Patent GB-443629-A (GB)
Title: Process for dyeing pelts
IPC: D06P3/30
Filed: 1934-08-01
Abstract: Aniline black and like dyeing.--Pelts, pretreated with a metallic mordant, are dyed by treatment, at a temperature not above 32 DEG C., in an aqueous hydrogen peroxide bath containing approximately equimolecular proportions of, on the one hand, a dioxy or polyoxy compound of the benzene series, a dioxynaphthalene, an aminooxynaphthalene or a halogen substitution product of an oxynaphthalene or aminooxynaphthalene and, on the other hand, an aminodiphenylamine or another aromatic or heterocyclic amine, and containing an emulsifying or wetting agent.  Specified emulsifying and wetting agents are turkey red oil, sulphonated aliphatic hydrocarbons from brown coal tar, e.g. sulphonated solar oil, water-soluble condensation products of unsaturated fatty acids with sulphonic acids of aromatic oxycompounds (cf. Specification 346,425), sulphonated alkylnaphthalenes, fatty alcohol sulphonates and the condensation product of example 1 of Specification 240,318, [Class 2 (iii)]; the wetting action may in some cases be assisted by a small proportion of an organic solvent.  The following examples are specified: (1) A white rabbit skin, mordanted with a chromium salt, is dyed a dull olive brown by treatment for 3 hours in an aqueous solution at room temperature containing hydrogen peroxide, a mixture in equimolecular proportions of 2 : 7-aminonaphthol and 1 : 4-diaminobenzene, and the wetting agent described in example 1 of Specification 240,318; (2) A dull yellow brown dyeing is obtained if the 1 : 4-diaminobenzene in (1) is replaced by 1 : 3-diaminobenzene and the wetting agent by that of p  example 1 or 2 of Specification 346,425; (3) A white lambskin, mordanted with a chromium salt, is dyed a dull violet brown by treatment for 3 hours in an aqueous solution at 30 DEG  C. containing hydrogen peroxide, a mixture in equimolecular proportions of 1 : 5-aminonaphthol and 1-chloro-2 : 4-diaminobenzene, and turkey red oil; (4) A dull yellow brown dyeing is obtained if the 1-chloro-2 : 4-diaminobenzene in (3) is replaced by 1-nitro-2 : 4-diaminobenzene.  The samples furnished under Sect. 2 (5) are of chromium-mordanted lambskin dyed with (1) a mixture of p-aminodiphenylamine and 1 : 5-dioxynaphthalene in conjunction with the emulsifying agent of example 1 of Specification 346,425, (2) a mixture of p-phenylenediamine and 2 : 7-dioxynaphthalene in conjunction with the same emulsifying agent, (3) a mixture of 8-aminoquinoline and 1 : 6-dioxynaphthalene in conjunction with turkey red oil, (4) a mixture of m-toluylenediamine and 6-bromo-2-naphthol in conjunction with turkey red oil, (5) a mixture of 2-nitro-1 : 4-phenylenediamine and 1 : 5-aminonaphthol in conjunction with the emulsifying agent of example 1 of Specification 240,318, (6) a mixture of 4-methyl-3-aminodiphenylamine and 1 : 2 : 4-trioxybenzene in conjunction with turkey red oil, (7) a mixture of 4-chloro-3 : 5-diaminotoluene and 1 : 7-dioxynaphthalene in conjunction with the emulsifying agent of example 1 of Specification 346,425.  4-Chloro-3 : 5-diaminotoluene is obtained by reducing 4-chloro-3 : 5-dinitrotoluene with zinc dust and hydrochloric acid.