JP2001084585A - Floppy disk and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording medium of high recording density, a small deformation amount and excellent characteristics. SOLUTION: This floppy disk is provided with at least a magnetic layer, a protective layer and a lubricant layer on both surfaces of a flexible supporting body substrate. In this method for manufacturing floppy disk, the film formation speed of a layer to be formed on a flexible supporting body by a vacuum film formation method is >=0.3 mm/second and <9.5 mm/second and at least one metal thin film layer of a material whose heat conductivity at 20 deg.C is <0.25 cal/cm.s.deg is formed right above the flexible supporting body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a removable magnetic recording medium used for an auxiliary recording device and an image recording device of a computer, and more particularly to a magnetic recording medium having a high recording density of 1 gigabit per square inch or more. .

[0002]

2. Description of the Related Art Tape-shaped magnetic recording media such as digital video tapes have been used as high-density recording media for large-capacity digital information such as auxiliary storage of computers. There is a demand for higher capacity and higher recording or reproduction speed. Due to these demands, a removable hard disk has recently been used as a large-capacity, high-density digital recording medium. However, the existing gigabyte-class removable media uses rigid disc-shaped substrates such as glass and aluminum, so when an impact is applied to the device, the media itself cannot absorb the impact, causing a head crash. In some cases, both the medium and the head were severely damaged. For this reason, those using a rigid substrate such as a removable hard disk have not yet solved the problem of impact resistance, and have problems in using a magnetic recording medium using the rigid substrate in a portable device. This is one of the problems in the spread of digital disk cameras and the like using a magnetic recording medium using a rigid base.
By changing the rigid substrate to a flexible substrate, it is possible to reduce the weight of the recording section, reduce damage at the time of head crash, and realize a high-density removable magnetic recording medium excellent in impact resistance.

[0003] In order to meet such a demand, we are developing an ultra-high recording density recording medium using a flexible support. The magnetic layer for high-density recording is formed by a vacuum film-forming method, but it is necessary to heat the substrate at a temperature of 50 to 300 ° C. in order to secure magnetostatic characteristics and electromagnetic conversion characteristics.

[0004] In addition, when the thermal damage of the flexible support is increased by sputtered particles, thermal deformation occurs, which deteriorates the read / write characteristics of the head and the characteristics of the magnetic recording medium. Depending on the sputtering conditions, when the sputtering rate is increased, the internal stress of the sputtered film is increased, and static deformation such as curling of the disk may occur.

In addition, since the flexible support is made of a synthetic resin, the thermal conductivity is lower than that of a metal support such as aluminum. Therefore, when a film is formed directly on the support, If the deposition rate is high, heat generated by the collision of the sputtered particles accumulates on the support surface, and the temperature of the support surface may rise to a temperature higher than the glass transition temperature, such as oligomers contained in the support. Ingredients are generated or undulation is generated on the surface of the support, and the surface flatness is reduced. Also, when the amount of heat applied is large, there is a problem that distortion occurs due to a temperature difference between the inside of the support and the surface, and the support is deformed.

In order to prevent deformation of the support, it is effective to reduce the sputtering rate. However, when the sputtering rate is reduced, the deposition time is increased. If the film formation time is too long, the gas components contained inside the synthetic resin-made flexible support accumulate in the film formation apparatus, and the probability of contact with sputtering particles generated during film formation increases, The problem is that the crystal orientation of the formed film is deteriorated.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a magnetic recording medium having a flexible support as a base, which is intended to reduce the deformation of a layer formed by vacuum film formation on the flexible support and the deterioration of surface characteristics. It is an object of the present invention to provide a floppy disk and a method of manufacturing the same.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a floppy disk having at least a magnetic layer, a protective layer and a lubricant layer on both sides of a flexible support substrate. The deposition rate of the formed layer is 0.3 nm /
By setting the thickness to not less than Sec and not more than 9.5 nm / sec, thermal deformation of the support due to sputtered particles, deformation such as curling due to an increase in internal stress, deterioration in surface properties, crystal orientation of the underlayer / magnetic layer The inventors have found that a decrease can be prevented, and have reached the present invention.

That is, according to the present invention, a floppy disk having at least a magnetic layer, a protective layer, and a lubricant layer on both surfaces of a flexible support substrate is formed on the flexible support by a vacuum film forming method. A method for manufacturing a floppy disk, characterized in that a layer forming speed is 0.3 nm / sec or more and less than 9.5 nm / sec. In addition, a thermal conductivity of 0.25 cal / cm was placed directly above the flexible support under an environment of 20 ° C.
The method of manufacturing a floppy disk according to the above, wherein at least one metal thin film layer made of a material having less than s · deg is formed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various methods are known as vacuum film forming methods, and it is known that a film forming method by sputtering has a high energy of evaporated particles. Therefore, during the film formation process in which the evaporated particles collide with the substrate, the temperature of the support is significantly increased. As a material of the flexible support, a film composed of a polymer material having a glass transition point is generally used. Therefore, when the film forming speed is increased and the energy of the evaporating particles is further increased, the temperature of the support reaches the transition temperature or higher, and thermal deformation occurs.

In addition, since the thermal conductivity of the polymer material of the support is low, when the film formation rate is high, heat due to the collision of the film-forming particles accumulates on the surface of the support and exceeds the glass transition temperature on the surface of the support. Even if undulation occurs on the surface of the support and deformation of the support does not occur, oligomers contained in the polymer material are generated on the surface, and the surface property is reduced. It was also found that when the amount of heat applied to the surface increased, distortion occurred due to the temperature difference between the inside of the support and the surface, and the support was deformed. This deformation lowers the characteristics at the time of writing and reading by the magnetic head, and substantially lowers the characteristics of the magnetic recording medium.

[0012] Even after the formation of the metal thin film layer on the support, the temperature rise of the support due to the evaporating particles may have an effect. In other words, the thermal conductivity of the metal thin film is higher than that of the polymer material of the support, and the heat generated at the time of film formation is transmitted to the surface of the support and increases the temperature of the surface of the support. As in the case of forming a film, the surface property is reduced. In addition, the film forming sputtering speed is increased, the internal stress of the sputtered film is increased, and the magnetic recording medium may be deformed such as curl.

Therefore, as a result of paying attention to the relationship between the deformation of the flexible support and the film forming speed, when a thin metal film is formed on the support in a floppy disk using the flexible support as a substrate, the film is formed. It has been found that by setting the speed to a range of less than 9.5 nm / sec, it is possible to significantly suppress thermal damage to the support.

On the other hand, in order to prevent the deformation of the support due to the film formation rate, it is effective to greatly reduce the film formation rate.
However, since the flexible support is a polymer material, a large amount of gas is generated by heating. Therefore, when the film formation rate was reduced and the film formation time was long, the probability of contact with the gas generated from the support remaining in the chamber of the film formation apparatus was increased, and the film was formed on the flexible support. The crystal orientation of the layer deteriorates. In addition, the density of the formed film is reduced, and problems arise in the corrosion resistance and durability of the prepared floppy disk.

Similarly, the influence of the gas generated is that
It is thought that the crystal orientation of the magnetic layer is sharply reflected, and the relationship between the degree of crystal orientation and the film formation rate shows that a thin metal film is formed on a floppy disk using a flexible support as a substrate. In this case, the film forming speed is set to 0.3 nm /
It has been found that the orientation changes greatly from the second. For the reasons described above, in a floppy disk using a flexible support as a substrate, when a metal thin film is formed on the support, the film formation rate should be 0.3 nm / sec or more.
By specifying the range of less than 9.5 nm / sec, it is possible to prevent deformation, decrease in surface properties, and decrease in crystal orientation of the underlayer and the magnetic layer during manufacture of the floppy disk. Preferably, the film formation rate is 0.5 to 8.0 nm / sec.

Suitable supports for the floppy disk of the present invention include materials such as polyethylene terephthalate, polyethylene naphthalate, polyimide, polyamide, polyamideimide, and polybenzoxazole. The support has a Young's modulus of 200 to 1600 k.
g / mm ² , and particularly preferably 30 g / mm ^2.
0 to 800 kg / mm ² .

The thickness of the support is 20 to 200 μm,
More preferably, it is 30 to 80 μm. Support thickness is 20
If the thickness is smaller than μm, the amount of deformation such as curling of the support becomes large, the surface runout during rotation of the disk becomes large, and stable contact with the head cannot be maintained. 200 μm
Above this, the impact force when the head comes into contact with the magnetic recording medium is strong, and the head or the magnetic recording medium is damaged.

The support is provided with a flat layer to improve flatness. A heat-resistant polymer material can be used as the flat layer material. Particularly preferred are silicone resins,
Materials such as polyamide resin, polyamide imide resin, and polyimide resin. These materials are not only excellent in heat resistance, but also can achieve good surface properties and magnetostatic properties. The thickness of the flat layer is 0.1 to 5.0 μm, preferably 0.5 to 3.0 μm, and more preferably 0.8 to 3.0 μm.
The range is 2.0 μm. If the film thickness is smaller than 0.1 μm, the projections on the support cannot be completely filled, and when a magnetic layer is formed, a sufficient loss cannot be obtained because of a spacing loss. On the other hand, when it is larger than 5.0 μm, the flat layer cannot follow the thermal deformation of the support, and cracks occur.

On the surface of the support, small projections such as Si
Fine particles such as O ₂ , Al ₂ O ₃ and TiO ₂ are provided.
The particle size of the fine particles used is preferably from 5 to 50 nm, particularly preferably from 10 to 40 nm. The height of the protrusions on the surface of the formed flat layer is preferably in the range of 2 to 40 nm. If the protrusion height on the flat layer surface is smaller than 2 nm, the frictional force between the slider and the magnetic recording medium increases, and the head or the magnetic recording medium is damaged. If it is larger than 40 nm, the spacing loss becomes remarkable, and sufficient recording / reproducing characteristics cannot be obtained.

The underlayer materials include Cr, Ti, Ni,
W, Mo, V, Ta, B, Si, Nb, Zr, Al, M
An alloy with at least one metal element among n, or an oxide, nitride, or phosphide thereof is preferable. Particularly preferred is an alloy containing Cr as a main component.
The r concentration is 77 to 100 at%, particularly preferably 80 to 100 at%.
95 at%, with the balance being other metals. Also,
The thickness of the underlayer is 5 nm to 500 nm, particularly preferably 10 nm to 100 nm. 100 underlayers
If the thickness is larger than nm, the particle diameter of the magnetic layer increases, and the noise of the magnetic recording medium increases. The underlayer is formed by DC sputtering or high-frequency sputtering. The deposition rate of the underlayer can be adjusted by changing the power supplied to the target and the distance between the target and the substrate on which the film is formed.

Examples of the magnetic material used for the magnetic film formed on the underlayer include metals or alloys mainly composed of cobalt, and a CoCr alloy is preferable.
An alloy with t, Ta, Ni, Si, B, Ni, and Pd, or an oxide or a nitride is desirable. Among them, Co-Cr-
Pt and Co-Cr-Pt-Ta are preferred. The Cr concentration in the magnetic layer is 10 to 30 at%, particularly preferably 15 to 25 at%. A granular medium composed of an alloy containing Co as a main component and a nonmagnetic material is also possible. Pt, Sm, Ir, Re, T
Those containing at least one non-magnetic element among a, Cr, Nb, B and W are preferable. As the nonmagnetic material, ceramics such as SiO ₂ , SiN, Al ₂ O ₃ , MgO, and MgF ₂ or semimetals such as B and Si are desirable.
The volume fraction of the Co-based alloy in the medium is preferably in the range of 40 to 95% by volume, preferably 50 to 90% by volume. The thickness of the magnetic layer is from 10 to 300 nm, particularly preferably from 15 to 60 nm.

The magnetic layer is preferably provided by sputtering among the vacuum film forming methods. Sputtering is preferable because it can form a film without changing the composition of many elements. The magnetic layer is formed by DC sputtering or high frequency sputtering. The deposition rate of the magnetic layer can be adjusted by changing the power supplied to the target and the distance between the target and the substrate on which the film is deposited. The underlayer and the magnetic layer are preferably formed continuously without reducing the degree of vacuum in the apparatus.

When a flat layer is formed on the flexible support, the flat layer is formed, and when the flat layer is not formed, the underlayer is formed directly on the surface of the flexible support. However, the layer formed in contact with the surface of the flexible support has a thermal conductivity of 0.25 cal under an environment of 20 ° C.
It is preferable to use a metal thin film layer of a material less than / cm · s · deg in order to reduce the temperature rise on the surface of the support during film formation.

It is preferable to form a protective film on the magnetic layer. The protective film is a carbon film made of an amorphous, diamond-like structure, graphite, or a mixture thereof formed by a plasma CVD method, a sputtering method, or the like, and is particularly preferably a hard amorphous carbon film generally called diamond-like carbon. It is. This hard carbon film is a hard carbon film having a Vickers hardness of 1000 kg / mm ² or more, preferably 2000 kg / mm ² or more.
The thickness of the protective layer is preferably from 2.5 nm to 30 nm, particularly preferably from 5 nm to 25 nm.

In the magnetic recording medium of the present invention, in order to improve running durability and corrosion resistance, it is preferable to add a lubricant or a rust inhibitor to the magnetic film or the protective film. For example, hydrocarbon-based lubricants, fluorine-based lubricants, extreme pressure additives, and the like, which are used as lubricants in the above, can be used.

As the hydrocarbon lubricant, stearic acid,
Carboxylic acids such as oleic acid, esters such as butyl stearate, sulfonic acids such as octadecylsulfonic acid, phosphoric esters such as monooctadecyl phosphate, alcohols such as stearyl alcohol and oleyl alcohol, and carboxylic acids such as stearamide. Examples thereof include acid amides and amines such as stearylamine.

Examples of the fluorine-based lubricant include lubricants in which part or all of the alkyl groups of the hydrocarbon-based lubricant are substituted with a fluoroalkyl group or a perfluoropolyether group. Examples of the perfluoropolyether group include a perfluoromethylene oxide polymer, a perfluoroethylene oxide polymer, a perfluoro-n-propylene oxide polymer (CF ₂ CF ₂ CF ₂ O) _n , and a perfluoroisopropylene oxide polymer (CF ( CF ₃ ) CF
₂ O) _n or a copolymer thereof. Examples of extreme pressure additives include phosphates such as trilauryl phosphate, phosphites such as trilauryl phosphite, thiophosphites and thiophosphates such as trilauryl trithiophosphite, dibenzyl disulfide and the like. And sulfur-based extreme pressure agents.

The above lubricants may be used alone or in combination.
used. Apply these lubricants on the magnetic film or protective film.
As a method of imparting water to a lubricant, a lubricant is dissolved in an organic solvent
Ear bar method, gravure method, spin coating method, dip
Apply by a coating method or adhere by vacuum evaporation.
Just do it. The amount of lubricant to be applied is 1 to 30 mg / m ^Two
Is preferably 2 to 20 mg / m^Two Is particularly preferred.

Examples of the rust preventives usable in the present invention include nitrogen-containing heterocyclic compounds such as benzotriazole, benzimidazole, purine and pyrimidine, derivatives having an alkyl side chain introduced into the mother nucleus thereof, benzothiazole, 2-benzothiazole,
Examples thereof include nitrogen- and sulfur-containing heterocyclic compounds such as mercapton benzothiazole, tetrazaindene ring compounds, and thiouracil compounds, and derivatives thereof.

[0030]

The present invention will be described below with reference to examples. Example 1 Both sides of a 75 μm thick polyethylene naphthalate support
A silicone resin flat layer of organosiloxane
Sputtering on flexible support coated 1.0μm
Argon partial pressure of 1 using a device (730H manufactured by Anelva)
5.0mTorr, input power 12.0W / cm^Two,support
Under the condition of body temperature 30 ° C, without applying bias voltage,
The distance between the plate and the target was 45 cm. Underlayer deposition
The speed was 0.8 nm / sec. Next, the
Lugon partial pressure 0.8mToor, input power 12.0W / c
m ^Two Co: 68 at%, Cr: 20 at%,
Pt: Co alloy thin film having composition of 12 at%
Under the condition of 30 ° C., without applying a bias voltage,
Is formed as 1.2 nm / sec, and a floppy disk is formed.
Produced.

Example 2 The input power during the formation of the underlayer was 18.0 W / cm ² ,
A floppy disk was produced in the same manner as in Example 1 except that the underlayer deposition rate was changed to 7.2 nm / sec.

Example 3 The input power at the time of forming the magnetic layer was 18.0 W / cm ² ,
A floppy disk was produced in the same manner as in Example 1 except that the magnetic layer deposition rate was changed to 7.6 nm / sec.

Example 4 The input power during the formation of the underlayer was set to 18 W / cm ² , the deposition rate of the underlayer was set to 7.2 nm / sec, and the input power during the formation of the magnetic layer was set to 18 W / cm. ² , and the deposition rate is 7.6.
A floppy disk was produced in the same manner as in Example 1 except that the floppy disk was changed to nm / sec.

Example 5 Cr: 70 at% and 30 at% Cu:
A floppy disk was manufactured in the same manner as in Example 1 except that the alloy was changed.

Example 6 The input power at the time of forming the underlayer was 18.0 w / cm ² ,
A floppy disk was produced in the same manner as in Example 5, except that the underlayer deposition rate was changed to 7.9 nm / sec.

Example 7 The input power at the time of forming the magnetic layer was 18.0 W / cm ² ,
A floppy disk was produced in the same manner as in Example 5, except that the magnetic layer deposition rate was changed to 7.6 nm / sec.

Example 8 The power applied during the formation of the underlayer and the magnetic layer was 18 W / cm
^A floppy disk was produced in the same manner as in Example 5, except that the underlayer deposition rate was changed to 7.9 nm / sec and the magnetic layer deposition rate was changed to 7.6 nm / sec.

Example 9 A 75 μm-thick polyethylene naphthalate support was coated on both sides with a 1.0 μm-thick silicone resin flat layer made of an organosiloxane using a sputtering apparatus (730H made by Anelva) on a flexible support. , Argon partial pressure 1
Under the conditions of 5.0 mTorr, input power of 16.0 W / cm ² and support temperature of 25 ° C., without applying a bias voltage, C
o: 66, Ni: 7, Cr: 9, Pt: 13, Si
A 40 nm-thick magnetic film having a composition of O ₂ : 5 (at%) was prepared. The distance between the substrate and the target was 45 cm. The deposition rate of the magnetic film was 5.2 nm / sec.

Example 10 The magnetic layer was made of Co: 72, Ni: 3, Cr: 10, Pt: 1.
3. A floppy disk was produced in the same manner as in Example 9 except that SiO2 was changed to ₂ : 2.

Comparative Example 1 Example 1 was repeated except that the input power was 4.5 W / cm ² , the underlayer deposition rate was changed to 0.20 nm / sec, and the magnetic layer deposition rate was changed to 0.15 nm / sec. A floppy disk was produced in the same manner as described above.

Comparative Example 2 A floppy disk was produced in the same manner as in Comparative Example 1 except that only the power applied to the underlayer was changed to 25.5 W / cm ² and the film formation rate of the underlayer was changed to 10.3 nm / sec. did.

Comparative Example 3 A floppy disk was produced in the same manner as in Comparative Example 1 except that only the input power of the magnetic layer was changed to 18.0 W / cm ² and the deposition rate of the underlayer was changed to 7.6 nm / sec. did.

Comparative Example 4 A floppy disk was produced in the same manner as in Example 2 except that the power supplied to the magnetic layer was changed to 18.0 W / cm ² and the magnetic layer deposition rate was changed to 7.6 nm / sec.

Comparative Example 5 A floppy disk was manufactured in the same manner as in Example 1 except that only the power supplied to the magnetic layer was changed to 26.0 W / cm ² and the film forming speed of the magnetic layer was changed to 11.2 nm / sec. did.

Comparative Example 6 A floppy disk was produced in the same manner as in Comparative Example 2 except that only the power supplied to the magnetic layer was changed to 26.0 W / cm ^2, and the deposition rate of the magnetic layer was changed to 11.2 nm / sec. did.

Comparative Example 7 Example 5 was the same as Example 5 except that the input power was 4.5 W / cm ² , the underlayer deposition rate was changed to 0.25 nm / sec, and the magnetic layer deposition rate was changed to 0.15 nm / sec. A floppy disk was produced in the same manner.

Comparative Example 8 A floppy disk was produced in the same manner as in Comparative Example 7, except that only the power applied to the underlayer was changed to 25.5 W / cm ^2, and the deposition rate of the underlayer was changed to 11.1 nm / sec. did.

Comparative Example 9 A floppy disk was prepared in the same manner as in Comparative Example 7 except that only the input power of the magnetic layer was changed to 18.0 W / cm ^2, and the deposition rate of the underlayer was changed to 7.6 nm / sec. did.

Comparative Example 10 A floppy disk was produced in the same manner as in Comparative Example 8 except that only the input power of the magnetic layer was changed to 26.0 W / cm ^2, and the deposition rate of the underlayer was changed to 11.2 nm / sec. did.

[0050] Comparative Example 11 and input power 25.5W / cm ² of the base layer, only the input power of the magnetic layer was 26.0W / cm ^2, an underlayer deposition rate 11.1 nm / sec, underlayer deposition Speed of 11.2 nm /
A floppy disk was produced in the same manner as in Comparative Example 7 except that the time was changed to seconds.

Comparative Example 12 A floppy disk was manufactured in the same manner as in Example 9 except that the input power was set to 5.1 W / cm ² and the magnetic layer deposition rate was changed to 0.1 nm / sec.

Comparative Example 13 A floppy disk was produced in the same manner as in Example 9 except that the input power was changed to 26.3 W / cm ² and the magnetic layer deposition rate was changed to 12.3 nm / sec.

The floppy disks of Examples and Comparative Examples obtained as described above were evaluated by the following measuring methods or evaluation methods, and the results are shown in Table 1. The method for measuring the film formation rate is also described below. (1) Film formation speed A resist is applied on polyethylene naphthalate. The corresponding nonmagnetic underlayer and magnetic layer are sputtered on the resist-coated support. The sputtered support is removed with a solvent for dissolving the resist, and the thickness of the sputtered film after the removal of the resist is measured with a contact-type film thickness measuring device (Delon manufactured by Sloan).
ktak IIA). The film formation rate is calculated from the time required for sputtering and the measured film thickness. (2) Thermal Conductivity of Sputtered Film A support having a sputtered film formed thereon is cut into a size of 2 mm × 5 mm, and a chip heater is fixed to one end of a sample piece with an epoxy resin. Thermocouples were installed at both ends of the sample, and the temperature was calculated from the input power, the time from the start of heating, the distance, and the amount of temperature rise. The sample was measured in an atmosphere at 20 ° C.

(3) Evaluation of surface properties The surface after sputtering was subjected to an atomic force microscope (AFM).
(Digital Instruments NanoScope)
-III). As for Ra on the surface of the magnetic layer, it is 0.
A rating of 8 or less was evaluated on the basis of good, and a rating of 0.8 or more was evaluated on the basis of poor. (4) Occurrence of Oligomer In a magnification of 80 times with a differential interference microscope, 10 visual fields were observed at random. If even one visual field generated oligomer, it was regarded as defective, and if no oligomer was generated, it was regarded as good.

(5) Deformation: curl amount and number of concave portions After punching out a magnetic recording medium into a 3.5-inch floppy disk shape, the center portion was horizontally fixed to a holding rod having the same diameter of 25 mm as the inner diameter of the floppy disk. Insert 27
The floppy disk is fixed in the vertical direction with a holding plate consisting of a disk of mm. The displacement for one round is measured. The difference between the most convex part and the most concave part of the floppy disk was defined as the curl amount. Excellent when the curl is less than 0.3 mm, good when 0.3 mm or more and less than 0.5 mm, 0.5 m
The case of more than only was evaluated as poor. The non-uniform deformation of the disk was evaluated based on the number of recesses having a height of 0.3 mm from the minimum height of the disk at the outer periphery of the disk. When the number of recesses was up to 2, it was good, and when it was more, it was bad. (6) Crystal orientation of underlayer / magnetic layer Biaxial X-ray diffractometer (RINT2500H, manufactured by Rigaku Corporation)
Was used to measure the crystal orientation. The measurement was the θ-2θ method,
Cu was used as the radiation source, the tube applied voltage was 50 kV, and the tube current was 300 mA. The crystal orientation defines the diffraction intensity ratio between the magnetic layer (110), which is an in-plane orientation component, and the (101) plane where the axis of easy magnetization grows obliquely to the film plane. I
When the (110) / I (101) intensity ratio was less than 1.0, it was evaluated as poor, when it was 1.0 or more and less than 3.0, it was evaluated as good, and when it was 3.0 or more, it was evaluated as excellent.

[0056]

[Table 1] Deposition rate (nm / sec) Deformation Thermal conductivity Number Number of recesses Crystal orientation Orico-domer underlayer Magnetic layer Cal / cm • S • deg (mm) (pcs) I (110) / I (101) Example 1 0.8 0.5 0.16 0.15 0 3.1 Good Good Excellent Excellent Good Excellent Example 2 7.2 0.5 0.16 0.23 0 5.2 Good Good Excellent Good Excellent Excellent Example 3 0.8 7.6 0.16 0.20 0 6.2 Good Good Excellent Excellent Good Excellent Example 4 7.2 7.6 0.16 0.22 0 6.8 Good Good Excellent Good Excellent Excellent Example 5 1 0.0 0.5 0.29 0.32 1 3.3 Good Bad Good Good Good Excellent Example 6 7.9 0.5 0.29 0.39 1 5.2 Good Bad Good Good Excellent Excellent Example 7 1.0 7.6 0.29 0.41 1 4.3 Good Bad Good Good Good Excellent Example 8 7.9 7.6 0.29 0.49 16 2 good bad good good excellent Example 9 - 5.2 0.2 0.26 1 2.3 good Good Good Good Good Example 10 - 5.1 0.26 0.33 1 2.1 good Good Good Good Good Comparative Example 1 0.2 0.15 0.16 0.03 0 0.1 Good Good Excellent Excellent Good Bad Comparative Example 2 10.3 0.15 0.16 0.91 3 0.9 Bad Good Bad Bad Bad Comparative Example 3 0.2 7.6 0.16 0.23 10.8 Good Good Excellent Excellent Good Bad Comparative Example 4 10.3 7.6 0.16 1.21 3 5.6 Bad Good Bad Bad Excellent Comparative Example 5 0.2 11.2 0.16 1.21 3 1.1 Bad Good Bad Bad Good Comparative Example 6 10.3 11.2 0.16 2.62 3 6.8 Bad Good Bad Bad Excellent Comparative Example 70 .25 0.15 0.29 0.12 0 0.6 good Bad Excellent Good Bad Comparative Example 8 11.1 0.15 0.29 1.01 20.5 Bad Bad Bad Bad Bad Comparative Example 9 0.25 7.6 0.29 0.32 21.1 Good Bad Good Bad Good Comparative Example 10 11.1 7.6 0.29 1.03 3 6.3 Bad Bad Bad Bad Excellent Comparative Example 11 0.25 11.2 0.29 1.09 3 1.3 Bad Bad Bad Bad Good Comparative Example 12 11.1 11.2 0.29 3.01 3 6.9 Defective Defective Defective Defective Comparative Example 13 --- 0.1 0.2 0.030 0.9 Good Defective Excellent Excellent Defective Comparative Example 14 11.1 12.3 0.2 0.36 3 1.3 Bad Bad Bad Bad Good

[0057]

According to the present invention, the amount of deformation is reduced and the crystal orientation of the magnetic layer is reduced by setting the film formation rate during vacuum film formation and the thermal conductivity of the film formed on the support to predetermined values. A magnetic recording medium excellent in the above can be obtained.

Claims (4)

[Claims] In a floppy disk having at least a magnetic layer, a protective layer, and a lubricant layer on both sides of a flexible support substrate, forming a layer formed on the flexible support by a vacuum film forming method A method for manufacturing a floppy disk, wherein the speed is 0.3 nm / sec or more and less than 9.5 nm / sec. 2. The method of manufacturing a floppy disk according to claim 1, wherein at least one nonmagnetic layer having an amorphous or microcrystalline structure is formed between the flexible support and the magnetic layer by a vacuum film forming method. . 3. A metal thin film layer having a thermal conductivity of less than 0.25 cal / cm.s.deg. In a 20.degree. C. environment is formed directly above a flexible support. The method for producing a floppy disk according to claim 1. 4. A floppy disk produced by the manufacturing method according to claim 1.