JPH05147378A - Information recording medium and recording in information recording medium - Google Patents

Abstract

PURPOSE:To improve the resistance of a recording head and an information recording medium and prevent unlawful acts such as the reading of recorded information from an outer device by shielding a visible light, alteration, forgery and defacement by making possible the non-contact printing of data in the information recording medium. CONSTITUTION:An infrared absorptive heat generation layer 3 and a thermal recording layer 4 which thermally develops a color or changes a color or is removed by fusion, are laminated sequentially on a substrate 2. The infrared absorptive heat generation layer 3 generates heat by irradiation with an infrared beam, and the thermal recording layer 4 develops a color or changes a color, or is removed by fusion. Thus characters are recorded and printed in the non- contact mode. In addition, an infrared absorptive heat generation layer 23, a thermal recording layer 24 and a visible light shielding layer 25 are laminated sequentially on the substrate 22. Subsequently, it is possible to prevent recorded information from being read by an outer device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium capable of recording / reproducing information, and in particular, an information recording medium capable of indirectly performing thermal recording without directly contacting a heating device such as a thermal head. And a recording method for an information recording medium.

[0002]

2. Description of the Related Art Currently, tickets, coupons, commuter passes or prepaid cards for transportation, such as railroads, buses, and exclusive roads for automobiles, prepaid cards used for distribution, gift certificates, gift certificates, prepaid for payment prepaid. Cards, various cards used for finance, securities, bank passbooks, etc., and information recording media have come to be used for entrance tickets, membership cards, etc.
Various information recording methods have been devised so as to enable large-scale processing and to be convenient. For example, a magnetic recording method capable of magnetically recording and reproducing information, a recording method using an IC capable of recording and reproducing as electronic information, a thermal recording method capable of optically reproducing, a thermal transfer recording method, a discharge breakdown recording method, etc. There is. For the former two, the recorded information can only be read mechanically, and for the latter, in particular, in addition to binarized data such as bar code and carla code, OC
The R character has the characteristic that it can be visually read by the user as well as being mechanically read. Therefore, various information recording media are provided with an information display surface, and are combined with other recording methods such as a magnetic recording method, which are excellent in machine reading and have a large information recording capacity.

A recording system that is visible and easy to read has been adopted on the information display surface. As a heat-sensitive recording system, a heat-sensitive coloring layer using a leuco dye-based or diazo compound-based heat-sensitive material or a low melting point metal such as tin. Those having a heat-sensitive recording layer using a thin film, a heat-sensitive transfer sheet provided with a heat-sublimable ink layer or a heat-meltable transfer ink layer as a heat-transfer recording method, aluminum as a discharge breakdown recording method,
There are those in which a conductive metal thin film layer such as magnesium, zinc, or bismuth that can be destroyed by discharge is formed.

These are formed on a part, the whole surface or both surfaces of one side of the surface of the information recording medium, and coded information or OCR character information is printed on the thermosensitive coloring layer by heating printing using a thermal head, It is recorded irreversibly by melting and removing the low melting point metal thin film layer, transferring ink from a heat-sensitive transfer sheet, or destroying and disappearing the conductive metal thin film layer by discharge printing using a discharge breakdown head. An information recording medium that uses a reversible thermosensitive recording material as another information recording medium, such as Japanese Patent Application Laid-Open No. 53-46041, is capable of repeating coloring and decoloring at specific temperatures. Although present, this recording method is also based on heating printing using a thermal head as in the above.

Further, since it is difficult to maintain confidentiality on the visible information display surface and only information that can be seen by a third party can be recorded, information having high confidentiality is recorded. In Japanese Patent Laid-Open No. 62-278083, a concealing layer that transmits infrared rays is laminated, and it is difficult to directly read from the outside by utilizing the difference in reflectance of infrared rays.

[0006]

However, in each of the above recording methods, since the recording head such as a thermal head is brought into direct contact with the information recording surface of the information recording medium to perform printing, the recording head is not worn or soiled. When the recording head that has been worn or soiled is used for printing, it becomes difficult to perform accurate printing on the information recording surface of the information recording medium, dirt is attached to the information recording surface, or the information recording surface If the recording head adjustment such as printing pressure is incorrect, the head rubs the information recording surface when printing information, causing problems such as scratches or stains on the information recording surface. .. Even if a concealment layer is provided to record highly confidential information, the printed mark remains on the concealment layer by directly contacting the recording head from above, so the information can be read by a third party. Falsification, forgery,
There was a risk of alteration.

Therefore, the present invention has been made to solve the above-mentioned problems, and enables printing on an information recording surface of an information recording medium in a non-contact manner so that a recording head, particularly a storage head, can be printed. Preventing deterioration and reducing maintenance, maintaining stable print quality, reading recorded information from the recorded traces on the concealment layer by printing, falsification,
The purpose is to prevent illegal acts such as forgery and alteration.

[0008]

The present invention, which has been made to achieve the above object, is characterized in that at least an infrared absorption heat-generating layer and a heat-sensitive recording layer which develops or discolors or melts by heat are sequentially laminated on a substrate. This is an information recording medium. Further, it is an information recording medium characterized in that at least an infrared absorbing heat generating layer, a thermosensitive recording layer which develops or discolors or melts by heat, and a visible light shielding layer which does not transmit visible light and transmits infrared light are sequentially laminated on a substrate. .. Further, it is a recording method for an information recording medium, characterized in that the infrared absorbing heat generating layer is made to generate heat by irradiation of an infrared laser, and the heat causes the heat sensitive recording layer to develop or change color or to be melted and removed.

[0009]

The infrared absorbing heat generating layer and the heat sensitive recording layer which is colored or discolored by heat or melted and removed by heat are successively laminated on the substrate, so that the infrared absorbing heat generating layer generates heat upon irradiation of infrared rays and is provided in contact with the heat. The heat-sensitive recording layer is colored or discolored, or melted and removed, and non-contact recording and printing can be performed.Therefore, abrasion due to contact of the recording head, inaccurate information recording on the information recording medium, and rubbing of the information display surface Can prevent scratches and dirt. Irradiation of infrared rays by sequentially stacking at least an infrared absorption heat-generating layer, a heat-sensitive recording layer that develops or discolors or melts and removes heat by heat, and a visible light blocking layer that does not transmit visible light and transmits infrared light on the substrate. The infrared absorbing heat generating layer heats up due to the heat, and the heat-sensitive recording layer provided in contact with the heat is colored or discolored or melted and removed, so that non-contact recording and printing can be performed and the information display surface cannot be visually observed. Since it can be hidden, wear due to contact of the recording head, incorrect recording of information on the information recording medium,
It is possible to prevent scratches and stains due to rubbing of the information display surface and to make it difficult to read information recorded from the outside.

[0010]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view of an information recording medium according to the first invention of the present invention, FIG. 2 is a schematic diagram for explaining a recording method on the information recording medium according to the first invention, and FIGS. FIG. 5 is another embodiment of the information recording medium according to the first invention of the invention, FIG. 5 is a sectional view of the information recording medium according to the second invention of the present invention, and FIG. 6 is an information recording medium according to the second invention. FIG. 7 is a schematic view for explaining the recording method of, and FIGS. 7 and 8 show another embodiment of the information recording medium according to the second invention of the present invention.

Reference numeral 1 shown in FIG. 1 denotes an information recording medium according to the first aspect of the present invention, in which an infrared absorbing heat generating layer 3 which absorbs infrared rays and generates heat on the surface of a substrate 2 thereof, is colored or discolored or melted by heating. The heat-sensitive recording layer 4 to be removed is laminated. Even if the heat-sensitive recording layer 4 can record information, for example, bar-shaped marks, characters, numbers, etc., as a pattern, the information, for example, bar-shaped marks, characters, numbers, etc., can be recorded as a pattern at the card manufacturing stage. It may be a thermosensitive recording layer formed in advance, and the presence thereof may be simply confirmed. If necessary, a primer layer, a magnetic recording layer, or the like may be provided as an intermediate layer between the substrate 2 and the infrared absorption heat generating layer 3, and the magnetic recording layer is provided to provide an information recording medium capable of magnetic recording. It is also possible to provide a primer layer or the like as an intermediate layer between the infrared absorbing heat generating layer 3 and the heat sensitive recording layer 4, and further, the heat sensitive recording layer 4
A protective layer may be provided thereon, and a primer layer may be provided therebetween. In addition, the infrared absorption heating layer 3 and the heat-sensitive recording layer 4
May be formed on both sides of the substrate 2, or on a part or the entire surface of the substrate 2.

The substrate 2 is polyvinyl chloride, polyester,
Resins such as polycarbonate, polymethylmethacrylate and polystyrene, paper, synthetic paper and the like can be used alone or in combination. The shape can also be selected according to the application such as card shape or sheet shape,
Further, it can be appropriately selected from the above materials in consideration of the physical properties required according to the use, such as strength, rigidity, hiding property, and light opacity.

The infrared absorbing heat generating layer 3 is required to exhibit absorption and heat generation with respect to the wavelength of the recording laser light as its characteristic. For example, there are black inks such as carbon, cyanine dyes, naphthalocyanine dyes, triphenylmethane dyes, naphthoquinone dyes, squarylium dyes, indoaniline dyes, etc. for organic inks, and these are used alone or as a polymer binder. A dispersion dispersed in a binder is formed to a thickness of about 1 to 10 μm by a coating / printing method such as a spin coating method, a roll coating method, a knife edge method, an offset printing method, a gravure printing method, a screen printing method. It is a thing. In addition, Cu, F in inorganic type
There is a refractory metal such as e, Ni or Cr, or an alloy or compound thereof, and a thickness of 0.05 to 0.2 μm using a forming method such as a vacuum deposition method, a sputtering method, or a plating method.
It is formed to a degree. This infrared absorption heating layer 3
Can be set arbitrarily on the medium, as long as it is within the range for recording information.

In the present invention, the heat-sensitive recording layer 4 is of a dye coloring type, a metal compound coloring type, a dispersion of these in a polymer binder, or a metal removing type, which is colored by heating to change its color. Recording, the colored or discolored part has weak reflection to infrared rays or has an absorption property for infrared rays, and the uncolored or undiscolored part has different optical characteristics to infrared rays, especially uncolored Alternatively, in the uncolored portion, or at least in the metal thin film layer, it is necessary that at least infrared rays are sufficiently transmitted before recording, and preferably 30% or more and 70% or less in the wavelength region of infrared laser light used for recording. It is desirable to have a rate.

In the dye coloring type, the metal compound coloring type and those dispersed in a polymer binder, (1) dye coloring type is composed of a combination of a color developer having a phenolic hydroxyl group and a leuco dye. As leuco dyes, crystal violet lactone, 3-indolino-3-p
-Dimethylaminophenyl-6-dimethylaminophthalide, 3-diethylamino-7-chlorofluorane, 2-
(2-Chlorophenylamine) -diethylaminofluorane, 2- (2-fluorophenylamino) -6-diethylaminofluorane, 2- (2-fluorophenylamino) -6-di-n-butylaminofluorane, 3 -Diethylamino-7-cyclohexylaminofluorane,
3-diethylamino-5-methyl-7-t-butylfluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-
p-Butylanilinofluorane, 3-cyclohexylamino-6-chlorofluorane, 2-anilino-3-methyl-6- (n-ethyl-p-toluidino) -fluorane, 3-pyrrolidino-6-methyl-7. -Anilinofluorane, 3-pyrrolidino-7-cyclohexylaminofluorane, 3-n-methylcyclohexylamino-6-methyl-7-anilinofluorane, 3-n-ethylpentylamino-6-methyl-7- Anilino fluoran etc. can be used. Further, as the color developer, 4,4'-isopropylidenephenol, benzyl-p-hydroxybenzoate, 4,4'-dihydroxy-3,5'-diallyldiphenylsulfone, methyl-bis (hydroxyphenyl) acetate, gallic acid Esters, p-phenylphenol and the like can be used.

(2) Metal compound coloring type As the metal compound coloring type, ferric stearate
Combination of ferric myristylate with tannic acid / gallic acid, combination of oxalic acid Ag / Pb / Hg / Th salt with thiouric acid / sodium thiosulfate, stearic acid Ni / Co / Cu salt and CaS / SrS・ A combination with BaS, a combination of silver oxalate / mercury oxalate and glycerin / polyhydroxy alcohol, a combination of silver behenate / silver stearate and hydroquinone / spiroindane, ferric laurate / ferric pelargonate and Combination with thiosemicarbazides, combination of lead caproate / lead behenate and thiourea derivative, combination with ferric stearate / copper stearate and lead dibutylthiocarbamate, nickel acetate and thiooxalic acid / thioacetamide Combination of organic amine molybdate and aromatic polyvalent Combination of a Dorokishi compounds can be used.

The polymer binder as a binder may be a methacrylic resin such as hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, starch, styrene-maleic acid copolymer, polymethylmethacrylate / polyethylmethacrylate alone. Alternatively, copolymers, polystyrene, acrylic-styrene copolymers, polyester resins, chroman resins, ABS resins, nitrocellulose and the like can be used.

The above-mentioned dye-coloring type and metal compound-coloring type are dispersed in a polymer binder as a binder, respectively, and formed by an appropriate forming method such as offset printing method, gravure printing method, screen printing method and the like. The thickness is about 1 to 10 μm.

In the metal removal type, low melting point metals such as tin, bismuth, tellurium, indium, aluminum, lead, zinc and alloys thereof can be used.
Using a forming method such as a sputtering method or a plating method,
The thickness is about 0.05 to 0.2 μm.

The protective layer has a protective effect against external rubbing and scratches, and includes hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol,
Starch, styrene-maleic acid copolymer, homo- or copolymer of methacrylic resin such as polymethylmethacrylate / polyethylmethacrylate, polystyrene, acrylic-styrene copolymer, polyester resin, chroman resin, ABS resin, nitrocellulose Resin or fluorine-based resin, or resin mixed with silicon-based resin using spin coating method, roll coating method, knife edge method, offset printing method, gravure printing method, screen printing method, etc. The thickness is about 1 to 5 μm.

2A and 2B are explanatory views for explaining the recording system of the present invention with respect to the information recording medium of the present invention having the above-mentioned structure. As shown in (a), the infrared laser light 11 oscillated from the infrared laser light source 10 is condensed by the objective lens 12 and is irradiated onto the recording portion of the information recording medium 1, whereby the infrared absorption heat generating layer 3 When the irradiated portion 8 absorbs the laser light energy and generates heat, the heat causes the heat-sensitive recording layer 4 to be formed on the infrared absorbing heat-generating layer 3 as shown in (b).
The heated portion 9 is colored or discolored or melted and the information is recorded. The infrared laser used at this time has a wavelength range of 800 to 1200 nm, and a gas laser, a solid-state laser, a liquid laser, a semiconductor laser, or the like is used. Although not shown, in order to record information on the information recording medium 1 by the recording device, X- of the information recording medium 1 or the laser light source 10 is used.
The laser light source 10 is oscillated electrically so that the laser light from the laser light source 10 is scanned in the Y direction and the laser light from the laser light source 10 is moved and radiated at the recording position. Control to change the light intensity,
The amount of light from the laser light source 10 is kept constant, and the laser light is controlled by an optical shutter such as a liquid crystal.

The information recorded on the information recording medium 1 is read by the user visually or the information display surface of the information recording medium 1 is irradiated with laser light such as a semiconductor laser which is a light emitting element, or white light. It is possible to perform identification by detecting the difference in the reflectance of the reflected light from the information display surface, which is irradiated by the light and is received by the light receiving element such as CCD.

Hereinafter, specific examples of the present invention will be described in detail. (Example 1) As shown in FIG. 1, a black ink consisting of 10 parts of black carbon, 40 parts of vinyl acetate / urethane resin, 50 parts of toluene, and 50 parts of ethyl acetate on a polyethylene terephthalate (PET) substrate 2 having a thickness of 188 μm. Is 5 μm thick by roll coating
Infrared absorbing heat generating layer 3 was formed. Next, a thermosensitive color developing layer coating liquid consisting of ferric myristate 5 parts tannic acid 1.5 parts methacrylic resin 10 parts toluene 70 parts was uniformly dispersed in a sand mill, and applied and dried by a gravure coating method to a thickness of 5 μm. The thermosensitive recording layer 4 was formed to obtain the information recording medium of the present invention.

(Embodiment 2) As shown in FIG.
8 μm polyethylene terephthalate (PET) substrate 2
An infrared absorbing heat generating layer 3 made of a copper thin film having a thickness of 0.01 μm was formed thereon by a vacuum deposition method. Next, a thermosensitive color developing layer coating liquid consisting of 2- (2-chlorophenylamino) -6-diethylaminofluorane 5 parts 4,4′-isopropylidenephenol 20 parts methacrylic resin 15 parts toluene 100 parts was uniformly applied by a sand mill. The dispersion was dispersed, coated and dried by a gravure coating method to form a thermosensitive recording layer 4 having a thickness of 3 μm. Further, a coating liquid consisting of 5 parts of zinc stearate, 40 parts of methacrylic resin, 40 parts of toluene and 45 parts of toluene was applied by a gravure coating method and dried to form a protective layer 6 having a thickness of 3 μm to obtain an information recording medium of the present invention.

(Third Embodiment) As shown in FIG.
8 μm polyethylene terephthalate (PET) substrate 2
A magnetic coating solution containing γ-iron oxide and vinyl chloride-based resin as main components was applied and dried by a gravure coating method to form a magnetic recording layer 7. Next, an infrared absorption heating layer 3 having a thickness of 1 μm was formed by roll coating with an ethanol solution of a naphthalocyanine dye. Next, the thermosensitive recording layer 4 made of a tin thin film having a thickness of 0.1 μm was formed by a vacuum vapor deposition method. Further, a coating solution consisting of 5 parts of zinc stearate, 40 parts of methacrylic resin, 40 parts of toluene and 45 parts of toluene was applied and dried by a gravure coating method to form a protective layer 5 having a thickness of 3 μm, whereby an information recording medium of the present invention was obtained.

When the information recording media obtained in Examples 1 to 3 were irradiated with a laser beam having a wavelength of 830 nm, an output of 5.0 mW and a beam diameter of 50 μm, good recording was performed.

Next, reference numeral 21 shown in FIG.
In the information recording medium according to the invention, an infrared absorbing heat generating layer 23 that absorbs infrared rays and generates heat, and a heat sensitive recording layer 24 that develops or changes color or melts when heated are laminated on the surface of a substrate 22. Although the heat-sensitive recording layer 24 can record information, for example, bar-shaped marks, characters, numbers, etc. as a pattern, the information, for example, bar-shaped marks, characters, numbers, etc., can be recorded as a pattern at the card manufacturing stage. It may be a thermosensitive recording layer formed in advance, and the presence thereof may be simply confirmed. Furthermore, it makes visible light opaque,
A visible light shielding layer 25 that transmits infrared rays is sequentially stacked. If necessary, the base 22 and the infrared absorbing heat generating layer 2
3, a primer layer, a magnetic recording layer, etc. may be provided as an intermediate layer, and by providing a magnetic recording layer, an information recording medium capable of magnetic recording can be provided. A primer layer or the like may be provided as an intermediate layer with the recording layer 24, a primer layer or the like may be provided as an intermediate layer between the heat-sensitive recording layer 24 and the visible light shielding layer 25, and a visible light shielding layer is further provided. A protective layer may be provided on 25, and a primer layer may be provided between them.
The infrared absorption heat generating layer 23, the heat sensitive recording layer 24, and the visible light shielding layer 25 may be formed on both sides of the base 22, or on a part or the whole of the base 22.

Infrared absorbing heat generating layer 23, heat sensitive recording layer 24
Are omitted because they are the same as the infrared absorbing heat generating layer 3 and the thermal recording layer 4 of the first invention of the present invention. The visible light shielding layer 25 invisiblely hides the color recorded or discolored or melted and removed portions recorded on the thermosensitive recording layer 24 and the remaining portion, and is formed to prevent visual reading of information. It is necessary to have a function of not transmitting or having a high reflectance in the visible light region and having a high transmittance in the infrared region. For example, a process ink having a spectral reflectance characteristic as shown in FIG. 9 [(a) yellow, (b) cyan,
(C) magenta] is mixed with a gray ink by an appropriate ratio using spin coating method, roll coating method, knife edge method, offset printing method, gravure printing method, screen printing method, or the like. The visible light shielding layer 25 is formed to have a thickness of about 2 to 3 μm.

The protective layer has a protective effect against external rubbing and scratches, and includes hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol,
Starch, styrene-maleic acid copolymer, homo- or copolymer of methacrylic resin such as polymethylmethacrylate / polyethylmethacrylate, polystyrene, acrylic-styrene copolymer, polyester resin, chroman resin, ABS resin, nitrocellulose Resin or fluorine-based resin, or resin mixed with silicon-based resin using spin coating method, roll coating method, knife edge method, offset printing method, gravure printing method, screen printing method, etc. The thickness is about 1 to 5 μm.

FIGS. 6A and 6B are explanatory views for explaining the recording system of the present invention with respect to the information recording medium of the present invention having the above-mentioned structure. As shown in (a), the infrared laser light 11 oscillated from the infrared laser light source 10 is condensed by the objective lens 12 and irradiated onto the recording portion of the information recording medium 21, whereby the infrared absorption heat generating layer 23 When the irradiated portion 28 absorbs the laser light energy and generates heat, the heat causes the heated portion 29 of the heat-sensitive recording layer 24 formed on the upper portion of the infrared absorbing heat generating layer 23 to develop or discolor as shown in (b). Alternatively, it is melted and removed, and the information is recorded. The infrared laser used at this time has a wavelength range of 800 to 1200 nm, and a gas laser, a solid-state laser, a liquid laser, a semiconductor laser, or the like is used. Although not shown, in order to record information on the information recording medium 21 by the recording device, the information recording medium 21 or the laser light source 10 is irradiated with moving light in the X-Y directions, and the laser light from the laser light source 10 is used by a polygon mirror. The laser light scanning is performed by moving and irradiating the laser light, and the oscillation of the laser light source 10 is electrically controlled so that the laser light is irradiated at the recording position, and the light amount is changed. The laser light is controlled by the optical shutter.

The information recorded on the information recording medium 2 can be read by the user's visual identification, or the laser light of the semiconductor laser or the like which is a light emitting element, or the irradiation light of white light can be used as the information display surface of the information recording medium 2. It is possible to perform identification by detecting the difference in the reflectance of the reflected light from the information display surface, which is irradiated by the light and is received by the light receiving element such as CCD.

Hereinafter, specific examples of the present invention will be described in detail. (Example 4) As shown in FIG. 5, a black ink consisting of 10 parts of black carbon, 40 parts of vinyl acetate / urethane resin, 50 parts of toluene, and 50 parts of ethyl acetate on a polyethylene terephthalate (PET) base material 22 having a thickness of 188 μm. Is 5 μm thick by roll coating
The infrared absorbing heat generating layer 23 of No. 1 was formed. Next, tri- (p-aminophenyl) -fluorene 5 parts 4,4'-isopropylidenephenol 20 parts methacrylic resin 15 parts toluene 100 parts A thermosensitive color developing layer coating liquid was uniformly dispersed in a sand mill to obtain a gravure coat. Then, the heat-sensitive recording layer 24 having a thickness of 3 μm was formed by coating and drying by a coating method. Further, a visible light shielding ink (for example, a gray ink in which process inks ((a) yellow, (b) cyan, (c) magenta) having a spectral characteristic as shown in FIG. 9) are mixed in an appropriate ratio) is gravure. The visible light shielding layer 25 having a thickness of 3 μm was formed by coating and drying by a coating method to obtain an information recording medium of the present invention.

(Embodiment 5) As shown in FIG.
8 μm polyethylene terephthalate (PET) substrate 2
An infrared absorption heat generating layer 23 made of a copper thin film having a thickness of 0.01 μm was formed on No. 2 by a vacuum vapor deposition method. Next, 3,3′-bis [2- (4-dimethylaminophenyl) -2- (4-methoxyphenyl) ethynyl] -4,5,6,7-tetrachloro-1 (3H) -isovinzo A thermosensitive color developing layer coating solution consisting of 5 parts of fluoranone, 15 parts of methacrylic resin and 100 parts of toluene was evenly dispersed in a sand mill, and applied and dried by a gravure coating method to form a thermosensitive recording layer 24 having a thickness of 3 μm. Next, a visible light shielding ink (for example, a gray-based ink obtained by mixing process inks ((a) yellow, (b) cyan, (c) magenta) having a spectral characteristic as shown in FIG. 9) in an appropriate ratio) Was applied and dried by a gravure coating method to form a visible light shielding layer 25 having a thickness of 3 μm. Further, a coating liquid consisting of 5 parts of zinc stearate, 40 parts of methacrylic resin, 40 parts of toluene and 45 parts of toluene was applied and dried by a gravure coating method to form a protective layer 26 having a thickness of 2 μm, and the information recording medium of the present invention was obtained.

(Embodiment 6) As shown in FIG.
8 μm polyethylene terephthalate (PET) substrate 2
A magnetic coating liquid containing γ-iron oxide and vinyl chloride acetate resin as the main components was applied and dried by a gravure coating method to form a magnetic recording layer 27. Next, an infrared absorption heating layer 3 having a thickness of 1 μm was formed by roll coating with an ethanol solution of a naphthalocyanine dye. Next, the thermosensitive recording layer 24 made of a tin thin film having a thickness of 0.01 μm was formed by a vacuum vapor deposition method. Next, an infrared dye ink (for example ...) Was applied and dried by a gravure coating method to form a visible light shielding layer 25 having a thickness of 3 μm. Further, a coating liquid consisting of 5 parts of zinc stearate, 40 parts of methacrylic resin, 40 parts of toluene and 45 parts of toluene was applied and dried by a gravure coating method to form a protective layer 26 having a thickness of 3 μm, and the information recording medium of the present invention was obtained.

When the information recording media obtained in Examples 4 to 6 were irradiated with laser light having a wavelength of 830 nm, an output of 5.0 mW and a beam diameter of 50 μm, good recording was performed.

[0036]

As described above, according to the present invention, the infrared absorbing heat generating layer which emits heat by absorbing infrared rays and the heat-sensitive recording layer which develops or discolors or melts and removes by heat are sequentially formed. The infrared absorbing heat generating layer generates heat by irradiation, and the heat causes the heat-sensitive recording layer provided in contact with the color to change color or change color or melt and be removed, so that non-contact recording and printing can be performed. It is possible to perform recording with excellent durability without wear and stain of the head, and since it is optical recording, it is possible to achieve high recording accuracy, high density recording, and high recording speed. Further, by sequentially forming an infrared absorbing heat generating layer which emits heat by absorbing infrared rays, a heat sensitive recording layer which develops or discolors or melts and removes heat by heat, and a visible light shielding layer which is opaque to visible light and transparent to infrared light. The infrared absorption heat generating layer generates heat by irradiation of infrared rays, and the heat causes the heat-sensitive recording layer provided in contact with the color to change color or change color or melt and be removed, thereby enabling non-contact recording and printing and information display. Since the surface can be hidden so that it cannot be seen, it is possible to perform recording with excellent durability without wear and stain on the information recording medium and the recording head, and since it is optical recording, high recording accuracy is achieved. High-density recording is possible, the recording speed is fast, it is impossible to read the recorded information from the appearance, and high-security recording is possible. Achieve the cormorant effect.

[Brief description of drawings]

FIG. 1 is a sectional view of an information storage medium according to a first aspect of the present invention.

2A and 2B are schematic diagrams illustrating a recording method for an information recording medium according to the first aspect of the present invention, in which FIG. 2A shows the time when laser light is irradiated, and FIG. 2B shows the time after laser light irradiation. ..

FIG. 3 is another embodiment of the information recording medium according to the first invention of the present invention.

FIG. 4 is another embodiment of the information recording medium according to the first invention of the present invention.

FIG. 5 is a sectional view of an information recording medium according to a second invention of the present invention.

6A and 6B are schematic diagrams illustrating a recording method for an information recording medium according to a second aspect of the present invention, in which FIG. 6A shows a laser beam irradiation time and FIG. 6B shows a laser beam irradiation time point. ..

FIG. 7 is another embodiment of the information recording medium according to the second invention of the present invention.

FIG. 8 is another embodiment of the information recording medium according to the second invention of the present invention.

FIG. 9 is a reflectance showing a spectral reflectance characteristic of the visible light shielding layer;
It is a wavelength curve figure, (a) yellow, (b) cyan,
(C) It is each reflectance-wavelength curve figure of magenta.

[Explanation of symbols]

 1, 21 Information recording medium 2, 22 Base material 3, 23 Infrared absorbing heat generating layer 4, 24 Thermal recording layer 25 Visible light shielding layer 6, 26 Protective layer 7, 27 Magnetic recording layer 10 Laser light source 10 11 Infrared laser light 12 Objective lens

Claims (5)

[Claims] 1. An infrared absorbing heat generating layer on a substrate,
An information recording medium comprising a thermosensitive coloring layer or a thermosensitive recording layer composed of a metal thin film layer, which are sequentially laminated. 2. An infrared absorption heat generating layer on a substrate,
An information recording medium comprising a thermosensitive recording layer comprising a thermosensitive coloring layer or a metal thin film layer, and a visible light shielding layer which is opaque to visible light and transmits infrared light, which are sequentially laminated. 3. The information recording medium according to claim 1, wherein a protective layer is provided on the thermosensitive recording layer. 4. The information recording medium according to claim 2, wherein a protective layer is provided on the visible light shielding layer. 5. A recording method for an information recording medium, characterized in that an infrared absorbing heat generating layer is caused to generate heat by irradiation of an infrared laser, and the heat causes the heat sensitive recording layer to develop or change color or melt and be removed.