Patent ID: 11912815
Assignee: DOW GLOBAL TECHNOLOGIES LLC
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C  A | IPC C

Claim 6:
7. A method of making a flexible polyurethane foam, comprising
A. forming a reaction mixture by mixing at least the following components:
a) a polyol mixture that comprises
i) 45 to 80 weight-%, based on the weight of the polyol mixture, of an ethylene oxide copolymer containing 45 to 70% by weight polymerized ethylene oxide based on the total weight of the ethylene oxide copolymer, or mixture of two or more thereof, the ethylene oxide copolymer or mixture thereof having a number average hydroxyl functionality of 2 to 4 and an average hydroxyl equivalent weight of 175 to 600;
ii) 10 to 30 weight-%, based on the weight of the polyol mixture, of a propylene oxide polymer containing at least 70% by weight polymerized propylene oxide based on the total weight of the propylene oxide polymer, a hydroxyl functionality of 2 to 4 and an average hydroxyl equivalent weight of greater than 500 to 2000, or mixture of two or more thereof, and
iii) 5 to 29 weight-%, based on the weight of the polyol mixture, of a liquid polyester polyol having a hydroxyl functionality of 2 to 4 and a hydroxyl equivalent weight of 175 to 900 with the proviso that the hydroxyl equivalent weight is 175 to 600 when the polyester polyol is a polycaprolactone, or a mixture of two or more thereof;

b) water in an amount of 1 to 4 parts by weight per 100 parts by weight of the polyol mixture;
c) an aromatic polyisocyanate that comprises polymeric diphenylmethane isocyanate (MDI), in an amount sufficient to provide an isocyanate index of 50 to 120;
d) at least one urethane catalyst and
e) at least one foam-stabilizing surfactant,
and
B. subjecting the reaction mixture formed in step A. to conditions at which the reaction mixture reacts to form the flexible polyurethane foam.