Kabushiki Kaisha Hayashibara Seibutsu Kagaku Kenkyujo

Matsushita Electric Industrial Co., Ltd.

Dai Nippon Printing Co., Ltd.

Ishihara Sangyo Kaisha, Ltd.

Kabushiki Kaisha Nippon Kanko Shikiso Kenkyusho

Shigeo Yasui

Toshio Kawata

Chiaki Kasada

Kentaro Yano

Yasushi Aizawa

Ayashi Noguchi

Katsumi Orita

Masashi Ono

Hiroshi H Eguchi

Tatsuo Uchida

Ryohei Takiguchi

Sadaharu Suga

Komei Kafuku

Kei Takahata

Seiko Kobayashi

Ayako Hohsaka

Shigeru Kishino

Dai Matsuura

Masakuni Ohkawa

Shigeo Senzai

Yoshie Hata

The present invention provides organic dye compounds having their absorption maxima in a region ranging from the ultraviolet region to a relatively short wavelength visible region and uses thereof. The present invention provides specific monomethine cyanine dyes, light absorbents and optical recording media comprising the monomethine cyanine dyes, and a process for producing the monomethine cyanine dyes which comprises a step of reacting a quaternary ammonium salt of nitrogen atom-containing heterocyclic compound having a reactive methyl group with a quaternary ammonium salt of nitrogen atom-containing heterocyclic compound having an appropriate leaving group.

Cyanine dyes

The present invention provides styryl dyes which have absorption maxima at a wavelength of 400 nm or less and are sensitive to a laser beam with a wavelength of 450 nm or less, light absorbents and optical recording media which comprise the styryl dyes, and a process for producing the styryl dyes which comprises reacting with an aldehyde compound a quaternary ammonium salt of nitrogen atom containing heterocyclic compound having an active methyl or active methylene group.

Styryl dye

Optical recording media using mixtures of benzoindolenic trimethine cyanine dyes, where the first benzoindolenic trimethine cyanine dye bears a heterocyclic azo dye metal complex as the counterion and the second benzoindolenic trimethine cyanine dye has a different type of counterion. This combination of these benzoindolenic trimethine cyanine dyes coated on a substrate results in high density media, where the dyes have a high solubility and heat resistance.

Cyanine dye

The present invention provides organic compounds which improve the light resistance of organic dye compounds without substantially deteriorating their preferable light properties when applied to them, and have satisfactory solubility in organic solvents and compatibility with organic dye compounds. The object of the present invention is solved by formazan metal compounds which comprise specific formazan compounds as ligands; process thereof; light-resistant improvers, optical recording media, and light absorbents, which all comprise the formazan metal complexes; and formazan compounds as intermediates for producing the formazan metal complexes

Formazan metal complex

The object of the present invention is to provide organic dye compounds which exert satisfactory optical absorption properties and thermal resistance when used in high density optical recording media. The above object is solved by specific trimethine cyanine dyes, light absorbents and optical recording media which comprise the cyanine dyes, and preparations for the cyanine dyes comprising either reacting a benzoindolium compound having a compatible leaving group with a pyrazinoimidazolium compound having a reactive methyl group; or reacting a benzoindolium compound having a reactive methyl group with a pyrazinoimidazolium compound having a compatible leaving group.

The present invention provides organic dye compounds which exert excellent recording characteristics in high-density optical recording media, and uses thereof. The present invention solves the objects of the present invention by providing non-symmetric trimethine cyanine dyes having a specific structure and properties, light absorbents and optical recording media comprising the cyanine dyes, and a process for preparing the cyanine dye comprising a step of reacting either 3,3-dimethyl-5-nitroindolium compounds or 3,3-dimethyl-5-sulfonamideindolium compounds, which have a reactive methyl group or an appropriate leaving group, with 3,3-dimethylbezoindolium compounds, which have a reactive methyl group or an appropriate leaving group.

Heat transfer sheet

A novel organic compound, 7,7,8,8-tetracyanoquinodimethane having a higher alkyl group containing at least ten carbon atoms, may be formed in a monomolecular layer or film by Langmuir-Blodgett's technique.

7,7,8,8-tetracyanoquinodimethane and method for preparing the same

New dichroic dyestuffs for the guest-host type liquid crystal and new liquid crystal compositions containing said dyestuff having an excellent improved dichroism and being prepared by introducing at least one group selected from the group consisting of phenyl, cyclohexyl, phenylcarbonyloxy and phenyloxycarbonyl group into a phenyl, a cyclohexyl or a naphthyl group at its 4-position, which is arranged at the end of a known dichroic dyestuff molecule along the major axis of the molecule.

Dichroic dyestuffs for liquid crystal and liquid crystal composition

In an electrophotographic photosensitive material comprising an electroconductive substrate having positioned thereon a photosensitive layer comprising as main components titanium dioxide and a binding material, the photosensitivity and whiteness can be improved by allowing a specific cyanine dye compound to exist in said photosensitive layer.

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Okayama, Japan

Shigeo Yasui