Production process of organosilane polysulfide

Abstract

The invention discloses a production process of organosilane polysulfide. The production process comprises the following steps of: 1, adding elemental sulfur in sodium hydroxide at a temperature of 90-100 DEG C by batches according to the calculation proportion, controlling the reaction temperature and keeping for a period of time to form polysulfide Na2Sn, wherein n has the meaning described in the specification; 2, enabling the polysulfide obtained in the step 1 to condensate with an organosilane compound in the following formula (2) under the existence of a phase transfer catalyst and a hydrolysis buffer agent to obtain a sulfur-containing silane crude product (RO)3-mRmSi-Alk-X(2), wherein X is chlorine, bromine and iodine, and R, Alk and m have the meanings described in the specification; 3, separating a water phase from an organic phase; 4, enabling the organic phase to be in contact with ion change resin for carrying out decoloring and desalting; and 5, distilling, cooling and filtering to obtain an organosilane polysulfide finished product.

Description

technical field [0001] The invention relates to a production process of green and environment-friendly organosilane polysulfides. Background technique [0002] Sulfur-containing organosilane coupling agents have been widely used in various industrial fields. Especially in the rubber industry, the addition of silane coupling agent can significantly enhance the performance of silica, improve the tensile strength of vulcanized rubber and the thermo-oxidative aging performance of rubber. In particular, bis-[γ-(triethoxysilyl)propyl]tetrasulfide (HP-669) has multifunctional effects on rubber, and can be used as an advanced vulcanizing agent, activator, reinforcing agent, Softeners and flexibilizers can improve the tensile strength, wear resistance, fatigue resistance and elasticity of the rubber particles. They are used to treat rubber and fillers, so that the obtained rubber can delay coking, accelerate vulcanization and improve the reinforcing effect. [0003] Traditional bis...

AI Technical Summary

Problems solved by technology

Due to the inability to control these side reactions in the prior art, the sulfur chain length n of the prepared polysulfides is all less than 4, most of them are less than 3, and the content of tetrasulfides is low

Among them, the existence of side reactions ① and ② makes the sulfur content in the product low, and the existence of side reactions ③-⑥ makes the color and appearance of the product poor and prone to precipitation

[0015] The use of hydrogen sulfide or sodium hydrogen sulfide leads to a large amount of hydrogen sulfide tail gas, which seriously pollutes the environment

And prior art does not teach the method for absorbing and treating tail gas

[0016] The use of sodium hydroxide in the prior art to directly react with elemental sulfur still cannot avoid the above-mentioned problems, the average value n is mostly less than 4, and the content of tetrasulfides is low, and the content of S5-S6 is high, which affects product quality

[0017] In addition, there are multiple other disadvantages in the above-mentioned method: the price of sodium metal and sodium ethylate used is very expensive, and there is a large potential safety hazard in the storage process of sodium metal; using an organic solvent as a medium is not environmentally friendly, and its recovery The production cost is very high, especially when ethanol is used, because of its low flash point, there is a great potential safety hazard; raw materials and products are easily hydrolyzed when exposed to water, and it must be ensured that the reaction is carried out in an anhydrous state, and it is difficult to obtain on an industrial scale and maintain the required anhydrous conditions; nitrogen protection is required in the reaction process, strict requirements for operation, difficult control of process conditions, and increased production costs

When alkali metal or ammonium hydrosulfide is used as raw material in phase transfer catalysis technology, dangerous and odorous hydrogen sulfide will be produced in the side reaction, even if the final product contains a small amount of hydrogen sulfide, it will seriously affect its product quality

Another problem involved with the use of phase transfer catalysis techniques is the hydrolysis of the alkoxy groups on the organosilane compound or the starting silane reactant by the aqueous phase reactant leading to gelation

In addition, the state-of-the-art phase transfer catalysis method produces a large amount of unreacted sulfur-containing species, which may precipitate in the stored product, resulting in a change in the sulfide distribution of the product, so there is also a need to improve the stability, appearance and purity of the final product

Active carbon is used in the decolorization treatment of the prior art, which has defects such as large amount of decolorizing agent, unsatisfactory decolorization effect, poor storage stability of the finished product, and darkening of the color after 3-6 months.

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