Method for preparing polysiloxane by hydrolyzing dimethyl dichlorosilane

A technology of dimethyldichlorosilane and polyorganosiloxane, which is applied in the field of preparing polyorganosiloxane by hydrolysis of dimethyldichlorosilane, can solve the problem that it is difficult to obtain a stable effect viscosity and does not involve the recovery of by-product HCl gas. Purification, etc.

Active Publication Date: 2010-11-03
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

With this concentration of HCl used in the hydrolysis process of step 1 and the use of high temperature in step 2, it is difficult to obtain a stabilizing effect and control the viscosity of the final product
[0018] None of the above inventions involve the recovery and purification of by-product HCl gas, the neutralization and purification process of the product organosiloxane, and the optimization of the circulation process of a complete set of processes

Method used

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  • Method for preparing polysiloxane by hydrolyzing dimethyl dichlorosilane
  • Method for preparing polysiloxane by hydrolyzing dimethyl dichlorosilane
  • Method for preparing polysiloxane by hydrolyzing dimethyl dichlorosilane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Introduce dimethyldichlorosilane, concentrated hydrochloric acid, and dilute acid produced by secondary hydrolysis into the metering tank, turn on the acid circulation pump and feed them into the primary hydrolysis reactor at a ratio of 1:1.5:1 (wt), to carry out the hydrolysis reaction. Open the steam valve, adjust the temperature of the heat exchanger, control the hydrolysis temperature between 10°C and 60°C, and measure the viscosity change of the primary hydrolyzate produced at different hydrolysis temperatures. See Table 1.

[0032] Table 1 Different reaction temperatures correspond to different primary hydrolyzate viscosities

[0033]

Embodiment 2

[0035] At 10°C, introduce dimethyldichlorosilane monomer, saturated concentrated hydrochloric acid and dilute hydrochloric acid produced by secondary hydrolysis into the primary hydrolysis reactor, dimethyldichlorosilane monomer, saturated concentrated hydrochloric acid and secondary hydrolysis produce The dilute hydrochloric acid ratio is 1:1.5:0.5~1:1.5:3. The influence of different mass ratios of reactants on the decomposition rate of dimethyldichlorosilane was determined. See Table 2.

[0036] Table 2 Different ratios of reactants correspond to different decomposition rates of dimethyldichlorosilane

[0037] The ratio of dimethyldichlorosilane to dilute hydrochloric acid

Embodiment 3

[0039]At 60°C, introduce dimethyldichlorosilane monomer, saturated concentrated hydrochloric acid and dilute hydrochloric acid produced by secondary hydrolysis into the primary hydrolysis reactor, and dimethyldichlorosilane monomer, saturated concentrated hydrochloric acid and secondary hydrolysis produce The dilute hydrochloric acid ratio is 1:1.5:0.5~1:1.5:3. The influence of different mass ratios of reactants on the decomposition rate of dimethyldichlorosilane was determined. See Table 3.

[0040] Table 3 Different ratios of reactants correspond to different decomposition rates of dimethyldichlorosilane

[0041] The ratio of dimethyldichlorosilane monomer to dilute hydrochloric acid

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Abstract

The invention relates to a method for preparing polysiloxane by hydrolyzing dimethyl dichlorosilane, which comprises two continuous hydrolysis steps (1) and (2) and a neutralization step (3): step (1), dimethyl dichlorosilane, concentrated hydrochloric acid of the concentration greater than 35 percent and dilute generated by secondary hydrolysis are hydrolyzed at 10-60DEG C and under the pressure of 0-0.3MPa according to the weight ratio of 1: 1.5: 0.5-1: 1.5: 3; step (2), hydrolysis is carried out in excess water, and the reaction temperature is normal temperature; and step (3), the neutralization reaction is carried out, resin is adopted to adsorb a filter unit, the stuffing is cation-base exchange resin with large surface area, and the height of the stuffing is 2-4 meters; the content of the hydrolysate Cl- is less than 10ppm, the product siloxane prepared in the method has the viscosity less than 50mPa.S, and the content of impurity in hydrogen chloride gas is less than 10ppm.

Description

Technical field: [0001] The invention relates to a method for preparing polyorganosiloxane by hydrolyzing dimethyldichlorosilane. This reaction method is based on the very high reactivity of silicon-chlorine bonds with water. Background technique: [0002] Dimethyldichlorosilane is transformed into linear or cyclic polyorganosiloxane through hydrolysis and polycondensation, which can be used to synthesize silicone oil, silicone rubber, etc., and are widely used in electronics, daily chemicals, electric power, building materials, aviation , aerospace and other fields. [0003] In the 1970s, the continuous hydrolysis-condensation reaction process of dimethyldichlorosilane was successfully developed and industrialized smoothly. Many countries applied for related patents on the hydrolysis process of dimethyldichlorosilane. [0004] French patent 2,512,028 reports organohalogenated silanes, especially Me 2 SiCl 2 method of hydrolysis. The organohalogenated silane is hydrolyz...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G77/24
Inventor 黄英超王刚金美仙崔香淑孙凤利王福民陈丽娟
Owner PETROCHINA CO LTD
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