A primer composition comprises, in combination, an organopolysiloxane having at least two alkenyl groups in one molecule, an organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in one molecule, a platinum catalyst, and an organosilicon compound having the following average unit formula,
R¹aXbSiO(4-a-b)/2
in which R¹ represents a member selected from the group consisting of unsubstituted or substituted monovalent hydrocarbon groups, acryloxy group, a methacryloxy group and an epoxy group, X represents a hydrolyzable group, 0 ≦ a ≦ 3, and 2 ≦ b ≦ 4 provided that 2 ≦ a+b ≦ 4 , the organosilicon compound having at least two hydrolyzable groups bonded to the silicon atom in one molecule. The primer composition is effective in adhesion between various substrates and condensation reaction-type silicone rubber therethrough. The composition keeps high adhesion force under severe conditions.
一种底漆组合物由以下物质组合而成:一个分子中至少有两个烯基的有机聚
硅氧烷、一个分子中至少有两个氢原子与
硅原子键合的有机氢聚
硅氧烷、
铂催化剂和具有以下平均单元式的
有机硅化合物、
R¹aXbSiO(4-a-b)/2
其中 R¹ 代表选自由未取代或取代的一价烃基团、
丙烯酰氧基、甲基
丙烯酰氧基和环氧基团组成的组,X 代表可
水解基团,0 ≦ a ≦ 3,2 ≦ b ≦ 4,条件是 2 ≦ a+b ≦ 4,
有机硅化合物在一个分子中至少有两个可
水解基团与
硅原子键合。该底涂组合物能有效地粘合各种基材和通过其的缩聚反应型
硅橡胶。该组合物在苛刻条件下也能保持较高的附着力。