Toner aggregation and coalescence processes
US5403693A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1993 |
| Grant date | Apr 4, 1995 |
| Priority date | — |
| Expiry date | Jun 25, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S528/936
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for the preparation of toner compositions with controlled particle size comprising: PA1 (i) preparing a pigment dispersion in water, which dispersion is comprised of a pigment, an ionic surfactant in amounts of from about 0.5 to about 10 percent by weight of water, and an optional charge control agent; PA1 (ii) shearing the pigment dispersion with a latex mixture comprised of a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant, a nonionic surfactant, and resin particles, thereby causing a flocculation or heterocoagulation of the formed particles of pigment, resin, and charge control agent; PA1 (iii) stirring the resulting sheared viscous mixture of (ii) at from about 300 to about 1,000 revolutions per minute to form electrostatically bound substantially stable toner size aggregates with a narrow particle size distribution; PA1 (iv) reducing the stirring speed in (iii) to from about 100 to about 600 revolutions per minute, and subsequently adding further anionic or nonionic surfactant in the range of from about 0.1 to about 10 percent by weight of water to control, prevent, or minimize further growth or enlargement of the part…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.