Fast-cure polyurethane sealant composition containing silyl-substituted guanidine accelerators

Claim 1

A one-component, moisture-curable sealant composition comprising a mixture of (a) a silane-terminated polyurethane polymer of the formula ##STR12## wherein R is lower alkyl of from 1 to 6 carbon atoms; R 1 is a divalent bridging radical selected from the group consisting of a divalent hydrocarbon radical, a divalent hydrocarbon ether radical, and a divalent hydrocarbon amino radical; A is selected from the group consisting of --S-- and --NR 2 -- where R 2 is hydrogen or alkyl of from one to six carbon atoms; (b) from 0.2 to 1.0 parts by weight of an aminosilane per 100 parts by weight of said silane-terminated polyurethane polymer, said aminosilane having the structure ##STR13## wherein x is an integer of from one to three; R 3 and R 4 may be the same or different and are selected from alkyl of from one to four carbon atoms; R 5 is alkyl of from one to four carbon atoms or alkoxyl of from one to four carbon atoms; R 6 is hydrogen or --(CH 2 ) y NHR 7 wherein R 7 is hydrogen or 13 (CH 2 ) z NH 2 and wherein y and z may be the same or different and are integers of from one to three; (c) from 0.2 to 1.0 parts by weight of an accelerator per 100 parts by weight of said silane-terminated polyurethane polymer, said accelerator selected from the group consisting of compounds or mixtures thereof having the structure ##STR14## where x and R are as previously defined; R 8 , is hydrogen or ##STR15## where R 3 , R 4 , R 5 , and x are as defined above; R 9 and R 10 are hydrogen or, when taken together with the carbon atoms to which they are attached, form a saturated six-membered carbocyclic ring; and R 11 , R 12 , R 13 , and R 14 are independently hydrogen or alkyl of from one to four carbon atoms.