Magnetic recording medium lubricant consisting of an amine salt of carboxylic acid, an amine salt of perfluoroalkyl carboxylic acid or an fluoro amine salt of perfluoro carboxylic acid

DETAILED DESCRIPTION It is therefore an object of the present invention to provide a magnetic recording medium exhibiting superior lubricating properties under various operating conditions and sustained lubricating effects as well as excellent runnability, abrasion resistance and durability.
The present inventors have conducted eager researches towards accomplishment of the above object and found that the combination of carboxylic acid and the amine salt meets the above object.
This finding has led to fulfilment of the present invention.
Thus the magnetic recording medium of the present invention is characterized in that it comprises at least a magnetic layer on a non-magnetic base and an amine salt of carboxylic acid.
Such amine salt of carboxylic acid may be synthesized from an ordinary carboxylic acid and an organic amine.
It may also be an amine salt of perfluoroalkyl carboxylic acid, synthesized from perfluoroalkyl carboxylic acid, obtained upon substituting fluorine for hydrogen of a hydrocarbon group and an organic amine, or a fluoroamine salt of perfluoroalkyl carboxylic acid, synthesized from the above perfluoroalkyl carboxylic acid and an organic amine having a fluorinated alkyl chain.
Such amine salt of carboxylic acid, synthesized from carboxylic acid and an organic amine, exhibits high solubility in halogen-base organic solvents, such as freon, due to the presence of the hydrophobic amine salt having a long chain length.
The hydrophobic amine salt having a long chain length contributes to the lowering of the surface energy and the coefficient of friction so that it exhibits satisfactory lubricating properties.
Thus it displays high practical utility when employed as the lubricant for the magnetic recording medium.
Also the presence of two chains in each molecule constituting the amine salt contributes to improved intermolecular entanglement and intermolecular shearing stress and hence to improved durability.
These lubricating properties are not affected even under hostile operating conditions, such as low temperatures