GB971048A - Pigment dyes - Google Patents

Abstract

Plaster of Paris and cement are coloured red with a pigment of the formula <FORM:0971048/C1/1>ALSO:In examples, a pigment of the formula <FORM:0971048/C3/1> (2) wherein X is NH and rings A and D are each linearly fused with benzene rings, is ground with nitrocellulose, dibutyl phthalate and an ethyl alcohol/ethyl glycol mixture to give a yellow printing colour; (3) wherein X is 0, is mixed with a lacquer containing nitrocellulose, dibutylphthalate, benzyl butyl phthalate, the product obtained by treating cyclohexanone with sodium hydroxide, butyl acetate, methyl acetate, and toluene to give a greenish-yellow lacquer, (pigments wherein X is NH, ring D forms part of a phenazine residue and ring A may or may not be linearly fused to a benzene ring may also be used); (4) wherein X is NH, ring D forms part of a phenazine residue and ring A is linearly fused to a benzene ring, is ground with xylene and a mixture of linseed oil and the esterification product from phthalic acid, glycerin and pentaerythritol to give a red-orange lacquer; (5) wherein X is NH and ring D is linearly fused to a benzene ring, is ground with an unsaturated polyester resin drying without the aid of paraffin and then mixed with monostyrene, a cyclohexanone peroxide paste in dibutyl phthalate, cobalt naphthenate in white spirit and silicone oil in xylene to give a yellow paint for wood; (6) wherein X is 0 and ring D forms part of an anthraquinone residue, is mixed with polyvinyl chloride, di-isooctyl phthalate and titanium dioxide to give a red polyvinyl chloride; and (7) wherein X is NH, is mixed and homogenised with polystyrene granulate or polyethylene to give a yellow plastic.ALSO:Quinoxaline derivatives of the formula <FORM:0971048/C4-C5/1> wherein X is NH, O or S and which may carry substituents and/or other rings fused linearly or angularly are made by heating a 2 : 3-dichlorquinoxaline at a temperature above about 125 DEG C. with an appropriate o-diamino-, o-amino-hydroxy- or o-amino-mercapto-aromatic or heterocyclic compound at a mol. ratio of about 1 : 1 using a carboxylic acid-N : N-dialkylamide as a solvent. The invention also comprises pigments of the above formula wherein X is NH, O or S and which may be substituted and/or have linearly fused rings, having a mean particle size in the range of from 0.02 to 1 micron. The pigments may be made by the process above and then if necessray be subjected to salt-milling or acid-pasting. When additional fused rings are present these may be such that ring A in the formula above also forms part of a naphthalene nucleus and/or ring D also forms part of naphthalene, anthracene, anthraquinone or phenazine nuclei. The pigments colour a variety of materials. In examples (1) a yellow printing ink is made by grinding aluminium hydroxide and a linseed oil varnish with one of a number of pigments of the above general formula, and a yellow wall-paper colour is made by mixing a paste of a pigment of the above general formula where a benzene ring is linearly fused to ring D with heavy spar, aluminium sulphate, sodium carbonate and water, adding barium chloride and mixing the precipitate obtained with glue solution.