US 7,033,716 : Two-stage milling process for preparing cocrystals of titanyl fluorophthalocyanine and titanyl phthalocyanine, and electrophotographic element containing same

 

Inventors:
Molaire, Michel F. (Rochester, NY, US)
Kaeding, Jeanne E. (Rochester, NY, US)
Zubil, Theodore (Rochester, NY, US) 
Assignee:
Eastman Kodak Company (Rochester, NY, US) 

An amorphous mixture consisting essentially of TiOFPc and TiOPc and containing more than 75 weight percent of substantially chlorine-free TiOPc is produced by forming a mixture of crude crystalline TiOFPc and crude crystalline, substantially chlorine-free TiOPc that contains less than 80 weight percent TiOPc, treating the mixture under conditions effective to form a substantially amorphous mixture of TiOFPc and TiOPc containing less than 75 weight percent TiOPc, which is then treated with water, and dried. A further amount of crude crystalline, substantially chlorine-free TiOPc sufficient to form a new mixture containing more than 75 weight percent of substantially chlorine-free TiOPc is added, and the new mixture is converted to a substantially amorphous mixture of TiOFPc and TiOPc. A nanoparticulate cocrystalline composition is obtained by forming a slurry in an organic solvent of the dried substantially amorphous mixture, and wet milling the slurry to form the cocrystalline composition.

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