| 摘要 |
Anti-forgery coating for security articles is made by first grinding a crystalline rare earth luminiferous substance to a particle size of 25-50 microns, and uniformly dispersing 8-15wt.% of the prod. into a UV-curable liq. binder comprising an epoxy acrylate resin and a photoinitiator. One or both faces of the article is then coated with the varnish such that the whole of the information carried on the article is coated, the thickness of the coating being adjusted such that the luminiferous crystals form a monomolecular layer. A transparent protective film is then applied over the article whilst the varnish is still wet and the whole is calendered to even out the coating, to remove excess varnish, and to preserve the monomolecular distribution of the luminiferous pigment. The protective films are then sealed to the edges of the article by high frequency welding and the whole is exposed to UV to cure the varnish. Process allows prodn. of forge-proof documents, identity cards, etc., using prodn. line techniques. |
