G03G9/10

ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER, DEVELOPER, AND IMAGE FORMING METHOD
20180011413 · 2018-01-11 · ·

An object of the present invention is to provide an electrostatic charge image developing toner, a two-component developer, and an image forming method, each capable of employing a two-component trickle touchdown developing system which ensures excellent image density stability and no occurrence of ghost and is used in an electrophotographic copier or an electrostatic recording device. The present invention provides an electrostatic charge image developing toner having positive chargeability; containing a styrene acrylic resin as the binding resin; and containing a nigrosine-containing positive charge control agent and a negative charge control agent as the charge control agent, in which the percentage content of the percentage content of the negative charge control agent in all charge control agents is not less than the percentage content of the positive charge control agent.

ELECTROSTATIC CHARGE IMAGE DEVELOPER, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS, AND IMAGE FORMING METHOD

An electrostatic charge image developer contains: a toner containing a toner particle and an external additive; and a carrier containing a magnetic particle and a resin layer covering the magnetic particle; and the toner particle has a surface property index value of 1.0 or more and less than 2.0; and the carrier has a surface having a ratio B/A of a surface area B to a plane view area A of 1.020 or more and 1.100 or less, the plane view area A and the surface area B being obtained by three-dimensional analysis of the surface of the carrier.

ELECTROSTATIC CHARGE IMAGE DEVELOPER, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

An electrostatic charge image developer includes: toner particles; silica particles treated with a silicone oil, which are externally added to the toner particles; and a carrier, wherein a volume average particle diameter of the carrier is equal to or greater than 20 μm and smaller than 30 μm, and a quantity ratio of an elemental silicon derived from a silicone oil and an elemental silicon derived from silica which are present on the surface of the carrier (silicone oil-derived elemental silicon/silica-derived elemental silicon) is in a range of 0.05 to 0.2.

ELECTROSTATIC CHARGE IMAGE DEVELOPER, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

An electrostatic charge image developer includes: toner particles; silica particles treated with a silicone oil, which are externally added to the toner particles; and a carrier, wherein a volume average particle diameter of the carrier is equal to or greater than 20 μm and smaller than 30 μm, and a quantity ratio of an elemental silicon derived from a silicone oil and an elemental silicon derived from silica which are present on the surface of the carrier (silicone oil-derived elemental silicon/silica-derived elemental silicon) is in a range of 0.05 to 0.2.

IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD USING A TONER CARRIER CONTAINING SILICON DERIVED FROM SILICA AND SILICONE OIL

An image forming apparatus includes a charging unit that includes a conductive member which contacts with a surface of an image holding member, and that applies only a DC voltage to the conductive member to charge the surface of the image holding member; and a cleaning unit that has a blade which contacts with the surface of an image holding member and cleans the surface with the blade after a toner image is transferred onto a recording medium, wherein a developer includes toner particles, silica particles treated with a silicone oil, and a carrier, a volume average particle diameter of the carrier is from 20 μm to 35 μm, and a quantity ratio of an elemental silicon derived from a silicone oil and an elemental silicon derived from silica which are present on the surface of the carrier is from 0.05 to 0.2.

ELECTROSTATIC CHARGE IMAGE DEVELOPING WHITE TONER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, AND TONER CARTRIDGE

An electrostatic charge image developing white toner includes a white toner particle and a yellow toner particle that includes an organic yellow pigment, wherein a content ratio (by number) of the yellow toner particles to all of toner particles included in the toner is from 0.01% by number to 3% by number.

Electrostatic charge image developing carrier, electrostatic charge image developer, developer cartridge, process cartridge, and image forming apparatus

An electrostatic charge image developing carrier includes a magnetic core particle, and a coating layer that coats surfaces of the magnetic core particle, wherein the coating layer includes a binder resin, thermosetting resin particles, and crosslinked resin particles, and the crosslinked resin particle contains a polymer formed by polymerizing a monomer component including the same monomer as a monomer used in the polymerization of the binder resin.

Magnetic carrier and two-component developer

A magnetic carrier is provided which can suppress a decrease in glossiness even in a long term use for POD which requires high glossiness. A magnetic carrier includes a filled core particle in which a silicone resin is filled in pores of a porous magnetic core particle and a vinyl resin coating a surface of the filled core particle. In a pore distribution of the porous magnetic core particle measured by a mercury intrusion method, a cumulative pore volume in a pore diameter range of 0.1 to 3.0 μm is 35.0 to 95.0 mm.sup.3/g, and in a pore distribution of the filled core particle measured by a mercury intrusion method, a cumulative pore volume in a pore diameter range of 0.1 to 3.0 μm is 3.0 to 15.0 mm.sup.3/g. The magnetic carrier includes 1.2 to 3.0 parts by mass of the vinyl resin to 100.0 parts by mass of the filled core particle.

ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, AND TONER CARTRIDGE

An electrostatic charge image developing toner includes a carbodiimide compound and a polyester resin prepared by subjecting an alcohol component and a carboxylic acid component to condensation polymerization, wherein the alcohol component includes an aliphatic polyol in an amount of 60 mol % to 100 mol %.

Image forming apparatus and image forming method

An image forming apparatus is provided. The image forming apparatus includes an image bearer and a cleaning blade configured to remove toner particles remaining on the image bearer. The cleaning blade includes an elastic member in contact with a surface of the image bearer to remove the toner particles. The elastic member has a Martens hardness of from 3 to 8 N/mm.sup.2 when measured by a nanoindentation method with a load of 1 μN. The toner particles comprise toner base particles and an external additive, and the external additive comprise silica particles. A liberation ratio (Xs) of the silica particles liberated from the toner particles is from 40% to 75% when measured by an ultrasonic vibration method. A proportion (R70) of the silica particles having a volume-based particle diameter of 70 nm or more in the silica particles liberated from the toner particles is from 70% to 90% by number.