Abstract: In the optical information recording medium of the present invention, a first recording layer having a translucent film and a second recording layer having a reflection film are layered. At least one layer of the first recording layer is provided, and the translucent film reversibly varies its reflectance and its transmittance according to a temperature variation caused by difference in a converging state of reproducing light. This ensures to obtain a sufficient amount of the reproducing light reflected from the first and second recording layers.

Abstract: This invention is to provide a kind of near-field optical disk. This near-field optical disk is formed by a recording layer, a suitable thickness of near-field layer, a silver halide compound of light scattering layer, and a protection layer on the substrate layer in sequence. It is not necessary to increase the energy of transmitting beam for that the recording layer of this near-field optical disk and the transmitting beam has accomplished recording at a near-field distance to obtain the higher recording density.

Abstract: An optical recording medium comprising at least a recording layer and a reflecting layer on a substrate wherein the recording layer contains at least one dipyrromethene-metal chelate compound represented by general formula (1): wherein R1 to R6 independently represent hydrogen, halogen, nitro, cyano, hydroxyl, amino, carboxyl, sulfo, substituted or unsubstituted alkyl with up to 20 carbon atoms, alkoxy, alkylthio, aryloxy, arylthio, alkenyl, acyl, alkoxycarbonyl, carbamoyl, acylamino, aralkyl, aryl or heteroaryl; R7 represents halogen, aryl, heteroaryl, alkoxy, alkylthio, aryloxy or arylthio; A represents substituted or unsubstituted aromatic or heterocyclic ring with up to 20 carbon atoms; L1 represents substituted or unsubstituted bivalent residue forming a ring together with carbon atoms to which it attaches and optionally containing a hetero atom; and M1 represents transition metal element.

Abstract: A colored optical disk and method for making the same are disclosed herein. The method comprises: disposing a first semi-reflective data layer on a first resin layer, wherein the first resin layer has light transmission at a desired reading wavelength of greater than about 60%; disposing a top side of a first fully reflective data layer on a side of said first semi-reflective data layer opposite said first resin layer, wherein reflectivity of the first fully reflective data layer and the first semi-reflective data layer is individually about 18 to about 30%, and wherein a difference in the reflectivity between the first fully reflective data layer and the first semi-reflective data layer is less than about 5%; disposing a separating layer between said first fully reflective data layer and said first semi-reflective data layer; disposing a second resin layer on a bottom side of said first fully reflective data layer; and adding color to at least a portion of the optical disk.

Abstract: The present invention relates to an aminium salt or diimonium salt compound that is appropriate for use, for examples, in an optical recording medium to get the good characteristics in regeneration and storage stability as well as an infrared ray screening filter to get the excellent light fastness and heat fastness; and the use thereof. The aminium salt or diimonium salt compound comprises an aminium cation represented by the formula (1) as described below or a diimonium cation represented by the formula (2) as described below: (In the formula, m is an integer of 1 or 2; the two nitrogen atoms (quaternary nitrogen atoms in Formula (2)) bound to the ring A in Formula (1) or Formula (2) bind to the four B phenyl groups to whose 4-positions the optionally substituted four amino groups are substituted; and at least one of said four amino groups has a cyanoalkyl group as the substituent) with an anion.

Abstract: Embodiments of optical discs and methods for making the same are disclosed. In one embodiment, the optical disc comprises: at least two plastic substrates comprising a bonding layer and a data layer disposed therebetween, wherein at least one of the substrates is a read side substrate comprising greater than or equal to about 0.05 wt % colorant, based upon the total weight of the read side substrate, and wherein the read side substrate has a UV Bonding Index of greater than or equal to about 0.5. One method for making the optical disc comprises: forming a first plastic substrate comprising greater than or equal to about 0.05 wt % colorant, based upon the total weight of the first plastic substrate, wherein a UV Bonding Index of the first plastic substrate is controlled to be greater than or equal to about 0.5, disposing a data layer between the first plastic substrate and a second substrate, bonding the first plastic substrate to the second plastic substrate with a bonding layer, and curing the bonding layer.

Abstract: In a write once optical recording medium comprising a recording layer and a light transmitting protective layer formed successively on a supporting body, for recording and reproduction by irradiating a laser beam of a 380 to 450 nm wavelength from the light transmitting protective layer side, &lgr;max≦370 nm on the premise that the wavelength providing the peak optical absorption coefficient of the recording layer is defined to be &lgr;max.

Abstract: An optical information recording medium recordable at a high density two times or more higher than that of currently-used CD-Rs by using a material having optimum optical characteristics as an organic dye material of a recording layer. The optical information recording medium comprises a recording layer on a transparent substrate having a spiral pregroove formed thereon, wherein the track pitch Tp of the pregroove is 1.0 &mgr;m≦Tp≦1.2 &mgr;m and the optical phase difference &Dgr;S is 0.15≦&Dgr;S≦0.55.

Abstract: An optical disk has a multi-layer tuned optical coating overlying both small bumps to store pre-recorded information and lands onto which information is written to and read. The optical coating includes a phase-change metal/alloy layer formed over the disk substrate and a dielectric layer formed over the phase-change layer. An optical disk according to the invention has specific topological features and sizes.

Abstract: Metallized azo thioether dyes having an azo group linking a substituted 3-hydroxypyridine nucleus to a phenyl nucleus are disclosed. The phenyl nucleus has an thioether substituent ortho to the azo group but does not have electron withdrawing substituents on the phenyl nucleus. The dyes are useful in optical recording elements.

Abstract: An optically readable media (10) has an information-encoding layer (16) and at least one color-forming layer (12) that embodies an optical readout-limiting mechanism. In a first embodiment the at least one color-forming layer contains an additive that does not interfere with the optical readability of the media for a duration of a readout period. The additive, upon exposure to a source of optical radiation that is suitable for reversing the color-forming layer from an optical readout inhibiting state to an optical readout enabling state, undergoes a transformation that maintains the color-forming layer in the optical readout inhibiting state. More specifically, exposure to the source causes the color-forming layer to photobleach and the additive to oxidize, where the oxidation of the additive permanently inhibits the optical readability of the media. The additive may be a leuco dye.

Abstract: The invention relates to ionic compounds in which the anionic load has been delocalized. A compound disclosed by the invention includes an anionic portion combined with at least one cationic portion Mm+ in sufficient numbers to ensure overall electronic neutrality; the compound is further comprised of M as a hydroxonium, a nitrosonium NO+, an ammonium —NH4+, a metallic cation with the valence m, an organic cation with the valence m, or an organometallic cation with the valence m. The anionic load is carried by a pentacyclical nucleus of tetrazapentalene derivative bearing electroattractive substituents. The compounds can be used notably for ionic conducting materials, electronic conducting materials, colorant, and the catalysis of various chemical reactions.

Abstract: In a multilayer recordable optical medium, each recording layer includes a luminophore that fluoresces under reading laser light and a quencher capable of quenching the luminophore fluorescence. Initially, the luminophore and the quencher are not intermixed, so that the default state of the luminophore is fluorescent. During writing, focused writing radiation heats a spot in the medium so as to cause the luminophore and the quencher to be intermixed, thereby quenching the fluorescence.

Abstract: A recording medium is fabricated by forming a light reflecting layer on a dye recording layer capable of recording information, with a sputtering mechanism. The sputtering mechanism has a target, an electromagnet in the shape of a solenoid disposed in horizontally facing relationship to the target, and a coaxial cylindrical permanent magnet disposed in vertically facing relationship to the target. The permanent magnet has an outer circumferential region serving as an N pole and an inner circumferential region serving as an S pole. The electromagnet is electrically connected to a DC power supply via a controller which controls the intensity of a current flowing through the electromagnet.

Abstract: 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.

Abstract: There is disclosed an optical recording medium having at least a recording layer provided on a light-transmissive substrate having grooves and lands with prepits, wherein said lands are generally rectangular or trapezoidal in cross section having a top surface and sidewalls, as well as a specified land height (h1), and said prepits are formed in a land in the center area of the land in a width direction thereof, and spaced from the adjacent grooves by boundary walls of a specified height (h2). The optical recording medium permits address information and disc rotation control information to be accessed accurately even if a track pitch is small, and which still can be manufactured efficiently, with the added capability of signal recording in high density and reproduction of high-quality signals.

Abstract: The invention relates to ionic compounds in which the anionic load has been delocalized. A compound disclosed by the invention includes an anionic portion combined with at least one cationic portion Mm+ in sufficient numbers to ensure overall electronic neutrality; the compound is further comprised of M as a hydroxonium, a nitrosonium NO+, an ammonium —NH4+, a metallic cation with the valence m, an organic cation with the valence m, or an organometallic cation with the valence m. The anionic load is carried by a pentacyclical nucleus of tetrazapentalene derivative bearing electroattractive substituents. The compounds can be used notably for ionic conducting materials, electronic conducting materials, colorant, and the catalysis of various chemical reactions.

Abstract: The invention provides an optical recording medium preventing deterioration of an organic dye, having improved durability and being highly reliable, as well as a process for producing the same. The recording layer (3) including an organic dye as the main component, and the reflective layer (4) comprising a metal selected from Cu, Ag and Au or an alloy containing at least one of these metals, are formed in this order on substrate (2). An ultraviolet-curable material is laminated on the reflective layer (4) and cured by irradiation with UV rays at 200 to 1000 mJ/cm2 in such a manner that a cure shrinkage factor is not more than 10% by volume to form the protective layer (5) so that the organic acid content in the resulting ultraviolet-cured resin is not more than 10 ppm by weight, whereby the optical disk (1) is obtained. The dye is preferably a cyanine type dye, and the reflective layer is preferably Cu, Ag or an alloy containing at least one of these metals.

Abstract: The object of the present invention is to provide an optical recording medium which is excellent in the recording sensitivity and suitable for the high speed recording.

Abstract: An optical information recording medium composed of a substrate and a recording layer having a dye compound of the formula (I): R1R2C═L1—L2═L3—NR3R4  (I) in which each of R1 and R2 is an electron-attracting group (i.e., electron-withdrawing group) having a Hammett's substituent constant &sgr;p in the range of 0.2 to 0.

Abstract: An optical storage medium that is compatible with a semiconductor laser having a beam with a short wavelength (i.e. between 500 and 700 nm), which includes a highly stable dye layer. The optical storage medium of the invention includes an optically transparent substrate having at least one major surface on which at least one groove is formed, a storage layer on the substrate and a metal reflection layer on the storage layer. The storage layer contains a composite consisting of from about 3 weight % to about 30 weight % of a metal complex compound and a cyanine dye. The cyanine dye absorbs light in the wavelength between 500 and 700 nm, and has an asymmetric molecular structure. The optical storage medium of the invention reduces jitter components in high density data storage and conforms to DVD specifications.

Abstract: A high-density recordable optical recording disk with a cyanine dye mixture as a recording layer. The cyanine dye mixture at least comprises cyanine dye I and cyanine dye II.

Abstract: An organic write-once optical recording medium includes a surface plasmon super-resolution layer. The surface plasmon super-resolution layer is a three-layer structure including a first dielectric layer, a second dielectric layer, and a metal layer sandwiched between said first dielectric layer and said second dielectric layer. The metal layer with a certain thickness performs the surface plasmon effect when a laser beam with a suitable wavelength irradiates thereon. By the design and arrangement of the surface plasmon super-resolution layer, the small size of information-carrying pits and the recording marks in the range of around 100 nm is accessible. As a result, the super-resolution without the limit of the optical diffraction is achieved.

Abstract: A novel optical recording medium having at least a recording layer and a reflective layer on a substrate is herein disclosed, wherein at least one dipyrromethene metal chelate compound represented by formula (1) is contained in the recording layer: wherein R1 and R9 are each independently an alkenyl group, an aryl group or a heteroaryl group; R2 to R8 are each independently a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl, alkoxy, alkenyl, acyl, alkoxycarbonyl, aralkyl, aryl or heteroaryl group having 20 or less carbon atoms; and M is a transition metal.

Abstract: An optical recording medium is provided that includes a spirally grooved polymer substrate, a recording layer, a reflecting layer, and a protection layer. The recording layer includes one or a mixture of phthalocyanine dyes. The phthalocyanine dye includes a bicyclo-alkyl substituent, providing solubility in any of a plurality of solvents that will not damage the surface of the substrate.

Abstract: An inorganic write-once optical recording medium includes a surface plasmon super-resolution layer. The surface plasmon super-resolution layer is a three-layer structure including a first dielectric layer, a second dielectric layer, and a metal layer sandwiched between said first dielectric layer and said second dielectric layer. The metal layer with a certain thickness performs the surface plasmon effect when a laser beam with a suitable wavelength irradiates thereon. By the design and arrangement of the surface plasmon super-resolution layer, the small size of information-carrying pits and the recording marks in the range of around 100 nm is accessible. As a result, the super-resolution without the limit of the optical diffraction is achieved.

Abstract: An information recording medium is disclosed, comprising a substrate having provided thereon a recording layer capable of recording information by a laser ray, wherein the recording layer contains a dye compound represented by formula (I-1): 1

Abstract: The optical recording medium includes at least a recording layer, a recording supplemental layer, a reflection layer and a protection layer on a light permeable substrate, each of the recording layer and the recording supplemental layer is made mainly of an organic pigment material, with the optical recording medium, recording and reproducing is possible using a laser beam having a wavelength of &lgr;1 and also recording and/or reproducing is possible using a laser beam having a wavelength of &lgr;2 which is shorter than &lgr;1, a spectral absorbance of the recording layer is in the range between 5% and 35% at a wavelength of &lgr;1 and not less than 15% at a wavelength of &lgr;2, and the recording supplemental layer has a peak of spectral reflectance at a wavelength in the vicinity of &lgr;2.

Abstract: A hemicyanine dye having formula (1) and an optical recording medium using the hemicyanine dye as an optical recording medium are provided: 1

Abstract: An optical data storage medium includes a substrate, an optical data storage layer overlaid on the substrate and a reversible image recording layer overlaid on the optical data storage layer, in which information is recorded in the reversible image recording layer so as to be visible. The reversible image recording layer, which includes a matrix resin and a low-molecular-weight organic substance dispersed in the matrix resin, may preferably be thermosensitive and change its transparency or color tone in response to heat.

Abstract: Composition and use of polymers in appropriate solvent(s) with or without addition of selected dye combinations are proposed for developing a thin-layer coating on the transparent layer of optical storage media such as audio and video CDs, laser discs (LD) and DVDs for improvement of the sound and/or video quality during either recording and/or playback of the encoded digital information. The invention can also be incorporated in manufacture of recordable (CD-R) and re-writeable CD (CD-RW) media. In that case, the proposed composition is applied on the polycarbonate transparent surface of optical storage media at the final stages of recordable media manufacturing.

Abstract: An optical recording medium having a structure including that a recording layer containing organic coloring matter and a reflecting layer that are sequentially formed on a light-transmissive substrate thereof so that an information signal is recorded/reproduced when the optical recording medium is irradiated with a laser beam made incident on the light-transmissive substrate, the optical recording medium incorporating: a light absorbing layer which is formed more adjacent to an incident point of the laser beam as compared with the reflecting layer, through which the laser beam passes and which absorbs light in an absorption wavelength region for the recording layer. Photo-deterioration of the recording layer composed of organic coloring matter occurs owing to a portion of natural light which has the wavelength which exists in the absorbing wavelength region for the organic coloring matter.

Abstract: Disclosed is a method for producing a heat mode type optical information-recording medium having, on a substrate, a dye recording layer capable of recording information by being irradiated with a laser beam, the method comprising the step of applying a dye solution for forming the dye recording layer onto the substrate while rotating the substrate, wherein a period of time, which ranges from a point of time at which application of the dye solution is started to a point of time at which a valve is fully open, is not less than 0.1 second. In order to satisfy this condition, the opening degree of a first speed controller is not less than 5% and not more than 50%. Accordingly, the opening speed of the valve of a valve apparatus is not less than 5% and not more than 50% with respect to the maximum speed.

Abstract: An optical memory device and a method for manufacturing thereof. An optical memory device has at least one data layer formed on a substrate. An upper surface of the substrate is formed with a pattern comprising a plurality of regions which are capable of obtaining, when covered by a recording medium, desired optical properties different from those of the substrate. The patterned surface of the substrate is coated with the recording medium. The recording medium is removed from the patterned surface after the recording regions have obtained the desired optical properties.

Abstract: An optical recording layer of an optical recording medium comprises a dye material represented by the formula (I), wherein R1 is a hydrogen atom, a methyl group, or an ethyl group, R2 and R3 each is, independent from each other, a substituted or unsubstituted C1 to C12 alkyl group, A⊖ is an anion selected from the group consisting of halogen atoms, ClO4⊖, BF4⊖, PF6⊖, SbF6⊖, CF3SO2⊖, C2F5SO3⊖, CF3COO⊖, and CH3C6H4SO3⊖, X is hydrogen, alkyl, alkoxy, halogen, nitro, or fused benzene, Y is hydrogen, alkoxy, halogen, alkyl, aryl, alkoxycarbonyl, aryloxycarbonyl, alkylamine, arylamine, alkylamide, arylamide, alkylsulfonyl, aryl sulfonyl, alkoxysulfonyl, aryloxysulfonyl, nitro, or cyano groups.

Abstract: An optical information recording medium having a recording layer comprising a dye layer containing a trimethine-based cyanine dye having nitro group attached to a benzene ring or to a naphthalene ring, both being bonded to indole ring, is capable of minimizing the second peak in relative to the main peak shown in FIG. 1, thus enabling the spectrum consisting of a main peak and a second peak to become sharp. The recording layer is capable of performing the recording and reading with a laser beam having a wavelength falling within a range of 620 nm to 690 nm.

Abstract: An optical data recording medium in which the shape of the dye spectrum of a dye film having a thin film thickness per unit absorbance is controlled so as to enable improvements in the recording speed during high speed recording, jitter, and modulation, wherein the optical data recording medium is characterized in that 0<D/C≦100, and 80≦D/B, where D (nm) is the mean film thickness of the light-absorbing layer, C (Abs) is the maximum absorbance (based on molecular absorption) of the light-absorbing substance, B (Abs) is the maximum absorbance (based on association absorption) of the light-absorbing substance, D/C is the unit absorbance thickness based on the molecular absorption, and D/B is the unit absorbance thickness based on the association absorption.

Abstract: An optical recording medium having a light absorption layer formed on a substrate having a spiral groove by means of the vacuum deposition and a reflective layer formed on the light absorption layer, wherein: (1) the groove of the substrate has a groove section of which cross section is a trapezoidal; (2) a ratio of a groove width (W) to a track pitch (TP) (W/TR) of the substrate falls within a range of 0.25 to 0.45; (3) a groove depth (D) is 20 to 80% of (&lgr;/4n) (wherein A is a wavelength of a laser beam, and n is a refractive index of the substrate); and (4) angles a1 and a2 formed by both side surfaces of the groove section and surfaces vertical to a groove bottom surface on cross lines between the both side surfaces of the groove section and the groove bottom surface are 45 to 80°, and a difference between a1 and a2 (a1−a2) is not more than ±10°.

Abstract: In the optical recording medium including a substrate having pregrooves, and a metal recording thin film, a buffering layer and a reflecting layer which are stacked in sequence on the substrate, the buffering layer is formed of one or more dyes having a refractive index (n) of 1.4 or more and an absorption coefficient (k) of 1.6 or less at a wavelength of 650 nm, and a refractive index (n) of 1.8 or more and an absorption coefficient (k) of 0.001 or more at a wavelength of 780 nm. Therefore, the optical recording medium is reproducible by a CD player and a DVD player. Also, due to a metal recording thin film layer formed on a substrate, the amplitude of a recording signal is increased and the optical reliability is also improved. Also, because of a thin buffering layer, the manufacturing costs can be reduced. Also, by adding a material whose weight is rapidly lost during decomposition to the buffering layer, the recording sensitivity and the optical reliability can be much improved.

Abstract: Metallized azo ether dyes having an azo group linking a substituted 3-hydroxypyridine nucleus to a phenyl nucleus are disclosed. The phenyl nucleus has an ether substituent ortho to the azo group. The phenyl nucleus is free of strong electron withdrawing substituents. The dyes are useful in optical recording elements.

Abstract: The invention relates to an optical storage medium comprising a substrate and a storage layer, wherein the storage layer comprises a compound of the formula (I) or (II) in which A and A′, independently of one another, are unsubstituted or mono- or di-halo-, -hydroxy-, —C1-C6alkyl-, —C1-C6alkoxy-, -cyano- or -nitro-substituted phenyl, pyridyl, pyrrolyl, imidazolyl, furyl or thienyl, which can, if desired, be fused to a benzene ring, are halide, tetrafluoroborate or unsubstituted or with one or more halogen substituted C1-C6alkane-sulfonate, benzenesulfonate, C1-C6alkylbenzenesulfonate, C1-C6alkylsulfate or di-C1-C6alkyl-phosphonate of N—C1-C6alkyl-pyridiniumyl, or are unsubstituted or mono- or di-hydroxy-substituted C2-C6alkyl or C2-C6alkenyl, whose chain may be uninterrupted or interrupted by one or two oxygen atoms, B and B′, independently of one another, are 2 H, S, S2 or SO2, and n and n′, independently of one another, are each a number from 1 to 4.

Abstract: In an optical recording medium using writing and reading light having a wavelength of up to 690 nm and having a recording layer and preferably a reflective layer, the recording layer contains a chelate compound having an azo compound of specific structure as a ligand (i.e., azo metal complex dye). This results in an optical recording medium of the heat mode having advantages including the dye's sufficient solubility in a coating solvent which does not attack polycarbonate substrates and improved write/read characteristics with light having a wavelength of up to 690 nm.

Abstract: A recordable optical medium includes a transparent substrate, a dye recording layer on the transparent substrate, a reflective layer provided on the dye layer wherein the reflective layer comprises a mixture of silver and palladium in such proportions that the palladium comprises between 0.25 and 2.5 atomic percent of the mixture, and a protective layer formed over the reflective layer.

Abstract: An optical information recording disc of DVD (Digital Video Disc) type having an information recordable layer(s) between a pair of substrates (i.e., sandwich structure) shows an improved mechanical strength and an improved storage stability when the substrate has an exposed area on its outer peripheral edge and the exposed area is placed in contact with a resin layer, or the substrate has an enlarged surface area (preferably it is exposed) on its outer peripheral edge and the enlarged surface area is placed in contact with a resin layer. An apparatus for preparing an optical information recording disc of DVD type having an improved mechanical strength and an improved storage stability is further disclosed.

Abstract: A high-density optical disk comprises a transparent substrate having a guide groove having a depth of 100 to 200 nm, width of 0.2 to 0.4 &mgr;m arranged with a track pitch of 0.7 to 1.0 &mgr;m. A recording layer is made of an organic pigment exhibiting a specific main weight reduction in a thermogravimetric analysis and a specific exothermic peak in a differential thermal analysis.

Abstract: A perishable media information storage mechanism, including a substrate, a data layer for recording data thereon the information storage mechanism, a reflective layer, and a protective lacquer coating. The data layer includes a material responsive to at least one predetermined data elimination factor and includes one of a decayable dye material, a liquid crystal material, a photosensitive material or a plurality of magnetoresistive memory cells. The data layer is characterized as recording data and eliminating access to data in response to at least one of a predetermined use or time factor. In addition, included is a method for fabricating a perishable media information storage mechanism including the steps of providing a substrate, forming a data layer on a surface of the substrate, forming a reflective layer on an uppermost surface of the data layer, and forming a protective coating on an uppermost surface of the reflective layer.

Abstract: A structure of an optical recording medium that mainly includes a first dielectric layer, a dye layer, a second dielectric layer, and a reflective layer formed on a substrate in sequence, and a method for fabricating an optical recording medium of the foregoing structure. The additional dielectric layers of the optical recording medium, instead of a quencher used in a conventional optical recording medium, increase the lifetime of a dye layer and reduce the fabrication cost. Furthermore, the additional dielectric layers are capable of isolating the dye layer from oxygen and moisture to enhance the lightfastness of the dye layer.

Abstract: An information recording medium is disclosed, comprising a substrate having provided thereon a recording layer capable of recording information by a laser ray, wherein the recording layer contains a dye compound represented by formula (I-1): wherein R1, R2, R3 and R4 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted heterocyclic group, L1, L2 and L3 each independently represents a methine group which may have a substituent, m represents 0, 1, 2 or 3, Xk+ represents a cation and k represents an integer of from 1 to 10, provided that when m is 2 or 3, the plurality of L2 and L3 groups may be the same or different. Also disclosed is an information recording method using the above-described information recording medium.

Abstract: An optical information recording medium provided on a substrate thereof with a recording layer comprising a dye-containing layer, wherein the recording layer further comprises an organometallic dye compound containing a metal or a metallic ion, which is characterized in that an absorption spectrum curve of the recording organic dye is intersected with an absorption spectrum curve of the organometallic dye compound, and that the organometallic dye compound exhibits a maximum absorption wavelength on a longer wavelength side in relative to a maximum absorption wavelength of the recording organic dye.

Abstract: Optical disc, e.g., CD-R, DVD, DVD-R, comprising a polymer substrate and a radiation-cured coating provided by curing a radiation-curable coating composition having a pH greater than or equal to 3 and comprising at least one acrylate monomer, and advantageously diacrylate monomers and oligomers and monomers having acrylate functionalities of from 1 to at least 3, wherein the optical disc exhibits jitter of no greater than about 35 ns after being subjected to an environment having a temperature of at least 80° C. and a relative humidity of at least 85% for a period of at least 96 hours.