Mitsui Chemicals, Inc.

Mitsui Toatsu Chemicals, Incorporated

Katsuru Matsumoto

Nobuhiro Hirayama

Kenji Uchiyama

Shoji Kawasaki

Katsuo Uramoto

Tamami Fukui

Sumio Hirose

Eishi Tanaka

Yuko Suzuki

Hiroshi Mase

Takayuki Sanada

Junko Tobita

A lithographic printing original plate, a lithographic printing plate using the lithographic printing original plate and a process for producing the lithographic printing plate are disclosed. The lithographic printing original plate has, on a substrate, a photosensitive layer made of a crosslinked polymer comprising a hydrophilic polymer, a crosslinking agent and a light absorbing compound or comprising a hydrophilic polymer, a crosslinking agent, a light absorbing compound and a hydrophobic polymer, and has properties that the photosensitive layer is changed from ink-repellent to ink-receptive by irradiation with a light.

Lithographic printing plate

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

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

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Kyoto, Japan

Katsuru Matsumoto