Rigid polyurethane foam prodn. with reduced after-expansion and cracking

摘要

Prepn. of rigid polyurethane foam with reduced after-expansion and decreased mould release times comprises reacting (a) organic and/or modified organic polyisocyanates with (b) high molecular cpd(s). contg. at least 2 reactive H atoms and opt. (c) low molecular chain extender and/or crosslinker in the presence of (d) blowing agent, (e) catalyst, (f) alkali metal salt (I) and opt. (g) other ancillaries and/or additives. (I) is dialkali H phosphate (IA) with an alkali content of 50-2500 ppm w.r.t. the amt. of components (b)-(g). Also claimed is the obtd. foam.