curing agent with a relatively high softening point, the process temperature was too high during production, resulting in more reaction between the phenolic curing agent and the epoxy resin. Therefore, the storage time of the epoxy resin composition was significantly shortened. In Comparative Example 2, due to the use of a large amount of inorganic fillers, the mechanical properties of the prepreg became poor, the strength was significantly reduced, and the impact toughness was very poor.

[0164] Table 2

[0165]

[0166] It can be seen from the data in Table 2 that the laminate prepared using the epoxy resin composition provided by the present invention has good flame retardancy.

[0167] The applicant declares that the present invention uses the above examples to illustrate the epoxy resin composition of the present invention, its preparation method and application, but the present invention is not limited to the above examples, that is, it does not mean that the present invention must rely on the above examples to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An epoxy resin composition, characterized in that The epoxy resin composition comprises the following components in parts by weight: The solid resin includes solid epoxy resin; the softening point of the phenolic curing agent is 60-90°C.

2. The epoxy resin composition according to claim 1, characterized in that The epoxy resin composition has a viscosity of 12000-24000 cPs at 70° C.; Preferably, the liquid epoxy resin comprises liquid bisphenol A epoxy resin and / or liquid bisphenol F epoxy resin; Preferably, the epoxy equivalent of the liquid epoxy resin is 150-210.

3. The epoxy resin composition according to claim 1 or 2, characterized in that The solid epoxy resin includes any one of solid bisphenol A epoxy resin, DOPO epoxy resin or novolac epoxy resin or a combination of at least two thereof; Preferably, the epoxy equivalent of the solid epoxy resin is 250-2500; Preferably, the solid resin further comprises a thermoplastic resin; Preferably, the thermoplastic resin comprises any one or a combination of at least two of phenoxy resin, polysulfone, polyamide-imide or polyetheretherketone; Preferably, the mass percentage of the thermoplastic resin in the solid resin is 1-6%.

4. The epoxy resin composition according to any one of claims 1 to 3, characterized in that The phenolic curing agent includes any one of phenol formaldehyde type phenolic resin, o-cresol phenolic resin, XYLOK phenolic resin or trifunctional phenolic resin or a combination of at least two thereof.

5. The epoxy resin composition according to any one of claims 1 to 4, characterized in that The latent curing agent includes a dicyandiamide curing agent; Preferably, the epoxy resin composition further comprises 1-10 parts by weight of an accelerator; Preferably, the accelerator includes any one or a combination of at least two of dichlorophenyl dimethyl urea, phenyl dimethyl urea, tolyl dimethyl urea, p-chlorophenyl dimethyl urea, 1,1-dimethyl-3-(3-trifluoromethylphenyl) urea or methylene diphenyl dimethyl urea; Preferably, the epoxy resin composition further comprises 0.2-1 parts by weight of a defoamer; Preferably, the defoaming agent includes a silicone-based defoaming agent and / or a defoaming agent that does not contain silicone.

6. A method for preparing the epoxy resin composition according to any one of claims 1 to 5, characterized in that: The preparation method comprises: The liquid epoxy resin, the solid resin, the phenolic curing agent and the latent curing agent are mixed uniformly to obtain the epoxy resin composition.

7. The preparation method according to claim 6, characterized in that: The mixed material also includes a accelerator and / or a defoamer; Preferably, the mixing method comprises the following steps: (1) dividing the solid resin into two parts, and dividing the liquid epoxy resin into two parts; performing a first mixing of the first part of the liquid epoxy resin and the first part of the solid resin to obtain a first mixture; The first mixture is mixed with a second portion of solid resin to obtain an epoxy resin intermediate; Mixing the second portion of liquid epoxy resin, the latent curing agent, optionally the accelerator, and optionally the defoaming agent for a third time to obtain a curing agent slurry; (2) performing a fourth mixing of the epoxy resin intermediate and the phenolic curing agent to obtain a second mixture; The second mixture is mixed with the curing agent slurry in a fifth step to obtain the epoxy resin composition.

8. The preparation method according to claim 7, characterized in that: The mass ratio of the first solid resin to the second solid resin is 1:(4-50); Preferably, the mass ratio of the first portion of liquid epoxy resin to the second portion of liquid epoxy resin is (2-10):1; Preferably, the temperature of the first mixing is 120-160°C; Preferably, the first mixing time is 1-4h; Preferably, the temperature of the second mixing is 110-140°C; Preferably, the second mixing time is 1-4h; Preferably, the viscosity of the epoxy resin intermediate at 70° C. is 4000-9000 cPs; Preferably, the temperature of the third mixing is 20-40°C; Preferably, the viscosity of the curing agent slurry at 50° C. is 1400-3500 cPs; Preferably, the temperature of the fourth mixing is 70-90°C; Preferably, the fourth mixing time is 1-2h; Preferably, the temperature of the fifth mixing is 50-80°C; Preferably, the fifth mixing time is 5-20 min.

9. A prepreg, characterized in that: The prepreg comprises a reinforcing material and the epoxy resin composition according to any one of claims 1 to 5 attached thereto after impregnation and drying.

10. A laminated board, characterized in that: The laminate comprises at least one prepreg according to claim 9.

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