| 摘要 |
A composition which is curable to a solid elastomer on exposure to moisture comprises: (1) a liquid silanol chain stopped diorganopolysiloxane of formula: HO[(R1)2SiO)nH and (2) an organotri-isothiocyanatosilane of formula RSi(NCS)3. R and R1 are monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals or cyanoalkyl radicals and n has a value of at least 10. The examples relate to compositions in which R and R1 are methyl or phenyl radicals. 4 parts by weight MeSi(NCS)3 are mixed with 100 parts of a silanol chain stopped dimethylpolysiloxane, having a viscosity of 3,000 centipoises at 25 DEG C., and heated for 5 minutes at 75 DEG C. to ensure intimate mixing. After cooling to room temperature, the liquid mixture was completely and uniformly cured to a tough, elastic silicone rubber within 24 hours and it tightly adhered to an aluminium surface. Conventional fillers may also be present.
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