| abstract |
A process for making a polyurethane foam, the process comprising combining, at an isocyanate index of at most 120: (a) a polyol component comprising, per hundred parts by weight: (i) from 10 to 70 parts by weight of a first polyol having a number average molecular weight in the range of from 2000 to 12000 Dalton, and a functionality in the range of from 2 to 6; and (ii) from 90 to 30 parts by weight of a second polyol having a number average molecular weight in the range of from 300 to 1500 Dalton, a functionality in the range of from 2 to 6, and a hydroxyl value in the range of from 100 to 600 mg KOH/g; (b) an amine catalyst component consisting of: (i) in the range of from 0.2 to 0.6 parts per hundred parts by weight of polyol component (pphp) of triethylenediamine or a delayed action form thereof, and optionally in the range of from 0.05 to 0.20 pphp bis(dimethylaminoethyl)ether or a delayed action form thereof; or (ii) an amount of one or more tertiary amines or delayed action forms thereof having a catalytic gelling and/or blowing activity equivalent to (i); and (c) foam-forming reactants comprising an aromatic polyisocyanate, to obtain the polyurethane foam. |