Patent EP-2251206-A1 (EP)
Inventor: PALKOVITS ROLAND DR
IPC: C09D7/61
Filed: 2009-05-15
Abstract: The material such as paper, cardboard, corrugated cardboard, plastic film, injection- or die-casting plastic part, metal, ceramic surface, lacquer layer or corrosion protective layer, which is coated or compounded with a mixture of molybdenum salt consisting of ammonium molybdate, alkylamine molybdate or alkalimolybdate, alkali silicomolybdate or phosphomolybdate or analogous tungsten compound or vanadium compound, is claimed, where the entire structure is spatially defined by the effect of light and is recognizably changed in color for the human eye in a structured manner. The material such as paper, cardboard, corrugated cardboard, plastic film, injection- or die-casting plastic part, metal, ceramic surface, lacquer layer or corrosion protective layer, which is coated or compounded with a mixture of molybdenum salt consisting of ammonium molybdate, alkylamine molybdate or alkalimolybdate, alkali silicomolybdate or phosphomolybdate or analogous tungsten compound or vanadium compound, is claimed, where the entire structure is spatially defined by the effect of light and is recognizably changed in color for the human eye in a structured manner. The paper, cardboard, corrugated cardboard, plastic film, injection- or die-casting plastic part, metal, ceramic surface, lacquer layer or corrosion protective layer is provided with a covering layer (4) made of organic or silico-organic transparent material on one-side or both side. The entire structure is spatially defined by the effect of pixel- or vector-like working light source, where the color change takes place without significant release of particles. The structure is changed by laser light of a gas laser e.g. carbon dioxide laser, LED-light, short-arc lamp or flash discharge lamp or by thermal print heads. The odorous molecules released by the heat are bound by the additives of an absorber such as cyclodextrin. The change of the structure recognizable for the human eye is palpable by profiling the surface at the same time the covering layer is not perforated. A part of the color change takes place by a chemical reaction of thermal decomposition products of the matrix such as paper, and by generating chromophoric compounds from colorless and/or color-weak molybdenum salts by thermal effect of the laser. The addition or setting of an intermediate layer between the molybdenum salt layer and the covering layer made of glass powder or minerals increases the color strength and/or displaces the color. The covering layer is applied over the molybdenum salt layer consisting of polyethylene or polypropylene, polystyrene and their copolymers with other polymers. A layer with light-scattering characteristics is used as covering layer over the molybdenum salt layer and is converted into a transparent melted layer by the laser. The transparent covering layer has UV-stabilizer and has a thickness of less than 200 mu . Independent claims are included for: (1) a method for marking a paper, cardboard, corrugated cardboard, plastic film, injection- or die-casting plastic part, metal, ceramic surface, lacquer layer or corrosion protective layer; and (2) a method for producing a paper, cardboard, corrugated cardboard, plastic film, injection- or die-casting plastic part, metal, ceramic surface, lacquer layer or corrosion protective layer.