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Toner processes

  • US 5,650,256 A
  • Filed: 10/02/1996
  • Issued: 07/22/1997
  • Est. Priority Date: 10/02/1996
  • Status: Expired due to Term
First Claim
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1. A process for the preparation of toner comprising:

  • (i) preparing a pigment dispersion, which dispersion is comprised of a pigment, and an ionic surfactant;

    (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, and wherein said resin contains an acid functionality;

    (iii) heating the above sheared blend below about the glass transition temperature (Tg) of the resin to form electrostatically bound toner size aggregates;

    (iv) adding anionic surfactant to stabilize the aggregates obtained in (iii);

    (v) coalescing said aggregates by heating said bound aggregates above about the Tg of the resin;

    (vi) reacting said resin of (v) with acid functionality with a base to form an acrylic acid salt, and which salt is ion exchanged in water with a base or a salt, optionally in the presence of metal oxide particles, to control the toner triboelectrical charge, which toner is comprised of resin and pigment; and

    (vii) optionally drying the toner obtained.

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