JP6503838B2 - Printing method - Google Patents

Description

  In the present invention, a thermal transferable color material layer is provided on one side of a substrate sheet, and a thermal transfer is provided on the other side of the substrate sheet such that the first back layer and the second back layer are in contact with each other. The present invention relates to a sheet and a printing method using the thermal transfer sheet.

  Conventionally, a thermal transfer sheet is used in computers, facsimiles, identification photographs, etc., to output characters, figures, face photographs, etc. to a transferee such as plain paper or image receiving paper. Generally, as a thermal transfer sheet, a melt-type thermal transfer sheet in which a transferable wax ink layer is provided on a base film such as a polyester film and a dye type ink layer such as cyan, magenta and yellow on a base film, ie, a sublimation thermal transfer sheet There is.

In the melt-type thermal transfer system, heat is applied to the sheet from the base film side of the melt-type thermal transfer sheet by a thermal head, and the wax ink layer of the heated portion is transferred to the transfer target (melt-type thermal transfer). To transfer (output) characters, figures, etc.
On the other hand, in the sublimation type thermal transfer system, heat is applied to the thermal transfer sheet from the base film side by the thermal head to transfer each dye layer such as cyan, magenta and yellow to the transfer target in proportion to the heat of the thermal head (sublimation type Thermal transfer (transfer), and transfer (output) figures, portraits, etc. by density gradation.

The fusion-type thermal transfer method is suitable for transfer in applications where high contrast is required for binary images of characters and the like because output is performed by area gradation.
On the other hand, the sublimation thermal transfer method is suitable for transferring an image that requires high color reproducibility, such as a face photograph or a landscape photograph, since the sublimation tone thermal transfer method outputs the density gradation of each dye ink such as cyan, magenta and yellow.

  When characters and images are transferred to a transfer target using the above thermal transfer sheet, the characters and image portions of the wax ink layer and the dye layer are transferred to the transfer target, so the wax ink of the used heat transfer sheet after transfer In the layer or the dye layer, the transfer trace from which the character or the image portion has been left remains. When creating confidential documents such as contract documents, patent application documents, know-how documents, etc., since the contents of these confidential documents are recorded as transfer marks on the used thermal transfer sheet, for disposal etc. There was a problem that sufficient attention was required.

  In order to solve the above problems, for example, Patent Document 1 discloses a yellow residual image, a magenta residual image, and a cyan residual image using the used thermal transfer sheet obtained after thermal transfer, and the position of each dye layer of the thermal transfer sheet. Then, there is proposed a method of printing such that when the identification parts for cueing are overlapped, they shift from each other. However, although this method makes it difficult to see the image that you want to keep secret, it does not disappear, so it is insufficient as a countermeasure.

Further, in Patent Document 2, a thermal transfer is performed by providing a black ink layer of thermal transferability on one side of a substrate via a copy prevention layer which is a colored layer for preventing copying without having thermal transferability. A recording medium, wherein the copy protection layer has a different color from the black ink layer, and the color difference between the copy protection layer and the black ink layer when the color is expressed in a specific range (L ^* a ^* b ^* color system) It is disclosed that ΔEab ^* is 3.0 to 30). However, in this recording medium, there is a problem that defects such as coating unevenness of the black ink layer are hardly visible on the copy prevention layer when the black ink layer is coated at the time of manufacture.

  Further, to solve the above-mentioned transfer marks, Patent Document 3 discloses a thermal transfer sheet provided with a heat-meltable black ink layer provided releasably on a substrate, the substrate and the heat-meltable black ink A thermal transfer sheet is described in which the leuco dye and the developer are contained between the layers and on the back of the substrate and also on the substrate. However, in this thermal transfer sheet, the layer (base material) containing the leuco dye and the developer is likely to develop color by heating at the time of production of the thermal transfer sheet, and the coating of the heat melting black ink layer at the time of production There is a problem that film defects are difficult to identify.

  In order to solve the above problems, Patent Document 4 discloses a thermal transfer sheet in which a dye layer and a transferable protective layer are sequentially provided on one side of a substrate and a back layer is provided on the other side of the substrate. In the residual processing method, it is described that the dye and the protective layer are thermally transferred onto the thermal transfer image receiving sheet, and then the thermal transfer sheet is heated to thermally fuse the opposing residual transferable protective layer and the back layer. However, in this thermal transfer sheet, the protective layer on the surface has a heat-sealing function, so there is a risk that the thermal transfer image-receiving sheet may be blocked in a winding manner before the dye and the protective layer are thermally transferred. It is.

JP, 2008-18701, A JP, 2000-289353, A JP, 2013-18259, A JP 2008-49663 A

The present invention has been made in such a situation, and it is a measure to ensure that the trace of the transfer trace can not be read against the problem that the transfer trace of the thermal transfer sheet remains and causes problems, and also the thermal transfer sheet Even if there is a coating defect of the heat transferable color material layer at the time of production, the defect can be easily found out visually and the heat transfer without causing troubles such as blocking before printing with the heat transfer sheet It aims at providing a printing method using a sheet .

The above object is achieved by the present invention described below. That is, according to the present invention, the heat transferable color material layer of at least one color and the protective layer are sequentially formed on one surface of the substrate sheet, and the back surface layer is provided on the other surface of the substrate sheet , The protective layer is formed by sequentially laminating a release layer and a transfer layer from the substrate sheet side, and the release layer is a transfer target using a thermal transfer sheet containing a resin having a glass transition temperature of 0 ° C. to 60 ° C. Forming an image by thermal transfer, thermally transferring the transfer layer of the protective layer so as to at least cover the image, and winding the thermal transfer sheet at a winding unit, the thermal transfer being wound by the winding unit The printing method is characterized in that the sheet is heated to fuse the back layer of the thermal transfer sheet and the surface to which the transfer layer is transferred.

  Further, the printing method is characterized in that the heating for fusing the back layer and the surface to which the transfer layer is transferred is performed by heating with a heat roller or a thermal head from the back layer side of the thermal transfer sheet.

According to the present invention, it is possible to make it impossible to reliably read the trace of the transfer trace of the thermal transfer sheet, and even if there is a coating defect of the thermal transferable color material layer at the time of manufacturing the thermal transfer sheet It became possible to easily find out the coating defect visually by observing through the work surface. Furthermore, it has become possible to prevent the use of a thermal transfer sheet to be used, such as blocking, before it is printed on a thermal transfer image-receiving sheet.

It is a schematic plan view which shows one Embodiment of the thermal transfer sheet of this invention. It is a schematic sectional drawing in XX of the thermal transfer sheet shown in FIG. It is a schematic diagram explaining an example of a printing method of the present invention.

Next, embodiments of the invention will be described in detail.
FIG. 1 shows one embodiment of the thermal transfer sheet of the present invention. In the illustrated thermal transfer sheet 1, the thermally transferable color material layer 3 and the protective layer 4 are provided in a surface sequential manner on one surface of the base sheet 2. That is, the thermal transferable color material layer 3, the protective layer 4, the thermal transferable color material layer 3, the protective layer 4, ..., and the thermal transferable color material layer 3 and the protective layer 4 are repeatedly provided in a surface sequence. In the illustrated thermal transfer sheet, although the thermal transferable color material layer 3 is shown in one color (one unit), the color transfer material layer of yellow, magenta, cyan, and black may be provided surface-sequentially as needed. A full color thermal transfer image can be formed, followed by a protective layer.

  2 is a schematic cross-sectional view taken along line XX of the portion of the protective layer 4 of the thermal transfer sheet 1 shown in FIG. 1, and the release layer 6 and the transfer layer 7 are sequentially formed on one surface of the substrate sheet 2 It laminates | stacks and it is the structure by which the back layer 5 was provided in the other surface of the base material sheet 2. As shown in FIG. In the thermal transfer sheet 1 of the present invention, the release layer 6 contains a resin having a glass transition temperature of 0 ° C. or more and 60 ° C. or less. In FIG. 2, a protective layer 4 composed of a release layer 6 and a transfer layer 7 is shown on one side of the substrate sheet 2. When the thermal transfer sheet 1 is heated, the release layer 6 to the transfer layer are heated. 7 is transferred to a transfer target, and the transfer layer 7 functions as a protective layer.

Hereinafter, each structure of the thermal transfer sheet of the present invention will be described.
(Base sheet)
The base sheet 2 used for the thermal transfer sheet 1 of the present invention may be any base sheet 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 sheet generally has a thickness of about 0.5 to 50 μm, preferably about 1.5 to 10 μm. The base sheet may be subjected to surface treatment in order to improve the adhesion to the layer in contact with the base sheet. As the surface treatment, known resin surface modification techniques such as corona discharge treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, plasma treatment, grafting treatment, etc. should be applied. Can. The surface treatment may be performed only one kind or two or more kinds.

  Among the above-described surface treatments, corona treatment or plasma treatment is preferable in terms of low cost. Also, if necessary, an undercoat layer (primer layer) may be formed on one side or both sides. The above-mentioned primer treatment can be carried out, for example, by applying a primer solution to an unstretched film at the time of film formation of melt extrusion of a plastic film, and then stretching treatment. Moreover, it is also possible to coat and form a primer layer (adhesive layer) between a base material sheet and the back layer mentioned later. The 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 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. be able to.

(Heat transferable color material layer)
The thermal transfer sheet according to the present invention is provided with the thermal transferable color material layer 3 on the surface of the above-mentioned base sheet opposite to the surface on which the back layer is provided. In the thermal transfer sheet of the present invention, when the desired image is mono-color, only the layer of one color appropriately selected as the thermally transferable color material layer may be formed, or the desired image is a full color image. Can be formed by selecting cyan, magenta and yellow (and, if necessary, black) as the heat transferable color material layer.

  When the thermal transfer sheet of the present invention is a sublimation type thermal transfer sheet, a layer containing a sublimation dye as a thermal transferable color material layer, that is, a dye layer is formed, and when a thermal transfer type thermal transfer sheet, A thermally fusible ink layer colored with a pigment or the like is formed as a thermally transferable coloring material layer. Hereinafter, although the case where the thermal transfer sheet according to the present invention is a sublimation type thermal transfer sheet will be described as an example, it may be a heat melting type, and the present invention is not limited to only a sublimation type thermal transfer sheet.

  The sublimation dye to be used for the sublimation dye layer is not particularly limited, and conventionally known dyes can be used. Examples of the sublimable dyes include: diarylmethane dyes; triarylmethane dyes; thiazole dyes; merocyanine dyes; pyrazolone dyes; methine dyes; indoaniline dyes; acetophenone azomethines, pyrazoloazo methines, imidazolazo azomethines Azomethine dyes such as imidazoazo methine and pyridone azomethine; xanthene dyes; oxazine dyes; cyanostyrene dyes such as dicyanostyrene and tricyanostyrene; thiazine dyes; azine dyes; acridine dyes; benzene azo dyes; Azo dyes such as thiophene azo, isothiazole azo, pyrrole azo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo, disazo, etc .; spiropyran dyes; Dyes; fluoran dyes; rhodamine lactam dyes; naphthoquinone dyes; anthraquinone dyes; quinophthalone dyes; and the like, and more specifically, compounds exemplified in JP-A-7-149062. It can be mentioned.

  In the dye layer, the sublimable dye is in an amount of 5 to 90% by weight, preferably 20 to 80% by weight, based on the total solid content of the dye layer. When the amount of the sublimable dye used is less than the above range, the print density may be low, and when it is above the range, the storage stability and the like may be decreased.

  As the binder resin for supporting the dye, one having heat resistance and having a suitable affinity to the dye can be generally 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 may optionally contain additives such as a mold release agent, inorganic fine particles and organic fine particles. As the above-mentioned mold release agent, silicone oil, phosphoric ester, etc. are mentioned. 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 above-mentioned dye layer dissolves or disperses the above-mentioned dye and binder resin in an appropriate organic solvent or water together with an additive to be added if necessary, to prepare a coating solution, and further, a gravure printing method, It can form by apply | coating and drying the said coating liquid on one side of the above-mentioned base material sheet by well-known means, such as the screen printing method and the 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 coating amount of the dye layer, dried 0.2~6.0g / m ² in solid standard, preferably 0.2 to 3.0 g / m ² approximately.

(Protective layer)
The thermal transfer sheet of the present invention has a structure in which a thermal transferable color material layer and a protective layer are provided in a surface-sequential manner on a substrate sheet, and the protective layer 4 has at least a release layer 6 and a transfer layer 7 laminated. .
The release layer 6 may be appropriately selected from those which transfer to a transfer target during thermal transfer, or those which remain on the base sheet side, or those which cause cohesive failure, but the release layer is a base sheet by thermal transfer. It remains on the side so that the interface between the release layer and the transfer layer becomes the surface of the protective layer after the thermal transfer, which is a problem that remains with the transfer trace of the thermal transfer sheet in the present invention. It is preferably carried out because it makes more sure the method of making the trace of the transcription trace unintelligible.

(Release layer)
The release layer 6 enhances the releasability of the transfer layer in the thermal transfer sheet at the time of thermal transfer from the base sheet, and remains on the surface of the thermal transfer sheet used after thermal transfer to take up the thermal transfer sheet. In the vicinity, the thermal transfer sheet is heated to fuse the back layer and the release layer. The release layer contains a resin having a glass transition temperature of 0 ° C. or more and 60 ° C. or less in order to perform the above-described functions such as releasability and fusion property.

  Specifically as a resin whose said glass transition temperature is 0 degreeC or more and 60 degrees C or less, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, a polyester resin etc. can be used. The mass average molecular weight converted to standard polystyrene in these resins is preferably 10,000 to 200,000. When the glass transition temperature of the resin contained in the release layer is higher than 60 ° C., the fusion property with the back layer is unfavorably weakened when processing so as not to read the trace of the transfer mark of the thermal transfer sheet. On the other hand, when the glass transition temperature of the resin contained in the release layer is less than 0 ° C., blocking is apt to occur when stored in the form of a roll of a thermal transfer sheet. In addition, all the glass transition temperature prescribed | regulated by this invention is measured based on JISK7121.

The resin having a glass transition temperature of 0 ° C. or more and 60 ° C. or less is preferably contained at 50% by mass or more, and more preferably 80% by mass or more based on the total solid content of the release layer.
The reason is that it takes into consideration blocking during storage of the thermal transfer sheet in a wound state and adhesion to the back layer when processing is performed so as not to read the trace of the transfer trace of the thermal transfer sheet. All resins and waxes other than resins having a glass transition temperature of 0 ° C. or more and 60 ° C. or less contained in the release layer have a glass transition temperature (softening point or melting point in the case of wax) of less than 0 ° C. If the amount of the resin having a glass transition temperature of 0 ° C. or more and 60 ° C. or less is small, the blocking is likely to occur. On the other hand, when the glass transition temperature of a resin other than the resin having a glass transition temperature of 0 ° C. or more and 60 ° C. or less, the softening point or the melting point of wax exceeds 60 ° C., the glass transition temperature is 0 ° C. If the amount of the resin at 60 ° C. or less is small, the adhesion to the back layer is undesirably reduced.
As described above, it is necessary to increase the content of the resin having a glass transition temperature of 0 ° C. or more and 60 ° C. or less in the release layer, and in the present invention, the above-mentioned definition is reached.

  Although the resin contained in the release layer is mainly composed of a resin having a glass transition temperature of 0 ° C. or more and 60 ° C. or less, a wax may be contained in the release layer. It is also possible to use wax as the main component of the release layer. As the wax, one not having a glass transition temperature but having a melting point of 0 ° C. or more and 60 ° C. or less is preferably used. Specific examples of the wax include natural waxes such as beeswax, spermaceti wax, wood wax, rice bran wax, carnauba wax, candelilla wax, montan wax and the like; paraffin wax, microcrystalline wax, oxidized wax, ozokerite, ceresin, ester wax, Synthetic waxes such as polyethylene wax can be mentioned.

  When the melting point of the wax to be contained in the release layer is higher than 60 ° C., it is not preferable because the fusion property with the back layer is weakened when processing so as not to read the trace of the transfer mark of the thermal transfer sheet. On the other hand, when the melting point of the wax contained in the release layer is less than 0 ° C., blocking is likely to occur when storing in a wound state of the thermal transfer sheet.

The release layer can be adjusted by adding an organic filler such as polyamide, acrylic resin or silicone resin, or an inorganic filler such as silica or talc to adjust the peeling force of the transfer layer from the base sheet.
The method for forming the release layer may be the same as the method described in the above-mentioned dye layer, and the thickness thereof is about 0.5 to 5.0 g / m ² on a dry solid basis.

(Transfer layer)
A transfer layer 7 is formed on the above release layer, and the transfer layer is transferred from the thermal transfer sheet to perform the function of a protective layer. The transfer layer can be formed of various resins conventionally known as resins for forming a protective layer. As the resin for forming a protective layer, for example, as a thermoplastic resin, polyester resin, polystyrene resin, acrylic resin, polyurethane resin, acrylic urethane resin, epoxy resin, phenoxy resin, resin obtained by modifying each of these resins with silicone, these A mixture of each of the above resins, an ionizing radiation curable resin, an ultraviolet blocking resin and the like can be exemplified. In addition to this, an ultraviolet absorber, an organic filler and / or an inorganic filler can be added as appropriate.

  The transfer layer containing the ionizing radiation curable resin is particularly excellent in plasticizer resistance and scratch resistance. As the ionizing radiation curable resin, known ones can be used. For example, a radically polymerizable polymer or oligomer is crosslinked and cured by ionizing radiation irradiation, a photopolymerization initiator is added as necessary, and an electron beam is used. And those polymerized and crosslinked by ultraviolet light can be used.

  An ultraviolet blocking resin and a transfer layer containing an ultraviolet absorber have a main purpose to impart light resistance to printed matter. As the ultraviolet blocking resin, for example, a resin obtained by reacting and bonding a reactive ultraviolet absorber to a thermoplastic resin or the above ionizing radiation curable resin can be used. More specifically, it is possible to add an addition polymerizable two-component to a conventionally known non-reactive organic ultraviolet absorber such as a salicylate type, phenyl acrylate type, benzophenone type, benzotriazole type, coumarin type, triazine type, and nickel chelate type. Examples thereof include those into which reactive groups such as heavy bonds (for example, vinyl group, acryloyl group, methacryloyl group, etc.), alcoholic hydroxyl group, amino group, carboxyl group, epoxy group, and isocyanate group are introduced.

UV absorbers are conventionally known non-reactive organic UV absorbers, and include salicylates, phenyl acrylates, benzophenones, benzotriazoles, coumarins, triazines, and nickel chelates.
The method for forming the transfer layer may be the same as the method described for the dye layer described above using the materials described above, and the thickness thereof is about 3 to 30 g / m ² on a dry solid basis.

(Back layer)
A back layer 5 is provided on the heat transferable color material layer of the base sheet in the heat transfer sheet of the present invention, and the side opposite to the side on which the protective layer is provided.
The back layer is provided on the other surface of the substrate sheet in order to improve heat resistance, travelability of the thermal head at the time of printing, and the like.

  The back layer 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 the aromatic polyisocyanate, 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, 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-described hydroxyl group-containing thermoplastic resin using the hydroxyl group, and improves the coating strength and heat resistance of the back layer.

  Moreover, in addition to the above-mentioned thermoplastic resin, in the back layer, for the purpose of improving slip property, mold release agent such as wax, higher fatty acid amide, phosphoric acid ester compound, metal soap, silicone oil, surfactant, etc., fluorocarbon resin Etc., and various additives such as silica, clay, talc, inorganic particles such as calcium carbonate can be contained. In the present invention, the thermal transfer sheet after the thermal transferable color material layer and the like are transferred is heated to fuse the back layer and the release layer in a wound form, and the transfer trace of the thermal transferable color material layer of the thermal transfer sheet To make it impossible to read the trace of In order to enhance the adhesion by fusion between the back layer and the release layer at this time, it is preferable not to use a release agent in the above-mentioned back layer but to use an additive of organic powder and inorganic particles.

The back layer is, for example, the reverse of the heat transferable color material layer and the protective layer of the substrate sheet, in which a coating liquid obtained by dispersing or dissolving the above-mentioned thermoplastic resin and various additives added as necessary in a suitable solvent is used. 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, and the like on the side surface. The coating amount of the back layer, from the viewpoint of improvement of such as heat resistance, it is preferable that the coating amount after drying is 3 g / m ² or less, and more preferably to 0.1-2 g / m ^2.

(Printing method)
The printing method of the present invention will be described.
FIG. 3 is a schematic view for explaining one example of the printing method of the present invention, and using the thermal transfer sheet 1 of the present invention, a thermal transfer image is formed on the transfer receiving body 10 using the first transfer device 30. Furthermore, the protective layer is thermally transferred to at least cover the thermal transfer image. Thereafter, the thermal transfer sheet 1 is taken up by the take-up unit 41, and the thermal transfer sheet 1 taken up by the take-up unit 41 is heated using the second transfer device 42 inline and separated from the back layer. It is the schematic of the whole apparatus 50 for demonstrating fuse | staining a type | mold layer.

As the thermal transfer sheet 1, the thermally transferable color material layer 3 and the protective layer 4 are formed sequentially on one side of the base sheet 2 as shown in FIG. 1, and the other side of the base sheet 2 is back side The thermal transfer sheet 1 provided with the layer 5 sequentially was used. However, the protective layer 4 has a configuration in which a release layer and a transfer layer are sequentially laminated from the base sheet 2 side.
The apparatus 50 includes a delivery unit 20 for delivering the thermal transfer sheet 1 in a direction indicated by an arrow R1, a first transfer device 30 disposed downstream of the delivery unit 20, and a downstream side of the first transfer device 30. A thermal transfer sheet 1 used by transferring and forming an image and a protective layer by thermal transfer in a direction indicated by an arrow R2, that is, a winding unit for winding the thermal transfer sheet 1 after the thermal transferable color material layer and the protective layer are transferred 41 and a second transfer device 42 for heating the thermal transfer sheet 1 transferred and used and taken up by the take-up unit 41 from the back layer 5 side.

  The thermal transfer sheet 1 is delivered from the delivery unit 20, conveyed along the plurality of guide rolls 21, reaches the first transfer device 30, and transfers a desired pattern onto the transfer target 10 to form a thermal transfer image. The first transfer device 30 includes a platen roll 32 for supporting the transfer target body 10, a first heating body 31 provided to face the platen roll 32 with the thermal transfer sheet 1 and the transfer target body 10 interposed therebetween, for example, a print head ,have. The first heater 31 is provided on the back layer 5 side of the thermal transfer sheet 1. The thermal transferable color material layer 3 of the thermal transfer sheet 1 is heated in a predetermined pattern by the first heating body 31, whereby the color material of the thermal transferable color material layer 3 of the thermal transfer sheet 1 or the color material layer is a base material A transfer target body 10 having a receiving layer 12 provided thereon is transferred in a predetermined pattern, and a thermal transfer image 13 is formed on the receiving layer 12.

Furthermore, in the image receiving surface of the image receiving surface 10 having the thermal transfer image 13 formed in the above-described predetermined pattern, the transfer layer 7 constituting the protective layer of the thermal transfer sheet 1 using the first transfer device 30 It is transferred so as to cover the thermal transfer image 13 and becomes a protective layer.
In FIG. 3, between the first heating member 31 and the platen roll 32 in the first transfer device 30, the transfer target body 10 and the thermal transfer sheet 1 are a transfer layer 7 of a protective layer and a thermal transfer image 13 of the transfer target body 10. An enlarged view is shown showing a state in which the surface (receptive layer 12) having the above is superimposed and heated and pressed. A back layer 5 is provided on the back of the thermal transfer sheet 1, and the back layer 5 and the first heating member 31 are in contact with each other. The back layer side of the thermal transfer sheet 1 is heated in a predetermined pattern from the first heating body 31 to transfer the thermal transfer image 13 of a predetermined pattern to the transfer target body 10. Furthermore, on the thermal transfer image, the transfer layer 7 is heated from the thermal transfer sheet 1 from the first heating member 31 and is solidly transferred so as to cover the thermal transfer image.

  The winding device 40 shown in FIG. 3 is configured of a winding portion 41 for winding the thermal transfer sheet 1 after the thermal transferable color material layer and the transfer layer are transferred, and a second transfer device 42. . In FIG. 3, the second heating member 43 constituting the second transfer device 42 in the winding device 40 is in contact with the back layer 5 of the thermal transfer sheet 1 after the thermal transferable color material layer and the transfer layer are transferred. The state is shown in an enlarged view. The second heating member 43 rotates in the direction indicated by the arrow R3 to heat the heat transferable color material layer in a predetermined pattern and further heat the back layer of the heat transfer sheet 1 after the transfer layer of the protective layer is transferred. . After the thermal transfer image of the predetermined pattern is formed by the first transfer device 30, after the transfer layer of the protective layer is transferred to the transfer target, the thermal transfer sheet 1 is wound by the winding portion 41, and the second heating member 43 is By using the second transfer device 42, the entire surface of the back layer 5, for example, the back layer, of the thermal transfer sheet 1 taken up by the take-up unit 41 is uniformly heated by the second heating unit 43. Then, the release layer 6 on which the transfer layer is transferred and the surface is exposed, and the back layer 5 at a position in contact with the winding are fused by melting of the release layer. As a result, it is possible to make the first transfer device 30 of the thermally transferable color material layer incapable of visually recognizing the trace of the transfer mark by the thermal transfer of the predetermined pattern.

  In the example of the printing method of the present invention shown in FIG. 3, the method (apparatus) in which two heating members are provided is shown, but the first heating member and the second heating member are made common, and one heating member S is You may use. However, in this case, the thermal transfer image is formed on the transfer target using the heating body S, and the transfer layer is transferred onto the thermal transfer image, and the thermal transfer sheet is taken up by the take-up unit 41. It is preferable that S move to heat the thermal transfer sheet from the back layer side. In this case, the heating body S can be set so as to be movable in the conveyance direction of the thermal transfer sheet.

  Although FIG. 3 shows an example of heating the entire surface of the back layer of the thermal transfer sheet in a solid manner with the second heating body, the pattern of heating is not limited to this, and the traces of transfer marks of the thermal transferable color material layer If it is possible to make it unreadable, any pattern can be selected.

(Subject)
As the material to be transferred 10 used in the printing method of the present invention, any conventionally known material to be transferred can be used. For example, natural pulp paper, coated paper, tracing paper, a plastic film which does not deform due to heat at the time of heat transfer, glass, metal, ceramics, wood, cloth, etc. may be used. A conventionally known receiving layer 12 can be provided to easily fix a heat transferable coloring material such as a dye on the substrate.

Hereinafter, the present invention will be more specifically described by way of examples. These descriptions do not limit the present invention. In the following description, “part” or “%” is on a mass basis unless otherwise noted.

Example 1
A composition for heat transferable color material layer, a composition A for release layer, a composition 1 for transfer layer, a composition 2 for transfer layer and a composition for back layer having the following composition were prepared respectively.
(Composition for heat transferable cyan color material layer)
C. I. Solvent Blue 63 3.5 parts · Polyvinyl acetal resin (manufactured by Sekisui Chemical Co., Ltd., trade name Eslek KS-5)
3.5 parts, 46.5 parts of toluene, 46.5 parts of methyl ethyl ketone

(Composition A for Release Layer)
Polyester resin (glass transition temperature 53 ° C., Byron 220) 100 parts Silicone resin filler (average particle diameter 1 μm, Tospearl 120, manufactured by Momentive Performance Materials) 2 parts Methyl ethyl ketone 50 parts Toluene 50 parts

(Composition for Transfer Layer 1)
-Alumina sol (solid content 10%) 50 parts (Alumina sol 200 (feather-like form) manufactured by Nissan Chemical Industries, Ltd.)
Polyvinyl pyrrolidone resin (K-90 ISP) 5 parts Water 25 parts Isopropyl alcohol 20 parts

(Composition for transfer layer 2)
-Acrylic resin (glass transition temperature 105 ° C, Dianal BR 87, manufactured by Mitsubishi Rayon Co., Ltd.) 20 parts-Methyl ethyl ketone 40 parts-Toluene 40 parts

(Composition for back layer)
-Polyvinyl acetal resin (hydroxyl value 12 mass%) 60.6 parts (S-LEC KS-1 Sekisui Chemical Co., Ltd.)
Polyisocyanate (NCO = 17.3% by mass) 4.2 parts (Barnock D750 Dainippon Ink and Chemicals, Inc.)
-Stearyl phosphate zinc 10 parts (LBT 1830 refined, manufactured by Sakai Chemical Industry Co., Ltd.)
-10 parts of zinc stearate (SZ-PF Sakai Chemical Industry Co., Ltd. product)
・ Polyethylene wax 3 parts (Poly wax 3000, made by Toyo Address)
・ Ethoxylated alcohol-modified wax 7 parts (UNITOX 750, manufactured by Toyo Adore Co., Ltd.)
-Talc 1.5 parts (Micro Ace P-3 Nippon Talc Industry Co., Ltd.)
-200 parts of methyl ethyl ketone-100 parts of toluene

A 6 μm thick polyethylene terephthalate was prepared as a substrate sheet.
The prepared composition for the back layer is coated on one side of the substrate sheet with a gravure coater so that the thickness after drying is 2.0 g / m ² , and dried at 100 ° C. A back layer was formed.

Then, the prepared composition for a thermal transferable cyan color material layer is coated on the other surface of the substrate sheet by a gravure coater so that the thickness after drying is 1.0 g / m ² , After drying at 100 ° C., a heat transferable color material layer was formed in the arrangement as shown in FIG.
With the arrangement of the protective layer as shown in FIG. 1 on the surface of the base sheet provided with the above-mentioned heat transferable color material layer, the composition A for the release layer has a thickness after drying of 2.0 g / such that m ^2, was coated by a gravure coater, dried at 100 ° C., to form a release layer. It is coated with a gravure coater so that the thickness after drying the composition 1 for a transfer layer becomes 0.5 g / m ² on the release layer in the same shape as the shape in which the release layer is formed. Then, the transfer layer 1 was formed. Furthermore, on the transfer layer 1, the composition 2 for transfer layer is coated with a gravure coater so that the thickness after drying is 2.0 g / m ² , and dried to form a transfer layer 2. Then, a protective layer was formed under the lamination condition of base sheet / release layer / transfer layer 1 / transfer layer 2 to prepare a thermal transfer sheet as shown in FIGS.

(Example 2)
A thermal transfer sheet was produced in the same manner as in Example 1 except that the release layer coating liquid was changed to the following.
(Composition B for Release Layer)
Polyester resin (glass transition temperature 60 ° C., Byron GK 250) 100 parts Silicone resin filler (average particle size 1 μm, Tospearl 120, manufactured by Momentive Performance Materials) 2 parts Methyl ethyl ketone 50 parts Toluene 50 parts

(Example 3)
A thermal transfer sheet was produced in the same manner as in Example 1 except that the release layer coating liquid was changed to the following.
(Composition for Release Layer C)
Acrylic resin (glass transition temperature 35 ° C., DIALAL BR-79) 100 parts Silicone resin filler (average particle size 1 μm, Tospearl 120, manufactured by Momentive Performance Materials) 2 parts Methyl ethyl ketone 50 parts Toluene 50 Department

(Comparative example 1)
A thermal transfer sheet was produced in the same manner as in Example 1 except that the composition for release layer was changed to the composition D for release layer described below in the thermal transfer sheet prepared in Example 1 above.
(Composition for Release Layer D)
Silicone modified acrylic resin (glass transition temperature 69 ° C., made by Daicel Chemical Industries, Ltd., Celltop 226, solid content 50%) 100 parts silicone resin filler (average particle diameter 1 μm, Tospearl 120, Momentive Performance) Materials company) 2 parts · methyl ethyl ketone 50 parts · toluene 50 parts

(Comparative example 2)
A thermal transfer sheet was produced in the same manner as in Example 1 except that the composition for release layer was changed to the composition for release layer E described below in the thermal transfer sheet prepared in Example 1 above.
(Composition E for Release Layer)
Polyester resin (glass transition temperature 67 ° C., Byron 200) 100 parts Silicone resin filler (average particle diameter 1 μm, Tospearl 120, manufactured by Momentive Performance Materials) 2 parts Methyl ethyl ketone 50 parts Toluene 50 parts

(Comparative example 3)
A thermal transfer sheet was prepared in the same manner as in Example 1 except that the composition for release layer was changed to the composition for release layer F described below in the thermal transfer sheet prepared in Example 1 above.
(Composition for Release Layer F)
Polyester resin (glass transition temperature -15 ° C, Byron 550) 100 parts Silicone resin filler (average particle diameter 1 μm, Tospearl 120, manufactured by Momentive Performance Materials) 2 parts Methyl ethyl ketone 50 parts Toluene 50 parts

  Printing and post-heating were performed using the whole apparatus as shown in FIG. 3 using each thermal transfer sheet of the above-mentioned Example and Comparative Example. However, the thermal transferable color material layer is transferred to the transfer receiving object by the first transfer device, the pattern of the photograph of the face is printed, an image is formed, and the transfer layer of the protective layer is covered to cover the image. Heat transferred to the Thereafter, the thermal transfer sheet after the thermal transferable color material layer and the transfer layer are transferred is heated in a solid state by the second transfer device, and the back layer and the release layer to which the transfer layer is transferred and exposed Was made to fuse.

  However, the transfer target used for printing is a sublimation thermal transfer image-receiving paper for sublimation transfer printer SELPHY CP710 manufactured by Canon Inc.

In the form of a wound thermal transfer sheet prepared in the above example and comparative example and not printed, it is left for 2 days under normal temperature storage, and blocking occurs between the back layer side and the transfer layer side of the thermal transfer sheet The condition was visually observed and evaluated under the following conditions.
(Evaluation of blocking resistance)
○: No blocking was observed, which is good.
Fair: Blocking is observed in part, but can be used without problems.
X: Blocking is recognized and it is inferior.

In the samples subjected to the above printing and post-heating using the respective thermal transfer sheets prepared in the above Examples and Comparative Examples, the adhesion between the back layer side and the release layer side was visually observed, and It evaluated on condition of.
(Evaluation of fusion bonding by post-heating)
○: The above-mentioned fusion is observed and it is good. That is, it is possible to make the trace of the transfer trace of the heat transferable color material layer of the heat transfer sheet unreadable.
X: The above-mentioned fusion is not recognized and it is defective. That is, the trace of the transfer trace of the thermal transferable color material layer of the thermal transfer sheet can be read.

The above evaluation results are as follows.

The thermal transfer sheet of the above-described embodiment was capable of performing thermal transfer to ensure that the trace of the transfer mark after image formation can not be read. Furthermore, even if there is a coating defect of the thermal transferable color material layer at the time of production of the thermal transfer sheet, the thermal transfer sheet in the examples visually observes the coating defect by transmitting through the coated surface. It was easy to find out at Furthermore, in the thermal transfer sheet of the example, there was no problem in use such as blocking in a winding form before printing on the thermal transfer image receiving sheet.
On the other hand, in the thermal transfer sheets of Comparative Examples 1 and 2, in the release layer in the protective layer, the glass transition temperature of the resin contained in the release layer is higher than 60 ° C., and the melt of the back layer side and the release layer side The adhesion is low, the back layer side and the release layer side are not adhered, the trace of the transfer trace of the thermal transferable color material layer of the thermal transfer sheet can be read, and the information leaks. was there.

  In the thermal transfer sheet of Comparative Example 3, the glass transition temperature of the resin contained in the release layer in the protective layer was lower than 0 ° C., and blocking occurred when the thermal transfer sheet was wound and stored. In Comparative Example 3, as described above, blocking occurs during storage, and the above-described printing and post-heating can not be performed to evaluate the adhesion between the back layer side and the release layer side. The

DESCRIPTION OF SYMBOLS 1 heat transfer sheet 2 base material sheet 3 heat transferable color material layer 4 protective layer 5 back layer 6 release layer 7 transfer layer 10 transfer body 10 base material 12 receiving layer 13 heat transfer image 20 delivery part 21 guide roll 30 1st transfer apparatus 31 first heating body 32 platen roll 40 winding device 41 winding portion 42 second transfer device 43 second heating body 50 overall device

Claims (2)

A heat transferable color material layer of at least one color and a protective layer are sequentially formed on one side of a base sheet, and a back layer is provided on the other side of the base sheet , and the protective layer is a base. A release layer and a transfer layer are sequentially laminated from the sheet side, and the release layer forms an image on a transferred object by thermal transfer using a thermal transfer sheet containing a resin having a glass transition temperature of 0 ° C. to 60 ° C. After the transfer layer of the protective layer is thermally transferred to at least cover the image, the heat transfer sheet is taken up by a take-up unit, and the heat transfer sheet taken up by the take-up unit is heated; A printing method comprising fusing the back layer of the thermal transfer sheet and the surface to which the transfer layer has been transferred. 2. The printing according to claim 1 , wherein the heat for fusing the back layer and the surface to which the transfer layer is transferred is heated from the back layer side of the thermal transfer sheet by a heat roller or a thermal head. How .

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