| 主权项 |
1. A predominantly open-cell, cold-formable, rigid polyurethane foam with >50 vol % open-cell content to DIN ISO 4590-86 and with a uniform cell structure, obtained by reacting an organic polyisocyanate component A) comprising
A1) 0 to 10 wt %, based on the organic polyisocyanate component A), of 2,2′-diphenyl-methane diisocyanate, A2) 0 to 30 wt %, based on the organic polyisocyanate component A), of 2,4′-diphenyl-methane diisocyanate and A3) 25 to 75 wt %, based on the organic polyisocyanate component A), of 4,4′-diphenylmethane diisocyanate, with a component B consisting of B1) 20 to 70 wt %, based on component B, of a polyoxyalkylene polyol having a hydroxyl number of 25 to 60 mg KOH/g and a number-average functionality of 2 to 4, B2) 20 to 50 wt %, based on component B, of a polyoxypropylene polyol having a hydroxyl number of 300 to 900 mg KOH/g and a number-average functionality of 2.5 to 4, B3) 0 to 25 wt %, based on component B, of a polyoxyalkylene polyol having a hydroxyl number of 150 to 550 mg KOH/g and a functionality of 2, B4) 0 to 20 wt %, based on component B, of a polyol containing an ester group and having a hydroxyl number of 200 to 500 mg KOH/g and a number-average functionality of 2 to 5, B5) 0.1 to 15 wt %, based on component B, of a propylene oxide-ethylene oxide copolymer having a hydroxyl number of 25 to 200 mg KOH/g and a functionality of 5 to 8, B6) 0 to 3 wt %, based on component B, of glycerol, B7) 1 to 7 wt %, based on component B, of water, B8) 0.5 to 4 wt %, based on component B, of a catalyst B9) optionally an auxiliary and/or an adjuvant, the NCO index is from 85 to 125, and the sum of components B1) to B9) is 100 wt %. |
