Method for manufacturing magnetic recording medium
View Patent ↗The method is for manufacturing the magnetic recording medium in which a magnetic coating containing a ferromagnetic powder and a binder is applied on a nonmagnetic support. The magnetic coating includes: a magnetic liquid containing a ferromagnetic powder and a binder, and an abrasive liquid containing an abrasive and a solvent. The abrasive liquid may further contain the binder. The magnetic liquid and the abrasive liquid are each separately subjected to dispersion treatment, then the abrasive liquid is filtered, and then the magnetic liquid and the abrasive liquid are mixed. The obtained magnetic recording medium has a smooth magnetic layer surface, good electromagnetic conversion properties and excellent running durability and shows little wear of a head.
1. A method for manufacturing a magnetic recording medium in which a magnetic coating is applied on a nonmagnetic support, the magnetic coating including: a magnetic liquid containing a ferromagnetic powder and a binder; and an abrasive liquid containing an abrasive and the binder, the method comprising the steps of:
subjecting the magnetic liquid to dispersion treatment;
subjecting the abrasive liquid to dispersion treatment separately from the magnetic liquid, and then filtering the abrasive liquid; and
then mixing the magnetic liquid and the abrasive liquid.
2. The method as defined in claim 1 , wherein the filtering step for the abrasive liquid comprises the step of carrying out classification with a cross-flow type filtration apparatus.
3. The method as defined in claim 1 , wherein the dispersion treatment of the abrasive liquid is carried out by applying an ultrasonic wave.
4. The method as defined in claim 3 , wherein the filtering step for the abrasive liquid comprises the step of carrying out classification with a cross-flow type filtration apparatus.
5. A method for manufacturing a magnetic recording medium in which a magnetic coating is applied on a nonmagnetic support, the magnetic coating including: a magnetic liquid containing a ferromagnetic powder and a binder; and an abrasive liquid containing an abrasive and a solvent, the method comprising the steps of:
subjecting the magnetic liquid to dispersion treatment;
subjecting the abrasive liquid to dispersion treatment separately from the magnetic liquid, and then filtering the abrasive liquid; and
then mixing the magnetic liquid and the abrasive liquid.
6. The method as defined in claim 5 , wherein the filtering step for the abrasive liquid comprises the step of carrying out classification with a cross-flow type filtration apparatus.
7. The method as defined in claim 5 , wherein the dispersion treatment of the abrasive liquid is carried out by applying an ultrasonic wave.
8. The method as defined in claim 7 , wherein the filtering step for the abrasive liquid comprises the step of carrying out classification with a cross-flow type filtration apparatus.