Binder for inorganic additives, and magnetic recording medium containing the binder

摘要

The invention relates to a binder comprising a polyurethane resin containing recurring units of the formula <IMAGE> in which X is a hydrogen atom, an ammonium group, an alkali metal, an alkaline earth metal or a heavy metal, Y is a divalent radical derived from an organic diisocyanate compound, Z1 and Z2 are identical or different and each is a divalent organic group of the formula -O-(R1)m-O- or -(OR2)n-O-, in which R1 and R2 are C1-C3-alkylene groups, and m and n are each an integer from 2 to 8, which is suitable as a binder for use in the production of a magnetic recording medium.