Abstract: A composition comprising a plurality of discrete carrier-swellable polymer particles (preferably polyNIPAM particles) and a corresponding carrier (e.g. water), which particles have a low polydispersity index and are present in an amount of at least 0.1% by weight of the composition may be used to impart structural-image properties (such as structural colour) to a substrate by coating or printing methods. Additional benefits of adherence to low-energy surface substrates and enhanced rheological properties for printing compositions may also be provided. The compositions and methods used in the invention allow visual effects or security applications to be incorporated into substrates in a low-cost and convenient manner.

Abstract: A flexographic printing composition which comprises a carrier-swellable particle composition, such as a microgel particle composition, has improved printing performance and printing resolution, especially where the flexographic printing composition is an aqueous printing composition and the carrier is water. The composition is particularly beneficial for flexographic printing of such an aqueous printing ink onto low-energy surface substrates or impermeable substrates, in which the ink has improved adhesion, even in the absence of corona discharge treatment. The use of surfactant in an amount of at least 0.5% by weight of the ink composition enhances printed density and/or reduces mottling in solid printed areas.

Abstract: A donor element for use in laser thermal imaging has a layer which comprises an infrared-absorbing material, an image dye and a polymer matrix comprising a thermally degradable polymer and a non thermally degradable polymer there being an interaction between the infrared-absorbing material and the non degradable polymer to facilitate retention of the infrared-absorbing material in the donor element. The degradable and non degradable polymers are preferably copolymers both of which contain methacrylic acid as a monomer. The degradable polymer is preferably a copolymer of methoxyethyl cyanoacrylate and methacrylic acid preferably in molar proportions of from 1:1 to 12:1. The non degradable polymer is preferably a copolymer of methyl methacrylate and methacrylic acid, preferably in molar proportions of from 1:1 to 15:1. The element may be prepared from an aqueous solid particle dispersion which has been prepared by milling the components together in a ball mill.

Abstract: A donor element for use in laser thermal imaging has a layer which comprises an infrared-absorbing material, an image dye and a polymer matrix comprising a thermally degradable polymer and a non thermally degradable polymer there being an interaction between the infrared-absorbing material and the non degradable polymer to facilitate retention of the infrared-absorbing material in the donor element. The degradable and non degradable polymers are preferably copolymers both of which contain methacrylic acid as a monomer. The degradable polymer is preferably a copolymer of methoxyethyl cyanoacrylate and methacrylic acid preferably in molar proportions of from 1:1 to 12:1. The non degradable polymer is preferably a copolymer of methyl methacrylate and methacrylic acid, preferably in molar proportions of from 1:1 to 15:1.