JPH0373383A - Magnetic sheet - Google Patents

Abstract

PURPOSE:To furnish a magnetic sheet wherein visual confirmation of contents of magnetic recording and renewing of visual information are possible by a method wherein a thermosensitive recording layer is composed of resin matrix material and organic low molecular substance dispersed in said matrix material, and transparency varies reversibly following variation of temperature. CONSTITUTION:The title magnetic sheet is composed of a magnetic sheet component 3 in which a magnetic recording layer 2 is provided at least on side surface of a base material 1 and a thermosensitive recording layer 5 capable of recording and erazing reversely information which is provided on said magnetic recording layer 2 via a protective layer 4. The thermosensitive recording layer 5 is composed of a matrix material 6 and organic low molecular substance 7 dispersed therein, and transparence varies reversely following variation of temperature. Further, an overcoat 8 is provided on the thermosensitive recording layer. By using thus a composite type magnetic sheet capable of being visually read, information of the magnetic recording layer can be recorded on the thermosensitive recording layer by using a heating recording apparatus such as a thermal head or the like, and visual recognition comes capable being performed. Further, renewal of information in which record is erazed and is recorded again by using the same apparatus becomes possible.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a heat-sensitive recording layer that can reversibly record and erase information on the magnetic recording layer side of a magnetic sheet member or on the opposite side, ＠Regarding a composite magnetic sheet that can visually display information on a recording layer.

[Prior Art and Problems] Conventionally, various magnetic sorts have been used as prepaid cards and the like in the fields of communication and transportation. M! A method of coloring and printing thermosensitive coloring dyes etc. coated on a magnetic sheet using a heating recording device such as a thermal head, or a method of displaying the outline by punching holes at specific positions on a magnetic sheet. etc.

Among these methods, the method of displaying by coloring and printing with heat-sensitive coloring dyes, etc. is not reversible and only writes information by adding information, and the amount of information is limited by the area of the magnetic sheet. On the other hand, using the punch-hole method, it is difficult to display and read accurate information.

Conventionally, heat-sensitive recording materials that can record and erase information reversibly include polyester J, a heat-sensitive layer consisting of a resin such as polyamide and organic low-molecular substances such as higher alcohols and higher fatty acids dispersed therein. It has been proposed (Japanese Unexamined Patent Publication No. 55-154198). Forming and erasing images using such materials utilizes changes in the transparency of the heat-sensitive layer due to temperature, and images are obtained as transparent images on a white background or as white images on a colorless background. Such known examples have been proposed as recording paper that can be used repeatedly, but none have been used as a means for visually displaying magnetic information contained in a magnetic sheet.

An object of the present invention is to provide a magnetic sheet in which the contents of magnetic recording can be visually confirmed and the information can be visually updated.

[Means for Solving the Problems] That is, the present invention provides a magnetic sheet in which a protective film is provided on the magnetic recording layer side of a magnetic sheet, and a heat-sensitive recording layer on which information can be recorded and erased reversibly is formed. A magnetic sheet that is provided with a magnetic recording layer of a magnetic sheet and has a heat-sensitive recording layer on the opposite side of the magnetic sheet, which is capable of reversibly recording and erasing information, the heat-sensitive recording layer The present invention provides a magnetic sheet comprising a resin matrix material and an organic low-molecular substance dispersed in the matrix material, and whose transparency changes reversibly as the degree of a degree changes.

FIG. 1 is a schematic cross-sectional view showing a specific example of a magnetic sheet of the present invention in which a heat-sensitive recording layer is provided on the magnetic recording layer side of a magnetic sheet member. In FIG. 1, the magnetic sheet of the present invention has a magnetic recording layer (2) on at least one side of a base material (1) f,
- a magnetic sorting member (3) and reversible information recording provided on the magnetic recording layer (2) via a protective layer (4);
It consists of an erasable heat-sensitive recording layer (5). The heat-sensitive recording layer (5) is composed of a matrix material (6) and an organic low-molecular substance (7) dispersed therein, and an overcoat (8) is provided on the heat-sensitive i2 recording layer. ing.

FIG. 2 is a schematic cross-sectional view showing another example of the present invention, in which a heat-sensitive recording layer is provided on the opposite side of the magnetic recording layer. In this example, the heat-sensitive recording layer (5) is formed on the support (9), and the magnetic recording layer (
Coloring 1 (10) and adhesive layer (1) are opposite to 2-).
1).

By forming a heat-sensitive recording layer that can reversibly record and erase information on either side of the magnetic sort and using a composite magnetic sheet that is readable to the naked eye, information on the magnetic recording layer can be read by a thermal head, etc. It is possible to record on the heat-sensitive recording layer using a heating recording device, and visual recognition becomes possible. Furthermore, it becomes possible to erase and rewrite records and update information using the same device. Furthermore, with the magnetic sheet of the present invention, the amount of information is not limited by the area of the magnetic sheet, as is the case with writing methods using heat-sensitive coloring dyes or the like.

Visual recording using a heat-sensitive recording layer utilizes changes in transparency depending on the temperature of the heat-sensitive body. That is, the heat-sensitive recording layer used in the present invention is in a cloudy, opaque state at room temperature below a predetermined temperature. When heated to a certain temperature range, it becomes transparent and remains transparent even when returned to room temperature. but,
When the temperature is further increased from the above-described certain temperature range, it becomes translucent, and when the temperature is lowered, it returns to its initial cloudy and opaque state. Therefore, images can be formed and recorded by partially changing the heating and cooling history of the heat-sensitive recording layer.

The magnetic sheet member used in the present invention is a conventionally known magnetic sheet in which a magnetic recording layer made of a matrix material containing a magnetic material is coated on a base material such as plastic, glass, paper, cloth, or metal. It's okay to be rejected.

On the other hand, the matrix material of the heat-sensitive recording layer has good transparency;
In addition, a polymer that is mechanically stable and easy to form into a film is preferred. As such matrix/lux materials,
Polyvinyl chloride: Vinyl chloride-based copolymers such as vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, vinyl chloride-acrylate copolymer, etc. Polymers; vinylidene chloride copolymers such as vinylidene chloride-vinyl chloride copolymers and vinylidene chloride-acrylonitrile copolymers; polyesters; acrylonitrile/chlorinated polyethylene resins; benzenedithiol-divinylbenzene copolymers, etc. . These matrix resins can be used alone or in combination of two or more.

The organic low-molecular substance used is one whose refractive index changes as the state changes due to heating, and at the same time maintains this state through interaction with the matrix member. There is a favorable combination between the matrix material and the organic low-molecular substance,
The material is selected so that it has a temperature range where the refractive index of the matrix material and the refractive index of the organic low-molecular substance are equal and a different temperature range.

The organic low-molecular substances to be blended into the matrix material include alkanols; alkanediols; halogen alkanols or halogen alkanediols; alkylamines; alkanes; alkenes; alkynes; halogen alkanes: halogen alkenes; halogen alkynes: cycloalkanes and cycloalkenes; Cycloalkynes; saturated or unsaturated halogenated fatty acids or their esters, amides,
or ammonium salts; arylcarboxylic acids or esters, amides, or ammonium salts thereof; halogenated arylcarboxylic acids or esters, amides, or ammonium salts thereof; thioalcohols; thiocarboxylic acids or esters, amides, or ammonium salts thereof;
Examples include organic low-molecular substances such as carbon salt esters of thioalcohols and mixtures thereof. These compounds preferably have 10 to 60 carbon atoms, preferably 10 to 38 carbon atoms, and particularly preferably 10 to 30 carbon atoms. The alcohol-derived moiety in the ester is saturated or unsaturated and may be further substituted with halogen. The halogen atom is chlorine or bromine, with chlorine being particularly preferred. Preferably, the halogen compound has i to 20 halogen substituents.

The aryl group is preferably phenyl or substituted phenyl.

More specific examples of the organic low molecular weight substances include saturated or unsaturated fatty acids having 10 to 30 carbon atoms, such as palmitic acid, arachidic acid, behenic acid, oleic acid, linoleic acid, lylunic acid, or the like; Mention may be made of one or more compounds selected from esters, amides and ammonium salts.

In addition, in this specification, an organic low molecular substance is 100 to 700
, preferably an organic compound having a molecular weight of 300 to 500.

In addition, from the viewpoint of printability, the combination of matrix material and organic low-molecular substance is preferable to polyvinyl chloride, vinyl chloride copolymer, vinylidene chloride copolymer rather than chlorinated polyethylene or benzenedithiol-divinylbenzene polymer. A system in which a higher fatty acid-based organic low-molecular substance is dispersed in polyester, polyester, or acrylonitrile is preferable.

The mixing ratio of the matrix material and the organic low-molecular substance is preferably 3 to 16 parts by weight per 1 part by weight of the organic low-molecular substance. If the size of the matrix material is less than 3, it is difficult to form a film in which the organic low molecular weight substance is properly retained in the matrix material. On the other hand, if the matrix material exceeds 16 parts by weight, the amount of organic low-molecular substances that become cloudy due to substitution is small, making it impossible to read recorded information clearly, making it undesirable as a recording material. It is preferable that the organic low-molecular substance is uniformly dispersed and sufficiently fixed in the matrix material, and may be partially compatible with the matrix material.

Furthermore, in order to impart appropriate physical properties to the heat-sensitive recording layer and improve processability, plasticizers, lubricants, stabilizers, additives, etc. may be added as necessary.

In the heat-sensitive recording layer thus formed, the organic low-molecular substance exists in a dispersed state as fine particles in the matrix material.

In order to mold the heat-sensitive recording layer on the magnetic sheet member, a known molding method such as various coating methods may be used for the polymer used as the matrix material. Further, each layer such as a magnetic recording layer, a protective layer, a heat-sensitive recording layer, and an overcoat layer may be provided directly or indirectly to each other.

When a heat-sensitive recording layer is provided on the magnetic recording layer side of the magnetic sheet member, a protective film is provided between the magnetic recording layer and the heat-sensitive recording layer. If there is no protective film between the two layers, the magnetic recording layer and the heat-sensitive recording layer coexist, resulting in a decrease in magnetic recording properties and a decrease in printability of the heat-sensitive recording layer, which is not preferable.

Various overcoats made of organic or inorganic substances may be used as such a protective film, but from the viewpoint of stability for thermal recording devices, 5iOz, SiO, MgO, ZnO
A protective film made of an inorganic material such as 1T t Ot, Altos, TatOs, etc. is preferred. Such a protective film made of an inorganic substance is formed as a thin film by a sputtering method, a vacuum thermal deposition method, or the like. If the film is too thick, it becomes impossible to write or erase information on the magnetic recording layer using a magnetic head, so the thickness of the protective layer is preferably 0.1 to 5 μm, preferably 0.2 to 2 μm.

In this case, the combined thickness of the protective film and the heat-sensitive recording layer formed on the upper surface of the magnetic recording layer is 3 to 15 μm, preferably 5 μm.
~10 μm. If the thickness is 15 μm or more, it becomes impossible to write or erase information on the magnetic recording layer using a magnetic head, and if the thickness is 3 μm or less, the printing properties on the heat-sensitive recording layer will deteriorate.

When an overcoat layer is provided on the heat-sensitive recording layer to protect the heat-sensitive recording layer from the heating device during recording,
This is preferred because the durability of the heat-sensitive recording layer in printing and decoloring recycling is improved. The overcoat layer may be made of organic materials such as silicone, acrylic, or SiO2.
, SinSMgO.

ZnO1Tilt, A1. Examples include inorganic substances such as O3 and Ta5ks.

On the other hand, when a heat-sensitive recording layer is provided on the side opposite to the magnetic recording layer of the magnetic sheet, the heat-sensitive recording layer having a thickness of 3 to 30 μm is provided on a support, and the support is attached to the base material of the magnetic sheet. Like the base material, the support may be plastic, glass, paper, cloth, metal, etc., but it is preferably one that clearly shows the change in cloudiness of the heat-sensitive recording layer, and is usually transparent plastic or colored paper. is preferred. Furthermore, when a plastic is used for the support, it is preferable to use a plastic that has good thermal weldability and adhesion to the matrix material, and a preferable plastic is selected depending on the type of matrix material used.

A known molding method can be used to mold the film-like heat-sensitive recording layer on the magnetic sheet support.

In order to attach the support on which the heat-sensitive recording layer is formed onto the magnetic sheet member, lamination can be performed using a known adhesive such as a common acrylic resin adhesive. For lamination, an adhesive layer is previously formed on at least one of the support on which the heat-sensitive recording layer is formed or the magnetic sheet member.

In the present invention, a colored layer or colored sheet known as a colored pigment or dye may be provided on the opposite side of the magnetic recording layer. This colored layer or colored sheet increases the contrast between cloudy and transparent.

[Function] The matrix material of the heat-sensitive recording layer forms a film in which organic low-grade substances such as higher fatty acids are uniformly dispersed. A low-molecular-weight organic substance is included in the matrix material, and changes in its state are more clearly expressed.

EXAMPLES Next, the composite magnetic sheet of the present invention will be described in more detail with reference to Examples. Note that parts below mean parts by weight.

Example 1-1 0.5 μl of S was deposited on the magnetic recording layer of a magnetic sheet.
In, a protective film was provided. Then, a solution having the following composition was applied thereon.

Behenic acid 2 parts Vinyl chloride-vinyl acetate copolymer 6 parts Tetrahydrofuran
Apply 32 parts of the molten limb with a wire bar,
A heat-sensitive recording layer having a thickness of 8 μm was provided by heating and drying.

Then, a solution having the following composition was applied thereon with a wire coat and dried by heating to form a wire coat layer having a thickness of 1 μm.゛Silicone acrylate/1-decoating material (manufactured by Shin-Etsu Chemical Co., Ltd., X-12-2150A) 10 parts catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., X-12-2150B)
Part 1 Example I-2 A magnetic sheet was produced in the same manner as in Example I, except that the protective film on the magnetic recording layer was made of butyral resin with a thickness of 0.5 μm.

Comparative Example r-l A magnetic sheet was produced in the same manner as in Example (2) except that no protective film was provided on the magnetic recording layer.

Comparative Example r-2 A 0.5 μR 5iOz protective film was provided on the magnetic recording layer, and the same heat-sensitive layer (20 μm) as in Example 1 was provided thereon.

Example n-1 Group 戊 Part by weight Behenic acid
2 parts Vinyl chloride-vinyl acetate copolymer 6 parts (manufactured by Union Carbide, V
YHH) Tetrahydrofuran 32 parts The above solution was applied onto a polyester film (25 μR) using a wire bar, heated and dried to provide a thermosensitive recording layer having a thickness of 10 μm.

Next, UV ink (manufactured by Toka Shiki Kagaku Kogyo Co., Ltd., UV Bon 400 black ink) was coated on the opposite side of the magnetic recording layer (188 μl thick) and cured with a UV lamp to form a colored layer. . A 2μ thick acrylic adhesive layer was provided thereon and laminated with a heat-sensitive recording layer to create a composite magnetic sheet capable of reversibly recording and erasing information.

Example n-2 Example n except that a solution with the following composition was used for the heat-sensitive recording layer.
A magnetic sheet was created in the same manner as in -1.

Composition Parts by weight Behenic acid 2 parts Vinyl chloride-vinyl acetate copolymer 6 parts (Union Carbide Co., Ltd.,
v y HH) Acrylic oligomer
0 parts 5 parts (manufactured by Kyoeisha Yushi Kagaku Co., Ltd.), KD-1,4
0) Tetrahydrofuran 32 parts Comparative Example 11-1 The same solution as in Example n-1 was applied with a wire bar to the opposite side of the magnetic recording layer (188 μl thick), and dried to form a heat-sensitive recording layer (15 μl thick). .

The same procedure as Example n-1 was carried out except that the colored layer was not provided.

Comparative Example It-2 Example [I-1
A colored layer similar to that in Example 11-1 was provided, and the same coloring layer as in Example 11-1 was applied directly on top of the colored layer, followed by heating and drying to form a thermosensitive recording H (15
μ shoulder thickness) was established.

Table 1 Ta.

Image density: The white image area was measured using a Macbeth RD-920 densitometer (
(manufactured by Daikane Electric Co., Ltd.).

Adhesion: Based on a base tape peel test of the heat-sensitive recording layer.

[Effects of the invention] By forming a heat-sensitive recording layer on either side of the magnetic sheet that can reversibly record and erase information, and using a composite magnetic sheet that is legible to the naked eye, the magnetic recording layer can be easily read. Visual recognition becomes possible by recording information on a heat-sensitive recording layer using a heating recording device such as a thermal head. In addition, the magnetic card of the present invention can erase and re-record information using a heating device, and the amount of information can be reduced due to the area of the magnetic sheet, which is a problem with methods that only write with heat-sensitive coloring dye. Not restricted.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing one example of the magnetic sheet of the present invention, and FIG. 2 is a schematic cross-sectional view showing another specific example of the magnetic sheet of the present invention. The main symbols in the figure are as follows. 1; Base material, 2: Magnetic recording layer, 3: Magnetic sheet member, 4.
Protective film, 5: Heat-sensitive recording layer, 6: Matrix material, 7:
Organic low molecular substance, 9: Support. Figure 1

Claims (7)

[Claims] (1) Providing a protective film on the magnetic recording layer side of the magnetic sheet member,
A magnetic sheet further comprising a heat-sensitive recording layer on which information can be recorded and erased reversibly, the heat-sensitive recording layer comprising a resin matrix material and an organic low-molecular substance dispersed in the matrix material. A magnetic sheet whose transparency changes reversibly with changes in temperature. (2) a matrix material in which the heat-sensitive recording layer is made of one or more copolymers selected from the group consisting of polyvinyl chloride, vinyl chloride copolymers, vinylidene chloride copolymers, polyesters, and acrylonitrile; Claim 1: The matrix material comprises a saturated or unsaturated fatty acid having 10 to 30 carbon atoms, and one or more organic low-molecular substances selected from the group consisting of esters, amides, and ammonium salts of the fatty acid. Magnetic sheet as described. (3) Claim 1 or 2 above, wherein the protective film is made of an inorganic substance.
Magnetic sheet as described. (4) The magnetic sheet according to claim 1, 2 or 3, further comprising an overcoat layer on the heat-sensitive recording layer. (5) A magnetic sheet in which a heat-sensitive recording layer capable of reversibly recording and erasing information is formed on a surface of a magnetic sheet member opposite to the surface on which the magnetic recording layer is provided, the heat-sensitive recording layer 1. A magnetic sheet comprising a resin matrix material and an organic low-molecular substance dispersed in the matrix material, the transparency of which changes reversibly with changes in temperature. (6) a matrix material in which the heat-sensitive recording layer is made of one or more copolymers selected from the group consisting of polyvinyl chloride, vinyl chloride copolymers, vinylidene chloride copolymers, polyesters, and acrylonitrile; It is characterized by comprising one or more organic low-molecular substances selected from the group consisting of saturated or unsaturated fatty acids having 10 to 30 carbon atoms, esters, amides, and ammonium salts of the fatty acids, dispersed in a matrix material. magnetic sheet. (7) The magnetic sheet according to claim 6, further comprising an adhesive layer between the magnetic sheet member and the heat-sensitive recording layer.