An epoxy-modified silicone resin and a high-temperature-resistant and high-strength mica composite material prepared by using the same

Abstract

This application relates to the technical field of mica composite materials for new energy vehicles, in particular to an epoxy-modified silicone resin and a high-temperature-resistant and high-strength mica composite material prepared by using the same. An epoxy-modified silicone resin is mainly prepared from a silicone resin and an epoxy-modified resin, and the molar ratio of the silicone resin to the epoxy-modified resin is controlled at 1:(0.25 - 0.35); the epoxy-modified resin is a bisphenol S-type epoxy resin combined with at least one of 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A-type epoxy resin; the silicone resin is a silane with double bonds. The mica composite material prepared by using the epoxy-modified silicone resin in this application not only has good fireproof performance but also has good mechanical strength, expanding the scope of application of mica composite materials.

Description

Technical Field

[0001] This application relates to the technical field of mica composite materials for new energy vehicles, and particularly relates to an epoxy-modified silicone resin and a high-temperature-resistant and high-strength mica composite material prepared by using the same. Background Art

[0002] New energy vehicles are supported by policies of various countries due to their good environmental protection, and quickly occupy the share of the automotive market, becoming the focus of development and research of major enterprises. Currently, the contradiction restricting the development of new energy vehicles lies in driving safety, such as reports of new energy vehicle battery accidents occurring from time to time.

[0003] In order to improve the safety performance of new energy vehicle batteries, vehicle manufacturers in various countries have strict fireproof and flame-retardant requirements for the materials used in their battery modules. Excellent fireproof and flame-retardant materials can effectively improve the safety performance of thermal runaway protection management of new energy vehicle batteries, and thus ensure the driving safety performance of the whole vehicle. The mica material has advantages such as high electrical insulation, large dielectric constant, small loss, high dielectric strength, and high chemical stability, making it a key base material in the thermal runaway management of battery modules.

[0004] The main preparation methods of mica plates in related technologies are mainly the following two. The first is the silicone-based mica material mainly prepared from silicone resin and mica powder; the second is the epoxy-based mica material mainly prepared from epoxy resin and mica powder. Among them, the biggest advantage of silicone mica paper / plate is its excellent fireproof performance, and the mechanical strength remains at 40 - 60% of the original after post-testing, but its mechanical strength is lower than that of epoxy mica materials. Epoxy mica materials have good mechanical strength, but their fire resistance is poor, and the mechanical strength remains below 2% of the original after weathering test. To sum up, the mica materials in related records have the problem that mechanical strength and fireproof performance cannot be achieved simultaneously. Summary of the Invention

[0005] In order to solve the above technical problems, this application provides an epoxy-modified silicone resin and a high-temperature-resistant and high-strength mica composite material prepared by using the same.

[0006] In the first aspect, an epoxy-modified silicone resin provided by this application is achieved through the following technical solutions:

[0007] An epoxy-modified silicone resin is mainly prepared from a silicone resin and an epoxy-modified resin. The molar ratio of the silicone resin to the epoxy-modified resin is controlled at 1:(0.25 - 0.35); the epoxy-modified resin is bisphenol S-type epoxy resin combined with at least one of 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A type epoxy resin; the silicone resin is at least one of silane A, silane B, and silane C with double bonds. The structural formula of the silane A with double bonds is as follows:

[0008] Among them, n = 8 - 12; the structural formula of the silane B with double bonds is as follows:

[0009] Among them, n = 9 - 15;

[0010] The structural formula of the silane C with double bonds is the same as that of silane A, except that n of the silane C with double bonds is 130 - 150.

[0011] In this application, the silanol groups react with the epoxy groups on the epoxy resin under the action of catalyst DMP-30 at about 110°C to form silicon-oxygen bonds. The silicone resin intermediate containing silicon functional groups can react with the hydroxyl groups in the epoxy resin molecules by dehydration or de-alcoholization reactions, thus forming a high-temperature-resistant and high-strength epoxy-modified silicone resin. In this application, a specially selected silane with double bonds reacts with a specific epoxy resin to produce a high-temperature-resistant and high-strength epoxy-modified silicone resin with the advantages of silicone resin and excellent properties of epoxy resin. The mica composite material prepared in this application not only has good fire resistance but also has good mechanical strength, expands the applicable range of mica composite materials, can meet the needs of different levels of customers, and has a better market prospect.

[0012] Preferably, the epoxy-modified resin is composed of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine and polybutadiene epoxy resin; 4,4'-diaminodiphenylmethane tetraglycidylamine accounts for 5 - 10% of the total molar amount of the epoxy-modified resin, and polybutadiene epoxy resin accounts for 10 - 20% of the total molar amount of the epoxy-modified resin.

[0013] By adopting the above technical solutions, it can be ensured that the mica composite material prepared in this application has good high-temperature resistance, fire retardancy, and certain toughness.

[0014] Preferably, the epoxy modified resin is composed of bisphenol S type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromodiphenol propane type epoxy resin; the 4,4'-diaminodiphenylmethane tetraglycidylamine accounts for 5-15% of the total molar amount of the epoxy modified resin; the polybutadiene epoxy resin accounts for 10-20% of the total molar amount of the epoxy modified resin; the tetrabromodiphenol propane type epoxy resin accounts for 8-15% of the total molar amount of the epoxy modified resin.

[0015] By adopting the above technical solution, it can be ensured that the mica composite material prepared in this application has good high-temperature resistance, has certain toughness, and improves the overall fireproof and flame-retardant performance.

[0016] Preferably, the molar ratio of the silicone resin to the epoxy modified resin is controlled at 1:(0.28-0.32); the epoxy modified resin is composed of bisphenol S type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromodiphenol propane type epoxy resin; the molar ratio of the bisphenol S type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromodiphenol propane type epoxy resin is (68-70):12:10:(8-10); the silicone resin is a silane A with a number average molecular weight of 1000 and having double bonds.

[0017] By adopting the above technical solution, the prepared mica composite material has good high-temperature resistance and fireproof and flame-retardant performance, and has certain toughness. It is an excellent high-temperature and high-strength mica composite material. This mica composite material has an advantage in production cost and is easy to be accepted by the market.

[0018] Preferably, the molar ratio of the silicone resin to the epoxy modified resin is controlled at 1:(0.32-0.35); the epoxy modified resin is composed of bisphenol S type epoxy resin, tetraglycidyl methyl dianiline epoxy resin, polybutadiene epoxy resin, and tetrabromodiphenol propane type epoxy resin; the molar ratio of the bisphenol S type epoxy resin, tetraglycidyl methyl dianiline epoxy resin, polybutadiene epoxy resin, and tetrabromodiphenol propane type epoxy resin is 68:12:10:10; the silicone resin is composed of a silane A with a number average molecular weight of 1000 and having double bonds and a silane C with a number average molecular weight of 10000 and having double bonds; the molar ratio of the silane A with a number average molecular weight of 1000 and having double bonds to the silane C with a number average molecular weight of 10000 and having double bonds is controlled at (75-80):(20-25).

[0019] In this application, long-chain silane C is used to replace polybutadiene epoxy resin to improve flexibility, and the molar ratios of bisphenol S-type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, and tetrabromodiphenol propane-type epoxy resin are regulated, so that the prepared mica composite material has better high-temperature resistance, flexibility, and tensile strength. The disadvantage is that the cost is relatively high, and the mica composite material is suitable for medium- and high-end models.

[0020] Preferably, it further includes a modified fluororesin. The modified fluororesin is perfluorooctylpropyl acrylate. The perfluorooctylpropyl acrylate reacts chemically with an organosilicon resin to produce a fluorosilicon intermediate, and the fluorosilicon intermediate reacts with bisphenol S-type epoxy resin to obtain an epoxy-modified fluorosilicon resin; the molar amount of perfluorooctylpropyl acrylate is equal to 8-15% of the molar amount of the organosilicon resin.

[0021] The perfluorooctylpropyl acrylate undergoes a polymerization reaction at 80-85 °C under the catalysis of AIBN to obtain a silicon-hydroxyl fluorosilicon intermediate. The obtained silicon-hydroxyl fluorosilicon intermediate is under nitrogen protection, at 110 °C and under the catalysis of DMP-30. The silicon hydroxyl group on the fluorosilicon intermediate undergoes a ring-opening reaction with the epoxy group of the epoxy resin at 110 °C, and then reacts to form a fluorine-silicon-epoxy-bonded polymer, that is, an epoxy-modified fluorosilicon resin is obtained. The prepared epoxy-modified fluorosilicon resin not only combines the advantages of organosilicon and epoxy resin but also endows it with the advantages of fluororesin, ensuring that this application has good mechanical strength and fireproof and flame-retardant properties while improving the overall weather resistance, stain resistance, and surface cleanliness, making the surface cleanliness of the finished product more easily meet the actual needs of customers and facilitating obtaining the recognition of the mass market.

[0022] Preferably, the preparation method of the epoxy-modified fluorosilicon resin is as follows: Accurately measure the perfluorooctylpropyl acrylate and the organosilicon resin and pre-mix them evenly with xylene to obtain a mixed solution. The mass of the xylene is equal to 48-54% of the total mass of the perfluorooctylpropyl acrylate and the organosilicon resin; Add the evenly mixed mixed solution into a reaction kettle with a reflux device, flush with nitrogen for protection, stir and heat up to 80 °C, keep warm for 5-10 minutes, and add the initiator AIBN dropwise every 20-25 minutes. The single-drop addition amount of the initiator AIBN accounts for 16-20% of the total mass of the initiator AIBN. The reaction temperature is maintained at 80-85 °C, and the reaction is carried out for 100-160 minutes to obtain a fluorosilicon intermediate resin. Mix epoxy resin and xylene evenly. The dosage of the xylene is equal to 20-40% of the mass of the epoxy resin. Heat it to 110-112 °C under nitrogen protection, dropwise add an appropriate amount of DMP-30, and then dropwise add the prepared fluorosilicon intermediate resin, and react for 2.0-2.5 hours, and cool to obtain the epoxy-modified fluorosilicon resin.

[0023] The preparation method of the epoxy-modified fluorosilicon resin in this application is relatively simple and convenient for industrial production and preparation.

[0024] In a second aspect, a high-temperature resistant and high-strength mica composite material prepared by using an epoxy-modified silicone resin is achieved through the following technical solutions:

[0025] A high-temperature resistant and high-strength mica composite material prepared by using an epoxy-modified silicone resin mainly comprises raw materials in the following parts by weight: 20 - 40 parts of an epoxy-modified silicone resin solution with a solid content of 48 - 52% obtained by viscosity modulation of the epoxy-modified silicone resin described in any one of claims 1 - 7, and 80 - 90 parts of surface-modified mica aggregate; the content of organic solvent in the epoxy-modified silicone resin solution is 48 - 52%, the content of the epoxy-modified silicone resin described in any one of claims 1 - 7 is 47.5 - 51%, and the balance is an anti-aging agent.

[0026] The mica composite material prepared by the epoxy-modified silicone resin in this application not only has good fireproof performance, but also has relatively better mechanical strength than silicone-based mica composite materials, combines the excellent mechanical strength of epoxy resin, expands the application range of mica composite materials, meets the needs of different customers, and has a good market prospect.

[0027] Preferably, it is mainly prepared from raw materials in the following parts by weight: 20 - 40 parts of an epoxy-modified silicone resin solution with a solid content of 48 - 52% obtained by viscosity modulation of the epoxy-modified silicone resin described in any one of claims 1 - 7, 80 - 90 parts of surface-modified mica aggregate, and 0.5 - 3 parts of surface-modified toughening and reinforcing agent; the toughening and reinforcing agent is at least one of aramid short fiber, alumina short fiber, zinc oxide whisker, and silicon carbide whisker; the preparation method of the surface-modified toughening and reinforcing agent includes the following steps: S1, preparing an aqueous solution of surface modifier, wherein each 1 L of the aqueous solution of surface modifier contains 4 - 6 g of γ-methacryloxypropyltrimethoxysilane KH570 and 0.5 - 2 g of bis(dioctylpyrophosphoryl)oxyacetyl peptide KR 138S; S2, placing the accurately measured toughening and reinforcing agent into the aqueous solution of surface modifier prepared in S1, performing ultrasonic dispersion treatment for 30 - 60 min, filtering out, and drying the moisture to obtain the finished surface-modified toughening and reinforcing agent.

[0028] The surface-modified toughening and reinforcing agent added in this application mainly plays a role in toughening and reinforcing, thereby improving the overall mechanical properties and flame retardant and fireproof properties, and achieving the purpose of further optimizing and upgrading the product quality. The surface treatment method of the toughening and reinforcing agent provided in this application is relatively simple and easy to realize industrial production.

[0029] Preferably, the surface-modified mica aggregate contains 8-15% of mica powder screened through 1000 mesh, 25-40% of mica powder with a particle size of 800-1000 mesh, 15-30% of mica powder with a particle size of 500-800 mesh, 10-15% of mica powder with a particle size of 300-500 mesh, and the balance is mica powder with a particle size of 160-300 mesh; The preparation method of the surface-modified mica aggregate includes the following steps:

[0030] S1, Weigh mica powder screened through 1000 mesh, mica powder with a particle size of 800-1000 mesh, mica powder with a particle size of 500-800 mesh, mica powder with a particle size of 300-500 mesh, and mica powder with a particle size of 160-300 mesh respectively for standby;

[0031] Meanwhile, prepare 5 identical aqueous solutions of surface modifiers. Each 1 L of the aqueous solution of surface modifiers contains 4-6 g of γ-methacryloxypropyltrimethoxysilane KH570 and 0.5-2 g of bis(dioctylpyrophosphoryl)oxyacetyl peptide KR138S;

[0032] S2, Place the mica powder screened through 1000 mesh, mica powder with a particle size of 800-1000 mesh, mica powder with a particle size of 500-800 mesh, mica powder with a particle size of 300-500 mesh, and mica powder with a particle size of 160-300 mesh weighed in S1 into the aqueous solution of surface modifiers respectively, perform ultrasonic dispersion treatment for 30-60 min, drain, and dry;

[0033] S3, Weigh the mica powder screened through 1000 mesh, mica powder with a particle size of 800-1000 mesh, mica powder with a particle size of 500-800 mesh, mica powder with a particle size of 300-500 mesh, and mica powder with a particle size of 160-300 mesh that have completed surface modification in S2 according to the ratio to obtain the finished surface-modified mica aggregate.

[0034] In this application, the preparation method of the surface-modified mica aggregate is relatively simple and convenient for industrial production. In addition, the mica filler in this application is prepared in the form of mica aggregate, which can improve the overall compatibility and dispersion uniformity of the prepared epoxy-modified silicone resin and mica aggregate. Furthermore, it can ensure the mechanical strength and fireproof and flame-retardant properties of the prepared mica composite material, and realize the further optimization and upgrading of product quality.

[0035] A preparation method of a high-temperature-resistant and high-strength mica composite material prepared by using epoxy-modified silicone resin includes the following steps:

[0036] Step 1, Preparation of epoxy-modified silicone resin; Meanwhile, preparation of surface-modified mica aggregate and preparation of surface-modified toughening and reinforcing agent are carried out;

[0037] Step 2, Use the epoxy-modified silicone resin in Step 1 to prepare an epoxy-modified silicone resin solution with a solid content of 48-52% for standby;

[0038] Step 3: Mix the accurately metered surface-modified mica aggregate and surface-modified toughening and reinforcing agent evenly, then add an epoxy-modified silicone resin solution with a solid content of 48-52% and a diluting solvent, and stir evenly to obtain a mica slurry;

[0039] Step 4: Place the mica slurry in Step 3 into a molding die and perform hot pressing to obtain a high-temperature-resistant and high-strength mica composite material.

[0040] The preparation method of the high-temperature-resistant and high-strength mica composite material provided in this application is relatively simple and easy to realize mass production. Moreover, the mica composite material prepared by the above method not only has good fire resistance but also has good mechanical strength, expanding the applicable range of the mica composite material and meeting the needs of customers at different levels.

[0041] In summary, this application has the following advantages:

[0042] 1. The mica composite material prepared in this application not only has good fire resistance but also has good mechanical strength, expanding the applicable range of the mica composite material and meeting the needs of customers at different levels.

[0043] 2. The preparation method of the high-temperature-resistant and high-strength mica composite material provided in this application is relatively simple and easy to realize mass production, which is conducive to industrial optimization, reduces production costs, and promotes market effect. Specific Embodiments

[0044] The following further elaborates on this application in combination with comparative examples and examples.

[0045] Examples

[0046] Example 1

[0047] An epoxy-modified silicone resin is prepared from a silicone resin and an epoxy-modified resin (the molar ratio of the silicone resin to the epoxy-modified resin is controlled at 1:(0.25-0.35)). The silanol groups in the silicone resin react with the epoxy groups on the epoxy resin under the action of a catalyst DMP-30 at about 110°C to form siloxane bonds. The silicone resin intermediate containing silicon functional groups can undergo dehydration or de-alcoholization reactions with the hydroxyl groups in the epoxy resin molecules, thus forming a high-temperature-resistant and high-strength epoxy-modified silicone resin.

[0048] The epoxy-modified resin is a bisphenol S-type epoxy resin (Suizhou Jiake Bioengineering Co., Ltd., the epoxy equivalent of the low-molecular-weight bisphenol S epoxy resin is (185-195 g / mol), and the softening point (Dush method) is 165-168 °C) in combination with 4,4'-diaminodiphenylmethane tetraglycidylamine (TGDOM, AG-80 epoxy resin, CAS No: 28768-32-3, molecular formula: C 25 H 30 N2O4, molecular weight: 422.52, viscosity: (50±1 °C) 3000-7000 mPa*s, epoxy value: ≥0.80 Eq / Kg), polybutadiene epoxy resin (CAS No. 129288-65-9, epoxy equivalent 220), tetrabromodiphenol propane type epoxy resin (CAS: 6812-78-8, epoxy resin 153-B (EX-48), epoxy equivalent (390-410 / mol); bromine content 46-50%) at least one of them.

[0049] The silicone resin is at least one of silane A, silane B, and silane C with double bonds.

[0050] The structural formula of silane A with double bonds is as follows:

[0051] Among them, n = 8-12.

[0052] The structural formula of silane B with double bonds is as follows:

[0053] Among them, n = 9-15.

[0054] The structural formula of silane C with double bonds is the same as that of silane A, except that n of silane C with double bonds is 130-150.

[0055] In this example, the silicone resin is specifically silane A with double bonds (JNC FM-7711) with a number average molecular weight of 1000. The molar ratio of the silicone resin to the epoxy-modified resin is 1:0.25. The epoxy-modified resin is composed of a bisphenol S-type epoxy resin and 4,4'-diaminodiphenylmethane tetraglycidylamine, and the molar ratio of the bisphenol S-type epoxy resin to 4,4'-diaminodiphenylmethane tetraglycidylamine is 0.2:0.05.

[0056] The preparation method of the epoxy-modified silicone resin is as follows: 0.2 mol of bisphenol S-type epoxy resin and 0.05 mol of 4,4'-diaminodiphenylmethane tetraglycidylamine are mixed evenly, then 200 mL of xylene is added and mixed evenly, 0.36 g of DMP-30 catalyst is added, nitrogen is introduced to exhaust air, and then the temperature is raised to 110 °C. A silane A (JNCFM-7711) with double bonds and a number-average molecular weight of 1000 is added dropwise at a dropping rate controlled at 4 g / min. After the dropping is completed, the reaction is maintained at 110 °C for 2.0 h, and then cooled to obtain the finished epoxy-modified silicone resin.

[0057] A high-temperature resistant and high-strength mica composite material prepared by using an epoxy-modified silicone resin is prepared from the following raw materials in parts by weight: 30 parts of an epoxy-modified silicone resin solution with a solid content of 50% is prepared by modulating the above-prepared finished epoxy-modified silicone resin, 4 parts of a curing agent, and 85 parts of surface-modified mica aggregate. The curing agent is composed of phthalic anhydride PA and endomethylenetetrahydrophthalic anhydride, and the mass ratio of phthalic anhydride PA to endomethylenetetrahydrophthalic anhydride is 80:20.

[0058] The epoxy-modified silicone resin solution with a solid content of 50% contains 50% of the epoxy-modified silicone resin, 1% of an anti-aging aid, and 49% of xylene solvent. The anti-aging aid is composed of antioxidant 1010, antioxidant 168, ultraviolet absorber UV-326, UV-531, and nano-titanium nitride with a mass ratio of 40:10:30:19:1.

[0059] The surface-modified mica aggregate contains 15% of mica powder screened through 1000 meshes, 40% of mica powder with a particle size of 800-1000 meshes, 25% of mica powder with a particle size of 500-800 meshes, 15% of mica powder with a particle size of 300-500 meshes, and 5% of mica powder with a particle size of 160-300 meshes.

[0060] The preparation method of the high-temperature resistant and high-strength mica composite material includes the following steps:

[0061] Including the following steps:

[0062] Step 1, preparation of the epoxy-modified silicone resin:

[0063] 0.2 mol of bisphenol S-type epoxy resin and 0.05 mol of 4,4'-diaminodiphenylmethane tetraglycidylamine are mixed evenly, then 200 mL of xylene is added and mixed evenly, 0.36 g of DMP-30 catalyst is added, nitrogen is introduced to exhaust air, and then the temperature is raised to 110 °C. A silane A (JNC FM-7711) with double bonds and a number-average molecular weight of 1000 is added dropwise at a dropping rate controlled at 4 g / min. After the dropping is completed, the reaction is maintained at 110 °C for 2.0 h, and then cooled to obtain the finished epoxy-modified silicone resin;

[0064] Preparation of mica aggregate after surface modification simultaneously:

[0065] S1.1, Weigh mica powder screened by 1000-mesh sieve, mica powder of 800 - 1000 mesh, mica powder of 500 - 800 mesh, mica powder of 300 - 500 mesh, and mica powder of 160 - 300 mesh respectively for standby;

[0066] Prepare 5 identical aqueous solutions of surface modifiers simultaneously. Each 1 L of the aqueous solution of surface modifier contains 6 g of γ-methacryloxypropyltrimethoxysilane KH570 and 2 g of bis(dioctylpyrophosphoryl) acetyl oxide peptide KR 138S;

[0067] S1.2, Put the mica powder screened by 1000-mesh sieve, mica powder of 800 - 1000 mesh, mica powder of 500 - 800 mesh, mica powder of 300 - 500 mesh, and mica powder of 160 - 300 mesh weighed in S1 into the aqueous solution of surface modifier respectively, perform ultrasonic dispersion treatment for 60 min, drain, and dry;

[0068] S1.3, Weigh the mica powder screened by 1000-mesh sieve, mica powder of 800 - 1000 mesh, mica powder of 500 - 800 mesh, mica powder of 300 - 500 mesh, and mica powder of 160 - 300 mesh that have completed surface modification in S2 according to the ratio to obtain the finished mica aggregate after surface modification; Step two, Prepare an epoxy-modified silicone resin solution with a solid content of 50% by using the epoxy-modified silicone resin and solvent xylene in step one, add accurately metered phthalic anhydride PA and endomethylenetetrahydrophthalic anhydride, stir and mix evenly for standby;

[0069] Step three, Add 850 g of the mica aggregate after surface modification to a mixed solution of 300 g of the epoxy-modified silicone resin solution with a solid content of 50% and 100 g of the diluting solvent xylene at a speed of 50 g / min. During the addition process, maintain stirring at 350 rpm. After the mica aggregate is added, maintain stirring for 10 min to obtain mica slurry;

[0070] Step four, Put the mica slurry in step three into a molding die, heat to remove the organic solvent, and then perform five-step hot pressing:

[0071] In the first-step hot pressing, the hot pressing temperature is 108 °C, the pressure is 0.5 MPa, after hot pressing for 25 s, release air for 3 s and then hot press for 10 s. The total hot pressing time is 38 s;

[0072] In the second-step hot pressing, the hot pressing temperature is 145 °C, the pressure is 0.8 MPa. After hot pressing for 25 s, release air for 3 s, then hot press for 25 s and release air for 3 s, then hot press for 25 s and release air for 3 s, then hot press for 25 s and release air for 3 s. The total hot pressing time is 100 s;

[0073] In the third step of hot pressing, the hot pressing temperature is 208 °C, the pressure is 1 MPa, and the hot pressing duration is 180 s;

[0074] In the fourth step of hot pressing, the hot pressing temperature is 130 °C, the pressure is 0.6 MPa, and the duration is 80 s;

[0075] In the fifth step of hot pressing, the hot pressing temperature is 95 °C, the pressure is 0.40 MPa, and the duration is 120 s. After completing the five-step hot pressing, the semi-finished mica board is placed at 78 °C for heat preservation treatment for 120 min and then naturally cooled to room temperature to obtain the high-temperature-resistant and high-strength mica composite material.

[0076] Example 2

[0077] The difference between Example 2 and Example 1 is that in this example, the silicone resin is specifically silane A (JNC FM-7711) with a number-average molecular weight of 1000 and double bonds. The molar ratio of the silicone resin to the epoxy-modified resin is 1:0.25. The epoxy-modified resin is composed of bisphenol S-type epoxy resin and polybutadiene epoxy resin, and the molar ratio of bisphenol S-type epoxy resin to polybutadiene epoxy resin is 0.2:0.05.

[0078] Example 3

[0079] The difference between Example 3 and Example 1 is that in this example, the silicone resin is specifically silane A (JNC FM-7711) with a number-average molecular weight of 1000 and double bonds. The molar ratio of the silicone resin to the epoxy-modified resin is 1:0.25. The epoxy-modified resin is composed of bisphenol S-type epoxy resin and tetrabromobisphenol A type epoxy resin, and the molar ratio of bisphenol S-type epoxy resin to tetrabromobisphenol A type epoxy resin is 0.2:0.05.

[0080] Example 4

[0081] The difference between Example 4 and Example 1 is that the epoxy-modified resin is composed of bisphenol S-type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, and polybutadiene epoxy resin, and the molar ratio of bisphenol S-type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, and polybutadiene epoxy resin is 85:5:10.

[0082] Example 5

[0083] The difference between Example 5 and Example 1 is that the epoxy-modified resin is composed of bisphenol S-type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, and polybutadiene epoxy resin, and the molar ratio of bisphenol S-type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, and polybutadiene epoxy resin is 75:8:17.

[0084] Example 6

[0085] The difference between Example 6 and Example 1 lies in that the epoxy-modified resin is composed of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine and polybutadiene epoxy resin, and the molar ratio of bisphenol S-type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, and polybutadiene epoxy resin is 70:10:20.

[0086] Example 7

[0087] The difference between Example 7 and Example 1 lies in that the epoxy-modified resin is composed of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A-type epoxy resin, and the molar ratio of bisphenol S-type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A-type epoxy resin is 77:5:10:8.

[0088] Example 8

[0089] The difference between Example 8 and Example 1 lies in that the epoxy-modified resin is composed of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A-type epoxy resin, and the molar ratio of bisphenol S-type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A-type epoxy resin is 66:8:16:10.

[0090] Example 9

[0091] The difference between Example 9 and Example 1 lies in that the epoxy-modified resin is composed of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A-type epoxy resin, and the molar ratio of bisphenol S-type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A-type epoxy resin is 50:15:20:15.

[0092] Example 10

[0093] The difference between Example 10 and Example 1 lies in that in this example, the silicone resin is specifically silane A (JNC FM-7711) with double bonds and a number average molecular weight of 1000. The molar ratio of the silicone resin to the epoxy-modified resin is 1:0.30.

[0094] Example 11

[0095] The difference between Example 11 and Example 1 lies in that in this example, the silicone resin is specifically silane A (JNC FM-7711) with double bonds and a number average molecular weight of 1000. The molar ratio of the silicone resin to the epoxy-modified resin is 1:0.35.

[0096] Example 12

[0097] The difference between Example 12 and Example 1 is that in this example, the silicone resin is specifically silane B (JNC FM-0711) with a number average molecular weight of 1000 and having double bonds. The molar ratio of the silicone resin to the epoxy modified resin is 1:0.25.

[0098] Example 13

[0099] The difference between Example 13 and Example 1 is that the molar ratio of the silicone resin to the epoxy modified resin is 1:0.32. The epoxy modified resin is composed of bisphenol S type epoxy resin and 4,4'-diaminodiphenylmethane tetraglycidylamine, and the molar ratio of bisphenol S type epoxy resin to 4,4'-diaminodiphenylmethane tetraglycidylamine is 8:2.

[0100] Example 14

[0101] The difference between Example 14 and Example 1 is that the molar ratio of the silicone resin to the epoxy modified resin is 1:0.32. The epoxy modified resin is composed of bisphenol S type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A type epoxy resin, and the molar ratio of bisphenol S type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A type epoxy resin is 68:12:10:10.

[0102] Example 15

[0103] The difference between Example 15 and Example 1 is that the molar ratio of the silicone resin to the epoxy modified resin is 1:0.32. The epoxy modified resin is composed of bisphenol S type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A type epoxy resin, and the molar ratio of bisphenol S type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin, and tetrabromobisphenol A type epoxy resin is 70:12:10:8.

[0104] Example 16

[0105] The difference between Example 16 and Example 14 is that in this example, the silicone resin is specifically silane A (JNC FM-7711) with a number average molecular weight of 1000 and silane A (JNC FM-7725) with a number average molecular weight of 10000, and the molar ratio is 0.8:0.2.

[0106] Example 17

[0107] The difference between Example 17 and Example 14 is that in this example, the silicone resin is specifically silane A with a double bond and a number average molecular weight of 1000 (JNC FM-7711) and silane A with a double bond and a number average molecular weight of 10000 (JNC FM-7725), and the molar ratio is 0.78:0.22.

[0108] Example 18

[0109] The difference between Example 18 and Example 14 is that in this example, the silicone resin is specifically silane A with a double bond and a number average molecular weight of 1000 (JNC FM-7711) and silane A with a double bond and a number average molecular weight of 10000 (JNC FM-7725), and the molar ratio is 0.75:0.25.

[0110] Example 19

[0111] The difference between Example 19 and Example 14 is that in this example, the silicone resin is specifically silane A with a double bond and a number average molecular weight of 1000 (JNC FM-7711) and silane A with a double bond and a number average molecular weight of 10000 (JNC FM-7725), and the molar ratio is 0.7:0.3.

[0112] Example 20

[0113] The difference between Example 20 and Example 14 is that in this example, the silicone resin is specifically silane A with a double bond and a number average molecular weight of 1000 (JNC FM-7711) and silane A with a double bond and a number average molecular weight of 10000 (JNC FM-7725), and the molar ratio is 0.9:0.1.

[0114] Example 21

[0115] The difference between Example 21 and Example 14 is that in this example, the silicone resin is specifically silane B with a double bond and a number average molecular weight of 1000 (JNC FM-0711) and silane A with a double bond and a number average molecular weight of 10000 (JNC FM-7725), and the molar ratio is 0.8:0.2.

[0116] Example 22

[0117] The difference between Example 22 and Example 14 is that in this example, the silicone resin is specifically silane A with a double bond and a number average molecular weight of 1000 (JNC FM-7711), silane B with a double bond and a number average molecular weight of 1000 (JNC FM-0711), and silane A with a double bond and a number average molecular weight of 10000 (JNC FM-7725), and the molar ratio is 0.5:0.3:0.2.

[0118] Example 23

[0119] The difference between Example 23 and Example 16 is that: it further includes a modified fluororesin, and the modified fluororesin is perfluorooctylpropyl acrylate. Perfluorooctylpropyl acrylate chemically reacts with silicone resin to produce a fluorosilicone intermediate, and the fluorosilicone intermediate reacts with bisphenol S type epoxy resin to obtain an epoxy-modified fluorosilicone resin; the molar amount of perfluorooctylpropyl acrylate is equal to 8% of the molar amount of silicone resin, and the molar ratio of silicone resin to epoxy resin is 1:0.28.

[0120] The preparation method of the epoxy-modified fluorosilicone resin is as follows:

[0121] Accurately measure perfluorooctylpropyl acrylate and silicone resin and pre-mix them evenly with xylene to obtain a mixed solution, and the mass of xylene is equal to 50% of the total mass of perfluorooctylpropyl acrylate and silicone resin; add the evenly mixed mixed solution into a reaction kettle equipped with a reflux device, flush with nitrogen for protection, stir and heat up to 80°C, keep the temperature for 10.0 min, add initiator AIBN dropwise every 20 min, and the single-drop addition amount of initiator AIBN accounts for 20% of the total mass of initiator AIBN. Keep the reaction temperature at 80°C and react for 150 min to obtain a fluorosilicone intermediate resin. Mix epoxy resin and xylene evenly, and the amount of xylene used is 40% of the mass of epoxy resin. Heat it to 110 - 112°C under nitrogen protection, add an appropriate amount of DMP-30 (accounting for 0.3% of the mass of epoxy resin), and then add the prepared fluorosilicone intermediate resin dropwise at a dropping rate of 8.0 g / min and react for 2.0 h, and cool to obtain the epoxy-modified fluorosilicone resin.

[0122] Example 24

[0123] The difference between Example 24 and Example 16 is that: the molar amount of perfluorooctylpropyl acrylate is equal to 12% of the molar amount of silicone resin, and the molar ratio of silicone resin to epoxy resin is 1:0.30.

[0124] Example 25

[0125] The difference between Example 25 and Example 16 is that: the molar amount of perfluorooctylpropyl acrylate is equal to 15% of the molar amount of silicone resin, and the molar ratio of silicone resin to epoxy resin is 1:0.35.

[0126] Example 26

[0127] Example 26 is different from Example 16 in that: a high temperature resistant and high strength mica composite material prepared by using epoxy modified silicone resin is prepared from the following raw materials in parts by weight: the finished epoxy modified silicone resin in Example 1 above is used for modulation to obtain 30 parts of epoxy modified silicone resin liquid with a solid content of 50%, 4 parts of curing agent, 85 parts of surface modified mica aggregate, and 0.3 part of surface modified toughening and reinforcing agent zinc oxide whisker.

[0128] Preparation method of surface modified toughening and reinforcing agent, including the following steps:

[0129] S1, prepare an aqueous solution of surface modifier, and each 1 L of the aqueous solution of surface modifier contains 6 g of γ-methacryloxypropyltrimethoxysilane KH570 and 2 g of bis(dioctylpyrophosphoryl) acetyl oxide peptide KR 138S;

[0130] S2, place the accurately measured toughening and reinforcing agent zinc oxide whisker into the aqueous solution of surface modifier prepared in S1, perform ultrasonic dispersion treatment for 60 min, drain, and dry the moisture to obtain the finished surface modified zinc oxide whisker.

[0131] Example 27

[0132] Example 27 is different from Example 16 in that: a high temperature resistant and high strength mica composite material prepared by using epoxy modified silicone resin is prepared from the following raw materials in parts by weight: the finished epoxy modified silicone resin in Example 1 above is used for modulation to obtain 30 parts of epoxy modified silicone resin liquid with a solid content of 50%, 4 parts of curing agent, 85 parts of surface modified mica aggregate, and 0.5 part of surface modified toughening and reinforcing agent zinc oxide whisker.

[0133] Example 28

[0134] Example 28 is different from Example 16 in that: a high temperature resistant and high strength mica composite material prepared by using epoxy modified silicone resin is prepared from the following raw materials in parts by weight: the finished epoxy modified silicone resin in Example 1 above is used for modulation to obtain 30 parts of epoxy modified silicone resin liquid with a solid content of 50%, 4 parts of curing agent, 85 parts of surface modified mica aggregate, and 1.5 parts of surface modified toughening and reinforcing agent zinc oxide whisker.

[0135] Example 29

[0136] Example 29 is different from Example 16 in that: A high-temperature resistant and high-strength mica composite material prepared by using epoxy-modified silicone resin is prepared from the following raw materials in parts by weight: Using the finished epoxy-modified silicone resin in Example 1 above, 30 parts of epoxy-modified silicone resin solution with a solid content of 50%, 4 parts of curing agent, 85 parts of surface-modified mica aggregate, and 3 parts of surface-modified toughening and reinforcing agent zinc oxide whiskers are obtained after modulation.

[0137] Example 30

[0138] Example 30 is different from Example 16 in that: A high-temperature resistant and high-strength mica composite material prepared by using epoxy-modified silicone resin is prepared from the following raw materials in parts by weight: Using the finished epoxy-modified silicone resin in Example 1 above, 30 parts of epoxy-modified silicone resin solution with a solid content of 50%, 4 parts of curing agent, 85 parts of surface-modified mica aggregate, and 3.5 parts of surface-modified toughening and reinforcing agent zinc oxide whiskers are obtained after modulation.

[0139] Comparative Example

[0140] Comparative Example 1 is different from Example 1 in that: The epoxy resin is only bisphenol S type epoxy resin.

[0141] Comparative Example 2 is different from Example 1 in that: The epoxy resin is only bisphenol A type epoxy resin E41.

[0142] Comparative Example 3 is different from Example 1 in that: The molar ratio of silicone resin to epoxy-modified resin is 1:0.20. The epoxy-modified resin is composed of bisphenol S type epoxy resin and polybutadiene epoxy resin, and the molar ratio of bisphenol S type epoxy resin to polybutadiene epoxy resin is 0.16:0.04.

[0143] Comparative Example 4 is different from Example 1 in that: The molar ratio of silicone resin to epoxy-modified resin is 1:0.40. The epoxy-modified resin is composed of bisphenol S type epoxy resin and polybutadiene epoxy resin, and the molar ratio of bisphenol S type epoxy resin to polybutadiene epoxy resin is 0.32:0.08.

[0144] Comparative Example 5 is different from Example 1 in that: The silicone resin is replaced with conventional KH570.

[0145] Comparative Example 6 is different from Example 1 in that: The silicone resin is replaced with conventional KH571.

[0146] Comparative Example 7 is different from Example 1 in that: The epoxy-modified resin is composed of bisphenol S type epoxy resin, 4,4-diaminodiphenylmethane tetraglycidylamine, and polybutadiene epoxy resin, and the molar ratio of bisphenol S type epoxy resin, 4,4-diaminodiphenylmethane tetraglycidylamine, and polybutadiene epoxy resin is 90:3:7.

[0147] The difference between Comparative Example 8 and Example 1 lies in that the epoxy-modified resin is composed of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine and polybutadiene epoxy resin, and the molar ratio of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine and polybutadiene epoxy resin is 60:12:23.

[0148] The difference between Comparative Example 9 and Example 1 lies in that the epoxy-modified resin is composed of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin and tetrabromodiphenol propane-type epoxy resin, and the molar ratio of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin and tetrabromodiphenol propane-type epoxy resin is 85:3:7:5.

[0149] The difference between Comparative Example 10 and Example 1 lies in that the epoxy-modified resin is composed of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin and tetrabromodiphenol propane-type epoxy resin, and the molar ratio of bisphenol S-type epoxy resin combined with 4,4'-diaminodiphenylmethane tetraglycidylamine, polybutadiene epoxy resin and tetrabromodiphenol propane-type epoxy resin is 50:11:23:16.

[0150] The difference between Comparative Example 11 and Example 23 lies in that the molar amount of perfluorooctylpropyl acrylate is equal to 5.0% of the molar amount of the silicone resin, and the molar ratio of the silicone resin to the pre-epoxy resin is 1:0.28.

[0151] The difference between Comparative Example 12 and Example 23 lies in that the molar amount of perfluorooctylpropyl acrylate is equal to 18% of the molar amount of the silicone resin, and the molar ratio of the silicone resin to the pre-epoxy resin is 1:0.35.

[0152] The difference between Comparative Example 13 and Example 23 lies in that perfluorooctylpropyl acrylate is replaced by 1H,1H-heptafluorobutyl acrylate.

[0153] The difference between Comparative Example 14 and Example 23 lies in that perfluorooctylpropyl acrylate is replaced by perfluorodecylethyl acrylate.

[0154] The difference between Comparative Example 15 and Example 26 lies in that a high-temperature resistant and high-strength mica composite material prepared by using an epoxy-modified silicone resin is prepared from the following raw materials in parts by weight: 30 parts of an epoxy-modified silicone resin solution with a solid content of 50% prepared by modulating the finished epoxy-modified silicone resin in Example 1 above, 4 parts of a curing agent, 85 parts of surface-modified mica aggregate, and 0.5 part of toughening and reinforcing agent zinc oxide whisker that has not been surface-modified.

[0155] The difference between Comparative Example 16 and Example 26 lies in: A high-temperature-resistant and high-strength mica composite material prepared by using epoxy-modified silicone resin is prepared from the following raw materials in parts by weight: The finished epoxy-modified silicone resin in Example 1 above is used for modulation to obtain 30 parts of epoxy-modified silicone resin liquid with a solid content of 50%, 4 parts of curing agent, 85 parts of mica material with D50 = 30 - 40um after surface modification, and 0.5 part of toughening and reinforcing agent zinc oxide whisker without surface modification.

[0156] Performance detection test

[0157] Detection method / Test method

[0158] The difference between Control Group 1 and Example 1 is that: The epoxy-modified organic resin is replaced by ordinary silicone resin - Shin-Etsu silicone resin KR242A from Japan.

[0159] The difference between Control Group 2 and Example 1 is that: The epoxy-modified organic resin is replaced by ordinary epoxy resin - specifically as follows: Bisphenol S type epoxy resin (Suizhou Jiake Bio-Engineering Co., Ltd., epoxy equivalent of low molecular weight bisphenol S epoxy resin (185 - 195 g / mol), softening point (Dush) 165 - 168 °C) is combined with 4,4'-diaminodiphenylmethane tetraglycidylamine (TGDOM, AG-80 epoxy resin, CAS No: 28768-32-3, molecular formula: C 25 H 30 N2O4, molecular weight: 422.52, viscosity: (50 ± 1 °C) 3000 - 7000 mPa*s, epoxy value: ≥0.80 Eq / Kg), tetrabromobisphenol A type epoxy resin (CAS: 6812-78-8, epoxy resin 153-B (EX-48), epoxy equivalent (390 - 410 / mol); bromine content 46 - 50%). Among them, the mass ratio of bisphenol S type epoxy resin, 4,4'-diaminodiphenylmethane tetraglycidylamine epoxy resin, and tetrabromobisphenol A type epoxy resin is controlled at 76:18:8. The curing agent is composed of phthalic anhydride PA and endomethylenetetrahydrophthalic anhydride, and the mass ratio of phthalic anhydride PA and endomethylenetetrahydrophthalic anhydride is 80:20. In addition, 1.0 part of surface-modified toughening and reinforcing agent - aramid short fiber (purchased 100D Kevlar fiber, cut length 51 mm) is added.

[0160] 1. Bending strength test: According to the test method for mica products GB / T 5019.2-2009, Article 11 "Bending strength and flexural modulus of elasticity" for testing, the specifications of the specimen after cutting: width about 25 mm, test span 16 mm, test speed 50 mm / min, indenter radius 5 mm.

[0161] 2. Tensile Strength Test: Test according to GB / T 1040.2-2022.

[0162] 3. Impact Strength Test: Test according to GB / T 1043.1-2008.

[0163] 4. Fire Resistance Test: Test according to T / ZZB 1722-2020. Instrument: A gas burner that can generate different high-temperature flame temperatures by adjusting the flow rate of propane or butane, and a K-type thermocouple thermometer with a 1.5m insulated stainless steel sheath. Specimen size and quantity: (200mm ± 10mm) * (280mm ± 10mm), 3 pieces. Measurement steps: Place the specimen vertically at a distance of 65mm ± 5m from the flame, ignite the flame, adjust the flow rate of propane or butane so that the temperature on the side of the specimen facing the flame in the middle is 1100 ± 100°C. Burn at this temperature and maintain the burning time for 5 minutes, then remove the flame and check whether the specimen has burned through.

[0164] 5. Flame Retardancy Test: Test according to the provisions of UL 94.

[0165] 6. Electrical Strength Test: Test according to Article 22, "Electrical Strength" in the test method for mica products of GB / T 5019.2-2009. The thickness of the specimen is 0.39mm - 0.41mm. Use a Φ25mm / Φ75mm cylindrical electrode system and the rapid voltage increase method (the voltage increase speed is 1.0kV / s). Conduct the test in No. 25 transformer oil at 23°C ± 2°C.

[0166] Data Analysis

[0167] Table 1 shows the test parameters of the composite mica materials in Examples 1-30 and Comparative Examples 1-16.

[0168]

[0169]

[0170]

[0171] Table 2 shows the fire resistance test parameters of the composite mica materials in Examples 1-30 and Comparative Examples 1-16.

[0172]

[0173]

[0174]

[0175] Combined with Examples 1-30 and Comparative Examples 1-16 and in combination with Tables 1-2, it can be seen that by comparing Examples 1-3 with Comparative Examples 1-2, the comprehensive mechanical properties and fire resistance of the composite mica materials prepared in Examples 1-3 are relatively better than those of Comparative Examples 1-2. That is, when bisphenol S-type epoxy resin is combined with at least one of tetraglycidyl methyl dianiline epoxy resin, polybutadiene epoxy resin, and tetrabromodiphenol propane-type epoxy resin, the mechanical properties and fire resistance of the prepared composite mica materials are relatively better.

[0176] Specifically, the flexural strength of Example 1 is better than that of Example 2, and the flexural strength of Example 2 is better than that of Comparative Example 1. However, the tensile strength and impact strength of Example 1 are slightly lower than those of Example 2. Therefore, the technical solution of using bisphenol S-type epoxy resin combined with tetraglycidyl methyl dianiline epoxy resin can significantly improve the flexural strength of the finished product, and both the tensile strength and impact strength are also improved. However, the improvement amplitudes of the tensile strength and impact strength in the technical solution of Example 1 are smaller than those of Example 2 (where bisphenol S-type epoxy resin is combined with polybutadiene epoxy resin), and the improvement amplitude of the flexural strength of Example 2 is smaller than that of Example 1.

[0177] Specifically, the mechanical strength of Example 3 is lower than that of Example 1, but the weather resistance of Example 3 is better than that of Example 1. Therefore, the technical solution of using bisphenol S-type epoxy resin combined with tetrabromodiphenol propane-type epoxy resin can relatively significantly improve the overall fire resistance.

[0178] Based on the technical orientations presented by Examples 1-2 and Comparative Examples 1-2, the present application conducts a compound combination of the epoxy resins used and thus seeks an excellent high-strength and high-temperature-resistant epoxy-modified silicone resin. Specifically, the epoxy resin is composed of bisphenol S-type epoxy resin combined with tetraglycidyl methyl dianiline epoxy resin and polybutadiene epoxy resin. Or specifically, the epoxy resin is composed of bisphenol S-type epoxy resin combined with tetraglycidyl methyl dianiline epoxy resin, polybutadiene epoxy resin, and tetrabromodiphenol propane-type epoxy resin.

[0179] In the epoxy resin system composed of bisphenol S epoxy resin, tetraglycidyl methyl dianiline epoxy resin, and polybutadiene epoxy resin, by combining Examples 1-6, Comparative Examples 1-2, and Comparative Examples 7-8 and referring to Tables 1-2, it can be seen that when the molar ratio of bisphenol S epoxy resin, tetraglycidyl methyl dianiline epoxy resin, and polybutadiene epoxy resin is controlled at (70-85):(5-10):(10-20), the prepared mica composite material has good flexural strength, tensile strength, impact strength, and fire resistance. Preferably, in the epoxy resin system composed of bisphenol S epoxy resin, tetraglycidyl methyl dianiline epoxy resin, polybutadiene epoxy resin, and tetrabromobisphenol A epoxy resin, by combining Examples 1-9, Comparative Examples 1-2, and Comparative Examples 7-10 and referring to Tables 1-2, it can be seen that when the molar ratio of bisphenol S epoxy resin, tetraglycidyl methyl dianiline epoxy resin, polybutadiene epoxy resin, and tetrabromobisphenol A epoxy resin is controlled at (50-77):(5-15):(10-20):(8-15), the prepared mica composite material has good flexural strength, tensile strength, impact strength, and fire resistance. From Examples 13-15, the preferred scheme is as follows: the oxygen-modified resin has a molar ratio of bisphenol S epoxy resin, tetraglycidyl methyl dianiline epoxy resin, polybutadiene epoxy resin, and tetrabromobisphenol A epoxy resin of (68-70):12:10:(8-10).

[0180] The amount of epoxy resin has a close influence on the properties of the finally obtained composite mica material. As can be seen by combining Examples 1, 10-13 and Comparative Examples 3-4 and referring to Tables 1-2, it is more appropriate to control the molar ratio of silicone resin to the epoxy-modified resin at 1:(0.25-0.35). Preferably, the molar ratio of silicone resin to epoxy-modified resin is controlled at 1:0.32-0.35. In this application, Examples 16-30 are carried out with the molar ratio of silicone resin to epoxy-modified resin controlled at 1:0.32.

[0181] By combining Examples 1-30 and Comparative Examples 1-16 and referring to Tables 1-2, it can be seen that by comparing between Examples 14-22, when the organic resin is composed of silane A with a number-average molecular weight of 1000 and having double bonds and silane C with a number-average molecular weight of 10000 and having double bonds, the tensile strength and impact strength of the prepared mica composite material are improved, thereby improving the overall mechanical strength and toughness. By comparing between Examples 14-22, it is more suitable to control the molar ratio of silane A with a number-average molecular weight of 1000 and having double bonds and silane C with a number-average molecular weight of 10000 and having double bonds at (75-80):(20-25) to ensure the tensile strength and impact strength of the prepared mica composite material.

[0182] Combined with Examples 1-30 and Comparative Examples 1-16 and in conjunction with Tables 1-2, it can be seen that by comparing between Example 16 and Examples 23-25, the epoxy-modified fluorosilicone resin prepared by introducing modified fluororesin can, to a certain extent, improve the flexural strength and fire resistance of the overall mica composite material. However, the improvement in tensile strength and impact strength is not obvious and even slightly decreases. However, the epoxy-modified fluorosilicone resin can endow the whole with better stain resistance, weather resistance and surface cleanliness, making the surface cleanliness of the finished product more easily meet the actual needs of customers and facilitating the recognition of the mass market. By comparing Example 16, 23-25 with Comparative Examples 11-12, it can be seen that it is more appropriate that the molar amount of perfluorooctylpropyl acrylate is 8-15% of the molar amount of silicone resin.

[0183] Combined with Examples 1-30 and Comparative Examples 1-16 and in conjunction with Tables 1-2, it can be seen that by comparing between Example 23 and Comparative Examples 13-14, using a specific perfluorooctylpropyl acrylate as the modified fluororesin of the epoxy-modified fluorosilicone resin can prepare a mica composite material with high performance, high strength and high temperature resistance. From the results of the small-scale test, only a specific perfluorooctylpropyl acrylate among the modified fluororesins of the epoxy-modified fluorosilicone resin can play a better role in reinforcing flexural strength, tensile strength, impact strength and fire resistance.

[0184] Combined with Examples 1-30 and Comparative Examples 1-16 and in conjunction with Tables 1-2, it can be seen that by comparing between Examples 26-30 and Comparative Example 15, the toughening and reinforcing agent after surface modification can effectively improve the flexural strength, tensile strength, impact strength and fire resistance of the whole. It is appropriate to control the addition amount of the toughening and reinforcing agent after surface modification within 0.5-3 parts.

[0185] Combined with Examples 1-30 and Comparative Examples 1-16 and in conjunction with Tables 1-2, it can be seen that by comparing between Example 27 and Comparative Example 16, using the mica aggregate after surface modification can improve the flexural strength, tensile strength, impact strength and fire resistance of the whole.

[0186] This specific embodiment is only an interpretation of the present application and does not limit the present application. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. An epoxy-modified silicone resin, characterized in that: The epoxy-modified silicone resin is mainly prepared from a silicone resin, an epoxy-modified resin, and a modified fluororesin. The molar ratio of the silicone resin to the epoxy-modified resin is controlled at 1:(0.25 - 0.35); the epoxy-modified resin is composed of bisphenol S type epoxy resin, tetraglycidyl methyl dianiline epoxy resin, polybutadiene epoxy resin, and tetrabromobisphenol propane type epoxy resin; the molar ratio of bisphenol S type epoxy resin, tetraglycidyl methyl dianiline epoxy resin, polybutadiene epoxy resin, and tetrabromobisphenol propane type epoxy resin is 68:12:10:10; the silicone resin is composed of silane A with a number average molecular weight of 1000 and having a double bond and silane C with a number average molecular weight of 10000 and having a double bond; the molar ratio of silane A with a number average molecular weight of 1000 and having a double bond to silane C with a number average molecular weight of 10000 and having a double bond is controlled at (75 - 80):(20 - 25); the modified fluororesin is produced by the chemical reaction of perfluorooctylpropyl acrylate with the silicone resin to produce a fluorosilicone intermediate, and the fluorosilicone intermediate reacts with bisphenol S type epoxy resin; the molar amount of perfluorooctylpropyl acrylate is equal to 8 - 15% of the molar amount of the silicone resin; The structural formula of the silane A with a double bond is as follows: ， where n = 8 - 12; The structural formula of the silane C with a double bond is the same as that of silane A, the difference being that n of the silane C with a double bond is 130 - 150.

2. An epoxy-modified silicone resin according to claim 1, characterized in that: The preparation method of the modified fluororesin is as follows: Accurately measure perfluorooctylpropyl acrylate and the silicone resin and pre-mix them evenly with xylene to obtain a mixed solution. The mass of the xylene is equal to 48 - 54% of the total mass of perfluorooctylpropyl acrylate and the silicone resin; Add the evenly mixed mixed solution into a reaction kettle equipped with a reflux device, charge nitrogen for protection, stir and heat up to 80°C, keep warm for 5 - 10 min, add the initiator AIBN dropwise every 20 - 25 min, and the single-drop addition amount of the initiator AIBN accounts for 16 - 20% of the total mass of the initiator AIBN. The reaction temperature is maintained at 80 - 85°C, and the reaction is carried out for 100 - 160 min to obtain a fluorosilicone intermediate resin. Mix epoxy resin and xylene evenly. The dosage of the xylene accounts for 20 - 40% of the mass of the epoxy resin. Heat it to 110 - 112°C under nitrogen protection, dropwise add an appropriate amount of DMP-30, and then dropwise add the prepared fluorosilicone intermediate resin, and react for 2.0 - 2.5 h, and cool to obtain the modified fluororesin.

3. A high-temperature and high-strength mica composite material prepared by using the epoxy-modified silicone resin according to any one of claims 1-2, characterized in that: It is mainly prepared from the following raw materials in parts by weight: 20 - 40 parts of an epoxy-modified silicone resin solution with a solid content of 48 - 52% obtained by viscosity modulation of the epoxy-modified silicone resin described in any one of claims 1 - 2, and 80 - 90 parts of surface-modified mica aggregate; the content of the organic solvent in the epoxy-modified silicone resin solution is 48 - 52%, the content of the epoxy-modified silicone resin described in any one of claims 1 - 2 is 47.5 - 51%, and the balance is an anti-aging aid.

4. A high-temperature resistant and high-strength mica composite material prepared by using epoxy-modified silicone resin according to claim 3, characterized in that: It is mainly prepared from the following raw materials in parts by weight: 20 - 40 parts of an epoxy-modified silicone resin solution with a solid content of 48 - 52% obtained by viscosity modulation of the epoxy-modified silicone resin described in any one of claims 1 - 2, 80 - 90 parts of surface-modified mica aggregate, and 0.5 - 3 parts of surface-modified toughening and reinforcing agent; the toughening and reinforcing agent is at least one of aramid short fiber, alumina short fiber, zinc oxide whisker, and silicon carbide whisker; the preparation method of the surface-modified toughening and reinforcing agent includes the following steps: S1, prepare an aqueous solution of surface modifier, where each 1 L of the aqueous solution of surface modifier contains 4 - 6 g of γ-methacryloxypropyltrimethoxysilane KH570 and 0.5 - 2 g of bis(dioctylpyrophosphoryl) oxide acetyl peptide KR 138S; S2, place the accurately measured toughening and reinforcing agent into the aqueous solution of surface modifier prepared in S1, perform ultrasonic dispersion treatment for 30 - 60 min, drain, and dry the moisture to obtain the finished surface-modified toughening and reinforcing agent.

5. A high-temperature and high-strength mica composite material prepared using epoxy-modified silicone resin according to claim 3 or 4, characterized in that: The surface-modified mica aggregate contains 8 - 15% of mica powder screened through 1000 meshes, 25 - 40% of mica powder with 800 - 1000 meshes, 15 - 30% of mica powder with 500 - 800 meshes, 10 - 15% of mica powder with 300 - 500 meshes, and the balance is mica powder with 160 - 300 meshes; the preparation method of the surface-modified mica aggregate includes the following steps: S1, weigh the mica powder screened through 1000 meshes, mica powder with 800 - 1000 meshes, mica powder with 500 - 800 meshes, mica powder with 300 - 500 meshes, and mica powder with 160 - 300 meshes respectively, and set aside. Meanwhile, prepare 5 portions of the same aqueous solution of surface modifier, where each 1 L of the aqueous solution of surface modifier contains 4 - 6 g of γ-methacryloxypropyltrimethoxysilane KH570 and 0.5 - 2 g of bis(dioctylpyrophosphoryl) oxide acetyl peptide KR 138S. S2, place the mica powder screened through 1000 meshes, mica powder with 800 - 1000 meshes, mica powder with 500 - 800 meshes, mica powder with 300 - 500 meshes, and mica powder with 160 - 300 meshes weighed in S1 into the aqueous solution of surface modifier respectively, perform ultrasonic dispersion treatment for 30 - 60 min, drain, and dry. S3, weigh the mica powder screened through 1000 meshes, mica powder with 800 - 1000 meshes, mica powder with 500 - 800 meshes, mica powder with 300 - 500 meshes, and mica powder with 160 - 300 meshes that have completed surface modification in S2 according to the ratio to obtain the finished surface-modified mica aggregate.

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