Resin composition, method for preparing glass fiber prepreg and application of glass fiber prepreg

Abstract

The invention relates to the technical field of glass fiber prepregs, and discloses a resin composition, a method for preparing a glass fiber prepreg and application of the glass fiber prepreg. The composition contains bisphenol F type epoxy resin, glycidyl ether type epoxy resin, a toughening agent and a curing agent, the degree of functionality of the glycidyl ether type epoxy resin is 3-4; the glycidyl ether type epoxy resin contains rigid functional groups; the weight ratio of the bisphenol F type epoxy resin to the glycidyl ether type epoxy resin is (1-5): 1. The glass fiber prepreg composition provided by the invention has the characteristics of moderate viscosity, weaker thixotropy and larger yield value, and is not sticky to a net and easy to clean when being applied to a prepreg silk-screen process, and the prepared prepreg is dry, not sticky to hands, good in flatness and excellent in storage stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of glass fiber prepreg, in particular to a resin composition, a method for preparing a glass fiber prepreg and the application of the glass fiber prepreg. BACKGROUND

[0002] The glass fiber prepreg is a kind of composite material taking glass fiber as reinforcing material and various polymer resins as resin matrix, which is widely used in various fields due to its strong plasticity and strength.

[0003] The existing glass fiber prepreg is mainly divided into epoxy resin system, unsaturated polyester resin system and phenolic resin system according to different resin systems. Among them, the epoxy resin glass fiber prepreg occupies the mainstream position in the market due to its excellent mechanical properties and bonding properties.

[0004] The main production process of the glass fiber prepreg at present is mainly in the form of "prepreg-rolling-drying". The prepreg produced by this production method is difficult to control in surface flatness due to the influence of the penetration difference between the formula components and the uneven force in the rolling process, and is prone to appear corrugation and wrinkle. Moreover, the prepreg produced by this production mode still needs to be cut into different shapes by cutting machine in the subsequent processing process, which causes great waste of resin.

[0005] The prepreg prepared by silk printing process can have specific pattern and higher thickness uniformity, but most prepregs applied in silk printing process will produce sticky net, which causes the problem of difficult cleaning of the screen plate.

[0006] Therefore, it is very meaningful to develop a new type of prepreg to solve the above problems. SUMMARY

[0007] The purpose of the present application is to overcome the problems of sticky net, uneven thickness and difficult cleaning of the screen plate caused by the traditional prepreg formula composition used in silk printing process.

[0008] In order to achieve the above purpose, the first aspect of the present application provides a resin composition, which contains bisphenol F type epoxy resin, glycidyl ether type epoxy resin, toughening agent and curing agent.

[0009] The number average molecular weight of the bisphenol F type epoxy resin is 400-900; the number average molecular weight of the toughening agent is 400-800.

[0010] The functionality of the glycidyl ether type epoxy resin is 3-4; and the glycidyl ether type epoxy resin contains rigid functional groups.

[0011] The weight ratio of the bisphenol F type epoxy resin to the glycidyl ether type epoxy resin is 1-5:1.

[0012] The second aspect of the present application provides a method for preparing a glass fiber prepreg, which is performed by using the components in the composition of the aforementioned first aspect, comprising:

[0013] (1) mixing a bisphenol F epoxy resin, a glycidyl ether epoxy resin, a toughening agent, and a curing agent to obtain a resin composition;

[0014] (2) silk printing the resin composition on a glass fiber cloth to obtain the glass fiber prepreg.

[0015] The third aspect of the present application provides the use of the glass fiber prepreg prepared by the method of the aforementioned second aspect in a glass fiber shell.

[0016] Compared with the prior art, the technical solution provided by the present application has at least the following beneficial effects:

[0017] (1) The resin composition provided by the present application uses a bisphenol F epoxy resin with moderate molecular weight as the main resin, utilizes its static viscoelasticity characteristics to make the resin glue slowly penetrate into the glass fiber to form a flat resin layer after silk printing; uses a multi-functional branched rigid glycidyl ether resin as an auxiliary resin to improve its dynamic viscoelasticity, so that the silk printing process is drip-free, screen-free, and easy to clean; introduces a toughening agent with a molecular weight matching that of the bisphenol F epoxy resin, so that the toughening agent has good compatibility with the main epoxy resin, effectively preventing the surface from sticking due to the migration of low molecular substances.

[0018] (2) The main resin and the auxiliary resin are used in a specific ratio (the weight ratio of the bisphenol F epoxy resin to the glycidyl ether epoxy resin is 1-5:1), which fully utilizes the low viscosity and high penetration of the bisphenol F epoxy resin, increases the content of epoxy groups, improves the reaction activity, and increases the crosslinking density. Under this ratio, the resin composition has good rheological properties, and the crosslinking reaction between the resins is promoted.

[0019] (3) The curing agent is added to form a complete resin composition, which has moderate viscosity, weak thixotropy, and large yield value. When applied to the silk printing prepreg process, it does not stick to the screen and is easy to clean. The prepared prepreg is dry, not sticky, has uniform thickness, good flatness, and good storage stability. The prepared glass fiber prepreg has the excellent characteristics of lightweight and high surface flatness when applied to a glass fiber shell.

[0020] ACCOMPA

[0021] Figure 1 is a cross-sectional view of the glass fiber prepreg prepared by Example 1 (left) and Comparative Example 1 (right) of the present application;

[0022] Figure 2 Surface images of glass fiber prepreg prepared from Example 1 (left) and Comparative Example 1 (right) of the present application. DETAILED DESCRIPTION

[0023] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not critical to the present application. Any numerical value, however, can be expressed as a range to include any and all subranges therebetween. The ranges of values are intended to cover all ranges including endpoints. For values having a minimum and maximum value, this range is intended to cover all hardware implementations of that range having a minimum value equal to any of the minimum values or having a maximum value equal to any of the maximum values.

[0024] As described above, the first aspect of the present application provides a resin composition comprising a bisphenol F type epoxy resin, a glycidyl ether type epoxy resin, a toughening agent and a curing agent;

[0025] The number average molecular weight of the bisphenol F type epoxy resin is 400-900; and the number average molecular weight of the toughening agent is 400-800.

[0026] The functionality of the glycidyl ether type epoxy resin is 3-4; and the glycidyl ether type epoxy resin contains a rigid functional group.

[0027] The weight ratio of the bisphenol F type epoxy resin to the glycidyl ether type epoxy resin is 1-5:1.

[0028] The components in the resin composition provided by the present application cooperate synergistically. Specifically, the bisphenol F type epoxy resin with a specific number average molecular weight is different from ordinary epoxy resins (bisphenol A epoxy resin, phenolic epoxy resin, bisphenol S epoxy resin, etc.), and the linear single-carbon bond short chain segment has good low viscosity characteristics. When this component is used as the main resin part of the formula, it not only provides a large number of reactive matrices, but also has low viscosity characteristics, which is beneficial to the full penetration of the resin glue into the glass fiber in the silk screen process (static viscoelasticity); the above-mentioned multifunctional branched rigid glycidyl ether type epoxy resin has weak thixotropy and high yield value, and can replace part of the bisphenol F type epoxy resin (the weight ratio of the main resin to the auxiliary resin is 1-5:1), so that the resin composition has good rheological properties and promotes the crosslinking reaction between the resins; the introduction of a toughening agent with a specific molecular weight makes the molecular chain length and polarity of the toughening agent close to those of the epoxy resin, so that the toughening agent can be uniformly dispersed in the epoxy resin matrix to form a uniform and stable microstructure; the curing agent is used to synergistically improve the uniformity of the resin composition through the silk screen mesh and the adhesion to the silk screen, and the prepared prepreg is not sticky to the hand, has uniform thickness, good flatness and good storage stability.

[0029] Preferably, the number average molecular weight of the glycidyl ether type epoxy resin is 400-800, in which case, good compatibility between the components is ensured, the resin composition has improved wettability for the glass cloth, and a stable resin content and uniform thickness of the prepreg are formed after curing.

[0030] Preferably, the rigid functional group is selected from at least one of a phenyl group, a naphthyl group and an adamantyl group. In this preferred case, the naphthyl group has ultra-low heat resistance, dimensional stability and low dielectric constant as a rigid group; the adamantyl group has low dielectric loss and good moisture resistance as a rigid group; the phenyl group has the advantages of low cost and good overall performance; and the use of the above rigid functional groups achieves precise and controllable optimization of the performance of the final resin composition.

[0031] Preferably, the molar amount of the rigid functional group is 2-4 moL per 1 moL of the glycidyl ether type epoxy resin. The inventors of the present application have found that, in this preferred case, the glycidyl ether epoxy resin with a moderate number of functional groups ensures that the resin composition has moderate viscosity and excellent rheological properties before curing, so that, under the shearing action in the preparation of the prepreg, the resin rapidly reduces viscosity, fully wets the fibers, and, at the same time, quickly recovers a certain structure by the interaction between the rigid functional groups when shearing stops, preventing excessive penetration.

[0032] Preferably, the glycidyl ether type epoxy resin is selected from at least one of tris(4-hydroxyphenyl)methane triglycidyl ether, 2,2',2”,2”′-[1,2-bis(methylene)tetra(4,1-phenylene methyleneoxy)]tetraoxymethylene, 4,4-methylenebis(N,N-diglycidylaniline), 1,3-bis(2',4'-bis(glycidyl ether)phenyl)adamantane, 2,2',2”,2”′-[[1,1'-binaphthalene]-2,2',7,7'-diyltetra(methylene)]tetraoxymethylene, and 2,2',2”,2”′-(methylenebis[1,2,7-naphthalenetriylbis(oxymethylene)])tetraoxymethylene. The inventors of the present application have found that, in this preferred case, the glycidyl ether epoxy resin has a molecular weight and a multi-branched rigid structure that are matched with those of a bisphenol F type epoxy resin, and has the characteristics of having no more polar group structures, which more effectively takes advantage of the rigid structure itself, improves the glass transition temperature (Tg) of the resin composition, and keeps the prepreg dry, which is beneficial for storage and use.

[0033] Further preferably, the glycidyl ether type epoxy resin is tris(4-hydroxyphenyl)methane triglycidyl ether and / or 2,2',2",2"'-[1,2-bis(methylene)tetra(4,1-phenylene methyleneoxy)]tetraoxymethylene. In this preferred case, the use of phenyl as the main component of the branched rigid group provides sufficient rigidity and strength while maintaining a certain movement ability of the molecular chain segment, and has excellent compatibility with other resins, facilitating the resin to fully infiltrate the glass fiber and flow flat, and then rapidly establishing a crosslinked network, thereby achieving the effect of high flatness; and further reducing the cost.

[0034] Preferably, the toughening agent has a viscosity of <500 mPa.S at 25°C. The inventors of the present application have found that in this preferred case, the moderate viscosity is conducive to subsequent silk-screening process.

[0035] Preferably, the toughening agent is polypropylene glycol diglycidyl ether. In this preferred case, there are fewer polar groups, and the reactivity is higher, which is conducive to the silk-screening process.

[0036] Preferably, the curing agent is a hydrogenated anhydride curing agent. The inventors of the present application have found that in this preferred case, the hydrogenated anhydride curing agent has the characteristics of not being easy to sublimate and good solubility with the epoxy resin, and is suitable for application in the prepreg production process.

[0037] Preferably, the hydrogenated anhydride curing agent is selected from at least one of tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrahydro methyl phthalic anhydride, and hexahydro methyl phthalic anhydride. In this preferred case, the viscosity of the complex of the hydrogenated anhydride curing agent after melting and the epoxy resin is very low, which is conducive to the penetration of the resin into the fiber.

[0038] According to another preferred specific embodiment, the ratio of the total epoxy group molar amount of the bisphenol F type epoxy resin, the glycidyl ether type epoxy resin and the toughening agent to the anhydride group molar amount of the curing agent is 1:0.6-0.9. In this preferred case, the crosslinking of the epoxy groups is facilitated, while avoiding too high a ratio which would affect the final overall effect, so that the curing degree of the prepared prepreg reaches an appropriate state, which is conducive to the later application.

[0039] Preferably, the composition further comprises an accelerator, and the composition contains 30-50 parts by weight of the bisphenol F type epoxy resin, 10-30 parts by weight of the glycidyl ether type epoxy resin, 10-20 parts by weight of the toughening agent, 22-55 parts by weight of the curing agent and 1.4-10.6 parts by weight of the accelerator. In this preferred case, by limiting the weight ratio range of each component, the precise cooperation of each component in this range is achieved, and the low viscosity and high flow flatness are optimally balanced.

[0040] Preferably, the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol and / or adipic acid. In this preferred case, the curing temperature of the anhydride curing agent can be reduced, and the application performance of the prepreg can be improved.

[0041] Preferably, the accelerator is 1.4-4 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol and 1.5-6.6 parts by weight of adipic acid. In this preferred case, 2,4,6-tris(dimethylaminomethyl)phenol greatly activates the epoxy group by forming an ion pair (such as a carboxylate ion anion), making it more susceptible to attack by anhydride, quickly starting and accelerating the curing reaction; adipic acid first reacts with anhydride to form an anhydride-carboxylic acid complex, which is more active than the original anhydride, which is beneficial to resin flow, full impregnation of glass fiber and bubble removal.

[0042] Preferably, the composition further contains 5-20 parts by weight of a solvent.

[0043] Preferably, the solvent is selected from at least one of acetone, butanone, benzene, toluene, N,N-dimethylformamide, dimethyl sulfoxide, ethylene glycol monomethyl ether acetate. In this preferred case, the overall solubility of the resin composition can be improved, which is beneficial to the uniform mixing of the components.

[0044] Further preferably, the solvent is N,N-dimethylformamide. This solvent is non-toxic and not easily volatile, and has good formulation leveling properties, which can improve the operability during silk screening.

[0045] As described above, the second aspect of the present application provides a method for preparing a glass fiber prepreg, which applies the components in the composition of the first aspect described above, comprising:

[0046] (1) stirring and mixing a bisphenol F type epoxy resin, a glycidyl ether type epoxy resin, a toughening agent, and a curing agent to obtain a resin composition;

[0047] (2) silk screening the resin composition on a glass fiber cloth to obtain the glass fiber prepreg.

[0048] According to one preferred embodiment, the method further comprises: in step (1), stirring and mixing the bisphenol F type epoxy resin, the glycidyl ether type epoxy resin, the toughening agent, the curing agent, and an accelerator to obtain the resin composition.

[0049] According to another preferred embodiment, the method further comprises: in step (2), drying the material after silk screening the resin composition on the glass fiber cloth.

[0050] The preparation method provided by the second aspect of the present application can effectively avoid the problems of poor surface flatness, easy occurrence of corrugation and wrinkles and resin waste of the prepreg produced by the production mode of "pre-impregnation-roller pressing-drying"; and the preparation method provided by the present application can form a glass fiber prepreg with good flatness.

[0051] The conditions of the drying treatment are not particularly required, and can be selected by those skilled in the art according to conventional technical means in the art; for example, the drying treatment is baking in a blast drying oven at 120-150℃ for 5-10min, which cannot be understood as a limitation to the present application by those skilled in the art.

[0052] As described above, the third aspect of the present application provides the use of the glass fiber prepreg prepared by the method of the aforementioned second aspect in a glass fiber shell.

[0053] In order to more clearly understand the technical features, objectives and beneficial effects of the present application, the present application will now be described in detail through examples, and it should be understood that the specific examples described herein are only used to explain the present application, and the protection scope of the present application is not limited to the following description. In the following examples, various raw materials and reagents used without special instructions are all commercially available products with a purity of analytical grade.

[0054] Bisphenol F type epoxy resin:

[0055] Bisphenol F type epoxy resin I: number average molecular weight of 423, purchased from Chuzhou Huisheng Electronic Technology Co., Ltd., with a trade name of HS-EP-400.

[0056] Bisphenol F type epoxy resin II: number average molecular weight of 786, purchased from Chuzhou Huisheng Electronic Technology Co., Ltd., with a trade name of HS-EP-800.

[0057] Bisphenol F type epoxy resin DI: number average molecular weight of 1240, purchased from Chuzhou Huisheng Electronic Technology Co., Ltd., with a trade name of HS-EP-1200.

[0058] Bisphenol A type epoxy resin: purchased from Nanya Electronic Materials (Kunshan) Co., Ltd., with a trade name of NPEL-128.

[0059] Glycidyl ether type epoxy resin:

[0060] Glycidyl ether type epoxy resin I: 2,2',2”,2”'-[1,2-bis(methylene) tetrakis(4,1-phenylene methyleneoxy)] tetraoxymethylene, with a functionality of 4, purchased from Jingmen Dongxin Biological Technology Co., Ltd., with a trade name of HS1031.

[0061] Glycidyl ether type epoxy resin II: tris(4-hydroxyphenyl)methane triglycidyl ether, functionality of 3, purchased from Jingmen Dongxi Biological Technology Co., Ltd., brand HS636.

[0062] Phenolic epoxy resin: functionality of 5, purchased from Jining Lido Chemical Co., Ltd., brand F-51.

[0063] Alicyclic epoxy resin: functionality of 2, purchased from Shanghai Guangyi Chemical Co., Ltd., brand 2021P

[0064] Alkyl glycidyl ether: functionality of 2, purchased from Jining Huakai Resin Co., Ltd., brand AGE-600.

[0065] Toughening agent:

[0066] Toughening agent I: polypropylene glycol diglycidyl ether, number average molecular weight of 800, viscosity of 200 mPa.S at 25℃, purchased from Jining Huakai Resin Co., Ltd., brand PPGDGE-800.

[0067] Toughening agent II: polypropylene glycol diglycidyl ether, number average molecular weight of 400, viscosity of 70 mPa.S at 25℃, purchased from Jining Huakai Resin Co., Ltd., brand PPGDGE-400.

[0068] Toughening agent DI: polypropylene glycol diglycidyl ether, number average molecular weight of 1500, viscosity of 600 mPa.S at 25℃, purchased from Jining Huakai Resin Co., Ltd., brand PPGDGE-1500.

[0069] Acrylic rubber resin: number average molecular weight of about 6000-15000, viscosity of 15000-30000 mPa.S at 25℃, purchased from Jining Huakai Resin Co., Ltd., brand HK-9050.

[0070] Curing agent:

[0071] Hydrogenated acid anhydride curing agent I: tetrahydrophthalic anhydride, CAS: 85-43-8.

[0072] Hydrogenated acid anhydride curing agent II: hexahydrophthalic anhydride, CAS: 85-42-7.

[0073] Promoter:

[0074] Promoter I: 2,4,6-tris(dimethylaminomethyl)phenol.

[0075] Promoter II: adipic acid.

[0076] Solvent: N,N-dimethylformamide.

[0077] Glass fiber cloth: glass fiber cloth of type 2116, 300 mm x 500 mm x 0.09 mm.

[0078] Example 1

[0079] This example is used to illustrate the preparation of a glass fiber prepreg according to the method of the following steps with reference to the formulation in Table 1:

[0080] (1) The bisphenol F type epoxy resin, glycidyl ether type epoxy resin, toughening agent, curing agent, and accelerator are mixed by stirring to obtain a resin composition;

[0081] (2) The resin composition is silk-screen printed on the glass fiber cloth, and then dried in a forced air drying oven (135°C baking for 10 min) to obtain the glass fiber prepreg.

[0082] Example 2

[0083] This example is carried out by a similar method to Example 1, except for the formulation, which is shown in Table 1.

[0084] The parts not listed are the same as in Example 1, and the glass fiber prepreg is obtained.

[0085] Example 3

[0086] This example is carried out by a similar method to Example 1, except for the formulation, which is shown in Table 1.

[0087] The parts not listed are the same as in Example 1, and the glass fiber prepreg is obtained.

[0088] Example 4

[0089] This example is carried out by a similar method to Example 1, except for the formulation, which is shown in Table 1.

[0090] The parts not listed are the same as in Example 1, and the glass fiber prepreg is obtained.

[0091] Table 1

[0092]

[0093]

[0094] Comparative Example 1

[0095] This comparative example is carried out by a similar method to Example 4, except that the bisphenol F type epoxy resin I in Example 4 is replaced by an equal amount of bisphenol A type epoxy resin;

[0096] The parts not listed are the same as in Example 4, and the glass fiber prepreg is obtained.

[0097] Comparative Example 2

[0098] This comparative example was performed using a similar method to Example 4, except that this comparative example used an equal mass of bisphenol F epoxy resin DI in place of bisphenol F epoxy resin I in Example 4;

[0099] The parts not mentioned were the same as in Example 4 to give the glass fibre prepreg.

[0100] Comparative Example 3

[0101] This comparative example was performed using a similar method to Example 4, except that this comparative example used an equal mass of a novolac epoxy resin in place of glycidyl ether epoxy resin II in Example 4;

[0102] The parts not mentioned were the same as in Example 4 to give the glass fibre prepreg.

[0103] Comparative Example 4

[0104] This comparative example was performed using a similar method to Example 4, except that this comparative example used an equal mass of a cycloaliphatic epoxy resin in place of glycidyl ether epoxy resin II in Example 4;

[0105] The parts not mentioned were the same as in Example 4 to give the glass fibre prepreg.

[0106] Comparative Example 5

[0107] This comparative example was performed using a similar method to Example 4, except that this comparative example used an equal mass of an alkyl glycidyl ether in place of glycidyl ether epoxy resin II in Example 4;

[0108] The parts not mentioned were the same as in Example 4 to give the glass fibre prepreg.

[0109] Comparative Example 6

[0110] This comparative example was performed using a similar method to Example 4, except that this comparative example used an equal mass of toughener DI in place of toughener II in Example 4;

[0111] The parts not mentioned were the same as in Example 4 to give the glass fibre prepreg.

[0112] Comparative Example 7

[0113] This comparative example was performed using a similar method to Example 4, except that this comparative example used an equal mass of an acrylic rubber resin in place of toughener II in Example 4;

[0114] The parts not mentioned were the same as in Example 4 to give the glass fibre prepreg.

[0115] Comparative Example 8

[0116] This comparative example was carried out in a similar manner as Example 4, except that the amount of bisphenol F type epoxy resin I used was 20 g and the amount of glycidyl ether type epoxy resin II used was 40 g.

[0117] The parts not listed were the same as in Example 4, and the glass fiber prepreg was obtained.

[0118] Test Example

[0119] 1. The viscosity (25°C) of the resin prepared in step (1) of each of the foregoing examples was tested according to the test method in GB / T 22314-2008 “Determination of viscosity of plastic epoxy resins”, using a DNJ-1 type rotational viscometer.

[0120] 2. The average thickness of the glass fiber prepreg prepared in each of the foregoing examples was tested according to the test method in GB / T 6672-2001 “Determination of thickness of plastic films and sheets by mechanical measurement method”.

[0121] The flatness was tested according to the test method in GB / T 2410-2024 “Flatness test method for plastic films and sheets”, using a laser displacement sensor to scan the three-dimensional surface topography, and the absolute value of the deviation of the maximum arc height point from the reference plane was determined, i.e. the flatness.

[0122] 3. The following method was used to evaluate the web sticking and the ease of cleaning of the screen plate during the silk screening process in step (2) of each of the foregoing examples.

[0123] Web sticking evaluation: 10 ± 0.1 g of the resin composition prepared in step (1) of each of the foregoing examples was evenly applied to a 300-mesh (Chinese standard) steel screen with a length and width of 100*100 mm. After standing for 30 s, a clean glass fiber cloth was placed completely over the screen, and after standing for 30 s, the web sticking grade was evaluated.

[0124] Screen plate easy cleaning evaluation: 10 ± 0.1 g of the resin composition prepared in step (1) of each of the foregoing examples was evenly applied to a 300-mesh (Chinese standard) steel screen with a length and width of 100*100 mm. After standing for 30 s, it was placed in a steel drum equipped with 5 L of tian na water and sealed for immersion for 2 min. After removal, the surface solvent residue was rinsed with flowing tian na water, and the surface resin residue was observed to evaluate the ease of cleaning of the resin. If there was no residue on the surface, it was evaluated as easy to clean, and if there was residue on the surface, it was evaluated as difficult to clean.

[0125] The test results are shown in Table 2.

[0126] Table 2

[0127]

[0128] Note: The sticky web condition level is explained as follows:

[0129] A: No sticky web, no web and glass fiber cloth adhesion

[0130] B: Slightly sticky web, slightly web and glass fiber cloth adhesion, but the web and glass fiber cloth can be easily separated

[0131] C: More sticky web, the web and glass fiber cloth can be separated with small force

[0132] D: Sticky web, the web and glass fiber cloth can be separated with large force

[0133] The present application exemplarily provides the cross-sectional view and surface view of the glass fiber prepreg prepared by the embodiment 1 and the comparative example 1 of the present application, respectively seen Figure 1 (taken by digital microscope), Figure 2 (taken by three-dimensional scanner CAV, scanned surface profile):

[0134] Figure 1 The left in the middle is the cross-sectional view of the glass fiber prepreg prepared by the embodiment 1, Figure 1 The right in the middle is the cross-sectional view of the glass fiber prepreg prepared by the comparative example 1; by Figure 1 It can be seen that the upper and lower interface of the cross section of the glass fiber prepreg prepared by the embodiment 1 is flat, without large protrusions and undulations, and has good flatness; the cross section of the glass fiber prepreg prepared by the comparative example 1 is rough, and part of the glass fiber is exposed and protruded, and has poor flatness, which shows that the resin composition provided by the present application has obvious advantages.

[0135] Figure 2 The left in the middle is the surface view of the glass fiber prepreg prepared by the embodiment 1, Figure 2 The right in the middle is the surface view of the glass fiber prepreg prepared by the comparative example 1; by Figure 2 It can be seen that the surface of the glass fiber prepreg prepared by the embodiment 1 is smooth and flat, and the surface of the glass fiber prepreg prepared by the comparative example 1 presents a large undulating pattern, which shows that the resin composition provided by the present application has obvious advantages.

[0136] From the above results, it can be seen that the resin composition provided by the present application has the characteristics of moderate viscosity, weak thixotropy and large yield value, and when applied to the silk screen prepreg process, it is not sticky to the web, easy to clean, the glass fiber prepreg prepared has good dryness, uniform thickness, good flatness and good storage stability.

[0137] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including that each technical feature is combined in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A resin composition, characterized in that, The composition contains bisphenol F type epoxy resin, glycidyl ether type epoxy resin, toughening agent and curing agent; The number-average molecular weight of the bisphenol F epoxy resin is 400-900; the number-average molecular weight of the toughening agent is 400-800. The functionality of the glycidyl ether type epoxy resin is 3-4; and the glycidyl ether type epoxy resin contains rigid functional groups. The weight ratio of the bisphenol F type epoxy resin to the glycidyl ether type epoxy resin is 1-5:

1.

2. The composition according to claim 1, characterized in that, The number average molecular weight of the glycidyl ether type epoxy resin is 400-800. And / or, the rigid functional group is selected from at least one of phenyl, naphthyl, and adamantyl groups; And / or, relative to 1 mol of the glycidyl ether epoxy resin, the molar amount of the rigid functional group is 2-4 mol.

3. The composition according to claim 1, characterized in that, The glycidyl ether type epoxy resin is selected from at least one of tri(4-hydroxyphenyl)methane triglycidyl ether, 2,2',2”,2”′-[1,2-didimethyltetra(4,1-phenylenemethoxy)]tetraethylene oxide, 4,4-methylene bis(N,N-diglycidylaniline), 1,3-bis(2',4'-bis(glycidyl ether)phenyl)adamantane, 2,2',2”,2”′-[[1,1'-binaphthyl]-2,2′,7,7'-diyltetra(methylene)]tetraethylene oxide, and 2,2',2”,2”′-(methylenebis[1,2,7-naphthyltriylbis(oxymethylene)])tetraethylene oxide.

4. The composition according to any one of claims 1-3, characterized in that, The toughening agent is polypropylene glycol diglycidyl ether.

5. The composition according to any one of claims 1-3, characterized in that, The curing agent is a hydrogenated anhydride curing agent; And / or, the hydrogenated anhydride curing agent is selected from at least one of tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrahydromethylphthalic anhydride, and hexahydromethylphthalic anhydride.

6. The composition according to claim 4, characterized in that, The ratio of the total molar amount of epoxy groups in the bisphenol F type epoxy resin, the glycidyl ether type epoxy resin, and the toughening agent to the molar amount of anhydride groups in the curing agent is 1:0.6-0.

9.

7. The composition according to any one of claims 1-3, characterized in that, The composition further includes an accelerator, and the composition contains 30-50 parts by weight of the bisphenol F type epoxy resin, 10-30 parts by weight of the glycidyl ether type epoxy resin, 10-20 parts by weight of the toughening agent, 22-55 parts by weight of the curing agent and 1.4-10.6 parts by weight of the accelerator.

8. The composition according to claim 7, characterized in that, The accelerator is 2,4,6-tris(dimethylaminomethyl)phenol and / or adipic acid; And / or, the accelerator is 1.4-4 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol and 1.5-6.6 parts by weight of adipic acid.

9. A method for preparing glass fiber prepreg, characterized in that, This method is performed using any of the components in the composition according to any one of claims 1-8, comprising: (1) Bisphenol F type epoxy resin, glycidyl ether type epoxy resin, toughening agent and curing agent are stirred and mixed to obtain a resin composition; (2) The resin composition is screen-printed onto glass fiber cloth to obtain the glass fiber prepreg.

10. The use of the glass fiber prepreg prepared by the method of claim 9 in a glass fiber shell.

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