Olympus Optical Company, Ltd.

Central Glass Company, Limited

Toagosei Chemical Industry, Co., Ltd.

Toshiyuki Kanno

Hitoshi Watanabe

Naoyuki Ueno

Yasuji Nagata

Hiroyuki Kato

Yoshio Abe

Kishiro Azuma

Shiro Kojima

Jun Kanehira

Kazuo Ueda

Kohei Hamanishi

Takashi Tsuda

Seiji Kondo

Yoshio Horio

Yasutaro Yasuda

Hideshi Takahashi

Yoshiko Uematsu

Shimako Nozaki

An optical information memory medium comprising a substrate, an improved underlying layer formed on the substrate surface, and a recording layer formed on the underlying layer and mainly consisting of an organic pigment is disclosed. In this optical information memory medium, the underlying layer is formed by causing a compound containing a hydroxyl or carboxyl group selected from the group consisting of a radical polymerizable monomer containing a hydroxyl or carboxyl group, a copolymer obtained from a monomer containing a hydroxyl or carboxyl group, and a polymer compound containing a hydroxyl or carboxyl group to react with a hydrolyzed condensate which is derived from an alkoxide or an aryloxide of a metal selected from the group consisting of Al, Ti, Zr, In, Zn, Mg, Ni, and Cu or from a chelate compound mainly consisting of the metal. An underlying layer formed of a hydrolyzed condensate which is derived from the alkoxide or the aryloxide of a metal selected from the group consisting of Al, Ti, Zr, In, Zn, Mg, Ni, and Cu is also disclosed.

Optical information memory medium

An erasable optical information recording medium has a transparent substrate, and a recording layer supported by the substrate. The recording layer includes a thin film of at least one polydiacetylene having side chains. The polydiacetylene is capable of undergoing a reversible planar-nonplanar transition of the main chain structure of the polydiacetylene due to a conformational change of the side chains produced by irradiation of light. When the recording layer is irradiated with light, the reversible planar-nonplanar transition occurs at the irradiated portions to cause a corresponding change of optical properties of the recording layer, thereby recording information thereinto and erasing information therefrom.

Optical information recording medium

An optical recording medium such as an optical disk, which is capable of reversibly repeating a recording/erasing cycle. This optical recording medium comprises a transparent substrate and recording layer formed on the substrate. This recording layer comprise a liquid crystalline high polymer having side chains and a dyestuff having a recording-light absorbing property. The side chain may preferably comprises mesogen group, a monocyclic or polycyclic compound such as phenyl, benzyl, naphthyl or anthryl group, and alkyl or aryl group having 1 to 18 carbon atoms.

Optical recording medium

An optical information recording medium has an optical information recording layer and a carrier for carrying said recording layer. The recording layer contains at least one organic dye represented by a formula: ##STR1## where R is a substituted or nonsubstituted phenylene group or naphthylene group, L is a methyne-based group, and Y is an unsaturated organic group.

An optical information recording medium includes an optical information recording layer supported on a substrate. The recording layer contains an organic dye represented by general formula: ##STR1## where R is 1,2-naphthylene group, 2,3-naphthylene group, 3,4-naphthylene group, or ##STR2##

A magnetic recording medium having a modified surface, consisting essentially of (a) a substrate, (b) a ferromagnetic metal thin film formed on one side of the substrate by a vacuum deposition method, an ion plating method, a sputtering method or a plating method and (c) a lubricating coating layer formed on the thin film or on the back of the substrate or on both of them. The recording medium has an improved running stability, durability and corrosion resistance.

Magnetic recording medium having a lubricating coating layer

A method of forming a colored and/or electrically conductive coating layer on a glass sheet by applying a paint containing an inorganic pigment and/or a metal powder together with a powdered glass frit and an organic liquid binder onto the glass sheet, by screen-printing for instance, so as to form a paint layer on the glass sheet surface, rendering the paint layer hard and untacky and thereafter firing the paint-applied glass sheet so as to melt the glass frit contained in the paint. The organic liquid binder comprises at least one acrylate which is selected from monofunctional acrylates and bifunctional acrylates and is polymerizable by radiation of ultraviolet rays. Hardening of the paint layer is accomplished by ultraviolet radiation of very short duration, and the polymerized acrylate can be completely burnt out at the firing step without leaving unburnt carbon which is detrimental to the coating layer.

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Tokyo, Japan

Toshiyuki Kanno