Epoxy resin composition and prepreg prepared using the same

Abstract

The present invention belongs to the technical field of electronic materials, and specifically relates to an epoxy resin composition and a prepreg prepared using the same. The composition is made of the following components in parts by weight: 20-35 parts of liquid epoxy resin, 45-65 parts of solid epoxy resin, 10-20 parts of curing agent, 8-20 parts of inorganic filler, and 80-130 parts of solvent; the curing agent has a chemical structural formula as follows: The present invention adopts a straight-chain epoxy curing agent with a dihydrazine structure, which not only contains active hydrogen that can react with epoxy groups, but also because of its own straight-chain long molecular chain structure, it is slow to react with epoxy groups at room temperature, and the room temperature storage stability of the epoxy resin composition is increased. The epoxy system after the prepared prepreg is cured has good bonding strength and heat shock resistance, and can meet the requirements of circuit board production.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic materials, and in particular relates to an epoxy resin composition and a prepreg prepared by using the same. Background Art

[0002] Epoxy resin has excellent physical properties, electrical insulation properties, chemical resistance and bonding properties. It can be used as coatings, casting materials, molding materials, crosslinking agents, and laminating materials. It can be used directly or indirectly to penetrate into all aspects of the national economy from daily necessities to high-tech fields. For example, composite materials in aircraft and aerospace equipment, packaging materials for large-scale integrated circuits, etc. However, in recent years, the requirements for the performance of epoxy resins have become higher and higher with the development of the industry, such as high purification, high heat resistance, high toughness, rapid curing and functionalization, and these characteristics are required to have a good balance, and multiple excellent characteristics are simultaneously possessed. At present, bisphenol A, bisphenol F, and phenolic epoxy are more common in the market, and biphenyl type, multi-functional type, self-flame retardant type and other epoxy resins also have their corresponding application markets.

[0003] In the production process of printed circuit boards, the bonding between materials requires a large amount of prepreg. For example, it is used to bond the inner layers together when making multi-layer printed boards, and to bond the substrate to other materials. At present, the most widely used epoxy prepreg on the market is this type of prepreg. The production process of this type of prepreg is mature and the performance is good, but this type of prepreg mostly uses amine curing agents and corresponding catalysts. When stored at room temperature, the resin and curing agent still undergo a slow chemical reaction. Therefore, epoxy prepregs are required to be stored at a temperature below 10°C, and the storage period is mostly 3 months. For example, the common FR-4 prepregs on the market, the series of non-flowing prepregs for rigid-flexible boards, and the epoxy prepregs for low dielectric materials cannot be stored at 25°C for 3 months. When used on the actual production line, the prepreg needs to go through a series of processes from cutting to lamination. If it is not properly controlled, the long stay time on the line will cause the performance of the prepreg to decline, and even the product will expire. Therefore, prepregs that are stable in room temperature storage can effectively improve this problem. Summary of the invention

[0004] The object of the present invention is to provide an epoxy resin composition and a prepreg prepared by using the same in view of the deficiencies in the prior art. The straight-chain epoxy curing agent with a dihydrazine structure is used, which not only contains active hydrogen that can react with epoxy groups, but also has a slow reaction with epoxy groups at room temperature due to its own straight-chain long molecular chain structure, thereby increasing the room-temperature storage stability of the epoxy resin composition. The epoxy system of the prepared prepreg after curing has good bonding strength and heat shock resistance, and can meet the requirements of circuit board production.

[0005] The present invention provides an epoxy resin composition, which is prepared from the following components in parts by weight:

[0006] 20-35 parts of liquid epoxy resin, 45-65 parts of solid epoxy resin, 10-20 parts of curing agent, 8-20 parts of inorganic filler, 80-130 parts of solvent;

[0007] The curing agent has the following chemical structural formula:

[0008]

[0009] Furthermore, the epoxy equivalent of the liquid epoxy resin is 210-280 g / eq.

[0010] Furthermore, the epoxy equivalent of the solid epoxy resin is 700-780 g / eq.

[0011] Furthermore, the inorganic filler is selected from one or more of silicon dioxide, aluminum oxide, aluminum hydroxide, magnesium oxide, magnesium hydroxide, calcium carbonate and kaolin.

[0012] Furthermore, the solvent is a mixed solvent of butanone, ethyl acetate and dimethylformamide; the mass ratio of butanone, ethyl acetate and dimethylformamide is 4.5-5.5:3.5-4.5:0.5-1.5.

[0013] The present invention also provides a prepreg prepared from the epoxy resin composition, wherein the prepreg is obtained by impregnating a glass fiber cloth in the epoxy resin composition according to any one of claims 1 to 5 and drying the impregnated glass fiber cloth.

[0014] Furthermore, the drying temperature is 120-150° C. and the drying time is 5-10 min.

[0015] Furthermore, the content of the epoxy resin composition in the prepreg is 50-67%.

[0016] Furthermore, the curing temperature of the prepreg is 160-170° C., and the curing time is 60-120 min.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention adopts a straight-chain epoxy curing agent with a dihydrazine structure, which not only contains active hydrogen that can react with epoxy groups, but also has a long straight molecular chain structure, so that it reacts slowly with epoxy groups at room temperature. It can be used as a room-temperature latent curing agent for epoxy resin, thereby increasing the room-temperature storage stability of the epoxy resin composition, and can improve the problem that epoxy resin adhesives in the circuit board industry cannot be stored at room temperature.

[0019] (2) The semi-cured sheet prepared from the epoxy resin composition of the present invention has good storage stability, and the storage period at 25°C is greater than 3 months. The semi-cured sheet has good peel strength after curing, and passes the heat shock test at 288°C, 10s, and 3 times, and also has the characteristic of low water absorption. DETAILED DESCRIPTION

[0020] The following will combine the data in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Unless otherwise specifically stated, the various raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be purchased from the market or prepared by existing methods.

[0022] Example 1

[0023] An epoxy resin composition is prepared from the following components in parts by weight:

[0024] 20 parts of liquid epoxy resin, 65 parts of solid epoxy resin, 15 parts of curing agent, 20 parts of inorganic filler, 130 parts of solvent;

[0025] The curing agent has the following chemical structure:

[0026]

[0027] The liquid epoxy resin is epoxy resin E-42, and its epoxy equivalent is 210-280 g / eq.

[0028] The solid epoxy resin is epoxy resin NPES-903H, and its epoxy equivalent is 700-780 g / eq.

[0029] The inorganic filler is calcined kaolin.

[0030] The solvent is a mixed solvent of butanone, ethyl acetate and dimethylformamide, and the mass ratio of butanone, ethyl acetate and dimethylformamide is 5:4:1.

[0031] The preparation method of the epoxy resin composition comprises the following steps:

[0032] S1. Weigh 20 parts of epoxy resin E-42, 65 parts of epoxy resin NPES-903H, 15 parts of curing agent, 20 parts of calcined kaolin, 65 parts of butanone, 52 parts of ethyl acetate, and 13 parts of dimethylformamide;

[0033] S2. Stir epoxy resin E-42, epoxy resin NPES-903H and organic solvents such as butanone, ethyl acetate and dimethylformamide at room temperature until they are completely dissolved, then add curing agent and calcined kaolin and stir thoroughly, then put into a grinding barrel filled with zirconium oxide and grind thoroughly to obtain an epoxy resin composition.

[0034] Example 2

[0035] An epoxy resin composition is prepared from the following components in parts by weight:

[0036] 25 parts of liquid epoxy resin, 63 parts of solid epoxy resin, 12 parts of curing agent, 18 parts of inorganic filler, 120 parts of solvent;

[0037] The curing agent has the following chemical structure:

[0038]

[0039] The liquid epoxy resin is epoxy resin E-42, and its epoxy equivalent is 210-280 g / eq.

[0040] The solid epoxy resin is epoxy resin NPES-903H, and its epoxy equivalent is 700-780 g / eq.

[0041] The inorganic filler is calcined kaolin.

[0042] The solvent is a mixed solvent of butanone, ethyl acetate and dimethylformamide, and the mass ratio of butanone, ethyl acetate and dimethylformamide is 4.5:5.5:1.

[0043] The preparation method of the above epoxy resin composition is the same as that of Example 1.

[0044] Example 3

[0045] An epoxy resin composition is prepared from the following components in parts by weight:

[0046] 22 parts of liquid epoxy resin, 60 parts of solid epoxy resin, 18 parts of curing agent, 15 parts of inorganic filler, 100 parts of solvent;

[0047] The curing agent has the following chemical structure:

[0048]

[0049] The liquid epoxy resin is epoxy resin E-42, and its epoxy equivalent is 210-280 g / eq.

[0050] The solid epoxy resin is epoxy resin NPES-903H, and its epoxy equivalent is 700-780 g / eq.

[0051] The inorganic filler is calcined kaolin.

[0052] The solvent is a mixed solvent of butanone, ethyl acetate and dimethylformamide, and the mass ratio of butanone, ethyl acetate and dimethylformamide is 5:3.5:1.5.

[0053] The preparation method of the above epoxy resin composition is the same as that of Example 1.

[0054] Example 4

[0055] An epoxy resin composition is prepared from the following components in parts by weight:

[0056] 28 parts of liquid epoxy resin, 58 parts of solid epoxy resin, 14 parts of curing agent, 11 parts of inorganic filler, 110 parts of solvent;

[0057] The curing agent has the following chemical structure:

[0058]

[0059] The liquid epoxy resin is epoxy resin E-42, and its epoxy equivalent is 210-280 g / eq.

[0060] The solid epoxy resin is epoxy resin NPES-903H, and its epoxy equivalent is 700-780 g / eq.

[0061] The inorganic filler is calcined kaolin.

[0062] The solvent is a mixed solvent of butanone, ethyl acetate and dimethylformamide, and the mass ratio of butanone, ethyl acetate and dimethylformamide is 5.5:4:0.5.

[0063] The preparation method of the above epoxy resin composition is the same as that of Example 1.

[0064] Example 5

[0065] An epoxy resin composition is prepared from the following components in parts by weight:

[0066] 35 parts of liquid epoxy resin, 45 parts of solid epoxy resin, 20 parts of curing agent, 8 parts of inorganic filler, 80 parts of solvent;

[0067] The curing agent has the following chemical structure:

[0068]

[0069] The liquid epoxy resin is epoxy resin E-42, and its epoxy equivalent is 210-280 g / eq.

[0070] The solid epoxy resin is epoxy resin NPES-903H, and its epoxy equivalent is 700-780 g / eq.

[0071] The inorganic filler is calcined kaolin.

[0072] The solvent is a mixed solvent of butanone, ethyl acetate and dimethylformamide, and the mass ratio of butanone, ethyl acetate and dimethylformamide is 5:4:1.

[0073] The preparation method of the above epoxy resin composition is the same as that of Example 1.

[0074] The prepreg prepared by the above epoxy resin combination is the same as that in Example 1.

[0075] Comparative Example 1

[0076] An epoxy resin composition, substantially the same as in Example 1, except that:

[0077] The curing agent has the following chemical structure:

[0078]

[0079] Comparative Example 2

[0080] An epoxy resin composition is basically the same as that in Example 1, except that the curing agent is 4,4'-diaminodiphenyl sulfone.

[0081] Comparative Example 3

[0082] An epoxy resin composition is basically the same as Example 1, except that it contains 10 parts of liquid epoxy resin and 75 parts of solid epoxy resin.

[0083] Comparative Example 4

[0084] An epoxy resin composition is substantially the same as that in Example 1, except that only 85 parts of solid epoxy resin are used.

[0085] Comparative Example 5

[0086] An epoxy resin composition is basically the same as Example 1, except that epoxy resin CYD-128 is used instead of liquid epoxy resin, and epoxy resin CYD-019 is used instead of solid epoxy resin.

[0087] The epoxy resin compositions prepared in Examples 1-5 and Comparative Examples 1-5 are directly used to prepare prepregs, comprising the following steps:

[0088] The glass fiber cloth was impregnated in the epoxy resin compositions prepared in Examples 1-5 and Comparative Examples 1-5, respectively. The impregnated 1080# electronic grade glass fiber cloth was first dried at 120°C for 10 min until the surface was dry, and then further treated at 140°C to form a 80 μm prepreg. The prepreg was pressed against the rough surface of the electrolytic copper, and the sample was prepared by step-by-step temperature and pressure increase, with the maximum pressure being 30 kgf / cm 2 The maximum temperature is 160°C and the total pressing time is 160 min. The properties of the prepreg are shown in Table 1.

[0089] Table 1 Properties of prepregs after epoxy resin composition preparation without storage

[0090]

[0091]

[0092] The epoxy resin compositions prepared in Examples 1-5 and Comparative Examples 1-5 were placed in an environment at 25° C. for 3 months and then tested. Prepregs were then prepared according to the above method. The properties of the prepregs are shown in Table 2.

[0093] Table 2 Properties of prepregs after storage prepared from epoxy resin compositions

[0094]

[0095] The test methods for the characteristics in Table 1 and Table 2 are as follows:

[0096] Peel strength (PS, N / mm): Determined according to IPC-TM-6502.4.9 method to test the peel strength of 1oz electrolytic copper foil.

[0097] Solder resistance test: refer to IPC-TM-650 2.4.13.1 method, the test conditions are 288℃, 10s, 3 times.

[0098] Water absorption (%): The water absorption of state A is tested according to the method specified in IPC-TM-6502.6.2.1.

[0099] TGA thermogravimetric analysis, nitrogen atmosphere conditions, Td,2% refers to the temperature value when the weight loss is 2% in the thermogravimetric curve;

[0100] Bending strength: MTS 810 ceramic testing machine, loading rate 5 mm / min.

[0101] As shown in Table 1, the peel strength of the prepregs prepared in Examples 1-5 is higher than 1.45 N / mm, and the solder resistance is all qualified. Compared with Comparative Examples 1-5, after using other epoxy curing agents and adjusting the epoxy ratio and type, the peel strength decreases to varying degrees, and the solder resistance is also partially unqualified.

[0102] As can be seen from Table 2, the prepregs prepared in Examples 1-5 were placed in a 25°C environment for 3 months and then tested. Although the peel strength decreased slightly, the overall peel strength was higher than 1.40 N / mm, which was almost the same as the performance of the prepregs that were not stored. The soldering resistance was all qualified, meeting the requirements of the circuit board process. At the same time, the prepregs prepared in Comparative Examples 1-5 showed a serious decrease in peel strength and soldering resistance after being placed under the same conditions. The peel strength was 0.55-0.72 N / mm, and the soldering resistance was all unqualified. In summary, the samples prepared in Examples 1-5 have significantly improved their room temperature storage performance, which can effectively improve the problem of product expiration at room temperature.

[0103] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0104] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An epoxy resin composition, characterized in that Made from the following components in parts by weight: 20-35 parts of liquid epoxy resin, 45-65 parts of solid epoxy resin, 10-20 parts of curing agent, 8-20 parts of inorganic filler, 80-130 parts of solvent; The curing agent has the following chemical structural formula: The epoxy equivalent of the liquid epoxy resin is 210-280 g / eq, and the epoxy equivalent of the solid epoxy resin is 700-780 g / eq.

2. The epoxy resin composition according to claim 1, characterized in that The inorganic filler is selected from one or more of silicon dioxide, aluminum oxide, aluminum hydroxide, magnesium oxide, magnesium hydroxide, calcium carbonate and kaolin.

3. The epoxy resin composition according to claim 1, characterized in that The solvent is a mixed solvent of butanone, ethyl acetate and dimethylformamide; the mass ratio of butanone, ethyl acetate and dimethylformamide is 4.5-5.5:3.5-4.5:0.5-1.

5.

4. A prepreg prepared using the epoxy resin composition according to any one of claims 1 to 3, characterized in that: The glass fiber cloth is impregnated in the epoxy resin composition according to any one of claims 1 to 3, and the impregnated glass fiber cloth is dried to obtain a prepreg.

5. The prepreg according to claim 4, characterized in that: The drying temperature is 120-150° C. and the drying time is 5-10 min.

6. The prepreg according to claim 4, characterized in that: The epoxy resin composition content of the prepreg is 50-67%.

7. The prepreg according to claim 4, characterized in that: The curing temperature of the prepreg is 160-170° C., and the curing time is 60-120 min.

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