JPS6018823A - Magnetic recording medium and its production - Google Patents

Abstract

PURPOSE:To make a relative speed between a head and a disk approximately constant and to increase the recording range by using a cylindrical thermoplastic film as a substrate and coating the substrate with a magnetic metallic thin film either on the surface side or the back side. CONSTITUTION:A magnetic metallic thin film 2 is formed on the surface and/or back side of a substrate made of a cylindrical thermoplastic resin film having a smooth and seamless surface. A compound which is hardened by heat is coated on the film 2. Such substrate 1 is heated up at a <=100 deg.C temperature to form a protecting film 3. In such processes, a magnetic recording medum 5 is otained. The substrate 1 is produced in the following process. That is, a polyester sheet having a smooth surface is cut into a prescribed size. Thus cut sheet is set into a vacuum molding device to undergo a preheating process and sucked under vacuum onto a cylindrical male mold having a mirror surface which is kept at a prescribed temperature to be held there for a certain period of time. Then the molded product is released from the mold.

Description

[Detailed Description of the Invention] t1) The present invention relates to a cylindrical magnetic F-recording medium and a method for manufacturing the same, and more specifically, a cylindrical thermoplastic resin film with smooth front and back surfaces and a seamless cylindrical thermoplastic resin film as a base, and a method for producing the same on the base. The present invention relates to a magnetic recording device in which a metal magnetic thin film and its protective film are coated with or without a non-magnetic metal thin film, and a method for manufacturing the same.

Rejected The present invention will be described by taking as an example a magnetic recording medium used in an image recording and reproducing apparatus for frame-by-frame recording and normal recording of television image signals, but is not limited to such image recording and reproducing apparatuses. In addition, there are digital nF!s such as audio recording and playback devices and thunder detectors. It can also be widely applied to magnetic recording media used in recording/playback devices and the like.

In recent years, in the field of magnetic recording, magnetic recording devices have become 1JS type, and the need for magnetic recording media that can perform high-density recording has increased. In addition to the coated media of γ-Fθ203, which has been widely used, tape-shaped, disk-shaped magnetic wh recording media, metallic magnetic disks, etc., made of 00 alloy based on plating methods and vacuum evaporation, etc., have been proposed (2). However, one circumference of such a magnetic WF recorder FJ body is a TV 97 Yon image signal? When recording magnetically in units of feel r, the image quality is lower on the inner periphery of the magnetic MF' recording body than on the outer periphery because the relative speed between the head and the disk is smaller than on the outer cylinder. In addition, when trying to obtain image quality above a certain level, there is a limit to the inner circumference that can be recorded due to relative speed, so in order to increase the number of nrI recorded images, the outer diameter must be made thicker (L7
Therefore, the diameter of the disk becomes large and the entire magnetic recording/reproducing apparatus cannot be compactly packed.

The purpose of the present invention is to overcome these drawbacks, and by using a circular thermoplastic resin film substrate and covering the surface and back surface with a thin magnetic metal film, a spatula V and a disk can be formed. It is an object of the present invention to provide a magnetic H-recording medium and a method for manufacturing the same, which makes it possible to maintain a substantially constant relative speed between the two and to expand the recording range.

In other words, the first aspect of the present invention is a circular thermoplastic resin film with smooth front and back surfaces and seamless joints, and a metal magnetic muff is further coated on the surface and/or the entire surface of the groove. The second invention is a cylindrical thermoplastic resin film with smooth and seamless front and back surfaces, and a non-magnetic metal 2q film and a metal magnetic film on the surface and/or one side. Membrane and membrane
? The third invention is based on a cylindrical thermoplastic resin film with smooth front and back surfaces and no mesh. Either a non-magnetic metal thin film is coated on one surface, or a metal magnetic thin film is coated without bonding, and then a compound that hardens by heating is applied on top of it, and then heated at a temperature of 100℃ or less. This is a method for producing a magnetic field recording body that exhibits symptoms.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A detailed description of the present invention will be given below with reference to the drawings.

1M is a perspective view of a magnetic e-recording medium according to an embodiment of the present invention, FIG. 2 is a sectional view thereof, and FIG. 3 is a sectional view of another embodiment. As shown in FIGS. 1 and 2, (3) the magnetic recording material of the present invention is applied to the front and back surfaces of a substrate 1 made of a seamless cylindrical thermoplastic resin film with smooth front and back surfaces, respectively. A protective film 3 is coated on the metal magnetic thin film 2, and as shown in FIG. It is composed of a magnetic metal thin film 4, a metal magnetic thin film 2, and a protective film 3 coated on VJIF+.

Although not illustrated, the metal magnetic thin film and protective film applied to the surface and/or back surface of the substrate 1 made of a cylindrical thermoplastic resin film are shown in FIGS. 2 and 3. It is not limited to the front and back sides,
It may be on either side, and is determined by the conditions of use.

The magnetic recording medium 5 of the present invention has a metal magnetic thin film 2 formed on the front and/or back surface of a base 1 made of a cylindrical thermoplastic resin film with a smooth surface and a seamless surface. (4) After applying a compound that hardens by heating on top of the film, transfer it to C) (4) Prepare by forming a third protective film by heating at a temperature below 1000 m.

The substrate 1 made of a cylindrical thermoplastic resin film must have a smooth and seamless surface.
This is a recording feature. Therefore, since the metal magnetic thin film 2 and the protective film 3 are very thin, the surface condition of the base 1 made of a thermoplastic resin film is directly applied to the magnetic recording medium as unevenness. If the holes become large, the noise level during magnetic Pi'' recording and playback will increase, which is undesirable. Therefore, it is desirable that the surface condition of the substrate made of thermoplastic resin film be as smooth as possible. In the present invention, the thermoplastic resin film Specifically, the smoothness of the substrate is such that the center line average roughness Ra according to J.E.S. BO6 (No. 11) is 0.04 μm or less, and more preferably 0.01 μm.

In general, it is desirable that the front and back surfaces of the substrate for vapor-deposited tapes or plating tapes be as smooth as possible from the viewpoint of noise level. (Unwinding) 1. The Han IF II song at the time of winding is bad, which causes problems in manufacturing the product.Also, even if the tape is VC, there are problems such as poor tape feeding performance when the magnetic recording angle is raw. There is. In order to solve such contradictory problems, the actual situation is that some unevenness is formed at the expense of a certain level of noise level due to the surface unevenness.

The cylindrical magnetic nailing medium according to the present invention has a smooth surface and is manufactured as described above for manufacturing and magnetic recording and reproduction.
;'1iIv does not occur, so that a high-density magnetic flF recording medium can be obtained in which the noise level caused by the unevenness of the medium surface is reduced as much as possible.

The substrate made of a cylindrical thermoplastic resin film used in the present invention can be manufactured by various methods such as those described below.
This will be explained using an example in which a thermoplastic YXE polyester resin is used as the thermoneutral resin forming the structure of the substrate, but it is not limited to this.
It is also possible to use a mixture of vinyl chloride resin, acrylic resin, polycarbonate resin, etc., using an ester sheet with a smooth surface manufactured by a conventional method. The molded body is set in a mold and preheated (and then pulled down by 91% on a mirror-finished cylindrical male mold kept at a predetermined temperature, held for a certain period of time, and then released from the mold. In this case, the molded cylindrical There is no problem in making the shape of the male mold into a cylindrical body that is slightly tapered compared to the true cylindrical body so as to prevent the mold from being released from the male mold.

The vacuum-formed cylindrical shaped ester resin substrate is stretched 5 to 10 times as much as the first Bo-11 ester resin sheet. Is the strength sufficient for practical use? What you have is what you get.

Cylindrical in the present invention? The thickness of the substrate made of polyester resin is preferably about 10 to 100 μm.
If it exceeds 0 μmV, the contact between the spatula V and the magnetic recording medium will not be sufficient and the reproduction force will not be able to be sufficiently applied. On the other hand, if it is less than 10 μm, Mv becomes difficult in manufacturing the magnetic recording medium and in handling during magnetic recording and reproduction. A more preferable range is 2n to 50μ1.

Note that the sea bream method for producing a cylindrical, neutral resin film substrate is not limited to a hollow molding method, and it is sufficient that tr < cylindrical film substrate 7 is formed, and cannot be obtained even by, for example, an inflation method.

Before forming the metal magnetic thin film, a non-magnetic metal film may be coated on the surface and/or island surface of the substrate made of a cylindrical thermoplastic resin film. Depending on the method of forming the metal magnetic thin film, the desired magnetic properties may be obtained due to the influence of the crystal structure or molecular arrangement of the substrate separated from the thermoplastic resin film, and in such cases The above problem can be solved by coating a non-magnetic metal film before forming a metal magnetic thin film.As such a non-magnetic metal film, for example, Ni-P formed by electroless plating can be used.
.

There is a coating of N1-W-P and Au@. Its thickness is 0.
02 to 0.2 μm is sufficient.

Examples of methods for forming the metal magnetic thin film include vacuum evaporation, ion derating, sputtering, and electroless plating. Of these, cylindrical (9) thermoplastic #1 resin film is formed on the front and back surfaces of the aggregate, and the electroless plating method is suitable. If it is possible to uniformly coat the back side of a cylindrical thermoplastic resin film using the vacuum M deposition method, 7° ion rating method, and sputtering method, there is no need to limit the method to electroless plating. varies depending on the application, but is generally between 0.03 and 2.0 μm.

When distributing image Shingetsu, the media failure is 0.1 because the specified playback output is required over a wide frequency band.
~Q, about 5 μm is preferable [7].

In addition, when recording digital signals from a computer, etc., it is necessary to increase the resolution of the reproduced waveform, so the medium density is relatively thin (preferably about 0.03~Q, 1.am).On the other hand, the Co-0r vertical In the case of a magnetic medium, the thickness of the medium is generally about 1.2 to 2.0 μm. In this case, a sputtering method is used.

The peritoneum coated on top of the metal magnetic thin film is essential for preventing media corrosion [10] and abrasion caused by the head.

It is better for the protection film to have magnetic lWi'7 recording and playback special recording recolor characteristics.The gap between the spatula V and the metal magnetic thin film medium is large p < tr Reproduction by bassing loss This is preferable because the output loss will be large.

On the other hand, from the viewpoint of corrosion resistance and abrasion resistance, a certain amount of 19 μm is required, and taking into account single loss, it is generally preferable to have a thickness of about 0.02 to 0.5 μm.

Protective film'? Various methods have been proposed for forming magnetic gold on the surface of the film. For example, a method of changing only the surface layer of a metal magnetic material to a metal oxide film, Rh, C!, which has a relatively high hardness tW on the surface of a metal magnetic material! A method of forming a thin plating metal film on the surface of a magnetic metal material.
Method of forming pastes, carbides, perforations such as i by PVD methods such as sputtering and ion derating, 8
1. After applying the alkoxide of Tl@, the heat content is
There are methods such as forming a thin film of these oxides on the surface of a magnetic metal material, and forming a thin film of an organic polymer on the surface of a magnetic metal material. be.

(However, in the case of a magnetic MP recording medium comprising a cylindrical thermoplastic resin film substrate of the present invention, a material having a certain degree of hardness and flexibility is desirable.

The reason for the need for flexibility is not clear, but it improves the contact between the head and the magnetic recording medium.
is expected to be stable.

In the present invention, it is preferable to use a substrate made of a thermoplastic resin film that forms a film at a heating temperature of 150°C or lower, preferably 10°C or lower, preferably 80°C or lower.

[2] For polymer resin systems, urethane, acrylic resin, unsaturated polyester, epoxy resin, polysulfide V, and silicone resins may be used alone or in combination with two types of N. For inorganic polymer systems, the following conditions must be met: 5in2. by hydrolysis of metal alkoxide. Examples include TiO2.

These substances and a curing agent are dissolved in an organic solvent to form a coating solution at a predetermined temperature. After dipping into the solution, it is pulled up at a constant speed and a solvent is evaporated, preferably less than 8C1.
By heating and curing at a temperature below 0.8L, a time-keeping coating with a predetermined luminosity can be obtained.

As a hardening agent, in the case of polymeric resin systems, incyanate metal alkoxy V, organic or inorganic acids and bases are used to reduce the friction coefficient when sliding with magnetic HP recording media. It is also possible to add a lubricant into the protective film. Examples of such lubricants include fatty acids, fatty acid salts, saturated carbonized carbonized alcohols, fatty acid esters, fatty acid ethers, silicones, fluorinated oils, etc. Use it. Among the stiff materials, fatty acid esters and silicones are preferred when using Botno urethane as a protective film.

The lubricant is added in advance to the coating solution for forming a peritoneal membrane and applied at the same time as the protective film forming substance.The lubricant must be compatible with the decoy film forming substance. By 'f', an appropriate amount of lubricant is separated, the elbow retaining membrane is hardened, and at the same time a lubricant layer is formed on its surface (16).

It is also possible to have a two-layer structure for the intestinal retaining membrane.

For example, the first layer is a protective film containing a lubricant, and the second layer is a protective film containing a lubricant.

With such a two-layer structure Vc, the first protective film is firmly bonded to the metal magnetic thin film, and the second protective film containing lubricant has lubricating properties. It's small rice to hold on to.

Also, is there a protective film on the metal magnetic thin film? The adhesion of the protective film can be improved by uncoating it with an adhesion promoter before formation. For example, when a partial hydrolyzate of tetraalkoxysilane is used as a double-retaining film, a titanate cup IJing agent and an ethylene glycol resin (V phosphate) are used.

The amount of lubricant added to the protective film forming substance is [11,5~
21TI qA, preferably 1-10%, addition D
If the amount is too high, the lubricity will be poor, and if the amount added is too high, the strength of the protective film will decrease, so it is not preferable.

As explained above, the present invention provides a cylindrical thermoplastic (14) resin film with a non-magnetic metal thin film on the surface and/or back surface of the resin film. A magnetic F lead body and a method for manufacturing the same are produced in the order of the metal magnetic nσ and the pupil magnetic nσ, and the method for producing the same. You can do something.

Furthermore, since the base of the magnetic recording medium is a thermoplastic resin film, it is a light chain. Therefore, it is sufficient to use a smaller load for the motor that rotates this, and it has the feature that the entire sheathing can be stored compactly.

The present invention will be explained in detail below using examples. Note that all parts in the examples are parts by weight.

Example 1 A cylindrical substrate with a diameter of 35 x φ, a circumference of 3 nm and an average image surface phase of RaO, [11 μm] was made by vacuum forming from a 100 l1 m unstretched polyester sheet, and by electroless plating. 0 on both surfaces of the cylindrical substrate
．． A 2 μm thick Co-N1-P magnetic film was formed. m
-fit was pre-treated with i-plating by making it hydrophilic with a caustic soda solution and then activating it with balasium colloid).

An FtF electroless plating bath was used for the Co--N1-P magnetic writing film.

The protective film was formed on the magnetic fishing film body by dipping it in the VC coating solution of Shimoki, making a drawing hole, and then heating it at 60° C. for 5 hours.

Example 2 A Co-N1-P magnetic film similar to that in Example 1 was formed using TRF' (2 fif+ of Al and (Bl).
I made a similar coating solution 7, and the first month was (Al solution, the second time was (
60℃ after soaking and drying in 131 liquid respectively.
By adding it for 5 hours, the body was formed.

T Example 6 zo';$+i A Co-Ni-P magnetic film similar to Example 1 was formed.
Different types of coating liquids were used.The first time was with the fit solution, the second time was with the (BL solution, and the third time was with the (01 solution. (18) Example 2/15 A flange was formed at one end of the cylindrical magnetic recording medium as obtained in Example 1.2 and 6.
The surface of this magnetic recording medium K Mn-Zn is rotated at rpm.
& I made a 1-field V recording angle generation device for television signals by contacting crystal ferrite video heads. When I evaluated the steel sheet image with this casing, it was clear and stable, and it lasted for more than an hour. I tested it by touching it on each side, and both sides were clear at 7ri.
lii quality was obtained.

[Brief explanation of the drawing]

The drawings show a magnetic recording medium according to an embodiment of the present invention; FIG. 1 is a further view of the magnetic recording medium, FIG. 2 is a cross-sectional view thereof, and FIG. 3 is a cross-sectional view of another side. Code 1...Substrate 2...Metal magnetic thin film 3...Retaining film 4...Non-magnetic metal thin film 5...Magnetic envelope record procedure amendment book 1, case description 1982 Patent Application No. 1.24075 2, Title of the invention: Magnetic recording medium and its manufacturing method 3, Relationship with the case of the person making the amendment Patent applicant address: 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Invention of the specification Detailed explanation column 5, content of amendment 5-1) “Acrylic resin” and “polycarbonate,” line 20 on page 7 of the specification, 15-4) On page 13 of the specification,
Line 6 “Isocyane-1-J and [metal alkoxylide]
Added "," between "used" and "magnetic recording medium" in line 7, added "." between "used" and "magnetic recording medium" in line 8, and added "friction coefficient" in line 8.
is corrected as “friction coefficient”, and line 11 is corrected as “saturated hydrocarbon” and “
Add "," between "resin acid alcohol". 5-5) "Front side, page 15, line 19, 1st surface" of the specification is corrected to "front and back." 5-6) Specification, page 16, line 6 [Cobalt chloride 0.00
3mon/IJ [cobalt chloride 0.03mal
Correct it as L/A J. 5-7) Change “1 hour or more” to page 19, line 10 of the specification [1
Corrected to say after 0 hours.

Claims (2)

[Claims] (1) A magnetic recording medium comprising a cylindrical thermoplastic resin film with smooth front and back surfaces and no seams, the front and/or back surfaces of which are coated with a metal magnetic thin film and a protective film thereon. , (2) The front and back surfaces of a cylindrical thermoplastic resin film with smooth and seamless surfaces are coated with a non-magnetic metal thin film, a metal magnetic thin film, and a retaining film in this order. To the magnetic recording medium (3) The base is a cylindrical thermoplastic resin film with smooth front and back surfaces and no seams, and the front and/or back surfaces are coated with a non-magnetic metal thin film, or metal magnetic is coated without coating. A method for manufacturing a magnetic recording medium, characterized in that a thin film is coated, a compound that is cured by heating is applied thereon, and then the compound is cured by heating at a temperature below -100° C.