Patent ID: 7029833

Claim:
An image display medium comprising: a photoconductive layer containing a photochromic compound and an electron accepting compound; and a substrate, wherein the photochromic compound contains a fulgide compound, and the electron accepting compound contains a compound selected at least from: a) a phosphonic acid compound having an aliphatic group containing 12 or more carbon atoms; b) an aliphatic carboxylic acid compound having an aliphatic group containing 12 or more carbon atoms, wherein said aliphatic carboxylic acid compound is at least one member selected from the group consisting of: b-1) an alpha-hydroxyalphaticcarboxylic acid compound represented by the following Formula (II): where R 2 is an aliphatic group containing 12 or more carbon atoms, b-2) an aliphatic carboxylic acid compound containing 12 or more carbon atoms, and at least one of the carbon atoms is bonded to a halogen element at one of an alpha-position and a beta-position of the aliphatic carboxylic acid compound, b-3) an aliphatic carboxylic acid compound containing 12 or more carbon atoms, and the aliphatic carboxylic acid compound has at least one oxo group at any one of an alpha-position, a beta-position, and a gamma-position thereof, b-4) an aliphatic carboxylic acid compound represented by the following Formula (III): where R 3 is aliphatic group containing 12 or more carbon atoms, “X” is one of an oxygen atom and a sulfur atom; and “n” is 1 when “X” is an oxygen atom, and “n” is one of 1 and 2 when “X” is a sulfur atom, b-5) an aliphatic carboxylic acid compound represented by the following Formula (IV): where R 4 , R 5 , and R 6 are identical or different, and each express one of a hydrogen atom and an aliphatic group, in which at least one of R 4 , R 5 , and R 6 is an aliphatic group containing 12 or more carbon atoms, b-6) an aliphatic carboxylic acid compound represented by the following where R 7 and R 8 are identical or different, and each express one of a hydrogen atom and an aliphatic group, in which at least one of R 7 and R 8 is an aliphatic group containing 12 or more carbon atoms, and b-7) an aliphatic carboxylic acid compound represented by the following Formula (VI): where R 9 is an aliphatic group containing 12 or more carbon atoms, “n” is b 0 or 1, and “m” is an integer from 1 to 3, in which “m” is 2 or 3 when “n” is 0, and “m” is 1 or 2 when “n” is 1; and c) a phenolic compound having an aliphatic group containing 12 or more carbon atoms.