Novel lightfast additive molecule for inkjet ink

Abstract

Lightfast additives for inkjet inks are provided. These additives exhibit excellent lightfastness of many dyestuffs (both water-soluble and water-insoluble). The lightfast additives exhibit good water solubility and significant effect on dye and pigment molecules which fade most when exposed to UV, ambient light, etc., and are suitable for improving permanence of inkjet inks, including thermal inkjet ink, piezo inkjet ink, and the like. The lightfast additive comprises a molecule which is composed of three parts or moieties: A-X—B, where (a) moiety A is an aryl sulfonic acid or aryl carboxylic acid, either in acid form or salt form, with or without substituents (e.g., benzene sulfonic acid, naphthalene mono-sulfonic acid, naphthalene di-sulfonic acid, benzoic acid, benzene sulfonic acid sodium salt, and hydroxybenzenesulfonic acid sodium salt), that contributes to the water solubility and compatibility (molecular overlapping) with the dye molecule in the solid state; (b) moiety B is a triazine, benzotriazole, tetrazole, or benzimidazole, with or without substituents, that contributes to improvement of lightfastness of the dye; and (c) moiety X is a connector (—NR— or —O—) between A and B.

Dependencies are inferred from the claim text.