Volume hologram sheet to be embedded, forgery prevention paper, and card
AssigneeDai Nippon Printing Co., Ltd.
InventorsNobuko Oikawa, Minoru Azakami
Life of this patent
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Abstract
An object of the present invention is to provide a thin volume hologram sheet to be embedded sufficiently resistant to a mechanical stress such as a stress including a tensile stress, a shear stress and a compression stress at the time of processing even under a heating condition, a forgery prevention paper and a card using the same. The object is achieved by providing a volume hologram sheet to be embedded comprising a volume hologram layer, and a substrate disposed only on one side surface of the volume hologram layer using an adhesion means, wherein a peeling strength of the volume hologram layer and the substrate is 25 gf/25 mm or more.
Claims5
A card comprising a core sheet, a volume hologram sheet, and an over sheet,
- wherein the volume hologram sheet is embedded between the core sheet and the over sheet,
- the volume hologram sheet includes a volume hologram layer, a substrate, and an adhesion means,
- a peeling strength of the volume hologram layer and the substrate is 144 gf/25 mm or more,
- the adhesion means is an adhesive layer using a solvent-based thermosetting adhesive, and
- the adhesive layer is laminated between a first surface of the volume hologram layer and the substrate,
- wherein the volume hologram layer comprises epoxy group—containing acrylic resin, polyvinyl acetate, 1,6-hexane diol diglycidyl ether, diphenoxy ethanol fluoride diacrylate, diaryl iodonium salt, and 2,5-bis(4-diethyl amino benzylidene) cyclopentanone.
Dependencies are inferred from the claim text.