Patent GB-407016-A (GB)
Title: New monoazo dyestuffs
IPC: C09B45/16
Filed: 1932-07-07
Abstract: Monoazo dyestuffs are manufactured by coupling, in alkaline, acid or neutral solution, the diazo compound of a primary aromatic monoamine having a hydroxy, carboxyl or alkoxy group in the o-position to the amino group with the condensation product of an ethylene halohydrin and an aminonaphtholsulphonic acid (which product is probably a mixture of the mono- and di-N-hydroxyethylaminonaphtholsulphonic acids).  The products dye wool, silk and other fibres.  Those of the products which contain an o-hydroxyazo grouping are capable of forming complexes with di-or polyvalent metals, e.g. copper or chromium, which complexes may be formed in substance, or on the fibre after treatment, or by dyeing premordanted fibre, or by treating the fibre with metallic salt during the dyeing operation.  Suitable aminonaphtholsulphonic acids for the production of the coupling components are the 1 : 5 : 7-, 1 : 8 : 4-, 2 : 3 : 6-, 2 : 5 : 7- and 2 : 8 : 6- aminonaphtholsulphonic acids and 1 : 8 : 2 : 4-, 1 : 8 : 3 : 5-, 1 : 8 : 3 : 6-, 1 : 8 : 4 : 6-and 2 : 8 : 3 : 6- aminonaphtholdisulphonic acids.  In examples of the preparation of the coupling components: (1) 2 : 8 : 6- acid or 1 : 8 : 4- acid is dissolved in water with enough sodium carbonate to render the solution neutral, and reacted with ethylene chlorhydrin in the presence of sodium acetate; (2) the monosodium salt of 1 : 8 : 3 : 6-acid is similarly treated; (3) 2 : 5 : 7-acid is dissolved in water with enough sodium carbonate to render the solution neutral, and is reacted with ethylene chlorhydrin in the presence of chalk, after which calcined sodium carbonate is added and the product filtered. In each case the solution obtained may be used directly for the production of azo dyestuffs.  In examples of the production of the dyestuffs: (4) 4-nitro-2-aminophenol is diazotized and coupled in alkaline solution with the product of (2); the product dyes wool navy blue shades which change to dark green on afterchroming, a similar shade being obtained by the metachrome process; the coupling component may be replaced by either of the products of (1), that from 1 : 8 : 4-acid yielding slightly redder shades by direct dyeing and somewhat deeper afterchromed or metachromed shades, whilst that from 2 : 8 : 6-acid yields an olive brown shade by direct dyeing and a black-brown by afterchroming or by the metachrome process; (5) the product of (4) using as coupling component the product from 1 : 8 : 4-acid is treated in aqueous solution with chromium fluoride; the product dyes wool greenish navy blue shades; (6) the product of (4) using as coupling component the product from 1 : 8 : 3 : 6-acid is treated in aqueous solution with copper sulphate; the product dyes wool dark blue shades; (7) the dyestuff obtained by coupling diazotized 4-chloro-2-aminophenol with the condensation product from 1 : 8 : 4-acid is dissolved in water containing copper sulphate; the product dyes wool navy blue shades; (8) the product of (4) using as coupling component the product from 1 : 8 : 4-acid is treated in aqueous solution with copper sulphate; the product dyes wool blue shades; (9) diazotized picramic acid is coupled in alkaline solution with the product of (1) from 2 : 8 : 6-acid; the product dyes wool brown shades by the metachrome process.  Samples have been furnished under Sect. 2 (5) of the following dyestuffs: (A) anthranilic acid --> 2 - (b  - hydroxyethylamino) - 8 - naphthol - 6 - sulphonic acid; (B) o-anisidine --> 1-(b -hydroxyethylamino) - 8 - naphthol - 4 - sulphonic acid.  Specification 362,513 is referred to in the Provisional Specification.