GB878661A - Improvements relating to dioxazine pigments and their use - Google Patents

Abstract

Viscose or cellulose ester materials are dyed in the mass and polyvinyl chloride compositions and urea-alkyd resin lacquers are coloured by pigments of the formula:- <FORM:0878661/IV (a)/1> which are free from carboxylic acid and sulphonic acid groups and wherein X represents an acylamino group derived from a carboxylic acid and R1 is an alkyl, aralkyl or aryl group which may be substituted. Examples describe (7) a lacquer containing a pigment of the above formula, titanium dioxide, a 60% solution of a modified urea-alkyd resin in xylene/butanol 1 : 1, turpentine and xylene, and (8) a composition containing polyvinyl chloride, a pigment of the above formula, titanium dioxide, dioctyl phthalate and dibutyl tin dilaurate.ALSO:4-Acylamino-2:5-dimethoxy or diethoxyanilines are made by nitration and reduction of the condensation products from 2:5-dimethoxyaniline and m-chloro- or 2:4-dichloro-benzoyl chlorides, lactic acid, isonicotinyl chloride, furoyl chloride and b -methoxyethyl chloroformate, or of the condensation products from 2:5-diethoxyaniline and o- or p-chlorobenzoyl chlorides. 4-(o- or p-chlorobenzoyl-N-methyl-amino)-2:5-dimethoxy-aniline is made by nitration and reduction of the condensation product from 2:5-dimethoxy-N-methylaniline and o-or p-chlorobenzoyl chloride respectively. 4-(acetyl- or o-chlorobenzoyl-N-benzyl-amino)-2:5-dimethoxyaniline is made by nitration and reduction of the condensation products from 2:5-dimethoxy-N-benzylaniline and acetyl chloride or o-chlorobenzoyl chloride respectively. 4-(benzoyl- or acetyl-amino)-2:5-diphenoxy- or benzyloxy-anilines are made by nitration and reduction of the condensation products obtained from 2:5-diphenoxy- or dibenzyloxy-aniline and benzoyl or acetyl chloride. 4-(31:41- dichlorophenylcarbamylamino) -2:5-dimethoxy-aniline is made by nitration and reduction of the condensation product from 2:5-dimethoxyaniline and 3:4-dichlorophenyl-isocyanate. 4-phthalimido- 2:5- dimethoxyaniline is made by condensing 4-nitro-2:5-dimethoxyaniline with phthalic acid anhydride and reducing the nitro group.ALSO:The invention comprises dioxazine pigments of the general formula:- <FORM:0878661/IV(c)/1> where X is an acylamino group derived from a carboxylic acid and R1 is an alkyl, aralkyl or aryl group which may be substituted, the pigments being free from carboxylic acid and sulphonic acid groups. The pigments are made by condensing by known methods amines of the formula:- <FORM:0878661/IV(c)/2> where X and R1 are as above and Y is hydrogen or -OR2 where R2 has the values indicated for R1, with chloranil and simultaneously or subsequently converting by known methods the condensation products into triphendioxazine dyestuffs of the above general formula. They may be finely dispersed by treatment with sulphuric acid or aliphatic or aromatic carboxylic or sulphonic acids, or by milling with inorganic or organic salts and solid or liquid organic solvents. The pigments may be blended with phthalocyanine pigments.