JPH11208104A - Ink jet recording medium and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording medium and manufacturing method thereof having a high wettability and dyeing property, and good ink adsorptiveness, and also having an excellent capability even in water resistance as an ink receiving layer. SOLUTION: The ink jet recording medium includes an ink receiving layer 3 made by thermosetting a mixture of a cation-modified acrylic copolymer and polyvinyl acetal resin with an epoxy compound. In particular, the monomer component of the cation-modified acrylic compolymer is made into any one of methacryl acid methyl, acrylic acid methyl, methacryl acid 2-hydroxyethyl, or methacryl acid diamethyl aminoethyl quaternary ammonium salt, and the polyvinyl acetal resin is made by acetalizing polyvinyl alcohol of a saponification degree of 70-90% by 5-20 mol.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium for an ink jet printer and, more particularly, to a recording medium which simultaneously satisfies both wettability and absorbability to ink and water resistance.

[0002]

2. Description of the Related Art In recent years, various types of printers for computer output have become widespread. Above all, an ink jet printer is excellent in quietness, cost, and image quality, can reproduce a full-color image with high quality, has excellent performance not found in other systems, and can be expected to spread further. On the other hand, paper is often used for printer paper, and plastic films and synthetic papers are also used for applications requiring smooth images utilizing their smooth surface and transparency.

[0003] Ink-jet inks include:
In order to prevent clogging of the ink nozzle, a slow-drying ink in which a water-soluble dye or the like is dissolved in an aqueous solvent is used. Therefore,
Good if the recording paper is water-absorbent, such as paper, but if it is non-water-absorbing such as a plastic film, the ink will have poor drying properties after printing. A receiving layer is provided.

However, a structure in which an ink receiving layer is provided on a support such as a plastic film has not been obtained with sufficient performance. That is, in order to improve the wettability and dyeability of the slow-drying ink, or to improve the absorbability, a method of forming the ink receiving layer from a water-soluble resin, a hydrophilic resin, or the like has been proposed. By the aqueous solvent,
Alternatively, the ink receiving layer becomes wet and tacky in a high-humidity environment, and blocking occurs when recording media are stacked,
In addition, there is a problem that drying is poor and soiling is easy if touched by hand after printing. After all, the wettability, the dyeing property and the absorptivity and the water resistance, drying property and blocking resistance are mutually contradictory properties, and a property satisfying both properties has not been obtained.

[0005]

As described above, according to the prior art, in an ink jet recording medium using a non-water-absorbing support, satisfactory performance can be obtained even if a layer such as an ink receiving layer is devised. Was not obtained. Therefore, the present invention has been made in view of the problems of these conventional techniques, the purpose of the wettability and dyeing of the ink,
An object of the present invention is to provide an ink jet recording medium having water resistance and a method for manufacturing the same. Furthermore, OH
An object of the present invention is to provide an ink jet recording medium which satisfies the performance of having high transparency as in P, and a method for manufacturing the same.

[0006]

Means provided by the present invention for solving the above-mentioned problems are as follows. First, as set forth in claim 1, at least one surface of a support is provided with a cation-modified acrylic copolymer and a polyvinyl acetal. An ink jet recording medium having an ink receiving layer made of a resin obtained by thermosetting a mixture with a resin with an epoxy compound.

Here, usually, a cation-modified acrylic copolymer having excellent water resistance but poor ink absorption and a polyvinyl acetal resin having excellent ink absorption but poor water resistance are thermoset with an epoxy compound. Thereby, the properties of the cation-modified acrylic copolymer and the polyvinyl acetal resin are supplemented, and the ink is heat-cured with an epoxy compound, thereby simultaneously satisfying the wettability and dyeing properties of the ink and the water resistance. I can do it.
According to this, the ink receiving layer itself can have high transparency.

[0008] More preferably, as set forth in claim 2,
2. An ink jet recording medium based on the constitution of claim 1, wherein the monomer component of the cation-modified acrylic copolymer comprises at least methyl methacrylate, ethyl acrylate, and quaternary ammonium salt of dialkylaminoethyl methacrylate. It is characterized by the following. with this,
Methyl methacrylate contributes to water resistance, ethyl acrylate contributes to flexibility, and dialkylaminoethyl methacrylate quaternary ammonium salt contributes to dye fixability, respectively.
As a result, the above-mentioned various characteristics (wetting and dyeing properties of the ink, water resistance, and transparency) can be made more preferable.

Preferably, as set forth in claim 3, an ink jet recording medium based on the constitution of claim 1 or 2, wherein the cation-modified acrylic copolymer reacts with an epoxy group. It is characterized by having a monomer having a group. According to this, since it has a monomer having a substituent that reacts with an epoxy group,
The thermosetting property is enhanced, and better water resistance can be provided.

The acetal portion of the polyvinyl acetal resin according to the present invention is not limited, but from the viewpoint of performance as an ink jet recording medium, any one of formal, methylal, ethylal, propal, and butyral is preferred. More preferably,

According to a fourth aspect of the present invention, there is provided an ink jet recording medium based on any one of the first to third aspects, wherein the polyvinyl acetal resin has a saponification degree of 70 to 90%. Alcohol
It is characterized by being acetalized in an amount of 5 to 20 mol%. According to this, ink absorption and water resistance,
It is preferable to achieve a good balance.

If the degree of saponification of polyvinyl alcohol is less than 70% or more than 90%, the ink absorbency is significantly reduced, and if the degree of acetalization of polyvinyl alcohol is less than 5 mol%, the water resistance is significantly reduced. On the other hand, if the degree of acetalization exceeds 20 mol%, the ink absorbency is significantly reduced, which is not preferable.

Preferably, as set forth in claim 5, an ink jet recording medium based on any one of claims 1 to 4, wherein the epoxy compound is an aliphatic compound and is water-soluble. And is bifunctional or higher. According to this, the crosslink density of the resin at the time of curing is increased, and excellent effects are obtained because the water resistance is large.

According to a sixth aspect of the present invention, there is provided an ink jet recording medium based on any one of the first to fifth aspects, wherein the cation-modified acrylic copolymer and the polyvinyl acetal resin are water-soluble. And dissolved in a mixed solvent of alcohol and alcohol. This is excellent in that both ink absorption and water resistance can be achieved.

[0015] Preferably, as set forth in claim 7, an ink jet recording medium based on the constitution of claim 1 is characterized in that the ink receiving layer contains a filler. According to this, the ink absorption speed and the drying speed can be given, which is preferable. Further, it is preferable because transportability and blocking resistance are also improved.

Further, as set forth in claim 8, a coating solution obtained by mixing a cation-modified acrylic copolymer, a polyvinyl acetal resin and an epoxy compound is applied to at least one surface of a support, and then thermally cured. Forming an ink receiving layer by the method. According to this, it is excellent in that the balance between ink absorption and water resistance can be achieved at the same time.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In order to solve the above-mentioned problems, an ink jet recording medium according to the present invention comprises, on at least one surface of a support, a cation-modified acrylic copolymer having a group reactive with an epoxy group and a polyvinyl acetal resin. The basic configuration is to have an ink receiving layer made of a resin thermally cured with an epoxy compound (more preferably a polyfunctional epoxy compound).

The ink receiving layer in the present invention is a layer that receives ink. In the present invention, a specific resin is used in the layer to achieve both the dyeing property and wettability of the ink and the water resistance. Such an ink receiving layer is composed of a cation-modified acrylic copolymer having a group that reacts with an epoxy group and a resin obtained by thermosetting a polyvinyl acetal resin with an epoxy compound.

As the above acrylic copolymer, it is desirable that the monomer constituting the copolymer is an acrylic monomer having a quaternary ammonium base in the cation-modified part. Further, an acrylic monomer having a functional group such as a hydroxy group is preferably used as a portion having a group that reacts with an epoxy group.
It is desirable to use a hydrophobic monomer such as an acrylate ester.

Examples of the acrylic monomer having a quaternary ammonium base include dimethylaminoethyl (meth) acrylate, diethylamino (meth) acrylate, diethanolamino (meth) acrylate, dipropylamino (meth) acrylate, and dipropanolamino. (Meth) acrylate, dibutylamino (meth)
(Meth) having a tertiary amino group such as acrylate
There is a quaternized monomer of an acrylate monomer.

Further, the acrylic monomer having a quaternary ammonium base includes a functional group such as a carboxyl group or a hydroxyl group such as acrylic acid, methacrylic acid, or mono (meth) acrylate of these acids and a glycol such as ethylene glycol. Glycidyltrimethylammonium chloride, 3-chloro-2
And a monomer obtained by reacting a reactive quaternary ammonium salt such as -hydroxypropyltrimethylammonium chloride, 3-chloro-2-hydroxypropyltriethanolammonium chloride, glycidyldimethylbenzylammonium chloride, and glycidyldimethylbutylammonium chloride.

On the other hand, acrylic monomers having a group which reacts with an epoxy group include, for example, acrylic acid and methacrylic acid as monomers having a carboxyl group, and these monomers and ethylene glycol, propylene glycol, glycerin, pentaerythritol and the like. Esterified with polyhydric alcohol, ethylenediamine,
Examples include amidated products with polyvalent amines such as propylene diamine, acrylamide, methacrylamide and the like.

Examples of the hydrophobic monomer comprising (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate and the like. (Meth) acrylic acid ester or acrylamide,
Examples include monomers such as acrylonitrile, vinyl acetate, vinyl chloride, and styrene.

As the epoxy compound for curing the cation-modified acrylic copolymer and the polyvinyl acetal resin as described above, a bifunctional or more epoxy compound having two or more epoxy groups is used. Examples of such an epoxy compound include polyglycerol polyglycidyl ether, pentaethylitol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, resorcinol diglycidyl ether, and polypropylene glycol diglycol. It is an aliphatic and water-soluble epoxy compound such as glycidyl ether.

The cation-modified acrylic copolymer, polyvinyl acetal resin (main component), and epoxy compound (curing agent) as described above are all water, methanol, ethanol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, It is used as a coating liquid of a 10 to 50% by weight solution using one or more mixed solvents such as ethyl acetate, toluene and xylene.
In use, the equivalent ratio of the main agent / curing agent is about 1/0.
Mix by 1/2 and dilute if necessary.

For the above-mentioned purpose, it is also preferable to add a filler to the ink receiving layer. The amount of addition is appropriately used within a range where transparency is not impaired in applications where transparency is required such as for OHP.

Examples of such a filler include silica, clay, calcium carbonate, barium sulfate, alumina white, aluminum hydroxide, talc, bentonite, titanium oxide and the like as inorganic particles, and polymethacrylic acid as organic fine particles. Fine particles composed of a thermosetting resin such as methyl, polystyrene, fluororesin type vinyl resin, polyolefin resin such as polyethylene and polypropylene, thermoplastic resin such as polyamide, polybenzoguanamine resin and urea resin, and having an average particle size of 0. .1 to 30 μm,
Preferably, the thickness is 0.1 to 20 μm. Then, it is usually contained in the ink receiving layer at a ratio of about 0.1 to 20 wt%. If this content is too small,
Insufficient transportability and blocking resistance can be obtained. O
In the case of a transparent image such as an HP image, on the contrary, if the content is too large, transparency is impaired.

As the filler to be contained in the ink receiving layer, for example, particles such as white carbon such as silicic anhydride, hydrous silicic acid, hydrous calcium silicate, and hydrous aluminum silicate known as colloidal silica, alumina sol, etc. When inorganic fine particles having a diameter of usually about 10 to 300 nm are used, the ink printed on the ink receiving layer is appropriately diffused, which is effective in forming a high quality image. Such inorganic fine particles are contained in the ink receiving layer in an amount of about 5 to 90 wt%. In the case of a transparent image such as an OHP, the content is slightly reduced, and in the case of an opaque image, there is also a meaning of providing whiteness, and the content is increased.

In addition, the ink receiving layer may include,
In addition to the above fillers, other resins other than those mentioned above, or surfactants, ultraviolet absorbers, antioxidants, PH adjusters, defoamers and other additives are appropriately mixed within a range not departing from the performance. Is also good.

The thickness of the ink receiving layer is usually 1 to 50 μm.
m, preferably about 3 to 20 μm. here,
If the thickness is too small, the dyeing properties will be insufficient, and the drying property and the anti-blocking property will be reduced. Conversely, if the thickness is too large, the cost will increase and the curl will increase.

The ink receiving layer is formed by coating a coating solution obtained by mixing the above-mentioned base agent and curing agent at an appropriate equivalent ratio on at least one surface of a support by a known coating method such as gravure coating, roll coating, wire bar coating and the like. What is necessary is just to apply by means.

The material for the support of the ink jet recording medium is not particularly limited. In general, any suitable mechanical rigidity is sufficient, and known materials can be suitably used. For example, a film or plate made of a resin such as polyethylene terephthalate, polyester such as polyethylene naphthalate, polyolefin such as polyethylene and polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polycarbonate, cellophane, cellulose acetate, polyarylate, and polyether sulfone. Can be used. If the inkjet recording medium is used for applications requiring transparency, such as for OHP, a transparent PET film, a rigid polyvinyl chloride film, a polypropylene film, a triacetate film, etc. are used. Also, a glass plate or the like can be used. On the other hand, if it is not a transparent image application such as OHP, an opaque support such as white may be used, and synthetic paper, high quality paper, art paper, coated paper, cast coated paper, paperboard, white PET film, etc. are also suitable. . In some cases, an aluminum-deposited PET film or the like can be used as appropriate.

The thickness of the support 2 is appropriately selected in consideration of the strength in accordance with the application and is not particularly limited.
It is about 200 μm. In addition, the surface of the support 2 may be subjected to a corona discharge treatment or a known easy adhesion treatment such as an anchor layer made of polyurethane resin or the like for the purpose of improving the adhesion of the ink receiving layer provided on the surface.

The aqueous ink that can be used in the ink jet recording medium of the present invention may be a known ink for ink jet, and is usually a water-soluble dye, a wetting agent, a dye solubilizer, a preservative, water, and a water-miscible ink. Organic solvent, etc.

[0035] In the ink jet recording medium of the present invention described above acts, by using a specific acrylic copolymer and a polyvinyl acetal resin was thermally cured resin in the ink receiving layer, wettability and dyeing properties and water Sex is compatible. The cation-modified portion of the acrylic copolymer to be cured and the hydroxy group of the polyvinyl acetal resin mainly have ink absorbency, while being cured by the polyepoxy compound, so that water resistance is obtained. No melting or stickiness occurs.

In particular, the monomer component of the acrylic copolymer is a quaternary ammonium salt of methyl methacrylate, ethyl acrylate, 2-hydroxyethyl methacrylate, and dimethylaminoethyl methacrylate. By making polyvinyl alcohol having a degree of conversion of 90% or more into acetal of 5 to 20 mol%, wettability, dyeing properties, and water resistance are compatible with a good balance.

[0037]

The present invention will be described below more specifically with reference to examples and comparative examples. In addition, "part" shown in the text is based on weight and solid content unless otherwise specified.

As a support, a polyethylene terephthalate film (trade name: Lumirror E63S, manufactured by Toray Industries, Inc.) having a surface with a thickness of 100 μm, which was easily adhered, was used. Was applied by bar coating so that the film thickness after drying was 15 μm, and dried at 120 ° C. for 3 minutes. As described above, the examples (<Example 1> to <Example 12>) and the comparative examples (<
Each sample of the inkjet recording medium corresponding to Comparative Examples 1 to 8) was obtained.

[0039]

[Table 1]

Here, the symbols in Table 1 and their contents are as follows. A: Cation-modified acrylic copolymer resin (trade name: Julimer SP-50TF, manufactured by Nippon Pure Chemical Co., Ltd.) B: Polyvinyl acetal resin (trade name: Esrec KX-1, manufactured by Sekisui Chemical Co., Ltd.) C: Polyvinyl Acetal resin (trade name; S-LEC KX-5, manufactured by Sekisui Chemical Co., Ltd.) X: glycerol polyglycidyl ether (trade name;
Denacol EX-314, manufactured by Nagase Kasei Kogyo Co., Ltd. Y: Polyglycerol polyglycidyl ether (trade name: Denacol EX-521, Nagase Kasei Kogyo Co., Ltd.)
And 10% 2-methylimidazole aqueous solution (3 parts) Solvent; water (240 parts), isopropyl alcohol (1 part)
60 parts).

Table 2 shows the results of printing and evaluation of each of the ink jet recording medium samples obtained as described above. In addition, each evaluation item and the judgment display of the result are as follows. Then, printing is performed by using a Canon inkjet printer (BJC-420J) to form a recorded image with four color inks of yellow, magenta, cyan, and black.

[0042]

[Table 2]

<Evaluation Items> [Ink Absorption] Immediately after printing, the outflow of ink when the recording portion of the recorded matter was rubbed with a finger was evaluated. ◎: Completely dried and did not flow out at all. ○: The recording section is slightly wet, though it does not flow out. Δ: A small amount of outflow is observed. ×: A large amount of outflow is observed.

[Water resistance (recording part)] Water was dropped on the recording part with a dropper and immediately wiped off lightly with gauze. A: Ink hardly flows out. ；: The ink slightly leaked, but there was no significant change in color tone. Δ: Ink spilled, and change in color tone was observed. ×: The coating film is dissolved, and the ink is also peeled off.

[Water resistance (unrecorded portion)] Water was dropped on the coating film with a dropper, and immediately wiped lightly with gauze. A: There is almost no damage to the coating film. ；: Slight damage to the coating film, but no problem in practical use. Δ: Dissolves in a part of the coating film. ×: Most of the coating film is dissolved.

<Overall Evaluation of Results> As is clear from the results shown in (Table 2), the ink jet recording media obtained in Examples 1 to 12 according to the present invention all have ink absorbency and water resistance. Was excellent. Furthermore,
Because of its excellent transparency, it had excellent suitability as an OHP sheet. On the other hand, all of the samples prepared as Comparative Examples 1 to 8 were inferior to the above Examples, and could not satisfy the objective performance of the present invention.

[0047]

As described above, according to the ink-jet recording medium and the method for manufacturing the same according to the present invention, an ink-jet recording medium and a method for manufacturing the same, which simultaneously satisfy the wettability and dyeability of the ink and the water resistance, are provided. Can be provided,
Further, since the transparency of the ink receiving layer is high, it is difficult to impair the transparency of the entire inkjet recording medium.
An inkjet recording medium and a method for manufacturing the same that can simultaneously satisfy performances sufficiently suitable for applications requiring high transparency, such as for a P sheet, can also be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of an ink jet recording medium according to the present invention using a cross-sectional view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ink jet recording medium 2 ... Support body 3 ... Ink receiving layer

Claims (8)

[Claims] 1. An ink-jet recording medium comprising, on at least one side of a support, an ink-receiving layer made of a resin obtained by thermosetting a mixture of a cation-modified acrylic copolymer and a polyvinyl acetal resin with an epoxy compound. . 2. The cation-modified acrylic copolymer according to claim 1, wherein the monomer component comprises at least methyl methacrylate, ethyl acrylate, and quaternary ammonium dialkylaminoethyl methacrylate. Ink jet recording medium. 3. The ink jet recording medium according to claim 1, wherein the cation-modified acrylic copolymer has a monomer having a substituent that reacts with an epoxy group. 4. The method according to claim 1, wherein the polyvinyl acetal resin comprises polyvinyl alcohol having a degree of saponification of 70 to 90%,
The inkjet recording medium according to claim 1, wherein the ol% acetal is formed. 5. The epoxy compound is an aliphatic compound,
The inkjet recording medium according to any one of claims 1 to 4, wherein the inkjet recording medium is water-soluble and is bifunctional or higher. 6. The ink jet recording medium according to claim 1, wherein the cation-modified acrylic copolymer and the polyvinyl acetal resin are dissolved in a mixed solvent of water and alcohol. 7. The ink jet recording medium according to claim 1, wherein the ink receiving layer contains a filler. 8. An ink receiving layer is formed by applying a coating liquid obtained by mixing a cation-modified acrylic copolymer, a polyvinyl acetal resin and an epoxy compound to at least one surface of a support, and then thermally curing the support. A method for manufacturing an ink jet recording medium, comprising: