Verfahren zur kontinuierlichen Herstellung gefärbter Polyurethan-Schaumstoffe

摘要

1,264,772. Dyed polyurethane foams. FARBENFABRIKEN BAYER A.G. 7 Jan., 1970 [8 Jan., 1969], No. 733/70. Headings C3C and C3R. Dyed polyurethane foams are produced continuously by reacting a polyhydroxyl compound and a polyisocyanate in the presence of a solution of a dye containing at least one amino and/or hydroxyl group which is capable of reacting with isocyanates under the conditions of polyaddition, dissolved in an alkanephosphonic acid dialkyl ester of the formula wherein R and R1 independently represent C 3-8 alkyl groups. The alkanephosphonic ester preferably has a low vapour pressure at 200‹ C., and is exemplified by dibutyl butane phosphonate. Specified dyestuffs are 4-amino-21-hydroxy- 51-methylazobenzene, an azo dye of 5-amino- 3-phenyl-1,2,4-thiadiazole and N,N-dihydroxyethyl-m-toluidine, an azo dye of 4-nitroaniline and N,N-dihydroxyethyl-m-toluidine, an azo dye of 3-nitro-4-aminotoluene and N,N-dihydroxyethylaniline, and 3-amino-4-ethoxy-21- methyl-4'-(N,N-dihydroxyethyl)-azobenzene.