Abstract: Disclosed is an ultraviolet-curable resin composition for multilayer optical discs, which contains (A) dioxane glycol di(meth)acrylate and/or tricyclodecane dimethylol di(meth)acrylate, and (B) a photopolymerization initiator.

Abstract: The present invention relates to an optical disc having a cured product layer of an ultraviolet-curable resin composition containing (A) dicyclopentenyloxyethyl acrylate, (B) urethane (meth)acrylate and/or (C) epoxy (meth)acrylate, and (D) photopolymerization initiator, and a resin composition for the cured product layer thereof and a cured product therewith; and the optical disc of the present invention has less warping after curing and is excellent in transparency and durability and therefore suitable for next generation high density optical discs where recording and/or reproducing are performed using a blue laser; the resin composition for said cured product layer has less deterioration with age and less viscosity change in recycle and is suitable for a coating agent of optical discs and for efficient production of optical discs.

Abstract: Optical recording mediums comprising a substrate and a recording layer and a light transmitting layer sequentially disposed on the substrate; wherein the substrate comprises one or more parts selected from the group consisting of injection molded parts, injection molded sandwich structures having a molded surface layer and a molded core layer or two injection molded parts which are UV-bonded, and combinations thereof; and wherein the substrate has a Young's modulus E of at least 2.15 GPa and a Q factor of lower than 160 measured at 25° C. at 2000 Hz in accordance to ASTM E 756-05.

Abstract: A recording layer including a novel organic compound for a high density optical recording medium is provided. The information may be recorded on the recording layer at a 2× speed or higher speed with a relatively lower writing power so that heat distribution of the recording layer in the irradiated area is not likely to become steep both in time and space. The organic compound incorporated in the recording layer has the following general chemical structural formula (I).

Abstract: Disclosed is an adhesive which enables to obtain a bonded optical disk, wherein optical disks having a total reflection film or a translucent reflection film made of silver or a silver alloy are bonded together, which exhibits high adhesion strength between the reflection film and a cured product of the adhesive as well as between a polycarbonate substrate and the cured product of the adhesive, while having high durability equivalent to those of the conventional optical disks using translucent reflective film made of gold.

Abstract: An optical information medium having a light transmission layer obtained by curing a composition containing a urethane di(meth)acrylate (A) of the formula (I) and the other urethane di(meth)acrylate (B), and having a tensile elastic modulus of 600 to 1300 MPa at 25° C. and a light transmittance of 80% or more at wavelength of 400 nm (in the formula, R1=an alicyclic diisocyanate residue, R2=an alkylene group or an organic group containing a cycloalkyl group or ester bond, R3=H or methyl group.

Abstract: Disclosed is an optical information recording medium which includes at least one substrate, at least one thin film of silver or a silver alloy, and an ultraviolet-cured resin layer, in which the at least one thin film and the ultraviolet-cured resin layer are in contact with each other and are arranged on or above the at least one substrate. In the recording medium, the ultraviolet-cured resin layer contains a cured resin of at least one acrylic monomer cured by the action of ultraviolet rays, and this ultraviolet-cured resin layer has a content of a resin-derived organic component of 99 percent by mass or more and has a surface electrical resistance of 2.0×1013? or more.

Abstract: A substate possesses a transparent protective layer derived from a radiation-curable acrylate composition which comprises: a) at least one urethane polyacrylate possessing a number average molecular weight of at least about 400 per acrylate group and having a Tg of not greater than about 40° C.; b) at least one crosslinking polyacrylate having a Tg of at least about 50° C.; c) at least one hydrophobic monoacrylate; and, d) at least one photoinitiator.

Abstract: A method is disclosed to purify a polymeric material by filtering a melt comprising poly(arylene ether) and poly(alkenyl aromatic) through a melt filtration system. The method provides a filtered polymeric composition having reduced levels of particulate impurities. The filtered polymeric composition prepared is suitable for use in data storage media applications.

Abstract: A method is disclosed to purify a polymeric material by filtering a melt comprising poly(arylene ether) and poly(alkenyl aromatic) through a melt filtration system. The method provides a polymeric material having reduced levels of particulate impurities. The polymeric material prepared is suitable for use in data storage media applications.

Abstract: The invention relates to novel photoinitiators and their use in light adjustable compositions. The initiatives comprise two or more multiphoton chromophores linked by a bridging compound. The bridging compound consists of a material that is compatible with the base material of the light adjustable composition. The novel photoinitiator permit the readjustment of light adjustable material without the need for significant amounts of photoabsorbers.

Abstract: A data storage medium includes a haze-prevention layer between a heat-resistant thermoplastic substrate and a reflective metal layer. The haze-prevention layer includes a metal having a tensile modulus of at least about 15×106 pounds per square inch. The data storage medium resists hazing of the reflective layer at elevated temperatures.

Abstract: A reflective article useful, for example, in automotive headlights includes a haze-prevention layer between a heat-resistant thermoplastic substrate and a reflective metal layer. The haze-prevention layer includes a metal having a tensile modulus of at least about 15×106 pounds per square inch. The article resists hazing of the reflective layer at elevated temperatures.

Abstract: A disc-shaped recording medium having transcription characteristics for fine signals simultaneously with resonance characteristics and stiffness which are characteristics contrary to the transcription characteristics. At least a recording layer and a light transmitting layer are sequentially formed on a substrate and light is illuminated from a light transmitting layer side to record and/or reproduce information signals. The substrate includes a core layer formed of a resin composition comprised of a mixture of two or more resin sorts. The resin composition has tan?, as an index indicating the internal loss, equal to not less than 0.015 as a system in its entirety. The resin composition constituting the core layer is a compounded resin of the incompatible system and is of an islands-sea structure.

Abstract: A stamper reception layer 11 of an optical disk producing sheet 1 is composed of a polymeric material that has energy-curing properties and possesses a pre-curing storage elastic modulus of 103 to 106 Pa. The number of deposits on a stamper can thus be reduced with this optical disk producing sheet 1.

Abstract: Disclosed is a film comprising PMMA and a fluorescent substance having a xanthene skeleton and a lactone ring and/or a fluorescent substance having a xanthene skeleton and a group —COOR, where R represents a hydrogen atom or a substituent, capable of forming an intramolecular lactone ring, said fluorescent substances being dispersed in the PMMA. The film is useful as an optical memory.

Abstract: An optical disc-producing sheet 1, which has an adhesive layer 11 having a specific heat capacity after curing of not more than 1.9 J/g·° C. at 80° C. and a protective sheet 12, is laminated onto an information recording layer 3 (a laminate of a reflecting layer 31, a dielectric layer 32, a phase change layer 33 and a dielectric layer 32′) formed on an optical recording medium substrate 2. According to this optical disc, recorded information can be reproduced accurately even in the case that recording/erasure or reproduction of information has been carried out repeatedly.

Abstract: There is provided an ultraviolet curing resin composition for an optical disk such as to improve the light resistance of reflective thin films made of silver or silver alloy and protect them against corroding and perform a high adhesive strength, in the optical disks. The composition comprises (1) a (meth)acrylate compound having a number average molecular weight of 700 to 3000 derived from epoxy resin, (2) a (meth)acrylate monomer having one or more of unsaturated ethylene groups, and (3) a polymerization initiator, such as 2,2-dimethoxy-2-phenylacetophenone, benzoylethyl ether and benzoylisobutyl ether, represented in the following general formula (I). Also, a tetrazole derivative may be additionally mixed into the composition.

Abstract: An article is disclosed that includes: a) a first polycarbonate substrate; b) a second polycarbonate substrate; and c) an adhesive composition disposed between the first polycarbonate substrate and the second polycarbonate substrate such that the first polycarbonate substrate is bonded to said second polycarbonate substrate through the adhesive composition; the adhesive composition includes an adhesive polymer that includes the reaction product of 1) an N-vinyl containing monomer selected from the group consisting of N-vinyl caprolactam, N-vinyl pyrrolidone, and N-vinylimidazole, and combinations thereof, and 2) an acrylic acid ester monomer of a non-tertiary alcohol having an alkyl group that includes 4 to 20 carbon atoms.

Abstract: An optical disk for recording or/and reproducing information by using a laser beam includes a substrate formed by an inorganic material having elastic modulus of 2400 MPa or more, or a mixture of inorganic and plastic materials; a reflective layer formed on the substrate; a cover layer formed on the reflective layer; and a protective layer formed on the cover layer, wherein, the laser beam for recording or/and reproducing the information is incident on the protective layer and the cover layer.

Abstract: The present invention relates to a multi-layered disc-shaped information recording medium having a plurality of signal recording layers each carrying information signals. In preparing the recording medium, a first substrate obtained on punching a sheet obtained in turn by having a signal recording pattern transcribed on it from a first stamper and by forming a semi-transparent film on a signal surface is bonded to a second substrate obtained on injection molding a synthetic resin material. The second substrate is prepared by having transcribed to it a signal recording pattern formed on a second stamper provided on an injection molding device. A reflective film is formed on a signal surface having the transcribed second substrate. The first and second substrates are bonded together on their signal recording layers by a transparent adherent layer.

Abstract: A hybrid film, comprising a first polymer film having a plasma-treated surface and a second polymer film having first and second surfaces, with the first surface of the second polymer film being disposed along the first plasma-treated surface of the first polymer film, has superior thermal and mechanical properties that improve performance in a number of applications, including food packaging, thin film metallized and foil capacitors, metal evaporated magnetic tapes, flexible electrical cables, and decorative and optically variable films. One or more metal layers may be deposited on either the plasma-treated surface of the substrate and/or the radiation-cured acrylate polymer. A ceramic layer may be deposited on the radiation-cured acrylate polymer to provide an oxygen and moisture barrier film.

Abstract: The invention provides a two-part adhesive composition making it possible to mutually bond disk substrates within a relatively short time and to produce an optical disk, and an optical disk having a metal film, corrosion of which is restricted under a high-temperature high-humidity condition, and which is produced by using the two-part adhesive composition. A two-part adhesive composition of the invention comprises first and second parts each containing urethane acrylate having a polytetramethylene glycol skeleton and an acrylate having a hydroxyl group in its molecule, wherein the first part further contains a diacyl peroxide and the second part further contains a tertiary amine. Organic peroxide is preferably diacyl peroxide and a setting promoter is preferably a tertiary amine. Either one, or both, of the first and second parts may further contain a photo-polymerization initiator.

Abstract: A method for determining the water strain of an article is provided in the present invention by predetermining a maximum tilt range and radius for the article. Further embodiments of the present invention include a storage medium for data and a polymer for use in a storage medium for data where the storage medium comprises a plurality of layers wherein the aforementioned water strain is calculated for the plurality of layers.

Abstract: An optical recording medium comprises a substrate, a recording film formed on the substrate, and a protective film formed by applying and curing a protective film forming composition on the recording film, wherein the protective film forming composition comprises 60 to 85 wt % of trimethylolpropane triacrylate modified with ethylene oxide, and 25 to 65 parts by weight of tripropyleneglycol diacrylate per 100 parts by weight of the trimethylolpropane triacrylate modified with ethylene oxide.

Abstract: A UV-curable binder composition, a coating material which contains such a binder composition, a photoiniator mixture suitable for use in these coating materials, and a magnetic recording medium which contains such a UV-curable coating material are described.

Abstract: A disc-shaped recording medium having transcription characteristics for fine signals simultaneously with resonance characteristics and stiffness which are characteristics contrary to the transcription characteristics. At least a recording layer and a light transmitting layer are sequentially formed on a substrate and light is illuminated from a light transmitting layer side to record and/or reproduce information signals. The substrate includes a core layer formed of a resin composition comprised of a mixture of two or more resin sorts. The resin composition has tan&dgr;, as an index indicating the internal loss, equal to not less than 0.015 as a system in its entirety. The resin composition constituting the core layer is a compounded resin of the incompatible system and is of an islands-sea structure.

Abstract: A photopolymerizable composition comprising (A) 100 parts by weight of a mixture of (meth)acrylic acid ester monomers, (B) from 0.1 to 5 parts by weight of a surfactant having a perfluoroalkyl group and represented by the general formula (1) CF3(CF2)nAM  (1) wherein A represents —CO2— or —SO3—, M represents an alkali metal, and n is an integer of 3 to 9, and (C) from 0.2 to 10 parts by weight of a photopolymerization initiator, and a plastic optical disk provided with a cured coating of the photopolymerizable composition on at least one side thereof.

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.