JPH01296429A - Recording medium and its production - Google Patents

Abstract

PURPOSE:To improve the reliability of the vapor deposition type magnetic recording medium and to realize high-density recording by forming plural layers of monomolecular films consisting of silane surfactants on the surface of a magnetic recording layer formed by vapor deposition on a medium substrate as protective films. CONSTITUTION:The magnetic recording layer 2 is formed by a sputtering method, etc., on the disk substrate 1 for magnetic recording. Plural layers of the monomolecular films are formed as protective films 8 by a method of alter nately executing, plural times, a stage of forming one layer of a monomolecule- adsorbed film by chemical adsorption of the silane surfactant to a monomolecu lar state and a stage of denaturing the sensitive group of the activating agent by executing irradiation of energy rays such as electron rays on X-rays or plasma treatment in an atmosphere contg. O2 or N2. The high-density thin org. film is thereby formed on the surface of the medium with a uniform thick ness without having the pinholes and further, lubricity is provided to the medium surface by incorporating F into the surface, by which the slipperiness of the head is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a soul-contemplative recording medium and a method for manufacturing the same. For more information, please refer to magnetic tape, magnetic disk,
The present invention relates to a method for forming a protective film on a recording layer of a magnetic recording medium such as a magnetic card or a magneto-optical disk, and a magnetic recording medium manufactured using the method.

2. Description of the Related Art Conventionally, magnetic recording media can be roughly divided into coating type and vapor deposition type.

In coating-type magnetic recording media, magnetic powder such as γ-Fe203 containing Fe2O3 or CO is generally mixed and dispersed in a mixture of polyvinyl butyral, toluene, methyl isobutyl, etc. to form a paint, and 4 is applied to the surface of the media substrate. ~5μ
This is a method of coating with a thickness of m.

Problems to be Solved by the Invention Although this method is easy to manufacture, there is a limit to the size of the magnetic powder, and the performance is insufficient for high-density recording.

On the other hand, vapor deposition type recording media have better recording density than coating type recording media, but have problems with durability because the magnetic metal layer is exposed on the surface. Therefore, metals of 1,000 to 2,000% are deposited by electron beam or sputtering, overcoated, and a lubricant is applied to provide lubricity to the surface of the magnetic recording medium, but the durability is still insufficient. The current situation is that this has not been achieved. Furthermore, since the overcoat or lubricant cannot be applied thinly and uniformly, the gap between the recording magnetic head and the recording layer becomes large, making it impossible to fully utilize the high-density recording inherent to the vapor deposition type.

In view of the drawbacks of the conventional methods described above, the purpose of the present invention is to:
The object of the present invention is to provide a method for applying an overcoat and a lubricant thinner, more uniformly, and without pinholes, thereby improving the reliability of vapor-deposited magnetic recording media and realizing high-density recording.

Means for Solving the Problems The present invention forms a single molecule of a silane surfactant directly or indirectly on the surface of a magnetic recording layer formed by vapor deposition on a media substrate. After the film is formed, energy rays (light, electron beam,
rays, gamma rays, ion beams, etc.) or plasma treatment to modify the sensitive groups of the silane surfactant. The present invention provides a high-density recording medium characterized in that a monomolecular film of is formed as a protective film.

According to the present invention, it is possible to form a very thin, high-density organic thin film with a uniform thickness and no pinholes on the surface of a magnetic recording medium, in which a plurality of monomolecular protective films are chemically bonded between the layers. It becomes possible to form a high-performance surface protection film.

Example Examples will be described below using FIGS. 1 to 7.

For example, as shown in FIG. 1, a magnetic recording layer 2 (
After forming a magnetic metal (such as Fe-Ni1 Ni-Co, old... or magnetic metal oxide film), C is added as a silane surfactant.
Using H2"CH-(CH2)n-8i Cla (.: an integer. About 10 to 20 is easiest to handle), 2
A solution of 80% n-hexane, 12% carbon tetrachloride, and 8% chloroform dissolved at a concentration of about 10-3 to 5 x 10-2 Mol/1 is prepared, and the medium substrate on which the magnetic recording layer is formed is immersed. Then, since natural oxide is formed on the metal surface deposited as the magnetic recording layer, a monomolecular adsorption film 3 made of silane surfactant is formed on the surface (20~
30 mm thick) is formed.

Next, the vinyl group 4 (CHp=CH-) is irradiated with an energy beam (electron beam, A hydroxyl (-OH) group 5 (Figure 3) or an amine (-NH2) group 6 (Figure 4) is added to 4. Note that the addition of these sensitive groups to vinyl groups is called FTI.
Confirmed by R analysis. In addition, -OH groups and -NH2 groups can be added to the vinyl groups arranged on the surface at this time by processing in plasma containing O2 and N2. By repeating the chemisorption step and the τ1 processing step for OH groups or NN2 groups using the same reaction solution,
A high-density monomolecular cumulative film 7 (protective film 8 (FIG. 1)) in which a plurality of monomolecular films are chemically bonded to each other can be obtained on the surface of a magnetic recording medium or the like. (Figures 5 and 6
Figure) Furthermore, when attempting to form a monomolecular film containing F in the final layer, it is necessary to use CF3-C as a reagent in the final adsorption step.
F2- (CH2) l1l-8i Chemical adsorption is performed using a surfactant containing F such as C13, or after film formation, the outermost monomolecular film is further deposited in a fluorine-containing residue. By plasma treatment, a monomolecular cumulative film containing F can be formed on the surface.

On the other hand, a substrate on which a silane surfactant was formed by a chemical adsorption method was coated with a long-chain fatty acid (e.g., CH2-(CH2).-CO
OHl. is 10-25) or a long-chain alcohol (e.g. CH3-(CH2).-0H1. is 10-2
By immersing it in an aqueous solution containing 5), a monomolecular film of long-chain fatty acids or long-chain alcohols can be further adsorbed and formed on the surface of the monomolecular film made of the silane surfactant.

For example, 10-5 mo of CN3-(CN2)IT-OH
By immersing it in an aqueous solution containing l/l at 10° C. for 30 minutes, a monomolecular film 9 of long-chain alcohol can be formed by adsorption with the OH groups facing up.

(Figure 7) In the above example, an example was shown in which a monomolecular cumulative film was formed directly on the surface of a magnetic recording medium, but it is also possible to deposit a substance such as C or WlMo on the magnetic recording medium to form these films. It goes without saying that the same effect can be obtained even if a monomolecular cumulative film is formed through the oxide film. Furthermore, although the description has been made using a magnetic disk as an example, it goes without saying that the present invention can also be applied to magnetic tape, magnetic cards, and magneto-optical recording media if a transparent material such as PMMA is used as the medium base.

In addition to forming a protective film on magnetic recording media, this method can also be used to
It can also be applied as a protective film for optical recording media and semiconductor devices.

Effects of the Invention According to the present invention described above, a high-density organic thin film in which a plurality of monomolecular protective films are chemically bonded to each other on the surface of a magnetic recording medium etc. can be formed without pinholes and with a uniform thickness. Very thin (can be formed.

Therefore, when the substrate is a magnetic recording medium or the like, the efficiency of the recording/reproducing head can be improved and noise can be reduced, which is a great effect. That is, by chemically adsorbing an ultra-thin film consisting of multiple monomolecular films onto the surface of a substrate using the method of the present invention,
A pinhole-free organic protective film with a uniform thickness can be obtained. Furthermore, by including F in the surface of the organic thin film, the protective film can be given slipperiness, and the slipperiness of the head can be improved. Therefore, the effect of improving wear resistance is significant.

2. The embodiments described above have been explained using a magnetic recording medium as the substrate, but it is clear that the present invention can be used for optical disks, re-hoods, and any other device that aims to improve wear resistance or protect the surface. It is.

Note that diacetylene derivatives [for example, CH2=CH-(CH2)] can be used as materials for chemisorption. -CC-CC
-(CH2)II-3i Cla (nl, : integer), etc.), crosslinking can be generated by ultraviolet irradiation to provide in-plane conductivity, and it is also possible to prevent charging of the substrate surface. It is possible.

[Brief explanation of the drawing]

1 to 7 show cross-sectional views of a magnetic recording medium for explaining the present invention in detail, FIG. 1 is a conceptual diagram, and FIGS. 2 to 7 show a portion A in FIG. It is a process sectional view enlarged to the level. 1... Media base, 2... Magnetic recording layer,
3... Monomolecular adsorption membrane, 4... Vinyl group, 5... Hydroxyl group, 6... Amino group, 7
... Monomolecular cumulative film, 8... Monomolecular film of long chain alcohol. Name of agent: Patent attorney Toshio Nakao and one other person

Claims (8)

[Claims] (1) A recording medium characterized in that a plurality of monomolecular films made of a silane surfactant are directly or indirectly formed on the surface of a recording layer formed on an arbitrary medium substrate. (2) The recording medium according to claim 1, wherein the plurality of monomolecular protective films are chemically bonded to each other between the layers. (3) The recording medium according to claim 1 or 2, wherein the uppermost monomolecular film contains F. (4) The recording medium according to claim 1, wherein the uppermost monomolecular film contains an -OH group. (5) forming a recording layer on the surface of the medium substrate, chemically adsorbing a silane surfactant, and chemically bonding silicon of the activator and oxygen on the recording layer directly or indirectly onto the recording layer; A step of forming a single layer of a monomolecular film, and a step of chemically adsorbing a silane surfactant after forming a single layer of a monomolecular film, irradiating it with a high energy beam in a gas atmosphere containing N_2 or O_2 or performing plasma treatment. , a method for manufacturing a recording medium characterized by repeating the process multiple times. (6) As a silane surfactant, CH_2=CH-(C
The method for manufacturing a recording medium according to claim 5, characterized in that a chemical substance represented by H_2)_n-SiCl_3 (n: an integer) is used. (7) The method for manufacturing a recording medium according to claim 6, characterized in that an optically transparent material is used as the medium substrate. (8) a step of forming a recording layer on the surface of the medium substrate; a step of chemically adsorbing a silane surfactant and chemically bonding silicon of the activator with oxygen on the recording layer to form a monolayer layer; A method for producing a recording medium, comprising the steps of immersing it in an aqueous solution in which a chain fatty acid or long chain alcohol is dissolved, and further adsorbing and accumulating another long chain fatty acid or alcohol monolayer.