申请人:Bausch & Lomb Incorporated
公开号:US04195030A1
公开(公告)日:1980-03-25
A process is disclosed which involves the preparation of monomeric organosilicon esters in a much shorter time and at a much higher purification than previously known in the art. More specifically, the process comprises reacting a cyclosilalkoxane having the general formula: ##STR1## wherein R is a monovalent hydrocarbon radical free of aliphatic unsaturation, R' is selected from the group consisting of H and CH.sub.3 and n is an integral of from 1 to 2 inclusive with a free radical polymerizable monocarboxylic acid. The cyclosilalkoxane is contacted with the free radical polymerizable monocarboxylic acid in the presence of a solvent. The solvent forms an azeotropic mixture with the water formed by the reaction. During the reaction, the azeotropic mixture is continuously removed from the reaction. Also present in the reaction solution is a protonating acid catalyst and a free radical polymerization preventing inhibitor. The process further comprises heating the solution to a temperature which forces the reaction to completion at an accelerated rate. During the reaction sufficient oxygen is supplied to the reaction mixture in order to convert the inhibitor present in the reaction mixture from an inactive to an active form. This process forms a substantially pure free radical polymerizable monomeric unsaturated organosilicone ester in about 3 to about 6 hours.
本发明揭示了一种制备单体有机硅酯的方法,相比以往的技术,该方法能够在更短的时间内、更高的纯化度下完成。更具体地,该方法包括将具有以下一般式的环状硅烷醇与自由基聚合的单羧酸反应:##STR1## 其中,R是不含有脂肪族不饱和的一价碳氢基团,R'选自H和CH.sub.3的群,n为1到2之间的整数。在溶剂的存在下,将环状硅烷醇与自由基聚合的单羧酸接触。溶剂与反应产生的水形成共沸混合物。在反应过程中,将共沸混合物连续地从反应中移除。反应溶液中还存在质子化酸催化剂和自由基聚合抑制剂。该方法还包括加热溶液至加速反应完成的温度。在反应过程中,向反应混合物提供足够的氧气,以将反应混合物中的抑制剂从不活性转化为活性形式。该方法在约3至6小时内形成了高纯度的自由基聚合单体不饱和有机硅酯。