Method for producing and device for producing magnetic recording medium
View Patent ↗The present invention provides a device and a method for producing a magnetic recording medium having a lubricant membrane with a uniform thickness on a surface. The device for producing the magnetic recording medium includes: a hanger device that is inserted into the central hole of the magnetic recording medium and supports the magnetic recording medium in a hanging state; and a raising and lowering device that raises and lowers one of the hanging device and an immersion tank with respect to the other thereof. The hanger device includes a support plate of which an upper end comes into contact with an inner circumference of the magnetic recording medium and a liquid-cutting plate which extends from a lower end of the support plate and is distant by a space along the inner circumference of the magnetic recording medium from the inner circumference of the magnetic recording medium.
1. A method for producing a disk-shaped magnetic recording medium having a central hole, the method comprising:
forming a lubricant membrane on a surface of the magnetic recording medium by immersing the magnetic recording medium into an immersion tank that has a liquid lubricant, while inserting a hanger device into the central hole of the magnetic recording medium and supporting the magnetic recording medium in a hanging state, and then raising the magnetic recording medium from the immersion tank,
wherein the hanger device includes
a pair of support plates of which upper ends come into contact with an inner circumference of the magnetic recording medium, and
a pair of liquid-cutting plates which extend in opposite directions to one another from lower ends of the pair of support plates and which is distant by a space along the inner circumference of the magnetic recording medium from the inner circumference of the magnetic recording medium without contact with the inner circumference of the magnetic recording medium,
wherein a groove portion engaging with the inner circumference of the magnetic recording medium is formed in the upper end of the support plate, and
the pair of liquid-cutting plates is coplanar with the groove portion so as to be coplanar with the disk-shaped magnetic recording medium in a plane parallel to a data record surface of the magnetic recording medium, and the pair of liquid-cutting plates is placed at the inner circumference of the magnetic recording medium while raising the magnetic recording medium from the immersion tank.
2. The method for producing a disk-shaped magnetic recording medium having a central hole according to claim 1 , wherein the liquid-cutting plate is bent throughout from a midway portion to a lower end thereof in a direction in which the liquid-cutting plate is separated from the inner circumference of the magnetic recording medium.
3. The method for producing a disk-shaped magnetic recording medium having a central hole according to claim 1 , wherein a lower end of the liquid-cutting plate is located below a position at which an accumulating liquid in the space between the liquid-cutting plate and the inner circumference of the magnetic recording medium is to be cut.
4. The method for producing a disk-shaped magnetic recording medium having a central hole according to claim 1 , wherein a slit notched in a vertical downward direction in the support plate is formed in a bottom of the groove portion.
5. The method for producing a disk-shaped magnetic recording medium having a central hole according to claim 1 , wherein the hanger device supports a plurality of the magnetic recording media in a state of being arranged in a row.
6. The method for producing a disk-shaped magnetic recording medium having a central hole according to claim 1 ,
wherein the space by which each of the pair of liquid-cutting plates is distant is uniform.