Toner aggregation processes
US5405728A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1993 |
| Grant date | Apr 11, 1995 |
| Priority date | — |
| Expiry date | Jun 25, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/0812
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for the preparation of toner compositions comprising PA1 (i) preparing a pigment dispersion in water, which dispersion is comprised of a pigment, an ionic surfactant and optionally a charge control agent; PA1 (ii) shearing the pigment dispersion with a latex containing a controlled solid contents of from about 50 weight percent to about 20 percent of polymer or resin, counterionic surfactant and nonionic surfactant in water, counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant thereby causing a flocculation or heterocoagulation of the formed particles of pigment, resin and charge control agent to form a dispersion of solids of from about 30 weight percent to 2 percent comprised of resin, pigment and optionally charge control agent in the mixture of nonionic, anionic and cationic surfactants; PA1 (iii) heating the above sheared blend at a temperature of from about 5.degree. to about 25.degree. C. about below the glass transition temperature (Tg) of the resin while continuously stirring to form toner sized aggregates with a narrow size dispersity; and PA1 (iv) heating the electrostatically bound aggregated particles at a temperatu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.