US 5,418,108 A · Toner emulsion aggregation process

Abstract

A process for the preparation of toner compositions with controlled particle size and selected morphology comprising (i) preparing a pigment dispersion in water, which dispersion is comprised of pigment, ionic surfactant, and optionally a charge control agent; (ii) shearing the pigment dispersion with a polymeric latex comprised of resin of submicron size, 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, resin and charge control agent, and generating a uniform blend dispersion of solids of resin, pigment, and optional charge control agent in the water and surfactants; (iii) (a) continuously stirring and heating the above sheared blend to form electrostatically bound toner size aggregates; or (iii) (b) further shearing the above blend to form electrostatically bound well packed aggregates; or (iii) (c) continuously shearing the above blend, while heating to form aggregated flake-like particles; (iv) heating the above formed aggregated particles about above the Tg of the resin to provide coalesced particles of toner; and optionally (v) separating said toner particles from water and surfactants; and (vi) drying said toner particles.

Claims26

Dependent claims

A process for the preparation of toner compositions with controlled particle size and selected morphology consisting essentially of

(i) preparing a pigment dispersion in water, which dispersion is comprised of pigment, ionic surfactant, and optionally a charge control agent;
(ii) shearing the pigment dispersion with a polymeric latex comprised of resin of submicron size, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant and a nonionic surfactant thereby causing the formation of a uniform blend dispersion of resin particles, pigment particles, and optional charge control agent particles in water and surfactants, and wherein said resin particles, pigment particles, and optional charge control agent particles are flocculated or heterocoagulated together in said dispersion;
(iii) (a) continuously stirring and heating the above sheared blend to form electrostatically bound toner size aggregates;
or
(iii) (b) further shearing the above blend to form electrostatically bound well packed aggregates;
or
(iii) (c) continuously shearing the above blend, while heating to form aggregated flake particles;
(iv) heating the above formed aggregated particles above about the Tg of the resin to provide coalesced particles of toner;
and optionally
(v) separating said toner particles from water and surfactants;
and
(vi) drying said toner particles.

9 more elements

A process for the preparation of toner comprising

(i) preparing a pigment dispersion, which dispersion is comprised of pigment and an ionic surfactant;
(ii) shearing the pigment dispersion with a polymeric latex comprised of resin with a size of from about 0.05 to about 1 micron in average volume diameter, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant, and a nonionic surfactant thereby causing the formation of a uniform dispersion of pigment particles and resin in said surfactants, and wherein pigment particles and resin contained in said dispersion and wherein said pigment particles and resin are flocculated or heterocoagulated together in said dispersion;
(iii) (a) stirring and heating the uniform dispersion of pigment particles and resin particles (ii) to form electrostatically bound toner size aggregates;
or
(iii) (b) shearing the above uniform dispersion of pigment particles and resin particles (ii) further from 2 to about 24 hours to form electrostatically bound densely packed aggregates;
or
(iii) (c) shearing the above uniform dispersion of pigment particles and resin particles (ii), while heating, to form electrostatically bound toner size aggregates in the form of flakes;
and
(iv) heating the statically bound aggregated particles above about the glass transition temperature of the resin to provide coalesced particles of toner.

6 more elements

Dependencies are inferred from the claim text.

Toner emulsion aggregation process

Life of this patent

Toner emulsion aggregation process

Life of this patent

Abstract

Claims26