Method for preparing dimethyl silicone polymer by hydrolyzing dimethyl dichlorosilane with concentrated acid

A technology of dimethyldichlorosilane and polydimethylsiloxane, which is applied in the field of preparing polydimethylsiloxane by hydrolyzing dimethyldichlorosilane with concentrated acid, and can solve the problem of low content of polysiloxane rings To achieve the effect of increasing the content of ring body, promoting the separation of oil phase and reducing the probability of contact

Active Publication Date: 2013-11-27
HOSHINE SILICON IND CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The invention provides a method for preparing polydimethylsiloxane by hydrolyzing dimethyldichlorosilane with concentrated acid to solve the problem of low content of polysiloxane rings in the hydrolyzate of the traditional method

Method used

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  • Method for preparing dimethyl silicone polymer by hydrolyzing dimethyl dichlorosilane with concentrated acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Hydrolysis reaction

[0033] 2000kg / hr dimethyldichlorosilane and 20000kg / hr concentrated hydrochloric acid with a concentration of 38% enter the packed tower reactor for hydrolysis reaction, the temperature is 25°C, the operating pressure is 0.2MPa, and the residence time is 134s. After the reaction The mixture and the heptane of 27.5kg / hr enter the gas-liquid separator for gas-liquid separation, and the separated wet hydrogen chloride enters the desorption tower for analysis, and the obtained sour oil mixture 21120kg / hr enters the acid separator.

[0034] Acid

[0035] 21120kg / hr acid-oil mixture and 400kg / hr, dilute hydrochloric acid obtained from pickling enter the static mixer together, after being fully mixed, enter the gravity sedimentation separator, the system temperature is controlled at 32°C, and the mixture is separated to obtain a hydrolyzate of 1400kg / hr , the obtained hydrochloric acid enters the upper packed column reactor for recycling.

[0036] pickl...

Embodiment 2

[0045] Hydrolysis reaction

[0046]2000kg / hr dimethyldichlorosilane and 30000kg / hr circulating concentrated hydrochloric acid with a concentration of 40% enter the packed tower reactor for hydrolysis reaction, the temperature is 35°C, the operating pressure is 0.3MPa, and the residence time is 200s. The reacted mixture enters the gas-liquid separator together with 45 kg / hr of heptane for gas-liquid separation. The separated wet hydrogen chloride enters the desorption tower for desorption. The obtained sour oil mixture 31232kg / hr enters the acid separator.

[0047] Acid

[0048] 31232kg / hr acid oil mixture and 600kg / hr, dilute hydrochloric acid obtained from pickling enter the static mixer together, and enter the gravity sedimentation separator after thorough mixing, the system temperature is controlled at 37 °C, and the mixture is phase separated to obtain hydrolyzate 1430kg / hr , the obtained hydrochloric acid enters the upper packed column reactor for recycling.

[0049] ...

Embodiment 3

[0058] Hydrolysis reaction

[0059] 2000kg / hr dimethyldichlorosilane and 40000kg / hr circulating concentrated hydrochloric acid with a concentration of 42.9% enter the packed tower reactor for hydrolysis reaction at a temperature of 45°C, an operating pressure of 0.4MPa, and a residence time of 268s. The reacted mixture enters the gas-liquid separator together with 68 kg / hr of heptane for gas-liquid separation. The separated wet hydrogen chloride enters the desorption tower for desorption. Obtain sour oil mixture 41141kg / hr into the acid divider.

[0060] Acid

[0061] 41141kg / hr acid oil mixture and 2200kg / hr, dilute hydrochloric acid obtained from pickling enter the static mixer together, and enter the gravity sedimentation separator after thorough mixing, the system temperature is controlled at 42 °C, and the mixture is phase separated to obtain hydrolyzate 1510kg / hr , the obtained hydrochloric acid enters the upper packed column reactor for recycling.

[0062] pickling ...

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Abstract

The invention discloses a method for hydrolyzing dimethyl dichlorosilane with concentrated acid. The method comprises the following steps: mixing the dimethyl dichlorosilane with hydrochloric acid to carry out hydrolytic reaction; mixing the obtained reaction liquid with a solvent; finally, performing separating operation on the obtained mixed solution to obtain hydrolysis product and hydrogen chloride gas. Through the adoption of the method, the content of cyclic polysiloxane in hydrolysate obtained from the dimethyl dichlorosilane through the concentrated acid hydrolyzing method is effectively increased; the design is reasonable, hydrolysate with low chlorine ion content can be obtained in no need of multi-stage phase separation procedures, and the hydrochloric acid and solvent obtained after separation can be recycled, so that the resource use ratio is improved, and the production cost is saved.

Description

technical field [0001] The invention belongs to the technical field of organic chemical industry, and in particular relates to a method for preparing polydimethylsiloxane by hydrolyzing dimethyldichlorosilane with concentrated acid. Background technique [0002] At present, the methods for preparing polydimethylsiloxane by hydrolysis of dimethyldichlorosilane mainly include azeotropic acid hydrolysis and concentrated acid hydrolysis. The polysiloxane ring content in the hydrolyzate obtained by the azeotropic acid hydrolysis method is about 60%, and the chloride ion content in the hydrolyzate is relatively low, but the by-product hydrochloric acid produced by this method needs a lot of energy to be released Hydrogen chloride gas, used in the synthesis of methyl chloride. The concentrated acid hydrolysis method can directly obtain hydrogen chloride gas without a distillation desorption device. Due to the advantages of low cost, low energy consumption, short process, and less ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G77/34C08G77/06
Inventor 方红承胡敬辉彭金鑫柯友志曹华俊董浩罗燚母清林
Owner HOSHINE SILICON IND CO LTD
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