JPH07179066A - File for preserving thermal transfer recording sheet - Google Patents

Abstract

PURPOSE:To provide a file excellent in blocking resistance and transparency. CONSTITUTION:A file for preserving a thermal transfer recording sheet is obtained by using a film of which the haze value prescribed by ASTM D1003 is 10% or less as a base material and providing a coating layer containing 5-50mg/m of particles with an average particle size of 1-15mum on the surface coming into contact with the thermal transfer recording sheet of the base material.

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 to a file for saving a thermal transfer recording sheet excellent in blocking resistance and transparency. is there.

[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 requiring a small number of copies, and thus is widely used. It is being used.

Recently, the field of application of the sublimation type thermal transfer printer, which has been particularly attracting attention, includes the production of color proofs in the printing field where high image quality close to that of a photograph 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 made of polyester on a support such as plain paper, synthetic paper, film or film laminated in order to improve the fixing property of a heat transfer dye. By providing an image receiving layer made of a thermoplastic resin such as a vinyl resin such as a vinyl resin, a polyvinyl chloride resin, a polycarbonate resin, a polyvinyl butyral resin, an acrylic resin, a cellulose resin, an olefin resin, or a polystyrene resin It is made.

The dye-dyeing property of the image-receiving layer and the image storability in such a sublimation type thermal transfer recording sheet largely depend on the thermoplastic resin forming the image-receiving layer. In order to improve the fixing property of the transfer dye, there is a method of using a thermoplastic resin having good dyeing property or including a plasticizer in the image receiving layer. When the image is discolored due to the influence of sebum or sweat, or when it is adhered to a plastic material containing a plasticizer for a long time, the dye may transfer to the plastic material or the plastic material and the recording sheet may block. There was a problem that caused it.

For this reason, a thermoplastic resin having a specific structure as described in JP-A-2-223485 and JP-A-5-131758 can be used, or JP-A-4-223
It has been attempted to improve the storability of an image by adding an ester compound having a specific structure as described in JP-B-85079 and JP-A-4-310794, but such an identification has been made. Even if a material having a structure is used, it is the actual situation that sufficient plasticizer resistance cannot be obtained.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a file for saving a thermal transfer recording sheet, which has excellent blocking resistance and transparency, which cannot be realized by such a conventional technique.

[0010]

Means for Solving the Problems As a result of intensive studies aimed at achieving the above object, the present inventors have found that a file having a low haze value is used as a base material in a file for storing a thermal transfer recording sheet. By using a specific amount of a coating layer containing particles having an average particle diameter in a specific range on the surface of the base material in contact with the recording sheet, the contact area between the file and the recording sheet is reduced, and blocking occurs. It was found that a file for storing a thermal transfer recording sheet having good blocking resistance and transparency can be obtained because it is less likely to occur and high transparency is maintained, and the present invention has been completed.

That is, the thermal transfer recording sheet storage file of the present invention is a thermal transfer recording sheet storage file on which an image is formed by a thermal transfer printer, and the file base material has a haze value of 1 defined by ASTM D1003.
A coating layer containing 0 to 50% or less of particles having an average particle diameter of 1 to 15 μm in an amount of 5 to 50 mg / m ² is provided on the surface in contact 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 exceeds 10%, the transparency of the file is lowered, and it is difficult to observe the image in detail when the thermal transfer recording sheet is left 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 etc. are mentioned.

The thickness of the film is preferably about 20 to 100 μm from the viewpoint of handleability and cost.

The average particle size of the particles contained in the coating layer provided on the surface of the substrate which contacts the thermal transfer recording sheet is 1 to 15 μm.
It is preferably in the range of m. If the average particle size is less than 1 μm, the contact area between the storage file and the thermal transfer recording sheet increases, and thus blocking easily occurs. On the other hand, when the average particle size exceeds 15 μm, the light scattering increases due to the increase in the particle size, and the transparency of the file decreases.

The coating amount of the above particles is 5 to 50 m.
It is preferably in the range of g / m ² . Coating amount is 5mg
If it is less than / m ² , the contact area between the storage file and the thermal transfer recording sheet increases, and thus blocking easily occurs. On the other hand, when the coating amount exceeds 50 mg / m ² , the light scattering increases due to the increase in the number of particles, and the transparency of the file decreases.

Examples of such particles include inorganic pigments such as silica, alumina, talc, kaolin, clay, zinc oxide, titanium oxide, calcium carbonate, barium sulfate, melamine resin fine particles, urethane resin fine particles, and epoxy resin. Fine particles, silicone resin particles, polystyrene resin particles, polyacrylic ester resin particles,
Organic pigments such as polyurethane resin particles, styrene / butadiene resin particles, guanamine resin particles, starch particles, and cellulose powder can be used.

Such particles include binders, dispersants, surfactants, antistatic agents, crosslinking agents, plasticizers, pH adjusters,
It is applied to a substrate by dispersing it in water or an organic solvent together with a thickener and the like. For example, as the binder, polyurethane, polyester, polyvinyl chloride, polyamide, polyether, organic solvent-soluble resin such as polycarbonate,
Water-soluble resins such as polyvinyl alcohol, starch, gelatin, and casein, resin emulsions such as polyacrylic ester resin emulsion, polyvinyl acetate resin emulsion, styrene / acrylic resin emulsion, and styrene / butadiene resin emulsion can be used. .

As the dispersant, sodium polyacrylate, sodium hexametaphosphate, etc., and as the surfactant, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant. As the antistatic agent, inorganic salts such as sodium chloride and potassium chloride, organic antistatic agents such as polyethylene glycol-based, polystyrene sulfonic acid-based, polyacrylic acid ester-based, and the like, and as the cross-linking agent, melamine / formalin resin,
Urea resin, polyamide resin, polyethyleneimine resin,
As a plasticizer such as epoxy resin, phthalate ester,
Trimellitic acid ester, pyromellitic acid ester, etc.
Acids such as hydrochloric acid, sulfuric acid, nitric acid and acetic acid and bases such as sodium hydroxide, potassium hydroxide and ammonia can be used as pH adjusting agents, and sodium alginate, carboxymethyl cellulose, polyacrylamide and the like can be used as thickening agents. is there.

The coating layer containing such particles is generally formed by gravure method, reverse roll method, wire bar method, extrusion die method, comma method, curtain method, air knife method, slide hopper method, blade method, etc. Can be applied to the base material by various coating methods.

In the present invention, for the purpose of preventing blocking between files, the surface of the substrate which is not in contact with the thermal transfer recording sheet is provided with conductivity and releasability within a range not impairing the effects of the present invention. A coating layer can be provided.

In such a coating layer, a pigment, a binder, a dispersant, a surfactant, an antistatic agent, a crosslinking agent, a plasticizer, an antioxidant, a pH adjusting agent, a thickener and the like are added to water or an organic solvent. Disperse, gravure method, reverse roll method, wire bar method, extrusion die method, comma method,
The base material can be coated by a general coating method such as a curtain method, an air knife method, a slide hopper method, or a blade method.

[0024]

In the present invention, a film having a low haze value is used as a base material, and a specific amount of a coating layer containing particles having an average particle diameter in a specific range is applied to the surface of the base material in contact with the recording sheet. As a result, the contact area between the file and the recording sheet is reduced, blocking is less likely to occur, and high transparency is maintained, so that a file for storing a thermal transfer recording sheet having good blocking resistance and transparency can be obtained.

[0025]

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 polyvinyl chloride film having a haze value of 1.8% and a thickness of 50 μm was coated on one side with a gravure coater to prepare a coating solution for coating layer having the following composition and a dry coating amount of 0.48 g / m 2. ^It was coated so that it would be ² and dried. 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) Polystyrene-based resin fine particles (average particle size 6 μm) 1 part by weight Polyvinyl alcohol 20 parts by weight Polystyrene sulfonic acid sodium salt 1 part by weight Glyoxal 1 part by weight Sulfosuccinic acid octyl ester 0.1 parts by weight water 176 9.9 parts by weight

Example 2 In Example 1, the substrate has a haze value of 1.5% and a thickness of 50.
A file for storing a thermal transfer recording sheet was prepared in exactly the same manner as in Example 1 except that the polyethylene terephthalate film having a thickness of μm was used.

Example 3 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 polyvinyl alcohol film having a thickness of μm was used.

Example 4 In Example 1, the substrate was made to have a haze value of 9.6% and a thickness of 50.
A file for storing a thermal transfer recording sheet was prepared in the same manner as in Example 1 except that the polyvinyl chloride film having a thickness of μm was used.

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 coating layer was changed to the following composition. (Coating layer coating liquid formulation 2) Silicone-based resin fine particles (average particle size 1 μm) 1 part by weight Polyvinyl chloride 20 parts by weight Dioctyl phthalate 2 parts by weight Toluene 100 parts by weight Methyl ethyl ketone 77 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 coating formulation 3) Starch granules (average particle size 15 μm) 1 part by weight Styrene / acrylic ester resin emulsion 20 parts by weight Polystyrene sulfonic acid sodium salt 1 part by weight Sulfosuccinic acid octyl ester 0.1 parts by weight Water 177. 9 parts by weight

Example 7 In Example 1, the dry coating amount of the coating liquid for the coating layer was 0.12.
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 .

Example 8 In Example 1, the dry coating amount of the coating liquid for the coating layer was 1.13.
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 polyvinyl chloride 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 polyethylene terephthalate film having a haze value of 1.5% 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 3 A semitransparent polyvinyl chloride film having a haze value of 30.2% and a thickness of 50 μm and having irregularities on the surface was folded in half and 3
Two of the sides were glued to prepare a file for saving a thermal transfer recording sheet.

Comparative Example 4 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 polyvinyl chloride film was changed to 0 μm.

Comparative 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 coating layer was changed to the following composition. (Coating Layer Coating Mixture 4) Styrene / Betadiene Resin Fine Particles (Average Particle Size 0.8 μm) 1 part by weight Polyvinyl alcohol 20 parts by weight Polystyrene sulfonic acid sodium salt 1 part by weight Glyoxal 1 part by weight Sulfosuccinate octyl ester 0.1 Parts by weight Water 176.9 parts by weight

Comparative 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 the coating layer was changed to the following composition. (Coating layer coating liquid formulation 5) Polystyrene-based resin fine particles (average particle size 18 μm) 1 part by weight polyvinyl alcohol 20 parts by weight Polystyrene sulfonate sodium salt 1 part by weight glyoxal 1 part by weight octyl sulfosuccinate 0.1 parts by weight water 176 9.9 parts by weight

Comparative Example 7 In Example 1, the dry coating amount of the coating liquid for the coating layer was 0.10.
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 8 In Example 1, the dry coating amount of the coating liquid for the coating layer was 1.19.
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 .

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.

(Blocking resistance) 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 the file for storing the thermal transfer recording sheet, and a load of 50 g / cm ² was applied from above. The blocking property after standing at 30 ° C. and 65% RH for 1 month was evaluated. The evaluation was evaluated as ◯ when the thermal transfer recording sheet and the file did not have blocking at all, Δ when slightly blocked, and x when the blocking was remarkable and could not be used.

(Transparency) A thermal transfer recording sheet printed by using a sublimation type thermal transfer full color printer S3600-30 manufactured by Mitsubishi Electric was placed in the file for storing the thermal transfer recording sheet, and the image on the recording sheet was visually observed to make a file. ○ If there is no fog and the image can be observed in detail, ○, if there is some fog 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.

[0047]

[Table 1]

As is clear from Table 1, the thermal transfer recording sheet storage files of Examples 1 to 8 were free from blocking with the thermal transfer recording sheet and had good transparency. The thermal transfer recording sheet storage files of Comparative Examples 1 and 2 were not provided with the coating layer containing the particles of the present invention, and thus were significantly blocked with the thermal transfer recording sheet. The files for storing the thermal transfer recording sheets of Comparative Examples 3 to 4 used a translucent polyvinyl chloride film having irregularities on the surface or a polyethylene film having a high haze value as a base material, so the transparency was low and the thermal transfer recording to the file was made. Detailed images could not be observed with the sheet still inside. In the file for storing the thermal transfer recording sheet of Comparative Example 5, the average particle size of the particles contained in the coating layer was too small, so that the contact area between the thermal transfer recording sheet and the file increased and blocking occurred. Comparative Example 6
In the file for saving thermal transfer recording sheet, the average particle size of the particles contained in the coating layer was too large, so the light scattering increased and the transparency deteriorated. Could not be observed. In the file for storing the thermal transfer recording sheet of Comparative Example 7, since the coating amount of the coating layer containing particles was too small, the contact area between the thermal transfer recording sheet and the file increased and blocking occurred. The file for storing the thermal transfer recording sheet of Comparative Example 8 had too much coating amount of the coating layer containing particles, so that the light scattering increased and the transparency deteriorated. I was not able to observe such images.

[0049]

According to the present invention, a film having a low haze value is used as a base material, and a coating layer containing particles having an average particle diameter in a specific range is provided on the surface of the base material in contact with the thermal transfer recording sheet. By applying a specific amount, a thermal transfer recording sheet storage file having good blocking resistance and transparency can be obtained.

Claims (1)

[Claims] 1. A file for storage of a thermal transfer recording sheet on which an image is formed by a thermal transfer printer, the base material of the file having a haze value of 10% or less defined by ASTM D1003, and a surface in contact with the recording sheet. A file for storing a thermal transfer recording sheet, characterized in that a coating layer containing 5 to 50 mg / m ² of particles having an average particle size of 1 to 15 μm is provided.