Toner for developing electrostatic images
US5773183A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1996 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Nov 15, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/08782
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A toner for developing an electrostatic image has a binder resin, a colorant and a charge control agent. The binder resin has a polyester resin having an acid value of from 15 to 40 and a hydroxyl value of 45 or less. The toner has, in its molecular weight distribution as measured by gel permeation chromatography, tetrahydrofuran-soluble matter having a weight average molecular weight Mw of 100,000 or more, having a ratio of weight average molecular weight Mw to number average molecular weight Mn, Mw/Mn, of not less than 35, containing from 70% to 94% of a low-molecular weight region component having a molecular weight of less than 150,000, containing from 1% to 10% of a medium-molecular weight region component having a molecular weight of from 150,000 to 500,000, and containing from 5% to 25% of a high-molecular weight region component having a molecular weight of more than 500,000. The high-molecular weight region component is more than the medium-molecular weight region component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.