JPH10324052A - Water-base ink absorber, laminated film having absorber layer, and manufacture of the laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a water-base ink absorber, which has the excellent drying characteristics of water-base ink and the excellent weathereability and water resistance after printing by a method wherein the absorber includes a polyurethane produced by crosslinking an urethane resin, at least some part of the polyol component of which is polyethylene oxide, with a hardener and the crosslinking density of which is a specified value. SOLUTION: The laminated film for a water-color ink is produced by providing a water-color ink absorber layer 2 on the surface of a base layer 1 for fixing a water-color ink. An ink absorber includes a polyurethane, which is produced by crosslinking an urethane resin, at least some part of the polyol component of which is polyethylene oxide, with a hardener. In addition, the crosslinking density of the polyurethane is set to be 1×10<-6> -1×10<-3> mol/g. The polyurethane in the water-color ink absorber absrobs the water content in an ink at the contact of the polyurethane with the water-color ink and simultaneously swells. In addition, since being crosslinked with the hardener, this polyurethane with higher water resistance and weatherability results.

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 present invention relates to a laminated film having a layer and a method for producing the laminated film.

[0002]

2. Description of the Related Art Recently, a film printed by an ink-jet printer is bonded to various substrates, and used for outdoor or indoor signboards, drapes, roll screens, blinds, curtains, shutters, wall coverings, and the like. 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. Hei 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. I have.

Japanese Patent Application Laid-Open No. Hei 7-186522 describes that a base film is formed of a plastic film having shape conformity, and that an adhesive layer is formed on the back surface of the film.

JP-A-8-118792 describes that the ink absorbing layer is formed of a water-absorbing polyurethane resin containing 5-80% by weight of polyoxyethylene groups.

[0008]

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 resin or fiber, the aqueous ink is not absorbed. It is difficult to print the target picture or pattern sharply. In particular, aqueous inks include water and non-volatile organic solvents (ethylene glycol, diethylene glycol, methyl carbitol, etc.)
Is used as a solvent and its drying speed is slow, so when performing multicolor printing, when printing the first color and printing the second color, the inks of the first and second colors are mixed and blurred Therefore, the drying time needs to be long, and the workability is not good.

On the other hand, according to the laminated film in which the ink absorbing material layer is provided on the base film, the printability can be improved, but the sharpness of the pattern, the drying property of the aqueous ink, and the Sufficient performance is not always obtained in adhesion, weather resistance after printing, water resistance, and the like.

Accordingly, the present invention provides an aqueous ink absorbing material having excellent drying properties of an aqueous ink, excellent weather resistance after printing, and excellent water resistance, a laminated film having a layer of the ink absorbing material, and a method for producing the same. Is provided.

[0011]

The present inventor has solved the above problem by using a water-absorbing polyurethane as a water-based ink absorbing material and setting the cross-linking concentration of the polyurethane resin to a predetermined value. It has been found that the expected effects can be obtained, and the present invention has been completed.

That is, the invention of this application is a water-based ink absorbing material provided on a surface of a base for fixing a water-based ink, wherein a urethane resin in which at least a part of a polyol component is polyethylene oxide is crosslinked with a curing agent. Wherein the polyurethane has a crosslink concentration of 1 × 10 ^-6 to 1 × 10 ^-3 mol / g.

The polyurethane of the above-mentioned water-based ink absorbing material is:
Due to the presence of polyethylene oxide, when it comes into contact with the aqueous ink, it absorbs the water in the ink and swells at the same time. Further, this polyurethane is cross-linked by a curing agent, and therefore, the weather resistance and water resistance of the ink absorbing material are high.

The crosslinking concentration (crosslinking concentration) is the amount of crosslinking points expressed in mole units, and is 1 × 10 ⁻⁶ mol / g.
When the amount is less than 1 × 10 ⁻³ mol / g, the hardness becomes too high and becomes unsuitable as an ink absorbing material.

<Regarding Urethane Resin> The urethane resin is a resin obtained by solution polymerization or bulk polymerization using at least polyethylene oxide as a polyol component and an organic isocyanate and, if necessary, a chain extender.

Polyols that can be used in combination with polyethylene oxide include polyether polyols such as polyoxypropylene polyol and polyoxytetramethylene glycol, and polyester polyols such as polycaprolactone polyol and polyadipate ester polyol.

The concentration of polyethylene oxide in the polyol component is preferably from 20 to 100% by weight.

Examples of the organic isocyanate include aromatic isocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate (MDI), aliphatic isocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, and alicyclic isocyanates such as water-added MDI. Other trifunctional isocyanates and prepolymers can also be used.

As the chain extender, ethylene glycol,
Glycols such as 1,4-butanediol, and amines such as ethylenediamine and isophoronediamine. Of these, urethane resins using aliphatic and / or alicyclic isocyanates are preferred.

Such a urethane resin is a substantially chain polymer having a hydroxyl group or an amino group in its molecule, and can be dissolved in an organic solvent such as dimethylformamide, methyl ethyl ketone, toluene and the like. it can.

The molecular weight of the urethane resin is preferably from 5,000 to 500,000 in terms of number average molecular weight, more preferably from 10,000 to 100,000.

<Regarding the Curing Agent> As the curing agent, a polyisocyanate compound is preferable. Examples of the polyisocyanate compound include, in addition to the above-mentioned organic isocyanate, adducts of an organic isocyanate and trimethylolpropane or the like, or polyfunctional isocyanate compounds such as a prepolymer with a polyol or the like, a dimer, a trimer, or the like. .

As the organic isocyanate, an aliphatic or alicyclic isocyanate is preferable.

The curing agent reacts with the above-mentioned urethane resin and crosslinks it, whereby the weather resistance of the ink absorbing material is improved.
Produces a polyurethane that has the effect of improving water resistance.

<Regarding Inorganic Powder and Organic Powder> The powder in the ink absorbing material assists or accelerates the water absorption by the polyethylene oxide, and improves the drying property of the ink and the fixing property of the ink. The powder (water-absorbing agent) may be an inorganic substance, a protein or other organic substance, and is preferably silica, collagen, cross-linked acrylic acid, or calcium carbonate. The intended effect can be obtained by using.

The amount of these components is preferably 50 to 500 parts by weight, more preferably 100 to 300 parts by weight, based on 100 parts by weight of the polyurethane.

<Regarding the thickness of the ink absorbing material> The thickness of the ink absorbing material as described above, that is, the layer thickness of the ink absorbing material provided on the surface of the base, ensures that the ink absorbing material absorbs the aqueous ink. 5 for drying and fixing
It is preferably at least 10 μm, more preferably at least 10 μm. Also, regardless of the upper limit,
When the ink absorbing material layer is formed by coating on the base, it is advantageous from the viewpoint of coating workability to make the thickness up to about 50 μm, but even if the thickness is 100 μm, it is still 200 μm. However, there is no problem in fixing the aqueous ink.

<Formation of Ink Absorbing Material Layer on Base> As a means for forming the aqueous ink absorbing material layer on the surface of the base, the above-mentioned coating can be adopted. Then, a release paper may be attached to one side of the adhesive via an adhesive layer, the release paper may be peeled off, and a film of an ink absorbing material may be attached to a base to form an ink absorbing material layer. Therefore, the base in that case does not need to be in the form of a film.

When the ink absorbing material layer is formed on a film-shaped 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 can be formed on the back surface of such a laminated film (the surface of the base layer opposite to the ink absorbing material layer).

As the pressure-sensitive adhesive when the pressure-sensitive adhesive layer is provided on the ink absorbing material or the base, for example, an acrylic pressure-sensitive adhesive can be employed. The type does not matter.

In the case where the ink absorbing material layer is formed on the surface of the base by the above-mentioned coating, if there is a concern that the adhesion between the base and the ink absorbing material becomes insufficient,
A primer which mediates the adhesion between the two may be applied, and an ink absorbing material may be applied thereon. Further, the ink absorbing material layer may be formed on the base surface via the pressure-sensitive adhesive layer by a transfer method.

<About the production method of the laminated film> The laminated film as described above can be produced as follows. That is, a substantially chain-like urethane resin in which at least a part of the polyol component is polyethylene oxide is dissolved in an organic solvent, and a curing agent is added to prepare a liquid for an ink absorbing material. The solution for application is applied to a base film and dried by heating to form a crosslink concentration of 1 × 10 ^-6 to 1 on the base film.
An ink absorber layer containing × 10 ⁻³ mol / g of polyurethane is formed.

In this case, the number average molecular weight is 5,000 to 50.
100,000 parts by weight of 0000 or 10,000 to 100,000 urethane resin, 1 to 30 parts by weight of a curing agent,
Alternatively, 3 to 20 parts by weight may be blended.

When the inorganic powder or the organic powder is blended with the ink absorbing material, a urethane resin, a curing agent, and at least one of the inorganic powder and the organic powder are blended with the above-mentioned organic solvent, and the mixture is stirred. By doing so, the ink absorbing material liquid may be prepared.

<Aqueous Ink> As described above, the aqueous ink applied to the ink absorbing material according to the present invention uses a pigment or a dye or both of the pigment and the dye as a colorant and a dispersant. A water-soluble ink, regardless of its 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,
Preferably, the solvent is a mixture of water and a non-volatile hydrophilic organic solvent.

[0036]

According to the invention relating to the water-based ink absorbing material and the laminated film of this application, the water-based ink absorbing material provided on the surface of the base crosslinks a urethane resin comprising a polyol containing polyethylene oxide with a curing agent. Since it contains a water-absorbing polyurethane having a crosslinking concentration of 1 × 10 ⁻⁶ to 1 × 10 ⁻³ mol / g, it is possible to enhance the drying property, weather resistance and water resistance of the aqueous ink.

According to the invention relating to the method for producing a laminated film, a liquid for an ink absorbent is prepared by adding a urethane resin and a curing agent to an organic solvent, and is applied to a base film and then dried by heating. As a result, the desired aqueous ink absorbing material layer containing polyurethane can be formed.

[0038]

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.

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 and 28 parts by weight of a titanium-based pigment, a Ba-Zn-based stabilizer and an acrylic-based processing aid were mixed with a material having a thickness of 50 μm by calendering. A film for a base layer as shown in No. 1 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
The pressure-sensitive adhesive layer 3 of 30 μm was formed by coating and drying. Then, 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 ink absorbing material layer 2,
Urethane resin (Lac Skin U manufactured by Seiko Chemical Co., Ltd.)
-2599: Sumidur-N-75 (curing agent) as a curing agent for 100 parts by weight of a urethane resin solution comprising a system containing polyethylene oxide dissolved in a mixed solvent of dimethylformamide (DMF) and methyl ethyl ketone, solid content 30%). Sumitomo Bayer Urethane Co., Ltd .: NC0
% = 16.2%, solid content 75%), 3 parts by weight were mixed, and 36 parts by weight of calcium carbonate (manufactured by Shiraishi Industry Co., Ltd .: Callite KT) as a water absorbing agent and 100 parts by weight of DMF as a solvent were added. By stirring for minutes, a liquid for an ink absorbing material was prepared.

This ink absorbing material liquid is applied to the surface of the base layer film on which the release paper 4 is laminated by a bar coater, and dried by heating to a thickness of 30%.
An ink absorber layer 2 having a thickness of μm was formed. The polyurethane crosslink concentration of the obtained ink absorbing material layer is 1.3 × 10 ⁻⁴ mol / g.

(Example 2) Sumidur as a curing agent
Except that 5 parts by weight of N-75 was used, it was produced in the same manner as in Example 1. The resulting polyurethane crosslink concentration of the ink absorbing material layer is 2.1 × 10 ^-4 mol / g.

Example 3 A sample was prepared in the same manner as in Example 1 except that silica (Carplex BS-304F, manufactured by Shionogi & Co., Ltd.) was used instead of calcium carbonate as a water absorbing agent. The polyurethane crosslink concentration of the obtained ink absorbing material layer is 1.3 × 10 ⁻⁴ mol / g.

Comparative Example 1 Sumidur as a curing agent
Except not using N-75, it produced by the same method as Example 1. The crosslinking concentration of the polyurethane in the obtained ink absorbing material layer is 0 mol / g.

<Evaluation of Examples and Comparative Examples> -Measurement Test for Physical Properties- The following evaluations were performed for the above Examples and Comparative Examples. Table 1 shows the results.

<Dryability of Ink> An ink jet printer (JV-1300) manufactured by Mimaki Engineering Co., Ltd.
), And the dried state after 10 minutes was evaluated by finger touch. <Weather resistance> After irradiation for 200 hours using a weatherometer according to JIS B7753, a change in appearance was observed.

<Water resistance> The specimen was immersed in warm water of 60 ° C. for 14 days, and the change in appearance was observed.

[0051]

[Table 1]

According to Table 1, although there is no difference in the drying property of the water-based ink, the ink sticking property, and the ink concentration, the weather resistance and the water resistance of Examples 1 to 3 are higher than those of the comparative example. It is excellent, and the effect of crosslinking the urethane resin with the curing agent is recognized.

[Brief description of the drawings]

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

FIG. 2 is a 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

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C09D 11/00 C09D 11/00 175/04 175/04

Claims (9)

[Claims] 1. A water-based ink absorbing material provided on a surface of a base for fixing a water-based ink, wherein at least a part of a polyol component contains a polyurethane obtained by crosslinking a urethane resin which is a polyethylene oxide with a curing agent. And the crosslinking concentration of the polyurethane is 1 × 10 ⁻⁶ to 1 × 10 ^−3.
Water-based ink absorbing material, characterized in that the amount is mol / g. 2. The water-based ink absorbing material according to claim 1, wherein the urethane resin has a hydroxyl group or an amino group. 3. The water-based ink absorbing material according to claim 1, wherein the curing agent is a polyisocyanate compound. 4. The water-based ink absorbing material according to claim 1, wherein at least one of an inorganic powder and an organic powder is blended. 5. A laminated film, wherein a layer of the water-based ink absorbing material according to claim 1 is formed on a surface of a base layer. 6. The laminated film according to claim 5, wherein an adhesive layer is formed on the back surface of the base layer. 7. A liquid for an ink absorbing material is prepared by dissolving a substantially chain urethane resin in which at least a part of a polyol component is polyethylene oxide in an organic solvent, and adding a curing agent. The ink absorbing material liquid is applied to the base film and dried by heating to form a crosslink concentration of 1 × 10 ^-6 to 1 on the base film.
A method for producing a laminated film, comprising forming an ink absorbing layer containing × 10 ^-3 mol / g of polyurethane. 8. The method for producing a laminated film according to claim 7, wherein the urethane resin has a number average molecular weight of 5,000 to 5,000.
000, based on 100 parts by weight of the urethane resin.
A method for producing a laminated film, comprising 1 to 30 parts by weight of a curing agent. 9. The method for producing a laminated film according to claim 7, wherein the organic solvent is blended with a urethane resin, a curing agent, and at least one of an inorganic powder and an organic powder,
A method for producing a laminated film, wherein the above-mentioned liquid for an ink absorbing material is prepared by stirring.