Compositions which are stable in the absence of oxygen are formed by mixing the following substantially in the absence of oxygen:
(A) 100 parts by weight of at least one mercapto-functional organosilicon-organic copolymer or mixtures of at least two different types of components selected from the following three types: the above copolymers, mercapto- functional organic compounds free of silicon atoms and mercapto-functional organosilicon compounds wherein all three types contain an average of at leasttwo mercapto groups per molecule;
(B) 0-200 parts byweight of at least one filler;
(C) a catalytic amount, preferably from 0.1 to 6 parts by weight, of an iron carbonyl catalyst selected from the group consisting of Fe(CO)5, Fe2(CO)9, Fe3(CO)12, dicyclopentadienyldiiron tetracarbonyl, butadieneiron tricarbonyl and cyclohexadieneiron tricarbonyl; and
(D) 0.1-6 parts by weight of an acid, such as 2-ethylhexanoic acid, which meets a particular set of criteria.
The compositions polymerize or cure to form higher molecular weight products at room temperature upon exposure to oxygen. These compositions are especially useful as coatings such as for paper or as electrical insulation because they possess a rapid rate of surface cure. Elastomeric sealant compositions can be prepared which rapidly become tack-free at the surface and are less prone to surface contamination by foreign matter such as dust during cure.
通过在无氧条件下混合以下物质,可形成在无氧条件下稳定的混合物:
(A) 100 份(按重量计)至少一种巯基官能团有机
硅共聚物或至少两种不同 类型组分的混合物,这些组分选自以下三种类型:上述共聚物、不含
硅原子 的巯基官能团有机化合物和巯基官能团
有机硅化合物,其中所有三种类型 的化合物平均每个分子至少含有两个巯基;
(B) 0-200 份(按重量计)的至少一种填料;
(C) 催化量,最好是 0.1 至 6 份(重量)的
羰基铁催化剂,该催化剂选自 Fe(CO)5、Fe2(CO)9、Fe3(CO)12、二
环戊二烯四
羰基铁、
丁二烯三
羰基铁和
环己二烯三羰基铁组成的组;以及
(D) 0.1-6 重量份符合特定标准的酸,如 2-乙基
己酸。
这些组合物在室温下与
氧气接触后会聚合或固化形成较高分子量的产品。这些组合物由于表面固化速度快,因此特别适合用作纸张等的涂层或电绝缘材料。制备出的弹性密封剂组合物可迅速在表面形成无粘性,并且在固化过程中不易受到灰尘等异物的表面污染。