| 摘要 |
<p>An unfilled silioxane convertible to the solid, elastic state and containing a basic catalyst and low molecular weight siloxanes as contaminants, is stabilized by mixing the siloxane with from 0,5 to 5,0 parts (by weight) of silica having an average particle size of from 10 to 30 m m per 100 pts. of siloxane or with 150 to 10,000 pts. of iodine per 106 pts of siloxane. Preferably the mixture is then heated to volatilize the low molecular weight contaminants. The stabilized siloxane may be dispersed, with or without an emulsifying agent, in a solvent, e.g. Toluene, mineral spirits, carbon tetrachloride or diethyl ether or mixtures thereof, and curing agents, e.g. benzoyl peroxide or t-butylperbenzoate may be added thereto. In examples a siloxane gum, made by equilibrating a mixture of dimethyl siloxane cyclic trimer and tetramer with KOH or potassium silanoate, is stabilized in the above manner. Uses: for coating fibrous materials (see Group VIII).</p> |
