Photoconductive member and perylene processes
AssigneeXerox Corporation
InventorsJames M. Duff, Ah-Mee Hor, C. Geoffrey Allen
Life of this patent
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Abstract
A process for the preparation of perylene tetracarboxylic acid dianhydride comprising the dissolution thereof in an aqueous alkaline solution, or optionally an amine solution; converting the salt formed to the corresponding tetracarboxylic acid of said perylene tetracarboxylic dianhydride; heating the resulting tetracarboxylic acid; washing the dianhydride formed until the filtrate pH indicates substantially complete removal of the acid; and drying said dianhydride.
Claims19
A process for the purification of 3,4,9,10-perylene tetra carboxylic acid dianhydride comprising the dissolution of said anhydride in an amine solution at from about 25.degree. C. to about 90.degree. C.;
- filtration of the resultant solution through a fine porosity filter with a pore size of from about 0.1 to about 1 micron, primarily to remove colloidal black contaminants present in a amount of from about 0.5 to about 1.5 weight percent of the dianhydride;
- converting the salt formed to 3,4,9,10-perylene tetracarboxylic acid by acidifying the solution with hydrochloric acid, and thereafter heating the resulting suspension at from about 75.degree. C. to about 100.degree. C. to form 3,4,9,10-perylene tetracarboxylic acid dianhydride;
- filtering and washing the anhydride formed with water until the filtrate pH is from about 6 to about 7;
- and freeze drying the resulting wet filter cake to provide 3,4,9,10-perylene tetracarboxylic acid dianhydride.
A process for the purification of 3,4,9,10-perylene tetracarboxylic acid dianhydride consisting of the dissolution of said acid dianhydride in an aqueous alkali metal hydroxide solution at from about 25.degree. C. to about 90.degree. C.;
- filtration of the resultant solution through a fine porosity filter with a pore size of from about 0.1 to about 1 micron, primarily to remove colloidal black contaminants present in an amount of from about 0.5 to about 1.5 weight percent of the dianhydride;
- converting the alkali metal salt formed to 3,4,9,10-perylene tetracarboxylic acid by acidifying the solution with hydrochloric acid, and thereafter heating the resulting suspension at from about 75.degree. C. to about 100.degree. C. to form 3,4,9,10-perylene tetracarboxylic acid dianhydride;
- filtering and washing the anhydride formed with water until the filtrate pH is from about 6 to about 7, and which pH indicates complete removal of the acid;
- and freeze drying the resulting wet filter cake to provide substantially pure 3,4,9,10-perylene tetracarboxylic acid dianhydride.
A process for the purification of 3,4,9,10-perylene tetracarboxylic acid dianhydride comprising the dissolution of said acid dianhydride in an aqueous alkali metal hydroxide solution at from about 25.degree. C. to about 90.degree. C.;
- filtration of the resultant solution through a fine porosity filter with a pore size of from about 0.1 to about 1 micron, primarily to remove colloidal black contaminants present in an amount of from about 0.5 to about 1.5 weight percent of the dianhydride;
- converting the alkali metal salt formed to 3,4,9,10-perylene tetracarboxylic acid by acidifying the solution with hydrochloric acid, and thereafter heating the resulting suspension at from about 75.degree. C. to about 100.degree. C. to form 3,4,9,10-perylene tetracarboxylic acid dianhydride;
- filtering and washing the anhydride formed with water until the filtrate pH is from about 6 to about 7, and which pH indicates complete removal of the acid;
- and freeze drying the resulting wet filter cake to provide substantially pure 3,4,9,10-perylene tetracarboxylic acid dianhydride.
A photoconductive imaging member comprised of a photogenerating layer comprised of a perylene bisamide obtained from a perylene tetracarboxylic acid dianhydride, and which dianhydride is prepared by the dissolution of said acid dianhydride in an aqueous alkali metal hydroxide solution;
- filtration of the resultant solution through a fine porosity filter with a pore size of from about 0.1 to about 1 micron;
- converting the alkali metal salt formed to 3,4,9,10-perylene tetracarboxylic acid, and thereafter heating the resulting suspension to form 3,4,9,10-perylene tetracarboxylic acid dianhydride.
Dependencies are inferred from the claim text.