GB885452A - New monoazo dyestuff pigments containing n-pyrenyl-acylamino groups and their manufacture and use - Google Patents

Abstract

Polyvinyl chloride is coloured in blue to red shades by incorporating therein a monoazo dyestuff free from sulphonic or carboxylic acid groups or sulphonamide groups of formula <FORM:0885452/IV (a)/1> wherein R1 is a benzene residue bound in the 1-positio to the azo linkage and in the 5-position to the carbonyl group, containing in the 2-position an alkoxy group, R2 is a naphthalene residue in which the azo linkage, the hydroxyl group and the - CONH Pyr group are in 1 : 2 : 3-position relatively to one another and Pyr is a pyrene residue (see Group IV(c)). In an example a pigment of the above formula wherein the alkoxy group in R1 is methoxy is added to a mixture of polyvinyl chloride and dioctyl phthalate and the mixture is rolled to give a ruby-coloured foil. Specification 820,444 is referred to.ALSO:The invention comprises monoazo dyestuffs free from sulphonic or carboxylic acid groups or sulphonamide groups of formula <FORM:0885452/IV (c)/1> wherein R1 is a benzene residue bound in the 1-position to the azo linkage and in the 5-position to the carbonyl group, and containing in the 2-position an alkoxy group, and R2 is a naphthalene residue in which the azo linkage, the hydroxyl group and the -CONHPyr group are in 1 : 2 : 3-position relatively to one another and Pyr is a pyrene residue. They are prepared by reacting a dicarboxylic acid halide of formula <FORM:0885452/IV (c)/2> with an aminopyrene. The acid halides may be prepared by treating the corresponding azo dyestuff dicarboxylic acids with phosphorus halides or oxyhalides or with thionyl chloride in the presence of inert solvents such as chlorobenzenes, toluene, xylene or nitrobenzene. The dyestuffs are blue to bordeaux coloured pigments and are used to colour compounds such as polymers, cellulose derivatives and rubber. In an example the dyestuff 3-amino-4-methoxybenzoic acid 2 : 3-hydroxynaphthoic acid is converted into the corresponding acid chloride by the process described in Specification 820,444 and the acid chloride is reacted with 3-aminopyrene in o-dichlorobenzene solution and in the presence of pyridine. Alternative reactants specified are 3-amino-4-ethoxybenzoic acid and 6-bromo-2 : 3-hydroxynaphthoic acid.