JPS6365029B2 - - Google Patents

Description

[Detailed description of the invention]

In the present invention, a heat-melt transfer ink layer colored yellow, a heat-melt transfer ink layer colored magenta, and a heat-melt transfer ink layer colored cyan are heated in an arbitrary image shape on the same recording paper. The present invention relates to a color thermal transfer recording medium used in a recording system that forms a multicolor print image on the recording paper by melt transfer and subtractive color mixing using each of the ink layers of each color and two or more of the ink layers. As shown in Japanese Unexamined Patent Publication No. 56-98190, this type of recording system and a color thermal transfer recording medium used therein are already known. This type of conventional color thermal transfer recording medium not only can record a much larger amount of information better than conventional monochromatic recording, but is also extremely advantageous in recording colored images on hard surfaces. . In response to the demand for such color thermal transfer recording media, and a necessary condition for color thermal transfer recording, in the case of direct thermal melt transfer to recording paper,
The above-mentioned Japanese Patent Laid-Open No. 56-98190 discloses a method that allows thermal melt transfer to be performed in almost the same way as when an ink layer is thermally transferred again onto the ink layer that has been heat melt transferred to recording paper. This is the color thermal transfer recording medium shown. However, in conventional color thermal transfer recording media based on such prior art techniques, subtractive color mixing does not occur well, and therefore color images often cannot be reproduced with faithful colors. The present invention has been completed as a result of research into the causes of the defects, and the causes of the defects will now be explained. In the first place, in hot-melt transfer recording media, the heat during transfer melts and softens the ink layer, which is solid at room temperature, increasing its adhesion to the recording paper, and conversely decreasing its adhesion to the base material, causing the ink layer to melt and soften. An image is formed on the recording paper by the transfer of an ink layer from the material onto the recording paper, and the ink layer is extremely thin with a thickness of several μm. Therefore, it was expected that when heat-melt transfer was performed on top of an ink layer that had already been transferred onto recording paper, both ink layers would melt together and fuse with each other, resulting in mixing, although not completely. . It was thought that subtractive color mixing occurred when inks were mixed together like paint. On the other hand, the basic function of thermal transfer recording media is to form a printed image by transferring onto recording paper.Therefore, in conventional thermal transfer recording media, the color quality of the recording paper itself To minimize the effects of dirt, etc. on
It was thought that it was better to make the ink layer opaque. The inventors of the present invention repeated various experiments based on this understanding, but were unable to produce good subtractive color mixture. Therefore, as a result of detailed analysis of the state of the overlapped portions of ink layers with poor subtractive color mixing, it was found that the ink layers were overlapped in a layered manner and were hardly mixed with each other. In addition, there is a relationship between the overlapping state of the ink layers and the physical properties of the ink.
In the case of inks with a penetration of 10,000 cP (measured at a temperature 30°C higher than the melting point) and a penetration of 0.1 to 50, both inks exist layered on top of each other; Most were not mixed with each other. It has also become clear that depending on the printing conditions, paint-like mixtures may occur to a large extent. Based on these findings, the present inventors broke away from the conventional perception that it is better for the ink layer of a thermal transfer recording medium to be opaque, and completed the present invention. That is, the present invention is capable of forming a hot melt transfer ink layer colored yellow, a hot melt transfer ink layer colored magenta, and a hot melt transfer ink layer colored cyan on the same recording paper in an arbitrary image form. Used in a recording system that forms a multicolor print image on the recording paper by thermal melt transfer and subtractive color mixing formed by each of the ink layers of each color and by layering two or more of the ink layers. A recording medium for color thermal transfer, wherein the thermal melt transfer ink arranged in a layer on one side of the base material has a melting point of 50 to 50.
The temperature is within the range of 150℃, the viscosity is within the range of 20 to 10000cP (measured at a temperature 30℃ higher than the melting point), and the penetration is within the range of 0.1 to 50. The present invention provides a color thermal transfer recording medium characterized in that it is a transparent ink colored in a predetermined color by a transparent colorant that is colored transparently when mixed in a vehicle. However, even if the ink layers having the above-mentioned physical properties are transferred by thermal melt transfer and overlapped with each other in a layered manner, the ink layer is a transparent colored ink layer. , the color of the lower ink layer is also visible through the upper ink layer, and the colors of both inks are visually mixed without mixing of the inks. In the past, subtractive color mixing did not occur sufficiently and only the color of the ink layer on top became stronger.In order to eliminate this, the color density of the ink layer that should be on top was diluted. When the ink layer was directly transferred onto the recording paper, there was a problem that the color density was insufficient. According to the present invention, printing conditions (temperature, printing pressure, printing speed, etc.) such that both ink layers microscopically exhibit a paint-like mixed state when transferring ink layers of different colors in a superimposed manner are provided. Even if these ink layers are transparent, there is an advantage that ideal subtractive color mixing is still ensured. Hereinafter, the recording medium of the present invention will be explained using the drawings. FIG. 1 is a schematic plan view showing an embodiment of the color thermal transfer recording medium of the present invention, and FIG.
3 is a schematic plan view showing another embodiment of the recording medium of the present invention, and FIGS. 4 a to 4 c are schematic explanatory diagrams showing a color image creation method using the recording medium of the present invention, respectively. It is. As shown in FIGS. 1 and 2, the recording medium 10 of the present invention has a thermal transfer ink layer (hereinafter referred to as a thermal transfer ink layer) of each color of yellow, magenta, and cyan continuously disposed on a substrate 8 along its length. or, as shown in FIG. 3, in addition to these heat-sensitive transfer ink layers 9Y, 9M, and 9C, a black heat-sensitive transfer ink layer 9B is arranged. Similarly, they are continuously arranged and formed on the base material 8. These heat-sensitive transfer ink layers are formed of repeating units A containing yellow, magenta, and cyan, optionally black, and each heat-sensitive transfer ink layer has a length substantially equal to the recording paper such as plain paper on which it is recorded. It is formed by FIGS. 4a-4c schematically illustrate a method of creating a color image using the recording medium shown in FIGS. 1-2. As shown in FIG. 4a, the yellow heat-sensitive transferable ink layer 9Y in the recording medium 10 of the present invention is first stacked on the recording paper 7 so as to face each other across the entire width of the recording paper 7. 10
A predetermined image is fused and transferred onto the recording paper 7 in accordance with the yellow signal Y by the thermal head 2 which moves from one end of the recording paper 7 to the other along the yellow signal Y. When the thermal head 20 moves from one end of the recording paper 7 to the other, the thermal head 20 is returned to its original position, and at the same time, the recording medium 10 is also moved in the same direction as the thermal head 20 to print the next magenta. The heat-sensitive transfer ink layer 9M is placed opposite to the same portion of the recording paper 7, and the printing operation as shown in FIG. 4a is repeated again in accordance with the magenta signal M. Similarly, the cyan heat-sensitive transfer ink layer 9C is placed opposite the recording paper 7, and the printing operation is repeated according to the cyan signal C. Therefore, the recording paper 7 corresponding to the width of the recording medium 10
When color printing is completed at the location, the recording paper 7 is moved by a length corresponding to the width of the recording medium 10 in a direction perpendicular to the moving direction of the recording medium 10, and the same operation as described above is repeated again. In this way, a color image is created on the recording paper 7 sequentially from the edge along its width direction or length direction, and the same color image as the original color original is reproduced on the recording paper 7. Therefore, in the recording medium 10 of the present invention, each image of yellow, magenta, and cyan, and if necessary, black, is sequentially formed on one sheet of recording paper 7 in sections from one end of the recording paper 7 to the other. , a desired color image is created by overlapping within these sections, and it provides a recording medium that can be used for so-called field sequential color printing. Further, the recording medium in the present invention usually has a width of 3 to 35 mm.
Since it is extremely compact (mm) and the thermal head used is also small, it has the excellent advantage that the printer itself can be made compact and can be manufactured at low cost. Thermal transferable ink layers 9Y, 9 in the present invention
M and 9C each contain transparent colorants of yellow, magenta, and cyan (hereinafter referred to as transparent colorants), and are a single layer consisting of a binder agent and a softener. Transparent colorants that form yellow include, for example, zinc yellow zinc chromate (zinc yellow),
Lemon Yellow (Barium Chromate), Naphthol Yellow S, Hansa Yellow 5G, Hansa Yellow
3G, Hansa Yellow G, Hansa Yellow GR, Hansa Yellow A, Hansa Yellow RN, Hansa Yellow R,
One or more pigments such as benzidine yellow, benzidine yellow G, benzidine yellow GR, permanent yellow NCG, and quinoline yellow lake, and dyes such as auramine are used. In addition, as a transparent colorant that forms magenta,
For example, permanent red 4R, brilliant fast scarlet, brilliant carmine.
One or more types of pigments such as BS, Permanent Carmine FB, Resole Red, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, and dyes such as Rhodamine are used. . Furthermore, as a transparent colorant that forms cyan,
For example, one or more of pigments such as Victoria Blue Lake, metal-free phthalocyanine blue, phthalocyanine blue, and fast sky blue, and dyes such as Victoria Blue are used. Here, when the pigments forming yellow, magenta and cyan are dispersed in a vehicle (binder, softener, etc.),
A transparent pigment. Each transparent colorant may be used in an amount of 1 to 20 parts (by weight, hereinafter the same), more preferably 5 to 15 parts, based on the total amount of the heat-sensitive transferable ink layer. When the content of the transparent colorant exceeds the above range, transparency decreases and color reproduction becomes difficult, and when it falls below the above range, coloring power decreases, both of which are undesirable. Further, the black heat-sensitive transferable ink layer 9B
contains a coloring agent such as carbon black or nigrosine base, and is used when it is difficult to reproduce a clear black color by overlapping three colors of yellow, magenta and cyan. The heat-sensitive transferable ink layer of the present invention contains a colorant, a binder agent, and a softener in proportions of 1 to 20 parts, 20 to 80 parts, and 3 to 25 parts, respectively, based on 100 parts of the total amount of the ink layer. The ink layer has a thickness of 1 to 10 microns and is formed by hot melt coating or solvent coating the composition on the base material 8. As a binder agent, the penetration is 10 to 30 (25℃)
It is preferable to use a solid wax such as carnauba wax, microcrystalline wax, wood wax, beeswax, ceresin wax, spermaceti wax, etc. to improve the heat sensitivity of the resulting ink layer. However, if necessary, low molecular weight polyethylene, oxidized wax,
An easily meltable substance such as ester wax may be used in combination. Suitable softeners include easily heat-meltable substances such as petroleum resins, polyvinyl acetate, polystyrene, styrene-butadiene copolymers, cellulose esters, cellulose ethers, and acrylic resins, or lubricating oils. used for. Furthermore, in the present invention, a powdery thermally conductive substance and/or extender pigment may be blended in order to impart good thermal conductivity and melt transferability to the thermally transferable ink layer. Examples of powdered thermally conductive substances include aluminum, copper, tin, and zinc, whose thermal conductivity is 6.0×.
10 ^-4 to 25.0×10 ^-4 cal/sec・cm・℃ is preferably used. As extender pigments, relatively highly transparent ones such as colloidal silica, magnesium carbonate, calcium carbonate, clay, kaolin, calcium silicate, Aerosil, and white carbon are preferably used. These thermally conductive substances and extender pigments are used in amounts of 0 to 30 parts and 0 to 10 parts, respectively, per 100 parts of the total ink layer.
It is blended in the ratio of 1 part. The heat-sensitive transferable ink layer obtained in this way has a melting point of 50 to 50 to improve its melt transferability (including melt transferability onto recording paper and melt transferability onto an ink layer already transferred on recording paper).
It is preferable that the ink layer has a viscosity of 20 to 10,000 cP at 150°C (measured at a temperature 30°C higher than the melting point), and since the ink layer is soft, it becomes easily stained, so it is preferable that the ink layer is hard. Penetration (JIS K
2530) can be suitably used within the range of 0.1 to 50. The base material 8 in the present invention preferably has appropriate heat resistance strength and excellent thermal conductivity, for example, has a thickness of 3 to 25 μm and a density of 0.8 to 1.5 μm.
g/cm ³ of plastic film (cellophane, polyimide, polyester, polyethylene, polystyrene, polypropylene, etc.) or paper (condenser paper, glassine paper, synthetic paper, laminated paper, etc.) is preferably used. In the present invention, the heat-sensitive transfer ink layers 9Y, 9M, 9C, and 9B of each color may be formed on the base material with gaps between them.
In order to facilitate color printing operations, it is preferable to form adjacent ink layers on a substrate in close contact with each other so as to butt each other. To place adjacent ink layers in close contact with each other, letterpress coating,
Any coating method commonly used in normal color printing, such as gravure coating, flexographic coating, or silk screen coating, may be used as appropriate. As detailed above, in the recording medium of the present invention, the thermal transfer ink layers 9Y, 9M, and 9C of at least three colors of yellow, magenta, and cyan are sequentially printed onto a sheet of recording paper 7 by the thermal head 20. This method is suitable for use in a new color printing method in which images are melt-transferred and the images are superimposed to obtain a desired clear color image. However, in the color printing method using the recording medium of the present invention, the mechanism of the color printer or color facsimile does not become complicated, it is easy to handle, the reliability is significantly improved, and it can be manufactured at low cost. Therefore, it can greatly contribute to the practical application of thermal color printers and color facsimile machines. In addition, since the recording medium of the present invention has extremely excellent melt transfer properties, the amount of transferred ink layer can be adjusted by changing the intensity of the pulse signal applied to the thermal head 20. It is possible to obtain a color image that is faithful to the tone reproduction and the original color tone, and the color image is extremely durable.Furthermore, since ordinary plain paper can be used as the copy sheet 7, the running cost is low. It can have remarkable effects such as: The thermal transfer ribbon of the present invention can greatly contribute to the practical application of color printers using thermal printers, color facsimiles, color video printers, color copy machines, etc.
Its practical value is extremely great. Next, the recording medium of the present invention will be explained with reference to Examples and Comparative Examples. Example 1 A polyester film having a thickness of 9 μm and a density of 1.4 g/cm ³ was used as a base material, and the base material was cut into a strip having a width of 8 mm. Next, heat-sensitive transferable ink layers of yellow, magenta, and cyan having the compositions shown in Table 1 are coated onto the substrate by hot melt coating to a width of 210 mm, which corresponds to the width of an A4 plate, along the length of the substrate.
A recording medium as shown in FIG. 1 was obtained by sequentially applying the following coatings. Thermal transfer ink layer has a thickness of 5μ and a melting point of 90.
℃, viscosity 250cP (120℃), and penetration level 2.

[Table] In order to create color images using the recording medium obtained in this way, we used a single-color thermal serial printer (Canon Ward, manufactured by Canon Inc.) for experimental purposes.
55), yellow, magenta, and cyan images were sequentially melt-transferred onto A4 size plain paper.
In the experiment, a yellow ink layer was first overlapped with one edge of plain paper, a yellow image was transferred onto the plain paper using a thermal head, and then the recording medium was moved and a magenta ink layer was overlapped at the same location on the plain paper. A magenta image was transferred, and a cyan image was further transferred in the same manner. Thus, the color image in which the yellow, magenta, and cyan images were superimposed was clear and had high resolution. Example 2 In addition to the yellow, magenta, and cyan heat-sensitive transfer ink layers, a black heat-sensitive transfer ink layer having the following composition was sequentially applied onto the substrate, but the same procedure as in Example 1 was carried out as shown in FIG. 3. I got a recording medium like the one shown. (Ingredients) (Part) Carbon black 10 Carnauba wax 30 Microcrystalline wax (melting point 95
℃) 30 Petroleum resin 10 Colloidal silica 10 Aluminum powder 10 Using the obtained recording medium, a color image was created on plain paper in the same manner as in Example 1. As a result, the color image, especially the black color, was clearer than that of Example 1. Example 3 A recording medium was obtained in the same manner as in Example 1, except that capacitor paper with a thickness of 10 μm and a density of 1.2 g/cm ³ was used as the base material. Example 4 Example 1 except that auramine-based, rhodamine B-based, and Victoria Blue B-based dyes were each used as yellow, magenta, and cyan transparent colorants at a ratio of 10 parts to 100 parts of the total amount. I obtained a recording medium in the same way. Each thermal transfer ink layer obtained has a thickness of
5μ, melting point 90°C, viscosity 300cP (120°C), and penetration level 4. Color images were created in the same manner as in Example 1 using each of the recording media obtained in Examples 3 and 4. As a result, all the color images obtained were clear and had high resolution.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing an embodiment of the color thermal transfer recording medium of the present invention, and FIG.
3 is a schematic plan view showing another embodiment of the recording medium of the present invention; FIGS. 4 a to 4 c are schematic explanatory diagrams showing a color image creation method using the recording medium of the present invention; FIG. 5 is a schematic explanatory diagram showing a color printing method. (Main symbols in the drawing) 7: Recording paper, 8: Base material,
9Y, 9M, 9C: thermal transferable ink layer, 10: recording medium, A: repeating unit.

Claims (1)

[Scope of Claims] 1. Any image of a hot melt transfer ink layer colored yellow, a hot melt transfer ink layer colored magenta, and a hot melt transfer ink layer colored cyan on the same recording paper. Heat-melt transfer into shape,
A color thermal transfer recording medium used in a recording system that forms a multicolor print image on the recording paper by subtractive color mixing formed by each of the ink layers of each color and by layering two or more of the ink layers. The heat-melting transfer ink arranged in a layer on one side of the base material has a melting point in the range of 50 to 150 °C and a viscosity in the range of 20 to 10,000 cP (value measured at a temperature 30 °C higher than the melting point). Penetration 0.1~50
For color thermal transfer, the transparent ink is colored in a predetermined color with a transparent colorant that is colored transparently by being mixed into a transparent heat-melting transfer vehicle. recoding media. 2. The color thermal transfer recording medium according to claim 1, wherein the transparent colorant is an organic pigment that becomes transparent when dispersed in the vehicle. 3. The color thermal transfer recording medium according to claim 1 or 2, wherein the yellow, magenta, and cyan ink layers are arranged on the base material so as not to overlap each other. 4. Claims 1, 2, or 4, wherein each of the yellow, magenta, and cyan color ink layers has a thickness of 1 to 10 μm, and the colorant content in each ink layer is 1 to 20% by weight. 3. The color thermal transfer recording medium according to item 3.