Magnetic recording binder containing aminoalkylphosphonate salt

摘要

A magnetic recording medium is prepared by applying a magnetic coating composition onto a non-magnetic support and curing said composition, said coating composition containing ferromagnetic particles dispersed in a binder comprising a thermoplastic resin selected from the group consisting of polyurethanes and polyester wherein there is chemically bonded to said resin at least one aminoalkylphosphonate represented by the formula: wherein R1 and R2 are the same or different oxyalkyl radicals having from 2 to 12 carbon atoms, R3 is an alkylene radical having from 1 to 12 carbon atoms, or an aralkylene radical having from 7 to 10 carbon atoms R4 is an alkyl radical having from 1 to 12 carbon atoms, a cycloalkyl radical having from 5 to 12 carbon atoms, or an aryl radical having from 6 to 12 carbon atoms wherein the aryl radical may contain a halogen atom, a hydroxyl group, or an amino group, and M+ is a metal ion or an ammonium ion.