JPS60183187A - 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 conductive layer is provided at a side edge part or a boundary part of at least one of the layers. CONSTITUTION:A combination of leuco dye layers (a), (b), (c), (d) for yellow, magenta, cyan and black colors and a color developer layer (e) arranged in the direction of the arrow is provided as a repeating unit to produce a thermal transfer sheet. In this case, the conductive layer K is provided at a side edge part of the color developer layer (e). The thermal transfer sheet can be obtained by applying respective leuco dye liquids and a color developer liquid as inks to a base such as a paper by letterpress printing or the like, the conductive layer K being obtained by vapor-depositing a conductive metal such as Al.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention utilizes a color reaction between a leuco dye and a color developer to obtain a multicolor image.

Furthermore, the present invention relates to a heat-sensitive transfer sheet for multicolor images, which can perform multiple transfers by combining the same heat-sensitive transfer sheet with a receiving sheet 1-.

[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 created by recording a plurality of images on a support. Since a heat-sensitive coloring layer is provided and each color is developed in a different color, the number of tones of a colored image is limited, and is limited to two to three colors at most. Furthermore, according to Japanese Patent Application Laid-Open No. 57-69094, 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, the heating temperature is adjusted. By changing
A method for obtaining full color images 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.

[Purpose] The present invention provides a thermal transfer sheet 1 for multicolor images, which can obtain high density, clear, full-color multicolor images without color shift, and can also obtain a large number of transferred images.
The purpose is to provide

〔composition〕

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

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 the respective colors are arranged in sets, and the sets are arranged as repeating units on the support. In addition, 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, a thermal transfer sheet of the present invention will be explained with reference to the drawings.

In Figures 1 to 4, a is a leuco dye layer that develops yellow, b is a leuco dye layer that develops magenta, C is a leuco dye layer that develops cyan, and d is a leuco dye layer that develops black. , and e represents a color developer layer and h represents a conductive layer.

1 and 4, each of the leuco dye layers a to d and the developer layer e are disposed laterally with respect to the arrow direction, and the developer layer e
is arranged between each leuco dye layer a-d as a repeating unit, and FIG. Fig. 6 shows an example in which the combinations shown in Fig. 6 are used as repeating units.
The developer layer e shows an example in which a repeating unit is a combination arranged in the vertical direction. 1, 3, and 4 are embodiments of the second invention, and FIG. 2 is an embodiment of the first invention.

The heat-sensitive transfer sheet as described above uses each leuco dye liquid and color developer liquid as inks, and is coated on a support (for example, one sheet of paper, one synthetic paper, plastic film, etc.) by letterpress printing, gravure printing, etc. can be easily created. - An example of such a heat-sensitive transfer sheet is shown in Japanese Patent Application No. 100686/1986.

In the present invention, a conductive layer k is provided at the side edge or boundary 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. Figure 1 shows an example in which a conductive layer k is provided at the side edge of a color developer layer e, and Figure 2 shows an example in which a conductive layer k is provided at the side edge of a leuco dye layer a that develops yellow, which is one of the leuco dye layers. An example of setting k,
FIG. 3 shows an example in which a conductive layer k is provided at the side end portion of a leuco dye layer d that develops black, which is one of leuco dyes.

In the case of the present invention, the conductive layer can be disposed at the side edges of the leuco dye layer or the color developer layer as described above, or it can be disposed at the boundary between the layers. An example of this case is shown in FIG. The conductive layer can be easily obtained by a conventionally known conductive layer forming method such as vapor deposition of a conductive metal such as aluminum.

The thermal transfer sheet I of the present invention has a conductive layer k at a predetermined position.
Since it is provided, its position can be detected electrically. A diagram explaining the principle is shown in FIG. Figure 5(a)
is an explanatory diagram before the conductive layer k disposed on the surface of the thermal transfer sheet 1-T reaches the detection electrodes N, -N2;
Figure (b) is an explanatory diagram when the thermal transfer sheet T moves and the conductive layer k reaches the detection electrodes N and N2. When the conductive layer k reaches the position detection electrodes N□, N2 of the thermal transfer sheet 1-, conduction occurs between the detection electrodes N1, N2, a separately provided detection circuit is activated, and the position of the thermal transfer sheet is detected. In response to the operation of the detection circuit, the thermal transfer sheet drive system linked to the detection circuit operates to transfer the image to the receiving sheet.
The heat-sensitive transfer sheet can be accurately moved to a predetermined position. In this way, the movement of the thermal transfer sheet 1 is accurately stopped, and the leuco dye layer a, which constitutes the repeating unit,
The set containing b, c, d is set at the correct position. Next, after this set of leuco dye layers a, b, c, and d is used a predetermined number of times (this number of uses is, for example, the number of times the color developer layer e is used, or the number of times a predetermined leuco dye layer ), the thermal transfer sheet drive system operates again to move the thermal transfer sheet, and in the same way, the leuco dye layers a, b,
A set including c and d is set. Furthermore, when providing a conductive layer for detection at the side end or boundary of 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.

Leuco dyes that develop yellow, magenta, cyan, and black colors used in the present invention include:

Any of the materials conventionally used for pressure-sensitive paper and thermal paper can be applied, and those based on triphenylmethane, fluoran, phenothiazine, auramine, subqpyran, and indolinophthalide are preferably used. Ru.

Specific examples of these leuco dyes are shown below, but of course the present invention is not limited thereto.

Yellow dye: 3.6-simethoxyfluorane, 3-cyclohexylamino-6-chlorofluoran, 3-(P-dimethylaminophenyl)-3-phenylphthalide, etc.

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

Cyan dye: 3,3-bis(p-dimethylaminophenyl)-phthalide, 3,3-bis(p-dimethylaminophenyl)-6
-Simethylaminophthalide (also known as crystal violet lactone), 3,3-bis(P-diethylaminophenyl)-6-dimethylaminophthalide, 2-bis(P-dimethylaminophenyl)methyl-5- Dimethylamino-benzoic acid, 3-(P-dimethylaminophenyl)-3-(p-dibenzylaminophenyl) phthalide, and the like.

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

In addition, as a color developer used in the present invention, an electron-accepting substance 1
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=t;erL-butylphenol (98), 4-hydroxydiphenyl ether (84), l-naphthol (
98), 2-naphthol (121), methyl-4-hydroxybenzoate (131), 4-hydroxyace1
~phenone (109), 2,2'-dihydroxydiphenyl ether (79), 4-phenylphenol (1
66), 4-1zert, -octylcatechol (1
09), 2,2'-dihydroxydiphenyl (103
), 4,4′-methylenebisphenol (160),
2,2'-methylenebis(4-chlorophenol) (
164), 2,2'-methylenebis(4-methyl-6
-terL-butylphenol) (12,5), 4,4
'-Isopropylidenediphenol (156), 4,
4'-isopropylidene bis(2-chlorophenol) (90), 4.4'-isopropylidene bis(2,
6-dibromophenol) (172), 4,4'-isopropylidenebis(2-tert;-butylphenol) (11,0), 4,4'-isopropylidenebis(2-methylphenol) (1,36) , 4゜4'-isopropylidene bis(2,6-dimethylphenol)
(168), 4.4'-5ec-butylidene diphenol (119), 4,4'-Secondary-butylidene bis(2-methylphenol) (142), 4.4'
-cyclohexylidene diphenol (180), 4,4
′ Cyclohexylidene bis(2-methylphenol)
(184), salicylic acid (1,63), salicylic acid methalyl ester (74), salicylic acid phenacyl ester (11,0), 4-hydroxybenzoic acid methyl ester (131), 4-hydroxybenzoic acid ethyl ester (
116), 4-hydroxybenzoic acid isopropyl ester (86), 4-hydroxybenzoic acid butyl ester (
71), 4-hydroxybenzoic acid isoamyl ester (
50), 4-hydroxybenzoic acid phenyl ester (1
7g), 4-hydroxybenzoic acid benzyl ester (1
11), '4-hydroxybenzoic acid cyclohexyl ester (119), 5-hydroxysalicylic acid (200)
, 5-chlorsalicylic acid (172), 3-chlorsalicylic acid (178), thiosalicylic acid (164), 2-chloro-5-21-lobenzoic acid (165), 4-methyl-oxyphenol (53), 2-hydroxybenzyl alcohol (87), 2,5-dimethylphenol (75), benzoic acid (122), ortho-I-ruylic acid (107'),
Meta-1-ruic acid (111), para-toluic acid (181)
), or-1-chlorobenzoic acid (1-/12), metaoxybenzoic acid (200), 2,4-dihydroxyacetic acid (
-phenone (97), resorcinol monobenzoate (1,35), 4-hydroxybenzophenone (1
33), 2,4-dihydroxybenzophenone (144
, ), 2-Nano 1 ~ Itsuku Acid (18/I), ■
-Hydroxy-2-naphthoic acid (1,95)
, 3,4-dihydroxybenzoic acid ethyl ester (12
8), 3,4-dihydroxybenzoic acid phenyl ester (489), 4-hydroxypropiophenone (15
0), salicyl salicyle-1-(148), phthalic acid monobenzyl ester (107).

171-bis(4'-hydroxyphenyl)ethane (
126), 1.1-bis(4'-hydroxyphenyl)propane (130), 1.1-bis(4'-hydroxyphenyl)hexane (111), 1.1-bis(4'-hydroxy phenyl)heptane (120), 1.1-bis(4'-hydroxyphenyl)-2-propylpentane (12g).

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).

1.1-bis(3'-methyl-4'-hydroxyphenyl)propane (94), 1.1-bis(3'-methyl-4'-hydroxyphenyl)butane (135).

1.1-bis(3'-methyl-4'-hydroxyphenyl)pentane (97), 1.1-bis(3'-methyl-4'-hydroxyphenyl)hexane (78), 1.1-bis (3'-methyl-4'-hydroxyphenyl)hebutane (85), 2-(3'-methyl-4'-hydroxyphenyl)-
2-(4'-hydroxyphenyl)propane (120
), 2,2-bis(3'-methyl-4'-hydroxyphenyl)pentane (128).

2.2-bis(5'-methyl-47-hydroxyphenyl)hexane (104), 2.2-bis(3'-methyl-4'-hydroxyphenyl)4-methyl butane (129).

1.1-bis(λ'-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 (84), 2-(4'-hydroxy-3',5'-dimethylphenyl)-2-(4'-hydroxyphenyl)propane (127).

Bis(3'-methyl-5'-ethyl-4'-hydroxyphenyl)methane (105), 1,,1-(3'-methyl-57-butyl-4'-
hydroxyphenyl)butane (104), 2.2-bis(4-hydroxyphenyl)octane (8
3), bis(4-hydroxyphenylmercapto)methane (5
5), ■, 2-bis(4-hydroxyphenylmercap 1~)
Ethane (173), l:3-bis(to 4-hydroxyphenylmercap 1)
Propane (82), 1,4-bis(4-hydroxyphenylmercapto)butane (181).

1.5-bis(4-hydroxyphenylmercapto)pentane (98).

1.6-bis'(4-hydroxyphenylmercapto)
Hexane (166), (1), 3-bis(4-hydroxyphenylmercapto)ace1-one (74), 1,5-bis(4-hydroxyphenylmercapto)-
3-oxapentane (93), ■, 7-bis(4-hydroxyphenylmercapto)-
3,5-dioxahebutane (108), 1,8-bis(
4-hydroxyphenylmercapto)-3) 5-dioxaoctane (100), etc.

The leuco dye layer and/or color developer layer used in the present invention includes:
In order to increase the density of the transferred image and to obtain a transferred image of high density and uniform density even after multiple transfers, it is preferable to further contain a porous filler, if necessary. As this porous material.

At least oil absorption ff150m Q/100g (JIS
K5101 method), preferably 150 m Q /
100g or more is used. q ico dye layer and/or
The proportion of the porous filler contained in the color developer layer is 0.01-1 parts by weight, preferably 0.03-0.5 parts by weight, per 1 part by weight of the leuco dye or developer. Specific examples of such porous fillers include inorganic and organic fine powders such as silica, aluminum silicate, alumina, aluminum hydroxide, magnesium hydroxide, urea-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
Coating amount of 20g/m, preferably 0.3-10g/m'
(based on dry solids). In addition, as a binder for supporting the leuco dye and color developer on the support, it is preferable to contain a resin having a melting point or softness and other points of 50 to 130°C. Either thermoplastic or thermosetting materials 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 1, polyester, fluororesin, silicone resin, Natural rubber, chloride rubber, butadiene rubber, olefin rubber, phenolic resin, urea resin, melamine resin, epoxy resin, polyimide, etc.

The resins mentioned above can be used in the form of East German polymers, copolymers, or mixtures 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 binding force to the support will be weakened, making it impossible to support the leuco dye and color developer on the support with sufficient binding force. When the amount exceeds parts by weight, the thermal sensitivity of the product decreases, and the resulting transferred image density becomes low. The amount of resin is +'0.0 per 1 part by weight of leuco dye or color developer.
It is preferable to use it in a range of 5 to 0.5 parts by weight in order to obtain uniform image density in 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 (the surface containing the leuco dye layer or the leuco dye layer and the color developer layer) of the heat-sensitive transfer sheet, and one color tone information is obtained. In response to the.

Then, the conductive layer is used to accurately move the transfer sheet to the thermal transfer sheet 1, and the thermal printing is performed from the back side of the thermal transfer sheet using the heating means of the thermal printer. A multicolor image may be formed. In this case, the receiving sheet may be ordinary paper or synthetic paper when used for the thermal transfer sheet 1 having a leuco dye layer and a color developer layer.

The amount of color developer transferred to the receiving sheet 1-, in which a plastic film or the like is used, is 1 to 10 parts by weight, preferably 2 to 5 parts by weight, per 1 part by weight of the leuco dye transferred. Good. When forming an image in this way, the total amount of leuco dye and color developer transferred is about 1' to the support.
The amount of transfer may be approximately t,/rrr, and a high-density image can be obtained with this amount of transfer.

On the other hand, when using the heat-sensitive transfer sheet 1- having only a leuco dye layer, the receptor sheet used is one in which a color developer layer is provided on a support.

In the present invention, the heat-sensitive transfer sheet is heated in accordance with the color tone information, as described above. For example, the thermal transfer sheet of the second invention (FIGS. 1 and 3).

4), if the desired color of the recorded image is yellow, magenta, cyan, or black, 4
The leuco dye layer and the color developer layer, which develop colors corresponding to the respective colors, are heated, and the leuco dye and the color developer are caused to undergo a transfer reaction onto the receiving sheets 1 to 1. In this case, the heating order of the leuco dye layer and the color developer layer is arbitrary; the color developer layer may be heated after the leuco dye layer, or the heating order may be reversed. −
- On the other hand, when obtaining 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 types of 90 ico dye layers are heated, or the developer layer may be heated. After heating the layer, the two leuco dye layers may be heated. In addition, when using the heat-sensitive transfer sheet of the second invention (Fig. 2), an appropriate leucocontainer is added as described above so that an image of a desired color can be obtained on the receptor sheet having a color developer layer. The dye layer may be selected and transferred by heating.

〔effect〕

According to the present invention, a clear multicolor image can be formed on a receiving sheet, and the same thermal transfer sheet 1 to
can be used to obtain multiple copies. In addition, in the case of the present invention, the thermal transfer sheet J- has a plurality of leuco dye layers that develop different colors, or a plurality of leuco dye layers that develop different colors and a color developer layer. 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 prepared in the same way as the previous one by simply moving the same thermal transfer sheet. Since it can be used for many purposes, it is suitable for making a large number of copies. Moreover, in the case of the present invention, to thermal transfer sheet 1.
2 is provided with a conductive layer that serves as a means for accurately detecting its position (the position of the leuco dye layer or color developer layer on the thermal transfer sheet 1). By operating in conjunction with the thermal transfer sheet drive system, the thermal transfer sheet 1- can be accurately moved and set, and a clear multicolor image without color shift can be obtained.

[Brief explanation of the drawing]

FIGS. 1 to 5 are explanatory diagrams of the heat-sensitive transfer sheet used in the present invention. In FIG. 1, each leuco dye Na to d and the color developer layer e are arranged horizontally in the direction of the arrow, and the color developer layer e is arranged between each leuco dye layer a''d. Fig. 2 shows an example in which a conductive layer k is disposed on the side edge of a heat-sensitive transfer sheet in which the combination shown in Fig. 2 is a folding unit. Fig. 3 shows an example in which conductive layers are disposed on the side edges of thermal transfer sheets 1 to 1 in which the disposed combination is a repeating unit. An example is shown in which a conductive layer k is disposed at the side edge of the thermal transfer sheet 1, in which the color developer layer e is arranged in the vertical direction as a repeating unit. An example is shown in which a conductive layer is provided at the boundary between the leuco dye layer and the color developer layer in the thermal transfer sheet of 1. Figure 5 shows the principle for detecting the position of the thermal transfer sheet 1 of the present invention. It is an explanatory diagram. a... Leuco dye layer that develops yellow b... Leuco dye layer C that develops magenta... Cyan Leuco dye layer d that develops color
・・・・・・Leuco dye layer e that develops black color
...... Color developer layer k... Conductive layer N1. ＋"2... Conductive layer detection electrode... Thermal transfer sheet 1 ~ Patent applicant Rico Co., Ltd. - Representative patent attorney Toshiaki Ikeura No. 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) A combination of a leuco dye layer that is used in combination with a receptor sheet that has a color developer layer and that develops different colors for multicolor development, and a leuco dye layer that develops different colors. A thermal transfer sheet comprising a repeating unit as a repeating unit, characterized in that a conductive layer is provided at a side edge or boundary of at least one leuco dye layer forming the repeating unit. Heat transfer sheet. (2) Used in combination with a receptor sheet, having a leuco dye layer and a developer layer that develop different colors for multicolor development, and a leuco dye layer and a developer layer that develop different colors. In the thermal transfer sheet 1 in which the combination with the dye layer is configured as a repeating unit, the beveled end portion of at least one layer selected from the leuco dye layer and the color developer layer constituting the repeating layer or Border ◆: A heat-sensitive transfer sheet for multicolor images characterized by providing a conductive layer.