New water soluble tris:azo dyestuff cpds. used for dyeing leather - are 2(4-(4-azo-anilino)-3-sulpho-phenyl-azo)-7-azo-1-naphthol-3-sulphonic acid coupled with 1,3-di:aminobenzene-4-sulphonic acid, etc.

摘要

New water-soluble trisazo dyestuffs (I) are 2-(4-(4-azo-anilino)-3-sulphophenyl -azo) -7-azo-l-naphthol-3-sulphonic acid cpds., coupled with 1,3-diaminobenzene-4-sulphonic acid and an acetoacetarylide or phenylmethylpyrazolone sulphonic acid of the formula (I). In (I), one K = a 1,3-diaminobenzene-4-sulphonic acid gp. and the other K = an acetoacetarylide gp., opt. substd. by Cl, OMe or -SO2NH2, or a phenylmethylpyrazolone sulphonic acid, opt. substd. by Cl. (I) may be prepd. by conventional diazotisation and coupling. USE/ADVANTAGE - (I) are claimed for dyeing leather. They give black tones with higher colour strength and, in pt., better fastness than the usual dyestuffs. In an example, 14 g 4,4'diaminodiphenylamine-2- sulphonic acid were bisdiazotised and coupled with 12 g 2-amino-8-hydroxy-naphthalene -6-sulphonic acid in slightly acid to alkaline medium. The prod. was diazotised and coupled with 9.5 g 1,3-diaminobenzene-4-sulphonic acid in slightly acid to alkaline medium, then coupled with 8.8 g acetoacetanilide in strongly alkaline soln. The resultant dyestuff (A) dyed leather strong black with a reddish tinge. Compared with a conventional dyestuff (B) (DE3135538), example 3), which had a bluish-black tone, it gave stronger dyeing with glove, calfskin suede and pigskin suede leather. The rubbing fastness (N/F) was (A) 3-4/3-4, (B) 3/2 dry and (A) 2/2-3, (B) 2/2 wet; and the fastness to perspiration (A) 4/5, (B) 3/4-5.