| 摘要 |
1310761 Organosilicon compositions DOW CORNING Ltd 19 April 1971 [13 March 1970] 12260/70 Heading C3T An organosilicon composition comprises the product obtained by mixing together (A) an organopolysiloxane having at least two silanol groups per molecule and (B) a silacyclobutane of the general formula wherein R is H, or C 1-6 alkyl, R<SP>1</SP> and R<SP>11</SP> each represent a monovalent hydrocarbon or halogenated hydrocarbon radical or an atom or radical reactive with a silanol group, at least one of R<SP>1</SP> and R<SP>11</SP> being an atom or radical reactive with a silanol group, such as halogen atoms, C 1-5 alkoxy, acyloxy or amino radicals. The organopolysiloxane may vary from low molecular weight mobile liquids to high molecular weight solvent soluble resins, but is particularly a curable silicone rubber of the formula wherein y is an integer such that the viscosity of the diorganopolysiloxane is greater than 500 cS at 25‹ C. and the X radicals are mainly CH 3 , any remaining radicals being phenyl and/or vinyl radicals. (B) is preferably present in a proportion of from 0À5-5% wt. based on the weight of (A). The composition may be cured by heating to from 180‹ C. to its decomposition temperature. Lower temperatures such as 15-35‹ C. can be used if a substance is included which is effective in opening the silacyclobutane ring such as chloroplatinic acid, AlCl 3 organometallic compounds such as stannous octoate or acetate, dibutyltin dilaurate or diacetate and dicobalt octacarbonyl, or acids, bases, acid clays and fume silica. The compositions may be compounded with fillers, e.g. quartz, diatomaceous earths and zirconium silicate, solvents and pigments. Uses.-Potting compositions, sealing materials, adhesives, laminating resins, coating materials and electrical insulation. |
