Abstract: An optical information recording medium including a substrate, a recording layer formed on the substrate, and a transparent sheet provided on the recording layer via an adhesive layer. The adhesive layer has a peak of loss modulus at a temperature of 0° C. or lower, and exhibits an E1′/E2′ ratio of 2.0 or less, wherein E1′ and E2′ represent storage moduli of the adhesive layer at 25° C. and 80° C., respectively.

Abstract: The present invention provides a magnetic particle-coated material having a layer including a CuAu type or Cu3Au type ferromagnetic ordered alloy phase on an organic support. Further, the present invention provides a method of manufacturing a magnetic particle-coated material that sequentially includes a step of manufacturing alloy particles capable of forming a ferromagnetic ordered alloy phase, a step of coating an organic support with the alloy particles to form a coating film, and a step of annealing the coating film in a reducing atmosphere to make the alloy particles into magnetic particles, and further includes a step of oxidizing the alloy particles, the oxidizing step being performed between the alloy particle manufacturing step and the annealing step.

Abstract: The present invention provides an optical information recording medium including a substrate with an on-groove and an in-groove, having successively disposed thereon a dye recording layer and a transparent sheet, wherein a width of the on-groove ranges from 50 to 140 nm, and a barrier layer is formed between the recording layer and the transparent sheet. The invention also provides an optical information recording method including irradiating the optical information recording medium with laser light from the side of the medium provided with a cover layer to form a void at a signal pit portion in the dye recording layer and thereby carrying out recording of information as well as an optical information recording medium on which information has been recorded by the method.

Abstract: An information recording medium showing a high light-resistance has a recording layer containing a dye compound having the following formula (I-1) or (I-2): 1

Abstract: The present invention provides an optical information recording medium comprising a substrate including a groove that has a track pitch of 200 to 400 nm and a depth of 20 to 150 nm, the substrate having successively disposed thereon a light-reflective layer, a recording layer containing a dye and on which information is recordable by a laser beam having a wavelength of 600 nm or less, and a cover layer, wherein the recording layer contains at least two organic solvent-soluble compounds each having an absorption maximum in the range of 300 to 450 nm and a specific absorbance at a recording laser wavelength.

Abstract: An information recording medium showing a high light-resistance has a recording layer containing a dye compound having the following formula (IV-2): in which each of Y2 and Z2 is a group of atoms required for forming a carbon ring or a heterocyclic ring; each of L6, L7, L8, L9 and L10 is a methine group which may have one or two substituents; M2+ is an onium ion; and each of m1 and n1 is 0, 1 or 2.

Abstract: An optical recording medium that is excellent in both C/N and reproducing durability and is capable of carrying out high density recording with excellent sensitivity and reflectivity. The optical recording medium comprises a substrate having grooves with specified dimensions, and a recording layer comprising an organic substance having at least one maximum absorption peak in each of a range from 600 to 800 nm and a range from 300 to 400 nm. In another aspect, the optical information recording medium includes a recording layer comprising a certain organic substance and capable of recording information by irradiation with laser light having a wavelength of from 380 to 500 nm through a lens having an aperture (NA) of 0.7 or more, and a substrate having grooves with specified dimensions.

Abstract: An optical information recording medium including a substrate having a groove that has a track pitch of 200 to 400 nm and a depth of 10 to 150 nm, the substrate having successively disposed thereon a light-reflective layer, a recording layer and a cover layer, wherein information is recordable and reproducible by irradiating a laser beam having a wavelength of 500 nm or less from a side of the medium disposed with the cover layer, and the light-reflective layer contains aluminum or an aluminum alloy.

Abstract: The invention provides a method for manufacturing an optical information recording medium having a track pitch of 200 to 400 nm and a groove depth of 20 to 150 nm, and being capable of recording and reproducing using a light with a wavelength of 450 nm or less, the method at least comprising: a metal reflective layer forming step for forming a metal reflective layer on a substrate; a recording layer forming step for forming a recording layer of an organic dye type on said metal reflective layer; and a cover layer forming step for forming a cover layer on said recording layer; in this order.

Abstract: The invention provides an optical information recording medium, for use with a laser irradiating a laser beam having a wavelength of 380 to 500 nm through an objective lens with a numerical aperture of at least 0.7, the optical information recording medium comprising, in the following order: a substrate; a recording layer; a layer of acrylic adhesive; and a cover layer. A light reflecting layer may be provided between the substrate and the recording layer. Also a cover layer formed by an acrylic adhesive material may be provided instead of the layer of the acrylic adhesive material and the cover layer.

Abstract: A high-density optical information recording medium comprising, on a substrate, a recording layer capable of recording information by irradiation of a laser beam at a wavelength of from 380 to 500 nm, wherein the recording layer contains a compound represented by the following general formula (I): 1

Abstract: An optical information recording medium including a substrate having successively disposed thereon a recording layer, an interlayer, a pressure sensitive adhesive layer and a cover film in which information is recordable and reproducible by irradiating laser light and the pressure sensitive adhesive layer contains a polymer having a glass transition temperature Tg of 0° C. or lower, as well as a method for producing an optical information recording medium including adhering a cover layer to a surface of a recording layer so that a pressure sensitive adhesive layer is abutted on the surface of the recording layer, and an optical information recording medium produced by the method.

Abstract: An optical information recording medium including a substrate, a recording layer, and a cover layer in this order; wherein information is recorded or reproduced by irradiating a laser beam having an wavelength in the range of 380 to 500 nm on the recording layer through a lens having a numerical aperture NA of 0.7 or more; the recording layer includes an organic substance; and the extinction coefficient k of the recording layer is at least 0.1 and less than 0.3.

Abstract: The present invention is an optical information recording medium comprising a substrate having disposed in an order thereon a recording layer, an interlayer, and a cover layer, wherein recording and reproduction are carried out by the irradiation with a laser light having a wavelength in the range of 380 to 500 nm through a lens having a lens numerical aperture NA of 0.7 or more, wherein the recording layer is a layer of an organic substance and the thickness of the interlayer is within a range of 1 nm to 9 nm.

Abstract: An optical information recording medium including a substrate having succesively disposed thereon a recording layer and a cover layer, wherein information is recorded and reproduced by irradiating a laser beam having a wavelength of 380 to 500 nm through a lens having a numerical aperture NA of at least 0.7 and the recording layer contains an organic substance and has an attenuation coefficient k of more than 0.3.

Abstract: An optical recording medium that is excellent in both C/N and reproducing durability and is capable of carrying out high density recording with excellent sensitivity and reflectivity. The optical recording medium comprises a substrate having grooves with specified dimensions, and a recording layer comprising an organic substance having at least one maximum absorption peak in each of a range from 600 to 800 nm and a range from 300 to 400 nm. In another aspect, the optical information recording medium includes a recording layer comprising a certain organic substance and capable of recording information by irradiation with laser light having a wavelength of from 380 to 500 nm through a lens having an aperture (NA) of 0.7 or more, and a substrate having grooves with specified dimensions.

Abstract: The present invention provides an optical information recording medium including a substrate having a groove that has a track pitch of 200 to 400 nm and a depth of 20 to 150 nm, the substrate having successively disposed thereon a light-reflective layer, a recording layer on which information is recordable by a laser beam having a wavelength of 450 nm or less, an adhesive layer containing an adhesive, and a cover layer having a thickness of 0.01 to 0.5 mm, wherein a surface of the light-reflective layer at a side thereof at which the recording layer is disposed has a ten-point average roughness Rz of 70 nm or less, a central surface average roughness SRa of 30 nm or less, and an average projection diameter Dv, at a height of 15 nm from a reference plane, of 75 nm or less.

Abstract: The present invention provides an optical information recording medium comprising a substrate including a groove that has a track pitch of 200 to 400 nm and a depth of 20 to 150 nm, the substrate having successively disposed thereon a light-reflective layer, a recording layer containing a dye and on which information is recordable by a laser beam having a wavelength of 600 nm or less, and a cover layer, wherein the recording layer contains at least two organic solvent-soluble compounds each having an absorption maximum in the range of 300 to 450 nm and a specific absorbance at a recording laser wavelength.

Abstract: An information recording medium showing a high light-resistance has a recording layer containing a dye compound having the following formula (I-1) or (I-2): 1

Abstract: The present invention provides an optical information recording medium that includes a substrate including a groove with a track pitch of 200 to 400 nm and a groove depth of 20 to 150 nm and having successively disposed thereon a light reflecting layer, a recording layer containing a dye in which information is recorded by irradiation with a laser beam having a wavelength of no greater than 450 nm, an adhesive layer, and a cover layer with a thickness of 0.01 to 0.5 mm. A surface of the optical information recording medium on a side disposed with the cover layer has a center surface average roughness (SRa1) of no greater than 3.0 nm when measured over a large surface area and a center surface average roughness (SRa2) of no greater than 3.0 nm when measured over a minute surface area.