JP2001180132A - Thermal magnetic recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a card which can record the frequency of use, a residual sum, etc., clearly and readably on the side of a magnetic layer, is simple in layer structure, and has an excellent forgery preventing effect. SOLUTION: In a thermal magnetic recording material in which a magnetic recording layer containing ferromagnetic powder and a binder as main components is formed on a base material, and a hiding layer is formed on the magnetic recording layer, a sublimatable dye is contained in the magnetic recording layer, and the hiding layer comprises a sublimatable dye acceptable component and white pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive magnetic recording medium. More specifically, the present invention relates to a coupon, a gift card, an intelligent transportation system,
The present invention relates to a thermosensitive magnetic recording medium which can be visualized by thermally printing a part of magnetic recording information used for a highway card and other various automatic system cards, and can prevent forgery.

[0002]

2. Description of the Related Art Due to the rapid spread of telephone cards and orange cards, prepaid cards have been attracting attention, and practical use in the field of various distribution services such as transportation is rapidly spreading. The widespread use of such thermosensitive magnetic recording materials is due to the fact that the information storage capacity of the magnetic recording layer is large, the readability of the written information is simple and accurate, and the information can be easily processed by an automatic ticket gate or a vending machine. It is thought that this is due to the fact that it can be performed and that fractional amount processing is possible and that it is effective for labor saving.

[0003] As a prepaid card balance display method,
Conventionally, the punch hole method has been adopted. However, this method has a drawback that an accurate balance cannot be grasped only by a card, so that the use history is not clear and punch dust is accumulated in a reader / writer. is there. Therefore, in order to enable accurate balance display, a thermal recording method has been adopted.

Conventionally, a magnetic recording layer is provided on one surface of a base paper,
Thermosensitive magnetic composite recording paper with a thermosensitive recording layer on the opposite surface is used for boarding tickets, boarding passes, etc.
Also, it has been used for various cards.

However, the magnetic recording layer of such a conventional recording material is colored by magnetic powder used as a main component thereof, and no consideration is given to printing or printing thereon. Was something. Therefore, as a method of solving such a problem, a method of adding a coloring pigment to a magnetic paint to form a desired coloring on the magnetic recording layer when forming the magnetic recording layer, and a method of forming a magnetic recording layer by the method described in 20
As disclosed in US Pat. No. 4991, it has been proposed to apply a white pigment paint on the magnetic recording layer. With these methods, printing of visible information on the magnetic recording layer is possible,
However, the usage status such as the balance display is printed on the magnetic recording layer by thermal recording or the like and cannot be visualized.

In order to visualize the remaining amount, Japanese Patent Laid-Open No.
In -364982, a magnetic recording layer was formed on one surface of a support, a heat-sensitive recording layer was provided on the magnetic recording layer, and a protective layer cured by ultraviolet light was provided on the heat-sensitive recording layer. Thermosensitive magnetic composite recording materials have been proposed. In this recording material, it is considered that an image once printed can be rewritten after erasing the printing again.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the number of times of use and the remaining amount can be clearly and easily readablely recorded on the magnetic layer side, and the layer structure is simple.
An object of the present invention is to provide a card having an excellent anti-counterfeiting effect.

[0008]

The present invention employs the following configuration to solve the above-mentioned problems. That is, the first of the present invention
The invention relates to a "support, a magnetic recording layer formed on one surface of the support and containing a ferromagnetic powder and a binder as main components, and a concealing layer provided on the magnetic recording layer. Wherein the magnetic recording layer contains a sublimable dye and the concealing layer comprises a sublimable dye-accepting component and a white pigment. The second invention of the present invention relates to the first aspect, wherein the white pigment of the concealing layer is an inorganic pigment.
The thermosensitive magnetic recording medium according to the invention described above. " Third of the present invention
The invention of the present invention is the "thermosensitive magnetic recording medium according to the first invention, wherein the white pigment of the concealing layer is hollow fine particles made of a thermoplastic resin". The fourth invention of the present invention provides a "thermosensitive magnetic recording medium according to any one of the first to third inventions, wherein a protective layer comprising a water-soluble polymer and / or a synthetic resin emulsion as a main component is provided on the concealing layer." It is. The fifth invention of the present invention provides a "thermosensitive magnetic recording medium according to any one of the first to third inventions, wherein a protective layer comprising an ionizing radiation-curable resin as a main component is provided on the concealing layer".
It is. The ionizing radiation-curable resin refers to a resin that is cured by electron beams and ultraviolet rays.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the thermosensitive magnetic recording medium of the present invention, its magnetic recording layer contains a ferromagnetic powder, a binder and a sublimable dye as main components, and a concealing layer on this magnetic recording layer is It is characterized by comprising a sublimable dye-accepting component and a white pigment.

<Layer Structure> First, with regard to the layer structure, as shown in FIG. 1, a thermosensitive magnetic recording medium 1 of the present invention comprises a support 2 and a magnetic recording layer formed thereon sequentially. The layer 3 and the concealing layer 4 are essential requirements. Further, a protective layer 5 and an ionizing radiation-curable resin protective layer 6 are provided as necessary. Further, the recording layer 7 can be provided on the other surface of the support.

<Support> The support used in the present invention is composed of a synthetic resin film or base paper. Examples of the synthetic resin film used for the support include, for example, polyethylene terephthalate, and a film made of a polyester resin material such as polybutylene terephthalate, a film made of a cellulose derivative material such as a cellulose triacetate film, and a polyolefin resin such as a polypropylene film and polyethylene. And a composite laminated film thereof. In addition, as the base paper for the support, high-quality paper, processed base paper, synthetic paper, and the like can be used, but the type is not particularly limited. Generally 50 as support
It is preferable to use one having a thickness of 200 μm.

In addition to the surface sizing treatment, the support base paper is preferably coated with an undercoat layer containing a binder such as synthetic resin and starch, and an inorganic pigment and an organic pigment as main components. Thereby, the magnetic recording layer can be applied thinly and uniformly. The coating amount of the undercoat layer is 3 to 30 g / m ² , preferably 5 to 15 g / m ² .

<Magnetic Recording Layer> The magnetic recording layer contains a magnetic powder, an adhesive and a sublimable dye as main components. As the magnetic powder, γ-iron monoxide, cobalt-modified γ-iron monoxide, barium ferrite, chromium oxide, strontium ferrite and the like can be used. Among these, Oersted barium ferrite and strontium ferrite having an Oersted of 1500 to 5000 are preferable in order to prevent magnetic recording information from being erased by ordinary magnetism.

As the adhesive, polyvinyl alcohol, casein, starch, hydroxyethylcellulose, methylcellulose, carboxymethylcellulose,
Water-soluble polymers such as gelatin, styrene-maleic anhydride copolymer, acrylonitrile-butadiene copolymer, methyl acrylate-butadiene copolymer, ethylene-maleic anhydride copolymer, styrene-butadiene copolymer Coalesce, acrylic resin, latex of water-insoluble resin such as vinyl acetate resin, or emulsion, or polyurethane resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer,
A water-insoluble resin such as a polyester resin can be used. Among them, water resistance, abrasion resistance, because of good flexibility, etc., styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, methyl acrylate-butadiene copolymer, vinyl chloride resin, polyurethane resin and the like Emulsion-based water-soluble resins are preferred.

In addition, as the resin used in the present invention, a resin soluble in an organic solvent such as toluene, xylene, isopropyl alcohol, methyl ethyl ketone, methyl isobutyl ketone, mineral spirit, solvent naphtha and the like can be used. For example, vinyl chloride / vinyl acetate copolymer, vinyl chloride / vinyl acetate / maleic acid copolymer, polyurethane resin, saturated polyester resin, polyester polyurethane resin, epoxy resin, phenoxy resin, nitrocellulose resin, melamine resin, chlorinated polyethylene resin, etc. Is mentioned.

A magnetic powder coating containing these magnetic powder, an adhesive and a sublimable dye as main components is prepared using either an aqueous solvent or an organic solvent. As the organic solvent, those described above can be used. The prepared magnetic paint is air knife coater,
The base paper is coated with a roll coater, a bar coater, or the like, and a magnetic recording layer is provided. In general, the weight of the magnetic recording layer after drying is preferably 5 to 60 g / m ² . More preferably, it is 10 to 40 g / m ² , and there are a vacuum deposition method, a sputtering method, a gas phase reaction method, and the like, and a coating method is preferable in terms of economy.

<Regarding Sublimation Dye Contained in Magnetic Recording Layer> The sublimation dye used in the present invention is a known sublimation or vaporizable dye, and is required to have good thermal stability. Nonionic dyes are preferred.
For example, the color index No. And C. I. Desparse yellow 1,3,7,8,16,41,42,5
4, 60, 64, 71, 77, 116 and the like. I. 1,4,6,11,15,17,5 of Desper Red
0, 55, 59, 60, 73, 83, 135, 146
167, 364, and the like. I. Desparse blue 3,
14, 19, 24, 26, 55, 56, 60, 64, 7
2,87,99,108,287,301,334, and the like. I. 28 of desperse violet, C.I. I.
4,13,31,36,56 of Desperse Violet
C. I. Solvent Yellow 14, 16, 2
9, 56, 77, 116 and the like. I. Solvent Green 3 etc., C.I. I. Solvent Red 23.2
5, 27, and the like. I. Solvent Blue 11,3
5,36,49,50,63,70,83,97,10
5,111 and the like. I. Solvent Bio Red 13
C. I. Solvent Black 3, C.I. I. Solvent Red 18, 19, 23, 24, 25, 81, 13
5,143,146,182 and the like, as well as aminoanthraquinone, diaminoanthraquinone, dihydroanthraquinone, diaminodihydroxyanthraquinone and the like. Dyes used in sublimation thermal transfer printers, which have recently become popular, are also preferably used. Further, a fluorescent whitening agent having the above performance can also be used. Specific examples thereof include oxazole-based compounds Ubitex ER and coumarin-based compounds Bla described in Shin-Dye Chemistry (Toyo Hosoda, published by Gihodo) 295-301.
nkoPorACF, naphthalimide-based compounds, and the like. As a UV absorber, the Journal of the Society of Color Materials 6
Vol. 5, No. 5, 298-307 (1992), benzotriazole-based compounds, benzophenone-based compounds, cyanoacrylate-based compounds, salicylic acid-based compounds, and the like. These sublimable dyes can be used alone or in combination of two or more. Among these, the colored sublimable dyes are preferable because the hue can be easily adjusted.

The sublimable dye to be added to the magnetic recording layer is not particularly limited, as long as required magnetic properties can be obtained. Preferably, one to one in the magnetic recording layer
20% by weight. More preferably, it is 3 to 15% by weight.

<Concealment Layer> The concealment layer disposed on the magnetic recording layer contains a white pigment and a sublimable dye receptor as main components, and is formed by an aqueous or organic solvent-based paint containing these. Is done. As the white pigment contained in the hiding layer, a known pigment is used. For example, examples of inorganic pigments include calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, and inorganic fine particles such as surface-treated calcium and silica. Urea-formalin resin, styrene.
Hollow fine particles such as organic fine powders such as methacrylic copolymers and polystyrene resins are exemplified. These white pigments can be used alone or in combination of two or more. Among these, hollow fine particles made of titanium oxide or a thermoplastic resin are preferably used because of their excellent hiding effect.

The coating for forming the concealing layer contains such a white pigment and a sublimable dye receptor as main components, and is further prepared by blending an additive or a coating modifier as required. As the solvent, the same adhesive and solvent as those used for the magnetic recording layer can be used. The coating for forming a concealment layer as described above is applied on the magnetic recording layer using a reverse coater, a roll coater, a blade coater, or a gravure coater,
Drying, thereby forming a hiding layer. In addition, the hiding layer can be provided by printing. The coating amount of the concealing layer is preferably 1 to ²⁰ g / m ² , and more preferably ² to 15 g / m ² . When it is less than 1 g / m ^2, it is difficult to apply the concealing layer uniformly, and when it is more than 20 g / m ^2, it is necessary to increase the coating amount of the magnetic layer in order to obtain the output of the magnetic layer. is there.
In an appropriate coating range, a decrease in magnetic properties due to the provision of the concealing layer is hardly recognized.

The above-mentioned sublimable dye acceptors include vinyl chloride / vinyl acetate copolymer, vinyl chloride / vinyl acetate / maleic acid / copolymer, polyester resin, polyurethane resin, saturated polyester resin, polyester polyurethane resin, epoxy resin And phenoxy resin, nitrocellulose, melamine resin, chlorinated polyethylene type thermoplastic resin and the like. More preferably, it is a polyester resin because of good dyeing properties. These resins are used as a hydrophobic resin emulsion in the case of a water-based coating, and are used by melting in a solvent in the case of a solvent-based coating.
The amount of the sublimable dye receptor to be added is not particularly limited, but is preferably from 10 to 80% by weight in the receptor layer.

The binder used in the hiding layer has the same effect on the sublimable dye acceptor, but may also be a known aqueous resin or solvent-based resin. For example,
Water-soluble resins such as polyvinyl alcohol, casein, starch, hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, water-soluble polymers such as gelatin, and styrene-maleic anhydride copolymer,
Latex or emulsion of water-insoluble resin such as ethylene-maleic anhydride copolymer, styrene-butadiene copolymer, acrylic resin, vinyl acetate resin, or polyurethane resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer And a water-insoluble resin such as a polyester resin. PVC / vinyl acetate copolymer as solvent resin,
PVC / vinyl acetate / maleic acid copolymer, polyurethane resin,
Saturated polyester resins, polyester polyurethane resins, epoxy resins, phenoxy resins, nitrocellulose resins, melamine resins, chlorinated polyethylene resins, and the like. It is not particularly limited to these.

<Protective Layer> In the thermosensitive magnetic recording medium of the present invention, a protective layer may be formed on the concealing layer. The protective layer usually contains a water-soluble polymer substance or a hydrophobic polymer substance as a main component, to which a pigment and a crosslinking agent are added. In the present invention, the protective layer is effective for protecting the recording layer from mechanical damage and reducing the adverse effect on the thermal head. Further, in order to protect the sublimable dye captured by the receiving layer in the concealing layer, it is necessary to form a layer having no affinity with the sublimable dye.

As the water-soluble polymer substance used in the protective layer, those having a barrier effect, such as polyvinyl alcohol resin and casein, are preferable. As the polyvinyl alcohol-based resin, polyvinyl alcohol having any degree of polymerization and saponification degree can be used. Further, as a water-soluble polymer substance, an unsaturated carboxylic acid or a partial or complete ester, salt, anhydride, nitrile, amide, unsaturated sulfonic acid or a salt thereof, having 2 to 30 carbon atoms
Α-olefin, vinyl ether, polyvinyl alcohol copolymerized and modified with a saturated branched fatty acid vinyl, etc., subjected to urethanization, acetalization, etherification, grafting, phosphoric esterification, sulfate esterification, or acetic esterification. Modified polyvinyl alcohol and the like can also be used. The degree of polymerization of such a polymer substance is 30
It is preferably in the range of 0 to 1700, particularly 500
A value of from 1000 is desirable from the viewpoint of paint viscosity and coatability.

Examples of the hydrophobic polymer used in the protective layer include acrylate and / or methacrylate copolymers such as styrene, butadiene, and acrylate and / or methacrylate copolymers. Which are used as aqueous emulsions. In the composition of the protective layer, the amount of the water-soluble polymer or the total amount of the water-soluble polymer and the hydrophobic polymer is preferably 50% by weight or more based on the total weight of the protective layer. Below this range, the abrasion resistance, plasticizer resistance, oil resistance, and solvent resistance of the resulting thermal recording material may be insufficient.

Examples of the water-soluble crosslinking agent used in the protective layer include dialdehyde compounds such as glyoxal and polyaldehyde, polyamine compounds such as polyethyleneimine, epoxy polyamide resins, and diglycidyl compounds such as glycerin diglycidyl ether. Dimethylol urea; metal salts such as ammonium persulfate, ferric chloride and magnesium chloride; and inorganic compounds such as chitosan, ammonium chloride and boric acid. Although there is no particular limitation on the amount of the crosslinking agent added, it is generally preferable that the amount is 3 to 30% by weight based on the weight of the water-soluble polymer substance.

The pigment added to the protective layer is effective for improving the printability and whiteness of the obtained recording material and improving the smoothness thereof. Examples of such pigments include kaolin, clay, talc, calcium carbonate, calcined clay, titanium oxide, diatomaceous earth, silica, synthetic aluminum silicate, synthetic magnesium silicate, aluminum oxide, polystyrene fine particles, and urea-formalin resin fine particles. At least one kind can be used. The content of the pigment in the protective layer is preferably 50% or less based on the total weight of the protective layer.

The amount of the protective layer applied is appropriately adjusted to such an extent that the thermal conductivity and the magnetic properties from the thermal head to the color forming layer are not impaired, but it is usually preferably 1 to 5 g / m ² . More preferably, it is set to 1 to 3 g / m ² . By doing so, a desired effect can be obtained without lowering the thermal sensitivity and magnetic properties of the thermosensitive coloring layer.

After forming the above-mentioned protective layer by coating, it is desirable to apply a surface smoothing treatment with a super calender or the like. When the Beck smoothness of the protective layer is 1000 seconds or less, even if an overcoat layer of an ultraviolet curable resin is provided on the protective layer, a good glossy surface may not be obtained. It is preferable to adjust the Bekk smoothness to 10,000 seconds, preferably 3000 to 5000 seconds.

<About the ionizing radiation-curable resin protective layer>
In the thermosensitive magnetic recording medium of the present invention, an overcoat layer made of a resin material cured by an electron beam and ultraviolet rays may be formed on the protective layer. This overcoat layer is formed by using a solventless type of electron beam and ultraviolet curable resin, and is not only excellent in abrasion resistance, water resistance and solvent resistance of the head but also cured by electron beam and ultraviolet light. Therefore, there is no adverse effect on the thermosensitive coloring layer or the magnetic recording layer. In addition, since crosslinking and curing can be sufficiently performed, when the recording material of the present invention is used as a magnetic card, the recording material has a sufficient film strength and a good gloss on the surface. Further, in order to protect the sublimable dye captured by the receiving layer in the concealing layer, it is necessary to form a layer having no affinity with the sublimable dye.

As the conventionally known ionizing radiation curable substance used in the present invention, a compound having an ethylenically unsaturated bond can be exemplified. The form of the ionizing radiation curable substance may be any of a monomer, a prepolymer, and a polymer. When the substance is a prepolymer or a polymer, it may be referred to as an ultraviolet curable resin or an electron beam curable resin.

For example, (1) aliphatic, alicyclic, aromatic, araliphatic polyhydric alcohols and poly (meth) acrylates of polyalkylene glycols (2) aliphatic, alicyclic, aromatic, araliphatic Poly (meth) acrylate of polyhydric alcohol obtained by adding alkylene oxide to polyhydric alcohol of group (3) Polyester poly (meth) acrylate (4) Polyurethane poly (meth) acrylate (5) Epoxy poly (meth) acrylate (6) ) Polyamide poly (meth) acrylate (7) Poly (meth) acryloyloxyalkyl phosphate ester (8) Vinyl or diene compound having (meth) acryloyloxy group in side chain or terminal (9) Monofunctional (meth) ) Acrylate, vinylpyrrolidone, (meth) acryloyl compound (10) ethylenically unsaturated Cyano compounds having the interleaf

(11) Mono- or polycarboxylic acids having an ethylenically unsaturated bond and their alkali metal salts, ammonium salts, amine salts, etc. (12) Ethylenically unsaturated (meth) acrylamide or alkyl-substituted (meth) acrylamide (13) Vinyl lactam and vinyl lactam compound (14) Polyether having ethylenically unsaturated bond and its ester (15) Ester of alcohol having ethylenically unsaturated bond (16) Ethylenic unsaturated bond (17) Aromatic compounds having one or more ethylenically unsaturated bonds, such as styrene and divinylbenzene (18) Polyorganosiloxane compounds having a (meth) acryloyloxy group on the side chain or at the terminal (19 Silicone compound having an ethylenically unsaturated bond (20) above (1) to (19) multimeric or oligoester (meth) acrylate modified compounds of the compounds described

Of these, a polyfunctional substance is more desirable than a monofunctional substance in the present invention because the cured film has higher heat resistance and toughness. In particular, the substance used for the uppermost layer which is in direct contact with the thermal head desirably has a high glass transition point of the cured product, and the bifunctional is neopentyl glycol diacrylate (Tg of cured product, 7%).
0 ° C), tripropylene glycol diacrylate (90 ° C), bisphenol A EO modification (n =
4) Diacrylate (same as above, 75 ° C.), and those having three or more functional groups include trimethylolpropane triacrylate (same as above,> 250 ° C.) and pentaerythritol triacrylate (same as above,> 250 ° C.) , Trimethylolpropane PO-modified (n = 3) triacrylate (120 ° C.), ditrimethylolpropane tetraacrylate (> 250 ° C.), pentaerythritol tetraacrylate (> 250 ° C.), dipentaerythritol penta / Hexaacrylate (> 2
50 ° C.) can be preferably used.

These ionizing radiation-curable substances can be used alone or as a mixture of several kinds of resins. It is desirable that the coating be performed without a solvent, but the coating may be performed by dissolving in an organic solvent, or the coating may be performed in an aqueous emulsion state.

In the overcoat layer of the present invention, for compatibility with a thermal head, particularly for preventing sticking,
Pigments and / or lubricants (release agents) can be included. The coating amount of the overcoat layer is 1 to 5 g / m ^2.
And more preferably 1 to 3 g / m ² .

The ionizing radiation-curable resin protective layer of the present invention preferably contains a pigment. By including the pigment in the uppermost layer, even when excessive energy is applied from the thermal head at the time of high-temperature coloring, which is usually observed by heat sensitivity, it is possible to prevent adhesion of the residue to the thermal head and sticking. Examples of such a pigment that can be used in the uppermost layer include the pigments exemplified in the thermosensitive coloring layer. The compounding amount of the pigment in the protective layer is 2 to 50 parts by weight, more preferably 3 to 40 parts by weight based on 100 parts by weight of the resin. In the case of curing with ultraviolet rays, it is necessary to use a compounding amount that does not hinder the curing of the resin due to the hiding effect of the pigment, and is preferably 30 parts by weight or less based on 100 parts by weight of the resin.

<Regarding the Recording Layer Formed on the Other Surface of the Support> In the present invention, on the other surface of the support (the side opposite to the magnetic layer), in order to increase the added value of the thermosensitive magnetic recording material, A thermosensitive magnetic recording medium that has been processed to provide higher functions can be obtained. As a typical case, a conventionally known recording layer described below can be formed.

(1) Thermal recording layer formed on the other surface of the support A thermal recording layer may be formed on the other surface of the support. A thermosensitive coloring layer containing a colorless or pale color dye precursor, a color developer and a binder is formed by a conventionally known coating method. The weight of the thermosensitive coloring layer is generally 3
It is preferably from 10 to 10 g / m ² .

The dye precursor used in the present invention is a substantially colorless electron-donating compound which can react with a developer under heating to form a color. Among such color-forming dye precursors, those having a solubility in toluene of 1% by weight or less at room temperature as described above include, for example,
2,2-bis {4- [6 '-(N-cyclohexyl-N
-Methylamino) -3'-methylspiro [phthalide-
3,9'-Xanthen] -2'-ylamino] phenyl} propane, 2- (2-fluorophenylamino)-
A compound comprising at least one member selected from fluoran compounds such as 6-diethylaminofluoran can be used. These dye precursors are preferably refined using a disperser such as a sand grinder or an attritor so that the average particle size is 1 μm or less.

The color developer used in the present invention comprises an electron-accepting organic acidic substance capable of reacting with a color-forming paint under heating to form a color. Such a developer can be liquefied or vaporized at room temperature or higher, preferably at 70 ° C. or higher, and can react with the chromogenic dye to form a color. As described above, the developer used in the present invention has a solubility in toluene of 1% by weight or less at room temperature as described above. For example, 3,4-dihydroxyphenyl-p-tolylsulfone, bis- (3 -Allyl-4-hydroxyphenyl) -sulfone, stearyl gallate, methyl-bis (4-hydroxyphenyl) acetate, n-butyl-bis (4-hydroxyphenyl) acetate, 4-hydroxy-4-isopropoxydiphenylsulfone, And 1,1-bis- (4
-Hydroxy-phenyl) -cyclohexane and at least one member selected therefrom can be used.

In the present invention, the developer is usually 1 to 5 parts by weight, preferably 1.5 to 3 parts by weight, per 1 part by weight of the dye precursor.
Mix and use in parts by weight.

In the present invention, as the binder contained in the thermosensitive coloring layer, a polymer substance soluble in toluene at normal temperature as described above is used. However, when mixed with the respective dispersions of the dye precursor and the developer, it is preferable that the mixture does not develop color, aggregate, or have a high viscosity, and is formed. It is preferred that the heat-sensitive recording layer film satisfy requirements such as toughness, no desensitizing effect, and no sticking to the thermal head.

Therefore, in the present invention, it is preferable to use a methyl methacrylate copolymer resin as a binder satisfying the above requirements. Such a methyl methacrylate copolymer resin has a glass transition point (T
Preferably, G) is in the range of 75 ° C. to 105 ° C., for example a copolymer of methyl methacrylate with an acrylate and / or methacrylate (eg butyl methacrylate) or styrene. The binder is generally used based on the total dry weight of the thermosensitive coloring layer.
It is preferably used in an addition amount of 15 to 30% by weight.

In the thermosensitive magnetic recording medium of the present invention, the thermosensitive coloring layer formed on the other surface of the support may contain a pigment, particularly a white pigment, if necessary. Such pigments include, for example, calcium carbonate, magnesium carbonate,
Kaolin, clay, talc, calcined clay, silica, diatomaceous earth, synthetic aluminum silicate, zinc oxide, titanium oxide, aluminum hydroxide, barium sulfate, surface-treated inorganic fine powders such as calcium carbonate and silica, and urea -Fine powders of organic resins such as formalin resin, styrene / methacrylic acid copolymer, and polystyrene resin.

The heat-sensitive coloring layer may contain, if necessary, a small amount of auxiliary additives (eg, fillers, surfactants, heat-fusible substances (or lubricants)) commonly used in conventional heat-sensitive recording materials. 10% or less based on the weight of the heat-sensitive coloring layer).

Examples of the heat-fusible substance include stearamide, stearic acid ethylenebisamide, oleamide, palmitylamide, coconut fatty acid amide, and the like.
Fatty acid amides such as behenic acid amide; zinc stearate, calcium stearate, polyethylene wax,
Waxes such as carnauba wax, paraffin wax, ester wax; dimethyl terephthalate, dibutyl terephthalate, dibenzyl terephthalate, dibutyl isophthalate, phenyl 1-hydroxynaphthoate, 1,2-di (3-methyl Phenoxy) ethane, 1,2-diphenoxyethane,
1-phenoxy-2- (4-methylphenoxy) ethane, diphenyl carbonate, p-benzylbiphenyl, 2,
2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'-butylidenebis (6-t-butyl-3-methylphenol), 1,1,3-tris (2-
Methyl-4-hydroxy-5-t-butylphenyl) butane, 2,2'-methylenebis (4-ethyl-6-t-
Butylphenol), 2,4-di-t-butyl-3-methylphenol, 4,4'-thiobis (3-methyl-6
Hindered phenols such as -t-butylphenol); and 2- (2'-hydroxy-5'-methylphenyl) -benzotriazole and 2-hydroxy-
Sensitizers such as 4-benzyloxybenzophenone, lubricants,
Antioxidants, UV inhibitors, and the like can be used.

These additives are used in conventional addition amounts, but the heat-fusible substance is generally used as a developer.
It is preferable that the thermosensitive coloring layer contains the thermosensitive coloring layer in a proportion of 4 parts by weight or less with respect to part by weight.

In order to form a thermosensitive coloring layer, a coating solution containing the above components and a solvent (for example, toluene) is prepared, and this is coated on a support by a known coating method, for example, a roller coating method, a gravure coating method, or the like. May be applied by a wire coating method or the like and dried.

In the thermosensitive magnetic recording medium of the present invention, a photograph or a design may be printed according to the purpose of use. The thermosensitive magnetic recording medium suitable for various uses can be obtained by printing the pattern and precautions on the use of the card on the protective layer and providing an ultraviolet-curable resin protective layer thereon.

(2) Ink jet recording layer formed on the other side of the support As the pigment used in the present invention, commercially available pigments such as amorphous synthetic silica, aluminosilicate, kaolin, clay, calcined clay, Zinc oxide, tin oxide, aluminum hydroxide, boehmite, pseudoboehmite, alumina, calcium carbonate, satin white, aluminum silicate, smectite, magnesium silicate, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene plastic pigment, urea resin plastic pigment, Examples include, but are not limited to, various pigments known in the field of general coated paper or inkjet recording paper, such as benzoguanamine-based plastic pigments. Among these pigments, amorphous synthetic silica, aluminosilicate, boehmite and pseudo-boehmite are particularly preferably used.

As the resin used in the present invention, a cationic resin is particularly preferred. Dyes and pigments, which are coloring components in inks used in ink jet printers, often have an anionic group, and thus a cationic ink fixing agent is indispensable in the ink receiving layer. When the main component pigment is an anionic pigment such as silica, the use of a cationic resin as the binder resin not only makes the water resistance of the printed image more robust, but also reduces the coloring substances that occur in the receiving layer after printing. Color changes over time due to movement,
This is preferable because an effect of preventing image bleeding is expected. In order to change color tone over time after printing, it is also effective to use a resin having a high affinity for a hydrophilic high-boiling point solvent contained in the ink alone or as a mixture. Examples of hydrophilic high-boiling solvents contained in the ink include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol monomethyl ether, 2-pyrrolidone, thiodiglycol, and triethylene glycol mono. There are butyl ether, 1,5-pentanediol and the like, examples of the aqueous binder having a high affinity for these solvents include polyvinylpyrrolidone, polyacryloylmorpholine, polyhydroxyalkyl acrylate, and hydroxypropyl cellulose. It is not limited to these.

In addition, a surfactant is mixed with an antifoaming agent as an additive to improve workability at the time of coating and to improve the wettability of the base material to obtain a uniform ink receiving layer. They may be blended, and starch or synthetic resin particles may be mixed to prevent blocking of the recording medium and to improve the paper permeability of the printer. In addition, various pigments other than the main component can be added to adjust the transparency and surface gloss, and lightfastness improvers such as ultraviolet absorbers and light stabilizers are added to improve the preservability of printed images. You can also.

As a method for adding these additives, a method may be used in which the additives are mixed in advance with a water-based paint, or a method in which a coating layer is first formed and then a solution containing the additives is overcoated, sprayed, or impregnated. May be added later. When the additive is added to the water-based paint in advance, if the paint is gelled by the shock of the addition, re-dispersion using a mechanical means is also an effective means. For example, when a cationic resin is added to a dispersion of an anionic pigment such as silica, the paint temporarily gels due to the electrostatic properties of both, but coating is possible if redispersed using mechanical means. In the dried coating film, both are strongly bound electrostatically, so that the water resistance of the coating film is sufficiently maintained even if the cationic resin is not particularly crosslinked. As a coating method, known coating means, for example, a bar coating method, a roll coating method, a blade coating method, an air knife coating method, a gravure coating method, a die coating method, a curtain coating method, and the like can be used. Absent.

The amount of coating is 1 to 60 g / dry weight.
m ² is preferable, and more preferably 3 to 50 g / m ^2.
It is about. Here, if the amount is less than 1 g / m ² , the ink absorption tends to be insufficient, and if it is more than 60 g / m ² , the cost increases, which is not preferable.

(3) Thermal transfer receiving layer formed on the other surface of the support As the pigment used in the present invention, commercially available pigments such as amorphous synthetic silica, aluminosilicate, kaolin, clay, calcined clay, Zinc oxide, tin oxide, aluminum hydroxide, boehmite, pseudoboehmite, alumina, calcium carbonate, satin white, aluminum silicate, smectite, magnesium silicate, magnesium carbonate, magnesium oxide, diatomaceous earth, styrene plastic pigment, urea resin plastic pigment, Examples include, but are not limited to, various pigments known in the field of general coated paper or inkjet recording paper, such as benzoguanamine-based plastic pigments. Among these pigments, amorphous synthetic silica, aluminosilicate, boehmite and pseudo-boehmite are particularly preferably used.

The aqueous binder used in the present invention includes:
For example, polyvinyl alcohol and derivatives thereof of various molecular weights and degrees of saponification, starch, derivatives of starch, methoxycellulose, carboxymethylcellulose, methylcellulose, cellulose derivatives such as ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide-acrylic acid Ester copolymer,
Acrylic acid amide-acrylic acid ester-methacrylic acid ester copolymer, styrene-maleic anhydride copolymer alkali salt, polyacrylamide and derivatives thereof,
Water-soluble resins such as polyethylene glycol, and polyvinyl acetate, polyurethane, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polyacrylate, vinyl chloride-vinyl acetate copolymer,
Polybutyl methacrylate, ethylene-vinyl acetate copolymer, styrene-butadiene-acrylic copolymer, resins such as polyvinylidene chloride, furthermore, glue, casein, soy protein, gelatin, sodium alginate, etc. It is not limited to these. These resins may be used alone or in two
More than one kind can be mixed and used.

In addition, by mixing an antifoaming agent as an additive, the workability during coating can be improved, and the wettability of the substrate can be improved to form a uniform coated surface.

As the coating method, known coating means such as a bar coating method, a roll coating method, a blade coating method, an air knife coating method, a gravure coating method, a die coating method and a curtain coating method can be used. This is not the case.

The amount of coating is 3 to 30 g / dry weight.
about m ² are preferred, more preferably 5 to 20 g / m ²
It is about. Here, if it is less than 3 g / m ² , the ink absorption tends to be insufficient, and if it is more than 30 g / m ² , the cost increases, which is not preferable.

[0061]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which, of course, are not intended to limit the scope of the present invention. In each example, "part" and "%"
Indicates "parts by weight" and "% by weight" unless otherwise specified.

Example 1 A thermosensitive magnetic recording medium was manufactured by the following steps. Preparation of ferromagnetic dispersion for coating solution for magnetic recording layer Barium ferrite (trade name: MC127 manufactured by Toda Kogyo) 100 parts Sublimation dye (trade name: Kayset Red B) 10 parts Sodium polycarboxylate (trade name: ARON) T-40 manufactured by Toa Gosei Co., Ltd. 2 parts Solid content concentration: 40% Styrene-maleic acid ester (trade name: Polymalon 385 manufactured by Arakawa Chemical Co.) 5 parts Solid content concentration: 25% Water is added to this to give a concentration of 50. % Of a pre-dispersion was prepared, and then the pre-dispersion was dispersed by a sand grinder to prepare a coating solution.

(2) Preparation of Coating Solution for Magnetic Recording Layer A soft urethane emulsion (trade name: Iselux S-3020N, manufactured by Hodogaya Chemical Co., Ltd.) was added to the above dispersion.
0 parts were added to prepare a coating solution having a dry weight of 46.4%.

(3) Preparation of Hidden Layer Coating Solution Titanium oxide (trade name: KR-460, manufactured by Titanium Co., Ltd.) 100 parts Sodium polycarboxylate (trade name: ARON T-40 manufactured by Toa Gosei Co., Ltd.) 2 parts Concentration: 40% Water 100 parts Water-dispersed polyester resin (trade name: Resem ES-1 manufactured by Chukyo Yushi Co., Ltd.) 40 parts Non-volatile content: 30%, average particle diameter: 0.2 μm, MW: 15000-20000, Tg: 67 ° C, softening point: 163 ° C Polyvinyl alcohol (trade name: PVA105, manufactured by Kuraray Co., Ltd.) 15 parts Solid content concentration: 20% The above dispersion was dispersed with a high-speed stirrer (manufactured by Nikkiso Co., Ltd.) to prepare a coating liquid.

(4) Preparation of thermosensitive magnetic recording medium The coating liquid for the magnetic recording layer obtained in the above (2) was coated on a base paper (LBKP 100%) having a basis weight of 120 g / m ² by a gravure coater to obtain a solid content of 30 g / m ^2. And dried to form a magnetic recording layer. The coating solution for the concealing layer obtained in the above (3) was further coated with a gravure coater to give a solid coating amount of 5 g.
/ M ² , and dried to form a thermosensitive magnetic recording medium.

The above thermosensitive magnetic recording medium was cut into a card having a predetermined size, and a card printer testing machine having a line dot type thick film type head (0.66 mJ / dot, 14 V, 1 msec)
ON), the obtained color density was measured with a Macbeth reflection densitometer (RD-914 type) using a magenta filter and evaluated. Table 1 shows the results.

The thermosensitive magnetic recording medium was cut into a card having a predetermined size, and the magnetic recording characteristics were evaluated using a commercially available reader / writer. Table 1 shows the results. Reader / writer conditions: Transport speed 19 cm / s Permalloy head with a recording head gap of 30μ Permalloy head with a recording head gap of 30μ Recording frequency 50FRPI

<Example 2> An ultraviolet curable resin (trade name: Kayanova N-1815) was coated on the concealing layer with a gravure coater.
Nippon Kayaku Co., Ltd.) was applied in the same manner as in Example 1 except that the solid content was applied at 2 g / m ² . Table 1 shows the test results.

[0069]

[Table 1]

(Note of Table 1) * 1 The value of% display with respect to the read output of the reference note of the cybernet standard. The appropriate range of this value is 75% to 130%.

[0071]

As is clear from Table 1, the thermosensitive magnetic recording media of the examples according to the present invention obtained satisfactory recording characteristics. Also, there was no problem in readability.

The thermosensitive magnetic recording medium of the present invention had excellent whiteness even in the sublimable dye-receiving layer on the magnetic recording layer, and a clear recorded image was obtained. In addition, according to the present invention, both magnetic information and visible information can be recorded on one side of the card without deterioration of the magnetic characteristics, and a very large amount of information can be recorded. Therefore, it has extremely high practicality.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a thermosensitive magnetic recording medium of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 thermosensitive magnetic recording medium 2 support 3 magnetic recording layer 4 concealing layer 5 protective layer 6 ionizing radiation-curable protective layer 7 recording layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C005 HA01 HB07 JA01 KA06 KA08 KA15 KA25 KA37 KA45 LB06 2H111 AA01 AA07 AA27 AB01 BA01 BA03 BA09 BA33 BA39 BA53 BA55 BA61 BA76 CA01 CA03 CA33 5D006 AA01 AA04 FA09 BA09 DA01

Claims (5)

[Claims] 1. A support comprising: a support; a magnetic recording layer formed on one surface of the support and containing a ferromagnetic powder and a binder as main components; and a concealing layer provided on the magnetic recording layer. 3. The thermosensitive magnetic recording material according to claim 1, wherein the magnetic recording layer contains a sublimable dye, and the concealing layer comprises a sublimable dye-accepting component and a white pigment. 2. The thermosensitive magnetic recording medium according to claim 1, wherein the white pigment of the concealing layer is an inorganic pigment. 3. The thermosensitive magnetic recording medium according to claim 1, wherein the white pigment of the concealing layer is hollow fine particles made of a thermoplastic resin. 4. The thermosensitive magnetic recording medium according to claim 1, wherein a protective layer containing a water-soluble polymer and / or a synthetic resin emulsion as a main component is provided on the concealing layer. . 5. A protective layer comprising an ionizing radiation-curable resin as a main component is provided on the concealing layer.
3. The thermosensitive magnetic recording medium according to any one of 3.