Continuous preparation system for hydroxy terminated polydimethylsiloxane

Abstract

Disclosed is a continuous preparation system for preparing hydroxyl polysiloxane, comprising a material trough, a thermotank, catalyzer and a water trough, a pre-reaction jar, a horizontal push jar and a controller. A heating device and a material thermocouple are connected in the thermotank; a viscosity measuring meter is installed on a pipe which is connected to the outlet of the horizontal push jar; the controller comprises an initialization module used for determining the flux of a material screw pump and the flux of a catalyzer screw pump according to process conditions, a startup moduleused to start up the controller when the temperature measured by the material thermocouple reaches the working temperature, to determine the output frequency of a first transducer and the output frequency of a second transducer according to process conditions and to start a first driving motor and a second driving motor, a transducer frequency regulation module which, based on process characteristic, regulates the output frequency of the first transducer and the output frequency of the second transducer under the condition of keeping the ratio of output frequency of the first transducer to output frequency of the second transducer constant according to viscosity feedback signal. The continuous preparation system is of good control and high production efficiency and the product is of strong stability.

Description

technical field [0001] The invention relates to a continuous preparation system of hydroxyl polysiloxane. Background technique [0002] The industrial production of hydroxypolysiloxane can be traced back to the base-catalyzed two-step batch method used by Dow Corning in the 1950s. For a long time since then, this process has been used in the world for production. [0003] The synthesis principle of the two-step batch method is to use cyclosiloxane as a monomer and a strong base as an initiator to first polymerize into high molecular weight polysiloxane, and then further hydrolyze it into a suitable molecular weight hydroxyl polysiloxane. The quality of the product prepared by this method is unstable, that is, under the same material ratio and process, the fluctuation range of the conversion rate of the reaction system, product viscosity and molecular weight reaches more than 20% to 50%, even up to 100% in severe cases. In addition, the two-step batch method also has proble...

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Problems solved by technology

[0008] In order to overcome the shortcomings of poor control performance, low production efficiency and poor product stability of the existing hydroxypolysiloxane preparation system, the present invention provides a continuous hydroxypolysiloxane with good control performance, high production efficiency and strong product stability. chemical preparation system

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