REFRACTIVE INDEX DISTRIBUTION FORMING MATERIAL AND HOLOGRAPHIC DRY PLATE

摘要

PROBLEM TO BE SOLVED: To obtain a refractive index distribution forming material having a high diffraction efficiency and high transparency by using a low-mol.wt. copolymer and high-mol.wt. copolymer which are respectively specific in the maximal values of a weight average mol.wt. in terms of polystyrene as the compsn. component of a binder polymer. SOLUTION: This refractive index distribution forming material has a binder polymer, a photopolymerizable and a photopolymerization initiator. The binder polymer has a vinyl/acrylic copolymer consisting of the high-mol.wt. copolymer having the maximal values of the weight average mol.wt. in terms of the polystyrene within the range of 1×10<5> to 1×10<6> and a vinyl/acrylic copolymer consisting of the low-mol.wt. copolymer having the maximal values of the weight average mol.wt. in terms of the polystyrene within the range of 8×10<2> to 4×10<4> . The photopolymerizable monomer has a vinyl/acrylic monomer having an arom. ring or halogen and/or a vinyl/ acrylic copolymer having a multifunctional group. The photopolymerization initiator polymerizes the photopolymerizable monomer by photoirradiation.