POLYURETHANE ELASTOMER AND METHOD OF ITS OBTAINING Russian patent published in 2012 - IPC C08G18/10 C08G18/32 C08G18/42 C08G18/48 C08G18/76 C08G18/72 C08J5/00 

FIELD: chemistry.

SUBSTANCE: claimed invention relates to casting polyurethane elastomer and to method of its obtaining. Said elastomer includes product of reaction: (a) of prepolymer with end NCO-groups, (b) aliphatic diisocyanate and (c) aromatic di- or polyamine, where reagents are present in such amounts that equivalent ratio of NCO-groups to the sum of reaction-able NCO-groups is in the interval from 0.8:1 to 1.2:1. Component (a) is obtained by interaction of: (1) diphenylmethanediisocyanate with content of 2,4'-MDI-isomer more than 80 wt %, with (2) highly molecular polyol, selected from group, consisting of polyoxyalkylenepolyols with the mean molecular weight from 250 to 10000, complex polyester polyols with mean molecular weight from 250 to 10000, and their mixtures, at temperature from 30°C to 150°C, during time sufficient for formation of prepolymer with end NCO-groups, OH-groups of said polyol reacting with NCO-groups of said diphenylmethane diisocyanate in the range from 1.5 : 1 to 20 : 1. Component (b) is selected from group, consisting of isomers of 1,1'-methylenebis(4-isocyanatocyclohexane), 1,4-cyclohexane diisocyanate, isoforon diisocyanate, 1,3-xilylene diisocyanate, hexamethylene diisocyanate, isomers of m-tetramethylxylylene diisocyanate (TMXD1), their mixtures and their prepolymers.

EFFECT: obtaining polyurethane elastomers with improved characteristics of processing during casting process, including reduces tendency to cracking, long casting viability, safety, as they do not contain toxic toluylene diisocyanate, as well as possibility to obtain larger and more complex components.

4 cl, 9 ex, 4 tbl