An optical recording medium includes a plurality of information signal layers. The plurality of information signal layers include a recording layer having a first surface that faces a light irradiation surface and a second surface on the side opposite to the first surface, a first dielectric layer that is provided on the side of the first surface, and a second dielectric layer that is provided on the side of the second surface. The second dielectric layer provided in the information signal layer positioned on the innermost side when viewed from the light irradiation surface contains indium oxide and tin oxide. The recording layer provided in the information signal layer positioned on the innermost side when viewed from the light irradiation surface contains an oxide of a metal MA, an oxide of a metal MB, an oxide of a metal MD, and an oxide of a metal ME, the metal MA is at least one selected from the group consisting of Mn and Ni, the metal MB is at least one selected from the group consisting of W, Mo, Zr and Ta, the metal MD is at least one selected from the group consisting of Cu and Ag, the metal ME is Nb, the contents of the metal MA, the metal MB and the metal ME satisfy the relationship of 0.30≤a.sub.1/(b.sub.1+e.sub.1)≤0.41 (where, a.sub.1: atomic ratio [atomic %] of the metal MA with respect to a total amount of the metal MA, the metal MB, the metal MD and the metal ME, b.sub.1: atomic ratio [atomic %] of the metal MB with respect to a total amount of the metal MA, the metal MB, the metal MD and the metal ME, and e.sub.1: atomic ratio [atomic %] of the metal ME with respect to a total amount of the metal MA, the metal MB, the metal MD and the metal ME), and the atomic ratio e.sub.1 of the metal ME with respect to a total amount of the metal MA, the metal MB, the metal MD and the metal ME is 5 atomic % or more and 18 atomic % or less.

A recording-medium binding device includes first and second tooth groups. The first tooth group includes first and second tooth rows. The second tooth group includes third and fourth tooth rows. The third tooth row to be engaged with the first tooth row forms, together with the first tooth row, a first tooth row pair. The fourth tooth row to be engaged with the second tooth row forms, together with the second tooth row, a second tooth row pair. A second engaging height in the second tooth row pair is smaller than a first engaging height in the first tooth row pair. A second effective tooth top width in the second tooth row pair is larger than a first effective tooth top width in the first tooth row pair.

A recording-medium binding device includes first and second tooth groups. The first tooth group includes first and second tooth rows. The second tooth group includes third and fourth tooth rows. The third tooth row to be engaged with the first tooth row forms, together with the first tooth row, a first tooth row pair. The fourth tooth row to be engaged with the second tooth row forms, together with the second tooth row, a second tooth row pair. A second engaging height in the second tooth row pair is smaller than a first engaging height in the first tooth row pair. A second effective tooth top width in the second tooth row pair is larger than a first effective tooth top width in the first tooth row pair.

Described are adhesive compositions that contain adhesive polymer and carbon nanotubes; devices (e.g., electronic devices and electronic device enclosures) and compositions that include one of these adhesive compositions; and uses of such adhesive compositions as part of an electronic device.

An optical recording medium includes a first disk, a second disk, and an adhesive layer for bonding the first disk to the second disk. The first disk and the second disk each include a substrate having a first surface and a second surface and having a gradient on an outer peripheral portion of the second surface, two or more information signal layers disposed on the first surface, an intermediate layer disposed between adjacent information signal layers, and a cover layer covering the two or more information signal layers and the intermediate layer. The second surface of the substrate included in the first disk faces the second surface of the substrate included in the second disk with the adhesive interposed therebetween.

An optical recording medium includes a first disk, a second disk, and an adhesive layer for bonding the first disk to the second disk. The first disk and the second disk each include a substrate having a first surface and a second surface and having a gradient on an outer peripheral portion of the second surface, two or more information signal layers disposed on the first surface, an intermediate layer disposed between adjacent information signal layers, and a cover layer covering the two or more information signal layers and the intermediate layer. The second surface of the substrate included in the first disk faces the second surface of the substrate included in the second disk with the adhesive interposed therebetween.

Conventionally, in making a double-sided optical disc by attaching recording substrates to each other via an ultraviolet curable adhesive layer, there was a problem that the ultraviolet curable adhesive layer was slow to cure. It is thought that this is because the out gases leached from the recording substrate disturbed the cure reaction of the adhesive layer. In contrast, in the optical disc of the present disclosure, it is possible to cure the adhesive layer in a short time in attaching the recording substrates to each other via the ultraviolet curable adhesive layer, by providing a gas barrier layer at an attachment surface of a substrate to inhibit out gases from leaching from the substrate to the ultraviolet curable adhesive layer.

Conventionally, in making a double-sided optical disc by attaching recording substrates to each other via an ultraviolet curable adhesive layer, there was a problem that the ultraviolet curable adhesive layer was slow to cure. It is thought that this is because the out gases leached from the recording substrate disturbed the cure reaction of the adhesive layer. In contrast, in the optical disc of the present disclosure, it is possible to cure the adhesive layer in a short time in attaching the recording substrates to each other via the ultraviolet curable adhesive layer, by providing a gas barrier layer at an attachment surface of a substrate to inhibit out gases from leaching from the substrate to the ultraviolet curable adhesive layer.

An optical recording medium includes a first disk, a second disk, and an adhesive layer for bonding the first disk to the second disk. The first disk and the second disk each include a substrate having a first surface and a second surface and having a gradient on an outer peripheral portion of the second surface, two or more information signal layers disposed on the first surface, an intermediate layer disposed between adjacent information signal layers, and a cover layer covering the two or more information signal layers and the intermediate layer. The second surface of the substrate included in the first disk faces the second surface of the substrate included in the second disk with the adhesive interposed therebetween.

An optical recording medium includes a first disk, a second disk, and an adhesive layer for bonding the first disk to the second disk. The first disk and the second disk each include a substrate having a first surface and a second surface and having a gradient on an outer peripheral portion of the second surface, two or more information signal layers disposed on the first surface, an intermediate layer disposed between adjacent information signal layers, and a cover layer covering the two or more information signal layers and the intermediate layer. The second surface of the substrate included in the first disk faces the second surface of the substrate included in the second disk with the adhesive interposed therebetween.