JPH06219046A - Thermal recording medium - Google Patents

Abstract

PURPOSE:To provide an excellent thermal recording medium withstanding physical stimulation such as friction or scratch and stable against chemicals such as an acid, alkali or alcohol. CONSTITUTION:In a thermal recording medium 10 wherein a color layer 2, a metal membrane layer 3, an adhesive layer 4 and a protective layer 5 are successively provided on a support 1, a vinyl chloride/vinyl acetate/phosphoric ester copolymer wherein the wt. average mol.wt. ratio of phosphoric ester is 0.1-20.0% is added as the binder of the adhesive layer 4. A magnetic recording layer may be provided in place of the color layer 2. Further, the layers 2, 3, 4, 5 may be successively provided on a support having a magnetic recording layer provided to at least one surface thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used, for example, as a printout of a computer, a recording sheet for receiving a facsimile, a ticket such as a boarding pass, a boarding pass, etc., or a label, a card, etc., especially as a prepaid card. The present invention relates to a thermosensitive recording medium capable of recording such as printing by a physical change due to heating.

[0002]

2. Description of the Related Art Generally, a so-called heat-sensitive recording method, in which an image display of characters and the like is obtained by utilizing a physical or chemical change of a substance by heat energy such as heating, causes noise during recording. Since it does not require development and fixing, it is not only for copying machines but also for computer printouts, facsimile reception records, tickets, labels, and print records on various cards. Widely used. As a recording medium used in this thermal recording system, for example, a recording medium using a leuco body such as a fluoran dye as a color former is widely used because of its excellent thermal sensitivity.

However, this recording medium easily develops color even under pressure and an organic solvent such as alcohol, and has problems in light resistance, heat resistance, water resistance and storability of printed records.

Therefore, for example, a thermosensitive recording medium using a metal thin film layer has been put into practical use. This thermal recording medium destroys the metal thin film layer based on a pattern of an image to be recorded by a heat source such as a thermal head, a laser beam, or a flash light, and a colored layer provided below the metal thin film layer is destroyed. By exposing, an image is formed.

Therefore, since the image display such as printing is formed by the contour of the metal thin film layer, its light resistance, heat resistance, water resistance and storability of print records are heat sensitive using the above-mentioned dye as a color former. Excellent compared to recording media.

A thermal recording medium using a metal thin film layer is used for prepaid cards, tickets, labels, etc.
In practice, it is necessary to provide a protective layer as the uppermost layer in order to protect the metal thin film layer from physical irritation such as rubbing and scratching, and chemicals such as acid, alkali and alcohol.

As the protective layer, it is generally known that a resin such as a heat resistant acrylic resin or an epoxy resin is mixed with an appropriate amount of an inorganic or organic pigment and a lubricant such as wax or silicone. . Furthermore, JP-A-59-1
JP-A-99284 and JP-A-2-62287 also describe a technique in which the protective layer has a multi-layered structure and the functions of surface strength and adhesiveness to a medium are separated to aim at improvement of the required characteristics. .

[0008]

However, even in a recording medium provided with such a protective layer, under severe conditions such as when the card is accidentally washed, for example, when it is used as a prepaid card, There is a problem that the protective layer is peeled off. Further, in the field of use as a so-called magnetic card having a magnetic recording layer, there has been a problem that the protective layer is scraped off by high-speed transportation found in automatic ticket gates and the like. Further, there is a problem that the chemical resistance of the metal thin film layer is remarkably lowered due to peeling and scraping of the protective layer.

The present invention has been made in view of the above circumstances, and an object thereof is to endure physical stimuli such as friction and scratching, and to be stable and excellent against chemicals such as acids, alkalis and alcohols. Another object is to provide a heat-sensitive recording medium.

[0010]

One of the thermosensitive recording media of the present invention is a thermosensitive recording medium comprising a support, on which a colored layer, a metal thin film layer, an adhesive layer and a protective layer are sequentially formed,
The adhesive layer contains a vinyl chloride-vinyl acetate-phosphate ester copolymer having a phosphate ester weight average molecular weight ratio in the range of 0.1 to 20.0%.

Another one of the thermosensitive recording media of the present invention is a thermosensitive recording medium comprising a magnetic recording layer, a metal thin film layer, an adhesive layer and a protective layer, which are sequentially formed on a support, wherein the adhesive layer contains phosphorus. Weight average molecular weight ratio of acid ester is 0.1 to 2
It is characterized by containing a vinyl chloride-vinyl acetate-phosphate ester copolymer in the range of 0.0%.

Another one of the thermosensitive recording media of the present invention is a thermosensitive recording comprising a colored layer, a metal thin film layer, an adhesive layer and a protective layer which are sequentially formed on a support having a magnetic recording layer on at least one surface. In the medium, the adhesive layer contains a vinyl chloride-vinyl acetate-phosphate ester copolymer having a phosphate ester weight average molecular weight ratio in the range of 0.1 to 20.0%.

Still another one of the thermosensitive recording media of the present invention comprises a magnetic recording layer, a metal thin film layer, an adhesive layer and a protective layer which are sequentially formed on the other surface of a support having a magnetic recording layer on one surface. In the heat-sensitive recording medium containing the above, the adhesive layer contains a vinyl chloride-vinyl acetate-phosphate ester copolymer having a weight average molecular weight ratio of phosphate ester in the range of 0.1 to 20.0%. To do.

The present invention will be described in detail below with reference to the drawings.

1 to 6 are schematic sectional views of the thermal recording medium of the present invention. In the figure, 1 is a support, 2 is a colored layer, 3 is a metal thin film layer, 4 is an adhesive layer, 5 is a protective layer, 6 is an anchor layer, 7 is a magnetic recording layer, and 8 is a protective layer.

The thermal recording medium 10 shown in FIG. 1 has a colored layer 2, a metal thin film layer 3, an adhesive layer 4 and a protective layer 5 on one side of a support 1.
Have a layered structure in which they are sequentially laminated. The thermosensitive recording medium of the present invention may have a laminated structure having the colored layer, the metal thin film layer, the adhesive layer and the protective layer in FIG. 1 provided on both sides of the support.

The thermosensitive recording medium 20 shown in FIG. 2 has the same basic structure as the thermosensitive recording medium 10, but has a layer structure in which the anchor layer 6 is provided between the coloring layer 2 and the metal thin film layer 3. .

The thermal recording medium 30 shown in FIG. 3 has a layer structure in which a magnetic recording layer 7 is provided instead of the colored layer 2 in the thermal recording medium shown in FIG. The thermosensitive recording medium of the present invention may have a laminated structure including the magnetic recording layer, the metal thin film layer, the adhesive layer and the protective layer shown in FIG. 3 provided on both sides of the support.

The thermosensitive recording medium 40 of FIG. 4 has the same basic structure as the thermosensitive recording medium 30, but has a layer structure in which the anchor layer 6 is provided between the magnetic recording layer 7 and the metal thin film layer 3. is doing.

The thermosensitive recording medium 50 shown in FIG. 5 has a colored layer 2, a metal thin film layer 3, an adhesive layer 4 and a protective layer 5 on one surface of the support 1.
Are sequentially laminated, and the magnetic recording layer 7 and the protective layer 8 are sequentially provided on the other surface of the support. In the thermal recording medium of the present invention, a metal thin film layer and an adhesive layer may be interposed between the magnetic recording layer 7 and the protective layer 8 in FIG.

The thermosensitive recording medium 60 shown in FIG. 6 has a magnetic recording layer 7 on the other surface of the support in the thermosensitive recording medium 40 shown in FIG.
The protective layer 8 and the protective layer 8 are sequentially provided.

Next, each of the above layers will be specifically described.

As the support 1 used in the present invention, a conventionally known film, paper, glass, metal or the like can be used as it is. Specific examples thereof include various heat-resistant resin films such as polyethylene terephthalate (PET), polyimide, polyether, polycarbonate, polysulfone, cellophane, and aromatic polyamide, and condenser paper, sulfuric acid paper, art paper, nematic paper, coat. Paper base materials such as paper, laminated paper and polyethylene synthetic paper, glass base materials such as quartz, and metal base materials such as aluminum can be preferably used.

The colored layer 2 is capable of displaying an image when it is optically exposed by heating the metal thin film layer 3 in accordance with the formation of an image pattern. For example, ethyl cellulose, hydroxyethyl cellulose, cellulose. Acetate propionate, cellulose derivative such as cellulose acetate, polystyrene, styrene resin or styrene copolymer resin such as poly-α-methylstyrene, homopolymer or copolymer resin of acrylic resin or methacrylic resin such as polybutyl methacrylate, rosin, Rosin-modified phenol resin, rosin-modified maleic acid resin, rosin ester resin such as polymerized rosin, vinyl acetate resin, coumarone resin, vinyltoluene resin, vinyl chloride resin, polyester resin, polyurethane resin, butyral resin, etc. Various inorganic or organic coloring pigments or coloring dyes are added to a binder resin such as a fat copolymer according to the color to be colored, and if necessary, a plasticizer, a stabilizer, a wax, a curing agent, a dispersant. After the addition of, by using a colored paint or ink prepared by sufficiently kneading with a solvent or a diluent, a so-called gravure method, a roll method, a knife-edge method, a coating method such as an offset method or a printing method, it is formed. It

As the colorant, pigments, dyes and the like can be used. As specific examples of the color pigments, as cyan dyes, diaceriton fast brilliant bull-R (trade name) manufactured by Mitsubishi Kasei Co., Ltd., Kaya Ron Polyester Bull-B
-SF Conc (manufactured by Nippon Kayaku Co., Ltd., etc.) and magenta dyes such as Diaceriton Fast Red R (manufactured by Mitsubishi Kasei Co., Ltd.), Kayaron Polyester Pink RC
As yellow color dyes such as LE (manufactured by Nippon Kayaku Co., Ltd.), Kayaron Polyester Light Yellow-5G-S
(Nippon Kayaku Co., Ltd., trade name), Eisenspiro inero
GRH (trade name, manufactured by Hodogaya Chemical Co., Ltd.) and the like can be mentioned.

Cyan color pigments such as cerulean blu and phthalocyanine blu, magenta color pigments such as brilliant carmine and alizarin lake, and yellow pigments such as hansa yellow and bisazo yellow.
Etc. Examples of black pigments include carbon black, graphite, oil black and the like.

Further, Fe, Ni, Al and other metals, Fe
Metal oxides such as ₂ O ₃ and SnO ₂ can also be used.

The coloring dye can be selected from disperse dyes, oil-soluble dyes, acid dyes, mordant dyes, vat dyes, basic dyes and the like which are generally used in transfer printing of fibers and thermal transfer inks. .

Specific examples thereof include dyes of azo type, anthraquinone type, nitro type, styryl type, naphthoquinone type, quinophthalone type, azomethine type, coumarin type, condensed polycyclic type and the like. Also, phosphorescent / fluorescent pigments and the like can be used.

The thickness of the colored layer is set in the range of 0.5 to 10 μm.

The metal thin film layer 3 is made of Te, Sn, Al, B.
i, Pb, Zn or the like metal or an alloy thereof, and using these metals or compounds of these metals such as Te carbide or the like, vacuum deposition method, sputtering method, CVD
Can be formed on the upper surface of the colored layer 2 provided on the support 1 by a method, a plating method, or the like. In this case, the metal thin film layer 3 preferably has a low melting point so that it can be used as a heat-sensitive recording layer, and the thickness thereof is 100 Å to 1 μm, preferably 300 to 600.
It is selected to be about Angstrom.

The adhesive layer 4 is made of vinyl chloride containing phosphoric acid ester having a weight average molecular weight ratio of 0.1 to 20.0%.
It is characterized in that it contains a vinyl acetate-phosphate ester copolymer.

The weight average molecular weight ratio of the phosphoric acid ester of the vinyl chloride-vinyl acetate-phosphoric acid ester copolymer is
When it is less than 0.1%, the adhesiveness to the metal thin film layer 3 is lowered, and the weight average molecular weight ratio of the phosphoric acid ester is 20.0.
When it is more than%, the vinyl chloride-vinyl acetate-phosphoric acid ester copolymer may be deteriorated in light stability and heat stability.
The weight average molecular weight ratio of the phosphoric acid ester is 0.1 to 20.
It needs to be 0%.

In the adhesive layer constituting the present invention, in addition, polyester resin, polyurethane resin, acrylic resin, vinyl chloride-vinyl acetate resin, epoxy resin,
It is also possible to mix at least one resin selected from cellulose resins and aminoalkyd resins.
In that case, it is desired that the vinyl chloride-vinyl acetate-phosphoric acid ester copolymer is in the range of 5% by weight or more, preferably 20% by weight or more in terms of the total solid content of the adhesive layer 4. That is, when the vinyl chloride-vinyl acetate-phosphoric acid ester copolymer is less than 5% by weight, the adhesiveness to the metal thin film layer 3 decreases, which is not preferable. The weight average molecular weight of the vinyl chloride-vinyl acetate-phosphate ester copolymer is preferably 300 or more. When the weight average molecular weight of the vinyl chloride-vinyl acetate-phosphate ester copolymer is less than 300, the chemical resistance and abrasion resistance of the adhesive layer are deteriorated, and the adhesiveness with the metal vapor deposition layer is deteriorated, which is preferable. Absent. Furthermore, the glass transition temperature of the vinyl chloride-vinyl acetate-phosphate ester copolymer is 30.
It is preferably at least ° C. The glass transition temperature of the vinyl chloride-vinyl acetate-phosphate ester copolymer is 30 ° C.
If it is less than the above range, the chemical resistance and wear resistance of the adhesive layer are deteriorated, and heat fusion to the thermal head occurs, which is not preferable.

The adhesive layer 4 contains, in addition to the above resin components, a lubricant such as wax, an inorganic or organic pigment (including the above-described coloring pigment), a plasticizer, a stabilizer, a curing agent, a dispersant, and an organic solvent, if necessary. Using a paint or ink prepared by sufficiently dispersing or dissolving and mixing with a three-roll or a stirrer such as a disper, by a known gravure method, roll method, knife edge method, offset method, or other coating method or printing method. It is formed on the metal thin film layer 3.

The thickness of the adhesive layer is preferably in the range of 0.1 to 5 μm. A particularly preferred range is 1 to 2 μm. When the thickness of the adhesive layer is less than 0.1 μm, the adhesive strength with other layers is lowered, and when it is more than 5 μm, the drying speed of the adhesive layer becomes slow and peeling occurs inside the adhesive layer, which is preferable. .

The protective layer 5 includes the adhesive layer 4 and the metal thin film layer 3.
In addition to physical and chemical protection, it is necessary to design so that sticking and residue will not occur during thermal recording. In the present invention, the protective layer 5 is composed of at least a heat resistant resin and a lubricant.

The heat resistant resin is, for example, a polyester resin, a polyurethane resin, an epoxy resin, various fiber resins, a polyimide resin, a polyamide resin, a polyarylate resin, a polycarbonate resin, a phenol resin, an alkyd resin. Resins, melamine resins, styrene resins, silicone resins, fluororesins, and thermoplastic resins composed of copolymers of these resins, thermosetting resins, UV curable resins, EB curable resins Out of
It is composed of at least one, and its glass transition point (Tg) is selected to be 30 ° C. or higher, preferably 50 ° C. or higher.

When Tg is lower than 30 ° C.,
At the time of heat-sensitive recording, sticking may occur or abrasion resistance may be reduced.

The lubricant has the function of preventing sticking with the heat-sensitive head and reducing the coefficient of friction to improve wear resistance. Waxes such as polyethylene wax, paraffin wax and microcrystalline wax, Zinc stearate, higher fatty acid metal salts such as calcium stearate, stearic acid amides, fats and oils such as higher fatty acid amides such as behenic acid amides, known materials such as silicone oil, Teflon fine powder, and boron nitride fine powder are used. If necessary, heat-resistant inorganic pigments such as silica, calcium carbonate, magnesium hydroxide, zeolite, clay and talc can also be used. The particle size of the pigment used is preferably 0.1 to 10 μm, more preferably 1 to 5 μm.

The content ratio of the binder, lubricant and pigment is preferably 50 to 95% by weight, respectively.
It is 2 to 30% by weight and 2 to 40% by weight.

When the content of the lubricant is less than 2% by weight, the abrasion resistance is deteriorated and sticking occurs during heat sensitive recording. If it exceeds 30% by weight, the heat resistance of the protective layer is deteriorated, and the amount of dust attached to the thermal head increases.

When the content of the pigment is less than 2% by weight, the amount of dust adhered to the thermal head increases. If it exceeds 40% by weight, the background density is increased, the appearance is deteriorated, and the thermal head is significantly worn.

The protective layer 5 is also formed on the adhesive layer in the same manner as the adhesive layer 4. The thickness of the protective layer 5 is the same as that of the adhesive layer 4.
For the same reason as above, 0.1 to 5 μm, especially 1 to 2
The range of μm is preferred.

The anchor layer 6 is composed of the colored layer 2 and the metal thin film layer 3.
In addition to improving the mutual adhesiveness between the two, the function of improving the thermal energy sensitivity by promoting the destruction of the metal thin film layer 3 at the time of thermal recording.

Therefore, a resin having an appropriate thermoplasticity, specifically, an acrylic resin such as polystyrene or polymethylmethacrylate, a cellulose resin such as cellulose acetate propionate, a vinyl chloride-vinyl acetate copolymer, Polyester resins, polyurethane resins, epoxy resins, aminoalkyd resins and copolymers of these resins may be used alone or in combination of two or more.

Further, in order to control the thermoplasticity, a heat-melting substance such as a plasticizer or wax may be added, and a certain solvent resistance is imparted to facilitate formation of the next layer. Alternatively, a curing agent may be added.

Furthermore, in order to control the glossiness of the metal thin film layer, a pigment that can be used in the above-mentioned protective layer 5 may be added. The anchor layer 6 is also formed similarly to the adhesive layer 4 and the protective layer 5 described above.

The thickness of the anchor layer is not particularly limited, but when a magnetic recording layer is provided instead of the coloring layer, a thick anchor layer will hinder reading and writing of magnetic recording. It is necessary to make a decision in consideration of the characteristics of the magnetic recording layer.

When a pigment having an average particle size of 1 to 10 μm is mixed in at least one of the anchor layer 6 and the coloring layer 2, glare of the coating layer is reduced, and The recorded image display is easy to see.

When the average particle size of this pigment is less than 1 μm, the effect of preventing glare does not appear, and when it is more than 10 μm, the unevenness of the surface becomes large, and the contact area with the thermal head is small. It will be
Thermal recording will not be performed sufficiently.

Examples of the pigment include inorganic white pigments such as silica, calcium carbonate, aluminum hydroxide, clay and talc, crosslinked polystyrene, polyethylene beads,
Colored pigments such as organic transparent or white pigments such as silicone beads, red lead, ultramarine blue, titanium yellow, red lead yellow, and plastic type fluorescent pigments can be used.

The magnetic recording layer 7 is formed by dispersing a magnetic material in a binder resin, has a function of recording data or the like related to or corresponding to image display, and has an appropriate structure. Data can be read and written by a magnetic card reading and writing device.

Magnetic materials include Fe ₂ O ₃ , barium ferrite and other ferrites, magnetite, etc., iron,
Any known material such as a metal such as nickel, manganese, chromium or an alloy thereof can be used, and as the binder resin, those exemplified for the colored layer can be similarly used.

In the present invention, the magnetic recording layer may have a single-layer structure composed of one layer, or may have a layer structure composed of two or more layers having different magnetic characteristics. May be. The film thickness of the magnetic recording layer is usually set in the range of 0.1 to 30 μm.

The magnetic recording layer in the present invention may be one in which a coating layer is formed over the entire surface of the support, or a coating layer is partially formed in a stripe shape or a bar code shape. Good.

In the present invention, when the magnetic recording layer is provided between the support and the metal thin film layer, the colored layer does not necessarily have to be provided.

For the protective layer 8, the material of the protective layer 5 can be applied as it is.

[0059]

EXAMPLES Next, examples of the thermal recording medium according to the present invention will be described. All parts are parts by weight.

Example 1 A thermosensitive recording medium of the present invention was prepared by successively laminating the following layers by coating on the surface of a milk-white polyethylene terephthalate film support having a thickness of 188 μm.

1) Colored layer: The following composition having the following composition was dried at a drying temperature of 110 ° C. and then coated on a support so that the thickness and the surface smoothness were 3 μm and 500 seconds, respectively.

36 parts of linear polyester resin (manufactured by Toyobo Co., Ltd., trade name: Byron 200) 5 parts of carbon 5 parts of fine powder silica (trade name of Tokuyama Soda Co., Ltd., trade name; Fineseal X70, average particle size 2.0 μm) ) -Isocyanate-based curing agent 2 parts (Nippon Polyurethane Company, trade name; Coronate L) -Methyl ethyl ketone 93 parts-Toluene 51 parts

2) Metal thin film layer: 60 when the tin is measured by the vacuum vapor deposition method and the film thickness is measured by the crystal oscillator method.
It was vapor-deposited so as to have a thickness of 0 angstrom.

3) Adhesive layer: The following composition was applied at a drying temperature of 110 ° C. to a thickness of 1.0 μm after drying to form an adhesive layer.

-Vinyl chloride-vinyl acetate-phosphate ester copolymer 67 parts (manufactured by Denki Kagaku Kogyo, trade name; Denkavinyl 1000P) (weight average molecular weight of phosphoric acid ester 1%)-acrylic resin 28 parts (Siden Chemical company, trade name; Cybinol X592-440S) (Acid value: 54, OH value: 36, Tg: 86 ° C) -Methyl ethyl ketone 300 parts-Toluene 600 parts

4) Protective layer: A protective layer having the following composition was dried at a drying temperature of 110 ° C. and then coated to a thickness of 1.0 μm to form a protective layer.

Epoxy resin 16 parts (Okaka Shell Epoxy Co., trade name; Epicoat 1010 Tg 85 ° C.) Polyester resin 16 parts (Toyobo Co., trade name: Byron 290 Tg 80 ° C.) Lubricants Polyethylene wax 4 parts (Mitsui Chemical Industry Co., Ltd., product name; Mitsui High Wax 100P) -Pigment tetrafluoroethylene 4 parts (Kitamura Co., product name; KTL500F) -Toluene 190 parts-Methyl ethyl ketone 190 parts

Example 2 A thermosensitive recording medium of the present invention was prepared by successively laminating the following layers by coating on the surface of a milky-white polyethylene terephthalate film support having a thickness of 188 μm.

1) Magnetic recording layer • Magnetic powder: barium ferrite 100 parts BaO · 6 (Fe ₂ O ₃ ) (coercive force 2750 oersted) • Binder: vinyl chloride-vinyl acetate-vinyl alcohol copolymer 20 parts (UCC) Company name, VAGH) Polyurethane resin 20 parts (Nippon Polyurethane Co., trade name; Nicholan N-2304) ・ Face: carbon black 3 parts ・ Dispersant: lecithin 1 part ・ Soluble: toluene 60 parts methyl ethyl ketone 60 parts Methyl isobutyl ketone 60 parts

The above mixture was dispersed by a ball mill for 8 hours, and then the following curing agent was added. -Hardening agent: Polyisocyanate 75% ethyl acetate solution 12 parts (manufactured by Japan Polyurethane Co., trade name; Coronate L)

After adding the above curing agent and dispersing for 1 hour,
It was applied by a solvent coating method on a milky white polyethylene terephthalate film having a thickness of 188 μm, and while the coating material was in an undried state, an orientation treatment was performed by a magnetic field orientation treatment device, followed by drying at 100 ° C. for 5 minutes, and a thickness of 15 μ
m, and a magnetic recording layer having a surface smoothness of 500 seconds was formed.

2) Anchor layer: The following composition was applied at a drying temperature of 110 ° C. so that the coating amount after drying would be 18 g / m ² .

100 parts of water-based polyolefin resin (manufactured by Iron and Steel Chemical Co., Ltd., trade name; Saixen AC solid content 30%) 5 parts of finely powdered silica (manufactured by Tokuyama Soda Co., Ltd., trade name; Fineseal X70, average particle size) 2. 0 μm) -trimethylolpropane-tri-β-aziridinylpropionate 1 part-isopropyl alcohol 15 parts-water 25 parts

3) Metal thin film layer: 60 when tin is measured by a vacuum vapor deposition method by a film thickness measuring method by a crystal oscillator method.
It was vapor-deposited so as to have a thickness of 0 angstrom.

4) Adhesive layer: An adhesive layer having the following composition was dried at a drying temperature of 110 ° C. and then applied to a thickness of 0.75 μm to form an adhesive layer.

-Vinyl chloride-vinyl acetate-phosphoric acid ester copolymer 56 parts (manufactured by Denki Kagaku Kogyo, trade name; Denka vinyl 1000P) (weight average molecular weight of phosphoric acid ester 1%)-acrylic resin 24 parts (Siden Chemical company, trade name; Cybinol X592-440S) (Acid value: 54, OH value: 36, Tg: 86 ° C) -Methyl ethyl ketone 30 parts-Toluene 60 parts

5) Protective layer: A protective layer was formed by applying the following composition at a drying temperature of 100 ° C. to a thickness of 0.75 μm.

Acrylic resin 15 parts (manufactured by Saiden Chemical Co., trade name; Cybinol S-14 Tg 80 ° C.) Polyurethane resin 15 parts (manufactured by Mitsubishi Kasei Co., trade name; Mitec MX-4014 Tg 70 ° C.) Lubricant 5 Part (Axel, trade name; Mold Wiz F-57 solid content 8%)-pigment aluminum hydroxide 5 parts-toluene 190 parts-methyl ethyl ketone 114 parts-cyclohexanone 76 parts

Comparative Example 1 A thermal recording medium for comparison was prepared in the same manner as in Example 1 except that the adhesive layer in Example 1 was changed as follows.

Adhesive layer: Drying temperature 11 with the following composition
After drying at 0 ° C, apply it to a thickness of 1.0 μm,
The adhesive layer of the present invention was formed.

-Vinyl chloride-vinyl acetate copolymer 56 parts (manufactured by UCC, trade name; VYHD) -Acrylic resin 24 parts (manufactured by Saiden Chemical Co., trade name; Cybinol X592-440S) (acid value: 54, OH value: 36, Tg: 86 ° C) -Methyl ethyl ketone 30 parts-Toluene 60 parts

Comparative Example 2 A thermal recording medium for comparison was prepared in the same manner as in Example 2 except that the adhesive layer in Example 2 was changed as follows.

Adhesive layer: The one having the following composition was dried at a temperature of 11
After drying at 0 ° C, apply it to a thickness of 1.0 μm,
The adhesive layer of the present invention was formed.

56 parts of polyester resin (manufactured by Toyobo Co., Ltd., trade name: Byron 200) 24 parts of acrylic resin (manufactured by Saiden Chemical Co., trade name; Cybinol X592-440S) (acid value: 54, OH value: 36, Tg: 86 ° C) ・ Methyl ethyl ketone 30 parts ・ Toluene 60 parts

An evaluation test was conducted on the following characteristics of the examples and comparative examples described above, and the results shown in Table 1 below were obtained.

(1) Recording characteristics A thermal printing apparatus equipped with a thin film type thermal head having a dot density of 6 lines / mm was used to print and record with a pulse width of 2.5 ms and an applied energy of 0.6 W. The recording density and the background density were measured using a Macbeth densitometer RD-914 (visual filter).

(2) Head matching property Printing was carried out 10000 times continuously under the above recording conditions, and the state of sticking and residue was examined.

(3) Light resistance After exposure with a fade meter for 6 hours, the densities of the recorded portion and the background were similarly measured with a Macbeth densitometer.

(4) Water resistance Water resistance was examined by immersing in water at 20 ° C. for 3 days.

(5) Alcohol resistance A 50% aqueous solution of ethanol was added dropwise and wiped off after 2 minutes to examine the alcohol resistance.

(6) Acid resistance Acid resistance was examined by immersing in 5% acetic acid water for 24 hours.

(7) Alkali resistance Alkali resistance was examined by immersing in an aqueous solution of 1% sodium carbonate for 24 hours.

(8) Saline resistance The salt resistance was examined by immersing in 5% saline for 24 hours.

(9) Oil resistance Cotton seed oil was applied and allowed to stand at 20 ° C for 24 hours to examine the oil resistance.

(10) Plasticizer resistance A plastic eraser (Dragonfly Mono) was loaded with a weight of 100 g and left at 20 ° C. for 24 hours to examine the plasticizer resistance.

(11) Heat resistance After being left in a dryer at 100 ° C. for 10 minutes, the temperature was returned to room temperature, and scratches were performed with a nail to examine heat resistance.

(12) Wear resistance The wear resistance was examined by passing the gate of the automatic ticket gate 2000 times in the same direction.

(13) Adhesiveness A cellophane tape peeling test was conducted to examine the adhesiveness at the interface of each layer such as the adhesive layer and the protective layer.

(14) Washing resistance To approximately 35 ° C. hot water, 30 cc of hot water and 40 parts of neutral detergent are added.
Put the equivalent of mg and wash the card for 15 minutes.

The above evaluation results are shown in Table 1 below, ◯: good,
Δ: Slightly bad, ×: Defects were shown in 3 stages.

[0101]

[Table 1]

As is clear from the results of Table 1, Example 1
It was revealed that the samples Nos. 2 to 2 are superior to Comparative Examples 1 to 2 in all the items of the test.

[0103]

As described above, the heat-sensitive recording medium of the present invention has a vinyl chloride-vinyl acetate-phosphoric acid in which the weight average molecular weight ratio of the phosphoric acid ester is in the range of 0.1 to 20.0% in the adhesive layer. Since it contains an ester copolymer,
The metal thin film layer and the protective layer are firmly adhered to each other, and, for example, rubbing against the magnetic head for reading / writing data on the magnetic recording layer or the thermal head for printing causes extremely peeling or scratches on the protective layer or the metal thin film layer. It becomes difficult to stick.

Further, since the protective layer is less likely to be peeled off or scratched, corrosion of the metal thin film layer by chemicals such as acids, alkalis and alcohols is significantly reduced.

As described above, according to the present invention, it is possible to provide an excellent thermosensitive recording medium which is stable against physical irritation such as friction and scratching and chemicals such as acid, alkali and alcohol.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing the configuration of an embodiment of a thermal recording medium according to the present invention.

FIG. 2 is a schematic sectional view showing the configuration of another embodiment of the thermal recording medium according to the present invention.

FIG. 3 is a schematic sectional view showing the configuration of another embodiment of the thermal recording medium according to the present invention.

FIG. 4 is a schematic sectional view showing the configuration of another embodiment of the thermal recording medium according to the present invention.

FIG. 5 is a schematic sectional view showing the constitution of another embodiment of the thermosensitive recording medium according to the present invention.

FIG. 6 is a schematic sectional view showing the configuration of another embodiment of the thermal recording medium according to the present invention.

[Explanation of symbols]

1 Support 2 Colored layer 3 Metal thin film layer 4 Adhesive layer 5 Protective layer 6 Anchor layer 7 Magnetic recording layer 8 Protective layer 10, 20, 30, 40, 50, 60 ... Thermal recording medium

Claims (4)

[Claims] 1. A thermosensitive recording medium comprising a colored layer, a metal thin film layer, an adhesive layer and a protective layer, which are sequentially formed on a support, wherein the adhesive layer has a weight average molecular weight ratio of 0.1 to 0.1. A thermosensitive recording medium comprising a vinyl chloride-vinyl acetate-phosphate ester copolymer in the range of 20.0%. 2. A magnetic recording layer sequentially formed on a support,
A thermosensitive recording medium including a metal thin film layer, an adhesive layer and a protective layer, wherein the adhesive layer has a weight average molecular weight ratio of phosphoric acid ester in the range of 0.1 to 20.0%. A heat-sensitive recording medium containing a copolymer. 3. A thermosensitive recording medium comprising a colored layer, a metal thin film layer, an adhesive layer and a protective layer which are sequentially formed on a support having a magnetic recording layer on at least one surface thereof, wherein the adhesive layer comprises a phosphoric ester. The weight average molecular weight ratio is 0.1 to 20.
A heat-sensitive recording medium containing a vinyl chloride-vinyl acetate-phosphate ester copolymer in the range of 0%. 4. A thermosensitive recording medium comprising a magnetic recording layer, a metal thin film layer, an adhesive layer and a protective layer, which are sequentially formed on the other surface of a support having a magnetic recording layer on one surface thereof, wherein the adhesive layer has phosphoric acid. The weight average molecular weight ratio of the ester is 0.1 to 20.
A heat-sensitive recording medium containing a vinyl chloride-vinyl acetate-phosphate ester copolymer in the range of 0%.