Method for synthesizing di-[propyltriethoxysilane]-tetrasulfide

Abstract

The invention discloses a method for synthesizing di-[propyltriethoxysilane]-tetrasulfide, which comprises the following steps of: (1) mixing and stirring water, sodium sulfide, sodium hyposulfate, elemental sulfur and diethyl hydroxylamine, pumping n-amylamine and isobutylamine into the mixture under the vacuum degree of 0.04 to 0.06MPa, and reacting the mixture for 20 to 40 minutes at the temperature of between 30 and 50 DEG C; (2) adding dodecyltrimethylammonium chloride, tetrabutyl ammonium bromide and hydroxy pyridine into the reaction solution obtained in the (1) under normal pressure, stirring the solution, then adding gamma-chloropropyltriethoxysilane into the solution, reacting the solution for 30 to 60 minutes at the temperature of between 40 and 50 DEG C, continuously reacting the solution for 60 to 80 minutes at the temperature of between 60 and 80 DEG C, filtering the oil phase, and pumping the filtrate into a distillation still; and (3) distilling the filtrate in the distillation still under the vacuum degree of more than or equal to 0.096MPa at the temperature of less than or equal to 160 DEG C when the temperature of the top gas phase is more than 108 DEG C to obtain a product Si-69.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a method for synthesizing bis-[propyltriethoxysilane]-tetrasulfide. Background technique [0002] Bis-[propyltriethoxysilane]-tetrasulfide (hereinafter referred to as Si-69) is a sulfur-containing multifunctional group silane coupling agent successfully used in the rubber and plastic industry. Its application makes the rubber The physical and mechanical properties are improved, the tensile strength, tear strength, wear resistance, etc. can be significantly improved, the permanent deformation can be reduced, and the viscosity of the rubber can be reduced, and the processing performance can be improved. It is especially suitable for vulcanized rubber systems with silica or silicate as reinforcing agents. The applicable polymers include natural rubber (NR), styrene-butadiene rubber (SBR), isoprene rubber (IR), butadiene rubber Acrylic rubber (BR), nitrile rubber (NBR) and ethylene...

AI Technical Summary

Problems solved by technology

Although the above-mentioned several methods have certain advantages, they still have the following disadvantages: (1) the raw material is expensive and difficult to store, and the production cost is high; (2) it is easy to cause product Si-69 hydrolysis failure; (3) method (1) and Method (2) uses metallic sodium, and the risk of operation increases, and the operation requirements are strict, and the process conditions are difficult to control; (4) the total yield of the product is low, and the purity is low, and the product purity is only 96% (GC) (equivalent) (5) The color of the product after distillation is red or dark yellow; (6) Part of the product will be decomposed during the production process, resulting in the total sulfur content in the product index not meeting the requirements, and precipitation or separation during product storage. layers, affecting product use and shortening shelf life

Si-69 with high impurity content and low purity produced by the above method cannot be used in some fields such as aerospace materials and anti-corrosion materials, even if it is used for the tensile strength, tear strength and wear resistance of products in ordinary rubber manufacturing Waiting is also lower