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US 9,176,409 B2Granted
Toner, development agent, toner container, and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorsMasayuki Ishii, Toyoshi Sawada
Life of this patent
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Abstract
Toner contains a mother toner particle containing a binder resin and a coloring agent and an external additive to cover the mother toner particle, wherein the external additive contains a resin particle, wherein the resin particle has an outer shell layer formed of silica or modified silica, wherein the resin particle has a non-spherical form with a shape factor (SF) of 1.20 or greater as calculated by the following relationship 1, Shape factor(SF)=[(Absolute maximum length of particle)2/Projected area of particle)]×(π/4) Relation 1.
Claims6
Toner comprising:
- a mother toner particle comprising:
- a binder resin;
- and
- a coloring agent;
- and
- an external additive to cover the mother toner particle,
- wherein the external additive comprises a resin particle,
- wherein the resin particle has an outer shell layer comprising silica or modified silica,
- wherein an amount of the silica or the modified silica in the resin particle having the outer shell layer is from 2% by weight to 10% by weight based on a total amount of the resin particle having the outer shell layer, and
- wherein the resin particle having the outer shell layer has a non-spherical form with a shape factor of 1.20 or greater as calculated by formula:
- Shape factor=[(Absolute maximum length of particle)2/(Projected area of particle)]×(π/4).
8 more elements
Dependencies are inferred from the claim text.