Vinyl sulfonated and not sulfonated hydroxy - functional polyurethane copolymers of macromonomer and their use for magnetic recording medium includes

摘要

The invention relates to vinyl sulfonated and non-sulfonated hydroxy functional polyurethane copolymers prepared from macromonomer diols and their use in magnetic recording media. The sulfonated hydroxy functional copolymer comprises: a polyurethane backbone; at least one SO₃M group pendant from the polyurethane backbone, wherein the polyurethane backbone has an SO₃M equivalent weight of from about 2,000 to about 100,000, and wherein M is selected from the group consisting of H⁺, NR₄+ wherein R can be H⁺ or an alkyl group, Li⁺, Na⁺, K⁺, and mixtures thereof; at least two crosslinkable hydroxy groups pendant from the polyurethane backbone, wherein the polyurethane backbone has a hydroxy equivalent weight of from about 500 to about 50,000; and at least one vinyl polymeric segment B pendant from the polyurethane backbone.