JPH02235689A - Transfer medium for thermally sensitive recording - Google Patents

Abstract

PURPOSE:To obtain a transfer medium for thermally sensitive recording capable of keeping a formed image in satisfactory storage by providing a significantly light- fastness improving layer containing at least one type or more of ultraviolet absorber, optical stabilizer or antioxidant on a color material layer. CONSTITUTION:A transfer medium for thermally sensitive recording 1 consists of a base 2, a significantly light-fastness improving layer 4 provided on a color material layer 3 formed on one surface of the base 2, and a heat-resistant layer 5 formed on the other surface of the base 1. The base is made of paper and various resin films and the color material layer contains thermally sublimable or evaporable dye and binder resin. The color material layer 3 side and an image-receiving medium 7 are placed together, and are selectively heated in accordance with an image using a thermal head. Consequently, the dye sublimates and migrates from the color material layer 3 to the image-receiving medium 7 to form an image. In this case, an optical stabilizer or an antioxidant are transferred from the significantly light-fastness improving layer 4 to the image-receiving medium 7, or sublimates in or fuses, diffuses and migrates to the latter. Thus the optical stabilizer is supplied to only the color developing part of the image-receiving medium. Consequently the image can be kept in storage for a long time without deteriorating the whiteness of the part where no image is formed.

Description

[Detailed description of the invention] Rescue date five delta machine antitrust The present invention relates to a sublimation type transfer body for thermal recording.

More specifically, the present invention relates to a heat-sensitive recording transfer member capable of forming recorded images with excellent storage stability on an image receptor.

Conventional Technology In recent years, with the spread of information terminals such as personal computers, word processors, televisions, and VTRs, the use of color displays has rapidly progressed, and the demand for printers that output these still images as color images is increasing year by year. . Recording methods for such full-color printers include an electrophotographic method, an inkjet method, a thermal transfer method, and the like. Among these, the thermal transfer method is widely used because it is noiseless, the apparatus is easy to maintain, and can be miniaturized.

This thermal transfer method consists of a combination of a fixed color ink sheet and an image receiving paper. Image formation is performed by heat-melting transfer or sublimation transfer of ink from a thermal transfer material (ink sheet) to a thermal transfer receiving paper using thermal energy controlled by electrical signals from a laser or thermal head, etc. Depending on the transfer method, it can be divided into thermal melt transfer type and sublimation transfer type.

Among these, the sublimation transfer type thermal transfer method generally uses a thermal transfer paper having a coloring material layer in which easily sublimable disperse dyes are bound by paint glue, and superimposes the coloring material layer on the coloring material layer using the thermal energy of a thermal head. The dye is sublimated and transferred to the image receptor to form an image. Such transfer paper is known to have three color ink layers containing yellow, magenta, and cyan sublimable dyes arranged in sequential order.
A full-color image is formed by overlapping and printing the three color material layers. In addition, a heat-resistant layer is provided on the side of the transfer paper that comes into contact with the thermal head.
No. 7467, JP-A-57129789, etc. disclose heat-resistant resins and resins in which a lubricant such as a surfactant or wax is added.

In such a sublimation transfer type thermal transfer method, the amount of sublimable dye that corresponds to the amount of thermal energy of the thermal head sublimates, making it easy to obtain intermediate tones and to control the gradation as desired. It has five advantages and is considered to be the most suitable method for full-color printers in terms of price.On the other hand, as a thermal transfer image receptor used in such a sublimation transfer type thermal transfer method, for example, saturated polyester resin A dyeing resin layer made of a thermoplastic resin with excellent dyeability for sublimation dyes, such as polyamide resin, epoxy resin, or acrylic resin, is provided on a base sheet such as plain paper, synthetic paper, or plastic film, and then Some are equipped with a heat-resistant layer to prevent fusion with the thermal head.

Problems to be Solved by the Invention However, the heat-sensitive transfer material used in the conventional dye-sublimation thermal transfer method has the drawback that the dye transferred to the image receptor fades over time due to ultraviolet rays in natural light, etc., making it difficult to see. Conventionally, no consideration has been given to the transfer body itself for thermal recording to address these problems, and generally light stabilizers (ultraviolet absorbers), antioxidants, etc. are added to the image receptor. , methods to avoid photodegradation have been adopted. On the other hand, since the temperature of the thermal head reaches 300 degrees Celsius during printing, there is a risk that the dyeing resin on the image receptor will soften due to the heat and fuse with the transfer body, making it impossible to run or causing abnormal dye transfer. In order to prevent this, the dyed resin is cured, especially photocured. Since such photocuring is prevented by the combination of the above-mentioned light stabilizers, etc., the dyeing resin layer containing these stabilizers fuses to the transfer body during printing, making it impossible to run or causing abnormal dye transfer. There is a risk that this may occur. Therefore, conventionally there has been a limit to the amount of light stabilizers and antioxidants that can be added to image receptors.

The present invention relates to a heat-sensitive recording transfer body in which a coloring material layer containing a dye and a binder resin that sublimes or vaporizes by heat is provided on a substrate, further above the coloring material layer. The present invention provides a transfer body for heat-sensitive recording, characterized in that it is provided with a light resistance improving layer containing one or more of an ultraviolet absorber, a light stabilizer, or an antioxidant.

Next, the present invention will be specifically explained with reference to the drawings. As shown in FIG. 1, the thermal recording transfer member (1) of the present invention comprises a base (2), a coloring material layer (3) provided on one surface of the base, and a coloring material @( 3), and a heat-resistant layer (5) provided on the other surface of the base (1).

Examples of the substrate used in the transfer body of the present invention include paper and various resin films, such as capacitor paper, polycarbonate film, polyimide film, and polyester film.

The coloring material layer contains a dye that sublimes or vaporizes by heat and a binder resin. Examples of the binder resin used in the color material layer include polyester resin, polyamide resin, epoxy resin, polycarbonate resin, butyral resin, and acrylic resin.

Further, as the dye, any sublimation or vaporizable dye conventionally known in this field can be used.

Further above the colorant layer is a separate layer containing a light stabilizer and an antioxidant. As the light stabilizer and antioxidant 12, those commonly used in the past can be used. For example, any material that can be thermally transferred, sublimated, vaporized, or melted and diffused can be used.

Examples of light stabilizers include salicylic acid-based penzotriazole-based, penzophenone-based, penzoate-based cyanoacrylate-based, hindered amine-based, nickel-based, and the like. Furthermore, examples of antioxidants include phenol-based, amine-based, sulfur-based, and phosphorus-based antioxidants.

Each of these light stabilizers, ultraviolet absorbers, and antioxidants may be used alone, or two or more types may be used in combination as appropriate.

The light stabilizer and the like may be dispersed in a binder resin, or may form a single layer without using a binder. The layer thickness is 0.1 μm or more, preferably 0.2-0
．． It is 3 μm. If the amount of these stabilizers, ultraviolet absorbers, etc. is less than the above range, the amount transferred to the image receptor will decrease and the storage stability of recorded images will not improve.

In order to manufacture the transfer body of the present invention, any conventionally known transfer body manufacturing method can be used, and the thickness of the coloring material layer is usually 0.5 to 5 μm, preferably 0.5 to 2 μm.
That's about it.

Next, a method of performing transfer using the transfer body for thermal recording of the present invention will be explained. In FIG. 1, (6) represents a thermal head, and (7) represents an image receptor. The transfer body (1) for thermal recording of the present invention is stacked with the coloring material layer (3) side on the image receptor (7), heated selectively according to the image by the thermal head (6), and the coloring material layer The dye sublimes (vaporizes) and transfers from (3) to the image receptor (7) to form an image. At the same time, the light stabilizer or antioxidant in the light fastness improving layer (4) is transferred to the image receptor (7), or sublimated (vaporized), melted and diffused, and the light stabilizer or antioxidant is transferred only to the colored part of the image receptor. etc. will be supplied.

Therefore, it is possible to improve the long-term storage stability of the image without reducing the whiteness of the portion (white portion) where no image is formed.

Function: When the transfer member of the present invention is overlapped with an image receiving member for printing, part or all of the light fastness improving layer is thermally transferred to the surface of the image receiving paper along with the transfer of the dye.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A hexane solution (1% by weight) of UV-curable silicone X62-7223 manufactured by Shin-Etsu Chemical Co., Ltd. was applied to a polyphenylene sulfide film (thickness 6 μR) using a gravure coater and dried (dry coating amount: 0. 1 g/m”)
. Next, it was irradiated with ultraviolet rays of 20 taJ/cm" to form a heat-resistant layer. On the other hand, a sublimable dye (Kaya Set Red, manufactured by Nippon Kayaku Co., Ltd.) and a saturated polyester (
Byron 20SS, manufactured by Toyobo Co., Ltd.) (binder/dye ratio: Y: 70/30, M: 75/25)
, C+60/40) using a gravure coater (
The coating thickness was 1 μm), and the coloring material layer was formed. A methanol solution (3%) of an ultraviolet absorber (SBIOI: Shiraishi Calcium) was applied onto the coloring material layer using a gravure coater and dried at room temperature to provide a light resistance improving layer.

On the other hand, the image receptor is made of PP synthetic paper (manufactured by Oji Yuka Co., Ltd.) with a saturated polyester tree as a dyeing resin. (Byron #200
) was applied (thickness: 10 μm). Next, UV-curable silicone manufactured by Shin-Etsu Chemical Co., Ltd. was applied as a heat-resistant layer (thickness: 0.05 μm) on the dyed layer to obtain an image-receiving sheet. These transfer sheets and image-receiving sheets were combined and printed using a video printer (manufactured by Hitachi, Ltd., VY-25).

This image-receiving paper was irradiated with ultraviolet rays with an integrated light intensity of 3.6 J/cg+", and the light resistance (chromaticity difference before and after irradiation: ΔE) was measured. The results were shown in Figure 2.As is clear from Figure 2, the light resistance of the image-receiving paper was improved by providing a light resistance improving layer on the color embossing of the transfer sheet. improved.

Comparative Example 1 A transfer paper was produced in the same manner as in Example 1 except that the light resistance improving layer was not provided. The results of measuring light resistance are shown in FIG.

Effect of moxibustion According to the transfer body of the present invention, when printing by heating with a thermal head, etc., the sublimable dye in the color material layer sublimates and transfers to the dyeing resin layer of the image receptor for thermal recording, and at the same time improves light resistance. By transferring, sublimating (vaporizing) or melting and diffusing the light stabilizer or antioxidant in the layer to the image receptor, it is possible to supply the light stabilizer etc. only to the coloring part of the image receptor.
The storage stability of the formed image is significantly improved. Further, since the light fastness improving layer is provided separately from the coloring material layer, printer malfunctions caused by abnormal transfer or fusion between the transfer member and the image receiver do not occur.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating a printing process using the transfer body for thermal recording of the present invention, and FIG. 2 is a graph showing the results of a light resistance test.

Claims (3)

[Claims] (1) In a transfer body for heat-sensitive recording in which a coloring material layer containing a dye that sublimes or vaporizes by heat and a binder resin is provided on a substrate, further above the coloring material layer, an ultraviolet absorber,
1. A transfer material for heat-sensitive recording, comprising a light resistance improving layer containing one or more of a light stabilizer and an antioxidant. (2) The transfer body for heat-sensitive recording according to claim 1, wherein the light resistance improving layer does not contain a binder resin. (3) The transfer body for heat-sensitive recording according to claim 1, wherein the light resistance improving layer has a thickness of 0.1 μm or more.