Patent classifications
G03G9/1139
ELECTROSTATIC CHARGE IMAGE DEVELOPING CARRIER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD
An electrostatic charge image developing carrier, containing: a magnetic particle; and a resin coating layer that coats the magnetic particle and contains inorganic particles, and the electrostatic charge image developing carrier has a surface of a surface roughness satisfying a ratio B/A of a surface area B to a plan view area A of 1.020 or more and 1.100 or less, the plan view area A and the surface area B being obtained by three-dimensional analysis of the surface, and the magnetic particle has a surface roughness satisfying 0.5 μm≤Sm≤2.5 μm and 0.3 μm≤Ra≤1.2 μm, and Sm represents an average ruggedness interval and Ra represents an arithmetic average surface roughness.
Process cartridge and image forming apparatus
A process cartridge is provided, which is configured to recover, with a developing member, developer remaining on an image bearing member after transfer of a developer image to a transfer receiving member, wherein a charging member has a shaft that is conductive and an elastic layer supported on the shaft and being in contact with the image bearing member; the elastic layer has a matrix containing a first rubber, and a plurality of domains containing a second rubber and an electron-conductive agent and interspersed within the matrix. The electric resistance of the domains is lower than the electric resistance of the matrix. The matrix is exposed on an outer surface of the elastic layer and forms multiple depressed portions, and the domains include a domains exposed at a bottom section of the depressed portion.
CARRIER FOR DEVELOPING ELECTROSTATIC LATENT IMAGE, TWO-COMPONENT DEVELOPER, IMAGE FORMING APPARATUS, PROCESS CARTRIDGE, AND IMAGE FORMING METHOD
A carrier for developing an electrostatic latent image is provided. The carrier comprises a core particle having an internal void ratio of from 0.0% to 2.0% and a coating layer coating the core particle. The coating layer contains flat chargeable particles satisfying Formula 1 blow:
1.0≤R1/R2≤3.0 Formula 1
where R1 [nm] and R2 [nm] represent a major axis and a thickness, respectively, of each of the flat chargeable particles. The carrier has an apparent density of from 2.0 to 2.5 g/cm.sup.3.
CARRIER FOR FORMING ELECTROPHOTOGRAPHIC IMAGE, DEVELOPER, IMAGE FORMING METHOD, IMAGE FORMING APPARATUS, AND PROCESS CARTRIDGE
A carrier for forming an electrophotographic image is provided. The carrier comprises a core particle and a coating layer coating the core particle. The coating layer contains a conductive component comprising an element A, and a coating resin comprising an element B. The element A is undetected in the coating resin by an energy dispersive X-ray spectrometer, and the element B is undetected in the conductive component by the energy dispersive X-ray spectrometer. A standard deviation of a value A/B is 0.4 or less, where the value A/B is a ratio of the element A to the element B in intensity measured by the energy dispersive X-ray spectrometer.
CARRIER AND TWO-COMPONENT DEVELOPER
A carrier includes carrier particles. Each of the carrier particles includes a carrier core and a coating layer covering the surface of the carrier core. The coating layer contains a silicone resin and conductive particles. Each of the conductive particles includes a transparent conductive substrate composed of a transparent conductive material and a film covering a surface of the transparent conductive substrate. The film contains silica.
Carrier and two-component developer
A carrier includes carrier particles. Each of the carrier particles includes a carrier core and a coating layer covering the surface of the carrier core. The coating layer contains a silicone resin and conductive particles. Each of the conductive particles includes a transparent conductive substrate composed of a transparent conductive material and a film covering a surface of the transparent conductive substrate. The film contains silica.
TWO-COMPONENT DEVELOPER, DEVELOPING DEVICE, AND IMAGE FORMING DEVICE
A two-component developer 100 includes a carrier 200 and a toner 300. The carrier 200 satisfies the relationships 100≤α≤220 and 300≤β≤480 when a voltage is applied in 1 V steps by a bridge resistance measurement method, where α (V) is a carrier voltage value obtained when a current value flowing through the carrier 200 reaches 1.0.sup.−7 (A), and β (V) is a carrier voltage value obtained when the current value reaches 1.0.sup.−5 (A).
TONER, TONER CARTRIDGE, AND IMAGE FORMING APPARATUS
A toner includes toner base particles and an external additive. The external additive is adhered to surfaces of the toner base particles, which contain a crystalline polyester resin and an ester wax. The proportion of an ester compound with a carbon number of C.sub.1, the content of the ester compound with a carbon number of C.sub.1 being highest among the ester compounds constituting the ester wax, is 65 mass % or more with respect to 100 mass % of the ester wax. The carbon number distribution of the ester compounds constituting the ester wax has only one maximum peak in a region where the carbon number is 43 or more. The external additive contains silica particles having a volume average primary particle diameter D.sub.50of 40 to 75 nm. The moisture content of the silica particles is less than 1.0 mass % with respect to 100 mass % of the silica particles.
Positively charged toner for electrostatic-image development
A positively charged toner for development of an electrostatic image, containing matrix particles containing at least a binder resin and a release agent, coated with inorganic fine particles, the binder resin containing a crystalline resin, the release agent containing ester wax (W) containing a dipentaerythritol unit as a constitutional component, the inorganic fine particles containing positively charged silica (S1) and negatively charged silica (S2), and the positively charged silica (S1) having an average particle diameter that is smaller than an average particle diameter of the negatively charged silica (S2), and the negatively charged silica (S2) having an average particle diameter of 10 nm or more and 90 nm or less.
Ferrite carrier core material for electrophotographic developer, carrier for electrophotographic developer, and developer
Provided are a ferrite carrier core material for an electrophotographic developer having a full length L.sub.1 of grain boundary and a circumference length L.sub.2 of the core material in a cross-section of the core material, and satisfying a relationship of 2≤L.sub.1/L.sub.2≤9; a carrier for an electrophotographic developer including the ferrite carrier core material and a coating layer containing a resin provided on a surface of the ferrite carrier core material; and an electrophotographic developer including the carrier and a toner.