JP3349792B2 - File for storing inkjet recording sheets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a file for storing an ink jet recording sheet after printing, and more particularly to a file for storing an ink jet recording sheet having excellent blocking resistance and transparency. is there.

[0002]

2. Description of the Related Art In an ink jet recording system, fine droplets of ink are made to fly by various operating principles and adhere to a recording sheet such as paper or film to record an image or a character. Ink jet printers have features such as high-speed printing, low noise, great flexibility in recording patterns, and no need for development or fixing, and can form complex images accurately and quickly. In recent years, it has been widely used in various applications as a hard copy creation device for image information such as characters and various figures created by a computer.

In the ink jet recording system, it is easy to perform multi-color recording by using a plurality of ink nozzles. The multi-color ink jet recording method can be used to obtain images comparable to multi-color prints and color photographs, and is widely used in applications with a small number of copies, because it can be cheaper than printing and photographic techniques. It is getting.

Recently, the fields of application of ink-jet printers, which have attracted particular attention, include the production of color proofs in the printing field, which requires high image quality close to photographs, and the output of design images in the design field. Further, characters and image information created by a computer are output to a transparent recording sheet using an ink jet printer, and are used as a document for an overhead projector for presentation in a conference or the like.

In general, a recording sheet used in such an ink jet recording system has an ink receiving composition comprising a water-soluble resin, an inorganic pigment, an additive and the like on a support such as paper or film in order to improve the ink absorption. It is produced by providing a layer. Then, an image containing a dye, a pigment, water, a water-soluble organic solvent, and the like is attached to a recording sheet using an ink jet printer to form an image.

However, since such a recording sheet uses a water-soluble resin as described above, it has high water absorption,
If the recording sheet after printing is stored in a file made of a normal transparent film, there is a problem that the recording sheet and the file are likely to be blocked particularly under high humidity conditions. In order to prevent blocking, a file made of a translucent film with an uneven surface has been developed.However, since such a file has low transparency, an image on a recording sheet is not stored in the file. There was an unsightly problem.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a file for storing an ink jet recording sheet which is excellent in blocking resistance and transparency which cannot be realized by such a conventional technique.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, in a file for storing an ink jet recording sheet, a film having a low haze value was used as a base material. By using and coating a specific amount of a coating layer containing particles having a specific range of average particle diameter on a surface of the base material that comes into contact with the recording sheet, the ink jet recording sheet having good blocking resistance and transparency can be stored. The present inventors have found that a file for use can be obtained, and have completed the present invention.

That is, the file for storing an ink jet recording sheet of the present invention is a file for storing an ink jet recording sheet on which an image is formed by an ink jet printer, wherein the file has a haze value specified by ASTM D1003 of 10% or less. With the base material,
A coating layer containing 5 to 50 mg / m ² of particles having an average particle size of 1 to 15 μm is provided on a surface of the base material which is in contact with the ink jet recording sheet.

Hereinafter, the file for storing the ink jet recording sheet of the present invention will be described in detail. A film having a low haze value is used as a base material, and a coating layer containing particles of a specific size is provided on a surface of the base material in contact with the ink jet recording sheet, so that the contact area between the file and the recording sheet is reduced, and blocking is performed. In addition, since high transparency is maintained, a file for storing an ink jet recording sheet having good blocking resistance and transparency can be obtained.

In the present invention, ASTM D100 is used as a base material of a file for storing an ink jet recording sheet.
A film having a haze value specified in 3 of 10% or less is preferable. If the haze value of the film exceeds 10%,
Since the transparency of the file is reduced, it is difficult to observe the image in detail while the inkjet recording sheet is stored in the file. Examples of such a film include a polyethylene film, a polypropylene film, a polyester film, a polyamide film, a polyvinyl chloride film, a polyvinylidene chloride film, a polystyrene film, a polycarbonate film, a polysulfone film, and an acetate film. The thickness of the film is from 20 to 1 in terms of handleability and cost.
About 00 μm is appropriate.

The average particle size of the particles contained in the coating layer provided on the surface of the substrate in contact with the ink jet recording sheet is 1
It is preferably in the range of 15 to 15 μm. Average particle size is 1
If the thickness is less than μm, the contact area between the storage file and the inkjet recording sheet increases, so that blocking tends to occur. When the average particle size exceeds 15 μm, light scattering increases due to an increase in the particle size, so that the transparency of the file decreases.

The coating amount of the particles is 5 to 50 m.
It is preferably in the range of g / m ² . 5mg coating amount
If it is less than / m ² , the contact area between the storage file and the inkjet recording sheet increases, so that blocking tends to occur. The coating amount is 50 mg / m
If it exceeds 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, and barium sulfate; melamine resin fine particles, urethane resin fine particles, and epoxy resin. Fine particles, silicone resin fine particles, polystyrene resin fine particles, polyacrylate resin fine particles,
Organic pigments such as polyurethane resin fine particles, styrene / butadiene resin fine particles, guanamine resin fine particles, starch particles, and cellulose powder can be used.

Such particles include a binder, a dispersant, a surfactant, an antistatic agent, a crosslinking agent, a plasticizer, a pH adjuster,
It is dispersed in water or an organic solvent together with a thickener or the like and applied to a substrate. 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 polyacrylate resin emulsion, polyvinyl acetate resin emulsion, styrene / acrylic resin emulsion, and styrene / butadiene resin emulsion can be used. .

The dispersing agents include sodium polyacrylate and sodium hexametaphosphate, and the surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. As antistatic agents, inorganic salts such as sodium chloride and potassium chloride, and organic antistatic agents such as polyethylene glycol-based, polystyrene sulfonic acid-based, and polyacrylic acid ester-based agents; crosslinkers include melamine / formalin resins;
Urea resin, polyamide resin, polyethylene imine resin,
As plasticizers such as epoxy resins, phthalate esters,
Trimellitic acid esters, pyromellitic acid esters, etc.
As a pH adjuster, 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 a thickener, sodium alginate, carboxymethylcellulose, polyacrylamide, and the like can be used. is there.

The coating layer containing such particles is formed by a general method such as a gravure method, a reverse roll method, a wire bar method, an extrusion die method, a comma method, a curtain method, an air knife method, a slide hopper method, and a blade method. It can be applied to the substrate by any suitable coating method.

In the present invention, in order to prevent blocking between files, the surface of the base material which is not in contact with the ink jet recording sheet is provided with conductivity and releasability within a range not to impair the effects of the present invention. A coating layer can be provided.

Such a coating layer is formed by adding a pigment, a binder, a dispersant, a surfactant, an antistatic agent, a cross-linking agent, a plasticizer, an antioxidant, a pH adjuster, a thickener and the like to water or an organic solvent. Disperse, gravure method, reverse roll method, wire bar method, extrusion die method, comma method,
The substrate can be coated by a general coating method such as a curtain method, an air knife method, a slide hopper method, and a blade method.

[0020]

EXAMPLES The present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 A coating liquid having the following composition was applied to one side of a polyethylene terephthalate film having a haze value of 1.8% and a thickness of 50 μm using a gravure coater to a dry coating amount of 0.48 g /
m ² and dried. Then, the film was folded in two with the surface provided with the coating layer inside, and two of the three sides were glued to prepare a file for storing an ink jet recording sheet. (Coating layer coating liquid composition 1) Polystyrene-based resin fine particles (average particle size: 6 μm) 1 part by weight Polyvinyl alcohol 20 parts by weight Polystyrene sulfonate sodium salt 1 part by weight Polyoxal 1 part by weight Sulfosuccinic acid octyl ester 0.1 part by weight Water 176 .9 parts by weight

Example 2 In Example 1, the substrate was 3.9% in haze value and 50% in thickness.
A file for storing an ink jet recording sheet was prepared in exactly the same manner as in Example 1 except that the film was changed to a μm polypropylene film.

Example 3 In Example 1, the substrate was 9.6% in haze and 50 in thickness.
Example 1 except for changing to a μm polyethylene film
A file for storing an ink jet recording sheet was prepared in exactly the same manner as described above.

Example 4 A file for storing an ink jet recording sheet was prepared in exactly 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 composition 2) Silicone resin fine particles (average particle diameter 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 5 A file for storing an ink jet recording sheet was prepared in exactly the same manner as in Example 1 except that the coating liquid for the coating layer was changed to the following composition. (Coating composition for coating layer 3) Starch granules (average particle size 15 μm) 1 part by weight Styrene / acrylate resin emulsion 20 parts by weight Sodium polystyrenesulfonate 1 part by weight Octyl sulfosuccinate 0.1 part by weight Water 177. 9 parts by weight

Example 6 The same procedure as in Example 1 was carried out except that the dry coating amount of the coating liquid for the coating layer was 0.12.
A file for storing an ink jet recording sheet was prepared in exactly the same manner as in Example 1 except that the concentration was changed to g / m ² .

Example 7 In Example 1, the dry coating amount of the coating liquid for the coating layer was 1.13.
A file for storing an ink jet recording sheet was prepared in exactly the same manner as in Example 1 except that the concentration was changed 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 an ink jet recording sheet.

COMPARATIVE EXAMPLE 2 A translucent polyvinyl chloride film having a haze value of 30.2% and a thickness of 50 μm and having irregularities on its surface was folded in two, and
Two of the sides were glued to prepare a file for storing an ink jet recording sheet.

Comparative Example 3 In Example 1, the substrate was 12.5% in haze value and 5% in thickness.
A file for storing an ink jet recording sheet 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 file for storing an ink jet recording sheet was prepared in exactly 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 composition 4) Styrene / phthalic acid 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 Polyoxal 1 part by weight Sulfosuccinic acid octyl ester 0.1 176.9 parts by weight water

Comparative Example 5 A file for storing an ink jet recording sheet was prepared in exactly 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 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 Polyoxal 1 part by weight Sulfosuccinate octyl ester 0.1 part by weight Water 176 .9 parts by weight

Comparative Example 6 In Example 1, the coating amount of the coating liquid for the coating layer was 0.10
A file for storing an ink jet recording sheet was prepared in exactly the same manner as in Example 1 except that the concentration was changed to g / m ² .

Comparative Example 7 In Example 1, the coating amount of the coating liquid for the coating layer was 1.19.
A file for storing an ink jet recording sheet was prepared in exactly the same manner as in Example 1 except that the concentration was changed to g / m ² .

In order to evaluate the performance of the file for storing an ink jet recording sheet prepared as described above, an image receiving layer coating solution having the following composition was applied to both sides of a 100 μm thick polyethylene terephthalate film in a dry coating amount of 5 g.
/ M ² , an inkjet recording sheet coated and dried was used. (Image-receiving layer coating liquid formulation) Carboxymethyl methylcellulose 100 parts by weight Colloidal silica 10 parts by weight Sulfosuccinic acid octyl ester 1 part by weight Water 889 parts by weight

The performance of the file for storing an ink jet recording sheet was evaluated by the following method. (Blocking resistance) Desk Writer 5 manufactured by Hewlett Packard
An ink jet recording sheet printed using a 50C ink jet printer is subjected to 24 hours at 25 ° C. and 80% RH.
After storing for a period of time, place in the file for storing the ink jet recording sheet, apply a load of 25 g / cm ²
After standing for a while, the ink-jet recording sheet and the file having no blocking were evaluated as ○, the one having slight blocking was evaluated as ブ ロ ッ キ ン グ, and the one having severe blocking and unusable was evaluated as ×. (Transparency) Put the inkjet recording sheet printed using a Hewlett Packard Desk Writer 550C inkjet printer into the file for storing the inkjet recording sheet, visually observe the image on the recording sheet, and make sure that the image is detailed without fogging. Those that could be observed were rated as 、, those that were slightly hazy and a little more difficult to observe detailed images, and those that were too cloudy to observe detailed images and were unusable. Table 1 summarizes the above evaluation results.

[0037]

[Table 1]

As is clear from Table 1, the files for storing the ink jet recording sheets of Examples 1 to 7 did not have blocking with the ink jet recording sheets and had good transparency. In the file for storing an ink jet recording sheet of Comparative Example 1, since the coating layer containing the particles of the present invention was not provided, blocking with the ink jet recording sheet was remarkable. The files for storing the ink jet recording sheets of Comparative Examples 2 and 3 were made of a translucent polyvinyl chloride film or a polyethylene film having a high haze value as a base material, and thus had low transparency and were recorded by ink jet recording on a file. A detailed image could not be observed with the sheet inserted. In the file for storing the ink jet recording sheet of Comparative Example 4, the contact area between the ink jet recording sheet and the file was increased because the average particle diameter of the particles contained in the coating layer was too small, and blocking occurred.
In the file for storing an ink jet recording sheet of Comparative Example 5, since the average particle diameter of the particles contained in the coating layer was too large, the light scattering increased and the transparency was reduced. Detailed images could not be observed. In the file for storing the ink jet recording sheet of Comparative Example 6, the contact area between the ink jet recording sheet and the file was increased because the coating amount of the coating layer containing the particles was too small, and blocking occurred. In the file for storing an ink jet recording sheet of Comparative Example 7, since the coating amount of the coating layer containing particles was too large, light scattering was increased and transparency was reduced. Could not be observed.

[0039]

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

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 4-83675 (JP, U) JP-A-59-29278 (JP, U) JP-A 60-96070 (JP, U) JP-A 59-29 157869 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B42F 7/00

Claims (1)

(57) [Claims] 1. A file for storing an ink-jet recording sheet on which an image is formed by an ink-jet printer, wherein the file is based on a film having a haze value of 10% or less specified by ASTM D1003, and A file for storing an ink jet recording sheet, wherein a coating layer containing particles having an average particle size of 1 to 15 μm and containing 5 to 50 mg / m ² is provided on a surface in contact with the recording sheet.