Fuji Photo Film Company, Limited

Nippon Zeon Company, Ltd.

Masao Yabe

Yoshio Inagaki

Keiichi Adachi

Kyoichi Naruo

Takeji Ochiai

Mitsuru Sawano

Yoshio Tani

Tamotsu Suzuki

Sumitaka Tatsuta

Masayoshi Sekiya

Shinichiro Ohara

Younosuke Takahashi

Yoshihisa Usami

Takanori Hioki

Masaki Okazaki

Yusuke Ishihara

Ryuji Shirahata

Seiichi Watanabe

Yasuo Nishikawa

Yoshihiro Jimbo

Naoto Yanagihara

Noriyuki Hosoi

Akio Yanai

Yonosuke Takahashi

Nobuyuki Yamamoto

Hideki Matsuzawa

Manabu Higuchi

Tadashi Irie

Tetsuji Jitsumatsu

Hideki Matsubara

Ken Kawatta

Kazuhiro Ono

A heat-sensitive recording material for laser recording is provided including a support having thereon a heat-sensitive layer including at least a first substantially colorless coloring component, a second substantially colorless coloring component which reacts with the first substantially colorless coloring component to develop a color, and an infrared-absorbing dye.

Heat-sensitive recording material for laser recording

A cyanine compound of the following formula: ##STR1## wherein T.sup.1 and T.sup.2 each independently represents an atomic group which is necessary for forming a condensed benzene ring; L.sup.3 represents a methine group or a trivalent connecting group formed by conjugated double bonding of 3, 5 or 7 methine groups; R.sup.21, R.sup.22, R.sup.23 and R.sup.24 each independently represents an alkyl group having 1 to 12 carbon atoms or a phenyl group both of which may or may not be substituted; Y is an anion and q is a number which is necessary for neutralizing a positive charge; provided that at least one of R.sup.21, R.sup.22, R.sup.23 and R.sup.24 is an alkyl group having 3 or more carbon atoms and which may or may not be substituted when L.sup.3 consists of 1, 3 or 5 methine groups. The cyanine compound can be used as a coloring material, a sensitizing dye for photographic use, a recording dye for use in optical information recording media, a staining agent, a pharmaceutical agent, and the like. Further, the cyanine dye can be used in an optical filter and in an optical information recording medium.

Cyanine compound having a hetero ring containing an imidazole nucleus

An optical information recording medium for carrying out recording, readout or erasing by laser beam which comprises a support having carried thereon a recording layer containing dye(s) represented by the general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 independently represent substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups, or substituted or unsubstituted aryl groups, L represents a substituted or unsubstituted methine group, or a linking group formed by linkage of 3, 5 or 7 substituted or unsubstituted menthine groups through conjugated double bonds, Z represents an atomic group for completing an aromatic ring optionally having substituent(s), and X.sup.- represents a monovalent or divalent anion for neutralization of electron charge of the cationic part. The present optical information recording media have adequate recording characteristics and have a dye recording layer which is capable of maintaining the characteristics over a long period and thus is excellent in stability.

Optical information recording medium

A method of optically recording information on an information recording medium comprising a disc-shaped substrate having a pregroove comprising a groove having a depth of 800 to 2,000 angstroms and a half width of 0.2 to 0.7 .mu.m thereon, a recording layer comprising a dye for optically recording information by means of a laser beam which is provided on the substrate, and a reflecting layer of a metal which is provided on the recording layer is disclosed. The recording method is carried out by irradiating a bottom part of the pregroove having the recording layer thereon with a laser beam from the substrate side under rotation of the recording medium. Further, an information recorded medium which is recorded with information by the above method is also disclosed.

Method for optically recording information and information recorded

Disclosed is an information storage medium having an air-sandwich structure which comprises two disc-shaped substrates joined together through a ring-shaped inner spacer and a ring-shaped outer spacer. These spacers are made of the same kind of resin as those forming the disc substrates and the resin of the spacers has a viscosity-average molecular weight larger than that of the resin of the substrates. Also disclosed is a process for producing the information storage medium by joining the spacers to the disc substrates by means of ultrasonic welding.

Information storage medium and process for producing the same

An optical information recording medium for carrying out recording, readout or erasing with layer beams, which comprises a support having carried thereon at least one compound represented by the general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 independently represent substituted or unsubstituted alkyl groups, or substituted or unsubstituted aryl groups, Z represents an atomic group for forming a substituted or unsubstituted aromatic ring, and L represents a linking group for forming a carbocyanine. The present optical information recording media have an excellent recording performance and stability, and dyes used therein have no explosive property and thus can safely and readily be prepared.

The present invention relates to an optical information recording medium which comprises a support having provided thereon recording layer(s) on which information can be recorded and/or read out with a laser beam, wherein the recording layer contains at least one of the compounds represented by the following formula (I): ##EQU1## wherein .phi. and .PSI. each represents a heterocyclic residue having nitrogen atom(s), and L represents an optionally substituted methine group, or an optionally substituted trimethine, pentamethine, heptamethine or nonamethine group each formed by linkage through conjugated double bonds, provided that L and at least one of .phi. and .PSI. combine to form a ring; and X.sup.1 .theta. represents a 1-valent negative ion and l represents 1, 2 or 3, provided that X.sup.1 .theta. may bind to .phi., L or .PSI. as a substituent is provided by the invention.

An optical recording medium comprising at least one recording layer on a substrate and a protective layer overlying the recording layer, the protective layer comprising a UV cured resin composition containing a urethane acrylate, N-vinylpyrolidone, a trifunctional or higher functional acrylate, and a photoinitiator.

Optical recording medium

The present invention is directed to an optical information recording medium for carrying out recording, readout and erasing with laser beams which comprises a support having carried thereon at least one of the compounds represented by the following general formulae (I), (II), (III) and (IV): ##STR1## wherein X and X' each represents an atomic group necessary for forming a carbon ring or an atomic group necessary for forming a specific heterocyclic ring; L.sup.1 mainly represents a methine group, or a group formed by linking 3 or 5 methine groups in turn to form conjugated double bonds; and Q and Q' each represents an atomic group whereby a conjugated double bond chain is completed; ##STR2## wherein L.sup.1 and Q are as defined in general formula (I); Z represents an atomic group necessary for forming a carbon ring or heterocyclic ring; R.sup.1 to R.sup.3 and E represent various substituents; and M represents an ion, etc.; ##STR3## in the above general formulae (III) and (IV), A represents an atomic group necessary for forming a pyridine, pyrimidine, pyrazine or triazine ring; and L.sup.2 represents a methine group, or a group formed by linking 3 or 5 methine groups in turn to form conjugated double bonds. Optical information recording media of the invention each have a high C/N and thus adequate recording characteristics, and have a high stability with respect to long-term preservation or long-time reading. These effects may further be enhanced by using a singlet oxygen quencher.

A process for the preparation of an information recording medium comprising a substrate and a recording layer for writing and/or reading information by means of a laser beam which is provided on the substrate, wherein said recording layer is formed on the substrate by coating a solution which contains a dye in a solvent containing diacetone alcohol over the substrate to form a dye-coated layer, and drying the coated layer is disclosed. Also disclosed is a process for the preparation of an information recording medium comprising a substrate, an intermediate layer and a recording layer, superposed in order.

Process for the preparation of information recording medium

A novel information recording medium comprising a substrate and a recording layer for writing and/or reading information by means of a laser beam which is provided on the substrate is disclosed. The recording layer contains a dye having at least one chromophore selected from the group consisting of an amidinium ion chromophore, a carboxyl ion chromophore and a dipolar amide chromophore, and an organic solvent-soluble silver salt. Alternatively, the recording layer contains said chromophore and this recording layer is arranged in contact with a layer of an organic solvent-soluble silver salt.

Information recording medium

The present invention relates to an optical information recording medium for carrying out recording, reproduction and erasing with laser beams which comprises a support having carried thereon at least one methine dye which consists of an azulene nucleus, at least one of 10 carbon atoms of which is replaced by chalcogen atom(s) and/or nitrogen atom(s), and further whose 7-membered ring part is substituted with a methine bond having at the terminal an auxochrome which forms a conjugated resonance chromophore together with a 10 .pi. electron system of the nucleus. Optical information recording media of the invention have adequate recording characteristics having high C/N, and have high stabilities against long-term preservation or against long-time reading.

Disclosed is an optical disk used as a recording medium of the type described as an air-sandwiched structure including two disk-shaped substrates, which are secured to each other by way of an inner and outer plastic spacer. Together, the two substrates and the inner and outer spacer define a closed inner space, and at least one inner surface of one of the two substrates is provided with a light-sensitive recording layer. Typically, such a recording layer is sensitive to high energy light such as that from a laser beam. Each of the disk-shaped substrates includes a central hole of equal size and shape, wherein the inner spacer is ring-shaped and is positioned with its central opening coaxial with the holes in the substrates. The improvement resides in that the inside diameter of the central hole of the inner spacer is larger than the diameter of the holes of the substrates, and in that a recessed seat is provided by recessed portions formed on both substrates adjacent to and around the holes of each substrate, for precisely fitting and aligning the inner spacer to both disk-shaped substrates. Such a structure ensures accurate positioning of the optical disk on a drive spindle without interference of excess adhesive used in securing the inner spacer to the substrates, as well as to ensure that the recording medium can be rotated with high precision.

Recording medium of air-sandwich structure

A method of recording information comprising the steps of: irradiating a light-absorbing material (which is arranged in contact with a polymer blend which changes in its phase condition between a homogeneous state and a phase-separated state in response to change of its temperature across its cloud point) with a laser beam for causing the light-absorbing material to absorb energy of the beam and generate a heat, whereby elevating the temperature of the polymer blend near the light-absorbing material to a temperature of above the cloud point to change the phase condition of the polymer blend into a state which is different from the original state before the elevation of the temperature; and rapidly cooling the polymer blend to fix the polymer blend in its changed phase condition. An information recording medium preferably employed for the method is also disclosed.

Method of recording information and information recording medium

A process for preparing an information recording medium in the form of an optical disc comprising a substrate and a recording layer. The recording layer is formed on the substrate by coating a dye solution which comprises a dye dissolved in a solvent of a fluorine-containing compound over the substrate, and drying thus coated layer.

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Fujinomiya, Japan

Masao Yabe