JP2001301315A - Ink jet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording medium used for ink jet recording, which has the storage stability of an ink jet recording image and is so excellent in light resistance and environmental gas resistance that the fading and discoloring of the image especially due to light and environmental gas can be prevented from occurring. SOLUTION: In the ink jet recording medium, in which an ink accepting layer is provided on at least one side of a base material, the ink accepting layer includes a flavonoid compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium used in various ink jet recording apparatuses, and more particularly to a recording medium capable of obtaining a clear image and having excellent storage stability. The present invention relates to an inkjet recording medium.

[0002]

2. Description of the Related Art Inkjet printers have been increasingly used in recent years because of their features such as clearness of recording, quietness of sound, and ease of colorization. Ink jet printers must use ink that is difficult to dry in order to prevent clogging of the jet nozzle due to drying of the ink, and dissolve binders, dyes, solvents, additives, etc. in water as ink having such properties. Dispersed water-soluble inks are used. In general, a recording sheet having an ink receiving layer formed of a water-soluble resin such as polyvinyl alcohol and a pigment such as alumina or silica formed on a base material is used so that the ink is promptly absorbed by the surface and dried. Have been. However, images formed by ink-jet recording of characters, figures, etc. formed on recording paper using water-soluble inks gradually fade or discolor due to the effects of sunlight, ultraviolet rays, etc. Printed matter using oil-based ink,
At present, light resistance is inferior to silver halide photographic images.

[0003] In recent years, as ink-jet printers that are inexpensive and have sharpness and color are widely used, ink-jet recording paper is required to have recording characteristics and storage stability equivalent to silver halide photographs. There is a strong demand for improvement in light resistance against image quality deterioration due to sunlight or ultraviolet rays, and improving the light resistance of images is now an essential condition of ink jet recording paper.

[0004]

In view of this situation, many proposals have been made regarding the improvement of light resistance of resins, pigments and other additives used in the ink receiving layer. For example, improvement of light fastness including an antioxidant as an additive has been studied, and is disclosed in JP-A-07-195824 and JP-A-07-199524.
Ascorbic acid, as represented by -179797;
It has been proposed that the addition of an enzyme such as a monooxygenase to the ink receiving layer improves the light fastness. However, conventional proposals for improvement of light fastness, including the use of these antioxidants, do not yet provide sufficient light fastness and are inferior to silver halide photography.

The present inventor has conducted various studies on the storage stability of an ink-jet recorded image. As a result, the storage stability of the image has been improved in addition to the light resistance to sunlight and ultraviolet rays and the environmental gas (which has not been studied so far). (Ozone, nitrogen oxides, sulfur oxides, etc.), it is important to improve the deterioration of the image, that is, to improve the environmental gas resistance. Accordingly, the present invention provides an ink jet recording medium having excellent light fastness and environmental gas resistance, which can prevent the storage stability of an ink jet recorded image, in particular, fading and discoloration of the image due to light and environmental gas. The purpose is.

[0006]

Means for Solving the Problems The present inventor has made various studies in view of the above circumstances, and as a result, by including a specific antioxidant in the ink receiving layer, it has been possible to achieve an extremely effective method.
The inventors have found that the light resistance and environmental gas resistance of an image are improved, and have completed the present invention. That is, the present invention provides an ink jet recording medium having an ink receiving layer provided on at least one surface of a substrate, wherein the ink receiving layer contains a flavonoid compound. The flavonoid compound is preferably contained in the ink receiving layer in an amount of 0.05 to 20.0% by weight. Hereinafter, preferred embodiments according to the present invention will be described in detail.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The ink jet recording medium of the present invention has a layer constitution in which at least one ink receiving layer is provided on at least one surface of a substrate by a laminating means such as a coating method. There may be three or more layers. Hereinafter, the materials constituting the base material and the ink receiving layer will be described.

(1) Substrate The substrate used in the present invention is a chemical pulp such as LBKP and NBKP, GP, PGP, RMP, TMP, CTMP,
The main components are wood pulp such as mechanical pulp such as CMP and CGP, waste paper pulp such as DIP, and calcium carbonate,
Pigment such as kaolin, titanium dioxide, sizing agent, fixing agent, retention agent, cationizing agent, mixed with one or more additives such as paper strength enhancer, fourdrinier paper machine, round paper machine, Base paper manufactured by various devices such as a twin-wire paper machine, and further, the base paper is subjected to size press treatment with starch, polyvinyl alcohol, or the like, or processed base paper provided with an anchor coat layer, or provided with a coat layer thereon. Art paper,
Coated paper such as coated paper and cast coated paper is also included. Such base paper and coated paper may be provided with the ink receiving layer as it is, or a calender device such as a machine calender, a TG calender, or a soft calender may be used for the purpose of flattening the surface.

Further, as a substrate, a polyolefin resin layer may be provided on the base paper by coating or laminating. In addition, a film material of a synthetic resin such as polyethylene, polypropylene, polyester, nylon, rayon, polyurethane, or a mixture thereof, or a woven fabric or a nonwoven fabric formed by fiberizing these synthetic resins can be used as a base material.

(2) Ink-receiving layer The ink-receiving layer in the present invention is not particularly limited, and may be finely coated with a binder or the like by a paper machine size press or the like. Any material may be used, such as a material obtained by applying and drying a paint containing a pigment as a main component. That is, the ink receiving layer of the present invention needs to contain at least a flavonoid compound, and the flavonoid compound is formed by being dispersed in a binder, and a pigment and other additives are used as necessary. ing.

(A) Flavonoid compound The flavonoid compound used in the ink receiving layer of the present invention is a generic name of a group of compounds having a diphenylpropane structure represented by the following formula (1) as a basic skeleton, and glycosides thereof. Say something that includes

Embedded image

The flavonoid compounds are classified into chalcone, flavone, flavanols, flavonols, flavanones, anthocyanidins and the like, and various atomic groups such as gallic acid are bonded by ether bond or the like, and phenolic compounds are phenolic compounds. There are numerous derivatives in which a substituent such as a hydroxyl group is substituted, and these various compounds are appropriately used. Further, the glycoside is, for example, the above-mentioned formula (1)
And those in which a sugar is ether-bonded to the hydroxyl group bonded to the 3-position, and those in which the sugar is bonded to the hydroxyl group at the 7-position or 4′-position are not particularly limited. In addition, as a kind of sugar, glucose is large, and in addition, rhamnose, galactose, xylose, and the like are included.

Specific examples of the flavonoid compounds as described above include epicatechin, catechin, epigallocatechin,
Epicatechin gallate, epigallocatechin gallate, naringin, taxifolin, kaempferol, quercetin, rutin, myricetin, chrysin, apigenin, malvidin, cyanidin, apigenidine and the like.

In the present invention, among the above-mentioned flavonoid compounds, particularly preferred are flavanols, flavonols and flavanones which are derivatives having substituents such as phenolic hydroxyl groups capable of donating hydrogen and electrons, and particularly preferred are flavanols and flavonols. Are preferred, of which quercetin, rutin and catechin are preferred. In the present invention, the flavonoid compound is contained in the ink receiving layer paint.
It can be added in various forms such as dispersion, emulsification, and dissolution, and is appropriately selected in combination with the composition of the paint, the type of the solvent, and the additive. The amount of addition is not particularly limited, but is 0.05 to 20.0% by weight, preferably 0.5 to 20.0% by weight in the ink receiving layer.
10.0% by weight, particularly preferably 1.0 to 5.0% by weight
Is appropriate. If the amount is less than 0.05% by weight, the effect of storage stability cannot be obtained. If the amount is more than 20.0% by weight, the ink absorbency and the strength of the coating film may be reduced.

(B) Binder resin In the present invention, the binder resin contained in the ink receiving layer includes polyvinyl alcohol, vinyl acetate, oxidized starch, etherified starch, carboxymethyl cellulose,
Cellulose derivatives such as hydroxyethyl cellulose, water-soluble resins such as maleic anhydride resin, casein, gelatin, soy protein, silyl-modified polyvinyl alcohol; conjugated diene copolymers such as styrene-butadiene copolymer and methyl methacrylate-butadiene copolymer Copolymer latex; Acrylic polymer latex such as polymer or copolymer of acrylic ester and methacrylic ester; Vinyl polymer latex such as ethylene vinyl acetate copolymer; Thermosetting synthetic resin such as melamine resin and urea resin Water-based adhesives such as polymethyl methacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, alkyd resin, etc .; .

(C) Pigment In the ink receiving layer of the present invention, one or more pigments can be used for absorbing and drying the ink. Examples of pigments include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate,
Satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudo boehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrohaloisite, magnesium carbonate, magnesium hydroxide, etc. Examples include white inorganic pigments, styrene-based plastic pigments, acrylic-based plastic pigments, acrylic-based plastic segments, polyethylene, microcapsules, and organic pigments such as urea resins and melamine resins.

Among the above, as the white pigment contained in the ink receiving layer, porous inorganic pigments such as synthetic amorphous silica, magnesium carbonate, and alumina are used because of the excellent drying properties and absorbency of the inkjet ink. preferable.
Among these, the present invention particularly has an excellent effect on both printing quality and storage stability (water resistance, abrasion resistance, light resistance, environmental gas resistance, indoor storage stability, storage stability against direct sunlight). It is preferable to use sedimentation type and gel type synthetic amorphous silica having a surface area of about 200 to 600 g / m2.

(D) Other additives Furthermore, in the ink receiving layer, other additives such as a pigment separating agent, a thickening agent, a fluidity improving agent, an antifoaming agent, a foam inhibitor, a release agent, and a foaming agent. Agents, penetrants, coloring dyes, coloring pigments, optical brighteners, ultraviolet absorbers, antioxidants, preservatives, anti-binders, water-proofing agents, wet paper strength enhancers, etc., as necessary. You can also.

Next, a method for manufacturing the ink jet recording medium of the present invention will be described. The ink receiving layer is formed by dissolving or dispersing a material for forming the layer in water or a suitable solvent, and applying a coating liquid prepared by various blade coaters, roll coaters, air knife coaters, bar coaters, rod blade coaters. , A short dwell coater, a size press, and other various devices are appropriately used on-machine or off-machine to form a coating on a substrate.

The coating amount of the ink receiving layer is 5 to 50.
g / m2 is preferred, and particularly preferably 10 to 30 g / m2. If the coating amount is less than the above range, the ink absorbency and the fixability may not be sufficiently obtained, and if the coating amount is too large, the productivity is reduced and the cost is increased. The ink absorbing layer may be provided in a single layer or in two or more layers so as to have such a coating amount. When two or more ink receiving layers are laminated,
The flavonoid compound may be contained in any one of the ink receiving layers, or may be contained in a plurality of ink receiving layers.
Here, when the flavonoid compound is put in a plurality of ink receiving layers, the content of the flavonoid compound in each receiving layer is:
In order to achieve the effects of the present invention, it is desirable to keep the applied amount constant within the range of 0.05 to 20.0% by weight even if the applied amount fluctuates.

After the ink receiving layer is applied, the surface can be smoothed using a calender such as a machine calender, a TG calender, a super calender, or a soft calender to adjust the glossiness to a desired level.

The ink jet recording medium of the present invention has the above-mentioned structure. However, it is possible to increase the added value by laminating a glossiness adjusting layer on the surface of the ink receiving layer. This glossiness adjustment layer adjusts the glossiness to make high gloss paper,
Medium gloss paper, light gloss paper, etc. can be made separately. In addition, there is also an effect of preventing ink from being excessively soaked and improving optical density and saturation. As a material for the gloss adjusting layer, a mixed material of the binder resin and the pigment used in the ink receiving layer can be used as a coating liquid.

In order to laminate the gloss adjusting layer on the ink receiving layer, a cast coating method can be applied in addition to the coating method used for forming the ink receiving layer. Also,
After applying a coating liquid for a glossiness adjusting layer to a release film having a surface gloss such as a polyolefin resin film, a tetrafluoroethylene resin film, or a peelable silicon-processed resin film, the surface of the film is preliminarily undried. A method in which the ink receiving layer provided on the base material is overlaid and dried, and then the release film is peeled and removed can be applied. Furthermore, the ink receiving layer may be formed on a base material in advance, a release film may be stacked on the ink receiving layer, and the release film may be peeled off after drying.

The blending ratio of the binder resin and the pigment in the glossiness adjusting layer is preferably 5 to 50% by weight of the binder resin with respect to the pigment, from the viewpoint of maintaining the gloss.
0% by weight is more preferred. When high gloss paper having excellent gloss is used, it is preferable to use colloidal silica as a pigment. The thickness of the glossiness adjusting layer is preferably 5 to 12 μm, and 8 to 10 μm in order to maintain good glossiness without impairing the function of the ink receiving layer.
m is more preferable.

[0025]

Next, examples based on the present invention and comparative examples with respect to the present invention are shown to clarify the present invention. In each of Examples and Comparative Examples, the base material was 160 g / m2 in basis weight.
2, a high-quality paper having an air permeability of 50 seconds was applied to one surface of the substrate, and a coating liquid having the following composition (solid content: ink receiving layer: 00% by weight, glossiness adjusting layer: 00% by weight) was applied and dried. An ink receiving layer and a gloss adjusting layer were sequentially laminated to form an ink jet recording medium. The coating amount was 10 g / m2 after drying all layers. In the following description, “parts” means “% by weight (solid content)”.

<Example 1> [Ink receiving layer] Binder resin Partially saponified PVA (manufactured by Kuraray Co., trade name; PVA420) 30 parts Ethylene-vinyl acetate emulsion (Kuraray Co., trade name; OM5500) 16 parts Pigment ... Silica gel (manufactured by Mizusawa Chemical Co., Ltd., trade name: P78D) 40 parts Flavonoid: Quercetin (manufactured by Wako Pure Chemical Industries, Ltd.) 4 parts Other cationic dye fixing agent (manufactured by Sumitomo Chemical Co., Ltd., trade name: 784S) 10 parts [Glossy Degree adjusting layer] Binder resin Partially saponified PVA (trade name; T-330, manufactured by Nippon Synthetic Chemical Company) 5 parts Pigment colloidal silica (trade name, manufactured by Nissan Chemical Co., Snowtex UP) 95 parts

<Example 2> [Ink receiving layer] Binder resin Partially saponified PVA (trade name; PVA420, manufactured by Kuraray Co., Ltd.) 30 parts Ethylene-vinyl acetate emulsion (trade name, OM5500, manufactured by Kuraray Co., Ltd.) 16 parts Pigment ... Silica gel (manufactured by Mizusawa Chemical Co., Ltd., trade name; P78D) 40 parts Flavonoid: rutin (manufactured by Wako Pure Chemical Industries, Ltd.) 4 parts Other cationic dye fixing agent (manufactured by Sumitomo Chemical Co., Ltd., trade name: 784S) 10 parts [Glossy Degree adjustment layer] Binder resin Partially saponified PVA (trade name; T-330, manufactured by Nippon Synthetic Chemical Co., Ltd.) 5 parts Pigment colloidal silica (Nissan Chemical Co., trade name; Snowtex UP) 95 parts

<Comparative Example 1> [Ink receiving layer] Binder resin Partially saponified PVA (manufactured by Kuraray Co., trade name: PVA420) 31 parts Ethylene-vinyl acetate emulsion (Kuraray Co., Ltd .: OM5500) 17 parts Pigment: silica gel ( Mizusawa Chemical Co., Ltd., trade name; P78D) 41 parts Other cationic dye fixing agent (Sumitomo Chemical Co., Ltd., trade name; 784S) 11 parts Glossiness adjusting layer Binder resin: partially saponified PVA (Nippon Synthetic Chemical Company) 5 parts Pigment: silica sol (Nissan Chemical Industries: Snowtex UP) 95 parts

<Comparative Example 2> [Ink receiving layer] Binder resin Partially saponified PVA (Kuraray Co., trade name; PVA420) 30 parts Ethylene-vinyl acetate emulsion (Kuraray Co., trade name; OM5500) 16 parts Pigment ... Silica gel (manufactured by Mizusawa Chemical Co., Ltd., trade name: P78D) 40 parts Flavonoid: ascorbic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 4 parts Other cationic dye fixing agent (manufactured by Sumitomo Chemical Co., trade name: 784S) 10 parts [ Glossiness Control Layer] Binder Resin Partially Saponified PVA (Nippon Synthetic Chemical Company, trade name; T-330) 5 parts Pigment Colloidal Silica (Nissan Chemical Company, trade name; Snowtex UP) 95 parts

Four color patches of cyan, magenta, yellow, and black were applied to the ink jet recording media of the above Examples and Comparative Examples using a commercially available ink jet printer (trade name: PM-700C, manufactured by Seiko Epson Corporation). As a result of printing, clear color images were obtained on all recording media. Using these images, print density, gloss, light fastness, and environmental gas fastness were evaluated in the following manner.

The print density was measured by measuring the reflection density of each color using a spectrophotometer (trade name: SPM50, manufactured by Gretag Macbeth) to evaluate the image print density characteristics. The gloss is J
The 60-degree specular gloss of each color was measured according to the measurement method specified in IS Z8741.

The light resistance test was performed using a xenon weatherometer (trade name: Ci5000, manufactured by Atlas).
Black panel temperature 63 ° C, relative humidity 50%, 340n
m UV irradiation intensity 0.35W / m2, 30kJ
/ M2 exposure test. The density of each color after exposure was measured using a spectrophotometer (manufactured by Greta Macbeth: SPM50), and the density residual rate of the color having the lowest density residual rate was 90%.
The above is ○, the residual concentration ratio is 80 to 90%, and the residual concentration ratio is 8
Less than 0% was evaluated as x.

The environmental gas resistance test was conducted at a temperature of 25 ° C. and a humidity of 6
A print sample was placed in a 0% glass container, and allowed to stand in a container into which ozone was introduced from an ozone generator so as to have a concentration of 70 ppm for 24 hours, and then a spectrophotometer (trade name, manufactured by Gretag Macbeth, trade name; The density of each color was measured using SPM50), and the density remaining rate of the color having the lowest density remaining rate was 90%.
The above is ○, the residual concentration ratio is 80 to 90%, and the residual concentration ratio is 8
Less than 0% was evaluated as x.

The evaluation results are as shown in Table 1. All the ink jet recording media of the present invention can provide clear images having good print density and glossiness, and have excellent light resistance and environmental gas resistance. Had. On the other hand, since the flavonoid compound was not used in the ink jet recording medium of Comparative Example, it was inferior in light resistance and environmental gas resistance.

[0035]

[Table 1]

[0036]

By including a flavonoid compound in the ink receiving layer, it is possible to prevent a decrease in print density and glossiness and a change in color tone of an image recorded on an ink jet recording medium due to the influence of sunlight or environmental gas. ,
An ink jet recording medium having greatly improved storage stability of a recorded image can be obtained. Therefore, it can be used for a wide range of applications such as long-term storage materials and posters such as posters.

Continued on the front page (72) Inventor Kazushige Katagiri 3-1 Yosoba Tomoe-cho, Shizuoka-shi, Shizuoka Prefecture Inside the Paper Division of Hamakawa Paper Mills Co., Ltd. (72) Inventor Sumiichi Tatsuhashi 3 Yoyo-sombe-cho, Shizuoka-shi, Shizuoka No. 1 Inside the Paper Division of the Hamakawa Paper Mill Co., Ltd. (72) Inventor Kiyoshi Iwamoto No. 3-1 Yomibacho, Shizuoka City, Shizuoka Prefecture F-term in the Paper Division of the Hamakawa Paper Mill Co., Ltd.

Claims (3)

[Claims] 1. An ink jet recording medium provided with an ink receiving layer on at least one surface of a substrate, wherein the ink receiving layer contains a flavonoid compound. 2. The ink jet recording medium according to claim 1, wherein the flavonoid compound is contained in the ink receiving layer in an amount of 0.05 to 20.0% by weight. 3. The ink jet recording medium according to claim 1, wherein the flavonoid compound is at least one compound selected from flavonols, flavanols and flavanones.