Viscoelastic polyurethane foam with improved sound insulation - by reaction of poly:isocyanate(s) with polyether- and polyester-poly:ol mixts. contg. di:propylene glycol poly:adipate

摘要

Viscoelastic flexible PU foam material (I) are produced by reaction of (a) opt. modified polyisocyanates with (b) mixts. of polyether-polyols (b1) and polyester-polyols (b2) and opt. (c) low- mol.wt. chain-extenders in the presence of (d) catalysts, (e) blowing agents and opt. (f) other additives and auxiliary substances; the novelty is that (b2) are dipropylene glycol-adipic acid polyesters with OH no. 20-150. Mixts. (b) are claimed, comprising 15-50 pts.wt. polyether-polyols, polyoxypropylenepolyoxyethylene-polyols, polymer-modified polyoxyalkylene-polyols or mixts. of at least 2 of these types, and 50-85 pts.wt. (b2) as in 1. above. USE/ADVANTAGE - (I) are useful for the prodn. of sound insulating foam liners, etc., esp. to reduce the noise level in motor vehicles and machines; other applications include carpet backing, furniture, building components, etc. The invention provides (I) with improved relaxation properties, resulting in better sound insulation; the starting materials are relatively inexpensive, and miscible in the required proportions.