Merck Patent Gmbh

Merck Patent Gesellschaft MIT Beschrankter Haftung

Merck Patent Gesellschaft

Merck Patent Gesellschaft MIT Beschr&auml;nkter Haftung

Reiner Delp

Matthias Kuntz

Gerhard Pfaff

Helge Bettina Kniess

Dieter Heinz

John Patrick

Rodney Riddle

Robert Hammond-Smith

Hans-Juergen Brehm

Laser-markable pigments which are distinguished by the fact that an absorber is coated with a marker and optionally with a diffusion barrier are described. Further, processes for the preparation of the laser-markable pigments and methods for using them are described. The absorber is preferably an inorganic pigment or a filler. The marker is preferably an intrinsically laser-markable polymer, particularly a polyethylene terephthalate, acrylonitrile-butadiene-styrene, polystyrene, polyphenylene ether, liquid-crystal polymer or polyphenylene sulfide.

Laser-markable pigments containing an absorber coated with a marker

The invention relates to an optically variable marking comprising a semiopaque substrate with a first surface that is covered with an optically variable layer that is for example a liquid crystal polymer layer or a layer comprising pearlescent pigments, and a second surface that is partially covered with a metal layer in the shape of a pattern, to methods of its preparation and to its use for decorative or security applications.

Optically variable marking

The present invention relates to the colored inscription or marking of plastics and surface coatings, including powder coatings, in which a colorant is transferred into the plastic or surface coating by laser radiation with the aid of a laser light-absorbent substance.

Colored inscription and marking of plastics and surface coatings

Laser-markable plastics

The present invention relates to laser-markable plastics which comprise, as dopant, graphite particles having one or more coatings.

The present invention relates to laser-markable plastics of which a feature is that they comprise as dopant anthracene- or pentaerythritol-coated effect pigments or a mixture comprising one or more effect pigments and anthracene and/or pentaerythritol.

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Darmstadt, Germany

Reiner Delp