JPS59200793A - Anodic magnetic film of al having two-layered structure - Google Patents

Abstract

PURPOSE:To obtain the titled magnetic film having a U-shaped magnetic mode and suitable for use as a high density magnetic recording material by coating an anodic magnetic film of Al having vertical magnetic anisotropy with a metal having high magnetic permeability to provide a two-layered structure. CONSTITUTION:An anodic film is formed on Al or an Al alloy by electrolysis in a sulfuric acid bath, and a magnetic metal or alloy such as a Co-Ni alloy is filled into the micropores in the anodic film and deposited thinly on the whole surface of the film by electrochemical treatment to form an anodic magnetic film having vertical magnetic anisotropy and large coercive force. The surface of the anodic magnetic film is uniformly coated with a metal having high magnetic permeability, horizontal magnetic anisotropy and small coercive force such as Ni, Co, Fe or an alloy thereof by electroplating or chemical plating. An anodic magnetic film of Al having a two-layered structure is obtd.

Description

[Detailed Description of the Invention] When an anode film of Al or A1 alloy is produced and a magnetic metal or alloy is electrochemically deposited and filled into the fine pores of the film, this film becomes a unique magnetic film. It has been found that it exhibits the following properties. (Japanese Patent A 843
639 and 846018) For example, an anode film is formed on the surface of an Al material in a sulfuric acid electrolytic bath, and then a co-Hi gold alloy C is formed.

When N1, co, Fe, lJi -11 is precipitated, the magnetic anisotropy shows a horizontal direction.
'e, co-Fe metals and alloys are known to exhibit perpendicular magnetic anisotropy.

On the other hand, the coercive force of the magnetic film is relatively high, often reaching σe of 1. This value also differs depending on the type of electrolyte used in anode treatment or the type of deposited metal. Generally, in the case of a phosphoric acid or oxalic acid film with a large diameter micropore, the coercive force is smaller than that of a sulfuric acid film with a small diameter.

The magnitude of residual magnetization is determined by the amount of magnetic gold precipitated in the micropores.
It is recognized that the quantity VC1 of 3 is proportional to
It's happening. The sulfuric acid film exhibits a porosity of about 8 to 10 mm, which is small, but when a magnetic film with a large Fθ is deposited,
The residual magnetism can be as high as about 100 θmu/C,C.

This 6y anode magnetic coating has excellent mechanical and chemical properties. In other words, +ii44 of the magnetic head
It has strong resistance to calendar wear against ijυ, and also has a
Another characteristic is that it is stable.

Now, in south density magnetic recording (1), a perpendicular magnetic head suitable for the magnetization mode of a magnetic film having perpendicular anisotropy is used. At present, the recommended head is one with a single magnetic helical pole and an iris of 2%, which are sandwiched from both sides of the perpendicular magnetic film by the pair of the dominant and secondary poles. It has a structure.

However, since this magnetic head uses six sides of the magnetic film at the same time, it is possible to use both sides of the magnetic film separately instead of the conventional combination of a horizontal magnetic anisotropic film and a ring-type magnetic head. I can't come.

After 7, a magnetic head was proposed that made it possible to record and record signals by using only one side of a perpendicular magnetic film in contrast to the cross-polar magnetic head. That is, when a metal or alloy with high magnetic permeability is placed at the bottom ends 77 ((() of adjacent parallel perpendicular magnetic domains and a magnetic circuit is formed, the magnetization mode 'd Ll 'r=iiV and the magnetic It is possible to use the magnetic head 3.1 with only one side of the surface in'+ of the film.In addition, magnetic heads such as inverted U-shaped or M-shaped magnetic heads have been developed with a magnetic-\nod structure. High-density recording is possible.In this case, the high magnetic permeability metal used must have 1. horizontal hunting anisotropy and a low retentivity. be.

Most of the perpendicular magnetic jitters currently in practical use are made of Qo-Cr alloys, and are made by sprocketing or plating on heat-resistant Funstinox film or Al plates. has been done.

The high magnetic permeability metal used in combination is Ni
, F's Nl-based alloys, etc., can be used in a similar manner.

Now, since the AI anode magnetic film has perpendicular magnetism or unilaterality, it is possible to perform 1-degree magnetic recording.
By simulating it with polyethylene, polyester film, etc., readable material can be
As I get older, the application of the tape and printer's playlist is still not open to the public. Furthermore, by processing a j-permeability metal as an intermediate layer, it is possible to create a magnetic film that exhibits a U-shaped magnetic mode.

Generally, when an Al anode magnetic film is immersed in VC in a metal salt bath and then heated using alternating current or direct current between the counter electrode and the opposite electrode, the metal is deposited at the bottom of the micropores. precipitation,
Sequentially, each hole in the temporary tank is filled and deposited up to the entrance. Furthermore,
When electrolyzed, it is observed that it oozes out to the outside of the micropores and precipitates on the surface of the film.

Since the secondary electrolytic bath composition and conditions used at this time are not suitable for replacing a good metal layer, electroplating or chemical plating is used to deposit another VC1 magnetic metal. It is best to plate the soil with a high quality metal layer.

In other words, the metal or alloy that does not have high magnetic permeability is coated with an or structure that connects the magnetic metal or alloy in the micropores, so the anode magnetic coating along the U-shaped 8-mole You can get 752 things.

This film has A1 base material remaining under the film, so
When only A1 of the magnetic head is chemically dissolved and removed, the bottom of the anode magnetic film becomes exposed and is used as a sliding surface with the magnetic head.

Furthermore, the metal plated surface on the opposite side, other materials, and other materials may be bonded to a polyester film or bonded to an A1 alloy plate to be used as a solid magnetic material. Monkey too.

Furthermore, by adhering an anode magnetic film to both sides of the polyester film, two magnetic films can be created that can be used on both the front and back sides.

Examples will be described below.

Example 1 The surface of an Al foil with a purity of 99.9 and a thickness of about 20 μm was coated with J-oil, Z, and agricultural degree 150. /l is 1 [in acid C line, hidden degree 20℃, ? L, style: 151.5 A/! ? 7? In this case, an anode film with a thickness of about 10 μm was produced. Next, concentrated a n-k p cobalt 5? /l
, nickel sulfate 351/1, boric acid 30? /l, glycerin 2Dg/1, temperature 25°C, p) 76 voltage) (in the bath, the anode film was immersed in oil, and a carbon plate was used as a counter electrode,
Electrolysis was carried out using alternating current (50 Hz) at a voltage of 15 V.

When treated for about 20 minutes, the Co-M1 alloy i-1'-like pores become full, σ, and are deposited uniformly and thinly on the entire surface.
child.

Hibihime, Ki, once sulfurized rice Ninocool 200 Y/l, nickel chloride 40? /l, boric acid 5 OSJ/2, temperature 5
The anode film was immersed in an electrolytic bath of 0°C and pl (5),
As a fantasy, N1 board, electric current 1.5A? Electrolysis was carried out for about 1 minute. As a result, lJi plating was applied to the surface of the anode film.

Next, a polyurethane adhesive was applied onto the N1 plating, and a polyester film with a thickness of about 20 μm was adhered. After drying at about 100° C., a laminate base of psystinox and Al foil was prepared.

Finally, this film was immersed in a bromine methanol solution heated to about 60° C. to chemically dissolve and remove A1.

This magnetic film has a coercive force of about 800σθ in the perpendicular direction, a residual magnetism of about 5 Q emu/c, c, and exhibits magnetic properties as well as flexibility, so it has a suitable magnetic property for front disks. It is considered a material.

Example 2 J, 1 foil made of the same material as in the previous section and having a thickness of about 10 μm was used, and after degreasing, the concentration was 1507/l- for sulfuric acid and 300/l for phosphoric acid.
? An anode film with a thickness of about 6 μm was produced in an electrolytic bath with a temperature of 20° C. and a current density of 1.5 μm. Then, the concentration was 509/l (cobal sulfate), 711illic acid 30/l
f/l, glycerin 20 f/l, temperature 1/25°C, 1
) The anode film was immersed in an electrolytic bath of H5.5, and AC electrolysis was performed in the same manner as in the previous section.

After about 20 minutes, cobalt was found to be uniformly deposited on the surface.

Subsequently, the concentrations were nickel sulfate 402/l, sodium citrate 25//l, sodium hypophosphite 2017'/4 acetic acid 7t, anthene chloride 52A, warm'
L'! The anode film was immersed in a chemical plating bath at -60°C and pH 5.5 for about 10 minutes, and N1 chemical plating was applied for 70 minutes.
I got 110.

A polyurethane adhesive was applied to the N1 plated surfaces of the two membranes thus prepared, and the adhesive was applied to both sides of a polyester film having a thickness of approximately 20 μm.

Finally, the thoroughly dried film was immersed in a humidified bromine methanol solution at about 60° C. to dissolve and remove A1 in Table II].

This magnetic film exhibits a coercive force of about 800σe in the perpendicular direction and a residual magnetism of 3 Q emu/c, c, and can be used as a flexible double-sided magnetic material.

Claims (1)

[Claims] (1) A mother recording material characterized by having two layers formed by coating a high magnetic permeability metal on an Al anode magnetic film having perpendicular magnetic anisotropy (2) Anode magnetic film This means that an anodic growth type anode film is formed on Al or A1 alloy by a method, and then a magnetic metal or alloy □
Claim (1): Electrochemically precipitated and filled into the fine pores of the film, and further precipitated uniformly on the surface of the film to create a magnetic film having perpendicular magnetic anisotropy and exhibiting high coercive force. Method (3) High permeability metals are Hi, C01Fθ, and alloys containing them as main components, which have horizontal magnetic anisotropy and exhibit low coercive force. The method according to claim (1), in which the surface is uniformly coated with plating or dense chemical plating jfD L.