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US 5,614,342 : Methods for preparing cocrystals of titanyl fluorophthalocyanines and unsubstituted titanyl phthalocyanine, electrophotographic elements, and titanyl phthalocyanine compositions



Molaire, Michel F. (Rochester, NY)
Kaeding, Jeanne E. (Rochester, NY) 


Eastman Kodak Company (Rochester, NY) 
Cocrystallized titanyl phthalocyanine-titanyl fluorophthalocyanine compositions, preparation methods, and electrophotographic elements utilizing the compositions. The method has the steps of: admixing crude titanyl phthalocyanine and crude titanyl fluorophthalocyanine to provide a pigment mixture; increasing the amorphousness of the pigment mixture as determined by X-ray crystallography using X-radiation characteristic of Cu Kα at a wavelength of 1.541 Å of the Bragg angle 2θ to provide an amorphous pigment mixture; contacting the amorphous pigment mixture with organic solvent having a gammac hydrogen bonding parameter of less than 8.0; and prior to the contacting, substantially excluding the amorphous pigment mixture from contact with organic solvent having a gammac hydrogen bonding parameter greater than 9.0.