JPH07179091A - Heat transfer recording sheet keeping file - Google Patents

Abstract

PURPOSE:To make keeping quality of a heat transfer recording image favorable, by a method wherein a heat transfer recording sheet keeping file is prepared by providing a layer of coating having a specific haze value and containing a specific quantity of an ultraviolet absorbing agent on a non-adhesive surface to a recording sheet. CONSTITUTION:A heat transfer recording sheet keeping file is prepared of a film provided with a layer of coating which has a haze value of not exceeding 10% to be regulated by ASTM-D1003 and contains at least 1mg/m<2> of an ultraviolet absorbing agent on a non-contacting surface with a recording sheet. A polyethylene film, a polypropylene film, a polyester film or a polyamide film is available as an exemplification of the foregoing film. 2, 4- dihydroxybenzophenone or 2-hydroxy-4-methoxybenzophenone is available as exemplification of the foregoing ultraviolet absorbing agent. As for the foregoing layer of coating, a pigment or a binder is dispersed into water or an organic solvent and can be applied to the film by a coating method such as a gravure method or a reverse roll method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file for saving a thermal transfer recording sheet after printing, and more specifically, a file for saving a thermal transfer recording sheet excellent in storability and transparency of a thermal transfer recording image. It is about.

[0002]

2. Description of the Related Art In recent years, as a means for color hard copy, an apparatus using a thermal transfer recording system has been widely used because of its advantages such as light weight, compact size, no noise, excellent operability and maintainability. . This thermal transfer system is roughly classified into two types, that is, a heat melting type and a heat transfer type or a sublimation type. In particular, the latter is excellent in reproducibility of multi-gradation images and is printed using a sublimation type thermal transfer printer.

The principle of such a sublimation type thermal transfer printer is to convert an image into an electric signal, and further convert the electric signal into a heat signal by a thermal head to apply a heat transfer medium (hereinafter referred to as a heat transfer medium). , Ink donor sheet) is heated, and dye is transferred from the ink donor sheet to the image receiving layer of the thermal transfer image receiving sheet by sublimation or diffusion in the medium, thereby recording information.

The sublimation type thermal transfer recording system can obtain an image comparable to a multicolor printed matter or a color photograph. Further, it is less expensive than a printing technique or a photographic technique in an application in which the number of copies to be produced is small. It is being used.

Recently, the field of application of the sublimation type thermal transfer printer, which has been receiving particular attention, is the production of color proofs in the printing field where high image quality close to that of photographs is required, and the output of design images in the design field. Furthermore, the characters and image information created by the computer are output to a transparent recording sheet using a sublimation thermal transfer printer,
It is also used as a manuscript for an overhead projector for presentations at conferences and the like.

Generally, a recording sheet used in such a sublimation type thermal transfer recording system is heated on a support such as a plain paper, a synthetic paper, a film or a film laminated in order to improve the fixing property of a heat transfer dye. It is prepared by providing an image receiving layer comprising a plastic resin, a release agent, an additive and the like.

By the way, when an image printed by the sublimation type thermal transfer recording system is exposed to sunlight or a fluorescent lamp for a long time,
It is known that the dye is decomposed and re-sublimated to cause fading. Therefore, a dye having high light resistance is used, a method of adding an ultraviolet absorber to the image-receiving layer of a thermal transfer recording image-receiving sheet, as described in JP-A-61-229594, and Sho 60-101090 gazette, the same 6
As described in JP-A No. 1-32789, it has been attempted to improve the light fastness of an image by a method of providing a protective layer containing an ultraviolet absorber on the image receiving layer of a thermal transfer recording image receiving sheet. .

However, in addition to the light resistance of dyes that can be used in the thermal transfer recording system being limited, a UV absorber is added to the image receiving layer of the thermal transfer recording image-receiving sheet, or a protective film containing an ultraviolet absorber is provided on the image receiving layer. When a layer is provided, there is also a problem that it reacts with the components in the image-receiving layer and dyes to be colored.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a file for storing a thermal transfer recording sheet, which has good storage stability and transparency of a thermal transfer recording image which could not be realized by such a conventional technique.

[0010]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a film having a low haze value is used as a base material in a file for storing a thermal transfer recording sheet. By using a coating layer containing a specific amount of an ultraviolet absorber on the surface of the base material that does not contact the thermal transfer recording sheet, fading of the thermal transfer recording image due to light can be prevented, and the thermal transfer recording sheet and the ultraviolet absorber can be prevented. Since it was possible to prevent coloring due to contact with the above, it was found that a file for storing a thermal transfer recording sheet having good storage stability and transparency of the thermal transfer recording sheet was obtained, and the present invention was completed.

That is, the file for storing a thermal transfer recording sheet of the present invention is a file for storing a thermal transfer recording sheet on which an image is formed by a thermal transfer printer, and the base material of the file is a haze value 10 defined by ASTM D1003.
% Or less, and a coating layer containing an ultraviolet absorber of 1 mg / m ² or more is provided on the non-contact surface with the recording sheet.

The thermal transfer recording sheet storage file of the present invention will be described in detail below.

In the present invention, a film having a haze value of 10% or less defined by ASTM D1003 is preferable as the base material of the file for storing the thermal transfer recording sheet. When the haze value of the film is more than 10%, the transparency of the file decreases, and it becomes difficult to observe the image in detail when the thermal transfer recording sheet is contained in the file.

Examples of such a film include polyethylene film, polypropylene film, polyester film, polyamide film, polyvinyl chloride film,
Polyvinylidene chloride film, polystyrene film,
Polycarbonate film, polysulfone film,
An acetate film or the like can be used. In addition, the thickness of the film is 2 from the viewpoint of handleability and cost.
About 0 to 100 μm is suitable.

Examples of the ultraviolet absorber added to the coating layer provided on the surface of the substrate which is not in contact with the thermal transfer recording sheet include, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-.
4-n-octoxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4
-Octadecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,
2 ', 4,4'-tetrahydroxybenzophenone, 2
-Hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-chlorobenzophenone and other benzophenone compounds, 2 (2'-hydroxy-5'- Methylphenyl) benzotriazole, 2
(2′-hydroxy-3 ′, 5′-di-t-butylphenyl) benzotriazole, 2 (2′-hydroxy-
3'-t-butyl-5'-methylphenyl) benzotriazole and other benzotriazole compounds, phenyl salicylate, p-octylphenyl salicylate, p-
Salicylic acid ester compounds such as t-butylphenyl salicylate, resorcinol monobenzoate, 2'-
Examples thereof include compounds such as ethylhexyl-2-cyano-3-phenylcinnamate.

The amount of the ultraviolet absorber added to the coating layer provided on the surface of the substrate which is not in contact with the thermal transfer recording sheet is 1 mg / m 2.
It is preferably ² or more. Here, the added amount is 1 mg
If it is less than / m ² , the UV blocking effect is low, and the light resistance of the thermal transfer recorded image is lowered when it is stored in the file for thermal transfer recording sheet storage.

In the present invention, the coating layer provided on the surface of the substrate which is not in contact with the thermal transfer recording sheet is an organic solvent containing the above ultraviolet absorber together with a binder, an antistatic agent, a crosslinking agent, a plasticizer, a surfactant and the like. Alternatively, it is dissolved or dispersed in water and applied to the substrate.

For example, as the binder, an organic solvent-soluble resin such as polyurethane, polyester, polyvinyl chloride, polyamide, polyether and polycarbonate,
Water-soluble resins such as polyvinyl alcohol, starch, gelatin and casein, resin emulsions such as polyacrylic acid ester type resin emulsions, polyvinyl acetate type resin emulsions, styrene / acrylic type resin emulsions and styrene / butadiene resin emulsions can be used.

As the antistatic agent, inorganic salts such as sodium chloride and potassium chloride, organic antistatic agents such as polyethylene glycol type, polystyrene sulfonic acid type, polyacrylic acid ester type, etc., and melamine / Formalin resin, urea resin, polyamide resin, polyethyleneimine resin, epoxy resin, etc., plasticizers such as phthalic acid ester, trimellitic acid ester, pyromellitic acid ester, etc., and surfactants such as anionic surfactant, cation. A cationic surfactant, an amphoteric surfactant, a nonionic surfactant and the like can be used.

The coating layer containing such an ultraviolet absorber can be formed by a gravure method, a reverse roll method, a wire bar method,
The base material can be coated by a general coating method such as an extrusion die method, a comma method, a curtain method, an air knife method, and a slide hopper method.

In the present invention, for the purpose of preventing blocking of the thermal transfer recording sheet and the file for storing the thermal transfer recording sheet, the surface of the substrate which is in contact with the thermal transfer recording sheet is electrically conductive or separated within a range not impairing the effects of the present invention. A coating layer can be provided to impart moldability.

Such a coating layer includes a pigment, a binder, a dispersant, a surfactant, an antistatic agent, a cross-linking agent, a plasticizer, and a pH.
General agents such as gravure method, reverse roll method, wire bar method, extrusion die method, comma method, curtain method, air knife method, slide hopper method, etc. The base material can be applied by a coating method.

[0023]

In the present invention, when a film having a low haze value is used as the substrate and a coating layer containing an ultraviolet absorber is provided on the surface of the substrate which is not in contact with the thermal transfer recording sheet, the effect of blocking the ultraviolet rays causes It is possible to prevent discoloration of the thermal transfer recording image stored in the image due to light, and by preventing the thermal transfer recording sheet and the ultraviolet absorber from contacting, it is possible to prevent coloring due to the reaction between the components in the image receiving layer and the ultraviolet absorber. Therefore, a thermal transfer recording sheet storage file having good storage stability and transparency of the thermal transfer recording image can be obtained.

[0024]

The present invention will be described in more detail by way of examples, but the contents of the present invention are not limited to these.

Example 1 A polyethylene terephthalate film having a haze value of 1.8% and a thickness of 50 μm was coated on one side with a gravure coater to give a coating solution having the following composition in a dry coating amount of 0.53 g /
It was coated and dried so as to be m ² . Then, the surface provided with the coating layer of this film was folded in two, and two of the three sides were glued to prepare a file for storing a thermal transfer recording sheet. (Coating layer coating liquid formulation 1) Polycarbonate resin 98 parts by weight 2,4-Diethyloxybenzophenone 1 part by weight Polyethylene glycol antistatic agent 1 part by weight Toluene 150 parts by weight Methyl ethyl ketone 150 parts by weight

Example 2 In Example 1, the substrate was made to have a haze value of 3.9% and a thickness of 50.
A thermal transfer recording sheet storage file was prepared in exactly the same manner as in Example 1 except that the film was changed to a polypropylene film of μm.

Example 3 In Example 1, the substrate was made to have a haze value of 9.6% and a thickness of 50.
Example 1 except that the polyethylene film was changed to μm.
A file for saving a thermal transfer recording sheet was prepared in exactly the same manner as.

Example 4 A thermal transfer recording sheet storage file was prepared in the same manner as in Example 1 except that the coating liquid for the coating layer was changed to the following composition. (Coating layer coating solution formulation 2) Poly vinyl chloride resin 80 parts by weight Dioctyl phthalate 15 parts by weight 2 (2'-Hetoxy-5-methylphenyl) benzethriasol 5 parts by weight Toluene 150 parts by weight Methyl ethyl ketone 150 parts by weight

Example 5 A thermal transfer recording sheet storage file was prepared in the same manner as in Example 1 except that the coating liquid for the coating layer was changed to the following composition. (Coating layer coating composition 3) Polyurethane resin 85 parts by weight Phenyl salicylate 15 parts by weight Toluene 150 parts by weight Methyl ethyl ketone 150 parts by weight

Example 6 A thermal transfer recording sheet storage file was prepared in the same manner as in Example 1 except that the coating liquid for coating layer was changed to the following composition. (Coating liquid for coating layer 4) Polyacrylic acid ester resin emulsion 99 parts by weight 2'-ethylhexyl-2-cyano-3-phenylcinnamate 1 part by weight

Example 7 In Example 1, the dry coating amount of the coating liquid for the coating layer was 0.11.
A thermal transfer recording sheet storage file was prepared in exactly the same manner as in Example 1 except that the file was set to g / m ² .

Comparative Example 1 A polyethylene terephthalate film having a haze value of 1.8% and a thickness of 50 μm was folded in two and two of the three sides were glued to prepare a file for storing a thermal transfer recording sheet.

Comparative Example 2 A semi-transparent polyvinyl chloride film having a haze value of 30.2% and a thickness of 50 μm and having irregularities on the surface is folded into two and 3
Two of the sides were glued to prepare a file for saving a thermal transfer recording sheet.

Comparative Example 3 In Example 1, the substrate was made to have a haze value of 12.5% and a thickness of 5.
A thermal transfer recording sheet storage file was prepared in exactly the same manner as in Example 1 except that the polyethylene film was changed to 0 μm.

Comparative Example 4 A thermal transfer recording sheet storage file was prepared in the same manner as in Example 1 except that the coating liquid for coating layer was changed to the following composition. (Coating layer coating liquid formulation 5) Polycarbonate resin 99.9 parts by weight 2,4-dihydroxybenzophensophenone 0.1 part by weight Toluene 150 parts by weight Methyl ethyl ketone 150 parts by weight

Comparative Example 5 In Example 1, the dry coating amount of the coating liquid for the coating layer was 0.08.
A thermal transfer recording sheet storage file was prepared in exactly the same manner as in Example 1 except that the file was set to g / m ² .

Comparative Example 6 In Example 1, a film for storing a thermal transfer recording sheet was prepared by folding the film in two with the surface on which the coating layer was provided being inside and gluing two of the three sides.

Comparative Example 7 In Example 5, a film for storing a thermal transfer recording sheet was prepared by folding the film in two with the surface provided with the coating layer on the inside and gluing two of the three sides.

In order to evaluate the performance of the thermal transfer recording sheet storage file produced as described above, YUP
One side of O150 (made by Oji Oil Chemical Co., Ltd., polypropylene synthetic paper) was coated with an image receiving layer coating solution having the following composition at a dry coating amount of 5 g / m ^2.
A thermal transfer recording sheet coated and dried so as to be used was used. (Composition of coating liquid for image receiving layer) VAGH (manufactured by Union Carbide, vinyl chloride / vinyl acetate) 100 parts by weight BYRON 200 (manufactured by Toyobo, saturated polyester resin) 20 parts by weight 2-ethylhexyl phthalate 20 parts by weight SF8417 (Toray Industries) Corning silicone, amino-modified silicone oil) 0.5 parts by weight SF8411 (Toray Industries Corning silicone, epoxy-modified silicone oil) 1.5 parts by weight Toluene 100 parts by weight Methyl ethyl ketone 100 parts by weight

The performance of the file for storing the thermal transfer recording sheet was evaluated by the following method.

(Light resistance of thermal transfer recording image) A thermal transfer recording sheet printed by using a sublimation type thermal transfer full color printer S3600-30 manufactured by Mitsubishi Electric was put in a file for storing the thermal transfer recording sheet, and an Atlas Ci35 weatherometer manufactured by Toyo Seiki was used. Then, a light resistance test was carried out under the conditions of an irradiation amount of 0.38 W / m ² and an irradiation time of 60 hours, the ratio of the optical density before and after the light resistance test in the black image area was obtained, and this was converted into a percentage and evaluated.

(Coloring of thermal transfer recording sheet) A thermal transfer recording sheet printed by using a sublimation type thermal transfer full color printer S3600-30 manufactured by Mitsubishi Electric was put in a file for storing the thermal transfer recording sheet, and stored at 30 ° C. and 80% RH for 1 month. After being stored for a while, the coloring state in the non-image area of the thermal transfer recording sheet was visually observed, and those showing almost no coloring were evaluated as ◯, those having a slight coloring were evaluated as Δ, and those having remarkable coloring were evaluated as ×.

(Transparency) A thermal transfer recording sheet printed by using a sublimation type thermal transfer full color printer S3600-30 manufactured by Mitsubishi Electric was put in a file for storing the thermal transfer recording sheet, and the image on the thermal transfer recording sheet was visually observed to form a file. ○ When there is no cloudiness and the image can be observed in detail, ○, when there is some cloudiness and detailed image observation is a little difficult, △,
The image that could not be observed in detail because it was extremely cloudy and could not be used was marked with x.

The results of the above evaluations are summarized in Table 1.

[0045]

[Table 1]

As is clear from Table 1, the thermal transfer recording sheet storage files of Examples 1 to 7 were good in light resistance and transparency of the thermal transfer recorded images, and the thermal transfer recording sheets were not colored. However, in the file for storing the thermal transfer recording sheet of Comparative Example 1, the light resistance of the thermal transfer recorded image was deteriorated because the coating layer containing the ultraviolet absorber was not provided. The file for storage of the thermal transfer recording sheet of Comparative Example 2 uses a semi-transparent polyvinyl chloride film having irregularities on the surface as a base material,
Since no coating layer containing an ultraviolet absorber was provided, the transparency was low and the light resistance of the thermal transfer recorded image was also low. Comparative Example 3
In the file for storing the thermal transfer recording sheet, since a polyethylene film having a high haze value was used as the base material, the transparency was lowered, and it was difficult to observe the image in detail with the thermal transfer recording sheet put in the file. Comparative Example 4
In the files for storing thermal transfer recording sheets Nos. 5 to 5, the light resistance of the thermal transfer recorded image was deteriorated because the amount of the ultraviolet absorber contained in the coating layer was too small. The files for storing the thermal transfer recording sheets of Comparative Examples 6 to 7 had the coating layer containing the ultraviolet absorber applied to the surface of the base material in contact with the thermal transfer recording sheet, and thus the components of the image receiving layer of the thermal transfer recording sheet and the ultraviolet absorber. Coloring due to the reaction was observed.

[0047]

According to the present invention, a film having a low haze value is used as a substrate, and a coating layer containing a specific amount of an ultraviolet absorber is provided on the surface of the substrate which is not in contact with the thermal transfer recording sheet. This makes it possible to obtain a file for storing a thermal transfer recording sheet, which has good storability and transparency of the thermal transfer recording image.

Claims (1)

[Claims] 1. In a file for storing a thermal transfer recording sheet on which an image is formed by a thermal transfer printer, a base material of the file has a haze value of 10% or less defined by ASTM D1003 and a non-contact surface with the recording sheet. A file for storing a thermal transfer recording sheet, characterized in that a coating layer containing 1 mg / m ² or more of an ultraviolet absorber is provided on the sheet.