Continuous hydrolysis process of organic dichlorosilane

Abstract

A continuous hydrolysis process for organic dichlorosilane in order to prepare low-viscosity linear or cyclic organic siloxane includes at least three stages of cyclic hydrolysis reaction system. Each cyclic hydrolysis reaction system includes internal and external cyclic units.

Description

Brief description of the invention [0001] The invention relates to a continuous hydrolysis process of organodichlorosilane, which comprises at least three stages of circulating hydrolysis reaction system, and each stage of circulating hydrolysis reaction system further includes two circulation units: an inner circulation unit and an outer circulation unit. Organodichlorosilane is the main product of organosilicon monomer synthesis, such as dimethyldichlorosilane, and the low-viscosity linear or cyclic organosiloxane prepared by hydrolysis of organodichlorosilane is the main raw material of polyorganosiloxane , it can be used to synthesize silicone oil, silicone rubber, etc., and is widely used in industries such as electronics, daily chemicals, electric power, and building materials. Background of the invention [0002] The hydrolysis process and technology of organodichlorosilane can be found in many published technical information books, for example, W.Noll described in " ...

AI Technical Summary

Problems solved by technology

[0004] USP4609751 describes the use of a static mixer for concentrated acid hydrolysis, that is, the hydrolysis of equivalent water, the alkyl halosilane is not completely hydrolyzed, and the product contains a small amount of Cl-terminated alkylsiloxane, which makes post-processing difficult, and due to the use of alkali Neutralization produces a large amount of waste water

[0005] Chinese patent application 9311087 discloses the hydrolysis method of organodichlorosilane, adding a small amount of alkylsulfonic acid and its alkali metal anionic surfactant during hydrolysis, and improving the environmental protection under the premise of not emulsifying when removing siloxane residual HCl. solid yield, but can not get gaseous hydrogen chloride

In the second step, the crude hydrolyzate is treated with steam at 110°C to 160°C to reduce the chlorine content and generate hydrochloric acid. At the same time, the hydrochloric acid generated in the second step is used in the first step. Although this method can obtain gas phase hydrogen chloride , but it adopts 25% hydrochloric acid as the water source, and the concentration of hydrochloric acid under this concentration is not saturated. In addition, in the second step of thick hydrolyzate treatment, high-temperature steam treatment is used, and the viscosity of the hydrolyzate is finally difficult to control. Low viscosity hydrolyzate is easy to handle in subsequent processing

[0013] 1. This process method must obtain as much anhydrous hydrogen chloride gas with sufficient pressure as possible, and the gas phase hydrogen chloride can be directly used to synthesize methyl chloride;

Images