Verfahren zur Herstellung von stabilen Metallphthalocyaninen

Stable metal phthalocyanines are prepared by heating together a phthalic anhydride or a corresponding free acid, or a monoester thereof, or an ammonium salt thereof, or an amide or imide of the said acid, or an o-cyanobenzoic acid or an ammonium salt or an ester thereof, with urea or a heat-decomposition product thereof (other than ammonia) and a substance consisting of or containing a metal adapted to give a stable - metal phthalocyanine. The term phthalic anhydride includes also the anhydrides of naphthalene-1 : 2- and 2 : 3-dicarboxylic acids; substituted acids mentioned are the halogen-, nitro- and carboxy derivatives of phthalic acids. An excess of urea or heat-decomposition product over the theoretical requirements is usually necessary since it behaves both as a reactant and as a flux. Pressure or the presence of additional reagents such as sulphaminic acid, imidodisulphonic acid or nitrile trisulphonic acid (cf. Specification 457,786), may be an advantage. The general reaction temperature is 200--220 DEG C. Reaction may take place in stages so that the heating of a metal yielding substance with a phthaluric acid or a phthalimimide is p included in the invention. In examples: (a) a mixture of phthalic anhydride, urea and aluminium chloride are heated together at 210 DEG C.; instead of aluminium chloride, ferric chloride, ferrous chloride, chromium fluoride, chromium chloride, cobaltous chloride, cupric chloride or nickelous chloride may be used, and in the case of cupric chloride the yield may be improved by working in the presence of ammonium sulphamate; (b) 4-chlorophthalic anhydride, urea and cupric chloride are heated together at 210 DEG C.; (c) 3 : 6-dichlorphthalic anhydride, urea and cupric chloride or nickel chloride are heated together at 210 DEG C.; (d) 4 : 5-dichlorphthalic anhydride, urea and cupric chloride are heated together at 210 DEG C.; (e) phthalic anhydride, 3 : 6-dichlorphthalic anhydride, urea and cupric chloride are heated together at 220--240 DEG C.; (f) o-cyanobenzoic acid, or the methyl ester thereof, or phthalic acid monoethyl ester is heated with urea and aluminium chloride or cupric chloride at 210--240 DEG C.; (g) phthalic diamide urea and cupric chloride, or cuprous chloride or copper bronze are heated together at 160--220 DEG C.; (h) phthalimide urea and cupric chloride are heated together at 160--220 DEG C., the reaction optionally being carried out in an autoclave; (i) diammonium phthalate, urea (or the product obtai