JPS60183186A - Thermal transfer sheet for multicolor image - Google Patents

Abstract

PURPOSE:To obtain clear multicolor images having high density and free of misregistration of colors, by a method wherein a combination of leuco dye layers capable of forming different colors is provided as a repeating unit, and a hole is provided in a side edge part of at least one of the layers. CONSTITUTION:A combination of leuco dye layers (a), (b), (c), (d) for yellow, magneta, cyan and black colors arranged in the direction of the arrow is provided as a repeating unit to produce a thermal transfer sheet, while a hole (h) is provided at a side edge part of the leuco dye layer (a). The thermal transfer sheet can be produced by applying respective leuco dyes as inks to a base such as a paper, a synthetic paper and a plastic sheet by letterpress printing, gravure printing or the like.

Description

Detailed Description of the Invention [Technical Field] The present invention makes it possible to obtain a multicolor image by utilizing the color reaction between a leuco dye and a color developer. This invention relates to a heat-sensitive transfer sheet for multicolor images that can be used in combination with a receiving sheet 1 to perform multiple transfers.

[Prior art]

Conventionally, a method of obtaining a multicolor recorded image using a color reaction between a leuco dye and a color developer is known, but in this case, a multicolor image is obtained by Because of the method in which heat-sensitive coloring layers are provided and each layer is colored in a different color, the number of tones of the colored image is limited, and is limited to two or three colors at most. Furthermore, according to Japanese Patent Application Laid-Open No. 57-6909/I, when thermal transfer is performed on paper using a thermal transfer material in which a plurality of thermal inks with different melting points and tones are applied to a support in a mosaic pattern, A method for obtaining full-color images by changing the heating temperature is shown. However, with such a transfer material coated with thermal ink in a mosaic pattern, it is difficult to obtain a clear full-color image, and it is also impossible to obtain a large number of transferred images using the same transfer material.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermal transfer sheet for multicolor images that is capable of obtaining high-density, clear, full-color multicolor images without color shift, and also capable of obtaining a large number of transferred images. do.

〔composition〕

According to the present invention, as a first invention, a receiving sheet having a color developer layer is used in any combination, has a leuco dye layer that develops different colors for multicolor coloring, and has a leuco dye layer that develops different colors for multicolor coloring, and a receptor sheet having a color developer layer. In the thermal transfer sheet 1-, in which a combination of leuco dye layers that develop a color are formed as a repeating unit, a perforation is provided at the side edge of at least one of the leuco dye layers constituting the repeating unit. Thermal transfer sheets 1 to 1 for multicolor images are provided, and as a second invention, a leuco dye layer and a color developer layer, which are used in combination with a receiving sheet and develop different colors for multicolor development, are provided. and a combination of a leuco dye layer and a color developer layer that develop different colors is configured as a repeating unit,
There is provided a heat-sensitive transfer sheet for multicolor images, characterized in that perforations are provided at the side edge of at least one layer selected from the leuco dye layer and the color developer layer constituting the repeating unit.

In the first invention, leuco dye layers that develop different colors for multiple colors are provided on the same support, but in this case,
The leuco dye layers that develop different colors are arranged in sets, and the sets are arranged as repeating units on the support. Further, in the second invention, a leuco dye layer and a color developer layer that develop different colors for multiple colors are provided on the same support. The leuco dye layer and the developer layer form a set, and the set is configured as a repeating unit on the support.

The multicolor leuco dye layer used in the present invention may be any layer as long as it develops a desired color, but generally a leuco dye layer that develops each color of yellow, magenta, cyan, and black is selected. By using such four leuco dye layers, seven full colors can be easily obtained. That is, the leuco dye layer that develops each color of yellow, magenta, cyan, and black can be used alone to produce each color, and the combination of a leuco dye layer that develops yellow and a leuco dye layer that develops magenta can be used. By combining a leuco dye layer that develops red and yellow colors and a leuco dye layer that develops cyan color, blue color can be obtained by combining a leuco dye layer that develops green and cyan colors and a leuco dye layer that develops magenta color. can.

Next, the thermal transfer sheet 1- of the present invention will be explained with reference to the drawings. In Figures 1 to 3, a is a leuco dye layer that develops a yellow color, b is a leuco dye layer that develops a magenta color, and C is a leuco dye layer that develops a magenta color.
is a leuco dye layer that develops a cyan color, d is a leuco dye layer that develops a black color, e is a color developer layer, and h is a leuco dye layer that develops a cyan color.
indicates perforation.

FIG. 1 shows an example in which a repeating unit is a combination in which leuco dye layers a to d are arranged in a horizontal direction with respect to the arrow direction, and FIG. 2 shows each leuco dye layer with respect to the arrow direction. a-d
and color developer e' are arranged in the lateral direction, and an example in which the combination in which color developer e is arranged between each leuco dye Ma-d is used as a repeating unit is shown. FIG. 3 shows an example in which the repeating unit is a combination in which the leuco dye layers a '' d are arranged in the horizontal direction and the color developer layer e is arranged in the vertical direction with respect to the direction of the arrow. This is an embodiment of the first invention, and FIGS.
The figure shows an embodiment of the second invention.

Thermal transfer sheets 1 to 1 as described above are coated onto a support (e.g., paper, synthetic paper, plastic film, etc.) by letterpress printing, gravure printing, etc. using each leuco dye liquid and color developer liquid as inks. By doing so, it can be easily created. An example of such a heat-sensitive transfer sheet is shown in Japanese Patent Application No. 58-100686.

In the present invention, perforations are provided at the side edges of at least one layer selected from a leuco dye layer or a combination of a leuco dye layer and a color developer layer constituting a repeating unit. FIG. 1 shows an example in which perforations are provided at the side ends of the leuco dye layer a, FIG. 2 shows an example in which perforations 11 are provided at the side ends of each color developer layer e, and FIG. 3 shows the leuco dye layer a. An example is shown in which a perforation]l is provided at the side end of layer d. The shape of the perforation may be arbitrary, such as circular or square.

Since the thermal transfer sheets 1 to 1 of the present invention have perforations at predetermined positions, the perforations can be used to
The position of ~ can be detected. A diagram explaining the principle is shown in FIG. FIG. 4(a) is an explanatory diagram of the state before the perforations provided on the surface of the thermal transfer sheet 1' reach the detection side electrode A, and FIG. 1' is an explanatory diagram when it moves on the metal member B and the perforation reaches the detection forceps electrode. When the perforation reaches the position detection needle electrode A of the thermal transfer sheet 1~, the detection copper electrode A and the metal member B
A separately provided detection circuit is activated, the position of the thermal transfer sheet is detected, and in response to the activation of the detection circuit, the thermal transfer sheet drive system linked to the detection circuit is activated. The thermal transfer sheet can be accurately moved to a predetermined position relative to the receiving sheet. In this way, the movement of the heat-sensitive transfer sheet is accurately stopped, and the set including the leuco dye layers a, b, c, and d constituting the repeating unit is cured at an accurate position. Next, this set of leuco dye layers a
, b, c, d is used a predetermined number of times (this number of uses is, for example.

(This can correspond to the number of uses of the color developer layer e or the number of uses of a predetermined leuco dye layer), the heat-sensitive transfer sheet drive system operates again, moves the heat-sensitive transfer sheet, and creates a new repeating unit in the same way. Constituent leuco dye layers a, b,
A set including c and d is set.

Furthermore, when providing perforations for detection at the side edges between each leuco dye layer, each leuco dye layer can be accurately moved and set at a predetermined position. In this way, a clear color image without color shift can be obtained.

As the leuco dyes that develop yellow, magenta, cyan, and black colors used in the present invention, any of those conventionally used for pressure-sensitive paper and thermal paper can be used, including triphenylmethane-based, fluoran-based, Phenothiazine, auramine, spiropyran, and indolinophthalide are preferably used. Specific examples of these leuco dyes are shown below, but of course the present invention is not limited thereto.

Yellow dyes: 3.6-dime-1-xyfluorane, 3-cyclohexylamino-6-chlorofluorane, 3-(p-dimethylaminophenyl)-3-phenylphthalide, etc.

Magenta dye: 3-diethylamino-7,8-benzfluorane, 3-
diethylamino-6-methyl-7-chlorofluorane,
3-di(■-ethyl-2-methylindole)-3-yl-phthalide, 3-diethylamino-6-phenyl-7
-Azafluoran etc.

Cyan dye: 3.3-His(P-dimethylaminophenyl)-phthalide, 3.3-bisCp-dimethylaminophenyl)=
6-dimethylaminophenyl (also known as crystal violet lactone), 3.3-bis(p-diethylaminophenyl)-6-dimethylaminophthalide, 2-bis(p-dimethylaminophenyl)methyl-5-dimethylamino -benzoic acid, 3-(ρ-dimethylaminophenyl)-3-(p-dibenzylaminophenyl) phthalide, etc.

Black dye: 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6
-Methyl-7-anilinofluorane, 3-diethylamino-7-piperidinofluorane, etc.

In addition, the color developer used in the present invention includes an electron-accepting substance,
For example, phenolic substances, organic acids, salts or esters thereof, etc. are used, and from the viewpoint of practicality, those with a melting point of 200° C. or lower are preferably used. Specific examples of color developers preferably applied in the present invention are shown below. Note that the numbers in parentheses indicate the melting point.

4-Sert-butylphenol (98), 4-hydroxydiphenyl ether (84), 1-nano-1-l (98), 2-nano-1-l (121), methyl-4-
Hydroxybenzoate (131), 4-hydroxyace1-phenone (109), 2,2′-dihydroxydiphenyl ether (79), 4-phenylphenol (166), 4-Lert-octylcatechol (1
09), 2,2'-dihydroxydiphenyl (103
), 4,4′-methylenebisphenol (160),
2,2'-methylenebis(4-chlorophenol) (
164), 2,2'-methylenebis(4-methyl-6
't;erl;-butylphenol) (125), 4,
4'-isobropylidene diphenol 156), 4
, 4'-isopropylidene bis(2-chlorophenol) (90), 4.4'-isopropylidene bis(2-chlorophenol)
, 6-dibromophenol) (1,72), 4,4'
-isopropylidene bis(2-tert-butylphenol) (110), 4,4'-isopropylidene bis(
2-methylphenol) (136), 4゜4'-isopropylidene bis(2,6-dimethylphenol) (16
8), 'L4' 5ee-butylidene diphenol (1
19), 4,4'-Secondary-butylidene bis(2
-methylphenol) (,142), 4,4'-cyclohexylidene diphenol<180), 4,4'cyclohexylidene bis(2-methylphenol) (18'
4), salicylic acid (163), salicylic acid methalyl ester (74), salicylic acid phenacyl ester (11)
0), 4-hydroxybenzoic acid methyl ester (L31
), 4-hydroxybenzoic acid ethyl ester (l l”
6), 4-hydroxybenzoic acid isopropyl ester (86), 4-hydroxybenzoic acid butyl ester (7)
1), 4-hydroxybenzoic acid isoamyl ester (5
0), 4-hydroxybenzoic acid phenyl ester (17
8)', 4-hydroxybenzoic acid benzyl ester (]
, 1.1), 4-hydroxybenzoic acid cyclohexyl ester (119), 5-hydroxysalicylic acid (20
0), 5-chlorsalicylic acid (172), 3-chlorsalicylic acid (178), thiosalicylic acid (1,64), 2
-Chloro-5-21-lobenzoic acid ('165), 4-methyl-oxyphenol (53), 2-hydroxybenzyl alcohol (87), 2,5-dimethylphenol (7
5), benzoic acid (122), or-1-toluic acid (10
7), metatoluic acid (111), paratoluic acid (L
SI ), orthochlorobenzoic acid (142), metaoxybenzoic acid (200), 2,4-dihydroxyace1-
Phenone (97), resorcinol monobenzony 1
~(135), 4-hydroxybenzophenone <133
), 2,4-dihydroxybenzophenone (], 44
), 2-naphtoic acid (,1,84),■
-Hydroxy-2-naf1-ic acid (195)
, 3,4-dihydroxybenzoic acid ethyl ester (12
8), 3,4-dihydroxybenzoic acid phenyl ester (189), 4-hydroxypropiophenone (150
), salicyl salicylate (, l/18), phthalic acid monobenzyl ester (107).

], 1-bis(4'-hydroxyphenyl)ethane (
126), 1.1-bis(4'-hydroxyphenyl)propane (1,30), 1.1-bis(4'-hydroxyphenyl)hexane (111).

], l-bis(4'-hydroxyphenyl)hebutane (120)-1, ]-bis(4'-hydroxyphenyl)-2-propylpentane (128).

1.1-bis(4'-hydroxyphenyl)-2-ethylhexane (87), 2.2-bis(4'-hydroxyphenyl)hebutane (101), 3.3-bis(4'-hydroxyphenyl) ) Hexane (155).

1.1-bis(3'-methyl-4'-hydroxyphenyl)ethane (101), 1-bis(3'-methyl-4'-hydroxyphenyl)propane (94), 1.1-bis( 3'-methyl-4'-hydroxyphenyl)butane (135), ], ■-bis(3'-methyl-4'-hydroxyphenyl)pentane (97).

(2) 1-bis(3'-methyl-4'-hydroxyphenyl)hexane (78).

1.1-Bis(3'-methyl-47-hydroxyphenyl)hebutane(85)-2-(3'-methyl-4'-hydroxyphenyl)-
2-(4'-hydroxyphenyl)propane (t2o
), 2,2-bis(3'-methyl-4'-hydroxyphenyl)pentane (12B), 2,2-bis(5'-methyl-41-hydroxyphenyl)hexane (104), 2,2- Bis(3'-methyl-4'-hydroxyphenyl)4-methylpentane (129), 1,1-bis(
3'-methyl-4'-hydroxyphenyl)4-methylbutane (124), 3.3-bis(3'-methyl-4'-hydroxyphenyl)hexane (90), 5.5-bis(3'-methyl) -4'-hydroxyphenyl)nonane (128), 2-(4'-hydroxyphenyl)-2-(3'-
Chlor-4'-hydroxyphenyl)propane (101
), 2,2-bis(3′-isopropyl-4′-hydroxyphenyl)propane (97).

2.2-bis(3'-tert-butyl-4'-hydroxyphenyl)propane (117), 2.2-bis(
3'-chloro-4'-hydroxyphenyl)propane (8/I).

2-(4'-hydroxy-3',5'-dimethylphenyl)-2-(/I'-hydroxyphenyl)propane (127).

Bis(3'-methyl-5'-ethyl-4'-hydroxyphenyl)methane (105), 1,. 1-(3'-methyl-5'-butyl-4'-hydroxyphenyl)butane (104), 2.2-bis(4-hydroxyphenyl)octane (8
3), bis(4-hydroxyphenylmercapto)methane (5
5), ■, 2-bis(4-hydroxyphenylmercapto)ethane (173), ■, 3-bis(4-hydroxyphenylmercaptopropane (82), ■, 4-bis(4-hydroxyphenylmercapto) 1- )
Butane (181), ■,5-bis(4-hydroxyphenylmercapto)pentane (98), 1,6-bis(4-hydroxyphenylmercaphexane (166), 1,3-bis(4-hydroxyphenylmercapto) 1-)
.

Acetone (74), 1,5-bis(/I-hydroxyphenylmercapto)
-3-Oxabentane (93), 1,7-bis(4-hydroxyphenylmercapto)-
3,5-dioxahebutane (108), 1,8-bis(
4-hydroxyphenylmercapto)-3,5-dioxaoctane (100) and the like.

In the leuco dye layer and/or color developer layer used in the present invention, in order to increase the transferred image density and to obtain a transferred image with high density and uniform density in multiple transfers, as necessary, Furthermore, it is preferable to contain a porous filler. This porous filler has an oil absorption capacity of at least 50 m Ill
/1'00g (according to JT.S K5101 method), preferably 1.50m Q 1100g or more. The proportion of the porous filler contained in the leuco dye layer and/or developer layer is 0.01 to 1 part by weight, preferably 0.03 to 1 part by weight, per 1 part by weight of the leuco dye or developer.
It is 0.5 part by weight. Specific examples of such porous fillers include silica, aluminum silicate, alumina, aluminum hydroxide, magnesium hydroxide, urea-
Examples include inorganic and organic fine powders such as formalin resin and styrene resin.

When providing a leuco dye layer and a color developer layer on a support, the leuco dye and color developer are usually added in an amount of 0.1 to
The coating amount is 20 g/t, preferably 0.3 to 10 g/t (based on dry solids). Further, in order to support the leuco dye and color developer on the support, it is preferable to include a resin having a melting point or softening point of 50 to 130°C as the σ binder. In this case, the resin is a thermoplastic resin. Alternatively, any thermosetting material can be used. When considering the heat resistance and heat sensitivity of the transfer sheet, it is preferable to use a resin having a melting point of 130° C. or lower.

It is sufficient from the viewpoint of thermal sensitivity that the resin has a softening point of 130° C. or lower. Specific examples of such resins include the following.

Polystyrene, polypropylene, polystyrene.

Petroleum resin, acrylic resin, vinyl chloride resin, vinyl acetate resin, vinylidene chloride resin, polyvinyl alcohol, cellulose resin, polyamide, polyacetal, polycarbonate, polyester, fluororesin, silicone resin, natural rubber, chlorinated rubber, butadiene rubber, olefin rubber,
Phenol resin, urea resin, melamine resin, epoxy resin, polyimide, etc.

The resins mentioned above can be used in the form of a single polymer, a copolymer, or a mixture of a plurality of resins. The amount of this resin used is in the range of 0.01 to 1 part by weight per 1 part by weight of the leuco dye or color developer. If the amount of this resin is less than 0.01 part by weight, the layer binding force to the support will be weakened, making it impossible to support the leuco dye and color developer on the support with sufficient adhesion force. When the amount exceeds 1 part by weight, the thermal sensitivity of the product decreases and the resulting transferred image density becomes low. The amount of resin is 0.05 to 1 part by weight of leuco dye or color developer.
It is preferable to use the amount in an amount of 0.5 parts by weight in order to obtain uniform image density during multiple transfers.

In the present invention, in order to obtain a multicolor image using the heat-sensitive transfer sheet, a receiving sheet is placed on the transfer layer surface of the heat-sensitive transfer sheet (the surface containing the leuco dye layer or the leuco dye layer and the color developer layer).
-, the thermal transfer sheet is accurately moved using the perforation, and according to the dark tone information, thermal printing is performed from the back side of the thermal transfer sheet using a heating means such as a thermal printer, and the leuco dye is printed on the receiving sheet. A multicolor image may be formed by the reaction between the color developer layer and the color developer layer. In this case, acceptance sheet 1~
In the case of using thermal transfer sheets 1 to 1 having a dye layer and a color developer layer, paper, synthetic paper, plastic film, etc. are used. The amount of color developer transferred to the receiving sheet is 1 part by weight of the leuco dye transferred.
The proportion is preferably 10 to 10 parts by weight, preferably 2 to 5 parts by weight. When forming an image in this way, the total amount of leuco dye and color developer transferred to the support is approximately 1 g/rr.
The amount of transfer may be approximately r, and a high-density image can be obtained with this amount of transfer.

On the other hand, when thermal transfer sheets 1 to 1 having only a leuco dye layer are used, the receiving sheet is one in which a developer layer is provided on a support 2.

In the present invention, the heat-sensitive transfer sheet is heated in accordance with the color tone information, as described above. For example, when using the thermal transfer sheet of the second invention (Figs. 2 and 3), when the desired color of the recorded image is yellow, magenta, cyan, or black, the color is developed corresponding to each color. The leuco dye layer and the developer layer are heated to cause a transfer reaction between the leuco dye and the developer on the receiving sheet. In this case, the heating order of the leuco dye layer and the color developer layer is arbitrary;
The developer layer may be heated after the leuco dye layer, or the heating order may be reversed. On the other hand, to obtain a red recorded image, the leuco dye layer that develops a yellow color, the leuco dye layer that develops a magenta color, and the color developer layer are heated. To obtain a green recorded image, the leuco dye layer that develops yellow, the leuco dye layer that develops cyan, and the color developer layer are heated, and the leuco dye layer that develops cyan and the magenta layer to obtain a blue recorded image. The leuco dye layer and developer layer are heated to develop a color. When obtaining the above-mentioned red, green, and blue recorded images, the heating order may be arbitrary. For example, the developer layer may be heated after the two leuco dye layers are heated, or the developer layer may be heated after the two leuco dye layers are heated. After heating the layer, 2
The leuco dye layer of the seeds may be heated. In addition, when using the thermal transfer sheet of the first invention (FIG. 1), it is necessary to apply an appropriate coating on the receiving sheet 1 to 1 having the color developer layer so that an image of a desired color can be obtained. It is sufficient to select a suitable leuco dye layer and perform heat transfer.

〔effect〕

According to the present invention, a clear multicolor image can be formed on a receiving sheet I-; and a large number of copies can be obtained using the same thermal transfer sheet. In addition, in the case of the present invention, a plurality of leuco dye layers that develop different colors or a plurality of leuco dye layers and a color developer layer that develop different colors are combined on the thermal transfer sheet. Since they are formed as a repeating unit, even if one set of leuco dye layer or color developer layer is consumed, the next set can be applied in the same manner as the previous one by simply moving the same thermal transfer sheet. This makes it suitable for making a large number of copies. Moreover, in the case of the present invention, there are perforations on the thermal transfer sheet (the position of the leuco dye layer or developer layer of the thermal transfer sheet) that serve as a means for accurately detecting the position. By operating the position detection circuit in conjunction with the thermal transfer sheet drive system, it is possible to accurately move and set the thermal transfer sheet to obtain a clear multicolor image without one color shift. can.

[Brief explanation of drawings]

FIGS. 1 to 3 are explanatory diagrams of a heat-sensitive transfer sheet used in the present invention. FIG. 1 shows an example in which perforations are provided at the side ends of thermal transfer sheets 1 to 1 in which the combination of leuco dye layers a to d arranged laterally in the direction of the arrow is used as a reversing unit. and the second
The figure shows a combination in which each leuco dye layer a to d is disposed in a horizontal direction with respect to the arrow direction, and a color developer layer e is disposed between each leuco dye layer a to d. An example is shown in which perforations 11 are provided at the side edges of a thermal transfer sheet.
The figure shows an example in which perforations are provided at the side edges of a thermal transfer sheet in which the repeating unit is a combination in which the leuco dye layer ad is arranged horizontally and the color developer layer e is arranged vertically in the direction of the arrow. shows. FIG. 4 is an explanatory diagram of the principle for detecting the position of the heat-sensitive transfer sheet of the present invention. a... Leuco dye layer that develops yellow color b...
...Leuco dye layer C that develops magenta color...
Leuco dye layer d that develops a cyan color...Leuco dye layer e that develops a black color...Developer layer h...Perforation A...Perforation detection needle Electrode B...Metal member T...Thermal transfer sheet Patent applicant Rico Co., Ltd. - Representative patent attorney Toshiaki Ikeura Figure 1 Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) Used in combination with a receiving sheet 1- having a color developer layer, having a leuco dye layer that develops different colors for multicolor development, and a leuco dye layer that develops colors of the different colors. A thermal transfer sheet for multicolor images, characterized in that a combination of the following is formed as a repeating unit, wherein perforations are provided at the side edge of at least one of the leuco dye layers constituting the repeating unit. 1~. (2) A leuco dye that is used in combination with a receptor sheet and has a leuco dye layer and a color developer layer that develop different colors for multicolor development, and a leuco dye that develops the different colors. In thermal transfer sheets 1 to 1 in which a combination of a layer and a color developer layer is configured as a repeating unit, the side of at least one layer selected from a leuco dye layer and a color developer layer in which the repeating unit is implanted; A thermal transfer sheet for multicolor images characterized by perforations at the edges.