JPH0279211A - Magnetic recording body, its production, and magnetic memory - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance of a metallic medium and to reduce the friction coefficient between the memory and head by coating a substrate coated with a magnetic thin film with an org. compd. layer contg. the metal salt of a fatty acid and a fluorinated polyether polymer. CONSTITUTION:The substrate is coated with a magnetic thin film, and the surface is coated with the org. compd. layer contg. the metal salt of a fatty acid and a fluorinated polyether polymer. As a result, the metal magnetic thin film poor in corrosion resistance is coated with the thin film, and protected from moisture, chlorine, etc., and the fluorinated polyether polymer and metal salt of the fatty acid having excellent lubricity are not easily moved on the storage by the impact and wear of a head and the centrifugal force of the memory.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a magnetic storage body (hereinafter referred to as a storage body) used in a magnetic storage device RA (magnetic disk device, magnetic drum device, magnetic tape device, and magnetic storage device). ) and its manufacturing method.

[Conventional technology]

In a storage body having a magnetic thin film, a recording/reproducing head (
It is required to have sufficient mechanical reliability to withstand contact with the head (hereinafter referred to as head) and corrosion resistance sufficient to withstand force-bearing environments such as moisture and chlorine.

Conventionally, the substrates used are A1 alloy substrates, glass plates, ceramic plates, etc., which have been subjected to non-magnetic plating treatment such as alumite treatment and N1-P plating, and then polished to make them mirror-finished and have a surface density.Next, Ni -P.

Non-magnetic plating such as N1-Cu-P, coating with Cr, Bi, etc., coating with magnetic thin film, and further 5i02 (including polysilicic acid), AIN, C, 5isN4 and Al 20
A protective film such as a solid solution of step 3 is coated, and a thin layer of a liquid lubricant represented by perfluoropolyether or a solid lubricant represented by higher alcohol or fatty acid is coated with or without an intermediate layer using a coupling agent. coated.

Although the above-mentioned memory bodies have a certain level of durability and have already begun to appear on the market, they have major drawbacks.

Magnetic storage device equipped with the above storage body at 40°C 180%
If the storage medium is left in an environment of R, H, etc., a weak point will occur in one or two places on one memory body, leading to a defect error. Furthermore, repeated contact between the storage body and the head increased the coefficient of friction between them, often causing the spindle motor to stop.

[Problem to be solved by the invention]

Conventional techniques have had the problem of not being able to ensure sufficient corrosion resistance of the magnetic thin film, and not being able to ensure sufficient mechanical reliability between the storage body and the head.

The present invention solves the above problems, and its purpose is to dramatically improve the corrosion resistance of metal media in environments containing moisture and chlorine, and to improve the coefficient of friction between the storage body and the head. It is an object of the present invention to manufacture and provide a highly reliable memory body that can significantly reduce the amount of water and maintain its effects over a long period of time, and to provide a magnetic memory device using the memory body.

[Means to solve the problem]

The present invention is characterized in that a magnetic thin film is coated on a substrate, and an organic layer containing at least a metal salt of a fatty acid and a fluorinated polyether polymer is coated on the magnetic thin film.

Furthermore, a thin film made of at least one substance selected from carbide, nitride, oxide, or carbon is formed between the magnetic thin film and the organic compound layer. or,
Furthermore, a thin film of a coupling agent having different functional groups in the molecule is formed between the thin film made of at least one substance selected from carbide, nitride, oxide, or carbon and the organic compound layer. shall be.

The magnetic thin film can be coated using the same materials and manufacturing methods as in the prior art* Co + Fe + N
x A metal consisting of TCr, Ta, P, a noble metal element, etc. is coated by a dry film forming method such as a wet plating method or a sputtering method.

Carbides, nitrides, and oxides include Al, B, Y,
Si, Ti, Zr, Hf, Nb,
Ta, Cn, Mo.

It is a compound of elements selected from W, and the mixing and lamination thereof are arbitrary. The carbon may be graphite, diamond, or amorphous (including i-carbon) alone, mixed, or laminated, and a film thickness of 100 to 400 carbon is appropriate for each. The above-mentioned compounds and carbon can be coated by a PVD method or CVD method such as a sputtering method or an ion blasting method, and the oxide can also be coated by a thermal decomposition method of an organometallic compound.

A coupling agent having different functional groups in the molecule is, for example, an organometallic compound having a hydrolyzable group on one side of the molecule and at least one kind of functional group such as an amino group or an imino group on the other side. % Formula % Here, R' is an organic group having at least one functional group such as an amino group or an imino group, and R is an alkyl group having 1 to 5 carbon atoms. Also, M is Si, Ti, Zr, Nb, Hf
, Ta, etc., and m is the valence of each metal element. Further, 1 is an integer from 1 to (m-1).

Representative organometallic compounds are shown below.

NH2-(OH2)t-NH-(CHt)see-3i-(
OCHs)s Hs NH2(CH2) 2-NH-(CH2)s-31-(
OCHz)p NH2(CH2)2-NH-(CH2)2-NH-(C
H2) 2-S i -(OCHs) These are:
All of these are diluted with a soluble solvent such as alcohol, applied by a known method such as a spray method, a spinner method, a dipping method, or a pyrosol method, and then baked to form a polycondensation film.
? The J1 degree is determined by the desired film thickness, and a monomolecular thickness is sufficient, and there is no problem with a film with a thickness of around 200 or less, and baking at 60°C to 200°C for 5 to 20 minutes is sufficient. It is.

Metal salts of fatty acids are typified by metal salts of saturated, unsaturated, linear, and branched fatty acids with Li, Na, Ca, Mg, and Zn, and fluorinated polyether polymers are The molecule contains a polar group such as a C0OH group, a functional group such as an epoxy group, a nitrogen-containing group having an unpaired electron, and an organic group containing a cyclic chain, and is mainly a perfluoroalkyl polyether.

These are mixed, diluted in a soluble solvent such as Freon 113, applied by a known method such as a spray method, a spinner method, a dipping method, or a pyrosol method, and then baked as necessary. , 3 to 10 minutes is sufficient, and a film thickness of around 50A or less is sufficient.

[Effect]

According to the present invention, a thin film made of a substance selected from carbides, nitrides, oxides, or carbon having excellent adhesion, high hardness, and denseness is applied to various magnetic thin films including metal magnetic thin films with poor corrosion resistance. This protects the magnetic thin film from moisture, chlorine, etc. that can cause negative forces.

However, carbides, nitrides, and oxides all have poor lubricity, and even carbon, which has relatively excellent lubricity, has insufficient lubricity, and attempts have been made to coat the surface with a lubricant.

As mentioned above, liquid lubricants typified by perfluoropolyether polymers and solid lubricants typified by higher alcohols and fatty acids are being considered as the above-mentioned lubricants. As a result, the film thickness decreased and the initial excellent lubricating ability was lost over time. Furthermore, the impact force of the head could not be absorbed completely and the head reached the magnetic thin film, resulting in a head crash.

In the present invention, a magnetic thin film, a thin film made of a substance selected from carbides, nitrides, oxides, or carbon, a thin film of a coupling agent having an affinity with a fluorinated polyether polymer, and a metal salt of a fatty acid are formed. Therefore, the fluorinated polyether polymer and the metal salt of fatty acid, which have excellent lubrication ability, do not easily move on the storage medium due to impact wear of the head or rotational centrifugal force of the storage medium. In addition, both fluorinated polyether polymers and metal salts of fatty acids are substances with excellent heat resistance, and metal salts of fatty acids in particular have excellent impact resistance, so they can withstand strong impacts from heads, which are becoming increasingly difficult to trade. It withstood well and was able to completely eliminate head crashes.

As described above, it has become possible to manufacture and provide a memory body with excellent long-term mechanical reliability and storage reliability, and furthermore, by using this memory body, the long-term reliability of a magnetic memory device has been significantly improved.

〔Example〕

After applying non-magnetic N1-P alloy plating to a thickness of approximately 15 μm on a mirror-finished disc-shaped aluminum alloy substrate, polishing is performed to obtain a surface roughness of Ra = 50 to 100A, Rn
Add a stripe to ax=500~100OA, and further Co-
N1-P alloy plating was applied to a thickness of about 0.05 μm.

Using the above substrate, a thin film of each substance was coated as shown in Table 1 using a magnetron sputtering device. Furthermore, the degree of vacuum achieved is 1xl
The substrate was preheated at 80° C. for 10 minutes at a power of 4 W/cm” below O-'torr.

On the other hand, using the above substrate, various organic metal compounds were coated by the dipping method shown in Table 2, and then baked to cover the polycondensation film. The processing liquid solvents are methanol and Freon 11.
3 (volume ratio 1:3), concentration is 1.0W/V%
The liquid temperature was 25°C.

In addition, the pulling speed was 10 cm/min, and the firing was 150 cm/min.
℃ for 30 minutes.

Next, combine the coupling agent in Table 3 with methanol and Freon 11.
3 (volume ratio 1:3) and diluted to 0.005 W/V%, applied by a dipping method, baked, and coated with the polycondensation film. The liquid temperature is 25°C, and the pulling speed is Locm/min.
The firing was performed at 110°C for 110 minutes.

The metal salts of the fatty acids shown in Table 3 and the fluorinated polyether polymers were then coated. Details of product names and abbreviations for both materials will be given later.

The above material is diluted in Freon 113 and soaked at 0.01W/V.
%), applied by dipping method. The dipping method was performed at a liquid temperature of 25° C. and a pulling rate of 10 Cm/min.

Table 1 Table 2 Table 3 - Krytx: DuPont Fluorinated Oil 15
7FS/L&M is a single functional group (C00H group) type at the end of the molecule.
DIAC is a functional group between the ends of the molecule (COOH group) type, Z-AM2001 is a natural ring group group at both ends of the molecule, and FC-A is CFs-CF20 (02
F40) Low (CF20) I-CF- (CFa○)
m-(C2F40)0OH--CFtOCFi, o and n represent integers, and the molecular weight is about 2500.

A memory body manufactured by the above manufacturing method and a 3370 type thin film head (Flyhide 0.15μm, 9m/5e
A magnetic storage device was manufactured using e) and evaluated by the following test. The results are shown in Table 4.

(1) C3S durability test C8S operation (rise and fall time 10see)
Determine the change in appearance before and after, the coefficient of static friction, and the rate of decrease in output.

(2) Corrosion Resistance Test The product was left in an environment of 80° C. and 90% R, H, and after the time had passed, the number of missing pits was measured, and the time when the number of missing pits increased was determined to be the end of its life.

Table 4 [Effects of the invention] Magnetic storage devices using thin-film storage as a storage medium compatible with high recording densities have been on the market for some time, but their use has been limited to some due to concerns about long-term reliability. .

According to the present invention, the magnetic thin film is practically unaffected even if the storage medium is used under hot and humid conditions, and mechanical reliability is improved even when using heads that are becoming increasingly hard and have low fly-hide properties. Because of the high resistance, even if the magnetic storage device is further miniaturized and installed in a magnetic storage device used in harsh environments, no deterioration in the characteristics of either the storage body or the head will be observed.

As described above, manufacturing of highly durable memory bodies compatible with high recording density,
By providing and using the storage body, it has become possible to provide a highly reliable magnetic storage device.

that's all Applicant: Seiko Epson Corporation

Claims (9)

[Claims] (1) A magnetic memory body characterized in that a substrate coated with a magnetic thin film is coated with an organic compound layer containing at least a metal salt of a fatty acid and a fluorinated polyether polymer. (2) A thin film made of at least one substance selected from carbide, nitride, oxide, or carbon is formed between the magnetic thin film and the organic compound layer.
The magnetic memory described above. (3) A thin film of a coupling agent having different functional groups in the molecule is formed between the organic compound layer and a thin film made of at least one substance selected from carbide, nitride, oxide, or carbon. The magnetic storage body according to claim 2, characterized in that: (4) Production of a magnetic memory body comprising the steps of coating a magnetic thin film on a substrate, and coating the magnetic thin film with an organic compound layer containing at least a metal salt of a fatty acid and a fluorinated polyether polymer. Method. (5) The method further comprises the step of forming a thin film made of at least one substance selected from carbides, nitrides, oxides, and carbon between the magnetic thin film and the organic compound layer. A method for manufacturing a magnetic storage body. (6) Forming a thin film of a coupling agent having different functional groups in the molecule between the organic compound layer and a thin film made of at least one substance selected from carbides, nitrides, oxides, or carbon. 6. The method of manufacturing a magnetic storage body according to claim 5, further comprising: (7) A magnetic storage device characterized by using the magnetic storage body according to claim 1. (8) A magnetic storage device characterized by using the magnetic storage body according to claim 2. (9) A magnetic storage device characterized by using the magnetic storage body according to claim 3.