An ink composition for inkjet printing

Abstract

An inkjet ink comprises a cellulosic polymer for forming a porous network structure, a blend comprising a solvent and nonsolvent, the solvent being more volatile than the nonsolvent, and a film-forming binder insoluble in acetone but soluble in both the nonsolvent and the blend. The nonsolvent may be water and the solvent may be acetone, methanol, ethanol, or propanol. The cellulosic polymer may be cellulose acetate propionate or cellulose acetate butyrate. The binder may be polyvinyl pyrrolidone or an ionic polymer with a nonpolymeric counterion. Another inkjet ink comprises a cellulosic polymer, a solvent, a nonsolvent, and a film-forming binder soluble in the nonsolvent and in a blend comprising the solvent and nonsolvent, wherein the solvent is more volatile than the nonsolvent. In this ink, the cellulosic polymer and binder are incompatible such that when the solvent and nonsolvent evaporate, the cellulosic polymer and binder form a heterogeneous structure having two glass transition temperatures. A printed deposit is also disclosed, which comprises a light scattering layer having a porous network structure comprising a cellulosic polymer and a binder layer that binds the light scattering layer to a substrate upon which the printed deposit is disposed.

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