JP2001293963A - Transfer type image protecting film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer type image protecting film whose dye constituting an image formed on a printing paper will not bleed into the surface of the image and is excellent in the storage stability of the image. SOLUTION: In the transfer type image protecting film wherein an image protecting layer 2, consisting of a thermoplastic resin, is laminated on a substrate film 1 while the image protecting layer 2 is transferred by heat on the image to be protected, the thermoplastic resin of the image protecting layer 2 contains a hydroxyalkyl(metha)acrylate unit in the main chain thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer type wherein an image protection layer made of a light-transmitting thermoplastic resin is laminated on a base film, and the image protection layer is thermally transferred onto a protected image. It relates to an image protection film.

[0002]

2. Description of the Related Art A dye receiving layer of photographic paper is formed by a sublimation type thermal transfer method using an ink ribbon using a sublimable or heat diffusible dye soluble in an aromatic solvent such as toluene or a ketone solvent such as MEK. Conventionally, a transparent film is laminated on an image formed in the above for the purpose of protecting the image. Various methods for laminating such a transparent film are known, for example, a method in which a transparent film is thermocompression-bonded to an image surface using a heat roller, and a method in which a transparent film is adhered using an adhesive at room temperature. However, these methods have a problem in that the image forming process and the laminating process of the transparent film are not automatically performed in one printer, and complicated processing operations must be performed completely separately.

[0003] Therefore, as a transfer-type image protection film that enables self-lamination of a film-like image protection layer continuously to image formation inside a printer using a thermal transfer head, a light-transmissive film is formed on a base film. (Japanese Patent Application Laid-Open Nos. 60-204397 and 59-8).
No. 5,793, JP-A-59-76298).

[0004]

By the way, in the case of the transfer type image protection film disclosed in the above-mentioned publication, the transfer image protection layer after thermal transfer has an aromatic solvent such as toluene or MEK used at the time of its formation. In some cases, about 1% of a ketone-based solvent such as the above remains. In such a case, the dye constituting the image formed on the photographic paper (that is, a dye soluble in toluene or the like) bleeds on the image surface, deteriorating the image quality. If the paper is sandwiched between the mount such as an album and the cover film,
There is a problem that the dye passes through the image protective layer and is retransferred to the cover film. There is a demand for further improving the image storability of a transfer-type image protection film.

An object of the present invention is to solve the problems of the prior art described above, and a dye constituting an image formed on photographic paper does not bleed to the image surface.
Moreover, an object of the present invention is to provide a transfer-type image protection film having excellent image storability.

[0006]

Means for Solving the Problems The present inventors have found that a solvent such as toluene capable of dissolving a sublimable dye should not remain in the image protective layer of a transfer type image protective film. Consists of a specific light-transmitting thermoplastic resin capable of forming a film using an alcoholic solvent (methanol, ethanol, propanol, etc.) that does not dissolve the sublimable dye without using a solvent such as toluene. We have found what we need to do and completed the present invention.

That is, the present invention provides a transfer-type image protection film in which an image protection layer made of a thermoplastic resin is laminated on a base film, and the image protection layer is thermally transferred onto a protected image. A transfer-type image protection film, wherein the thermoplastic resin of the protective layer contains a hydroxyalkyl (meth) acrylate unit in the main chain.

[0008]

FIG. 1 is a view showing one embodiment of the transfer type image protection film of the present invention. This transfer type image protection film has a structure in which a transparent image protection layer 2 for protecting an image is formed on a base film 1. If necessary, a known release resin layer 3 may be provided between the base film 1 and the image protection layer 2, and a known ultraviolet absorbing layer 4 may be further provided on the image protection layer 2. A heat-resistant lubricating layer may be provided on the back surface. When an image to be protected is protected by using such a transfer-type image protection film, the image protection layer 2 of the base film 1 is overlaid on the image to be protected, and the image protection layer 2 is heated and pressed from the base film 1 side. Is thermally transferred onto the protected image.

In the present invention, as the thermoplastic resin of the image protective layer 2, a resin containing a hydroxyalkyl (meth) acrylate unit in the main chain is used. here,
"Hydroxyalkyl (meth) acrylate unit"
The term "hydroxyalkyl acrylate units and hydroxyalkyl methacrylate units"
Is included.

The thermoplastic resin containing a hydroxyalkyl (meth) acrylate unit in the main chain used in the present invention has a low affinity for a general sublimable dye,
Moreover, it is a resin capable of forming a film using an alcohol-based solvent (methanol, ethanol, propanol, etc.). Therefore, if a thermoplastic resin containing a hydroxyalkyl (meth) acrylate unit in the main chain is used, the image protection layer 2 can be formed without using toluene, MEK, or the like.

When the weight average molecular weight of such a thermoplastic resin is too small, whitening of the coating film occurs due to moisture absorption,
Further, the heat resistance is lowered, and if the heat resistance is too large, the solubility in a solvent is lowered and gelation is caused.
~ 65000. When the softening point is too low, a peeling sound or a peeling line is generated at the time of thermal transfer, and the surface of the coating film is roughened. The upper limit of the softening point is not particularly limited, but the weight average molecular weight is 6
In the case of about 5000, the temperature is considered to be about 150 ° C.

Specific examples of the hydroxyalkyl (meth) acrylate unit include a hydroxyethyl (meth) acrylate unit and a hydroxypropyl (meth) acrylate unit.
A hydroxyethyl (meth) acrylate unit having a low monomer cost and a high affinity for alcohol is preferred.

The thermoplastic resin constituting the image protective layer 2 is as follows:
The main chain may further contain a methyl methacrylate unit in an amount of 40% by weight or less in addition to the hydroxyalkyl (meth) acrylate unit.

The above-mentioned image protective layer 2 is formed by polymerizing a hydroxyalkyl (meth) acrylate monomer together with a methyl methacrylate monomer, if necessary, in an alcohol-based solvent by a known coating method. (For example, a gravure coating method).

As the base film 1 constituting the transfer type image protection film of the present invention, a base film in a conventional image protection film can be used.

The transfer type image protection film of the present invention is shown in FIG.
As shown in (1), it can be formed in a part of the thermal transfer type ink ribbon. In the thermal transfer ink ribbon, an ink layer of each color of yellow Y, magenta M, and cyan C and a sensor mark 5 are formed on a base film 1 in a plane-sequential manner, and an image protection layer 2 is formed on the same plane as these. It has a formed structure. With such a structure, when thermal transfer recording is performed by a printer using an ink ribbon, the image protective layer 2 can be thermally transferred onto an image by the thermal head of the printer used for the image formation. .

The ink layer in the embodiment shown in FIG. 2 may be either an ink layer for sublimation thermal transfer recording or an ink layer for hot-melt thermal transfer recording. it can. For example, in the case of an ink layer for sublimation thermal transfer recording,
Methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose resins such as cellulose acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetoacetal, polyvinyl acetate, vinyl resins such as polystyrene,
In addition, it can be composed of a material in which a sublimable or heat diffusible dye is dispersed in various urethane resins or the like.

Although an example in which ink layers of yellow Y, magenta M, and cyan C are formed face-sequentially as the ink layer has been described, an ink layer of black or the like may be further formed. An ink layer of only one color may be formed.

In addition, when performing sublimation type thermal transfer recording, an ink ribbon is transferred from the ink ribbon to the transfer object prior to the image transfer so that a good image can be formed even if the dye receiving layer is not formed on the transfer object. The dye receiving layer may be transferred,
In order to transfer such a dye receiving layer, a known dye receiving layer having thermal transferability may be formed on the same side of the ink ribbon as the ink layer. For such a dye receiving layer, a thermoplastic resin, a thermosetting resin, a UV curable resin, or the like having good dyeing properties can be used. For example, polyester resin, cellulose ester resin, polycarbonate resin, polyvinyl chloride resin, polyvinyl acetate resin, polyamide resin, polyvinyl chloride resin, polystyrene resin, styrene acrylate resin, polyurethane resin, polyamide resin, urea resin,
Other examples include the above copolymers.

The transfer type image protection film of the present invention is basically formed by applying an acrylic resin solution for an image protection layer on a base film by a known coating method and drying the solution to form an image protection layer. Can be produced. The ink layer, the release resin layer, the heat-resistant lubricating layer, and the like can be formed by a known method.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

Examples 1 to 4 A back coating solution having the composition shown in Table 1 was coated on one surface of a polyethylene terephthalate film (Lumirror, manufactured by Toray Industries, Ltd.) having a thickness of 6.0 μm as a substrate film by a gravure coating method. Then, a backing layer was formed by curing in a 55 ° C. oven for 5 days.

[0023]

[Table 1] (Back layer coating liquid composition) Component parts by weight Polyvinyl acetal resin 5.0 (Denka butyral # 3000K, manufactured by Denki Kagaku Kogyo KK) Isocyanate hardener 0.5 (Coronate L, Nippon Polyurethane Industry Co., Ltd.) Phosphate ester 20 (Phosphanol GB520, manufactured by Toho Chemical Co., Ltd.) Silica 0.5 (Nipsil E-200A, manufactured by Nippon Silica Industry Co., Ltd.) Methyl ethyl ketone 37 Toluene 37

Next, a hydroxyethyl acrylate monomer (HEA) and a methyl methacrylate monomer (MMA) were solution-polymerized on the other surface of the base film coated with the back layer at the ratio (monomer molar ratio) shown in Table 2. The obtained thermoplastic resin solution was applied by a gravure coating method and dried to form an image protection layer, thereby producing transfer-type image protection films of Examples 1 to 4. This transfer type image protection film is manufactured by UPC-88 manufactured by Sony Corporation.
A thermal transfer ink ribbon was produced by bonding the ink ribbon to a 40 ink ribbon so as to replace the image protection layer area of the ink ribbon.

[0025]

Table 2 Example MMA / HEA 10/100 2 220/80 340/60 450/50

(Evaluation) Using the thermal transfer type ink ribbon of Examples 1 to 4 in which the transfer type image protection film of the present invention was built and a video printer UP-D8800 manufactured by Sony Corporation, a 150 μm thick composite was prepared. Paper (YUPO FPG-
150: Oji Yuka Co., Ltd.), an image pattern having a black solid transfer density of 2.0 was formed on a photographic paper having a 6 μm-thick dye receiving layer formed thereon, and the image protective layer was further transferred onto the image pattern.

The obtained print was cut into a size of 5 cm × 5 cm, and a dye bleed amount evaluation sheet (Nakabayashi Album, Okamoto Super Film Non-Tack D, Altron # 480 of Mitsubishi Chemical Vinyl) was attached. A 1 kg weight is put on the plate, left for 5 hours in an environment of 50 ° C., and the transfer density of the dye transferred to the bleed amount evaluation sheet of the bonded dye is measured using a Macbeth TR9.
24. As a control, a commercially available UPC-
The transfer density of the dye when the image protective layer of the 8840 ink ribbon was transferred was also measured. Table 3 shows the obtained results.

[0028]

[Table 3] Example bleed amount evaluation sheet Commercial product 1 2 3 4 Nakabayashi album 0.03 0.00 − − − Okamoto Supper Film Non-tack D 0.80 0.00 − − − Mitsubishi Chemical Hydration Altron # 480 1.20 0.00 0.00 0.00 0.02

From the results shown in Table 3, the use of hydroxyalkyl (meth) acrylate as the resin constituting the image protective layer of the transfer-type image protective film can suppress the bleeding of the dye on the image surface. It can be seen that storage stability can be improved.

[0030]

According to the present invention, in the transfer type image protection film, bleeding of the dye on the image surface can be eliminated, and the image storability can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a transfer-type image protection film of the present invention.

FIG. 2 is a plan view of the transfer type image protection film of the present invention.

[Explanation of symbols]

 1 Base film, 2 Image protection layer

Claims (4)

[Claims] An image protection layer comprising a thermoplastic resin laminated on a base film, wherein the image protection layer is thermally transferred onto a protected image. A transfer-type image protection film, wherein the plastic resin contains a hydroxyalkyl (meth) acrylate unit in the main chain. 2. The transfer type image protection film according to claim 1, wherein the hydroxyalkyl (meth) acrylate unit is a hydroxyethyl (meth) acrylate unit. 3. The transfer-type image protection film according to claim 1, wherein the thermoplastic resin of the image protection layer further contains a methyl methacrylate unit in the main chain thereof in an amount of 40% by weight or less. 4. The transfer type image protection film according to claim 1, wherein the image protection layer is formed by using a coating solution obtained by dissolving a thermoplastic resin in an alcohol solvent.