Fluorescent toner processes

A process for the preparation of fluorescent toner compositions consisting essentially of

• (i) preparing a mixed pigment dispersion, which dispersion consists essentially of a fluorescent pigment and a colored pigment, an ionic surfactant, and optionally a charge control agent;
• (ii) shearing said pigment dispersion with a latex or emulsion blend comprised of resin, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant and a nonionic surfactant;
• (iii) heating the above sheared blend below the glass transition temperature (Tg) of the resin to form electrostatically bound toner size aggregates;
• and
• (iv) heating said bound aggregates above the Tg of the resin and wherein the fluorescent pigment is excitable by ultraviolet light in the frequency range of from about 254 to about 366 nanometers, and fluoresces in the visible spectrum of from about 400 to about 700 nanometers, and wherein the fluorescent pigment is selected from the group consisting of 4,4'-bis(styryl)biphenyl, 2-(4-phenylstilben-4-yl)-6-t-butylbenzoxazole, .beta.-methylumbelliferone, 4-methyl-7-dimethylaminocoumarin, 4-methyl-7-aminocoumarin, N-methyl-4-methoxy-1,8-naphthalimide, 9,10-bis(phenethynyl)anthracene, and 5,12-bis(phenethynyl)naphthacene, and the colored pigment is selected from the group consisting of magnetite, cyan, magenta, and yellow pigments.

A process for the preparation of fluorescent toner compositions with controlled particle size consisting of

• (i) preparing a pigment dispersion mixture in water, which dispersion consists of a fluorescent pigment and a visible pigment, and an ionic surfactant;
• (ii) shearing the pigment dispersion with a latex blend comprised of resin, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant and a nonionic surfactant thereby causing a flocculation or heterocoagulation of resin and pigment mixture of a said fluorescent pigment and a said visible pigment to form a uniform dispersion of solids in the water and surfactant;
• (iii) heating the above sheared blend at a temperature of from about 5.degree. to about 20.degree. C. below the Tg of the resin to form electrostatically bound toner size aggregates;
• (iv) heating the electrostatically bound toner sized aggregates at a temperature of from about 5.degree. to about 50.degree. C. above the Tg of the resin to provide a mechanically stable toner composition comprised of resin, fluorescent pigment and visible pigment;
• and optionally
• (v) separating said toner compositions;
• and
• (vi) drying said toner compositions, and wherein the fluorescent pigment is excitable by ultraviolet light in the frequency range of from about 254 to about 366 nanometers and fluoresces in the visible spectrum of from about 400 to about 700 nanometers, and wherein the fluorescent pigment is selected from the group consisting of 4,4'-bis(styryl)biphenyl, 2-(4-phenylstilben-4-yl)-6-t-butylbenzoxazole, .beta.-methylumbelliferone, 4-methyl-7-dimethylaminocoumarin, 4-methyl-7-aminocoumarin, N-methyl-4-methoxy-1,8-naphthalimide, 9,10-bis(phenethynyl)anthracene, and 5,12-bis(phenethynyl)naphthacene, and the visible pigment is selected from the group consisting of magnetite, cyan, magenta, and yellow pigments.

A process for the preparation of fluorescent toner composition consisting essentially of

• (i) preparing a pigment dispersion mixture in water, which dispersion consists essentially of a fluorescent pigment and a nonfluorescent colored pigment charge control agent, and an ionic surfactant;
• (ii) shearing the pigment dispersion with a latex blend comprised of resin, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant and a nonionic surfactant thereby causing a flocculation or heterocoagulation of said resin, and said fluorescent pigment and said nonfluorescent pigment, and charge control agent to form a uniform dispersion of solids in the water and surfactant;
• (iii) heating the above sheared blend below or equal to the glass transition temperature (Tg) of the resin to form electrostatically bound toner size aggregates;
• (iv) heating the electrostatically bound toner size aggregates above or equal to the Tg of the resin to provide a toner composition comprised of resin;
• followed by optionally
• (v) separating said toner composition from said water by filtration;
• and
• (vi) drying said toner composition, and wherein the fluorescent pigment is excitable by ultraviolet light in the frequency range of 254 to 366 nanometers, and fluoresces in the visible spectrum of 400 to 700 nanometers, and wherein the fluorescent pigment is selected from the group consisting of 4,4'-bis(styryl)biphenyl, 2-(4-phenylstilben-4-yl)-6-t-butylbenzoxazole, .beta.-methylumbelliferone, 4-methyl-7-dimethylaminocoumarin, 4-methyl-7-aminocoumarin, N-methyl-4-methoxy-1,8-naphthalimide, 9,10-bis(phenethynyl)anthracene, and 5,12-bis(phenethynyl)naphthacene, and the colored nonfluorescent pigment is selected from the group consisting of magnetite, cyan, magenta, and yellow pigments.