| 摘要 |
1327960 Silicone rubber articles DOW CORNING CORP 8 Sept 1971 [30 Oct 1970] 41840/71 Heading C3T [Also in Divisions A5 G2 and H1] A filled silicone rubber article has a surface resistant to dirt pick-up, the surface having been treated for at least one minute with cold plasma from a gas and thereafter exposed to ambient atmospheric conditions for at least 4 hours. The gas may be air, nitrogen, helium, argon, neon, krypton, xenon or hydrogen. The cold plasma can be prepared using an electrical power source or radio frequency or microwave power sources. In example 1 a silicone rubber stock prepared from 100 parts of a dimethylvinylsiloxy terminated polydiorganosiloxane gum having 94 mol. per cent dimethylsiloxane units, 5À5 mol. per cent diphenylsiloxane units and 0À5 mol. per cent methylvinylsiloxane units, 70 parts of a trimethylsiloxy treated fumed SiO 2 filler, 17 parts of a trimethylsiloxy terminated polydiorganosiloxane fluid having dimethylsiloxane units and methyl hydrogen siloxane units and 0À8% wt. silicon-bonded hydrogen atoms, 0À595 part of a Pt catalyst and 0À272 parts methylbutynol, is moulded into lens shaped articles which are cured by heating. The optically clear cured articles are then treated with cold plasma using air or argon and varying electrical power sources for varying times and then exposed to ambient conditions for 16 hours. In Example 2 moulded silicone rubber slabs of a similar composition to (1) are treated for 40 min. per side with an argon plasma at atm. pressure at 5-6 KV from a 3 KHz source. In Example 3 a commercial 150 watt electrodeless cold plasma unit at a pressure of 0À9 mm.Hg. using nitrogen, argon or helium is used for the plamsa treatment of rubber test pieces. Uses.-Lenses for protective eye covers, gas mask facial coverings, encapsulating electrical equipment, art objects, decorative strippings or mouldings, medical devices, tubing, and catheters. |
