Method for preparing methyl phenyl vinyl silicone resin

Abstract

The invention discloses a method for preparing a methyl phenyl vinyl silicone resin, which comprises the following steps of: under a condition of a nitrogen atmosphere at the temperature of between 30 and 45 DEG C, dissolving a certain amount of methyl trimethoxy silane, vinyl trimethoxy silane and alkyl dimethoxy silane in ethanol; adjusting the pH of the system to between 2.8 and 3.5; after full reaction, adding the methyl trimethoxy silane, the vinyl trimethoxy silane, the alkyl dimethoxy silane and deionized water into the mixture to perform isothermal reaction for 0.5 to 1 hour at the temperature of between 50 and 60 DEG C; raising the temperature to between 72 and 78 DEG C, performing the isothermal reaction again for 8 to 10 hours, and then dropping an end capping agent and deionized water into the mixture; performing reaction at the temperature of between 72 and 78 DEG C for 6 to 10 hours to obtain a white emulsion; and standing the mixture until complete demixing, separating the mixture to obtain an oily matter at a lower layer, and performing vacuum drying on the oily matter to obtain a product of the methyl phenyl vinyl silicone resin. In the method, the process is simple, the product is easy to separate and purify, the reactions are mild and are easy to control, and the processability is greatly improved.

Description

technical field [0001] The invention relates to a method for synthesizing an organosilicon polymer, in particular to a method for preparing an organosilicon resin, and belongs to the technical field of organic polymer materials. Background technique [0002] Silicone resin has the characteristics of both organic resin and inorganic materials, such as excellent heat resistance, weather resistance, electrical insulation, water repellency and chemical resistance, etc. It is a promising electrical insulation material. The number of organic groups contained in the silicone resin, that is, the R / Si value (the average number of organic groups connected to a silicon atom) and the phenyl (Ph) content (the percentage of the number of organic groups occupied by the phenyl group) are the factors that control the silicone resin. important indicator of quality. R / Si value mainly affects the dryness of silicone resin, paint film hardness, softness, thermal weight loss and heat cracking re...

AI Technical Summary

Problems solved by technology

[0009] There are following deficiencies in the above preparation method: 1) adopt toxic toluene as solvent, it is difficult to recycle, pollute the environment, endanger human health; 2) the reaction monomer is organochlorosilane, the monomer source is limited, and a large amount of hydrogen chloride is generated in the reaction process Gas, together with the heat released by dissolving in water, promotes the spontaneous condensation reaction between silicon hydroxyl groups, resulting in difficult control of the degree of polymerization, the reaction system is prone to gel, and the hydrochloric acid generated by the reaction will cause corrosion to equipment; 3) The synthesis process is cumbersome , the types of reaction products are complex, need to be washed many times, and there are problems such as poor storage and unstable quality; 4) long cycle, low efficiency, and difficult to control the degree of reaction

As the reaction proceeds, the molecular weight of the produced methylphenylvinyl silicone resin gradually increases, and its polarity becomes weaker and weaker, so the resulting product is more and more difficult to separate out in the above-mentioned non-polar or weakly polar solvents. The larger the molecular weight of the product is, the higher the molecular weight of the product is, so the final product has poor manufacturability. It is solid or semi-solid with poor fluidity at room temperature, and cannot be used in occasions that require high material manufacturability, such as vacuum impregnation technology, resin transfer molding process, etc.

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