Positively charged toner for use in electrostatography
US5532097A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1994 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Dec 6, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/09758
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A dry toner powder the toner particles of which are triboelectrically positively charged and are suited for development of an electrostatic charge pattern, wherein said toner particles contain: (1) one or more triboelectrically positively chargeable thermoplastic resins serving as binder having a volume resistivity of at least 10.sup.13 .OMEGA.-cm, and (2) at least one substance having a volume resistivity lower than the volume resistivity of said binder, and wherein said substance(s) (2) when present in said binder in a concentration of 5% by weight lower(s) thereof the volume resistivity of said binder by a factor of at least 3.3, and wherein said toner powder containing particles including a mixture of said ingredients (1) and (2) under triboelectric charging conditions is capable of obtaining an absolute median (q/d) charge/diameter value (x) lower than 10 fC/10 .mu.m but not lower than 1 fC/10 .mu.m, and said toner powder under the same triboelectric charging conditions but free from said substance(s) (2) then has an absolute median q/d value (x) at least 50% higher than when said substance(s) (2) is (are) present, and wherein the distribution of the charge/diameter values of …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.