Magnetic recording media comprising a cured dispersion coating of a magnetizable pigment and polyurethane polymer containing a vinyl polymeric segment pendant from the polyurethane backbone

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 SO. sub.3 M group pendant from the polyurethane backbone, wherein the polyurethane backbone has an SO.sub.3 M equivalent weight of from about 2, 000 to about 100,000, and wherein M is selected from the group consisting of H.sup.+, NR.sub.4.sup.+ wherein R can be H.sup.+ or an alkyl group, Li. sup.+, Na. sup.+, K.sup.+, 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 pendant from the polyurethane backbone.