Felix Schoeller Gmbh & Co. Kg

Felix Schoeller Jr Foto- Und Spezialpapiere Gmbh & Co. Kg

Felix Schoeller Jr Gmbh & Co. Kg

Felix Schoeller, Jr. Gmbh & Co.

Hans-Udo Tyrakowski

Eckehard Saverin

Rolf Ebisch

Hans-Ulrich Berner

The invention relates to a photographic support material with a backlayer and to a coating composition for producing this backlayer. The layer is distinguished by excellent writing properties with pencils and is free of contaminations by aged developing baths. It is composed of carboxylated acrylate copolymer, organic polyacid, coarse-grained silica, thickener and, preferably, colloidal aluminium-modified silica.

Photographic support material with a backlayer containing coarse silica

A photographic support material comprising a plastic foil or plastic coated paper coated on the rear side with a composition that can be printed with thermal printers and does not pick up dirt or discoloration in developing baths, has good adhesive tape adhesion, good printability with conventional printers, good abrasion resistance and bath resistance, and a good antistatic finish. The coating composition comprises an aqueous mixture of colloidal aluminum modified silica, a polyfunctional aziridine, an alkali salt of an organic polyacid, and a plastic dispersion with free carboxyl groups, a residual monomer content of &lt; 200 ppm, &gt; 50 mol % rigid monomers in the polymer and the interfacial tension of the dried film of &gt; 50 dyn/cm.

Reverse side coating of photographic support materials

A coating mass for the production of a layer on the reverse side of photographic support materials of plastic foils or plastic coated papers is particularly distinguished by extraordinarily low dirt absorption and discoloration, even from greatly aged development baths. This is obtained through a mixture of colloidal aluminum modified silica, the alkali salt of an organic polyacid, a styrene/butadiene latex with a low content of free carboxyl groups and residual monomers, and a surface tension of &gt;45 dyn/cm. The coating mass is so composed that the dried back coating has an interfacial surface tension of &gt;50 dyn/cm.

Coating mass for the back of photographic support materials

A photographic support material comprising a plastic foil or plastic coated paper coated on the rear side with a composition that can be printed with thermal printers and does not pick up dirt or discoloration in developing baths, has good adhesive tape adhesion, good printability with conventional printers, good abrasion resistance and bath resistance, and a good antistatic finish. The coating composition comprises an aqueous mixture of colloidal aluminum modified silica, a polyfunctional aziridine, an alkali salt of an organic polyacid, and a plastic dispersion with free carboxyl groups, a residual monomer content of &lt;200 ppm, &gt;50 mol % rigid monomers in the polymer and the interfacial tension of the dried film of &gt;50 dyn/cm.

The invention relates to a multifunctional back layer for a photographic element and to a coating composition for manufacturing the multifunctional layer which comprises at least four components: (a) a surface-hydroxylated aluminum-modified silica, (b) an alkali-metal salt of an organic polyacid, (c) an aqueous dispersion of copolymers of acrylic-acid-alkyl-ester including free carboxylic groups of from 1-10 mole-% and of free hydroxyl groups of from 5-20 mole-%, wherein the sum of free carboxylic groups and free hydroxy groups does not exceed 25 mole-%, and (d) a trifunctional aziridine as a cross-linking means. The multifunctional back layer of the photographic element according to the invention exhibits a low reception for dirt during passage through roller-transport developing machines, a high abrasion-proofness, wear resistance, stability in alkaline developer solutions, good printability during printing with conventional printing inks, good markability, inscriptability and lettering, as well as a good adhesive tape adhesion.

Multifunctional layer for a photographic element and a coating

A photographic support material is disclosed for light sensitive coatings in the form of a plastic coated paper or a plastic foil whose backside has a coating allowing writability. The back coating comprises a terpolymer latex of styrene-butadiene-methacrylate, a hard silicic acid, and an aluminium modified colloidal silicic acid sol. The coating may also include an aqueous solution of a salt of an organic polyacid. The quantities of the additives used result in optimal characteristics of printability, writability using various pens and lead pencils, minimal soiling in old developing baths, minimal coloring in developing solutions, good tape adhesion and, when required, good antistatic characteristics.

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Hasbergen, Germany

Hans-Udo Tyrakowski