JPH0991694A - Production of magnetic recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a magnetic recording medium having good surface property and stable quality by stabilizing the travelling state of a web in a calendering process in which the web is held and pressed between metal rolls and adding a uniform treatment effect to the web. SOLUTION: A web is subjected to calendering by a heat-generating metal roll 1 and a metal roll 2 having a jacket which seals a heat medium inside. By this method, the temp. distribution in the width direction of the roll 2 is made uniform by the latent heat of the heat medium in the jacket, which stabilizes the travelling state of the web. Thus, the obtd. magnetic recording medium has no variation in the quality due to wrinkles or inhomogeneous heat, but the obtd. medium has good surface property and stable quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic recording medium, and more particularly, to a nipping and pressing process (calendering) while running a non-magnetic flexible support having a magnetic layer coated thereon. , A method for manufacturing a magnetic recording medium for smoothing the surface of the magnetic layer.

[0002]

2. Description of the Related Art Conventionally, as a magnetic recording medium such as a magnetic tape, a magnetic disk, etc. for audio, video and computer data, generally, on a non-magnetic flexible support,
A coated magnetic recording medium has been used in which a magnetic coating material containing a magnetic powder, a binder, an abrasive, a dispersant, a lubricant and a conductive agent is applied to form a magnetic layer.

As a method of manufacturing such a coating type magnetic recording medium, for example, while a long strip-shaped non-magnetic flexible support is run, a magnetic coating is applied on the support to form a magnetic layer. After that, it is subjected to orientation treatment, drying treatment, calendering, etc., and once wound into a roll shape, it is cut into a suitable width and length into a tape shape, or a disk is punched or the like. There is a method of packaging these into a product.

The calendering in the method of manufacturing such a magnetic recording medium is mainly aimed at increasing the density of the magnetic layer and improving the surface quality, and conventionally has a heat generating mechanism inside.
Using a metal roll whose surface temperature can be adjusted (exothermic metal roll) and a roll having at least a surface made of resin, that is, an elastic roll having only a surface layer of the roll or an entire roll made of resin, a magnetic layer on a support. By sandwiching a magnetic recording medium raw material coated with (hereinafter, may be simply referred to as "raw material") and applying pressure and heat, the density of the magnetic layer is increased or the surface property of the magnetic layer surface is improved. The performance of the magnetic recording medium is improved by improving the magnetic recording medium.

In the conventional calendering using a heat-generating metal roll and an elastic roll, the elastic roll itself is deformed when pressed, and the dimensional error of the roll due to the uneven heat distribution in the width direction on the roll surface is absorbed. . However, since the elastic roll is deformed, the contact area between the roll and the roll becomes large at the time of sandwiching the roll. Therefore, the pressure applied to the roll cannot be large. Further, since the surface property of the elastic roll is insufficient, it is difficult to satisfy the surface smoothness of the obtained magnetic recording medium, and the surface smoothing of the magnetic layer is insufficient due to the deformation of the elastic roll. However, the effect of smoothing the surface of the magnetic layer of the large-capacity magnetic recording tape was not sufficient.

Therefore, recently, in order to further increase the density of the magnetic layer and also improve the surface property of the magnetic layer, a metal roll having an elastic modulus much larger than that of the elastic roll is used instead of the elastic roll. It is used to perform calendering by sandwiching and pressing a raw material between metal rolls. The surface of this metal roll is mirror-finished, and its elastic modulus is much higher than that of an elastic roll, so there is less deformation when pressed and a higher pressure can be applied to the magnetic recording medium. Processing can be performed.

[0007]

However, in the calendering in which the material roll is sandwiched and pressed between the metal rolls, the dimensional error of the roll is absorbed by the deviation of the heat distribution in the roll width direction due to the deformation of the metal roll itself at the time of pressing. Because it ’s not enough,
Even if the cylindricity of the heat-generating metal roll is sufficiently increased, a difference in calendering effect occurs in the width direction of the metal roll,
It was not possible to consistently produce products of consistent quality. In particular, when the dimensional difference in the width direction due to the heat distribution is significant, the running of the raw fabric is not stable, and wrinkles may occur.

The present invention solves the above-mentioned problems of the prior art, stabilizes the running of the material in calendering in which the material is sandwiched and pressed between metal rolls, and has a uniform processing effect to provide good surface properties and high quality. An object of the present invention is to provide a method for manufacturing a stable magnetic recording medium.

[0009]

A method of manufacturing a magnetic recording medium according to the present invention comprises a non-magnetic flexible support provided with a magnetic layer,
In a method for manufacturing a magnetic recording medium by sandwiching and pressing between a first metal roll and a second metal roll, a heat-generating metal roll having a heat generating mechanism is used as the first metal roll, and a second metal roll is used. As the above, a metal roll having a jacket in which a heat medium is enclosed is used.

That is, the inventors of the present invention have made earnest studies on the calendering in the manufacturing method of the magnetic recording medium. As a result, when the calendering is performed between the metal rolls, the heat medium is placed inside the metal roll paired with the heat-generating metal roll. By using a metal roll provided with a jacket encapsulating, the temperature distribution in the width direction of the roll becomes uniform due to the latent heat of the heat medium in the jacket, the running of the material becomes stable, and the obtained magnetic recording medium is The present invention has been completed by finding that there is no difference in quality due to wrinkles and heat unevenness, the surface properties are good, and the quality is stable.

In the present invention, in particular, a first metal roll having a heat generating mechanism by an induction coil inside and a jacket containing a heat medium provided between the roll surface and the heat generating mechanism is used. It is preferable that such a metal roll can further improve the instability during production.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings.

In the present invention, a calendering apparatus as shown in FIG. 1, for example, is used for the calendering process of a magnetic recording medium having a magnetic layer coated on a non-magnetic flexible support, that is, a raw material. To be In FIG. 1, 1 (1A, 1B) is a metal roll having a heat generating mechanism inside (hereinafter, referred to as "heat-generating metal roll") as a first metal roll, and 2 (2.
A, 2B) is a metal roll having a jacket in which a heat medium is enclosed (hereinafter, referred to as a second metal roll).
It is called "adjustment metal roll". ) 3 is an original fabric, 4 is a supply side roll, 5 is a winding side roll, 6 is a pressure piston, 7 is a guide roll, and 8 is a mount.

In the apparatus shown in FIG. 1, heat-generating metal rolls 1 and adjusting metal rolls 2 are installed alternately and a raw fabric is passed between the metal rolls 1 and 2 to perform a plurality of times (two times in FIG. 1). The raw material 3 that is to be rendered and sent from the supply-side roll 4 is first sandwiched and pressed between the adjusting metal roll 2A and the heat-generating metal roll 1A, and then the adjusting metal roll 2B and the heat-generating metal roll 2A. It is calendered by being nipped and pressed between the roll 1B and 1B, and is wound around the winding-side roll 5. The heat-generating metal roll 1 is arranged so as to contact the original magnetic layer side, and the adjusting metal roll 2 is arranged so as to contact the original non-magnetic flexible support side.

FIG. 2 is an enlarged sectional view showing an embodiment of the adjusting metal roll used in the present invention. In FIG.
Reference numeral 11 is a jacket, 12 is an iron core, and 13 is a rotating shaft.

In the present embodiment, the jacket 11 provided inside the adjusting metal roll 2 is a plurality of independent tubular members extending in the axial direction of the adjusting metal roll 2, and the tubular jacket 11 is an adjusting member. The metal rolls 2 are arranged concentrically with each other at equal intervals. The space inside the tubular jacket 11 is filled with the heat medium 14 in an amount smaller than the volume of the space, preferably 50 to 95% by volume of the volume of the space in the jacket. Even if the amount of the heat medium enclosed is more than 95% by volume or less than 50% by volume, the temperature distribution cannot be sufficiently homogenized by evaporation and condensation of the heat medium described later.
Thus, if the tubular jacket 11 is arranged, the stability of the temperature distribution can be further improved.

The installation position of the jacket 11 inside the adjusting metal roll 2 depends on the material of the metal forming the adjusting metal roll 2 and the size of the adjusting metal roll 2, but is generally within 100 mm from the surface of the adjusting metal roll 2. It is preferable to provide in the range of. Note that carbon steel or the like is generally used as the metal constituting the main body portion 2A of the adjusting metal roll 2, and chromium or nickel is optionally added to the roll surface for adjusting the surface roughness of the roll surface. Etc. are plated.

As the heat medium 14 sealed in the jacket 11, any heat medium having a large latent heat may be used, and any heat medium can be used. Specific examples include water and alcohols.

Since the surface roughness of the adjusting metal roll 2 affects the surface property of the magnetic recording medium after the treatment, Ra0.002
The surface roughness is preferably .about.0.06 .mu.m, more preferably 0.005 to 0.03 .mu.m. On the other hand, the surface roughness of the heat-generating metal roll 1 is Ra 0.001 to 0.1 μm, particularly 0.00
2 to 0.06, and particularly preferably 0.005 to 0.03 μm. The surface temperature of the heat-generating metal roll 1 depends on the composition of the magnetic layer and the linear pressure of the calender, but is 70 to 1
50 ° C, especially 60-130 ° C, especially 80-110 ° C
It is preferred that

In the present invention, the heat-generating metal roll is also preferably provided with a jacket having the same structure as that of the adjusting metal roll between the internal heat-generating mechanism and the roll surface. Instability can be further reduced.

Although any heat generating mechanism can be used inside the heat generating metal roll, the heat generating mechanism using an induction coil is preferable because of uniform heat conduction.

The linear pressure in calendering is 50-40.
It is preferably 0 Kg / cm, and generally, the width of the long strip-shaped non-magnetic flexible support is designed to be narrower than that of any roll. Also, the running speed of the material is generally 1
It is set to about 200 m / s.

The raw fabric 3 exchanges heat with the heat-generating metal roll 1 when it is sandwiched and pressed between the heat-generating metal roll 1 and the adjusting metal roll 2 and passes therethrough. In this case, the heat-generating metal roll 1
Since it is on the high temperature side, a temperature drop occurs. At this time, the original 3
A temperature distribution can be created in the width direction. In addition, since the pair of rolls has a lower temperature than the original fabric, a partial temperature rise occurs,
Form a temperature distribution in the width direction. In the conventional calendering that uses a metal roll as a pair to form a heat-generating metal roll, the temperature distribution causes a bias in thermal expansion,
A difference in calendering pressure occurs in the width direction of the roll, and a difference in calendering effect occurs in the width direction. However, according to the present invention, the heating medium 14 enclosed in the jacket 11 inside the roll of the adjusting metal roll 2 evaporates at the high temperature portion inside the jacket 11 and condenses at the low temperature portion to make the temperature distribution uniform, The calendaring effect can be made uniform.

By the calendering using the adjusting metal roll 2 as described above, even in the manufacture of a high density magnetic recording medium in which the total thickness of the raw material 3 is extremely thin as 4 to 10 μm and high dimensional accuracy is required, A high-quality magnetic recording medium can be manufactured by suppressing deformation of the original fabric due to expansion or the like.

In the method for producing a magnetic recording medium of the present invention, the non-magnetic flexible support used for the magnetic recording medium includes polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene and polyethylene, and cellulose acetate. Cellulose derivatives such as, and various plastics such as polycarbonate, polyamide, and polyimide can be used. Among them, polyesters such as polyethylene terephthalate and polyethylene naphthalate are preferable because of their excellent mechanical properties, heat resistance, electrical properties, chemical resistance and the like. However, since these polyester films are highly crystallographically oriented, they have poor adhesion to the magnetic layer. Therefore, in order to improve the adhesion between these support and the magnetic layer or the conductive layer, the support may be treated with a surface modifier such as an alkali, an aqueous amine solution, trichloroacetic acid or a phenol.

The thickness of the non-magnetic flexible support is 3-100.
The thickness is preferably μm, and particularly preferably 3 to 10 μm for producing a high density magnetic recording medium.

The magnetic layer is usually formed by applying a magnetic coating material, in which magnetic powder is dispersed in a binder, to a support in the form of a liquid. If necessary, the magnetic paint may further contain a dispersant, a lubricant, an abrasive, a conductive agent and the like.

As the magnetic powder, any powder such as metal magnetic powder and oxide magnetic powder can be used. Specifically, examples of the metal powder include Fe, Ni, Co, Fe-Co, and Fe.
-Ni, Fe-Co-Ni, Fe-Ni-Zn, Fe-
Fe, Co, Ni such as Co-Ni-Cr and Co-Ni
Examples include ferromagnetic metal and ferromagnetic alloy powders. Examples of the magnetic oxide powder include γ-Fe ₂ O ₃ (γ-ferrite), C
Examples thereof include iron oxide magnetic powder such as o-containing γ-ferrite, Cr ₂ O, barium ferrite, and strontium ferrite. Among them, a metal magnetic powder having a major axis diameter of 0.01 to 0.5 μm, particularly 0.01 to 0.1 μm is preferable because the magnetic powder density in the magnetic layer is improved and the surface property is improved. It is preferable because a high density magnetic recording medium having an S / N ratio can be obtained. If the major axis diameter of the magnetic powder is less than 0.01 μm, sufficient magnetic properties will not be exhibited.

The content of the magnetic powder in the magnetic layer is 5
The amount is preferably 0 to 90% by weight, particularly 85 to 90% by weight. If this ratio is less than 50% by weight, a high coercive force cannot be obtained because the filling rate of the magnetic powder in the magnetic layer is low. On the other hand, if it exceeds 90% by weight, the dispersibility in the magnetic coating composition may be reduced and the mechanical strength of the magnetic layer may be reduced.

As the binder, one having excellent adhesion to the support and abrasion resistance is appropriately used. For example, polyurethane resins, polyester resins, cellulose acetate butyrate, cellulose diacetate, cellulose derivatives such as nitrocellulose, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinylidene chloride copolymers, vinyl chloride-acrylic copolymers. Examples thereof include vinyl chloride resins such as polymers, various synthetic rubbers such as styrene-butadiene copolymers, epoxy resins, phenoxy resins, etc., which may be used alone or in admixture of two or more kinds at any ratio. You can The content of the binder in the magnetic layer is 2 to 15% by weight,
It is particularly preferable to use it so as to be 5 to 13 wt%.

By using a low molecular weight polyisocyanate compound having a plurality of isocyanate groups together with such a binder, it is possible to form a three-dimensional network structure in the magnetic layer and improve its mechanical strength. In this case, examples of the low molecular weight polyisocyanate compound include trimethylolpropane adduct of tolylene diisocyanate. Such a low molecular weight polyisocyanate compound is preferably used in a proportion of 5 to 100% by weight with respect to the binder.

As the lubricant, various kinds of lubricants such as aliphatic type, fluorine type, silicone type and hydrocarbon type can be used. Examples of aliphatic lubricants include fatty acids, fatty acid metal salts, fatty acid esters, fatty acid amides, and aliphatic alcohols. Examples of the fatty acid include oleic acid, lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid. Examples of the fatty acid metal salt include magnesium salts, aluminum salts, sodium salts and calcium salts of these fatty acids.
Examples of the fatty acid ester include butyl ester, octyl ester and glyceride of the above fatty acids, and examples of the fatty acid amide include amides of the above acids, linoleic acid amide and caproic acid amide. Examples of the aliphatic alcohol include lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, oleyl alcohol and the like. Examples of the fluorine-based lubricant include perfluoroalkyl polyether and perfluoroalkyl carboxylic acid. Examples of the silicone lubricant include silicone oil and modified silicone oil. Also,
Solid lubricants such as molybdenum disulfide and tungsten disulfide and phosphoric acid esters can also be used. Examples of the hydrocarbon lubricant include paraffin, squalane, wax and the like.

The amount of these lubricants used is such that the content in the magnetic layer is usually 0.1 to 10% by weight, preferably 1 to 7% by weight. When two magnetic layers are laminated, the content of the lubricant may be different between the upper layer and the lower layer.

As the polishing agent, for example, α-alumina,
β-alumina, γ-alumina, α-iron oxide, silicon nitride, boron nitride, titanium oxide, silicon dioxide, tin oxide, zinc oxide, calcium carbonate, calcium sulfate, barium sulfate, molybdenum disulfide, tungsten oxide, silicon carbide, Chromium oxide and the like can be used alone or in combination of two or more. As a specific example, AKP-20, AKP-30, AKP-50, HIT manufactured by Sumitomo Chemical Co., Ltd.
-50, HIT-100, Toda Kogyo TF-100,
TF-120, TF-140, FT-10 made by Ishihara Sangyo Co., Ltd.
00, FT-2000, TTT-4D, S made by Titanium Industry
TT-30, STT-65C, Nippon Chemical Industry S-
1, G5, G7, and the like, and of these, those having a relatively high hardness, for example, those having a Mohs hardness of 5 or more are preferably used. The number average particle diameter of the abrasive is preferably 0.5 μm or less. The amount of the abrasive used is preferably in the range of 1 to 10% by weight in the magnetic layer.

As the antistatic agent, carbon black,
Conductive metals and their compounds and oxides, natural surfactants such as saponins, nonionic surfactants such as alkylene oxides and glycerin, higher alkylamines, quaternary ammonium salts, pyridinium salts and other multicyclic salts Cationic surfactants, anionic surfactants containing acidic groups such as carboxylic acid groups, sulfonic acid groups, phosphoric acid groups, sulfuric acid ester groups, phosphoric acid ester groups, amino acids, aminosulfonic acids, sulfuric acid or phosphoric acid esters of aminoalcohols And amphoteric surfactants and the like are used. These surfactants may be used alone or in a mixture.

Among these, acetylene black, black for color, furnace, and carbon black are particularly preferable.
Thermal or the like can be used, and specific examples thereof are BLACKPEARLS 2000, 100 manufactured by Cabot Corporation.
0, 900, 800, VULCAN XC-72, RAVEN 8800, 800 manufactured by Columbian Carbon Co., Ltd.
0, 7000, # 3750B, # 375 manufactured by Mitsubishi Chemical Corporation
0, # 3250B, # 3250, # 950, # 850
B, # 650B, # 45, # 40, # 5, MA-77,
MA-7 etc. are mentioned. These carbon blacks may be used alone or in combination of two or more. Further, the surface of carbon black may be treated with a dispersant or the like, or a part thereof may be graphitized for use.

As the conductive metal and its compound or oxide, tin oxide, indium tin oxide or the like can be used.

The amount of the antistatic agent used is usually preferably in the range of 0 to 10% by weight based on the content in the magnetic layer. These are used as antistatic agents, but they may also be used as, for example, lubricity improvers.

As the dispersant, there are used fatty acids having 12 to 18 carbon atoms such as capric acid, lauric acid, myristic acid, oleic acid, linoleic acid, and metal soaps containing these alkali or alkaline earth metal salts, lecithin and the like. To be done.
The amount of the dispersant used is 1 to 10% by weight based on the content in the magnetic layer.
It is preferred that

Examples of the solvent used for applying the magnetic paint include ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, alcohols such as methanol, ethanol, propanol and isopropyl alcohol, esters such as methyl acetate, ethyl acetate and butyl acetate. Examples thereof include ethers such as diethyl ether and tetrahydrofuran, aromatic hydrocarbons such as benzene, toluene and xylene, and aliphatic hydrocarbons such as hexane.

In the preparation of the magnetic coating material, as the method of kneading and dispersing the above-mentioned components and the order of addition of the respective components, a conventional method suitable for ordinary kneading and dispersion of the magnetic coating material is used.

As a method for applying the magnetic coating material to the non-magnetic flexible support, various methods such as air doctor coating, blade coating, reverse roll coating, gravure coating and the like which are usually applied are adopted. When a plurality of magnetic coating materials are applied, the lower layer coating solution and the upper layer coating solution may be applied simultaneously in a wet state, or each layer may be applied sequentially.

The dry thickness of the magnetic layer is 0.1 to 5.0.
μm, especially 0.3-2.0 μm, especially 0.3-1.
It is preferably 5 μm. If the thickness of the magnetic layer is too large, the resolution may decrease, which is not suitable as a high density magnetic recording medium. Further, if it is too thin, the durability and output tend to be reduced.

[0044]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

Example 1 A magnetic coating material having the following composition was applied to a support (thickness 7 μm) made of a polyester film having a width of 300 mm by a bar coater so that the film thickness after drying was 1.0 μm, and the magnetic coating was applied. Layers were formed to produce a magnetic recording medium stock. The content of the ferromagnetic metal powder in the formed magnetic layer was 8
0% by weight.

Magnetic coating composition (parts by weight) Ferromagnetic metal (Fe-Ni) powder (major axis diameter 0.08 μm) 100 Polyurethane resin (UR8200 manufactured by Toyobo Co., Ltd.) 8 Vinyl chloride resin (MR110 manufactured by Zeon Corporation) 6 Polyisocyanate (Coronate L Nippon Polyurethane Co., Ltd.) 4 Alumina (particle size 0.1 to 0.2 μm) 3 Butyl stearate 4 Methyl ethyl ketone 250 Cyclohexanone 250 The obtained raw fabric is calendered under the following conditions using the apparatus shown in FIG. I went.

Calendering conditions Exothermic metal roll: An exothermic metal roll having an exothermic mechanism by an induction coil. Surface temperature = 80 ° C. Surface roughness Ra = 0.01 μm Adjusting metal roll: A roll whose main body is made of carbon steel, and as shown in FIG. 2, a jacket having a void diameter of 10 mm and a roll radius of 50 mm from the roll surface. 20 rolls are provided at the same depth and at the same depth as the rolls, and the roll surface is chrome-plated. The jacket was filled with 90% by volume of water in the voids of the jacket as a heat medium. Surface roughness Ra = 0.01 μm Calendering linear pressure: 100 Kg / cm Original fabric running speed: 60 m / s Original fabric after calendering is 4 mm in the traveling direction.
Cut to width and 30mm from the edge of the original (the tip in the running direction)
Take the magnetic tape A from the position of
The magnetic tape B was taken from a position of 50 mm, and the performance of the magnetic tapes A and B was evaluated by the following measuring method. The results are shown in Table 1.

Measurement method Output and S / N ratio: Determined using a digital oscilloscope and a spectrum analyzer under the conditions of a head gap of 0.4 μm and a recording frequency of 50KFRP1. In addition,
For the output, the magnetic tape B of Example 1 was used as a standard sample, and the relative evaluation value was shown.

Surface property (Ra): Measured using a contact type surface roughness meter Taristep manufactured by Taylor Hobson.

Presence of wrinkles: The appearance was visually observed.

Example 2 Except that the temperature of the heat-generating metal roll surface was 100 ° C., the same procedure as in Example 1 was carried out, and the evaluation results are shown in Table 1.

Example 3 The same procedure as in Example 2 was carried out except that a heating metal roll having a jacket having the same structure as that of the adjusting metal roll was used between the heating mechanism and the roll surface. Shown in 1.

Comparative Example 1 The same procedure as in Example 1 was repeated except that an aromatic heat-resistant polyester resin roll (surface roughness: Ra = 0.02) was used in place of the adjusting metal roll, and the evaluation results were obtained. The results are shown in Table 1.

Comparative Example 2 The same procedure as in Example 1 was carried out except that a metal roll having no jacket was used instead of the adjusting metal roll, and the evaluation results are shown in Table 1.

[0055]

[Table 1]

As is clear from Table 1, according to the present invention, the surface property is excellent, the S / N ratio and the output are good as a result, and there is little variation between products depending on the position of the raw material. Is obtained. Therefore, the yield of products is improved, which is extremely advantageous industrially.

[0057]

As described in detail above, according to the method for manufacturing a magnetic recording medium of the present invention, calendering can be stably performed without causing heat unevenness and wrinkles, and at the same time, surface property,
It is possible to manufacture a magnetic recording medium having excellent electromagnetic conversion characteristics such as output and S / N ratio. The method of the present invention is particularly effective for manufacturing a high density magnetic recording medium having a thickness of 10 μm or less.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a calendar device suitable for carrying out the present invention.

FIG. 2 is a cross-sectional view showing an example of a metal roll used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exothermic metal roll 2 Adjusting metal roll 3 Original roll 4 Supply side roll 5 Winding side roll 6 Pressurizing piston 11 Jacket 12 Iron core 13 Rotating shaft 14 Heat medium

Claims (2)

[Claims] 1. A method for producing a magnetic recording medium by sandwiching and pressing a non-magnetic flexible support having a magnetic layer coated between a first metal roll and a second metal roll. The method for producing a magnetic recording medium is characterized in that a heat-generating metal roll having a heat-generating mechanism is used as the metal roll, and a metal roll having a jacket in which a heat medium is enclosed is used as the second metal roll. 2. The method according to claim 1, wherein the first heating roll has a heating mechanism by an induction coil, and a jacket enclosing a heating medium is provided between the roll surface and the heating mechanism. A method for manufacturing a characteristic magnetic recording medium.