Mitsui Toatsu Chemicals, Incorporated

Mitsui Chemicals, Inc.

Nobuhiro Hirayama

Kenji Uchiyama

Shoji Kawasaki

Hisatomo Sato

Hiromi Akiyama

Masaaki Shin

Akira Misawa

Katsuru Matsumoto

Tetsunosuke Shiomura

Kazumi Mizutani

Yoshiho Sonobe

Masahiro Kouno

Norihide Inoue

Akio Fujiwara

Katsuo Uramoto

Tamami Fukui

Keiichi Ishikawa

Eishi Tanaka

Kazuya Tsukamoto

Junko Tobita

Tateo Otsuki

Katuo Uramoto

A resin composition is provided for an electro-photographic toner. The composition comprises 5 to 95 parts by weight of a high molecular weight vinyl copolymer polymer and 95 to 5 parts by weight of a low molecular weight vinyl copolymer. The former ethylene polymer has a weight average molecular weight (Mw) of from 200,000 to 1,000,000 and a ratio (Mw/Mn) of the weight average molecular weight (Mw) to a number average molecular weight (Mn) of from 8 to 300, and the latter vinyl copolymer has a weight average molecular weight of from 3,000 to 20,000. At least one of the former and latter vinyl copolymer, preferably, the former vinyl copolymer is an ethylene polymer which has been obtained by conducting polymerization in the presence of a monomer having an ionization potential of from 10.0 to 15.0 eV and a difference of from 9.0 to 15.0 eV in level between a highest occupied molecular orbital (HOMO) and a lowest unoccupied molecular orbital (LUMO), both determined by computational chemistry. The resin composition shows excellent charging characteristics even without a charge control agent or with a charge control agent in a reduced amount. A toner containing the resin composition is also provided.

Resin composition for electrophotographic toner, and toner

Described herein are propylene waxes and a production process thereof. The waxes are each produced by polymerizing propylene in a reaction vessel while using a solid catalyst in the presence or absence of an organoaluminum compound. A hydrogen partial pressure of a gas phase in the reaction vessel, said gas phase being formed of the propylene and hydrogen, is maintained at 10% or higher. The solid catalyst is formed of a transition metal compound or a reaction product between the transition metal compound and an organometallic compound, an aluminoxane and a fine particulate carrier. Also described herein is a heating-roll fixing type toner composition composed essentially of a binder resin or a binder resin composition, a colorant and, as a releasing agent, the wax.

Syndiotactic polypropylene wax, production process thereof, and heating

A toner composition for electrophotography comprises at least a binder, a coloring agent and optionally a low molecular weight wax in an amount ranging from 0.5 to 20 parts by weight per 100 parts by weight of the binder as essential components wherein the binder comprises, as a principal component, a resin mixture prepared by heating a resin solution comprising a styrene resin and a block copolymer which comprises blocks derived from at least one member selected from ethylenic hydrocarbons and conjugated diene hydrocarbons and blocks derived from styrene and/or a hydrogenated product thereof in an amount ranging from 0.1 to 20 parts by weight per 100 parts by weight of the styrene resin to remove the solvent. The low molecular weight wax may be included in the binder.

Toner composition for electrophotography

A resin composition for an electrophotographic toner is here disclosed which comprises an ethylene series high polymer (Y) and an ethylene series polymer (X) prepared from 100 parts of a bifunctional ethylene series unsaturated monomer and 0.01-10 parts by weight of a substance having three or more peroxide groups in the molecule and/or a substance having one or more unsaturated functional groups and one or more peroxide groups in the molecule, Mw/Mb (Mw is weight-average molecular weight, and Mb is weight-average molecular weight between crosslinking points) of said polymer (X) being from 2 to 99, Mw of said polymer (X) being 50,000 or less. This resin composition is excellent in the balance of various physical properties required for the toner, and particularly, it is excellent in offset resistance and toner strength.

Resin composition for electrophotographic toner

A resin composition for use in an electrophotographic toner which comprises an ethylenic polymer (L) having a M.sub.w of not greater than 20,000 and an acid value of 2 to 100 mg KOH/g, and an ethylenic polymer (H) having a M.sub.w of not less than 150,000, a M.sub.w /M.sub.n ratio of not less than 5.0 and a time constant for triboelectric charging (.tau.) of 1.2 to 25, the ethylenic polymers (L) and (H) being present in a weight ratio ranging from 15:85 to 85:15. This resin composition can improve the triboelectric charging properties of the toner.

Resin composition for use in an electrophotographic toner

The present invention provides electrophotographic toner which comprises as a principal component a mixture of 20-80 parts by weight of a first ethylene polymer (X) whose weight-average molecular weight (Mw) is at least 200,000 and a second ethylene polymer (Y) whose Z average molecular weight/number-average molecular weight (Mz/Mn) is at least 6 and Mw is not greater than 50,000. According to this invention, electrophotographic toner of wide non-offset range can be obtained and, images of stable quality in a low heat quantity, which have not been attained by the prior art, can be obtained.

Electrophotographic toner having two ethylene polymers

This invention discloses electrophotographic toners and the methods for their preparation. The electrophotographic toners contain resin and coloring agents as primary components. The resin is a non-crosslinked polymer of vinyl monomers or its mixtures, and has a number average molecular weight (Mn) of 2,000-15,000, a Z average molecular weight (Mz) of not less than 400,000 and Mz/Mn of 50-600. The electrophotographic toners exert an excellent fixing ability at high duplication speed or at lower temperatures.

Electrophotographic toner production process

Electrophotographic toner composition

Herein disclosed is a binder for dry toners which comprises a copolymer resin obtained by reacting 10 to 50% by weight of a polyester resin which has free carboxyl groups, whose acid value ranges from 10 to 100 and whose number-average molecular weight ranges from 1,000 to 5,000 and 90 to 50% by weight of a mixture of a vinyl compound having a glycidyl group and the an another vinyl compound, wherein the amount of the vinyl compound having a glycidyl group corresponds to the number of the glycidyl groups equal to 0.25 to 1.5 time that of the carboxyl groups present in the polyester resin. The binder for dry toners is used in the electrophotography technique.

Binder for dry toner

Electrophotographic toner

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Hiratsuka, Japan

Nobuhiro Hirayama