PIGMENT BASED INKS FOR INKJET PRINTING

摘要

An ink composition comprising (a) water, (b) pigment particles, (c) at least one humectant, (d) at least one polyurethane having an average molecular weight of at least 10,000 and a sufficient number of acid groups to provide an acid number from 60 to 130, and being present at a weight concentration of greater than 0.7%, and (e) at least one water soluble acrylic polymer comprising carboxylic acid groups, present at a weight concentration of greater than 0.6%, wherein the acid groups on the polyurethane and acrylic polymers are at least partially neutralized only with a monovalent inorganic base.