KR100255042B1 - A film for inkjet printer - Google Patents

Abstract

PURPOSE: Provided is a transparent film for an inkjet printer which shows optimal physical property at various kinds of printers by formulation architecture so that it includes versatility. CONSTITUTION: In the transparent film for the inkjet printer wherein an ink absorption layer is coated in one side of film, the transparent film for the inkjet printer is characterized by including the ink absorption layer that consists of soluble polymer as a binder component, 0.5-20wt.% of an inorganic filler, 0.05-5wt.% of starch phosphate ester as an organic filler and 0.01-0.1wt.% of aluminium sulfate, calcium sulfate or magnesium sulfate as an additive.

Description

Transparent film for inkjet printers {A film for inkjet printer}

The present invention relates to a transparent film for an inkjet printer, and more particularly, in a transparent film for an inkjet printer, in which a base film, an undercoat layer, and an ink absorbing layer are laminated, a water-soluble polymer having excellent durability and light transmittance as a binder in the ink absorbing layer. Was introduced into the binder, and the inorganic starch and the organic starch as the filler contained the modified starch together to improve not only the ink absorbing power but also the light resistance and the light transmitting property, and the undercoating layer was directly coated on the base film between the base film and the ink absorbing layer. By increasing the adhesion of the ink absorbing layer to the substrate, various inkjet printing methods can be obtained, which can be used simultaneously by several company's inkjet printers, and the ink absorbing ability of various inkjet printers is excellent, and the color and image quality are excellent. It relates to a conical transparencies.

Inkjet printing has been widely used by consumers because of its high output speed, low printer cost, and the ability to provide high resolution images in recent years. In addition, the inkjet printer has an advantage of using a variety of recording media such as general paper, specially coated special paper, envelopes, and labels.

One of such recording media, an ink jet printer film has an ink absorbing layer composed of a hydrophilic material on a base film such as hydrophobic cellulose acetate or polyester (e.g. polyethylene terephthalate) so that the film can easily absorb ink. It is designed to be. It is mainly used as a presentation tool in overhead projectors, and may be extended to exterior wall decoration, design, and advertising.

The most widely used transparent film for inkjet printers has a coating layer designed to be suitable for an aqueous dye type inkjet printer. For example, a single coating layer consisting of a mixture of a water-soluble binder component such as polyvinyl pyrrolidone and a hydrophilic binder component such as gelatin and polyvinyl alcohol (US Pat. No. 4,503,111, Japanese Patent Publication No. 62-214985), or ink Two layers consisting of ink permeable layer of a weakly hydrophilic binder component such as polyvinylacetate and polyurethane resin, and ink fixing layer of water-soluble and hydrophilic binder component such as polyvinylpyrrolidone, polyvinyl alcohol, gelatin, etc. Coating layers (Japanese Patent Laid-Open No. 61-35278, German Patent No. 3,523,269) are known.

In addition, a method using a homopolymer or a copolymer of a cation-modified polymer and polyvinylpyrrolidone [US Patent No. 5,270,103], a method using a copolymer of polyvinyl alcohol and polycyclohexyleneisophthalate [US Patent No. 5,139,867] No. 5,126,193], a method using a copolymer of vinylpyrrolidone and vinyl acetate [US Pat. Nos. 4,425,405, 4,503,118], a method of using polyvinyl alcohol and polyvinylbenzyl ammonium chloride [US Pat. No. 4,547,405] ], A method using a mixture of polyvinylpyrrolidone and gelatin or polyvinyl alcohol [US Pat. No. 4,503,111] and a method using a copolymer of poly (N-vinylpyrrolidone) and a quaternary ammonium salt [European Patent No. 545,470 A1] such as polyvinylpyrrolidone and water-soluble polymers or ion-modified water-soluble polymers mixed or copolymerized There is not.

However, due to the change in the inkjet printer market, not only the printing methods such as bubble type and piezo type have been diversified, but also the inks used in inkjet printers have been diversified. High quality images and use have been restricted. Accordingly, there is a demand for development of an inkjet printer film having excellent durability and excellent ink absorption ability in various types of inkjet printers and excellent color and image quality.

While the techniques disclosed in the cited patents related to transparent films for inkjet printers are generally concentrated on ink absorption or water resistance, the image problems such as primary colors, mixed color density, color error, and turbidity which are most important in actual printer output are described. It doesn't put much weight. This has caused a number of problems in terms of versatility that can provide excellent images in various inkjet printing methods and various kinds of printers. Therefore, there is an urgent need to develop a general-purpose product technology capable of displaying a clear image during printing with excellent ink absorption and durability in one inkjet printer with a transparent film for one inkjet printer.

In the present invention, by designing a coating layer showing the optimum physical properties in various printers at the same time by introducing a variety of additives to improve the binder and properties having a versatility, while also taking advantage of the advantages of improving the ink absorption ability and anti-sticking advantages of silica, The use of silica particles with small particle size dispersed in water to solve the decrease in light transmittance, and in particular, by introducing an organic filler of modified starch into the ink absorbing layer together with an inorganic filler, simultaneously improving ink absorption and light transmittance, The object of the present invention is to provide a transparent film for an inkjet printer that can be provided with a castle and can print excellent images in various inkjet printers.

1 is a perspective view of a film for an ink jet printer, in which an undercoat and an ink absorbing layer are coated on a plastic substrate film.

<Description of the code | symbol about the principal part of drawing>

1: base film 2: undercoating layer

3: ink absorption layer

In the present invention, an ink absorbing layer is coated on one side of a base film, and the ink absorbing layer comprises a water-soluble polymer as a binder component, and a coating liquid for forming the ink absorbing layer in a transparent film for an ink jet printer containing a filler and an additive therein. It is characterized by containing 0.5-20 weight% of inorganic fillers and 0.05-5 weight% of organic fillers of a modified starch with respect to a binder.

The present invention will be described in more detail as follows.

In the present invention, a transparent film for an inkjet printer in which an ink absorbing layer is applied to a surface of a base film, the coating liquid forming the ink absorbing layer contains a water-soluble polymer as a binder, and an inorganic filler and an organic filler of a modified starch as a filler. The present invention relates to a transparent film for an inkjet printer, which is contained together, so that the light transmittance and the ink absorption ability are simultaneously improved, and thus a general-purpose clear image can be displayed in various types of inkjet printers.

The binder component used in the coating liquid for forming the ink absorption layer of the present invention improves the ink absorption ability by increasing the affinity with the aqueous dye which is the main component of the ink. As the water-soluble polymer used as the binder, polyvinyl alcohol having a suitable molecular weight Vinyl polymers such as polyvinylpyrrolidone; Cellulose polymers such as hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, methyl cellulose, and hydroxypropyl methyl cellulose; Acrylic polymers such as polyacrylic acid and polymethyl methacrylate; Imine-based polymers such as polyethylene imine; And oxide type polymers, such as polyethylene oxide and a polypropylene oxide, etc. can be used. The water-soluble polymer used as the binder is slightly different depending on the type, molecular weight, solubility, etc., but is preferably used alone or mixed in a range of 5 to 15% by weight in the coating liquid forming the ink absorbing layer. In the case of mixing and using the water-soluble polymer, the combination ratio is not particularly limited, but may be used in combination within an appropriate range for better physical properties of the film for inkjet printer.

Among the various inkjet printers, a binder (or a mixed binder) that can be used universally is selected and used.In inkjet printers, the ink and printing mechanisms are different depending on the printing method and the characteristics of each company, and thus, a universal binder is selected and used. Doing so is not easy and requires advanced formulation skills.

In addition, in the present invention, in addition to the binder component, the coating solution forming the ink absorbing layer contains an inorganic filler and an organic filler together to improve the light transmittance and the ink absorbing power. Inorganic fillers are used to further improve the ink absorption of the film and to eliminate the sticking phenomenon between the films generated when the binder is used alone. As such an inorganic filler, hydrophilic silica, titanium oxide, alumina, calcium carbonate, mica and the like can be used, and preferably hydrophilic silica is used. The amount of the inorganic filler to be added varies significantly depending on the purpose of introduction or various conditions. The amount of the inorganic filler is added to the coating liquid forming the ink absorbing layer within the range of 0.5 to 20% by weight.

However, even if the inorganic filler is added to eliminate the crushing phenomenon, it is not soluble in water, so it is difficult to disperse it in an aqueous solution, and additional dispersion equipment is required, and inorganic filler particles are distributed on the film surface during coating. Since the light transmittance of the film is lowered, in the present invention, solid silica is not used as an inorganic filler but is dispersed in water to introduce a silica dispersion having an inorganic filler particle size of 10 μm or less, thereby increasing ink absorption.

Further, in addition to the inorganic filler, a very small amount of the inorganic compound is added to the coating liquid forming the ink absorbing layer within a range that allows light transmittance to significantly increase the ink absorbing power of the film. In the present invention, the metal sulfate as the inorganic compound, for example, aluminum sulfate One or more of calcium sulfate and magnesium sulfate. The metal sulfate to be added uses 0.01 to 1.0% by weight based on the coating liquid for forming the ink absorbing layer.

As another filler, an organic filler contained in the coating liquid forming the ink absorbing layer is a modified starch such as an anion modified starch such as starch phosphate ester. Starch phosphate ester is mainly used as a binder for surface sizing or coating of paper or board, and has excellent ink absorption, permeability, moisture moisturization, etc., and dispersibility is very good. However, it does not dissolve in water at room temperature, so it is heated to 90 ℃ or higher and used as a solution. In the present invention, unlike the use of the conventional modified starch, the film is used as an organic filler rather than a binder in the film for inkjet printers by using such a property that it does not melt at room temperature. Such modified starch is used in an amount of 0.05 to 5% by weight based on the coating liquid for forming the ink absorbing layer. When used together with an inorganic filler silica dispersion, it has a synergistic effect in terms of ink absorption, and also makes it easy to control unique surface feel and surface area.

In addition, the coating liquid for forming the ink absorbing layer contains conventional additives such as fluorescent dyes, dispersants, antistatic agents and the like. In particular, since the fluorescent dye as an additive has a phenomenon that the light transmittance (apparent light transmittance) felt by the eye increases, when used appropriately, the light transmittance of the transparent film can be further improved.

In general, the greater the coating amount of the ink absorbing layer tends to increase the ink absorbency, but once the constant coating amount is reached, no further ink absorbency is improved. Generally, about 10-25 g / m <2> of coating amount of an ink absorption layer is suitable, and the thickness is about 8-20 micrometers ideally.

Water is often used as a solvent of the coating liquid for forming the ink absorbing layer, but when only water is used alone, there is a disadvantage in that the drying time after coating is increased. Therefore, it is preferable to use alcohol as a solvent by mixing an appropriate amount of alcohol with water in a range that does not degrade the physical properties of the coating solution much better than water.

In addition, the transparent film for an inkjet printer of the present invention introduced an undercoat layer 2 between the base film 1 and the ink absorbing layer 3 to prevent the ink absorbing layer from being detached from the base film. It is preferable that the undercoat layer 2 be coated as thinly as possible. The coating amount is preferably about 0.5 to 2 g / m 2, and the coating thickness is about 1 μm. The undercoating layer is preferably coated with a coating liquid containing 2 to 5 wt% of p-chlorophenol in toluene.

As described above, the ink absorbing layer and the undercoating layer are attached to each other. As shown in FIG. 1, the undercoating layer 2 is coated on the plastic base film 1, and the ink absorbing layer 3 is coated thereon. Can be prepared.

At this time, the base film is usually used a lot of hydrophobic polyester (polyethylene terephthalate) commonly used in general copiers, its thickness is easy to handle, the thickness of about 100 ㎛ to prevent bending during drying the coated film It is suitable. In addition, most of transparent films such as polycarbonate and cellulose acetate may be used according to the use of the film for inkjet printer.

Although this invention is demonstrated in detail based on an Example, this invention is not limited to an Example.

Example 1

Each of the following compositions was coated on a polyethylene terephthalate-based film having a thickness of 100 μm using a bar coater, and then sufficiently dried in an oven at a temperature of 100 to 120 ° C. for 30 to 60 seconds to prepare a transparent film for an inkjet printer.

Undercoat Layer:

p-chlorophenol 3% by weight

Toluene 97% by weight

* Coating amount: 1 g / ㎡

Ink absorbing layer:

Polyvinyl alcohol (product made in Japan Kuraray, CM-318) 6.6 weight%

1.9% by weight of hydroxypropylmethyl cellulose (60SH-50 made in Japan Shin Etsu)

Silica Dispersion (Korea Kyung Myung Industrial Co., SILICA Sol; Silica 30%) 3.3 wt%

0.2 wt% polyethylene oxide (US Union Carbide, WSRN-3000)

0.2% by weight of anion modified starch (product made in Netherlands Avebe, NYLGUM A45)

43.9% by weight of water

Ethanol 43.9 wt%

* Coating amount: 15-20 g / ㎡

Example 2

In the same manner as in Example 1, the composition and the coating amount of the ink absorbing layer was prepared as follows to prepare an inkjet printer transparent film.

Polyvinyl alcohol (product made in Japan Kuraray, CM-318) 3.3 weight%

3.3% by weight of polyvinylpyrrolidone (made by German BASF, Luviskol K-90)

1.9% by weight of hydroxypropylmethyl cellulose (60SH-50 made in Japan Shin Etsu)

Silica Dispersion (Korea Kyung Myung Industrial Co., SILICA Sol; Silica 30%) 3.3 wt%

0.2 wt% polyethylene oxide (US Union Carbide, WSRN-3000)

0.2% by weight of anion modified starch (product made in Netherlands Avebe, NYLGUM A45)

43.9% by weight of water

Ethanol 43.9 wt%

* Coating amount: 15-20 g / ㎡

Example 3

A transparent film for an inkjet printer was manufactured in the same manner as in Example 2.

Polyvinyl alcohol (product made in Japan Kuraray, CM-318) 6.6 weight%

1.9% by weight of hydroxypropylmethyl cellulose (60SH-50 made in Japan Shin Etsu)

Silica Dispersion (Korea Kyung Myung Industrial Co., SILICA Sol; Silica 30%) 3.3 wt%

0.2 wt% polyethylene oxide (US Union Carbide, WSRN-3000)

0.2% by weight of anion modified starch (product made in Netherlands Avebe, NYLGUM A45)

0.05% by weight of aluminum sulfate (Japan Junsei, Al ₂ (SO ₄ ) ₃ , 14-18 H ₂ 0)

43.875 weight% of water

Ethanol 43.875 wt%

* Coating amount: 15-20 g / ㎡

Example 4

A transparent film for an inkjet printer was manufactured in the same manner as in Example 2.

Polyvinyl alcohol (product made in Japan Kuraray, CM-318) 6.6 weight%

1.9% by weight of hydroxypropylmethyl cellulose (60SH-50 made in Japan Shin Etsu)

Silica Dispersion (Korea Kyung Myung Industrial Co., SILICA Sol; Silica 30%) 3.3 wt%

0.2 wt% polyethylene oxide (US Union Carbide, WSRN-3000)

0.2% by weight of anion modified starch (product made in Netherlands Avebe, NYLGUM A45)

0.15% by weight of fluorescent dyes (Korea Light Synthetic Agent, SYNO WHITE SDL CONC.)

43.825% by weight of water

Ethanol 43.825 wt%

* Coating amount: 15-20 g / ㎡

Example 5

A transparent film for an inkjet printer was manufactured in the same manner as in Example 2.

Polyvinyl alcohol (product made in Japan Kuraray, CM-318) 3.3 weight%

3.3% by weight of polyvinylpyrrolidone (made by German BASF, Luviskol K-90)

1.9% by weight of hydroxypropylmethyl cellulose (60SH-50 made in Japan Shin Etsu)

Silica Dispersion (Korea Kyung Myung Industrial Co., SILICA Sol; Silica 30%) 3.3 wt%

0.2 wt% polyethylene oxide (US Union Carbide, WSRN-3000)

0.2% by weight of anion modified starch (product made in Netherlands Avebe, NYLGUM A45)

0.05% by weight of aluminum sulfate (Japan Junsei, Al ₂ (SO ₄ ) ₃ , 14-18 H ₂ 0)

0.15% by weight of fluorescent dyes (Korea Light Synthetic Agent, SYNO WHITE SDL CONC.)

43.8% by weight of water

Ethanol 43.8 wt%

* Coating amount: 15-20 g / ㎡

Comparative Example 1

In the same manner as in Example 1, the composition of the ink absorption layer was changed as follows to prepare a transparent film for an inkjet printer.

5% by weight of polyvinyl alcohol (product made in Japan Kuraray, CM-318)

5% by weight of polyvinylpyrrolidone (made by German BASF, Luviskol K-90)

45 wt% water

Ethanol 45 wt%

* Coating amount: 15-20 g / ㎡

Comparative Example 2

In the same manner as in Example 1, the composition of the ink absorption layer was changed as follows to prepare a transparent film for an inkjet printer.

5% by weight of polyvinyl alcohol (product made in Japan Kuraray, CM-318)

5% by weight of polyvinylpyrrolidone (made by German BASF, Luviskol K-90)

0.5 wt% polyethylene oxide (US Union Carbide, WSRN-3000)

44.75 weight% of water

Ethanol 44.75 wt%

* Coating amount: 15-20 g / ㎡

Comparative Example 3

In the same manner as in Example 1, the composition of the ink absorption layer was changed as follows to prepare a transparent film for an inkjet printer.

5% by weight of polyvinyl alcohol (product made in Japan Kuraray, CM-318)

5% by weight of polyvinylpyrrolidone (made by German BASF, Luviskol K-90)

6.66% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

41.67 weight% of water

Ethanol 41.67 wt%

* Coating amount: 15-20 g / ㎡

Comparative Example 4

In the same manner as in Example 1, the composition of the ink absorption layer was changed as follows to prepare a transparent film for an inkjet printer.

Polyethylene oxide (US Union Carbide, WSRN-3000) 5% by weight

Silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%) 16.67 wt%

0.05% by weight of aluminum sulfate (Japan Junsei, Al ₂ (SO ₄ ) ₃ , 14-18 H ₂ 0)

0.2% by weight of fluorescent dyes (Korea Light Synthetic Agent, SYNO WHITE SDL CONC.)

39.04% by weight of water

Ethanol 39.04 wt%

* Coating amount: 15-20 g / ㎡

Comparative Example 5

In the same manner as in Example 1, the composition of the ink absorption layer was changed as follows to prepare a transparent film for an inkjet printer.

Polyvinyl alcohol (product made in Japan Kuraray, CM-318) 6.6 weight%

1.9% by weight of hydroxypropylmethyl cellulose (60SH-50 made in Japan Shin Etsu)

Silica Dispersion (Korea Kyung Myung Industrial Co., SILICA Sol; Silica 30%) 3.3 wt%

44.1% by weight of water

Ethanol 44.1 wt%

* Coating amount: 15-20 g / ㎡

Comparative Example 6

In the same manner as in Example 1, the composition of the ink absorption layer was changed as follows to prepare a transparent film for an inkjet printer.

8.5% by weight of polyvinyl alcohol (product made in Japan Kuraray, CM-318)

Silica Dispersion (Korea Kyung Myung Industrial Co., SILICA Sol; Silica 30%) 3.3 wt%

0.2 wt% polyethylene oxide (US Union Carbide, WSRN-3000)

0.2% by weight of anion modified starch (product made in Netherlands Avebe, NYLGUM A45)

0.05% by weight of aluminum sulfate (Japan Junsei, Al ₂ (SO ₄ ) ₃ , 14-18 H ₂ 0)

43.875 weight% of water

Ethanol 43.875 wt%

* Coating amount: 15-20 g / ㎡

Comparative Example 7

In the same manner as in Example 1, the composition of the ink absorption layer was changed as follows to prepare a transparent film for an inkjet printer.

Polyvinyl alcohol (product made in Japan Kuraray, CM-318) 9.9 weight%

1.9% by weight of hydroxypropylmethyl cellulose (60SH-50 made in Japan Shin Etsu)

0.2 wt% polyethylene oxide (US Union Carbide, WSRN-3000)

0.2% by weight of anion modified starch (product made in Netherlands Avebe, NYLGUM A45)

0.05% by weight of aluminum sulphate (manufactured by Japan Junsei, Al2 (SO4) 3, 14-18H20)

43.875 weight% of water

Ethanol 43.875 wt%

* Coating amount: 15-20 g / ㎡

Comparative Example 8

In the same manner as in Example 1, the composition of the ink absorption layer was changed as follows to prepare a transparent film for an inkjet printer.

1.9% by weight of polyvinyl alcohol (product made in Japan Kuraray, CM-318)

6.6% by weight of hydroxypropylmethyl cellulose (manufactured by Japan Shin-Etsu, 60SH-50)

Silica Dispersion (Korea Kyung Myung Industrial Co., SILICA Sol; Silica 30%) 3.3 wt%

0.2 wt% polyethylene oxide (US Union Carbide, WSRN-3000)

0.2% by weight of anion modified starch (product made in Netherlands Avebe, NYLGUM A45)

43.9% by weight of water

Ethanol 43.9 wt%

* Coating amount: 15-20 g / ㎡

Experimental Example 1 Measurement of Transmittance, Ink Absorption, and Bleeding

Transmittances of the inkjet printer films prepared in Examples 1 to 5 and Comparative Examples 1 to 8 were measured in an area of 400 to 700 nm using an ultraviolet spectrometer, and these films were used in an inkjet printer (DESKJET 500C) manufactured by Hewlett-Packard Co., Ltd. After printing a black block image, the ink absorption was measured by applying a pressure of 18 g / m &lt; 2 &gt; In addition, several primary colors (yellow, magenta, cyan), mixed colors (green, red, blue), and black were printed on the Hewlett-Packard Inkjet Printer (DESKJET 500C) of the US and the Inkjet Printer (SIJ-630V) of Samsung Electronics of Korea. Next, the bleeding phenomenon between colors was evaluated as time passed.

division Transmittance (% Transmittance, 700 nm) Ink Absorption (sec) Bleeding Example One 83 50 to 75 none 2 79 40 to 70 3 81 45 to 70 4 80 45 to 70 5 78 35 to 65 Comparative example One 86 300 to 350 none 2 78 200 to 250 3 83 250 to 300 4 73 60 to 90 has exist 5 83 150 to 250 none 6 81 75 to 90 7 82 75 to 120 8 79 70-100 has exist

According to the results of Table 1, the film (Examples 1 to 5) containing the inorganic filler and the organic filler of the modified starch together according to the present invention (Examples 1 to 5) is excellent in light transmittance as well as in ink absorption, and does not have a bleeding phenomenon. It was confirmed that.

However, a film (Comparative Examples 1 to 2) containing a mixed binder of polyvinyl alcohol and polyvinylpyrrolidone in the ink absorbing layer and containing no fillers (Comparative Examples 1 and 2) does not cause any problem in light transmittance or bleeding, There is a downside to falling.

In addition, even in the case of the film (Comparative Example 3) in which silica oxide was added as a polyethylene oxide and an inorganic filler in order to improve the ink absorption in this mixed binder, the ink absorption was poor. On the other hand, when polyethylene oxide is used as the binder of the ink absorbing layer and a small amount of aluminum sulfate is added thereto, as in Comparative Example 4, the ink absorption is excellent, but the bleeding phenomenon occurs and the light transmittance is also reduced. Therefore, it is important to reduce the disadvantages of each other while utilizing the advantages of polyethylene oxide, aluminum sulfate, and polyvinyl alcohol (or polyvinylpyrrolidone) binders. The polyvinyl alcohol (or polyvinylpyrrolidone) binder When the excess amount was added and a small amount of the polyethylene oxide binder and the silica dispersion were added, the physical properties of the ink absorbance, light transmittance, and bleeding were excellent.

Starch phosphate ester is used as a binder which is excellent in ink absorption, permeability, moisture moisturization, etc. Here, it is added as an organic filler without dissolving in a solvent. It is used together with silica dispersion which is an inorganic filler in Examples 1 to 5 and Comparative Example 6. This resulted in synergistic effect in terms of ink absorbency (including polyethylene oxide addition), and also very good in dispersibility so that the unique surface feel (easy to distinguish front and back of transparent film for inkjet printers) and surface control were very easy.

Experimental Example 2 Measurement of Light Density

After black block printing using Hewlett-Packard's inkjet printer (DESKJET 500C, DESKJET 660K) and Samsung's printer (SIJ-630V), light density over time was measured, color, image stability and durability were measured. The results are shown in Table 2 below.

division Deskjet 500C Deskjet 660K SIJ-630V 1 hours 100 hours 1 hours 100 hours 1 hours 100 hours Example One 1.12 1.13 1.35 1.38 1.16 1.12 2 1.13 1.11 1.37 1.36 1.16 1.15 3 1.15 1.14 1.34 1.33 1.13 1.13 4 1.13 1.10 1.37 1.36 1.16 1.15 5 1.16 1.14 1.34 1.33 1.13 1.14 Comparative example One 1.08 1.10 0.95 0.87 1.15 1.14 2 1.09 1.01 1.00 1.01 1.10 1.08 3 1.10 1.08 0.92 0.90 1.12 1.14 4 1.17 0.98 1.78 1.42 1.19 0.99 5 1.16 1.15 1.36 1.36 1.09 1.06 6 1.13 1.10 1.12 0.98 1.15 1.11 7 1.14 1.14 1.28 1.09 1.16 1.14 8 1.15 1.14 1.40 1.39 1.19 1.09

As shown in Table 2, in the case of Comparative Examples 1 to 4 and 6 to 7 where hydroxypropylmethylcellulose and silica dispersion were not added together to the polyvinyl alcohol (or polyvinylpyrrolidone) main binder, black dye Ink (DESKJET 500C) or mixed black dye ink (SIJ-630V) has good printability and has some color stability and durability. However, in the DESKJET 660K printer using pigment-type black ink, the initial optical density after printing or the optical density significantly decreases over time compared to the initial optical density, which is a mud-cracking phenomenon. This is because the black pigment ink of the DESKJET 660K printer is not suitable for printing, such as cracking of the printed image after printing or over time. This problem is basically when polyvinyl alcohol (or polyvinylpyrrolidone) is used as the main binder and an appropriate amount of hydroxypropylmethylcellulose and silica dispersion is added, the printing image is excellent not only in dye ink but also in pigment type ink. As in 5, color, image stability, and persistence can be maintained. However, if the amount of hydroxypropyl methyl cellulose is greater than polyvinyl alcohol, the bleeding phenomenon appears as in Comparative Example 8 of Table 1.

Thus, as in Examples 1 to 5, polyvinyl alcohol (or polyvinylpyrrolidone) was used as the main binder, and an appropriate amount of hydroxypropylmethylcellulose and silica dispersion was added (including starch phosphate ester and polyethylene oxide addition). When coated with an absorbing layer, the ink absorbency, light transmittance is excellent, there is no bleeding phenomenon, and color or image stability over time is also suitable for use as a transparent film.

As described above, the transparent film for an inkjet printer according to the present invention has a general purpose with a formulation design showing optimal physical properties simultaneously in various types of printers as compared to the conventional transparent film having optimal physical properties for only one printer. In addition to the starch phosphate ester which is not applied in the prior art, the transparent film has a surface that is easily distinguished from the front and rear, and has excellent ink absorption and light transmittance, no bleeding phenomenon, and stability of color or image over time. There is an effect it has.

Claims (1)

In a transparent film for an ink jet printer, wherein an ink absorbing layer is coated on one side of the base film, and the ink absorbing layer contains a water-soluble polymer as a binder component and contains organic and inorganic fillers and additives including a modified starch. The coating liquid forming the ink absorbing layer contains 0.5 to 20% by weight of inorganic filler, 0.05 to 5% by weight of starch phosphate ester as organic filler, and 0.01 to 0.1% by weight of aluminum sulfate, calcium sulfate or magnesium sulfate as an additive. Transparent film for an inkjet printer, characterized in that.

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