| 摘要 |
A one-component room temperature-vulcanizing silicone rubber-forming composition consists essentially of (1) 140 pts. (by wt.) of an organopolysiloxane having bonded to the Si atoms (a) ketoxime radicals in amount to cause the siloxane to cure to an elastomer in the presence of moisture, and (b) monovalent hydrocarbon and/or halohydrocarbon radicals, and (2) 25 to 55 pts. of a carbon black having an average particle diameter of less than 50 m m and a structure index of from 130 to 200. Siloxanes (1) are described and claimed in Specification 975,603. In one embodiment the siloxane (1) may be formed in situ in the composition by mixing together a hydroxyl-terminated siloxane, an alkenyl silane ketoxime and carbon black, the mixing and subsequent storing being conducted in the absence of moisture. Curing cataysts, e.g. dibutyltin-diacetate, dibutyltin-dilaurate, stannous octoate and ferric octoate, may also be added. In a typical Example (1) a hydroxylated dimethyl polysiloxane was mixed with C black and ViSi (ON=C.Et.Me)3, and the product was extruded and allowed to cure in the atmosphere. Comparative compositions are also given. Uses.-As caulking materials, coating compositions and for potting electrical equipment.
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