Synthesis method of gamma-thiopropyl trimethoxy silane

Abstract

The invention discloses a synthesis method of gamma-thiopropyl trimethoxy silane, comprising the following steps of: (1) dissolving NaHS into water and adjusting a pH (Potential of Hydrogen) value to be less than 7.0; (2) uniformly mixing gamma-chloropropyl trimethoxy silane, ethanol, a phase transfer catalyst and a stabilizing agent to react; (3) vacuumizing a synthesis reaction kettle and introducing mixed gas of N2 and CO2; adjusting a kettle temperature of the synthesis reaction kettle to 65-70 DEG C; then respectively feeding a mixed solution obtained by the step (1) and a mixed solution obtained by the step (2) into the synthesis reaction kettle in a flowing way to carry out synthesis reaction; and (4) layering reaction products and distilling an upper-layer oil phase to obtain the product gamma-thiopropyl trimethoxy silane. The synthesis reaction can be carried out under a stable low-pressure condition; in a synthesis process, two raw materials are fed into the reaction kettle in a flowing way to react, so that the mixing uniformity and the reaction uniformity of the materials are reinforced, the reaction conversion rate is improved, the reaction time is shortened and the product purity is improved.

Description

technical field [0001] The invention relates to the synthesis technology of gamma-mercaptopropyltrimethoxysilane, in particular to a synthesis method using a phase transfer method. Background technique [0002] γ-mercaptopropyl trimethoxysilane is a reactive and cross-linkable bifunctional multifunctional sulfur-containing silane coupling agent, its mercaptopropyl functional group (-SH) can be combined with unsaturated fat, polyester At the same time, the trimethoxy functional group is hydrolyzed to generate silanol, which can interact with inorganic substances to firmly bond organic polymers and inorganic fillers together. In the glass fiber industry, as a reinforcing material, in addition to improving the strength of the composite material, it can also effectively reduce the degradation of the bond force caused by moisture intrusion, effectively maintain or improve the wet mechanical properties and stability of the composite material; in the rubber industry , often used t...

AI Technical Summary

Problems solved by technology

The disadvantages are: the raw material γ-chloropropyl triethoxysilane, thiourea, potassium iodide or sodium iodide must be dried for at least four hours before use, which increases the operation process; the reaction cycle is long; the raw material γ-chloropropyl triethoxysilane The content of ethoxysilane and solvent water is strict, and the water content in the reaction equipment is strict; the conversion rate of raw material γ-chloropropyltriethoxysilane is not high, and the product cost is high

The downside is: H 2 S has high toxicity, high operating safety, high requirements for equipment materials and sealing, large investment for the same production scale, and poor operating site environment

The disadvantage is: whether it is reduced with hydrogen or NaBH 4 Reduction, due to the high activity of free hydrogen, it is easy to reduce the methoxy group, resulting in low product purity and many by-products; in addition, sodium polysulfide Na 2 S n The value of n is very wide, unevenly distributed from 2 to 7, multiple reduction reactions occur, and the final product components are complex and difficult to separate

The disadvantages are: the raw material γ-chloropropyltriethoxysilane is severely hydrolyzed, and the resulting gel wraps the raw material, making it difficult to carry out the reaction. The obtained product has high impurity content and is difficult to separate, so the product cost is relatively high

In the absence of a phase transfer catalyst, the two phases are isolated from each other, several reactants cannot come into contact, and the reaction proceeds very slowly

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