Kao Corporation

Hidenori Tachi

Yoshihiro Fukushima

Shinji Moriyama

Katsutoshi Aoki

Yasuyuki Tamane

Koji Akiyama

Masayuki Maruta

Takashi Kubo

Yasunori Inagaki

Yoshihiro Ueno

Hiroyuki Kawaji

Norihiro Fukuri

Jun Shimizu

Yutaka Kanamaru

Yoshitomo Kimura

Eiji Morimoto

A resin binder for use in a toner for electrophotography, containing a polycondensation resin obtainable by polycondensing an alcohol component containing an aliphatic polyhydric alcohol having two or more secondary carbon atoms with a hydroxyl group bound thereto (an alcohol A), and a carboxylic acid component, wherein the alcohol A is contained in an amount of from 10 to 100% by mol, of the alcohol component; and a toner for electrophotography containing the resin binder. The toner for electrophotography of the present invention is suitably used in developing latent images formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

Electrophotographic toner

A toner comprising a resin binder and a colorant comprising a composite oxide of two or more metals, wherein the composite oxide has a BET specific surface area of 0.5 to 7 m/g and a saturation magnetization of from 1 to 40 Am/kg; and a two-component developer comprising the above toner and a carrier having a saturation magnetization of from 40 to 100 Am/kg. 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 black colorant comprising a composite oxide of two or more metals, and a charge control agent comprising a quaternary ammonium salt. The toner is suitably used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

A resin composition having a softening point of from 80&#xb0; to 165&#xb0; C., obtained by reacting a poly Calkylene terephthalate having a melting point of 200&#xb0; C. or more with a low-molecular weight polyester having a number-average molecular weight of from 400 to 2500; a resin binder for a toner comprising the above resin composition; a toner comprising the above resin binder; a process for preparing a resin composition having a softening point of from 80&#xb0; to 165&#xb0; C., comprising the step of reacting a poly Calkylene terephthalate having a melting point of 200&#xb0; C. or more with a low-molecular weight polyester having a number-average molecular weight of from 400 to 2500. The resin composition can be suitably used as a resin binder for a toner used for developing electrostatic latent images formed in electrophotography, electrostatic recording method, electrostatic printing, and the like.

Resin composition

A toner for development of electrostatic latent images, comprising a resin binder comprising a resin having a softening point of from 120&#xb0; to 170&#xb0; C., a glass transition point of from 58&#xb0; to 75&#xb0; C., and a percentage of chloroform-insoluble component of from 5 to 50% by weight; and a resin having a softening point of 90&#xb0; C. or more and less than 120&#xb0; C., a glass transition point of from 58&#xb0; to 75&#xb0; C., and a percentage of chloroform-insoluble component of less than 5% by weight; and at least one low-melting point wax having a melting point of from 60&#xb0; to 90&#xb0; C. The toner for development of electrostatic latent images has low lowest fixing temperature and is excellent in the offset resistance, the blocking resistance and the durability.

Toner for development of electrostatic latent images

A toner for electrostatic image development comprising a high-softening point polyester having a softening point of 120&deg; C. or more and 170&deg; C. or less; a low-softening point polyester having a softening point of 80&deg; C. or more and less than 120&deg; C.; and a composite oxide of two or more metals, wherein the composite oxide has a BET specific surface area of 7 m /g or more. The toner is suitably used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.

Toner for electrostatic image development

A positively chargeable toner for two-component development comprising a resin binder; a colorant; a releasing agent comprising a wax having a melting point of 50&deg; to 120&deg; C.; and an external additive comprising a positively chargeable silica, the positively chargeable silica having an absolute deviation of an error of 0.1 or less, against an approximate straight line showing an adhesion state of silicon atoms to carbon atoms, and a free ratio of 5% or less, wherein the positively chargeable toner is usable together with a ferrite carrier having a saturation magnetization of from 40 to 100 Am /kg. This positively chargeable toner is used for development of an electrostatic latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.

Positively chargeable toner for two-component development

A full color toner for nonmagnetic one-component development 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 toners by triboelectric charging, the full color toner for nonmagnetic one-component development including (a) fine resinous particles including at least a colorant and a binder resin having a polyester resin as a main component; and (b) additives externally applied onto a surface of the fine resinous particles, the additives including inorganic fine particles consisting of positively chargeable, inorganic fine particles and negatively chargeable, inorganic fine particles when subjecting the additives to triboelectric charging with an iron powder.

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Wakayama, Japan

Hidenori Tachi