One component heat-pre:curable and moisture-hardenable compsns. - contain urethane] prepolymer with free isocyanate gps., vinyl] polymer contg. siloxy gps., and partly inactivated poly:isocyanate

摘要

Sealing compsns. (I) contain as main components (A) urethane prepolymer having active, free NCO gp. content 1-6% (all pts. wt.), prepd. by reacting polyol with excess polyisocyanate. (B) vinyl polymer contg. siloxy gp. of formula (I). R1, R2, R3 (same or different) = 1-4C alkyl or Ph with no. average mol. wt. 3000-30,000. (C) partly inactivated solid polyisocyanate obtd. by inactivating 0.2-10% NCO gps. in solid polyisocyanate with inactivating agent. (''Sealing compsns.'' include adhesives and protecting coatings). USE/ADVANTAGE - In prodn. of motor vehicles and in building industry, partic. for sealing glass windows to metal or plastic substrates on prodn. lines. Temporary supporting means for articles to be bonded together are not required as (I) can be pre-cured rapidly by heat for complete curing by moisture, (I) have good storage stability.