Bayer Aktiengesellschaft

Sony Corporation

Josef-Walter Stawitz

Horst Berneth

Friedrich-Karl Bruder

Serguei Kostromine

Rainer Hagen

Rafael Oser

Wilfried Haese

Thomas Bieringer

Thomas Sommermann

Peter Landenberger

Karin Hassenr&uuml;ck

Christoph Thiebes

Stephan Michaelis

Karin Hassenrück

Frank-Michael Stohr

Ulrich Feldhues

Joachim Wolff

Masanobu Yamamoto

Karl-Josef Herd

Wolfgang Harms

Manfred Hoppe

Hidetoshi Watanabe

Yuichi Sabi

Sakuya Tamada

Dietrich Hildebrand

Manfred Groll

Takashi Iwamura

Mitsuaki Oyamada

Joachim Grutze

Karl-Heinz Reinhardt

Max Schwarz

Karl-Heinz Schundehutte, Deceased

Rolf Schulz

Optical data carrier comprising a preferably transparent substrate which may, if desired, have previously been coated with one or more reflection layers and to whose surface a light-writeable information layer, if desired one or more reflection layers and if desired a protective layer or a further substrate or a covering layer have been applied, which can be written on or read by means of blue, red or infrared light, preferably laser light, where the information layer comprises a light-absorbent compound and, if desired, a binder, characterized in that at least one cyanine dye is used as light-absorbent compound.

Optical data carrier comprising a cyanine dye as light-absorbent compound in the information layer

An optical recording medium having at least a recording layerand a light transmitting layerformed on a substrate, in which the recording layeris made of an organic material for absorbing an incident light of wavelength of 360 nm to 460 nm, and inducing physical change or chemical change to vary the refractive index, the light transmitting layeris 10 &#x3bc;m to 177 &#x3bc;m in thickness, the relation between absorption coefficient 'k' and pyrolysis temperature Tof organic material is950(&#xb0; C.)&#x3c;(Tdec (&#xb0; C.)&#x2212;20)/k&#x3c;4100&#xb0; C.&#x2003;&#x2003;(1),and the absorption coefficient 'k' is k&#x3e;0.0.

Optical recording medium

The invention relates to an optical data carrier having a preferably transparent substrate that has optionally previously been coated with one or more reflection layers and to the surface of which has been applied a light-writeable information layer, optionally one or more reflection layers, and optionally a protective layer or a further substrate or a covering layer, such that the optical data carrier can be written on or read by means of blue light (preferably laser light having a specified wavelength) or by means of infrared light (preferably laser light having a specified wavelength), wherein the information layer contains

Optical data carrier comprising a phthalocyanine dye as light-absorbent compound in the information layer

The present invention relates to a process for preparing 1-amino-4-hydroxyanthraquinones of the formula (I)

Preparation of 1-amino-4-hydroxyanthraquinones

Process for preparing compounds of the formula (I)where

Preparation of styryl dyes

A novel crystal form of C.I. Solvent Orange 60 gives a higher space-time yield in dye synthesis and is more easily finished.

Crystal form of a perinone dye

Bridged perinones/quinophthalones

Preparation of styryl compounds

Optical data carrier comprising a preferably transparent substrate which may, if desired, have previously been coated with one or more reflection layers and to whose surface a light-writeable information layer, if desired one or more reflection layers and if desired a protective layer or a further substrate or a covering layer have been applied, which can be written on and read by means of infrared light, preferably laser light, particularly preferably light having a wavelength in the range 750-800 nm, in particular 770-790 nm, where the information layer comprises a light-absorbent compound and, if desired, a binder, characterized in that at least one cobalt(III) phthalocyanine in which the Co metal centre bears two axial substituents R and R which represent, independently of one another, CN, SCN, alkoxy or alkylthio is used as light-absorbent compound.

Optical data store comprising an axially substituted cobalt phthalocyanine in the light-writeable information layer

An optical data storage medium containing a preferably transparent substrate which has optionally already been coated with one or more reflecting layers and onto the surface of which a photorecordable information layer, optionally one or more reflecting layers, and optionally a protective layer or an additional substrate or a top layer are applied, which data storage medium can be recorded on and read using blue or red light, preferably laser light, wherein the information layer contains a light-absorbing compound and optionally a binder, characterized in that at least one diaza hemicyanine dye is used as the light-absorbing compound.

Optical data storage medium containing a diaza hemicyanine dye as the light-absorbing compound in the information layer

Optical data stores containing a Co-phthalocyanine complex in the information layer recordable using light

An optical data storage medium containing a preferably transparent substrate which has optionally already been coated with one or more reflecting layers and onto the surface of which a photorecordable information layer, optionally one or more reflecting layers, and optionally a protective layer or an additional substrate or a top layer are applied, which data storage medium can be recorded on and read using blue or red light, preferably laser light, wherein the information layer contains a light-absorbing compound and optionally a binder, characterized in that at least one triazacyanine dye is used as the light-absorbing compound.

Optical data storage medium containing a triazacyanine dye as the light-absorbing compound in the information layer

Reaction of pyrazolones and methyleneindolines with orthoformic esters is an advantageous one-step process for preparing asymmetrical methine dyes.

Process for preparing asymmetrical methine dyes

Preparation of arylaminohydroxyanthraquinones

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Odenthal, Germany

Josef-Walter Stawitz