Acid-containing A-B block copolymers as grinding aids in liquid electrostatic developer preparation
US5053306A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1990 |
| Grant date | Oct 1, 1991 |
| Priority date | — |
| Expiry date | Mar 7, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/12
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Process for the preparation of toner particles for electrostatic liquid developers comprising PA1 (A) dispersing at ambient temperature colorant, A-B diblock polymer grinding aid as described, and a carrier liquid; PA1 (B) adding to the dispersion a thermoplastic resin and dispersing at an elevated temperature to plasticize and liquify the resin; PA1 (C) cooling the dispersion as described while grinding with particulate media, PA1 (D) separating the dispersion of toner particles average by area particle size less than 10 .mu.m, from the particulate media, and PA1 (E) adding during or subsequent to step (B) at least one ionic or zwitterionic charge director compound. Steps (A) and (B) can be combined by adding the thermoplastic resin to the other ingredients and dispersing at an elevated temperature. The liquid developer can be prepared omore quickly by the process than by other known processes. The liquid developers are useful in copying, in making color proofs, etc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.