JPH0872421A - Thermal transfer printing paper - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the runnability of photographic paper used for thermal transfer recording, prevent double feeding, and reduce set-off when image-formed photographic papers are superposed. A thermal transfer printing paper having a sheet-shaped substrate having a dye receiving layer on one surface and a backcoat layer on the other surface, wherein the backcoat layer has a phenoxy resin content of 10% by weight or more and a polyester polyurethane resin content of 10% by weight. % Or more. Alternatively, the back coat layer may contain a urethane resin having a hydrophilic group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printing paper having a back coat layer. More specifically, the present invention is a thermal transfer printing paper that can be suitably used for sublimation type thermal transfer recording. By providing a specific backcoat layer, the running property in a printer is improved and The present invention relates to a photographic printing paper for thermal transfer, which can prevent feeding and set-off.

[0002]

2. Description of the Related Art An ink ribbon having an ink layer made of a sublimable or heat-diffusible dye and a printing paper having a dye receiving layer are superposed on each other and the ink layer is heated by a thermal head or the like according to image information. A sublimation type thermal transfer recording method is known in which a dye is transferred from an ink layer to a dye receiving layer of a printing paper to form an image. According to this method, it is possible to form a continuous color full-color image,
It has attracted attention as a method for making a hard copy of a video image.

FIG. 1 is a sectional view of a general printing paper 1 used for sublimation type thermal transfer recording. As shown in the figure,
The photographic printing paper 1 has a dye receiving layer 3 on one surface of a sheet-shaped substrate 2 and a back coat layer 4 on the other surface.

Here, the dye receiving layer 3 is a layer that receives the dye transferred from the ink ribbon during thermal transfer recording and holds the image formed by the dye. Such a dye receiving layer 3 is formed of a thermoplastic resin such as polyester, cellulose ester, polycarbonate, polyvinyl chloride or the like which is easily dyed with a dye.

The back coat layer 4 is (1) to reduce friction of the printing paper in the printer for thermal transfer recording to improve the running property, or (2) should be sent to the printer one by one. To prevent the double feed phenomenon in which multiple sheets of paper are sent to the printer when they are stacked, or (3) even if the printing paper is mistakenly sent to the printer with the front and back sides reversed. Is provided so as not to fuse with the ink ribbon in the printer, thereby preventing troubles in the printer and forming a certain amount of image on the printing paper.
Conventionally, such a back coat layer is often formed of an acrylic resin.

[0006]

However, in the conventional thermal transfer printing paper having a back coat layer, the runnability is improved, double feeding is prevented, and when the printing paper is turned upside down and is mistakenly sent to the printer. It was not possible to achieve sufficient trouble prevention at the same time. Further, when another printing paper is placed on top of the printing paper on which the image is formed, the dye migrates from the image of the printing paper on which the image is formed to the back surface of the printing paper placed on it. Set-off was also a problem.

The present invention is intended to solve the above-mentioned drawbacks of the prior art, and improves the running property of thermal transfer printing paper, prevents double feeding, and reverses the printing paper to the printer. The purpose is to prevent troubles caused by erroneous delivery and prevent set-off.

[0008]

The present inventors have found that the above object can be achieved by forming a back coat layer of photographic paper using a specific resin, and have completed the present invention.

That is, the present invention is, as a first invention, a thermal transfer printing paper having a dye receiving layer on one surface of a sheet-like base material and a back coating layer on the other surface, wherein the back coating layer is phenoxy. Provided is a photographic printing paper for thermal transfer, which contains 10% by weight or more of a resin and 10% by weight or more of a polyester polyurethane resin.

As a second aspect of the present invention, in a thermal transfer printing paper having a dye receiving layer on one surface of a sheet-like substrate and a back coating layer on the other surface, the back coating layer is hydrophilic. Provided is a photographic printing paper for thermal transfer, which comprises a urethane resin having a functional group.

The present invention will be described in detail below.

The photographic printing paper of the present invention, like the photographic printing paper shown in FIG. 1, basically has a laminated structure of a sheet-shaped substrate, a dye receiving layer and a back coat layer. According to the first aspect of the present invention, the back coat layer contains 10% by weight or more of a phenoxy resin and 10% by weight or more of a polyester polyurethane resin.

The phenoxy resin has a high Tg and is a resin that is hard under the conditions of use of photographic paper. Therefore, by including a phenoxy resin in the back coat layer,
It is possible to prevent thermal fusion of the printing paper inside the printer and ensure stable running performance. Further, the phenoxy resin has low dyeability. Therefore, it is possible to prevent set-off.

As the phenoxy resin, various kinds can be used, but from the viewpoint of preventing set-off,
In particular, the following equation (1)

[0015]

Embedded image Those having the structure of are preferred. Also, the molecular weight (Mn)
It is possible to preferably use about 10,000 to 50,000.

If the content of the phenoxy resin in the back coat layer is too small, it is not possible to sufficiently prevent thermal fusion of the printing paper in the printer, and it is not possible to sufficiently prevent set-off. . On the other hand, if the amount is too large, it becomes difficult to adhere to the substrate. Therefore, 10% by weight of the back coat layer
The above is preferably 50 to 70% by weight.

On the other hand, the polyester polyurethane resin is
It is added in order to improve the film forming property of the back coat layer and to impart the dyeing property to the extent that a dye image can be formed on the back coat layer. By imparting dyeability to the back coat layer in this way, even if the printing paper is mistakenly sent to the printer with the front and back reversed, an image equivalent to that when the printing paper is correctly sent to the printer is obtained. Can be formed.

As the polyester polyurethane resin, a copolymer of a polyester resin such as phthalic acid type polyester and an isocyanate such as MDI type, TDI type, XDI type or HDI type can be used.
It is preferable to use a copolymer with a DI or HDI isocyanate. The molecular weight (Mn) thereof is preferably about 10,000 to 50,000.

If the content of the polyester polyurethane resin in the back coat layer is too small, the film forming property of the back coat layer cannot be sufficiently improved, and the back coat layer should also have sufficient dyeing property. I can't. On the other hand, if the amount is too large, it is not preferable in terms of preventing set-off. Therefore, 10% by weight or more of the back coat layer, preferably 3
0 to 50% by weight.

In addition to the above-mentioned phenoxy resin and polyester polyurethane, various additives may be blended in the back coat layer, if necessary. For example, in order to further improve the slipperiness, a lubricant such as silicone oil or a fluorine compound can be added. In addition, a conductive agent can be added to prevent static electricity. In addition to these, fillers and the like can be appropriately mixed.

The backcoat layer comprising the above components is mixed with a solvent to prepare a coating material for forming a backcoat layer, which is applied to a sheet-shaped substrate by a conventional method.
It can be formed by drying.

In the photographic printing paper of the first aspect of the present invention, the sheet-shaped base material and the dye receiving layer can be constructed in the same manner as the conventional thermal transfer printing paper.

For example, the dye receiving layer can be formed of a dyeing resin such as polyester, cellulose ester, polycarbonate, polyvinyl chloride or the like. In particular, it is preferable to use cellulose ester such as cellulose acetate butyrate, polyester, or the like from the viewpoint of improving the transfer sensitivity.

If desired, the dye receiving layer may also contain various additives. For example, in order to improve the whiteness of the dye receiving layer to improve the clarity of the transferred image, to give the image surface writability, and to prevent the retransfer of the transferred image, a fluorescent whitening agent or a white pigment is used. Can be included. Here, as the white pigment, titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, fine powder silica or the like can be used. Further, in order to improve the light resistance of the transferred image, an ultraviolet absorber, a light stabilizer, an antioxidant and the like can be used. Further, a releasing agent may be contained in order to improve the releasing property from the ink ribbon at the time of thermal transfer. As the release agent, polyethylene wax, amide wax, solid wax such as Teflon powder, fluorine-based or phosphate-based surfactant, silicone oil, high melting point silicone wax, etc. can be used. Above all, it is preferable to use silicone oil from the viewpoint of releasing property and durability.
Further, an antistatic agent can be contained in order to suppress the generation of static electricity. Antistatic agents include cationic surfactants (quaternary ammonium salts, polyamines, etc.), anionic surfactants (alkylbenzene sulfonates, alkyl sulfate sodium salts, etc.), zwitterionic surfactants, nonionics. Various surfactants such as type surfactants can be used. Such an antistatic agent may be contained in the dye receiving layer or may be applied to the surface of the dye receiving layer by coating or the like.

As the method for forming the dye receiving layer, the components for forming the dye receiving layer are uniformly mixed with a solvent if necessary to prepare a coating material, and the coating material is applied to a sheet-like base material, or Alternatively, it can be formed by applying a hot melt of each component onto a sheet-shaped substrate and curing.

As the sheet-shaped substrate, paper such as high-quality paper, coated paper, various plastic sheets, or composite sheets of these can be used.

On the other hand, the photographic printing paper of the second present invention is different from the photographic printing paper of the first present invention in that the back coat layer contains a urethane resin having a hydrophilic group. This second
In the present invention, since the urethane resin having a hydrophilic group is contained in the back coat layer, the phenoxy resin or polyester polyurethane resin contained in the back coat layer in the first invention may not be contained.

Here, the hydrophilic group of the urethane resin may be a polar group such as a hydroxyl group, a carboxylic acid group, a sulfonic acid group or salts thereof, and sodium sulfonate and a hydroxyl group are particularly preferable. Further, as the urethane resin, 0.001 of such a hydrophilic group is contained in the resin.
Those having at least wt% are preferable, and those having 0.01 to 5 wt% are particularly preferable.

In general, the dye forming an image on photographic paper is lipophilic, and therefore, when the urethane resin having a hydrophilic group as described above is used for the back coat layer, it is possible to prevent set-off favorably. Become. Further, by including this urethane resin in the back coat layer, the friction coefficient of the back coat layer can be lowered to improve the running property of the printing paper in the printer, and the double feeding can be prevented. It will be possible.

If the content of the urethane resin having a hydrophilic group in the back coat layer is too small, the set-off cannot be sufficiently prevented.
It is preferable to make the above.

In addition to the urethane resin having a hydrophilic group, the second
The back coat layer of the photographic paper of the present invention may contain a phenoxy resin or polyester polyurethane which is an essential component of the back coat layer in the photographic paper of the first present invention. Further, various additives similar to those of the photographic printing paper of the first aspect of the present invention can be contained.

As a method of forming such a back coat layer, for example, a prepolymer of a water-soluble urethane resin having a hydrophilic group, which is hardened by heating (heat-reactive water-soluble urethane resin), Other components, if necessary, may be mixed with a solvent to prepare a coating material for forming a backcoat layer, which may be applied to a sheet-shaped substrate by a conventional method and dried.

Also in the photographic printing paper of the second invention, the sheet-shaped substrate and the dye receiving layer can be constructed in the same manner as the conventional thermal transfer printing paper, as in the first invention.

There is no particular limitation on the image forming method for the photographic printing paper of the first and second inventions. For example, a sublimation type thermal transfer recording ink ribbon is used and a commercially available video printer or the like is used. Thus, sublimation type thermal transfer recording can be performed.

[0035]

In the photographic printing paper of the first aspect of the present invention, the back coat layer contains 10% by weight or more of the phenoxy resin and 10% by weight or more of the polyester polyurethane resin. Can also be prevented. Further, due to the action of the polyester polyurethane resin, the back coat layer becomes dyeable. Therefore, even when the printing paper is mistakenly sent to the printer with the front and back reversed, it is possible to form an image of the same degree as when the printing paper is correctly sent to the printer.

Further, in the photographic printing paper of the second aspect of the present invention, since the back coat layer contains a urethane resin having a hydrophilic group, settling is prevented by the action of the hydrophilic group. Further, the action of the urethane resin improves the running property of the printing paper in the printer and prevents the double feeding.

[0037]

EXAMPLES The present invention will be specifically described below based on examples.

Examples 1 and 2, Comparative Examples 1 to 4 As a sheet-like substrate, a synthetic paper having a thickness of 150 μm (FPG-150 manufactured by Oji Yuka Co., Ltd.) was prepared, and the dry film thickness was 10 μm on the surface. A coating composition for forming a dye-receptive layer having the following composition was applied so as to obtain the following composition and cured at 120 ° C. for 2 minutes.

[Receptor layer forming paint] (parts by weight) • Acetal resin (KS-1, manufactured by Sekisui Chemical Co., Ltd.) 100 • Polyisocyanate (Coronate L, manufactured by Nippon Polyurethane Co., Ltd.) 5 • MEK 100 Toluene 300 Next, a backcoat layer-forming coating composition having the composition shown in Table 1 was applied to the back surface of the sheet-shaped substrate so that the dry film thickness was 1 μm, and cured (condition: 60 ° C., 2 days) to print. Paper was made.

[0040]

[Table 1] Examples for forming backcoat layer Comparative example Paint components (parts by weight) 1 2 1 2 3 4 Phenoxy resin (* 1) 20 − 100 − − − Phenoxy resin (* 2) − 60 − − − − Polyester polyurethane (* 3) ) 80 − − 100 − − Polyester polyurethane (* 4) − 40 − − − − Epoxy resin (* 5) − − − − 5 − Methacrylic resin (* 6) − − − − 95 − Acrylic ester copolymer ( * 7) − − − − − 100 Silicone oil (* 8) 3 3 3 3 − − Silicone oil (* 9) − − − − 3 3 Conducting agent (* 10) 20 20 20 20 20 20 MEK 300 300 300 300 300 300 Toluene 300 300 300 300 300 300 (* 1) YP-50, Tohto Kasei (* 2) PKHH, UCC (* 3) Byron 200, Sekisui Chemical Co., Ltd. (* 4) Byron 1400, Sekisui Chemical ( Co., Ltd. (* 5) Epocoat DX-2SS, Shell Co., Ltd. (* 6) Delpet 560F, Asahi Kasei (* 7) Plycor WL-81, Rohm and Haas (* 8) SF8427 , Toray Dow Corning Silicone (* 9) YF3818, Toshiba Silicone Co., Ltd. (* 10) SAFTMER ST1000, Mitsubishi Petrochemical Co., Ltd. (Evaluation) Sublimation type thermal transfer ink ribbon (VPM30STA) , Sony Corp.)
With a printer (CVP-G7, manufactured by Sony Corporation), 12
Gradation steer step printing was performed. Then, at that time, it was observed whether or not the printing paper and the ink ribbon were fused, and whether or not the printing paper was double-fed. Further, in order to evaluate the degree of set-off of the obtained image, the back coat layer surface of the same type of photographic paper is overlaid on the printing screen and left (condition: 50 ° C., 3 days),
The optical density of the back coat layer of the printed photographic paper was measured using a Macbeth densitometer, and the density of the dye transferred to the back coat layer was evaluated. The results are shown in Table 2.

[0041]

[Table 2] From Table 1 and Table 2, it can be seen that by incorporating the phenoxy resin and the polyester polyurethane resin in the back coat layer, the running property is improved and the set-off can be prevented.

Examples 3 to 4 A dye receiving layer was formed on a sheet-like substrate in the same manner as in Example 1,
A coating material for forming a back coat layer having the composition shown in Table 3 was applied to the back surface of the sheet-shaped substrate so that the dry film thickness was 1 μm, and cured (condition: 60 ° C., 1 day) to produce a photographic paper.

Printing was performed on the produced printing paper in the same manner as in Example 1, and the presence or absence of fusion of the printing paper and the ink ribbon at that time and the presence or absence of double feeding of the printing paper were observed and obtained. The degree of set-off of the image was evaluated by the dye transfer density as in Example 1. Table 3 shows the results.

[0044]

[Table 3] (* 11) Elastron E37, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. (* 12) Elastron S24, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. (* 13) Elastron Catalyst 64, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. Table 3 Therefore, even when the urethane resin having a hydrophilic group is contained in the back coat layer, the running property is improved as in the case where the phenoxy resin and the polyester polyurethane resin are contained in the back coat layer. It can be seen that this can be prevented.

[0045]

According to the photographic paper of the present invention, the runnability is improved, double feeding is prevented, and troubles caused when the photographic paper is turned upside down and mistakenly fed to the printer are further prevented. Can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a general printing paper.

[Explanation of symbols]

 1 photographic paper 2 sheet-like substrate 3 dye receiving layer 4 back coat layer

Claims (6)

[Claims] 1. A thermal transfer printing paper having a dye-receptive layer on one surface of a sheet-like substrate and a backcoat layer on the other surface, wherein the backcoat layer comprises 10% by weight of a phenoxy resin.
A photographic printing paper for thermal transfer containing the above and 10% by weight or more of a polyester polyurethane resin. 2. A phenoxy resin is represented by the following formula (1): The photographic printing paper for thermal transfer according to claim 1, which has the structure of 3. The thermal transfer printing paper according to claim 1, wherein the polyester polyurethane resin has a molecular weight (Mn) of 10,000 to 50,000. 4. A thermal transfer printing paper having a dye receiving layer on one surface of a sheet-like substrate and a back coating layer on the other surface, wherein the back coating layer contains a urethane resin having a hydrophilic group. A photographic printing paper for thermal transfer characterized in that 5. The thermal transfer printing paper according to claim 4, wherein the urethane resin forming the back coat layer has a hydroxyl group, a sulfonic acid group, a carboxylic acid group or a salt thereof as a polar group. 6. The thermal transfer printing paper according to claim 4, wherein the back coat layer contains 10% by weight or more of a urethane resin having a hydrophilic group.