Patent ID: 7238460

Claim:
An optical recording medium having a surface layer provided on a substrate, the surface layer serving as a recording layer, and comprises a composition containing a polymer composed of a block copolymer or a graft copolymer with a phase-separated structure of two or more kinds of phase-insoluble polymer components each having a size of 10 to 100 nm, the optical recording medium, comprising: phase-separated domains including one or more kinds of specific volatile substances dispersed therein in a one-to-one correspondence with each other, said specific volatile substances being formed by homogeneously depositing said specific volatile substances in a vapor state on the respective surfaces of said specific phase-separated domains in a one-to-one correspondence with each other, and dispersing and penetrating molecules of said deposited specific volatile substances into said corresponding specific phase-separated domains in a state in which the recording layer is disposed in a closed container capable of controlling a pressure and temperature thereof, with the upper limit of the temperature in the closed container being a melting point of a volatile substance and the pressure in the container at a temperature no greater than the upper limit temperature being less than or equal to the saturated vapor pressure of the volatile substance; and matrix composed of polymer components of the specific phase-separated domains and phase-insoluble polymer components and being other phase-separated domains which do not contain the volatile substance, wherein said specific phase-separated domain constitutes a basic unit for optical recording, said volatile substance is a photochromic compound capable of photoisomerization, and the difference in refractive index between the specific phase-separated domain having the photochromic compound penetrated and dispersed therein and the matrix is in the range of 0 to 0.02 in one isomerization state and is 0.06 or greater in the other isomerization state.