Konishiroku Photo Industry Co., Ltd.

Konica Corporation

Sekisui Chemical Co., Ltd.

Japan Synthetic Rubber Co., Ltd.

Takahira Kasuya

Goichi Yamakawa

Hideaki Morita

Makoto Tomono

Jiro Takahashi

Hiroyuki Takagiwa

Tsuneo Wada

Ken-ichi Kishi

Isao Furuta

Keiji Sato

Minoru Tsuneyoshi

Hiroyuki Yamada

Yoshiaki Kobayashi

Meizo Shirose

Masafumi Uchida

Satoru Ikeuchi

Shinichiro Yasuda

Kunio Ito

Minoru Kohara

Tadashi Kaneko

Hiroya Masaki

Hirozo Funaki

Kenzi Tuzita

Shoichi Nakano

Fumio Koizumi

There is disclosed a color toner having an excellent fixability, an improved antioffset property and a superior transparency of an image fixed on an OHP sheet. The color toner comprises 100 parts by weight of a polyester resin prepared by condensation polymerization of the following components (1) and (2), 0.1 to 5 parts by weight of a zinc complex of an aromatic oxycarboxylic acid which may have a substituent, and 1 to 20 parts by weight of a colorant;

Color toner

The present invention relates to toners for electrophotography wherein the main resin component comprises a lower molecular weight polymer and a higher molecular weight polymer each of which is different from the other wherein the higher molecular weight polymer has a glass transition point of at least 50.degree. C. and the lower molecular weight polymer has a glass transition point no higher than 65.degree. C. The above polymers comprise one or more polymers selected from styrene polymers, arcylic polymers, and styrene-acrylic copolymers. Generally, the lower molecular weight polymer has a weight average molecular weight of 50,000 or less and the higher molecular weight polymer has a weight average molecular weight of 80,000 or more.

Toner for electrophotography

A toner for developing an electrostatic latent image containing a polyester resin binder obtained by condensation polymerization of a diol component and a mixture of acid components. The acid components are an aliphatic unsaturated dicarboxylic acid or an acid anhydride thereof and a polybasic carboxylic acid having not less than three carboxylic acid groups or an acid anhydride thereof. A ratio of the polybasic carboxylic acid having not less than three carboxylic acid groups or the acid anhydride thereof to the total acid components is in the range of from 5 mol % to less than 30 mol %.

Developer composition for developing electrostatic image and toner image

Toner for developing an electrostatic latent image comprising (a) a polyester resin obtained by polymerizing a composition containing an alcohol and a carboxylic acid, at least one of said alcohol and carboxylic acid containing multifunctional component of not less than tri-valents and (b) an epoxy resin.

Toner for developing electrostatic latent image

The present invention relates to toners for developing electrostatically charged images which are comprised of a polyester binder resin condensed from diols of the formula ##STR1## with a polyhydric carboxylic acid or a derivative thereof wherein the polyhydric carboxylic acid is a mixture of dihyridic carboxylic acid or its alkylesters and about 30 mole % to about 80 mole % of the total acid content of more hydric carboxylic acids or therein hydrids.

Toner for developing an electrostatically charged image

A developer for developing an electrostatic latent image comprising colored electroscopic particles and at least one silicon dioxide powder having its particles made hydrophobic with a specified organosilicon compound is disclosed. Silicon atoms in said organosilicon compound are bonded to silicon atoms on the surface of individual silicon dioxide particles through oxygen atoms. At least one organic group in the organosilicon compound has a total carbon number of 8 or more and is a saturated or unsaturated aliphatic organic group with at least 5 carbon atoms or an organic compound having a hydrocarbon ring. In a preferred embodiment, such a silicon dioxide powder is used in combination with another silicon dioxide powder whose particles are rendered hydrophobic by an organosilicon compound wherein any of the organic groups present has a total carbon number of 7 or less and is a saturated or unsaturated organic group with not more than 4 carbon atoms or an organic group having a hydrocarbon ring.

Developer for electrostatic latent image and method of forming image

A method of fixing a toner image on a supporting member by bringing the supporting member supporting thereon the toner image into pressure contact with a fixing roller, wherein an elasticity improving agent for increasing the elasticity of the toner upon coming into contact with the toner is disposed on a member which comes into direct or indirect contact with the outer circumferential surface of the fixing roller. The elasticity improving agent is a material causing the reaction which increases the molecular weight of the binder resin of the binder and/or a reaction promoter for such a reaction. The elasticity improving agent is selected from a group consisting of:

Method of fixing toner image

There are disclosed an electrostatic image developer which comprises a carrier comprising iron powder particles coated with a resin and a toner comprising a low molecular weight polypropylene, and an electrostatic image developer which further comprises as binder a homopolymer of a styrene or a copolymer of a styrene with an another vinyl monomer containing 10 to 70% by weight of a high molecular component having a molecular weight of 100,000 to 10,000,000. The electrostatic image developer of the present invention can accomplish good developing without forming fogging even when provided in a great number of developments, thus exhibiting a great durability, and is also free from image contamination by the off-set phenomenon to give an excellent copied image.

Developer composition for developing an electrostatic image

An electrostatic image developing toner comprises a binder resin which contains at least 60% by weight of a styrene-butadiene copolymer. The copolymer contains a component A having a molecular weight of at least 100,000 in an amount of at least 20% by weight relative to the binder resin, and a component B having a molecular weight of at least 500,000 in the component A is not more than 15% by weight relative to the binder resin. The toner has adequate flowability and noncoagulation property and is capable of forming a superior visible image in a contact heat fixing system.

Electrostatic image forming toner

A method for manufacturing a toner for use in electrophotography comprising polymerizing a monomer to provide the polymer constituent of the toner in the presence of both a coloring agent and an anti-offset agent. Specific anti-offset agents are set forth and the toner made by the foregoing process is also disclosed.

Method for manufacturing toner for electrophotography

A toner for developing an electrostatic latent image comprising a resin prepared by emulsion polymerization of a first polymer to yield a first emulsion, emulsion polymerization of a second polymer to yield a second emulsion, mixing said first and second emulsions and coagulating said mixture, wherein said second polymer has characteristics different from those of said first polymer.

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Hachioji, Japan

Takahira Kasuya