JP6705259B2 - Thermal transfer sheet - Google Patents

Description

The present invention relates to a thermal transfer sheet having a layer containing a invisible light absorbing material containing an invisible light absorbing material and a transferable receiving layer in a surface-sequential manner on a substrate.

Some IC cards and cards used in card games or the like have a code pattern unique to the card recorded with an ink that absorbs invisible rays such as infrared rays. It is known to read by (see Patent Document 1).

When a card on which such a code pattern is printed is observed from the surface, a code pattern formed by an ink that absorbs invisible light is often observed even when visually observed even though the code pattern is formed on the card surface. There is a risk that the card may be read, and the card may be forged or modified.

To solve such a problem, it has been proposed that a code pattern is coated with a concealing layer so that the code pattern is not easily read (see Patent Document 2). ..

However, the laminated bodies disclosed in Patent Documents 1 and 2 are formed by printing the information including the code pattern on the outer surface of the laminated body by offset printing, and the information is fixed. It was difficult to change information on demand easily.

JP, 2004-155081, A JP-A-58-45999

Invented in such a situation, by using the thermal transfer sheet of the present invention, it is possible to more difficult forgery and remodeling of the card, etc., further the layer containing an invisible light absorbing material in the card etc. It is an object of the present invention to provide a thermal transfer sheet that can easily change the information formed in (1) on demand. Further, the thermal transfer sheet is a thermal transfer sheet having a invisible light absorbing material-containing layer containing an invisible light absorbing material and a transferable receiving layer on a base material in a frame order. In the thermal transfer sheet of this form, the invisible light absorbing material-containing layer is transferred to a card or the like to be transferred to form a code pattern, and the area of the code pattern and the area other than the area are included, An object of the present invention is to provide a thermal transfer sheet capable of achieving both transferability and adhesiveness with a transfer target when transferring the transferable receiving layer from the thermal transfer sheet.

The above object is achieved by the present invention described below. That is, the present invention has an invisible light absorbing material-containing layer containing an invisible light absorbing material and a first thermoplastic resin, and a transferable receiving layer containing a second thermoplastic resin in a face-sequential manner on a substrate. A thermal transfer sheet, comprising an adhesive layer containing a third thermoplastic resin and particles on a transferable receiving layer, wherein one or both of the first thermoplastic resin and the second thermoplastic resin is a main component monomer. And the main component monomers of the third thermoplastic resin are of the same type.
The printed matter such as a card obtained by the transfer of the thermal transfer sheet is more difficult to forge or modify, and the information formed on the printed matter can be easily changed to variable information on demand. In addition, information such as a code pattern formed by transferring the invisible light absorbing material-containing layer of the thermal transfer sheet to a card or the like can be normally read by a dedicated sensor.
Further, by this thermal transfer sheet, the invisible light absorbing material-containing layer is transferred to a card or the like that is a transfer target to form a code pattern, and the area of the code pattern and the area other than the area are included, When the transferable receiving layer is transferred from the thermal transfer sheet, both the transferability and the adhesiveness to the transfer target are good.

Further, it is preferable that the first, second, and third thermoplastic resins are at least one selected from vinyl chloride-based, acrylic-based, and polyester-based thermoplastic resins. As a result, when the transferable receiving layer is transferred from the thermal transfer sheet to the area including the code pattern area and the area other than the area, both transferability and adhesiveness to the transfer target are better. Becomes
Further, in addition to the invisible light absorbing material-containing layer and the transferable receiving layer, it is preferable to have a color material layer in a frame order. This makes it possible to efficiently form in-line a thermal transfer image by a color material layer and information by a layer containing an invisible light absorbing material on a card or the like.
Further, the particles of the adhesive layer preferably contain 40% or more and 85% or less by mass of the solid content of the entire adhesive layer. With this thermal transfer sheet, the invisible light absorbing material-containing layer is transferred to a card or the like that is the transfer target to form a code pattern, and the thermal transfer is performed in the area including the code pattern area and the area other than the area. When the transferable receiving layer is transferred from the sheet, both the transferability and the adhesiveness to the transfer target become better.

By transferring the thermal transfer sheet of the present invention to a transfer target such as a card, it is possible to make forgery or modification of the card or the like more difficult, and further, the information formed by the invisible light absorbing material-containing layer on the card or the like. (Code pattern) can be easily changed on demand.
When the thermal transfer sheet of the present invention is used, the invisible light absorbing material-containing layer is transferred to a card or the like as a transfer target to form a code pattern, and the area of the code pattern and a portion other than the area are included. When the transferable receiving layer is transferred from the thermal transfer sheet to the range, both the transferability and the adhesiveness with the transfer target can be improved.

It is a schematic sectional drawing which shows one embodiment of the thermal transfer sheet of this invention. It is a schematic sectional drawing which shows other embodiment of the thermal transfer sheet of this invention.

Next, embodiments of the invention will be described in detail.
FIG. 1 is a schematic cross-sectional view showing one embodiment of a thermal transfer sheet of the present invention, in which an invisible light absorbing material-containing layer containing an invisible light absorbing material and a first thermoplastic resin is provided on one surface of a base material 2. The thermal transfer sheet 1 has a structure in which 3 and a layer in which the transferable receiving layer 4 containing the second thermoplastic resin and the adhesive layer 5 containing the third thermoplastic resin are laminated are repeated frame-sequentially.
FIG. 2 is a schematic cross-sectional view showing another embodiment of the thermal transfer sheet of the present invention, in which one surface of the substrate 2 contains an invisible light absorbing material and an invisible light absorbing material containing a first thermoplastic resin. Layer 3, a transferable receiving layer 4 containing a second thermoplastic resin, and a layer in which an adhesive layer 5 containing a third thermoplastic resin is laminated, and further a yellow coloring material layer (Y) and a magenta coloring material layer (M ) And a color material layer 6 composed of three colors of a cyan color material layer (C) are repeatedly arranged in a frame order.

Hereinafter, each layer constituting the thermal transfer sheet 1 of the present invention will be described in detail.
(Base material)
The base material 2 of the thermal transfer sheet has heat resistance capable of withstanding heat energy (for example, heat of a thermal head) when transferring the invisible light absorbing material-containing layer 3 or the like to the transfer target, and the invisible light absorbing material-containing layer. As long as it has mechanical strength and solvent resistance capable of supporting 3 etc., it can be used without particular limitation. For example, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, high heat-resistant polyester such as polyether ketone or polyether sulfone, polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, polyvinyl chloride, polyvinylidene chloride, Examples include stretched or unstretched films of plastics such as polystyrene, polyamide, polyimide, polymethylpentene, and ionomer.

Corona discharge treatment, plasma treatment, ozone treatment, flame treatment, primer (also known as anchor coat, adhesion promoter, and easy adhesive) coating treatment, pre-heat treatment, dust treatment, vapor deposition treatment, alkali treatment on the base material 2. Alternatively, an easy adhesion treatment such as provision of an antistatic layer may be performed. Moreover, the base material 2 may contain additives such as a filler, a plasticizer, a colorant, and an antistatic agent, if necessary. The thickness of the base material 2 is not particularly limited, but is preferably 2 μm or more and 10 μm or less. By setting the thickness of the base material 2 within the above numerical range, it is possible to improve the transferability of the invisible light absorbing material-containing layer 3 and the like while maintaining the mechanical strength.

(Adhesive layer)
The thermal transfer sheet of the present invention comprises a base material 2, an invisible light absorbing material-containing layer 3 containing an invisible light absorbing material and a first thermoplastic resin, and a transferable receiving layer 4 containing a second thermoplastic resin. It has a frame-sequential structure, has an adhesive layer 5 containing a third thermoplastic resin on the transferable receiving layer 4, and mainly or both of the first thermoplastic resin and the second thermoplastic resin. The component monomer and the main component monomer of the third thermoplastic resin are of the same type, and the adhesive layer 5 further contains particles. In the present invention, the main component monomer means a monomer used in a molar ratio of 50% or more with respect to all the monomers used in the thermoplastic resin. However, in the case of using a polycondensation compound and a polyaddition compound as the thermoplastic resin, assuming that the resin is, for example, a polyester resin, the total content of the same kind of polyvalent carboxylic acid monomer and the same kind of polyhydric alcohol monomer is The main component monomer is a monomer that accounts for 50% or more by mole of all the monomers used in the polymerization.

In the present invention, it is preferable that the first, second, and third thermoplastic resins are at least one selected from vinyl chloride-based, acrylic-based, and polyester-based thermoplastic resins. By selecting the resin, the area of the code pattern formed by transferring the invisible light absorbing material-containing layer 3 to a card or the like that is the transfer target, and the range including the area other than the area, from the thermal transfer sheet. When transferring the transferable receiving layer 4, the transferability and the adhesiveness between the transfer target and the transfer target can be improved.

In the above, one or both of the first thermoplastic resin contained in the invisible light absorbing material-containing layer 3 and the second thermoplastic resin contained in the transferable receiving layer 4, and the third thermoplastic resin contained in the adhesive layer 5. It is specified that the main component monomers of the thermoplastic resin are the same type. Examples of the same type of monomer include, for example, vinyl chloride-based resin, a copolymer of vinyl chloride and vinyl acetate monomers, a copolymer of vinyl chloride and acrylate monomers, and the like. Good.

上記のＲ₁及びＲ₃はＨ又はＣＨ₃であればよく、Ｒ₂及びＲ₄は炭素数１〜１６のアルキル基のアクリル酸（メタクリル酸）エステルであればよい。 In addition, in the acrylic resin, the monomers represented by the following general formulas 1 and 2 that satisfy the following conditions are the same type of monomer.

R ₁ and R ₃ described above may be H or CH ₃ , and R ₂ and R ₄ may be acrylic acid (methacrylic acid) esters of alkyl groups having 1 to 16 carbon atoms.

The main component monomer of one or both of the first thermoplastic resin and the second thermoplastic resin may be one or more monomers selected from the compounds satisfying the general formula 1, The main component monomer of the thermoplastic resin may be one or more monomers selected from the compounds satisfying the general formula 2. In the case of two or more monomers, the total amount thereof may occupy 50% or more of the entire resin in each of the corresponding first, second and third thermoplastic resins.

In the case of polyester resins, polycondensation compounds of polyhydric carboxylic acid monomers represented by the following general formulas (a) and (b) and polyhydric alcohol monomers represented by the following general formulas (c) and (d) are used. The monomers of the same type satisfy the following conditions.

(A) HOOCR ₅ COOH
(B) HOOCR ₆ COOH

The above R ₅ and R ₆ may be linear or branched alkyl.

(C) HOR ₇ OH
(D) HOR ₈ OH
The above R ₇ and R ₈ may have a structure containing an aliphatic or aromatic ring in the main chain. However, if one is aliphatic, the other is also aliphatic, and if one is an aromatic ring, the other must also be an aromatic ring.

In addition, one or both of the first thermoplastic resin and the second thermoplastic resin, the main component monomer is one or more polyvalent carboxylic acid monomers selected from the compounds satisfying the general formula (a). The total content of one or more polyhydric alcohol monomers selected from the compounds satisfying the general formula (c) accounts for 50% or more of the entire first or second thermoplastic resin. The main component monomer of the third thermoplastic resin is one or more polyvalent carboxylic acid monomer monomer selected from the compounds satisfying the general formula (b) and the compound satisfying the general formula (d). It is assumed that the total content of the one or more polyhydric alcohol monomers selected in the above accounts for 50% or more of the entire third thermoplastic resin.

In this way, one or both of the first thermoplastic resin contained in the invisible light absorbing material-containing layer 3 and the second thermoplastic resin contained in the transferable receiving layer 4, and the first thermoplastic resin contained in the adhesive layer 5. Since the main component monomers of the thermoplastic resin of 3 are the same type, the area of the code pattern formed by transferring the invisible light absorbing material-containing layer 3 to a card or the like to be transferred and the portion other than the area In the range included, both the transferability when transferring the transferable receiving layer 4 from the thermal transfer sheet and the adhesiveness with the transfer target could be made good.

An adhesive layer 5 is provided on the transferable receiving layer 4 in order to improve the adhesion between the transferred material and the transferable receiving layer 4. When the material of the adhesive layer 5 is transferred from the thermal transfer sheet to the transferable receiving layer 4 in a range including a region where the invisible light absorbing material-containing layer 3 is transferred to the transfer target and a portion other than the region, It was set so that both the transferability and the adhesiveness to the transferred material would be good.

A vinyl chloride-based copolymer is mainly used as the above-mentioned vinyl chloride-based thermoplastic resin. The vinyl chloride-based copolymer is one in which at least vinyl chloride is used as a monomer for obtaining a polymer and is copolymerized with another monomer, for example, a copolymer of vinyl chloride and vinyl acetate, a chloride Examples thereof include a copolymer of vinyl and acrylate, a copolymer of vinyl chloride and methacrylate, a copolymer of vinyl chloride, vinyl acetate and acrylate, and a copolymer of vinyl chloride, acrylate and ethylene. As described above, it may be a binary copolymer or a ternary or higher copolymer, and the monomers may be randomly distributed or may be block copolymerized.

Among the above-mentioned copolymers, a vinyl chloride-vinyl acetate copolymer is preferable because it is particularly good in both transferability of the receiving layer and the like and adhesiveness to the transferred material. As the vinyl chloride-vinyl acetate copolymer, those having a copolymerization ratio of vinyl chloride and vinyl acetate of vinyl chloride/vinyl acetate in the range of 1 to 19 can be used. The vinyl chloride-vinyl acetate copolymer used in the present invention has a number average molecular weight of 1,000 or more and 1,000,000 or less. In particular, when the number average molecular weight of the vinyl chloride-vinyl acetate copolymer is 5,000 or more and 50,000 or less, excellent transferability and adhesiveness between the transfer target and the solvent used in forming the adhesive layer 5 are obtained. It is preferable because it has excellent solubility.
The glass transition temperature of the vinyl chloride-vinyl acetate copolymer used is about 70 to 80°C. The glass transition temperatures described in the present invention are all determined by the DSC (Differential Scanning Calorimetry) method in accordance with JIS-K-7121:2012.

Examples of the acrylic thermoplastic resin (acrylic resin) include a polymer of acrylic acid or methacrylic acid monomer or its derivative, a polymer of acrylic acid ester or methacrylic acid ester monomer or its derivative, acrylic acid or methacrylic acid. Examples thereof include those containing a copolymer of an acid monomer and another monomer or a derivative thereof, and a copolymer of an acrylic acid ester or a methacrylic acid ester monomer and another monomer or a derivative thereof.

The acrylic resin is preferably a copolymer of an acrylic acid ester or methacrylic acid ester monomer and another monomer or a derivative thereof. Examples of the acrylic acid ester or methacrylic acid ester monomer include alkyl acrylate and alkyl methacrylate, and preferably methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, lauryl acrylate, and lauryl methacrylate. Can be mentioned. Examples of other monomers include aromatic hydrocarbons, aryl group-containing compounds, amide group-containing compounds, vinyl chloride and the like, preferably styrene, benzyl styrene, phenoxyethyl methacrylate, acrylamide, and methacrylamide. it can.

An amorphous polyester resin is mainly used as the above-mentioned polyester-based thermoplastic resin. The amorphous polyester resin is a polyester resin that does not show crystallinity in the solid state. The term "amorphous" as used herein also includes those in which a local crystal part such as a folded structure and a part in which the molecular chains are isotropically oriented coexist. As such an amorphous polyester resin, Elitel series (hydroxyl-terminated or carboxyl-terminated polyester, manufactured by Unitika Ltd.), Byron series (hydroxyl-terminated or carboxyl-terminated amorphous polyester, manufactured by Toyobo Co., Ltd.), Nichigo Polyester series (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like can be obtained.

Examples of the amorphous polyester resin include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol. , Neopentyl glycol, cyclohexane-1,4-dimethanol, hydrogenated bisphenol A, and at least one selected from alcohol components such as ethylene oxide and propylene oxide adducts of bisphenol A, and terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid. Acid, cyclohexane-1,4-dicarboxylic acid, adipic acid, azelaic acid, maleic acid, fumaric acid, itaconic acid, and at least one selected from carboxylic acid components such as acid anhydrides thereof are obtained by polycondensation. The polymer etc. which were mentioned can be mentioned.

A first thermoplastic resin contained in the invisible light absorbing material-containing layer 3, one or both main component monomers of the second thermoplastic resin contained in the transferable receiving layer 4, and a third thermoplastic resin contained in the adhesive layer. It has been explained above that the main component monomers of are the same type. Accordingly, also in the adhesive layer 5, it is preferable to use a vinyl chloride-based, acrylic-based, or polyester-based thermoplastic resin as the binder resin that is the third thermoplastic resin.
The third thermoplastic resin contained in the adhesive layer 5 has only to be contained as a main component with respect to the entire binder resin forming the adhesive layer 5, and specifically, it is contained in an amount of 50% or more on a mass basis. Just do it. The content is more preferably 70% or more, and further preferably 90% or more with respect to the entire binder resin constituting the adhesive layer 5.
Regarding the blending of the third thermoplastic resin, the first thermoplastic resin contained in the invisible light absorbing material-containing layer 3 as a main component and the second thermoplastic resin contained in the transferable receiving layer 4 as a main component. The same applies to thermoplastic resins.

The third thermoplastic resin which is the main component that constitutes the adhesive layer 5 is as described above, and examples of the thermoplastic resin other than the main component include, for example, ethyl cellulose, cellulose derivatives such as cellulose acetate butyrate, polystyrene, Examples thereof include styrene copolymers such as poly α-methylstyrene, rosin, rosin-modified maleic acid resin, ester rubber, polyisobutylene rubber, butyl rubber, styrene butadiene rubber, butadiene acrylonitrile rubber, and polychlorinated olefins.

The adhesive layer 5 contains particles, and the particles include basic lead carbonate (2PbCO ₃ Pb(OH) ₂ ), zinc oxide (ZnO), titanium oxide (TiO ₂ ), strontium titanate (SrTiO ₃ ). White pigments such as The titanium oxide has a smaller specific gravity than other white pigments, has a large refractive index and is chemically and physically stable, and therefore has a large hiding power and coloring power as a pigment. It has excellent durability against the environment. Therefore, it is preferable to use titanium oxide as the white pigment.
It is preferable that the above particles are contained in an amount of 40% or more and 85% or less based on the mass of the solid content of the entire adhesive layer 5. When the content ratio of the particles is less than 40% of the whole adhesive layer, the hiding property is insufficient and the whiteness of the adhesive layer is also insufficient. On the other hand, when the content ratio of the particles is more than 85%, the adhesiveness of the adhesive layer is lowered.

The adhesive layer 5 is applied by dissolving or dispersing a single or a plurality of materials selected from the above-mentioned materials, and various additives added as necessary in an appropriate solvent such as an organic solvent or an aqueous solvent. A liquid is prepared, and this is applied onto the substrate described above by a means such as a gravure printing method, a screen printing method or a reverse coating method using a gravure plate, and dried to form an adhesive layer. be able to. The aqueous solvent is a solvent containing water as a main component, and is composed of water, or water and a water-soluble organic solvent such as methanol, ethanol, acetone, N,N-dimethylformamide, N,N-dimethylacetamide, or tetrahydrofuran. Mention may be made of mixed solvents.

The thickness of the adhesive layer 5 is not particularly limited, but is preferably in the range of 0.1 μm or more and 20 μm or less.

(Invisible light absorbing material-containing layer)
The invisible light absorbing material-containing layer 3 can be formed by using the invisible light absorbing material described below in the ink containing the invisible light absorbing material and the binder resin which is the first thermoplastic resin. However, a peeling layer having peelability by heating can be provided between the base material 2 of the thermal transfer sheet and the invisible light absorbing material-containing layer 3 if necessary.
Regarding the blending of the first thermoplastic resin contained in the invisible light absorbing material-containing layer 3, it is sufficient that the first thermoplastic resin is contained as a main component with respect to the entire binder resin constituting the invisible light absorbing material-containing layer 3. Specifically, it may be contained at 50% or more on a mass basis. It is more preferable that the content of the invisible light absorbing material-containing layer 3 is 70% or more, and further preferably 90% or more, based on the entire binder resin.

The first thermoplastic resin which is the main component that constitutes the invisible light absorbing material-containing layer 3 is as described above, and examples of the thermoplastic resin other than the main component include cellulose such as ethyl cellulose and cellulose acetate butyrate. Derivatives, polystyrene, styrene copolymers such as poly α-methylstyrene, rosin, rosin-modified maleic acid resin, ester rubber, polyisobutylene rubber, butyl rubber, styrene butadiene rubber, butadiene acrylonitrile rubber, polychlorinated olefins, etc. You can

The invisible light absorbing material-containing layer 3 is prepared by dissolving or dispersing in an appropriate solvent such as water or an organic solvent by adding one or more materials selected from the following materials and various additives as necessary. A coating liquid is prepared, and the coating liquid is formed on the base material 2 described above by a means such as a gravure printing method, a screen printing method, or a reverse coating method using a gravure plate, and the like. be able to.
The thickness of the invisible light absorbing material-containing layer 3 is not particularly limited, but is preferably in the range of 0.1 μm or more and 5 μm or less. By setting the thickness of the invisible light absorbing material-containing layer 3 in a preferable range, information (image) such as a code pattern that can be sufficiently identified in infrared light or ultraviolet light can be obtained. If the thickness of the invisible light absorbing material-containing layer 3 is too thin, the detection performance when detecting an image formed using the invisible light absorbing material-containing layer 3 tends to decrease. In addition, the transferability when the invisible light absorbing material-containing layer 3 is transferred onto the transfer target tends to decrease.

On the other hand, when the thickness of the invisible light absorbing material-containing layer 3 is too thick, when the invisible light absorbing material-containing layer 3 is transferred onto the transfer target, tailing or crushing of characters tends to occur. .. The tailing referred to in the specification of the present application means that, when a specific layer is transferred onto a transfer target, the boundary between the transfer region and the non-transfer region of the specific layer is a starting point, and the non-transfer region side is defined from the boundary. It means a phenomenon that a specific layer is transferred so as to protrude. In addition, the character collapse referred to in the specification of the present application means that a non-transferred area surrounded by or sandwiched between transfer areas expressed as characters is transferred by the same phenomenon as the tailing, and the original character is reproduced. It means a phenomenon that is not possible.

(Ink containing invisible light absorbing material)
The invisible light absorbing material-containing ink contains an invisible light absorbing material and contains a binder resin. The invisible light absorbing material referred to in the present specification means a material that does not absorb visible light, or hardly absorbs visible light, absorbs infrared light or ultraviolet light, or is excited by infrared light or ultraviolet light. To do.
The infrared ray absorbing material-containing ink of the invisible light ray absorbing material-containing ink can be composed of an infrared ray absorbing material and a binder resin. Examples of the infrared absorbing material include diimonium compounds, aminium compounds, phthalocyanine compounds, dithiol organometallic complexes, cyanine compounds, azo compounds, polymethine compounds, quinone compounds, diphenylmethane compounds, triphenylmethane compounds. Examples thereof include compounds, oxole compounds, and carbon black. The infrared absorbing material-containing ink may contain one or more infrared absorbing materials as described above.
In addition, in the specification of the present application, the infrared ray has a maximum absorption wavelength (λmax) region of 750 nm or more and 2500 nm or less.

As the binder resin in the ink containing the invisible light absorbing material, that is, as the first thermoplastic resin, for example, polyester resin, polyvinyl resin, fluorine resin, polystyrene resin, polyacrylic resin, cellulose resin, polycarbonate Known resins such as polyolefin resins such as resin, polyamide resin and polypropylene resin, polyvinyl alcohol resin, polyimide resin, phenol resin and polyurethane resin can be mentioned.
A first thermoplastic resin contained in the invisible light absorbing material-containing layer 3, one or both main component monomers of the second thermoplastic resin contained in the transferable receiving layer 4, and a third thermoplastic resin contained in the adhesive layer. It has been explained above that the main component monomers of are the same type. Along with this, also in the invisible light absorbing material-containing layer 3, it is preferable to use a vinyl chloride-based, acrylic-based, or polyester-based thermoplastic resin as the binder resin that is the first thermoplastic resin.

The content of the binder resin in the infrared ray absorbing material-containing ink is preferably 20% by mass or more and 99.9% by mass or less, and more preferably 60% by mass or more and 99% by mass or less.
The infrared ray absorbing material-containing ink can form a code pattern as the unique information on the transfer target (card), and the information of the code pattern can be read by using an optical reading device using infrared rays. ..

The ultraviolet absorbing material-containing ink of the invisible light absorbing material-containing ink can be composed of an ultraviolet absorbing material and a binder resin. Examples of the ultraviolet absorbing material include organic ultraviolet absorbing materials such as benzotriazole-based compounds, triazine-based compounds, benzophenone-based compounds and benzoate-based compounds, and inorganic ultraviolet rays such as titanium oxide, zinc oxide, cerium oxide, iron oxide and barium sulfate. Absorption materials and the like can be mentioned. The ultraviolet absorbing material-containing ink may contain one kind of the ultraviolet absorbing material alone, or may contain two or more kinds.
The invisible light absorbing material-containing ink may contain both an infrared absorbing material and an ultraviolet absorbing material.
In the specification of the present application, ultraviolet rays have a maximum absorption wavelength (λmax) region of 280 nm or more and 400 nm or less.

The ultraviolet absorbing material-containing ink can be composed of the above ultraviolet absorbing material and a binder resin, and as the binder resin, the binder resin described in the above infrared absorbing material-containing ink can be similarly used. Further, the content of the binder resin in the ink containing the ultraviolet absorbing material is preferably 20% by mass or more and 99.9% by mass or less, and more preferably 60% by mass or more and 99% by mass or less.
The ink containing the ultraviolet absorbing material can form a code pattern as unique information on the transfer target (card), and the information of the code pattern can be read by using an optical reading device using ultraviolet rays. ..

(Transferable receiving layer)
The transferable receiving layer 4 is preferably non-absorbent of invisible light rays.
As a material for forming the transferable receiving layer 4, a conventionally known resin material that easily accepts a heat transferable coloring material such as a sublimation dye or a hot melt ink can be used. For example, polyolefin resin such as polypropylene, polyvinyl chloride, halogenated resin such as polyvinylidene chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer or vinyl such as polyacrylic acid ester. Examples thereof include resins, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, copolymers of olefins such as ethylene and propylene with other vinyl polymers, ionomers and cellulose resins. Among these, vinyl chloride-vinyl acetate copolymers and polyester resins are preferable.

A first thermoplastic resin contained in the invisible light absorbing material-containing layer 3, one or both main component monomers of the second thermoplastic resin contained in the transferable receiving layer 4, and a third thermoplastic resin contained in the adhesive layer 5. It has been described above that the main component monomers of the resin are the same type. Accordingly, also in the transferable receiving layer 4, it is preferable to use a vinyl chloride-based or polyester-based thermoplastic resin as the binder resin which is the second thermoplastic resin.
Regarding the blending of the second thermoplastic resin contained in the transferable receiving layer 4, it is sufficient that the second thermoplastic resin is contained as a main component with respect to the whole binder resin constituting the transferable receiving layer 4, and specifically It may be 50% or more as a standard. It is more preferable that the content of the binder resin in the transferable receiving layer 4 is 70% or more, and more preferably 90% or more.

The second thermoplastic resin which is the main component constituting the transferable receiving layer 4 is as described above, and examples of the thermoplastic resin other than the main component include, for example, cellulose derivatives such as ethyl cellulose and cellulose acetate butyrate. Polystyrene, styrene copolymers such as poly α-methylstyrene, rosin, rosin-modified maleic acid resin, ester rubber, polyisobutylene rubber, butyl rubber, styrene butadiene rubber, butadiene acrylonitrile rubber, polychlorinated olefins, etc. ..

The transferable receiving layer 4 may contain a release agent in order to suppress heat fusion with the coloring material layer during printing. Examples of the release agent include solid waxes such as polyethylene wax, amide wax, Teflon (registered trademark) powder, fluorine-based or phosphate-based surfactants, silicone oil, reactive silicone oil, and curable silicone oil. Various modified silicone oils, various silicone resins, and the like.
The transferable receiving layer 4 is prepared by dispersing or dissolving the above resin material and an additive such as a releasing agent, which is added as necessary, in a suitable solvent to prepare a transferable receiving layer coating solution. Can be formed by coating and drying on the base material 2 or any layer provided on the base material 2 by means such as a gravure printing method, a screen printing method or a reverse coating method using a gravure plate. it can. The thickness of the transferable receiving layer 4 is not particularly limited and is usually 0.3 μm or more and 10 μm or less.

(Color material layer)
The thermal transfer sheet may be provided with a coloring material layer 6 so that the invisible light absorbing material-containing layer 3 and the transferable receiving layer 4 are arranged in the frame order.
The color material layer 6 is a sublimation dye layer containing a conventionally known sublimation dye such as yellow (Y), magenta (M), cyan (C), and if necessary, black or the like, or the above various types. It is possible to use a heat-fusible coloring material layer made of a hot-melt ink containing a coloring agent such as a colored pigment.
Hereinafter, the sublimation dye layer as the color material layer 6 will be described in detail. However, the color material layer 6 is not limited to the sublimation dye layer, and a heat-meltable color material layer formed by heat-meltable ink is also included in the present invention. Can be applied at.

The sublimation dye layer preferably contains a sublimation dye, for example, diarylmethane dye, triarylmethane dye, thiazole dye, merocyanine dye, pyrazolone dye, methine dye, indoaniline dye, acetophenone. Azomethine, pyrazoloazomethine, imidazole azomethine, imidazoazomethine, azomethine dyes such as pyridone azomethine, xanthene dyes, oxazine dyes, dicyanostyrene, cyanostyrene dyes such as tricyanostyrene, thiazine dyes, azine dyes, Acridine dyes, benzene azo dyes, pyridone azo, thiophene azo, isothiazole azo, pyrrole azo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo, azo dyes such as disazo, spiropyran dyes, indolinospyropyran dyes, fluorane dyes Examples thereof include dyes, rhodamine lactam dyes, naphthoquinone dyes, anthraquinone dyes, quinophthalone dyes, and more specifically, MSRedG (manufactured by Mitsui Toatsu Chemicals, Inc.), Macrolex Red Violet R (manufactured by Bayer), and CeresRed. 7B (manufactured by Bayer), red dye such as Samaron Red F3BS (manufactured by Mitsubishi Chemical), Holon Brilliant Yellow 6GL (manufactured by Clariant), PTY-52 (manufactured by Mitsubishi Chemical), Macrolex Yellow 6G (manufactured by Bayer). Yellow dyes such as Kayaset Blue 714 (manufactured by Nippon Kayaku Co., Ltd.), Waxoline Blue AP-FW (manufactured by ICI), Holon Brilliant Blue SR (manufactured by Sando), MS Blue 100 (Mitsui Toatsu Chemicals, Inc.). C.), C.I. I. Blue dyes such as Solvent Blue 22 can be used.

The content of the dye in the sublimation dye layer is preferably 50 parts by mass or more and 350 parts by mass, and 80 parts by mass or more, 300 parts by mass, with respect to 100 parts by mass of the total solid content of the binder resin described below. Is more preferably within the range. When the content of the sublimation dye is less than the above range, the print density tends to decrease, and when it exceeds the above range, the storage stability tends to decrease.

The sublimation dye layer preferably contains a binder resin for supporting the dye, and examples thereof include a cellulose resin, a vinyl resin, an acrylic resin, a polyurethane resin, a polyamide resin, a polyester resin, and a polyvinyl resin. Butyral resin, polyvinyl acetal resin, etc. are mentioned.
The content of the binder resin in the sublimation dye layer is preferably 20% by mass or more and 80% by mass or less based on the total solid content of the sublimation dye layer.

The sublimation dye layer is a coating liquid prepared by dissolving or dispersing in a suitable solvent such as water or an organic solvent by adding one or more materials selected from the above-mentioned materials and various additives as necessary. Can be prepared and applied onto a substrate or the like by a means such as a gravure printing method, a screen printing method, or a reverse coating method using a gravure plate, and dried to form the composition.
The thickness of the sublimation dye layer is not particularly limited and is usually in the range of 0.2 μm or more and 5 μm or less.

In the above, as the thermal transfer sheet of the present invention, the invisible light ray absorbing material-containing layer 3 and the transferable receiving layer 4 are surface-sequentially provided on the substrate 2, and the adhesive layer 5 is provided on the transferable receiving layer 4. Although explained in terms of the configuration, a peeling layer or the like can be provided between the base material 2 and the invisible light absorbing material-containing layer 3 or between the base material 2 and the transferable receiving layer 4.

(Back layer)
The thermal transfer sheet may include a back surface layer on the surface (back surface) opposite to the surface of the base material 2 having the invisible light absorbing material-containing layer 3 and the like. The back layer is a layer provided as desired in order to prevent adverse effects such as heat fusion, sticking, and wrinkles when heated by a thermal head or the like from the back surface side of the substrate during thermal transfer.

There is no limitation on the material of the back layer, for example, a cellulose resin such as ethyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, nitrocellulose, cellulose acetate butyrate, cellulose acetate propionate, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral. , Polyvinyl acetal, polyvinyl-based resin such as polyvinylpyrrolidone, polymethyl methacrylate, polyethyl acrylate, polyacrylamide, acrylic resin such as acrylonitrile-styrene copolymer, polyamide resin, polyamideimide resin, coumarone indene resin, polyester Examples include simple resins or mixtures of natural or synthetic resins such as resin, polyurethane resin, silicone-modified or fluorine-modified urethane.

The back layer preferably contains a slip agent, and examples thereof include metal soap, wax, silicone oil, fatty acid ester, filler, talc, and surfactant.
The back layer is prepared by adding a single or a plurality of materials selected from the above-mentioned materials and various additives as necessary, and dissolving or dispersing them in an appropriate solvent such as water or an organic solvent to prepare a coating liquid. Then, it can be formed by coating and drying it on the substrate by a means such as a gravure printing method, a screen printing method or a reverse coating method using a gravure plate.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
(Example 1)
<Preparation of thermal transfer sheet>
A 4.5 μm-thick PET film was used as a base material, and a back layer coating solution having the following composition was applied thereon so that the coating amount when dried was 1.0 μm, and the back layer was dried. Was formed.

(Coating liquid for back layer)
-Polyvinyl butyral resin 1.8 parts by mass (Sekisui Chemical Co., Ltd., S-REC BX-1)
5.5 parts by mass of polyisocyanate (manufactured by DIC Corporation, Burnock D750)
・Phosphate ester type surfactant 1.6 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd., Prysurf A208N)
・Talc 0.35 parts by mass (Nihon Talc Industry Co., Ltd., Microace P-3)
-Toluene 18.5 parts by mass-Methyl ethyl ketone 18.5 parts by mass

A part of the surface opposite to the side provided with the back surface layer of the base material was coated with the coating liquid 1 for an invisible light absorbing material-containing layer having the following composition so that the coating amount when dried was 0.8 μm. After coating and drying, an invisible light absorbing material-containing layer was formed.

(Coating liquid 1 for invisible light absorbing material-containing layer)
-Acrylic resin (polymethylmethacrylate) 17 parts by mass (Mitsubishi Rayon Co., Ltd., Dianal BR-87)
-Diimonium salt 1.5 parts by mass (CIR-RL manufactured by Nippon Carlit Co., Ltd.)
・Toluene 45 parts by mass ・Methyl ethyl ketone 45 parts by mass

For the transferable receiving layer having the following composition so that the invisible light absorbing material-containing layer formed as described above is face-sequentially formed on a part of the surface of the substrate opposite to the side on which the back layer is provided. The coating liquid was applied so that the coating amount when dried was 1.0 μm, and dried to form a transferable receiving layer.

(Coating liquid for transferable receiving layer)
-Vinyl chloride-vinyl acetate copolymer resin 16.8 parts by mass (manufactured by Nisshin Chemical Industry Co., Ltd., Solvene CNL, copolymerization ratio is vinyl chloride/vinyl acetate=90/10)
Organic modified silicone oil 1.0 part by mass (Shin-Etsu Chemical Co., Ltd., X-22-3000T)
-Organic modified silicone oil 1.0 part by mass (Shin-Etsu Chemical Co., Ltd., X-24-510)
-0.7 parts by mass of organically modified silicone oil (KF-352A, manufactured by Shin-Etsu Chemical Co., Ltd.)
・Methyl ethyl ketone 40 parts by mass ・Toluene 40 parts by mass

On the transferable receiving layer formed as described above, the adhesive layer coating liquid 1 having the following composition was applied so that the coating amount when dried was 1.2 μm, and the adhesive layer was dried. Was formed to prepare the thermal transfer sheet of Example 1. (See Figure 1)

(Coating liquid 1 for adhesive layer)
-Acrylic resin (polymethylmethacrylate) 8.0 parts by mass (Mitsubishi Rayon Co., Ltd., Dianal BR-87)
-Vinyl chloride-vinyl acetate copolymer 2.0 parts by mass (manufactured by Nissin Chemical Industry Co., Ltd., Solvain CNL, copolymerization ratio is vinyl chloride/vinyl acetate=90/10)
・Titanium oxide 40 parts by mass (CR-50, manufactured by Ishihara Sangyo Co., Ltd.)
-Toluene 30 parts by mass-Methyl ethyl ketone 30 parts by mass

(Example 2)
In the thermal transfer sheet of Example 1 above, the coating liquid 1 for the invisible light absorbing material-containing layer was changed to the coating liquid 2 for the invisible light absorbing material-containing layer having the following composition, and the adhesive layer coating liquid 1 was used for adhesion. A thermal transfer sheet of Example 2 was prepared in the same manner as in Example 1 except that the layer coating liquid 2 was used.

(Coating liquid 2 for invisible light absorbing material-containing layer)
-Vinyl chloride-vinyl acetate copolymer 8.0 parts by mass (manufactured by Nisshin Chemical Industry Co., Ltd., Solvain CNL, copolymerization ratio is vinyl chloride/vinyl acetate=90/10)
-Polyester resin 9.0 parts by mass (Toyobo Co., Ltd., Byron 200)
-Diimonium salt 1.5 parts by mass (CIR-RL manufactured by Nippon Carlit Co., Ltd.)
・Toluene 45 parts by mass ・Methyl ethyl ketone 45 parts by mass

(Coating liquid 2 for adhesive layer)
・Polyester resin 8.0 parts by mass (Toyobo Co., Ltd., Byron 200)
-Vinyl chloride-vinyl acetate copolymer 2.0 parts by mass (manufactured by Nissin Chemical Industry Co., Ltd., Solvain CNL, copolymerization ratio is vinyl chloride/vinyl acetate=90/10)
・Titanium oxide 40 parts by mass (CR-50, manufactured by Ishihara Sangyo Co., Ltd.)
-Toluene 30 parts by mass-Methyl ethyl ketone 30 parts by mass

(Example 3)
In the thermal transfer sheet of Example 1 described above, the thermal transfer sheet of Example 3 was produced in the same manner as in Example 1 except that the coating liquid 1 for adhesive layer was changed to the coating liquid 3 for adhesive layer.

(Coating liquid 3 for adhesive layer)
-Vinyl chloride-vinyl acetate copolymer 10 parts by mass (manufactured by Nisshin Chemical Industry Co., Ltd., Solvain CNL, copolymerization ratio is vinyl chloride/vinyl acetate=90/10)
・Titanium oxide 40 parts by mass (CR-50, manufactured by Ishihara Sangyo Co., Ltd.)
-Toluene 30 parts by mass-Methyl ethyl ketone 30 parts by mass

(Example 4)
The thermal transfer sheet of Example 4 was prepared in the same manner as in Example 1 except that the adhesive layer coating liquid 1 was changed to the adhesive layer coating liquid 4 in the thermal transfer sheet of Example 1 described above.

(Coating liquid 4 for adhesive layer)
-Acrylic resin (polymethylmethacrylate) 10 parts by mass (Mitsubishi Rayon Co., Ltd., Dinal BR-87)
・Titanium oxide 40 parts by mass (CR-50, manufactured by Ishihara Sangyo Co., Ltd.)
-Toluene 30 parts by mass-Methyl ethyl ketone 30 parts by mass

(Example 5)
Similar to the thermal transfer sheet of Example 1 described above, the coating amount of the invisible light absorbing material-containing layer coating liquid 1 was dried on a part of the surface of the substrate opposite to the side on which the back layer was provided. , 0.8 μm, and dried to form an invisible light absorbing material-containing layer. The transferable receiving layer was applied with a coating liquid for a transferable receiving layer so that the coating amount for the invisible light absorbing material-containing layer was frame-sequential so as to be 1.0 μm, and then dried. Was formed. The adhesive layer coating liquid 1 was applied onto the transferable receiving layer so that the coating amount when dried was 1.2 μm, and dried to form an adhesive layer. (See Figure 2)

As shown in FIG. 2, a primer layer coating solution having the following composition was applied so as to be surface-sequential to the above-mentioned transferable receiving layer so that the coating amount when dried was 0.1 μm, It dried and the primer layer was formed. On the primer layer, a yellow dye layer coating liquid (Y), a magenta dye layer coating liquid (M), and a cyan dye layer coating liquid (C) having the following compositions were applied to each layer by a gravure printing machine. Was coated and dried so that the coating amount when dried was 0.7 μm, and the sublimation dye layer was repeatedly formed in this order in a frame-sequential manner to prepare a thermal transfer sheet of Example 5.

(Coating liquid for primer layer)
Alumina sol 2.5 parts by mass (Nissan Chemical Co., Ltd., alumina sol 200)
-Polyvinylpyrrolidone resin 2.5 parts by mass (ISP Japan Co., Ltd., PVP K-60)
-Water 47.5 parts by mass-Isopropyl alcohol 47.5 parts by mass

(Yellow dye layer coating liquid (Y))
Solvent Yellow 93 2 parts by mass Disperse Yellow 201 4 parts by mass Polyvinyl acetal resin 5 parts by mass (Sekisui Chemical Co., Ltd., KS-5)
・Toluene 50 parts by mass ・Methyl ethyl ketone 50 parts by mass

(Coating liquid for magenta dye layer (M))
Disperse Red 60 3 parts by mass Disperse Violet 26 3 parts by mass Polyvinyl acetal resin 5 parts by mass (Sekisui Chemical Co., Ltd., KS-5)
・Toluene 50 parts by mass ・Methyl ethyl ketone 50 parts by mass

(Coating liquid for cyan dye layer (C)
Solvent Blue 63 3 parts by mass Disperse Blue 354 3 parts by mass Polyvinyl acetal resin 5 parts by mass (Sekisui Chemical Co., Ltd., KS-5)
・Toluene 50 parts by mass ・Methyl ethyl ketone 50 parts by mass

(Comparative Example 1)
In the thermal transfer sheet of Example 1 described above, the thermal transfer sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that the coating liquid 1 for adhesive layer was changed to the coating liquid 5 for adhesive layer.

(Coating liquid 5 for adhesive layer)
・Polyester resin 10 parts by mass (Polyester WR-905 Nippon Synthetic Chemical Industry Co., Ltd.)
・Isopropyl alcohol 10 parts by mass ・Water 30 parts by mass

<Formation of printed matter>
A genuine paper of a sublimation type transfer printer (DS-40 manufactured by DNP Photolucio Co., Ltd.) was prepared as a transferred body.

The invisible light absorbing material-containing layer included in the thermal transfer sheet produced as described above was heat-melt transferred onto the transfer target so as to form a code pattern by the following test printer. The thickness of the invisible light absorbing material-containing layer on the transferred material was 0.8 μm.
(Test printer)
Thermal head: KEE-57-12GAN2-STA (manufactured by Kyocera Corporation)
Heating element average resistance value: 3303 (Ω)
Print density in main scanning direction: 300 (dpi)
Sub-scanning direction print density: 300 (dpi)
Printing voltage: 18 (V)
One line cycle: 1.5 (msec.)
Printing start temperature: 35 (℃)
Pulse duty ratio: 85%

In addition, the transferable receiving layer and the adhesive layer provided in the thermal transfer sheet are simultaneously heat-melt transferred onto the transferred material and the code pattern (the layer containing the invisible light absorbing material) by using the above test printer, and each printed matter is transferred. It was made.
Further, in Example 5, the test printer was further used to transfer the dye from the dye layer provided in the thermal transfer sheet to the receiving layer transferred to the transfer target to form an image, thereby producing a printed matter. .. The image formed a gray image of 128/256 gradation.

In the thermal transfer sheet and the printed matter produced under the above conditions, the transferability and the adhesiveness to the transfer target when the transferable receiving layer was transferred from the thermal transfer sheet to the transfer target under the following conditions were examined.
(Transferability)
Using the thermal transfer sheet produced in each of the examples and comparative examples, the invisible light absorbing material-containing layer is transferred from the thermal transfer sheet to form a code pattern. Next, when the transferable receiving layer is transferred from the thermal transfer sheet to the transfer target in the area including the code pattern area and the area other than the area, the transferability is evaluated based on the following evaluation criteria. Evaluated.
(Evaluation criteria)
◯: Transferred without any problems in the code pattern area and other areas.
X: A defective portion was conspicuously generated in the transfer of the receiving layer including the area of the code pattern.

(Adhesiveness)
In each of the prints obtained above, a cellophane tape was rubbed by hand one reciprocatingly on the area where the transferable receiving layer was transferred in the area of the code pattern and the area other than the area, and immediately 180° peeling direction Then, the peeling adhesiveness was evaluated by the following evaluation criteria.
(Evaluation criteria)
◯: In the area of the code pattern and the area other than that, there was no object picked up on the side of the cellophane tape, there was no problem, and the adhesiveness was good.
X: Those taken on the cellophane tape side including the area of the code pattern were conspicuously observed, and there was a problem, and the adhesiveness was poor.

The evaluation results of the transferability and adhesiveness are shown in Table 1 below.

For each of the above prints, it was examined whether the code pattern could be read using an optical reading device using infrared rays. As a result, the code pattern could be read normally on all the prints.
From the above evaluation results, the thermal transfer sheet of the comparative example has a problem in the transferability of the transferable receiving layer in the range including the area of the code pattern formed on the transfer target and the part other than the area, and There was a problem with the adhesion between the transfer body and the receiving layer.
However, the thermal transfer sheets of all the examples include the transferability of the transferable receiving layer, the transferable material and the receiving layer within the range including the area of the code pattern formed on the transferable material and the area other than the area. The adhesiveness with both was good.
Further, in the thermal transfer sheet of Example 5, the information (code pattern) by the invisible light absorbing material-containing layer and the thermal transfer image by the coloring material layer can be efficiently formed in-line on the transfer target.

1 Thermal Transfer Sheet 2 Base Material 3 Invisible Light Absorbing Material-Containing Layer 4 Transferable Receiving Layer 5 Adhesive Layer 6 Coloring Material Layer

Claims (4)

An invisible light absorbing material-containing layer containing an invisible light absorbing material and a first thermoplastic resin, which is adjacent to the base material, and a transferable receiving layer containing a second thermoplastic resin are arranged on the substrate in a frame-sequential manner. A thermal transfer sheet having
An adhesive layer that is disposed on the side opposite to the base material side of the transferable receiving layer and that is a layer farthest from the base material, the adhesive layer including a third thermoplastic resin and particles;
Thermal transfer sheet, wherein the main component monomer of the first thermoplastic resins, and the main component monomers of the third thermoplastic resin are the same kind. The thermal transfer sheet according to claim 1, wherein the first, second, and third thermoplastic resins are at least one selected from vinyl chloride-based, acrylic-based, and polyester-based thermoplastic resins. .. The thermal transfer sheet according to claim 1 or 2, further comprising, in addition to the invisible light absorbing material-containing layer and the transferable receiving layer, a coloring material layer in a frame sequential manner. The particles contained in the adhesive layer are white pigments and are contained in an amount of 40% or more and 85% or less by mass based on the solid content of the entire adhesive layer. The thermal transfer sheet according to any one of 3 above.

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