JPS59203239A - Production of magnetic disc - Google Patents

Abstract

PURPOSE:To obtain a disc which permits high density recording, has good durability, and is free from faults such as deformation and failure of a head, damage of a magnetic film, etc. by forming a lubricating layer bound chemically with a lubricative material on the surface of the magnetic recording layer formed on a magnetic disc. CONSTITUTION:The silicone compd. expressed by the formulas I , II, III (X1-X6 are Cl, R1-O-, R1 is alkyl, R2-R7 are residual siloxane group or alkyl, alkyl ester or alkyl ether contg., >=1F, R3 and R4, R5 and R6 and R7 are the same or different kinds) or the lubricative material expressed by the formula IV (R9 is residual siloxane group or alkyl, alkyl ester or alkyl ether contg. >=1F) is coated on the surface of the thin magnetic film formed on a magnetic disc or on the surface of the nonmagnetic film laminated with the thin nonmagnetic film on the magnetic film or the magnetic disc is dipped in the soln. of the above-described lubricative material and is then removed from the soln. and is dried. The excess lubricative material is washed and the magnetic disc is obtd. The lubricative material is thus chemically bound and the disc having excellent durability is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a magnetic disk that is capable of high-density magnetic recording and has good durability.

2. Description of the Related Art Magnetic disks have been used as recording devices for electronic computing PAs and the like, and efforts have been made to increase the recording density, particularly in recent years. This increase in recording density is largely due to improvements in magnetic thin films, but at the same time there are trends toward decreasing the thickness of magnetic thin films, decreasing the gap length of magnetic heads, and decreasing the flying height of magnetic heads. It has a minute size. Therefore, how to stably manufacture a uniform magnetic thin film with no defects, and how to ensure long-term durability (+--) even at low flying heights are critical issues in the development of high-density disks. It has become.

In particular, with recent high-density magnetic disks, when the disk stops rotating, the base air remains on the magnetic film, and the head floats as the disk rotates.
C8S (hereinafter abbreviated as C8S) is used for the magnetic disk and head. In order to avoid mechanical damage and obtain sufficient durability, it is important to increase the lubricity of the RDI disk surface. Lubricants, particularly liquid lubricants, have been used.

However, simply coating a liquid lubricant on a magnetic thin film does not provide a sufficient lubrication function.

That is, if an excessive amount of liquid lubricant is present, the head will be attracted to the coating film when the rotation is stopped, and if the rotation is started as it is, problems such as deformation and damage of the head and scratches on the magnetic thin film will occur. Conversely, if the amount of lubricant is small, C8S repeatability (hereinafter referred to as C8S resistance) is
(abbreviated as "sex") worsens. It is difficult to eliminate such problems simply by adjusting the amount of lubricant on the magnetic thin film.
Conventionally, a method has been adopted in which lubricant is impregnated not only on the surface but also inside the magnetic thin film. Furthermore, for this purpose, resin compositions that can stably form micropores have been selected as binder resins for amorphous island membranes.

However, in recent years, due to the trend of increasing the density of magnetic disks,
From the direction of coating the magnetic powder together with the resin binder to form the entire magnetic thin film, the thin film is formed using an alloy film or snow vine, and the so-called continuous film medium is used. In this complicated method using a continuous magnetic film, the conventional method using a binder resin as a means for imparting gripping properties to the surface cannot be adopted. Therefore, a method using a solid lubricant has been adopted, but the solid lubricant accumulates on the head, resulting in a decrease in C8S resistance, and sufficient performance has not been achieved.

In view of the above circumstances, it is currently desired to develop a new method for imparting lubricity to the surface of a disk using a continuous magnetic film.

In view of this technical background, the present invention provides a method for manufacturing a magnetic disk with high density and excellent durability. It is characterized by being combined to form a ml slip layer.

The present invention will be explained in detail below along with examples.

In contrast to conventional magnetic disks in which a magnetic thin film is formed from magnetic powder and a resin binder, the method of the present invention controls the lubricant layer on the surface using the micro-bore structure of the resin. This method is preferably carried out for magnetic disks using a continuous magnetic film, which cannot be manufactured, by chemically bonding a lubricating substance to the surface of the magnetic recording layer, thereby controlling the surface temperature lubricating layer. The chemical bonds of lubricating substances are
The formation of chemical bonds with a lubricant substance may be carried out directly on a magnetic thin film or through a non-magnetic thin film, and the non-magnetic thin film may be a protective film for the magnetic thin film. By fixing a lubricating substance on the surface using this method, which is carried out by reacting an alkoxyorganosilane compound, chloroorganosilane compound, or carbonyl compound with the hydroxyl group on the surface or the surface of a nonmagnetic thin film to form an ether bond or an ester bond. This provides the same effect as the lubricant control achieved by the micro-bore structure of conventional disks made of magnetic thin film resin. Furthermore, in the present invention, since the lubricating substance bends over the surface of the magnetic disk as a molecular-sized film, the flying height of the head can be reduced, making it suitable for magnetic disks that perform high-density magnetic recording.

The lubricating substances used in the present invention include derivatives of commonly used silicon-based or halocarbon-based lubricants, that is, chloroorganosilane compounds having a lubricant structure;
Although alkoxyorganosilane compounds, p) or carboxylic acid compounds are also used, particularly good performance was obtained with perfluoro compounds as a lubricant structure. A general method for bonding the ilJ fh rostrum to the surface of a magnetic film or the surface of a non-magnetic thin film on a magnetic film is to attach it to a solution of a lubricating substance in a dry atmosphere when using a chloroorcassilane compound or an alkoxyorganosilane compound. Dipping is done by Vr-. For carbonyl compounds, the esterification reaction is carried out in a solution using dicyclohexylcarbodiimide (DCC) and dimethylaminopyridine as catalysts. After a lubricating substance is chemically bonded to the surface by such a reaction, a magnetic disk having surface Vc lubricity can be obtained by washing and drying. In order to improve the surface permeability of the lubricating substance, the magnetic disk may be subjected to gold heat treatment or, if a non-magnetic thin film is present, oxidation or reduction treatment may be performed in advance. On the other hand, in the present invention,
Chemically bonded to the surface of the magnetic disk: Is it a slippery substance? ii. (i) A lubricant can be impregnated to completely form the hook lubrication.As the pre-sickness agent, one is selected that has good compatibility with the lubricating substance chemically bonded to the surface reduction surface of the magnetic disk. In addition, as a result of experiments, when a fluorine-based compound derivative was used as a lubricating substance, the fluorine-based lubricant still gave good results.

A commercially available lubricant can be used as the lubricant to be impregnated.Since the lubricant is retained as a thin film on the surface due to the lubricating substance chemically bonded to the surface, head problems caused by an excess or deficiency of lubricant on the surface of the hook can be avoided. Liquid lubricants can be used without problems of adsorption or deterioration of C8S resistance. In addition, solid lubricants also maintain a uniformity of 11% due to the action of lubricating substances chemically bonded to their surfaces, improving C8S resistance.Experiments have shown that liquid lubricants have better results. Gave. In addition, when using the lubricant impregnated in this way, the lubricating substance chemically bonded to the surface of the magnetic disk vC4
Does it not only give dark smoothness but also a magnetic disk? It goes without saying that the adhesion of the lubricant can also be improved, but the present invention is not limited to the following examples.

[Example 1] Magnetic disk (sample 1) having a ferrite magnetic thin film formed by sputtering and N1-Co-P formed by plating method
Silicon oxide capture film on alloy magnetic thin film (thickness 100A)
A magnetic disk (sample 2) on which silicon oxide was formed (sample 2) and a magnetic disk (sample 3) on which silicon oxide (thickness: 100^) was formed on sample 1 by a suction method were prepared. Each sample was thoroughly washed with water and acetone and dried. Next, 60% of the compound represented by formula (1) was added to a 0.1 M dry g-fluorooctane bath solution.
After soaking for 1 minute, fluorooctane and Freon 11
C8 resistance until head crash occurs after washing with 3.
S property was measured. The measurement results are shown in light 1.

(CH,0S,SiMoCF2S,.F(1) [Example 2
] Three magnetic disks each of Sample 1, Sample 2, and Sample 3 as in Example 1 were prepared, and each sample was thoroughly washed and dried in the same manner. Next, after immersing each of the compounds O0 and IM perfluorooctane solution shown in formulas (2) to (4) for 60 minutes,
- Washed with 9-fluorooctane and Freon 113, and measured C8B resistance until head crash occurred. The measurement results are shown in Table 2.

Ce-8i-(OF2S,.F t2)X
CF2+soF Cl \ Cl-8isoCFt +so F (41/ Cl Table 2 [Example 3] The same magnetic disk as Sample 3 of Example 1 was prepared, and washed and dried in the same manner. Separately, formula (5) Prepare a 0.1 M benzene bath solution of the compound shown in , add 0.1 M synchrocarbodiimide and 0.01 M dimethylaminopyrinone.
Prepare a solution containing M.

A magnetic disk was immersed in the bath liquid, and a 1 nJ reaction was carried out for 24 hours while stirring at 40° C. for surface treatment.

After the reaction, the magnetic disk is washed with benzene and acetone.

When we measured the C8S resistance of the manufactured magnetic disk until the occurrence of a helad crush, it was 4.5 x 10' times for the one without surface treatment, while it was 3.5 times after treatment.
Improved to x 10' times.

HOOC+ CF2+so F (51
[Example 4] Three types of magnetic disks having a lubricating substance chemically bonded to their surfaces were prepared in the same manner as in Example 1, and fc was conducted.

A commercially available liquid lubricant Fomblin Y 04 (Fomblin, Y: Nippon Montageson KK) was applied to the surface of this magnetic disk by a spin code method.

The coating film thickness estimated from the gravimetric method was approximately 200A. After application 3. Both types of magnetic disks exhibited C8S resistance of 10 times or more.

As explained above, the present invention has found that surface lubricity and C8S resistance can be improved by chemically bonding a lubricious substance to the surface of a magnetic disk using a so-called continuous film magnetic medium. It is something that According to the method of the present invention, it is possible to obtain extremely stable lubricity on the surface of a magnetic disk, and the lubricating film is also a thin film, which is advantageous in manufacturing magnetic disks for high-density recording with a low flying head. be.

patent applicant Nippon Telegraph and Telephone Corporation agent Patent attorney Hikari Ishibe (1 other person)

Claims (9)

[Claims] (1) A method for manufacturing a magnetic disk, which comprises forming a lubricant layer by chemically bonding a lubricating biological substance to the surface of a magnetic recording layer of the magnetic disk. (2) A method for manufacturing a magnetic disk according to claim 1, characterized in that a lubricating substance is chemically bonded to the surface of a magnetic thin film that is a magnetic recording layer. (3) A magnetic disk as set forth in claim 1, wherein the magnetic recording layer is a non-magnetic thin film laminated on a magnetic thin film, and where chemical bonding of a lubricating substance to the surface of the non-magnetic thin film is prohibited. manufacturing method. (4) A method for manufacturing a magnetic disk according to claim 1, 2, or 3, characterized in that the lubricant is impregnated with a lubricant. (5) Claim 1 or 2 or 3 or 4 is characterized in that the lubricating substance is a silicon compound having the following general formula ('r)(b)e[- A method of manufacturing a magnetic disk. (B) (B) ＼ 7 However, XI j X2 , X8 , XI, &
, XetJ: chlorine or R1-〇- group (R1 is an alkyl group), '&, Rs, '&, Rs, Ra
, Rr represents a siloxane residue or an alkyl group, an alkyl ester group, or an alkyl ether group containing one or more fluorine atoms, R8 and R4 are the same or different, R
6, Ro and R7 are the same or different. (6) In claim 5, R2, Rs
. A method for manufacturing a magnetic disk, wherein R4, R, , R6, R, and r are a perfluoroalkyl group, a perfluoroalkyl ester group, or a perfluoroalkyl ether group. (7) Scope of Patent ++4 Request for Paragraph 1, Paragraph 2, or Paragraph 3
4. A method for manufacturing a magnetic disk, characterized in that the lubricating substance is a carbuquimol compound having the following general formula. ) HOOC-R. However, Ro is a siloxane residue, an alkyl group, an alkyl ester group, or an alkyl ether group containing at least one fluorine atom. (8) A method for manufacturing a magnetic disk according to claim 7, characterized in that Ro is a perfluoroalkyl group, a perfluoroalkyl ester group, or a perfluoroalkyl ether group. (9) In claim 4, the lubricant to be impregnated is an alkyl, ester, or ether containing one or more fluorine atoms, or a liquid or solid τ having a lA structure.
``Method for manufacturing a magnetic disk characterized by a lubricant (QO)'' In claim 9, the lubricant is impregnated with a lubricant having a perfluoroalkyl-6, perfluoroester, or perfluoroether structure on the front side. A method for manufacturing a magnetic disk, characterized in that: