Toner aggregation processes
US5501935A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1995 |
| Grant date | Mar 26, 1996 |
| Priority date | — |
| Expiry date | Jan 17, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/0975
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for the preparation of toner compositions consisting essentially of (i) preparing a pigment dispersion, which dispersion is comprised of a pigment, an ionic surfactant, and optionally a charge control agent; (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; (iii) heating the above sheared blend below about the glass transition temperature (Tg) of the resin to form electrostatically bound toner size aggregates with a narrow particle size distribution; (iv) subsequently adding further anionic or nonionic surfactant solution to minimize further growth in the coalescence (v); and (v) heating said bound aggregates above about the Tg of the resin and wherein said heating is from a temperature of about 103.degree. to about 120.degree. C., and wherein said toner compositions are spherical in shape.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.