A method for preparing high temperature resistant silicone glass fiber sleeve

Abstract

The present invention relates to the technical field of glass fiber sleeves, and discloses a method for preparing a high-temperature resistant silicone glass fiber sleeve, comprising vinyl silicone oil, vinyl silicon-containing polyimide, hydrogen-containing silicone oil, a tackifier, and a platinum water catalyst; a high-temperature resistant silicone resin coating is formed on the surface of the glass fiber sleeve, and the vinyl silicon-containing polyimide contains a siloxane structure, which has good compatibility with the vinyl silicone oil matrix, and is conducive to improving the phase separation phenomenon between the two. After high-temperature heat treatment, the coating does not crack. During the vulcanization process, the hydrogen-containing silicone oil can react with the vinyl silicone oil and the vinyl silicon-containing polyimide alkenyl group to undergo a silylation reaction, thereby improving the heat resistance of the coating, and at the same time improving the crosslinking degree of the silicone resin molecular chain and the molecular chain force, which is conducive to improving the breakdown voltage and showing better voltage resistance performance.

Description

Technical Field

[0001] The invention relates to the technical field of glass fiber sleeves, in particular to a method for preparing a high-temperature resistant silicone glass fiber sleeve. Background Art

[0002] Glass fiber insulation sleeve is a sleeve material obtained by reinforcing and weaving glass fiber, and wires, electronic components, etc. are arranged inside the sleeve. It is widely used in the fields of power equipment and so on. Usually, a polymer coating is applied on the surface of the glass fiber sleeve, which can protect the glass fiber sleeve and prevent the sleeve from being damaged, thereby ensuring the safety of the internal parts of the sleeve. Common coatings for glass fiber sleeves include silicone resin, polyurethane, acrylic resin, etc. Among them, silicone resin has good mechanical properties, excellent dielectric properties, and high flexibility, which can improve the high temperature resistance, voltage resistance and other properties of glass fiber insulation sleeves.

[0003] Polyimide has high mechanical strength, high temperature resistance and good voltage resistance. It is widely used in materials such as silicone resin, silicone rubber and polyurethane to improve the heat resistance, mechanical properties and voltage resistance of the materials. However, the compatibility of polyimide and silicone resin is very poor, and there is a phase separation phenomenon between the two. The present invention aims to modify silicone resin by using vinyl silicon polyimide to improve the high temperature resistance and voltage resistance of glass fiber casing. Summary of the invention

[0004] The technical problem solved by the invention is to provide a method for preparing a silicone glass fiber sleeve with high temperature resistance and voltage resistance.

[0005] Technical solution: A method for preparing a high temperature resistant silicone glass fiber casing:

[0006] (1) Add N,N-dimethylformamide, dianhydride monomer, diamine monomer and the structural formula The vinyl silicon-containing diamine is stirred and reacted at 20-30°C for 12-18h, the solution is poured into a mold, the temperature is gradually increased in a heating box, the mold is demolded, and the mold is ground and crushed to obtain a vinyl silicon-containing polyimide.

[0007] (2) Adding vinyl silicone oil, vinyl silicon-containing polyimide, hydrogen-containing silicone oil, a tackifier, and a platinum water catalyst into a container, stirring and mixing, and then physically coating the mixture on a glass fiber sleeve, and vulcanizing the mixture to obtain a high-temperature resistant silicone resin glass fiber sleeve.

[0008] Preferably, the molar amounts of the diamine monomer and the vinyl silicon-containing diamine in (1) are 65-90% and 10-35% of the molar amount of the dianhydride monomer, respectively.

[0009] Preferably, the diamine monomer is p-phenylenediamine, biphenylenediamine or 4,4-diaminodiphenyl ether; and the dianhydride monomer is pyromellitic anhydride, 4,4'-biphenyl ether dianhydride or 3,3'4,4'-benzophenonetetracarboxylic dianhydride.

[0010] Preferably, in the gradient heating process in (1), the temperature is kept at 120°C for 2 hours, 150°C for 1 hour, 200°C for 2 hours, 240°C for 2 hours, 270°C for 1 hour, and 300°C for 1 hour.

[0011] Preferably, in (2), the mass of the vinyl silicon-containing polyimide and the hydrogen-containing silicone oil are 2-12% and 2.5-4% of the mass of the vinyl silicone oil, respectively.

[0012] Preferably, the vulcanization temperature in (2) is 130-160° C. and the time is 10-30 min.

[0013] Preferably, the preparation method of vinyl silicon-containing diamine is:

[0014] S1. Add N,N-dimethylformamide, dimethyldichlorosilane, methyl 3-hydroxy-5-nitrobenzoate and pyridine to a flask at -5 to 0°C, wherein the molar amounts of methyl 3-hydroxy-5-nitrobenzoate and pyridine are 200-210% and 200-220% of the molar amount of dimethyldichlorosilane, respectively; then react at 30-45°C for 3-6h, remove N,N-dimethylformamide by distillation under reduced pressure, wash with water, add the product to methanol, add potassium hydroxide aqueous solution, heat to 60-80°C, react for 5-8h, remove methanol by distillation under reduced pressure, add hydrochloric acid to adjust the solution pH to 4-5, precipitate, filter the solvent, wash with water, and dry to obtain intermediate 1. The reaction formula is as follows:

[0015]

[0016] S2. Add tetrahydrofuran, intermediate, 3-butene-1-ol, N,N-dicyclohexylcarbodiimide (DCC), 4-dimethylaminopyridine (DMAP) to a flask equipped with a condenser reflux tube, wherein the molar amount of 3-butene-1-ol, N,N-dicyclohexylcarbodiimide, and 4-dimethylaminopyridine are 220-240% of the molar amount of the intermediate, 220-240% of the molar amount, and 18-24% of the molar amount of the intermediate, respectively; react at 40-55°C for 12-18h, distill under reduced pressure, and recrystallize the product after washing with water with ethanol to obtain intermediate 2. The reaction formula is as follows:

[0017]

[0018] S3. Add 20-28% hydrochloric acid solution, tin dichloride, and intermediate 2 to a flask equipped with a condenser reflux tube, wherein the molar amount of tin dichloride is 100-130% of the molar amount of intermediate 2; react for 2-3 hours in a nitrogen atmosphere, then heat to 60-85°C, react for 6-12 hours, cool the flask in an ice water bath, add sodium carbonate to adjust the pH of the solution to neutral, filter and wash the precipitate with water, then add the precipitate to ethanol for recrystallization to obtain vinyl silicon-containing diamine. The reaction formula is as follows:

[0019]

[0020] Technical effect of the present invention: The present invention utilizes a novel vinyl silicon-containing diamine to carry out polymerization reaction with a diamine monomer and a dianhydride monomer to obtain a vinyl silicon-containing polyimide having an alkenyl group in the side chain and a siloxane structure in the main chain.

[0021] The present invention uses vinyl silicone oil as the main agent of silicone resin, vinyl silicon-containing polyimide as an additive, and hydrogen-containing silicone oil as a crosslinking agent to form a high-temperature resistant silicone resin coating on the surface of the glass fiber casing. The vinyl silicon-containing polyimide contains a siloxane structure and has good compatibility with the vinyl silicone oil matrix, which is conducive to improving the phase separation phenomenon between the two. After high-temperature heat treatment, the coating does not crack.

[0022] The side chain of the vinyl silicon-containing polyimide of the present invention contains alkenyl groups, and hydrogen-containing silicone oil is used as a cross-linking agent. During the vulcanization process, the hydrogen-containing silicone oil can undergo a silylation reaction with the alkenyl groups of the vinyl silicone oil and the vinyl silicon-containing polyimide, thereby achieving chemical cross-linking of the vinyl silicone oil and the vinyl silicon-containing polyimide, causing the two to undergo chemical bonding, further improving the interfacial bonding force between the vinyl silicone oil and the vinyl silicon-containing polyimide, and after high-temperature heat treatment, the coating does not crack. In addition, the silicon-containing polyimide has excellent high-temperature resistance and a very high thermal decomposition temperature. When added to silicone resin, the heat resistance of the coating can be improved. After high-temperature heat treatment, the coating still maintains good performance, does not turn yellow, and does not crack. In addition, the vinyl silicon-containing polyimide forms a stable chemical cross-linking network with the vinyl silicone oil. After low-temperature treatment at -10°C, the coating still maintains good mechanical properties and does not crack.

[0023] The vinyl silicon-containing polyimide of the present invention has good compatibility with the silicon-containing polyimide, vinyl silicone oil and silicone resin, and can undergo a cross-linking reaction with the vinyl silicone oil, thereby increasing the cross-linking degree and molecular chain interaction force of the silicone resin molecular chain, making it difficult to orient the polar groups in the molecular chain, thereby increasing the breakdown voltage and showing better voltage resistance performance. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0025] The tackifier of the present invention is SK-Z01 P, Shenzhen Tianqi New Materials. Vinyl silicone oil, specification model 5000cs, Shenzhen Xinyongsheng New Materials. Hydrogen-containing silicone oil, model SM8011, Yantai Shunming New Materials.

[0026] Example 1

[0027] (1) At 0°C, 10 mL of N,N-dimethylformamide, 4 mmol of dimethyldichlorosilane, 8.4 mmol of methyl 3-hydroxy-5-nitrobenzoate and 8.4 mmol of pyridine were added to a flask, and then reacted at 30°C for 4 h. N,N-dimethylformamide was removed by distillation under reduced pressure. After washing with water, the product was added to 10 mL of methanol, and 10 mL of 3 mol / L potassium hydroxide aqueous solution was added. The mixture was heated to 70°C and reacted for 8 h. The methanol was removed by distillation under reduced pressure. Hydrochloric acid was added to adjust the pH of the solution to 5 to precipitate the precipitate. The solvent was filtered, washed with water and dried to obtain Intermediate 1.

[0028] (2) In a flask equipped with a reflux tube, 15 mL of tetrahydrofuran, 3 mmol of the intermediate, 6.6 mmol of 3-butene-1-ol, 6.6 mmol of N,N-dicyclohexylcarbodiimide, and 7.2 mmol of 4-dimethylaminopyridine were added, and the mixture was reacted at 45°C for 18 h. The mixture was distilled under reduced pressure, and the product was washed with water and recrystallized with ethanol to obtain intermediate 2.

[0029] (3) Add 10 mL of 28% hydrochloric acid solution, 30 mmol of tin dichloride and 3 mmol of intermediate 2 to a flask equipped with a condenser reflux tube, react for 3 h in a nitrogen atmosphere, then heat to 60 ° C and react for 12 h. Cool the flask in an ice water bath, add sodium carbonate to adjust the pH of the solution to neutral, filter and wash the precipitate with water, then add the precipitate to ethanol for recrystallization to obtain vinyl silicon-containing diamine.

[0030] (4) Add 200 mL of N,N-dimethylformamide, 10 mmol of 4,4-diaminodiphenyl ether, 6.5 mmol of pyromellitic anhydride, and 3.5 mmol of vinyl silicon-containing diamine into a flask, stir and react at 20°C for 18 hours, pour the solution into a mold, and keep it in a heating box at 120°C for 2 hours, 150°C for 1 hour, 200°C for 2 hours, 240°C for 2 hours, 270°C for 1 hour, and 300°C for 1 hour, demold, grind and crush to obtain vinyl silicon-containing polyimide.

[0031] (5) Add 100 g of vinyl silicone oil, 2 g of vinyl silicon-containing polyimide, 2.5 g of hydrogen-containing silicone oil, 5.3 g of tackifier, and 0.4 g of platinum water catalyst into a container, stir and mix well, then physically coat the mixture on the glass fiber sleeve, and vulcanize at 130 ° C for 20 min. Control the coating thickness to 50 μm to obtain a high-temperature resistant silicone resin glass fiber sleeve.

[0032] Example 2

[0033] (1) At -5°C, 5 mL of N,N-dimethylformamide, 4 mmol of dimethyldichlorosilane, 8 mmol of methyl 3-hydroxy-5-nitrobenzoate, and 8 mmol of pyridine were added to a flask, and then reacted at 35°C for 6 h. N,N-dimethylformamide was removed by distillation under reduced pressure. After washing with water, the product was added to 15 mL of methanol, and 15 mL of a 4.5 mol / L potassium hydroxide aqueous solution was added. The mixture was heated to 60°C and reacted for 8 h. The methanol was removed by distillation under reduced pressure. Hydrochloric acid was added to adjust the pH of the solution to 4 to precipitate the precipitate. The solvent was filtered, washed with water, and dried to obtain Intermediate 1.

[0034] (2) Into a flask equipped with a reflux tube, 20 mL of tetrahydrofuran, 3 mmol of the intermediate, 7.2 mmol of 3-butene-1-ol, 7.2 mmol of N,N-dicyclohexylcarbodiimide, and 5.4 mmol of 4-dimethylaminopyridine were added, and the mixture was reacted at 55°C for 12 h. The mixture was distilled under reduced pressure, and the product was washed with water and recrystallized with ethanol to obtain intermediate 2.

[0035] (3) Add 15 mL of 20% hydrochloric acid solution, 30 mmol of tin dichloride and 3 mmol of intermediate 2 to a flask equipped with a condenser reflux tube, react for 3 h in a nitrogen atmosphere, then heat to 85 ° C. and react for 6 h. Cool the flask in an ice water bath, add sodium carbonate to adjust the pH of the solution to neutral, filter and wash the precipitate with water, then add the precipitate to ethanol for recrystallization to obtain vinyl silicon-containing diamine.

[0036] (4) Add 150 mL of N,N-dimethylformamide, 10 mmol of p-phenylenediamine, 8 mmol of 4,4'-biphenyl ether dianhydride, and 2 mmol of vinyl silicon-containing diamine into a flask, stir and react at 30°C for 12 hours, pour the solution into a mold, and keep it in a heating box at 120°C for 2 hours, 150°C for 1 hour, 200°C for 2 hours, 240°C for 2 hours, 270°C for 1 hour, and 300°C for 1 hour. Demould and grind to obtain vinyl silicon-containing polyimide.

[0037] (5) Add 100 g of vinyl silicone oil, 7 g of vinyl silicon-containing polyimide, 3.2 g of hydrogen-containing silicone oil, 5.3 g of tackifier, and 0.5 g of platinum water catalyst into a container, stir and mix well, then physically coat the mixture on the glass fiber sleeve, and vulcanize at 160° C. for 10 min. Control the coating thickness to be 50 μm to obtain a high-temperature resistant silicone resin glass fiber sleeve.

[0038] Example 3

[0039] (1) At -5°C, 10 mL of N,N-dimethylformamide, 4 mmol of dimethyldichlorosilane, 8.4 mmol of methyl 3-hydroxy-5-nitrobenzoate, and 8.4 mmol of pyridine were added to a flask, and then reacted at 45°C for 3 h. N,N-dimethylformamide was removed by distillation under reduced pressure. After washing with water, the product was added to 15 mL of methanol, and 15 mL of a 4.5 mol / L potassium hydroxide aqueous solution was added. The mixture was heated to 80°C and reacted for 5 h. The methanol was removed by distillation under reduced pressure. Hydrochloric acid was added to adjust the pH of the solution to 5 to precipitate the precipitate. The solvent was filtered, washed with water, and dried to obtain Intermediate 1.

[0040] (2) In a flask equipped with a reflux tube, 15 mL of tetrahydrofuran, 3 mmol of the intermediate, 6.6 mmol of 3-butene-1-ol, 6.6 mmol of N,N-dicyclohexylcarbodiimide, and 6.6 mmol of 4-dimethylaminopyridine were added, and the mixture was reacted at 40°C for 18 h. The mixture was distilled under reduced pressure, and the product was washed with water and recrystallized with ethanol to obtain intermediate 2.

[0041] (3) Add 15 mL of 20% hydrochloric acid solution, 36 mmol of tin dichloride, and 3 mmol of intermediate 2 to a flask equipped with a condenser reflux tube, react for 2 h in a nitrogen atmosphere, then heat to 70° C. and react for 12 h. Cool the flask in an ice-water bath, add sodium carbonate to adjust the pH of the solution to neutral, filter and wash the precipitate with water, then add the precipitate to ethanol for recrystallization to obtain vinyl silicon-containing diamine.

[0042] (4) Add 200 mL of N,N-dimethylformamide, 10 mmol of benzenediamine, 9 mmol of 3,3'4,4'-benzophenonetetracarboxylic dianhydride, and 1 mmol of vinyl silicon-containing diamine into a flask, stir and react at 25°C for 18 hours, pour the solution into a mold, and keep it in a heating box at 120°C for 2 hours, 150°C for 1 hour, 200°C for 2 hours, 240°C for 2 hours, 270°C for 1 hour, and 300°C for 1 hour, demold, grind and crush to obtain vinyl silicon-containing polyimide.

[0043] (5) Add 100 g of vinyl silicone oil, 12 g of vinyl silicon-containing polyimide, 4 g of hydrogen-containing silicone oil, 5.3 g of tackifier, and 0.5 g of platinum water catalyst into a container, stir and mix well, and then physically coat the mixture on the glass fiber sleeve. Vulcanize the mixture at 140 ° C for 30 min, control the coating thickness to 50 μm, and obtain a high-temperature resistant silicone resin glass fiber sleeve.

[0044] Comparative Example 1

[0045] (1) Add 100 g of vinyl silicone oil, 2.5 g of hydrogenated silicone oil, 5.3 g of tackifier, and 0.4 g of platinum water catalyst into a container, stir and mix well, and then physically coat the mixture on a glass fiber sleeve. Vulcanize the mixture at 130° C. for 20 min, and control the coating thickness to be 50 μm to obtain a high-temperature resistant silicone resin glass fiber sleeve.

[0046] Comparative Example 2

[0047] (1) Add 200 mL of N,N-dimethylformamide, 10 mmol of 4,4-diaminodiphenyl ether, and 10 mmol of pyromellitic anhydride to a flask, stir and react at 20°C for 18 hours, pour the solution into a mold, keep it in a heating box at 120°C for 2 hours, 150°C for 1 hour, 200°C for 2 hours, 240°C for 2 hours, 270°C for 1 hour, and 300°C for 1 hour, demold, grind and crush to obtain polyimide;

[0048] (2) Add 100 g of vinyl silicone oil, 2 g of polyimide, 2.5 g of hydrogenated silicone oil, 5.3 g of tackifier, and 0.4 g of platinum water catalyst into a container, stir and mix well, then physically coat the mixture on the glass fiber sleeve, and vulcanize at 130° C. for 20 min. Control the coating thickness to be 50 μm to obtain a high temperature resistant silicone resin glass fiber sleeve.

[0049] Comparative Example 3

[0050] (1) Add 200 mL of N,N-dimethylformamide, 10 mmol of 4,4-diaminodiphenyl ether, 6.5 mmol of pyromellitic anhydride, and 3.5 mmol of bis(4-aminophenoxy)dimethylsilane (CAS No. 1223-16-1, structural formula: ), stirring and reacting at 20°C for 18h, pouring the solution into a mold, keeping it in a heating box at 120°C for 2h, 150°C for 1h, 200°C for 2h, 240°C for 2h, 270°C for 1h, and 300°C for 1h, demolding, grinding and crushing to obtain silicon-containing polyimide;

[0051] (2) Add 100 g of vinyl silicone oil, 2 g of silicon-containing polyimide, 2.5 g of hydrogen-containing silicone oil, 5.3 g of tackifier, and 0.4 g of platinum water catalyst into a container, stir and mix well, then physically coat the mixture on the glass fiber sleeve, and vulcanize at 130° C. for 20 min. Control the coating thickness to be 50 μm to obtain a high-temperature resistant silicone resin glass fiber sleeve.

[0052] Place the high temperature resistant silicone fiberglass casing at different temperatures for 240 hours and observe whether the casing turns yellow or cracks.

[0053] Table 1 High and low temperature resistance test of glass fiber casing surface

[0054]

[0055] It can be seen from the test results in the above table that in Examples 1 to 3, vinyl silicone oil, vinyl silicon-containing polyimide, and hydrogen-containing silicone oil are used as the main components of the silicone resin coating on the surface of the glass fiber casing. The vinyl silicon-containing polyimide contains a siloxane structure and has good compatibility with the vinyl silicone oil matrix, which is conducive to improving the phase separation phenomenon between the two. After high-temperature heat treatment, the coating does not crack. In addition, the side chain of the vinyl silicon-containing polyimide contains an olefin group. Using hydrogen-containing silicone oil as a cross-linking agent, during the vulcanization process, the hydrogen-containing silicone oil can react with the olefin groups of the vinyl silicone oil and the vinyl silicon-containing polyimide by hydrosilylation, achieving chemical crosslinking of the vinyl silicone oil and the vinyl silicon-containing polyimide, causing the two to undergo chemical bonding, further improving the interfacial bonding between the vinyl silicone oil and the vinyl silicon-containing polyimide, and after high-temperature heat treatment, the coating does not crack. Silicon-containing polyimide has excellent high temperature resistance and a high thermal decomposition temperature. When added to silicone resin, it can improve the heat resistance of the coating. After high-temperature heat treatment, the coating still maintains good performance, does not turn yellow, and does not crack. Vinyl silicon-containing polyimide forms a stable chemical cross-linking network with vinyl silicone oil. After low-temperature treatment at -10°C, the coating still maintains good mechanical properties and does not crack.

[0056] The silicone resin of Comparative Example 1 does not contain vinyl silicon-containing polyimide, and the heat resistance of the silicone resin is poor. After low-temperature and high-temperature heat treatment, it is easy to turn yellow and crack.

[0057] In Comparative Example 2, when preparing polyimide, no vinyl silicon-containing diamine was added, and the obtained polyimide did not contain a siloxane structure, and had poor compatibility with the vinyl silicone oil in the silicone resin. The two were easily phase separated, and the polyimide did not contain an olefin group, and could not chemically bond with the vinyl silicone oil. The interfacial bonding force was low, and after low-temperature and high-temperature heat treatment, the silicone resin coating was prone to yellowing and cracking.

[0058] Comparative Example 3 uses conventional bis(4-aminophenoxy)dimethylsilane to replace vinyl silicon-containing diamine, and the obtained polyimide contains a siloxane structure, which is very compatible with vinyl silicone oil, and the two are not easy to phase separate, which can improve the heat resistance of silicone resin. After high-temperature heat treatment at 60-160°C, the silicone resin coating does not turn yellow or crack. However, bis(4-aminophenoxy)dimethylsilane does not contain alkenyl, which makes it impossible for polyimide to chemically bond with vinyl silicone oil, and the interfacial bonding force between the two is low. After high-temperature heat treatment at 200°C, the silicone resin coating is prone to yellowing and cracking.

[0059] The silicone glass fiber sheathing was tested with a withstand voltage tester. A bare copper rod with a wire gauge of 3.35mm×8.5mm and a length of 300mm was used to cover the prepared glass fiber sheathing breakdown voltage. After the sample was covered with aluminum foil, an AC power frequency voltage breakdown test was carried out.

[0060] Table 2 Breakdown voltage test of glass fiber casing surface

[0061]

[0062]

[0063] The breakdown voltage of the silicone resin in Comparative Example 1 is only 4.6kV. In Comparative Example 2, polyimide is added, and its compatibility with silicone resin is very poor, and the increase in breakdown voltage is relatively low, only 5.3kV. The silicon-containing polyimide added in Comparative Example 3 has good compatibility with vinyl silicone oil and silicone resin, and the breakdown voltage increases greatly, reaching 7.2kV. The vinyl silicon-containing polyimide added in Examples 1-3 has good compatibility with vinyl silicone oil and silicone resin, and can undergo cross-linking reaction with vinyl silicone oil, thereby increasing the cross-linking degree and molecular chain force of the silicone resin molecular chain, making it difficult to orient the polar groups in the molecular chain, thereby increasing the breakdown voltage and showing better voltage resistance.

[0064] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a high temperature resistant silicone glass fiber sleeve, characterized in that: The preparation method is: (1) Add N,N-dimethylformamide, dianhydride monomer, diamine monomer and the structural formula The vinyl silicon-containing diamine is stirred and reacted at 20-30°C for 12-18h, the solution is poured into a mold, the temperature is gradually increased in a heating box, the mold is demoulded, and the vinyl silicon-containing polyimide is obtained. (2) Add vinyl silicone oil, vinyl silicon-containing polyimide, hydrogen-containing silicone oil, a tackifier, and a platinum water catalyst into a container, stir and mix, and then apply the mixture to a glass fiber sleeve, and vulcanize the mixture to obtain a high-temperature resistant silicone resin glass fiber sleeve.

2. The method for preparing the high temperature resistant silicone glass fiber sleeve according to claim 1, characterized in that: The molar amounts of the diamine monomer and the vinyl silicon-containing diamine in (1) are 65-90% and 10-35% of the molar amount of the dianhydride monomer, respectively.

3. The method for preparing the high temperature resistant silicone glass fiber sleeve according to claim 2, characterized in that: The diamine monomer is p-phenylenediamine, biphenylenediamine or 4,4-diaminodiphenyl ether; the dianhydride monomer is pyromellitic anhydride, 4,4'-biphenyl ether dianhydride or 3,3'4,4'-benzophenonetetracarboxylic anhydride.

4. The method for preparing the high temperature resistant silicone glass fiber sleeve according to claim 1, characterized in that: In the process of gradient heating in (1), the temperature is kept at 120°C for 2 hours, 150°C for 1 hour, 200°C for 2 hours, 240°C for 2 hours, 270°C for 1 hour, and 300°C for 1 hour.

5. The method for preparing the high temperature resistant silicone glass fiber sleeve according to claim 1, characterized in that: The mass of the vinyl silicon-containing polyimide and the hydrogen-containing silicone oil in (2) is 2-12% and 2.5-4% of the mass of the vinyl silicone oil respectively.

6. The method for preparing the high temperature resistant silicone glass fiber sleeve according to claim 1, characterized in that: The vulcanization temperature in (2) is 130-160° C. and the time is 10-30 min.

7. The method for preparing the high temperature resistant silicone glass fiber sleeve according to claim 2, characterized in that: The preparation method of the vinyl silicon-containing diamine is as follows: S1, adding N,N-dimethylformamide, dimethyldichlorosilane, methyl 3-hydroxy-5-nitrobenzoate and pyridine to a flask at -5 to 0°C, then reacting at 30-45°C for 3-6h, removing N,N-dimethylformamide by distillation under reduced pressure, adding the product to methanol after washing with water, adding potassium hydroxide aqueous solution, heating to 60-80°C, reacting for 5-8h, removing methanol by distillation under reduced pressure, adding hydrochloric acid to adjust the pH of the solution to 4-5, precipitating a precipitate, filtering the solvent, washing with water, and drying to obtain an intermediate 1; S2. Add tetrahydrofuran, intermediate 1, 3-butene-1-ol, N,N-dicyclohexylcarbodiimide and 4-dimethylaminopyridine to a flask equipped with a condenser reflux tube, react at 40-55° C. for 12-18 hours, distill under reduced pressure, wash with water, and recrystallize the product with ethanol to obtain intermediate 2; S3. Add 20-28% by mass hydrochloric acid solution, tin dichloride and intermediate 2 to a flask equipped with a condenser reflux tube, react for 2-3 hours in a nitrogen atmosphere, then heat to 60-85°C and react for 6-12 hours. Cool the flask in an ice water bath, add sodium carbonate to adjust the pH of the solution to neutral, filter and wash the precipitate with water, then add the precipitate to ethanol for recrystallization to obtain vinyl silicon-containing diamine.

8. The method for preparing the high temperature resistant silicone glass fiber sleeve according to claim 7, characterized in that: The molar amounts of methyl 3-hydroxy-5-nitrobenzoate and pyridine in S1 are 200-210% and 200-220% of the molar amount of dimethyldichlorosilane, respectively.

9. The method for preparing the high temperature resistant silicone glass fiber sleeve according to claim 7, characterized in that: The molar amounts of 3-butene-1-ol, N,N-dicyclohexylcarbodiimide and 4-dimethylaminopyridine in S2 are 220-240%, 220-240% and 18-24% of 1 mole of the intermediate, respectively.

10. The method for preparing the high temperature resistant silicone glass fiber sleeve according to claim 7, characterized in that: The molar amount of tin dichloride in S3 is 100-130% of the molar amount of intermediate 2.

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