Kao Corporation

Masahito Yamazaki

Satoshi Kunii

Koji Kameyama

Koji Akiyama

Takashi Kubo

Yoshihiro Fukushima

Hiroyuki Kawaji

Nobumichi Kamiyoshi

Yutaka Kanamaru

Kohei Katayama

Kouhei Katayama

Jiro Takemoto

A method for producing a positively chargeable toner, including: step 1: melt-kneading a toner raw material composition containing a resin binder, a positively chargeable charge control agent, and fine fluororesin particles, and a recycled powder; step 2: cooling a melt-kneaded mixture obtained in the step 1, and pulverizing a cooled mixture; and step 3: classifying a pulverized product obtained in the step 2, wherein the resin binder in the toner raw material composition contains 50% by mass or more of a polyester having a softening point of 125&#xb0; C. or higher and 170&#xb0; C. or lower. The positively chargeable toner obtainable by the method of the present invention is suitably used in developing latent images formed in, for example, an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or the like.

Method for producing positively chargeable toner

A toner for electrostatic image development containing toner matrix particles having at least a resin binder and a colorant, and an external additive, the external additive having composite oxide particles (an external additive A) that have titania and silica, wherein the external additive A has a core-shell structure in which a core portion has the titania and a shell portion has the silica, wherein the titania is present in the external additive A in an amount of from 75 to 95% by weight, and the resin binder comprising a polyester obtained by polycondensing a carboxylic acid component comprising an isophthalic acid compound and an alcohol component (a polyester A).

Toner for electrostatic image development

A toner for non-contacting fusing containing toner matrix particles containing a resin binder and an external additive having an average particle size of from 10 to 100 nm, wherein the external additive is externally added to the toner matrix particles, wherein the resin binder contains one or more polyesters, wherein a carboxylic acid component of the polyester contains one or more isophthalic acid compounds and one or more fumaric acid/maleic acid compounds, wherein the isophthalic acid compound is contained in an amount of from 10 to 35% by weight, the fumaric acid/maleic acid compound is contained in an amount of from 1 to 15% by weight, and the isophthalic acid compound and the fumaric acid/maleic acid compound are contained in a total amount of from 20 to 36% by weight, of a total amount of the entire raw material monomers of the polyester in the resin binder, and wherein the toner has a softening point of from 90&#xb0; to 120&#xb0; C. The toner is suitably used in developing latent images formed in, for example, electrophotography, an electrostatic recording method, an electrostatic printing method, or the like.

Toner for non-contact fusing

A toner for electrostatic image development containing a resin binder, a negatively chargeable charge control agent, and a positively chargeable charge control agent, wherein the resin binder contains at least one polyester, wherein a carboxylic acid component of the polyester contains isophthalic acid and/or an ester thereof and fumaric acid and/or an ester thereof, provided that if two or more polyesters are used, the carboxylic acid component is taken as an overall component, and wherein the negatively chargeable charge control agent contains a metal-containing azo dye and/or a metal complex of salicylic acid, and wherein the toner has a softening point of from 90&#xb0; to 120&#xb0; C. The toner for electrostatic image development of the present invention can be suitably used in developing latent images formed in, for example, electrophotography, an electrostatic recording method, an electrostatic printing method, or the like.

A toner for electrostatic image development, containing a resin binder and a wax, wherein the resin binder contains an amorphous polyester obtained by polycondensing a carboxylic acid component containing fumaric acid in an amount of from 55 to 100% by mole, with an alcohol component, wherein the wax contains an ester of pentaerythritol and a fatty acid having 15 to 25 carbon atoms, and a method of forming fixed images, including the step of applying the toner for electrostatic image development to a non-contact fixing type image-forming apparatus. The toner for electrostatic image development of the present invention is suitably used for, for example, developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.

A toner for electrostatic image development containing an external additive comprising composite oxide particles made of titania and silica (external additive A), and hydrophobic silica particles (external additive B), wherein the external additive A has a core-shell structure in which a core portion is made of titania and a shell portion is made of silica, wherein the titania is contained in the external additive A in an amount of from 75 to 95% by weight, and wherein the external additive B has a carbon content of from 2.8 to 6.0% by weight. The toner for electrostatic image development of the present invention is 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.

A toner for electrostatic image development containing (a) a toner matrix particle containing a resin binder, and (b) an external additive added to the toner matrix particles, wherein the resin binder contains a polyester A obtained by polycondensing an alcohol component and a carboxylic acid component containing isophthalic acid and/or an ester thereof, and wherein the external additive contains fine silica particles containing a metal or a metal oxide; and A method of forming fixed images including the step of applying the toner for electrostatic image development to an image-forming apparatus according to a non-contact fusing method. The toner for electrostatic image development of the present invention is suitably used in developing latent images formed in, for example, electrophotography, an electrostatic recording method, an electrostatic printing method, or the like.

A toner for electrostatic image development containing a resin binder and a charge control agent, wherein the resin binder contains a polyester A obtained by polycondensing a carboxylic acid component containing isophthalic acid and/or an ester thereof, and an alcohol component, and wherein the charge control agent contains an azo-iron complex represented by the formula (I): wherein each of Rand R, which may be identical or different, is a linear or branched alkyl group having 3 to 8 carbon atoms; each of R, R, R, and R, which may be identical or different, is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a halogen atom, a nitro group, or a carboxyl group; and Ais a cation. The toner for electrostatic image development is suitably used in developing latent images formed in, for example, electrophotography, an electrostatic recording method, an electrostatic printing method, or the like.

A process for preparing a toner for electrophotography containing mother toner particles which contain a resin binder containing a crystalline polyester and a linear amorphous polyester and an external additive, wherein the process includes an external addition step of mixing the mother toner particles and at least a part of the external additive and the step of carrying out a heat-treating step at the external addition step or later. The toner for electrophotography obtained according to the present invention is suitably used for, for example, developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.

Process for preparing toner for electrophotography

A toner in which mother toner particles containing at least a resin binder and a colorant are coated with an external additive, wherein the mother toner particles contain fine powders of a fluororesin having an average particle size of 1 &#x3bc;m or less in an amount of from 4 to 10 parts by weight, based on 100 parts by weight of the resin binder, and a toner in which mother toner particles containing at least a resin binder and a colorant are coated with an external additive, wherein the external additive contains fine powders of a fluororesin having an average particle size of 1 &#x3bc;m or less in an amount of from 0.3 to 2 parts by weight, based on 100 parts by weight of the mother toner particles. The toner of the present invention is suitably used for, for example, developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.

Toner and two-component developer

A positively chargeable toner comprising a resin binder, a specified compound represented by the formula (I), and a higher fatty acid with a long-chain alkyl group having 8 to 22 carbon atoms and/or a metal salt thereof. The positively chargeable toner is a positively chargeable toner used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

Positively chargeable toner

A toner for electrostatic image development, containing a resin binder containing a polyester having monomer units wherein at least one monomer is selected from the group consisting of fumaric acid and maleic acid, including mixtures thereof; a colorant; and a charge control agent containing a negatively chargeable charge control agent and a positively chargeable charge control agent, wherein the unreacted monomers of fumaric acid, maleic acid or both fumaric acid and maleic acid are contained in the toner in an amount of 0.20% by weight or less. The toner for electrostatic image development of the present invention may be used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

A toner comprising a resin binder, a colorant, and fine inorganic particles having a BET specific surface area of 30 m/g or less, wherein the fine inorganic particles are added as an external additive, wherein the toner has a storage modulus at 100&#xb0; C. using a 25 mm parallel plate of 7&#xd7;10Pa or less, a storage modulus at 60&#xb0; C. using a 7.9 mm parallel plate of from 3&#xd7;10to 1&#xd7;10Pa, and a storage modulus at 70&#xb0; C. using a 7.9 mm parallel plate of from 7&#xd7;10to 3&#xd7;10Pa; and a two-component developer comprising the toner. The toner can be used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

Toner

A toner comprising a resin binder, a colorant, and externally-added inorganic fine particles, comprising large-particle size inorganic particles comprising 50% by volume or more of particles having a particle size of from 100 to 583.9 nm, and having a BET specific surface area of 1 to 40 m/g. The toner can be used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

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Wakayama, Japan

Masahito Yamazaki