Method of making liquid developer for electrostatic photography
US4842975A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1987 |
| Grant date | Jun 27, 1989 |
| Priority date | — |
| Expiry date | Dec 22, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/131
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A liquid developer for electrostatic photography is described, comprising at least a resin dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 ohms.cm and a dielectric constant of not more than 3.5. The resin is a copolymer resin obtained by polymerizing a solution containing at least one monofunctional monomer (A) which is soluble in the non-aqueous solvent but becomes insoluble upon polymerization and at least one specified monomer (B) containing an aliphatic group having at least 8 carbon atoms and being copolymerizable with the monomer (A), in the presense of a resin not containing a grafting group polymerizable with the monomers and being soluble in the non-aqueous solvent. The resin may be colored by dissolving at least one organic dye in the dispersion of the resin and heating the mixture. The developer has excellent dispersion stability, redispersibility, fixability and preservability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.