Verfahren zur Herstellung halogenmethylsubstituierter Phthalocyaninsulfonsäureverbindungen

Sulphonated halomethyl-phthalocyanines are prepared by treating metal-free or metal-containing (e.g. Cu, Co, Ni or Fe) phthalocyanines with a halomethylating agent R-O-CH2X in the presence of chlorosulphonic acid or 5-65% oleum for a time required to provide a product containing at least one halomethyl and at least one sulphonic acid substituent where R is 1-4 C alkyl, -CH2X or -CH2-R1, wherein R1 is 1-4 C alkoxy or -OCH2X and X is halogen, e.g. F, Cl, Br or I. By selecting the acid or strength of the oleum phthalocyanines containing 1-3 substituents of each kind can be obtained. The preferred halomethylating agents are bischloro- and bisbromo-methyl ether. Examples are given.