Catalyst for reaction of isocyanate and sulfydryl and preparation method of catalyst

Abstract

The invention discloses a catalyst for reaction of isocyanate and sulfydryl. The catalyst is prepared by reaction of mercaptosilane and dibutyltin diacetate, has quite high reaction activity for reaction of isocyanate and sulfydryl, is quite high in final conversion rate, solves the problem of reaction of isocyanate and sulfydryl, and provides more technical methods for introduction of sulfydryl-containing materials into polyurethane materials.

Description

technical field [0001] The invention belongs to the field of catalysts, and in particular relates to a catalyst capable of efficiently catalyzing the reaction between isocyanate and mercapto groups and a preparation method thereof. Background technique [0002] Isocyanate and mercapto group can react to produce thiourethane. Compared with traditional polyurethane structure, this special polyurethane structure has better low temperature flexibility and better adhesion characteristics. However, due to the very low reactivity of isocyanate and mercapto groups, the typical reaction between isophorone diisocyanate and 3-mercaptopropyltrimethoxysilane usually needs to be catalyzed by dibutyltin dilaurate at 80°C. More than hours (Yu Zongping, Qiu Fengxian, Ding Hailin, et al. Synthesis and properties of UV-curable mercaptoacrylate [J]. Information Recording Materials, 2015, v.16; No.85(06):14-17.). However, isocyanate and hydroxyl usually only need 2-4 hours to complete the react...

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Problems solved by technology

However, due to the very low reactivity of isocyanate and mercapto groups, the typical reaction between isophorone diisocyanate and 3-mercaptopropyltrimethoxysilane usually needs to be catalyzed by dibutyltin dilaurate at 80°C. Over hours (Yu Zongping, Qiu Fengxian, Ding Hailin, et al. Synthesis and properties of UV-curable mercaptoacrylate[J]. Information Recording Materials, 2015, v.16; No.85(06):14-17.)

However, isocyanate and hydroxyl usually only need 2-4 hours to complete the reaction under the same reaction conditions. Too long reaction time will affect production efficiency, and long-term reaction at high temperature will cause more side reactions between moisture and isocyanate , affecting product performance

It has been reported in the literature that triethylamine has better reactivity to isocyanate and mercapto as a catalyst. In the actual preparation of urethane acrylate, it is found that the odor of triethylamine is very large, and the residual odor is difficult to remove. It is impossible to prepare clean odor products, and three Ethylamine has poor selectivity to the reaction between isocyanate and hydroxyl, and has high activity in catalyzing the side reaction between isocyanate and moisture

In the system that needs to catalyze the reaction between isocyanate and hydroxyl group and the reaction between isocyanate and mercapto group at the same time, triethylamine will cause more side reactions of isocyanate and water reaction, which will affect the viscosity and structural regularity of the product, which is not good for performance

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