Patent ID: 7923174

Claim:
A holographic recording composition comprising a bifunctional or greater isocyanate, a mixture of polyfunctional alcohols comprising a bifunctional alcohol and a trifunctional or greater alcohol, a titanocene-based radical polymerization initiator, a bifunctional or greater acrylate monomer, and an amidine salt denoted by General Formula (1): wherein R 1 , R 2 , and R 3 each independently denotes an alkyl group, aryl group, amino group, or acyl group, R 1 and R 2 may be bonded together to form a ring, R 2 and R 3 may be bonded together to form a ring, and A − denotes an anion selected from the group consisting of halogen anion, sulfonate anion, tetrafluoroborate anion, hexafluorophosphate anion, perchloric acid anion, and octanoic acid anion.