Features of the application of polyurethane ionomers as binders in pigment compositions for printing

The features of formation of polymer films from aqueous dispersions of polyurethane ionomers and the possibility of resolving a number of technological problems of pigment printing due to specific properties acquired by polyurethanes when ionic groups are introduced into their macromolecules are showed in the paper. A feature of the investigated aqueous dispersions is their lyophilicity, which is due to the introduction of ionic groups in salt form into the polymeric chains. Due to lyophilicity, film formation from these dispersions proceeds through the stages of formation of intermediate reversible gels with flocculation contacts, which easily break down. It is shown in the article that this property of dispersions of polyurethane ionomers provides to printing compositions on its’ basis the ability to be easily removed from working areas of printing equipment when it is washed, significantly extends the service life of printing templates, eliminates the build-up of binder polymer, and the need to add special substances to print compositions for this goal, which reduce the stability of colors...