Toner processes
US5650256A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1996 |
| Grant date | Jul 22, 1997 |
| Priority date | — |
| Expiry date | Oct 2, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/0815
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for the preparation of toner comprising: PA0 (i) preparing a pigment dispersion, which dispersion is comprised of a pigment, and an ionic surfactant; PA0 (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; PA0 (iii) heating the above sheared blend below about the glass transition temperature (Tg) of the resin to form electrostatically bound toner size aggregates; PA0 (iv) adding anionic surfactant to stabilize the aggregates obtained in (iii); PA0 (v) coalescing said aggregates by heating said bound aggregates above about the Tg of the resin; PA0 (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 PA0 (vii) optionally drying the toner obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.