| abstract |
The polyurethanes and polyureas resulting from ambient-temperature-curing isocyanate-terminated urethane prepolymers with N-alkyl-substituted aromatic polyamines and, optionally, with an added polyol, but primary amine-free, in the presence of a combination catalyst comprising an aliphatic carboxylic acid, e.g., adipic, stearic, oleic acids, and an organometallic catalyst containing, e.g., tin, mercury, bismuth, etc. are broadly useful as coating on the surface of objects made of metal, wood, glass, plastic or masonry materials such as concrete, bricks, etc. or as castings cured in situ. One-shot and quasi-prepolymer systems are also disclosed. The diamine N,N'-di-(sec-butyl)-4,4'-methylenedianiline is a particularly useful diamine. |