JP2021011105A - Recording medium and recording medium with peeling substrate - Google Patents

Abstract

To provide a recording medium that makes it possible to prepare a printed matter by using a conventional printer without using a thermal transfer sheet, and a recording medium with a peeling substrate.SOLUTION: A recording medium 10 has a substrate 11 containing a colorant, a concealment layer 12, and a protective layer 13. The concealment layer is heated to be transparent.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a recording medium and a recording medium with a release base material.

Conventionally, energy is applied to a thermal transfer sheet provided with a base material and a transfer layer by a thermal head provided in a printer to transfer the transfer layer onto a transfer target such as paper or a plastic sheet to form an image. , A thermal melt transfer method for producing a printed matter is known.
Since the image formed by the thermal fusion transfer method has a high density and excellent sharpness, this method is suitable for recording binary images such as characters and line art. Further, according to the Fused Deposition Modeling method, variable information such as an address, customer information, number, and bar code can be recorded on a transfer target by using a computer and a thermal transfer printer.

After the image is formed, the thermal transfer sheet is wound by a take-up roller, but the thermal transfer sheet may leave print marks, and a means for producing a printed matter in place of the thermal transfer sheet has been required.

For example, Patent Document 1 proposes a method of recording information and producing a printed matter by melting and breaking a metal thin film layer included in a thermal recording medium.

Japanese Unexamined Patent Publication No. 8-58231

The present disclosure has been made in view of the above problems, and the problem to be solved is to include a recording medium and a release base material capable of producing a printed matter by an existing printer without using a thermal transfer sheet. It is the provision of recording media.

In the first aspect, the recording medium includes a base material containing a coloring material, a concealing layer, and a protective layer, and the concealing layer becomes transparent by heating.

In one embodiment, the recording medium is further provided with a coloring layer between the base material and the concealing layer so as to cover a part of the base material, and the coloring layer is a coloring material contained in the base material. Contains different colorants.

In the second aspect, the recording medium includes a base material, a concealing layer, and a protective layer, and includes a coloring layer containing a coloring material under the base material and at least one of the base materials and the concealing layer.
The concealing layer is characterized in that it becomes transparent by heating.

In one embodiment, the concealing layer comprises hollow particles and a binder.

In one embodiment, the resin constituting the hollow particles is a styrene resin.

In one embodiment, the binder is a polyolefin.

In one embodiment, the ratio of the content of hollow particles in the concealing layer to the binder is 40/60 or more and 95/5 or less on a mass basis.

In one embodiment, the porosity of the concealing layer is 20% by volume or more and 90% by volume or less.

In one embodiment, the thickness of the concealing layer is 0.5 μm or more and 30 μm or less.

In one embodiment, the protective layer comprises a polyvinyl acetal and an isocyanate compound.

In one embodiment, the L value of the recording medium before heating, measured from the protective layer side, is 60 or more.

In one embodiment, the L value of the recording medium after heating, measured from the protective layer side, is 30 or less.

The recording medium with a release base material of the present disclosure is characterized by including a release base material, an adhesive layer, and the above-mentioned recording medium.

According to the present disclosure, it is possible to provide a recording medium and a recording medium with a release base material capable of producing a printed matter by an existing printer without using a thermal transfer sheet. Further, the printed matter produced by using the recording medium of the present disclosure and the recording medium with a release base material has high scratch resistance.

It is the schematic sectional drawing which shows one Embodiment of the recording medium of this disclosure. It is the schematic sectional drawing which shows one Embodiment of the recording medium of this disclosure. It is the schematic sectional drawing which shows one Embodiment of the recording medium of this disclosure. It is the schematic sectional drawing which shows one Embodiment of the recording medium of this disclosure. It is the schematic sectional drawing which shows one Embodiment of the recording medium of this disclosure. It is the schematic sectional drawing which shows one Embodiment of the recording medium with a release base material of this disclosure. It is the schematic sectional drawing which shows one Embodiment of the recording medium with a release base material of this disclosure. It is the schematic sectional drawing which shows one Embodiment of the recording medium with a release base material of this disclosure. It is the schematic sectional drawing which shows one Embodiment of the recording medium with a release base material of this disclosure. It is the schematic sectional drawing which shows one Embodiment of the recording medium with a release base material of this disclosure.

(Recording medium in the first aspect)
In the first aspect of the present disclosure, as shown in FIG. 1, the recording medium 10 includes a base material 11 containing a coloring material, a concealing layer 12, and a protective layer 13.
Further, in one embodiment, as shown in FIG. 2, the recording medium 10 further includes a colored layer 14 between the base material 11 and the concealing layer 12 so as to cover a part of the base material 11. ..
Hereinafter, each layer constituting the recording medium in the first aspect will be described.

The L value of the recording medium before heating is preferably 60 or more, and more preferably 80 or more.
The L value of the recording medium after heating is preferably 30 or less, and more preferably 20 or less.
In the present disclosure, the measurement of the L value is performed by a spectroscopic densitometer (manufactured by X-rite, eXact, filter M1: D50 at all wavelengths including the UV range, illuminant (light source) D50, angle 2 °, density status. It is performed using ISO Status T).
In the present disclosure, the L value is measured at room temperature (23 ° C.) and normal pressure (1 atm), and a spectroscopic densitometer (manufactured by X-rite, eXact, light source: D50, viewing angle: 2). °, Concentration measurement filter: ANSI Status T).
Further, the L value is measured from the protective layer side.
Further, the L value of the heat-sensitive recording medium after heating is performed on the heat-sensitive recording medium after heating the heat-sensitive recording medium from the protective layer side under the following printer conditions.
(Test printer)
-Energy gradation: 180/255 gradation-Thermal head: KEE-57-12GAN2-STA (Kyocera Corporation)
-Average resistance value of heating element: 3303 (Ω)
-Main scanning direction printing density: 300 (dpi)
-Secondary scanning direction print density: 300 (dpi)
・ Printing voltage: 18 (V)
-Line cycle: 1.5 (msec.)
-Printing start temperature: 35 (° C)
-Pulse duty ratio: 85 (%)

(Base material)
The base material has heat resistance that can withstand the heat energy applied when the concealing layer is made transparent, and is particularly strong as long as it has mechanical strength and solvent resistance that can support the layer provided on the base material. Can be used without restrictions.

As the base material, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), 1,4-polycyclohexylene methylene terephthalate, terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, etc. Polyester, Polyester such as Nylon 6 and Nylon 6,6, Polyethylene (PE), Polyethylene (PP), Polyethylene such as Polymethylpentene, Polyvinyl Chloride, Polyvinyl Alcohol (PVA), Polyvinyl Acetal, Vinyl Acetate, Vinyl Chloride -Vinyl acetate copolymer, vinyl resin such as polyvinylpyrrolidone (PVP), (meth) acrylic resin such as polyacrylate, polymethacrylate and polymethylmethacrylate, imide resin such as polyimide and polyetherimide, cellophane, cellulose A film composed of a cellulose resin such as acetate, nitrocellulose, cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB), a styrene resin such as polystyrene (PS), a polycarbonate, and an ionomer resin (hereinafter, simply "Resin film") can be used.
Among the above-mentioned resins, polyesters such as PET and PEN are preferable, and PET is particularly preferable, from the viewpoint of heat resistance and mechanical strength.
In the present disclosure, "(meth) acrylic" includes both "acrylic" and "methacrylic". Further, "(meth) acrylate" includes both "acrylate" and "methacrylate".

Further, the above-mentioned laminated body of the resin film can also be used as a base material. The laminate of the resin film can be produced by using a dry lamination method, a wet lamination method, an extraction method, or the like.
When the base material is a laminate of resin films, at least one layer may contain a coloring material described later. For example, three resin films can be laminated, and the coloring material can be contained only in the resin film located in the middle.

In the first aspect, the substrate comprises a colorant, which may be a pigment or a dye. From the viewpoint of light resistance, pigments are preferable.
Further, the color of the coloring material is not particularly limited, and it is preferable to appropriately change the color according to the intended use.
Examples of the coloring material include red coloring materials such as cadmium red, cadmium red, chrome red, vermilion, red iron oxide, azo pigment, alizarin lake, quinacridone, and cochineal lake perylene, yellow ocher, aureolin, cadmium yellow, and cadmium orange. Yellow colorants such as chrome yellow, zink yellow, naples yellow, nickel yellow, azo pigments, greenish yellow, blue colorants such as ultramarine, rock ultramarine, cobalt, phthalocyanine, anthraquinone, indicoid, green pigments Examples include green colorants such as cinnabar green, cadmium green, chrome green, phthalocyanine, azomethine, and perylene, black colorants such as carbon black, white colorants such as silica, calcium carbonate, and titanium oxide, and aluminum pigments. Metal-based coloring materials such as.

When the base material is a resin film, the resin film may be a stretched film or an unstretched film, but from the viewpoint of strength, a stretched film stretched in the uniaxial direction or the biaxial direction is used. It is preferable to use it.

The thickness of the base material is preferably 10 μm or more and 500 μm or less, and more preferably 80 μm or more and 230 μm or less. As a result, the mechanical strength of the base material can be improved. In addition, the image density of the printed matter produced by the recording medium of the present disclosure can be improved.

(Concealment layer)
The concealing layer is a layer that conceals the colorant-containing base material before heating and makes it transparent by heating. By making the concealing layer transparent, the colorant-containing base material in the transparent portion becomes apparent. An image can be formed by adjusting the actualized portion of the colorant-containing base material.
The concealing layer may be provided so as to cover the entire surface of the colorant-containing base material, or may be provided so as to cover a part thereof.

The concealment rate of the concealing layer is preferably 40% or more, more preferably 60% or more, and further preferably 70% or more.
In the first aspect of the present disclosure, the concealment rate of the concealing layer is measured as follows.
First, the reflection density (R0) of a recording medium provided with a base material containing a coloring material, a concealing layer and a protective layer is measured with a reflection densitometer (RD-918 manufactured by X-Rite). The reflection density is measured from the surface on the protective layer side.
Next, this recording medium is heated from the protective layer side under the following printer conditions to make the concealing layer transparent. The reflection density (R1) of the recording medium after heating is measured from the protective layer side. The concealment rate can be calculated by substituting the measured R0 and R1 into the following equation.
Concealment rate of concealment layer (%) = [1- (R0 / R1)] × 100
(Test printer)
-Energy gradation: 180/255 gradation-Thermal head: KEE-57-12GAN2-STA (Kyocera Corporation)
-Average resistance value of heating element: 3303 (Ω)
-Main scanning direction printing density: 300 (dpi)
-Secondary scanning direction print density: 300 (dpi)
・ Printing voltage: 18 (V)
-Line cycle: 1.5 (msec.)
-Printing start temperature: 35 (° C)
-Pulse duty ratio: 85 (%)

The reflection concentration of the recording medium before heating is preferably 0.3 or less, more preferably 0.1 or less.
The reflection density of the recording medium after heating is preferably 1.0 or more, and more preferably 1.5 or more.
In the present disclosure, the reflection density of the recording medium before heating is measured from the surface on the protective layer side in the recording medium provided with the base material containing the coloring material, the concealing layer and the protective layer. Further, the reflection density of the recording medium after heating is such that when the recording medium having the base material containing the coloring material, the concealing layer and the protective layer is heated from the protective layer side and the transparency does not proceed, the reflection density of the protective layer side It can be measured from the surface. The heating method is not particularly limited, and can be performed by using a laminator, a test printer, or the like as described above.

In one embodiment, the concealing layer comprises hollow particles and a binder made of a resin material. By heating the concealing layer having such a structure to a temperature equal to or higher than the melting temperature of the resin material constituting the hollow particles, the resin wall of the hollow particles is crushed to become a continuous layer and become transparent.

Examples of the resin material constituting the hollow particles include crosslinked styrene-acrylic resin, styrene resin such as polystyrene, (meth) acrylic resin, phenol resin, fluororesin, polyamide, imide resin, polycarbonate and polyether.
Among these, the hollow particles are preferably composed of a styrene resin, whereby the concealing layer has a high concealing property before heating, and its transparency is remarkably improved by heating, which is good. Images can be formed (hereinafter, in some cases, simply referred to as image formability).
Further, the hollow particles may be foamed particles or non-foamed particles.

The average particle size of the hollow particles is preferably 0.1 μm or more and 15 μm or less, and more preferably 0.1 μm or more and 10 μm or less. As a result, the base material can be well concealed before heating. In addition, the smoothness of the concealing layer can be improved, and the design of the obtained printed matter can be improved.
The average particle size conforms to JIS-Z-8819-2 (issued in 2001) using a particle size distribution / particle size distribution measuring device (for example, Nanotrack particle size distribution measuring device, manufactured by Nikkiso Co., Ltd., etc.). Can be measured.

The average hollow ratio of the hollow particles is preferably 30% or more and 80% or less, and more preferably 35% or more and 80% or less. As a result, the base material can be well concealed before heating. In addition, the transparency of the concealing layer can be improved more remarkably than heating, and the image forming property can be further improved.
The average hollow ratio can be obtained as follows. First, an aqueous dispersion in which hollow particle components are dispersed in water is prepared, and the aqueous dispersion of the hollow particles is dried to obtain a dried product, and then a transmission electron microscope (manufactured by Hitachi High Technology). (100), the particles forming the hollow particle component in the dried body are observed, the diameter (inner diameter) of the inner surface side of the particles is measured, and the average of them is taken as the average particle inner diameter. Next, the average hollow ratio can be calculated by determining the volume of the hollow portion from the average particle inner diameter, dividing the value by the apparent volume of the particles from the average particle (particle outer diameter), and multiplying by 100.
In one embodiment, the hollow particles can be produced by enclosing a foaming material such as butane gas in resin particles or the like and heating and foaming the particles. In one embodiment, the hollow particles can also be produced by utilizing emulsion polymerization.
Alternatively, commercially available hollow particles may be used.

The content of the hollow particles in the concealing layer is preferably 50% by mass or more and 90% by mass or less, and more preferably 60% by mass or more and 70% by mass or less. As a result, the base material can be well concealed before heating. In addition, the transparency of the concealing layer by heating can be improved more remarkably, and the image formability can be further improved.

Examples of the binder contained in the concealing layer together with the hollow particles include polyurethane, polyolefin, polyester, gelatin, ethylene-vinyl alcohol copolymer (EVA), polyvinyl alcohol, polyethylene xside, polyvinylpyrrolidone, purulan, carboxymethyl cellulose, and hydroxyethyl cellulose. Examples thereof include dextran, dextrin, polyacrylic acid and salts thereof, agar, and casein.
Among these, polyolefin is preferable. By using polyolefin as a binder, it is possible to suppress the erosion of the solvent into the concealing layer when the coating liquid for forming the protective layer is applied onto the concealing layer, and it is possible to suppress the deterioration of the concealing property (hereinafter referred to as erosion inhibitory property). .. Further, from the viewpoint of erosion inhibitory property, among polyolefins, polyolefins modified with maleic acid, (meth) acrylic acid and the like (acid-modified polyolefins) are more preferable.

The content of the binder in the concealing layer is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less. This makes it possible to improve the retention of hollow particles in the concealing layer.

The ratio of the content of hollow particles in the concealing layer to the content of the binder is preferably 55/45 or more and 95/5 or less, and more preferably 60/40 or more and 90/10 or less on a mass basis. preferable. Thereby, the hiding property and the image forming property can be further improved while maintaining the holding property of the hollow particles in the hiding layer.

The porosity of the concealing layer containing the hollow particles and the binder is preferably 20% by volume or more and 90% by volume or less, and more preferably 40% by volume or more and 80% by volume or less. As a result, the base material can be well concealed before heating.
The porosity can be calculated by the following formula.
Pv (volume%) = {(Va-Vt) / Va} x 100
Pv (volume%): Porosity of concealing layer Va: Apparent volume of concealing layer Vt: Theoretical volume of concealing layer Vt is calculated from the weight of the concealing layer, the weight ratio of the constituent material, and the true specific weight of the constituent material. it can.

In the concealing layer having the above structure, the above material is dispersed or dissolved in water or an appropriate solvent to prepare a coating liquid, which is used as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, or a bar coating. It is formed by applying it on a base material or a colored layer by a known means such as a method and a rod coating method to form a coating film, and drying this at a temperature equal to or lower than the melting temperature of the resin material constituting the hollow particles. it can.

In one embodiment, the concealing layer is composed of a porous resin film having voids inside. By heating the concealing layer having such a structure to a temperature equal to or higher than the melting temperature of the resin material constituting the porous resin film, the voids are crushed to form a continuous layer and become transparent.

The porous resin film is made of a resin material, and examples of the resin material include polyolefin, vinyl resin, polyester, styrene resin, and polyamide.

The porosity of the porous resin film is preferably 30% by volume or more and 90% by volume or less, and more preferably 60% by volume or more and 80% by volume or less. As a result, the base material can be well concealed before heating.
The porosity of the porous resin film can be calculated by the following formula.
Pv (volume%) = {(Va-Vt) / Va} x 100
Pv (% by volume): Porosity of the porous resin film Va: Apparent volume of the porous resin film Vt: Theoretical volume of the porous resin film Vt is the weight of the porous resin film, the weight ratio and composition of the constituent materials. It can be calculated from the value of the true specific gravity of the material.

The concealing layer having the above structure can be formed by producing a porous resin film by a known method and laminating it with a base material or a colored layer via a conventionally known adhesive or the like.
The porous resin film can be produced, for example, by forming a film of a mixture of incompatible organic fine particles or inorganic particles kneaded with the above-mentioned resin material.
Further, in one embodiment, the porous resin film can be produced by forming a mixture of a first resin material and a second resin material having a melting point higher than that of the first resin material into a film. In this case, the second resin material functions as a core material for forming fine voids. The mixing amount of the second resin material is preferably 2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the first resin material. For example, a porous resin film can be produced by forming a film containing polypropylene as the first resin material and acrylic resin as the second resin material. Alternatively, a commercially available porous resin film may be used.

In one embodiment, the concealing layer comprises resin particles. When the concealing layer having such a structure is heated to a temperature equal to or higher than the melting temperature of the resin particles, the resin particles are crushed to form a continuous layer and become transparent.

Examples of the resin material constituting the resin particles include vinyl resins such as EVA, polyolefins, styrene resins, and (meth) acrylic resins.

The average particle size of the resin particles is preferably 0.1 μm or more and 15 μm or less, and more preferably 0.1 μm or more and 10 μm or less. As a result, the base material can be well concealed before heating.

The content of the resin particles in the concealing layer is preferably 40% by mass or more and 95% by mass or less, and more preferably 50% by mass or more and 90% by mass or less. As a result, the base material can be well concealed before heating.

Further, the concealing layer may contain the above binder together with the resin particles.

In the concealing layer having the above structure, the above material is dispersed or dissolved in water or an appropriate solvent to prepare a coating liquid, which is used as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, or a bar coating. It can be formed by applying it on a base material or a colored layer by a known means such as a method and a rod coating method to form a coating film, and drying the coating film at a temperature equal to or lower than the melting temperature of the resin particles.

As long as the characteristics of the present disclosure are not impaired, the concealing layer may contain additives such as fillers, plastic materials, antistatic materials, ultraviolet absorbers, inorganic particles, organic particles, mold release materials and dispersants.

The thickness of the concealing layer is preferably 0.5 μm or more and 30 μm or less, and more preferably 5 μm or more and 15 μm or less. As a result, the base material can be well concealed before heating.

(Protective layer)
The recording medium of the present disclosure is provided with a protective layer on the concealing layer, whereby the scratch resistance of the printed matter produced by the recording medium of the present disclosure can be improved.

The material constituting the protective layer can be used without particular limitation as long as it can maintain the transparency of the protective layer and impart durability to the printed matter.
In one embodiment, the protective layer comprises at least one resin material, eg, (meth) acrylic resin, polyester, cellulose resin, polystyrene, polyamide, vinyl resin, polycarbonate, silicone resin, thermocurable resin and active light beam. Examples include cured resin.

The transmittance of the protective layer is preferably 70% or more, and more preferably 75% or more.
In the present disclosure, the transmittance of the protective layer is measured as follows.
First, the reflection density (R2) of the base material containing the coloring material is measured with a reflection densitometer (RD-918 manufactured by X-Rite).
Next, the reflection density (R3) of the laminate provided with the base material containing the coloring material and the protective layer is measured. The reflection density is measured from the surface on the protective layer side.
The transmittance can be calculated by substituting the measured R2 and R3 into the following equation.
Transmittance of protective layer (%) = (R3 / R2) x 100

In a preferred embodiment, the protective layer contains a hydroxyl group-containing resin that is cured by the reaction with the isocyanate compound described below, and examples thereof include polyvinyl alcohol, polyvinyl acetal, (meth) acrylic polyol, and the like, among which scratch resistance From this point of view, polyvinyl acetal is preferable, and polyvinyl butyral is more preferable.

Further, the hydroxyl group-containing resin preferably has a hydroxyl value of 5% by mass or more and 30% by mass or less, and more preferably 10% by mass or more and 25% by mass or less. As a result, the scratch resistance of the printed matter can be further improved.
In the present disclosure, the "hydroxyl value" means the ratio of the hydroxyl group-containing monomer in the resin, and is a value calculated as the ratio (mass%) of the hydroxyl group-containing monomer to the total mass of the resin.

When the protective layer contains a hydroxyl group-containing resin, it preferably contains an isocyanate compound.
As the isocyanate compound, a polyisocyanate compound having two or more isocyanate groups in the molecule is preferable. For example, xylene diisocyanate, paraphenylene diisocyanate, 1-chloro-2,4-phenyldiisocyanate, 2-chloro-1,4-phenyldiisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,5-naphthalene. Diisocyanate, trizine diisocyanate, p-phenylene diisocyanate, trans-cyclohexane, 1,4-diisocyanate, hexamethylene diisocyanate, 4,4'-biphenylenediocyanide, triphenylmethane triisocyanate and 4,4', 4 "-trimethyl-3. , 3', 2'-triisocyanate-2,4,6-triphenylcyanurate and the like.

In one embodiment, the protective layer may contain fillers such as inorganic particles and organic particles.
Examples of the inorganic particles include clay minerals such as talc and kaolin, carbonates such as calcium carbonate and magnesium carbonate, hydroxides such as aluminum hydroxide and magnesium hydroxide, sulfates such as calcium sulfate, aluminum oxide and silica. Oxides, as well as inorganic fine particles such as graphite, sulphate and boron hydroxide.
Organic particles include (meth) acrylic resin, Teflon (registered trademark) resin, silicone resin, lauroyl resin, phenol resin, acetal resin, polystyrene, polyamide, and other organic resin fine particles, and cross-linking by reacting these with a cross-linking material. Examples include resin fine particles.
Among the above, when the printer to be used is provided with a thermal head as a heating member, talc is preferable because it can effectively remove the adhering debris while suppressing the wear of the thermal head.

From the viewpoint of wear suppression and debris removal of the thermal head, the average particle size of the filler is preferably 0.5 μm or more and 3 μm or less, and more preferably 0.7 μm or more and 2.7 μm or less.
In the present disclosure, the average particle size of the filler means the median diameter D50 measured by the laser diffraction method.

The content of the filler in the protective layer is preferably 5% by mass or more and 40% by mass or less. As a result, wear of the thermal head can be further suppressed, and adhering debris can be removed more effectively.

The protective layer can include a lubricant, which can improve the transportability of the recording medium in the printer.
Examples of the lubricating material include polyolefin waxes such as polyethylene wax and polypropylene wax, ethoxylated alcohol-modified waxes, paraffin waxes, montan waxes, and metal soaps.
Examples of the metal soap include a polyvalent metal salt of an alkyl phosphate, a metal salt of an alkyl carboxylic acid, and the like.
The alkyl group in the alkyl phosphate is preferably having 12 or more carbon atoms, and the stearyl group is particularly preferable because it has excellent slipperiness. The metal salt in the polyvalent metal salt of the alkyl phosphate is preferably zinc or aluminum salt.
Regarding the metal salt of the alkylcarboxylic acid, the alkyl group preferably has 11 or more carbon atoms, particularly preferably a dodecyl group or a heptadecyl group, and preferably a magnesium salt, a zinc salt or an aluminum salt as the metal salt.

The content of the lubricant in the protective layer is preferably 0.5% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 10% by mass or less. As a result, the transportability of the recording medium in the printer can be further improved.

In addition, the protective layer may contain the above-mentioned additives as long as the characteristics of the present disclosure are not impaired.

The thickness of the protective layer is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.2 μm or more and 3 μm or less. As a result, the scratch resistance of the printed matter can be further improved while maintaining the image formability. In addition, the transportability of the recording medium in the printer can be further improved.

In one embodiment, the protective layer disperses or dissolves the above-mentioned material in water or a suitable solvent to obtain a coating liquid, which is used as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, and the like. It can be formed by applying it on a concealing layer to form a coating film by a known means such as a bar coating method and a rod coating method, and drying the coating film.
Further, in one embodiment, the protective layer may have a multi-layer structure. For example, the above-mentioned material may be dispersed or dissolved in water or an appropriate solvent on a resin film such as a PET film to prepare a coating liquid, and the coated and dried product may be used as a protective layer. With such a configuration, the scratch resistance of the printed matter can be further improved.
Lamination of the protective layer having the above-mentioned structure on the concealing layer can be performed by applying a conventionally known adhesive to the surface of the resin film, drying the adhesive layer, forming an adhesive layer, and passing through the adhesive layer. I.

(Colored layer)
In the first aspect, the recording medium may include a colored layer between the substrate and the concealing layer to cover a portion of the substrate.

In one embodiment, the colored layer comprises a colorant different from the colorant contained in the substrate. With such a configuration, images of different colors can be formed depending on the transparent portion of the concealing layer, and the design can be further enhanced.

As the coloring material contained in the coloring layer, the above-mentioned ones can be appropriately selected and used.

The content of the coloring material in the colored layer is preferably 10% by mass or more and 60% by mass or less, and more preferably 20% by mass or more and 50% by mass or less. Thereby, the image density of the printed matter produced by the recording medium of the present disclosure can be improved.

The colored layer can include resin materials such as polyester, polyamide, polyolefin, vinyl resin, (meth) acrylic resin, imide resin, cellulose resin, styrene resin, polycarbonate, and ionomer resin and epoxy resin.

The content of the resin material in the colored layer is preferably 20% by mass or more and 90% by mass or less. Thereby, the ease of forming the colored layer can be improved.

In one embodiment, the recording medium 10 includes two or more colored layers 14 containing different coloring materials, as shown in FIG. With such a configuration, images of different colors can be obtained depending on the transparent portion of the concealing layer, and the design can be further enhanced.

The thickness of the colored layer containing the coloring material is preferably 0.2 μm or more and 3 μm or less, and more preferably 0.4 μm or more and 1.5 μm or less. Thereby, the image density of the printed matter produced by the recording medium of the present disclosure can be improved.

In addition, the colored layer can contain foamed particles. As a result, the colored layer of the heated portion becomes a convex portion, and the design of the printed matter can be further improved.

In addition, the colored layer may contain the above-mentioned additives as long as the characteristics of the present disclosure are not impaired.

The colored layer containing the coloring material is prepared by dispersing or dissolving the above material in water or an appropriate solvent to obtain a coating liquid, which is used as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, or a bar. It can be formed by applying it on a substrate by a known means such as a coating method and a rod coating method to form a coating film, and drying the coating film.

(Recording medium in the second aspect)
In the second aspect of the present disclosure, the recording medium 10 includes a base material 11, a concealing layer 12, and a protective layer 13, and is placed under the base material 11 and at least one of the base material 11 and the concealing layer 12. A colored layer 14 containing a coloring material is provided (see FIGS. 4 and 5).
Hereinafter, each layer constituting the recording medium in the second aspect will be described, but since the configuration of the protective layer is the same as that in the first aspect, the description is omitted here.

The L value of the recording medium before heating is preferably 60 or more, and more preferably 80 or more.
The L value of the recording medium after heating is preferably 30 or less, and more preferably 20 or less.

(Base material)
In the second aspect, the substrate may or may not contain a colorant.
When the base material contains a coloring material different from the coloring material contained in the coloring layer, and the coloring layer is on the base material and is provided so as to cover a part thereof, the concealing layer is made transparent. Images of different colors can be formed depending on the location, and the design can be further enhanced.
Since other configurations are the same as those in the first aspect, the description thereof will be omitted.

(Colored layer)
In the second aspect, the recording medium is provided with a colored layer under the base material and at least one between the base material and the concealing layer, and the colored layer is provided so as to cover a part of the base material. It may be provided so as to cover the whole. Further, the recording medium may include two or more colored layers.
Since other configurations are the same as those in the first aspect, the description thereof will be omitted.

(Concealment layer)
The concealment rate of the concealing layer is preferably 60% or more, more preferably 70% or more.
In the second aspect of the present disclosure, the concealment rate of the concealing layer is measured as follows.
First, the reflection density (R0') of a recording medium provided with a base material, a colored layer, a concealing layer and a protective layer is measured with a reflection densitometer (RD-918 manufactured by X-Rite). The reflection density is measured from the surface on the protective layer side.
Next, the recording medium is heated from the protective layer side to make the concealing layer transparent, and the heating is stopped when the transparency does not proceed. The reflection density (R1') of the recording medium after heating is measured from the protective layer side. The concealment rate can be calculated by substituting the measured R0'and R1' into the following equation.
The heating method is not particularly limited, and as described above, it can be performed by using a laminator, a test printer, or the like.
Concealment rate of concealment layer (%) = [1- (R0'/ R1')] x 100
Since other configurations are the same as those in the first aspect, the description thereof will be omitted.

The reflection concentration of the recording medium before heating is preferably 0.3 or less, more preferably 0.1 or less.
The reflection density of the recording medium after heating is preferably 1.0 or more, and more preferably 1.5 or more.
In the present disclosure, the reflection density of the recording medium before heating is measured from the surface on the protective layer side in the recording medium provided with the base material, the colored layer, the concealing layer and the protective layer. Further, the reflection density of the recording medium after heating is the surface on the protective layer side when the recording medium having the base material, the colored layer, the concealing layer and the protective layer is heated from the protective layer side and the transparency does not proceed. Can be measured from. The heating method is not particularly limited, and can be performed by using a laminator, a test printer, or the like as described above.

(Protective layer)
The transmittance of the protective layer is preferably 70% or more, and more preferably 75% or more.
In the present disclosure, the transmittance of the protective layer is measured as follows.
First, the reflection density (R4) of the laminate provided with the base material and the colored layer is measured with a reflection densitometer (RD-918 manufactured by X-Rite). The reflection density is measured from the surface on the colored layer side.
Next, the reflection density (R5) of the laminate provided with the base material, the colored layer and the protective layer is measured. s The reflection density is measured from the surface on the protective layer side.
The transmittance can be calculated by substituting the measured R4 and R5 into the following equation.
Transmittance of protective layer (%) = [1- (R5 / R4)] x 100
Since other configurations are the same as those in the first aspect, the description thereof will be omitted.

(Recording medium with release base material)
As shown in FIGS. 6 to 10, the recording medium 20 with a release base material of the present disclosure includes a release base material 21, an adhesive layer 22, and a recording medium 10 in the first or second aspect. It is characterized by.

(Release base material)
The recording medium with a release base material of the present disclosure includes a release base material that can be peeled off from the pressure-sensitive adhesive layer on the pressure-sensitive adhesive layer, whereby it is possible to prevent the adhesive strength of the pressure-sensitive adhesive layer from decreasing over time.

The release base material includes paper base materials such as high-quality paper, art paper, coated paper, resin coated paper, cast coated paper, paperboard, synthetic paper and impregnated paper, polyester, polyamide, polyolefin, vinyl resin, and (meth) acrylic resin. , An imide resin, a cellulose resin and the like can be used. Further, these laminated bodies may be used.

The release base material may have a release layer on the surface on the adhesive layer side. The release layer may contain a wax such as silicone wax and a resin material such as silicone resin, fluororesin, (meth) acrylic resin, urethane resin and vinyl resin.

Further, the surface of the release base material on the adhesive layer side may be subjected to surface treatment such as corona treatment, plasma treatment, frame treatment and ozone treatment.

The thickness of the release base material is preferably 30 μm or more and 200 μm or less, and preferably 50 μm or more and 150 μm or less. As a result, the peeling base material can be more easily peeled from the adhesive layer, and wrinkles (hereinafter referred to as peeling wrinkles) can be suppressed from occurring in the adhesive layer at the time of peeling.

(Adhesive layer)
The recording medium with a release base material includes an adhesive layer. As a result, a sticker-type recording medium can be used.

In one embodiment, the adhesive layer comprises one or two adhesive materials such as (meth) acrylic adhesive material, epoxy adhesive material, polyamide adhesive material, polystyrene adhesive material, silicone adhesive material and urethane adhesive material. Including more than seeds.

The content of the pressure-sensitive adhesive in the pressure-sensitive adhesive layer is preferably 50% by mass or more, and more preferably 70% by mass or more. Thereby, the adhesiveness of the adhesive layer can be improved.

In one embodiment, the pressure-sensitive adhesive layer contains the above additives to the extent that the properties of the present disclosure are not impaired.

In the adhesive layer, the above material is dispersed or dissolved in water or a suitable solvent to prepare a coating liquid, which is used as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and the like. It can be formed by applying it on a base material or the like to form a coating film by a known means such as a rod coating method, and drying the coating film.

The present disclosure will be described in more detail with reference to the following examples, but the present disclosure is not limited to these examples.

Example 1
A 100 μm-thick PET film (manufactured by Mitsubishi Chemical Corporation, S100 # 100) is prepared as a base material, and a coating liquid for forming an adhesive layer having the following composition is applied to one surface thereof, dried, and the thickness is increased. A 75 μm-thick PET film (Mitsubishi Chemical (Mitsubishi Chemical)) that forms a 9 μm adhesive layer, applies the following release layer forming coating dispersion as a release base material, and dries to form a 2 μm-thick release layer. S100 # 75) manufactured by Co., Ltd. was laminated.
(Coating liquid for forming adhesive layer)
・ (Meta) acrylic adhesive 15 parts by mass (manufactured by Soken Chemical Co., Ltd., SK Dyne 1251)
-Hardened material 0.33 parts by mass (manufactured by Soken Chemical Co., Ltd., L-45)
-Hardened material 0.1 parts by mass (manufactured by Soken Chemical Co., Ltd., E-AX)
・ Ethyl acetate 16.14 parts by mass (coating liquid for release layer)
・ Addition polymerization agent Silicone 100 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., KS847H)
・ 200 parts by mass of toluene

On the other surface of the base material (PET film having a thickness of 100 μm), a coating liquid for forming a colored layer having the following composition was applied and dried to form a colored layer having a thickness of 1 μm.
(Coating liquid for forming a colored layer)
・ Carbon black 50 parts by mass ・ Polyester 50 parts by mass ・ Melamine filler 3 parts by mass ・ Water 10 parts by mass ・ Isopropanol (IPA) 30 parts by mass

On the colored layer formed as described above, a coating liquid for forming a concealing layer having the following composition was applied and dried to form a concealing layer having a thickness of 20 μm.
(Coating liquid for forming a concealing layer)
-Acrylic-styrene copolymer hollow particles 6 parts by mass (Roam & Haas Company, Low Pake (registered trademark) OP-62, average particle diameter 0.4 μm, hollow ratio 37.5%)
-Urethane resin 4 parts by mass (manufactured by DIC Corporation, Hydran (registered trademark) AP-40N)
・ 100 parts by mass of water

A coating liquid for forming a protective layer having the following composition is applied and dried on the concealing layer formed as described above to form a protective layer having a thickness of 1 μm, thereby obtaining the recording medium with a release base material of the present disclosure. It was.
(Coating liquid for forming a protective layer)
-Polyvinyl butyral A 86.8 parts by mass (manufactured by Sekisui Chemical Co., Ltd., Eslek (registered trademark) BM-2, hydroxyl value 19% by mass)
-Isocyanate compound A 9.7 parts by mass (manufactured by DIC Corporation, Burnock (registered trademark) D750)
-Zinc A stearyl phosphate 1 part by mass (manufactured by Sakai Chemical Industry Co., Ltd., purified by LBT-1830)
-Zinc stearate A 1 part by mass (manufactured by Sakai Chemical Industry Co., Ltd., SZ-PF)
-Talc A 0.5 parts by mass (manufactured by Nippon Talc Industry Co., Ltd., Micro Ace (registered trademark) P-3)
・ Polyethylene wax 1 part by mass (manufactured by Toyo Adre Co., Ltd., polywax 3000)
・ Methyl ethyl ketone (MEK) 200 parts by mass ・ Toluene 100 parts by mass

Example 2
The coating liquid for forming a protective layer was applied to one surface of a polyethylene film having a thickness of 4.5 μm and dried to form a protective layer having a thickness of 1 μm.
An adhesive is applied and dried on the other surface of the PET film to provide an adhesive layer having a thickness of 2 μm, and the release base material, the pressure-sensitive adhesive layer, the base material, and the coloring produced in Example 1 are provided through the adhesive layer. A recording medium with a peeling base material (peeling base material, adhesive layer, base material, colored layer, concealing layer, adhesive layer, PET film, protective layer) was prepared by laminating with a concealing layer of a laminate having a layer and a concealing layer. ..

Example 3
A recording medium was prepared in the same manner as in Example 1 except that the adhesive layer and the release base material were not provided.

Example 4
A recording medium with a release base material was produced in the same manner as in Example 1 except that the composition of the coating liquid for forming the protective layer was changed as follows.
(Coating liquid for forming a protective layer)
-Polyvinyl butyral A 46 parts by mass-Isocyanate compound A 50.5 parts by mass-Zinc stearyl phosphate A 1 part by mass-Zinc stearate A 1 part by mass-Tark A 0.5 parts by mass-Polyethylene wax 1 part by mass-MEK 200 Parts by mass / 100 parts by mass of toluene

Example 5
A recording medium with a release base material was produced in the same manner as in Example 1 except that the composition of the coating liquid for forming the protective layer was changed as follows.
(Coating liquid for forming a protective layer)
・ (Meta) acrylic polyol resin 27.7 parts by mass (manufactured by Taisei Fine Chemicals Co., Ltd., 6KW-700)
・ Isocyanate compound A 56.3 parts by mass ・ Phosphate ester A 16 parts by mass (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Plysurf (registered trademark) A208S)
・ MEK 400 parts by mass

Example 6
A recording medium with a release base material was produced in the same manner as in Example 1 except that the composition of the coating liquid for forming the protective layer was changed as follows.
(Coating liquid for forming a protective layer)
-Acrylic modified silicone 10 parts by mass-Isocyanate compound B 2 parts by mass (Dialomer (registered trademark) SP901 manufactured by Dainichiseika Kogyo Co., Ltd.)
・ MEK 20 parts by mass ・ Toluene 20 parts by mass

Example 7
A recording medium with a release base material was produced in the same manner as in Example 1 except that the composition of the coating liquid for forming the protective layer was changed as follows.
(Coating liquid for forming a protective layer)
・ Styrene-acrylonitrile copolymer 11 parts by mass ・ Linear saturated polyester 0.3 parts by mass ・ Zinc stearyl phosphate 6 parts by mass ・ Melamine filler 3 parts by mass ・ MEK 80 parts by mass

Example 8
Examples except that the compositions of the coating liquid for forming the concealing layer and the coating liquid for forming the protective layer were changed as follows, and the thicknesses of the concealing layer and the protective layer were changed to 10 μm and 1.5 μm, respectively. A recording medium with a release base material was prepared in the same manner as in 1.
(Coating liquid for forming a concealing layer)
20 parts by mass of polystyrene hollow particles A (manufactured by Sansui Co., Ltd., A-170, average particle diameter 1 μm, hollow ratio 72%)
10 parts by mass of polyolefin (manufactured by Toyobo Co., Ltd., HARDLEN® NZ-1015, Tg 80 ° C)
・ 40 parts by mass of water ・ 80 parts by mass of IPA (coating liquid for forming a protective layer)
-Polyvinyl butyral B 1.8 parts by mass (Sekisui Chemical Co., Ltd., Eslek (registered trademark) BX-1)
-Isocyanate compound A 5.5 parts by mass-Phosphate ester B 1.6 parts by mass (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Prysurf (registered trademark) A208N)
・ Talc A 0.35 parts by mass ・ MEK 18.5 parts by mass ・ Toluene 18.5 parts by mass

Example 9
A recording medium with a release base material was produced in the same manner as in Example 8 except that the composition of the coating liquid for forming the concealing layer was changed as follows.
(Coating liquid for forming a concealing layer)
20 parts by mass of polystyrene hollow particles A ・ 10 parts by mass of (meth) acrylic resin (manufactured by Sansui Co., Ltd., A-304)
・ 40 parts by mass of water ・ 80 parts by mass of IPA

Example 10
A recording medium with a release base material was produced in the same manner as in Example 8 except that the composition of the coating liquid for forming the concealing layer was changed as follows.
(Coating liquid for forming a concealing layer)
・ Polystyrene hollow particles A 20 parts by mass ・ Urethane resin 10 parts by mass (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Superflex (registered trademark) 130)
・ 40 parts by mass of water ・ 80 parts by mass of IPA

Comparative Example 1
A recording medium with a release base material was produced in the same manner as in Example 1 except that the protective layer was not provided.

<< Scratch resistance evaluation >>
Regarding the recording medium with a release base material (recording medium in Example 3) produced in the above Examples and Comparative Examples, the protective layer surface is heated by the following printer to make the concealing layer transparent, an image is formed, and a printed matter is produced. Obtained. When the formed image was visually confirmed, it was confirmed that the concealing layer was well made transparent in all the recording media with the release base material and the recording medium, and the image was well formed. It was.
(Test printer)
-Energy gradation: 180/255 gradation-Thermal head: KEE-57-12GAN2-STA (Kyocera Corporation)
-Average resistance value of heating element: 3303 (Ω)
-Main scanning direction printing density: 300 (dpi)
-Secondary scanning direction print density: 300 (dpi)
・ Printing voltage: 18 (V)
-Line cycle: 1.5 (msec.)
-Printing start temperature: 35 (° C)
-Pulse duty ratio: 85 (%)

The printed matter prepared as described above was cut into a 2 cm × 2 cm test piece, and a weight of 300 g was placed on the test piece via a test cloth (Kanakin No. 3) and reciprocated 10 times.
The test piece after 10 round trips was visually observed and evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
A: No peeling occurred on the surface.
B: There was some peeling on the surface, but there was no problem.
NG: There was a lot of peeling on the surface.

<< Evaluation of transportability >>
Using the recording medium with a release base material (Recording medium in Example 3) obtained in the above Examples and Comparative Examples, 10 prints were prepared by the same method as in the scratch resistance test.
The transportability of the recording medium with a release base material and the recording medium was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
A: We were able to produce 10 prints without causing poor transportation.
B: With one or more sheets, transport failure occurred and a printed matter could not be produced.

<< Concealment Evaluation >>
The L value of the recording medium with a release base material (Recording medium in Example 3) prepared in the above Examples and Comparative Examples was measured by a spectroscopic densitometer (manufactured by X-rite, eXact, light source: D50, viewing angle: 2). °, Concentration measurement filter: ANSI Status T) was used for measurement, and evaluation was performed based on the following evaluation criteria. The evaluation results are summarized in Table 1. The L value was measured from the protective layer side.
(Evaluation criteria)
A: The L value was 60 or more, and the concealment property could be confirmed.
B: The L value was 50 or more and less than 60.
C: L value was 40 or more and less than 50.
D: The L value was less than 40, and there was a problem in concealment.

<< Evaluation of image formation >>
The protective layer surface of the recording medium with a release base material (recording medium in Example 3) obtained in the above Examples and Comparative Examples was heated by the following printer to make the entire concealing layer transparent.
(Test printer)
-Energy gradation: 180/255 gradation-Thermal head: KEE-57-12GAN2-STA (Kyocera Corporation)
-Average resistance value of heating element: 3303 (Ω)
-Main scanning direction printing density: 300 (dpi)
-Secondary scanning direction print density: 300 (dpi)
・ Printing voltage: 18 (V)
-Line cycle: 1.5 (msec.)
-Printing start temperature: 35 (° C)
-Pulse duty ratio: 85 (%)

The L value of the recording medium with a peeling base material in which the concealing layer was made transparent was measured using the above spectrophotometric colorimeter and evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1. The L value was measured from the protective layer side.
(Evaluation criteria)
A: The L value was less than 20, and extremely high transparency could be confirmed.
B: The L value was 20 or more and less than 30, and high transparency could be confirmed.
C: L value was 30 or more and less than 40, and transparency could be confirmed.
D: L value was 40 or more and less than 50.
E: The L value was 50 or more, and there was a problem with transparency.

10: Recording medium, 11: Base material, 12: Concealing layer, 13: Protective layer, 14: Colored layer, 20: Recording medium with release base material, 21: Release base material, 22: Adhesive layer

Claims (14)

A base material containing a coloring material, a concealing layer, and a protective layer are provided.
A recording medium in which the concealing layer becomes transparent by heating. A colored layer is further provided between the base material and the concealing layer so as to cover a part of the base material.
The recording medium according to claim 1, wherein the colored layer contains a coloring material different from the coloring material contained in the base material. It is provided with a base material, a concealing layer, and a protective layer.
A coloring layer containing a coloring material is provided under the base material and at least one of the base material and the concealing layer.
A recording medium in which the concealing layer becomes transparent by heating. The recording medium according to any one of claims 1 to 3, wherein the concealing layer contains hollow particles and a binder. The recording medium according to claim 4, wherein the resin constituting the hollow particles is a styrene resin. The recording medium according to claim 4 or 5, wherein the binder is polyolefin. The recording medium according to claim 6, wherein the polyolefin is an acid-modified polyolefin. The recording medium according to any one of claims 4 to 7, wherein the ratio of the content of the hollow particles in the concealing layer to the binder is 40/60 or more and 95/5 or less on a mass basis. The recording medium according to any one of claims 1 to 8, wherein the porosity of the concealing layer is 20% by volume or more and 90% by volume or less. The recording medium according to any one of claims 1 to 9, wherein the thickness of the concealing layer is 0.5 μm or more and 30 μm or less. The recording medium according to any one of claims 1 to 10, wherein the protective layer contains a polyvinyl acetal and an isocyanate compound. The recording medium according to any one of claims 1 to 11, wherein the L value before heating measured from the protective layer side is 60 or more. The recording medium according to any one of claims 1 to 12, wherein the L value after heating measured from the protective layer side is 30 or less. A recording medium with a release base material, comprising a release base material, an adhesive layer, and a recording medium according to any one of claims 1 to 13.