WO2019026901A1

WO2019026901A1 - Thermal transfer sheet, printing sheet, and thermal transfer printing device

Info

Publication number: WO2019026901A1
Application number: PCT/JP2018/028642
Authority: WO
Inventors: 良正小林; 大二郎杉原; 家重　宗典; 誠橋場
Original assignee: 大日本印刷株式会社
Priority date: 2017-07-31
Filing date: 2018-07-31
Publication date: 2019-02-07
Also published as: EP3530477A4; EP3530477A1; EP3530477B1

Abstract

Provided is a thermal transfer sheet that prevents changes in color development characteristics during high-resolution printing, suppresses production costs, and can be identified by a thermal transfer printing device. The thermal transfer sheet 5 according to one embodiment comprises a dye layer 52 and a protection layer 54 that are formed on one surface of a base material 50. The protection layer 54 contains an invisible-light-absorbing material and has provided thereto an identification mark 55 that includes a recess and/or a protrusion.

Description

Thermal transfer sheet, printing sheet and thermal transfer printing apparatus

The present invention relates to a thermal transfer sheet, a printing sheet and a thermal transfer printing apparatus.

Thermal transfer printers that print characters, images, and the like on a transfer target such as an image receiving sheet by using a thermal transfer sheet (ink ribbon) are in widespread use. The thermal transfer sheet has a ribbon (support layer) extending in a band, a dye layer formed on the ribbon, and, if necessary, a protective layer and a hot-melt ink layer.

In the conventional thermal transfer sheet, dye layers and protective layers of three colors of yellow, magenta and cyan are repeatedly provided in a face-sequential manner, and carbon black, aluminum, etc. are formed between the dye layers or between the dye layer and the protective layer. The detection mark is formed by the ink using the pigment of (1). The thermal transfer printing apparatus has determined the print start position or identified the type and size of the thermal transfer sheet by reading the detection mark of the loaded thermal transfer sheet. However, by providing the region for forming the detection mark between the dye layers, the total length of the thermal transfer sheet becomes long, the amount of use of the substrate increases, and the manufacturing cost increases. In addition, when the detection mark is formed by printing on the base film, the detection mark may be printed on an unnecessary portion by ink skipping or the like, which may lead to a defect of the thermal transfer image.

In Patent Document 1, dye layers of two or more colors are formed face-sequentially, one of the dye layers has a two-layer structure, one of the two layers forms a detection mark, and the detection mark is detected. A thermal transfer sheet has been proposed in which a color difference is provided between a portion adjacent to a mark. However, since the process of providing one detection (dye) layer anew for the detection mark is required, the manufacturing cost has been increased. In addition, there is a possibility that the coloring characteristics may change in high resolution printing.

In

Patent Documents

2 and 3, a thermal transfer dye sheet having a yellow dye layer, a magenta dye layer, a cyan dye layer, etc., and a printing area such as a binary code which produces a difference in optical density detectable by a printer in the yellow dye layer. A thermal transfer sheet has been proposed in which a (detection mark) is formed by changing the thickness of the yellow dye layer so that it can be detected by a printer. However, since the thickness of the dye layer is increased or decreased in order to cause a difference in optical density, there is a possibility that the coloring characteristics may change in high resolution printing.

Patent Documents

4 and 5 propose a thermal transfer sheet in which a dye layer of one or more colors is formed face-sequentially, and a detection layer is provided between the substrate and the dye layer, or between the substrate and the back layer. There is. However, since a process of providing a new detection layer is required, the manufacturing cost has been increased.

Patent No. 5799525 European Patent No. 1872960 European Patent No. 2035233 Patent No. 5760763 gazette JP, 2013-1047, A

The present invention has been made in view of the above-described conventional situation, and it is an object of the present invention to provide a thermal transfer sheet which can be distinguished by a thermal transfer printing apparatus while preventing a change in coloration characteristics in high resolution printing and suppressing manufacturing costs. It will be an issue. Another object of the present invention is to provide a printing sheet that can be identified by a thermal transfer printing apparatus. Another object of the present invention is to provide a thermal transfer printing apparatus which performs printing processing by identifying the loaded thermal transfer sheet or printing sheet.

The thermal transfer sheet according to the present invention is a thermal transfer sheet in which a dye layer and a protective layer are formed on one side of a substrate, the protective layer contains an invisible light absorbing material, and at least one of a recess and a protrusion And an identification mark including

In the thermal transfer sheet according to one aspect of the present invention, the identification mark includes a ridge or a ridge.

In the thermal transfer sheet according to one aspect of the present invention, the ridges or grooves are provided along the sheet short direction.

In the thermal transfer sheet according to one aspect of the present invention, the identification mark is provided on the periphery of the protective layer which is not transferred to the printing paper.

The thermal transfer printing apparatus according to the present invention has a thermal head and a platen roll, and the thermal transfer sheet according to any one of claims 1 to 4 and the printing paper are superposed to form a space between the thermal head and the platen roll. The thermal transfer printing apparatus according to claim 1, wherein the thermal head heats the thermal transfer sheet to transfer the dye, forms an image on the printing paper, and transfers the protective layer onto the image. A detector which is provided between a supply unit to be supplied and the thermal head and which detects the identification mark, a storage unit which stores a table in which the type of the thermal transfer sheet and the pattern of the identification mark are associated; An identification unit for referring to a table and identifying a thermal transfer sheet supplied by the supply unit from a pattern detected by the detector; .

In the thermal transfer printing apparatus according to one aspect of the present invention, the pattern of the identification mark is the number, the number, the width, the shape or the position of the identification mark.

A thermal transfer printing apparatus according to the present invention has a thermal head and a platen roll, and a thermal transfer sheet provided with a dye layer and a protective layer containing an invisible light absorbing material is overlaid on a printing paper to obtain the thermal head and the platen roll. And the thermal head heats the thermal transfer sheet to transfer the dye, thereby forming an image on the printing paper, and transferring the protective layer onto the image. A detector provided between a supply unit for supplying the thermal transfer sheet and the thermal head, which irradiates the protective layer with invisible light to measure the intensity of transmitted light or reflected light; type of the thermal transfer sheet; A storage unit for storing a table in which strengths are associated, and a thermal transfer sheet supplied by the supply unit from the measurement result of the detector with reference to the table And identifying the identification unit, in which comprises a.

In the thermal transfer printing apparatus according to one aspect of the present invention, printing conditions for each type of thermal transfer sheet are associated with the table, and printing processing is performed under the printing conditions according to the type of thermal transfer sheet identified by the identification unit. Do.

The printing sheet according to the present invention is a printing sheet comprising a substrate, an intermediate layer provided on the substrate, and a receiving layer provided on the intermediate layer, the intermediate layer containing an invisible light absorbing material And an identification mark including at least one of a recess and a protrusion.

In the printing sheet according to one aspect of the present invention, the identification mark includes a ridge or a ridge.

The thermal transfer printing apparatus according to the present invention has a thermal head and a platen roll, and the thermal transfer sheet of the present invention and the printing sheet of the present invention are superposed and transported between the thermal head and the platen roll. A thermal transfer printing apparatus, wherein the thermal head heats the thermal transfer sheet to transfer dye, forms an image on the print sheet, and transfers the protective layer onto the image, and a supply unit for supplying the thermal transfer sheet And a thermal head, wherein a first detector for detecting a first identification mark provided on the protective layer, and a second detector for detecting a second identification mark provided on the intermediate layer A table in which the type of the thermal transfer sheet and the pattern of the first identification mark are associated, and the type of the printing sheet and the pattern of the second identification mark are associated The type of the thermal transfer sheet is identified from the pattern detected by the first detector with reference to the storage unit storing the table and the table, and the type of the printing sheet is identified from the pattern detected by the second detector. And an identification unit.

In the thermal transfer printing apparatus according to one aspect of the present invention, a light source for irradiating the thermal transfer sheet and the printing sheet with invisible light is provided, and the printing sheet is irradiated with the invisible light transmitted through the protective layer. The first detector receives the light from the protective layer, and the second detector receives the light from the printing sheet transmitted through the protective layer.

In the thermal transfer printing apparatus according to one aspect of the present invention, the protective layer of the thermal transfer sheet contains an ultraviolet light absorbing material, and the intermediate layer of the printing sheet contains a fluorescent brightening agent.

According to the present invention, it is possible to identify a thermal transfer sheet with a thermal transfer printing apparatus while preventing a change in color development characteristics in high resolution printing and suppressing the manufacturing cost.

FIG. 1 is a schematic diagram of a thermal transfer printing apparatus according to an embodiment of the present invention. It is a top view of the thermal transfer sheet concerning the embodiment. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. Figures 4a and 4b show examples of cross sections of the protective layer 5a and 5b are plan views of the protective layer. 6a, 6b are plan views of the protective layer. 7a and 7b are plan views of the protective layer. 8a and 8b are plan views of the protective layer. It is a top view of a protective layer. It is a top view of a protective layer. It is a top view of a thermal transfer sheet. It is a schematic block diagram of the thermal transfer printing apparatus which concerns on another embodiment. It is a top view of a printing sheet. 14a and 14b are cross-sectional views taken along the line XIV-XIV of FIG.

FIG. 1 is a schematic view of a thermal transfer printing apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of a thermal transfer sheet 5 used in the thermal transfer printing apparatus, and FIG. 3 is a cross sectional view of the thermal transfer sheet 5 is there.

In the thermal transfer sheet 5, a dye layer 52 containing a dye and a binder resin and a transferable protective layer (hereinafter, referred to as a protective layer 54) are repeatedly provided on one surface of a base 50 in a face-sequential manner. The back layer 57 is provided on the other side of the The dye layer 52 includes a surface-sequential yellow (Y) dye layer, a magenta (M) dye layer, and a cyan (C) dye layer. A dye primer layer may be provided between the dye layer 52 and the protective layer 54 and the substrate 50. In addition, a back primer layer may be provided between the substrate 50 and the back layer 57.

The thermal transfer printing apparatus uses the thermal transfer sheet 5 to perform sublimation transfer of Y, M, and C on a printing sheet 7 (printing paper, image receiving paper) to print an image, thereby forming a protective layer on the image. Is equipped.

A supply unit 3 formed by winding the thermal transfer sheet 5 is provided on the downstream side of the thermal head 1, and a recovery unit 4 is provided on the upstream side of the thermal head 1. The thermal transfer sheet 5 delivered from the supply unit 3 passes through the thermal head 1 and is recovered by the recovery unit 4.

A rotatable platen roll 2 is provided below the thermal head 1. The printing unit 40 including the thermal head 1 and the platen roll 2 sandwiches the printing sheet 7 and the thermal transfer sheet 5 and heats the thermal transfer sheet 5 to thermally transfer the dye onto the printing sheet 7 to form an image.

Also, the printing unit 40 heats the protective layer 54 to transfer the protective layer onto the image. By increasing the transfer energy (print energy by the printing section 40) when forming the protective layer, the surface of the protective layer has a matte tone with low gloss, and by lowering the transfer energy, the protective layer has a gloss with high gloss. become.

On the upstream side of the thermal head 1, a rotatably driven capstan roller 9a for transporting the printing sheet 7 and a pinch roller 9b for pressing the printing sheet 7 onto the capstan roller 9a are provided.

The printing sheet 7 is wound around the printing paper roll 6 and fed from the printing paper roll 6. A well-known thing can be used for the printing sheet 7. The printing sheet 7 is fed out (conveyed forward) and taken up (conveyed backward) by the drive unit 30 including the printing paper roll 6, the capstan roller 9a, and the pinch roller 9b.

The printing sheet 7 on which the image formation and the transfer of the protective layer have been performed by the printing unit 40 is cut out as a printed sheet 7a by the cutter 8 on the downstream side. The print sheet 7a is discharged from a discharge port (not shown).

In the present embodiment, the protective layer 54 of the thermal transfer sheet 5 contains an invisible light absorbing material. As the invisible light absorbing material, for example, a fluorescent whitening agent, an ultraviolet absorbing material and an infrared absorbing material can be mentioned. In the vicinity of the supply unit 3, a detector 20 corresponding to the type of the invisible ray absorbing material is provided.

When the protective layer 54 contains a fluorescent whitening agent, a fluorescent sensor is used as the detector 20, and the protective layer 54 is irradiated with ultraviolet light, and the fluorescence emitted from the protective layer 54 is received to measure the fluorescence intensity. When the protective layer 54 contains an ultraviolet absorbing material or an infrared absorbing material, an ultraviolet sensor or an infrared sensor is used as the detector 20, and the protective layer 54 is irradiated with ultraviolet light or infrared light, and the intensity of reflected light or transmitted light (reflectance, Measure the transmittance). Here, the ultraviolet light refers to one having a maximum absorption wavelength (λmax) range of 280 nm to 400 nm, and the infrared light refers to one having a maximum absorption wavelength (λmax) range of 780 nm to 1 mm. The wavelength range of visible light is greater than 400 nm and less than 780 nm.

An identification mark 55 is formed on the protective layer 54, and the measurement value of the detector 20 is different between the identification mark 55 and the area other than the identification mark 55.

For example, as shown in FIG. 3 and FIG. 4 a, the identification mark 55 is a concave portion thinner than the area other than the identification mark 55. Alternatively, as shown in FIG. 4 b, the identification mark 55 may be a convex portion thicker than the area other than the identification mark 55.

For example, the identification mark 55 may be a convex or concave (line pattern) along the width direction of the thermal transfer sheet (the sheet short direction orthogonal to the sheet longitudinal direction). In this case, when the detector 20 irradiates the protective layer 54 of the thermal transfer sheet 5 delivered and conveyed from the supply unit 3 with ultraviolet light or infrared light and scans it in the longitudinal direction, the measured value at the edge portion of the identification mark 55 Since it changes, patterns such as the number, the number, the width, the shape, and the position of the identification marks 55 can be detected.

For example, when the protective layer 54 contains a fluorescent whitening agent, the position at which the detector 20 starts to receive fluorescence corresponds to the front edge of the protective layer 54. Subsequently, the position where the fluorescence intensity increases (decreases) corresponds to one edge of the identification mark 55, and then the position where the fluorescence intensity decreases (increases) corresponds to the other edge of the identification mark 55. The position where the detector 20 stops receiving fluorescence corresponds to the trailing edge of the protective layer 54.

A plurality of thermal transfer sheets 5 can be loaded into the thermal transfer printing apparatus. The type of the thermal transfer sheet 5 and the pattern (number, number, width, shape, position) of the identification mark 55 are recorded in association with each other on a table T of the storage unit 12 described later. For example, as shown in FIGS. 5a and 5b, the number of identification marks 55 differs depending on the type of the thermal transfer sheet 5. Also, for example, as shown in FIGS. 6a and 6b, the widths w1 and w2 of the identification mark 55 differ depending on the type of the thermal transfer sheet 5. Further, for example, as shown in FIGS. 7a and 7b, the position of the identification mark 55 in the sheet longitudinal direction differs depending on the type of the thermal transfer sheet 5. For example, as shown in FIGS. 8a and 8b, the identification mark 55 is formed only in part of the sheet width direction, and the position of the identification mark 55 in the sheet width direction differs depending on the type of the thermal transfer sheet 5. The type of the thermal transfer sheet 5 may be expressed by combining the number, the number, the width, the shape, the position, and the like of the identification marks 55.

The identification mark 55 of the ridge portion or the concave portion may be provided along the sheet longitudinal direction as shown in FIG. The identification mark 55 may not be straight but may be a wavy line. Further, the identification mark 55 is not limited to the line pattern, and may be a pattern such as a checkered pattern, a heart, a star, or a spade as shown in FIG.

The control device 10 controls driving of each part of the thermal transfer printing apparatus, and performs identification processing of the thermal transfer sheet 5 and printing processing. The control device 10 is a computer having a storage unit 12 including a CPU (central processing unit), a flash memory, a ROM (Read-Only Memory), a RAM (Random Access Memory), and the like. The storage unit 12 stores a control program and the table T described above. The identification unit 11 is realized by the CPU executing the control program.

The identification unit 11 refers to the table T and identifies the type of the thermal transfer sheet 5 from the detection result of the identification mark 55 by the detector 20. In the table T, suitable printing conditions (printing speed, applied energy at the time of printing), types of the printing sheet 7 to be used, and the like may be associated and recorded for each type of the thermal transfer sheet 5. If the type of the printing sheet 7 loaded in the thermal transfer printing apparatus does not correspond to the type of the thermal transfer sheet 5 identified, the control device 10 outputs a warning sound or a warning display, or cancels the printing process. You may

Next, the configuration of the thermal transfer sheet 5 will be described.

[Base material]
The base material 50 used for the thermal transfer sheet 5 may be any base material as long as it has a conventionally known degree of heat resistance and strength. For example, polyethylene terephthalate film, 1,4-polycyclohexylene dimethylene terephthalate film, polyethylene naphthalate film, polyphenylene sulfide film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, acetate Examples thereof include cellulose derivatives such as cellulose, polyethylene films, polyvinyl chloride films, nylon films, polyimide films, resin films such as ionomer films, and the like.

The substrate 50 generally has a thickness of about 0.5 μm to 50 μm, preferably about 3.0 μm to 10 μm. The substrate 50 may be subjected to surface treatment in order to improve the adhesion to the layer in contact with the substrate 50. As the surface treatment, known resin surface modification techniques such as corona discharge treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, roughening treatment, chemical treatment, plasma treatment, grafting treatment and the like can be applied. The surface treatment may be performed only one kind or two or more kinds.

Among the above-mentioned surface treatments, corona treatment or plasma treatment is preferred in terms of low cost. Moreover, you may form an undercoat layer in one side or both surfaces of the base material 50 as needed. The primer treatment for forming the undercoat layer can be performed, for example, by applying a primer liquid to the unstretched film at the time of film formation of melt extrusion of a plastic film, and then performing stretching treatment. It is also possible to apply a back primer layer (adhesive layer) between the substrate 50 and the back layer 57 by coating. The back primer layer is, for example, polyester resin, polyacrylate resin, polyvinyl acetate resin, polyurethane resin, styrene acrylate resin, polyacrylamide resin, polyamide resin, polyether resin, polystyrene resin It can be formed using a vinyl resin such as polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyvinyl alcohol resin, polyvinylidene chloride resin, polyvinyl acetal resin such as polyvinyl acetoacetal or polyvinyl butyral, cellulose resin, etc. .

[Dye layer]
As the dye layer 52, it is preferable to use a material in which a sublimable dye is melted or dispersed in a binder resin. Sublimable dyes include, for example, diarylmethane dyes, triarylmethane dyes, thiazole dyes, merocyanine dyes, pyrazolone dyes, methine dyes, indoaniline dyes, acetophenone azomethine, pyrazoloazo methine, imidazolazo azomethine and imidazo. Azomethine dyes such as azomethine and pyridone azomethine; xanthene dyes; oxazine dyes; cyanostyrene dyes such as dicyanostyrene and tricyanostyrene; thiazine dyes; azine dyes; acridine dyes; benzene azo dyes; pyridone azo, thiophene Azo dyes such as azo, isothiazole azo, pyrrole azo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo, and disazo; spiropyran dyes; indolino spiropyran dyes ; Fluoran dyes; rhodamine lactam dyes; naphthoquinone dyes; anthraquinone dyes; quinophthalone dyes; and the like.

In the dye layer, the sublimable dye is in an amount of 5% by weight to 90% by weight, preferably 20% by weight to 80% by weight, based on the total solid content of the dye layer. By setting the use amount of the sublimable dye in the above range, it is possible to set a suitable printing density and to suppress a decrease in storage stability.

As a binder resin for carrying a dye, generally, one having heat resistance and a suitable affinity to the dye can be used. Examples of the binder resin include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxycellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate and cellulose butyrate; polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetoacetal, polyvinyl pyrrolidone Etc .; acrylic resins such as poly (meth) acrylates and poly (meth) acrylamides; polyurethane resins; polyamide resins; polyester resins; and the like. Among the above-mentioned binder resins, from the viewpoint of excellent heat resistance, dye transferability and the like, cellulose resins, vinyl resins, acrylic resins, urethane resins, polyester resins and the like are preferable, and vinyl resins are more preferable. Particularly preferred are polyvinyl butyral and polyvinyl acetoacetal.

The dye layer 52 may use additives such as a mold release agent, inorganic fine particles, organic fine particles and the like. The release agent may, for example, be silicone oil or phosphoric acid ester. Examples of the inorganic fine particles include carbon black, aluminum, molybdenum disulfide and the like. Moreover, polyethylene wax etc. are mentioned as organic particulates.

The dye layer 52 is prepared by dissolving or dispersing the above-mentioned dye and binder resin together with additives, as required, in an appropriate organic solvent or water to prepare a coating solution, and further, a gravure printing method, screen It can form by apply | coating the said coating liquid to one side of the above-mentioned base material 50, and drying by well-known means, such as a printing method and a reverse roll coating printing method using a gravure plate.

Examples of the organic solvent include toluene, methyl ethyl ketone, ethanol, isopropyl alcohol, cyclohexanone and dimethylformamide [DMF]. The thickness of the dye layer is 0.2 μm or more and 6.0 μm or less, preferably 0.2 μm or more and 3.0 μm or less in dry thickness.

[Protective layer]
As the protective layer 54, one obtained by adding a fluorescent whitening agent, an ultraviolet light absorbing material or an infrared light absorbing material to various resins conventionally known as a resin for forming a protective layer is used. The resin for forming a protective layer includes, for example, polyester resin, polystyrene resin, acrylic resin, polyurethane resin, acrylic urethane resin, vinyl chloride-vinyl acetate copolymer, resin obtained by modifying each of these resins with silicone, and each of these resins And mixtures thereof.

Examples of fluorescent whitening agents include fluorescein compounds, thioflavine compounds, eosin compounds, rhodamine compounds, coumarin compounds, imidazole compounds, oxazole compounds, triazole compounds, carbazole compounds, pyridine compounds, imidazorone compounds. It is possible to use a series compound, a naphthalic acid derivative, a stilbene sulfonic acid derivative, a stilbene tetrasulfonic acid derivative, a stilbene hexasulfonic acid derivative and the like.

Examples of UV absorbing materials include organic UV absorbing materials such as benzotriazole compounds, triazine compounds, benzophenone compounds, and benzoate compounds, and inorganic materials such as titanium oxide, zinc oxide, cerium oxide, iron oxide, and barium sulfate. Examples include ultraviolet light absorbing materials. In particular, it is preferable to use a benzotriazole-based compound.

Examples of the infrared absorbing material include dimonium compounds, aminium compounds, phthalocyanine compounds, dithiol organic metal complexes, cyanine compounds, azo compounds, polymethine compounds, quinone compounds, diphenylmethane compounds, triphenylmethane compounds Compounds, oxols and the like can be mentioned.

The protective layer 54 is formed by applying and drying a coating liquid containing the above-described resin to which the above-mentioned fluorescent whitening agent, ultraviolet light absorbing material or infrared light absorbing material is added, using, for example, the gravure printing method. Minute concave portions called cells are formed on the surface of the plate cylinder used for gravure printing, and the coating liquid filled in the concave portions is applied to the substrate 50. In the present embodiment, asperities on the surface of the plate cylinder are adjusted to form the protective layer 54 having concave portions or convex portions (identification marks 55) different in film thickness.

The thickness of the protective layer 54 (the region other than the identification mark 55) is preferably 0.1 μm or more and 2.0 μm or less in dry thickness. The thickness of the identification mark 55 portion is preferably 65% or more and 80% or less, or 125% or more and 150% or less of the thickness of the area other than the identification mark 55.

When the identification mark 55 is a recess, by making the thickness of the identification mark 55 part 80% or less of the thickness of the area other than the identification mark 55, the detection value by the detector 20 in the identification mark 55 and other areas is obtained. A sufficient difference occurs and the identification mark 55 is easy to detect. Further, by setting the thickness of the identification mark 55 to 65% or more of the thickness of the area other than the identification mark 55, it is difficult to visually recognize the unevenness of the identification mark 55 in the printed sheet 7a on which the thermal transfer image is formed. .

When the identification mark 55 is a convex portion, the thickness of the identification mark 55 portion is 125% or more of the thickness of the area other than the identification mark 55, the detection value by the detector 20 in the identification mark 55 and other areas And the identification mark 55 is easy to detect. Further, by setting the thickness of the identification mark 55 portion to 150% or less of the thickness of the area other than the identification mark 55, it is difficult to visually recognize the unevenness of the identification mark 55 portion in the printed sheet 7a on which the thermal transfer image is formed. .

[Back layer]
A back layer 57 is provided on the side of the thermal transfer sheet 5 opposite to the side on which the dye layer 52 and the protective layer 54 of the substrate 50 are provided. The back layer 57 is provided on the other surface of the substrate 50 in order to improve the heat resistance and the running performance of the thermal head 1 at the time of printing.

The back layer 57 can be formed by appropriately selecting a conventionally known thermoplastic resin or the like. As such a thermoplastic resin, for example, a polyolefin resin such as polyester resin, polyacrylate resin, polyvinyl acetate resin, styrene acrylate resin, polyurethane resin, polyethylene resin, polypropylene resin, etc. Polystyrene-based resin, polyvinyl chloride-based resin, polyether-based resin, polyamide-based resin, polyimide-based resin, polyamide-imide-based resin, polycarbonate-based resin, polyacrylamide resin, polyvinyl chloride resin, polyvinyl butyral resin, polyvinyl acetoacetal resin, etc. Thermoplastic resins, such as polyvinyl acetal resin, these silicone modified products, etc. are mentioned.

In addition, a curing agent may be added to the above-described resin. As a polyisocyanate resin which functions as a curing agent, although conventionally known ones can be used without particular limitation, among them, it is desirable to use an adduct of aromatic isocyanate. As aromatic polyisocyanates, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, or a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate, trans-cyclohexane-1,4-diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, tris (isocyanatophenyl) thiophosphate and the like, and in particular 2,4-toluene diisocyanate, 2,6-toluene diisocyanate Alternatively, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is preferred. Such a polyisocyanate resin crosslinks the above-mentioned hydroxyl group-containing thermoplastic resin using the hydroxyl group, and improves the coating film strength and heat resistance of the back layer 57.

In addition to the above thermoplastic resin, the back layer 57 is a wax, a higher fatty acid amide, a phosphoric acid ester compound, a metal soap, a silicone oil, a release agent such as a surfactant, or the like in order to improve slip properties. Various additives such as organic powder such as resin, inorganic particles such as silica, clay, talc, calcium carbonate can be contained.

The back layer 57 may be, for example, a coating liquid prepared by dispersing or dissolving the above-mentioned thermoplastic resin and various additives added as necessary in a suitable solvent, and the dye layer 52 and the protective layer 54 of the substrate 50 It can form by apply | coating and drying by well-known means, such as a gravure printing method, the screen-printing method, the reverse roll coating printing method using a gravure plate, on the opposite side. The thickness of the back layer is preferably 3 μm or less at the time of drying, and more preferably 0.1 μm or more and 2 μm or less, from the viewpoint of improvement of heat resistance and the like.

In the printing process using such a thermal transfer sheet 5, first, the print sheet 7 and the Y layer of the dye layer 52 are aligned, and the thermal head 1 contacts the platen roll 2 through the print sheet 7 and the thermal transfer sheet 5. Contact. Next, the capstan roller 9a and the recovery unit 4 are rotationally driven, and the printing sheet 7 and the thermal transfer sheet 5 are fed rearward. During this time, the area of the Y layer is selectively heated sequentially and sequentially by the thermal head 1 based on the image data, and Y is sublimation-transferred from the thermal transfer sheet 5 onto the printing sheet 7.

After sublimation transfer of Y, the thermal head 1 ascends and separates from the platen roll 2. Next, the printing sheet 7 and the M layer are aligned. In this case, the printing sheet 7 is sent forward by a distance corresponding to the print size, and the thermal transfer sheet 5 is sent backward by a distance corresponding to the margin between the Y layer and the M layer.

Similar to the method of sublimation transfer of Y, M and C are sequentially sublimation transferred onto the printing sheet 7 based on the image data, and an image is formed on the printing sheet 7.

After the image formation, the printing sheet 7 and the protective layer 54 are aligned, and the thermal head 1 heats the protective layer 54 to transfer the protective layer from the thermal transfer sheet 5 onto the printing sheet 7 so as to cover the image. In the protective layer 54, the thickness of the identification mark 55 portion is 65% to 80% or 125% to 150% of the thickness of the area other than the identification mark 55. Can not be perceived with the naked eye of the human being, and there is no influence on the finish of the print.

The identification mark 55 is provided on the periphery outside the printing area of the protective layer 54 so that the identification mark 55 portion is not unintentionally changed depending on the storage period or storage environment of the print object to affect the appearance of the print object. The identification mark 55 may not be transferred to the printing sheet 7. Further, in order to suppress the influence of the printed matter on the appearance, the linear identification mark 55 may be positioned only at the peripheral portion of the printed matter.

In the present embodiment, since the identification mark 55 is provided on the protective layer 54 and not provided on the dye layer 52, there is no change in the coloring characteristic. In addition, since the coating liquid for forming a protective layer to which the invisible light absorbing material is added may be coated after adjusting the irregularities of the printing cylinder in gravure printing, there is no increase in the coating process for forming the identification mark 55 , Can reduce the manufacturing cost. The identification mark 55 may be configured by only one of the recess and the protrusion, or may be configured by combining the recess and the protrusion.

In the above embodiment, an example in which the pattern (number, number, width, shape, position, etc.) of the identification mark 55 formed on the protective layer 54 is changed for each type of the thermal transfer sheet 5 has been described. In each case, the concentration of the invisible light absorbing material added to the protective layer forming resin may be changed (the thickness of the protective layer 54 is not changed). In this case, the detection value by the detector 20 differs depending on the type of the thermal transfer sheet 5. On the table T of the storage unit 12, the type of the thermal transfer sheet 5 and the intensity of the transmitted light or the reflected light are recorded in association with each other.

Further, the type of invisible light absorbing material to be added to the protective layer forming resin may be changed for each type of the thermal transfer sheet 5. In this case, absorption wavelengths of ultraviolet light and infrared light differ depending on the type of the thermal transfer sheet 5. In the table T of the storage unit 12, the type of the thermal transfer sheet 5 and the absorption wavelength are recorded in association with each other.

As shown in FIG. 11, the identification mark 55 is provided on the rear side in the sheet longitudinal direction in the protective layer 54, and this identification mark is used as a detection mark for determining the position of the subsequent dye layer 52 (Y layer). You may The identification mark 55 may be provided in an area not transferred to the printing sheet 7, for example, in the vicinity of the Y layer.

In the above embodiment, the identification mark 55 (first identification mark) is provided on the protective layer 54 to identify the type of the thermal transfer sheet 5, but not only the thermal transfer sheet 5 but also the print sheet 7 has the identification mark (first 2) An identification mark may be provided to identify the type.

FIG. 12 is a schematic configuration view of the thermal transfer printing apparatus which also identifies the type of the printing sheet 7, FIG. 13 is a plan view of the printing sheet 7, and FIGS. 14a and 14b are cross-sectional views of the printing sheet 7. While the thermal transfer printing apparatus shown in FIG. 1 is provided with the detector 20 (first detector), FIG. 12 shows the thermal transfer printing apparatus as the detector 20 (first detector) and the detector 60 (second detection) Unit) is provided.

The printing sheet 7 has a configuration in which the receiving layer 71 is provided on one surface of the substrate 70 and the back surface layer 72 is provided on the other surface. Between the base 70 and the receiving layer 71, an intermediate layer 73 for improving the adhesion between the base 70 and the receiving layer 71 is provided. The printing sheet 7 may further have other layers.

The intermediate layer 73 contains an invisible light absorbing material. As the invisible light absorbing material, for example, a fluorescent whitening agent, an ultraviolet absorbing material and an infrared absorbing material can be mentioned. The invisible light absorbing material contained in the intermediate layer 73 is different from the invisible light absorbing material contained in the protective layer 54. The detector 20 corresponds to the type of invisible light absorbing material contained in the protective layer 54, and the detector 60 corresponds to the type of invisible light absorbing material contained in the intermediate layer 73. .

When the intermediate layer 73 contains a fluorescent brightening agent, a fluorescent sensor is used as the detector 60, and the printing sheet 7 is irradiated with ultraviolet light, and the fluorescence emitted from the printing sheet 7 is received to measure the fluorescence intensity. When the intermediate layer 73 contains an ultraviolet light absorbing material or an infrared light absorbing material, an ultraviolet light sensor or an infrared light sensor is used as the detector 60, and the printing sheet 7 is irradiated with ultraviolet light or infrared light, and the intensity of reflected light or transmitted light (reflectance, Measure the transmittance).

When the detector 20 and the detector 60 are disposed close to each other as shown in FIG. 12, the light source for emitting the ultraviolet light may be common. The ultraviolet light emitted from the light source passes through the protective layer 54 and is applied to the intermediate layer 73. The ultraviolet light reflected from the intermediate layer 73 or the fluorescence emitted from the intermediate layer 73 passes through the protective layer 54 and is detected by the detector 60.

The detector 60 may be provided between the printing unit 40 and the printing paper roll 6.

An identification mark 75 is formed on the intermediate layer 73 of the printing sheet 7, and the measurement value of the detector 60 is different between the identification mark 75 and the area other than the identification mark 75.

For example, in the intermediate layer 73, as shown in FIG. 14a, the identification mark 75 is a concave portion thinner than the area other than the identification mark 75. Alternatively, in the intermediate layer 73, as shown in FIG. 14b, the identification mark 75 may be a convex portion that is thicker than the area other than the identification mark 75.

For example, the identification mark 75 may be a convex or concave line (line pattern) along the width direction of the printing sheet 7 (the sheet short direction orthogonal to the sheet longitudinal direction). In this case, when the detector 60 irradiates ultraviolet light or infrared light to the printing sheet 7 fed and conveyed from the printing paper roll 6 and scanning in the longitudinal direction, the measured value changes at the edge portion of the identification mark 75 The pattern such as the number, the number, the width, the shape, and the position of the identification mark 75 can be detected. The identification marks 75 are repeatedly provided at regular intervals.

For example, when the intermediate layer 73 contains a fluorescent whitening agent, the position at which the fluorescence intensity received by the detector 60 increases (decreases) corresponds to one edge of the identification mark 75, and then the fluorescence intensity decreases. The (increased) position corresponds to the other edge of the identification mark 75.

A plurality of types of printing sheets 7 can be loaded into the thermal transfer printing apparatus. In the table T of the storage unit 12, the type of the printing sheet 7 and the pattern (number, number, width, shape, position) of the identification mark 75 are recorded in association with each other. For example, the number, the width, the position, and the like of the identification marks 75 differ depending on the type of the printing sheet 7.

The identification unit 11 refers to the table T and identifies the type of the print sheet 7 from the detection result of the identification mark 75 by the detector 60.

A suitable combination of the thermal transfer sheet 5 and the printing sheet 7 may be registered in the table T. If the type of the thermal transfer sheet 5 identified by the identification unit 11 and the type of the printing sheet 7 do not match the registered combination, the control device 10 outputs a warning sound or a warning display or cancels the printing process. You may

After the printing process in the printing unit 40, the boundary between the print sheet area and the margin area of the printing sheet 7 is cut in the width direction by the cutter 8. The print sheet area is discharged from the discharge port as the print sheet 7a. On the other hand, the margin area is cut out as a margin piece and collected in a collection container (not shown) disposed immediately below the cutter 8.

The image is printed slightly larger than the printed sheet area. As a result, even if the cutting position of the cutter 8 is slightly shifted, the printed sheet 7a having an image formed on the entire surface can be obtained.

The above-mentioned identification mark 75 may be provided in the margin area collected as a margin piece.

As the base 70 of the printing sheet 7, high quality paper, coated paper, resin coated paper, art paper, cast coated paper, paperboard, synthetic paper (polyolefin type, polystyrene type), synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated Paper, synthetic resin internal paper, cellulose fiber paper etc. can be mentioned. There is no limitation in particular about the thickness of the base material 70, and it is about 10 micrometers or more and 300 micrometers or less.

The receiving layer 71 contains a binder resin and a release agent. As the binder resin, conventionally known resin materials which can easily receive the dye of the dye layer of the thermal transfer sheet can be used. The release agent is for improving the releasability of the thermal transfer sheet from the dye layer, and silicone oil, polyethylene wax, amide wax, fluorine type or phosphate type surfactant, etc. can be used.

As the back layer 72, one having a desired function can be appropriately selected and used according to the application of the printing sheet 7 and the like. For example, it is preferable to use the back surface layer 72 having the transportability improvement function of the printing sheet 7 and the curl prevention function.

For the intermediate layer 73, a resin obtained by adding an invisible light absorbing material to a conventionally known resin having a role of well adhering the base 70 and the receiving layer 71 is used. As resin, a polyurethane resin, an acrylic resin, a polyethylene resin, a polypropylene resin, an epoxy resin etc. can be mentioned, for example.

The thickness of the intermediate layer 73 (region other than the identification mark 75) is preferably 0.1 μm to 2.0 μm in dry thickness. The thickness of the identification mark 75 portion is preferably 65% or more and 80% or less, or 125% or more and 150% or less of the thickness of the area other than the identification mark 75.

When the identification mark 75 is a recess, by making the thickness of the identification mark 75 part 80% or less of the thickness of the area other than the identification mark 75, the value detected by the detector 60 in the identification mark 75 and other areas is used. A sufficient difference occurs and the identification mark 75 is easy to detect. Further, by setting the thickness of the identification mark 75 to 65% or more of the thickness of the area other than the identification mark 75, it is difficult to visually check the unevenness of the identification mark 75 appearing on the surface of the receiving layer 71. However, when the identification mark 75 is provided in the margin area, unevenness does not appear in the printed sheet 7a.

When the identification mark 75 is a convex portion, by making the thickness of the identification mark 75 part 125% or more of the thickness of the area other than the identification mark 75, the detection value by the detector 60 in the identification mark 75 and other areas And the identification mark 75 is easy to detect. Further, by setting the thickness of the identification mark 75 to 150% or less of the thickness of the area other than the identification mark 75, it is difficult to visually recognize the unevenness of the identification mark 75 in the printed sheet 7a on which the thermal transfer image is formed. . However, as described above, when the identification mark 75 is provided in the margin area, the unevenness does not appear in the printed sheet 7a.

The identification mark 75 may be configured by only one of the recess and the protrusion, or may be configured by combining the recess and the protrusion.

Although an example of changing the pattern (number, number, width, shape, position, etc.) of identification mark 75 for each type of printing sheet 7 has been described, the invisible light absorbing material contained in intermediate layer 73 for each type of printing sheet 7 The concentration of the intermediate layer 73 may be changed (the thickness of the intermediate layer 73 is not changed). In this case, the detection value (light reception intensity) by the detector 60 differs depending on the type of the printing sheet 7. In the table T of the storage unit 12, the type of the print sheet 7 and the detected value are recorded in association with each other.

As shown in FIG. 12, the detector 20 and the detector 60 are disposed close to each other to share the light source for irradiating ultraviolet light, and the identification mark 55 and the identification mark in a state where the protective layer 54 and the printing sheet 7 overlap. When 75 is detected, the identification mark 55 and the identification mark 75 may be detected simultaneously or separately.

In order to simultaneously detect the identification mark 55 and the identification mark 75, if the invisible light absorbing material contained in the protective layer 54 and the invisible light absorbing material contained in the intermediate layer 73 are of the same type, they are detected by the detector It is difficult to determine whether the change in light intensity is due to the identification mark 55 or the identification mark 75.

Therefore, when the identification mark 55 and the identification mark 75 are simultaneously detected, it is preferable that the invisible light absorbing material contained in the protective layer 54 and the invisible light absorbing material contained in the intermediate layer 73 be different types. In particular, in consideration of the quality of the printed product (printed sheet 7a) to be produced, it is preferable that the protective layer 54 contains an ultraviolet light absorbing material and the intermediate layer 73 contains a fluorescent brightening agent.

Further, the intermediate layer 73 is irradiated with the ultraviolet light transmitted through the identification mark 55 of the protective layer 54. In order to suppress the amount of attenuation when ultraviolet light passes through the identification mark 55 and to irradiate the intermediate layer 73 with ultraviolet light of a sufficient strength, it is preferable to form the identification mark 55 as a recess.

The present invention is not limited to the above embodiment as it is, and at the implementation stage, the constituent elements can be modified and embodied without departing from the scope of the invention. In addition, various inventions can be formed by appropriate combinations of a plurality of constituent elements disclosed in the above embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components in different embodiments may be combined as appropriate.

This application is based on Japanese patent application 2017-148112 filed on July 31, 2017 and Japanese patent application 2018-008302 filed on January 22, 2018, which is incorporated by reference in its entirety. .

DESCRIPTION OF SYMBOLS 1 thermal head 2 platen roll 3 supply part 4 collection | recovery part 5 thermal transfer sheet 7 printing sheet 10 control apparatus 11 identification part 12 memory | storage part 20 detector (1st detector)
40 printing section 50 base material 52 dye layer 54 protective layer 55 identification mark 60 detector (second detector)
75 Identification mark

Claims

A thermal transfer sheet having a dye layer and a protective layer formed on one side of a substrate,
The thermal transfer sheet, wherein the protective layer contains an invisible light absorbing material, and is provided with an identification mark including at least one of a concave portion and a convex portion.
The thermal transfer sheet according to claim 1, wherein the identification mark includes a ridge portion or a concave portion.
The thermal transfer sheet according to claim 2, wherein the ridges or the ridges are provided along the sheet width direction.
The thermal transfer sheet according to any one of claims 1 to 3, wherein the identification mark is provided at a peripheral portion of the protective layer which is not transferred to the printing paper.
A thermal head and a platen roll, and the thermal transfer sheet according to any one of claims 1 to 4 and the printing paper are superposed and transported between the thermal head and the platen roll, and the thermal head A thermal transfer printing apparatus which heats the thermal transfer sheet to transfer a dye, forms an image on the printing paper, and transfers the protective layer onto the image,
A detector provided between a supply unit for supplying the thermal transfer sheet and the thermal head to detect the identification mark;
A storage unit that stores a table in which the type of the thermal transfer sheet and the pattern of the identification mark are associated;
An identification unit that refers to the table and identifies the thermal transfer sheet supplied by the supply unit from the pattern detected by the detector;
Thermal transfer printing apparatus comprising:
The thermal transfer printing apparatus according to claim 5, wherein the pattern of the identification mark is the number, the number, the width, the shape, or the position of the identification mark.
A thermal transfer sheet having a thermal head and a platen roll and provided with a protective layer containing a dye layer and an invisible light absorbing material and a printing paper are superposed and transported between the thermal head and the platen roll. The thermal transfer printing apparatus, wherein the thermal head heats the thermal transfer sheet to transfer a dye, forms an image on the printing paper, and transfers the protective layer onto the image.
A detector provided between a supply unit for supplying the thermal transfer sheet and the thermal head, which irradiates the protective layer with invisible light to measure the intensity of transmitted light or reflected light;
A storage unit that stores a table in which the type of the thermal transfer sheet is associated with the strength;
An identification unit that refers to the table and identifies a thermal transfer sheet supplied by the supply unit from the measurement result of the detector;
Thermal transfer printing apparatus comprising:
Printing conditions for each type of thermal transfer sheet are associated with the table,
The thermal transfer printing apparatus according to any one of claims 5 to 7, wherein the printing process is performed under the printing condition according to the type of the thermal transfer sheet identified by the identification unit.
A printing sheet comprising a substrate, an intermediate layer provided on the substrate, and a receptor layer provided on the intermediate layer,
The intermediate layer contains an invisible light absorbing material, and is provided with an identification mark including at least one of a concave portion and a convex portion.
10. The printing sheet according to claim 9, wherein the identification mark includes a ridge portion or a concave portion.
A thermal transfer sheet according to any one of claims 1 to 4 having a thermal head and a platen roll, and the printing sheet according to any one of claims 9 to 10, the thermal head and the platen roll The thermal head heats the thermal transfer sheet to transfer the dye, forms an image on the printing sheet, and transfers the protective layer onto the image;
A first detector provided between a supply unit for supplying the thermal transfer sheet and the thermal head to detect a first identification mark provided on the protective layer;
A second detector for detecting a second identification mark provided on the intermediate layer;
A table in which a type of a thermal transfer sheet is associated with a pattern of the first identification mark, and a storage unit storing a table in which a type of a printing sheet is associated with a pattern of the second identification mark;
An identification unit that identifies the type of the thermal transfer sheet from the pattern detected by the first detector with reference to the table, and identifies the type of the printing sheet from the pattern detected by the second detector;
Thermal transfer printing apparatus comprising:
A light source for irradiating the thermal transfer sheet and the printing sheet with invisible light is provided.
The printing sheet is irradiated with invisible light transmitted through the protective layer,
The first detector receives light from the protective layer,
The thermal transfer printing apparatus according to claim 11, wherein the second detector receives the light from the printing sheet transmitted through the protective layer.
The thermal transfer printing apparatus according to claim 12, wherein the protective layer of the thermal transfer sheet contains an ultraviolet light absorbing material, and the intermediate layer of the printing sheet contains a fluorescent brightening agent.