JPH0237606B2 - - 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 for 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 frictional state as at the start of the operation. The frictional force generated between the head and the magnetic storage material under these contact friction conditions may wear out the head and the magnetic storage material, and may eventually cause scratches on the head and the metal magnetic thin film medium. Further, in the contact friction state, a slight change in the posture of the head makes the load applied to the head uneven, and may cause scratches on the surface of the head and the magnetic storage body. Furthermore, during recording and reproducing, the head suddenly comes into contact with the magnetic storage body, and a large frictional force acts between the head and the magnetic storage body, often resulting in destruction of the head and the magnetic storage body. In order to protect the head and the magnetic memory from such contact friction, contact wear and contact breakage between the head and the magnetic memory, it is necessary to coat the surface of the magnetic memory with a protective coating. The second problem is that magnetic metals are easily corroded, and this corrosion causes the magnetic properties of the magnetic metals to deteriorate or disappear.
Alternatively, localized corrosion may lead to increased errors. Various protective films have been proposed to solve the above two problems, but no one has yet been found that is excellent in both wear resistance and corrosion resistance. For example, as seen in Special Publication No. 52-17402,
A protective film made by treating the surface of a magnetic memory element with an oxidizing agent containing chromic acid or its salts does not have sufficient wear resistance, and inorganic corrosion inhibitors such as chromic acid or its salts may actually attack magnetic metals. This leads to non-uniformity in the film thickness of the magnetic metal and increases 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 involves coating a mirror-polished base body with a metal magnetic medium, and covering this medium with a protective film either directly or through a non-magnetic metal to produce a magnetic storage body. The present invention is characterized in that the magnetic storage body is formed by immersing the magnetic memory in an organic corrosion inhibitor solution so that the organic corrosion inhibitor is included in the protective film. 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 containing an organic corrosion inhibitor is coated on the metal magnetic medium 3. There is. In FIG. 2, the metal magnetic medium 3 is coated with a protective film 4 containing an organic corrosion inhibitor via a nickel-phosphorus alloy as a non-magnetic alloy 5. In FIG. The metal magnetic medium 3 may be any metal or alloy containing Co, Ni, or Fe. The protective film 4 is also made of glass, silicon oxide, silicon nitride,
Including silicon compounds such as silicic acid polymer (polysilicic acid), non-magnetic metals such as Rh and Cr, non-magnetic alloys such as NiP, Al, Co, Ni, Cr, Ti, Zr or
Nonmagnetic metal oxides of metals such as Ce or alloys thereof can be used. 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. These organic corrosion inhibitors are used as a solution by dissolving them in organic solvents such as alcohols, ketones, and esters. However, the liquid organic corrosion inhibitor can be used as it is without diluting it with an organic solvent. By immersing the magnetic storage body coated with the protective film in a liquefied organic corrosion inhibitor solution, the organic corrosion inhibitor is included in the protective film. According to this method, the organic corrosion inhibitor first penetrates into the parts of the protective film where corrosive liquids (such as water) are most likely to penetrate, so that the anticorrosion effect can be further improved. Next, the method for manufacturing the magnetic storage body 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 disk 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 thermal straightening as the substrate 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. On this cobalt-nickel-phosphorus plating film, a 2% n-butyl alcohol solution of tetrahydroxysilane was applied to a thickness of 0.1 μm, and after drying, it was baked at 200°C for 5 hours and polysilicic acid was coated as a protective film 4. did. Next, the whole was immersed in a 23% anhydrous methyl alcohol solution of dicyclohexylamine nitrite for 5 hours to incorporate dicyclohexylamine nitrite into the protective film, thereby producing a magnetic disk having the structure shown in FIG. Example 2 Same as Example 1, except that metal magnetic medium 3
A nickel-phosphorus alloy is placed on top of the non-magnetic alloy 5.
The nickel-phosphorus alloy was plated to a thickness of 0.02 μm, and a protective film made of polysilicate containing an organic corrosion inhibitor was coated on the nickel-phosphorus alloy in the same manner as in Example 1 to form a magnetic material having the structure shown in FIG. I made a disk. Example 3 Same as Example 1, except that metal magnetic medium 3
Sputter SiO ₂ as a protective film 4 on top of the
The SiO 2 protective film was coated to a thickness of 0.1 μm, and then immersed in a 2.2% isoprepyl alfur solution of dicyclohexylamine nitrite for 24 hours to fully incorporate the organic corrosion inhibitor into the SiO ₂ protective film to create a magnetic disk. Ivy. Example 4 Same as Example 2, except that metal magnetic medium 3
A magnetic disk was made using Co-Mn-P. Example 5 Same as Example 3, 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 with a thickness of 0.1 μm is applied as a protective film 4 on top.
The magnetic disk was then plated to a thickness of 100 ml, and then immersed in a 23% methyl alcohol solution of dicyclohexylamine nitrite for 10 hours to fully impregnate the organic corrosion inhibitor in the nickel-phosphorus alloy to produce a magnetic disk. Example 7 Same as Example 1, except that metal magnetic medium 3
was oxidized to form a film consisting of Co and Ni oxides to form the protective film 4, and then immersed in a 9.2% ethyl alcohol solution of dicyclohexylamine nitrite for 16 hours to oxidize Co and Ni. A magnetic disk was fabricated by sufficiently impregnating an organic corrosion inhibitor in a protective film made of a material. Example 8 Same as Example 7, except that metal magnetic medium 3
A nickel-phosphorus alloy was plated on top to a thickness of 0.1 μm, and the surface was oxidized to form a film made of Ni oxide to form the protective film 4. After that, 7.9% dicyclohexylamine nitrite was plated. A magnetic disk was prepared by immersing it in a dioxane solution for 4 hours to fully impregnate the organic corrosion inhibitor in the protective film made of Ni oxide. Example 9 A magnetic disk was made as in Example 1, but using a saturated isopropyl alcohol solution of diisobutylamine benzoate as the organic corrosion inhibitor. Example 10 A magnetic disk was made as in Example 1, but using dicyclohexylamine (100%) as the organic corrosion inhibitor. Comparative Examples 1 to 8 Corresponding to Examples 1 to 8, in the same manner as them,
However, magnetic disks were made without using an organic corrosion inhibitor, and Comparative Examples 1 to 8 were prepared. Using each of the magnetic disks shown in Examples 1 to 10 and Comparative Examples 1 to 8, 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】

[Table] From the above results, it was found that the magnetic memory produced by the production method of the present invention has excellent environmental resistance. The magnetic disks of Examples 1 to 5, 9, and 10 were subjected to CSS repetition tests 20,000 times, but no abnormalities such as scratches or wear marks on the surface were observed. From the above, it was found that the magnetic memory produced 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 substrate, 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 a protective film is coated on the medium directly or via a non-magnetic metal to form a magnetic storage body. The magnetic storage body is immersed in an organic corrosion inhibitor solution consisting of a primary, secondary, or tertiary amine or a nitrite, benzoate, or carbonate thereof, so that the organic corrosion inhibitor is included in the protective film. A method for manufacturing a magnetic memory body, characterized in that: 2. The method of manufacturing a magnetic memory body according to claim 1, wherein the protective film is a silicon compound. 3. The method for manufacturing a magnetic memory body according to claim 1, wherein the silicon compound is polysilicic acid. 4. The method of manufacturing a magnetic memory body according to claim 1, wherein the protective film is a nonmagnetic metal or an alloy. 5 The non-magnetic metal or alloy is Rh, Ni-P or
The method for manufacturing a magnetic memory body according to claim 4, wherein the magnetic memory body is made of Cr. 6. The method of manufacturing a magnetic memory body according to claim 1, wherein the protective film is a metal oxide. 7. The method of manufacturing a magnetic memory body according to claim 6, wherein the metal oxide is Al, Co, Ni, Cr, or an oxide thereof. 8. The method for manufacturing a magnetic memory according to claim 1, wherein the organic corrosion inhibitor is dicyclohexylamine nitrite.