Toner for developing electrostatic image
US5750303A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1997 |
| Grant date | May 12, 1998 |
| Priority date | — |
| Expiry date | Apr 30, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/09328
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A toner for developing an electrostatic image includes toner particles constituted by at least a binder resin, a colorant, a polar resin and a release agent. The polar resin has at least one terminal group which has been modified by a polycarbonate acid having at least three carboxyl groups. The polar resin has an acid value of 3-35 mgKOH/g. The polar resin may preferably be a polyester resin having an acid value of 4-35 mgKOH/g and having a number-average molecular weight (Mn) of 3,000-15,000, a weight-average molecular weight (Mw) of 6,000-50,000, and an Mw/Mn of 1.2-3.0 based on GPC. The polar resin (preferably polyester resin) having modified by a polycarboxylic acid having at least three carboxylic groups to provide a specific acid value is effective in improving resultant toner performances, such as low-temperature fixability, anti-offset characteristic at high temperatures, triboelectric chargeability, and flowability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.