JPH07117364A - Dye heat transfer image receiving tack paper - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a dye thermal transfer tack paper that is inexpensive and can obtain high density and high quality prints. A release paper having a dye image-receiving layer on one surface of a sheet-like substrate, an adhesive layer on the opposite surface, a release paper substrate and a release agent layer formed thereon. A dye thermal transfer image-receiving tack paper, characterized in that layers are adhered, and that the release paper substrate contains a foamed porous paper.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a dye thermal transfer tack paper. More specifically, the present invention relates to a tack paper type dye thermal transfer image-receiving sheet which is excellent in print image density and image quality when used in a sublimation type thermal transfer printer.

[0002]

2. Description of the Related Art In recent years, development of a color hard copy of a thermal transfer system, especially a sublimation type thermal transfer printer has been rapidly advanced. Sublimation thermal transfer printers have three colors (yellow,
The magenta, cyan) sublimation dye layer is heated by continuously controlling the heating energy of the thermal head, and the transfer amount of the dye of each color is changed to form the transfer formation of a full-color image of density gradation. It is possible.

In the image receiving paper used in such a sublimation type thermal transfer printer, a dye image receiving layer formed on one surface of a sheet-like support and an adhesive layer formed on the opposite side of the support are used. There is an increasing demand for a so-called tack paper type dye thermal transfer receiving sheet in which a release paper is attached to the adhesive layer surface. In such a dye thermal transfer tack paper, when using a paper-based release paper that has been widely used for tack paper applications, the image quality of the print is poor, so a costly film-based release paper is used. There is.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dye thermal transfer image receiving tack paper which can obtain high density and high quality prints and is low in cost.

[0005]

Means for Solving the Problems As a result of intensive studies by the present inventors, in a dye thermal transfer image-receiving tack paper, by using a foamed porous paper as a release paper substrate, high density,
The present invention has been completed by finding that high-quality prints can be obtained.

That is, the dye thermal transfer image-receiving tack paper of the present invention comprises a sheet-like support, an image-receiving layer which is formed on at least one surface of the support and which receives a dye transferred from an ink sheet by heating. A pressure-sensitive adhesive layer formed on the other surface of the support, and a release paper releasably adhered to the pressure-sensitive adhesive layer, the release paper being formed on the release paper substrate. And a release agent layer releasably joined to the pressure-sensitive adhesive layer, and the release paper substrate contains a foamed porous paper. The release paper substrate used in the present invention may have a plastic film intermediate layer that covers at least one surface of the foamed porous paper and supports the release agent layer.

[0007]

The sheet-like support used in the present invention includes:
Paper base materials such as coated paper, art paper, high-quality paper, laminated paper in which a resin such as polyolefin is laminated on paper base materials, films of polyester, nylon, polyolefin, etc.,
An example is biaxially stretched synthetic paper containing a polyolefin resin and an inorganic pigment as main components. Further, these base materials may be appropriately laminated and used.

In the image-receiving tacky paper of the present invention, the dye image-receiving layer provided on one surface of the sheet-like support is mainly composed of a dye-receiving resin capable of dyeing a sublimable dye transferred from the ink ribbon. To be done. Such dyeing resin, polyester resin, vinyl chloride-vinyl acetate copolymer resin, polycarbonate resin, acrylic resin,
Examples include cellulose derivatives and the like. The thickness of the image receiving layer is preferably 1 to 10 μm, more preferably 2 to 7 μm. If the dye-receptive layer is too thin, the image may be deteriorated and the gloss of the printed surface may be deteriorated. On the other hand, if it is too thick, not only is the effect saturated and uneconomical, but the print density may decrease.

In the image receiving layer of the image receiving tack paper of the present invention,
In order to prevent fusion with the ink ribbon due to heating of the thermal head during printing, it is preferable to add a cross-linking agent, a slip agent, a release agent, etc., if necessary. Further, if necessary, an antioxidant, a pigment, an ultraviolet absorber or the like may be added to the image receiving layer. These additives may be mixed with the main component of the image receiving layer and coated, or may be coated as a separate coating layer on and / or below the image receiving layer.

The image-receiving layer of the present invention is formed by applying a coating liquid for forming an image-receiving layer and drying it according to a conventional method using a coater such as a bar coater, a gravure coater, a comma coater, a blade coater and an air knife coater. You can

The foamed porous substrate of the release paper used in the image receiving tack paper of the present invention will be described in detail below. The pulp for making the foamed porous substrate paper of the present invention is not particularly limited, for example, wood pulp such as chemical pulp and mechanical pulp of softwood and hardwood, waste paper pulp, non-wood pulp such as hemp and cotton, polyethylene, Synthetic pulp or the like made of polypropylene or the like can be used, and these may be used in combination.

In addition to the above pulp, various fibers such as organic fibers such as acrylic fibers, rayon fibers, phenol fibers, polyamide fibers and polyester fibers, inorganic fibers such as glass fibers, carbon fibers and alumina fibers may be mixed. You can However, from the viewpoint of maintaining the paper-making property at a practically possible level, it is better to add pulp in an amount of 50% by weight or more, whereby excellent sheet texture and strength can be obtained.

In the present invention, the foam capsule used for forming the foam porous release paper substrate has a volume of 10 when heated.
Includes as a core substance a liquid that increases by up to 100 times,
When this is heated at a relatively low temperature of 80 to 200 ° C. for a short time, it expands 4 to 5 times in diameter and 10 to 100 times in volume. The foam capsules are microcapsules having an average particle size of 10 to 30 μm. This microcapsule has a core substance of a volatile organic solvent such as isobutane, pentane, a low-boiling halogenated hydrocarbon, and methylsilane, and is composed of a copolymer of vinylidene chloride, acrylonitrile, an acrylic ester, a methacrylic ester, and the like. It is wrapped with a thermoplastic resin thin film layer. When the microcapsules are heated above the softening point of the thin film-forming thermoplastic resin, the film begins to soften, and at the same time, the vapor pressure of the volatile organic solvent contained therein rises and the microcapsules expand. Since such microcapsules expand at a relatively low temperature in a short time to form closed cells, a release paper substrate material having excellent heat insulating properties can be obtained. The density of the foamed porous paper used as the release paper substrate is 0.2 to 0.8 g / cm ³ , and more preferably 0.2 to 0.5 g / cm ³ .

In order to obtain a porous paper having a density of 0.2 to 0.5 g / cm ³ , the amount of microcapsules is 1
The amount is preferably 1 to 40 parts by weight, more preferably 3 to 20 parts by weight, and the foaming temperature is preferably in the range of 110 to 140 ° C with respect to 00 parts by weight. If the content of the microcapsules is less than 1 part by weight or the foaming temperature is lower than 110 ° C., sufficient foaming may not be obtained, and if the content of the microcapsules exceeds 40 parts by weight, uniform foaming may not be obtained. Further, if the foaming temperature is higher than 140 ° C., the microcapsule film may be melted, and closed cells may not be obtained.

In addition to the above-mentioned microcapsules, various types of conventionally used anionic, nonionic, cationic or amphoteric retention aids and paper strength enhancers are used in pulp slurries for producing foamed porous paper. Agents and sizing agents may be appropriately selected and mixed.

Using the above-mentioned constituent raw materials as main raw materials, paper is made into a sheet using an ordinary paper making machine. First, a wet sheet is obtained through the wire part in the papermaking process, then dehydrated by the press part and dried by the dryer part. At this time, the microcapsules that are heated on the heating surface of the multi-cylinder type or Yankee type dryer of the dryer part foam at the same time as drying, and the microcapsules mixed in the sheet foam to form a large number of closed cells in the paper. And a foamed porous sheet excellent in heat insulation is obtained.

[0017] The basis weight of the foamed porous sheet for forming a release paper substrate is preferably from 10 to 100 g / m ^2, more preferably from 20~90g / m ^2. If the basis weight is less than 10 g / m ² , a release paper base sheet with sufficient heat insulation cannot be obtained. If it is more than 100 g / m ² , the load on the dryer in the drying process of the paper machine is large, which is economical. The sex may become worse.

When a release paper is produced using foamed porous paper as a base material, various plastic films are provided on the front and back surfaces of the foamed porous paper in order to facilitate the coating of the release agent and prevent its penetration. It is preferable to form the intermediate layer by laminating. Examples of the plastic film used for this purpose include polyolefin, polyester, polyurethane, polycarbonate, polystyrene, vinyl chloride resin, acrylic resin, and cellulose resin. Examples of the polyolefin film include polyethylene, polypropylene or copolymers thereof, polyolefin synthetic paper, and copolymers such as ethylene acrylic acid and ethylene vinyl acetate.

The intermediate layer film may contain a filler such as titanium dioxide or calcium carbonate, or a plasticizer such as phthalates. The intermediate layer film can be produced by a known method such as an extrusion method, a calendar method, a casting method, an inflation method. The weight of the intermediate layer is preferably 10 to 30 g / m ² .

For laminating the foamed porous paper substrate and the plastic film intermediate layer, a method of laminating the foamed porous paper and the plastic film using an adhesive, and an extrusion coating of the foamed porous paper with a plastic resin are carried out. There are ways to do it. It is also possible to laminate another plastic film while extruding a certain plastic resin as an adhesive.

When a release paper layer is formed by using a foamed porous paper laminated with a plastic film as a release paper substrate, a known release agent such as a silicone release agent or a fluorine release agent can be used. It is desirable to use a silicone release agent. As a silicone-based release agent,
Both condensation type and addition type can be used. As a coating method, a reverse roll coater, a bar coater, a gravure coater or the like can be used, and a known method such as heat curing, UV curing or EB curing can be used as a curing method. Generally, the release agent layer is preferably formed with a coating amount (solid content) of 0.2 to 1.2 g / m ² .

Further, when the image receiving tack paper runs in the printer, an antistatic agent can be applied to the back surface of the release paper in order to prevent occurrence of running trouble due to static electricity.

As the pressure-sensitive adhesive used in the present invention, known pressure-sensitive adhesives such as acrylic type, synthetic rubber type, natural rubber type and silicone type can be used. The adhesive may be applied to the surface of the release agent layer of the release paper and dried, and then the adhesive may be attached to the back surface of the support sheet having the image receiving layer on the front surface side, or may be adhered to the back surface of the support sheet. After coating and drying the agent, the release agent layer surface of the release paper may be attached thereto. A cross-linking agent or a filler can be added to the pressure-sensitive adhesive, if necessary. Generally, the pressure-sensitive adhesive layer is preferably formed with a coating amount (solid content) of 10 to 30 g / m ² .

[0024]

The present invention will be described in detail with reference to the following examples, but the scope of the present invention is not limited thereto.
In the examples, "%" and "parts" all indicate "% by weight" and "parts by weight" unless otherwise specified.

Example 1 A biaxially stretched film having a thickness of 50 μm (trademark: YUPO FPG5) containing polyolefin as a main component and containing an inorganic pigment.
0, made by Oji Oka Synthetic Paper) as a sheet-shaped support,
To form a dye image image-receiving layer, a paint-1 having the following composition was applied onto one surface of the composition at a solid content of 8 g / m ^{2 by} a die coating method and dried.

The paint -1 Component Parts by weight saturated polyester resin (trademark: Byron 200, Toyobo Co., Ltd.) 100 parts Silicone resin (Trademark: SH3746, Toray Dow Corning Silicone Co.) 5 parts Toluene / methyl ethyl ketone = 5/1 mixed solvent 595 Department

A foamed porous paper used as a release paper substrate was produced by the following production method. Production of foam paper 80% hardwood bleached pulp beaten to 450 ml Canadian standard freeness (CSF) and 470 Canadian standard freeness (CSF)
A pulp (100 parts) consisting of 20% bleached softwood pulp beaten to ml was dispersed in water to prepare a pulp slurry. In this pulp slurry, expandable microcapsule particles (Matsumoto Yushi-Seiyaku Co., Ltd., trademark: Matsumoto Microsphere F-30D, particle diameter 10 to 20 μm, maximum foaming temperature 13
0 ° C.) 10 parts, dry paper strength enhancer (trade name: Polystron 117 manufactured by Arakawa Chemical Industry Co., Ltd.) 0.2 part, cationized starch (trade name: CATO-15 manufactured by Oji National) 1.0
Parts, 0.03 parts of alkyl ketene dimer type sizing agent (trade name: Size Pine K903 manufactured by Arakawa Chemical Industry Co., Ltd.), and 0.4 parts of wet paper strength enhancer (trade name: Kamen 557H manufactured by DIC Hercules) while stirring well The pulp concentration was adjusted to 0.03% and the pH value was adjusted to 7.3 to prepare a papermaking raw material. The obtained papermaking raw material is subjected to papermaking with a cylinder paper machine, while being dried with a Yankee dryer,
After foaming the microcapsules, the microcapsules were dried with a continuous multi-cylinder dryer to prepare a foam paper for a release paper substrate having a basis weight of 60 g / m ² , a thickness of 120 μm and a density of 0.5 g / cm ³ .

Production of Release Paper A 25 μm-thick polyester film (trade name: Lumirror, manufactured by Toray) was laminated on one surface of the foam paper by a dry lamination method using a polyester adhesive. Then, the above polyester film was attached to the other surface of the foamed paper in the same manner. On one surface of the obtained release paper substrate, a silicone-based release agent (trademark: KS-8
No. 30, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied by a gravure coating method so as to have a solid content of 0.6 g / m ^2, and dried to form a release agent layer to prepare a release paper.

On the opposite surface of the sheet-like support, an adhesive (trade name: Olivine BPS-4891, made by Tokyo Ink)
Was applied to give a solid content of 18 g / m ² to form a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer and the release agent layer of the release paper were superposed and joined so as to be peelable. A dye heat transfer image-receiving tack paper was obtained by the above steps.

On the tack paper type dye thermal transfer image-receiving sheet obtained as described above, printing was carried out using a sublimation video printer (trademark: VY-P1, manufactured by Hitachi Ltd.), and the color density of the obtained print image. And evaluated the image quality. For the color density, the maximum density of the print image was measured with a Macbeth densitometer RD-914 (trademark).
Sensory evaluation was performed at each stage. Three-level evaluation 3: Excellent 2: Normal 1: Inferior The evaluation results are shown in Table 1.

Comparative Example 1 A dye thermal transfer image-receiving tack paper was prepared in the same manner as in Example 1. However, a coated paper (manufactured by Shin Oji Paper Co., Ltd., trademark: OK coat) having a basis weight of 104.7 g / m ² was used as the release paper substrate. The results are shown in Table 1.

Example 2 A dye thermal transfer image-receiving tack paper was prepared in the same manner as in Example 1. However, both sides of the foamed paper described in Example 1 were extrusion coated with polyethylene (trade name: Yukaron LK-50, manufactured by Mitsubishi Yuka) to a thickness of 30 μm. The results are shown in Table 1.

Comparative Example 2 A dye thermal transfer image-receiving tack paper was prepared in the same manner as in Example 2. However, instead of the foam paper for the release paper substrate, the basis weight 10
4.7 g / m ² coated paper (manufactured by Shin Oji Paper Co., Ltd., trademark: OK coated) was used. The results are shown in Table 1.

[0034]

[Table 1]

[0035]

The dye thermal transfer image-receiving tack paper of the present invention makes it possible to obtain a high-density and high-quality print at a low cost by using a foam paper as a release paper substrate. It has high practical value.

Claims (2)

[Claims] 1. A sheet-shaped support, an image-receiving layer formed on one surface of the support for receiving a dye transferred from an ink sheet by heating, and on the other surface of the sheet-shaped support. The pressure-sensitive adhesive layer formed, and having a release paper layer releasably adhered to the pressure-sensitive adhesive layer, the release paper,
Dye thermal transfer, characterized in that it has a release paper substrate and a release agent layer formed thereon and releasably bonded to the pressure-sensitive adhesive layer, wherein the release paper substrate contains foamed porous paper. Tack paper. 2. The dye thermal transfer image-receiving tack paper according to claim 1, wherein the release paper substrate has the foamed porous paper and a plastic film layer formed on the release layer forming side thereof.