摘要 |
Compositions stable in the absence of oxygen are formed by mixing the following substantially in the absence of oxygen (A) mercapto-functional organosiloxanes containing an average of at least two mercapto-funceional substituents per molecule, (B) optionally, at least one filler; (C) a catalytic amount of a metal carbonyl compound selected from the group consisting of Fe(CO)5, Fe2(CO)9, Fe;(CO)12, dicyclopentadienyldiiron tetracarbonyl, butadieneiron tricarbonyl, cyclohexadieneiron tricarbonyl, Ni(CO)4, dicyclopentadienyldinickel dicarbonyl, Mn2(CO)10, methylcyclopentadienylmanganese tricarbonyl and cyclopentadienylcobalt dicarbonyl, preferably from 0.1 to 6 parts by weight of iron carbonyl catalyst per 100 parts by weight of part (A). The compositions polymerize or cure upon exposure to oxygen. By utilizing various types and amounts of mercapto-functional organosiloxanes, higher molecular weight products useful as encapsulating gels, coating resins and elastomeric sealants can be obtained by exposing the compositions of the present invention to oxygen. |