Optical information recording medium and production process thereof

An optical information recording medium production process comprising:

• a laminated body preparing step for preparing a laminated body in which a recording layer, at which recording of information by laser light with a wavelength of 500 nm or less is possible, is formed on a substrate in which a groove with a track pitch of 200 to 400 nm and a groove depth of 10 to 150 nm is formed;
• and
• a co-adhering step including the sub-steps of
• regulating a co-adhering position in accordance with an outer peripheral face of the substrate, and
• co-adhering a cover sheet with the laminated body, an internal diameter of the cover sheet being greater than an internal diameter of the substrate.

An optical information recording medium produced by a process comprising:

• a laminated body preparing step for preparing a laminated body in which a recording layer, at which recording of information by laser light with a wavelength of 500 nm or less is possible, is formed on a substrate in which a groove with a track pitch of 200 to 400 nm and a groove depth of 10 to 150 nm is formed;
• and
• a co-adhering step including the sub-steps of
• regulating a co-adhering position in accordance with an outer peripheral face of the substrate, and
• co-adhering a cover sheet with the laminated body, an internal diameter of the cover sheet being greater than an internal diameter of the substrate.

An optical information recording medium production process comprising:

• a laminated body preparing step for preparing a laminated body in which a recording layer, at which recording of information by laser light with a wavelength of 500 nm or less is possible, is formed on a substrate in which a groove with a track pitch of 200 to 400 nm and a groove depth of 10 to 150 nm is formed;
• and
• a co-adhering step including the sub-steps of
• placing a cover sheet on a flat table, and
• co-adhering the laminated body on the cover sheet such that the recording layer is between the substrate and the cover sheet.

An optical information recording medium produced by a process comprising:

• a laminated body preparing step for preparing a laminated body in which a recording layer, at which recording of information by laser light with a wavelength of 500 nm or less is possible, is formed on a substrate in which a groove with a track pitch of 200 to 400 nm and a groove depth of 10 to 150 nm is formed;
• and
• a co-adhering step including the sub-steps of
• placing a cover sheet on a flat table, and
• co-adhering the laminated body on the cover sheet such that the recording layer is between the substrate and the cover sheet.

An optical information recording medium production process comprising the steps of:

• preparing a laminated body, including forming a recording layer, at which recording of information by laser light with a wavelength of 500 nm or less is possible, on a substrate in which a groove with a track pitch of 200 to 400 nm and a groove depth of 10 to 150 nm is formed;
• co-adhering a cover sheet on the recording layer of the laminated body, the cover sheet being provided with a release sheet at a face of the cover sheet which is opposite to a face thereof that is to be co-adhered, at least a portion of the release sheet including a protruding portion which protrudes to an outer side relative to the cover sheet;
• and
• after co-adhering the cover sheet to the laminated body, releasing the release sheet, starting from the protruding portion.

An optical information recording medium produced by a process comprising:

• preparing a laminated body, including forming a recording layer, at which recording of information by laser light with a wavelength of 500 nm or less is possible, on a substrate in which a groove with a track pitch of 200 to 400 nm and a groove depth of 10 to 150 nm is formed;
• co-adhering a cover sheet on the recording layer of the laminated body, the cover sheet being provided with a release sheet at a face of the cover sheet which is opposite to a face thereof that is to be co-adhered, at least a portion of the release sheet including a protruding portion which protrudes to an outer side relative to the cover sheet;
• and
• after co-adhering the cover sheet to the laminated body, releasing the release sheet, starting from the protruding portion.