Imperial Chemical Industries Limited

Barry Pack

Richard A Hann

Kazuhiko Sakata

Warren T Smith

Alan James Butters

Jeffrey Michael Howell

A receiver medium for inkjet printing includes a porous substrate, having on at least one surface thereof a porous ink-absorbent coating having a colloidal particulate material, a water-insoluble liner binder polymer, and optionally a film forming polymer dispersion. On printing, the medium rapidly absorbs ink to give a touch-dry surface. The receiver medium can also have a satin finish surface. Also disclosed is a method of making the receiver medium.

Inkjet receiver media

The present invention relates to a coating material for producing a porous ink-absorbent coating on a substrate to be used in ink-jet printers, comprising radiation curable material and particulate material in a liquid carrier, wherein the weight ratio of particulate material to radiation curable material is greater than 1:1. Also disclosed is a process for preparing a coated substrate using such a coating material. Advantageously, the coating material of the present invention does not crack upon curing, and conveniently forms a porous coating having a glossy surface, while retaining a porous structure for ink-absorption.

Coated substrate for use in ink-jet printers

Thermal transfer printing dyesheet

A dyesheet is provided for thermal transfer printing, comprising a base sheet having a thermal transfer dye layer on one surface, and on the other a heat resistant backcoat comprising a crosslinked reaction product of radically polymerising a compound having a plurality of polymerisable unsaturated groups per molecule, wherein the backcoat is formulated to minimise scratching of the print during printing. The formulation comprises a) a compound having a single radically polymerisable unsaturated group which is copolymerised with the compound having a plurality of polymerisable unsaturated groups per molecule, and b) a multivalent metal salt of a long chain alkyl or alkylphenyl phosphate ester as slip agent. These two factors (a & b) work together, and if either is omitted, relief from scratching does not generally occur.

Thermal transfer dyesheet

A dyesheet is provided for thermal transfer printing, comprising a base sheet having a dyecoat containing a thermal transfer dye layer on one surface, and on the other a croselinked heat resistant backcoat formulated to minimize dye migration from the dyecoat to the backcoat during storage. The backcoat comprises the reaction product of radically copolymerising in a layer of coating composition, a) at least one organic compound having a plurality of radically polymerisable unsaturated groups per molecule, and b) at least one organic compound having per molecule a single unsaturated group radically copolymerisable with constituent a, and having at least one alicyclic group per molecule. Preferred additional constituents include slip agents, especially a multivalent metal salt of a long chain alkyl or alkylphenyl phosphate ester.

To enhance the optical density of colors produced by thermal transfer printing, a dyesheet is used having an intermediate dye-barrier layer between the substrate and the dyecoat. This layer consists essentially of a reaction product of polymerizing acrylic functional groups in a layer of a coating composition comprising: (a) an organic resin comprising at least one polyfunctional material having a plurality of pendant or terminal acrylic groups per molecule available for cross-linking, at least 50% by weight of the polyfunctional material having at least 4 such acrylic functional groups per molecule; and (b) at least one linear organic polymer soluble or partially soluble in the resin, and comprising 1-40% by weight of the resin/polymer mixture.

Thermal transfer printing dyesheet and dye barrier composition therefor

For a thermal transfer dyesheet, a protective backcoat is provided by polymerizing acrylic functional groups in a composition comprising: an organic resin comprising at least one polyfunctional material having a plurality of pendant or terminal acrylic groups per molecule available for cross-linking, at least 10% by weight of the polyfunctional material having 4-8 such acrylic groups per molecule; at least one linear organic polymer soluble or partially soluble in the resin, and comprising 1-40% by weight of the resin/polymer mixture; a slip agent selected from derivatives of long chain carboxylic or phosphoric acids, long alkyl chain esters of phosphoric acid, and long alkyl chain acrylates; an antistatic agent soluble in the resin, and a solid particulate antiblocking agent less than 5 .mu.m in diameter. Resins having predominently 5-7 acrylic functional groups per molecule, are preferred for enhancing protection against the thermal head, especially when used in a mixture also containing molecules having only 2-4 such acrylic groups per molecule. The effect of using such mixtures to cross link molecules of both high and low acrylic functionalities in the presence of the linear polymers, is to enable good thermal protection to be provided by a durable low friction coating, which also cleans the thermal head during printing.

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Ipswich, United Kingdom

Barry Pack