Лако-красочные материалы — производство

The copper phthalocyanine derivatives are of major industrial importance as green dyes and organic pigments (halogenated products). The first phthalocya­nine dye was polysulfonated CuPc [25]. Since then, many patents describing var­ious phthalocyanine compounds have been registered [35]. Substituted phthalo­cyanine s are either accessible through synthesis from phthalocyanine derivatives (with the advantage of defined products) or by substitution of phthalocyanines [35, p. 255], [36, pp. 171, 192]. The latter method is favored in industry for eco­nomic reasons.

Synthesis. Usually a substituted phthalodinitrile or a substituted phthalic acid is used as starting material. A mixture of an unsubstituted and substituted starting material in approximate ratios, respectively, of 1:3, 2:2, or 3:1 can also be used. When reactivities of the two starting materials are approximately equal, Pc deriv­atives whose degree of substitution closely corresponds to the ratio of the starting materials are obtained. More often, however, a mixture of products results.

With the exception of tetrachlorophthalic acid, substituted phthalic acids, phthalimides, or phthalonitriles are industrially not readily accessible in pure form.

Substitution. Copper phthalocyanine is preferred as starting material. Very little is known about the position of substitution. With the exception of hexadeca — chloro CuPc, all commercial Pc substitution products, as well as the tetrasubsti — tuted derivatives synthesized from mono substituted phthalic acids, are mixtures of isomers. Despite the 16 hydrogen atoms that can be substituted, only two dif­ferent monosubstituted Pc’s are possible. The number of disubstituted isomers is higher. Mono — to heptasubstituted Pc derivatives have not yet been isolated in isomerically pure form. In addition, only a limited number of isomers are accessi­ble in pure form by synthesis. Only symmetrically substituted phthalic acids, phthalimides, or phthalodinitriles (3,6-di-, 4,5-di-, or 3,4,5,6-tetrasubstituted de­rivatives) yield pure isomers of octa — or hexadecasubstituted phthalocyanine de­rivatives. All other substituted phthalic acids give mixtures of isomers.