PURPOSE: To obtain a magnetic recording medium which has excellent durability and exhibits good electromagnetic conversion characteristics by incorporating polyester polyol and polyisocyanate compd. contg. phthalic acid as one of synthetic raw materials as constituting components into a binder of a magnetic layer.
CONSTITUTION: The binder contains, as the constituting components, the polyester polyol and polyisocyanate compd. contg. the phthalic acid as one of the synthetic raw materials. Namely, the above-mentioned specific polyester polyol and polyisocyanate compd. induce a polyurethanation reaction and finally forms a polyurethane polymer at the time of forming the magnetic layer. This polymer has the three- dimensional network structure uniform and dense over the entire part of the magnetic layer and imparts the high modulus of elasticity of a coated film to the magnetic layer. The magnetic powder is simultaneously strongly bonded by this network structure. As a result, the magnetic recording medium is improved in the wear resistance of the magnetic layer and is capable of exhibiting the durable performance even when the magnetic powder and magnetic metallic powder consisting of fine particles are used. In addition, the recording medium has the excellent electromagnetic conversion characteristics as well.
| JPS59168929 | MAGNETIC RECORDING MEDIUM |
| JPH01245421 | MAGNETIC RECORDING MEDIUM |
KAWARAI MASAYOSHI
AZUMA HIROSHI
