POLYURETHANE FOAM

摘要

1530909 Polyurethane foam CARL FREUDENBERG 14 Nov 1975 [30 Nov 1974] 46979/75 Heading C3R [Also in Division Dl] A hydrophilic polyurethane foam in which the polyurethane contains branched polyethylene glycol units and polyester units is prepared by reacting together a branched polyethylene glycol adduct having isocyanate groups, a polyester having hydroxy and/or isocyanate groups and water. The polyester used is preferably a polyisocyanate adduct, having isocyanate groups, of a polyester having hydroxy groups, and may have a M.Wt. of 500-20,000. The polyester itself is preferably derived from one or more dicarboxylic acids and one or more alkylene glycols; or it may be a polymerized lactones, e.g. #-caprolactone. The polyethylene glycol may have a M.Wt. of from 200-20,000. Preferred polyisocyanates for making the branched polyethylene glycol adduct and the polyester isocyanate adduct are di- and triisocyanates, e.g. tolylene diisocyanate, 4,41- diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, triphenylmethane triisocyanate, trimethylolpropane/ tolylene diisocyanate adduct and 1,6-hexamethylene diisocyanate/H 2 O adduct. The foam may be applied to a textile sheet material, e.g. a woven, non-woven or knitted fabric, the weight ratio of textile sheet to wet foam generally being from 1 : 2 to 1 : 10 to give a coated or impregnated product having hydrophilic properties. In the example a non-woven fabric consisting of polypropylene fibres and viscose fibres is impregnated with a foam formulation prepared by mixing a branched polyethylene glycol adduct having NCO groups, and a poly(ethylene glycol) adipate adduct with water, the polyester adduct having been prepared by the reaction of a polyethylene glycol adipate with a liquid 4,41-diphenylmethane diisocyanate/polycarbodiimide condensate.