JP3317567B2 - Thermosensitive recording material and thermosensitive magnetic recording medium using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material and a heat-sensitive magnetic recording medium which are excellent in heat resistance, washing resistance and hand cream resistance. In particular, the present invention is a ticket, a commuter pass,
Cards such as ticket paper such as toll tickets and prepaid cards and P
The present invention relates to a thermosensitive recording material and a thermosensitive magnetic recording medium applicable to labels, sheets, tapes, and the like such as OS labels.

[0002]

2. Description of the Related Art A thermosensitive recording material using a leuco dye which is an electron-donating colorless dye and an electron-accepting compound (a color developer) which forms the leuco dye can be easily printed. It is widely used because it is possible and the obtained recording medium is good. Examples of usage include facsimile, printer, commuter pass, prepaid card, boarding pass, coupon, and the like.

[0003] In particular, in recent years, the use of heat-sensitive recording materials as commuter passes, prepaid cards, tickets, and the like has increased in many cases. Therefore, various physical properties required for the heat-sensitive recording layer of the heat-sensitive recording material are required to withstand more severe environments than conventional ones according to the use environment.

For example, commuter passes and prepaid cards are sometimes washed by mistake with clothes, but they are required to function normally after washing. Conventionally, for the purpose of improving the water resistance of the heat-sensitive recording layer of the heat-sensitive recording material, a protective layer is provided on the heat-sensitive recording layer. Also,
JP-A-5-3250 discloses a heat-sensitive recording medium containing an isocyanate-based or aziridine-based curing agent in at least one of a heat-sensitive recording layer and a protective layer. Thus, a certain level of water resistance is also taken into account in conventional thermal recording materials. However, none of the heat-sensitive recording materials had sufficient water resistance to washing. In other words, the card surface was rubbed by washing, and the recording functionality and recording preservability were lost due to peeling and abrasion of the heat-sensitive recording layer, and the card could not be used.

[0005] Further, with respect to coupons, it is usual to print on a large number of sheets at once, in which case the thermal head often stores excessive heat. As a result, the coupon is wrinkled and the heat-sensitive recording layer is easily peeled off by melting. Although conventional heat-sensitive recording materials are required to have a certain level of heat resistance, they cannot be said to have sufficient heat resistance in the above-mentioned usage forms. In the case of a ticket or commuter pass,
With the spread of automatic ticket gates, the chance of touching the surface with a finger has increased significantly compared to the past. For this reason, it has recently been proposed as a new problem that chemicals such as hand cream used for protecting hands have a bad influence on a heat-sensitive recording layer of a ticket or a commuter pass.

The commuter pass, prepaid card, boarding pass, coupon, and the like are thermosensitive recording materials having a thermosensitive recording layer, and are thermosensitive magnetic recording media further having a magnetic recording layer. From the viewpoint of the magnetic recording characteristics of the thermosensitive magnetic recording medium, the thermosensitive recording layer, the protective layer, and the like provided on the magnetic recording layer are preferably thin. This is because the smaller the thickness of the heat-sensitive recording layer and the protective layer, the more the magnetic output of the magnetic recording layer can be improved. However, from the viewpoint of protecting the heat-sensitive recording layer as described above, a protective layer having a certain thickness is required. Therefore,
If the durability of the heat-sensitive recording layer itself is improved, the thickness of the protective layer can be reduced, and as a result, the magnetic output of the magnetic recording layer can be improved.

Accordingly, an object of the present invention is to provide a heat-sensitive recording which has better washing resistance than before and has other physical properties such as heat and humidity resistance, alcohol resistance, sweat resistance, heat resistance and the like. It is to provide materials. Further, the present invention uses a heat-sensitive recording material having the above-mentioned excellent washing resistance and the like,
It is an object of the present invention to provide a thermosensitive magnetic recording medium capable of reducing a protective layer and improving a magnetic output.

Another object of the present invention is to provide, in addition to washing resistance, better heat resistance and better chemical resistance, especially hand cream resistance, and other physical properties, such as heat and humidity resistance, An object of the present invention is to provide a heat-sensitive recording material having the same alcoholic property, sweat resistance and the like as before. Further, the present invention is to provide a thermosensitive magnetic recording medium capable of thinning a protective layer and improving magnetic output by using the above-mentioned thermosensitive recording material having excellent washing resistance, heat resistance and chemical resistance. is there.

[0009]

The present invention relates to a heat-sensitive recording material having a heat-sensitive recording layer containing a color former, a color developer and a binder, wherein the binder contains a hydrazine self-crosslinking acrylic resin. (1st mode). Further, the present invention is a heat-sensitive recording material having a heat-sensitive recording layer and a magnetic recording layer containing a color former, a developer and a binder, wherein the binder contains a hydrazine self-crosslinking acrylic resin. The present invention relates to a thermosensitive magnetic recording medium (first embodiment).

Further, the present invention relates to a heat-sensitive recording material having a heat-sensitive recording layer containing a color former, a color developer and a binder on a substrate, wherein the binder contains a hydrazine self-crosslinking acrylic resin, and The present invention relates to a heat-sensitive recording material (second embodiment), wherein the heat-sensitive recording layer has a crosslinked structure with an aziridine-based curing agent. Furthermore, the present invention is a heat-sensitive recording material having a heat-sensitive recording layer and a magnetic recording layer containing a color former, a developer and a binder on a substrate, wherein the binder contains a hydrazine self-crosslinking acrylic resin. And a thermosensitive magnetic recording medium (second embodiment), wherein the thermosensitive recording layer has a crosslinked structure with an aziridine-based curing agent. Hereinafter, the present invention will be described.

The substrate used in the present invention has a sheet shape or a plate shape. As the base material, vinyl chloride, nylon, cellulose diacetate, cellulose triacetate, polystyrene, polyethylene, polypropylene,
Plastics such as polyester, polyimide, and polycarbonate, metals such as copper and aluminum, paper, impregnated paper, and the like can be used alone or in combination as a composite. A preferable material may be appropriately selected from the above materials in consideration of physical properties required as the base material, for example, strength, rigidity, concealing property, light opacity and the like. The thickness of the substrate is about 0.005 to 5 mm.

The heat-sensitive recording layer contains a leuco dye as a color former,
It is basically composed of a developer and a binder. Leuco dyes include triphenylmethanes such as crystal violet lactone and malachite green lactone:
Fluoranes such as 2-benzo-6-diethylaminofluoran: Auramines such as N-benzoyl auramine:
In addition, phenothiazines: spiropyrans and the like can be used.

As the developer, a compound having a phenolic hydroxyl group, that is, a phenolic compound can be used. For example, phenol, o-cresol, p-cresol, p-ethylphenol, t-butylphenol, 2,6-di-t-butyl-4-methylphenol,
Nonylphenol, dodecylphenol, styrenated phenol, 2-2'-methylene-bis (4-methyl-6
-T-butylphenol), α-naphthol, β-naphthol, hydroquinone monomethyl ether, guaiacol, eugenol, p-chlorophenol, p-bromophenol, o-chlorophenol, o-bromophenol, 2,4,6-trichlorophenol , O-phenylphenol, p-phenylphenol, p- (p-
(Chlorophenyl) phenol, o- (o-chlorophenyl) phenol, salicylic acid, ethyl p-oxybenzoate, propyl p-oxybenzoate, octyl p-oxybenzoate, dodecyl p-oxybenzoate, catechol,
Hydroquinone, resorcinol, 3-methylcatechol, 3
-Isopropylcatechol, pt-butylcatechol, 2,5-di-tert-butylhydroquinone, 4,4'-
Methylene diphenol, bisphenol A, 1,2-dioxynaphthalene, 2,3-dioxynaphthalene, chlorcatechol, promocatechol, 2,4-dihydroxybenzophenone, phenolphthalene, o-cresolphthalein, protocatechuic acid Methyl, ethyl protocatechuate, propyl protocatechuate, octyl protocatechuate, dodecyl protocatechuate,
Pyrogallol, oxyhydroquinone, phloroglysin,
2,4,6-trioxymethylbenzene, 2,3,4-
Trioxyethylbenzene, methyl gallate, ethyl gallate, propyl gallate, butyl gallate, hexyl gallate, octyl gallate, dodecyl gallate, cetyl gallate, stearyl gallate, 2,3,5-trioxynaphthalene, Tannic acid, phenolic resin and the like are mentioned as examples of the phenolic compound.

In the present invention, a hydrazine self-crosslinking acrylic resin or a mixture of hydrazine self-crosslinking acrylic resin and another resin is used as the binder. Examples of resins that can be mixed include aqueous emulsions of oil-soluble resins such as xylene resins, phenol resins, coumarone resins, vinyl toluene resins, terpene resins, vinyl toluene / butadiene copolymer resins, vinyl toluene / acrylate copolymer resins, and polyvinyl alcohol. Examples thereof include water-dispersible emulsions of resins, methylcellulose resins, hydroxyethylcellulose resins, carboxymethylcellulose resins, methylvinylether / maleic anhydride copolymer resins, polyacrylic resins, gelatin, gum arabic and the like.

The hydrazine self-crosslinking acrylic resin is
It has a hydrazine group (—NHNH ₂ ) and a carbonyl group in the polymer chain, and has a crosslinked structure formed by the reaction between the hydrazine group and the carbonyl group. Such an acrylic resin is an acrylic copolymer containing acrylic acid or a derivative thereof as a monomer component, and includes -COO
H, -NH _2, those having a functional group -OH and the like.
Examples of such acrylic monomers include acrylic organic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, hydroxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylic acid. Examples thereof include (meth) acrylic acid hydroxyalkyl ester acids such as acid 2-hydroxypropyl and hydroxybutyl (meth) acrylate, (meth) acrylic sodium aminoalkyl esters, and acrylamides. However, it is not limited to this. The acrylic copolymer used in the present invention is -CO as described above.
OH, -NH _2, at least one acrylic monomer having a functional group -OH, etc. are those having as a copolymer component, a copolymer thereof with another copolymerizable vinyl monomer. Such other vinyl monomers include alkyl (meth) acrylates,
Examples include (meth) acrylic acid phenyl ester, acrylonitrile, vinyl chloride, vinyl acetate, styrene and derivatives thereof. However, it is not limited to this.

The amount of hydrazine contained in the hydrazine self-crosslinking acrylic resin used in the present invention can be appropriately determined according to the amount of carbonyl groups in the acrylic resin. Generally, the amount is preferably about equimolar to the carbonyl group in the acrylic resin. Incidentally, the amount of carbonyl groups in the acrylic resin is generally in the range of 0.2% to 10%, preferably 3 to 8% in terms of resin solid content ratio.

In the heat-sensitive recording material and the heat-sensitive magnetic recording medium according to the second embodiment of the present invention, an aziridin-based curing agent is further used together with the acrylic resin as described above in order to crosslink the resin. As the aziridine-based curing agent, for example, trimethylolpropane-tri-β-aziridinylpropionate, teramethylolmethane-tri-β-aziridinylpropionate-N, N′-diphenylmethane-4,4′- Bis (1-aziridinecarboxamide), N, N'-hexamethylene-1,6'-bis (1
-Aziridinecarboxamide) and the like. The amount of the aziridine-based curing agent is, for example, 0.1 to 5
%, Preferably in the range of 0.5 to 1.5%.

In order to form a heat-sensitive recording layer using the above-mentioned components, the solid content ratio of the leuco dye is 10 to 60% by weight (preferably 20 to 40% by weight), and the color developer is 10 to 60% by weight (preferably). 20 to 40% by weight), a binder of 10 to 70% by weight (preferably 20 to 40% by weight), and at least one of the above components is dissolved, and the leuco dye and the developer are dissolved or dispersed in water. The coating may be formed on the entire surface or in a pattern on the substrate by a known printing method or coating method using the obtained coating, and the thickness of the heat-sensitive recording layer is usually about 1 to 15 μm.

The heat-sensitive recording layer of the present invention may further contain conventional additives, if necessary. For example, silicon-based, wax-based antifoaming agent, foam inhibitor, aluminum hydroxide, calcium carbonate, silica, inorganic pigments such as talc, polyolefin resin, polystyrene resin,
Examples include organic pigments composed of urea-formalin resin, metal salts of higher fatty acids, lubricants such as fluorocarbon fine particles of waxes, ultraviolet absorbers, dispersants, wetting agents, leveling agents and the like.

The magnetic recording layer of the thermosensitive magnetic recording medium of the present invention is composed of γ-Fe ₂ O ₃ , Co-coated γ-Fe ₂ O ₃ , F
_{e 3 O 4, CrO 2,} Fe, Fe-Cr, Fe-Co,
Co-Cr, Co-Ni, MnAl, Ba ferrite,
A dispersion in which conventionally known magnetic fine particles such as Sr ferrite are dispersed in an appropriate resin or an ink vehicle,
It can be formed on a substrate by a conventionally known coating method such as a gravure method, a roll method, and a knife edge method. or,
The magnetic recording layer is made of Fe, Fe-Cr, Fe-Co, Co-
Using a metal such as Cr or an alloy thereof, a vacuum deposition method,
It can also be formed on a substrate by a sputtering method, a plating method, or the like.

When the magnetic recording layer is formed by a coating method, its thickness is 1 to 100 μm, preferably 5 to 100 μm.
About 20 microns. When the magnetic recording layer is formed by a vacuum deposition method, a sputtering method, or a plating method,
Its film thickness is about 100 Å to 1 μm, preferably about 500 to 2,000 Å.

As a binder resin or an ink vehicle in which magnetic fine particles such as γ-Fe ₂ O ₃ are dispersed, butyral resin, vinyl chloride / vinyl acetate copolymer resin, urethane resin, polyester resin, cellulose resin, acrylic resin, A styrene / maleic acid copolymer resin alone or a copolymer obtained by combining monomer components of these resins is used, and a rubber-based resin such as a nitrile rubber or a urethane elastomer is added as necessary. Further, in the dispersion obtained by dispersing the magnetic fine particles in the resin, if necessary, a surfactant, a silane coupling agent, a plasticizer, a wax, a silicone oil, carbon and other pigments can be added. .

The heat-sensitive recording material and the heat-sensitive magnetic recording medium of the present invention may have various layers in addition to the above-mentioned substrate, heat-sensitive recording layer and magnetic recording layer. Examples of such a layer include a magnetic barcode, a colored layer that can also function as a concealing layer of a magnetic recording layer, a protective layer, and an anchor coat layer.

The magnetic bar code can be composed of a regular bar pattern and a dummy pattern. Among them, the regular bar pattern is a magnetic material having a coercive force of 20 Oe or less, for example, Sendust, Permalloy, Mn-Zn ferrite, γ- Fe ₂ O ₃ , Co-γ-Fe ₂ O ₃ , iron powder, etc. are uniformly dispersed in a binder such as a polyester resin, a vinyl chloride resin, a polyurethane resin, etc. to form an ink, and the printing method such as an offset method or a screen printing method is used. Print and form. The dummy pattern is formed by printing a non-magnetic material such as alumina in the same manner as the normal bar pattern. As the material of the magnetic bar constituting the magnetic barcode, the same material as the magnetic recording layer can be used. However, as the magnetic bar, one having a magnetic characteristic different from that of the magnetic recording layer (for example, carbonyl iron powder) can be used, and a dummy bar made of a nonmagnetic material having a similar shape to the magnetic bar can be used in combination. . The thickness of these magnetic bars and dummy bars is usually about 0.5 to 20 μm. The magnetic barcode is magnetized by a magnetic head to obtain a magnetic re-output, and its pattern can be read.

The coloring layer is made of a cellulose derivative such as ethyl cellulose, ethyl hydroxyethyl cellulose, cellulose acetate propionate, or cellulose acetate; a styrene resin such as polystyrene or poly-α-methylstyrene; a styrene copolymer resin; polymethyl methacrylate; Ethyl methacrylate, polyethyl acrylate,
Acrylic resin or methacrylic resin such as polybutyl acrylate alone or copolymerized resin, rosin, rosin modified maleic acid resin, rosin modified phenol resin, rosin ester resin such as polymerized rosin, polyvinyl acetate resin, cumarone resin, vinyl toluene resin , Vinyl chloride resin, polyester resin, polyurethane resin, butyral resin, and other binders, various pigments are added according to the color to be colored, and, if necessary, a plasticizer, a stabilizer, a wax,
After adding a grease, a drying agent, a drying aid, a curing agent, a thickening agent, and a dispersing agent, using a coloring paint or ink which is sufficiently kneaded with a solvent or a diluent, a normal gravure method, a roll method, It can be formed in a desired portion by a coating method such as a nifege method or an offset method or a printing method.

The protective layer can be formed by laminating a synthetic resin film or applying a synthetic resin paint. As the synthetic resin constituting the protective layer, those similar to the synthetic resins used for forming the colored layer can be widely used in consideration of the use or the adhesion to other layers. In particular, the use of a reaction-curable synthetic resin is advantageous in terms of surface hardness and prevention of contamination, and the use of an ultraviolet-curable synthetic resin is preferable because curing after application can be performed instantaneously. Also, silicone or the like can be added to the protective layer to give the surface smoothness. In the present invention, since various resistances of the heat-sensitive recording layer can be improved, it is possible to provide a heat-sensitive recording material having the same properties as the conventional one even with a thinner protective layer. Further, in a thermosensitive magnetic recording medium, the magnetic output can be improved by reducing the thickness of the protective layer.

The anchor coat layer is formed using a coating for the anchor coat layer appropriately selected in consideration of the properties of the binder resin constituting the heat-sensitive recording layer and the binder resin constituting other layers such as the magnetic recording layer. Can be formed. As the binder resin used for the anchor coat layer, polyester resin, vinyl chloride / vinyl acetate copolymer resin, polyurethane resin, polyvinyl butyral resin, acrylic resin, cellulose resin, styrene / maleic acid copolymer resin, rubber resin, poly Vinyldene chloride resin, polyamide resin and the like can be used.

The anchor coat layer plays a role in enhancing the adhesion on the contact surface of the heat-sensitive recording layer with the other, for example, the adhesion between the magnetic recording layer and the heat-sensitive recording layer, and effectively prevents the heat-sensitive recording layer from peeling off. be able to.

Magnetic information is recorded in the magnetic recording layer by a usual method such as a magnetic head. On the other hand, visible information such as barcodes, OCR characters, names, expiration dates and the like are recorded by causing a chemical change in the thermosensitive coloring agent by a heating means such as a thermal head or a hot stamp.

Next, an embodiment of the present invention will be described with reference to the drawings. In the example of the thermal recording material of the present invention shown in FIG. 1, a thermal recording layer 2 is provided on a substrate 1, and a protective layer 3 is further provided thereon. In the example of the thermosensitive magnetic recording medium having the protective layer shown in FIG. 2, the magnetic recording layer 4, the concealing layer 5,
A heat-sensitive recording layer 2 and a protective layer 3 are sequentially provided. Further, a magnetic barcode 6 is provided in a part of the concealing layer 5 on the magnetic recording layer 4. Incidentally, the magnetic bar code 6 includes a dummy bar. The magnetic recording layer 4 can be provided on the entire surface of the substrate 1 or on a part of the surface of the substrate 1, for example, in a strip shape.

[0031]

According to the present invention, a heat-sensitive recording material having excellent washing resistance can be provided. Further, according to the present invention, it is possible to provide a heat-sensitive recording material having excellent heat resistance, which has excellent washing resistance and does not change its properties even when it comes into contact with a thermal head at a higher temperature than before. Further, according to the present invention, in the thermosensitive magnetic recording medium using the above thermosensitive recording material, the thickness of the protective layer can be made smaller than before, and as a result, the magnetic output can be improved.

[0032]

The present invention will be described in more detail with reference to the following examples. Example 1 A solution and B solution having the following compositions were respectively dispersed by a paint shaker using ceramic beads for 1 hour. The obtained liquid A and liquid B were stirred and mixed at a weight ratio (A / B) of 5/10 using a propeller mixer to obtain a coating liquid. The obtained coating liquid is applied to a 188 μPET (polyethylene terephthalate) substrate using a bar coater (application amount: 5 g).
/ M ² ) and dried in a 45 ° C. oven for 30 minutes to obtain a heat-sensitive recording material of the present invention. Further, as a protective layer, UV curable resin 161 medium (manufactured by T & K Toka) Haklinis U
After applying 1 μm of P2L (manufactured by T & K Toka), the composition was cured by irradiating ultraviolet rays to obtain a heat-sensitive recording material of the present invention having a protective layer.

Solution A (solid content: 25%, P / V ratio: 60/40) Leuco dye (Nippon Soda's PSD-300) 15 parts by weight Acrylic emulsion * (Hiros X-AE1027 manufactured by Seiko Chemical Co., Ltd.) 25 parts by weight Water 60 parts by weight Liquid B (solid content: 25%, P / V ratio: 60/40) Developer (D-8, manufactured by Nippon Soda) 15 parts by weight Acrylic emulsion * (AE1027, manufactured by Seiko Chemical Co., Ltd.) 25 parts by weight Water 60 parts by weight * Solution polymerization type styrene acrylic emulsion with a styrene acrylic mixing ratio of 1: 1 (styrene acrylic resin contains 5% carbonyl group in solid content ratio, and hydrazine is added in an approximately equimolar amount to the carbonyl group)

Examples 2 to 4 The liquid A and the liquid B obtained in Example 1 were mixed at a weight ratio (A / B) of 5/1.
0, and further add 0.5% aziridine to the mixture.
(Example 2) 1% (Example 3) and 2% (Example 4) were added and stirred and mixed using a propeller mixer to obtain a coating liquid. The obtained coating solution was applied to a 188 μPET base material using a bar coater (application amount: 5 g / m ² ), and 45
After drying in an oven at 30 ° C. for 30 minutes, a heat-sensitive recording material of the present invention was obtained. Further, a thermosensitive recording material of the present invention having a protective layer was obtained in the same manner as in Example 1.

Comparative Example 1 Liquid A and liquid B having the following composition were prepared in the same manner as in Example 1, and the obtained liquid A and liquid B were mixed at a weight ratio (A / B) of 5/10.
In the same manner as in Example 1 using a coating liquid obtained by stirring and mixing using a propeller mixer, a thermosensitive recording material of the present invention having a protective layer and a thermosensitive recording material having no protective layer were obtained. Was. Liquid A (solid content: 25%, P / V ratio: 60/40) Leuco dye (Nippon Soda's PSD-300) 15 parts by weight Acrylic emulsion * (Hyros RE-15 manufactured by Hoshi Kogaku Kogyo) 25 parts by weight Water 60 parts by weight Part B Liquid (solid content: 25%, P / V ratio: 60/40) Developer (D-8, manufactured by Nippon Soda) 15 parts by weight Acrylic emulsion * (Hiros RE-15, manufactured by Seiko Chemical Co., Ltd.) 25 parts by weight Water 60 parts by weight * Solution polymerization type styrene acrylic emulsion with a styrene: acrylic mixture ratio of 1: 1

Comparative Example 2 1% of aziridine was further added to the coating solution of Comparative Example 1, and the mixture was stirred and mixed using a propeller mixer. A thermosensitive recording material of the present invention having a protective layer and a thermosensitive recording material having no protective layer were obtained.

Test Examples The following tests were performed on the heat-sensitive recording materials of Examples 1 to 4 and Comparative Examples 1 and 2. The reflection density of the coloring portion and the background portion of the heat-sensitive recording material was measured using a reflection density measuring device [Macbeth RD91.
8]. Table 1 shows the results. In the numerical values in the two rows in Table 1, the upper row shows data before the test, and the lower row shows data after the test. (1) Color-forming property (background, color development at 130 ° C.) The reflection density of the background of the thermal recording material and the reflection density of the color-developed portion formed by pressing a block set at 130 ° C. at a pressure of 200 g / cm ² for 5 seconds were measured. did. (2) Heat and humidity resistance (background, color development at 130 ° C.) H. 2 in the atmosphere
The reflection density of the color-developed portion and the background portion before and after standing for 4 hours was measured. (3) Alcohol resistance (background, coloring at 130 ° C.) The reflection density of the coloring portion and the background was measured before and after the thermal recording material was immersed in ethanol (70%) for 2 minutes. (4) Sweat resistance (130 ° C. color development) ○: No abnormality in color development after immersing the heat-sensitive recording material in artificial sweat liquid (acid and alkali) for 72 hours in a normal temperature atmosphere.
When there was an abnormality, it was evaluated as x.

(5) Heat resistance (background, color development at 130 ° C.) H. 1 in the atmosphere
The reflection densities of the colored portion and the background portion before and after leaving for 00 hours were measured. (6) Water Resistance (Background, 130 ° C. Color Development) The reflection density of the color-developed portion and the background portion before and after immersing the heat-sensitive recording material in water at room temperature (about 20 ° C.) for 7 hours was measured. (7) Washing resistance A gauze was added to a gauze containing a 5-fold diluted solution of a laundry detergent top (Lion) without a protective layer of an ultraviolet curable resin, and
Rub back and forth 0 times. After the test, the color was developed at 130 ° C., and the reflection density was measured. Laundry detergent Just (Kao) in 30 liters of water 30
g, washing was performed for 15 minutes in a washing machine, and when no abnormality such as peeling was observed in the printed portion, the result was evaluated as “O”, and when an abnormality such as peeling was observed, as “X”. (8) Hot plate pressing test A block heated to 200 to 240 ° C was heated to 200 g / cm.
The sample was pressed against the heat-sensitive recording material at a pressure of ² for 1 second, and the case where there was no abnormality in the color-developed portion and no wrinkles were observed was evaluated as “O”. (9) Hand cream resistance Hand cream Vaseline (manufactured by Nippon Lever) was thinly applied to the surface of the heat-sensitive recording material, left for 6 hours, wiped off, and measured for pencil hardness.

[0039]

[Table 1]

From the results shown in Table 1, when comparing Example 1 with Comparative Example 1, there is no difference in terms of color development, heat and humidity resistance, alcohol resistance, sweat resistance, heat resistance and water resistance. From the viewpoint of washability, it can be seen that Example 1 using hydrazine self-crosslinking acrylic resin as a binder is excellent.

Further, when Examples 2 to 4 and Comparative Example 2 are compared, there is no difference in terms of color development, heat and humidity resistance, alcohol resistance, sweat resistance, heat resistance and water resistance, but washing resistance is high. In addition to the hot plate pressing test and the hand cream resistance, Examples 2 to 4 in which a hydrazine self-crosslinking acrylic resin having a crosslinkable structure with aziridine was used as a binder.
Is excellent.

Example 5 A 188 μm-thick polyethylene terephthalate film (Lumirror E-22 manufactured by Toray Industries, Inc.) was used as a substrate and a magnetic recording layer (12 μm-thick) was formed by gravure roll coating using a magnetic ink having the following composition. A concealing layer (4 μm thick) was formed on the magnetic recording layer by silk screen coating using a concealing ink having the following composition. Further, a heat-sensitive recording layer and a protective layer were provided in the same manner as in Example 1,
A thermosensitive magnetic recording medium of the present invention was obtained. The magnetic properties of this thermosensitive magnetic recording medium were measured using a ticketing device for a high coercive force magnetic card, and the results were good. Composition of magnetic ink Barium ferrite 33 parts by weight Partially saponified vinyl chloride-vinyl acetate copolymer resin 4.5 parts by weight Polyurethane elastomer resin 4.5 parts by weight Polyester resin 2 parts by weight Methyl isobutyl ketone 28 parts by weight Toluene 28 parts by weight Concealment Composition of ink for use Aluminum paste Sap2171 (manufactured by Showa Aluminum Powder) 13 parts by weight Rutile type titanium dioxide 17 parts by weight Vinyl chloride resin 8 parts by weight Vinyl acetate resin 8 parts by weight Cyclohexanone 27 parts by weight Petroleum-based solvent (trade name: Solvesso) 27 parts by weight Department

Examples 6 to 8 Heat-sensitive magnetic recording media of the present invention were obtained in the same manner as in Example 5, except that the heat-sensitive recording layers were changed to the heat-sensitive recording layers of Examples 2, 3 and 4. The magnetic properties of these thermosensitive magnetic recording media were measured using a high coercivity magnetic card ticketing apparatus, and all were good.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating an example of an embodiment of a heat-sensitive recording material of the present invention.

FIG. 2 is a schematic sectional explanatory view of an example of an embodiment of the thermosensitive magnetic recording medium of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (72) Yusuke Hamani, 1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. No. 1-1 Dai Nippon Printing Co., Ltd. (56) References JP-A-6-344662 (JP, A) JP-A-54-61542 (JP, A) JP-A-2-80286 (JP, A) JP JP-A-55-161689 (JP, A) JP-A-5-32050 (JP, A) JP-A-5-69668 (JP, A) JP-A-1-278388 (JP, A) JP-A-5-254250 (JP , A) (58) Field surveyed (Int.Cl. ⁷ , DB name) B41M 5/28-5/34

Claims (6)

(57) [Claims] 1. A heat-sensitive recording material having a heat-sensitive recording layer containing a color former, a developer and a binder on a base material,
The heat-sensitive recording material, wherein the binder contains a hydrazine self-crosslinking acrylic resin. 2. A heat-sensitive recording material having a heat-sensitive recording layer containing a color former, a color developer and a binder on a base material,
A thermosensitive recording material, wherein the binder contains a hydrazine self-crosslinking acrylic resin, and the thermosensitive recording layer has a crosslinked structure with an aziridine-based curing agent. 3. The method according to claim 1, wherein a protective layer is provided on the heat-sensitive recording layer.
Or the heat-sensitive recording material according to 2. 4. A thermosensitive magnetic recording medium having a thermosensitive recording layer and a magnetic recording layer containing a color former, a developer and a binder on a substrate, wherein the binder contains a hydrazine self-crosslinking acrylic resin. A thermosensitive magnetic recording medium, characterized in that: 5. A thermosensitive magnetic recording medium having a heat-sensitive recording layer and a magnetic recording layer containing a color former, a color developer and a binder on a substrate, wherein the binder contains a hydrazine self-crosslinking acrylic resin. And a thermosensitive magnetic recording medium, wherein the thermosensitive recording layer has a crosslinked structure with an aziridine-based curing agent. 6. The method according to claim 4, wherein a protective layer is provided on the heat-sensitive recording layer.
Or a thermosensitive magnetic recording medium according to 5.