Volume hologram transfer foil, and volume hologram multilayer structure
The invention provides (1) a volume hologram transfer foil comprising a substrate and protective layer, a volume hologram layer and a heat seal layer stacked on the substrate in this order, wherein a multilayer structure comprising the protective layer, the volume hologram layer and the heat seal layer in this order is releasable from the substrate, and (2) a volume hologram transfer foil wherein the above protective layer is used as a heat seal layer. The heat seal layer comprises a polyester resin having a glass transition temperature of −10° C. to −30° C. With the invention, thermo-compression adhesion of the volume hologram layer to any application member, especially a polyester resin card is improved, so that the invention provides a volume hologram transfer foil useful for prevention of illegal copying, and a volume hologram multilayer structure formed using such a transfer foil.
1. A volume hologram transfer foil, comprising a substrate and a protective layer, a volume hologram layer and a heat seal layer stacked on the substrate in this order wherein a multilayer structure comprising the protective layer, the volume hologram and the heat seal layer in this order is releasable from said substrate, characterized in that said heat seal layer is formed using an aqueous dispersion of a polyester resin having a glass transition temperature of −10° C. to −30° C. and a melting point of 80° C. to 200° C., and including a hydrophilic functional group.
2. The volume hologram transfer foil according to claim 1 , characterized in that the polyester resin has a number-average molecular weight of 18,000 to 80,000.
3. The volume hologram transfer foil according to claim 1 , characterized in that the heat seal layer contains a fine particle.
4. The volume hologram transfer foil according to claim 1 , characterized in that there is a releasing film additionally provided on the heat seal layer.
5. The volume hologram transfer foil according to claim 1 , characterized in that the volume hologram layer comprises a cation-polymerizable compound, a radical-polymerizable compound, a photoradical polymerization initiator system that is sensitive to specific wavelength light to polymerize the radical-polymerizable compound, and a photocation polymerization initiator system that is less sensitive to said specific wavelength light but is sensitive to another wavelength light to polymerize the cation-polymerizable compound.
6. The volume hologram transfer foil according to claim 1 , characterized in that there is a primer layer interposed between the volume hologram layer and the heat seal layer.
7. A Volume hologram transfer foil, comprising a substrate and a first heat seal layer, a volume hologram layer and a second heat seal layer stacked on said substrate in this order wherein a multilayer structure comprising the first heat seal layer, the volume hologram layer and the second heat seal layer in this order is releasable from said substrate, characterized in that the first and the second heat seal layer are each formed using an aqueous dispersion of a polyester resin having a glass transition temperature of −10° C. to −30° C. and a melting point of 80° C. to 200° C., and including a hydrophilic functional group.
8. The volume hologram transfer foil according to claim 7 , characterized in that the polyester resin has a number-average molecular weight of 18,000 to 80,000.
9. The volume hologram transfer foil according to claim 7 , characterized in that the first and the second heat seal layer each contains a fine particle.
10. The volume hologram transfer foil according to claim 7 , characterized in that there is a releasing film additionally provided on the second heat seal layer.
11. The volume hologram transfer foil according to claim 7 , characterized in that the volume hologram layer comprises a cation-polymerizable compound, a radical-polymerizable compound, a photoradical polymerization initiator system that is sensitive to specific wavelength light to polymerize the radical-polymerizable compound, and a photocation polymerization initiator system that is less sensitive to said specific wavelength light but is sensitive to another wavelength light to polymerize the cation-polymerizable compound.
12. The volume hologram transfer foil according to claim 7 , characterized in that there is a primer layer interposed between the volume hologram layer and the first and/the second heat seal layer.
13. A volume hologram multilayer structure, comprising a heat seal layer, a volume hologram layer and a protective layer stacked on an application member in this order, characterized in that the heat seal layer is formed using an aqueous dispersion of a polyester resin having a glass transition temperature of −10° C. to −30° C. and a melting point of 80° C. to 200° C. and including a hydrophilic functional group.
14. The volume hologram multilayer according to claim 13 , characterized in that the application member is a polyester resin card or a polyester film.
15. The volume hologram multilayer structure according to claim 13 , characterized in that there is a primer layer interposed between the volume hologram layer and the heat seal layer.
16. A volume hologram multilayer structure, comprising a first application member and a first heat seal layer, a volume hologram layer, a second heat seal layer and a second application member stacked on the first application member in this order, characterized in that the first and the second heat seal layer are each formed using an aqueous dispersion of a polyester resin having a glass transition temperature of −10° C. to −30° C. and a melting point of 80° C. to 200° C. and including a hydrophilic functional group.
17. The volume hologram multilayer structure according to claim 16 , characterized in that the first and the second application member each is a polyester resin card or a polyester film.
18. The volume hologram multilayer structure according to claim 16 , characterized in that there is a primer layer interposed between the volume hologram layer and the first and/or the second heat seal layer.