Patent classifications
G03G9/09791
Carrier for developing electrostatic charge image, electrostatic charge image developer, and image forming apparatus
A carrier for developing an electrostatic charge image has magnetic particles and a resin coating that covers the magnetic particles and contains at least one lubricant. The resin coating has a dispersed phase of the lubricant and meets requirement (1). Requirement (1): the lubricant content in a top layer>the lubricant content in a middle layer>the lubricant content in a bottom layer The top, middle, and bottom layers are of the resin coating divided into three in the direction of thickness, and the lubricant content is the percentage area of the dispersed phase of the lubricant in a cross-section of the layer taken along the thickness thereof.
Magenta toner
Provided is a magenta toner which is more excellent in durability in a high temperature and high humidity environment than conventional ones. The magenta toner comprises a binder resin, a magenta colorant, a release agent and an external additive. The release agent has a maximum endothermic peak in a range of from 70° C. to 80° C. during temperature increase, in a DSC curve measured by a differential scanning calorimeter. Needle-shaped oxide fine particles having an average long diameter of from 30 nm to 500 nm and an aspect ratio of from 4 to 20 are contained therein. Zinc stearate particles having a number average primary particle diameter of from 0.1 μm to 5 μm are contained at an amount of from 0.01 part by mass to 0.5 part by mass with respect to 100 parts by mass of the colored resin particles, as the external additives.
Image forming apparatus that suppresses occurrence of image smearing by maintaining a metal soap on a surface of a photoconductor
An image forming apparatus that executes an image forming operation for forming a toner image on a recording material and an application operation of applying a metal soap to a surface of an image bearing member by supplying a toner stored in a toner storing unit to the surface of the image bearing member from the developing member. A surficial moving speed of the image bearing member during the application operation is lower than the surficial moving speed of the image bearing member during the image forming operation, and a speed difference between the surficial moving speed of the developing member and the surficial moving speed of the image bearing member during the application operation is larger than that during the image forming operation.
ELECTROSTATIC IMAGE DEVELOPER, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS, AND IMAGE FORMING METHOD
An electrostatic image developer includes a toner containing toner particles, a carrier, and an external additive containing titanium dioxide particles of two types having different refractive indexes, fatty acid metal salt particles, and an abrasive.
Toner and image forming method
A toner comprises a toner particle including a binder resin, and inorganic fine particles A and silica particles B, wherein the inorganic fine particle A has a rectangular parallelepiped shape; an amount of the inorganic fine particles A is 0.3 to 3.0 mass parts per 100 mass parts of the toner particles; a number average particle diameter of the silica particles B is 80 to 200 nm; a fixing ratio of the inorganic fine particle A is 25% to 70%; where a separation amount of the inorganic fine particles A is denoted by YA (mg), and a separation amount of the silica particles is denoted by YB (mg), YA is 3.00 to 18.0, YA and YB satisfy the following formula,
YA/YB>0.75, and a surface potential difference C in a rubbing test using the inorganic fine particle A and the binder resin is −70 V to +70 V.
Toner
A toner including a toner particle that contains a binder resin, and an inorganic fine particle, wherein the inorganic fine particle contains aggregated particles; the aggregated particles contain primary particles of at least one metal salt selected from the group consisting of titanate metal salts and zirconate metal salts; the primary particles have a number-average particle diameter of from 15 nm to 55 nm; the aggregated particles have an aggregation diameter of from 80 nm to 300 nm, the aggregated particles have a volume resistivity of from 2×10.sup.9 Ω.Math.cm to 2×10.sup.13 Ω.Math.cm; and the aggregated particles cover a surface of the toner particle, and a coverage ratio of the aggregated particles with respect to the surface of the toner particle is from 0.3 area % to 10.0 area %.
CARRIER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE, ELECTROSTATIC CHARGE IMAGE DEVELOPER, AND IMAGE FORMING APPARATUS
A carrier for developing an electrostatic charge image has magnetic particles and a resin coating that covers the magnetic particles and contains at least one lubricant. The resin coating has a dispersed phase of the lubricant and meets requirement (1).
Requirement (1): the lubricant content in a top layer>the lubricant content in a middle layer>the lubricant content in a bottom layer
The top, middle, and bottom layers are of the resin coating divided into three in the direction of thickness, and the lubricant content is the percentage area of the dispersed phase of the lubricant in a cross-section of the layer taken along the thickness thereof.
White toner and method for producing same
A white toner comprising a toner particle including a binder resin, an inorganic white pigment, and a polyvalent metal salt compound, wherein the inorganic white pigment has an acidic group at a surface thereof; an amount of the inorganic white pigment in the toner particle is 10% to 50% by volume; the polyvalent metal salt compound is a specific compound; an absolute value of the difference between an SP value (J/cm.sup.3).sup.1/2 of the binder resin and that of the polyvalent metal salt compound is 0.0 to 6.0; and an amount of the polyvalent metal salt compound, an amount of a polyvalent metal, the amount of the inorganic white pigment, and an amount of the acidic group at a surface of the inorganic white pigment satisfy a specific relationship.
TONER
A toner includes toner particles and zinc stearate particles. The toner particles each include a toner mother particle containing a binder resin. The zinc stearate particles have a 50% volume cumulative diameter of at least 3.0 μm and no greater than 6.0 μm. A presence ratio of the zinc stearate particles having a particle diameter of no greater than 1.0 μm is no greater than 2.0% by volume relative to a total amount of the zinc stearate particles. A presence ratio of the zinc stearate particles having a particle diameter of at least 10.0 μm is no greater than 2.0% by volume relative to the total amount of the zinc stearate particles.
Toner and toner manufacturing method
A toner including a toner particle containing a binder resin and an external additive, wherein the external additive contains composite particles of an organosilicon polymer fine particle and a fatty acid metal salt.