JP2002183687A - Magnetic recording medium and method of manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable writing on an area of a magnetic layer in a magnetic recording medium. SOLUTION: The magnetic layer 13 is formed on a nonmagnetic support 12, and a writing layer 14, including natural collagen or silk yarn fine powder is formed on this magnetic layer 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic recording medium, for example, a membership card, an IC card, a credit card, a cash card, a bank cash dispenser card, a prebayed card such as an NTT telephone card and a JR orange card, a voice card, The present invention relates to a magnetic recording medium applied to a so-called magnetic card such as a ticket, a commuter pass, and others, and a method for manufacturing the same. More specifically, the present invention relates to a magnetic recording medium which can be written directly on a magnetic surface side with an aqueous ink or a pencil, and realizes costumes by easily attaching visible information, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a magnetic card as a magnetic recording medium has been widely used for the above-mentioned membership card, IC card, credit card, cash card, ticket, voice card, and the like. Such a magnetic recording medium has a magnetic layer that can be magnetically recorded on one or both sides of a nonmagnetic base material, and information is recorded on the magnetic layer by an analog signal or a digital signal.

FIG. 11 shows the structure of a magnetic card that has been widely used in the past. This magnetic card 1 has a magnetic layer 3 that can be magnetically recorded by analog or digital signals on a base material or a non-magnetic support 2 immediately, and further protects the magnetic layer 3 from a daily use environment. The protective layer 4 is formed on the magnetic layer 3 in order to secure the slidability with the head. Generally, polyethylene terephthalate (PET), vinyl chloride (P)
VC), high-quality paper, or the like. The magnetic powder used for the magnetic layer 3 includes γ-iron oxide (γ-Fe ₂ O ₃ ), cobalt-coated γ-iron oxide (Co-γFe ₂ O ₃ ), and barium ferrite (BaO · 6Fe ₂ O ₃ ). Etc. In particular,
Barium ferrite has recently been widely used because it has a large coercive force Hc and is hardly affected by an external magnetic field. As a material of the protective layer 4, a medium of a fibrous resin such as nitrocellulose or a thermoplastic resin such as polycarbonate is used. In order to improve abrasion resistance, scratch resistance and lubricity, α-Al ₂ O ₃ , Si
C or other polytetrafluoroethylene (PTF
It is widely known to disperse fine resin beads such as E).

The protective layer 4 usually does not contain an additive having a writable property (water absorption), and a signature or a title can be written directly on the protective layer 4 using a pencil or a water-based ink. It was impossible to do. Therefore, conventionally, when writing is required, as shown in the magnetic card 6 of FIGS. 12A and 12B, a sticker 5 having writing properties is attached on the protective layer 4 in a region away from the magnetic layer 3 to write. A configuration in which a possible region is provided locally is employed.

[0005] Further, in a magnetic card for a bank which is generally widely used, a PET sheet is stuck on the magnetic layer to protect the magnetic layer from scratches and dirt, thereby enabling normal information reproduction. In the case of a magnetic card in which the name needs to be described, a configuration in which a writable area is formed in a separate step as in FIGS. 12A and 12B has been adopted.

[0006]

When a writable area is formed on a magnetic card, for example, when a writable seal 5 is pasted on the protective layer 4 including the area having the magnetic layer 3, the magnetic layer 3 The distance to the magnetic head increases,
There is a possibility that a spacing loss occurs and a problem occurs in recording and reproduction of the magnetic signal. For this reason, in the case of the conventional magnetic card, as shown in FIGS. 12A and 12B, the magnetic layer 3 is formed in a partial area of the magnetic card 6, and the writable seal 5 is formed in the area where the magnetic layer 3 is not provided. Most of the configurations were provided.

The structure shown in FIG. 12 is useful for a magnetic card such as a credit card and a cash card which does not require much recording capacity. However, recording audio,
In the case of a magnetic card to be played, the recording capacity is limited,
There is a problem that long-time recording and reproduction cannot be performed.

SUMMARY OF THE INVENTION In view of the above, the present invention provides a magnetic recording medium and a method of manufacturing the magnetic recording medium, in which the formation area of the magnetic layer is not limited and the area of the magnetic layer is writable (so-called garment can be added). To provide.

[0009]

The magnetic recording medium according to the present invention comprises a magnetic layer formed on a non-magnetic support, and a writing layer containing natural collagen or silk fine powder formed on the magnetic layer. Constitute. The method for producing a magnetic recording medium according to the present invention includes a step of forming a magnetic layer on a non-magnetic support, a coating method on the magnetic layer, or a thermal transfer method, and a writing layer containing natural collagen or fine silk powder. Forming step.
The method for producing a magnetic recording medium according to the present invention includes a step of forming a laminated body integrally having a writing layer containing natural collagen or fine silk powder on the surface side of a magnetic layer by a thermal transfer method on a nonmagnetic support. Have.

In the magnetic recording medium of the present invention, a writing layer containing natural collagen or fine silk powder is formed on the magnetic layer, so that the writing layer also functions as a protective layer, and the water absorption of aqueous ink and the like is improved. Good writing characteristics can be obtained even as a thin layer. At the same time, the spacing loss is reduced, and the recording and reproduction of the information signal can be performed well. Since the writing layer is formed on the magnetic layer, it is possible to write on the area of the magnetic layer,
It is possible to eliminate restrictions on the area of the magnetic layer and the writable area. In the method for producing a magnetic recording medium according to the present invention, a writing layer containing natural collagen or fine silk powder is formed on the magnetic layer, so that a writing layer excellent in water absorption of aqueous ink or the like can be formed. Since the writing layer also serves as the protective layer, the formation of the protective layer is omitted. Since the writing layer is formed by a coating method or a thermal transfer method, the writing layer can be formed to have a uniform thickness and can be formed at low cost. In the method for producing a magnetic recording medium of the present invention, a laminate having a writing layer containing natural collagen or silk fine powder integrally formed on the surface side of a magnetic layer by a thermal transfer method is formed on a non-magnetic support. It becomes possible to form a writing layer excellent in water absorption of ink and the like, and the formation of a protective layer is also omitted. Since no adhesive or the like is interposed between the magnetic layer and the writing layer, the spacing loss during information recording is further reduced. The writing layer can be formed with a uniform thickness and can be formed at low cost.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a magnetic recording medium having a writing layer according to the present invention will be described with reference to the drawings.

The magnetic recording medium 11 according to the present embodiment
As shown in FIG. 1, a magnetic layer 13 for enabling magnetic recording is formed on a base material 12 made of a non-magnetic material, and writing is performed on the surface of the magnetic layer 13 also as a protective layer to enable writing. A layer, that is, a writing layer 14 capable of absorbing and fixing water-based ink, carbon of a pencil, printing ink, and the like is formed. The writing layer 14 is formed with a composition containing natural collagen or silk fine powder.

Examples of usable magnetic powder in the magnetic layer 13 include γ-Fe ₂ O ₃ , Co-coated γ-Fe ₂ O ₃ ,
Co-coated γ-Fe ₃ O ₄ , Co-coated γ-FeO _x (4 /
3 <X <3/2), barium ferrite (BaO.6F)
e ₂ O ₃ ), metal magnetic powders such as Fe, Co, N
i, Fe-Co, Fe-Ni, Fe-Co-Ni, Fe
-Mn-Zn, Fe-Co-Ni-Cr, Fe-Ni-Zn, Fe-Co-Ni-P, Fe-Co-B, Fe-Co-Cr-B, Fe-Co-V, Co-Ni , Mn-Bi, Mn-Al, etc., ferromagnetic metal particles composed of various ferromagnetic metals or alloy materials containing Fe, Co, and Ni as main components are preferable. Further, in order to improve these various properties, Al, Si, Ti, Cr, Mn, Cu, Zn,
An element to which elements such as Mg and P are added may be used.

As the binder for the magnetic layer 13 and the writing layer 14, any known materials can be used, and examples thereof include polyurethane resins, polyester resins, polyester polyurethane resins, and vinyl chloride-based copolymers such as vinyl chloride-based copolymers. Resin, acrylate resin, phenoxy resin, polyamide resin, cellulose derivative, phenol resin, epoxy resin, urea resin, melamine resin, alkyd resin,
Examples include polyvinyl acetal resin, silicone resin, various synthetic rubber resins, and mixtures thereof.

Further, the binder is used for improving the dispersion of the magnetic powder and the pigment in the magnetic paint and the writing paint.
It may have a suitable polar group introduced. Known polar groups can be used. These magnetic layers 13
, An additive, an antistatic agent and the like may be added. As the dispersant, a conventionally known dispersant such as a silane coupling agent can be used.

As the antistatic agent, carbon black,
Conductive fine powder such as carbon black graft polymer,
Non-ionic surfactants such as alkylene oxide, glycerin and glycidol, higher alkylamines, quaternary ammonium salts, cationic surfactants such as phosphonium or sulfonium, and carboxyl for dispersing metal fine particles Surfactants containing an acidic group such as a sulfonate group, a sulfate group or a phosphate group, amphoteric surfactants such as amino acids, aminosulfonic acids, and sulfuric acid or phosphate esters of amino alcohols, and natural surfactants, etc. Known antistatic agents can be used.

As the organic solvent, those usually used in magnetic recording media, for example, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as methyl acetate, ethyl acetate and ethylene glycol diacetate, ethylene glycol dimethyl ether, Ethers such as ethylene glycol monoethyl ether, dioxane, and tetrahydrofuran; aromatic hydrocarbons such as benzene, toluene, and xylene; and halogen hydrocarbons such as methylene chloride, ethylene chloride, carbon tetrachloride, chloroform, and dichlorobenzene. Conventionally known ones can be used. This solvent may be used alone or as a mixture of two or more.

Further, a hardening agent may be added to the magnetic paint as needed. Known curing agents can be used.

Examples of the material of the nonmagnetic support 12 include known films and papers such as polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins, cellulose triacetate, polycarbonate, polyaramid, polyamide, polyimide, polyamideimide and polysulfone. Alternatively, composite paper in which a molten resin is laminated on both sides of paper, vinyl chloride, or the like can be used. In order to obtain a high elastic modulus, polyethylene naphthalate, polyaramid, polyamide, polyimide, and reinforced polyethylene terephthalate are particularly preferable. These supports may be subjected to corona treatment, plasma treatment, easy adhesion treatment, dust removal treatment, or the like in advance. Further, a metal, iron, SUS, aluminum, tin copper plate or the like can also be used.

The writing layer 14 is composed of a composition containing a pigment, for example, a white pigment, a protein powder or a cellulose powder, a binder, and if necessary, an additive.

[0021] The protein powder is obtained by pulverizing natural collagen fibers. This protein powder is contained for the purpose of improving the writability of the aqueous ink due to the hydrophilic layered structure of the protein powder. Cellulose powder is obtained by pulverizing silk thread and is contained for the same purpose. Pigments include calcium carbonate, talc, diatomaceous earth,
Inorganic fine powder such as titanium oxide and barium sulfate can be used. As the binder, the binder described above can be used. As an additive, for example, calcium carbonate, barium sulfate, an additive such as acrylic fine powder, or the like for adjusting the viscosity of a writing paint for appropriately roughening the surface of the writing layer in order to improve the writing performance with a writing instrument. For example, additives such as silica can be used. In addition, a dispersant or a lubricant that does not impair the writing properties may be administered as an additive. Moreover, you may add a hardening | curing agent as needed.

The thickness of the writing layer 14 is such that a practical signal output (relative output ratio to an input signal is 50% or more) when reading recorded information is obtained, and the drying property of the ink during writing is good. In order to achieve the above, 2 μm to 1
It is preferably 0 μm. The amount of the natural collagen or silk fine powder to be added is 10 wt% to 45 wt% when the binder is 100 wt% as described later, in view of the writing characteristics and the viscosity of the writing paint which affects the workability of forming the writing layer.
% Is preferable.

As a method for forming the writing layer 14 on the magnetic layer 13, a coating method such as coating with a coater or the like similar to the magnetic paint, screen printing or offset printing, or the like,
Alternatively, a thermal transfer method can be used.

In FIG. 1, for example, a writing layer capable of printing, writing, etc. is formed on the back surface of the non-magnetic support 2 opposite to the magnetic layer, or the magnetic layer is formed in the same manner as the front surface. And a writing layer can be formed thereon.

Next, FIG. 2 shows a magnetic recording medium according to another embodiment of the present invention, together with a manufacturing method thereof. In this example, the writing layer is formed by a coating method. First, as shown in FIG. 2A, for example, the above-mentioned polyethylene terephthalate (PET) used for a general magnetic card, paper, composite paper in which a molten resin is laminated on both sides of paper, or vinyl chloride is used. On one surface of the non-magnetic support 12, a magnetic paint obtained by adding a magnetic powder to a binder (binder) and other additives as needed over the entire surface is coated with a coater or the like in the same manner as in manufacturing a normal magnetic tape. To form the magnetic layer 13.

Next, as shown in FIG. 2B, a writing paint is applied on the magnetic layer 13 by, for example, a coater similar to the formation of the magnetic paint, or by offset printing or screen printing. To form Thereafter or in advance, the design 1 such as a pattern or a character is formed on the other surface of the non-magnetic support 12.
6 is printed to obtain the target magnetic recording medium 17 shown in FIG. 2C. As the above-mentioned writing paint, for example, those having the composition shown in Table 1 can be used.

[0027]

[Table 1] [Composition of writing paint] Binder (acrylic binder) 100 wt% White pigment (titanium oxide or barium sulfate) 30-55 wt% Protein powder 10-45 wt% Calcium carbonate 10 wt% or less Other additives (silica etc.) ) 15 wt% or less

As an alternative to protein powder (fine powder of natural collagen fibers), the same amount of cellulose powder (fine powder of silk thread) may be added.

When the writing of an aqueous ballpoint pen (a silver ink of a Pentel hybrid pen is used in the test) is taken into consideration, the fixing and drying properties and the wettability (repelling property) of the ink become problems. Then, in order to examine an appropriate content of the protein (or cellulose) powder, the surface tension, the drying property, and the wettability were measured. In addition, the coating thickness of the writing layer 14 is 5
μm. In addition, the drying property was measured by measuring the shortest time that a written portion remained without disappearing when wiped off with a nonwoven fabric after a lapse of a predetermined time after writing. Table 2 shows the results.

Here, in order to confirm the writing characteristics and the coating workability, the measurement was performed on a base material coated with a writing paint having the following composition and containing no white pigment. [Writing paint] Acrylic binder 100 wt% Protein (or cellulose) binder Content of Table 2 Calcium carbonate 5 wt% Additive (silica) 5 wt%

[0031]

[Table 2]

From the results shown in Table 2, it was confirmed that the writing characteristics were satisfied when the content of the protein (or cellulose) powder was 10% by weight or more. However, when the content of the protein (or cellulose) powder exceeds 45 wt%, the viscosity (see surface tension) of the writing paint increases,
For example, in screen printing, the silk screen plate is clogged, and the workability of applying the writing layer is greatly deteriorated.
From the above, the content of protein (or cellulose) powder as a writing paint is optimally 10 to 45 wt%.

On the other hand, calcium carbonate, which is a content of protein (or cellulose) powder, has an effect of making the writing implement more easily caught on the surface of the writing layer (that is, the writing implement does not slip and becomes easier to write). Further, other additives such as silica can improve the cut of the ink at the time of writing and can reduce stringing.

Since the writing layer 14 shields the magnetic layer 13, if the coating thickness of the writing layer is large, the distance from the magnetic layer 13 to the magnetic head becomes large, causing a spacing loss.
There is a possibility that the recording / reproducing characteristics of the magnetic signal are impaired. Therefore, it is desirable to apply the writing layer 14 as thinly as possible.
Therefore, the relationship between the coating thickness, the spacing loss, and the drying property of the aqueous ink was examined. In the measurement of the spacing loss, barium ferrite was used as the magnetic paint, and a sine wave input signal of 140 Hz was used, and the relative output ratio to the input was examined. The content of the protein (or cellulose) powder was 10 wt%, and the filler particles used were all 1 to 2 μm. The results are shown in Table 3.

[0035]

[Table 3]

According to the results shown in Table 3, when the coating thickness of the writing layer 14 exceeds 10 μm, the output is reduced by half with respect to the input. Therefore, the coating thickness of the writing layer 14 is preferably 10 μm or less. On the other hand, when the coating thickness of the writing layer 14 is less than 2 μm, the drying property of the aqueous ink deteriorates to 360 seconds or more. Therefore, the coating thickness of the writing layer 14 is optimally 2 to 10 μm.

FIG. 3 shows another embodiment in which the magnetic recording medium according to the present invention is applied to photographic paper. The magnetic recording medium of the present embodiment, so-called photographic paper 21, is provided on one surface of the non-magnetic support 12 made of, for example, the above-mentioned polyethylene terephthalate (PET), paper, laminated composite paper, or the like, like the magnetic card. Forming an emulsion layer 22 by coating;
On the other surface, a magnetic layer 13 and a writing layer 14 according to the present invention are sequentially formed. According to the photographic paper 21, a photograph can be printed on the emulsion layer 22 on one side and information can be recorded on the magnetic layer 13 on the other side, and the recording information can be easily written on the writing layer 14. Also becomes possible.

FIG. 4 shows another embodiment in which the magnetic recording medium according to the present invention is applied to a postcard. The magnetic recording medium of the present embodiment, so-called postcard 24, is formed by sequentially forming a magnetic layer 13 and a writing layer 14 according to the present invention on the back surface of a non-magnetic support 25 made of a material suitable for a postcard (not particularly limited). You. According to the postcard 24, additional information such as video and audio can be recorded in addition to the normal use of the postcard by writing.

FIG. 5 shows a magnetic recording medium according to still another embodiment of the present invention, together with its manufacturing method. In this example, the writing layer is formed by thermal transfer printing. First, the configuration of the thermal transfer printing apparatus in the thermal transfer printing method will be described with reference to FIG. The thermal transfer printing device 40 includes a magnetic recording medium,
A lower jig 41 for positioning and fixing a so-called magnetic card;
A pair of supply reel 42 and take-up reel 43, and a heat-sensitive thermal transfer film 47 disposed on a magnetic card supplied from supply reel 42 and placed on lower jig 41 and taken up by take-up reel 43 after thermal transfer A plurality of rollers 44, 45, 46 for supporting the thermal transfer film 47, a transfer roller 48 for pressing the thermal transfer film 47 onto the surface of the magnetic card while rotating, and a state separated from the transfer surface 48a of the transfer roller 48; And a heater 50 for heating the transfer surface 48a of the transfer roller 48 to a predetermined temperature by heat reflection by the reflection plate 49.

As shown in FIGS. 7 and 8, a release layer 53 is formed on the entire surface of a long base film 52 of the heat-sensitive thermal transfer film 48. For example, a so-called transcript 55, which is formed by sequentially laminating a writing layer 14 and an adhesive layer (two-layer structure) 54 having a size corresponding to a magnetic card by a coating method, is attached and arranged at predetermined intervals. You.

In the present embodiment, as shown in FIG. 5A, a magnetic powder such as γ is deposited on a non-magnetic support such as polyethylene terephthalate (PET), vinyl chloride, or high-quality paper, which serves as a base material of a magnetic card. -Fe ₂ O ₃ , C
o Coated γFe ₂ O ₃ , barium ferrite (BaO · 6
A magnetic card base 56 formed by forming the magnetic layer 13 using Fe ₂ O ₃ ) or the like is prepared.

Next, as shown in FIGS. 5B and 6, the magnetic card base 56 is positioned and fixed on the lower jig 41 of the thermal transfer printing apparatus 40 so that the magnetic layer 13 faces upward. The magnetic card base 56 is transported together with the tool 41 to a position directly below the transfer roller 48 by a transport unit (not shown).
In this state, the pair of supply reels 42 and take-up reels 43 are rotated to position the thermal transfer film 47 at an initial position (a position corresponding to the magnetic card base 56) in the thermal transfer process. Next, the transfer roller 48 whose transfer surface 48 a is heated to a predetermined temperature by the heater 50 is lowered, and while the thermal transfer film 48 is pressed onto the magnetic card base 56,
The magnetic card base 56 is rotated, for example, in the longitudinal direction.

When the transfer roller 48 is pressed, when the transfer roller 48 applies heat and pressure from the base film 52 side of the transfer film 47, the adhesive layer 54 is softened and adheres to the magnetic layer 13 of the magnetic card base 56. At the same time, the release layer 53 also softens. Thereafter, the transfer roller 48
Rises, only the writing layer 14 is fixed on the magnetic layer 13 of the magnetic card base 56 via the adhesive layer 54 as shown in FIG. 5C. As a result, the transfer 55 of the thermal transfer film 47 from the initial position to the end position is transferred to the magnetic card base 56.
Is transferred to the upper surface of the magnetic layer 13.

By repeating such a process, the writing layer 14 can be sequentially thermally transferred onto all the magnetic card substrates 56. On the other hand, the base film 52 is discarded after being taken up by the take-up reel 43 together with the release layer 53. In this way, a target magnetic recording medium shown in FIG. 5D, that is, a so-called magnetic card 58 is obtained.

FIG. 9 shows a magnetic recording medium according to still another embodiment of the present invention, together with its manufacturing method. In this example, the writing layer and the magnetic layer are formed by thermal transfer printing. In the present embodiment, as shown in FIG. 9, a heat-sensitive thermal transfer film 61 is formed on a long base film 52 via a release layer 53 with a writing layer 14 and a magnetic layer 13 having a size corresponding to a magnetic card.
A plurality of adhesive layers (two-layer structure) 54 are sequentially laminated by, for example, a coating method, that is, a plurality of so-called transferred products 62 are arranged at predetermined intervals and are arranged.

In the present embodiment, FIG.
As shown in the figure, a non-magnetic support 1 serving as a
2 is positioned and fixed on the lower jig 41 of the thermal transfer printing apparatus 40 described above, the thermal transfer film 61 is positioned on the non-magnetic support 12, and heated and pressed by the transfer roller 48, and the transferred material is transferred onto the non-magnetic support 12. 62 is transferred via the adhesive layer 54. After the transferred material 62 is transferred, the base film 52 is peeled off together with the peeling layer 53 as shown in FIG. 9B by raising the transfer roller 48, and the non-magnetic support 12 shown in FIG.
A target magnetic recording medium, a so-called magnetic card 63, on which the magnetic layer 13 and the writing layer 14 are sequentially formed, is obtained.

Here, the writing paint used as the writing layer 14 may be composed of, for example, an acrylic binder suitable for a gravure printing method and having the composition shown in Table 1 containing protein powder or cellulose powder. it can.

The magnetic card 5 thus created
For Examples 8 and 63, when the fixing drying property and the wettability of the ink when writing with an aqueous ballpoint pen or the like were measured (using the same measuring method as described above), the same evaluation as shown in Table 2 above was obtained. Was. The thickness of the transfer-printed writing layer 14 (FIG. 5)
In the example of FIG. 10, the thickness of the writing layer 14 including the adhesive layer 54, FIG.
In the example, the relative output ratio of the magnetic signal to the writing layer 14 (thickness of the flea) and the drying property of the aqueous ink were measured (using the same measuring method as described above), and the same evaluation as shown in Table 3 was obtained. Was done.

According to the above-described magnetic recording medium according to the present embodiment, a magnetic recording / reproducing device such as an aqueous ballpoint pen is used on the surface of the writing layer 14 also serving as a protective layer formed on the magnetic layer 13. The entry can be made freely without affecting the reproduction. Since the writing layer 14 can be provided on the entire surface of the magnetic recording medium and the magnetic layer 13,
A wide writable area can be provided without reducing the area of the magnetic layer 13. Since the recordable area and the writable area are not restricted, a sufficient recording capacity can be obtained, and at the same time, the usability of the user can be improved.

Thus, for example, both sides can be written,
A postcard that can record and play back audio, a photograph that can record and play back audio, and a photo that can be written on the back of an image, a business card that has magnetically recorded information and a memo on the back, and the side after writing a word A word card that can record the pronunciation of a word can be realized.

[0051]

According to the present invention, information can be recorded and reproduced by providing a writing layer also serving as a protective layer on the surface of a magnetic layer provided on a nonmagnetic support. Writing can also be performed on the region on the magnetic layer, and the writable region on the surface of the magnetic recording medium can be expanded. For example, the entire surface of the magnetic recording medium becomes a writable and recordable area,
A sufficient recording capacity can be obtained, and at the same time, the usability of the user can be improved.

By including natural collagen or fine silk powder in the writing layer, good writing characteristics can be imparted even if the writing layer is formed relatively thin. In addition, since a writing layer that also serves as a protective layer is formed directly on the magnetic layer, this type of writable magnetic recording medium is provided at a lower cost than a conventional configuration in which a writable sheet is attached in a separate process. it can.

When the content of the natural collagen or fine silk powder is 10 to 45 wt%, the writing characteristics can be satisfied and the workability of applying the writing layer can be improved. When the thickness of the writing layer is 2 to 10 μm, the spacing loss is reduced, and the magnetic recording / reproduction characteristics are not impaired.
In addition, the drying property of the aqueous ink can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a magnetic recording medium according to an embodiment of the present invention.

2A to 2C are manufacturing process diagrams showing a magnetic recording medium according to another embodiment of the present invention together with a manufacturing method thereof.

FIG. 3 is a configuration diagram showing a magnetic recording medium according to another embodiment of the present invention.

FIG. 4 is a configuration diagram showing a magnetic recording medium according to another embodiment of the present invention.

5A to 5D are manufacturing process diagrams showing a magnetic recording medium according to another embodiment of the present invention together with a manufacturing method thereof.

FIG. 6 is a configuration diagram showing a thermal transfer printing apparatus used in the present embodiment.

FIG. 7 is a plan view showing an example of a thermal transfer film used in the present embodiment.

8 is a cross-sectional view taken along line AA of FIG.

FIG. 9 is a cross-sectional view showing another example of the thermal transfer film used in the present embodiment.

10A to 10C are manufacturing process diagrams showing a magnetic recording medium according to another embodiment of the present invention together with a manufacturing method thereof.

FIG. 11 is a configuration diagram showing an example of a conventional magnetic card.

FIG. 12A is a plan view showing another example of a conventional magnetic card. B is a cross-sectional view taken along line BB of FIG. 12A.

[Explanation of symbols]

11, 17: magnetic recording medium, 12: non-magnetic support, 13: magnetic layer, 14: writing layer, 21 ...
Photo paper, 22: emulsion layer, 24: postcard, 40 ...
-Thermal transfer printing device, 47, 61 ... thermal transfer film,
56: magnetic card base, 58, 63: magnetic card, 62: laminated body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G11B 5/84 G06K 19/00 BF term (reference) 2C005 HB04 HB05 HB09 HB13 JA02 KA01 KA03 KA07 KA15 KA23 KA27 KA42 LA14 5B035 AA00 BA05 BB02 BC00 5D006 AA01 AA05 DA01 5D112 AA07 BC01 CC01 FA00

Claims (8)

[Claims] 1. A magnetic recording medium comprising: a magnetic layer formed on a nonmagnetic support; and a writing layer containing natural collagen or fine silk powder formed on the magnetic layer. 2. The magnetic recording medium according to claim 1, wherein the writing layer contains 10 to 45 wt% of natural collagen or silk fine powder. 3. The magnetic recording medium according to claim 1, wherein said writing layer has a thickness of 2 to 10 μm. 4. The magnetic recording medium according to claim 1, further comprising the writing layer formed on the magnetic layer by a coating method. 5. The magnetic recording medium according to claim 1, further comprising the writing layer formed on the magnetic layer by a thermal transfer method. 6. A magnetic apparatus comprising: a step of forming a magnetic layer on a nonmagnetic support; and a step of forming a writing layer containing natural collagen or fine silk powder on the magnetic layer by a coating method. Manufacturing method of recording medium. 7. A step of forming a magnetic layer on a nonmagnetic support, and a step of forming a writing layer containing natural collagen or silk fine powder on the magnetic layer by a thermal transfer method. A method for manufacturing a magnetic recording medium. 8. A magnetic method comprising the step of forming, on a non-magnetic support, a laminate integrally having a writing layer containing natural collagen or fine silk powder on the surface side of a magnetic layer by a thermal transfer method. Manufacturing method of recording medium.