Toner aggregation processes
First Claim
1. A process for the preparation of toner compositions comprising(i) preparing a pigment dispersion in water, which dispersion is comprised of pigment, a counterionic surfactant with a charge polarity of opposite sign to the anionic surfactant of (ii) and optionally a charge control agent;
- (ii) shearing the pigment dispersion with a latex comprised of resin, anionic surfactant, nonionic surfactant, and water; and
wherein the latex solids content, which solids are comprised of resin, is from about 50 weight percent to about 20 weight percent thereby causing a flocculation or heterocoagulation of the formed particles of pigment, resin and optional charge control agent;
diluting with water to form a dispersion of total solids of from about 30 weight percent to 1 weight percent, which total solids are comprised of resin, pigment and optional charge control agent contained in a mixture of said nonionic, anionic and cationic surfactants;
(iii) heating the above sheared blend at a temperature of from about 5°
to about 25°
C. below about the glass transition temperature (Tg) of the resin while continuously stirring to form toner sized electrostatically bound aggregates with a narrow size dispersity; and
(iv) heating the electrostatically bound aggregates at a temperature of from about 5°
to about 50°
C. above about the Tg of the resin to provide a toner composition comprised of resin, pigment and optionally a charge control agent.
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Accused Products
Abstract
A process for the preparation of toner compositions comprising
(i) preparing a pigment dispersion in water, which dispersion is comprised of a pigment, an ionic surfactant and optionally a charge control agent;
(ii) shearing the pigment dispersion with a latex containing a controlled solid contents of from about 50 weight percent to about 20 percent of polymer or resin, counterionic surfactant and nonionic surfactant in water, counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant thereby causing a flocculation or heterocoagulation of the formed particles of pigment, resin and charge control agent to form a dispersion of solids of from about 30 weight percent to 2 percent comprised of resin, pigment and optionally charge control agent in the mixture of nonionic, anionic and cationic surfactants;
(iii) heating the above sheared blend at a temperature of from about 5° to about 25° C. about below the glass transition temperature (Tg) of the resin while continuously stirring to form toner sized aggregates with a narrow size dispersity; and
(iv) heating the electrostatically bound aggregated particles at a temperature of from about 5° to about 50° C. about above the (Tg) of the resin to provide a toner composition comprised of resin, pigment and optionally a charge control agent.
348 Citations
30 Claims
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1. A process for the preparation of toner compositions comprising
(i) preparing a pigment dispersion in water, which dispersion is comprised of pigment, a counterionic surfactant with a charge polarity of opposite sign to the anionic surfactant of (ii) and optionally a charge control agent; -
(ii) shearing the pigment dispersion with a latex comprised of resin, anionic surfactant, nonionic surfactant, and water; and
wherein the latex solids content, which solids are comprised of resin, is from about 50 weight percent to about 20 weight percent thereby causing a flocculation or heterocoagulation of the formed particles of pigment, resin and optional charge control agent;
diluting with water to form a dispersion of total solids of from about 30 weight percent to 1 weight percent, which total solids are comprised of resin, pigment and optional charge control agent contained in a mixture of said nonionic, anionic and cationic surfactants;(iii) heating the above sheared blend at a temperature of from about 5°
to about 25°
C. below about the glass transition temperature (Tg) of the resin while continuously stirring to form toner sized electrostatically bound aggregates with a narrow size dispersity; and(iv) heating the electrostatically bound aggregates at a temperature of from about 5°
to about 50°
C. above about the Tg of the resin to provide a toner composition comprised of resin, pigment and optionally a charge control agent. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A process for the preparation of toner with controlled particle size comprising
(i) preparing a pigment dispersion in water, which dispersion is comprised of a pigment and counterionic surfactant; -
(ii) shearing the pigment dispersion with a latex, which latex contains a resin content of from about 50 percent by weight to about 20 percent by weight, thereby causing a flocculation or heterocoagulation of the formed particles of pigment and resin;
diluting with water to form a uniform dispersion of total solids from about 30 percent by weight to about 2 percent by weight;(iii) heating the above sheared blend at a temperature of from about 5°
C. to about 25°
C. about below the glass transition temperature (Tg) of the resin while continuously stirring to form toner sized electrostatically bound aggregates with a narrow size dispersity;(iv) heating the electrostatically bound aggregates at a temperature of from about 5°
C. to about 50°
C. about above the Tg of the resin to provide said toner composition comprised of polymeric resin, pigment and optionally a charge control agent; and
optionally(v) separating said toner particles from the water; and (vi) drying said toner particles; wherein said latex comprises resin, anionic surfactant, nonionic surfactant and water, and said total solids components are comprised of resin and pigment. - View Dependent Claims (26, 27, 28, 29)
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30. A process for the preparation of toner compositions consisting essentially of
(i) preparing a pigment dispersion in water, which dispersion is comprised of pigment, a counterionic surfactant with a charge polarity of opposite sign to the anionic surfactant of (ii) and optionally a charge control agent; -
(ii) shearing the pigment dispersion with a latex comprised of resin, anionic surfactant, nonionic surfactant, and water; and
wherein the latex solids content, which solids are comprised of resin, is from about 50 weight percent to about 20 weight percent thereby causing a flocculation or heterocoagulation of the formed particles of pigment, resin and optional charge control agent;
diluting with water to form a dispersion of total solids of from about 30 weight percent to 1 weight percent, which total solids are comprised of resin, pigment and optional charge control agent contained in a mixture of said nonionic, anionic and cationic surfactants;(iii) heating the above sheared blend at a temperature of from about 5°
to about 25°
C. below about the glass transition temperature (Tg) of the resin while continuously stirring to form toner sized electrostatically bound aggregates with a narrow size dispersity; and(iv) heating the electrostatically bound aggregates at a temperature of from about 5°
to about 50°
C. above about the Tg of the resin to provide a toner composition comprised of resin, pigment and optionally a charge control agent.
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Specification