JPH06340175A - Reversible heat-sensitive magnetic recording material - Google Patents

Abstract

PURPOSE:To provide a reversible heat-sensitive magnetic recording material which records visible information and non-visible information necessary optionally at any time on one sheet of a recording material, repeated writing and erasure are possible and an image recording the visible information is superior in contrast. CONSTITUTION:A reversible heat-sensitive recording layer consisting mainly of a dye precursor, which is ordinarily colorless or light-colored, and a reversible developer, which allows the dye precursor to generate a color tone change by a difference in cooling rates after heating, is provided on one surface of a substrate and a magnetic recording layer consisting mainly of magnetic powder and a binder is provided on the reversible heat-sensitive recording layer and/or any other place and/or on the other surface of the substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reversible thermosensitive magnetic recording material capable of repeatedly writing and erasing an image by controlling thermal energy.

[0002]

2. Description of the Related Art Generally, a heat-sensitive recording material widely used has a heat-sensitive recording layer containing, on a support, an electron-donating, usually colorless or light-colored dye precursor and an electron-accepting developer as main components. It is provided, and by heating with a thermal head, a heating pen, a laser beam or the like, a dye precursor and a developer react instantaneously to obtain a recorded image. JP-B-43-416
No. 0, Japanese Patent Publication No. 45-14039 and the like.

In such a heat-sensitive recording material, once an image is formed, it is impossible to erase the portion and restore the state before the image is formed again. Therefore, when further information is recorded, the image is not formed. I had no choice but to add to the part. Therefore, when the area of the heat-sensitive recording portion is limited, there is a problem that the recordable information is limited.

In view of this, Japanese Patent Laid-Open No. 3-246091 discloses that an ordinary thermal recording layer is provided on both sides of a base paper.
A heat-sensitive recording material has been proposed which enables printing and recording on the back side. As a result, it is possible to print on both the front and back sides, and it has become possible to record twice as much information as the conventional thermal recording material. However, even with this heat-sensitive recording material, once an image is formed, it is impossible to erase that portion and return it to the state before image formation again, and therefore the amount of recordable information is still limited.

On the other hand, in JP-A-58-45998, a magnetic recording layer is provided on one surface of a support and an optically transparent state and an opaque surface are provided on the other surface so that printing can be easily performed on magnetic cards. A heat-sensitive recording type magnetic sheet provided with a heat-sensitive layer capable of reversibly changing between states has been proposed. However, since this heat-sensitive recording type magnetic sheet performs printing and the like by utilizing the change between the transparent state and the opaque state of the heat-sensitive layer, the contrast of printing and the like is small and it is practical. It was insufficient, and the amount of information due to this was limited, and it was insufficient to record various information.

[0006]

With the recent development of various media, information is diversified, and regarding recording of information, visible or invisible information that is desired to be stored once and is recorded once, or is recorded only once for confirmation. After that, visible or invisible information, which may be erased, is mixed, and the amount thereof is increasing remarkably. Therefore, a recording material capable of repeatedly recording all of this information on one sheet is desired. Moreover, it is preferable to use a maintenance-free system which is simple in recording means and can be downsized.

An object of the present invention is to record visible information and invisible information which are required at all times or at any time on one recording material,
An object of the present invention is to provide a reversible thermosensitive magnetic recording material which can be repeatedly written and erased and which has an excellent contrast in an image for recording visible information.

[0008]

As a result of research to solve this problem, the present inventor found that one surface of the support was
A support is provided with a reversible thermosensitive recording layer containing a colorless or light-colored dye precursor and a reversible developer that causes a reversible color change in the dye precursor due to the difference in cooling rate after heating. Of the surface of the reversible thermosensitive recording layer and / or a place different from this, and / or the other surface of the support,
By providing a magnetic recording layer containing magnetic powder and a binder as main components, the intended reversible thermosensitive magnetic recording material could be obtained.

The reversible thermosensitive recording layer in the reversible thermosensitive magnetic recording material of the present invention is proposed, for example, in Japanese Patent Application No. 4-347032, or in Japanese Patent Laid-Open Nos. 61-239444 and 63-173684. Kaihei 2--18829
It is a type disclosed in Japanese Patent Laid-Open No. 3 that develops a high density color upon heating and then decolorizes upon reheating, and the image has a large contrast and is easy to recognize. As this type,
Usually, a reversible thermosensitive recording layer containing a colorless or light-colored dye precursor and a reversible color developer that causes a reversible color tone change in the dye precursor due to a difference in cooling rate after heating is used.

Specific examples of such a reversible developer include, for example, a light absorber disclosed in JP-A-61-239444 and an ascorbic acid-6- disclosed in JP-A-63-173684. 0-acyl derivative, JP-A-2-18
The color-reducing agent disclosed in Japanese Patent No. 8293 can be mentioned. However, due to the contrast of images and the durability of repetition, the carbon number of 6 used in the reversible thermosensitive recording material proposed by the applicant in Japanese Patent Application No. 347032/1992. The electron-accepting compound having the above aliphatic hydrocarbon group is preferable, and the phenolic compound having at least one aliphatic hydrocarbon group having 6 or more carbon atoms is particularly preferable.

Examples of the reversible color developer used in the present invention include those represented by the general formula 1, but the invention is not limited thereto.

[0012]

[Chemical 1]

In the formula 1, n is an integer from 1 to 3 and m
Represents an integer of 0 or 1. R ¹ and R ² represent a substituent selected from an aliphatic hydrocarbon group, an alkoxy group, a halogen atom or a hydrogen atom, and may be the same or different from each other. R ³ represents an aliphatic hydrocarbon group. Y is a group represented by Formula 2. In addition, among the compounds represented by Chemical formula 1, R
It is preferably large number of carbon atoms of ^3, carbon number of R ³ is 5 or less is not sufficient decoloring effect. Further, when R ³ has 23 or more carbon atoms, the manufacturing cost is high, so R 3
It is particularly preferable that ³ is an aliphatic hydrocarbon group having 6 to 22 carbon atoms.

[0014]

[Chemical 2]

In Formula 2, 11 and 12 each represent an integer of 0 or 1. X ¹ and X ² each represent a divalent group having at least one hetero atom and may be the same or different. Ar represents an aromatic group which may have a substituent, and the aromatic group represented by Chemical formula 3 is particularly preferable.

[0016]

[Chemical 3]

In Formula 3, k1 and k2 each represent an integer of 0 or 1, and X ³ and X ⁴ each represent a divalent group having at least one hetero atom, and may be the same or different. . When k1 is 0, R ⁴ represents a substituent selected from an aliphatic hydrocarbon group, an alkoxy group, a halogen atom or a hydrogen atom, and when k1 is 1, R ⁴ represents an aliphatic hydrocarbon group. Further, when k2 is 0, R ⁵ represents a substituent selected from an aliphatic hydrocarbon group, an alkoxy group, a halogen atom or a hydrogen atom, and when k2 is 1, R ⁵ represents an aliphatic hydrocarbon group.

In formula 3, when R ⁴ and R ⁵ are aliphatic hydrocarbon groups, R ⁴ and R ⁵ are particularly preferably aliphatic hydrocarbon groups having 6 to 22 carbon atoms. Moreover, in Formula 1 and Formula 3, when R ^{1 to} R ⁵ are aliphatic hydrocarbon groups, R ^{1 to} R ⁵ are particularly preferably alkyl groups, cycloalkyl groups or alkenyl groups.

In formulas 2 and 3, the divalent group having at least one hetero atom represented by X ^{1 to} X ⁴ is, for example, an amide bond, a sulfonamide bond, an ester bond, a carbonic acid ester bond, Ether bond, sulfide bond, thioester bond, carbonyl group, amino bond,
Examples thereof include a urea bond, a thiourea bond, a urethane bond, and an azomethine bond. In particular, a divalent group selected from an amide bond, a sulfonamide bond, a sulfide bond, a urea bond, and an azomethine bond is preferable. It is not limited.

Next, specific examples of preferable reversible color developing agents used in the present invention will be given, but the present invention is not limited thereto.

4'-hydroxyheptane anilide, 4 '
-Hydroxy-3-methyloctaneanilide, 4'-hydroxytridecaneanilide, 4'-hydroxynonadecaneanilide, 3'-hydroxynonadecaneanilide,
2 ', 4'-dihydroxyheptadecane anilide, 4'
-Hydroxy-4-hexylbenzanilide, 4'-hydroxy-4-octadecylbenzanilide, 4'-hydroxy-4- (heptylthio) benzanilide, 4 '
-Hydroxy-4-octadecyloxybenzanilide, 4'-hydroxy-4-dodecylsulfonylbenzanilide, 4'-hydroxy-4- (N-heptadecylideneamino) benzanilide, 4'-hydroxy-3,
4-dioctyloxybenzanilide, 4'-hydroxy-3- (heptadecylthio) -5-pentadecyloxybenzanilide, 4'-hydroxy-3-heptadecylcarbonylamino-5-dodecylbenzanilide,
4'-hydroxy-3,5-bis (N-docosylideneamino) benzanilide,

N-cyclohexyl-4-hydroxybenzamide, N-cyclohexylmethyl-4-hydroxybenzamide, N-octadecyl-4-hydroxybenzamide, N-methyl-N-octadecyl-4-hydroxybenzamide, 4-hydroxy-4 '. -Heptylcarbonylaminobenzanilide, 4-hydroxy-4 '
-Octyloxycarbonylaminobenzanilide, N
-Octadecyl-2,3,4-trihydroxybenzamide, N-methyl-3-hydroxy-4'-octadecylbenzanilide, 4- (N-octylsulfonylamino) phenol, 4'-hydroxy-4-cyclohexylbenzenesulfonanilide 4'-hydroxy-4-
Octadecylaminobenzenesulfonanilide, N-octylidene-4- (4-hydroxyphenyl) aminosulfonylaniline,

4'-hydroxy-4-octadecyloxydiphenyl sulfide, N- (4-hydroxyphenyl) -N'-octadecyl urea, N- (3-allyl-4)
-Hydroxyphenyl) -N'-octadecylurea, N
-(4-hydroxyphenyl) -N '-(4-tetradecylphenyl) urea, N- (4-hydroxybenzylidene) octadecylamine, N- (4-hydroxybenzylidene) -4'-tetradecylcarbonyloxyaniline, N -(3-hydroxybenzylidene) dodecylamine, N- (4-hydroxy-α-methylbenzylidene)
-4'-octadecylaniline, N- (4-octadecylcarbonylamino) benzylidene-4'-hydroxyaniline and the like.

The colorless or light-colored dye precursor used in the reversible thermosensitive recording layer in the present invention is generally an electron donor used for pressure-sensitive recording paper, heat-sensitive recording paper, light-sensitive pressure-sensitive paper, electric heat-sensitive recording paper, heat-sensitive transfer paper and the like. Typified by sex compounds,
It is not particularly limited. Specific examples include the followings, but the present invention is not limited to these.

3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), 3,3-bis (p-dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) ) -3- (1,2-Dimethylindol-3-yl)
Phthalide, 3- (p-dimethylaminophenyl) -3-
(2-Methylindol-3-yl) phthalide, 3-
(P-Dimethylaminophenyl) -3- (2-phenylindol-3-yl) phthalide, 3,3-bis (1,
2-Dimethylindol-3-yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindol-3-yl) -6-dimethylaminophthalide, 3,
3-bis (9-ethylcarbazol-3-yl) -5-
Dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) -5-dimethylaminophthalide, 3-p-dimethylaminophenyl-3- (1-methylpyrrol-2-yl) -6 -Triarylmethane compounds such as dimethylaminophthalide.

Diphenylmethane compounds such as 4,4'-bis (dimethylaminophenyl) benzhydryl benzyl ether, N-chlorophenyl leuco auramine and N-2,4,5-trichlorophenyl leuco auramine.

Rhodamine B anilinolactam, Rhodamine B p-chloroanilinolactam, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-octylaminofluorane, 3-diethylamino-7-phenylflurane. Oran, 3-diethylamino-
7-chlorofluorane, 3-diethylamino-6-chloro-7-methylfluorane, 3-diethylamino-7-
(3,4-dichloroanilino) fluorane, 3-diethylamino-7- (2-chloroanilino) fluorane,

3-Diethylamino-6-methyl-7-anilinofluorane, 3- (N-ethyl-N-tolyl) amino-6-methyl-7-anilinofluorane, 3-piperidino-6-methyl- 7-anilinofluoran, 3-
(N-ethyl-N-tolyl) amino-6-methyl-7-
Phenethylfluorane, 3-diethylamino-7- (4
-Nitroanilino) fluorane, 3-dibutylamino-
6-methyl-7-anilinofluorane, 3- (N-methyl-N-propyl) amino-6-methyl-7-anilinofluorane, 3- (N-ethyl-N-isoamylamino-6-methyl -7-anilinofluorane, 3- (N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3- (N-ethyl-N-tetrahydrofuryl) amino-6-methyl-7 Xanthene compounds such as anilinofluorane.

Thiazine compounds such as benzoyl leuco methylene blue and p-nitrobenzoyl leuco methylene blue. 3-Methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3,3'-dichlorospirodinaphthopyran, 3-benzylspirodinaphthopyran, 3-methylnaphtho- (3-methoxybenzo) spiropyran, 3
There are spiro compounds such as propyl spiro benzopyran. These usually colorless to light-colored electron-donating dye precursors may be used either individually or in combination of two or more.

A binder may be added to the reversible thermosensitive recording layer for the purpose of improving the strength of the reversible thermosensitive recording layer. Specific examples of these binders include starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, polyvinyl alcohol, modified polyvinyl alcohol, sodium polyacrylate, acrylic acid amide / acrylic acid ester copolymer, and acrylic acid amide. / Acrylic acid ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, ethylene /
Water-soluble polymers such as alkali salts of maleic anhydride copolymer, polyvinyl acetate, polyurethane, polyacrylic acid ester, styrene / butadiene copolymer, acrylonitrile / butadiene copolymer, methyl acrylate / butadiene copolymer, Examples thereof include latex such as ethylene / vinyl acetate copolymer, but are not limited thereto.

A heat-fusible substance may be contained in the reversible thermosensitive recording layer as an additive for controlling the color developing sensitivity and the decoloring temperature of the reversible thermosensitive recording layer. As the heat-fusible substance, a substance having a melting point of 60 ° C. to 200 ° C. is preferable, and a substance having a melting point of 80 ° C. to 180 ° C. is particularly preferable. Further, a sensitizer used in general thermal recording paper can also be used. Specific examples thereof include waxes such as N-hydroxymethylstearic acid amide, stearic acid amide and palmitic acid amide, naphthol derivatives such as 2-benzyloxynaphthalene, biphenyl derivatives such as p-benzylbiphenyl and 4-allyloxybiphenyl, Polyether compounds such as 1,2-bis (3-methylphenoxy) ethane, 2,2'-bis (4-methoxyphenoxy) diethyl ether, bis (4-methoxyphenyl) ether, diphenyl carbonate, dibenzyl oxalate, shu Examples thereof include carbonic acid such as acid bis (p-methylbenzyl) ester and oxalic acid diester derivatives. Two or more kinds of them can be added in combination, but not limited thereto.

In the reversible thermosensitive recording layer, the amount of the reversible color developer used with respect to the dye precursor is preferably 5 to 5000% by weight, particularly preferably 10 to 3000% by weight. Further, the coating amount of the dye precursor, from the viewpoint of color density and cost,
It is preferably 0.01 to 2.0 g / m ² , and is preferably 0.
1 to 1.5 g / m ² is particularly preferable.

The reversible thermosensitive recording layer in the present invention is required to have durability because it repeatedly writes and erases an image by heating, and it is preferable to provide a protective layer as an upper layer of the reversible thermosensitive recording layer in order to prevent deterioration thereof. . Materials for forming the protective layer include water-soluble polymers, latexes, and polymerizable compounds. Examples thereof include polyurethane resin, polyester resin, epoxy resin, melamine resin, polyvinyl alcohol, nitrocellulose, methacrylic acid ester, acrylic acid oligomer, acrylic acid ester oligomer and the like. If necessary, a crosslinking agent such as an epoxy compound, a urea derivative, a vinyl compound, a phosphoric acid-based agent,
A curing agent such as a sulfonic acid-based, polyamide-based, or amine-based curing agent can be added. It is also possible to previously form a transparent film such as polyethylene or polyethylene terephthalate, and form a protective layer on the reversible thermosensitive recording layer by a means such as bonding. In this case, if necessary, an intermediate layer can be provided between the reversible thermosensitive recording layer and the protective layer. Further, an intermediate layer may be provided between the support and the reversible thermosensitive recording layer.

The reversible thermosensitive recording layer may usually contain a colorless or light-colored dye precursor and a reversible developer by dissolving or dispersing each compound in water or an organic solvent. Each solution or dispersion obtained by, for example, a method of dissolving or dispersing in water or an organic solvent after mixing, a method of dissolving and homogenizing each compound by heating and then cooling, and then dissolving or dispersing in water or an organic solvent. There is a method of mixing liquids, printing on a support, coating and drying, and the like. In this case, for example, each color-forming component may be contained in one layer to form a multilayer structure, but the invention is not particularly limited thereto.

The magnetic recording layer in the present invention contains magnetic powder,
Polyester resin, vinyl chloride resin, polyurethane resin, vinyl chloride / vinyl acetate copolymer resin, styrene /
It is uniformly dispersed in a binder such as a butadiene copolymer resin, a polyacrylic acid ester resin, an epoxy resin, etc., and additives such as a pigment, a dispersant, a surfactant and an antistatic agent described below are added depending on the purpose. It is formed from the resulting magnetic paint.
The binder is preferably a binder having a gel content of 5 to 75%.

Magnetic powders include γ-Fe ₂ O ₃ and Fe ₃
O ₄ , mixed crystal of γ-Fe ₂ O ₃ and Fe ₃ O ₄ , Co-containing γ
-Fe ₂ O _3, Co-containing Fe ₃ O _4, Ba ferrite,
Sr ferrite or the like is used. In order to prevent the trouble of erasing the magnetically recorded information by a normal permanent magnet, it is preferable to use Ba ferrite, Sr ferrite or the like having a coercive force of 1500 to 5000 Oersted.

In the magnetic recording layer, the amount of the binder used is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 1 part by weight, based on 1 part by weight of the magnetic powder. If the amount of the binder used is less than 0.05 parts by weight, the adhesion to the magnetic powder and the support will be reduced, the film strength will be reduced, and the abrasion resistance, repeatability, water resistance, chemical resistance will deteriorate, and smoothness When the amount is more than 10 parts by weight, the magnetic properties are deteriorated and the resolution and the output are likely to be insufficient. Further, the coating amount of the magnetic powder is preferably ² to 70 g / m ² , from the viewpoint of magnetic characteristics, recording reliability and cost, and is 5 to 50 g.
g / m ² is particularly preferred.

Further on the magnetic recording layer, nitrocellulose,
The protective layer of polyurethane resin, polyvinyl alcohol or the like may be provided by coating, printing, laminating or the like, and if necessary, an intermediate layer may be provided between the magnetic recording layer and the protective layer.

Further, the protective layer and / or the reversible thermosensitive recording layer and / or the magnetic recording layer and / or the intermediate layer include diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, Inorganic and organic pigments such as silicon oxide, aluminum hydroxide, urea-formalin resin, melamine resin and polyethylene resin,
In addition, higher fatty acid metal salts such as zinc stearate and calcium stearate, paraffin, oxidized paraffin,
Waxes such as polyethylene, polyethylene oxide, stearic acid amide, and castor wax may be added, and a dispersant such as sodium dioctylsulfosuccinate, a surfactant, an antistatic agent, and a fluorescent dye may be added.

As the support used in the present invention, paper, coated paper, various non-woven fabrics, woven cloth, laminated paper, synthetic paper, metal foil, synthetic resin, or white film formed by adding white pigment to synthetic resin A sheet, a foamed sheet, or a composite sheet obtained by combining these can be arbitrarily used according to the purpose. These may be opaque, translucent or transparent. The thickness of the support is not particularly limited as long as it can withstand repeated use, but is preferably 30 to
The thickness is 500 μm, particularly preferably about 40 to 300 μm.

In the reversible thermosensitive magnetic recording material of the present invention, a reversible thermosensitive recording layer is provided on one surface of the support, and the reversible thermosensitive recording layer is provided on the same side of the reversible thermosensitive recording layer and / or the support. And a magnetic recording layer is provided on the surface (support surface) where this layer is not provided and / or on the surface of the support opposite to the layer, the magnetic recording layer being on the reversible thermosensitive recording layer. In the case of laminating on, the support is preferably transparent.

The method of forming each layer constituting the reversible thermosensitive magnetic recording material of the present invention on the support is not particularly limited, and it can be formed by a conventional method. For example, a smearing device such as an air knife coater, a blade coater, a bar coater, a curtain coater, a planographic printing plate, a relief printing plate,
It is possible to use various printing machines using intaglio, flexo, gravure, screen, hot melt, and the like. Further, in addition to the usual drying process, each layer can be held by UV irradiation / EB irradiation. By these methods, it is possible to smear and print both sides of the support simultaneously or separately on one side.

In the reversible thermosensitive magnetic recording material of the present invention, for example, two reversible thermosensitive recording layers are formed on one surface of one support of the same or different type, and further another support is formed. It is also possible to form a layer including a magnetic recording layer on one side of the above, and then, by facing the reversible thermosensitive recording layer or the surface not including the magnetic recording layer of each support, and adhering them with an adhesive or the like. Alternatively, they can be formed by laminating each other on both sides of another support.

In the preferred reversible thermosensitive recording layer of the reversible thermosensitive magnetic recording material of the present invention, in order to form a color recorded image, rapid cooling after heating is required, and in order to erase the recorded image. It suffices if the cooling rate after heating is slow. For example, the color-developed state can be developed by heating the material by an appropriate method and then rapidly cooling it by pressing a low-temperature metal block or the like. In addition, if a heating is performed for a very short time using a thermal head, a laser beam or the like, the material is cooled immediately after the heating is completed, and thus a color-developed state can be developed. On the other hand, when heated with an appropriate heat source (thermal head, laser light, heat roll, heat stamp, high frequency heating, radiant heat from a light source such as a tungsten lamp or halogen lamp, hot air, etc.) for a relatively long time, recording Since not only the layers but also the support and the like are heated, even if the heat source is removed, the cooling speed is slow and the state is decolored. Therefore, even if the same heating temperature and / or the same heat source is used, the coloring state and the erasing state can be arbitrarily expressed by controlling the cooling rate.

The reversible thermosensitive magnetic recording material of the present invention may be printed or magnetically recorded on one side separately, and a heating means for image recording and printing and a magnetizing means such as a magnetic head may be provided on both sides of the reversible thermosensitive recording material. It is also possible to print and magnetically record both sides or one side at the same time by installing a plurality of them on one side. Printing and magnetic recording can be similarly performed on a reversible thermosensitive magnetic recording material having a reversible thermosensitive recording layer and a magnetic recording layer provided on only one surface.

[0046]

The present invention will be described in more detail with reference to the following examples. "Parts" and "%" in the examples mean "parts by weight" and "% by weight", respectively.

Example 1 25 parts of 3-di-n-butylamino-6-methyl-7-anilinofluorane was pulverized with 80 parts of 2.5% aqueous polyvinyl alcohol solution in a ball mill for 24 hours to obtain a dye precursor dispersion liquid. Got Next, 63 parts of 4'-hydroxy-n-heptaneanilide was pulverized with 200 parts of a 2.5% aqueous solution of polyvinyl alcohol in a ball mill for 24 hours to obtain a reversible developer dispersion. Mixing the two dispersions obtained,
A reversible heat-sensitive coating liquid was prepared by adding 130 parts of a 10% aqueous polyvinyl alcohol solution and stirring the mixture sufficiently. The obtained coating liquid was applied to one surface of a polyethylene terephthalate (PET) sheet having a thickness of 188 μ by a Meyer bar so that the solid content applied amount was 4 g / m ² , dried, and treated with a super calendar. A reversible thermosensitive recording layer was formed. Furthermore,
Polyvinyl alcohol was added to the surface of this reversible thermosensitive recording layer.
It was smeared to a thickness of μ and dried to form a protective layer.

Next, a coercive force of 2700 Oersted Ba
100 parts of ferrite, 30 parts of styrene / butadiene latex (T-2028 manufactured by Japan Synthetic Rubber Co., Ltd.), and 2 parts of water
A magnetic recording coating liquid was prepared by dispersing 00 parts in a ball mill. The obtained coating liquid was applied onto a reversible thermosensitive recording layer of a polyethylene terephthalate (PET) sheet having a reversible thermosensitive recording layer formed thereon, using a Meyer bar to apply a solid content of 30 g.
/ M ² and consisting smeared as, and dried at 105 ° C. After magnetic field orientation, the squareness (residual magnetic flux density / saturation magnetic flux density) is 0.83
A reversible thermosensitive magnetic recording material in which the above magnetic recording layers were laminated was obtained.

Example 2 25 parts of 3-di-n-butylamino-6-methyl-7-anilinofluorane was pulverized with 80 parts of a 2.5% aqueous polyvinyl alcohol solution in a ball mill for 24 hours to obtain a dye precursor dispersion. Got Next, 63 parts of N- (4-hydroxyphenyl) -N'-dodecylurea was pulverized with 200 parts of a 2.5% aqueous polyvinyl alcohol solution by a ball mill for 24 hours to obtain a reversible developer dispersion. The obtained two kinds of dispersion liquids are mixed, and a 10% polyvinyl alcohol aqueous solution 130
Parts were added and sufficiently stirred to prepare a reversible heat-sensitive coating liquid.
The resulting coating liquid is applied to one side of a 48 μ-thick high-quality paper with a Meyer bar so that the solid content of the coating is 3 g / m ² , dried, and processed with a super calendar to form a reversible thermosensitive recording layer. did. Further, a polyacrylic acid ester copolymer was smeared on the surface of the reversible thermosensitive recording layer to a thickness of 4 μm and dried to form a protective layer.

Next, the same magnetic recording coating solution as in Example 1 was applied to one surface of another quality paper having a thickness of 48 μm using a Meyer bar so as to obtain a solid content of 30 g / m ^2. After magnetic field orientation, it was dried at 105 ° C. to form a magnetic recording layer.

Next, an adhesive was applied to both sides of a 75 μ thick foamed polyethylene terephthalate (PET) sheet, and the uncoated surfaces of the two types of smeared paper obtained above were made to face each side of the foamed PET sheet. After bonding, both sides were processed with a calendar to obtain a reversible thermosensitive magnetic recording material.

Example 3 25 parts of 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide was pulverized with 80 parts of a 2.5% aqueous solution of polyvinyl alcohol in a ball mill for 24 hours to obtain a dye precursor dispersion liquid. Got Then, 63 parts of N- (4-hydroxyphenyl) -N'-dodecylurea was added to 2.5 parts.
% Aqueous solution of polyvinyl alcohol and pulverized with a ball mill for 24 hours to obtain a reversible developer dispersion. The resulting two types of dispersions were mixed, 130 parts of a 10% polyvinyl alcohol aqueous solution was added, and the mixture was sufficiently stirred to prepare a reversible heat-sensitive coating liquid. The obtained coating liquid was applied with a Mayer bar to 188
A part of one side of a μ-thickness polyethylene terephthalate (PET) sheet is smeared so that the solids smear amount is 4 g / m ² , dried, and processed with a super calendar to form a reversible thermal recording layer. did.

Next, the same magnetic recording coating solution as in Example 1 was used at a location different from the reversible thermosensitive recording layer on the surface of the polyethylene terephthalate (PET) sheet on which the reversible thermosensitive recording layer was previously provided (on the PET sheet). Then, a solid coating amount of 30 g / m ² was applied using a Meyer bar, and after magnetic field orientation, it was dried at 105 ° C. to obtain a reversible thermosensitive magnetic recording material further provided with a magnetic recording layer.

<Coloring / Decoloring Performance and Magnetic Properties> Example 1
Using the reversible thermosensitive magnetic recording materials of ~ 3, the following performance tests were carried out. The results are shown in Table 1. Test 1 (image formation) A thermal printing tester (manufactured by Okura Electric Co., Ltd.) was used with a thermal head KJJ-256-8MGF1 manufactured by Kyocera to apply a voltage of 26 ms at an applied pulse of 1.1 milliseconds to the smeared surface of the reversible thermosensitive recording layer.
Printed under the condition of bolt. The density of the obtained color image was measured using an optical densitometer (Macbeth RD918). The hues of the colored images of the reversible thermosensitive recording layers of Examples 1 to 3 are black, black and blue, respectively. Test 2 (Image erasure) 120 is printed on the color image area obtained by printing under the same conditions as Test 1.
After applying a heat stamp at ℃ for 1 second, test the concentration of the same part 1
It measured similarly to. Test 3 (Repeatability) Test 1 and Test 2 were repeated 100 times, and the density of the color image at the 100th time and the density of the image erasing portion at the 100th time were measured.

Test 4 (Magnetic Characteristics) A magnetic head was used to scan the coated surface of the magnetic recording layer to record (write) magnetic information. After repeatedly printing and erasing 100 times on the reversible thermosensitive recording layer coated surface, the magnetic recording layer coated surface on which magnetic information was recorded (written) was scanned by a magnetic head to read the information. The mark ◯ in Table 1 indicates that the information was read correctly.

[0056]

[Table 1]

[0057]

As described above, the reversible thermosensitive magnetic recording material of the present invention, in which the reversible thermosensitive recording layer containing the dye precursor and the reversible developer and the magnetic recording layer are provided on the support, forms one recording material. In addition, the visible information that is required at all times or at any time is printed and recorded,
Write or erase repeatedly, and apart from this,
It is possible to record necessary invisible information at all times or at any time, repeatedly write or erase, and select and record visible or invisible information that needs to be saved and transient visible or invisible information. It was Further, one reversible visible information record can be made to correspond to the other reversible invisible information record, and vice versa. Moreover, the color-developed image formed from the reversible thermosensitive recording layer in the reversible thermosensitive magnetic recording material of the present invention is excellent in contrast and can have various hues, so that it is easy to visually judge and confirm information. Not only can there be information differentiation.

Therefore, specifically, for example, the record of the balance of the card can be made rewritable invisible information, and the visible information corresponding thereto or visible information of a different type can be endlessly displayed on one card. Therefore, it is necessary to record enormous and diverse information at any time or at all times, such as a ticket, commuter pass, coupon ticket, admission ticket, meal ticket,
Alternatively, it can be widely applied as a prepaid card or the like.

Claims (1)

[Claims] 1. An ordinary colorless to light-colored dye precursor and a reversible developer that causes a reversible color change in the dye precursor due to a difference in cooling rate after heating, on one surface of a support. A reversible thermosensitive recording layer as a main component is provided, and the magnetic powder and the binder are provided on the reversible thermosensitive recording layer on the surface of the support and / or at a different position from this, and / or on the other surface of the support. A reversible thermosensitive magnetic recording material comprising a magnetic recording layer containing as a main component.