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US 6,183,924 B2Granted
Electrostatic image developer
AssigneeDaimippon Ink and Chemicals, Inc.
InventorsMinoru Nomura, Takashi Ito, Hitoshi Takayanagi, Kazuo Itoya
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AssigneeDaimippon Ink and Chemicals, Inc.
InventorsMinoru Nomura, Takashi Ito, Hitoshi Takayanagi, Kazuo Itoya
Estimating the term…
The present invention provides a novel developer comprising a spherically particulate toner having a volume-average particle diameter of from about 1 to 6 μm for use in the development of electrostatic image in electrophotographic copying machines or printers having a colorant content of from 8 to 20% by weight, if the colorant is carbon black, or from 3 to 20% by weight, if the colorant is an organic pigment, based on the sum of the weight of binder resin and colorant and a resin-coated carrier having a volume-average particle diameter of from 20 to 150 μm. The present invention also provides a suitable polymerization or emulsification process for the preparation of a particulate toner to be incorporated in the developer. The use of the electrostatic image developer makes it possible to not only improve the quality of images provided by copying machines or printers but also realize drastic reduction of the amount of toner to be consumed per sheet of printing paper.
An electrostatic image developer comprising a spherically particulate black toner containing a binder resin and a colorant and a resin-coated carrier, characterized in that said spherically particulate toner has a volume-average particle diameter of from 1 to 6 μm, and an average circularity of not less than 0.97, said colorant is carbon black, the content of which is from 8 to 20% by weight based on the sum of the weight of said binder resin and said colorant and said carrier has a volume-average particle diameter of from 20 to 150 μm.
An electrostatic image developer comprising a spherically particulate black toner containing a binder resin and a colorant and a resin-coated carrier, characterized in that said spherically particulate toner has a volume-average particle diameter of from 1 to 6 μm, and an average circularity of not less than 0.97, said colorant is carbon black, the content of which is from 9 to 15% by weight based on the sum of the weight of said binder resin and said colorant and said carrier has a volume-average particle diameter of from 20 to 150 μm.
An electrostatic image developer comprising a spherically particulate color toner containing a binder resin and a colorant and a resin-coated carrier, characterized in that said spherically particulate color toner has a volume-average particle diameter of from 1 to 6 μm and an average circularity of not less than 0.97, said colorant is an organic pigment, the content of which is from 3 to 20% by weight based on the sum of the weight of said binder resin and said colorant and said carrier has a volume-average particle diameter of from 20 to 150 μm.
An electrostatic image developer comprising a spherically particulate color toner containing a binder resin and a colorant and a resin-coated carrier, characterized in that said spherically particulate color toner has a volume-average particle diameter of from 1 to 6 μm and an average circularity of not less than 0.97, said colorant is an organic pigment, the content of which is from 5 to 10% by weight based on the sum of the weight of said binder resin and said colorant and said carrier has a volume-average particle diameter of from 20 to 150 μm.
Dependencies are inferred from the claim text.