MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain a binder compsn. for a magnetic layer which is good in compatibility with a polyester resin having good adhesiveness and is good in dispersibility and to obtain a tape having an excellent characteristic by contg. a specific polyester resin and specific urethane resin as a binder resin. CONSTITUTION:A binder resin contains at least a polyester resin having a -SO3M group (M is hydrogen or univalent alkali metal atom) at the side chain and urethane resin having a siloxane bond (silicone modified urethane). The polyester resin having the -SO3M group at the side chain is obtd. by copolymerizing sulfoisophthalic acid or sulfoterephthalic acid or metallic salt such as sodium or potassium thereof with a polyester resin. The silicone modified urethane is obtd. by substituting part of the polyol used for producing an ordinary urethane resin with a polyol or prepolymer having a siloxane bond or using isocyanate having a siloxane bond.