Processes for the preparation of titanyl phthalocyanines

A process for the preparation of titanyl phthalocyanine Type I with Bragg angles (2.THETA.) at 6.8, 9.2, 10.4, 12.3, 13.1, 15.0, 15.6, 16.0, 20.6, 23.2, 25.3, 26.2, 26.5, and 27.1.degree. (.+-.0.2.degree.) consisting essentially of the reaction of a titanium alkoxide with diiminoisoindoline in a solvent of chloronaphthalene;

• dissolving the obtained precursor Type I titanyl phthalocyanine in a solvent comprised of trifluoroacetic acid and methylene chloride;
• reprecipitating the dissolved pigment by addition to a methanol and water;
• subsequently washing the Type X titanyl phthalocyanine obtained with first methanol, then water;
• converting the Type X to Type IV by slurrying the Type X in monochlorobenzene;
• forming a slurry of the formed Type IV in methylene chloride;
• and isolating the said Type I titanyl phthalocyanine.

A process for the preparation of more perfect crystalline form of the Type I polymorph of titanyl phthalocyanine consisting essentially of (1) dissolving the precursor pigment, Type I titanyl phthalocyanine, in a mixture of trifluoroacetic acid and methylene chloride with from 5 percent of acid to about 25 percent of acid and 95 parts to 75 parts of methylene chloride, and wherein the amount of precursor pigment is from about 5 parts to about 25 parts, stirring the resulting mixture for a period of time, for example from about 5 minutes to about 24 hours at a temperature of from about 0.degree. to about 50.degree. C.;

• (2) pouring or adding the resultant solution into a rapidly stirred precipitant solvent in a ratio of from about 1 part of the pigment solution of (1) to 2 parts of precipitant solvent to about 1 part of the pigment solution to about 50 parts of solvent at a temperature of from about 0.degree. to about 100.degree. C. over a period of from 1 minute to about 60 minutes;
• (3) stirring the resulting dispersion containing Type X titanyl phthalocyanine at a temperature of from 0.degree. to about 100.degree. C. for a period of from about 5 minutes to about 24 hours;
• (4) subsequently separating the titanyl phthalocyanine Type X;
• (5) redispersing the resulting Type X in a solvent of methanol, acetone, water, or mixtures thereof from about 20 parts to about 100 parts of solvent to 1 part of Type X for a period of from about 5 minutes to 24 hours at a temperature of from 0.degree. C. to about 100.degree. C.;
• (6) isolating titanyl phthalocyanine Type X;
• (7) contacting the Type X obtained with chlorobenzene to form Type IV titanyl phthalocyanine;
• and (8) subsequently slurrying the Type IV obtained with dichloromethane or methylene chloride.