| 摘要 |
<p>1,213,404. Polysiloxane-coated ZnO and ZnS. GENERAL ELECTRIC CO. 20 Feb., 1968 [17 March, 1967], No. 8204/68. Heading C1A. [Also in Division C3] Zinc oxide or zinc sulphide coated with an organopolysiloxane is prepared by heating a cyclotrisiloxane selected from hexamethylcyclotrisiloxane, 2,4,6 - trimethyl - 2,4,6 - triphenylcyclotrisiloxane, cyclosiloxanes of formula mixtures thereof and mixtures of the above with hexaphenylcyclotrisiloxane in the presence of the heat-activated zinc chalcogen at 50-250‹ C. From 0-1 to 1600 parts of the zinc chalcogen may be used per 100 parts of cyclotrisiloxane. The ZnO or ZnS is heat activated by heating at 200-550‹ C. at pressures from 760 mm. to 10<SP>-6</SP> mm. Hg.</p> |
