METHOD OF PRODUCING POLYURETHANE FOAM Russian patent published in 2020 - IPC C08G18/48 C08G18/76 

FIELD: chemical industry.

SUBSTANCE: present invention relates to a polyurethane foam having elasticity of at least 50 % and a method for production thereof. Said method involves reacting: (i) a first polyester polyol, (ii) a second polyester polyol and (iii) one or more aromatic polyisocyanates in the presence of one or more gel-forming and/or foaming catalysts. First polyether polyol has polyester chains containing a proportion of ethylene oxide of not more than 20 %, where the residue of the ratio of alkylene oxide in the polyester chain is obtained from propylene- and/or butylene oxide. Proportion of primary hydroxyl groups in the first polyether polyol is not more than 20 %, the hydroxyl number is at least 40 and the nominal functionality is at least 2.5 and not more than 3.0. Second polyether polyol has polyester chains containing a proportion of ethylene oxide of at least 50 %, where the residue of the ratio of alkylene oxide in the polyester chain is obtained from propylene- and/or butylene oxide.

EFFECT: present method is an improved method of producing highly elastic polyurethane foam from polyester polyol, obtained using a DMC-catalysed process without the need for a separate periodic KOH-catalyzed ethylene oxide grafting step.

8 cl, 2 tbl, 2 ex