Toner emulsion aggregation processes
First Claim
1. A process for the preparation of toner compositions with controlled particle size consisting essentially of:
- (i) preparing a pigment dispersion in water, which dispersion is comprised of pigment, an ionic surfactant, and an optional charge control agent;
(ii) shearing at high speeds the pigment dispersion with a polymeric latex comprised of resin, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant and a nonionic surfactant thereby forming a uniform homogeneous blend dispersion comprised of resin, pigment, and optional charge agent;
(iii) heating the above sheared homogeneous blend below about the glass transition temperature (Tg) of the resin while continuously stirring to form electrostatically bounded toner size aggregates with a narrow particle size distribution;
(iv) heating the statically bound aggregated particles above about the Tg of the resin particles to provide coalesced toner comprised of resin, pigment, and optional charge control agent, and subsequently optionally accomplishing (v) and (vi);
(v) separating said toner; and
(vi) drying said toner.
4 Assignments
0 Petitions
Accused Products
Abstract
A process for the preparation of toner compositions with controlled particle size comprising:
(i) preparing a pigment dispersion in water, which dispersion is comprised of pigment, an ionic surfactant, and an optional charge control agent;
(ii) shearing at high speeds the pigment dispersion with a polymeric latex comprised of resin, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant and a nonionic surfactant thereby forming a uniform homogeneous blend dispersion comprised of resin, pigment, and optional charge agent;
(iii) heating the above sheared homogeneous blend below about the glass transition temperature (Tg) of the resin while continuously stirring to form electrostatically bounded toner size aggregates with a narrow particle size distribution;
(iv) heating the statically bound aggregated particles above about the Tg of the resin particles to provide coalesced toner comprised of resin, pigment, and optional charge control agent, and subsequently optionally accomplishing (v) and (vi);
(v) separating said toner; and
(vi) drying said toner.
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Citations
40 Claims
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1. A process for the preparation of toner compositions with controlled particle size consisting essentially of:
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(i) preparing a pigment dispersion in water, which dispersion is comprised of pigment, an ionic surfactant, and an optional charge control agent; (ii) shearing at high speeds the pigment dispersion with a polymeric latex comprised of resin, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant and a nonionic surfactant thereby forming a uniform homogeneous blend dispersion comprised of resin, pigment, and optional charge agent; (iii) heating the above sheared homogeneous blend below about the glass transition temperature (Tg) of the resin while continuously stirring to form electrostatically bounded toner size aggregates with a narrow particle size distribution; (iv) heating the statically bound aggregated particles above about the Tg of the resin particles to provide coalesced toner comprised of resin, pigment, and optional charge control agent, and subsequently optionally accomplishing (v) and (vi); (v) separating said toner; and (vi) drying said toner. - 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, 25, 26, 27, 28, 29, 30, 31, 32, 33, 38, 39, 40)
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34. A process for the preparation of toner consisting essentially of:
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(i) preparing a pigment dispersion in water, which dispersion is comprised of a pigment and an ionic surfactant; (ii) shearing at high speeds of from about 3,000 to about 15,000 revolutions per minute the pigment dispersion with a polymeric latex comprised of resin of submicron size in the range of from about 0.5 to about 1 micron, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant and a nonionic surfactant thereby resulting in a uniform homogeneous blend with particles of less than or equal to from about 0.5 to about 1 micron in average volume diameter, and which particles are comprised of resin and pigment; (iii) heating the above sheared homogeneous blend below, from about 5°
C. to about 25°
C., the glass transition temperature (Tg) of the resin and wherein the Tg of the resin is in range of from about 40°
C. to about 85°
C. and preferably in the range of from about 50°
C. to about 75°
C., while continuously stirring at from about 200 to about 1,000 revolutions per minute and preferably from about 300 to about 700 revolutions per minute to form electrostatically bound toner size aggregates with a narrow particle size distribution; and(iv) heating the statically bound aggregated particles at from about 5°
C. to about 50°
C. above the resin Tg to provide coalesced particles of a toner composition comprised of polymeric resin, pigment and, optionally a charge control agent. - View Dependent Claims (35)
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36. A process for the preparation of toner consisting essentially of:
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(i) preparing a pigment dispersion, which dispersion is comprised of pigment and ionic surfactant; (ii) shearing at high speeds of from about 3,000 to about 15,000 revolutions per minute 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 the formed particles of pigment and resin to form a uniform viscous dispersion of solids of resin and pigment, from about 5 to about 25 weight percent, in water, and anionic/nonionic/cationic surfactant system; (iii) heating the above sheared blend at a temperature of from about 5°
to about 25°
C. below the Tg of the resin particles while continuously stirring to form electrostatically bound relatively stable, for Coulter Counter measurements, toner size aggregates with a narrow particle size distribution;(iv) heating the statically bound aggregated particles at a temperature of from about 5°
to about 50°
C. above the Tg of the resin to provide a mechanically stable toner composition comprised of resin, and pigment; and
optionally(v) separating said toner; and (vi) drying said toner.
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37. A process for the preparation of toner comprising:
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(i) preparing a pigment dispersion, which dispersion is comprised of a pigment and an ionic surfactant; (ii) shearing at high speeds the pigment dispersion with a latex blend comprised of resin, a nonionic surfactant, and a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant thereby forming a uniform homogeneous dispersion; (iii) heating the above sheared blend below about, equal to, or slightly higher than the glass transition temperature (Tg) of the resin to form aggregates with a narrow particle size distribution; and (iv) heating the statically bound aggregated particles above, or equal to the Tg of the resin.
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Specification