Imperial Chemical Industries Limited

Peter A Gemmell

Richard A Hann

Roy Bradbury

Nicholas C Beck

David A Jackson

Kiyotaka Iiyama

Carol Leliaert

A dyesheet for thermal transfer printing comprises a substrate supporting a transfer coat comprising one or more thermally transferable dyes dispersed throughout a polymeric binder comprising a mixture of polyvinylbutyral and a cellulosic polymer in which the percentage by weight of polyvinylbutyral lies within the range 65-85%.

Thermal transfer dyesheet

A thermal transfer printing sheet suitable for the printing of black images in a dye diffusion thermal transfer printing process. The sheet comprises a substrate having a coating comprising a black dye mixture comprising from 5 to 60% of a dye of Formula 1, from 5 to 60% of Formula 2, from 5 to 60% of a dye of Formula 3 and/or from 1 to 60% of a dye of Formula 4.

Thermal transfer printing

A transfer sheet, suitable for use in a dye diffusion thermal transfer printing process for the production of images in accordance with a pattern information signal, comprising a substrate having a coating comprising a binder, one or more anthraquinone dyes of Formula I ##STR1## wherein R.sup.1 represents alkyl, alkenyl, cycloalkyl, haloalkyl, cyanoalkyl, alkoxyalkyl, alkoxyalkoxyalky, hydroxyalkyl, hydroxyalkoxyalkyl, hydroxyalkylthioalkyl, tetrahydrofurfuryl, alkenyloxyalkyl, tetrahydrofurfuryloxyalkyl, alkoxycarbonylalkyl, alkoxycarbonyloxyalkyl or alkoxycarbonyloxyalkyl, and

A method for improving the stability of a color print formed by dye-diffusion thermal transfer printing, comprises placing against the print a panel of transfer coat comprising a dye-absorbant binder which is substantially free from any thermally transferable materials, and heating at least those areas of the print to which one or more dyes have been transferred, thereby to cause absorption by said panel of dye molecules at the surface of the print. This may conveniently be carried out as part of the printing operation by using a dyesheet having a transfer coat comprising a plurality of uniform panels containing different colored thermally transferable dyes held in a dye-absorbant binder, and further panels comprising a dye-absorbant binder which is substantially free from any thermally transferable materials.

A thermal transfer printing sheet comprising a substrate having a coating comprising a mixture of dyes of 20-50% of Formula I and of 80-50% of Formula II. ##STR1## wherein: R.sup.1 is C.sub.1-12 -alkyl;

A dyesheet for thermal transfer printing comprises a substrate supporting a transfer coat comprising a plurality of uniform panels containing different colored thermally transferable dyes, and a further panel in which instead of a colored dye there is a thermally transferable colorless absorber of ultraviolet radiation. Using such a dyesheet, a layer of UV absorber can be applied very simply as an extension of the printing process, by causing the receiver to pass through the printer once more, in contact with the further panel, essentially as though the UV absorber were merely a further color to be added to the print.

A thermal transfer printing sheet suitable for use in a thermal transfer printing process, comprising a substrate having a coating comprising a binder and an anthraquinone of the Formula I: ##STR1## or a mixture of an anthraquinone dye of the Formula I and a disazo dye of Formula II:

A compound having ferroelectric liquid crystal properties of the formula: ##STR1## wherein A is the residue of a liquid crystal material or a liquid crystal compatible material;

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Ipswich, United Kingdom

Peter A Gemmell