JP4090545B2 - Thermal transfer image forming method - Google Patents

Description

【００５４】
上記の結果の通り、実施例及び参考実施例の熱転写画像形成方法ではフルカラー印画物情報により画像形成して、最大濃度が１．４５〜１．８０と高めであり、またハイライト部のインキ発色感度が良好である。但し、実施例１では、染料層の１画面を構成する各区画の塗布量が、印画始めの区画より後の区画にかけて、漸次減少していて、参考実施例１、２は染料層の１画面を構成する各区画の塗布量が同一であるが、実施例１が最も画像濃度が高かった。それに対し、比較例１の熱転写画像形成方法ではモノカラー印画物情報により、画像形成して、最大濃度が１．２０と低めである。また比較例２の熱転写画像形成方法ではフルカラー印画物情報ではあるが、熱転写シートがモノカラーの染料層ではなく、Ｙ、Ｍ、Ｃの染料層を用いたので、ハイライト部のインキ発色感度が良くない。
【００５５】
【発明の効果】
したがって、本発明の熱転写画像形成方法は、基材上に１画面の画像を形成することに当たり、３つの区画を有し、かつ該区画が、全て同一色相である染料層を設けた熱転写シートと、熱転写受像シートを重ねて組み合わせて熱転写して、モノカラーの熱転写画像形成物を作成するための画像形成方法において、見本画像をＲＧＢの各フィルターで、色変換して三原色ＲＧＢの色信号を得て、該信号データを印刷色ＹＭＣのデータに変換した互いに異なる情報を用いて、該情報と各区画の染料層を、Ｙのデータは第１番目の区画の染料層から、Ｍのデータは第２番目の区画の染料層から、そしてＣのデータは第３番目の区画の染料層から、１対１に対応させて、画像形成するもので、かつ前記３つの区画の染料層の塗布量が異なり、該各区画の染料層の塗布量が、印画始めの区画より後の区画にかけて、漸次減少していることにより、印画部の階調色差や色ムラを防止し、印画部のシャドウ部からハイライト部の濃度再現性に優れたモノカラー画像形成物が得られる。
【図面の簡単な説明】
【図１】本発明の熱転写画像形成方法の１つの実施形態を示すフローチャートである。
【図２】本発明の熱転写シートの１つの実施形態を示す平面図である。
【図３】本発明の熱転写シートの他の実施形態を示す平面図である。
【図４】本発明の熱転写シートの参考の実施形態を示す平面図である。
【図５】従来の熱転写シートの例を示す平面図である。
【図６】従来の熱転写シートの例を示す平面図である。
【符号の説明】
１、１’、１” 染料層（モノカラー）
２ 転写性保護層
３ 検知マーク
４ 余白[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermal transfer image forming method, and in particular, a thermal transfer sheet having a monocolor dye layer and a thermal transfer image receiving sheet are combined and thermally transferred, and the resulting image formed product has high transfer sensitivity and is free from gradation color differences and color unevenness. The present invention relates to a thermal transfer image forming method in which generation is prevented.
[0002]
[Prior art]
Conventionally, various thermal transfer recording methods are known. Among them, sublimation dyes can be dyed with sublimation dyes from a thermal transfer sheet using a sublimation transfer dye as a recording agent and supported on a substrate sheet such as a polyester film. There have been proposed methods for forming various full-color images by thermally transferring a sublimation transfer dye onto a thermal transfer image-receiving sheet having a dye-receiving layer formed on a material to be transferred, such as paper or plastic film.
In this case, a thermal head of the printer is used as the heating means, and the color dots in which a large number of heating amounts of three colors or four colors are adjusted by heating for a very short time are transferred to the receiving layer of the thermal transfer image receiving sheet, The full color of the original is reproduced by the multicolored dots.
Since the image formed in this manner is a dye used as a coloring material, it is very clear and excellent in transparency. Similar to images by offset printing or gravure printing, it is possible to form high-quality images comparable to mono-color or full-color photographic images.
[0003]
Utilizing high-quality images by sublimation transfer recording has started to be used as proofreading materials for various printing such as gravure printing, offset printing, and screen printing. In order to match the hue of images and the like with a main printed product, a conventional printed material for proofreading has been printed with proofing ink in the same manner as the main printing and the printing conditions, and dried and laboriously produced.
However, according to the above sublimation transfer recording method, there is no need for a printing plate or proofing ink, and if there is an original image of the image to be printed, the image is converted into an electrical signal, and the thermal transfer sheet and the thermal transfer image receiving sheet are converted. In combination, printing with a thermal transfer printer makes it easy to obtain a printed material for calibration.
In addition to the above-mentioned proofreading printed matter, sublimation transfer printed matter is used as an alternative to full-print products such as gravure printing and offset printing, and for amusement applications such as amusement parks and game centers, It has been practiced to produce monochromatic image objects such as sepia hues and monochromatic image objects as substituting for funeral photographs and the like by sublimation transfer recording.
[0004]
[Problems to be solved by the invention]
The printed matter obtained by the above-described sublimation transfer recording method is required to strictly match the resolution and the hue of the print portion with the sample product. That is, a printed matter of sublimation transfer recording that can be regarded as the same in the finished state as the sample product is required.
In other words, for mono-color images, there is no need to create a color difference in shades of shade from the shadow portion of the print area to the highlight area, and high-precision density reproducibility is also required from the shadow area of the print area to the highlight area. Has been.
[0005]
In a conventional monocolor print, a monochromatic thermal transfer sheet such as Bk single color or sepia single color as shown in FIG. 5 or a three-color thermal transfer sheet or Bk dye layer having a YMC dye layer as shown in FIG. A four-color thermal transfer sheet to which is added, and a thermal transfer sheet having a configuration in which a protective layer is further added are used. However, a monochromatic thermal transfer sheet such as Bk monochromatic or sepia monochromatic causes a decrease in the maximum print density, and a thermal transfer sheet such as YMC tends to cause problems such as gradation color difference and color unevenness. Furthermore, in the monocolor thermal transfer sheet, when the highlight transfer sensitivity is increased, the tone density changes and tone color difference also occurs in the tone portions other than the highlight portion as compared with the sample.
[0006]
JP-B-6-71827, JP-B-4-75832 and JP-A-4-226790 describe recording methods for improving the density of transferred images and improving dot reproducibility. This is a method to transfer the same image as the image or partially overlapped image, and it can improve the density of the shadow part of the printing part, but highlights from the shadow part of the printing part for mono-colored images. There is a problem that a color difference is likely to occur in the light and shade hues of the portion, that is, a gradation color difference and color unevenness occur.
Therefore, the present invention solves the above-mentioned problems of the prior art and prevents gradation color differences and color unevenness in the printed part when creating a monocolor thermal transfer image formed product, and from the shadow part of the printed part to the highlighted part. An object of the present invention is to provide a thermal transfer image forming method having excellent density reproducibility.
[0007]
[Means for Solving the Problems]
  That is, the thermal transfer image forming method of the present invention has three sections, and a thermal transfer sheet provided with a dye layer all having the same hue when forming a one-screen image on a substrate, In an image forming method for creating a monocolor thermal transfer image formed by superimposing and transferring thermal transfer image receiving sheets, a sample image is color-converted with RGB filters to obtain three primary color RGB color signals. , Using the different information obtained by converting the signal data into print color YMC data, the information and the dye layer of each section, the Y data from the dye section of the first section, and the M data the second The data of C from the dye layer of the third section and the data of C from the third section of the dye layer are imaged in a one-to-one correspondence, and the coating amount of the dye layer of the three sections is different.Thus, the amount of the dye layer applied in each section gradually decreases from the section at the beginning of printing to the section after the first section.It is characterized by that.
[0008]
[Action]
  In the present invention, when forming an image of one screen on a substrate, the image has three sections, and the sectionsBut,In an image forming method for creating a monochromatic thermal transfer image formed by superimposing a thermal transfer sheet provided with a dye layer of the same hue and a thermal transfer image receiving sheet in combination, a sample image is converted into each RGB filter. Then, color conversion is performed to obtain color signals of the three primary colors RGB, and the signal data is converted into print color YMC data.FirstFrom the compartment dye layer, the data for M isSecondFrom the compartment dye layer, and the data for C3rdAn image is formed in a one-to-one correspondence from the dye layer in the section, and the application amount of the dye layer in the three sections is different, so that gradation color differences and color unevenness in the printed portion are prevented, and printing is performed. A monocolor image formed with excellent density reproducibility from the shadow portion to the highlight portion can be obtained. In addition, the above-mentioned same hue dye layer can be applied in a smaller amount than a normal mono color film, that is, since the dye for three screens is transferred to the shadow portion, a sufficient print density can be maintained, and a higher print density can be obtained. The light portion can easily transfer the dye even with low transfer energy, and as a result, a printed matter with rich gradation expression from the highlight portion to the shadow portion can be obtained.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the invention will be described in detail below in the thermal transfer image forming method of the present invention.
(Thermal transfer image forming method) In the thermal transfer image forming method of the present invention, a single-screen image is formed on a base material, and a dye layer having three sections and all having the same hue is provided. The thermal transfer sheet and thermal transfer image-receiving sheet are combined and heat-transferred to create a monocolor thermal transfer image formation. The sample image is color-converted with each RGB filter and the color signals of the three primary colors RGB are generated. Using the different information obtained by converting the signal data into the data of the printing color YMC, the information and the dye layer of each section are obtained, the Y data is from the dye layer of the first section, and the M data is From the dye layer of the second section, and the data of C is imaged in a one-to-one correspondence from the dye layer of the third section, and the coating amount of the dye layer of the three sections Is differentThus, the amount of the dye layer applied in each section gradually decreases from the section at the beginning of printing to the section after the first section.It is characterized by that.
[0010]
  As a preferred example, as shown in FIG. 1, first, a sample image (a sample of a transferred image) is color-separated by RGB filters to obtain color signals of three primary colors RGB, and the signal data is printed. Color YMC data (information) is converted, Y data isFirstThe data of M is transferred from the dye layer of the section to the thermal transfer image-receiving sheet.SecondTransferred from the dye layer of the compartment to the thermal transfer image-receiving sheet, and the C data is3rdIt is transferred from the dye layer in the compartment to the thermal transfer image-receiving sheet to obtain a monocolor image formed product. Incidentally, if necessary after heat transfer of YMC, that is, when improving the weather resistance of the image and the durability against fingerprints or chemicals, the transferable protective layer can be thermally transferred onto the image-formed receiving layer.
[0011]
In the thermal transfer image forming method of the present invention, the dye layer preferably has two or more sections per screen, and the coating amount of the sections is different. That is, for example, in the case where the dye layer has a three-compartment structure for printing information color-separated by the RGB / YMC filters of the image, for example, the coating amount of the dye layer in the compartment corresponding to Y is about 1 μm. As a result, by reducing the coating amount, M is about 0.8 .mu.m and C is about 0.6 .mu.m, a printed matter with a high density gray hue that prevents gradation color differences and color unevenness can be obtained.
In this case, for example, Y dye, M dye and C dye are mixed and added to the dye layer having a gray hue as a monocolor, and particularly Y dye has a transfer sensitivity higher than that of M dye and C dye. If it is high and easy to transfer even at relatively low temperatures, the ratio of the dye constituent corresponding to Y is less than the ratio of the dye constituent corresponding to M and C, and the dye transfer sensitivity in the section corresponding to Y is increased. To balance with other dyes.
Therefore, as described above, when dyes having different hues are mixed in the monocolor dye layer and the transfer sensitivity of the dye is different, the component ratio of each dye in the dye layer is changed.
[0012]
The thermal transfer image forming method of the present invention is to produce a monocolor thermal transfer image formed product, and specific examples of the monocolor hue include sepia, green, purple, and gray.
In addition, as a means for applying heat energy at the time of thermal transfer image formation, any conventionally known heat applying means can be used. For example, a recording time such as a thermal printer (for example, a video printer VY-100 manufactured by Hitachi, Ltd.) can be used. 5 to 100 mJ / mm by controlling²By applying a certain degree of thermal energy, the intended purpose can be sufficiently achieved.
[0013]
(Thermal transfer sheet)
The image forming method of the present invention is one in which a thermal transfer sheet and a thermal transfer image receiving sheet are stacked and combined to perform thermal transfer. The thermal transfer sheet will be described here.
The thermal transfer sheet has two or more sections per screen on a base material, and the hue of the sections is monochromatic, and a dye layer having the same hue is provided.
For example, as shown in FIG. 2, three sections of the dye layer 1, 1 ′, 1 ″ are provided per screen on the substrate, the hue of the sections is monocolor, and all have the same hue. The dye layers 1, 1 ′, 1 ″ are repeatedly applied in the surface order.
[0014]
  FIG. 3 is a plan view showing another embodiment of the thermal transfer sheet of the present invention, in which three layers of dye layers 1, 1 ′, 1 ″ are provided per screen on a substrate, and the sections have the same hue. The color is monochromatic, and a detection mark 3 is provided at the head of the dye layer 1. The dye layers 1, 1 ', 1 "are repeatedly applied in the surface order. FIG. 4 shows the thermal transfer sheet of the present invention.referenceFIG. 2 is a plan view showing an embodiment of the present invention, wherein two dye layers 1, 1 ′ per screen are provided on a base material, and a transferable protective layer 2 is provided on the same base material. 1, 1 ′ and the transferable protective layer 2 are repeatedly applied in the surface order, and the dye layers 1, 1 ′ and the transferable protective layer 2 are spaced from each other by a margin 4 having a certain width. The detection marks 3 are provided at the heads of the dye layers 1 and 1 ′.
[0015]
Further, although not shown, a transferable receiving layer and a transferable adhesive layer can be provided on the same substrate having a dye layer. This is not necessary if the image-receiving sheet on which the image is to be formed is preliminarily formed with a receiving layer. However, when the substrate of the image-receiving sheet is plain paper, the transferable receiving layer can be thermally transferred to produce a thermal transfer image-receiving sheet. it can.
When the transferable receiving layer is used, the transferable adhesive layer is preferably used as an intermediate layer between the substrate of the image receiving sheet and the receiving layer. That is, after transferring only the transferable adhesive layer to the substrate of the image-receiving sheet, the image-receiving receptor layer is transferred onto the image-receiving sheet, and the transferable adhesive layer is transferred onto the image-formed receptor layer. Thereafter, there are cases where the image is transferred to the base material of the image receiving sheet together with the receiving layer (retransfer type or intermediate transfer medium type).
[0016]
The above-mentioned transferable protective layer, transferable receiving layer, and transferable adhesive layer may be provided on the same substrate having a dye layer or on a substrate different from the substrate having the dye layer. Good. However, it is preferable to provide each layer on the same substrate because the transport system of the thermal transfer printer is simple. In addition, when it is provided on a substrate different from the substrate having the dye layer, the thermal transfer sheet is replaced and installed in the printer, or a plurality of thermal heads are provided to transfer the dye layer, and other than the dye layer It is also possible to separately provide a thermal head for transferring the transferable protective layer and the transferable receiving layer, and to provide a separate transfer supply system for the thermal transfer sheet.
[0017]
(Base material)
The heat transfer sheet base material may be any material as long as it has a conventionally known degree of heat resistance and strength, for example, a paper having a thickness of about 0.5 to 50 μm, preferably about 3 to 10 μm, and various processing. Examples thereof include paper, polyester film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, and the like, and polyester film is particularly preferable.
The base material as described above is preferably subjected to primer treatment or corona discharge treatment on one or both surfaces of the base material as necessary. By this treatment, it is possible to improve the adhesion to the layer provided on the base material or to prevent the base material itself from being charged, thereby adding a function.
[0018]
(Dye layer)
The thermal transfer sheet of the present invention is provided with a dye layer on a substrate, the dye layer has two or more sections per screen, and the hues of the sections are monocolor, all having the same hue. It is characterized by.
The dye layer 1, 1 ', 1 "of the thermal transfer sheet is a gravure printing method, a screen printing method, etc. by adding a dye, a binder resin and other optional components in an appropriate solvent and dissolving or dispersing each component. The forming means is applied onto the substrate and dried to form.
[0019]
As the dye to be used, any dye used in a conventionally known thermal transfer sheet can be effectively used in the present invention, and is not particularly limited. For example, some preferred dyes include red dyes such as MS Red G, Macrolex Red Bioreet R, Ceres Red 7B, Samaron Red HBSL, and Resolin Red F3BS, and yellow dyes include hollon brilliant yellow. S-6GL, PTY-52, Macrolex Yellow 6G, and the like. Examples of blue dyes include Kayaset Blue 714, Waxoline Blue AP-FW, Holon Brilliant Blue S-R, MS Blue 100, and the like. .
When dyes having different hues are mixed in the same dye layer, it is necessary to select the dye so that the hue of the dye to be sublimated does not change depending on the energy at the time of printing. That is, when dyes having different hues are mixed in the same dye layer, it is necessary to use a dye having the same variation in the amount of sublimation due to temperature change.
[0020]
As the binder resin for supporting the heat transfer dye as described above, any conventionally known resin can be used, and preferable examples thereof include ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, acetic acid. Examples thereof include cellulose resins such as cellulose and cellulose acetate butyrate, vinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, and polyacrylamide, and polyesters.
[0021]
In addition, in order to improve releasability from the receiving layer at the time of printing, a polysiloxane segment or a fluorocarbon segment graft-bonded to the main chain of an acrylic, vinyl, polyester, polyurethane, polyamide or cellulose resin And a graft copolymer having at least one releasable segment selected from long-chain alkyl segments may be used as a binder resin for supporting a heat transferable dye. In the thermal transfer sheet of the present invention, the dye layer preferably has a three-compartment structure for printing information color-separated by the RGB / YMC filters of the image.
That is, the dye layer color-separates the image (which is a sample of the image to be transferred) with each RGB filter to obtain the color signals of the three primary colors RGB, and the signal data is converted to the print color YMC data. , Y data is transferred from the dye layer in the section corresponding to Y to the thermal transfer image-receiving sheet, M data is transferred from the dye layer in the section corresponding to M to the thermal transfer image-receiving sheet, and C data corresponds to C It is transferred to the thermal transfer image receiving sheet from the dye layer in the compartment.
[0022]
The coating thickness of the dye layer is 0.2 μm to 5 μm, preferably 0.4 μm to 2 μm in a dry state.
In the thermal transfer sheet of the present invention, the dye layer preferably has two or more sections per screen, and the coating amount of the sections is preferably different. For example, the dye layer has RGB / YMC of the image. In the case of a three-compartment structure that prints the information color-divided by each filter, the coating amount of the dye layer in the section corresponding to Y is about 1 μm, the coating amount of the dye layer corresponding to M and C is 0.8 μm, By setting the thickness to about 0.6 μm, it is possible to obtain a printed matter having a high-density gray hue and preventing gradation color differences and color unevenness in the print portion.
[0023]
In this case, for example, Y dye, M dye and C dye are mixed and added to the dye layer having a gray hue as a monocolor, and particularly Y dye has a transfer sensitivity higher than that of M dye and C dye. High and easy to transfer even at relatively low temperatures, so the dye component sensitivity corresponding to Y is less than the dye component component corresponding to M and C, and the dye transfer sensitivity in the section corresponding to Y To balance with others.
Therefore, as described above, when the dyes having different hues are mixed in the monochromatic dye layer and the transfer sensitivities of the dyes are different, the component ratio of each dye is changed.
[0024]
(Transferable protective layer)
In the thermal transfer sheet of the present invention, the dye layer and the transferable protective layer 2 can be provided on the same substrate. The transferable protective layer 2 is transferred onto the image-receiving layer to improve the weather resistance of the image and the durability against fingerprints and chemicals.
The transferable protective layer 2 is composed of at least a binder resin, has a suitable peelability from the base material, and after being transferred onto the receiving layer, selects a resin composition having the desired physical properties as the surface protective layer of the receiving layer To do. In general, cellulose derivatives such as ethyl cellulose, nitrocellulose, and cellulose acetate, acrylic resins such as polymethyl methacrylate, ethyl polymethacrylate, butyl polyacrylate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral Thermosetting resins such as vinyl polymer thermoplastic resins such as unsaturated polyester resins, polyurethane resins, and amino alkyd resins can be used as the transferable protective layer.
[0025]
In the case where friction resistance, chemical resistance, and contamination resistance are particularly required for an image-formed printed matter, an ionizing radiation curable resin can be used as the transferable protective layer resin. In order to further improve the scratch resistance, a lubricant, a surfactant for preventing contamination, an ultraviolet absorber for improving weather resistance, an antioxidant, and the like may be added to the resin.
The transferable protective layer is a bar coater, a gravure printing method, a screen printing method, or the like, which is obtained by appropriately adding an additive to the binder resin on the substrate and dissolving or dispersing the ink in a solvent such as water or an organic solvent. Can be formed by coating by a known method. The coating amount is preferably 0.1 to 20 μm after coating and drying.
[0026]
(Transferable receptor layer)
Moreover, the thermal transfer sheet of this invention can provide the dye layer and the transferable receiving layer 3 on the same base material. The transferable receiving layer 3 is composed of at least a binder resin, and various additives such as a release agent may be added as necessary. As the binder resin, it is preferable to use a resin that is easily dyed with a sublimable dye. Specifically, polyolefin resins such as polypropylene, halogenated resins such as polyvinyl chloride and polyvinylidene chloride, vinyl resins such as polyvinyl acetate and polyacrylic ester, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, Examples thereof include polystyrene resins, polyamide resins, copolymers of olefins such as ethylene and propylene, and other vinyl monomers, ionomers, and cellulose derivatives. Among these, vinyl resins and polyester resins are particularly preferably used.
[0027]
Furthermore, in order to prevent the transferable receiving layer from being thermally fused with the dye layer during printing, it is preferable to add a release agent to the binder resin. As the release agent, silicone oils, phosphate ester surfactants, fluorine compounds and the like can be used, and among these, those obtained by adding modified silicone oil and curing are particularly preferable. The amount of the releasing agent added is preferably 0.2 to 30 parts by weight with respect to 100 parts by weight of the binder resin forming the transferable receiving layer.
The transferable receiving layer is a bar coater or gravure printing method in which a necessary additive such as a release agent is added to the binder resin on the base material, and an ink dissolved or dispersed in a solvent such as water or an organic solvent is used. It can be formed by coating by a known method such as a screen printing method or a reverse roll coating method using a gravure plate. The coating amount is preferably about 0.1 to 10 μm after coating and drying.
[0028]
(Transferable adhesive layer)
In the thermal transfer sheet of the present invention, a dye layer, a transferable receiving layer, and a transferable adhesive layer can be provided on the same substrate.
For the transferable adhesive layer, a material having good adhesion to the base material of the image receiving sheet such as plain paper is used. Although it is necessary to select an appropriate material according to the base material, generally, a thermoplastic resin, a natural resin, rubber, wax or the like can be used. For example, cellulose derivatives such as ethyl cellulose and cellulose acetate butyrate, polystyrene copolymers such as polystyrene and poly α-methylstyrene, acrylic resins such as polymethyl methacrylate, polyethyl methacrylate, and polyethyl acrylate, polyvinyl chloride, polyvinyl acetate , Vinyl resins such as vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyester resin, nylon resin, epoxy resin, polyurethane resin, ionomer, ethylene acrylic acid copolymer, ethylene acrylic acid ester copolymer, and other synthetic resins And rosin as tackifier, rosin modified maleic resin, ester rubber, polyisobutylene rubber, butyl rubber, styrene butadiene rubber, butadiene acrylonitrile rubber, polyamide resin, polychlorinated olefin And the like. The transferable adhesive layer can be composed of a composition comprising one or more of the above materials.
The thickness of the transferable adhesive layer is determined so as to improve the adhesion performance with the transfer target, but is usually preferably 0.1 to 20 μm when dried. In order to control the peeling performance of the transferable adhesive layer from the substrate, a release layer may be provided between the substrate and the transferable adhesive layer, although not particularly illustrated.
[0029]
(Detection mark)
In the thermal transfer sheet of the present invention, a detection mark 3 indicating the start position of thermal transfer image formation as shown in FIGS.
The shape and color of the detection mark 3 need only be detectable by a detector (sensor), and are not limited. In terms of shape, a single-line stripe as shown in FIG. 3 or a mixture of single-line and double-line stripes as shown in FIG. 4 or a square at a partial position that does not cover the full width of the thermal transfer sheet. , Round shape and the like. However, since the detection mark 3 indicates the start position of the thermal transfer image formation, the detection mark 3 is formed for each length corresponding to one section, that is, a dye layer or a transfer property provided in a surface sequential manner. The detection mark 3 is formed at the head position of all of the protective layer, the transferable receiving layer, and the transferable adhesive layer, or the detection mark is formed only in the first section of the frame sequential unit or only in a certain layer. can do.
[0030]
The color of the detection mark only needs to be detectable by a detector. For example, in the case of a light transmission type detector, silver, black, or the like having high concealability may be used. Moreover, if it is a light reflection type detector, the color tone of a metallic luster etc. with high reflectivity is mentioned. However, when using a light-reflective detector, if the detection mark is covered with a color material layer, the reflection characteristics of the detection mark surface will be impaired. It is necessary that the detection marks are present on the outermost surface of the thermal transfer sheet.
The detection mark can be formed by a known printing method such as gravure printing or offset printing, or by hot stamping with a vapor transfer film transfer foil, or by sticking a colored film or adhesive film with adhesive on the back. There is no particular limitation.
[0031]
(Back layer)
The thermal transfer sheet of the present invention can be provided with a back layer on the back surface of the substrate. The back surface layer provided on the back surface of the base material is provided for the purpose of preventing thermal fusion between a heating device such as a thermal head and the base material and smooth running. Examples of the resin used for the back layer include cellulose resins such as ethyl cellulose, hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, nitrocellulose, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, Vinyl resins such as polyvinyl pyrrolidone, acrylic resins such as polymethyl methacrylate, polyethyl acrylate, polyacrylamide, acrylonitrile-styrene copolymers, polyamide resins, polyvinyl toluene resins, coumarone indene resins, polyester resins, polyurethanes A simple substance or a mixture of natural or synthetic resins such as resin, silicone-modified or fluorine-modified urethane is used. In order to further increase the heat resistance of the back layer, among the above resins, a resin having a hydroxyl group functional group may be used, and a polyisocyanate or the like may be used as a crosslinking agent to form a crosslinked resin layer. preferable.
[0032]
Further, in order to impart slidability with the thermal head, a solid or liquid release agent or lubricant may be added to the back layer to provide heat-resistant lubricity. Examples of release agents or lubricants include various waxes such as polyethylene wax and paraffin wax, higher fatty acid alcohols, organopolysiloxanes, anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Agents, fluorine surfactants, organic carboxylic acids and derivatives thereof, fluorine resins, silicone resins, fine particles of inorganic compounds such as talc and silica can be used. The amount of lubricant contained in the back layer is about 5 to 50% by weight, preferably about 10 to 30% by weight.
The thickness of such a back layer can be about 0.1 to 10 μm, preferably about 0.5 to 5 μm.
[0033]
(Image receiving sheet)
The image receiving sheet used for forming an image using the above thermal transfer sheet may be any one as long as the image receiving surface has dye acceptability with respect to the above-mentioned dye, and dye acceptability. In the case of paper, metal, glass, synthetic resin or the like that does not have a dye, a dye receiving layer may be formed on at least one surface thereof.
Examples of the transfer target that does not need to form the dye-receiving layer include polyolefin resins such as polypropylene, halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, vinyl polymers such as polyvinyl acetate and polyacrylic esters, Polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, copolymers of olefins such as ethylene and propylene and other vinyl monomers, cellulose resins such as ionomers and cellulose diacetates, polycarbonate And the like, fibers, woven fabrics, films, sheets, molded products, and the like.
Particularly preferable is a sheet or film made of polyvinyl chloride, which may have a single-layer or multi-layer laminate structure.
[0034]
In the present invention, the above-mentioned dyeable resin solution or dispersion is applied to the recording surface of the paper, metal, glass or other non-dyeable transfer material and dried, or the resin is used. By laminating the film, an image receiving sheet can be obtained.
Further, the dye receiving layer may be formed as described above from a resin having better dyeability even on the surface of the transfer target having the dyeability.
The dye-receiving layer thus formed may be formed from a single material or a plurality of materials, and various additives may be included within a range not impeding the purpose of the present invention. Is natural.
[0035]
In order to form the receiving layer, the above-described resin and various additives are dissolved or dispersed in an appropriate solvent to prepare a receiving layer forming ink, and this is applied to the surface of the recording material. For example, it can be formed by applying and drying by a forming means such as a gravure printing method, a screen printing method, or a reverse coating method using a gravure plate.
The above image-receiving sheet is a case where a receiving layer is formed in advance, and it is possible to form the transferable receiving layer by thermal transfer onto a base sheet of an image-receiving sheet such as plain paper. Since it explained, it abbreviate | omits here.
[0036]
【Example】
ExamplesReference examplesThe present invention will be described in detail with reference to comparative examples. In the text, “part” or “%” is based on weight unless otherwise specified.
(Example 1) As a base material, as shown in FIG. 2, a 6 μm-thick polyethylene terephthalate having a heat-resistant treatment on the back surface is provided with dye layers 1, 1 ′, 1 ″ using a Miyabar with the following composition: Thus, the thermal transfer sheet used in Example 1 was prepared, and the dye layer 1 was coated with a dye layer coating liquid A having the following composition, and the coating amount was 0.8 g / m when dried.²The dye layer 1 ′ was prepared using a dye layer coating solution B having the following composition, and the coating amount was 0.6 g / m when dried.², Dye layer 1 "was coated with a dye layer coating solution C having the following composition and the coating amount was 0.4 g / m when dried.²It is.
[0037]
Dye layer coating solution A
1.00 parts of yellow disperse dye
(C.I. Disperse Yellow 201)
Magenta disperse dye 2.20 parts
(C.I. Disper Thread 60)
Cyan disperse dye 5.00 parts
(CI Solvent Blue 63: Nippon Kayaku Co., Ltd.)
Polyvinyl butyral (ESREC BL-3: manufactured by Sekisui Chemical Co., Ltd.) 6.00 parts
Toluene 35 parts
Methyl ethyl ketone 35 parts
[0038]
Dye layer coating solution B
1.00 parts of yellow disperse dye
(C.I. Disperse Yellow 201)
Magenta disperse dye 2.20 parts
(C.I. Disper Thread 60)
Cyan disperse dye 5.00 parts
(CI Solvent Blue 63: Nippon Kayaku Co., Ltd.)
Polyvinyl butyral (ESREC BL-3: manufactured by Sekisui Chemical Co., Ltd.) 6.00 parts
42.9 parts of toluene
Methyl ethyl ketone 42.9 parts
[0039]
Dye layer coating solution C
1.00 parts of yellow disperse dye
(C.I. Disperse Yellow 201)
Magenta disperse dye 2.20 parts
(C.I. Disper Thread 60)
Cyan disperse dye 5.00 parts
(CI Solvent Blue 63: Nippon Kayaku Co., Ltd.)
Polyvinyl butyral (ESREC BL-3: manufactured by Sekisui Chemical Co., Ltd.) 6.00 parts
50 parts of toluene
50 parts of methyl ethyl ketone
[0040]
The above thermal transfer sheet was combined with a thermal transfer image receiving sheet under the following conditions, and an evaluation image (tone image) was formed using a commercially available thermal transfer printer. The applied information at the time of image formation is full color print information, that is, information formed by converting the color signals of the three primary colors RGB obtained by color separation of the image into data of the print color YMC.
Thermal transfer image receiving sheet
A reverse coating method using a gravure plate on one surface of synthetic paper (Oji Oil Chemical Co., Ltd. Yupo FPG150) as a base material, a receiving layer coating solution having the following composition was applied at a dry coating amount of 4.5 g / m² Was applied and dried to prepare a thermal transfer image-receiving sheet.
[0041]
Receiving layer coating solution
Polyester resin (Viron600: Toyobo Co., Ltd.) 4.0 parts
Vinyl chloride / vinyl acetate copolymer resin 6.0 parts
(# 1000A: Electrochemical Industry Co., Ltd.)
Amino-modified silicone oil 0.2 parts
(X-22-3050C: Shin-Etsu Chemical Co., Ltd.)
0.2 parts of epoxy-modified silicone oil
(X-22-3000E: Shin-Etsu Chemical Co., Ltd.)
Methyl ethyl ketone 44.8 parts
44.8 parts of toluene
[0042]
  (Reference Example 1) On the same base material used in Example 1, as shown in FIG. 3, the dye layers 1, 1 ′, 1 ″ are provided using a Miya bar, and the detection mark 3 having the following composition is formed on the dye layer 1. At the top,Reference Example 1The thermal transfer sheet used in was prepared. In addition, all the coating liquids of the dye layers 1, 1 ′, 1 ″ are the same as those used in the dye layer coating liquid C of Example 1, and the coating amounts are all when the dye layers 1, 1 ′, 1 ″ are dry. 0.4 g / m²It is.
Detection mark coating solution
  Carbon black 8.0 parts
  Urethane resin (HMS-20: Nippon Polyurethane Co., Ltd.) 15.0 parts
  Methyl ethyl ketone 38.5 parts
  Toluene 38.5 parts
[0043]
  More thanReference Example 1The thermal transfer sheet was combined with the same thermal transfer image-receiving sheet as used in Example 1, and an evaluation image (tone image) was formed using a commercially available thermal transfer printer. The applied information at the time of image formation is full color print information, that is, information is formed by converting the color signals of the three primary colors RGB obtained by color separation of the image into data of the print color YMC.
[0044]
(Reference Example 2) On the same base material used in Example 1, as shown in FIG. 3, using a Miya bar, dye layers 1, 1 ', 1 "are provided, andReference Example 1The detection mark 3 is provided by the detection mark coating liquid used inReference Example 2The thermal transfer sheet used in was prepared. The dye layer 1, 1 ', 1 "coating solution is the same as the dye layer coating solution A of Example 1, and the coating amount is 0.8 g / m when all are dried.²It is.
[0045]
  More thanReference Example 2The thermal transfer sheet was combined with the same thermal transfer image-receiving sheet as used in Example 1, and an evaluation image (tone image) was formed using a commercially available thermal transfer printer. However, the application information at the time of image formation was image formation based on full color printed material information, that is, information obtained by converting the color signals of the three primary colors RGB obtained by color separation of the image into data of the print color YMC.
[0046]
(Comparative Example 1) On the same base material used in Example 1, as shown in FIG.Reference Example 1The detection mark 3 was provided by the detection mark coating solution used in Step 1, and a thermal transfer sheet used in Comparative Example 1 was prepared. In addition, the coating liquid of the dye layer 1 uses the same thing as the dye layer coating liquid C of said Example, and the application quantity is 0.4 g / m at the time of drying.²It is.
[0047]
The thermal transfer sheet of Comparative Example 1 described above was combined with the same thermal transfer image-receiving sheet as used in Example 1, and an evaluation image (tone image) was formed using a commercially available thermal transfer printer. However, the application information at the time of image formation is monocolor printed matter information, that is, information on gray scales obtained by color-converting the image into a single color, and the same information is superimposed three times to form an image.
[0048]
(Comparative Example 2)
On the same base material used in Example 1, as shown in FIG. 6, dye layers Y, M, and C were provided using a Miya bar, and a thermal transfer sheet used in Comparative Example 2 was prepared. The coating liquid for the dye layers Y, M, and C has the following composition, and the coating amount is 0.5 g / m for all of Y, M, and C when dried.²It is.
Coating liquid for dye layer Y
Yellow disperse dye 2.61 parts
(CI Disperse Yellow 6G: Bayer Co., Ltd.)
20 parts of polyvinyl butyral (ESREC BX-1: Sekisui Chemical Co., Ltd.)
30 parts of toluene
30 parts of methyl ethyl ketone
[0049]
Coating solution for dye layer M
Magenta disperse dye (KC-27: Konica Corporation) 1.77 parts
20 parts of polyvinyl butyral (ESREC BX-1: Sekisui Chemical Co., Ltd.)
30 parts of toluene
30 parts of methyl ethyl ketone
[0050]
Coating liquid for dye layer C
Cyan disperse dye 3.31 parts
(CI Solvent Blue 63: Nippon Kayaku Co., Ltd.)
20 parts of polyvinyl butyral (ESREC BX-1: Sekisui Chemical Co., Ltd.)
30 parts of toluene
30 parts of methyl ethyl ketone
[0051]
The thermal transfer sheet of Comparative Example 2 described above was combined with the same thermal transfer image-receiving sheet as used in Example 1, and an evaluation image (tone image) was formed using a commercially available thermal transfer printer. However, the application information at the time of image formation was image formation based on full color printed material information, that is, information obtained by converting the color signals of the three primary colors RGB obtained by color separation of the image into data of the print color YMC.
[0052]
  Example aboveReference examplesIn addition, the maximum density and the ink color development sensitivity of the highlight portion were examined for the image formed products prepared in Comparative Examples. The evaluation method is as follows.
(Maximum density) The density of the maximum density part of each image-formed product was measured with a densitometer RD-918 manufactured by Macbeth, USA.
(Color development sensitivity) The ink color development sensitivity of the highlight portion of each image formed product was visually evaluated. The evaluation criteria are as follows.
○: The density and gradation reproducibility of the highlight portion are excellent.
(Triangle | delta): The density and gradation reproducibility of a highlight part are substantially favorable.
X: The density and gradation reproducibility of the highlight portion are not good.
[0053]
  The above results are shown in Table 1 below.
[Table 1]

[0054]
  As above results, the exampleAnd reference examplesIn this thermal transfer image forming method, an image is formed by full-color print product information, the maximum density is as high as 1.45 to 1.80, and the ink coloring sensitivity in the highlight portion is good. However, in Example 1, the coating amount of each section constituting one screen of the dye layer gradually decreased from the section at the start of printing to the section after the section,Reference Examples 1 and 2In Example 1, the coating amount of each section constituting one screen of the dye layer was the same, but Example 1 had the highest image density. On the other hand, in the thermal transfer image forming method of Comparative Example 1, an image is formed based on monochromatic print information, and the maximum density is as low as 1.20. Further, in the thermal transfer image forming method of Comparative Example 2, although it is full-color print product information, since the thermal transfer sheet uses Y, M, and C dye layers instead of a monocolor dye layer, the ink coloring sensitivity in the highlight portion is high. Not good.
[0055]
【The invention's effect】
  Accordingly, the thermal transfer image forming method according to the present invention includes a thermal transfer sheet having three sections and provided with a dye layer all having the same hue when forming an image of one screen on a substrate. In the image forming method for creating a monocolor thermal transfer image formed by superimposing the thermal transfer image-receiving sheets in combination, the sample image is color-converted by RGB filters to obtain the RGB color signals of the three primary colors Then, using the different information obtained by converting the signal data into the data of the printing color YMC, the information and the dye layer of each section are obtained, the Y data is from the dye layer of the first section, and the M data is the first data. From the dye layer of the second section, and the data of C is imaged in a one-to-one correspondence from the dye layer of the third section, and the coating amount of the dye layer of the three sections is DifferentTheThe application amount of the dye layer in each section gradually decreases from the first section to the section after the start of printing, thereby preventing gradation color differences and color unevenness in the print section, and from the shadow section of the print section to the highlight section. A monocolor image formed with excellent density reproducibility is obtained.
[Brief description of the drawings]
FIG. 1 is a flowchart showing one embodiment of a thermal transfer image forming method of the present invention.
FIG. 2 is a plan view showing one embodiment of the thermal transfer sheet of the present invention.
FIG. 3 is a plan view showing another embodiment of the thermal transfer sheet of the present invention.
FIG. 4 shows the thermal transfer sheet of the present invention.referenceIt is a top view which shows this embodiment.
FIG. 5 is a plan view showing an example of a conventional thermal transfer sheet.
FIG. 6 is a plan view showing an example of a conventional thermal transfer sheet.
[Explanation of symbols]
1, 1 ', 1 "dye layer (monocolor)
2 Transferable protective layer
3 Detection mark
4 margins

Claims (1)

When forming an image of one screen on the base material, the thermal transfer sheet having three sections and having the dye layer all having the same hue and the thermal transfer image receiving sheet are combined and heat-transferred. Then, in the image forming method for creating a monocolor thermal transfer image formed product, the sample image is color-converted by RGB filters to obtain color signals of the three primary colors RGB, and the signal data is the data of the print color YMC. Using the different information converted into, the information and the dye layer of each compartment, Y data from the first compartment dye layer, M data from the second compartment dye layer, and C from the data dye layer of the third compartment, so as to correspond to one-to-one, by way of image forming, and Ri the Do coating amount of the dye layer of the three compartments is different, the coating of the dye layer of the respective compartment The amount is after the first plot Toward image, the thermal transfer image forming method comprising that you have gradually decreased.

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