JP2001315433A - Manufacturing method for composition for aqueous ink receptor layer and recording material for aqueous ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for an aqueous ink receptor layer, which is capable of forming the ink receptor layer high in adhesive property to a substrate and excellent in a picturing resolution, and the manufacturing method of a recording material for an aqueous ink jet printer, which is capable of manufacturing the recording material comparatively simply by employing the composition. SOLUTION: The composition for the aqueous ink receptor layer, which is obtained by mixing 2-10 pts.wt. of an inorganic electrolyte and 0-100 pts.wt. of adsorptive porous material (preferably 2-10 pts.wt. of sodium chloride and 0-10 pts.wt. of silica grain) to 100 pts.wt. of a hydrophilic resin or vinyl acetal resin, for example, is applied on a PET film so as to obtain the thickness of 20 μm and is dried for 3 min at 110 deg.C to form a film for the ink receptor layer while the film is separated from the PET film thereafter and an OPP adhesive tape (the thickness of 60 μm) is laminated on the separated surface to obtain the recording paper for the aqueous ink jet printer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composition for an aqueous inkjet receiving layer and a method for producing a recording material for an aqueous inkjet printer using the composition.

[0002]

2. Description of the Related Art In general, recording paper for an aqueous ink jet printer is prepared by applying a liquid in which a material for forming an ink receiving layer is dissolved or dispersed on a paper or a resin film as a base material using a roll coater or the like. It was obtained by hot air drying. In recent years, higher resolution inkjet printers,
With the increase in speed, a large number of recording materials for water-based inkjet printers of a type in which a porous material such as silica or alumina is added to a hydrophilic resin in the same amount or more as the resin to improve the water absorption rate are proposed. .

[0003]

However, when a large amount of a porous material is added to a conventional recording material for an ink-jet printer as described above, the binder effect of the hydrophilic resin becomes extremely weak, and the ink receiving layer itself becomes weak. Poor cohesive strength and poor scratch resistance.For example, in the case of outdoor use, the image easily falls off because the hydrophilic resin binder on the surface of the ink receiving layer starts to degrade easily due to weak external force or deterioration due to light resistance over time. There was a problem that it became. Further, the water-based ink receiving layer material is a water-based paint, and as a drying condition after the coating, it is necessary to reach a high temperature range up to around 100 ° C. as a temperature at the time of drying the coated base material. It was sometimes difficult to directly apply and dry a thermoplastic resin base film to form a recording material.

Accordingly, the present inventors have conducted various studies on the above problems and found that the content of the porous material must be equal to or less than that of the resin in order to secure the cohesive force of the ink receiving layer. It has been found that when the content of the porous material is reduced, the water absorption rate of the ink decreases, but the absorption rate can be maintained by adding a predetermined amount of the inorganic electrolyte. The composition for an aqueous ink receiving layer of the present invention has been completed based on such findings, and a method for relatively easily producing a recording material having excellent printability using this composition has been studied. As a result, the method for producing a recording material for an aqueous inkjet printer according to the present invention has been completed.

That is, an object of the present invention is to provide a composition for an aqueous ink-receiving layer which can form an ink-receiving layer having high adhesion to a substrate and good drawing properties (resolution), and the use of this composition. An object of the present invention is to provide a method for producing a recording material for an aqueous inkjet printer, which can easily produce a recording material.

[0006]

Means for Solving the Problems To achieve the above object, the invention according to claim 1 is characterized in that 2 to 10 parts by weight of an inorganic electrolyte and 100 parts by weight of a hydrophilic resin are used, A composition for an aqueous ink receiving layer, which is contained in an amount of 0 to 100 parts by weight. The invention according to claim 2 is
The composition for an aqueous ink receiving layer according to claim 1 is applied to the surface of a release film, and dried to form a film for an ink reception layer, and then the film for an ink reception layer is removed from the release film. Provided is a method for producing a recording material for an ink jet printer, which peels off and attaches a peeled surface to a substrate.

According to a third aspect of the present invention, the composition for an aqueous ink receiving layer according to the first aspect is coated on the surface of a release film and dried to form a film for an ink receiving layer. The present invention also provides a method for producing a recording material for an ink jet printer in which the film for an ink receiving layer is peeled from a release film, and a substrate in a molten state is extruded and laminated on the peeled surface. Hereinafter, the present invention will be described in more detail.

[Ink Receiving Layer Composition] In the composition for an aqueous ink receiving layer of the present invention, a water-absorbing resin, an inorganic electrolyte and, if necessary, an adsorptive porous material suitable for an ink jet solvent are used. Specific examples of the hydrophilic resin used include hydrophilic water-absorbing materials such as polyvinyl alcohol, polyvinyl acetal, polyvinyl pyrrolidone, polyester, and polyacrylic acids. As the inorganic electrolyte used to quickly absorb the ink,
Sodium chloride and the like can be mentioned.
2 to 10 parts by weight, preferably 5 to 10 parts by weight with respect to 0 parts by weight
It is blended in the range of parts by weight.

When the amount is less than 2 parts by weight, the water absorption rate of the ink receiving layer is low, and the printed image is not clear. When the amount exceeds 10 parts by weight, the water resistance of the ink receiving layer becomes extremely poor. That is, by setting the content of the inorganic electrolyte in the ink receiving layer film after drying to 2 to 10 parts by weight, it is possible to obtain an image which maintains sharpness without bleeding due to inkjet.

The above-mentioned adsorptive porous material can increase the water absorption rate of the ink receiving layer by blending it. However, it can be used particularly when it is necessary to increase the water absorption rate. It is not an essential component in the aqueous ink receiving layer composition. Examples of the adsorptive porous material include inorganic fillers having a particle diameter of several μm or less, such as various minerals such as silica, alumina, and zeolite, and 0 to 100 parts by weight based on 100 parts by weight of the hydrophilic resin. , Preferably in the range of about 0 to 10 parts by weight. If the compounding amount per 100 parts by weight of the hydrophilic resin exceeds 100 parts by weight, the ink receiving layer is formed on the release film, and then separated from the release film and laminated on the base material layer. May fall off.

[Coating of Composition for Ink Receiving Layer] In the method for producing a recording material according to the present invention, first, the composition for aqueous ink receiving layer is coated on the surface of a release film or paper. To form a film for the ink receiving layer. At this time, the composition for ink receiving layer is dissolved or dispersed in a solvent capable of dissolving or dispersing, and the coating composition obtained by diluting to a viscosity suitable for each coating equipment is formed into a release film or the like. After coating, the solvent is removed by drying to form a film for an ink receiving layer. Coating is a roll coater, comma coater,
Alternatively, the drying can be performed by a reverse coater, and drying can be performed in a drying furnace usually attached to the coater, and the temperature condition can be set according to the kind and amount of the solvent.

[Releasability of Release Film] In the method for producing a recording material according to the present invention, it is necessary to release the ink receiving layer film formed as described above from a release film or the like. Is preferably about 2 to 20 N / m. When the peeling force is less than 2 N / m,
When handling a release film with an ink receiving layer,
The ink receiving layer may not float properly on the substrate because the ink receiving layer floats or falls off during transportation or in the step of laminating the substrate layer in the next step. / M when laminating with the substrate layer,
It becomes difficult to peel off the ink receiving layer from the release film, and there may be a problem that the ink receiving layer partially remains on the release film.

It is preferable to select a release film, a composition for an aqueous ink receiving layer, and manufacturing conditions so that the final peeling force falls within the above range. Performs a release treatment such as forming a silicone release agent or a wax layer, or performs an adhesive treatment such as a corona discharge treatment on the ink-receiving layer coated surface of the release film when the release force is too low. Is good.

[Method of laminating and fixing ink-receiving layer] As a method of laminating and fixing the ink-receiving layer film obtained by peeling from the release film and the substrate, the method of claim 2 usually employs an ink. A method in which a pressure-sensitive adhesive or adhesive layer is provided between the release surface of the receiving layer film and the substrate and bonded together is employed, and a dry lamination method is preferably employed. The substrate is not particularly limited, and includes, for example, a film or sheet made of a thermoplastic resin such as polyester, polypropylene, polyethylene, and soft vinyl chloride resin.

When laminating the ink receiving layer film and the base material layer with a pressure sensitive adhesive or an adhesive, it is necessary to select a material which sufficiently adheres and does not peel off.
For example, it can be selected from adhesives mainly composed of natural rubber, synthetic rubber, acrylic resin and silicone resin, and urethane, epoxy or vinyl acetate adhesives.

According to the third aspect of the present invention, the molten base material is extruded and laminated on the release surface of the ink receiving layer film released from the release film. In this case, a polyolefin-based resin, polyester or polyamide-based resin can be extruded as a base material. In order to further improve the adhesiveness with the ink-receiving layer, an adhesive resin is applied to the surface of the laminate with the ink-receiving layer film. It is also effective to provide a layer or perform an adhesive treatment such as an ozone treatment.

(Function) Since the composition for an aqueous ink receiving layer of the present invention contains a specific amount of an inorganic electrolyte with respect to a hydrophilic resin, an ink receiving layer excellent in printability can be formed. The inventors studied the composition for the aqueous ink receiving layer, for example, on the front and back of the ink receiving layer obtained by coating and drying on a release film, the ink absorption when printed by inkjet. The present invention was completed by paying attention to the point that there is a subtle difference in the present invention.

That is, since the printability is excellent only on the dry side, if the coating cannot be directly applied and dried on the film serving as the base layer, the base film having the releasability is applied and dried. After that, the ink receiving layer film is peeled from the release film, and at this time, the ink receiving layer is laminated and fixed to the base material layer with an adhesive or an adhesive on the peeled surface, so that the printability is excellent. Thus, an ink jet recording material can be obtained.

Conventionally, it has been difficult to select a thermoplastic resin such as a soft PVC, PP, or PE as a base material as a recording material due to heat at the time of coating and drying the ink receiving layer composition. However, in the present invention, as described above, the release surface of the ink receiving layer film once formed on a release film and the like, for example, because it is characterized by laminating a substrate, the thermoplastic resin Can be used, and the degree of freedom in selecting the resin type as the base material is high. Conventionally, when the ink receiving layer composition was directly applied to a substrate, there was a case where it was necessary due to a difference in wettability. Easy to stack into layers.

[0020]

(Example 1) A vinyl acetal resin solution (acetalization degree: about 9 mol%, vinylacetal resin: 8% by weight, solvent: 42% by weight of isopropyl alcohol, 50% by weight of water, 92% in total) as an ink receiving layer material %) With respect to 100 parts by weight, 5 parts by weight of an 8% by weight aqueous sodium chloride solution were mixed to obtain a composition for an aquatic ink receiving layer.

Using a baker-type applicator, polyethylene terephthalate (PE) was used as a release film so that the composition after drying had a thickness of 20 μm.
T) A film (Lumirror # 75, manufactured by Toray Industries, Inc.) was applied and dried at 110 ° C. for 3 minutes using a hot air drier to form a film for an ink receiving layer. Thereafter, the film was peeled off from the release film, and an OPP adhesive tape (Orien Tape, manufactured by Sekisui Chemical Co.,
m) was laminated to obtain an inkjet recording paper.

Example 2 A vinyl acetal resin solution (acetalization degree: about 9 mol%, vinyl acetal resin: 8% by weight, solvent: 42% by weight of isopropyl alcohol, 50% by weight of water, 92% by weight in total as an ink receiving layer material) 5) Aqueous sodium chloride solution (5 parts by weight) and silica particles (T32, manufactured by Tokuyama Corporation, T32, average particle size of about 1.5 μm) were primarily adjusted to 8% by weight with respect to 100 parts by weight. And 5 parts by weight to obtain a composition for an aqueous ink receiving layer. Using this composition, a film for an ink receiving layer having a thickness of 20 μm was formed on a release film under the same conditions as in Example 1. Thereafter, the film was peeled off from the release film, and an OPP adhesive tape (Orien tape, 60 μm thick, manufactured by Sekisui Chemical Co., Ltd.) was laminated on the peeled surface to obtain an inkjet recording paper.

Example 3 A curing agent was added to 100 parts by weight of a polyurethane-based adhesive for dry lamination (Takeda Chemical Co., Ltd., Takenate) on a base film (Oji Yuka Kabushiki Kaisha, polypropylene, YUPO, thickness 100 μm). 5 parts by weight of the mixture was applied by a gravure coater to a wet weight of 7 g / m ² and dried, and the release surface of the ink receiving layer film obtained in the same manner as in Example 2 was attached to the dried surface. This was used as an ink jet recording material.

Example 4 In the same manner as in Example 2, a film for an ink receiving layer was formed on a release film. After that, peel off this film from the release film,
Low density polyethylene (LK30 manufactured by Mitsubishi Chemical Corporation) on the release surface
Was extruded and laminated with a T-die so as to have a thickness of 70 μm to produce an inkjet recording paper.

(Comparative Example 1) PE subjected to corona discharge treatment
On a T film (Lumilar # 75, manufactured by Toray Industries, Inc.), 100 parts by weight of the vinyl acetal resin used in Example 1 as the ink receiving layer composition and silica particles 200 used in Example 2 were used.
The mixture with a weight part was applied so that the thickness after drying became 20 μm, and dried at 110 ° C. for 3 minutes using a hot air drier to obtain an ink jet recording paper.

(Comparative Example 2) The same OPP adhesive tape (thickness: 60 μm) as used in Example 1 was applied to the coating surface (the surface opposite to the release surface) of the ink receiving layer film produced in Example 2.
m) were laminated to obtain an ink jet recording paper.

(Comparative Example 3) The components constituting the ink receiving layer of a commercially available ink jet recording paper having an ink receiving layer formed on a substrate made of a vinyl chloride resin or the like were analyzed. Alcoholic resin 1
And 100 parts by weight of the alumina-based adsorptive porous material. This inkjet recording paper was used as a sample as it was.

[Evaluation] With respect to the samples obtained in each of the above Examples and Comparative Examples, the adhesion between the ink receiving layer and the substrate was determined.
When this was used as an output sheet, the drawing properties on the surface of the ink receiving layer by an ink jet printer and the glossiness were evaluated by the following methods, and the results are shown in Table 1.

<Measurement Method> Adhesion: 5 × 5 squares of 25 × 5 squares are formed on the surface of the ink receiving layer of the output sheet in a grid pattern, and a cellophane tape is attached thereto and then peeled off. 25 ink receiving layer
Those with the remaining number of pieces were evaluated as ○, those with 23 or more remaining as Δ, and those with only 22 or less remaining as X. Drawability: A square of 1 cm square was printed with a water pigment ink jet printer JV2 13006 color ink manufactured by MIMAKI, and a color chart of a JIS X9201 standard image was printed. did. Gloss: A 60-degree specular gloss was measured according to JIS K7105. Suga Test Instruments Co., Ltd., Digital Angle Gloss Meter UG
V-5D was used.

[0030]

[Table 1]

From Table 1, it can be seen that all of Examples 1 to 4 are excellent in adhesion and drawing properties, and compared with Comparative Examples 1 to 3, they contain an inorganic electrolyte and exhibit a good release property of the ink receiving layer film. Even if the content of the adsorptive porous material is reduced,
It is understood that a recording material for an aqueous ink jet printer having excellent drawing properties and excellent adhesion can be obtained as compared with the case where a large amount of porous material is used.

[0032]

The composition for an aqueous ink receiving layer of the present invention comprises:
The ink receiving layer is configured as described above, and can form an ink receiving layer having high adhesion to a base material and good drawing resolution. Further, the method for producing a recording material for an aqueous inkjet printer of the present invention is configured as described above, and according to the present invention, an ink receiving layer having high adhesion to a substrate and good drawing properties is relatively easily prepared. It is possible to provide a recording material for an aqueous ink jet printer having excellent printability, comprising: In addition, various thermoplastic resins can be selected as the base material.

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Claims (3)

[Claims] An inorganic electrolyte and a adsorptive porous material are contained in an amount of 2 to 10 parts by weight and 100 to 100 parts by weight of a hydrophilic resin, respectively.
A composition for an aqueous ink receiving layer, which is contained in an amount of 00 parts by weight. 2. The composition for an aqueous ink receiving layer according to claim 1 is coated on the surface of a release film and dried to form a film for an ink receiving layer. A method for producing a recording material for an ink jet printer, which is characterized by peeling from a release film and bonding a peeled surface and a substrate. 3. The composition for an aqueous ink receiving layer according to claim 1 is coated on the surface of a release film and dried to form a film for an ink receiving layer. A method for producing a recording material for an ink jet printer, which comprises peeling off a base material in a molten state on a release surface by peeling off from a release film and laminating.