Teijin Limited

Kiyoshi Chiba

Masahiko Sekiya

Utami Yonemura

Shigenobu Sobajima

Yuji Mitani

Kazutomi Suzuki

Kunio Itoh

Tetsuo Sato

Takashi Tomie

Norio Takagi

Hiroshi Okaniwa

Eiichi Hashimoto

Takayuki Ishizaki

Atsushi Oyamatsu

Kimio Kinoshita

Hiromitsu Ino

Kazuto Tokumitsu

Tohru Horiguchi

Tomokazu Umezawa

Tadanori Nakatani

Yoshihiko Takeda

A magneto-optical recording medium in which direct overwriting can be done by only modifying the power level and/or the pulse width of applied optical pulses, and without changing the direction of the bias magnetic field. The recording layer comprises first and second magnetic recording layers. The first magnetic layer is a rare-earth transition metal-amorphous alloy and has a perpendicular easy magnetization axis, a thickness of 10 to 200 nm, and a compensation temperature above room temperature. The second magnetic layer comprises an alloy of a first component of Co and/or Fe and a second component of a rare earth metal and/or a noble metal or an alloy of Co and at least one metal selected from Ti, Cr, Mn, Cu, Zn, Ga and Ge. The second magnetic layer is a material having an in-plane easy magnetization axis such that it has a magnetization axis parallel to the second magnetic layer if formed independently on a dielectric layer, the second magnetic layer having a thickness of not more than 3 nm.

Magneto-optical recording medium

A magneto-optical recording medium having an improved durability or reliability is obtained by providing a protecting layer of an alloy of titanium with one or more of chromium, rhenium and tantalum. This titanium alloy protecting layer has an improved resistance to oxygen, water, chlorine, and acids, etc. and provides an improved resistance to the environment and attacks from the synthetic resin substrate or other layers constituting the medium, such as a dielectric layer and a reflecting layer.

A magneto-optical layer sensitive to a light with a short wavelength such as 400 to 550 nm and having a perpendicular magnetization can be deposited on a substrate at a room temperature. The magneto-optical layer is of a tertiary polycrystalline having a composition, for example, Co.sub. aPt.sub.b Ru.sub.c where 20.ltoreq.a.ltoreq.70, 10.ltoreq.b.ltoreq.70, 10.ltoreq.c.ltoreq.60 and a+b+c=100 or Co.sub.d Pt.sub.e Re.sub.f where d.ltoreq.80, 5.ltoreq.e, 5.ltoreq.f, 40.ltoreq.4d-5f and d+e+f=100, and has an easy magnetization axis perpendicular to the main surface of the layer.

Magneto-optical layer and magneto-optical recording medium

The reproduction characteristics, particularly the C/N ratio of a reproduced signal of an optical recording medium are deteriorated by an unevenness or deformation of an optical recording layer due to a convex or concave configuration of underlying guide means that are formed on the surface of the substrate. This deterioration can be prevented by disposing a leveling layer under the recording layer, but the leveling layer lowers the efficiency of the servo tracking. This lowering of servo tracking efficiency is prevented by insertion of a dielectric layer between the leveling layer and the guides.

Magneto-optical recording medium comprising a specified substrate

A magneto-optical recording medium, comprising a substrate, a magneto-optical recording layer on the substrate, a transparent thermally-insulating layer of one selected from the group consisting of tantalum oxynitride and tantalum oxide on the magneto-optical recording layer, and a metal reflecting layer on the transparent thermally-insulating layer, the metal reflecting layer having a thermal conduction represented by a product of a thermal conductivity multiplied by a layer thickness of not less than 1.3.times.10.sup.-6 WK.sup.-1. Heat dispersion is improved while maintaining a high recording sensitivity.

In the magneto-optical recording medium with a transparent substrate, a film of dielectric indium oxide, tin oxide or metallic Ti is interposed between the substrate and the recording layer, to prevent deterioration of the properties thereof.

An optical recording medium comprising a transparent dielectric layer as a protecting and/or enhancing layer is provided, wherein the transparent dielectric layer is made of an oxide of at least one metal selected from the group consisting of indium, tin and tantalum, the oxide further containing at least one element selected from the group of nitrogen and bismuth. This transparent dieletric layer has an excellent adhesivity to a resin substrate, a low internal stress, and a high refractive index.

Optical recording medium

A metal reflecting layer of an aluminum or silver alloy containing gold has a lower thermal conductivity than aluminum or silver and gold while maintaining a high reflectivity, and thus an optical recording medium, particularly a magneto-optical recording medium, having a high recording sensitivity and a C/N ratio, as well as an improved durability, can be provided. The content of Au in the Al alloy is 0.5-20 at % and that in the silver alloy is 0.5-30 at %. Preferably, at least one of the group consisting of titanium, tantalum, zirconium and yittrium is added to an alloy of Al or Ag with Au, and the content of at least one of the group consisting of titanium, tantalum, zirconium and yittrium is preferably 0.3-5.0 at % in an Al-Au alloy and 0.3-12.0 at % in an Ag-Au alloy. More preferably, the total content of Au and at least one of the group consisting of titanium, tantalum, zirconium and yittrium is 1.0-15 at %.

An optical recording medium, particularly a magneto-optical recording medium, resistant to oxidation deterioration even in a hot and humid atmosphere, is provided by forming an organic protecting adhesive layer of a UV-curved resin having (1) an acid value of not more than 1.5; and (2) a softening point of not less than 50.degree. C. The UV-curved resin layer comprises 15 to 85% by weight of acrylate and/or methacrylate having at least three functionalities; 15 to 70% by weight of a compound having a linear structure and having a molecular weight of at least 300, the compound preferably having at least one ethylenically unsaturated bond and a molecular weight of at least 150 per ethylenically unsaturated bond; and (3) a photopolymerization initiator.

Amorphous alloy and production method thereof

A laminated multilayer sheet structure composed of (A) an opaque flexible sheet layer and (B) a flexible layer laminated to the surface of layer (A) and composed of a transparent thermic ray reflecting layer (B.sub.1) bonded to a transparent synthetic resin layer (B.sub.2). The sheet structure may be applied to the surface of a floor, wall, ceiling, partition or piece of furniture for indoor heat insulation.

Laminated multilayer sheet structure and its utilization

An insulative multi-pane window structure of a refrigerator or freezer, said structure being interposable between a colder inside region and a warmer outside region of the refrigerator or freezer to permit vision therebetween and including at least a first pane having a surface exposed in use to humidity-bearing air in the warmer region and a second pane opposite to and spaced apart from the first pane, at least one of the first and second panes having an infrared reflecting coating attached in a specific manner; characterized in that said infrared reflective coating is a transparent, electrically conductive laminated structure composed of

Insulative multi-pane window structure of refrigerator or freezer

A transparent, electrically conductive laminated structure composed of

Transparent, electrically conductive laminated structure and process for

When a file having coated thereon an electrically conductive coating which is transparent in a highly oxidized state and non-transparent in a lowly oxidized state or in a reduced state, such as a coating of indium oxide, is heated electrically or by laser beams or oxidized and/or reduced by electrolytic reaction, images consisting of transparent and non-transparent areas are formed on the film. This can be utilized, for example, in a facsimile system.

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Chofu, Japan

Kiyoshi Chiba