High-silica glass fiber thermal insulation cotton for automobiles and preparation method thereof

Abstract

The application discloses a high-silica glass fiber heat insulation cotton for automobiles and a preparation method thereof, and relates to the technical field of sound and heat insulation. The high-silica glass fiber is used as raw material, and the high-silica glass fiber has higher high-temperature resistance and high-temperature stability than conventional glass fibers, can maintain high mechanical strength for a long time, and avoids softening under high temperature. The phenolic resin is modified, a boron-silicon modified polyphenol monomer containing phenolic hydroxyl groups and boron and silicon elements is prepared, and participates in the condensation reaction of the phenolic resin, so that the phenolic resin has higher high-temperature resistance and flame retardance, and the glass fiber heat insulation cotton has higher safety performance.

Description

A high-silica glass fiber thermal insulation cotton for automobiles and its preparation method Technical Field

[0001] This invention relates to the field of thermal and sound insulation technology, specifically to a high-silica glass fiber thermal insulation cotton for automobiles and its preparation method. Background Technology

[0002] Automotive heat insulation cotton is a porous, fluffy functional material made with glass fiber as the core substrate and resin adhesive. It is widely used in key areas such as the engine compartment, chassis, and exhaust pipe area of ​​automobiles. It provides heat insulation and effectively blocks heat from the engine and exhaust pipe from being conducted into the passenger compartment. It also reduces the impact of the external ambient temperature on the interior, lowers air conditioning energy consumption, and improves driving comfort. Furthermore, its structure can effectively absorb wind noise, road vibrations, and engine mechanical noise during driving, further enhancing driving comfort. However, because the engine compartment and exhaust pipe area are exposed to temperatures above 150°C for extended periods, and some areas can reach temperatures above 300°C in short periods, and vehicles may face potential fire risks due to bumps and friction during driving, further treatment of automotive heat insulation cotton is necessary. Summary of the Invention

[0003] The purpose of this invention is to provide a high-silica glass fiber thermal insulation cotton for automobiles and its preparation method, so as to solve the problems raised in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a high-silica glass fiber thermal insulation cotton for automobiles, characterized in that the high-silica glass fiber thermal insulation cotton for automobiles is prepared by drying and curing high-silica glass fiber felt impregnated with modified phenolic resin adhesive.

[0005] The preparation method of the modified phenolic resin adhesive includes the following steps:

[0006] a. Under nitrogen atmosphere protection, heat DMF to 110~120℃ to remove water for 1~2 hours, then cool to room temperature. Disperse 4-carboxyphenylboronic acid pinacol ester into DMF, stir and mix evenly, then heat to 40~45℃ and add dicyclohexylcarbodiimide. After stirring and dispersing evenly, add 3-aminopropyltriethoxysilane dropwise. After the addition is complete, heat the mixed solution to 65~72℃ and stir the reaction for 4~6 hours. After cooling to room temperature, filter the reaction system and collect the filtrate for later use.

[0007] b. Heat the filtrate from step a to 50-55°C and set aside;

[0008] Take clean DMF, protect it under a nitrogen atmosphere, and heat it to 110-120℃ to remove water for 1-2 hours. After cooling to room temperature, divide it into two batches, and add resorcinol and aluminum ethoxide to each batch respectively. Stir and disperse evenly to obtain resorcinol DMF solution and aluminum ethoxide DMF solution.

[0009] Resorcinol DMF solution and aluminum ethoxide DMF solution were added dropwise at a uniform rate to the filtrate from step a, with continuous stirring during the addition. After the addition was completed, the temperature was raised to 65-70℃, and the reaction was continued to be stirred for 6-12 hours. Then, anhydrous ethanol was added to quench the reaction, filtered, and the filtrate was collected. The solvent was removed by rotary evaporation, and the rotary evaporated product was washed with low-temperature n-hexane 2-3 times. After vacuum drying, borosilicate-modified polyphenol monomers were obtained.

[0010] c. Under nitrogen atmosphere protection, mix borosilicate-modified polyphenol monomers with deionized water, heat to 50-55℃, stir and disperse evenly, add resorcinol, continue mixing and dispersing evenly, add ammonia water dropwise, adjust the pH value to 8.5-9.0, heat to 78-85℃, add saturated formaldehyde aqueous solution dropwise, after the addition is complete, keep warm and stir the reaction, during the stirring process, monitor the viscosity at any time, stop heating when the viscosity reaches 600-800 mPa.s, cool to 55-60℃, add toughening agent and anti-aging agent, continue mixing for 30-45 min, cool to 30-40℃, add deionized water, mix evenly, to obtain a modified phenolic resin adhesive with a resin solid content of 40-50%.

[0011] Furthermore, the diameter of the high-silica glass fiber is 7~12μm.

[0012] Furthermore, by weight, the amounts of each component added are 9-11.2 parts of 4-carboxyphenylboronic acid pinacol ester, 7.5-8.2 parts of dicyclohexylcarbodiimide, 10 parts of 3-aminopropyltriethoxysilane, 0.8-1 parts of aluminum ethoxide, and 12-15 parts of resorcinol.

[0013] Furthermore, in step b, the low-temperature n-hexane is n-hexane with a temperature of 0~2℃.

[0014] Furthermore, in step c, the amount of each component added, by weight, is 10-15 parts of borosilicate modified polyphenol monomer, 25-30 parts of resorcinol, 32-37 parts of saturated formaldehyde aqueous solution, 1.2-1.5 parts of toughening agent and 1-1.2 parts of anti-aging agent.

[0015] Furthermore, in step c, the toughening agent is either polyethylene glycol 400 or polyethylene glycol 800.

[0016] Furthermore, in step c, the anti-aging agent is resorcinol diglycidyl ether.

[0017] Furthermore, a method for preparing high-silica glass fiber thermal insulation cotton for automobiles includes the following steps:

[0018] S1. High-silica glass fibers are mixed, and then combed into a web to obtain high-silica glass fiber mat;

[0019] S2. The glass fiber felt prepared in step S1 is impregnated in modified phenolic resin adhesive for 15-30 minutes, then removed and dried at 110-120℃ for 20-30 minutes. After drying, it is hot-pressed to obtain high silica glass fiber heat insulation cotton for automobiles.

[0020] Furthermore, in step S2, during hot pressing, the applied pressure is 1~1.5MPa, the hot pressing temperature is 180~220℃, and the hot pressing time is 15~30min.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] In order to improve the safety, high temperature resistance, and flame retardant properties of automotive heat insulation cotton, this invention has carried out improved treatment on automotive heat insulation cotton.

[0023] This invention first uses high-silica glass fiber as raw material. Compared with conventional glass fiber, high-silica glass fiber has higher high temperature resistance and high temperature stability, and can maintain high mechanical strength for a long time, avoiding softening at high temperature.

[0024] Furthermore, this invention modifies the phenolic resin using 4-carboxyphenylboronic acid pinacol ester as a raw material. Under the action of the catalyst dicyclohexylcarbodiimide, the carboxyl group in 4-carboxyphenylboronic acid pinacol ester is activated, subsequently reacting with the amino group in 3-aminopropyltriethoxysilane to form an amide bond, thereby preparing an intermediate containing silane and boron. Both boron and silicon elements impart excellent flame retardant properties and hydrophobicity to the phenolic resin. Compared to conventional halogenated flame retardants, which produce large amounts of toxic, flame-retardant gases during flame retardation to dilute the oxygen content in the air, this invention utilizes a non-toxic gas-producing method. However, considering the confined environment inside a car, the toxic gases produced by halogenated flame retardants are difficult to remove in time, potentially harming the human body. Therefore, this invention uses a method that does not produce toxic gases. Boron and silicon elements were used as flame-retardant components to modify phenolic resin. The addition of boron and silicon elements also accelerated the formation of a flame-retardant silicon- and boron-containing carbon layer on the resin surface during high-temperature combustion, thereby preventing the combustion reaction from proceeding. This resulted in less smoke produced during the combustion of the resin material, significantly reducing the toxicity of combustion gases to the human body. Based on this, the present invention further reacts the boron- and silicon-containing intermediates with resorcinol. Under the action of aluminum ethoxide, the phenolic hydroxyl groups of resorcinol are activated into phenolic oxide anions, which then react with the ethoxy groups in 3-aminopropyltriethoxysilane. This process yields borosilicate-modified polyphenol monomers containing phenolic hydroxyl groups, boron, and silicon elements, which participate in the condensation reaction of phenolic resin, thereby enabling the phenolic resin to have higher high-temperature resistance and flame-retardant properties. Detailed Implementation

[0025] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The high-silica glass fiber used in the embodiments and comparative examples of this invention has a diameter of 9 μm.

[0027] Example 1. A method for preparing high-silica glass fiber thermal insulation cotton for automobiles, comprising the following steps:

[0028] S1. High-silica glass fibers are mixed, and then combed into a web to obtain high-silica glass fiber mat;

[0029] S2. The glass fiber felt prepared in step S1 is impregnated in modified phenolic resin adhesive for 30 minutes. After impregnation, it is taken out and dried at 120°C for 20 minutes. Then, it is hot-pressed and formed with a pressure of 1.5 MPa, a hot-pressing temperature of 220°C, and a hot-pressing time of 30 minutes. After hot pressing, it is taken out and cut and shaped to obtain high silica glass fiber heat insulation cotton for automobiles.

[0030] The preparation method of the modified phenolic resin adhesive includes the following steps:

[0031] a. Under nitrogen atmosphere protection, heat DMF to 120℃ to remove water for 1 hour, then cool to room temperature. Disperse 9 parts by weight of 4-carboxyphenylboronic acid pinacol ester into DMF, stir and mix evenly, then heat to 45℃ and add 7.5 parts of dicyclohexylcarbodiimide. After stirring and dispersing evenly, add 10 parts of 3-aminopropyltriethoxysilane dropwise. After the addition is complete, heat the mixed solution to 70℃ and stir the reaction for 6 hours. Then cool to room temperature, filter the reaction system, and collect the filtrate for later use.

[0032] b. Heat the filtrate from step a to 50-55°C and set aside;

[0033] Take clean DMF, protect it under a nitrogen atmosphere, heat it to 120℃ to remove water for 2 hours, then cool it to room temperature. Divide it into two batches, and add 12 parts of resorcinol and 0.8 parts of aluminum ethoxide to each batch respectively. Stir and disperse evenly to obtain resorcinol DMF solution and aluminum ethoxide DMF solution.

[0034] Resorcinol DMF solution and aluminum ethoxide DMF solution were added dropwise to the filtrate from step a at a constant rate, with continuous stirring during the addition. After the addition was completed, the temperature was raised to 65°C, and the reaction was continued to be stirred for 12 hours. Then, anhydrous ethanol was added to quench the reaction, filtered, and the filtrate was collected. The solvent was removed by rotary evaporation, and the rotary evaporated product was washed twice with low-temperature n-hexane and then dried under vacuum to obtain borosilicate-modified polyphenol monomer.

[0035] c. Under nitrogen atmosphere protection, mix 10 parts by weight of borosilicate modified polyphenol monomer with deionized water, heat to 55°C, stir and disperse evenly, add 25 parts of resorcinol, continue mixing and dispersing evenly, add ammonia water dropwise, adjust the pH value to 9.0, heat to 80°C, add 32 parts of saturated formaldehyde aqueous solution dropwise, after the addition is complete, keep warm and stir the reaction, monitor the viscosity during stirring, stop heating when the viscosity reaches 600 mPa·s, cool to 55°C, add 1.2 parts of polyethylene glycol 400 toughening agent and 1 part of resorcinol diglycidyl ether anti-aging agent, continue mixing for 30 min, cool to 40°C, add deionized water, mix evenly, and obtain a modified phenolic resin adhesive with a resin solid content of 45%.

[0036] Example 2. A method for preparing high-silica glass fiber thermal insulation cotton for automobiles, comprising the following steps:

[0037] Compared with Example 1, this example increases the amount of 4-carboxyphenylboronic acid pinacol ester added in step a;

[0038] S1. High-silica glass fibers are mixed, and then combed into a web to obtain high-silica glass fiber mat;

[0039] S2. The glass fiber felt prepared in step S1 is impregnated in modified phenolic resin adhesive for 30 minutes. After impregnation, it is taken out and dried at 120°C for 20 minutes. Then, it is hot-pressed and formed with a pressure of 1.5 MPa, a hot-pressing temperature of 220°C, and a hot-pressing time of 30 minutes. After hot pressing, it is taken out and cut and shaped to obtain high silica glass fiber heat insulation cotton for automobiles.

[0040] The preparation method of the modified phenolic resin adhesive includes the following steps:

[0041] a. Under nitrogen atmosphere protection, heat DMF to 120℃ to remove water for 1 hour, then cool to room temperature. Disperse 11.2 parts by weight of 4-carboxyphenylboronic acid pinacol ester into DMF, stir and mix evenly, then heat to 45℃ and add 7.5 parts of dicyclohexylcarbodiimide. After stirring and dispersing evenly, add 10 parts of 3-aminopropyltriethoxysilane dropwise. After the addition is complete, heat the mixed solution to 70℃ and stir the reaction for 6 hours. Then cool to room temperature, filter the reaction system, and collect the filtrate for later use.

[0042] b. Heat the filtrate from step a to 50-55°C and set aside;

[0043] Take clean DMF, protect it under a nitrogen atmosphere, heat it to 120℃ to remove water for 2 hours, then cool it to room temperature. Divide it into two batches, and add 12 parts of resorcinol and 0.8 parts of aluminum ethoxide to each batch respectively. Stir and disperse evenly to obtain resorcinol DMF solution and aluminum ethoxide DMF solution.

[0044] Resorcinol DMF solution and aluminum ethoxide DMF solution were added dropwise to the filtrate from step a at a constant rate, with continuous stirring during the addition. After the addition was completed, the temperature was raised to 65°C, and the reaction was continued to be stirred for 12 hours. Then, anhydrous ethanol was added to quench the reaction, filtered, and the filtrate was collected. The solvent was removed by rotary evaporation, and the rotary evaporated product was washed twice with low-temperature n-hexane and then dried under vacuum to obtain borosilicate-modified polyphenol monomer.

[0045] c. Under nitrogen atmosphere protection, mix 10 parts by weight of borosilicate modified polyphenol monomer with deionized water, heat to 55°C, stir and disperse evenly, add 25 parts of resorcinol, continue mixing and dispersing evenly, add ammonia water dropwise, adjust the pH value to 9.0, heat to 80°C, add 32 parts of saturated formaldehyde aqueous solution dropwise, after the addition is complete, keep warm and stir the reaction, monitor the viscosity during stirring, stop heating when the viscosity reaches 600 mPa·s, cool to 55°C, add 1.2 parts of polyethylene glycol 400 toughening agent and 1 part of resorcinol diglycidyl ether anti-aging agent, continue mixing for 30 min, cool to 40°C, add deionized water, mix evenly, and obtain a modified phenolic resin adhesive with a resin solid content of 45%.

[0046] Example 3. A method for preparing high-silica glass fiber thermal insulation cotton for automobiles, comprising the following steps:

[0047] Compared with Example 2, this example increases the amount of resorcinol added in step b;

[0048] S1. High-silica glass fibers are mixed, and then combed into a web to obtain high-silica glass fiber mat;

[0049] S2. The glass fiber felt prepared in step S1 is impregnated in modified phenolic resin adhesive for 30 minutes. After impregnation, it is taken out and dried at 120°C for 20 minutes. Then, it is hot-pressed and formed with a pressure of 1.5 MPa, a hot-pressing temperature of 220°C, and a hot-pressing time of 30 minutes. After hot pressing, it is taken out and cut and shaped to obtain high silica glass fiber heat insulation cotton for automobiles.

[0050] The preparation method of the modified phenolic resin adhesive includes the following steps:

[0051] a. Under nitrogen atmosphere protection, heat DMF to 120℃ to remove water for 1 hour, then cool to room temperature. Disperse 11.2 parts by weight of 4-carboxyphenylboronic acid pinacol ester into DMF, stir and mix evenly, then heat to 45℃ and add 7.5 parts of dicyclohexylcarbodiimide. After stirring and dispersing evenly, add 10 parts of 3-aminopropyltriethoxysilane dropwise. After the addition is complete, heat the mixed solution to 70℃ and stir the reaction for 6 hours. Then cool to room temperature, filter the reaction system, and collect the filtrate for later use.

[0052] b. Heat the filtrate from step a to 50-55°C and set aside;

[0053] Take clean DMF, protect it under a nitrogen atmosphere, heat it to 120℃ to remove water for 2 hours, cool it to room temperature, divide it into two batches, and add 15 parts of resorcinol and 0.8 parts of aluminum ethoxide to each batch respectively. Stir and disperse evenly to obtain resorcinol DMF solution and aluminum ethoxide DMF solution.

[0054] Resorcinol DMF solution and aluminum ethoxide DMF solution were added dropwise to the filtrate from step a at a constant rate, with continuous stirring during the addition. After the addition was completed, the temperature was raised to 65°C, and the reaction was continued to be stirred for 12 hours. Then, anhydrous ethanol was added to quench the reaction, filtered, and the filtrate was collected. The solvent was removed by rotary evaporation, and the rotary evaporated product was washed twice with low-temperature n-hexane and then dried under vacuum to obtain borosilicate-modified polyphenol monomer.

[0055] c. Under nitrogen atmosphere protection, mix 10 parts by weight of borosilicate modified polyphenol monomer with deionized water, heat to 55°C, stir and disperse evenly, add 25 parts of resorcinol, continue mixing and dispersing evenly, add ammonia water dropwise, adjust the pH value to 9.0, heat to 80°C, add 32 parts of saturated formaldehyde aqueous solution dropwise, after the addition is complete, keep warm and stir the reaction, monitor the viscosity during stirring, stop heating when the viscosity reaches 600 mPa·s, cool to 55°C, add 1.2 parts of polyethylene glycol 400 toughening agent and 1 part of resorcinol diglycidyl ether anti-aging agent, continue mixing for 30 min, cool to 40°C, add deionized water, mix evenly, and obtain a modified phenolic resin adhesive with a resin solid content of 45%.

[0056] Example 4. A method for preparing high-silica glass fiber thermal insulation cotton for automobiles, comprising the following steps:

[0057] Compared with Example 3, this example increases the amount of borosilicate-modified polyphenol monomer added in step c;

[0058] S1. High-silica glass fibers are mixed, and then combed into a web to obtain high-silica glass fiber mat;

[0059] S2. The glass fiber felt prepared in step S1 is impregnated in modified phenolic resin adhesive for 30 minutes. After impregnation, it is taken out and dried at 120°C for 20 minutes. Then, it is hot-pressed and formed with a pressure of 1.5 MPa, a hot-pressing temperature of 220°C, and a hot-pressing time of 30 minutes. After hot pressing, it is taken out and cut and shaped to obtain high silica glass fiber heat insulation cotton for automobiles.

[0060] The preparation method of the modified phenolic resin adhesive includes the following steps:

[0061] a. Under nitrogen atmosphere protection, heat DMF to 120℃ to remove water for 1 hour, then cool to room temperature. Disperse 11.2 parts by weight of 4-carboxyphenylboronic acid pinacol ester into DMF, stir and mix evenly, then heat to 45℃ and add 7.5 parts of dicyclohexylcarbodiimide. After stirring and dispersing evenly, add 10 parts of 3-aminopropyltriethoxysilane dropwise. After the addition is complete, heat the mixed solution to 70℃ and stir the reaction for 6 hours. Then cool to room temperature, filter the reaction system, and collect the filtrate for later use.

[0062] b. Heat the filtrate from step a to 50-55°C and set aside;

[0063] Take clean DMF, protect it under a nitrogen atmosphere, heat it to 120℃ to remove water for 2 hours, cool it to room temperature, divide it into two batches, and add 15 parts of resorcinol and 0.8 parts of aluminum ethoxide to each batch respectively. Stir and disperse evenly to obtain resorcinol DMF solution and aluminum ethoxide DMF solution.

[0064] Resorcinol DMF solution and aluminum ethoxide DMF solution were added dropwise to the filtrate from step a at a constant rate, with continuous stirring during the addition. After the addition was completed, the temperature was raised to 65°C, and the reaction was continued to be stirred for 12 hours. Then, anhydrous ethanol was added to quench the reaction, filtered, and the filtrate was collected. The solvent was removed by rotary evaporation, and the rotary evaporated product was washed twice with low-temperature n-hexane and then dried under vacuum to obtain borosilicate-modified polyphenol monomer.

[0065] c. Under nitrogen atmosphere protection, mix 15 parts by weight of borosilicate modified polyphenol monomer with deionized water, heat to 55°C, stir and disperse evenly, add 25 parts of resorcinol, continue mixing and dispersing evenly, add ammonia water dropwise, adjust the pH value to 9.0, heat to 80°C, add 32 parts of saturated formaldehyde aqueous solution dropwise, after the addition is complete, keep warm and stir the reaction, monitor the viscosity during stirring, stop heating when the viscosity reaches 600 mPa·s, cool to 55°C, add 1.2 parts of polyethylene glycol 400 toughening agent and 1 part of resorcinol diglycidyl ether anti-aging agent, continue mixing for 30 min, cool to 40°C, add deionized water, mix evenly, and obtain a modified phenolic resin adhesive with a resin solid content of 45%.

[0066] Comparative Example 1. A method for preparing high-silica glass fiber thermal insulation cotton for automobiles, comprising the following steps:

[0067] Compared with Example 1, this comparative example did not prepare borosilicate-modified polyphenol monomers, but only used resorcinol;

[0068] S1. High-silica glass fibers are mixed, and then combed into a web to obtain high-silica glass fiber mat;

[0069] S2. The glass fiber felt prepared in step S1 is impregnated in modified phenolic resin adhesive for 30 minutes. After impregnation, it is taken out and dried at 120°C for 20 minutes. Then, it is hot-pressed and formed with a pressure of 1.5 MPa, a hot-pressing temperature of 220°C, and a hot-pressing time of 30 minutes. After hot pressing, it is taken out and cut and shaped to obtain high silica glass fiber heat insulation cotton for automobiles.

[0070] The preparation method of the modified phenolic resin adhesive includes the following steps:

[0071] c. Under nitrogen atmosphere protection, mix 30 parts by weight of resorcinol with deionized water, heat to 55°C, stir and disperse evenly, then add ammonia water dropwise to adjust the pH to 9.0, heat to 80°C, and add 32 parts of saturated formaldehyde aqueous solution dropwise. After the addition is complete, keep the mixture warm and stir to react. During the stirring process, monitor the viscosity at any time. After the viscosity reaches 600 mPa·s, stop heating and cool to 55°C. Then add 1.2 parts of polyethylene glycol 400 toughening agent and 1 part of resorcinol diglycidyl ether anti-aging agent. Continue mixing for 30 minutes, then cool to 40°C and add deionized water. Mix evenly to obtain a modified phenolic resin adhesive with a resin solid content of 45%.

[0072] Comparative Example 2. A method for preparing high-silica glass fiber thermal insulation cotton for automobiles, comprising the following steps:

[0073] Compared with Comparative Example 1, this comparative example increased by 5 parts of decabromodiphenyl ether flame retardant;

[0074] S1. High-silica glass fibers are mixed, and then combed into a web to obtain high-silica glass fiber mat;

[0075] S2. The glass fiber felt prepared in step S1 is impregnated in modified phenolic resin adhesive for 30 minutes. After impregnation, it is taken out and dried at 120°C for 20 minutes. Then, it is hot-pressed and formed with a pressure of 1.5 MPa, a hot-pressing temperature of 220°C, and a hot-pressing time of 30 minutes. After hot pressing, it is taken out and cut and shaped to obtain high silica glass fiber heat insulation cotton for automobiles.

[0076] The preparation method of the modified phenolic resin adhesive includes the following steps:

[0077] c. Under nitrogen atmosphere protection, mix 30 parts by weight of resorcinol with deionized water, heat to 55°C, stir and disperse evenly, then add ammonia water dropwise to adjust the pH to 9.0, heat to 80°C, and add 32 parts of saturated formaldehyde aqueous solution dropwise. After the addition is complete, keep the mixture warm and stir to react. During the stirring process, monitor the viscosity at any time. When the viscosity reaches 600 mPa·s, stop heating and cool to 55°C. Then add 5 parts of decabromodiphenyl ether, 1.2 parts of polyethylene glycol 400 toughening agent, and 1 part of resorcinol diglycidyl ether anti-aging agent. Continue mixing for 30 minutes, then cool to 40°C and add deionized water. Mix evenly to obtain a modified phenolic resin adhesive with a resin solid content of 45%.

[0078] Detection:

[0079] According to GB / T 10299-2011 "Test Method for Hydrophobicity of Thermal Insulation Materials", the water droplet contact angle of the high silica glass fiber thermal insulation cotton for automobiles prepared in Examples 1-4 and Comparative Examples 1-2 was tested.

[0080] The tensile strength of the high silica glass fiber thermal insulation cotton for automobiles prepared in Examples 1-4 and Comparative Examples 1-2 was tested using a universal testing machine.

[0081] According to UL94 standard, the smoke density level test and flame retardant performance test were conducted on the high silica glass fiber thermal insulation cotton for automobiles prepared in Examples 1-4 and Comparative Examples 1-2.

[0082] The smoke density rating of the high silica glass fiber thermal insulation cotton for automobiles prepared in Examples 1-4 and Comparative Examples 1-2 was tested according to GB 38262-2019.

[0083] The thermal conductivity of the high silica glass fiber thermal insulation cotton for automobiles prepared in Examples 1-4 and Comparative Examples 1-2 was tested according to GB / T 10294-2008.

[0084] The test results are shown in the table below;

[0085]

[0086] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-silica glass fiber thermal insulation cotton for automobiles, characterized in that: The automotive high-silica glass fiber thermal insulation cotton is prepared by drying and curing high-silica glass fiber felt impregnated with modified phenolic resin adhesive; wherein, the preparation method of the modified phenolic resin adhesive includes the following steps: a. Under nitrogen atmosphere protection, DMF is heated to 110~120℃ to remove water for 1~2h, then cooled to room temperature, 4-carboxyphenylboronic acid pinacol ester is dispersed in DMF, stirred and mixed evenly, then heated to 40~45℃, dicyclohexylcarbodiimide is added, stirred and dispersed evenly, then 3-aminopropyltriethoxysilane is added dropwise, after the addition is completed, the mixed solution is heated to 65~72℃, stirred and reacted for 4~6h, then cooled to room temperature, the reaction system is filtered, and the filtrate is collected for later use; b. Heat the filtrate from step a to 50-55℃ and set aside. Take clean DMF, protect it under a nitrogen atmosphere, and heat it to 110-120℃ to remove water for 1-2 hours. After cooling to room temperature, divide it into two batches and add resorcinol and aluminum ethoxide to each batch respectively. Stir and disperse evenly to obtain resorcinol DMF solution and aluminum ethoxide DMF solution. Add the resorcinol DMF solution and aluminum ethoxide DMF solution dropwise to the filtrate from step a at a uniform rate, stirring continuously during the dropwise addition. After the dropwise addition is completed, heat to 65-70℃ and continue stirring for 6-12 hours. Add anhydrous ethanol to quench the reaction, filter, collect the filtrate, remove the solvent by rotary evaporation, wash the rotary evaporated product 2-3 times with low-temperature n-hexane, and then vacuum dry to obtain borosilicate-modified polyphenol monomer; c. Under a nitrogen atmosphere, the borosilicate-modified polyphenol monomer was mixed with deionized water and heated to 50-55°C. After stirring and dispersing evenly, resorcinol was added, and the mixture was further stirred and dispersed evenly. Then, ammonia water was added dropwise to adjust the pH to 8.5-9.

0. The temperature was then raised to 78-85°C, and a saturated formaldehyde aqueous solution was added dropwise. After the addition was complete, the mixture was kept at this temperature and stirred. During stirring, the viscosity was monitored continuously. When the viscosity reached 600-800 mPa·s, heating was stopped, and the mixture was cooled to 55-60°C. After adding toughening agents and anti-aging agents and continuing to mix for 30-45 minutes, the mixture is cooled to 30-40°C. Deionized water is then added and mixed thoroughly to obtain a modified phenolic resin adhesive with a resin solid content of 40-50%. The components added, by weight, are 9-11.2 parts of 4-carboxyphenylboronic acid pinacol ester, 7.5-8.2 parts of dicyclohexylcarbodiimide, 10 parts of 3-aminopropyltriethoxysilane, 0.8-1 parts of aluminum ethoxide, and 12-15 parts of resorcinol.

2. The high-silica glass fiber thermal insulation cotton for automobiles according to claim 1, characterized in that: The high-silica glass fiber has a diameter of 7~12μm.

3. The high-silica glass fiber thermal insulation cotton for automobiles according to claim 1, characterized in that: In step b, the low-temperature n-hexane is n-hexane with a temperature of 0~2℃.

4. The high-silica glass fiber thermal insulation cotton for automobiles according to claim 1, characterized in that: In step c, by weight, the amounts of each component added are 10-15 parts of borosilicate modified polyphenol monomer, 25-30 parts of resorcinol, 32-37 parts of saturated formaldehyde aqueous solution, 1.2-1.5 parts of toughening agent and 1-1.2 parts of anti-aging agent.

5. The high-silica glass fiber thermal insulation cotton for automobiles according to claim 1, characterized in that: In step c, the toughening agent is either polyethylene glycol 400 or polyethylene glycol 800.

6. The high-silica glass fiber thermal insulation cotton for automobiles according to claim 1, characterized in that: In step c, the anti-aging agent is resorcinol diglycidyl ether.

7. A method for preparing high-silica glass fiber thermal insulation cotton for automobiles as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1. High-silica glass fibers are mixed, and then combed into a web to obtain high-silica glass fiber mat; S2. The glass fiber felt prepared in step S1 is impregnated in modified phenolic resin adhesive for 15-30 minutes, then removed and dried at 110-120℃ for 20-30 minutes. After drying, it is hot-pressed to obtain high silica glass fiber heat insulation cotton for automobiles.

8. The method for preparing a high-silica glass fiber thermal insulation cotton for automobiles according to claim 7, characterized in that: In step S2, during hot pressing, the applied pressure is 1~1.5MPa, the hot pressing temperature is 180~220℃, and the hot pressing time is 15~30min.

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