JPS6396725A - Magnetic memory body - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance of a thin magnetic metallic film medium by coating a cured film consisting of a specific mixture on a substrate on which said metallic medium is coated, and further coating a fatty acid and one kind of metal salt consisting of Li, Na, K, Mg, and Ca on the cured film. CONSTITUTION:The cured film consisting of the mixture composed of one kind selected from formula I and one kind selected from formula II is coated on the substrate on which the metallic medium is coated; furthermore, the fatty acid and one kind of the metal salt consisting of Li, Na, K, Mg, and Ca is coated on the cured film. In formula, R is an alkyl group or hydrogen of 1-3C, (k) denotes 2 or 3, l denotes 0 or 1, (m) denotes 1, 2 or 3, (n) denotes 0, 1 or 2. In formula II, M is Ti, Ta, Nb, Hf or Zr, and (j) denotes the valency of said metal elements. The above-mentioned mixture is made into the cured film by dissolving the mixture in a general org. solvent, forming the coated film on the memory medium by a known coating method and subjecting the coated film to a heating treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic storage body C (hereinafter referred to as a storage body) used in a magnetic recording device (a magnetic disk device, a magnetic drum device, and a magnetic tape device).

[Conventional technology]

In a storage body having a metal magnetic thin film medium (hereinafter referred to as a metal medium), a recording/reproducing head (hereinafter referred to as a head) is used.
sufficient mechanical reliability to withstand contact with moisture,
Corrosion resistance is required to withstand corrosive environments such as chlorine and hydrogen sulfide.

Conventionally, the substrate has been an At alloy substrate that has been subjected to non-magnetic plating treatment such as alumite treatment or N1-P plating, and then has been polished to a mirror or streaky surface. Non-magnetic plating such as i-P, N1-W-P and O
After coating with r, Ti, etc., a ferromagnetic metal medium is coated, and further 5iOt (including &!J silicic acid), AtN, Ti
e, O, MoS.

etc. is coated with a protective film.

Although the above-mentioned memory bodies have a certain degree of durability and are already on the market, they have major drawbacks.

If a drive equipped with the above memory body is left in an environment of 40° C. and 80% RH, corrosion points will occur at 1.2 locations on each memory body, leading to defect errors. Also, due to repeated contact between the storage body and the head, the coefficient of friction between the two increases,
Eventually, a sticking phenomenon occurs in which the spindle motor for rotating the storage body stops.

Furthermore, since the conventional protective film is formed using a vacuum film forming method such as a sputtering method, the manufacturing cost is high.

[Problem that the invention seeks to solve]

With conventional technology, it is not possible to sufficiently ensure the corrosion resistance of the metal medium of the storage body, and there are reliability problems such as physical deterioration and sticking phenomenon of the storage body and head due to contact between the storage body and head, and manufacturing costs are high. The problem was that it was expensive.

The present invention solves the above problems, and its purpose is to dramatically improve the corrosion resistance of metal media against environments containing moisture, chlorine, hydrogen sulfide, etc., and to reduce the friction between the storage body and the head. The purpose of this invention is to provide, at a low cost, a memory body with significantly reduced coefficients and improved mechanical reliability.

[Means for solving problems]

In the memory body of the present invention, a cured film of a mixture of at least one maple selected from general formula A and at least one selected from general formula B is coated on a substrate coated with a metal medium, and further on the cured film. fatty acids, Li, NI! L, Ni, Mg
, Ca [General formula] Here, R is an alkyl group having 1 to 5 carbon atoms or hydrogen, and k is 2 or 5. , t is 0 or 1, and t is 1.2
Or 3, le represents 0°1 or 2.

[General formula B]

R6-M-(ou)jt Here, M is Ti, Ta, Nb, Hf, or Zr, j is the valence of the metal element, and t is 0 or 1 as above.
represents.

The above mixtures are easily soluble in common organic solvents such as alcohols, ketones, esters, halogenated hydrocarbons and aromatics. Decide the solvent and dissolution concentration depending on the desired film thickness and application method. Then, using the above solution,
A coating film is formed on the memory body by a known coating method such as a spinner method, a spray method, or a dipping method, and then a cured film is formed by heat treatment.

The thickness of the cured film is preferably 2001 to 8001, and the heating conditions are 80°C to 230°C and 10 minutes to 60 minutes. The mixing ratio is 5% or more of the substance represented by general formula B in terms of molar ratio,
30% or less is appropriate.

Next, the metal salt may be coated by a known coating method after being diluted in a solvent in the same manner as the above mixture, but heat treatment is not necessary.

Further, a desired film thickness of 20 to 2 oom is sufficient.

[Effect]

According to the structure of the present invention, the main skeleton is a si-tetraxane bond with a three-dimensional structure, and T is formed on the metal medium via an oxygen atom.
A cured film in which i, Ta, Nb, and Hf atoms are condensed in a substantially uniformly dispersed state is coated.

Since the coating strongly bonds with the natural oxide layer and /j' or OH groups on the surface of the metal medium, its adhesion is good.
The hardness of the three-dimensional condensation cured film is high, and it is difficult for moisture, water vapor, chlorine gas, etc. to permeate through it.

Furthermore, the affinity between the cured film and the metal salt is large, and the metal salt is retained on the cured film for a long period of time.

In order to exhibit the above effect, it is appropriate that the substance represented by the general formula B in the mixture raw material for forming a cured film has a molar ratio of 5% or more and 30% or less. Outside the above molar ratio range, both the density and hardness of the hardened film will be insufficient, resulting in decreased abrasion resistance and moisture resistance.

In addition, instead of the substance represented by the general formula, 5i-(O
When using alcoholades represented by R)4 and R1-8i-(OR)j-1, and alcoholades of metal elements other than those of the present invention in the substance represented by general formula B, the resulting hardening The hardness, density, and adhesion of the film were poor, and the abrasion resistance and moisture resistance were insufficient.

Since the metal salt of the present invention has excellent plastic deformation fluidity, it significantly reduces the coefficient of friction between the head and the storage body. Furthermore, both have high melting points of 100° C. or higher, and their characteristics do not deteriorate significantly even when subjected to frictional heat between the head and the storage body, or even when the drive is left at a high temperature of 80° C. or higher. This greatly improved the mechanical reliability of the memory.

〔Example〕

After applying non-magnetic N1-P alloy plating to a thickness of approximately 15 μm on a mirror-finished disk-shaped aluminum alloy substrate, the surface was polished to a surface roughness of 2 μm or less, and further 0o-Ni-P alloy plating was applied. was applied to a thickness of approximately 0.07 μm.

Next, add the materials shown in Table 1 to Diamond E6 at α5W/v%.
The above-described memory body was treated by a constant velocity pulling method (5 to 15 cm/m) using a treatment liquid dissolved at a concentration of , and then coated with a cured film by heating at 180° C. for 30 minutes.

Next, mix the metal salts shown in Table 1 with methanol and diaphragm.
In S-3 (Mol ratio 1; 1), Q, 05W/'7%
A thin film of the metal salt was coated using a treatment solution dissolved at a concentration of , using the same speed pulling method as described above.

The quality of the above-mentioned memory bodies was evaluated by the following method, and the results are shown in Table 2.

aSS Durability Test Determine the appearance change, static friction, and output reduction rate before and after the aSS explosion.

Three types of heads were used: 3370 mini monolithic, mini component, and thin film type.

Moisture resistance test When the product was left in an environment of 85°C and 80% RH, the number of missing bits was measured as the time passed, and the time when the number of missing bits increased was determined to be the end of the service life. ] Thin-film memory has been around for a long time as a memory compatible with high-density recording, but its use has been limited to some areas due to concerns about long-term reliability and high cost.

According to the present invention, the metal medium is not affected in any way at a practical level even when the memory body is used above heated water, and excellent mechanical properties can be achieved even with a misaligned head without having to choose the head material. Since it shows reliability, the characteristics of both the storage body and the head will not deteriorate even if the drive is used in harsh environments as it becomes smaller and smaller.

It has become possible to provide such a high-density, highly durable memory body using inexpensive disilane, a specific gold-4-alcolade material, and a metal salt.

The present invention can also be applied to sputter disks, magneto-optical disks, floppy disks, and magnetic tapes.

Claims (1)

[Claims] On a substrate coated with a metal magnetic thin film medium, [General formula A] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Here, R is an alkyl group having 1 to 3 carbon atoms or hydrogen; , k is 2 or 3, l is 0 or 1, m is 1, 2
Alternatively, n represents 0, 1 or 2. [General formula B] Rl-M-(OR)_j_-_l Here, M is Ti, Ta, Nb, Hf or Zr, j is the valence of the metal element, and l is 0 or 1 as above.
represents. A cured film of a mixture of at least one selected from general formula A and at least one selected from general formula B is coated, and further a fatty acid and Li, Na, K, Mg
, a magnetic memory body coated with at least one kind of metal salt consisting of Ca.