| 摘要 |
A moisture-resistant, self-sealing siloxane composition comprises a diorganopolysiloxane, a filler, a peroxidic or other curing agent and a boron compound selected from boron hydride and an N-alkyl-substituted borazane, borazene or borazine. The boron compound is used in an amount of 0.02 to 10% by weight of the composition, and may be added to the other ingredients or to the low molecular weight siloxanes prior to their polymerization to convertible siloxanes. Fillers specified are silica, Kiesel-guhr, quartz, alumina, titania and zinc and iron oxides. In typical examples (1) the siloxane obtained by polymerizing a,o -dihydroxy dimethylpolysiloxane with N-triethyl-borazane, was mixed with silica and bis-(2,4-dichlorobenzoyl) -peroxide and subsequently heat cured: (2) a copolymer comprising dimethyl- and methylvinyl-siloxane units was mixed with silica, iron oxide, bis-(2,4-dichlorobenzoyl)-peroxide and N-dimethylborazane.
|
