摘要:
The invention provides a toner for developing an electrostatic image including toner particles having a shape factor SF1 of 110 or more and including a binder resin, and particles of an external additive that adhere to the toner particles, wherein the particles of the external additive including first particles, and second particles which are adhered to the first particles and have a primary particle size of 0.2 times to 0.5 times as large as that of the first particles, and in an image obtained by observing the particles of the external additive with a microscope, when the projection surface area of the first particle is defined as S1 and the total of the projection surface areas of the second particles which are not hidden by the first particle is defined as S2, S2 being from 0.1 times to 0.5 times as large as S1.
摘要:
The invention provides a toner for developing an electrostatic image including toner particles having a shape factor SF1 of 110 or more and including a binder resin, and particles of an external additive that adhere to the toner particles, wherein the particles of the external additive including first particles, and second particles which are adhered to the first particles and have a primary particle size of 0.2 times to 0.5 times as large as that of the first particles, and in an image obtained by observing the particles of the external additive with a microscope, when the projection surface area of the first particle is defined as S1 and the total of the projection surface areas of the second particles which are not hidden by the first particle is defined as S2, S2 being from 0.1 times to 0.5 times as large as S1.
摘要:
A toner for developing an electrostatic image, including: toner particles containing at least a binder resin, a release agent, and a colorant; and an external additive having a volume average particle diameter (d) of from 70 nm to 400 nm, a ratio (d/σ) of the volume average particle diameter (d) to a standard deviation (σ) of a volumetric basis particle diameter of from 2.0 to 12, and an average circularity of from 0.5 to 0.9.
摘要:
An electrostatic charge image developing toner includes: toner particles; and an external additive having an average particle diameter of from about 70 nm to about 420 nm, an average circularity of equal to or less than about 0.9, and a standard deviation of the circularity of greater than 0.2.
摘要:
A method of producing a carrier for electrophotography includes: covering a surface of a core particle with a coating layer including resin particles and a crosslinking resin in an uncrosslinked state present in spaces between the resin particles; and applying a mechanical impact from the outer surface of the coating layer before crosslinking of the crosslinking resin.
摘要:
A positively chargeable two-component developer, including at least a toner and a carrier, wherein the toner contains a binder resin, a colorant, a wax, and a charge control agent, the binder resin contains at least a polyester resin and an addition polymerization resin grafted with a polyolefin, the wax and the addition polymerization resin grafted with a polyolefin are contained at a wax:addition polymerization resin grafted with a polyolefin ratio of from about 40:60 to about 80:20, and the carrier is a magnetic powder having a coating layer containing a methyl-containing silicone resin.
摘要:
An electrostatic charge image developing toner includes toner particles that contain a colorant, a binder resin and a release agent, and an external additive, in which the external additive contains inorganic particles including an aliphatic alcohol having 5 or more carbon atoms and a melting point of 20° C. or lower on the surfaces thereof.
摘要:
An electrophotographic toner composition comprising (A) toner particles with an average particle diameter of 9 .mu.m or less comprising at least a binder resin and a colorant, and (B) an additive, wherein the additive is a fine metal oxide powder surface coated with at least one agent for imparting hydrophobic property selected from the group consisting of the following formulae (1), (2) and (3):R.sub.1 Si(X).sub.3R.sub.1 R.sub.2 Si(X).sub.2R.sub.1 R.sub.2 R.sub.3 Si(X).sub.1wherein R.sub.1 represents a substituted or unsubstituted alkyl group having a molecular weight of 113 or more, R.sub.2 and R.sub.3 each represents hydrogen, an alkyl group or an allyl group, and X represents chlorine, an alkoxy group or an acetoxy group. The toner composition causes no impaction to a carrier and no adhesion of the toner particles to a photoreceptor, and can form stable, sufficient images for a long time.
摘要:
A toner composition for electrophotography comprising toner particles comprising a binder and a colorant and an additive, wherein the additive is crystalline titanium dioxide fine particles which have been treated with a coupling agent and which have a specific surface area of 60 to 100 m.sup.2 /g and a Karl Fischer moisture content of not more than 5% by weight. Compounds represented by formulae (I), (II) or (III) are used as the coupling agent: R.sup.1 Si(X).sub.3 (I) R.sup.1' R.sup.2 Si(X).sub.2 (II) R.sup.1' R.sup.2 R.sup.3 SiX (III) wherein R.sup.1 represents an alkyl group having 9 to 20 carbon atoms; R.sup.1' represents an alkyl group having 1 to 20 carbon atoms; R.sup.2 and R.sup.3 each represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 30 carbon atoms; and X represents a chlorine atom, an alkoxy group having 1 to 10 carbon atoms or an acetoxy-group having 3 to 5 carbon atoms.
摘要:
A color toner providing a toner image excellent in brightness, clearness and graininess and a process for producing the same are disclosed, wherein a proportion of dispersed pigment particles having a circle-equivalent diameter of 0.3 .mu.m or greater does not exceed 0.1% of the total number of said dispersed pigment particles. The process comprises kneading a water-containing pigment paste and a binder resin at a temperature of 100.degree. C. or higher under pressure in a heat and pressure kneader to remove a water content to obtain a pigment dispersion, melt-kneading the resulting pigment dispersion together with a binder resin, and grinding the mixture.