JPH08300778A - Thermal transfer sheet - Google Patents

Abstract

PURPOSE: To provide a thermal transfer sheet performing multicolor printing, wide in the printing region of a determined colorant layer and forming an image free from misregistration of respective colors. CONSTITUTION: In a thermal transfer sheet wherein printing is successively and repeatedly applied to one surface of a base material sheet, a colorant layer 11 consisting of a plurality of colors is set to one set and detection marks 1, 2 and 3, 4 are provided to the leading ends and terminal ends of colorant regions Y and C containing the (2n-1)-th colors containing repeated head colors Y.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color thermal transfer sheet, and more particularly to a thermal transfer sheet used in a color printer for obtaining a color hard copy based on image information such as a still image of a color TV.

[0002]

2. Description of the Related Art Conventionally, there are various thermal transfer methods for images. Among them, a thermal transfer sheet in which a dye layer composed of a sublimable dye and a binder is provided on a substrate sheet is used to transfer image data according to image information. A sublimation type thermal recording method is known as an image forming method in which a dye in a dye layer is sublimated (heat transferred) by a heating means such as a thermal head. In addition, a color material layer is formed by the same heating means using a heat transfer sheet in which a base film is provided with a heat-fusible color material layer made of a heat-stable colorant such as a pigment and a heat-fusible binder such as wax. A heat melting type recording method of forming an image by softening and transferring is also known as an image forming method.

In these thermal transfer sheets, a dye layer or a color material layer of a plurality of colors is usually repeatedly provided on a base sheet as a set of a plurality of colors. A detection mark is provided to determine the color position when printing. For example, a thermal transfer sheet is known in which a detection mark is provided only at the beginning of a set of color material layers, or a detection mark is provided for each color material layer. In particular, in order to obtain an accurate image, it is preferable to provide a detection mark for each color.

[0004]

However, due to the difference in film type, size, and manufacturer of the thermal transfer sheet, and in some cases, variations in the manufacturing lot and between the lots, the processing direction of the printing machine (hereinafter referred to as "specification"). Then, the length (pitch) of the printing region of each color material layer may differ with respect to (hereinafter, simply described as a processing direction). Also, due to tension fluctuations during running of the thermal transfer sheet inside the printer, when printing in multiple colors, the printing of the specific color of the printer did not match the set position, and a detection mark for cueing the thermal transfer sheet was provided. However, there is a problem in that in the printing of a plurality of colors, the color material layers other than the predetermined colors are transferred. The above problem can be solved by using a printer in which a detection mark is provided for each color and cueing for each color is performed by each detection mark. However, when the detection mark is provided for each color, when the thermal transfer sheet is rolled, the printed part of the mark becomes thick, which not only causes winding wrinkles and color loss but also the width of the printed part of the mark. There was a problem that the print width was reduced because all colors could not be printed in the processing direction.

The present invention has a problem that a color material layer other than a predetermined color is transferred in printing of a plurality of colors, and
An object of the present invention is to provide a thermal transfer sheet that solves the problems of winding wrinkles in the mark printed portion and reduction of the print width.

[0006]

In order to achieve the above object, in a thermal transfer sheet of the present invention, a set of color material layers of a plurality of colors is repeatedly printed on one side of a base sheet in a frame sequential manner. In the thermal transfer sheet, the detection marks are provided at the leading end and the trailing end of the printing portion of the color material layer of the (2n-1) th color including the repeated leading color.

The detection marks provided on the thermal transfer sheet of the present invention are, as shown in FIG. 1, a yellow print area Y, a red print area M, a deep blue print area C, and a black print area BK.
Detection marks 1, 2, 3 and 4 are provided at the leading end and the trailing end of the first color material layer Y and the third color material layer C of the thermal transfer sheet which is a set of color material layers. . In this case, the detection mark may be a block-shaped one at the end portion as shown in the figure, or may be provided over the entire width (not shown).

[0008]

With the detection mark constructed as described above, as shown in FIG. 1, the cue detection mark 1 provided in the yellow print area Y forms a yellow print, and the yellow print approaches the end. At this time, the detection mark 2 provided at the end portion causes the red print area to be located. When the printing of the red color is completed, the detection mark 3 provided in the printing area of the indigo color causes the printing area of the indigo color to be located. When the indigo print is completed, the detection mark 4 provided in the indigo print area starts the ink print. As described above, since the detection mark is provided in the yellow print area and the indigo print area among the four colors, and the detection mark is not provided in the other red print area and the black print area, The print areas of red and black can be utilized 100%. Therefore, for example, when the printer is used for proofreading, an image can be provided on a portion of the item to be printed, which cannot conventionally display the item, the management number, the printing condition, and the like.

The substrate sheet used for the thermal transfer sheet of the present invention may be of any type as long as it has conventionally known heat resistance and strength. For example, the thickness is 2 to 50
Polyester including μm polyethylene terephthalate, polystyrene, polypropylene, polysulfone, polyphenylene sulfide, polyethylene naphthalate, 1,4-polycyclohexylene dimethyl terephthalate, aramid, polycarbonate, polyvinyl alcohol, saponified ethylene / vinyl acetate copolymer, It is a stretched or unstretched sheet of cellulose triacetate or the like. The thickness is 2 to 50 μm, preferably 3 to 10 μm, depending on the type of material. Also,
Two or more kinds of these sheets may be laminated, or a coating film obtained by applying these materials to another sheet may be used. Further, a primer layer may be provided on one side or both sides of the sheet, if necessary.

On the back surface side of the base material sheet on which the color material layer is not provided, in addition to preventing fusion with the thermal head and stabilizing the running property, when the thermal transfer sheet is wound into a roll, It is preferable to provide a heat resistant slipping layer that prevents the material layer and the back surface from adhering to each other. The heat resistant slipping layer is made of an acrylic resin varnish containing a releasing agent such as curable silicone oil, silicone resin, or fluororesin, -OH group or -COOH.
It is also possible to use a varnish of a thermoplastic resin having a group by reacting two or more amino groups, or a diisocyanate group or a triisocyanate group. Further, the heat resistant slipping layer may be added with a phosphate ester type surfactant or a filler having a breaking property such as talc or mica to increase the slipping property.

The color material layer provided on the thermal transfer sheet of the present invention is
It may be a heat transfer layer containing a sublimable dye as a coloring material, or may be a coloring material layer in which a dye or a pigment is dispersed in a heat fusible manner. Of course, both may be used together and formed in a frame-sequential manner.

The heat transfer dye is a dye that undergoes melt diffusion or sublimation transfer by heat, and any of the dyes used in conventionally known heat transfer sheets can be used in the present invention. Is selected in consideration of hue, light resistance, and solubility in a binder. Preferred dyes are diarylmethane-based, triarylmethane-based, thiazole-based, methine-based such as merocyanine, indoaniline, acetophenone azomethine, pyrazoloazomethine, imidazole azomethine, imidazoazomethine, azomethine typified by pyridone azomethine, xanthene-based dyes. , Oxazine type, cyanostyrene type represented by dicyanostyrene, tricyanostyrene, thiazine type, azine type, acridine type, benzeneazo type, pyridone azo, thiophenazo, isothiazole azo, pyrrole azo, pyral azo, imidazole azo, thiadiazole azo, triazole Azos such as azo and disazo, spiropyrans, indolinospiropyrans, fluorans, rhodamine lactams, naphthoquinones, anthraquinones, quinos There are things such as the Talon system.

As the binder for the above-mentioned dye, those known in the prior art can be used. For example, cellulose derivatives such as methyl cellulose, ethyl cellulose, ethyl hydroxycellulose, hydroxypropyl cellulose, and cellulose acetate, polyvinyl alcohol, polyvinyl acetate, polyvinyl acetoacetal, polyvinyl butyral, polyvinyl resins such as polyvinylpyrrolidone, polyacrylic acid ester, and polymetha. There are acrylic resins such as acrylic acid ester, polyacrylamide and polymethacrylamide, polyurethane, polyamide, polyester and the like, and these can be used alone or in combination.
Among these, polyvinyl butyral and polyvinyl acetoacetal can be preferably used from the viewpoint of the heat transfer property of the dye and the storability of the thermal transfer sheet.

The coloring material constituting the heat-meltable coloring material layer is
From known organic or inorganic pigments or dyes, it is possible to appropriately select from those having sufficient coloring density and those which are not discolored or faded by light or heat. Further, it may be a substance that develops color by heating, or a substance that develops color by contact with a material provided on the surface of the transfer target.

Examples of the binder for the color material layer include paraffin wax, microcrystalline wax, various low molecular weight polyethylenes, candelilla wax, petrolactam, polyester wax and carnauba wax, Fischer-Tropsch wax, and wax.
In addition to natural or synthetic waxes such as whale wax, ivorot wax, wool wax and shellac, various wax-like substances such as fatty acid esters and fatty acid amides can be used.

The detection mark is formed by containing a conductive substance such as metal or carbon, and is electrically detected.
What is formed by containing a magnetic substance and is detected magnetically,
There is a mark that includes a pigment or dye that can be identified by the light source used and that is optically detected. Although any of these can be used, what can be simplified as an apparatus is an optical detection means. When the color material layer of each color and the detection mark overlap, and when the dye or pigment in the detection mark has a general hue, an appropriate color filter is used. Further, if an infrared-transparent dye is selected as the color material layer, the detection mark can be detected by infrared rays as an infrared-impermeable mark regardless of the hue of the transfer layer.

The infrared opaque mark is formed by ink containing an infrared opaque substance. The most suitable infrared impermeable substance is carbon black, which is most likely to absorb infrared rays. As the binder of the above ink, polyurethane, polyamide, vinyl chloride / vinyl acetate copolymer, vinyl chloride / acrylic copolymer, cellulose acetate butyrate, etc., or a two-liquid reaction type in which polyester or polyether is crosslinked with polyisocyanate It can also be used. The ratio of the binder to the infrared opaque substance 10 is preferably 100 to 3, and the mark thickness is 0.
It is 5 to 5 μm. When the ratio of the binder is 100 or more, the infrared opacity of the detection mark is insufficient, and when it is 3 or less, the physical properties of the film of the detection mark become brittle and may fall off.

The infrared opaque detection mark detecting device is constructed such that an infrared projector such as an infrared light emitting diode arranged on one surface of the running thermal transfer sheet and an infrared sensor, and an other surface of the thermal transfer sheet. And a computer connected to the infrared sensor to adjust and instruct the printing portion of the color based on the signal of the infrared sensor. Wavelength is 900-2500 nm,
Especially when a sensor that emits infrared rays of 900 to 1000 nm is used, the dye in the thermal transfer layer does not absorb infrared rays in this wavelength range, so that regardless of the hue, the infrared rays pass through the thermal transfer layer and the detection capability of the detection mark is high. To increase. Therefore, it is preferable to select and use as the dye of the thermal transfer layer, a dye that substantially passes the infrared wavelength in the above range.

The shape of the thermal transfer sheet of the present invention may be provided so that the front end and the end can be detected so that the position of the color material layer can be accurately detected, and the shape is not particularly limited. For example, one bar code or a plurality of bar codes can be combined. In addition, as shown in FIG. 2, a set of the color material layer 11 includes a yellow print area Y, a red print area M, a deep blue print area C, and a black print area BK.
Of the thermal transfer sheet having the leading color material layer Y and the third color material layer C provided with the detection marks 1, 2, 3 and 4 at the leading end and the trailing end, and the yellow printing area Y, It is also possible to configure the red-colored printing area M, the indigo-colored printing area C, and the black-colored printing area BK as one set of color material layers 12 without detection marks, and to alternately configure the respective color material layers. The detection mark may be directly provided on the base material sheet, and the color material layer may be further laminated, or conversely, the detection mark may be provided on the color material layer. In particular, as shown in FIG. 2, one set of color material layers 11, 12
The color material layer provided on the detection marks, which are alternately formed, can print 100% of all color images on the transfer target sheet, although there is some unevenness in quality depending on the conditions of the thermal head.

[0020]

EXAMPLES The present invention will be specifically described with reference to Examples. Incidentally, parts or% are based on weight, and the printed film is described by solid content. [Example 1] A polyethylene terephthalate sheet having a thickness of 6 µm is provided with a heat resistant slipping layer on one surface, and the other surface is subjected to gravure rotary printing using each color ink having the following composition and an ink for a detection mark, as shown in Fig. 1. The yellow print area Y, the red print area M, the indigo print area C, and the black print area BK.
Is provided at a coating amount of 1.5 g / m ² , respectively, and the front and end detection marks 1 and 2 are provided in the yellow print area Y, and the front and end detection marks 3 and 4 are provided in the deep blue print area C. A thermal transfer sheet was prepared in which the detection mark was not provided in the red print area M and the black print area BK. Further, it was cut into a desired width to form the thermal transfer sheet of the present invention. (Yellow ink 1) -Dye (Macrolex Yellow 6G) 2 parts-Polyvinyl acetoacetal (KS-5 Sekisui Chemical Co., Ltd.) 2 parts-Polyethylene wax 0.2 part-Toluene / methyl ethyl ketone (1/1) 88 Part (Red ink 1) Dye is a red dye (Macrolex
Same as the yellow ink except that it was replaced with 2.0 parts of red violet R). (Indigo color ink 1) Same as the yellow ink except that 2.0 parts of the indigo dye (Kayaset Blue 714) was used instead of the dye. (Black ink 1) -Dye (CI Solvent Blue 63) 5.5 parts (Baimicron SNVP 2670) 1.5 parts (CI Disperse Yellow 201) 1.4 parts-Polyvinyl acetoacetal (KS-5) ) 3.6 parts-Toluene / methyl ethyl ketone (1/1) 88 parts (detection mark ink) -Aluminum paste 15 parts-Polyethylene wax 2 parts-Vinyl chloride / vinyl acetate copolymer 7 parts-Acrylic resin 14 parts-Toluene / Methyl ethyl ketone (1/1) 62 parts

[Embodiment 2] As in Embodiment 1, the thickness 6
1 μm polyethylene terephthalate sheet is provided with a heat-resistant slip layer on one side, and the other side is subjected to gravure rotary printing using each color ink of the following composition and the ink for detection mark used in Example 1 to give a yellow color as shown in FIG. Print area Y, red print area M, indigo print area C, and black print area BK are provided at coating amounts of 1 g / m ² , respectively, and detection marks 1, 2 and indigo are provided in yellow print area Y. The detection marks 3 and 4 were provided in the color printing area C, and cut to a desired width to form the heat-melting type thermal transfer sheet of the present invention. (Yellow ink 2) 4 parts of yellow pigment (CI 21090) 12 parts of ethylene / vinyl acetate copolymer (Evaflex 420 manufactured by Mitsui Petrochemical Co., Ltd.) Paraffin wax (HNP-10 manufactured by Nippon Seiro Co., Ltd.) ) 12 parts-Carnauba wax 7 parts-Xylene 55 parts-Isopropyl alcohol 10 parts (Red ink 2) 4 parts of red dye (CI 15850) was used instead of the yellow dye of Yellow ink 1. (Indigo ink 2) 4 parts of red dye (CI 74160) was used instead of the yellow dye of Yellow Ink 1. (Black ink 2) 4 parts of carbon black was used instead of the yellow dye of Yellow Ink 1.

Using the thermal transfer sheets of Examples 1 and 2, light having a partial wavelength in the visible region to the infrared region and a sensor corresponding to wavelengths within the same region were used, and the color material layer side of the thermal transfer sheet was provided. An image of four colors was printed by a printer provided with a light emitting part and a sensor and detecting the reflected light of the thermal transfer sheet. The detection mark detection device was able to form a normal full-color image without color misalignment by only catching the detection marks provided in the yellow print area and the indigo print area.

[0023]

As described above, printing of the (2n-1) th color material layer including the repeated leading color of the thermal transfer sheet, which is repeatedly printed frame-sequentially with one color material layer of a plurality of colors as a set. The thermal transfer sheet having the detection marks at the leading end and the end of the portion is positioned by the detection mark provided at the end of the printing area before the printing area where no mark is provided, and printing is performed. Therefore, in the print area where no mark is provided, a high-quality image can be formed in the entire range without the unprintable portion that is seen in the detection mark portion.

[Brief description of drawings]

FIG. 1 is a view for explaining a detection mark of the present invention in a plan view.

FIG. 2 is a plan view showing another embodiment in which one set of detection marks of the present invention and another set without detection marks are alternately provided.

[Explanation of symbols]

 1, 2, 3, 4 Detection mark 11 One set of color material layer 12 One set of color material layer without detection mark Y Yellow print area M Red print area C Blue print area BK Black print area D Printing direction

Claims (1)

[Claims] 1. A thermal transfer sheet in which color material layers of a plurality of colors are grouped as one set and repeatedly printed on one side of a base material sheet in a frame sequential manner (2n-1).
A thermal transfer sheet, characterized in that detection marks are provided at the front end and the end of the printed portion of the color material layer.