Rhone-poulenc Systemes

Rohne-poulenc Chimie

Claude Ceintrey

Jacques Persello

Michel Crochemore

Monique Detain

Michel Sutter

Novel pigmentary colorants, well adapted for the production of electrostatic developer powders, are comprised of mineral core particulates, at least one mineral oxide and at least one dye, said at least one mineral oxide being deposited onto the surface area of the core particulates, and said at least one dye being absorbed onto the core particulates or onto the at least one mineral oxide and/or being at least partly physically confined within a matrix of the mineral oxide.

Core/oxide/dye pigmentary colorants

Diazotype materials which can be developed by heat and contain an

A tamperproof identification card such as a passport or credit card is provided. A diazo photosensitive composition is intimately mixed with a thermo-adhesive resin and is carefully deposited as a uniformly thin layer in one or more zones on a plastic support material. The zones of the photosensitive compositions are developed to reproduce identifying information such as a photograph, identification number, etc. A plastic protective film is then laminated to the support to protect the identifying information. Since the adhesive resin material is intimately mixed throughout the photosensitive composition, the protective plastic film cannot be removed without destroying the information.

Presensitized plastic card, tamperproof identification card prepared

An opaque recording material has an opaque sensitive layer which can be transparentized by application of heat or a suitable solvent for the opacifying styrene resin pigment which is dispersed in a polyvinylidene chloride film-forming resin binder. In a particular application, useful for overhead transparencies or for making photographic negatives for reproduction, heat and solvent are both applied to the opaque layer in selected different areas to transparentize the opaque layer. The opaque layer may be deposited on a transparent clear or colored support such as transparent polyester.

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Neuville Les Dieppe, France

Claude Ceintrey