IMPROVEMENT RELATING TO POLYURETHANES Russian patent published in 2019 - IPC C08G18/18 C08G18/48 C08G18/63 C08G18/32 C08G18/76 C08J9/08 C08G101/00 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing foamed polyurethane, involving combining, with an isocyanate index, not more than 120: (a) a polyol component (polyatomic alcohol) containing per hundred weight parts: (I) 10 to 70 parts by weight of a first polyatomic alcohol having a number-average molecular weight in range of 2,000 to 12,000 Daltons and functionality in range of 2 to 6; and (II) from 90 to 30 parts by weight of a second polyatomic alcohol, having a number-average molecular weight in range of 300 to 1,500 Daltons, functionality in range of 2 to 6, and a hydroxyl number in range of 100 to 600 mg KOH/g; (b) an amine catalyst comprising: (I) from 0.23 to 0.6 parts per hundred parts by weight of a polyol component (pphp) of triethylenediamine or a slow-acting form thereof and optionally from 0.05 to 0.20 pphp bis(dimethylaminoethyl)ether or a slow-acting form thereof or (II) one or more tertiary amines selected from N,N,N',N'-tetramethylhexamethylenediamine, N,N-dimethylcyclohexylamine, N-(2-dimethylaminoethyl)-N'-methylpiperazine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N',N''-pentamethyldiethylenetriamine, bis(2-dimethylaminoethyl)ether, N,N-dimethylaminoethoxyethanol, N,N-dimethylaminoethanol and N,N,N'-trimethylaminoethylethanolamine or slow-acting forms of said one or more tertiary amines having catalytic gelation activity and/or foaming activity equivalent to a combination in range of 0.2–0.6 parts per hundred weight parts of polyethylene component (pphp) of triethylenediamine or its form with delayed action, and optionally bis(dimethylaminoethyl) ether or its form with delayed action in range from 0.05 to 0.20 pphp; and (c) foaming reagents containing aromatic polyisocyanate to obtain foamed polyurethane. Invention also discloses a viscoelastic foam obtained using said method, and use of the amine catalyst disclosed above in the above method in order to counteract the formation of an aromatic diamine in foamed polyurethane and/or reduce the full rise time.

EFFECT: reduced accumulation of aromatic diamines when producing foamed polyurethane by using a certain amine catalyst, which leads to obtaining a viscoelastic foam with desirable properties and reduced total rise time.

13 cl, 2 tbl, 10 ex