Kao Corporation

Yasuhiro Hidaka

Masayuki Maruta

Shinichi Sata

Shin-ichi Sata

Hiroyuki Kawaji

Jun Shimizu

Katsutoshi Aoki

Yasuki Ohtawa

Akihiro Eida

Hisakazu Tajima

Koji Shimokusa

Shogo Watanabe

Hiroki Kakiuchi

Kohei Katayama

Kouhei Katayama

A toner for electrophotography containing a resin binder containing a crystalline resin and an amorphous resin, and a releasing agent, wherein the crystalline resin contains a crystalline composite resin C containing a polycondensation resin component and a styrenic resin component, wherein the polycondensation resin component is obtained by polycondensing a specified alcohol component and a specified carboxylic acid component, and wherein the amorphous resin contains an amorphous composite resin AC containing a polycondensation resin component and a styrenic resin component, wherein the polycondensation resin component is obtained by polycondensing an alcohol component and a specified carboxylic acid component, and an amorphous polyester AP obtained by polycondensing an alcohol component and a specified carboxylic acid component, wherein a softening point of the amorphous polyester AP is higher than a softening point of the amorphous composite resin AC, wherein a difference in softening points between the amorphous polyester AP and the amorphous composite resin AC is 10&#xb0; C. or more and 50&#xb0; C. or less. The toner for electrophotography of the present invention is suitably used in development of latent images or the like which is formed in, for example, electrostatic development method, electrostatic recording method, electrostatic printing method or the like.

Electrophotography toner

A method for forming fixed images including the step of applying a toner for electrostatic image development containing at least a resin binder, a colorant, and a releasing agent to an apparatus for forming fixed images without a filter in a gas discharge part, wherein the resin binder contains a polyester, and wherein the releasing agent is a hydrocarbon-based wax, wherein the hydrocarbon-based wax has a melting point as determined by a differential scanning calorimeter of from 70&#xb0; to 85&#xb0; C., and contains components melting at a temperature equal to or lower than 65&#xb0; C. having an amount of heat absorption as determined by a differential scanning calorimeter of less than 7.5 J/g, and a toner for electrostatic image development used in a method for forming fixed images. The method for forming fixed images of the present invention is suitably used in the development of a latent image formed in, for example, electrophotography, electrostatic recording method, electrostatic printing method or the like.

Method for forming fixed images

A toner for electrostatic image development containing at least a resin binder, the resin binder being composed of a crystalline resin and an amorphous resin, wherein the crystalline resin contains a crystalline polyester obtained by polycondensing an alcohol component containing an aliphatic diol having 2 to 10 carbon atoms and a carboxylic acid component containing an aromatic dicarboxylic acid compound and an aromatic tricarboxylic or higher polycarboxylic acid compound, wherein the crystalline polyester has a weight-average molecular weight of from 20,000 to 150,000, and wherein the crystalline resin and the amorphous resin are in a weight ratio, i.e. crystalline resin/amorphous resin, of from 55/45 to 95/5. The toner for electrostatic image development of the present invention can be suitably used in, for example, the development or the like of latent image formed in electrophotography, an electrostatic recording method, an electrostatic printing method, or the like.

Toner for electrostatic image development

A toner for electrophotography comprising a charge control agent comprising a specified iron-azo complex or a specified metal compound of a benzilic acid derivative, a colorant, and a resin binder comprising a polyester, the polyester being a polyester obtained by polycondensing an alcohol component containing a propylene oxide adduct of bisphenol A and a carboxylic acid component, wherein the propylene oxide adduct of bisphenol A has an average mole of propylene oxide added of from 2.4 to 4.0, and wherein an adduct with 2 mol of propylene oxide is contained in an amount of 60% by mol or less, and an adduct with 4 mol of propylene oxide is contained in an amount of 10% by mol or more, of the propylene oxide adduct of bisphenol A, and wherein the propylene oxide adduct of bisphenol A has a content ratio of primary hydroxyl groups of 10% by mol or less of the entire hydroxyl groups. The toner for electrophotography of the present invention is suitably used in developing latent images and the like formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

Toner for electrophotography

A toner for electrostatic image development, comprising a resin binder comprising a crystalline polyester; a releasing agent comprising a wax having a melting point of from 60 to 85&#xb0; C. and a penetration at 25&#xb0; C. of from 4 to 10; and a colorant. The toner for electrostatic image development can be used, for instance, for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

A toner for electrostatic image development, containing a resin binder containing a polyester, a colorant, and a releasing agent containing an ester wax and a petroleum wax; and a process for preparing a toner for electrostatic image development, including the step of melt-kneading raw materials for the above toner, wherein the melt-kneading step is carried out with an open-roller type kneader. The toner for electrostatic image development is used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

The positively chargeable toner includes a binder resin and a coloring agent, the binder resin including (a) a resin (1) capable of forming a matrix in the toner, the resin (1) being a hybrid resin of a polyester resin and a vinyl resin; and (b) a resin (2) capable of forming a domain dispersed in the matrix formed by the resin (1), the resin (2) being a vinyl resin having a positive charge functional group. This positively chargeable toner has a good evenness of chargeability and a high charging-up speed with a small proportion of a reversely charged toner upon triboelectric charging. Moreover, in a heat roller fixing method, fixing at a low temperature can be performed without using an offset inhibiting liquid.

Binder resin for toner and positively chargeable toner containing the same

A binder obtained by a process having the steps of mixing components (a) to (c): (a) a starting material monomer mixture of two different polymerization reactions, each of the polymerization reactions being carried out in an independent reaction path; (b) a compound which can react with both of the starting material monomers of the two different polymerization reactions; and (c) a releasing agent; and carrying out both of the two different polymerization reactions in one reaction vessel. A toner for developing an electrostatic image including the above binder.

Binder and toner for developing electrostatic image containing the same

Toner for electrophotography and reinforcing agent for said toner

The nonmagnetic one-component toner is usable in a developer device including a developer roller and a blade, the blade serving to regulate a toner layer formed on the developer roller into a uniform thickness and to supply electric charges to the toner by triboelectric charging, and the nonmagnetic one-component toner includes at least a binder resin, a colorant, and an iron compound. Here, the binder resin includes a polyester resin as a main component, and the iron compound has the general formula (I) and is contained in an amount of between 0.1 parts by weight or more and less than 1.0 part by weight, based on 100 parts by weight of the binder resin.

Nonmagnetic one-component toner

A nonmagnetic one-component toner is produced by the steps of applying inorganic fine particles having an average particle diameter of not less than 30 nm and less than 100 nm to the surface of the toner having a binder resin and a colorant; and removing agglomerations of the inorganic fine particles remaining unadhered on the toner surface using a cyclone in a gas stream. The inorganic fine particles used in the present invention have a particle diameter in suitable ranges, so that the resulting toner can have suitable powder fluidity, and that these inorganic fine particles are less likely to be embedded into the inner portion of the toner by the nip pressure exerted by such members as the charging blade. Therefore, by using the toner of the present invention, a nonmagnetic one-component developing system with small variations in image density and image quality after continuous copying can be provided.

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Wakayama, Japan

Yasuhiro Hidaka