| abstract |
A prepolymer is provided having an NCO value of 5-30% by weight which is the reaction product obtained by reacting an excessive amount of a diphenylmethane diisocyanate containing at least 85% by weight of 4,4'-diphenylmethane diisocyanate or a variant thereof with a polyol composition comprising at least one poly(oxyethylene-oxyalkylene) polyol having an average nominal hydroxyl functionality of 2 to 6, an average hydroxyl equivalent weight of from 1000 to 3000 and an average oxyethylene content of from 50 to 85% by weight. |