Pre-treatment composition for inkjet printing

Abstract

A coating composition for pre-treating a substrate prior to inkjet printing thereon, and an inkjet receiving medium comprising a substrate and having a topmost layer coated thereon, where the coating composition and topmost layer comprise one or more aqueous-soluble salts of multivalent metal cations, a cationic polyelectrolyte comprising amidine moieties, and one or more second polymer which is distinct from the cationic polyelectrolyte and which is selected from the group consisting of a polyamide-epichlorohydrin, a polyamine solution polymer, and a waterborne or water-dispersible polyurethane. The topmost layer is advantageously at a solid content of from 0.1 to 5 g/m2, and comprises from 30-90 wt % of the one or more aqueous soluble salts of multivalent metal cations, at least 0.01 g/m2 of the cationic polyelectrolyte comprising amidine moieties, and at least 0.005 g/m2 of the second polymer which is distinct from the cationic polyelectrolyte comprising amidine moieties.

Dependencies are inferred from the claim text.