KR100238109B1 - A film for ink-jet printer - Google Patents

Abstract

The present invention relates to a film for an inkjet printer, and more particularly, an ink fixing layer and an ink absorbing layer are mixed and coated on a film or plastic substrate having a multi-layer structure in which an ink fixing layer and an ink absorbing layer are coated on a plastic substrate, respectively. In the production of a film of a single film structure, the ink absorbing layer has a surface treated with a poly (styrene-ethylene glycol acrylate) copolymer on the surface of an acrylic resin prepared by crosslinking acrylic acid, in addition to a binder component, of a water-soluble polymer having excellent durability and light transmittance. It is related with the film for inkjet printers which shows a clear color image and the outstanding ink absorption power by containing together the fine powder of the acryl-type superabsorbent polymer obtained by the above.

Description

Film for Inkjet Printers

The present invention relates to a film for an inkjet printer, and more particularly, an ink fixing layer and an ink absorbing layer are mixed and coated on a film or plastic substrate having a multi-layer structure in which an ink fixing layer and an ink absorbing layer are coated on a plastic substrate, respectively. In the production of a film of a single film structure, the ink absorbing layer has a surface treated with a poly (styrene-ethylene glycol acrylate) copolymer on the surface of an acrylic resin prepared by crosslinking acrylic acid, in addition to a binder component, of a water-soluble polymer having excellent durability and light transmittance. It is related with the film for inkjet printers which shows a clear color image and the outstanding ink absorption power by containing together the fine powder of the acryl-type superabsorbent polymer obtained by the above.

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 for inkjet printers is an ink absorbing layer composed of hydrophilic materials on a hydrophobic plastic base such as cellulose acetate or polyester (e.g. polyethylene terephthalate), polysulfone, polystyrene, polycarbonate, polyolefin, etc. The film is designed to absorb ink easily. It is mainly used as a presentation tool in overhead projectors, and may be extended to exterior wall decoration, design, and advertising.

Conventional inkjet recording media manufacturing techniques include a method of coating a water-soluble polymer such as cellulose derivative or polyvinyl alcohol on a support [US Patent No. 3,889,270], and a method of coating a white pigment together with a water-soluble polymer [US Patent No. 4,269,891] No. 4,425,405] and a method of coating a water-soluble polymer in a multilayer structure [US Pat. Nos. 4,425,652, 4,301,195, 4,379,804], and the like.

However, the prior arts have disadvantages of inferior ink absorbency, and a method of using a superabsorbent polymer powder having a size of between 1 and 100 μm with a binder has been proposed to improve this problem (US Pat. No. 5,120,601). However, the superabsorbent resins used here are made of only one crosslinking reaction, and the use of such superabsorbent resins is limited in improving the ink absorbency. Especially, in the case of inkjet printing having a high injection volume, the ink absorbency is still insufficient. There is a disadvantage.

In the present invention, the ink absorbing layer contains a water-soluble polymer having excellent durability and light transmittance as a binder component in order to improve ink absorbency, particularly in the case of a large amount of injection, and in addition, the surface of the acrylic resin may be poly (styrene-ethylene glycol acrylate). By using fine powder of super absorbent polymer obtained by surface treatment with copolymer in ink absorbing layer, clear color image and excellent ink absorbing power, especially the time that water-soluble ink does not come out when contacted by hand after inkjet printing is shortened within 1 minute. An object of the present invention is to provide a film for an inkjet printer, which can increase the efficiency in printing.

1 is a perspective view of an ink jet printer film composed of a composite layer of an ink absorbing layer and an ink fixing layer on a plastic substrate,

Fig. 2 is a perspective view of a film for an ink jet printer composed of a mixed single layer of an ink absorbing layer and an ink fixing layer on a plastic substrate.

<Explanation of symbols for main parts of the drawings>

1 ink absorption layer 2 ink fixing layer

3a, 3b: plastic base material 4: mixed layer of ink absorbing layer and ink fixing layer

The present invention provides a composite layer structure film in which an ink fixing layer and an ink absorbing layer are coated on a plastic substrate, or a film of a single layer structure in which an ink fixing layer and an ink absorbing layer are mixed and coated on a plastic substrate.

The ink absorbing layer composition includes an ink jet printer film containing 35 to 65% by weight of a conventional water-soluble polymer and 0.1 to 10% by weight of an acrylic super absorbent polymer obtained by surface treatment with a poly (styrene-ethylene glycol acrylate) copolymer. It is characterized by.

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

[0001] The present invention provides a film for an ink jet printer in which an ink absorbing layer is applied on a plastic substrate, wherein the ink absorbing layer contains a water absorbent polymer together with a super absorbent resin to increase light transmittance, vivid color image, and ink absorbing power. It is about.

The acrylic superabsorbent polymer according to the present invention is obtained by surface-treating the surface of an acrylic resin prepared by crosslinking acrylic acid monomers with a poly (styrene-ethylene glycol acrylate) copolymer. The poly (styrene-ethylene glycol acrylate) copolymer (hereinafter referred to as "PSE copolymer") used as the surface treatment agent has styrene having lipophilic backbone and the ethylene glycol acrylate having hydrophilic side chain It is introduced in a pendant group. When the PSE copolymer is introduced to the surface of the acrylic resin, the lipophilic and hydrophilicity are simultaneously imparted to the surface of the resin to improve absorbency, and the absorption rate is increased due to the lipophilic property of the surface treating agent. In order to use such a PSE copolymer as a surface treatment agent, it is preferable that 50-95 mol%, especially 75-90 mol% of a styrene part is contained, 5-50 mol% of ethylene glycol acrylate as a long side chain, It is preferable to contain 10-25 mol% especially. If the styrene content in the PSE copolymer is less than 50 mol%, the lipophilic property is lowered and the absorption rate is lowered. On the other hand, if the content is more than 95 mol%, the surface crosslinking efficiency is not good and the strength of the gel is reduced. have. In addition, when the content of ethylene glycol acrylate as the side chain group is less than 5 mol%, it is difficult to form covalent bonds, so that the crosslinking efficiency is not good, and when it exceeds 50 mol%, there is a problem that the absorption rate is lowered. In the present invention, in the PSE copolymer which is a constituent of the composite surface treatment agent, a similar effect can be obtained by polymerizing with styrene monomer as α-methyl styrene, methyl methacrylate or vinyl chloride as a lipophilic monomer. Can be.

In addition, the above-described acrylic superabsorbent resin is used by pulverizing into a fine powder, but is used by pulverizing into a fine powder having a particle size of 0.1 to 10 ㎛.

In addition, the water absorbing polymer contained as a binder component in the ink absorbing layer is a water-soluble polymer having excellent ink absorbing power which has been commonly used, for example, a vinyl hydrophilic polymer such as polyvinyl alcohol, polyvinylpyrrolidone and derivatives thereof; Oxide-based polymers including polyethylene oxide and polypropylene oxide; Cellulose polymers; Acrylic hydrophilic polymers such as polyacrylamide and polyacrylic acid; And water-soluble polymers ion-modified. The binder component used for the ink absorbing layer is determined in consideration of viscosity, solubility, efficiency and the like.

Preferably, when the total ink absorbing layer composition contains 35 to 65% by weight of the usual water-soluble polymer and 0.1 to 10% by weight of the acrylic superabsorbent polymer, the water resistance and printing resolution of the inkjet film can be greatly improved.

In addition, in the present invention, an inorganic filler may be added to the ink absorbing layer in order 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. Such inorganic fillers include silica, titanium oxide, alumina, calcium carbonate, mica and the like, which are contained in the total ink absorbing layer composition in the range of 60% by weight or less. Even if the hydrophilic silica in the inorganic filler used in the present invention is not soluble in water, it is difficult to disperse it in an aqueous solution, but also requires a dispersing device, and the silica particles are distributed on the film surface during coating. Of light transmittance is reduced. Therefore, in the present invention, it is possible to increase ink absorption by using a silica liquid dispersion without using solid silica, and to increase the light transmittance of the film for an ink jet printer.

In addition, in the present invention, by containing a fluorescent dye as an additive to increase the apparent light transmittance, the light transmittance can be further improved if used appropriately within the range of 0.1 to 2% by weight in the total ink absorption layer composition.

The ink absorbing layer 1 containing the above components is coated on the ink fixing layer 2 coated on the plastic substrate 3a or the ink fixing layer 2 as shown in FIGS. 1 and 2. It is mixed with and coated on the plastic substrate (3b), the ink absorbency tends to increase as the coating amount of the ink absorbing layer is larger, but when the constant coating amount is reached, the ink absorbance is no longer improved. Therefore, the coating amount of the ink absorbing layer is suitably about 5 to 30 g / m 2, and the thickness thereof is preferably about 5 to 30 μm.

As the plastic base material of the present invention, a polyester (polyethylene terephthalate) film, which is widely used in general copiers, is used, and its thickness is easy to handle, and a thickness of about 100 μm is used to prevent bending during drying of the coated film. Most suitable.

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

Preparation Example: Synthesis of Acrylic Super Absorbent Polymer

(1) Synthesis of Acrylic Resin

Oxygen was removed while flowing high-purity nitrogen (nitrogen content 99.99%) at a flow rate of 80 cc / min in a 500 cc reactor equipped with a nitrogen gas inlet, a cooler, and a stirrer. 30 g of acrylic acid monomer, 100 ml of distilled water, and 0.1 mol% of crosslinking agent methylene bisacrylamide and 0.05 g of potassium persulfate were quantitatively injected into the reactor. Thereafter, dissolved oxygen was removed while passing through nitrogen gas, and the cooling water was flowed through the cooler while raising the temperature of the reactor to 70 ° C. While starting the stirring, the flow rate of nitrogen injected into the reactor was reduced to 20 cc / min and reacted for 4 hours to synthesize a gel-type acrylic acid polymer having a conversion rate of 95% based on the acrylic acid monomer. After the polymerization was terminated, 70% acrylic acid was neutralized based on the total amount of the acrylic acid monomers added using a 2N aqueous sodium hydroxide solution.

Thereafter, the neutralized gel was dried in an oven at 120 ° C. for 10 hours to obtain an acrylic resin in a white powder state.

(2) Synthesis of Surface Treatment Agent

Oxygen was removed while flowing high-purity nitrogen (nitrogen content 99.99%) at a flow rate of 80 cc / min in a 500 cc reactor equipped with a nitrogen gas inlet, a cooler, and a stirrer. 80 mol% of styrene as a monomer and 20 mol% of ethylene glycol acrylate and toluene as a reaction medium were added 5 times based on the monomer volume, and 0.005 mol% of azobisbutyronitrile (AIBN) as an initiator was injected into the reactor. It was. Thereafter, dissolved oxygen was removed while passing through nitrogen gas, and cooling water was flowed through the cooler while raising the temperature of the reactor to 70 ° C. When starting the stirring, the flow rate of nitrogen injected into the reactor was lowered to 20 cc / min and reacted for 6 hours. The poly (styrene-ethylene glycol acrylate) copolymer (PSE copolymer) having a copolymerization rate of 55% or more based on the styrene monomer Was synthesized. This was dropped in non-solvent methanol to produce a white precipitate, which was dried in a vacuum oven at 100 ° C. for about 10 hours to obtain a white PSE copolymer powder.

(2) Synthesis of Acrylic Super Absorbent Polymer

The acrylic resin surface prepared in the above (1) was surface coated using the PSE copolymer synthesized in the above (2) to obtain an acrylic superabsorbent polymer.

First, a PSE copolymer was dissolved in toluene, an organic solvent, to prepare a composite surface treatment solution. Then, the acrylic resin prepared above was dispersed in this solution. The solvent was volatilized while heating this solution at 100 to 120 ° C. for 10 to 30 minutes in a heating stirrer, thereby obtaining an acrylic superabsorbent polymer of the present invention whose surface was coated with a copolymer and an ionomer. Then, the superabsorbent polymer was pulverized by a pulverizer, and those having a particle size of 10 μm or more were filtered and powdered into fine powders having a particle size of 10 μm or less.

Example 1

The following composition was coated on a corona treated polyethylene terephthalate film having a thickness of 100 μm in the order of the ink fixing layer and the ink absorbing layer using a bar coater, respectively, and then dried in an oven (100 ° C., 1 minute). The film for inkjet printers was produced so that it might be set to 10 micrometers and about 5 micrometers of an ink absorption layer. As a solvent of the polymer solution, water and ethanol were used at 50:50.

Ink absorbing layer:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 40% by weight

10% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

20 wt% water

Ethanol 29.6 wt%

0.4% by weight of the particulate powder of the acrylic superabsorbent polymer prepared in Preparation Example

Ink fixing layer:

Polyvinyl alcohol (Japan Kuraray Co., CM-318) 10% solution 50% by weight

50% by weight of 10% solution of polyvinylpyrrolidone (Bavis, Germany)

Example 2

An inkjet printer film was manufactured in the same manner as in Example 1 except that the composition of the ink absorbing layer was performed as follows.

Ink absorbing layer:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 32% by weight

10% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

20 wt% water

Ethanol 37.2 wt%

0.8% by weight of particulate powder of the acrylic superabsorbent polymer prepared in Preparation Example

Example 3

An inkjet printer film was manufactured in the same manner as in Example 1 except that the composition of the ink absorbing layer was performed as follows.

Ink absorbing layer:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 40% by weight

10% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

20 wt% water

Ethanol 29.8 wt%

0.2% by weight of particulate powder of the acrylic superabsorbent polymer prepared in Preparation Example

Example 4

An inkjet printer film was manufactured in the same manner as in Example 1 except that the composition of the ink absorbing layer was performed as follows.

Ink absorbing layer:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 40% by weight

10% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

20 wt% water

Ethanol 29.9 wt%

0.1% by weight of the particulate powder of the acrylic superabsorbent polymer prepared in Preparation Example

Example 5

An inkjet printer film was manufactured in the same manner as in Example 1 except that the composition of the ink absorbing layer was performed as follows.

Ink absorbing layer:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 40% by weight

10% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

20 wt% water

Ethanol 29.98 wt%

0.02% by weight of particulate powder of the acrylic superabsorbent polymer prepared in Preparation Example

Example 6

An inkjet printer film was manufactured in the same manner as in Example 1 except that the composition of the ink absorbing layer was performed as follows.

Ink absorbing layer:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 20% by weight

Titanium dioxide (manufactured by Du Pont, RPD-2) 10% solution 30% by weight

20 wt% water

Ethanol 29.9 wt%

0.1% by weight of the particulate powder of the acrylic superabsorbent polymer prepared in Preparation Example

Example 7

The following monolayer composition was coated on a corona treated polyethylene terephthalate film having a thickness of 100 μm using a bar coater, and then dried in an oven (100 ° C., 1 minute) to absorb and fix ink. The film for inkjet printers was manufactured so that it might be set to 15 micrometers. As a solvent of the polymer solution, water and ethanol were used at 50:50.

Single layer composition:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 10% by weight

5% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

10 wt% water

Ethanol 24.6 wt%

0.4% by weight of the particulate powder of the acrylic superabsorbent polymer prepared in Preparation Example

Polyvinyl alcohol (Japan Kuraray Co., CM-318) 15% solution 25% by weight

Polyvinylpyrrolidone (Bavis, Germany, Luviskol K90) 15% solution 25% by weight

Example 8

A film for an inkjet printer was manufactured in the same manner as in Example 7, except that a single composition of the ink absorbing layer and the fixing layer was performed as follows.

Single layer composition:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 10% by weight

5% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

20 wt% water

Ethanol 39.7 wt%

0.3 wt% of the fine powder of the acrylic superabsorbent polymer prepared in Preparation Example

5% by weight methylcellulose

20% by weight of 15% solution of hydroxypropylmethylcellulose (SH-60SH, Shin-Etsu Corp., Japan)

Comparative Example 1

An inkjet printer film was manufactured in the same manner as in Example 1 except that the composition of the ink absorbing layer was performed as follows.

Ink absorbing layer:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 40% by weight

10% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

20 wt% water

Ethanol 30% by weight

Comparative Example 2

An inkjet printer film was manufactured in the same manner as in Example 1 except that the composition of the ink absorbing layer was performed as follows.

Ink absorbing layer:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 40% by weight

10% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

20 wt% water

Ethanol 29.6 wt%

0.4% by weight of vinyl acrylate alcohol copolymer (manufactured by Sumitomo Chem., Sumicagel SP-510)

Comparative Example 3

An inkjet printer film was manufactured in the same manner as in Example 6 except that the composition of the ink absorbing layer was performed as follows.

Ink absorbing layer:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 20% by weight

Titanium dioxide (manufactured by Du Pont, RPD-2) 10% solution 30% by weight

20 wt% water

Ethanol 30% by weight

Comparative Example 4

An inkjet printer film was manufactured in the same manner as in Example 6 except that the composition of the ink absorbing layer was performed as follows.

Ink absorbing layer:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 20% by weight

Titanium dioxide (manufactured by Du Pont, RPD-2) 10% solution 30% by weight

20 wt% water

Ethanol 29.9 wt%

0.1% by weight of vinyl acrylate alcohol copolymer (manufactured by Sumitomo Chem., Sumicagel SP-510)

Comparative Example 5

An inkjet printer film was manufactured in the same manner as in Example 7, except that the composition of the ink absorbing layer was performed as follows.

Single layer composition:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 10% by weight

5% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

10 wt% water

Ethanol 25 wt%

Polyvinyl alcohol (Japan Kuraray Co., CM-318) 15% solution 25% by weight

Polyvinylpyrrolidone (Bavis, Germany, Luviskol K90) 15% solution 25% by weight

Comparative Example 6

An inkjet printer film was manufactured in the same manner as in Example 7, except that the composition of the ink absorbing layer was performed as follows.

Single layer composition:

Polyethylene oxide (US Union Carbide, WSRN-3000) 10% solution 10% by weight

5% by weight of silica dispersion (Kyung Myung Industrial Co., SILICA Sol; Silica 30%)

10 wt% water

Ethanol 24.6 wt%

0.4% by weight of vinyl acrylate alcohol copolymer (manufactured by Sumitomo Chem., Sumicagel SP-510)

Polyvinyl alcohol (Japan Kuraray Co., CM-318) 15% solution 25% by weight

Polyvinylpyrrolidone (Bavis, Germany, Luviskol K90) 15% solution 25% by weight

Experimental Example: Measurement of Transmittance, Ink Absorption, and Smearability

About the film for inkjet printers manufactured in the said Examples 1-8 and Comparative Examples 1-6, the light transmittance was measured in the region of 400-700 nm using an ultraviolet spectrometer.

In addition, a black block image was printed on the films by a Hewlett-Packard company inkjet printer (DESKJET 500C), and then the pressure was set to 15.8 g / m 2 at a relative humidity of 30 ° C. and 50% for about 3 seconds to settle the ink on the film. Was measured to determine the ink absorption.

Also, after the ink was dried, the image bleeding was measured by the degree of movement of the ink at the boundary of the image. The bleeding of the image was 100 times in the font size 10 Times New Roman on the A4 size film prepared in the examples and comparative examples. A was printed and the degree of collapse of the triangle formed in the letter A was evaluated by an optical microscope 100 times.

◎: change in the image is within 3% change,

○: change in the image within 7%,

△: change in image within 15%

Evaluation of light transmittance, ink absorption, and bleeding as described above are shown in Table 1 below.

division Transmittance (% Transmittance, 700 nm) Ink Absorption (Min) Smearing Example 1 80 0.1 to 0.4 ◎ Example 2 73 0.7 to 0.8 ○ Example 3 82 0.4 to 0.5 ◎ Example 4 84 0.9 to 1.0 ○ Example 5 84 1.0 to 1.1 ○ Example 6 60 1.0 to 1.2 ◎ Example 7 81 0.3 to 0.5 ◎ Example 8 82 0.5 to 0.6 ◎ Comparative Example 1 84 1.2 to 1.3 ○ Comparative Example 2 76 0.7 to 0.8 ◎ Comparative Example 3 60 3.5 to 4.0 △ Comparative Example 4 59 2.0 to 2.2 ○ Comparative Example 5 85 1.1 to 1.2 ○ Comparative Example 6 76 0.6 to 0.8 ○

As shown in Table 1, the film for inkjet printers prepared in Examples 1 to 8 is a clear color image without bleeding by using a superabsorbent polymer coated with a hydrophilic and lipophilic polymer type crosslinking agent. It can be seen that the excellent ink absorption. In addition, it can be seen that satisfactory characteristics are exhibited not only in the ink absorbing power but also in the light transmittance in comparison with the case of using other super absorbent polymers which satisfies ink absorbing power to some extent.

As described above, it can be seen that the inkjet printer film of the present invention has an effect of showing a clear color image and excellent ink absorption by using an acrylic superabsorbent polymer surface-treated with a water-soluble polymer and a PSE copolymer in the ink absorption layer. .

Claims (2)

In a multi-layer structure film in which an ink fixing layer and an ink absorbing layer are coated on a plastic substrate, or a single film structure in which an ink fixing layer and an ink absorbing layer are mixed and coated on a plastic substrate, The ink absorbing layer composition contains 35 to 65 wt% of a conventional water-soluble polymer and 0.1 to 10 wt% of an acrylic super absorbent polymer obtained by surface treatment with a poly (styrene-ethylene glycol acrylate) copolymer. Dragon film. The method of claim 1, wherein the conventional water-soluble polymer is a vinyl-based hydrophilic polymer including polyvinyl alcohol, polyvinylpyrrolidone and derivatives thereof; Oxide-based polymers including polyethylene oxide and polypropylene oxide; Cellulose polymers; Acrylic hydrophilic polymers including polyacrylamide and polyacrylic acid; Inkjet printer film characterized in that the ion-modified polymer.

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