Moisture curable organosiloxane compositions exhibiting extended workability

摘要

A curable organosiloxane compsn. comprises: (a) a liq. curable polyorganosiloxane; (b) an organosilicon cpd. as curing agent; (c) a tin cpd. as curing catalyst; and (d) a silanol terminated polydiorganosiloxane as a working time extender. (a) contains >= two silanol gps. per mol. and exhibits a number average molecular wt. of >= 20,000. (b) contains >= 3 silicon bonded hydrolysable gps. per mol. the concn. of (b) is sufficient to cure (a) in the presence of moisture. Concn. of (c) is sufficient to promote curing of the compsn. in the presence of moisture. (d) has a number average molecular wt. 1000. Amt. of (d) is 0.6 wt.%. Also claimed is the following: (1) a method for extending the working time of an organosiloxane compsn. by combining (a), (b), (c) and (d).