×

Low shear toner aggregation processes

  • US 5,650,255 A
  • Filed: 09/03/1996
  • Issued: 07/22/1997
  • Est. Priority Date: 09/03/1996
  • Status: Expired due to Term
First Claim
Patent Images

1. An in situ chemical process for the preparation of toner comprised of(i) the provision of a latex, which latex is comprised of polymeric resin particles, an ionic surfactant and a nonionic surfactant;

  • (ii) providing a pigment dispersion, which dispersion is comprised of a pigment, a dispersing liquid, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant, and optionally a charge control agent;

    (iii) mixing said pigment dispersion with said latex with a stirrer equipped with an impeller, stirring at speeds of from about 100 to about 900 rpm for a period of from about 10 minutes to about 150 minutes;

    (iv) heating the above resulting blend of latex and pigment dispersion to a temperature below about the glass transition temperature (Tg) of the resin to form electrostatically bound toner size aggregates;

    (v) adding further aqueous ionic surfactant or stabilizer in the range amount of from about 0.1 percent to 5 percent by weight of reactants to stabilize the above electrostatically bound toner size aggregates;

    (vi) heating said electrostatically bound toner sized aggregates above about the Tg of the resin to form toner size particles containing pigment, resin and optionally a charge control agent;

    (vii) optionally isolating said toner, optionally washing with water; and

    optionally(viii) drying said toner.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×