JP2022064631A - Sublimation transfer sheet - Google Patents

Abstract

To provide a sublimation transfer sheet that can form a yellow image of high density and high chroma, without scumming.SOLUTION: A sublimation transfer sheet 10 has a transfer ink layer 12Y containing a sublimable dye. The sublimable dye contains both of a yellow dye represented by formula (1) and an anthraquinone yellow dye. The weight ratio of the yellow dye represented by formula (1) to the anthraquinone yellow dye is 90: 10-55: 45.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sublimation transfer sheet in which a transfer ink layer containing a sublimation dye is provided on a sublimation transfer sheet substrate.

Such sublimation transfer sheets are well known. By superimposing this sublimation transfer sheet on the transfer target and heating it, the dye in the transfer ink layer is sublimated, permeates the surface of the transfer target, is dyed, and develops color. Dyes need to sublimate at relatively low temperatures, which is why dyes without polar groups are widely used. As the transferred body to which the dye having no polar group is dyed to develop a color, a body having a surface made of a hydrophobic resin is used. For example, polyester or polyvinyl chloride. For paper or the like having a hydrophilic surface, a hydrophobic resin is laminated on the surface to form an image receiving layer.

Transfer is possible, for example, by heating with a thermal head. That is, by pressing the thermal head against the back surface of the sublimation transfer sheet and energizing the heat generating element of the thermal head to generate heat, the dye in the portion corresponding to the heat generating element can be selected and transferred. At this time, the dye is not transferred to the portion where the heat is not generated, even in the vicinity of the element where the heat is generated. In this way, the sublimation transfer sheet can be heated in a pattern to form a pattern image on the surface of the transferred object.

In this sublimation transfer method, the dye permeates the surface of the transferred object and is dyed to develop a color, so that various advantages are mentioned along with this. For example, the formed image is highly wear resistant. Even if the surface of the transferred object is worn, the dye penetrates into the inside, so that the image is not easily worn.

Further, since the density of the image can be controlled by the amount of the dye that has penetrated and dyed, it is easy to form an image with shades. Further, for the same reason, when sublimation dyes that develop different colors are used and transferred a plurality of times, an image of the mixed color can be formed.

For example, transfer using a transfer ink layer containing a sublimation dye that develops color in magenta, then transfer using a transfer ink layer containing a sublimation dye that develops yellow, and finally color development in cyan. By transferring using a transfer ink layer containing a sublimating dye, it is possible to form a full-color image consisting of three colors, magenta, yellow and cyan. Of course, this full-color image is a shaded image.

Since the image is formed by dyeing a dye having no polar group, it has a drawback that it has a relatively weak light resistance and easily fades.

By the way, in order to form a full-color image in this way, a transfer ink layer containing a sublimation dye that develops a magenta color, a transfer ink layer containing a sublimation dye that develops a yellow color, A sublimation transfer sheet in which transfer ink layers containing a sublimation dye that develops a color in cyan are arranged in a surface-sequential manner is also known (Patent Document 1).

Japanese Unexamined Patent Publication No. 2002-103828

By the way, when a full-color image is formed by using such a sublimation transfer sheet, in order to form a high-quality image, the color is not only the desired color but also the density and saturation. It is desired that an image with a high color can be transferred and formed. When the density and saturation cannot be increased sufficiently, the range of full-color images that can be formed by this transfer method is limited. It should be noted that even in the case of a monochromatic image, it is similarly desired to form an image with high density and high saturation.

Further, it is also required that the portion not transferred is not soiled by the dye. That is, it is necessary that the dye is sufficiently transferred in the heated portion to develop a high-concentration and high-saturation color with the desired color, while the dye is not transferred at all in the unheated portion.

The present invention has been made focusing on a transfer ink layer containing a sublimation dye that develops a yellow color among the transfer ink layers of each color, and can transfer and form a high-density and high-saturation yellow image. Moreover, at this time, it is an object of the present invention to provide a sublimation transfer sheet that does not cause background stains.

That is, the invention according to claim 1 is a sublimation transfer sheet having a transfer ink layer containing a sublimation dye on a sublimation transfer sheet substrate.
The sublimable dye contains both a yellow dye represented by the following chemical formula (1) and an anthraquinone-based yellow dye.
Further, the sublimation transfer sheet is characterized in that the weight ratio of the yellow dye represented by the chemical formula (1) to the anthraquinone-based yellow dye is 90:10 to 55:45.

次に、請求項２に記載の発明は、前記アントラキノン系黄色染料が、Ｃ．Ｉ．Ｄｉｓｐｅｒｓｅ Ｙｅｌｌｏｗ ２０１から成ることを特徴とする請求項１に記載の昇華転写シートである。

Next, in the invention according to claim 2, the anthraquinone-based yellow dye is C.I. I. The sublimation transfer sheet according to claim 1, wherein the sublimation transfer sheet comprises Disperse Yellow 201.

As can be seen from the examples and comparative examples described later, according to the present invention, a yellow image having high density and high saturation can be transferred and formed, and at this time, no background stain is generated. The transferred yellow image exhibits a yellow color with high color purity.

FIG. 1 relates to a specific example of a sublimation transfer sheet, FIG. 1 (a) is a plan view thereof, and FIG. 1 (b) is a cross-sectional view. FIG. 2 is a cross-sectional view of a specific example of the image receiving sheet. FIG. 3 is a cross-sectional view of a specific example of the protective layer transfer sheet. FIG. 4 is an explanatory diagram of the indirect transfer printing method.

Hereinafter, specific examples of the present disclosure will be described with reference to the accompanying drawings. FIG. 1 relates to a specific example of the sublimation transfer sheet of the present invention, FIG. 1 (a) is a plan view thereof, and FIG. 1 (b) is a cross-sectional view.

As can be seen from FIGS. 1 (a) and 1 (b), the sublimation transfer sheet 10 has three types of transfer ink layers 12Y, 12M, and 12C arranged in a surface-sequential manner on the film serving as the base material 11. It is a thing.

The three types of transfer ink layers 12Y, 12M, and 12C are transfer ink layers containing a sublimation dye, and the dye is dyed on the transferred object by heating to form a transfer image. The dyes contained in these three types of transfer ink layers 12Y, 12M, and 12C are dyes that develop colors in the three primary colors, respectively, and the dyes contained in the transfer ink layer 12Y are dyed on the transferred object. It develops a yellow color. Further, the dye contained in the transfer ink layer 12M is dyed on the transferred body to develop a magenta color, and the dye contained in the transfer ink layer 12C is dyed on the transferred body to develop a cyan color. In this example, the yellow transfer ink layer 12Y, the magenta transfer ink layer 12M, and the cyan transfer ink layer 12C are arranged in this order, but the order is not limited to this, and the arrangement may be arbitrary. In any case, a full-color transfer image can be formed on the transferred body by transferring and dyeing the dyes that develop colors in the three primary colors of these colors.

Examples of the sublimation transfer sheet base material 11 include synthetic resin films such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, cellophane, acetate, polycarbonate, polysulfone, polyimide, polyvinyl alcohol, aromatic polyamide, aramid, and polystyrene, and condenser paper. , Paraffin paper and other papers can be used. Of these, polyethylene terephthalate film is preferable in consideration of physical characteristics, processability, cost, and the like. The thickness thereof is not particularly limited, and is, for example, 2 to 50 μm.

The three types of transfer ink layers 12Y, 12M, and 12C containing a sublimation dye usually contain a binder for fixing the dye in addition to the sublimation dye.

Of these three types of transfer ink layers, the dye contained in the transfer ink layer 12Y that develops a yellow color needs to be both a yellow dye represented by the following chemical formula (1) and an anthraquinone-based yellow dye.

このように転写インキ層１２Ｙが化学式（１）で示される黄色染料とアントラキノン系黄色染料の両者を含有する場合には、後述する実施例及び比較例から分かるように、高濃度かつ高彩度の黄色の画像を転写形成することができ、しかも、この際、地汚れを生じない。そして、形成された黄色の画像は、高い色純度の黄色を呈するため、その他の転写インキ層１２Ｍ，１２Ｃによってマゼンタの画像及びシアンの画像を形成することにより、全体としてフルカラーの画像を表現することができる。

As described above, when the transfer ink layer 12Y contains both the yellow dye represented by the chemical formula (1) and the anthraquinone-based yellow dye, as can be seen from Examples and Comparative Examples described later, a high-concentration and high-saturation yellow color is used. The image can be transferred and formed, and at this time, no background stain is generated. Since the formed yellow image exhibits high color purity yellow, a magenta image and a cyan image are formed by the other transfer ink layers 12M and 12C to express a full-color image as a whole. Can be done.

Examples of the anthraquinone yellow dye include C.I. I. Disperse Yellow 201 can be preferably used. The total of the yellow dye and the anthraquinone-based yellow dye represented by the chemical formula (1) is 100 parts by weight, the yellow dye is 90 to 55 parts by weight, and the anthraquinone-based yellow dye is 10 to 40 parts by weight.

Further, as the dye contained in the transfer ink layer 12Y that develops color in magenta, C.I. I. Disperse Red 60, C.I. I. Disperse Violet 26, C.I. I. Solvent Red 27, or C.I. I. Solvent Red 19 and the like can be mentioned.

Further, as the dye contained in the transfer ink layer 12C that develops a cyan color, C.I. I. Disperse Blue 354, C.I. I. Solvent Blue 63, C.I. I. Solvent Blue 36, or C.I. I. Disperse Blue 24 and the like can be mentioned.

Next, as the binder contained in these three types of transfer ink layers 12Y, 12M, 12C containing a sublimating dye, polyvinyl alcohol, polyvinyl acetate, polyvinylpyrrolidone, polyvinyl acetal, polyvinyl butyral and other vinyl resins, and ethyl cellulose are used. , Methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, acetate cellulose, vinegar butyrate cellulose, cellulose acetate propionate cellulose and other cellulose-based resins, polyester resin, phenoxy resin, styrene-acrylic nitrile copolymer resin, polycarbonate resin, polyacrylamide resin and the like. A resin having excellent heat resistance, dye transferability, etc. can be used.

As described above, a full-color transfer image can be formed on the surface of the transfer target by sequentially transferring and dyeing using these transfer ink layers 12Y, 12M, and 12C.

The surface of the transferred object that can form an image using the sublimation transfer sheet 10 is hydrophobic. For example, since the surface of a plastic sheet, a plastic card, or the like is generally hydrophobic, an image can be formed as a transferred body. When a hydrophilic sheet such as paper is used as a transfer body, an image receiving layer of a hydrophobic resin is formed on the surface of the sheet to form an image receiving sheet, and an image can be formed on the image receiving sheet.

FIG. 2 is a cross-sectional explanatory view showing an example of such an image receiving sheet, and the image receiving sheet 20 is configured by laminating the image receiving layer 23 on the surface of the image receiving sheet base material 21 via the porous layer 22. There is.

As the image receiving sheet base material 21, paper base materials such as condenser paper, glassin paper, sulfate paper, high-quality paper, art paper, coated paper, resin coated paper, cast coated paper, wallpaper, backing paper, and board paper are preferably used. However, the present invention is not limited to this, and a plastic film such as a polyester film or a polypropylene film may be used.

The porous layer 22 cushions the pressure during thermal transfer and enables uniform image formation. As such a porous layer 22, for example, a binder resin in which hollow particles or a porous material are dispersed to impart cushioning property can be used. Further, a foamed polypropylene film, a foamed polyethylene terephthalate, or the like can be used as the porous layer 22, or the foamable resin can be applied to the image receiving sheet base material 21 and then foamed to form the porous layer 22. It is possible.

Next, the image receiving layer 23 is formed by dyeing a dye sublimated from the sublimation transfer sheet 10 to develop a color, and a layer containing a hydrophobic resin as a main component can be used. Above all, it is desirable to apply an emulsion in which a hydrophobic resin is dispersed in an aqueous solvent to form the image receiving layer 23. For example, polyester resin emulsion, acrylic resin emulsion, vinyl chloride resin emulsion, vinyl chloride-vinyl acetate resin emulsion, vinyl chloride-acrylic resin emulsion and the like.

By the way, two kinds of methods for forming an image on a final object using this sublimation transfer sheet 10 are known. One of them is a direct transfer printing method in which an image is formed by directly transferring the final object to the surface of the final object from the thermal transfer sheet 10. In another method, an intermediate transfer film is used as a transfer target, and the image is formed by transferring (primary transfer) from the sublimation transfer sheet 10 onto the intermediate transfer film, and then this image is transferred from the intermediate transfer film to the transfer target. This is an indirect transfer printing method for (secondary transfer). The indirect transfer printing method is sometimes called a retransfer printing method.

When forming an image on the image receiving sheet 20, the direct transfer printing method is convenient. In this method, first, the transfer ink layer 12Y is superposed on the image receiving layer 23 of the image receiving sheet 20, and the thermal head is pressed from the back surface of the sublimation transfer sheet 10 to select the heat generating element and generate heat, whereby the image receiving layer 23 yellow. Form an image of. Next, the sublimation transfer sheet 10 is intermittently moved to superimpose the transfer ink layer 12M on the image receiving layer 23, and superimpose it on the yellow image to form a red image. Similarly, the transfer ink layers 12C are overlapped to form a blue image. In this way, a full-color image composed of three colors of yellow, red, and blue can be formed on the image receiving layer 23. In this direct transfer printing method, since the formed image is exposed, it is desirable to laminate a protective layer on it to protect it. The protective layer can be transferred and laminated using the protective layer transfer sheet 30 shown in FIG.

As shown in the figure, the protective layer transfer sheet 30 is formed by laminating a transparent protective layer 32 on the base material 31, which can be easily peeled off from the base material 31 during thermal transfer and can be adhered to the surface of the transferred body 20. It is composed. In order to facilitate the peeling of the transparent protective layer 32 from the protective layer transfer sheet base material 31 during thermal transfer, a peeling layer may be provided between the protective layer transfer sheet base material 31 and the transparent protective layer 32.

As the protective layer transfer sheet base material 31, the same sheet as the sublimation transfer sheet base material 11 can be used. For example, synthetic resin films such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, cellophane, acetate, polycarbonate, polysulfone, polyimide, polyvinyl alcohol, aromatic polyamide, aramid, and polystyrene, and papers such as condenser paper and paraffin paper. ..

As the release layer, a material that melts due to heat during transfer can be preferably used. For example, paraffin wax, carnauba wax, montan wax, higher fatty acid, higher alcohol, higher fatty acid ester, higher fatty acid amide.

Further, as the transparent protective layer 32, for example, a polyester resin, a polyvinyl chloride resin, methyl polyacrylic acid, an acrylic resin, polystyrene or the like can be used.

Next, when forming an image on a plastic card, the image can be formed by the direct transfer printing method, but the image can also be formed by the indirect transfer printing method.

FIG. 4 is an explanatory diagram for explaining a method of forming an image on a card 40 by using an indirect transfer printing method. As described above, the indirect transfer printing method is a method in which the intermediate transfer film 60 is used as a transfer target. Although the intermediate transfer film 60 is known, it has an image receiving layer on the surface of the intermediate transfer film base material that can be easily peeled off from the intermediate transfer film base material and can be thermally adhered to the surface of the card 40.

The card 40 is placed on the mounting table 50, and as shown by the arrow in the figure, the card 40 can be moved in the front-rear direction together with the mounting table 50.

Then, first, the intermediate transfer film 60 is unwound from the unwinding roll 60a, while the thermal transfer sheet 10 is also unwound from the unwinding roll 10a, and the transfer ink layer 12Y of the sublimation transfer sheet 10 is the image receiving layer of the intermediate transfer film 60. The thermal head 70 is pressed from the back surface of the sublimation transfer sheet 10 to form a yellow image. Then, the dye is also transferred to the transfer ink layer 12M and the transfer ink layer 12C to form a red image and a blue image by superimposing the dye on the yellow image. In this way, a full-color image composed of three colors of yellow, red, and blue can be formed on the surface of the image receiving layer.

Next, the intermediate transfer film 60 is placed on the card 40 and heat-pressed from the back surface with a heat roll 80 to transfer the image receiving layer having the full-color image. In this way, an image can be formed on the card 40. In FIG. 4, 10b shows a take-up roll for winding up the thermal transfer sheet 10 after transfer, and 60b shows an intermediate transfer film 60 after transferring the image receiving layer.

Hereinafter, the present invention will be described based on examples.

In these explanations, only the matters related to the characteristic portions of the present invention will be described. For example, for the sublimation transfer sheet, the transfer ink layer 12Y that develops a yellow color after transfer will be described, but the transfer ink layer 12M that develops a red color (magenta) and the transfer ink layer 12C that develops a blue color (cyan) will be described. The explanation is omitted.

The dyes used for this transfer ink layer 12Y are as follows.
Dye 1: The yellow dye represented by the chemical formula (1).
Dye 2: C.I. I. Disperse Yellow 201.
Dye 4: C.I. I. Solvent Yellow 93.

Further, in these examples, the sublimation transfer sheet base material is a polyester film. The transferred body is an image receiving sheet formed by laminating an image receiving layer on the surface of the image receiving sheet base material via a porous layer, and the image receiving layer is formed by applying an aqueous emulsion of a vinyl chloride resin. be.

(Example 1)
As the yellow dye, a mixture of dye 1 (the yellow dye represented by the chemical formula (1)) and dye 2 (CI Disperse Yellow 201) is used to form a transfer ink layer 12Y to form a sublimation transfer sheet. And said. Assuming that the total is 100 parts by weight, the dye 1 is 90 parts by weight and the dye 2 is 10 parts by weight.

(Example 2)
A sublimation transfer sheet was produced in the same manner as in Example 1 except that the blending ratio of the dye 1 and the dye 2 was 70 parts by weight for the dye 1 and 30 parts by weight for the dye 2.

(Example 3)
A sublimation transfer sheet was produced in the same manner as in Example 1 except that the blending ratio of the dye 1 and the dye 2 was 55 parts by weight for the dye 1 and 45 parts by weight for the dye 2.

(Comparative Example 1)
A sublimation transfer sheet was produced in the same manner as in Example 1 except that the blending ratio of the dye 1 and the dye 2 was 45 parts by weight for the dye 1 and 55 parts by weight for the dye 2.

(Comparative Example 2)
A sublimation transfer sheet was produced in the same manner as in Example 1 except that only dye 1 (the yellow dye represented by the chemical formula (1)) was used as the yellow dye.

(Comparative Example 3)
A sublimation transfer sheet was produced in the same manner as in Example 1 except that a mixture of Dye 2 (CI Disperse Yellow 201) and Dye 3 (HSY2701 manufactured by Mitsubishi Chemical Corporation) was used as the yellow dye. Assuming that the total of the dye 2 and the dye 3 is 100 parts by weight, the dye 2 is 11 parts by weight and the dye 3 is 89 parts by weight.

(Comparative Example 4)
A sublimation transfer sheet was produced in the same manner as in Example 1 except that a mixture of Dye 2 (CI Disperse Yellow 201) and Dye 4 (CI Solvent Yellow 93) was used as the yellow dye. Assuming that the total of the dye 2 and the dye 4 is 100 parts by weight, the dye 2 is 85 parts by weight and the dye 4 is 15 parts by weight.

(Evaluation methods)
Using the sublimation transfer sheets of Examples 1 to 3 and Comparative Examples 1 to 4, a yellow image was transferred and formed on the above-mentioned image receiving sheet. The transfer method is a direct transfer printing method.

That is, first, the yellow transfer ink layer 12Y of the sublimation transfer sheet was superposed on the image receiving layer of the image receiving sheet, and the transfer was performed using a thermal simulator to print a solid yellow image. Then, using the protective layer transfer sheet, the protective layer was transferred so as to cover this yellow solid image.

The yellow image thus formed was evaluated from five viewpoints. That is, the density, saturation, hue angle, light resistance, and presence / absence of background stains of the image.

(Concentration evaluation method)
Using X-rite 528 manufactured by X-rite, the density (OD) of the yellow solid image was measured and evaluated according to the following criteria.
〇: Concentration OD is 2.3 or more.
X: Concentration OD is less than 2.3.

(Saturation evaluation method)
The chromaticity of the yellow solid image was measured using X-rite 528 manufactured by X-rite. The chromaticity is the chromaticity (L ^* , a ^* , b ^* ) in the L ^* a ^* b ^* color system. Then, the saturation C ^* was calculated according to the following equation.

そして、次の基準に従って彩度を評価した。
〇：彩度Ｃ^＊が１１０以上。
×：彩度Ｃ^＊が１１０未満。

Then, the saturation was evaluated according to the following criteria.
〇: Saturation C ^* is 110 or more.
X: Saturation C ^* is less than 110.

(Evaluation method of hue angle)
Using the chromaticity (L ^* , a ^* , b ^* ), the hue angle h was calculated according to the following equation.

そして、次の基準に従って色相角を評価した。
〇：色相角ｈが８５～９５度の範囲内にある。
×：色相角ｈが８５度未満。又は、色相角ｈが９５度より大きい。

Then, the hue angle was evaluated according to the following criteria.
〇: The hue angle h is in the range of 85 to 95 degrees.
X: Hue angle h is less than 85 degrees. Alternatively, the hue angle h is larger than 95 degrees.

(Evaluation method of light resistance)
The printed matter forming the yellow solid image was put into an Arlaut Weatherometer Ci4000 manufactured by Toyo Seiki Seisakusho Co., Ltd. for 36 hours. Then, the light resistance was evaluated according to the following criteria, with the quotient of the concentration after charging and the concentration before charging (concentration after charging / concentration before charging) as the concentration retention rate.
〇: Concentration retention rate is 80% or more.
X: Concentration retention rate is less than 80%.

(Evaluation method of ground stain)
Using X-rite 528 manufactured by X-rite, the density (OD) of the white background portion of the printed matter was measured and evaluated according to the following criteria.
〇: Concentration OD is less than 0.07.
X: Concentration OD is 0.07 or more.

(Evaluation results)
The results of these evaluations are shown in Table 1.

(Discussion)
From this result, when a mixture of dye 1 (the yellow dye represented by the chemical formula (1)) and dye 2 (CI Disperse Yellow 201) was used as the yellow dye (Examples 1 to 3, comparison). Example 1) When the hue angle is in the range of 85 to 95 degrees and yellow with high color purity is exhibited regardless of the blending ratio, whereas either of these dyes 1 and dye 2 is not blended. (Comparative Examples 2 to 4), it can be understood that the hue angle does not fall within this range and the color purity as yellow is low.

Further, when the mixture of the dye 1 and the dye 2 is used, the density and saturation of the image formed by printing are excellent regardless of the blending ratio, but when the blending ratio of the dye 1 is less than 55 parts by weight. (Comparative Example 1), ground stains are likely to occur.

10: Sublimation transfer sheet 10a: Sublimation transfer sheet unwinding roll 10b: Sublimation transfer sheet winding roll 11: Sublimation transfer sheet base material 12Y: Yellow color transfer ink layer 12M: Magenta color transfer ink layer
12C: Cyan-colored transfer ink layer 20: Image receiving sheet 21: Image receiving sheet base material 22: Porous layer 23: Image receiving layer 30: Protective layer Transfer sheet 31: Protective layer Transfer sheet base material 32: Transparent protective layer 40: Card 50: Card mounting table 60: Intermediate transfer film 60a: Intermediate transfer film unwinding roll 60b: Intermediate transfer film winding roll 70: Thermal head 80: Thermal roll

Claims (2)

Sublimation transfer sheet In a sublimation transfer sheet having a transfer ink layer containing a sublimation dye on a substrate.
The sublimable dye contains both a yellow dye represented by the following chemical formula (1) and an anthraquinone-based yellow dye.
Moreover, the sublimation transfer sheet is characterized in that the weight ratio of the yellow dye represented by the chemical formula (1) to the anthraquinone-based yellow dye is 90:10 to 55:45.

The anthraquinone-based yellow dye is C.I. I. The sublimation transfer sheet according to claim 1, wherein the sublimation transfer sheet comprises Disperse Yellow 201.

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