Benzocyclobutene modified phenyl silicone resin and preparation method thereof

Abstract

The invention relates to the field of silicon resin, in particular to benzocyclobutene modified phenyl silicon resin and a preparation method thereof, which are used for solving the problem that the application of the existing silicon resin in a high-temperature environment is limited due to poor high-temperature resistance, ablation resistance and charring performance of the existing silicon resin. The benzocyclobutene modified phenyl silicone resin contains a large number of benzene rings, so that the benzocyclobutene modified phenyl silicone resin is endowed with excellent high-temperature resistance, the thermal stability of the benzocyclobutene modified phenyl silicone resin is further improved after a benzocyclobutene structure is introduced, and the molecular structure of the benzocyclobutene modified phenyl silicone resin further contains a large number of phosphorus-containing structures and nitrogen-containing structures, so that the benzocyclobutene modified phenyl silicone resin can form more carbon protection layers during combustion, and the service life of the benzocyclobutene modified phenyl silicone resin is prolonged. The purposes of flame retardance and ablation resistance are achieved; the benzocyclobutene modified phenyl silicone resin has excellent high temperature resistance, ablation resistance, flame retardance and char forming performance and can be widely applied to the fields of aerospace, electrical industry, semiconductor packaging and the like, and the preparation method is simple, easy to operate and suitable for industrial production.

Description

Technical Field

[0001] The invention relates to the field of silicone resins, and in particular to a benzocyclobutene-modified phenyl silicone resin and a preparation method thereof. Background Art

[0002] At present, silicone resins are widely used in various industrial fields, such as coatings, seals, and insulating materials, due to their excellent chemical stability and mechanical properties. Traditional silicone resins usually include siloxane monomers formed by condensation or addition polymerization, and have relatively fixed structures and properties. However, although these traditional silicone resins have shown good thermal stability to a certain extent, they are prone to chemical degradation reactions under extremely high temperature or high-speed airflow conditions, and ablation will occur, resulting in a decrease in material performance, and even cracking and falling off. In addition, it is difficult to form a stable protective carbon layer, which limits their application in high-temperature environments.

[0003] Therefore, it is of great significance to develop a benzocyclobutene-modified phenyl silicone resin and a preparation method thereof that can significantly improve the high temperature resistance, ablation resistance and charring performance of silicone resin. Summary of the invention

[0004] In order to overcome the above technical problems, the purpose of the present invention is to provide a benzocyclobutene modified phenyl silicone resin and a preparation method thereof, which solves the problem that the existing silicone resin has poor high temperature resistance, ablation resistance and charring performance, which limits its application in high temperature environments.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A method for preparing a benzocyclobutene-modified phenyl silicone resin comprises the following steps:

[0007] Step s1: Add benzocyclobutene, iodine and acetic acid solution to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, stir and react for 20-30 minutes at a temperature of -5-0°C and a stirring rate of 300-400r / min, then add liquid bromine solution dropwise while stirring, and control the dropping rate to 1-2 drops / s. After the dropwise addition is completed, continue to stir and react for 40-50 hours. After the reaction is completed, pour the reaction product into distilled water, then extract with petroleum ether 2-3 times, combine the extracts and wash with saturated sodium sulfite solution, saturated sodium carbonate solution and distilled water 2-3 times in sequence, then dry with anhydrous sodium sulfate, then vacuum filter, and rotary evaporate the filtrate to remove the solvent to obtain an intermediate product;

[0008] Step s2: adding magnesium powder, iodine and tetrahydrofuran to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube and a constant pressure dropping funnel, introducing nitrogen protection, stirring and reacting for 20-30 minutes at a temperature of 25-30°C and a stirring rate of 300-400r / min, then adding the intermediate product solution dropwise while stirring, controlling the dropping rate to 1-2 drops / s, heating to reflux after the addition is complete, and continuing to stir and react for 1-2 hours, then cooling to 25-30°C and adding dimethoxymethylsilyl chloride, and continuing to stir and react for 20-30 minutes, then heating to reflux and continuing to stir and react for 6-8 hours, after the reaction is completed, cooling the reaction product to room temperature, then rotary evaporation to remove the solvent, and then using petroleum ether as an eluent for silica gel column chromatography to obtain benzocyclobutene monomer;

[0009] Step s3: Add DOPO, vinyl trimethoxysilane, azobisisobutyronitrile and diethylene glycol dimethyl ether into a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, stir and react for 10-15 minutes at a temperature of 25-30°C and a stirring rate of 300-400 r / min, then raise the temperature to 80-85°C and continue stirring and reacting for 20-30 hours. After the reaction is completed, cool the reaction product to room temperature, then rotary evaporate to remove the solvent, then add it to cyclohexane, then vacuum filter, and rotary evaporate the filtrate to remove the solvent to obtain a flame retardant monomer;

[0010] Step s4: adding pentaerythritol, mercaptopropionic acid, p-toluenesulfonic acid and cyclohexane into a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, stirring the mixture for 10-15 min at a temperature of 25-30° C. and a stirring rate of 300-400 r / min, then heating the mixture to reflux and continuing the stirring reaction for 6-8 h. After the reaction is completed, the reaction product is rotary evaporated to remove the solvent to obtain a mercapto crosslinking agent;

[0011] Step s5: Add diphenyldimethoxysilane, benzocyclobutene monomer, flame retardant monomer, γ-aminoethylaminopropyltrimethoxysilane, vinyltrimethoxysilane, anhydrous ethanol and deionized water into a three-necked flask equipped with a stirrer, a thermometer and an air duct, introduce nitrogen protection, and stir the reaction for 10-15 minutes at a temperature of 25-30°C and a stirring rate of 300-400r / min. Then, adjust the pH to 4-5 with hydrochloric acid solution, and then continue to stir the reaction for 3-4 hours at a temperature of 35-40°C. Then, add a thiol crosslinking agent and stir the reaction for 3-4 hours at a temperature of 65-70°C. After the reaction, cool the reaction product to room temperature, and then adjust the pH to 7 with sodium hydroxide solution. Then, remove the solvent by rotary evaporation to obtain benzocyclobutene modified phenyl silicone resin.

[0012] As a further solution of the present invention: the usage ratio of the benzocyclobutene, iodine, acetic acid solution and liquid bromine solution in step s1 is 10 mmol: 0.01-0.03 g: 15-20 mL: 5-7 mL.

[0013] As a further solution of the present invention: the liquid bromine solution in step s1 is a solution formed by dissolving liquid bromine in acetic acid solution at a ratio of 11-15 mmol:5 mL; the mass fraction of the acetic acid solution is 95%.

[0014] As a further solution of the present invention: the usage ratio of the magnesium powder, iodine, tetrahydrofuran, intermediate product solution and dimethoxymethylsilyl chloride in step s2 is 13-17 mmol: 0.01-0.03 g: 30-40 mL: 20-25 mL: 10 mmol.

[0015] As a further solution of the present invention: the intermediate product solution in step s2 is a solution formed by dissolving the intermediate product in tetrahydrofuran at a ratio of 11-13 mmol:20 mL.

[0016] As a further solution of the present invention: the usage ratio of the DOPO, vinyltrimethoxysilane, azobisisobutyronitrile and diethylene glycol dimethyl ether in step s3 is 10 mmol: 10 mmol: 0.02-0.04 g: 40-50 mL.

[0017] As a further solution of the present invention: the usage ratio of the pentaerythritol, mercaptopropionic acid, p-toluenesulfonic acid and cyclohexane in step s4 is 10 mmol: 45-50 mmol: 0.05-0.1 g: 50-60 mL.

[0018] As a further scheme of the present invention: the usage ratio of the diphenyldimethoxysilane, benzocyclobutene monomer, flame retardant monomer, γ-aminoethylaminopropyltrimethoxysilane, vinyltrimethoxysilane, anhydrous ethanol, deionized water and mercapto crosslinking agent in step s5 is 70-80mmol: 28-44mmol: 12-18mmol: 5-9mmol: 2-6mmol: 30-40mL: 60-70mL: 2-8mmol.

[0019] As a further solution of the present invention: the mass fraction of the hydrochloric acid solution in step s5 is 15-20%; the mass fraction of the sodium hydroxide solution is 25-30%.

[0020] As a further solution of the present invention: the benzocyclobutene-modified phenyl silicone resin is prepared according to the preparation method of the benzocyclobutene-modified phenyl silicone resin.

[0021] Beneficial effects of the present invention:

[0022] The invention discloses a benzocyclobutene modified phenyl silicone resin and a preparation method thereof. First, benzocyclobutene and liquid bromine are reacted, and the liquid bromine is used as a brominating agent to introduce bromine atoms into the benzene ring of benzocyclobutene to obtain an intermediate product. Then, a Grignard reaction is performed to make the intermediate product react with dimethoxymethylchlorosilane, so that the bromine atoms on the intermediate product are converted into a dimethoxymethylsilane structure to obtain a benzocyclobutene monomer. Then, DOPO and vinyl trimethoxysilane are reacted, and the PH on DOPO reacts with the alkenyl on the vinyl trimethoxysilane to obtain a flame retardant. Monomer, then using pentaerythritol and mercaptopropionic acid to react, the hydroxyl group on pentaerythritol and the carboxyl group on mercaptopropionic acid undergo esterification reaction, introducing a large number of mercapto groups to obtain a mercapto crosslinking agent, and finally using diphenyldimethoxysilane, benzocyclobutene monomer, flame retardant monomer, γ-aminoethylaminopropyltrimethoxysilane, and vinyltrimethoxysilane as polymerization monomers to polymerize to form silicone resin, and the mercapto group of the mercapto crosslinking agent and the alkenyl group in the silicone resin undergo click chemical reaction to form a complex crosslinking network, thereby greatly improving its stability, and obtaining benzocyclobutene-modified phenyl silicone resin;

[0023] The benzocyclobutene-modified phenyl silicone resin contains a large number of benzene rings, which give it excellent high temperature resistance. After the benzocyclobutene structure is introduced, the benzocyclobutene can form a polymer with a cross-linked network structure due to its unique thermal ring-opening polymerization mechanism, which further improves its thermal stability. In addition, the molecular structure of the benzocyclobutene-modified phenyl silicone resin also contains a large number of phosphorus-containing structures and nitrogen-containing structures. The phosphorus-containing molecules will generate strong acids such as metaphosphoric acid and polymetaphosphoric acid when burned, which promotes the formation of a carbon layer in the condensed phase to isolate heat exchange. The nitrogen-containing molecules When decomposing at high temperature, a large amount of non-combustible gas is generated, which can dilute the oxygen concentration near the flame and form a protective layer when heated, resulting in an increase in pyrolytic carbon and an improvement in carbon oxidation resistance. The enhancement of carbon oxidation resistance can retain more carbon and effectively block the transfer of heat, thereby achieving the purpose of flame retardancy and ablation resistance. The benzocyclobutene-modified phenyl silicone resin has excellent high temperature resistance, ablation resistance, flame retardancy and carbonization performance, and can be widely used in aerospace, electrical industry, semiconductor packaging and other fields. Moreover, the preparation method is simple, easy to operate, and suitable for industrial production. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Embodiment 1:

[0026] This embodiment is a method for preparing a benzocyclobutene-modified phenyl silicone resin, comprising the following steps:

[0027] Step s1: add 10mmol benzocyclobutene, 0.01g iodine and 15mL 95% acetic acid solution to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, stir and react for 20min at a temperature of -5°C and a stirring rate of 300r / min, then add dropwise 5mL of liquid bromine dissolved in 95% acetic acid solution at a ratio of 11mmol:5mL while stirring, control the dropping rate to 1 drop / s, continue stirring and react for 40h after the dropwise addition is completed, pour the reaction product into distilled water after the reaction is completed, then extract twice with petroleum ether, combine the extracts and wash twice with saturated sodium sulfite solution, saturated sodium carbonate solution and distilled water in turn, then dry with anhydrous sodium sulfate, then vacuum filter, and rotary evaporate the filtrate to remove the solvent to obtain an intermediate product;

[0028] Step s2: 13 mmol magnesium powder, 0.01 g iodine and 30 mL tetrahydrofuran are added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube and a constant pressure dropping funnel, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 25° C. and a stirring rate of 300 r / min for 20 min, and then 20 mL of the intermediate product solution formed by dissolving 11 mmol:20 mL of the intermediate product in tetrahydrofuran is added dropwise while stirring, and the dropping rate is controlled to be 1 drop / s. After the dropwise addition is completed, the mixture is heated to reflux and the stirring reaction is continued for 1 h, and then the temperature is lowered to 25° C. and 10 mmol dimethoxymethylsilyl chloride is added and the stirring reaction is continued for 20 min, and then the temperature is raised to reflux and the stirring reaction is continued for 6 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation, and then petroleum ether is used as an eluent for silica gel column chromatography to obtain benzocyclobutene monomer;

[0029] Step s3: 10 mmol DOPO, 10 mmol vinyltrimethoxysilane, 0.02 g azobisisobutyronitrile and 40 mL diethylene glycol dimethyl ether were added to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at 25° C. and a stirring rate of 300 r / min for 10 min, and then heated to 80° C. and continued to stir for 20 h. After the reaction, the reaction product was cooled to room temperature, and then rotary evaporated to remove the solvent, and then added to cyclohexane, and then vacuum filtered, and the filtrate was rotary evaporated to remove the solvent to obtain a flame retardant monomer;

[0030] Step s4: 10 mmol of pentaerythritol, 45 mmol of mercaptopropionic acid, 0.05 g of p-toluenesulfonic acid and 50 mL of cyclohexane were added into a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at a temperature of 25° C. and a stirring rate of 300 r / min for 10 min, then the temperature was raised to reflux and the stirring reaction was continued for 6 h. After the reaction was completed, the reaction product was rotary evaporated to remove the solvent to obtain a mercapto crosslinking agent;

[0031] Step s5: 70mmol diphenyldimethoxysilane, 28mmol benzocyclobutene monomer, 12mmol flame retardant monomer, 5mmolγ-aminoethylaminopropyltrimethoxysilane, 2mmol vinyltrimethoxysilane, 30mL anhydrous ethanol and 60mL deionized water are added to a three-necked flask equipped with a stirrer, a thermometer and an air duct, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 25°C and a stirring rate of 300r / min for 10min, and then the pH is adjusted to 4 with a 15% hydrochloric acid solution, and then the temperature is raised to 35°C and the stirring reaction is continued for 3h. Then 2mmol thiol crosslinking agent is added and the temperature is raised to 65°C and the stirring reaction is continued for 3h. After the reaction, the reaction product is cooled to room temperature, and then the pH is adjusted to 7 with a 25% sodium hydroxide solution, and then the solvent is removed by rotary evaporation to obtain benzocyclobutene modified phenyl silicone resin.

[0032] Embodiment 2:

[0033] This embodiment is a method for preparing a benzocyclobutene-modified phenyl silicone resin, comprising the following steps:

[0034] Step s1: add 10mmol benzocyclobutene, 0.02g iodine and 18mL 95% acetic acid solution to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, stir and react for 25min at a temperature of -3°C and a stirring rate of 350r / min, then add dropwise while stirring 6mL of liquid bromine dissolved in 95% acetic acid solution at a ratio of 13mmol:5mL, and control the dropping rate to 1 drop / s. After the dropwise addition is completed, continue to stir and react for 45h. After the reaction is completed, pour the reaction product into distilled water, then extract it twice with petroleum ether, combine the extracts and wash them twice with saturated sodium sulfite solution, saturated sodium carbonate solution and distilled water in turn, then dry it with anhydrous sodium sulfate, then vacuum filter it, and rotary evaporate the filtrate to remove the solvent to obtain an intermediate product;

[0035] Step s2: 15 mmol magnesium powder, 0.02 g iodine and 35 mL tetrahydrofuran are added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube and a constant pressure dropping funnel, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 28° C. and a stirring rate of 350 r / min for 25 min. Then, 22 mL of the intermediate product solution formed by dissolving the intermediate product in tetrahydrofuran at a ratio of 12 mmol:20 mL is added dropwise while stirring, and the dropping rate is controlled to be 1 drop / s. After the addition is completed, the mixture is heated to reflux and the stirring reaction is continued for 1.5 h. Then, the mixture is cooled to 28° C. and 10 mmol dimethoxymethylsilyl chloride is added and the stirring reaction is continued for 28 min. Then, the mixture is heated to reflux and the stirring reaction is continued for 7 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation. Then, petroleum ether is used as an eluent for silica gel column chromatography to obtain benzocyclobutene monomer;

[0036] Step s3: 10 mmol DOPO, 10 mmol vinyltrimethoxysilane, 0.03 g azobisisobutyronitrile and 45 mL diethylene glycol dimethyl ether were added into a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at 28° C. and a stirring rate of 350 r / min for 12 min, and then heated to 82° C. and continued to stir for 25 h. After the reaction, the reaction product was cooled to room temperature, and then rotary evaporated to remove the solvent, and then added to cyclohexane, and then vacuum filtered, and the filtrate was rotary evaporated to remove the solvent to obtain a flame retardant monomer;

[0037] Step s4: 10 mmol of pentaerythritol, 48 mmol of mercaptopropionic acid, 0.08 g of p-toluenesulfonic acid and 55 mL of cyclohexane were added into a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at a temperature of 28° C. and a stirring rate of 350 r / min for 12 min, then the temperature was raised to reflux and the stirring reaction was continued for 7 h. After the reaction was completed, the reaction product was rotary evaporated to remove the solvent to obtain a mercapto crosslinking agent;

[0038] Step s5: 75mmol diphenyldimethoxysilane, 36mmol benzocyclobutene monomer, 15mmol flame retardant monomer, 7mmol γ-aminoethylaminopropyltrimethoxysilane, 4mmol vinyltrimethoxysilane, 35mL anhydrous ethanol and 65mL deionized water are added to a three-necked flask equipped with a stirrer, a thermometer and an air duct, and nitrogen is introduced for protection. The reaction is stirred for 12 minutes at a temperature of 28°C and a stirring rate of 350r / min. Then, the pH is adjusted to 4.5 with a hydrochloric acid solution with a mass fraction of 18%, and then the temperature is raised to 38°C and the stirring reaction is continued for 3.5h. Then, 5mmol thiol crosslinking agent is added and the temperature is raised to 68°C and the stirring reaction is continued for 3.5h. After the reaction, the reaction product is cooled to room temperature, and then the pH is adjusted to 7 with a sodium hydroxide solution with a mass fraction of 28%, and then the solvent is removed by rotary evaporation to obtain benzocyclobutene modified phenyl silicone resin.

[0039] Embodiment 3:

[0040] This embodiment is a method for preparing a benzocyclobutene-modified phenyl silicone resin, comprising the following steps:

[0041] Step s1: add 10mmol benzocyclobutene, 0.03g iodine and 20mL 95% acetic acid solution to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, stir and react for 30min at a temperature of 0°C and a stirring rate of 400r / min, then add dropwise 7mL of liquid bromine dissolved in 95% acetic acid solution at a ratio of 15mmol:5mL while stirring, control the dropping rate to 2 drops / s, continue stirring and react for 50h after the dropwise addition is completed, pour the reaction product into distilled water after the reaction is completed, then extract with petroleum ether for 3 times, combine the extracts and wash with saturated sodium sulfite solution, saturated sodium carbonate solution and distilled water for 3 times in sequence, then dry with anhydrous sodium sulfate, then vacuum filter, and rotary evaporate the filtrate to remove the solvent to obtain an intermediate product;

[0042] Step s2: 17 mmol magnesium powder, 0.03 g iodine and 40 mL tetrahydrofuran are added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube and a constant pressure dropping funnel, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 30 min, and then 25 mL of the intermediate product solution formed by dissolving 13 mmol:20 mL of the intermediate product in tetrahydrofuran is added dropwise while stirring, and the dropping rate is controlled to be 2 drops / s. After the dropwise addition is completed, the mixture is heated to reflux and the stirring reaction is continued for 2 h, and then the temperature is lowered to 30° C. and 10 mmol dimethoxymethylsilyl chloride is added and the stirring reaction is continued for 30 min, and then the temperature is raised to reflux and the stirring reaction is continued for 8 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation, and then petroleum ether is used as an eluent for silica gel column chromatography to obtain benzocyclobutene monomer;

[0043] Step s3: 10 mmol DOPO, 10 mmol vinyltrimethoxysilane, 0.04 g azobisisobutyronitrile and 50 mL diethylene glycol dimethyl ether were added to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 15 min, and then heated to 85° C. and continued to stir for 30 h. After the reaction, the reaction product was cooled to room temperature, and then rotary evaporated to remove the solvent, and then added to cyclohexane, and then vacuum filtered, and the filtrate was rotary evaporated to remove the solvent to obtain a flame retardant monomer;

[0044] Step s4: 10 mmol of pentaerythritol, 50 mmol of mercaptopropionic acid, 0.1 g of p-toluenesulfonic acid and 60 mL of cyclohexane were added to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 15 min, then the temperature was raised to reflux and the stirring reaction was continued for 8 h. After the reaction was completed, the reaction product was rotary evaporated to remove the solvent to obtain a mercapto crosslinking agent;

[0045] Step s5: 80mmol diphenyldimethoxysilane, 44mmol benzocyclobutene monomer, 18mmol flame retardant monomer, 9mmolγ-aminoethylaminopropyltrimethoxysilane, 6mmol vinyltrimethoxysilane, 40mL anhydrous ethanol and 70mL deionized water are added to a three-necked flask equipped with a stirrer, a thermometer and an air duct, and nitrogen is introduced for protection. The reaction is stirred for 15 minutes at a temperature of 30°C and a stirring rate of 400r / min. Then, the pH is adjusted to 5 with a 20% hydrochloric acid solution, and then the temperature is raised to 40°C and the stirring reaction is continued for 4 hours. Then, 8mmol thiol crosslinking agent is added and the temperature is raised to 70°C and the stirring reaction is continued for 4 hours. After the reaction, the reaction product is cooled to room temperature, and then the pH is adjusted to 7 with a 30% sodium hydroxide solution. Then, the solvent is removed by rotary evaporation to obtain benzocyclobutene-modified phenyl silicone resin.

[0046] Comparative Example 1:

[0047] This comparative example is a method for preparing a benzocyclobutene-modified phenyl silicone resin, comprising the following steps:

[0048] 80mmol of diphenyldimethoxysilane, 40mL of anhydrous ethanol and 70mL of deionized water were added to a three-necked flask equipped with a stirrer, a thermometer and an air duct, and nitrogen was introduced for protection. The reaction was stirred for 15 minutes at a temperature of 30°C and a stirring rate of 400r / min. Then, the pH was adjusted to 5 with a 20% hydrochloric acid solution by mass, and then the temperature was raised to 40°C and the stirring reaction was continued for 4 hours. Then, the temperature was raised to 70°C and the stirring reaction was continued for 4 hours. After the reaction, the reaction product was cooled to room temperature, and then the pH was adjusted to 7 with a 30% sodium hydroxide solution by mass, and then the solvent was removed by rotary evaporation to obtain a phenyl silicone resin.

[0049] Comparative Example 2:

[0050] This comparative example is a method for preparing a benzocyclobutene-modified phenyl silicone resin, comprising the following steps:

[0051] Step s1: add 10mmol benzocyclobutene, 0.03g iodine and 20mL 95% acetic acid solution to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, stir and react for 30min at a temperature of 0°C and a stirring rate of 400r / min, then add dropwise 7mL of liquid bromine dissolved in 95% acetic acid solution at a ratio of 15mmol:5mL while stirring, control the dropping rate to 2 drops / s, continue stirring and react for 50h after the dropwise addition is completed, pour the reaction product into distilled water after the reaction is completed, then extract with petroleum ether for 3 times, combine the extracts and wash with saturated sodium sulfite solution, saturated sodium carbonate solution and distilled water for 3 times in sequence, then dry with anhydrous sodium sulfate, then vacuum filter, and rotary evaporate the filtrate to remove the solvent to obtain an intermediate product;

[0052] Step s2: 17 mmol magnesium powder, 0.03 g iodine and 40 mL tetrahydrofuran are added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube and a constant pressure dropping funnel, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 30 min, and then 25 mL of the intermediate product solution formed by dissolving 13 mmol:20 mL of the intermediate product in tetrahydrofuran is added dropwise while stirring, and the dropping rate is controlled to be 2 drops / s. After the dropwise addition is completed, the mixture is heated to reflux and the stirring reaction is continued for 2 h, and then the temperature is lowered to 30° C. and 10 mmol dimethoxymethylsilyl chloride is added and the stirring reaction is continued for 30 min, and then the temperature is raised to reflux and the stirring reaction is continued for 8 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation, and then petroleum ether is used as an eluent for silica gel column chromatography to obtain benzocyclobutene monomer;

[0053] Step s3: Add 80mmol diphenyldimethoxysilane, 44mmol benzocyclobutene monomer, 40mL anhydrous ethanol and 70mL deionized water into a three-necked flask equipped with a stirrer, a thermometer and an air duct, introduce nitrogen protection, and stir the reaction for 15min at a temperature of 30°C and a stirring rate of 400r / min. Then, adjust the pH to 5 with a 20% hydrochloric acid solution, and then continue to stir the reaction for 4h at 40°C, and then stir the reaction for 4h at 70°C. After the reaction, cool the reaction product to room temperature, and then adjust the pH to 7 with a 30% sodium hydroxide solution. Then, rotary evaporate to remove the solvent to obtain benzocyclobutene-modified phenyl silicone resin.

[0054] Comparative Example 3:

[0055] This comparative example is a method for preparing a benzocyclobutene-modified phenyl silicone resin, comprising the following steps:

[0056] Step s1: add 10mmol benzocyclobutene, 0.03g iodine and 20mL 95% acetic acid solution to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, stir and react for 30min at a temperature of 0°C and a stirring rate of 400r / min, then add dropwise 7mL of liquid bromine dissolved in 95% acetic acid solution at a ratio of 15mmol:5mL while stirring, control the dropping rate to 2 drops / s, continue stirring and react for 50h after the dropwise addition is completed, pour the reaction product into distilled water after the reaction is completed, then extract with petroleum ether for 3 times, combine the extracts and wash with saturated sodium sulfite solution, saturated sodium carbonate solution and distilled water for 3 times in sequence, then dry with anhydrous sodium sulfate, then vacuum filter, and rotary evaporate the filtrate to remove the solvent to obtain an intermediate product;

[0057] Step s2: 17 mmol magnesium powder, 0.03 g iodine and 40 mL tetrahydrofuran are added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube and a constant pressure dropping funnel, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 30 min, and then 25 mL of the intermediate product solution formed by dissolving 13 mmol:20 mL of the intermediate product in tetrahydrofuran is added dropwise while stirring, and the dropping rate is controlled to be 2 drops / s. After the dropwise addition is completed, the mixture is heated to reflux and the stirring reaction is continued for 2 h, and then the temperature is lowered to 30° C. and 10 mmol dimethoxymethylsilyl chloride is added and the stirring reaction is continued for 30 min, and then the temperature is raised to reflux and the stirring reaction is continued for 8 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation, and then petroleum ether is used as an eluent for silica gel column chromatography to obtain benzocyclobutene monomer;

[0058] Step s3: 80mmol diphenyldimethoxysilane, 44mmol benzocyclobutene monomer, 9mmol γ-aminoethylaminopropyltrimethoxysilane, 6mmol vinyltrimethoxysilane, 40mL anhydrous ethanol and 70mL deionized water are added to a three-necked flask equipped with a stirrer, a thermometer and an air duct, and nitrogen is introduced for protection. The reaction is stirred for 15 minutes at a temperature of 30°C and a stirring rate of 400r / min. Then, the pH is adjusted to 5 with a 20% hydrochloric acid solution by mass, and then the temperature is raised to 40°C and the stirring reaction is continued for 4 hours. Then, the temperature is raised to 70°C and the stirring reaction is continued for 4 hours. After the reaction is completed, the reaction product is cooled to room temperature, and then the pH is adjusted to 7 with a 30% sodium hydroxide solution by mass, and then the solvent is removed by rotary evaporation to obtain benzocyclobutene modified phenyl silicone resin.

[0059] Comparative Example 4:

[0060] This comparative example is a method for preparing a benzocyclobutene-modified phenyl silicone resin, comprising the following steps:

[0061] Step s1: add 10mmol benzocyclobutene, 0.03g iodine and 20mL 95% acetic acid solution to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, stir and react for 30min at a temperature of 0°C and a stirring rate of 400r / min, then add dropwise 7mL of liquid bromine dissolved in 95% acetic acid solution at a ratio of 15mmol:5mL while stirring, control the dropping rate to 2 drops / s, continue stirring and react for 50h after the dropwise addition is completed, pour the reaction product into distilled water after the reaction is completed, then extract with petroleum ether for 3 times, combine the extracts and wash with saturated sodium sulfite solution, saturated sodium carbonate solution and distilled water for 3 times in sequence, then dry with anhydrous sodium sulfate, then vacuum filter, and rotary evaporate the filtrate to remove the solvent to obtain an intermediate product;

[0062] Step s2: 17 mmol magnesium powder, 0.03 g iodine and 40 mL tetrahydrofuran are added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube and a constant pressure dropping funnel, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 30 min, and then 25 mL of the intermediate product solution formed by dissolving 13 mmol:20 mL of the intermediate product in tetrahydrofuran is added dropwise while stirring, and the dropping rate is controlled to be 2 drops / s. After the dropwise addition is completed, the mixture is heated to reflux and the stirring reaction is continued for 2 h, and then the temperature is lowered to 30° C. and 10 mmol dimethoxymethylsilyl chloride is added and the stirring reaction is continued for 30 min, and then the temperature is raised to reflux and the stirring reaction is continued for 8 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation, and then petroleum ether is used as an eluent for silica gel column chromatography to obtain benzocyclobutene monomer;

[0063] Step s3: 10 mmol DOPO, 10 mmol vinyltrimethoxysilane, 0.04 g azobisisobutyronitrile and 50 mL diethylene glycol dimethyl ether were added to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 15 min, and then heated to 85° C. and continued to stir for 30 h. After the reaction, the reaction product was cooled to room temperature, and then rotary evaporated to remove the solvent, and then added to cyclohexane, and then vacuum filtered, and the filtrate was rotary evaporated to remove the solvent to obtain a flame retardant monomer;

[0064] Step s4: 80mmol diphenyldimethoxysilane, 44mmol benzocyclobutene monomer, 18mmol flame retardant monomer, 9mmolγ-aminoethylaminopropyltrimethoxysilane, 40mL anhydrous ethanol and 70mL deionized water are added to a three-necked flask equipped with a stirrer, a thermometer and an air duct, and nitrogen is introduced for protection. The reaction is stirred for 15 minutes at a temperature of 30°C and a stirring rate of 400r / min. Then, the pH is adjusted to 5 with a 20% hydrochloric acid solution by mass, and then the temperature is raised to 40°C and the stirring reaction is continued for 4 hours. Then, the temperature is raised to 70°C and the stirring reaction is continued for 4 hours. After the reaction is completed, the reaction product is cooled to room temperature, and then the pH is adjusted to 7 with a 30% sodium hydroxide solution by mass, and then the solvent is removed by rotary evaporation to obtain benzocyclobutene modified phenyl silicone resin.

[0065] Comparative Example 5:

[0066] This comparative example is a method for preparing a benzocyclobutene-modified phenyl silicone resin, comprising the following steps:

[0067] Step s1: add 10mmol benzocyclobutene, 0.03g iodine and 20mL 95% acetic acid solution to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, stir and react for 30min at a temperature of 0°C and a stirring rate of 400r / min, then add dropwise 7mL of liquid bromine dissolved in 95% acetic acid solution at a ratio of 15mmol:5mL while stirring, control the dropping rate to 2 drops / s, continue stirring and react for 50h after the dropwise addition is completed, pour the reaction product into distilled water after the reaction is completed, then extract with petroleum ether for 3 times, combine the extracts and wash with saturated sodium sulfite solution, saturated sodium carbonate solution and distilled water for 3 times in sequence, then dry with anhydrous sodium sulfate, then vacuum filter, and rotary evaporate the filtrate to remove the solvent to obtain an intermediate product;

[0068] Step s2: 17 mmol magnesium powder, 0.03 g iodine and 40 mL tetrahydrofuran are added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube and a constant pressure dropping funnel, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 30 min, and then 25 mL of the intermediate product solution formed by dissolving 13 mmol:20 mL of the intermediate product in tetrahydrofuran is added dropwise while stirring, and the dropping rate is controlled to be 2 drops / s. After the dropwise addition is completed, the mixture is heated to reflux and the stirring reaction is continued for 2 h, and then the temperature is lowered to 30° C. and 10 mmol dimethoxymethylsilyl chloride is added and the stirring reaction is continued for 30 min, and then the temperature is raised to reflux and the stirring reaction is continued for 8 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation, and then petroleum ether is used as an eluent for silica gel column chromatography to obtain benzocyclobutene monomer;

[0069] Step s3: 10 mmol of pentaerythritol, 50 mmol of mercaptopropionic acid, 0.1 g of p-toluenesulfonic acid and 60 mL of cyclohexane were added to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 15 min, then the temperature was raised to reflux and the stirring reaction was continued for 8 h. After the reaction was completed, the reaction product was rotary evaporated to remove the solvent to obtain a mercapto crosslinking agent;

[0070] Step s4: 80mmol diphenyldimethoxysilane, 44mmol benzocyclobutene monomer, 6mmol vinyltrimethoxysilane, 40mL anhydrous ethanol and 70mL deionized water are added to a three-necked flask equipped with a stirrer, a thermometer and an air duct, and nitrogen is introduced for protection. The reaction is stirred for 15 minutes at a temperature of 30°C and a stirring rate of 400r / min. Then, the pH is adjusted to 5 with a 20% hydrochloric acid solution, and then the temperature is raised to 40°C and the stirring reaction is continued for 4 hours. Then, 8mmol of thiol crosslinking agent is added and the temperature is raised to 70°C and the stirring reaction is continued for 4 hours. After the reaction, the reaction product is cooled to room temperature, and then the pH is adjusted to 7 with a 30% sodium hydroxide solution. Then, the solvent is removed by rotary evaporation to obtain benzocyclobutene-modified phenyl silicone resin.

[0071] The performance of the benzocyclobutene-modified phenyl silicone resins of Examples 1-3 and Comparative Examples 1-5 was tested in the following manner:

[0072] Benzocyclobutene-modified phenyl silicone resin and DY-HMQ102 hydrogenated MQ silicone resin were mixed in a mass ratio of 9:1, and then 20 ppm of Karstedt catalyst was added to the total mass. The mixture was continued to be mixed, and after being mixed evenly, it was poured into a mold, heat-treated at 120°C for 1 hour, and the bubbles were removed by vacuum. Then, the temperature was continued to be raised and heat-treated at 180°C for 1 hour, and the performance was tested after curing.

[0073] The test results are shown in the following table:

[0074] sample <![CDATA[T 5% ,℃]]> Linear ablation rate, mm / s Residual weight, % LOI, % Example 1 515 0.017 81.59 45.9 Example 2 527 0.015 83.04 46.6 Example 3 540 0.012 84.33 47.5 Comparative Example 1 372 0.063 64.25 29.1 Comparative Example 2 447 0.028 70.56 39.2 Comparative Example 3 402 0.034 67.28 35.3 Comparative Example 4 496 0.021 80.89 43.6 Comparative Example 5 478 0.024 77.05 40.9

[0075] Referring to the data in the above table, it can be known that the benzocyclobutene-modified phenyl silicone resin of the present application has excellent high temperature resistance, ablation resistance and excellent charring property.

[0076] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0077] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for preparing a benzocyclobutene-modified phenyl silicone resin, characterized in that: The following steps are involved: Step s1: Stir benzocyclobutene, iodine and acetic acid solution for reaction, then add liquid bromine solution dropwise while stirring, continue stirring for reaction after the addition is complete, pour the reaction product into distilled water, extract, wash and dry the extract, then vacuum filter, and rotary evaporate the filtrate to obtain an intermediate product; Step s2: stirring magnesium powder, iodine and tetrahydrofuran for reaction, then adding the intermediate product solution dropwise while stirring, continuing to stir the reaction after the dropwise addition is completed, then adding dimethoxymethylsilyl chloride and continuing to stir the reaction, after the reaction is completed, cooling the reaction product, then rotary evaporating, and then performing silica gel column chromatography to obtain benzocyclobutene monomer; Step s3: stirring DOPO, vinyl trimethoxysilane, azobisisobutyronitrile and diethylene glycol dimethyl ether for reaction, cooling the reaction product after the reaction is completed, then rotary evaporating, then adding it to cyclohexane, then vacuum filtering, and rotary evaporating the filtrate to obtain a flame retardant monomer; Step s4: stirring pentaerythritol, mercaptopropionic acid, p-toluenesulfonic acid and cyclohexane for reaction, and after the reaction is completed, rotary evaporating the reaction product to obtain a mercapto crosslinking agent; Step s5: diphenyldimethoxysilane, benzocyclobutene monomer, flame retardant monomer, γ-aminoethylaminopropyltrimethoxysilane, vinyltrimethoxysilane, anhydrous ethanol and deionized water are stirred for reaction, and then the pH is adjusted with hydrochloric acid solution, and then a thiol cross-linking agent is added to continue stirring the reaction. After the reaction is completed, the reaction product is cooled, and then the pH is adjusted with sodium hydroxide solution, and then rotary evaporated to obtain benzocyclobutene modified phenyl silicone resin.

2. The method for preparing a benzocyclobutene-modified phenyl silicone resin according to claim 1, characterized in that: The usage ratio of the benzocyclobutene, iodine, acetic acid solution and liquid bromine solution in step s1 is 10 mmol: 0.01-0.03 g: 15-20 mL: 5-7 mL.

3. The method for preparing a benzocyclobutene-modified phenyl silicone resin according to claim 1, characterized in that: The liquid bromine solution in step s1 is a solution formed by dissolving liquid bromine in acetic acid solution at a ratio of 11-15 mmol:5 mL; the mass fraction of the acetic acid solution is 95%.

4. The method for preparing a benzocyclobutene-modified phenyl silicone resin according to claim 1, characterized in that: The dosage ratio of the magnesium powder, iodine, tetrahydrofuran, intermediate product solution and dimethoxymethylsilyl chloride in step s2 is 13-17 mmol: 0.01-0.03 g: 30-40 mL: 20-25 mL: 10 mmol.

5. The method for preparing a benzocyclobutene-modified phenyl silicone resin according to claim 1, characterized in that: The intermediate product solution in step s2 is a solution formed by dissolving the intermediate product in tetrahydrofuran at a ratio of 11-13 mmol:20 mL.

6. The method for preparing a benzocyclobutene-modified phenyl silicone resin according to claim 1, characterized in that: The usage ratio of the DOPO, vinyltrimethoxysilane, azobisisobutyronitrile and diethylene glycol dimethyl ether in step s3 is 10 mmol: 10 mmol: 0.02-0.04 g: 40-50 mL.

7. The method for preparing a benzocyclobutene-modified phenyl silicone resin according to claim 1, characterized in that: The usage ratio of the pentaerythritol, mercaptopropionic acid, p-toluenesulfonic acid and cyclohexane in step s4 is 10 mmol: 45-50 mmol: 0.05-0.1 g: 50-60 mL.

8. The method for preparing a benzocyclobutene-modified phenyl silicone resin according to claim 1, characterized in that: The usage ratio of the diphenyldimethoxysilane, benzocyclobutene monomer, flame retardant monomer, γ-aminoethylaminopropyltrimethoxysilane, vinyltrimethoxysilane, anhydrous ethanol, deionized water and mercapto crosslinking agent in step s5 is 70-80mmol:28-44mmol:12-18mmo l:5-9mmol:2-6mmol:30-40mL:60-70mL:2-8mmol.

9. The method for preparing a benzocyclobutene-modified phenyl silicone resin according to claim 1, characterized in that: The mass fraction of the hydrochloric acid solution in step s5 is 15-20%; the mass fraction of the sodium hydroxide solution is 25-30%.

10. A benzocyclobutene-modified phenyl silicone resin, characterized in that: The benzocyclobutene-modified phenyl silicone resin is prepared according to the preparation method of the benzocyclobutene-modified phenyl silicone resin according to any one of claims 1 to 9.