Patent GB-705590-A (GB)
Title: Manufacture of water-insoluble monoazo-dyestuffs
IPC: C09B29/32
Filed: 1950-12-08
Abstract: Azo dyestuffs of the formula <FORM:0705590/IV (a)/1> where ring a may have one or more alkyl, alkoxy or halogen substituents, and either X is alkoxy, Y is halogen and Z is alkoxy or alkyl, or X and Y are alkoxy and Z is halogen, or X is alkyl, Y is halogen and Z is alkoxy, are used as yellow pigments for colouring high molecular plastic masses, e.g. urea-formaldehyde, phenol-formaldehyde and amino-formaldehyde condensation products and polyvinyl compounds. They may also be used for colouring lacquers and may be added to spinning solutions for producing spun-dyed artificial silk of cellulose acetate or viscose.  In examples, (1) the dyestuff 2:5-dimethoxy-aniline-4-sulphonanilide \sM 1 -acetoacetylamino - 2 : 5 - dimethoxy-4-chlorobenzene is mixed with polyvinyl chloride, dibutyl phthalate and titanium dioxide and kneaded on hot rollers; the titanium dioxide may be wholly or partially replaced by other fillers normally used for rubber; (2) as in (1) using the dyestuff from 1-acetoacetylamino-2:5-diethoxy-4-chlorobenze; (3) the dyestuff 2:5 - dimethoxyaniline - 4 - sulphonanilide --> 1 - acetoacetylamino - 2 : 5 - dimethoxy - 4 - bromobenzene is ground with a urea-formaldehyde condensation product and wood meal and the mixture moulded in a press.  Other suitable dyestuffs are listed.ALSO:Azo dyestuffs of the formula <FORM:0705590/IV (b)/1> where ring a may have one or more alkyl, alkoxy or halogen substituents, and either X is alkoxy, Y is halogen and Z is alkoxy or alkyl, or X and Y are alkoxy and Z is halogen, or X is alkyl, Y is halogen and Z is alkoxy, are used as yellow pigments for colouring high molecular plastic masses.  In an example the dyestuff 2:5 - dimethoxyaniline - 4 - sulpho-o-toluidide --> 1-acetoacetylamino-2-methoxy-4-chloro-5-methylbenzene is added to rennet casein and zinc white and the mixture hardened with formaldehyde.  Other suitable dyestuffs are listed.ALSO:The invention comprises water-insoluble monoazo dyestuffs of the formula <FORM:0705590/IV(c)/1> where ring a may have one or more alkyl, alkoxy or halogen substituents; either X is alkoxy, Y is halogen and Z is alkoxy or alkyl, or X and Y are alkoxy and Z is halogen, or X is alkyl, Y is halogen and Z is alkoxy.  These are made by diazotizing the appropriate amide of 2 : 5-dimethoxysulphanilic acid and coupling with the appropriate acetoacetic arylide.  The latter is preferably used in aqueous suspension, obtained by dissolving it in alkali and reprecipitating with acetic acid.  They are yellow pigments suitable for plastic masses, spinning solutions and lacquers; for the last-named, the vehicle may be added to the finished dyestuff or to the coupling solution.  Examples show the production of the following: 2 : 5-dimethoxy sulphanilic anilide --> 1-acetoacetylamino-2 : 5-dimethoxy-4-chlorobenzene; 2 : 5-dimethoxysulphanilic anilide --> 3-acetoacetylamino-4-methoxy-6-chlortoluene; 2 : 5-dimethoxysulphanilic o-toluidide --> 3-acetoacetylamino-4-methoxy-6-chlortoluene; 2 : 5 - dimethoxylsulphanili anilide --> 1-acetoacetylamino-2 : 5-diethoxy-4-chlorbenzene; and 2 : 5 - dimethoxysulphanilic anilide --> 1-acetoacetylamino-2 : 5-dimethoxy-4-brombenzene. Other suitable components are listed, e.g. 1-acetoacetylamino-2 : 4-dimethoxy-5-chlorbenzene.  Specifications 462,601 and 462,674 are referred to.ALSO:Azo dyestuffs of the formula <FORM:0705590/V/1> where ring a may have one or more alkyl, alkoxy or halogen substitutents, and either X is alkoxy, Y is halogen and Z is alkoxy or alkyl, or X and Y are alkoxy and Z is halogen, or X is alkyl, Y is halogen and Z is alkoxy, are used as yellow pigments for colouring high molecular plastic masses, e.g. rubber.  In an example the dyestuff 2 - 5 - dimethoxyaniline-4-sulphonanilide --> 1 - acetoacetylamino - 2 - methoxy - 4-chloro-5-methylbenzene is mixed with rubber, filling material, sulphur and a vulcanization accelerator and the mass vulcanized in a hot press. Alternatively, rubber, the usual additions and the dyestuff may be immersed in sulphur monochloride in benzene and vulcanized cold. Other suitable dyestuffs are listed.