WO2021256236A1

WO2021256236A1 - Thermal transfer printing device, method for manufacturing printed article, and thermal transfer sheet

Info

Publication number: WO2021256236A1
Application number: PCT/JP2021/020797
Authority: WO
Inventors: 良司服部; 悠紀岩崎
Original assignee: 大日本印刷株式会社
Priority date: 2020-06-15
Filing date: 2021-06-01
Publication date: 2021-12-23
Also published as: JP7173413B2; JPWO2021256236A1

Abstract

The present invention prints an image on a transferred body such that a desired region of the image discolors at a desired time. A thermal transfer printing device according to one embodiment comprises: a printing unit that heats a thermal transfer sheet provided with a coloring material layer including a coloring material and a discoloration layer including a discoloring/decoloring compound which discolors the coloring material, that forms an image by transferring the coloring material from the coloring material layer to the transferred body, and that transfers the discoloring/decoloring compound from the discoloration layer to the transferred body; and a control unit that controls the printing unit by determining the thermal energy to apply to the discoloration layer on the basis of a period during which to maintain the image.

Description

Thermal transfer printing device, manufacturing method of printed matter, and thermal transfer sheet

The present disclosure relates to a thermal transfer printing device, a method for manufacturing a printed matter, and a thermal transfer sheet.

In the production of printed matter, it is widely practiced to form a thermal transfer image on a transferred object by using a sublimation type thermal transfer method or a melt type thermal transfer method. For example, in the formation of a thermal transfer image by a sublimation type thermal transfer method, a thermal transfer sheet having a dye layer on one surface of a substrate and a receiving layer, for example, a receiving layer on one surface of another substrate are provided. The image receiving sheet is used. Then, the receiving layer of the image receiving sheet and the dye layer of the thermal transfer sheet are superposed, and heat is applied from the back surface side of the thermal transfer sheet by the thermal head to transfer the dye of the dye layer onto the receiving layer. A printed matter on which a thermal transfer image is formed can be obtained. According to such a sublimation type thermal transfer method, the amount of dye transfer can be controlled by the amount of energy applied to the thermal transfer sheet, so that the image is very clear, and the image is very clear, and the transparency, halftone color reproducibility, and gradation are achieved. It is excellent in producing high-quality prints comparable to full-color photographic images.

With the conventional sublimation type thermal transfer method, the image formed on the image receiving sheet could not be decolorized / discolored at an arbitrary position. For example, Patent Document 1 discloses a method of repeatedly recording and erasing using a leuco dye. However, when the leuco dye was used, the entire image was erased, and it was not possible to erase only the desired region.

Japanese Unexamined Patent Publication No. 5-169841 Japanese Unexamined Patent Publication No. 2020-49441

It is an object of the present disclosure to provide a thermal transfer printing apparatus capable of printing an image on a transfer subject so that a desired region of the image is discolored (decolorized) at a desired time, a method for manufacturing a printed matter, and a thermal transfer sheet. do.

The thermal transfer printing apparatus according to the present disclosure heats a thermal transfer sheet provided with a coloring material layer containing a coloring material and a discoloring layer containing a discoloring and decolorizing compound that discolors the coloring material, and from the coloring material layer to a transferred object. A printing portion that transfers the coloring material to form an image and transfers the discoloring and decolorizing compound from the discoloring layer to the transferred object, and heat applied to the discoloring layer based on a period for maintaining the image. It includes a control unit that determines energy and controls the printing unit.

In the method for producing a printed matter according to the present disclosure, a thermal transfer sheet provided with a coloring material layer containing a coloring material and a discoloring layer containing a discoloring and decolorizing compound that discolors the coloring material is heated and transferred from the coloring material layer. The step of transferring the coloring material to the body to form an image, the step of determining the thermal energy to be applied to the discoloration layer based on the period for maintaining the image, and the step of determining the thermal energy based on the thermal energy. It comprises a step of heating and transferring the decolorizing compound from the discoloring layer to the transferred body.

The thermal transfer sheet according to the present disclosure is provided on one surface of the base material, a color material layer containing a color material provided on one surface of the base material, and the color material layer on one surface of the base material in a surface-sequential manner. , A plurality of discoloring layers containing a discoloring compound that discolors the coloring material and having different contents of the discoloring compound with respect to the total mass.

According to the present disclosure, an image can be printed on a transferred body so that a desired region of the image is discolored (decolorized) at a desired time.

It is a schematic block diagram of the thermal transfer printing apparatus which concerns on embodiment of this disclosure. It is sectional drawing of the thermal transfer sheet. 3a is a plan view of the printed matter immediately after production, FIG. 3b is a sectional view taken along line IIIb-IIIb of FIG. 3a, FIG. 3c is a plan view of the printed matter after the lapse of time, and FIG. 3d is a plan view of the printed matter. It is a cross-sectional view taken along the line IIId-IIId. FIG. 4 is a diagram showing the transitional change of the printed image for each transfer energy of the discoloration layer. 5a and 5b are sectional views of a thermal transfer sheet according to another embodiment. It is a figure which shows the time-dependent change of a print image. 7a is a plan view of the thermal transfer sheet according to another embodiment, and FIG. 7b is a sectional view taken along line VIIb-VIIb of FIG. 7a.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

As shown in FIG. 1, the thermal transfer printing device according to the embodiment includes a printing unit P, a control unit C, and a storage unit M, and the printing unit P has a thermal transfer sheet 100 based on printing data (image data). An image is formed by transferring the coloring material to the transferred body 200 from the above, and the discoloring and decolorizing compound is transferred from the thermal transfer sheet 100 to the formed image in a predetermined pattern to produce a printed matter. The decolorizing compound changes the structure of the coloring material constituting the image with the passage of time, and changes the color. Here, discoloration includes fading and disappearance (decolorization) of color. For example, a white pattern having the above-mentioned predetermined pattern appears in the image formed on the transferred body 200 due to the decolorization of the coloring material by the decolorizing compound.

As shown in FIG. 2, the heat transfer sheet 100 includes a base material 1, a dye layer 2 containing a dye provided on one surface of the base material 1, that is, the upper surface in FIG. 2, and the dye layer 2. It is provided with a discoloration layer 3 provided in a surface-sequential manner and containing a discoloration-decolorizing compound that changes the structure of the dye. The heat transfer sheet 100 may be provided with a heat-meltable ink layer 4 and a transfer layer 5 for transferring a so-called protective layer in a surface-sequential manner with the dye layer 2 and the discoloration layer 3, and may be provided on the other side of the base material 1. The back surface layer 6 may be provided on the surface, that is, on the lower surface in FIG. 2.

In this embodiment, an example in which a dye is used as a coloring material for forming an image and a dye layer 2 is provided as a coloring material layer on the thermal transfer sheet 100 will be described, but instead of the dye layer 2 or a dye layer In addition to 2, a color material layer containing a dye and a pigment, a color material layer containing a pigment, a color material layer containing inorganic particles such as carbon black, and the like may be provided. Further, the order of the panels (dye layer 2, discoloration layer 3, heat-meltable ink layer 4, transfer layer 5) provided on the base material 1 is not limited to that shown in FIG. It suffices if the discoloration layer 3 can be brought into contact with the portion of the image formed by transfer that is desired to be decolorized (discolored).

As shown in FIG. 1, in the printing section P, the thermal transfer sheet 100 is wound around the supply section 13, and the thermal transfer sheet 100 unwound from the supply section 13 passes through the thermal head 11 and is wound around the recovery section 14. It is designed to be collected.

A rotatable platen roll 12 is provided on the opposite side of the thermal head 11 with the thermal transfer sheet 100 interposed therebetween. The transfer paper 100 and the transferred body 200 are sandwiched between the thermal head 11 and the platen roll 12. The transferred body 200 is a thermal transfer image receiving sheet or various card base materials, and a receiving layer capable of receiving a dye is provided on one surface thereof. A known material can be used as the transferred body 200.

The thermal head 11 heats the dye layer 2 of the heat transfer sheet 100 and transfers the dye to the receiving layer of the transferred body 200, whereby the image 20 is formed as shown in FIGS. 3a and 3b. Subsequently, the thermal head 11 heats the discoloration layer 3 of the heat transfer sheet 100 in a predetermined pattern, so that the discoloration / decolorizing compound 30 is transferred onto the image 20. The decolorizing compound 30 transferred from the thermal transfer sheet 100 diffuses in the receiving layer of the transferred body 200.

When the thermal head 11 heats the heat-meltable ink layer 4 of the heat transfer sheet 100 in a predetermined pattern such as characters and symbols, the heat-melted ink layer 4 is transferred onto the transferred body 200, and the characters are transferred to the transferred body 200. And symbols are formed.

The thermal head 11 heats the transfer layer 5 of the thermal transfer sheet 100 and transfers it onto the transferred body 200. As a result, as shown in FIGS. 3a and 3b, a transfer layer (protective layer) 40 that covers the entire image 20 is formed. In this way, the image 20 is formed on the transferred body 200, and the imprint 300 is produced by transferring the discoloring and decolorizing compound 30 on the image 20 in a predetermined pattern.

If the printed matter 300 is left unattended, the color of the image 20 in the portion where the decolorizing compound 30 is transferred gradually disappears and is decolorized. As a result, as shown in FIGS. 3c and 3d, a new white pattern appears in the portion where the decolorizing compound 30 is transferred.

The period required for the decolorizing compound to decompose and decolorize the dye varies depending on the thermal energy applied by the thermal head 11 when transferring the decolorizing compound. The greater the thermal energy applied by the thermal head 11, the greater the amount of the decolorizing compound transferred (transferred) from the thermal transfer sheet 100 to the transferred body 200, and the more the discoloring and decolorizing compound receives the transferred body 200. It diffuses deep into the layer, reducing the time required for decolorization. For example, the thermal energy applied by the thermal head 11 can be adjusted by changing the number of times the discoloration layer 3 is heated and the printing speed (the transfer speed of the heat transfer sheet 100 and the transferred body 200).

In the thermal transfer printing apparatus according to the present embodiment, by utilizing such a property, an instruction of a period until the image is decolorized (decolorization period), in other words, an instruction of a period for maintaining the image is received and instructed. The discoloration layer 3 of the thermal transfer sheet 100 is heated so as to apply thermal energy according to the period of time, and the discoloration-discoloring compound is transferred to the transferred object 200.

As shown in FIG. 1, the storage unit M of the thermal transfer printing apparatus stores a table showing the relationship between the decoloring period and the thermal energy applied to the discoloration layer 3.

The control unit C is a computer having the functions of the input unit 71 and the transfer condition determination unit 72. The input unit 71 receives input of a color erasing period from a user via an input means such as a touch panel, a keyboard, and a mouse. For example, the input of the decoloring period is accepted in the format of "XX days", "XX months", "XX years", and the like. Further, instead of the period, the input of the decoloring date may be accepted, and the control unit C may calculate the period (decoloring period) from the current date and time to the decoloring date.

The transfer condition determination unit 72 refers to the table in the storage unit M, determines the applied energy corresponding to the input decolorization period, and controls the printing unit P. The thermal head 11 heats the discoloration layer 3 so as to apply the heat energy instructed by the control unit C. In order to apply the instructed thermal energy, the applied voltage of the thermal head 11 may be adjusted, or the transport speed of the transferred body 200 (heating time of the discoloration layer 3) may be adjusted. Further, the heating of the discoloration layer 3 may be performed in a plurality of times.

The portion (transfer pattern) for heating the discoloration layer 3 is set in advance.

The storage unit M may store a calculation formula for calculating thermal energy with the decolorization period as a variable instead of the table. In this case, the transfer condition determination unit 72 substitutes the input decolorization period into the calculation formula to calculate the thermal energy.

For example, as shown in FIG. 4, a dye is transferred to a transfer target 200 to form an image, and among the formed images, a discoloring and decolorizing compound is transferred in a pattern that covers images 20A and 20B for printing. Consider the case where the

objects

300A, 300B, and 300C are manufactured. The printed matter 300A sets the thermal energy applied by the thermal head 11 when transferring the decolorizing compound to "large", and the printed matter 300B sets the thermal energy applied by the thermal head 11 when transferring the decolorizing compound. Was set to "medium", and the thermal energy applied by the thermal head 11 when transferring the decolorizing compound was set to "small" in the printed matter 300C.

For example, after 6 months have passed since the

stamps

300A, 300B, and 300C were manufactured, the images 20A and 20B of the prints 300A were discolored and became a white pattern. Images 20A and 20B of the printed

objects

300B and 300C remain.

After another 6 months, the images 20A and 20B of the printed matter 300B are discolored and become a white pattern. Images 20A and 20B of the printed matter 300C remain.

After another 6 months, the images 20A and 20B of the printed matter 300C are discolored and become a white pattern.

In this way, by adjusting the applied energy at the time of transfer of the decolorizing compound, the decoloring period of the image formed on the printed matter can be controlled.

The decoloring period may be input by the user, or the control unit C may calculate and determine the decoloring period based on the print data (image data).

Next, the configuration of the thermal transfer sheet 100 will be described.

(Base material)
The base material 1 of the thermal transfer sheet 100 is not limited in any way, and conventionally known ones in the field of thermal transfer sheets can be appropriately selected and used. As an example, highly heat-resistant polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone or polyether sulfone, polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, polyvinyl chloride, and polyvinyl chloride Examples include stretched or unstretched films of plastics such as vinylidene, polystyrene, polyamide, polyimide, polymethylpentene or ionomer. Further, a composite film in which two or more kinds of these materials are laminated can also be used.

The thickness of the base material 1 is also not particularly limited, but is preferably 0.5 μm or more and 50 μm or less, more preferably 1 μm or more and 20 μm or less, and further preferably 1 μm or more and 10 μm or less.

(Dye layer)
The dye layer 2 is provided on one surface of the base material 1. As shown in FIG. 1, the dye layer 2 may be provided directly on the base material 1, and may be indirectly provided via another layer (not shown) such as various primer layers. May be good. Further, as shown in FIG. 1, the dye layer 2 may be a combination of a plurality of dye layers having different hues, that is, a yellow dye layer 2Y, a magenta dye layer 2M, and a cyan dye layer 2C, and may be a black dye layer. It may be a single dye layer (not shown).

Such a dye layer 2 contains a sublimation dye and a binder.

The sublimation dye is not particularly limited, and can be appropriately selected and used from conventionally known sublimation dyes. Specifically, diarylmethane dyes, triarylmethane dyes, thiazole dyes, merocyanine dyes, pyrazolone dyes, methine dyes, Indiananiline dyes, pyrazolometine dyes, acetophenone azomethine, pyrazoloazomethine, imidazole azomethine, Azomethine dyes such as imidazole azomethine and pyridone azomethine, xanthene dyes, oxazine dyes, cyanostyrene dyes such as dicyanostyrene and tricyanostyrene, thiazine dyes, azine dyes, acridin dyes, benzeneazo dyes, pyridone azo, Azo dyes such as thiophena azo, isothiazole azo, pyrrol azo, pyrazole azo, imidazole azo, thiadiazol azo, triazole azo, disazo, spiropyran dyes, indolinospiropiran dyes, fluorane dyes, rhodamine lactam dyes, naphthoquinone dyes. , Anthraquinone dyes, quinophthalone dyes and the like can be exemplified.

The binder resin is not particularly limited, and conventionally known ones can be used. For example, cellulose resins such as methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, acetate cellulose, butyrate cellulose, polyvinyl acetal such as polyvinyl butyral and polyvinyl acetoacetal, polyvinyl alcohol, polyvinyl acetate, polyvinylpyrrolidone, polyacrylamide and the like. Vinyl resin, polyester, phenoxy resin and the like can be mentioned. Of these, polyvinyl acetal can be preferably used. Only one kind of these binder resins may be used, or two or more kinds thereof may be used.

The dye layer 2 may contain a mold release material. Examples of the release material include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder, fluorine, phosphoric acid ester, and silicone-containing compounds. Of these, silicone-containing compounds are preferred. Examples of the silicone-containing compound include silicone oil and silicone resin.

The thickness of the dye layer 2 is not particularly limited, but is preferably 0.3 μm or more and 1.5 μm or less.

The method for forming the dye layer 2 is also not particularly limited, and a coating liquid for a dye layer is prepared by dispersing or dissolving a sublimation dye, a binder, and various additives added as needed in an appropriate solvent. This can be formed by coating and drying on the base material 1 or a layer arbitrarily provided on the base material 1.

(Thermal meltable ink layer)
The heat-meltable ink layer 4 may be a layer that satisfies the conditions that it is melt-softened by heating and can be transferred onto the transferred body 200, and includes, for example, a heat-meltable ink and a binder resin. The heat-meltable ink can be appropriately selected from known organic or inorganic pigments or dyes. The thickness of the heat-meltable ink layer 4 is not particularly limited, but is preferably in the range of 0.1 μm or more and 30 μm or less.

(Transfer layer)
It is preferable to use a transparent resin material having adhesiveness, light resistance and the like for the transfer layer 5. For example, (meth) acrylic resin, styrene resin, vinyl resin, polyolefin, polyester, polyamide, imide resin, cellulose resin, thermosetting resin, active photocurable resin and the like can be mentioned. The "active light curable resin" means a resin in a state in which the active light curable resin is irradiated with active light and cured. "Activated light" means radiation that chemically acts on an active photocurable resin to promote polymerization, and specifically, visible light, ultraviolet rays, X-rays, electron beams, α rays, and β rays. It means a line, a γ ray, etc.

The thickness of the transfer layer 5 is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less.

(Back layer)
By providing the back surface layer 6 on the other surface of the base material 1 of the thermal transfer sheet 100, heat resistance and running performance of the thermal head at the time of printing can be improved.

The back layer 6 can be formed by appropriately selecting a conventionally known thermoplastic resin or the like. Examples of such a thermoplastic resin include polyester, polyvinyl acid ester, polyvinyl acetate, styrene acrylate, polyurethane, polyethylene, polypropylene and other polyolefins, polystyrene, polyvinyl chloride, polyether, polyamide, polyimide, polyamideimide, and the like. Examples thereof include thermoplastic resins such as polyvinyl acetal such as polycarbonate, polyacrylamide, polyvinyl chloride, polyvinyl butyral, and polyvinyl acetacetal, and modified silicones thereof.

(Discoloration layer)
The discoloration layer 3 contains a discoloration-discoloring compound and a binder resin.

As the decolorizing compound, an acid generating material such as a photoacid generating material or a thermal acid generating material, a chelating material, a plastic material, or titanium oxide can be used.

Titanium oxide used in the present disclosure has a catalytic action on the redox of organic substances by irradiation with light having a specific energy, and in addition to pure titanium oxide, titanium hydroxide-containing, titanium hydrated oxide, and metatitanium metatitanium. Includes what is called acid, orthotitanium acid, titanium hydroxide. Titanium dioxide or one in a lower oxidation state is preferably used. The crystal type of titanium dioxide includes anatase type, rutile type, brookite type and the like, but the titanium oxide used in the present disclosure is preferably anatase type.

The photoacid generator generates acid by decomposition due to light irradiation. The thermoacid generator generates acid by decomposition with heating. The generated acid decolorizes (discolors) the dye.

As the acid generating material, for example, a chemically amplified photoresist or a compound used for photocationic polymerization can be used (organic electronics materials research group ed., "Organic materials for imaging", Bunshin Publishing (1993), See pages 187-192). Examples of compounds suitable for the present disclosure are given below.

First, diazonium, ammonium, iodonium, sulfonium, aromatic onium compounds such as phosphonium _{_{_{^{_{B (C 6 F 5) 4}}}}} -, PF 6 -, AsF 6 -, SbF 6 -, CF 3 SO 3 - and salts be able to. Specific examples of the onium compound are shown below.

Secondly, a sulfonate that generates sulfonic acid can be mentioned, and specific compounds thereof are exemplified below.

Thirdly, a halide that photogenerates hydrogen halide can be mentioned, and specific compounds thereof are illustrated below.

Fourth, an iron allen complex can be mentioned, and specific compounds thereof are illustrated below.

It is preferable that the discolorating compound is contained in the range of 0.1% or more and 80% or less with respect to the material solid content of the discoloring layer 3.

The thickness of the discoloration layer 3 is not particularly limited, but when the discoloration layer 3 is melt-transferred, the thickness is preferably such that the unevenness due to the discoloration layer 3 transferred to the transferred object is not noticeable, for example, 0.1 μm or more. It is preferably 1.5 μm or less. When the binder in the discoloration layer 3 is not transferred and only the discoloration-discoloring compound or the additive is transferred, the thickness of the discoloration layer 3 is preferably 0.1 μm or more and 5 μm or less.

The method for forming the discoloration layer 3 is also not particularly limited, and a discoloration layer coating liquid is prepared by dispersing or dissolving a discoloration-discoloring compound, a binder, and various additives added as needed in an appropriate solvent. Then, this can be formed by applying and drying on the base material 1 or a layer arbitrarily provided on the base material 1.

In the above embodiment, the amount of the decolorizing compound transferred / diffused from the discoloring layer 3 to the transferred body 200 changes depending on the thermal energy applied by the thermal head 11, but the discoloring layer is from the base material 1. It may be removable and melt-transferred together with the layer to the transfer target 200 side by applying energy from the thermal head 11.

When the entire discoloration layer is melt-transferred, the heat transfer sheet is provided with a plurality of discoloration layers having different contents of the discoloration compound (content of the discoloration compound with respect to the total mass of the discoloration layer) to erase the color. The color-changing layer to be transferred to the transfer target 200 is selected according to the color period. The higher the concentration of the decolorizing compound in the discoloring layer transferred to the transferred body 200, the shorter the decoloring period of the image formed on the transferred body 200 (faster decolorization).

For example, as shown in FIGS. 5a and 5b, the discoloration layers 3A and 3B having different contents of the discolorating compound so as to be peelable from the substrate 1 on the substrate 1 of the

thermal transfer sheets

100A and 100B. 3Cs are provided in sequence.

When the area to be decolorized by the transferred body 200 is wide, as shown in FIG. 5a, the panel areas of the

color changing layers

3A, 3B, and 3C are the dye layer 2 (yellow dye layer 2Y, magenta dye layer 2M, and magenta dye layer 2M, respectively). Make it the same as the cyan dye layer 2C).

When the area to be decolorized by the transferred body 200 is narrow, as shown in FIG. 5b, the total panel area of the

color changing layers

3A, 3B, and 3C is the dye layer 2 (yellow dye layer 2Y, magenta dye layer 2M, and). It may be the same as the cyan dye layer 2C).

In the table of the storage unit M of the thermal transfer printing device, the decoloring period corresponding to each of the discoloration layers 3A, 3B, and 3C is defined. The transfer condition determination unit 72 refers to the table, selects a discoloration layer corresponding to the decolorization period input by the user, and controls the thermal head 11. The thermal head 11 heats the discolored layer selected by the transfer condition determining unit 72 among the

discolored layers

3A, 3B, and 3C in a predetermined pattern, and transfers the discolored layer onto the transferred body 200 together with the layers.

As in the printed matter 300D shown in FIG. 6, the image to which the dye is transferred contains the first information J1, and the transfer pattern of the discoloration layer (discoloring and decolorizing compound) erases the image in the region including the first information J1. At the same time, the second information J2 may appear at another position by erasing the image. By giving information (second information J2) to the transfer pattern of the color-changing layer, it is possible to later express information that is not present in the printed matter immediately after production. For example, the image to which the dye is transferred represents the first information, and the areas other than the first information are solid images or patterns. The discoloration layer is transferred (for example, in a rectangular shape) so as to cover the first information, and the discoloration layer is transferred to a position different from the first information in a pattern representing the second information.

As shown in FIGS. 7a and 7b, the discoloration layer 3 may be provided on the transfer layer 5 (protective layer) of the thermal transfer sheet 100C. The color material is transferred from the color material layer (dye layer 2) to the transferred body to form an image, and the color change layer 3 is transferred together with the transfer layer 5 onto the image. The region where the discoloration layer 3 is provided on the transfer layer 5 of the thermal transfer sheet 100C is a position corresponding to a portion of the image to be transferred to be discolored (decolorized). In the image formed on the transferred body, the portion where the discoloration layer 3 transferred together with the transfer layer 5 comes into contact with the image gradually loses its color and is decolorized.

The dye layer 2 and the discoloration layer 3 may be provided on different thermal transfer sheets. In this case, the printing portion of the thermal transfer printing apparatus has a first thermal head that heats a first thermal transfer sheet provided with a dye layer 2 to form an image on a transfer subject, and a second thermal transfer provided with a discoloration layer 3. It is provided with a second thermal head that heats the sheet to transfer the decolorizing compound to the transferred object. When the discoloration layer is melt-transferred layer by layer, the thermal transfer printing device can set a plurality of thermal transfer sheets according to the concentration of the discolorating compound, and is provided with a plurality of thermal heads corresponding to the plurality of thermal transfer sheets. You may.

The printed matter may be produced using an intermediate transfer medium. In this case, the thermal transfer printing apparatus heats the thermal transfer sheet provided with the color material layer to form an image on the transfer layer of the intermediate transfer medium. After image formation, the discoloration layer is transferred onto the intermediate transfer medium, or the discoloration-decoloring compound in the discoloration layer is transferred. Then, the transfer layer of the intermediate transfer medium is transferred to the transfer target. The discoloration layer may be transferred onto the transfer target, and then the transfer layer may be transferred from the intermediate transfer medium onto the transfer target. An image may be formed on the transfer layer after the discoloration layer is transferred to the transfer layer of the intermediate transfer medium or the discoloration-discoloring compound in the discoloration layer is transferred.

The decolorizing compound contained in the discoloring layer generates an acid by heat or light and decolorizes (discolors) the dye. Therefore, it is preferable that a discoloring layer (discoloring / decolorizing compound) is provided on the surface side of the printed matter. For example, when the transferred body 200 provided with the receiving layer is used, it is preferable to transfer the discolored layer (transfer the decolorizing compound in the discolored layer) after forming an image to prepare a printed matter. On the other hand, when an intermediate transfer medium is used, an image is formed after the discoloration layer is transferred to the transfer layer of the intermediate transfer medium (the discoloration-decoloring compound in the discoloration layer is transferred), and then the transfer layer is transferred to the transferred material. It is preferable to transfer to to produce a printed matter.

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

Example (Preparation of discoloration-imparting layer transfer sheet)
On one surface of the base film (polyethylene terephthalate film "5AF56" manufactured by Toray Industries, Inc., thickness 4.5 μm), the coating liquid for heat-resistant slipping layer having the following composition is dried to a thickness of 1 μm. As described above, it was applied by a gravure coating method and dried to form a heat-resistant slippery layer. Further, a coating liquid for a primer layer having the following composition is applied on the surface of the base film opposite to the heat-resistant slipping layer by a gravure coating method so that the thickness after drying is 0.10 μm. Then, it was dried by exposing it to hot air at 110 ° C. for 1 minute to form a primer layer.

A coating liquid for a discoloration-imparting layer having the following composition is applied onto the primer layer by a wire bar coating method so that the thickness after drying is 0.6 μm, and the mixture is dried at 80 ° C. for 1 minute to impart discoloration. A layer (discoloration layer) was formed, and the thermal transfer sheet of the example was prepared.

<Coating liquid for heat-resistant slip layer>
-Polyvinyl butyral (ESREC (registered trademark) BX-1, manufactured by Sekisui Chemical Industry Co., Ltd.): 3.6 parts-Polyisocyanate (Barnock (registered trademark) D750, manufactured by DIC Co., Ltd.): 8.4 parts-Phosphorus Acid ester-based surfactant (Plysurf (registered trademark) A208N, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.): 2.8 parts, Tarku (Microace (registered trademark) P-3, manufactured by Nippon Tarku Kogyo Co., Ltd.) : 0.6 parts ・ Methyl ethyl ketone: 42.3 parts ・ Toluene: 42.3 parts

<Coating liquid for primer layer>
-Alumina sol (alumina sol 200 manufactured by Nissan Chemical Industries, Ltd.): 3 parts-Vinyl acetate-vinylpyrrolidone copolymer (PVP / VA E-335 ISP Japan Co., Ltd.): 7 parts-Water: 100 parts- Isopropyl alcohol: 100 parts

<Discoloration layer>
-Polyvinyl acetal (ESREC (registered trademark) KS-6Z, manufactured by Sekisui Chemical Co., Ltd.): 2 parts-Acid generator (TAZ110, Midori Kagaku): 2 parts-Toluene: 46.65 parts-Methylethylketone: 46.65 Department

(Making imprints)
Prepare the obtained thermal transfer sheet, the following evaluation printer, and a genuine ribbon and image receiving sheet for a sublimation type thermal transfer printer (manufactured by Dai Nippon Printing Co., Ltd., DS620) equipped with a dye layer containing a sublimable dye and a protective layer. did. Black (Bk) printing was performed with the following evaluation printer. The black print was printed by superimposing a yellow dye layer, a magenta dye layer, and a cyan dye layer.

≪Evaluation printer≫
・ Thermal head: F3598 (manufactured by Toshiba Hokuto Electronics Corporation)
-Average resistance value of heating element: 5015 (Ω)
-Main scanning direction printing density: 300 (dpi)
-Printing density in the sub-scanning direction: 300 (dpi)
-Print power: 0.21 (W / watt)
-Applied voltage: 25.5 (V)
-Line cycle: 2 (msec./line)
-Pulse Duty: 85%

Next, the color-changing layer was transferred onto the gradation pattern with the above printer by changing the transfer energy, and then the protective layer was transferred to produce a printed matter. The transfer energy was 0.22 (mJ / dot), 0.165 (mJ / dot), and 0.11 (mJ / dot).

Using an optical densitometer (manufactured by X-Rite, i1Pro2), the image density (OD value) of the printed matter immediately after production and the printed matter after being irradiated with sunlight for 72 hours was measured under the following measurement conditions. The concentration difference was calculated. The results are shown in Table 1 below. Immediately after the printed matter was produced, the density of the region where the discoloration-imparting layer was not transferred (black (Bk) image covered with the protective layer) was measured. After the sunlight irradiation, the density of the region to which the discoloration-imparting layer was transferred (black (Bk) image provided with the discoloration-imparting layer and the protective layer) was measured.

(Measurement condition)
-Density status: Status A
-Measurement lighting conditions: M0 (ISO 13655-2009)

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the intent and scope of the invention.
This application is based on Japanese Patent Application No. 2020-10317 filed on June 15, 2020, which is incorporated by reference in its entirety.

1 Base material 2 Dye layer 3 Discoloration layer 4 Heat-meltable ink layer 5 Transfer layer 6 Back layer 11 Thermal head 20 Image 30 Discoloration / decolorizing compound 40 Transfer layer (protective layer)
71 Input unit 72 Transfer condition determination unit 100 Transfer paper 200 Transfer paper 300 Printed object C Control unit M Storage unit P Printing unit

Claims

An image is obtained by heating a thermal transfer sheet provided with a color material layer containing a color material and a discoloration layer containing a discoloring compound that discolors the color material, and transferring the color material from the color material layer to a transfer target. And a printing portion for transferring the discolorating compound from the discoloring layer to the transferred object,
A control unit that determines the heat energy to be applied to the discoloration layer based on the period for maintaining the image and controls the printing unit.
A thermal transfer printing device equipped with.
A first thermal transfer sheet provided with a color material layer containing a color material is heated, and the color material is transferred from the color material layer to a transfer target to form an image, and the color material is discolored. A printing portion that heats a second thermal transfer sheet provided with a discoloration layer containing a compound and transfers the discoloration-decoloring compound from the discoloration layer to the transfer target.
A control unit that determines the heat energy to be applied to the discoloration layer based on the period for maintaining the image and controls the printing unit.
A thermal transfer printing device equipped with.
Further provided with a storage unit containing a table showing the relationship between the period for maintaining the image and the thermal energy applied to the discoloration layer.
The thermal transfer printing device according to claim 1 or 2, wherein the control unit determines thermal energy with reference to the table.
The control unit adjusts the voltage applied to the thermal head provided in the printing unit, the transport speed of the transferred body, or the heating time of the discolored layer by the thermal head based on the determined thermal energy. The thermal transfer printing apparatus according to any one of claims 1 to 3.
A heat transfer sheet provided with a color material layer containing a color material and a plurality of color change layers having different color changeable compounds in the total mass with respect to the color changeable compound that discolors the color material is heated. Then, the color material is transferred from the color material layer to the transferred body to form an image, and any of the plurality of color changing layers is transferred to the transferred body.
A control unit that selects a color change layer to be transferred to the transfer target from the plurality of color change layers based on the period for maintaining the image, and controls the printing unit.
A thermal transfer printing device equipped with.
The first heat transfer sheet provided with the color material layer containing the color material is heated, and the color material is transferred from the color material layer to the transferred object to form an image, and the color material is discolored. A printing image in which any of a plurality of second transfer papers including a compound and provided with a discoloring layer having different contents of the discoloring compound with respect to the total mass is heated to transfer the discoloring layer to the transferred object. Department and
A control unit that controls the printing unit by selecting a second thermal transfer sheet that transfers the discoloration layer to the transferred body from the plurality of second thermal transfer sheets based on the period for maintaining the image.
A thermal transfer printing device equipped with.
The image forming apparatus according to any one of claims 1 to 6, wherein the coloring material layer contains a dye, a pigment, or inorganic particles.
The thermal transfer printing apparatus according to any one of claims 1 to 7, wherein the decolorizing compound contains an acid generating material, a chelating material, a plastic material, or anatase-type titanium oxide.
The thermal transfer printing apparatus according to any one of claims 1 to 8, further comprising an input unit for receiving an input for a period for maintaining the image.
An image is obtained by heating a heat transfer sheet provided with a color material layer containing a color material and a discoloration layer containing a discoloring compound that discolors the color material, and transferring the color material from the color material layer to a transfer target. And the process of forming
A step of determining the thermal energy applied to the discolored layer based on the period for maintaining the image, and
A step of heating the transfer paper based on the heat energy and transferring the discoloration-decoloring compound from the discoloration layer to the transfer target.
A method for manufacturing a printed matter.
The image contains the first information
The tenth aspect of the present invention, wherein the decolorizing compound is transferred so as to cover the first information, and the decolorizing compound is transferred to a position different from the first information in a pattern representing the second information. Manufacturing method of imprints.
A step of heating a first heat transfer sheet provided with a color material layer containing a color material and transferring the color material from the color material layer to a transferred body to form an image.
A step of determining the thermal energy applied to the discoloration layer of the second thermal transfer sheet provided with the discoloration layer containing the discoloration-discoloring compound that discolors the coloring material based on the period for maintaining the image.
A step of heating the second transfer paper based on the heat energy and transferring the discolorating compound from the discoloring layer to the transferred body.
A method for manufacturing a printed matter.
A thermal transfer sheet provided with a colorant layer containing a colorant and a plurality of color changeable layers having different content of the color changeable compound with respect to the total mass of the color material is heated. Then, the step of transferring the color material from the color material layer to the transferred object to form an image,
A step of selecting a color-changing layer to be transferred to the transferred body from the plurality of color-changing layers based on the period for maintaining the image, and a step of selecting the color-changing layer.
A step of heating the transfer paper and transferring the selected color-changing layer to the transferred body.
A method for manufacturing a printed matter.
A step of heating a first heat transfer sheet provided with a color material layer containing a color material and transferring the color material from the color material layer to a transferred body to form an image.
A plurality of second thermal transfers provided with a discoloring layer containing a discoloring compound that discolors the coloring material and having different contents of the discoloring compound with respect to the total mass based on the period for maintaining the image. A step of selecting a second thermal transfer sheet for transferring the discoloration layer to the transfer object from the sheets, and a step of selecting the second thermal transfer sheet.
The step of heating the selected second transfer paper to transfer the discolored layer to the transferred body, and
A method for manufacturing a printed matter.
With the base material
A color material layer containing a color material provided on one surface of the base material, and
A plurality of compounds which are provided on one surface of the base material in a surface-sequential manner with the colorant layer and contain a discolorant compound that discolors the colorant, and the content of the discolorant compound with respect to the total mass is different from each other. With the discoloration layer,
A thermal transfer sheet.
The thermal transfer sheet according to claim 15, further comprising the color material layer, the plurality of color changing layers, and a transfer layer provided in a surface-sequential manner.
With the base material
A color material layer containing a color material provided on one surface of the base material, and
A protective layer provided on one surface of the base material and
A discoloration layer provided in a predetermined region on the protective layer and containing a discoloration-decolorizing compound that discolors the coloring material, and a discoloration layer.
A thermal transfer sheet.