Improvements in relation to security printing

An article comprising a substrate which carries a doped tin oxide wherein less than 50 mol% of the tin atoms in the tin oxide are substituted with a dopant element, e.g. antimony, tungsten, fluorine or phosphorus. The doped tin oxides may be used as invisible but IR-active pigments for confirming ge...

Ausführliche Beschreibung

Gespeichert in:

Bibliographische Detailangaben
Hauptverfasser:	David Malcolm Lewis, Dieter Guhl
Format:	Patent
Sprache:	eng
Schlagworte:	ADHESIVES BASIC ELECTRIC ELEMENTS BOOK COVERS BOOKBINDING CABLES CALCULATING CHEMICAL PAINT OR INK REMOVERS CHEMISTRY COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS COLOUR PRINTING COMPOSITIONS BASED THEREON COMPUTING CONDUCTORS CORRECTING FLUIDS COUNTING DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDEDFOR DYES ELECTRICITY FILES FILLING PASTES HANDLING RECORD CARRIERS IMPREGNATING OR COATING OF PAPER INKS INSULATORS LINING MACHINES LOOSE LEAVES METALLURGY MISCELLANEOUS APPLICATIONS OF MATERIALS MISCELLANEOUS COMPOSITIONS MOVABLE-STRIP WRITING OR READING APPARATUS NATURAL RESINS ORGANIC MACROMOLECULAR COMPOUNDS PAINTS PAPER NOT OTHERWISE PROVIDED FOR PAPER-MAKING PASTES OR SOLIDS FOR COLOURING OR PRINTING PERFORMING OPERATIONS PHYSICS POLISHES PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D PRESENTATION OF DATA PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITYFEATURES PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOTOTHERWISE PROVIDED FOR PRINTING PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES PRODUCTION OF CELLULOSE PULP COMPOSITIONS RECOGNITION OF DATA RECORD CARRIERS SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING ORDIELECTRIC PROPERTIES SPECIAL PRINTED MATTER STAMPS TEXTILES THEIR PREPARATION OR CHEMICAL WORKING-UP TRANSPORTING TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G TYPEWRITERS USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS USE OF MATERIALS THEREFOR WOODSTAINS
Online-Zugang:	Volltext bestellen
Tags:	Tag hinzufügen Keine Tags, Fügen Sie den ersten Tag hinzu!

Beschreibung
Zusammenfassung:	An article comprising a substrate which carries a doped tin oxide wherein less than 50 mol% of the tin atoms in the tin oxide are substituted with a dopant element, e.g. antimony, tungsten, fluorine or phosphorus. The doped tin oxides may be used as invisible but IR-active pigments for confirming genuineness of an article or for assessing its quality. A genuine article may be determined by measuring the absorption of the article, which may be non-uniform, at two different wavelengths in the infra-red range and calculating their ratio. The quality is assessed by comparing the IR absorption with a standard. The article may be a banknote, which has either the doped tin oxide (e.g. cassiterite, SnO2) distributed throughout the substrate or the doped tin oxide is applied as an ink composition. The ink compositions may have tin oxide with 5 20 mol% antimony or with 1.5 mol% fluorine. The banknote may contain a covert security image or hidden coating. The difference in colour dE between substrate with doped tin oxide and without it may be less than 2.