Fast-cure polyurethane sealant composition containing titanium ester accelerators

Claim 1

A one-component, moisture-curable sealant composition comprising a mixture of (a) a silane-terminated polyurethane polymer of the formula ##STR6## 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 polyurethane polymer, said aminosilane having the structure ##STR7## wherein x is an integer of from one to three; R 3 and R 4 are 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 --(CH 2 ) z NH 2 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 polyurethane polymer, wherein said accelerator has the structure ##STR8## wherein B is a direct bond or is --SO 2 --; R 8 is a hydrocarbyl group of from three to twenty carbon atoms, and R 9 is --(R 10--NH ) m --R 10 --NH 2 wherein m is zero or an integer of from one to four; R 10 is selected from a divalent hydrocarbyl radical of from two to ten carbon atoms, derived by removal of two hydrogen atoms from a branched or unbranched saturated or unsaturated acyclic hydrocarbon; a divalent hydrocarbaryl radical of from six to ten carbon atoms, and a divalent cyclohydrocarbyl radical of from three to ten carbon atoms.