JPS6016007B2 - Manufacturing method of magnetic disk - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a coating film constituting a magnetic layer in a magnetic disk as a recording medium of a magnetic disk device.

In recent years, magnetic disk drives have become more densely packed with contacts.
The start-stop method is adopted to reduce the flying gap between the magnetic head and the magnetic disk, so the magnetic disk coating on the media is wear-resistant without damaging the monolithic magnetic head. There is a growing demand for high strength materials with excellent head crush resistance and head flying ability.

Therefore, if hard alumina, silica, etc. are added to the paint to form a coating film, the strength of the coating will be improved, but the magnetic head will be destroyed, the output will decrease, and the recording characteristics will deteriorate. In view of these points, it is an object of the present invention to provide an improved method for manufacturing a magnetic disk so as to form a strong coating film without destroying the magnetic head, and to cure the resin without oxidizing it. Focusing on the fact that suitable strength can be obtained, we put a thermosetting resin together with a magnetic oxide in the paint and applied it onto the substrate to form a coating film, and then we coated the coating film in an inert gas atmosphere. It is made to harden by heat treatment.

The present invention will be explained in detail below with reference to the drawings. A thermosetting resin such as acrylic or epoxy is put in a paint together with a magnetic oxide such as gamma iron oxide, and this is applied onto an aluminum disk substrate. A magnetic layer coating is formed by applying it thinly and uniformly by spin coating or the like.

After that, the coating film is subjected to orientation treatment, etc., and then this coating film is placed in a high-temperature furnace together with the substrate, and heated at about 200℃ for about 30 minutes while supplying an inert gas such as nitrogen gas, and then heat-treated for phosphorization. In this way, the coating film is cured without oxidation in a nitrogen gas atmosphere, and a magnetic disk is manufactured. Next, the coating strength of the magnetic disk according to the present invention manufactured in this way will be explained. Using a high-density head of 600 ship PI and applying a normal head load of 10 w to 100 m of 1 pm, the contact was・The results of the head crush resistance and abrasion resistance test of the paint film when starting and stopping are shown in the attached drawing.

In this), the solid line A is manufactured according to the present invention, and the broken line B is the product manufactured according to the present invention.
is heat-treated in the atmosphere like a casing,
As a result, while the conventional product can perform contact start and stop times of about 2 m groups, the product of the present invention can perform contact start and stop times of about 70 times, which is about four times as many, and the strength of the coating film has been greatly improved. I understand that. Also, using a rod with an outer diameter of 6 ribs,
In a bending test of the paint film when bent at 80 degrees, the paint film of the conventional product peeled off and was easily removed when the bent extreme part was wiped with gauze, whereas the product of the present invention did not cause such peeling. , it also becomes stronger against bending. As described above, the magnetic disk manufactured by the manufacturing method of the present invention has a high coating strength, and since it does not contain additives such as hard alumina and sintering force, it is possible to prevent the magnetic head from being destroyed.

Furthermore, it is easy to manufacture and mass production is possible.

[Brief explanation of the drawing]

The attached drawing is a diagram showing the test results of the head crush resistance and abrasion resistance of the coating film.

Claims (1)

[Claims] 1. A method for manufacturing a magnetic disk, which comprises applying a coating material containing at least a magnetic oxide and a thermosetting resin onto a substrate, and curing the coating film by baking and heat-treating it in an inert gas.