JPH11321083A - Ink jet recording medium and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording medium, in which the wettability and dyeing property of ink and resistance to water are made compatible while favorable for a usage demanding transparency such as a copy sheet for OHP, and provide also manufacturing method thereof. SOLUTION: An ink jet recording medium is characterized in an ink receptor layer, provided on a substrate and coating composition, constituting the ink receptor layer, is provided with both of a photo curable constituent and thermosetting constituent whereby capable of being cured by light and heat while the coating composition constituting the same, is constituted of at least an acrylic copolymer, a polyfunctional monomer and a photopolymerization initiator.

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 having an excellent wettability and absorptivity.
The present invention relates to a recording medium having both 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.

[0004]

However, a structure in which an ink receiving layer is provided on a support such as a plastic film or the like has not been able to obtain satisfactory performance. That is,
In order to improve the wettability, dyeing properties, or absorbability of the slow-drying ink, a method of forming the ink receiving layer from a water-soluble resin, a hydrophilic resin, or the like has been proposed. Or the ink receiving layer becomes wet and sticky in an environment of high humidity, and there is a problem that blocking occurs when the recording media are stacked, or that the ink is poorly dried and easily stained when touched by hand after printing. . The wettability, the dyeing property and the absorptivity and the water resistance, the drying property and the blocking resistance are properties that are contradictory to each other, and a satisfactory performance satisfying these properties has not been obtained.

[0005] In the recording medium using the non-water-absorbing support as described above, satisfactory performance has not been obtained even if the layers such as the ink receiving layer are devised. The present invention has been made in view of the conventional technology, first, to provide an ink jet recording medium and a method for manufacturing the ink jet recording medium that can achieve both wettability and dyeing of the ink, and water resistance, O
It is an object of the present invention to provide an ink jet recording medium suitable for applications requiring transparency, such as a document sheet for HP, and a method for manufacturing the same.

[0006]

Means for Solving the Problems The present invention has been made to achieve the above object, and the invention according to claim 1 is provided with an ink receiving layer on at least one surface of a support, wherein the ink receiving layer is provided. An ink jet recording medium characterized in that the coating composition forming the receiving layer has both a photocurable component and a thermosetting component, and is curable by light and heat.
According to this, by curing with light and heat, it is possible to maintain a good balance between the ink absorbency and the water resistance of the ink receiving layer.

According to a second aspect of the present invention, based on the ink jet recording medium according to the first aspect, the coating composition forming the ink receiving layer comprises at least an acrylic copolymer, a polyfunctional monomer, and a photopolymerization initiator. It is characterized by the following. According to this, an ink receiving layer having excellent transparency can be obtained.

A third aspect of the present invention is based on the ink jet recording medium according to the second aspect, wherein the monomer component of the acrylic copolymer in the coating composition for the ink receiving layer is at least:
It is characterized by comprising a quaternary ammonium salt of dialkylaminoethyl (meth) acrylate as a dye fixing component, and alkoxy (meth) acrylamide as a thermosetting component.
According to this, the dyeability of the inkjet ink can be improved by including a cationic group in the acrylic copolymer in the ink receiving layer, and the water resistance can be improved by including a thermosetting component.

A fourth aspect of the present invention is based on the ink jet recording medium according to the second or third aspect, wherein the polyfunctional monomer of the ink-receiving layer coating composition has a (meth) acryloyl group, It is characterized by comprising an aliphatic monomer or oligomer having two or more radically polymerizable groups such as a (meth) acrylamide group or a vinyl group. According to this, having two or more radically polymerizable groups greatly contributes to water resistance due to crosslinking during photocuring.

[0010] The invention of claim 5 is based on the ink jet recording medium according to any one of claims 2 to 4, wherein the photopolymerization initiator of the ink receiving layer coating composition is soluble in water and an alcohol solvent. It is characterized by the following. This is because the acrylic copolymer and polyfunctional monomer of the ink receiving layer coating composition are mainly dissolved in water and alcoholic solvents,
Indispensable.

According to a sixth aspect of the present invention, an ink-receiving layer is formed on a support by applying and drying a composition having a light-curing and thermosetting component and being cured by light and heat on the support. A method for manufacturing an ink jet recording medium. According to this, it is possible to obtain an ink jet recording medium capable of maintaining a good balance between the ink absorbency and the water resistance of the ink receiving layer by curing with light and heat.

[0012]

In order to solve the above-mentioned problems and to achieve the object, the ink jet recording medium of the present invention has an ink receiving layer on at least one surface of a support, and forms the ink receiving layer. The present inventors have found that an ink jet recording medium exhibiting excellent performance in both formed image and water resistance can be obtained when the coating composition has light-curing and heat-curing components, and the present invention has been completed.

The cation-modified part of the acrylic copolymer of the ink receiving layer coating composition of the present invention is preferably an acrylic monomer having a quaternary ammonium base, such as dimethylaminoethyl (meth) acrylate or diethylamino (meth) acrylate. A) a (meth) acrylate monomer having a tertiary amino group such as acrylate, diethanolamino (meth) acrylate, dipropylamino (meth) acrylate, dipropanolamino (meth) acrylate, dibutylamino (meth) acrylate; And quaternized monomers.

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 a 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.

In the thermosetting portion of the acrylic copolymer, an acrylic monomer having an alkoxyamide group capable of self-crosslinking by heat is desirable. For example, N-methylolacrylamide, N-methoxymethylacrylamide, N-ethoxymethyl Examples include monomers such as acrylamide, N- (n-propoxymethyl) acrylamide, and N- (n-butoxymethyl) acrylamide.

The polyfunctional monomer of the ink receiving layer coating composition is a monomer or oligomer having a UV-curable group such as a (meth) acryloyl group, a (meth) acrylamide group or a vinyl group in the molecule. Having a hydrophilic group such as a hydroxyl group, a carboxyl group, an amide group, a sulfone group, an ammonium group, a phosphate group, or a polyethylene glycol group, which itself is water-soluble or water-dispersible, for example, polyethylene glycol (Meth) acrylate, polyethylene glycol di (meth) acrylamide, polyethylene glycol diglycidyl di (meth) acrylate, glycerin poly (meth)
Acrylate, self-emulsifying acrylate emulsion,
Self-emulsifying polyester acrylate emulsions and the like can be mentioned.

Other polyfunctional monomers other than those described above include those which themselves are not water-soluble or water-dispersible, but are made water-dispersible by adding a surfactant and stirring vigorously (forced emulsion). For example, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol dimethacrylate, 1,1
A water dispersion is obtained by adding a surfactant to 0-decanediol dimethacrylate, diethylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane triacrylate, polyester acrylate, urethane acrylate, etc., and vigorously stirring to form a water dispersion. The above polyfunctional monomers can be used in combination of two or more.

The photopolymerization initiator to be added to the ink receiving layer coating composition includes, for example, thioxanthone, benzoin, benzoin alkyl ether xanthone, dimethylxanthone, benzophenone, anthracene, benzyl, 2,2-diethoxyacetophenone, benzyl Methyl ketal, diphenyl disulfide, anthraquinone, 1-chloroanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, N,
One or more photopolymerization initiators such as N'-tetraethyl-4,4'-diaminobenzophenone and 1,1'-dichloroacetophenone are used.

These need to be dissolved in a hydrophilic solvent and added to the coating composition, or a water-soluble or water-dispersible one must be selected. The amount of the photopolymerization initiator used is desirably adjusted within the range of 0.2 to 10% by weight, preferably about 0.5 to 5% by weight of the whole composition.

Further, in order to promote curing in addition to such a photopolymerization initiator, for example, triethanolamine,
Tertiary amines such as 2-dimethylaminoethanol, dimethylaminobenzoic acid, isoamyl diethylaminobenzoate, dioctylaminobenzoic acid, lauryl dimethylaminobenzoate may be blended in an amount of about 0.05 to 3% by weight of the whole composition. it can.

The ink receiving layer coating composition as described above comprises:
Each is used as a coating liquid of a 10 to 50% by weight solution of one or more mixed solvents such as water, methanol, ethanol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, toluene, and xylene. .

It is preferable to add a filler to the ink receiving layer in order to improve transportability and blocking resistance. The amount of addition should be within a range that does not impair the transparency for use in transparent images such as OHP.

Examples of the filler include organic fine particles such as polymethyl methacrylate, polyvinylpyrrolidone, polystyrene, fluororesin vinyl resins, polyolefin resins such as polyethylene and polypropylene, and thermoplastic resins such as polyamides. , A fine particle made of a thermosetting resin such as a polybenzoguanamine resin or a urea resin, having a particle size of 0.1 to 30 μm, preferably 0.1 to 20 μm.
μm. These are usually contained in the ink receiving layer in an amount of about 0.1 to 20 wt%. If the amount is too small, sufficient transportability and blocking resistance cannot be obtained. OHP
In the case of a transparent image such as that described above, if the content is too large, the transparency is impaired.

The inorganic fine particles include clay, calcium carbonate, barium sulfate, aluminum hydroxide, talc, bentonite, titanium oxide, etc., and silicic anhydride, hydrous silicic acid, hydrous calcium silicate, and hydrous calcium oxide known as colloidal silica. The use of inorganic fine particles having a particle size of usually about 10 to 300 nm, such as white carbon such as aluminum silicate or alumina sol, diffuses the ink printed on the ink receiving layer appropriately and is effective in forming high quality images.
Such inorganic fine particles are used in the ink receiving layer in an amount of 5 to 90 watts.
About t% is contained. 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 have, depending on the purpose,
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 from 1 to 50 μm.
m, preferably about 3 to 20 μm. 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 main 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, or the like. What is necessary is just to apply by means.

Examples of the support for the ink jet recording medium include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polycarbonate, cellophane, cellulose acetate, and polyacrylate. A film or plate made of a resin such as polyether sulfone can be used. OH inkjet recording medium
If it is used for P, a transparent film, especially, a polyethylene terephthalate film, a hard polyvinyl chloride film, a polypropylene film, a triacetate film, or the like is used. Also, a glass plate or the like can be used. On the other hand, O
Unless it is used for a transparent image such as HP, an opaque support such as white may be used, and various papers such as synthetic paper, high-quality paper, art paper, coated paper, cast coated paper, and paperboard may be used.

The thickness of the support is appropriately selected in consideration of the strength in accordance with the use and is not particularly limited.
It is about 00 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 is a known ink jet ink, and is usually a water-soluble dye, a wetting agent, a dye solubilizing agent, a preservative, water, and a water-miscible ink. It consists of an organic solvent and the like.

<Function> As described above, the ink jet recording medium of the present invention has an ink receiving layer on at least one surface of the support, and the ink receiving layer coating composition has photocurable and thermosetting components. Then, by curing with light and heat, an ink jet recording medium having excellent performance in both formed image and water resistance can be obtained.

[0032]

The present invention will be described below more specifically with reference to examples and comparative examples. In the description, "parts" are based on weight and solids unless otherwise specified.

<Synthesis Example 1> In a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser, 12 g of methyl methacrylate and a quaternized dimethylaminoethyl methacrylate (DQ-100, Kyoeisha Co., Ltd.) 18 g of N- (n-butoxymethyl) acrylamide (NBMA, manufactured by Nitto Riken Kogyo) was introduced, and 100 g of distilled water and 1 g of isopropyl alcohol were introduced.
The mixture was dissolved by adding 00 g, and the mixture was stirred on a 60 ° C. oil bath under a nitrogen stream. Add 2 grams of 2,2'-azobis (2
-Methylpropionamidine) dihydrochloride (V
-50, manufactured by Wako Pure Chemical Industries, Ltd.) to initiate polymerization. The mixture was heated and stirred in a 60 ° C. oil bath for 3 hours, and the solvent was distilled off. I got

<Synthesis Example 2> In a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser, tetrahydrofurfuryl acrylate (biscoat # 150,
10 g of Osaka Organic Chemical Industry, 17 g of quaternized dimethylaminoethyl methacrylate (DQ-100, manufactured by Kyoeisha Chemical), and 23 g of N-methoxymethylacrylamide (NMMA, manufactured by Nitto Riken Kogyo) were introduced. 100 grams of distilled water, 10 isopropyl alcohol
0 g was added and dissolved, and the mixture was stirred on a 60 ° C. oil bath under a nitrogen stream. Add 2 grams of 2,2'-azobis (2-
Methylpropionamidine) dihydrochloride (V-
50, manufactured by Wako Pure Chemical Industries, Ltd.) to initiate polymerization, and the mixture was heated and stirred on a 60 ° C. oil bath for 3 hours, the solvent was distilled off, and the residue was dried under reduced pressure to obtain an acrylic copolymer B. Obtained.

<Examples 1 to 12> As a support, 100
A polyethylene terephthalate film (trade name: Lumirror E63S, manufactured by Toray Industries, Inc.) having a surface with a thickness of μm easily treated for adhesion, and an aqueous coating composition having the composition shown in Tables 1 and 2 below Was applied by bar coating so that the film thickness after drying was about 10 μm.
After drying for 3 minutes, photocuring was performed under a high-pressure mercury lamp of 120 W, and thermal curing was further performed at 120 ° C. for 5 minutes to obtain an ink jet recording medium.

A full-color image was formed on this recording medium using an ink jet printer (BJC-420J, manufactured by Canon Inc.).

<Comparative Examples 1 to 3 and Comparative Examples 5 to 7> An ink jet recording medium was obtained in the same manner as in the above example, except that no thermal curing was performed.

<Comparative Examples 4 and 8> An ink jet recording medium was obtained in the same manner as in the above example, except that photocuring was not performed.

[0039]

[Table 1]

However, P: IRGACURE 184 (manufactured by Ciba-Geigy) was added so as to be 2% of the total solids. Solvent: 2-methoxyethanol, prepared as a coating solution having a solid content of about 20%.

[0041]

[Table 2]

The following items were evaluated for the ink jet recording medium obtained as described above. The evaluation results are shown in Table 3.

<Ink Absorbency> 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 at all. ；: The recording part 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 lightly with gauze. A: Ink hardly flows out. ；: Ink slightly leaked, but no significant change in color tone. Δ: Inflow of ink and change in color tone are observed. ×: Most of the ink flows out. ●: Dissolves the entire coating film.

<Water resistance (unrecorded portion)> Water was dropped on the coating film with a dropper and immediately wiped off 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.

[0046]

[Table 3]

[0047]

As described in detail above, according to the present invention, the ink jet recording medium has an ink receiving layer made of a photo-curable and heat-curable coating composition,
By curing the receptor layer with light and heat, it was possible to obtain an ink jet recording medium having excellent performance in both recorded images and water resistance and a method for producing the same.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yuka Tada 1-5-1, Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd.

Claims (6)

[Claims] An ink receiving layer is provided on at least one surface of a support, and a coating composition forming the ink receiving layer has both a photocurable component and a thermosetting component, and is curable by light and heat. An ink jet recording medium characterized by the above-mentioned. 2. The ink jet recording medium according to claim 1, wherein the coating composition for the ink receiving layer comprises an acrylic copolymer, a polyfunctional monomer, and a photopolymerization initiator. 3. A method according to claim 1, wherein the monomer component of the acrylic copolymer comprises at least a quaternary ammonium salt of dialkylaminoethyl (meth) acrylate as a dye fixing component and an alkoxy (meth) acrylamide as a thermosetting component. The ink jet recording medium according to claim 2, wherein 4. The method according to claim 1, wherein the polyfunctional monomer has (meth)
4. The ink-jet printer according to claim 2, comprising an aliphatic monomer having two or more radical polymerizable groups such as an acryloyl group, a (meth) acrylamide group, or a vinyl group, and an oligomer. recoding media. 5. The ink jet recording medium according to claim 2, wherein said photopolymerization initiator is soluble in water and an alcohol solvent. 6. An ink-receiving layer is formed on a support by applying a light- and heat-curable composition having a light-curing and heat-curing component on a support and drying the composition. Of producing an inkjet recording medium.