Patent GB-329049-A (GB)
Title: Improvements in or relating to the manufacture of azo dyes
IPC: C09B35/22
Filed: 1929-02-21
Abstract: 329,049. Imperial Chemical Industries, Ltd., and Brightman, R. Feb. 21, 1929. Azo dyes.-New monoazo and primary disazo dyes are obtained by combining the diazotized oxamic acid derivatives of 4: 4<1>-diaminodiphenylamino- or tri-sulphide with coupling components, and in the case of the primary disazo dyes one molecular proportion of the diazo component may be replaced by a corresponding proportion of another diazo component. The products may be hydrolyzed to remove the oxalyl group whereupon the resulting aminoazo, aminodisazo, or diaminodisazo group compounds may be diazotized or tetrazotized and coupled with components to obtain disazo, trisazo, or tetradisazo dyes some of which are identical with dyes obtainable by the processes of Specifications 296,011, 296,047, and 321,483. According to the coupling components used the products are suitable for dyeing cellulose ester materials or for dyeing regenerated materials in level shades and many give dyeings fast to milling and storing on animal fibres. The following examples are specified : (1) The dyestuff 4-aminodiphenylsulphide- 4<1>-oxamic acid # (alkaline) phenyl-2 : 5 : 7- acid dyes viscose bright bluish red; if the coupling component is replaced by 1 : 8-aminonaphthol- 2 : 4-disulphonic acid the viscose is dyed violet; if the coupling component is replaced by phenyl- 2 : 8 : 6-acid the product gives brown dyeings fast to milling and stoving on wool. (2) The dyestuff 4-aminodiphenylsulphide-4<1>-oxamic acid # 1- phenyl-3-methyl-5-pyrazolone dyes acetate silk bright yellow; if the coupling component is replaced by 2: 6-naphthylaminesulphonic acid the product gives bright orange dyeings fast to milling and stoving on wool; if the coupling component is replaced by 2 : 8 : 6-acid the product dyes viscose red and gives red dyeings fast to milling on wool. (3) The dyestuff 4-aminodiphonyltrisulphide-4<1>-oxamic acid # salicylic acid dyes acetate silk bright yellow and gives yellow dyeings fast to milling on wool; if the coupling component is replaced by 2: 5: 7-acid the product dyes viscose level yellowish red shades. (4) The dyestuff 4-aminodiphenyltrisulphide-4<1>-oxamic acid # 1-(4'-sulpho) phenyl- 3-methyl-5-pyrazolone gives yellow dyeings very fast to milling on wool; if the coupling component is replaced by 2: 6-naphthylaminesulphonic acid the product dyes viscose level orangeyellow shades and gives orange-yellow dyeings fast to milling on wool. (5) The primary disazo dyestuffs 4-aminodiphenyltrisulphide-4<1>-oxamic acid # m-phenylenediamine # p-chloraniline dyes acetate silk orange-brown; the primary disazo dyestuff the oxamic acid derivative of thioaniline # m-phenylenediamine # p-nitraniline dyes acetate silk reddish brown. (6) The primary disazo dyestuff 4-aminodiphenylsulphide- 4<1>-oxamic acid # m-toluylenediamine # 2: 4-dinitroaniline dyes cellulose acetate silk reddish brown. Monooxamic acid derivatives of 4: 4<1>-diaminophenylmono- and tri-sulphides are obtained by boiling the parent diamino compounds with an aqueous solution of oxalic acid. Examples are. given.