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.

There is provided an optical recording medium substrate including a polycarbonate in which an average molecular weight is in a range from 15000 to 16000, and mass per unit volume at 25 C. is in a range from 1.1930 g/cm.sup.3 to 1.2000 g/cm.sup.3.

There is provided an optical recording medium substrate including a polycarbonate in which an average molecular weight is in a range from 15000 to 16000, and mass per unit volume at 25 C. is in a range from 1.1930 g/cm.sup.3 to 1.2000 g/cm.sup.3.

There is provided an optical recording medium substrate including a polycarbonate in which an average molecular weight is in a range from 15000 to 16000, and mass per unit volume at 25? C. is in a range from 1.1930 g/cm.sup.3 to 1.2000 g/cm.sup.3.

There is provided an optical recording medium substrate including a polycarbonate in which an average molecular weight is in a range from 15000 to 16000, and mass per unit volume at 25? C. is in a range from 1.1930 g/cm.sup.3 to 1.2000 g/cm.sup.3.

Provided is an optical recording medium capable of suppressing sticking between the optical recording mediums in a case where a plurality of optical recording mediums are superimposed on each other. The optical recording medium includes an optical recording medium main body having a first surface and a second surface, and a first convex structure layer provided on the first surface. The first convex structure layer has a surface provided with a plurality of first convexities, and includes first particles and a first resin material. The plurality of first convexities are formed by a part of the first particles included in the first convex structure layer, the part of the first particles protruding from the surface of the first convex structure layer.

Provided is an optical recording medium capable of suppressing sticking between the optical recording mediums in a case where a plurality of optical recording mediums are superimposed on each other. The optical recording medium includes an optical recording medium main body having a first surface and a second surface, and a first convex structure layer provided on the first surface. The first convex structure layer has a surface provided with a plurality of first convexities, and includes first particles and a first resin material. The plurality of first convexities are formed by a part of the first particles included in the first convex structure layer, the part of the first particles protruding from the surface of the first convex structure layer.

Provided is an optical recording medium capable of suppressing sticking between the optical recording mediums in a case where a plurality of optical recording mediums are superimposed on each other. The optical recording medium includes an optical recording medium main body having a first surface and a second surface, and a first convex structure layer provided on the first surface. The first convex structure layer has a surface provided with a plurality of first convexities, and includes first particles and a first resin material. The plurality of first convexities are formed by a part of the first particles included in the first convex structure layer, the part of the first particles protruding from the surface of the first convex structure layer.

Provided is an optical recording medium capable of suppressing sticking between the optical recording mediums in a case where a plurality of optical recording mediums are superimposed on each other. The optical recording medium includes an optical recording medium main body having a first surface and a second surface, and a first convex structure layer provided on the first surface. The first convex structure layer has a surface provided with a plurality of first convexities, and includes first particles and a first resin material. The plurality of first convexities are formed by a part of the first particles included in the first convex structure layer, the part of the first particles protruding from the surface of the first convex structure layer.