JP2001341438A - Thermal transfer accepting sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clear detection mark without transferring to a surface under a rolled state in a rolled thermal transfer accepting sheet. SOLUTION: In the thermal transfer accepting sheet, in which an accepting layer is provided on one side of a support, the accepting layer is wound in a roll and printed with an electron beam curing type ink or with an ultraviolet curing type ink.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer receiving sheet, and more particularly to a roll-shaped thermal transfer receiving sheet wound in a roll.

2. Description of the Related Art A thermal printer, particularly a dye thermal transfer printer capable of printing a clear full-color image, has attracted attention. Dye thermal transfer printer, the receiving layer containing the dye-dyeable resin of the receiving sheet is overlaid on the dye ink sheet, and the heat supplied from the thermal head etc.,
The image is formed by transferring a predetermined amount of the dye at a required portion of the dye layer onto the receiving layer. The ink sheet is composed of three colors of yellow, magenta and cyan, or four colors of black and black. A full-color image is obtained by repeatedly transferring the dyes of each color of the ink sheet to the receiving sheet in order.

With the development of thermal printers and the development of digital image processing by computers, the obtained images have been greatly improved, and the thermal transfer system is expanding its market. Typical examples include printing and proofing and printing of prints and designs, endoscopes in the medical field, image output of CT scans, facial and calendar photos in the amusement field, and ID cards and credit cards in the ID photo field. And the like.

Heretofore, as a receiving sheet, several tens of sheet sheets cut into a certain size have been used as a set, which is mounted on a cassette of a printer. In this case, when the friction between the receiving sheets is large or when the receiving sheets come into close contact with each other due to static electricity, there is a problem that conveyance failures in the printer easily occur such that several sheets are fed simultaneously. Therefore, in order to improve the transportability, printers have been developed in which a receiving sheet is set in a roll form, cut after printing, and used. Accordingly, there is an advantage that it is possible to cope with diversification of print size and increase of the number of prints.

[0003]

However, when printing yellow, magenta and cyan colors on a roll-shaped receiving sheet,
It is necessary that each print does not shift. In order to prevent this color shift, it is conceivable to print a detection mark indicating the printing start position on the back surface of the receiving sheet and print it using this as a guide. When printing on the back surface using oil ink, solvent ink, etc. that are often used, the print is transferred to the surface of the receiving sheet (receptive layer surface) that is in contact with the roll, and the surface of the receiving sheet becomes dirty. easy. In particular, the dye thermal transfer receiving sheet is required to have a storage property at a high temperature of about 50 ° C., but at this temperature, the above-described printing transfer is particularly likely to occur. In addition, if a detection mark is provided on the back surface using an aqueous ink having a low content of alcohol and wax, printing can be prevented from being transferred to the front surface of the receiving sheet, but if the printing speed is low and drying is insufficient, blocking occurs. In some cases, the printing ink is transferred to the surface. Further, the sharpness of the print surface is insufficient, and the position indicated by the detection mark becomes unclear, which is inconvenient.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to provide a roll-shaped thermal transfer receiving sheet which does not transfer to the surface in a roll state and provides a clear detection mark. . The surface of the receiving sheet (dye receiving layer) has high compatibility with the drying oil, mineral oil, solvent and the like of the ink vehicle. For this reason, when the receiving sheets overlap in the roll state, it is considered that the printing ink on the back surface is transferred to the front surface. To avoid this transfer, it is conceivable to use an aqueous ink having low compatibility with the receiving layer, but there are restrictions on the material for preventing the print transfer. That is, it is necessary to reduce the content of alcohol and wax. However, printing speed is slow,
In addition, the sharpness of the printed surface becomes insufficient. If the detection mark is unclear, the position indicated by the detection mark is also unclear, which is inconvenient.

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the problems can be solved by using a specific printing ink, and have reached the invention. The present invention relates to a thermal transfer receiving sheet provided with a receiving layer on one side of a support, wherein the receiving sheet is wound up in a roll shape, and is provided with printing with an electron beam curable ink or an ultraviolet curable ink. It is a thermal transfer receiving sheet characterized by the above.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is characterized in that the receiving sheet is wound up in a roll shape, and is provided with printing using an electron beam curable ink or an ultraviolet curable ink. The detection mark is most useful for printing with an electron beam-curable ink or an ultraviolet-curable ink, but it can also be applied to tint block printing, printing of a company name, logo or trademark, and the like.

The detection marks referred to in the present invention can be exemplified by the following marks, but are not limited thereto. Marks (alignment marks) provided at equal intervals on the roll-shaped receiving sheet and used for alignment when printing.
By printing each color of yellow, magenta, and cyan using this as a mark, it is possible to prevent the deviation of the printing of each color. This mark is desirably detectable by a sensor. A mark (remaining amount mark) for indicating the remaining amount of the roll-shaped receiving sheet. If the mark is provided according to the distance from the core, the remaining amount of the roll-shaped receiving sheet can be indicated. With this mark, the next sheet can be prepared before the sheet is cut. This mark does not need to be detected by the sensor, and it is sufficient if the remaining amount can be detected (recognized) visually. Of course, it is also possible to detect with a sensor and warn with a monitor, display and alarm. A mark (end mark) indicating that the printable portion of the receiving sheet has been eliminated by providing a detection mark near the core of the roll-shaped receiving sheet. This mark warns that the sheet has run out. It is preferable to detect with a sensor and warn with a monitor, display and alarm. These marks can be appropriately formed at appropriate positions on the front and back surfaces of the receiving sheet. Of course, it is visually preferable to provide it on the back surface. Further, when it is formed on the front side, it is preferable to form it on the margin of the sheet so as not to affect the thermal transfer recording.

According to the present invention, a detection mark or the like is printed by printing an electron beam curable ink or an ultraviolet curable ink. UV-curable inks include pigments, oligomers (prepolymers,
It comprises a photopolymerizable low polymer), a monomer (reactive diluent, a photopolymerizable monomer), a photopolymerization initiator (sensitizer), and other additives. The electron beam curable ink is composed of almost the same components as the ultraviolet curable ink except that no photopolymerization initiator is used.

Examples of the oligomer include epoxy acrylate, urethane acrylate, polyester acrylate, copolymer acrylate, polybutadiene acrylate, silicon acrylate, amino resin acrylate, alicyclic epoxy resin, glycidyl ether epoxy resin, urethane vinyl ether, and polyester vinyl ether. No.

As the monomer, for example, monofunctional acrylate, difunctional acrylate, trifunctional acrylate,
-6 functional acrylates, alicyclic epoxy resins, glycidyl ether epoxy resins, urethane vinyl ethers, and polyester vinyl ethers.

Examples of the photopolymerization initiator include benzophenone, acetophenone, thioxanthone, phosphine oxide, sulfonium salts and iodonium salts.

Known materials can be used for the pigments and additives.

In the case of an ultraviolet-curable ink, drying of the ink is performed by polymerizing the ink vehicle by irradiation of an ultraviolet lamp incorporated in a printing machine.
By printing in this way, drying of the ink is already completed before the paper is wound up or stacked, so even if the printing surface comes into contact and a certain amount of pressure is applied, printing transfer is acceptable. It can be suppressed to the extent possible. The printing accuracy and sharpness of this method are almost the same as those of general oil inks, and are much better than those using water-based inks. Further, in this printing method, the drying becomes faster as the irradiation of the ultraviolet ray is increased, so that the printing speed can be greatly increased as compared with the case of the aqueous ink.

In the case of an electron beam-curable ink, the irradiation is carried out by irradiating an electron beam from an electron beam irradiation device incorporated in a printing machine to polymerize the ink vehicle. Since the drying of the ink is performed instantaneously by electron beam irradiation, the occurrence of ink transfer after printing can be suppressed to an acceptable range, similarly to the ultraviolet curable ink.

The receiving sheet of the present invention has a structure in which a receiving layer is formed on a support. The receiving layer and the support of a known thermal transfer receiving sheet can be applied, except that a structure in which the receiving layer is wound up in a roll shape is employed. .

The receiving layer of the receiving sheet is a layer formed by applying and drying a coating liquid containing a resin having a high dye-dyeing property as a main component and appropriately adding a crosslinking agent, an anti-fusing agent, an ultraviolet absorber and the like. The resin having a high dye-dyeing property is not particularly limited, but a cellulose resin, a polyvinyl acetal resin, a polyester resin, a polycarbonate resin, an acrylic resin, polyvinyl chloride, or the like is used. If necessary, a crosslinking agent, silicone oil, a colored pigment, a colored dye, a fluorescent dye, a plasticizer, an antioxidant, a pigment, an ultraviolet absorber, and the like may be added as long as the effects of the present invention are not impaired. Isocyanate compounds and epoxy compounds are used as crosslinking agents, and benzotriazole, benzophenone, phenyl salicylate and cyanoacrylate compounds are used as ultraviolet absorbers. Lubricants and release agents are used as anti-fusing agents. For example, amino- or hydroxy-modified silicone oils, silicone resins such as acrylic silicone resins, prepolymers of silicone oil and isocyanate, silicone compounds, fluorine compounds, phosphoric acid Ester compounds and fatty acid ester compounds. It is preferable that these receiving layer components cause a crosslinking reaction via a crosslinking agent.

The coating amount of the receiving layer is adjusted within the range of 1 to 12 g / m ² , preferably 3 to 10 g / m ² . By the way, if the coating amount of the receiving layer is less than 1 g / m ² , the receiving layer cannot completely cover the base material surface, resulting in deterioration of image quality, or adhesion of the receiving layer and the ink sheet due to heating of the thermal head. Fusion problems may occur. On the other hand, when the coating amount of the receiving layer exceeds 12 g / m ² ,
Not only is the effect saturated and uneconomical, but also the strength of the receiving layer is insufficient, or the thickness of the receiving layer is increased, so that the heat insulating effect of the base material is not sufficiently exhibited, and the image density may be reduced.

Examples of the support include paper base materials such as high quality paper, coated paper, art paper, cast coated paper, and laminated paper;
A film (including synthetic paper) of polyolefin, polyester, nylon, or the like, or a laminate thereof can be used. The film may have a single-layer structure or a multilayer structure, and is preferably a porous film having voids (voids) inside by stretching.

On the back surface of the receiving sheet, a binder, an antistatic agent, a release agent, a higher fatty acid and its salt, an inorganic pigment,
A back surface treatment layer containing an organic pigment, a fluorescent dye or the like as appropriate can also be formed.

Hereinafter, the present invention will be described in more detail by way of examples, but it is needless to say that the present invention is not limited thereto. In the examples, "parts" and "%" all indicate "parts by weight" and "% by weight".

Example 1 "Receiving sheet" coated paper (trademark: OK Topcoat N)
127.9 g / m ² , manufactured by Oji Paper Co., Ltd.), on both surfaces of which a polyolefin resin as a main component, an inorganic pigment, a biaxially stretched 50 μm thick multilayer structure film (trade name: FPG50, Oji Yuka Synthetic Paper) was laminated and bonded by a dry lamination method with a urethane-based adhesive to prepare a sheet-like support. On the front side of the support, the following coating solution for a receiving layer is coated so that the coating amount of solid content is 8 g / m ² ,
The receiving layer was formed by drying (120 ° C., 1 minute). Further, this sheet was wound up in a roll form, and crosslinking of isocyanate was advanced in an oven at 60 ° C. to obtain a receiving layer laminated sheet. This is called a receiving sheet.

“Receptive layer coating liquid” 100 parts polyester resin (trade name: Byron 200, manufactured by Toyobo Co., Ltd.) 100 parts silicone resin (trade name: KF101, manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts isocyanate (trade name: Takenate D-140N) 5 parts, 300 parts toluene

"Ultraviolet curable ink printing" An ultraviolet curable ink (trade name: FDSP Toyo Ink K.K.) was applied to the non-receptive layer surface (back surface) of this receiving sheet by a letterpress rotary printing machine.
K. ), Four-color printing was performed. The drying of the ink
Immediately after the printing of each color, irradiation was performed with ultraviolet light from an ultraviolet lamp attached to the printing machine to obtain a receiving sheet.

Example 2 On the back surface (non-receptive layer surface) of a receiving sheet, the following liquid for a back coating layer was applied so as to have a solid coating amount of 3 g / m ² and dried (120 ° C., 1 minute) ) To form a back layer.

[Liquid for Back Coating Layer] Polyvinyl acetal resin solution (trade name: Esrec KX-1, manufactured by Sekisui Chemical Co., Ltd.) 25 parts Polyacrylate resin solution (trade name: Julimer AT613, manufactured by Nippon Pure Chemical Co., Ltd.) 12 parts Nylon resin particles (average particle size: 7 μm, manufactured by Shinto Fine Co., Ltd.) 3 parts Silicone resin (trade name: KF101, manufactured by Shin-Etsu Chemical Co., Ltd.) 2 parts Zinc stearate dispersion (trade name: Z-7-30, 3 parts Cationic conductive polymer (trade name: Chemistat 9800, manufactured by Sanyo Chemical Co., Ltd.) 6 parts Water 42 parts Isopropyl alcohol 56 parts

Thereafter, in the same manner as in Example 1, the back surface was subjected to UV curable ink coating printing to obtain a receiving sheet.

Example 3 On the non-receptive layer side (back side) of the receiving sheet, four-color printing was performed with an electron beam-curable ink (trade name: Dicure EBM, manufactured by Dainippon Ink and Chemicals). Drying of the ink was performed by electron beam irradiation using an electron beam irradiation device attached to the printing machine, and a receiving sheet was obtained.

COMPARATIVE EXAMPLE 1 Oil ink (TOYO KING BRIGH) was applied to the non-receptive layer surface (back surface) of the receiving sheet using an offset printing machine.
T, manufactured by Toyo Ink Co., Ltd.) to obtain a receiving sheet.

"Print transfer evaluation" After the paper wound around the reeler after printing was allowed to stand at 45 ° C. for 24 hours in this state, the paper was unwound, and the print was transferred (the ink used for printing on the back surface was transferred to the coated surface of the receiving layer. Or not). The determination of the print transfer is performed in the following two stages. ：: No transfer of back side printing to the receiving layer side. ×: Transfer of back side printing to the receiving layer surface.

[0030]

[Table 1]

[0031]

According to the receiving sheet of the present invention, the detection mark on the back surface is not transferred to the front surface in a roll state and is clear. Also, it is easy to manufacture and low cost.

Claims (4)

[Claims] 1. A thermal transfer receiving sheet provided with a receiving layer on one side of a support, wherein the receiving sheet is wound up in a roll and provided with printing with an electron beam curable ink or an ultraviolet curable ink. A heat transfer receiving sheet. 2. The thermal transfer receiving sheet according to claim 1, wherein the printing is a detection mark. 3. The thermal transfer receiving sheet according to claim 2, wherein the detection marks are provided at equal intervals. 4. The end mark according to claim 2, wherein the detection mark is an end mark.
Or the thermal transfer receiving sheet according to 3.