Sumitomo Chemical Company, Limited

Tadashi Yamamoto

Takemi Tokieda

Suketsugu Koumura

Seizo Konishi

Nobuzi Nishimura

Utazi Sawa

Masayuki Tsuji

A dye composition comprising at least one disazo dye of the formula (I) expressed in the form of a free acid, ##STR1## wherein each X.sub.1 and X.sub.2 is --SO.sub.2 CH.sub.2 CH.sub.2 OCOCH.sub.3, --SO.sub.2 CH.sub.2 CH.sub.2 OSO.sub.3 H or --SO.sub.2 CH.dbd.CH.sub.2, provided that at least one of X.sub.1 and X.sub.2 is --SO.sub.2 CH.sub.2 CH.sub.2 OCOCH.sub.3, and at least one disazo dye of the formula (II) expressed in the form of a free acid, ##STR2## Wherein each Y.sub.1 and Y.sub.2 is --SO.sub.2 CH.sub.2 CH.sub.2 OSO.sub.3 H, --SO.sub.2 CH.dbd.CH.sub.2 or --SO.sub.2 CH.sub.2 CH.sub.2 OH, provided that one of Y.sub.1 and Y.sub.2 is --SO.sub.2 CH.sub.2 CH.sub.2 OSO.sub.3 H or --SO.sub.2 CH.dbd. CH.sub.2, is produced by diazotizing a mixture of 4-aminophenyl-.beta.-sulfatoethylsulfone and 4-aminophenyl-.beta.acetoxyethylsulfone in a weight ratio of 30 to 70: 70 to 30 with a nitrite, and coupling the resulting mixture of the diazonium salts with 1-amino-8-naphthol-3,6-disulfonic acid. The dye composition is suitable for dyeing natural or regenerated cellulosic fiber materials in black.

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Toyonaka, Japan

Tadashi Yamamoto