Toughening resin and preparation method thereof, prepreg and preparation method thereof

Abstract

The invention provides toughened resin and a preparation method thereof, and a prepreg and a preparation method thereof, and relates to the technical field of prepregs. The toughened resin comprises the following raw materials in parts by weight: 80-100 parts of epoxy resin; 50 to 70 parts by weight of a bisphenol compound; 0.01-3 parts by weight of a catalyst; 30 to 65 parts by weight of a toughening agent; the toughening agent comprises first toughening particles and second toughening particles; wherein the volume average particle size of the first toughening particles is 5-10 [mu] m, and the volume average particle size of the second toughening particles is 10-15 [mu] m; the weight ratio of the first toughening particles to the second toughening particles is 1: (1.50-2.33). The toughened resin has good toughness, and can effectively improve the mechanical properties of the composite material prepared from the prepreg under the condition that the viscosity of the prepreg is not obviously increased.

Description

Technical Field

[0001] The present application relates to the technical field of prepregs, and in particular to a toughening resin and a preparation method thereof, a prepreg and a preparation method thereof. Background Art

[0002] Resin-based composite materials are fiber-reinforced materials based on thermosetting resins, thermoplastic resins, and modified or blended resins. They are usually prepared by impregnating the resin-based material into reinforcing fibers to obtain prepregs, and then curing and other treatments are performed to form a laminated board formed by laminating multiple prepregs. Among them, the resin-based material, as the core intermediate raw material of the composite material, plays a vital role in the surface molding effect and internal quality of the composite material.

[0003] Epoxy resin has become a common raw material for resin matrix materials because of its advantages such as high mechanical strength, strong adhesion, small curing shrinkage and good stability. However, since epoxy resin contains a large number of epoxy groups, the epoxy resin cured product is relatively brittle, which limits its application and development. In addition, the prepreg made from epoxy resin also affects the mechanical properties of the composite material made from the prepreg due to the high viscosity of the system and the uneven impregnation effect. Summary of the invention

[0004] The present application aims to provide a toughening resin and a preparation method thereof, a prepreg and a preparation method thereof. The toughening resin has good toughness and can effectively improve the mechanical properties of a composite material made from the prepreg without significantly increasing the viscosity of the prepreg.

[0005] According to a first aspect of the present application, a toughening resin is provided, comprising the following raw materials in parts by weight:

[0006] 80-100 parts by weight of epoxy resin;

[0007] 50-70 parts by weight of bisphenol compounds;

[0008] Catalyst 0.01-3 parts by weight;

[0009] 30 to 65 parts by weight of toughening agent;

[0010] The toughening agent includes first toughening particles and second toughening particles;

[0011] Wherein, the volume average particle size of the first toughening particles is 5 to 10 μm, and the volume average particle size of the second toughening particles is 10 to 15 μm;

[0012] The weight ratio of the first toughening particles to the second toughening particles is 1:(1.50-2.33).

[0013] In some embodiments of the present application, the weight ratio of the toughening agent to the epoxy resin is 1:(2.10-3.15).

[0014] In some embodiments of the present application, the weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin is 1:(2-2.25):(7.10-9.05).

[0015] In some embodiments of the present application, the ratio of the sum of the weight of the toughening agent and the bisphenol compound to the weight of the epoxy resin is 1:(0.9-1.1).

[0016] In some embodiments of the present application, the epoxy resin includes a combination of one or more of bisphenol A epoxy resin, bisphenol C epoxy resin, bisphenol F epoxy resin, and bisphenol S epoxy resin;

[0017] The bisphenol compound includes a combination of one or more of bisphenol A, bisphenol C, bisphenol F, bisphenol P, bisphenol S, and hydroxymethylated bisphenol A;

[0018] The catalyst comprises a combination of one or more of potassium persulfate, ethyltriphenylphosphonium bromide and triethanolamine.

[0019] According to a second aspect of the present application, a method for preparing a toughened resin is provided, comprising:

[0020] The epoxy resin and the bisphenol compound are mixed, the temperature is raised to a first preset temperature, and stirred for a first preset time to obtain a first mixture;

[0021] Adding the toughening agent to the first mixture, stirring at a second preset temperature for a second preset time, to obtain a second mixture;

[0022] The catalyst is added to the second mixture, and the mixture is stirred at a third preset temperature for a third preset time to obtain the toughened resin.

[0023] In some embodiments of the present application, the first preset temperature is 50-130° C., and the first preset time is 90-180 min;

[0024] The second preset temperature is 90-120°C, and the second preset time is 30-60 minutes;

[0025] The third preset temperature is 70-150° C., and the third preset time is 20-40 minutes.

[0026] According to a third aspect of the present application, a prepreg is provided, comprising:

[0027] A first toughening layer, a first resin layer, a reinforcing fiber layer, a second resin layer and a second toughening layer are stacked;

[0028] Wherein, the first toughening layer and the second toughening layer are coated with the toughening resin mentioned above.

[0029] In some embodiments of the present application, the surface density of the first toughening layer and the second toughening layer is 20 to 50 g / m 2 ;

[0030] The surface density of the first resin layer and the second resin layer is 20 to 50 g / m 2 ;

[0031] The surface density of the reinforcing fiber layer is 80 to 200 g / m 2 .

[0032] According to a fourth aspect of the present application, a method for preparing a prepreg is provided, comprising:

[0033] Covering the first resin layer and the second resin layer on the upper surface and the lower surface of the reinforcing fiber layer respectively to obtain a first intermediate;

[0034] The first toughening layer and the second toughening layer are respectively coated on the upper surface and the lower surface of the first intermediate body to obtain the prepreg.

[0035] The technical solution provided by the present application may include the following beneficial effects: the toughening resin of the present application has good toughness and can effectively improve the mechanical properties of the composite material made from the prepreg without significantly increasing the viscosity of the prepreg.

[0036] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0038] Figure 1 The present invention is a flow chart of a method for preparing a toughened resin according to an exemplary embodiment.

[0039] Figure 2 is a schematic diagram of a layer structure of a prepreg according to an exemplary embodiment.

[0040] Figure 3 It is a schematic flow chart of a method for preparing a prepreg according to an exemplary embodiment.

[0041] Reference numerals

[0042] 1. First toughening layer; 2. First resin layer; 3. Reinforced fiber layer; 4. Second resin layer; 5. Second toughening layer. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the present application will be clearly and completely described below in combination with the embodiments of the present application and the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be arbitrarily combined with each other.

[0044] The present application provides a toughening resin, comprising an epoxy resin, a bisphenol compound, a catalyst and a toughening agent, wherein the toughening agent is a combination of first toughening particles with a volume average particle size of 5 to 10 μm and second toughening particles with a volume average particle size of 10 to 15 μm, and the weight ratio of the first toughening agent to the second toughening agent is 1:(1.50 to 2.33). The toughened resin thus obtained has good toughness and can effectively improve the mechanical properties of a composite material made from a prepreg without significantly increasing the viscosity of the prepreg.

[0045] In an exemplary embodiment, the present application provides a toughened resin, comprising the following raw materials in parts by weight:

[0046]

[0047] The toughening agent includes first toughening particles and second toughening particles;

[0048] The volume average particle size of the first toughening particles is 5 to 10 μm, and the volume average particle size of the second toughening particles is 10 to 15 μm;

[0049] The weight ratio of the first toughening particles to the second toughening particles is 1:(1.50-2.33).

[0050] In this embodiment, by combining a bisphenol compound, a catalyst, a toughening agent and an epoxy resin, and compounding the first toughening particles with a volume average particle size of 5 to 10 μm and the second toughening particles with a volume average particle size of 10 to 15 μm in a weight ratio of 1: (1.50 to 2.33) as a toughening agent, the toughened resin thus obtained has good toughness and can effectively improve the mechanical properties of the composite material made from the prepreg without significantly increasing the viscosity of the prepreg.

[0051] Exemplarily, in one embodiment, the toughening resin includes the following raw materials in parts by weight:

[0052] 80 parts by weight of epoxy resin; 50 parts by weight of bisphenol compound; 0.01 parts by weight of catalyst; 30 parts by weight of toughening agent; the toughening agent comprises first toughening particles and second toughening particles; wherein the volume average particle size of the first toughening particles is 5 μm, and the volume average particle size of the second toughening particles is 10 μm; the weight ratio of the first toughening particles to the second toughening particles is 1:1.50.

[0053] In one embodiment, the toughening resin includes the following raw materials in parts by weight:

[0054] 90 parts by weight of epoxy resin; 60 parts by weight of bisphenol compound; 1 part by weight of catalyst; 45 parts by weight of toughening agent; the toughening agent comprises first toughening particles and second toughening particles; wherein the volume average particle size of the first toughening particles is 6 μm, and the volume average particle size of the second toughening particles is 12 μm; the weight ratio of the first toughening particles to the second toughening particles is 1:2.00.

[0055] In one embodiment, the toughening resin includes the following raw materials in parts by weight:

[0056] 100 parts by weight of epoxy resin; 70 parts by weight of bisphenol compound; 3 parts by weight of catalyst; 65 parts by weight of toughening agent; the toughening agent comprises first toughening particles and second toughening particles; wherein the volume average particle size of the first toughening particles is 10 μm, and the volume average particle size of the second toughening particles is 15 μm; the weight ratio of the first toughening particles to the second toughening particles is 1:2.33.

[0057] As a toughening component in prepreg, toughening agent can improve the toughness of prepreg. In related technologies, toughening agent is mostly thermoplastic resin such as polyethylene and polyethersulfone. Although such toughening agent can improve the problem of poor toughness of prepreg to a certain extent, adding a small amount will also cause the viscosity of prepreg to increase significantly, making the fluidity and impregnation effect of prepreg poor, affecting the comprehensive properties of composite materials such as strength and fatigue resistance.

[0058] The toughening agent in the present application is made of thermoplastic plastic as a base material, and is prepared by emulsification reaction with an organic solvent and an aqueous solution of polyvinyl alcohol. It should be noted that the first toughening particles and the second toughening particles in the toughening agent have the same chemical composition, and the only difference is the volume average particle size of the two.

[0059] In an exemplary embodiment, the toughening agent is prepared by the following method:

[0060] Weigh 63kg of chloroform and 27kg of methanol into a container, heat to 30°C and stir until uniform; then add 11kg of thermoplastic (CXT9413 / Shandong Xianglong New Materials), stir and dissolve to obtain a first dispersion system; weigh 100kg of a polyvinyl alcohol solution consisting of 7kg of polyvinyl alcohol and 93kg of deionized water, drop it into the first dispersion system at a rate of 0.3kg / min, stir until the system presents a uniform milky white emulsion, and obtain a second dispersion system; distill the second dispersion system at a vacuum degree of -0.09MPa for 8h to remove the organic solvent, wash the obtained slurry with water, classify it, and perform particle size classification to obtain a first screening intermediate with a volume average particle size of 5-10μm and a second screening intermediate with a volume average particle size of 10-15μm. The obtained first screening intermediate and second screening intermediate are rinsed and diluted with 65°C hot water. After solid-liquid separation and drying treatment of the first sieved intermediate and the second sieved intermediate, first toughening particles and second toughening particles are obtained.

[0061] In this embodiment, the toughening agent prepared by the above method has good compatibility with the epoxy resin and can improve the toughness of the epoxy resin.

[0062] In an exemplary embodiment, the weight ratio of the toughening agent to the epoxy resin is 1:(2.10-3.15).

[0063] In this embodiment, by controlling the weight ratio of the toughening agent to the epoxy resin to be 1:(2.10-3.15), the toughened resin thus obtained can have the advantages of high mechanical strength and good toughness. For example, the weight ratio of the toughening agent to the epoxy resin is 1:2.10, 1:2.95 or 1:3.15.

[0064] In an exemplary embodiment, the weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin is 1: (2-2.25): (7.10-9.05). Exemplarily, the weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin is 1: 2.00: 7.10. It can be understood that the weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin can also be other ratios within the above range. For example, the weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin is 1: 2.15: 8.25. Alternatively, the weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin is 1: 2.25: 9.05.

[0065] In an exemplary embodiment, the ratio of the sum of the weight of the toughening agent and the bisphenol compound to the weight of the epoxy resin is 1:(0.9-1.1). Exemplarily, the ratio of the sum of the weight of the toughening agent and the bisphenol compound to the weight of the epoxy resin is 1:0.9, 1:1.05 or 1:1.1.

[0066] In an exemplary embodiment, the epoxy resin includes a combination of one or more of bisphenol A epoxy resin, bisphenol C epoxy resin, bisphenol F epoxy resin, and bisphenol S epoxy resin;

[0067] The bisphenol compound includes a combination of one or more of bisphenol A, bisphenol C, bisphenol F, bisphenol P, bisphenol S, and hydroxymethylated bisphenol A;

[0068] The catalyst includes a combination of one or more of potassium persulfate, ethyltriphenylphosphonium bromide, and triethanolamine.

[0069] Epoxy resin is the main material of toughening resin, and it plays an important role in the mechanical properties of toughening resin. Bisphenol A epoxy resin is the largest and most widely used variety in epoxy resin, and its cured product has high strength, bonding strength and corrosion resistance, but its toughness and heat resistance are not high. Bisphenol C epoxy resin is an epoxy resin synthesized with bisphenol C as raw material. Compared with bisphenol A epoxy resin, bisphenol C epoxy resin has better tensile strength and bending strength. Bisphenol F epoxy resin has good mechanical properties, and compared with bisphenol A epoxy resin, it has the advantage of low viscosity. Bisphenol S epoxy resin has better flexural performance, compression resistance and thermal stability compared with bisphenol A epoxy resin due to the introduction of -SO2- polar group. In the present embodiment, epoxy resin can be selected from one of bisphenol A epoxy resin, bisphenol C epoxy resin, bisphenol F epoxy resin and bisphenol S epoxy resin. In order to have all the properties of epoxy resin, the epoxy resin in the present embodiment can also be used in combination with the above-mentioned several types of epoxy resin. For example, the epoxy resin includes bisphenol A epoxy resin and bisphenol C epoxy resin. Or, the epoxy resin includes bisphenol A epoxy resin, bisphenol F epoxy resin and bisphenol S epoxy resin. Or, the epoxy resin includes bisphenol A epoxy resin, bisphenol C epoxy resin, bisphenol F epoxy resin and bisphenol S epoxy resin.

[0070] In this embodiment, the bisphenol compound can be one of bisphenol A, bisphenol C, bisphenol F, bisphenol P, bisphenol S, and hydroxymethylated bisphenol A, or a combination of multiple of the above compounds. For example, the bisphenol compound is bisphenol A and bisphenol C. Alternatively, the bisphenol compound is bisphenol A, bisphenol C, and bisphenol F. Alternatively, the bisphenol compound is bisphenol A, bisphenol C, bisphenol F, bisphenol P, bisphenol S, and hydroxymethylated bisphenol A.

[0071] In this embodiment, the catalyst can be one of potassium persulfate, ethyl triphenyl phosphonium bromide, and triethanolamine, or a combination of multiple of the above catalysts. For example, the catalyst is potassium persulfate and ethyl triphenyl phosphonium bromide. Alternatively, the catalyst is ethyl triphenyl phosphonium bromide and triethanolamine.

[0072] In an exemplary embodiment, referring to Figure 1 , the present application provides a method for preparing a toughened resin, comprising:

[0073] S110, mixing the epoxy resin and the bisphenol compound, heating to a first preset temperature, and stirring for a first preset time to obtain a first mixture.

[0074] In step S110, the epoxy resin and the bisphenol compound are first mixed to improve the uniformity of the toughening resin raw material.

[0075] Among them, the first preset temperature is 50-130°C, and the first preset time is 90-180min. The first preset temperature can also be 80-130°C, and the first preset time can also be 90-120min. Exemplarily, the first preset temperature is 50°C, and the first preset time is 180min. It can be understood that the first preset temperature and the first preset time can also be other values ​​within the above range. For example, the first preset temperature is 80°C, and the first preset time is 120min. Alternatively, the first preset temperature is 130°C, and the first preset time is 90min.

[0076] S120, adding a toughening agent to the first mixture, and stirring at a second preset temperature for a second preset time to obtain a second mixture.

[0077] In step S120, a toughening agent is added to the first mixture, so that the toughening agent can be evenly and stably dispersed in the first mixture.

[0078] Among them, the second preset temperature is 90-120°C, and the second preset time is 30-60 minutes. Exemplarily, the second preset temperature is 90°C, and the second preset time is 60 minutes. It can be understood that the second preset temperature and the second preset time can also be other values ​​within the above range. For example, the second preset temperature is 105°C, and the second preset temperature is 45 minutes. Alternatively, the second preset temperature is 120°C, and the second preset time is 30 minutes.

[0079] S130, adding a catalyst to the second mixture, stirring at a third preset temperature for a third preset time to obtain a toughened resin.

[0080] In step S130, after the epoxy resin is mixed with the bisphenol compound and the toughening agent, a catalyst is added to avoid catalyst deactivation, thereby increasing the reaction rate of the toughening resin during curing.

[0081] Among them, the third preset temperature is 70-150°C, and the third preset time is 20-40min. The third preset temperature can also be 90-120°C, and the third preset time can also be 25-30min. Exemplarily, the third preset temperature is 70°C, and the third preset time is 40min. It can be understood that the third preset temperature and the second preset time can also be other values ​​within the above range. For example, the third preset temperature is 90°C, and the third preset time is 30min. Alternatively, the third preset temperature is 120°C, and the third preset time is 25min. Alternatively, the third preset temperature is 150°C, and the third preset time is 20min.

[0082] In an exemplary embodiment, referring to Figure 2 , the present application provides a prepreg, comprising:

[0083] A first toughening layer 1, a first resin layer 2, a reinforcing fiber layer 3, a second resin layer 4 and a second toughening layer 5 are stacked;

[0084] The first toughening layer 1 and the second toughening layer 5 are coated with the toughening resin.

[0085] In this embodiment, the first micron-sized toughening particles and the second toughening particles are introduced into the epoxy resin system to obtain a toughened resin; in the subsequent preparation process of the prepreg and the composite material, the micron-sized particles remain between the two layers of the reinforcing fiber layer 3 to play a role in interlayer toughening. The micron-sized particles enter the reinforcing fiber layer 3 under pressure. Since the micron-sized particles have a small size effect and a special surface effect, they can form an ideal bonding interface with the epoxy resin and the reinforcing fiber, forming a good interface interaction to improve the impact resistance of the composite material.

[0086] In this embodiment, the first resin layer 2 and the second resin layer 4 are formed by coating a resin matrix. The coating method includes the following steps: putting a toughening resin into a coating machine, uniformly coating the toughening resin on a release paper at a temperature of 90° C., and cooling to room temperature to obtain a first toughening layer 1 and a second toughening layer 5. It should be noted that in this embodiment, the chemical compositions of the first toughening layer 1 and the second toughening layer 5 may be the same or different.

[0087] In an exemplary embodiment, the reinforcing fiber layer 3 is formed by continuous reinforcing fibers, reinforcing fiber fabrics or chopped reinforcing fibers, etc., wherein the reinforcing fibers may be carbon fibers, glass fibers, aramid fibers, etc. For example, the reinforcing fibers may be SYT49S-12K carbon fibers produced by Zhongfu Shenying Carbon Fiber Co., Ltd., with a linear density of 800 g / km and a monofilament diameter of 7 μm.

[0088] In an exemplary embodiment, the first resin layer 2 and the second resin layer 4 are formed by coating a resin matrix, and the resin matrix includes the following raw materials in parts by weight:

[0089] Resin 50-100 parts by weight;

[0090] 5 to 50 parts by weight of curing agent.

[0091] In this embodiment, the first resin layer 2 and the second resin layer 4 are formed by coating a resin matrix. The coating method includes the following steps: putting the resin matrix into a coating machine, uniformly coating the resin matrix on a release paper at a temperature of 70° C., and cooling to room temperature to obtain the first resin layer 2 and the second resin layer 4. It should be noted that the chemical compositions of the first resin layer 2 and the second resin layer 4 in this embodiment may be the same or different.

[0092] Illustratively, in one embodiment, the resin matrix includes the following raw materials in parts by weight: 50 parts by weight of resin; and 5 parts by weight of curing agent.

[0093] In one embodiment, the resin matrix includes the following raw materials in parts by weight: 80 parts by weight of resin; and 10 parts by weight of curing agent.

[0094] In one embodiment, the resin matrix includes the following raw materials in parts by weight: 100 parts by weight of resin; and 50 parts by weight of curing agent.

[0095] Since the first toughening layer 1 and the second toughening layer 5 are respectively provided on the surfaces of the first resin layer 2 and the second resin layer 4 in the prepreg of the present application, a good toughening effect can be achieved, so the raw materials of the resin matrix can only be resin and curing agent. It can be understood that in order to make the composite material have better toughness, the above-mentioned toughening agent of the present application can also be added to the resin matrix.

[0096] In an exemplary embodiment, the resin includes a combination of one or more of bisphenol A epoxy resin, bisphenol C epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin or modified epoxy resin. The curing agent includes a combination of one or two of an amine curing agent and a phenolic curing agent. It should be noted that the type of the resin in the resin matrix and the epoxy resin in the toughening resin may be the same or different.

[0097] In this embodiment, by controlling the thickness ratio of each layer, the composite material formed by curing the prepreg has good comprehensive properties.

[0098] In an exemplary embodiment, the surface density of the first toughening layer 1 and the second toughening layer 5 is 20-50 g / m 2 The surface density of the first resin layer 2 and the second resin layer 4 is 20 to 50 g / m 2; The surface density of the reinforcing fiber layer 3 is 80 to 200 g / m 2 .

[0099] For example, the surface density of the first toughening layer 1 and the second toughening layer 5 is 20 g / m 2 The surface density of the first resin layer 2 and the second resin layer 4 is 20g / m 2 ; The surface density of the reinforcing fiber layer 3 is 80g / m 2 It can be understood that the surface density of the first toughening layer 1, the second toughening layer 5, the first resin layer 2, the second resin layer 4 and the reinforcing fiber layer 3 can also be other values ​​within the above range. For example, the surface density of the first toughening layer 1 and the second toughening layer 5 is 30g / m 2 The surface density of the first resin layer 2 and the second resin layer 4 is 30g / m 2 ; The surface density of the reinforcing fiber layer 3 is 140g / m 2 Alternatively, the surface density of the first toughening layer 1 and the second toughening layer 5 is 50 g / m 2 The surface density of the first resin layer 2 and the second resin layer 4 is 50g / m 2 ; The surface density of the reinforcing fiber layer 3 is 200g / m 2 .

[0100] In an exemplary embodiment, referring to Figure 3 , the present application provides a method for preparing a prepreg, comprising:

[0101] S210, covering the first resin layer 2 and the second resin layer 4 on the upper surface and the lower surface of the reinforcing fiber layer 3 respectively to obtain a first intermediate.

[0102] In step S210, the first resin layer 2 and the second resin layer 4 are respectively coated on the upper surface and the lower surface of the reinforcing fiber layer 3, and the temperature of the hot pressing roller is adjusted to 100°C and the impregnation pressure is adjusted to 3kg / cm, so as to obtain a first intermediate.

[0103] S220, coating the first toughening layer 1 and the second toughening layer 5 on the upper surface and the lower surface of the first intermediate respectively to obtain a prepreg.

[0104] In step S220, the first toughening layer 1 and the second toughening layer 5 are respectively coated on the upper surface and the lower surface of the first intermediate body, and the temperature of the hot pressing roller is adjusted to 100°C and the impregnation pressure is adjusted to 3kg / cm, so as to obtain a prepreg.

[0105] The specific implementation methods of the present application are further described below in conjunction with preferred embodiments, and examples of preferred value ranges of each component in the toughening resin provided in the present application are explained in detail.

[0106] Preferred Example 1

[0107] A toughening resin comprises the following raw materials in parts by weight:

[0108] 80-100 parts by weight of epoxy resin;

[0109] 50-70 parts by weight of bisphenol compounds;

[0110] Catalyst 0.01-3 parts by weight;

[0111] 30 to 65 parts by weight of toughening agent;

[0112] The toughening agent includes first toughening particles and second toughening particles;

[0113] The volume average particle size of the first toughening particles is 5 to 10 μm, and the volume average particle size of the second toughening particles is 10 to 15 μm;

[0114] The weight ratio of the first toughening particles to the second toughening particles is 1:(1.50-2.33).

[0115] Preferred Example 2

[0116] A toughening resin comprises the following raw materials in parts by weight:

[0117] 80-100 parts by weight of epoxy resin;

[0118] 50-70 parts by weight of bisphenol compounds;

[0119] Catalyst 0.01-3 parts by weight;

[0120] 30 to 65 parts by weight of toughening agent;

[0121] The toughening agent includes first toughening particles and second toughening particles;

[0122] The volume average particle size of the first toughening particles is 5 to 10 μm, and the volume average particle size of the second toughening particles is 10 to 15 μm;

[0123] The weight ratio of the first toughening particles to the second toughening particles is 1:(1.50-2.33);

[0124] The weight ratio of the toughening agent to the epoxy resin is 1:(2.10-3.15).

[0125] Preferred Example 3

[0126] A toughening resin comprises the following raw materials in parts by weight:

[0127]

[0128] The toughening agent includes first toughening particles and second toughening particles;

[0129] The volume average particle size of the first toughening particles is 5 to 10 μm, and the volume average particle size of the second toughening particles is 10 to 15 μm;

[0130] The weight ratio of the first toughening particles to the second toughening particles is 1:(1.50-2.33);

[0131] The weight ratio of toughening agent to epoxy resin is 1:(2.10-3.15);

[0132] The weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin is 1:(2-2.25):(7.10-9.05).

[0133] Preferred Example 4

[0134] A toughening resin comprises the following raw materials in parts by weight:

[0135]

[0136] The toughening agent includes first toughening particles and second toughening particles;

[0137] The volume average particle size of the first toughening particles is 5 to 10 μm, and the volume average particle size of the second toughening particles is 10 to 15 μm;

[0138] The weight ratio of the first toughening particles to the second toughening particles is 1:(1.50-2.33);

[0139] The weight ratio of toughening agent to epoxy resin is 1:(2.10-3.15);

[0140] The weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin is 1:(2-2.25):(7.10-9.05);

[0141] The ratio of the sum of the weight of the toughening agent and the bisphenol compound to the weight of the epoxy resin is 1:(0.9-1.1).

[0142] Preferred Example 5

[0143] A toughening resin comprises the following raw materials in parts by weight:

[0144] Epoxy resin 90-100 parts by weight;

[0145] 50-60 parts by weight of bisphenol compounds;

[0146] Catalyst 0.1-1.0 parts by weight;

[0147] 30 to 45 parts by weight of toughening agent;

[0148] The toughening agent includes first toughening particles and second toughening particles;

[0149] The volume average particle size of the first toughening particles is 5 to 10 μm, and the volume average particle size of the second toughening particles is 10 to 15 μm;

[0150] The weight ratio of the first toughening particles to the second toughening particles is 1:(1.50-2.33);

[0151] The weight ratio of toughening agent to epoxy resin is 1:(2.10-3.15);

[0152] The weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin is 1:(2-2.25):(7.10-9.05);

[0153] The ratio of the sum of the weight of the toughening agent and the bisphenol compound to the weight of the epoxy resin is 1:(0.9-1.1).

[0154] The method for preparing the toughened resin of preferred examples 1 to 5 comprises:

[0155] Mixing the epoxy resin and the bisphenol compound, heating to a first preset temperature, and stirring for a first preset time to obtain a first mixture;

[0156] Adding a toughening agent to the first mixture, stirring at a second preset temperature for a second preset time to obtain a second mixture;

[0157] A catalyst is added to the second mixture, and the mixture is stirred at a third preset temperature for a third preset time to obtain a toughened resin.

[0158] In order to more clearly explain the technical solution of the present application, the present application lists specific examples of toughened resins, and the beneficial effects of selecting the above-mentioned ranges of the contents of each component will be explained by providing specific experimental data through specific examples.

[0159] Example A1

[0160] A toughening resin is prepared by the following method:

[0161] (1) 100 kg of bisphenol A epoxy resin and 60 kg of bisphenol A were mixed, the temperature was raised to 110° C., and stirred for 100 min to obtain a first mixture.

[0162] (2) Add 30 kg of toughening agent to the first mixture, and stir at 110° C. for 45 min to obtain a second mixture.

[0163] (3) Add 1 kg of catalyst potassium persulfate to the second mixture, and stir at 110° C. for 20 min to obtain a toughened resin.

[0164] In order to more clearly explain the technical solution of the present application, the present application also lists Examples A2-A6 of toughened resin, wherein the formulas of Examples A2-A6 are shown in Table 1. It should be noted that in Examples A2-A6, except for the parameters listed in Table 1, the other parameters are the same as those of Example A1.

[0165] In Table 1, the meanings of ratio C1, ratio C2, ratio C3, and ratio C4 are as follows:

[0166] The ratio C1 is the weight ratio of the first toughening particles to the second toughening particles;

[0167] The ratio C2 is the weight ratio of toughening agent to epoxy resin;

[0168] The ratio C3 is the weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin;

[0169] The ratio C4 is the ratio of the sum of the weights of the toughening agent and the bisphenol compound to the weight of the epoxy resin.

[0170] Table 1 Raw material dosage of toughening resin of Examples A1-A6 (unit: kg)

[0171]

[0172] In Examples A1-A6, the toughening agent includes first toughening particles and second toughening particles, wherein the volume average particle size of the first toughening particles is 5-10 μm, and the volume average particle size of the second toughening particles is 10-15 μm.

[0173] Preparation of the first toughening layer and the second toughening layer: The toughening resin prepared in Examples A1-A6 was put into the resin tank of the coating machine, and the toughening resin was evenly coated on the release paper at a coating temperature of 90°C to obtain a surface density of 15 g / m 2 The first toughening layer and the second toughening layer have the same chemical composition.

[0174] Preparation of the first resin layer and the second resin layer: 20 kg of bisphenol A, 30 kg of bisphenol S epoxy resin and 70 kg of bisphenol A epoxy resin were mixed, heated to 120°C and dissolved, and then 0.1 kg of potassium persulfate was added, the temperature was raised to 180°C and the reaction was maintained for 3 hours to obtain a modified epoxy resin.

[0175] 120 kg of modified epoxy resin, 50 kg of bisphenol A epoxy resin, and 45 kg of 4,4'-diaminodiphenyl sulfone were mixed, heated to 70° C. and dissolved to obtain a resin matrix.

[0176] The resin matrix was put into the coating machine and evenly coated on the release paper at a temperature of 70°C. After cooling to room temperature, the surface density was 25g / m 2 The first resin layer and the second resin layer have the same chemical composition.

[0177] The first toughening layer, the second toughening layer, the first resin layer, the second resin layer and the reinforcing fiber layer composed of carbon fibers prepared by the above method are prepared to have a surface density of 110 g / m 2 The prepreg is prepared by:

[0178] The first resin layer and the second resin layer are respectively coated on the upper surface and the lower surface of the reinforcing fiber layer, and the temperature of the hot pressing roller is adjusted to 100°C and the impregnation pressure is 3kg / cm, so as to obtain a first intermediate. The first toughening layer and the second toughening layer are respectively coated on the upper surface and the lower surface of the first intermediate, and the temperature of the hot pressing roller is adjusted to 100°C and the impregnation pressure is 3kg / cm, so as to obtain a prepreg.

[0179] Table 2 shows specific examples B1-B6 of prepregs composed of toughened resin and carbon fiber according to examples A1-A6 in the present application.

[0180] Comparative Example 1: The main difference between this comparative example and Example B1 is that the toughening resin is prepared by the following method:

[0181] (1) 100 kg of bisphenol A epoxy resin and 60 kg of bisphenol A were mixed, the temperature was raised to 110° C., and stirred for 100 min to obtain a first mixture.

[0182] (2) Add 30 kg of toughening agent polyethersulfone to the first mixture, and stir at 110° C. for 45 min to obtain a second mixture.

[0183] (3) Add 1 kg of catalyst potassium persulfate to the second mixture, and stir at 110° C. for 20 min to obtain a toughened resin.

[0184] Performance Testing

[0185] According to the method of GB / T21239-2007 "Test method for compression performance of fiber reinforced plastic laminates after impact", the prepregs prepared by Examples B1-B6 and Comparative Example 1 were made into laminates, and the performance of the laminates was tested. The test results are recorded in Table 2.

[0186] Table 2 Performance test table of samples of Examples B1-B6 and Comparative Example 1

[0187]

[0188] According to the data in Table 2, it can be seen that the post-impact compressive strength of the laminate prepared by the prepreg of the embodiment of the present application is significantly higher than the post-impact compressive strength of the laminate in Comparative Example 1, indicating that the toughening resin of the present application can improve the toughness of the laminate made of the prepreg.

[0189] According to the data in Table 2 and in combination with Examples B1-B6, it can be seen that the amount and proportion of each raw material in the toughening resin have a significant effect on the mechanical properties of the laminated board made from the prepreg, among which the laminated boards made from Examples B1 and B6 have better comprehensive properties.

[0190] In summary, the toughening resin prepared using the raw material ratio of the present application has a good toughening effect on the prepreg, and can effectively improve the mechanical properties of the composite material made from the prepreg without significantly increasing the viscosity of the prepreg; and by controlling the thickness ratio of each layer of the prepreg, the mechanical properties of the composite material made from the prepreg can be further improved.

[0191] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0192] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application is described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A toughening resin, characterized in that: The invention comprises the following raw materials in parts by weight: 80-100 parts by weight of epoxy resin; 50-70 parts by weight of bisphenol compounds; Catalyst 0.01-3 parts by weight; 30 to 65 parts by weight of toughening agent; The toughening agent includes first toughening particles and second toughening particles; Wherein, the volume average particle size of the first toughening particles is 5 to 10 μm, and the volume average particle size of the second toughening particles is 10 to 15 μm; The weight ratio of the first toughening particles to the second toughening particles is 1:(1.50-2.33).

2. The toughened resin according to claim 1, characterized in that The weight ratio of the toughening agent to the epoxy resin is 1:(2.10-3.15).

3. The toughened resin according to claim 1, characterized in that The weight ratio of the first toughening particles, the second toughening particles, and the epoxy resin is 1:(2-2.25):(7.10-9.05).

4. The toughened resin according to claim 1, characterized in that The ratio of the sum of the weight of the toughening agent and the bisphenol compound to the weight of the epoxy resin is 1:(0.9-1.1).

5. The toughened resin according to claim 1, characterized in that The epoxy resin includes a combination of one or more of bisphenol A epoxy resin, bisphenol C epoxy resin, bisphenol F epoxy resin, and bisphenol S epoxy resin; The bisphenol compound includes a combination of one or more of bisphenol A, bisphenol C, bisphenol F, bisphenol P, bisphenol S, and hydroxymethylated bisphenol A; The catalyst comprises a combination of one or more of potassium persulfate, ethyltriphenylphosphonium bromide and triethanolamine.

6. A method for preparing a toughened resin according to any one of claims 1 to 5, characterized in that: include: The epoxy resin and the bisphenol compound are mixed, the temperature is raised to a first preset temperature, and stirred for a first preset time to obtain a first mixture; Adding the toughening agent to the first mixture, stirring at a second preset temperature for a second preset time, to obtain a second mixture; The catalyst is added to the second mixture, and the mixture is stirred at a third preset temperature for a third preset time to obtain the toughened resin.

7. The method for preparing the toughened resin according to claim 6, characterized in that: The first preset temperature is 50-130° C., and the first preset time is 90-180 minutes; The second preset temperature is 90-120°C, and the second preset time is 30-60 minutes; The third preset temperature is 70-150° C., and the third preset time is 20-40 minutes.

8. A prepreg, characterized in that: include: A first toughening layer, a first resin layer, a reinforcing fiber layer, a second resin layer and a second toughening layer are stacked; Wherein, the first toughening layer and the second toughening layer are coated with the toughening resin according to any one of claims 1 to 5.

9. The prepreg according to claim 8, characterized in that The surface density of the first toughening layer and the second toughening layer is 20 to 50 g / m 2 ; The surface density of the first resin layer and the second resin layer is 20 to 50 g / m 2 ; The surface density of the reinforcing fiber layer is 80 to 200 g / m 2 .

10. A method for preparing a prepreg according to any one of claims 8 to 9, characterized in that: include: Covering the first resin layer and the second resin layer on the upper surface and the lower surface of the reinforcing fiber layer respectively to obtain a first intermediate; The first toughening layer and the second toughening layer are respectively coated on the upper surface and the lower surface of the first intermediate body to obtain the prepreg.

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