Toner aggregation processes
US5366841A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1993 |
| Grant date | Nov 22, 1994 |
| Priority date | — |
| Expiry date | Sep 30, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/0815
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for the preparation of toner compositions comprising: PA0 (i) preparing a pigment dispersion in water, which dispersion is comprised of a pigment, an ionic surfactant and optionally a charge control agent; PA0 (ii) shearing the pigment dispersion with a latex blend comprised of resin particles, 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 to form a uniform dispersion of solids in the water, and surfactant; PA0 (iii) heating the above sheared blend at a critical temperature region about equal to or above the glass transition temperature (Tg) of the resin, while continuously stirring, to form electrostatically bounded toner size aggregates with a narrow particle size distribution and wherein said critical temperature is from about 0.degree. C. to about 10.degree. C. above the resin Tg, and wherein the resin Tg is from about 30.degree. C. to about 65.degree. C. and preferably in the range of from about 45.degree. C. to about 65.degree. C.; PA0 (iv) heating the statically bound ag…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.