| 摘要 |
<p>A composition for coating cooking utensils consists essentially of (1) 10 to 35% (by wt.) of a liquid methylpolysiloxane having at least 2% of Si-bonded -OH groups, (2) 65-90% of a hydrocarbylphenylsiloxane resin having at least 3% of Si-bonded -OH groups and a phenyl to Si ratio of at least 0-2 and a total hydrocarbon to Si ratio of from 1.2 to 1.7, and (3) as catalyst, a stannous salt of a carboxylic acid in amount of at least 1 part of Sn per 150 pts. of the combined wts. of (1) and (2). The compositions are preferably used in solution in a solvent, e.g. petroleum ether, toluene, xylene, perchlorethylene, 1,1,1-trichloroethane and methylene chloride. The compositions may also be used in aerosol form. A useful formulation consists (by wt.) of 3% of phenylmethylsiloxane resin, containing 3.5% of Si-OH gps. and having a phenyl/Si ratio=0.56 and a methyl/Si ratio=0.79, 0.5% of methylsiloxane liquid containing 3.5% of Si-OH gps. and a methyl/Si ratio=2.0 and 96.5% of 1,1,1-trichloroethane. The composition contained 1 pt. of Sn (as stannous octoate) per 100 pts. of total siloxane.ALSO:Cooking utensils made, e.g. of stainless steel, copper, aluminium, ceramic, tin or magnesium, are coated with a siloxane release agent as by painting, dipping or spraying. The release agent consists essentially, by weight, of (1) 10 to 35% of a liquid methylpolysiloxane having at least 2% of Si-bonded -OH groups, (2) 65% to 90% of a hydrocarbyl phenyl siloxane resin having at least 3% of Si-bonded -OH groups, and (3), as catalyst, a stannous carboxylate. (see Division C3). The compositions are preferably used in solution in a solvent, e.g. toluene, xylene, petroleum ether, perchlorethylene, methylene chloride and 1, 1, 1-trichloroethane, and may also be used in aerosol form.</p> |
