Patent classifications
G03G9/097
Toner for electrophotography, image forming method, and process cartridge
A toner for electrophotography, which contains a binder resin, and a release agent, wherein a maximum value of loss tangent of the toner at 95? C. to 115? C. is 8 or greater, as a viscoelasticity of the toner is measured, where the loss tangent is represented by the following formula: Loss tangent (tan ?)=loss elastic modulus (G)/storage elastic modulus (G).
Toner, developer, toner housing unit and image forming apparatus
A toner includes a binder resin; a release agent; and two or more inorganic fine particles as external additives. At least one of the inorganic fine particles is silica. When an ultrasonic oscillation is applied to a dispersion including the toner and a dispersant and a rate of the silica releasing from the toner is 20% based on total silica, an application energy of the ultrasonic oscillation is from 8 to 14 kJ, and from 70 to 130 kJ when the rate of the silica releasing from the toner is 50%.
Image forming apparatus
An image forming apparatus includes an image forming unit including an image carrier, a developing device that includes a developer containing a toner, and a cleaning device including a blade; and a transfer device. The toner contains toner particles having a volume-average particle size of 3 m or more and 5 m or less, a spherical inorganic external additive having a number-average particle size of 80 nm to 200 nm, and an organic component. In the cleaning device, an external additive residue in or near a contact region between the image carrier and the blade contains the organic component and an inorganic component, the area ratio of the organic component to the inorganic component is 3/7 or more and 7/3 or less, and the area ratio of the inorganic component that is spherical to the external additive residue is 30% or more.
Pressure fixation toner for developing electrostatic charge image, electrostatic charge image developer, and toner cartridge
A pressure fixation toner for developing an electrostatic charge image includes a styrene resin, a (meth)acrylic acid ester resin, and an oxidative polymerizable compound. The pressure fixation toner has a sea-island structure configured by a sea portion including the styrene resin and island portions including the (meth)acrylic acid ester resin. The (meth)acrylic acid ester resin has a glass transition temperature being lower than a glass transition temperature of the styrene resin by 30 C. or greater.
TONER AND METHOD FOR PRODUCING TONER
A toner comprising a toner particle including a resin component, wherein the resin component includes an olefin copolymer including ester group having specific structures Y1 and Y2 and an olefin copolymer including acid group having an acid value of from 50 mg KOH/g to 300 mg KOH/g, the amount of the olefin copolymer including ester group is 50% by mass or more, the toner particle has a surface layer including the olefin copolymer including acid group which has formed a salt with a metal, the metal is at least one metal selected from the group consisting of Mg, Ca, Sr, Al, and Zn, and the total amount of the metal in the toner is from 25 ppm to 500 ppm.
Silica fine powder and use thereof
Provided is an external additive for toner, which is suitable for producing a toner having excellent storage stability and chargeability. A silica fine powder suitable for being added to the external additive for toner is also provided. The silica fine powder has a specific surface area of 15 m.sup.2/g or more and 90 m.sup.2/g or less, a loose bulk density of 0.09 g/cm.sup.3 or more and 0.18 g/cm.sup.3 or less, a carbon content of 0.25 wt % or more and 0.90 wt % or less, and a hydrophobicity of 60% or more and 75% or less. It is preferable that a ratio (A)/(B) of the loose bulk density of the silica fine powder after surface treatment (A) to a loose bulk density of the silica fine powder before the surface treatment (B) be 1.05 or more and 1.60 or less.
External additive for toner, process for producing the same, and toner comprising the same
An external additive for a toner includes: a particulate of a polymerization product of at least one silicon compound selected from a silane compound represented by Chemical Formula 1: Si(OR.sup.1).sub.4 (wherein R.sup.1 is a C1 to C6 monovalent hydrocarbon group) and a hydrolysis-condensation product thereof. The particulate has the following properties: a number average particle diameter of about 50 nm to about 250 nm, a first specific surface area () measured by a gas adsorption method of about 13 m.sup.2/g to about 80 m.sup.2/g, and true density measured by a nominal volume expansion method of about 1.9 g/cm.sup.3 to about 2.1 g/cm.sup.3.
TONER AND IMAGE FORMING APPARATUS
A toner includes a plurality of toner particles each including a toner mother particle and an external additive adhering to a surface of the toner mother particle. The external additive includes hydrotalcite particles. The hydrotalcite particles have a number average primary particle diameter of at least 80 nm and no greater than 1,000 nm. The hydrotalcite particles have a volume resistivity of no greater than 1.010.sup.5 .Math.cm. An amount of the hydrotalcite particles is at least 0.5 parts by mass and no greater than 3.0 parts by mass relative to 100 parts by mass of the toner mother particles.
TONER
A toner comprising: a toner particle that contains a resin component and a silicone compound, wherein the resin component contains at least 50 mass % of olefin resin; a content of the silicone compound is from 1 mass part to 42 mass parts per 100 mass parts of the resin component; a weight-average molecular weight of the silicone compound as measured by GPC is from 1,000 to 25,000; and a content, in a molecular weight distribution of the silicone compound as measured by GPC, of a component having a weight-average molecular weight of not more than 500 is not more than 0.05 mass % of the silicone compound.
Toner for development electrostatic images
Provided is a toner for developing electrostatic images, which is less likely to cause filming, is excellent in printing durability, and is less likely to cause fog under a high temperature and high humidity environment. The toner for developing electrostatic images is a toner containing colored resin particles that contains a binder resin, a colorant and a charge control agent, and external additives, wherein the external additives include at least: silica fine particles A, silica fine particles B, and electroconductive metal oxide fine particles C; wherein the silica fine particles. A and B are silica fine particles surface-hydrophobized with at least one hydrophobizing agent; wherein the electroconductive metal oxide fine particles C have an electrical resistance of 70 cm or less and contain antimony-doped tin oxide.