Processes for the preparation of hydroxygallium phthalocyanine

A process for the preparation of Type V hydroxygallium phthalocyanine which comprises the formation of an alkoxy-bridged gallium phthalocyanine dimer by the reaction of a gallium alkoxide, which has been formed from reacting gallium trichloride in a solvent, with a sodium alkoxide, and selecting the resulting mixture of gallium alkoxide and sodium chloride byproduct for the reaction with ortho-phthalodinitrile or 1,3-diiminoisoindoline and a diol;

• hydrolyzing the resulting alkoxy-bridged gallium phthalocyanine dimer to hydroxygallium phthalocyanine;
• and subsequently converting the product obtained to Type V hydroxygallium phthalocyanine by a solvent treatment;
• and wherein said diol is selected from the group consisting of ethylene glycol, 1,3-propanediol,2-methyl-1,3-propanediol,2,2-dimethyl-1,3-propanediol 1,3butanediol,2,3-butanediol,1,4-butanediol,1,4-cyclohexanediol and 1,6-hexanediol.

A process for the preparation of an alkoxy-bridged gallium phthalocyanine dimer by the reaction of gallium trichloride with an alkali metal alkoxide in a solvent;

• thereafter removing the alkali metal halide byproduct formed;
• and reacting the obtained gallium alkoxide solution with ortho-phthalodinitrile or 1,3-diiminoisoindoline, and a diol.