| 摘要 |
1486790 Polyurethanes; polyureas SCHERING AG 8 Nov 1974 [10 Nov 1973] 48484/74 Addition to 1394732 Heading C3R [Also in Division C2] A compound (C) is obtainable by reacting a polyisocyanate (I) with a compound containing #1 ketimine group and #1 OH group, but not containing an enamine group, mole ratio NCO : OH being 1 : 1. A prepolymer (P) is made by reacting a compound containing #1 NH 2 and #1 OH group with an aliphatic or cyclic ketone and removing the water formed and any excess carbonyl compounds, and reacting the product with a polyisocyanate (I), mole ratio NCO : OH being 1 : 1. (I) may be an aliphatic diisocyanate, or an adduct of a polyhydroxy compound and excess of a polyisocyanate. A polyurea may be made from a preparation comprising a polyisocyanate and compound (C) or prepolymer (P) by mixing with water or exposure to water or water vapour, e.g. as atmospheric moisture. Examples employ ethanolamine, diethyleneglycolamine, hexanolamine-1,6, MIK, cyclohexanone, trifunctional polypropylene glycol, and isophorone diisocyanate; ketimines have formul� |
