Magnetic toner
US9588450B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2014 |
| Grant date | Mar 7, 2017 |
| Priority date | — |
| Expiry date | Jul 30, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G9/09725
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Provided is a magnetic toner in which enhancement of initial transfer efficiency and transfer efficiency that is stable during a long-term use are achieved by simultaneously suppressing the friction force between the toner and a drum and the cohesion between toners, and further the degradation in chargeability and fluidity caused by the deterioration of the toner. The magnetic toner includes: a magnetic toner particle; a first external additive; and a second external additive. The first external additive includes an organic-inorganic composite fine particle, a plurality of convexes derived from an inorganic fine particle being present on a surface of the organic-inorganic composite fine particle, and has a number-average particle diameter of 50 nm or more and 500 nm or less. The second external additive includes a silica fine particle and has a number-average particle diameter of 5 nm or more and 30 nm or less. A shear load calculated from a rotation torque is 0.50 kPa or more and 2.00 kPa or less when a disc-shaped disc is pressed against a surface of a magnetic toner powder layer, the magnetic toner powder layer being produced by applying a vertical load of 9.0 kPa to the magneti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.