Reference

Water-soluble polyazo dyes

Water-soluble polyazo dyes. Arsac, Aime; Frank, Pierre (Produits Chimiques Ugine Kuhlmann, Fr.). Fr. Demande FR 2349675 25 Nov 1977, 30 pp. (French). (France).Several reagents such as 7621-86-5 is used here. CODEN: FRXXBL. CLASS: IC: D06P003-32. APPLICATION: FR 74-36792 6 Nov 1974. DOCUMENT TYPE: Patent CA Section: 40 (Dyes, Fluorescent Whitening Agents, and Photosensitizers) Polyazo dyes [I; R, R2 = benzene, naphthalene, heterocyclic radical; R1 = H, Cl, alkyl; Z, Z1 = phenylene, naphthylene; m, n = 0, 1, 2; the mol. contains ( in R, R1, Z, Z1) 1-4 SO3H groups and 0-2 CO2H groups] were prepd. and used to dye leather.In this experiment, several chemicals are used like 7621-86-5 Thus, 2-(4-aminophenyl)-5-aminobenzimidazole [7621-86-5] was tetrazotized and coupled with 2-amino-5-hydroxy-7-naphthalenesulfonic acid [87-02-5] to give I (R = R2 = 2,5,7,1-H2N(HO)(HO3S)C10H4, R1 = H, m = n = 0) [67400-98-0], fast violet on leather. ..

Aqueous disazo dye concentrate

Aqueous disazo dye concentrate. Eastlack, George Franklin (du Pont de Nemours, E. I., and Co., USA). U.S. US 4082742 4 Apr 1978, 3 pp. (English). (United States of America). CODEN: USXXAM. CLASS: IC: C09B031-08. NCL: 260187000. APPLICATION: US 73-389196 17 Aug 1973. DOCUMENT TYPE: Patent CA Section: 40 (Dyes, Fluorescent Whitening Agents, and Photosensitizers) A concd. (~16%) soln. of I [67202-95-3], stable for 6 mo. at 25-30°, was prepd. by benzoylating aq. J acid [87-02-5] in the presence of triethanolamine (II) [102-71-6] as an acid acceptor and coupling the resulting soln. of benzoyl J acid [132-87-6] at 22-8° in the presence of II (to maintain pH 5-7) with an H2O-HOCH2CH2OH slurry of the filtered and water-washed diazonium salt [67174-91-8] obtained by diazotizing Na p-(p-aminophenylazo)benzenesulfonate [2491-71-6]. This method of prepn. avoids the use of strong alkali which, when present in solns. of I, hydrolyzed the benzamido group and alters the color of the dye.