Process for continuously preparing methyl silicone resin

Abstract

The invention relates to a process for manufacturing silicone resin, in particular to a process for continuously preparing methyl silicone resin. The process includes steps of hydrolyzing methyl trichlorosilane, dimethyl dichlorosilane and benzene solvents, to be more specific, mixing the methyl trichlorosilane, the dimethyl dichlorosilane and the benzene solvents with one another according to mass ratios to obtain mixtures, feeding the mixtures into a tubular hydrolysis reactor, filling the reactor with alkyl alcohol and washing water with diluted acid according to mass ratios and enabling the methyl trichlorosilane, the dimethyl dichlorosilane, the benzene solvents, the washing water with the diluted acid and the alkyl alcohol to jointly react to one another so as to obtain hydrolysate; washing the hydrolysate by the aid of water by three or more stages until the hydrolysate is neutral; continuously concentrating the hydrolysate in a vacuum state; carrying out condensation polymerization, to be more specific, adding catalysts into the hydrolysate when the effective content of siloxane reaches 50%-60% of kettle volumes, blowing inert gas into the hydrolysate and carrying out condensation polymerization reaction. The process has the advantages that wastewater discharge can be prevented, difficult problems of high discharge of the traditional washing water with acid, high contents of organic matters and difficulty in treating wastewater can be solved, and the product yield can be increased; the inert gas is blown into the hydrolysate in condensation polymerization procedures, accordingly, the low-molecular-weight removal time can be shortened, and yellowing of products can be prevented; system reaction conditions are stable, and the products are excellent in performance.

Description

technical field [0001] The invention relates to a production process of silicone resin, in particular to a continuous preparation process of methyl silicone resin. Background technique [0002] According to different raw materials, the preparation of silicone resin is mainly divided into two routes: alkoxysilane as raw material and chlorosilane as raw material. Due to the low cost of using chlorosilane monomers to produce silicone resins, mainstream products at home and abroad are still produced using chlorosilanes as raw materials. Mixed chlorosilane monomers are hydrolyzed under the protection of benzene-based solvents to prepare methyl silicone resin. In the traditional intermittent hydrolysis process, a large amount of water is required to be washed many times to make the hydrolyzate neutral. The production of 1 ton of silicone resin produces about 10-15 tons of washing wastewater, which not only pollutes the environment, but also reduces the product yield. Benzene-bas...

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Problems solved by technology

The harm of silicone resin waste water is mentioned in CN101602559B, and the treatment method mentioned in it is comparatively complicated, and it is difficult to realize industrialization

CN103694477A uses alkoxysilane as a raw material to prepare silicone resin, which uses membrane separation and rectification to separate acid medium oil, dilute acid and alcohol, which requires large equipment investment and high energy consumption

Due to the high viscosity of the material and the poor mass and heat transfer effect, the average reaction time of the polycondensation process is 4 to 10 hours. If the polycondensation reaction time is too long, the production efficiency is low and the production energy consumption is large. It is meaningful to develop a reaction device that is more suitable for the polycondensation process. major

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