Processes for the preparation of bisazo photogenerating pigments using an annealing step
AssigneeXerox Corporation
InventorsKock-Yee Law, Ihor W. Tarnawskyj
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Abstract
A process for the preparation of photogenerating pigments which comprises the reaction of a diaminofluorenone with an alkali nitrite, an acid, and a tetrafluoroborate; thereafter reacting the resulting product with an anilide coupler; and subsequently annealing the product obtained.
Claims26
A process for the preparation of bisazo photogenerating pigments which comprises the reaction of a diaminofluorenone with potassium nitrite or sodium nitrite, an acid solution, and a tetrafluoroborate;
- thereafter reacting the resulting tetrazonium salt product with an anilide coupler in a dimethyl formamide solvent containing an aqueous sodium acetate or sodium nitrate solution;
- recovering and subsequently drying the product by heating;
- thereafter cooling;
- and subsequently annealing the product obtained, which annealing is accomplished by heating in a vacuum said product to remove the dimethyl formamide and water, and which heating is accomplished at a temperature of from between about 95.degree. to about 195.degree. C.
A process for the preparation of bisazo photogenerating pigments which consists essentially of the reaction of diaminofluorenone with sodium nitrite, hydrochloric acid, and fluoroboric acid;
- thereafter reacting the resulting tetrazonium salt produce with an anilide coupler in a dimethyl formamide solvent containing an aqueous sodium acetate solution;
- recovering and subsequently drying the product by heating;
- thereafter cooling said product;
- and subsequently annealing the product obtained, which annealing is accomplished by heating said product in a vacuum at a temperature of from between about 95 to about 195.degree. C. to remove the dimethyl formamide solvent and water.
A process for the preparation of bisazo photogenerating pigments which consists essentially of the reaction of diaminofluorenone with sodium nitrite, hydrochloric acid, and fluoroboric acid;
- thereafter isolating and reacting the resulting tetrazonium salt product with an anilide coupler in a dimethyl formamide solvent containing an aqueous sodium acetate solution;
- recovering and subsequently drying the product by heating at a temperature of from about 70.degree. to about 80.degree. C.;
- thereafter cooling said product;
- and subsequently annealing the product obtained by the heating thereof in a vacuum at a temperature of from about 95.degree. to about 195.degree. C. to remove said dimethyl formamide and water.
Dependencies are inferred from the claim text.