초록 ▼

A polyurethane sealant including a polyurethane having terminal isocyanate groups and containing a dual curing catalysti of organic bismuth and organic tin, said polyurethane being the reaction product of a liquid poly (lower) alkylene polyol having a molecular weight of 6,000 or more and three to f

A polyurethane sealant including a polyurethane having terminal isocyanate groups and containing a dual curing catalysti of organic bismuth and organic tin, said polyurethane being the reaction product of a liquid poly (lower) alkylene polyol having a molecular weight of 6,000 or more and three to five hydroxyl groups and a sterically unhindered aromatic diisocyanate. The polyurethane sealant may be used in conjunction with a silane based primer and when applied to glass surfaces provides a high strength and rapidly curing seal.

대표청구항 ▼

A polyurethane sealant which when exposed to ambient moisture will cure rapidly to form a seal having high tensile strength consisting essentially of (A) a polyurethane polymer containing terminal isocyanate groups in an amount of not more than about 2.0 weight % based on the weight of said polyuret

A polyurethane sealant which when exposed to ambient moisture will cure rapidly to form a seal having high tensile strength consisting essentially of (A) a polyurethane polymer containing terminal isocyanate groups in an amount of not more than about 2.0 weight % based on the weight of said polyurethane, said terminal isocyanate groups being blocked to prevent further reaction by a volatile blocking agent, said polyurethane polymer being the reaction product of (1) a liquid poly (lower) alkylene ether polyol having a molecular weight of greater than about 6,000 and from three to five hydroxyl groups with (2) a sterically unhindered aromatic diisocyanate; (B) a catalytic curing effective amount of (a) an organic bismuth salt selected from the group consisting of bismuth tri-(2-ethyl hexoate) and bismuth tri-(neo-decanoate) and (b) an organic tin salt of the formula: [Figure] wherein each of R1 and R2 is alkyl of from 1 to 12 carbon atoms and each of R3 and R4 are lower alkyl; (C) up to 200 weight %, based on the weight of the polyol, of inert fillers: and (D) up to 100 weight %, based on the weight of the polyol, of polyurethane compatible plasticizers.