JPH0237604B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a magnetic storage device (magnetic disk device,
magnetic storage bodies used in magnetic drum devices, etc.)
In particular, the present invention relates to a method of manufacturing a magnetic storage body using magnetic metal as a storage medium. Generally, magnetic storage bodies that use magnetic metal as a storage medium have the following two main practical problems. The first problem is associated with a recording/reproducing method for a magnetic storage device that includes a recording/reproducing magnetic head (hereinafter referred to as a head) and a magnetic storage body. After the head and the magnetic storage surface are set in contact at the start of operation, a space corresponding to an air layer is created between the head and the magnetic storage surface by giving the magnetic storage the required rotation, and this state is maintained. In the so-called contact start-stop method of recording and reproducing, the rotation of the magnetic storage body stops at the end of the operation, and at this time the head and the surface of the magnetic storage body are in the same state of contact friction as at the start of the operation. The frictional force generated between the head and the magnetic storage body in this state can wear out the head and the magnetic storage body, and may eventually cause scratches on the head and the metal magnetic thin film medium. Changes in posture may make the load applied to the head uneven, causing scratches on the head and magnetic storage surface.Furthermore, the head may suddenly come into contact with the magnetic storage during recording and playback, causing damage between the head and the magnetic storage. A large frictional force acts on the head and magnetic storage, often resulting in destruction of the head and magnetic storage.In order to protect the head and magnetic storage from such contact friction, contact wear, and contact destruction between the head and magnetic storage. It is necessary to coat the surface of the magnetic memory with a protective film.The second problem is that magnetic metals are prone to corrosion, and this corrosion deteriorates or eliminates the magnetic properties of the magnetic metals.
Alternatively, localized corrosion may lead to increased errors. Various protective films have been proposed to solve the above two problems, but none that has both excellent wear resistance and corrosion resistance has yet to be obtained. For example, a protective film made by treating the surface of a magnetic memory with an oxidizing agent containing chromic acid or its salt, as seen in Japanese Patent Publication No. 52-17402, does not have sufficient abrasion resistance, and also contains chromic acid or its salt. Such inorganic corrosion inhibitors actually attack the magnetic metal, causing non-uniformity in the film thickness of the magnetic metal and increasing errors. Corrosion inhibitors that act radically on magnetic metals in this way are difficult to apply to applications that require precision of magnetic metals, such as magnetic storage bodies. An object of the present invention is to provide a method for manufacturing a magnetic memory body that does not affect magnetic metals and has excellent wear resistance and corrosion resistance. That is, the method for manufacturing a magnetic storage body of the present invention includes coating a metal magnetic medium on a mirror-polished base body;
The medium is coated with a protective film made of polysilicate containing an organic corrosion inhibitor by applying a solution of tetrahydroxysilane containing an organic corrosion inhibitor directly or via a non-magnetic metal and baking the medium. It is said that Next, the present invention will be explained in detail with reference to the drawings. The figure is a partial cross-sectional view of a magnetic memory body manufactured according to the present invention. In FIG. 1, aluminum alloy is most often used as the base 1 of the magnetic memory body because it is light, easy to work with, and inexpensive, but titanium alloy may also be used in some cases. The surface of the base is machined into a surface with small undulations (less than 50 μm in the circumferential direction and less than 100 μm in the radial direction). Next, a nickel-phosphorus alloy is coated on this base 1 as a base body 2 by plating, and this base body 2
The surface is mechanically polished to a maximum surface roughness of 0.03μm.
It will be mirror finished below. Next, a cobalt-nickel-phosphorus alloy is coated on the mirror-polished surface of the base body 2 as a metal magnetic medium 3 by plating, and a protective film 4 made of polysilicate containing an organic corrosion inhibitor is formed on the metal magnetic medium 3. is covered. In FIG. 2, the metal magnetic medium 3 is coated with a protective film 4 made of polysilicate containing an organic corrosion inhibitor via a nickel-phosphorus alloy as a non-magnetic alloy 5. As shown in FIG. The metal magnetic medium 3 may be any metal or alloy containing Co, Ni, or Fe. The protective film 4 is made by coating (spin coating) a solution of tetrahydroxysilane in an organic solvent containing a corrosion inhibitor, especially alcohols, ketones, or esters while rotating the magnetic storage body (spin coating), and then firing the coating. It is a polysilicic acid containing a corrosion inhibitor. This polysilicic acid adsorbs organic corrosion inhibitors well and is not removed even by firing. The nonmagnetic alloy 5 may be any nonmagnetic alloy such as Ni-P, Cr, Rh, etc. As an organic corrosion inhibitor, it is 1st class, 2nd class or 3rd class.
amines or their nitrites, benzoates or carbonates are the most effective, such as isopropylamine, diisopropylamine, triethanolamine, dicyclohexylamine, diisobutylamine, cyclohexylamine, dibutylamine or triethylamine nitrites, benzoic acid There are salts or carbonates. Next, the method for manufacturing a magnetic storage medium of the present invention will be explained in detail with reference to Examples and Comparative Examples. Example 1 The base body 2 was placed on a disk-shaped aluminum alloy plate whose surface had been finished with sufficiently small waviness (50 μm or less in the circumferential direction and 10 μm or less in the radial direction) by lathe processing and heat straightening as the base 1. Nickel-phosphorus alloy is plated to a thickness of approximately 50μm,
This nickel-phosphorus plating film has the maximum surface roughness.
Mirror polished to a thickness of 0.02μm and 30μm. Next, a cobalt-nickel-phosphorus alloy is deposited on this nickel-phosphorus plating film as a metal magnetic medium 3.
It was plated to a thickness of 0.05 μm. The following solution was applied by spin coating onto this cobalt-nickel-phosphorus plating film, dried, and then baked at 200°C for 5 hours to form a 0.1 μm thick polysilicic acid film containing an organic corrosion inhibitor. A protective film was coated to produce a magnetic disk having the structure shown in FIG. 2% tetrahydroxysilane, isopropyl alcohol solution
99.87g, dicyclohexylamine nitrite 0.13g Example 2 A magnetic disk was made in the same manner as in Example 1, but using the following solution. Tetrahydroxysilane 2% n-butyl alcohol solution 99g Dicyclohexylamine nitrite 1g Example 3 A magnetic disk was made in the same manner as in Example 1, except that the following solutions were used. Tetrahydroxysilane 2% ethyl alcohol solution 99.5g Diisobutylamine benzoate 0.5g Example 4 A magnetic disk was made in the same manner as in Example 1, except that the following solutions were used. Tetrahydroxysilane 2% triethylamine solution Example 5 Same as Example 1, except that metal magnetic medium 3
A magnetic disk was made using Co-Cr. Example 6 Same as Example 1, except that metal magnetic medium 3
A nickel-phosphorus alloy is placed on top of the non-magnetic alloy 5.
This nickel-phosphorus alloy was plated to a thickness of 0.02 μm, and a protective film 4 made of polysilicic acid containing an organic corrosion inhibitor was coated on the nickel-phosphorus alloy in the same manner as in Example 1 to obtain the structure shown in FIG. I made a magnetic disk. Comparative Example 1 A magnetic disk was made in the same manner as in Example 1, but without the organic corrosion inhibitor. Comparative Example 2 A magnetic disk was made in the same manner as in Example 5, but without the organic corrosion inhibitor. Comparative Example 3 A magnetic disk was made in the same manner as in Example 6, but without the organic corrosion inhibitor. Using each of the magnetic disks shown in Examples 1 to 6 and Comparative Examples 1 to 3, an underwater immersion test (120 hours) and an environmental test (90% relative humidity, temperature 40°C, 1 month) were conducted to determine the unit of corrosion point. The number of pieces per area and the rate of increase in the number of errors were investigated. As a result, the results shown in the table below were obtained.

[Table] From the above results, it was found that the magnetic storage medium manufactured by the manufacturing method of the present invention has excellent environmental resistance. Regarding the magnetic disks of Examples 1 to 6, 2
After repeated CSS tests 10,000 times, no abnormalities such as surface scratches or wear marks were observed. From the above, it was found that the magnetic storage medium manufactured according to the present invention has excellent reliability.

[Brief explanation of drawings]

FIGS. 1 and 2 are partial cross-sectional views of magnetic storage bodies manufactured according to the present invention, respectively. In the figure, 1 is a base, 2 is a base body, 3 is a metal magnetic medium, 4 is a protective film, and 5 is a nonmagnetic alloy.

Claims (1)

[Claims] 1. A metal magnetic medium is coated on a mirror-polished base body, and primary, secondary or tertiary amines or their nitrites are coated on this medium directly or via a non-magnetic metal. , a magnetic material characterized in that a solution of tetrahydroxysilane containing an organic corrosion inhibitor such as benzoate or carbonate is coated and baked to cover a protective film made of polysilicic acid containing the organic corrosion inhibitor. A method for manufacturing a memory body. 2. The method for manufacturing a magnetic memory according to claim 1, wherein dicyclohexylamine nitrite is used as the organic corrosion inhibitor.