JPH11245503A - Water ink absorbing material and laminate film having layer of the absorbing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct vivid printing capable of absorbing water ink quickly, having a superior ink adhesion after drying, and also having no irregularity of color or blotting of ink and the like by constituting a water ink absorbing material provided on a base surface with a straight chain poly-N-vinylacetamide(PNVA). SOLUTION: An ink absorbing material layer 2 to adsorb water ink is formed on the surface of a laminate film having an adhesive layer 3 and a separation liner provided on the rear surface of a base layer 1, and the straight chain structure PNVA has water absorptiveness, and has a property to be lubricated by water supply. If water absorption material has water absorption function plus a lubrication function, when ink is adhered thereto, the adhered part thereof absorbs ink; simultaneously, has a lubrication property, so that ink is prevented from spreading horizontally therearound from the adhered part. In addition, ink is also prevented from coming vertically into the inner part more than its necessity, and inasmuch as the absorption of ink is good, drying becomes quick and printing is made vivid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ink absorbing material used for printing with a water-based ink or printing (printing or copying) with a jet printer using the water-based ink, and a water-based ink absorbing material. The invention relates to a laminated film having a layer.

[0002]

2. Description of the Related Art Recently, with the spread of ink jet printers, films printed by the ink jet printers are bonded to various substrates, and signs for outdoor or indoor use, drapes, roll screens, blinds, curtains, shutters, walls, and the like. Use in equipment, posters, overhead projectors, etc., is being considered.

[0003] Printing by an ink jet printer is a method in which ink is ejected from a nozzle and adheres to a film. In the case of this printer, a water-based ink is generally used because the solvent-based ink dries quickly and the nozzles are easily clogged. This water-based ink is an ink in which a dispersant is water-soluble, using a pigment or a dye, or both the pigment and the dye as a colorant,
The target color is obtained by overlapping the blue, red, yellow, and black inks. For the film to be printed, thermoplastic resin films such as polyvinyl chloride, polypropylene, polyester, acrylic resin, etc. can be used depending on the application such as the place of use (outdoor, indoor, etc.) and the method of use (the method of bonding to the base material). It is selected from paper, cloth, tarpaulin and the like.

Japanese Patent Application Laid-Open No. 5-229246 discloses that an ink absorbing layer is provided on the surface of a plastic base film in order to enhance the sharpness of an image and the absorptivity of an aqueous ink by the ink jet printer. It is described that the absorbent layer is formed by applying an aqueous polyester resin dispersion to a base film. This coating liquid is obtained by modifying a polyester resin with a compound having a polymerizable double bond such as a vinyl monomer, and further copolymerizing an unsaturated carboxylic acid amide or the like. Japanese Patent Application Laid-Open No. 8-11421 describes that an ink absorbing material layer is formed by a coating liquid obtained by mixing polyvinylpyrrolidone, a water-insoluble acrylic resin, silica, and organic fine particles together with a solvent.

[0005]

However, when an attempt is made to print directly on the above-mentioned thermoplastic resin film, cloth, tarpaulin or the like with an aqueous ink, since the material is a resin or a fiber, the aqueous ink is absorbed. Without it, it is difficult to print the intended picture or pattern clearly. In particular, water and non-volatile organic solvents (ethylene glycol, diethylene glycol, methyl carbitol, etc.) are used as solvents in the aqueous ink, and the drying speed is low. Print 2
When a color tone is printed, the inks of the first color and the second color are liable to be mixed and smeared, so that it is necessary to take a long drying time and the workability is poor.

When printing on paper, the paper absorbs the water-based ink. However, the arrangement of the fibers of the paper is uneven and the surface is rough. Comes out. In addition, the bleeding of the ink is large, and the appearance after printing is multiplied by vividness.

Accordingly, the present invention provides a recording medium for an aqueous ink which can rapidly absorb an aqueous ink, has excellent ink adhesion after drying, and can perform vivid printing without color shading or ink bleeding. Materials (aqueous ink absorbing material and laminated film).

[0008]

On the other hand, in the present invention, the above-mentioned problem has been solved by modifying the aqueous ink absorbing material provided on the surface of the base for fixing the aqueous ink.

[0009] That is, one of the inventions of this application relates to a water-based ink absorbing material provided on the surface of a base for fixing the water-based ink, and the ink absorbing material is a linear poly-N- It is characterized by being constituted by vinylacetamide (hereinafter, this is appropriately referred to as “PNVA having a linear structure”).

[0010] N-vinylacetamide (NVA) is not only a water-soluble monomer, but also a nonionic monomer having both alcoholic properties, and becomes a powdery polymer having a linear structure by free radical polymerization. Since this linear PNVA has a property of swelling due to water absorption as well as having water absorbability, the PNVA exhibits a swelling effect on a water-based ink simultaneously with the absorption of the water. The meaning of both water absorption and swelling is as follows.

If the water absorbing function of the ink absorbing material layer forming the printing surface is too high when the water-based ink adheres to the printing surface, the dye or pigment contained in the ink is mixed with moisture to form the ink absorbing material layer. Spreads horizontally along the printing surface, and penetrates vertically from the printing surface into the inside. As a result, bleeding of the ink occurs, and the print density is reduced. On the other hand, when the water absorption function is reduced, the bleeding resistance is improved, but the ink absorbing power itself is reduced, so that the drying is delayed and the printing performance is poor.

On the other hand, in the case of the ink absorbing material in which the swelling function is added to the water absorbing function, when the ink adheres, the adhered portion absorbs the ink and swells at the same time. Therefore, it is possible to prevent the ink from spreading horizontally from the portion where the ink is attached,
In addition, it is possible to prevent the ink from vertically penetrating into the interior more than necessary (the bleeding of the ink and the decrease in the print density are eliminated). It will be clear.

Another invention of this application relates to a water-based ink absorbing material which is similarly provided on the surface of a base for fixing the water-based ink, wherein the ink absorbing material uses a polyether polyol containing polyethylene oxide. 100 parts by weight of a polyurethane resin (hereinafter, referred to as a "water-absorbing urethane resin") appropriately synthesized with a crosslinked poly-N-vinylacetamide (hereinafter, referred to as a "linear PNVA"). ") In an amount of 30 to 500 parts by weight.

The above water-absorbing urethane resin has polyethylene oxide having water absorbing property and swelling property with respect to water in its molecular structure. Due to the presence of this polyethylene oxide, when water-based ink adheres, the water content in the ink is reduced. And swells at the same time. Therefore, as in the case of the above invention, the ink does not spread horizontally from the portion where the ink has adhered to the surroundings and does not penetrate more vertically than necessary to lower the print density. Is excellent in absorption, so that the effect is obtained that drying is quick and printing is sharp.

Here, in the present invention, PNVA having a crosslinked structure is blended with the above-mentioned water-absorbing urethane resin, and the PNVA having the crosslinked structure is similar to the PNVA having a straight-chain structure as described above. In addition, the swelling effect is exhibited simultaneously with the absorption of the water, which contributes to prevention of bleeding of the ink, prevention of a decrease in print density, improvement of ink drying property, and improvement of print definition.

However, the desired effect of PNVA having a crosslinked structure cannot be sufficiently obtained if the amount of the PNVA is less than 30 parts by weight per 100 parts by weight of the water-absorbing urethane resin. On the other hand, if the amount exceeds 500 parts by weight, the adhesive strength of the ink absorbing material to the base decreases, and the P of the crosslinked structure decreases.
Since the NVA is too large, the PNVA cannot be reliably held by the water-absorbing urethane resin, and the state of the obtained coating film deteriorates even when applied to the base. With powder).

As described above, the water-based ink applied to the ink absorbing material according to the present invention uses a pigment or a dye, or both the pigment and the dye as a colorant, and has a water-soluble dispersant. However, it does not matter what type. For example, an aqueous ink composition comprising a pigment, a dispersant, and a solvent, wherein the dispersant has an aromatic ring or an alkyl group having a predetermined number of carbon atoms or more as a lipophilic portion, and a carboxylic acid (salt) group or a sulfonic acid. A polymer mainly containing an alkyl ester of acrylic acid or methacrylic acid having a group or the like as a hydrophilic portion, and the solvent is preferably a mixture of water and a non-volatile hydrophilic organic solvent. .

Another invention of this application relates to a laminated film characterized in that the above-described ink absorbing material layer is formed on the surface of a base layer.

The thickness of the ink absorbing material layer is preferably at least 5 μm, more preferably at least 10 μm, in order to ensure that the aqueous ink is absorbed and dried / fixed by the ink absorbing material layer. The upper limit of the thickness is not particularly limited. When the ink absorbing material layer is formed by coating the base layer, it is more advantageous to set the thickness to about 50 μm from the viewpoint of coating workability. Is 100
There is no problem in fixing the aqueous ink regardless of whether the thickness is 200 μm or 200 μm. However, it is not particularly necessary to increase the thickness beyond 200 μm.

When the ink absorbing material layer is formed on a film-like base surface to form a laminated film, the base layer film may be a vinyl chloride resin film,
A thermoplastic resin film such as a polyolefin-based resin film, a polyester-based resin film, and an acrylic-based resin film, a polyester-based cloth, a cotton cloth, or a tarpaulin can be used.

An adhesive layer may be formed on the back surface of the laminated film (the surface of the base layer opposite to the ink absorbing material layer) so that the adhesive layer is protected by a release liner. it can. The release liner is obtained by subjecting one or both sides of a paper or plastic film to a release treatment. As the pressure-sensitive adhesive, for example, an acrylic pressure-sensitive adhesive can be used, but any type can be used as long as the adhesiveness with the partner material can be obtained.

In the case where the ink absorbing material layer is formed on the surface of the base layer by the above-mentioned coating, if there is a concern that the adhesion between the base layer and the ink absorbing material layer becomes insufficient, both of the two may be used. A primer which mediates adhesion may be applied, and an ink absorbing material may be applied thereon. Further, post-processing may be performed in which the ink absorber layer or the laminated film is polished by applying humidity and pressure.

[0023]

Therefore, according to the invention of this application, the ink absorbing material is composed of poly-N-vinylacetamide having a linear structure, or the ink absorbing material is synthesized using a polyether polyol containing polyethylene oxide. 100 to 100 parts by weight of the obtained polyurethane resin and 30 to 500 parts by weight of a cross-linked poly-N-vinylacetamide, the water-based ink is quickly absorbed, and the ink has excellent drying properties and adhesion. In addition, it is possible to obtain a vivid print without color shading or ink bleeding.

Further, according to the laminated film having a pressure-sensitive adhesive layer and a release liner provided on the back surface of the base layer, the release liner can be peeled off and adhered to various substrates, and the construction is simple and easy.

[0025]

FIG. 1 shows a laminated film for aqueous ink. In the film, 1 is a base layer, 2 is an ink absorbing material layer formed on the surface of the base layer 1, 3 is an adhesive layer formed on the back surface of the base layer 1, and 4 is a release paper (release liner). .

FIG. 2 shows another example of the laminated film. That is, in this example, the primer layer 5 is provided between the base layer 1 and the ink absorbing material layer 2. The primer layer 5 is a layer for assisting the bonding between the base layer 1 and the ink absorbing material layer 2. For example, when the base layer 1 is formed of a polyester-based film, it depends on the material of the base layer 1. And a primer, for example, a polyester-based primer.

Hereinafter, specific examples and comparative examples will be described.

Example 1 Vinyl chloride resin (degree of polymerization: 10
50) 100 parts by weight of a plasticizer, 28 parts by weight of a titanium-based pigment, a Ba-Zn-based stabilizer, and an acrylic processing aid blended in a suitable amount by mixing a material with a thickness of 50 μm by calendering. A film for the base layer was obtained.

Next, in order to form the pressure-sensitive adhesive layer 3 on the back surface of the base layer film, an acrylic pressure-sensitive adhesive (main material is a mixture of 2-ethylhexyl acrylate, butyl acrylate, acrylic acid ( SK Dyne 1311 manufactured by Soken Chemical Co., Ltd., the curing agent is TDI
A base isocyanate and a curing agent in a ratio of 100: 3
) Was applied and dried. The thickness of the pressure-sensitive adhesive layer 3 is 30 μm. And
The release paper 4 having the adhesive layer 3 and the base layer 1 were laminated by a pressure roll.

Next, in order to form the primer layer 5 on the surface of the base layer 1, a modified polyester resin (Pes resin A-123 manufactured by Takamatsu Yushi Co., Ltd.) was used as a primer treatment agent.
D) was applied and dried. This primer layer 5
Has a thickness of 2 μm.

Next, in order to form the ink absorbing material layer 2,
Linear structure PNVA (GE-167 manufactured by Showa Denko KK)
Was dissolved in water at 2% and applied to the surface of the primer layer 5 and dried. The thickness of the ink absorber layer 2 is 20 μm.

(Example 2) The thickness of the ink absorbing material layer was set to 10
A laminated film was prepared in the same manner as in Example 1 except that the thickness was changed to μm.

Example 3 The thickness of the ink absorbing material layer was 5 μm.
A laminated film was prepared in the same manner as in Example 1 except that m was used.

(Example 4) As in Example 1, an ink absorbing material obtained by mixing a water-absorbing urethane resin and a PNVA having a crosslinked structure was applied to the surface of a base layer having an adhesive layer and a release paper on the back surface. It was coated and dried to obtain a laminated film. There is no primer layer.

That is, the water-absorbing urethane resin solution 100
36 parts by weight of PNVA having a crosslinked structure and 100 parts by weight of DMF (dimethylformamide) as a solvent were added to the parts by weight, and a coating solution obtained by stirring for 30 minutes was coated on the surface of the base layer, and dried. By doing so, an ink absorbing material layer was formed. The thickness of this ink absorbing material layer is 50 μm.

As the water-absorbing urethane resin, Rack Skin U2599-2 (resin solid content: 30%) manufactured by Seiko Kasei Kogyo Co., Ltd. is used. Was used. Therefore, in the ink absorbing material layer, since the resin solid content of the used water-absorbing urethane resin is 30%, the amount of the PNVN is calculated as 36 parts by weight when the amount of the solid resin is taken as 100 parts by weight.
0.3 = 120 parts by weight.

Example 5 A water-absorbing urethane resin solution (Rack Skin U2599-2 manufactured by Seiko Kasei Kogyo Co., Ltd.) was used as a coating liquid for forming an ink absorbing material layer.
0 parts by weight of crosslinked PNVA (NA manufactured by Showa Denko KK)
-01) and 120 parts by weight of DMF as a solvent were added, followed by stirring for 30 minutes. in this case,
The amount of the crosslinked PNVA per 100 parts by weight of the solid content of the water-absorbing urethane resin is 200 parts by weight. The thickness of the ink absorbing material layer is 30 μm, and other configurations are the same as those of the fourth embodiment.

Example 6 A water-absorbing urethane resin solution (Rack Skin U2599-2 manufactured by Seiko Chemical Industry Co., Ltd.) was used as a coating liquid for forming an ink absorbing material layer.
0 parts by weight of crosslinked PNVA (NA manufactured by Showa Denko KK)
-01) and 120 parts by weight of DMF as a solvent were added and stirred for 30 minutes. in this case,
The amount of the crosslinked PNVA per 100 parts by weight of the solid content of the water-absorbing urethane resin is 300 parts by weight. The thickness of the ink absorbing material layer is 30 μm, and other configurations are the same as those of the fourth embodiment.

Example 7 The thickness of the ink absorbing material layer was 10
A laminated film was prepared in the same manner as in Example 6 except that the thickness was changed to μm.

Comparative Example 1 A laminated film was prepared by laminating release paper on the back surface of the same base layer film as in Example 1 with an adhesive layer interposed therebetween. There is no primer layer and no ink absorber layer.

(Comparative Example 2) A water-absorbing urethane resin solution (Rack Skin U2599-2 manufactured by Seiko Chemical Industry Co., Ltd.) was used as a coating liquid for forming an ink absorbing material layer.
0 parts by weight of crosslinked PNVA (NA manufactured by Showa Denko KK)
-01) was added thereto and stirred for 30 minutes. In this case, the amount of the crosslinked PNVA per 100 parts by weight of the solid content of the water-absorbing urethane resin is 10 parts by weight. The thickness of the ink absorbing material layer is 30 μm, and other configurations are the same as those of the fourth embodiment.

(Comparative Example 3) A water-absorbing urethane resin solution (Rack Skin U2599-2 manufactured by Seiko Chemical Industry Co., Ltd.) was used as a coating liquid for forming the ink absorbing material layer.
0 parts by weight of crosslinked PNVA (NA manufactured by Showa Denko KK)
-01) was added thereto and stirred for 30 minutes. In this case, the amount of the crosslinked PNVA per 100 parts by weight of the solid content of the water-absorbing urethane resin is 20 parts by weight. The thickness of the ink absorbing material layer is 30 μm, and other configurations are the same as those of the fourth embodiment.

Comparative Example 4 The same laminated film as in Example 4 was used except that the same coating liquid as in Example 5 was used as the coating liquid for forming the ink absorbing material layer, and the thickness of the ink absorbing material layer was changed to 2 μm. Created.

(Comparative Example 5) A water-absorbing urethane resin solution (Rack Skin U2599-2 manufactured by Seiko Chemical Industry Co., Ltd.) was used as a coating liquid for forming an ink absorbing material layer.
0 parts by weight of crosslinked PNVA (NA manufactured by Showa Denko KK)
-01) was added thereto and stirred for 30 minutes. In this case, the solid content of the water-absorbing urethane resin is 10
The amount of the crosslinked structure PNVA per 0 parts by weight is 500 parts by weight. The thickness of the ink absorbing material layer is 30 μm, and other configurations are the same as those of the fourth embodiment.

Comparative Example 6 Copy paper (neutral paper) was used.

[Evaluation] The following items were evaluated for each of the above Examples and Comparative Examples.

<Surface Condition of Coated Surface> The surface condition of the ink absorbing material layer was visually evaluated. The criterion was "good" if there was no unevenness that was smooth and hindered printing, and "it was uneven" if there was such unevenness.

<Adhesiveness to base layer film> The ink absorbing material layer was cut in 100 cross-cuts (1 mm intervals) with a cutter, a cellophane tape was attached, and the ink absorbing material layer was rapidly peeled off in the 90 ° direction. The adhesion between the layer and the base layer film was evaluated. The criterion was “good” if the film did not peel off, and “bad” if the film did peel off.

<Ink Adhesion (Ink Bleeding, Repelling)> An ink jet printer (JV-130 manufactured by Miyuki Engineering Co., Ltd.) using an aqueous color ink (aquatic pigment) was applied to each of the printed surfaces of Examples and Comparative Examples.
Printing was performed in 0), and ink bleeding and the degree of bleeding were visually evaluated.

The criterion is that the evaluation is made in two stages of “very good” and “good” when there is no ink bleeding and no bleeding. ].

<Dryability of Ink> The dried state was evaluated by hand 10 minutes after printing by the above-mentioned ink jet printer. The criterion is "dry" if it is dry,
If it was not dried, it was regarded as "undried".

<Ink Density> After printing by the above-mentioned ink jet printer, the ink density and the density difference were visually evaluated. The criterion was a three-level evaluation of “very high density”, “high density”, and “low density” for the density of the ink, and “difference in density” and “no density” for the density difference of the ink.

<Adhesiveness of Ink> Ten minutes after printing by the above-mentioned ink jet printer, a cellophane tape was stuck on the printing surface and rubbed 10 times with a finger. The presence or absence was visually evaluated. The criterion was “no peeling” if the ink remained on the film side, and “peeling off” if no ink remained on the film side.

<Comprehensive Evaluation> Comprehensive evaluation was performed according to the formula XX based on the results of the above six evaluation items.

A mark indicates that the mark is very good, a mark indicates that the mark is next to the mark, a mark indicates that the mark is slightly worse, and a mark indicates that the mark is worse than the mark.

The evaluation results are shown in Table 1. The thickness is the thickness of the ink absorbing material layer.

[0057]

[Table 1]

(Evaluation Results) In Examples 1 to 7, the surface condition of the coated surface, the adhesion between the ink absorbing layer and the base layer film, the sticking property of the ink, the drying property of the ink, the concentration of the ink, and Is good in any of the adhesiveness of the above. Therefore, if the ink absorbing material layer is formed by the linear structure PNVA or the ink absorbing material layer is formed by blending the crosslinked structure PNVA with the water-absorbing urethane resin, the water-based ink is quickly absorbed and dried. It can be seen that the print can be printed vividly without any color shading or ink bleeding. In particular, Examples 1, 5 and 6 have very good ink sticking properties.

On the other hand, in Comparative Example 1 having no ink absorbing material layer, the printing performance was poor, and in Comparative Examples 2 and 3,
Even when the ink absorbing material layer is provided as described above, the printing performance is poor when the amount of PNVA is small. Comparative Example 4
Even if the amount of PNVA is appropriate as described above, the expected printing performance cannot be obtained when the ink absorbing material layer is thin. When the amount of PNVA is too large as in Comparative Example 5, the surface condition of the coated surface and the adhesiveness between the ink absorbing material layer and the base layer film are deteriorated, and the printing performance is also deteriorated.
In Comparative Example 6 using copy paper, the ink slightly bleed, and there was a problem of shading and low density.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a laminated film.

FIG. 2 is a cross-sectional view showing another embodiment of the laminated film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base layer 2 Ink absorber layer 3 Adhesive layer 4 Release paper 5 Primer layer

Claims (6)

[Claims] 1. A water-based ink absorbing material provided on a surface of a base for fixing a water-based ink, wherein the water-based ink absorbing material is composed of a linear poly-N-vinylacetamide. . 2. A water-based ink absorbing material provided on a surface of a base for fixing a water-based ink, wherein 100 parts by weight of a polyurethane resin synthesized using a polyether polyol containing polyethylene oxide has a crosslinked structure. Poly-N-vinylacetamide is 30 to
An ink absorbing material characterized by being blended in an amount of 500 parts by weight. 3. The method according to claim 1, wherein a surface of the base layer is provided.
A laminated film, wherein a layer of the water-based ink absorbing material described in (1) is formed. 4. The laminated film according to claim 3, wherein the thickness of the aqueous ink absorbing material layer is 5 μm or more. 5. The laminated film according to claim 3, wherein the base layer is a thermoplastic resin film, a polyester-based cloth,
A laminated film characterized by being cotton cloth or tarpaulin. 6. The laminated film according to claim 3, wherein an adhesive layer is provided on a back surface of the base layer, and a release liner is overlaid on the adhesive layer. Laminated film.