Optical information recording medium

Claim 2

An optical information recording medium comprising a substrate and a recording layer superimposed on said substrate, said recording medium being adapted to have information recorded thereon in the form of pits in said recording layer, and being adapted to have said information read by a laser beam, wherein the improvement comprises said recording layer is a thin film consisting essentially of a cyanine dye.

Claim 3

A recording medium as claimed in claim 1, wherein said recording layer is formed by coating a liquid containing said cyanine dye onto said substrate.

Claim 4

A recording medium as claimed in claim 1, wherein said recording medium further comprises an adhesive layer interposed between said recording layer and said substrate.

Claim 5

A recording medium as claimed in claim 1, wherein said recording medium further comprises a protective layer formed on said recording layer.

Claim 6

A recording medium as claimed in claim 1, wherein said recording layer has pits formed thereon, which pits comprise said information.

Claim 7

A recording medium according to claim 1 wherein said cyanine dye is a compound having two unsubstituted or substituted nitrogenous heterocyclic rings which are bonded by at least one methine chain, substituted methine chain or a group having a substituted or unsubstituted methine chain.

Claim 8

A recording medium according to claim 6, wherein said cyanine dye has a positive charge.

Claim 9

A recording medium as claimed in claim 6, wherein said cyanine dye contains a positively charged quaternary nitrogen atom in one of said heterocyclic rings.

Claim 10

A recording medium as claimed in claim 1, wherein said recording layer has a thickness in the range of 100 to 5000 angstroms.

Claim 11

A recording medium as claimed in claim 9, wherein said recording layer consists of said cyanine dye and at least one additive selected from the group consisting of a binder, an antioxidant, an infrared light absorbing agent, an ultraviolet light absorbing agent, and a dye other than said cyanine dye.

Claim 12

A recording medium as claimed in claim 10, wherein said recording layer has a thickness in the range of 200 to 600 angstroms.

Claim 13

An optical information recording medium comprising a substrate and a thin recording layer superimposed on said substrate, said recording layer consisting essentially of at least one cyanine dye selected from the group of compounds having the formulas: ##STR23## or an alkyl, alkoxy, hydroxy, acetyl, aryl or halogen substituted derivative thereof, in which R 2 is alkyl, alkoxyalkyl, hydroxyalkyl, aralkyl, carboxyalkyl, carboxylatoalkyl bonded with an alkali metal cation, sulfoalkyl or sulfonatoalkyl; A is ##STR24## alkoxy, hydroxy, acetyl, aryl or halogen substituted derivative thereof, in which R 2 is the same as for B, and X is a counter ion; Z is H, --OH, --COOH, halogen, C 1 -C 5 alkyl, phenyl, N-substituted amino, N-substituted alkyl, substituted or unsubstituted aryl, or --COOR', wherein R' is C 1 -C 5 alkyl, phenyl or substituted phenyl, and Z, when plural, may be same or different; and m and n are each 0, 1, 2 or 3, with the proviso m+n≦3.

Claim 14

An optical information recording medium comprising a substrate and a thin recording layer superimposed on said substrate, said recording layer consisting essentially of at least one cyanine dye selected from the group of compounds having the formulas: ##STR23## or an alkyl, alkoxy, hydroxy, acetyl, aryl or halogen substituted derivative thereof, in which R 2 is alkyl, alkoxyalkyl, hydroxyalkyl, aralkyl, carboxyalkyl, carboxylatoalkyl bonded with an alkali metal cation, sulfoalkyl or sulfonatoalkyl; A is ##STR24## alkoxy, hydroxy, acetyl, aryl or halogen substituted derivative thereof, in which R 2 is the same as for B, and X is a counter ion; Z is H, --OH, --COOH, halogen, C 1 -C 5 alkyl, phenyl, N-substituted amino, N-substituted alkyl, substituted or unsubstituted aryl, or --COOR', wherein R' is C 1 -C 5 alkyl, phenyl or substituted phenyl, and Z, when plural, may be same or different; and m and n are each 0, 1, 2 or 3, with the proviso m+n≦3.

Claim 15

A recording material as claimed in claim 12, wherein said cyanine dye is a compound of said general formula (1).

Claim 16

A recording material as claimed in claim 12, wherein said cyanine dye is a compound of said general formula (2).

Claim 17

A recording medium as claimed in claim 12, in which Z is hydrogen and R 2 is alkyl.

Claim 18

A recording medium as claimed in claim 12, wherein said recording layer has a thickness in the range of 100 to 5000 angstroms.

Claim 19

A recording medium as claimed in claim 12, wherein said recording layer has a thickness in the range of 200 to 600 angstroms.