| abstract |
A receiver medium for digital imaging comprises a substrate having a dye-receiving surface bearing a coating comprising a highly branched functionalised polymer of generally globular form, e.g. a dendrimer, dispersed in a host polymer. Functional groups at or near the surface of the branched polymer, may interact with and bind dye molecules having complementary functional groups, eg dyes as disclosed in WO 96/34766, e.g. by acid-base interaction, thus having the effect of chemically fixing the dye within the coating on the receiver medium. Because dye molecules can be chemically bound to the branched polymer in the receiver sheet, it is possible to use host polymer materials of lower Tg than generally required in the prior art, with the host polymer typically having a Tg of less than 50 °C. This means that dye molecules can have a significantly increased diffusivity through the coating, prior to interaction, resulting in a more even distribution of dye through the coating than has been possible hitherto. The invention also covers a method of making the receiver medium, a method of printing, and a receiver medium/dye combination. |