JP2002211108A - Inkjet recording paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording paper, in which the deterioration of a recorded image by ambient gas is prevented from developing and which has an excellent image preservability. SOLUTION: In the ink jet recording paper, in which an ink accepting layer is provided on at least one side of a support, the ink accepting layer includes at least silica and two kinds or more of cycloamyloses.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet mainly using an aqueous ink, and more particularly to an ink jet recording sheet having high environmental gas resistance and excellent storage stability.

[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. This ink jet printer needs to use an ink that is difficult to dry in order to prevent clogging of the jet nozzle due to drying of the ink, and therefore, an aqueous solution in which binders, dyes, solvents, additives, etc. are dissolved or dispersed in water. Inks are commonly used. However, images and the like formed on a recording medium using this water-based ink are susceptible to the storage environment, and the degree of image deterioration such as reduced image clarity, reduced density, and change in color tone uses pigment-based ink. At present it is larger than printed matter and silver halide photographs.

In recent years, as ink jet printers have become inexpensive and their sharpness and color have become familiar, the demands for image storability and the like have been gradually increased and become stricter. Therefore, it is now an essential condition of the inkjet recording paper to completely prevent deterioration of the recorded image due to the storage environment of these images. With respect to the prevention of deterioration in such a storage environment, a mordant or the like is added to the ink receiving layer for humidity, and for light,
Many methods such as adding an antioxidant have been proposed.

Further, in recent years, deterioration of recorded images due to environmental gases derived from daily activities such as ozone, nitrogen oxides, sulfur oxides, formalin, and ammonia contained in the air outdoors and indoors has been regarded as a problem. It has become. In particular, an ink-jet recorded image is strongly affected by ozone gas emitted from an electric device or the like, and significantly deteriorates image quality. Therefore, the ozone resistance of the recorded image is particularly important.

[0005]

However, at present,
Almost no study has been made on countermeasures against image degradation due to these environmental gases, and no effective preventive measures have been taken. Accordingly, an object of the present invention is to provide an ink jet recording sheet which prevents deterioration of a recorded image due to environmental gas and has excellent image storability.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to prevent deterioration of a recorded image due to environmental gas.
2 different in polymerization degree from silica at least in the ink receiving layer
It has been found that by including more than one type of cycloamylose, deterioration of the recorded image due to environmental gas, particularly ozone gas, which has the greatest influence, can be prevented, and excellent image storability can be obtained.

Some ink jet recording papers containing cycloamylose in the ink receiving layer have been reported so far, but these are not intended to prevent deterioration of the recorded image due to environmental gas. This is different from the present invention in which excellent environmental gas resistance is obtained by using two or more types of cycloamylose. Specifically, JP-A-11-286172 discloses a recording sheet containing cycloamylose as an essential component in addition to the main pigment, alumina sol and a gelling agent, for the purpose of improving light resistance. However, in this recording sheet, the gelling agent extremely lowers the ink absorbency of the ink receiving layer, causing a significant deterioration in the quality of the recorded image, and alumina sol is more environmentally friendly than silica. Therefore, it is difficult to satisfy both the required quality of the recorded image and the required storage stability because the storage stability of the recorded image tends to deteriorate.

Japanese Patent Application Laid-Open No. 11-263065 proposes an ink jet recording sheet using cycloamylose and surfactants in combination for the purpose of improving the wetting characteristics of the ink receiving layer. However, in the configuration of the recording sheet, cycloamylose acts on the binder and is consumed, and the combined use of a surfactant tends to reduce the effect of cycloamylose on the environmental gas. During the process, phenomena such as remarkable foaming may be caused, and the production efficiency may be reduced. Furthermore, surfactants have problems such as deterioration of light resistance of recorded images, and it has been difficult to obtain good storage stability of recorded images.

Therefore, the ink jet recording paper of the present invention is an ink jet recording paper provided with an ink receiving layer on at least one surface of a support, wherein the ink receiving layer has
It is characterized by containing at least silica and two or more types of cycloamyloses.

The cycloamylose in the present invention is preferably a mixture of cycloheptaamylose or a derivative thereof and cyclooctamylose or a derivative thereof, and the cycloamylose in the present invention is preferably cyclohexylamylose or a derivative thereof. It is preferable to use a mixture of three kinds of saamylose or a derivative thereof, cycloheptaamylose or a derivative thereof, and cyclooctaamylose or a derivative thereof.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The ink jet recording paper of the present invention has a layer structure in which at least one ink receiving layer is provided on at least one surface of a support by laminating means such as a coating method. The support may be on one side or both sides, or may be two or three or more layers. Further, a gloss adjusting layer adjusted to an appropriate gloss may be provided on the ink receiving layer. Hereinafter, materials constituting the support, the ink receiving layer, and the glossiness adjusting layer, a coating method, and the like will be described.

The support used in the present invention is LB
Chemical pulp such as KP, NBKP, GP, PGW, RM
Based on mechanical pulp such as P, TMP, CTMP, CMP and CGP, wood pulp such as waste paper pulp such as DIP, and synthetic fiber pulp such as polyethylene fiber, pigment and sizing agent, fixing agent, retention improver, paper One or more of various additives commonly used in papermaking, such as a force enhancer, may be used and mixed, if necessary, into a fourdrinier paper machine, a round paper machine,
It can be used for base paper manufactured by various devices such as a twin-wire paper machine, base paper obtained by size-pressing starch, polyvinyl alcohol, casein, gelatin, etc., base paper provided with an anchor coat layer, and photographic paper. Coated paper such as a baryta-coated coated paper, cast coated paper, or the like can be used. Further, resin-coated paper obtained by extruding a polyolefin resin such as a polyethylene resin or a polypropylene resin onto the base paper or coated paper by an extrusion coating method or the like can also be used.

The base paper and the coated paper may be provided with an ink receiving layer as it is. Further, in order to make a recording medium produced by using this support to have a more photographic paper feel, It is also possible to use a material in which the smoothness of the support and the coating property of the ink receiving layer are improved by using a calender such as a machine calender, a TG calender, and a soft calender at the stage before the layer coating.

Examples of pigments used in general ink-jet recording paper include alumina, silica, calcium carbonate and the like, which have a property of adsorbing and carrying a dye. Among these, alumina and silica are particularly suitable for ink absorption and recording. It is excellent in sharpness of color development and image density of an image, and is widely used. However, in the present invention, it is an essential condition that silica is used as a main pigment and that it is combined with two or more types of cycloamyloses. Both can be satisfied. On the other hand, in the case of alumina, the storage stability of a printed image, in particular, is inferior in light resistance. Therefore, even if alumina is used as the main pigment and used in the ink receiving layer in combination with cycloamylose, satisfactory light resistance can be obtained. Can not.

The silica used as the main pigment in the ink receiving layer of the present invention includes silica such as gel type silica, precipitated type silica, fumed silica, colloidal silica and the like, and the surface of these silica pigments is modified with a surface modifier. These surface-treated silicas can be used alone or in combination of two or more. When using a surface-treated silica which tends to deteriorate light resistance, for example, silica modified with an alumina component, it is necessary to determine the amount of modification of the silica surface in consideration of the degree of light resistance.

As the cycloamylose used in the present invention, D-glucose forms a cyclic bond by α1 → 4 bond, for example, cyclohexamylose having a degree of polymerization of 6 in which 6 molecules of D-glucose are bonded, 7 molecules of D-glucose are bonded. Cycloheptaamylose having a degree of polymerization of 7 and a degree of polymerization of 8 molecules bonded
Of cyclooctamylose. Also, D
Cycloamylose to which 9 or more glucose molecules are bound can also be used without distinction. Further, as a derivative of cycloamylose, a derivative in which the above-mentioned cycloamylose is substituted with a (substituted) alkyl group such as a hydroxy-substituted alkyl group or a methyl group, or a monosaccharide such as allose, glucose, glucose, and galactose , Lactose, oligosaccharides such as disaccharides or monosaccharides such as sucrose linked by three or more glycosidic bonds, oxidized sugars such as gluconic acid, amino sugars such as glucosamine,
A sugar having both a carboxyl group and an amino group such as sialic acid, a derivative in which a deoxy sugar such as deoxyribose is bonded, an oxirane group, an ethyleneimine group, and a vinyl polymerizable vinyl group are bonded to cycloamyloses. Can be used, or a cycloamylose polymer obtained by polymerizing or copolymerizing with another monomer can be used.

It is presumed that the effect of cycloamylose on the present invention is caused by the inclusion of a part or all of the dye in the ink in the hollow part of the cyclic structure of cycloamylose. Regarding the interaction of cycloamyloses, the inclusion compound is emulsified, solubilized, stabilized,
It is widely used in the fields of food and medicine because of its effects such as antioxidation.

In the present invention, various kinds of recorded images can be formed by mixing and using two or more kinds of cycloamyloses having different degrees of polymerization, ie, having different hollow portions in the cyclic structure of cycloamyloses. It is possible to protect the dye molecules in a well-balanced manner and prevent image deterioration due to environmental gas.

The reason why the environmental gas resistance is improved when two or more cycloamyloses are used is not clear, but is considered as follows. In other words, when cycloamyloses are used for ink jet recording paper, when the dye molecules in the ink reach the ink receiving layer during printing, the dye molecules undergo the interaction of the cycloamyloses and are protected from chemical changes due to environmental gas. It is thought that. However, since the types of functional groups and the three-dimensional structures of the cyan, magenta, and yellow dye molecules that form an image differ from one dye to another, each type of cycloamylose with a single degree of polymerization has all of these dye molecules. It is presumed that it is difficult to protect from environmental gas in a balanced manner.

In general, since the types and blending ratios of the dyes differ depending on the brand of the ink, the types, the amounts and the mixing ratios of the two or more cycloamyloses used in the present invention depend on the dye molecules of the ink used for recording. However, in the present invention, it is particularly preferable to use a mixture of two kinds of cycloheptaamylose or a derivative thereof and cyclooctaamylose or a derivative thereof. More preferably, it is preferable to use a mixture of three kinds of cyclohexamylose or a derivative thereof, cycloheptaamylose or a derivative thereof, and cyclooctaamylose or a derivative thereof. By using these cycloamyloses in combination,
Regardless of the type of ink, storage stability of a relatively versatile recorded image with respect to environmental gas can be ensured.
In addition, the amount of the cycloamylose used in the present invention is preferably 0.1% by weight or more, and preferably a binder or an additive that affects the cycloamylose used in the ink receiving layer. 0.3% by weight or more is preferred.

Further, when a surfactant is contained in the ink receiving layer, the hydrophobic portion of the surfactant is included in cycloamylose, and the effect of cycloamylose, which is the object of the present invention, is lost. It is preferable not to use a relatively low molecular weight additive having a hydrophobic portion such as a surfactant. When such an additive is used, it is necessary to increase the amount of the cycloamylose used so that the effect is sufficiently exhibited, and the amount of the cycloamylose used depends on the type and amount of the additive. Need to decide.
In addition, since the cycloamylose is included in the hydrophobic portion of the binder used in the ink receiving layer, the same consideration as in the above additive is required.

As the binder used in the present invention, water-soluble polymers used in the field of coated paper can be used without particular distinction.
Acid-modified polyvinyl alcohol, polyvinyl alcohols such as silanol-modified polyvinyl alcohol, starches such as starch, oxidized starch, etherified starch, and cationized starch, celluloses such as carboxymethyl cellulose, vinyl acetate, polyvinyl pyrrolidone, polyacrylamide, poly (Meth) acrylic acid and poly (meth) acrylic acid-2
Water-soluble polyacrylic acid resin such as hydroxyethyl,
It is preferable to use maleic anhydride resin, gelatin, casein, soybean protein, etc. alone or in combination of two or more.

Binders such as polymer emulsions, latexes and suspensions used in the field of coated paper can be used without particularity. In particular, styrene-butadiene copolymer, (meth) acrylate-butadiene Vinyl acetate such as a conjugated diene copolymer latex such as a copolymer, a vinyl acetate polymer or a copolymer of vinyl acetate and a vinyl polymerizable monomer having a functional group such as a carboxyl group, an amino group or a hydroxyl group; Acrylic polymer emulsions such as polymer-based emulsions, (meth) acrylic acid ester polymers or copolymers thereof with vinyl polymerizable monomers having a functional group such as a carboxyl group, an amino group or a hydroxyl group; ethylene Polyolefin polymers such as vinyl acetate copolymers and ethylene vinyl alcohol copolymers It is preferred to use alone or in combination of two or more and the like.

As the dye fixing agent, a polyamine resin having an amino group or a substituted amino group and a cationic resin having a quaternary ammonium group can be used. Further, as other additives, an ultraviolet absorber,
Antioxidants, water-soluble metal salts, pigment dispersants, thickeners, flow improvers, defoamers, defoamers, release agents, foaming agents, penetrants,
Coloring dyes, coloring pigments, optical brighteners, preservatives, fungicides,
Antibacterial agents, water-proofing agents, hardeners and the like can be used as required.

The coating method of the coating liquid for forming the ink receiving layer in the present invention includes a commonly used blade coater, air knife coater, roll coater, brush coater, curtain coater, bar coater, gravure coater, die coater. And a sprayer.

Coating amount of coating liquid for forming ink receiving layer
Is 0.5 to 50 g / m in terms of dry solid content.²In the range
It is preferable in terms of ink absorbency. In addition, 5g
/ M²Above, sufficient ink absorption speed can be secured
Particularly preferred for this purpose, 40 g / m ²If below, ink
It has no decrease in adhesive strength such as powder dropping on the surface of the receptor layer.
Preferred.

If necessary, a gloss adjusting layer may be provided on the ink receiving layer, that is, on the outermost surface. This glossiness adjustment layer is obtained by a 60-degree specular glossiness test method.
The glossiness is preferably 10 or more. As a method for forming the glossiness adjustment layer, a method such as a mirror surface drum casting method generally used in the field of coated paper can be used.

[0028]

EXAMPLES Examples and comparative examples based on the present invention will be described.
The effect of the present invention will be clarified. In each of Examples and Comparative Examples, a coating liquid prepared by dissolving and dispersing the materials shown in Table 1 in water was coated with an air knife coater to obtain a basis weight of about 90 g /
applied to the surface of woodfree paper having m ^2, dried, coating weight 10 g / m
² ink receiving layers were formed.

[0029]

[Table 1]

The ink jet recording paper obtained in each of the Examples and Comparative Examples was printed with a standard image or an image for evaluation such as a color patch using a commercially available ink jet printer (trade name: PM800C, manufactured by Seiko Epson Corporation). As a result, printed images having good image quality were obtained. Using these images, image storability was evaluated by the following method, and the results are shown in Table 1.

<Ozone resistance> For each evaluation image, an ozone weather meter (trade name: OMS-HVCR, manufactured by Suga Test Instruments Co., Ltd.) was used at a temperature of 25 ° C. and a relative humidity of 50.
% And an ozone concentration of 20 ppm for 1 hour. After that, a spectroscopic altimeter (trade name: GRETAGSPM)
50, manufactured by Gretag Macbeth Co., Ltd.), the reflection density of cyan in the evaluation image was measured, and the ozone resistance was evaluated based on the following criteria. ：: When the concentration after exposure is 70% or more of the concentration before exposure and there is no practical problem. ×: When the concentration after exposure is less than 70% of the concentration before exposure, which is not suitable for practical use.

<Light fastness> For each evaluation image, a xenon weather meter (trade name: Ci-5000, ATL)
An AS test was performed using a black panel temperature of 63 ° C., a relative humidity of 50%, and a UV intensity of 340 nm of 0.35 W / m ² at 30 kJ / m ² . Thereafter, the reflection density of magenta in the evaluation image was measured using a spectroscopic altimeter (trade name: GRETAG SPM50, manufactured by Gretag Macbeth), and the light resistance was evaluated based on the following criteria. ：: When the concentration after exposure is 80% or more of the concentration before exposure and there is no practical problem. X: When the concentration after exposure is less than 80% of the concentration before exposure, which is not suitable for practical use.

From the results shown in Table 1, in Examples 1 to 7 using silica and two or more types of cycloamylose, an ink jet recording sheet excellent in both ozone resistance and light resistance was obtained. On the other hand, Comparative Example 1, in which alumina was used instead of silica, was not suitable for practical use as an ink jet recording paper because it had excellent ozone resistance but poor light resistance. Further, in Comparative Example 2 containing no cycloamylose at all and Comparative Examples 3 to 5 using only one kind of cycloamylose having a single degree of polymerization, the ozone resistance is practically satisfactory although the light resistance is practically no problem. Poorly poor.

[0034]

As described above, according to the present invention,
In an ink jet recording paper provided with an ink receiving layer on at least one side of a support, the ink receiving layer contains at least silica and two or more types of cycloamyloses so that ozone can be obtained without deteriorating light resistance of a printed image. Greatly improves the preservability of environmental gases such as
An ink jet recording paper having excellent long-term storage properties can be provided.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeru Asai 3-1 Yosoba Tomoecho, Shizuoka City, Shizuoka Prefecture Inside the Paper Division of Hamakawa Paper Mill Co., Ltd. (72) Inventor Izumi Yoshizawa Yomune Tomoe, Shizuoka City, Shizuoka Prefecture 3-1 Machimachi Paper Mill Co., Ltd. Western Paper Division (72) Inventor Sumiichi Tatsuhashi 3-1 Yomibacho, Shizuoka-shi, Shizuoka Pref. Hamakawa Paper Mill Co., Ltd., Paper Division (72) Inventor Kazushige Katagiri No.3-1, Yohoma-cho, Shizuoka-shi, Shizuoka Prefecture Inside the paper business of Hamakawa Paper Mill Co., Ltd. (72) Inventor Kiyoshi Iwamoto No.3-1, Yoh Tomoecho-cho, Shizuoka-shi, Shizuoka Prefecture Reference) 2C056 EA13 FC06 2H086 BA15 BA21 BA33 BA35

Claims (3)

[Claims] 1. An ink jet recording sheet having an ink receiving layer provided on at least one surface of a support, wherein the ink receiving layer contains at least silica and two or more cycloamyloses. . 2. The ink jet recording paper according to claim 1, wherein the cycloamylose is a mixture of at least two kinds of cycloheptaamylose or a derivative thereof and cyclooctamylose or a derivative thereof. 3. The cycloamylose is a mixture of at least three types of cyclohexamylose or a derivative thereof, cycloheptaamylose or a derivative thereof, and cyclooctamylose or a derivative thereof. 2. The ink jet recording paper according to item 1.