JP2001030620A - Ink jet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the residual rate of recording density, and prevent the degradation of a color balance after fading from occurring and thereby upgrade the light resistance of an ink jet recording medium by adding at least an inorganic salt and a phenolic compound. SOLUTION: This ink jet recording medium is formed by adding at least at inorganic salt and a phenolic compound. In this case, the light resistance of the medium can be further improved by selecting a divalent or higher metallic salt, especially magnesium salt or calcium salt as the inorganic salt. In addition, the light resistance can be further improved by selecting a chemical compound with a sulfon group, especially hydroxybenzene sulfonic acid, sulfosalicylate or pyrocatechol-3,5-disulfonic acid as the phenolic compound. Further more preferably, one or more receptive layers comprising various kinds of materials having ink absorption are arranged on a support and further, the inorganic salt and the phenolic compound are added to form the ink jet recording medium.

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 material, and more particularly to an ink jet recording material having improved light fastness.

[0002]

2. Description of the Related Art An ink-jet recording system in which an aqueous ink is ejected from a fine nozzle onto a recording medium to form an image,
Terminal printers, facsimile machines, plotters, form printing, etc., because there is little noise during recording, color printing is easy, high-speed recording is possible, and it is cheaper than other printing devices. Widely used in In recent years, with the rapid spread of inkjet printers and higher image quality, there has been a strong demand for inkjet recording not only having high surface gloss and excellent appearance, but also excellent image storability, especially excellent light resistance. However, the inks used in this method require conditions such as not causing clogging of the inkjet nozzles and having a vivid color tone, so it is necessary to select pigment inks and dye inks with excellent light resistance. It is not possible at present.

[0003] Therefore, there have been proposed many techniques for imparting light resistance by incorporating various materials into ink jet recording paper. For example, Japanese Patent Application Laid-Open No. 57-87988 discloses an ink jet recording sheet comprising an ultraviolet absorber as at least one component.
In Japanese Patent Application Laid-Open No. H10-157, there is described an ink jet recording medium for forming a recorded image using an aqueous ink containing a water-soluble dye, wherein the recording medium contains a hindered amine compound. JP-A-4-201594 discloses a recording material having a substrate and an ink receiving layer provided on the substrate, wherein the ink receiving layer contains an ultrafine powder of a transition metal compound. The recording material is described. Although these recording media can provide a certain effect of improving light fastness, they have poor ink absorbency, and also have problems in light fastness such as a loss of color balance after fading.

In Japanese Patent Application Laid-Open No. 1-241487, a compound having a phenolic hydroxyl group as a light resistance improving additive is used in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of a resin binder composed of polyvinyl alcohol and a cationic water-soluble resin. Describes a recording material for aqueous ink recording in which a film blended in (1) is provided on the surface of a substrate sheet, but the effect of improving light resistance was insufficient. In addition, Japanese Patent Application Laid-Open No. 8-1327
No. 27 discloses an ink receiving layer containing a metal complex of polyvinyl alcohol and calcium chloride.
No. 6 discloses an ink jet recording sheet in which magnesium sulfate having a dry adhesion amount of 0.2 to 2.0 g / m ² is adhered to a support. However, these recording materials had a relatively good color balance after fading, but had insufficient recording density residual ratio, and were not at a usable level.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an ink jet recording medium having an excellent light resistance in which the residual ratio of the recording density and the color balance after color fading are not lost.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems. As a result, the ink jet recording medium contains at least an inorganic salt and a phenolic compound, thereby achieving excellent light fastness. The present invention was found by finding an ink jet recording medium having good properties. In particular, when the phenolic compound contains a sulfone group, more excellent light resistance can be obtained.

[0007] The high quality paper type is a grade that looks the same as plain paper without an external coating layer, and is coated or impregnated with a liquid containing a phenolic compound having a sulfonic acid group on a support such as high quality paper. Can be obtained. This liquid requires resin,
Although a sizing agent, a pigment and the like can be added, the coating amount is small and, for example, the dry coating amount is about 5 g / m ² or less in total on both sides. A coated paper type (mat type) ink jet recording body is a mode in which a coating layer (ink receiving layer) containing a pigment and a resin is provided on a support such as paper, synthetic paper, and film,
The ink receiving layer contains a phenolic compound having a sulfonic acid group. The receiving layer may be a multilayer. In addition, the glossy coating type ink jet recording medium has a mode in which at least the upper layer is a gloss layer and the gloss layer is a layer mainly composed of a resin, and a mode in which a fine pigment (particle size of 1 μm or less) is contained. . If necessary, a lower layer can be provided between the support and the upper layer. The glossy layer can be subjected to a smoothing treatment such as a film transfer method and a cast method.

[0008] The present invention includes, but is not limited to, the following embodiments. [1] An ink jet recording medium containing at least an inorganic salt and a phenolic compound. [2] The ink jet recording material according to [1], wherein the phenolic compound contains a sulfone group. [3] The inkjet according to [2], wherein the phenolic compound having a sulfone group is at least one selected from sulfosalicylates, hydroxybenzenesulfonates, and pyrocatechol-3,5-disulfonates. Record body. [4] The inkjet recording material according to [1], [2] or [3], wherein the inorganic salt is a divalent or higher valent metal salt. [5] The ink jet recording material according to [4], wherein the divalent or higher valent metal salt is an alkaline earth metal salt. [6] A receiving layer formed by impregnating a support with a coating solution containing an inorganic salt and a phenolic compound, or coating and drying a coating solution containing an inorganic salt and a phenolic compound [1]-
The inkjet recording material according to any one of [5]. [7] The ink jet recording medium according to [6], wherein the coating liquid contains a porous inorganic pigment and / or a cationic compound. [8] The ink jet recording material according to [7], wherein the porous inorganic pigment has an average particle size of 1 μm or less.

[9] The ink jet recording material according to [4], wherein the divalent or higher valent metal salt is at least one selected from a magnesium salt and a calcium salt. [10] The coating liquid contains a water-soluble binder. The ink-jet recording material according to [6], wherein: [11] The ink jet recording material according to [7] or [8], wherein the porous inorganic pigment is secondary particles (agglomerated particles) of silica and / or alumina silicate. [12] The ink-jet recording medium according to any one of [1] to [12], wherein at least two or more receiving layers are provided on a sheet-like substrate. [13] 75 ° gloss value according to JIS-P8142 is 20
% Or more, preferably 40% or more. [14] The inorganic salt is calcium chloride, and the phenolic compound is p-hydroxybenzenesulfonate or pyrocatechol-3,5-disulfonate [1]-
The inkjet recording material according to any one of [13]. [15] An ink receiving layer (lower layer) containing an aqueous resin on a support, and an ink receiving layer (upper layer) containing an inorganic salt, a phenolic compound and an aqueous resin is provided thereon [1] to [1]. The inkjet recording material according to any one of [14]. [16] The ink jet recording medium according to [15], wherein the ink receiving layer (upper layer) contains a porous inorganic pigment having an average particle diameter of 1 μm or less.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The recording medium of the present invention contains at least an inorganic salt and a phenol compound. The inorganic salt is not particularly limited, but various salts such as sodium, magnesium, calcium, aluminum, phosphorus, titanium, iron, nickel, copper, and zinc are appropriately selected, and a divalent or higher valent metal salt, particularly, a magnesium salt, By selecting a calcium salt, a recording medium having more excellent light resistance can be obtained.

On the other hand, the phenolic compound is not particularly limited, but includes hydroquinone, hydroquinone sulfonate, hydroquinone disulfonate, pyrocatechol,
Examples include pyrocatechol-3,5-disulfonate (also referred to as tiron), hydroxybenzoate, sulfosalicylate, hydroxybenzenesulfonate, arbutin (hydroquinone-β-D-glucoside), and various naphthols. Compounds having a sulfone group, especially hydroxybenzenesulfonate, sulfosalicylate, and pyrocatechol-3,5-disulfonate, are more excellent in light resistance. It is not clear why the light resistance is greatly improved by including these, but it is considered that the dye for inkjet recording which is weak to light irradiation is stabilized and protected in some form. Although the effects are not clear, it is considered that a compound having a phenolic hydroxyl group is involved in suppressing a decrease in recording density and an inorganic salt is involved in adjusting a color balance after fading.

Although the content is not particularly limited, each of the inorganic salt and the phenolic compound is 1 m ² of the recording material.
0.01 to 2 g per unit is preferred. If it is less than 0.01 g / m ² , a sufficient effect of improving light resistance cannot be obtained, and 2 g / m 2
Even if it exceeds ² , the effect is saturated. Each coating method may be applied alone, or may be mixed and applied.

The layer constitution of the ink jet recording medium of the present invention is not particularly limited, as long as the recording medium contains an inorganic salt and a phenolic compound. That is, papers mixed with the specific material, kneaded sheets, papers subjected to size press or impregnation, and papers obtained by applying a coating liquid containing an inorganic salt and a phenolic compound may be used. Paper-type recording paper) is preferably provided with one or more receiving layers mainly composed of various ink-absorbing materials on a support (coated paper-type recording paper), and preferably at least an upper layer thereof. The above-mentioned inorganic salt and phenolic compound are added to the receiving layer, or are contained in the upper receiving layer by preparing a coating solution and applying it.

Various hydrophilic resins can be used as a material of the ink receiving layer. If necessary, a pigment can be used together to obtain a recording medium having excellent water resistance, ink absorption speed, and ink drying property. Like the above-mentioned materials blended for improving light fastness, they may be blended in the support itself (high quality paper type). More preferably, it is used as a main component of the ink receiving layer provided on the support as described above. As the hydrophilic resin, for example, polyvinyl alcohol, cation-modified polyvinyl alcohol, polyvinyl alcohols such as modified polyvinyl alcohol such as silyl-modified polyvinyl alcohol, gelatin, casein, soybean protein, starch, natural resins such as cationic starch, carboxymethyl cellulose, Water solubility of cellulose derivatives such as methylcellulose, hydroxypropylcellulose and hydroxypropylmethylcellulose, polyvinylpyrrolidone, polyurethane, polyester, sodium polyacrylate, acrylic polymer latex, vinyl copolymer latex such as styrene-vinyl acetate copolymer, etc. Resins and water-dispersible resins. These can be used not only as an ink absorbing material but also as an adhesive (binder) when a recording layer containing the above-mentioned pigment as a main component is provided on a sheet-like substrate.

Examples of pigments include fine silica, alumina,
Examples include inorganic pigments such as hydrated alumina, calcined kaolin, and calcium carbonate, and organic pigments such as urea-formaldehyde resin fine particles, melamine-formaldehyde resin fine particles, and benzoguanamine resin fine particles. Preferably,
Particle size (when secondary particle size, secondary particle size) is 1 μm
The inorganic pigment having a particle size of 600 nm or less is more preferable. This makes it possible to obtain a recording medium having high gloss and high print density. More preferably, the average primary particle size is 3-4.
The average secondary particle size of the primary particles of 0 nm is 5
Inorganic pigments of not more than 00 nm, especially not more than 300 nm are contained. There is no lower limit on the aggregate particle size (secondary particle), but it is preferably at least 10 nm, more preferably at least 20 nm.
Examples of such a pigment include secondary particles of fine silica and secondary particles of aluminosilicate, and fine silica is particularly preferred. By using such a pigment in at least the upper layer of the ink receiving layer provided on the support, it is possible to obtain a recording medium having excellent ink absorbency and high gloss and high print density. The average particle diameter is a particle diameter observed with an electron microscope (an electron microscope photograph of 10,000 to 400,000 times is taken, and the Martin diameter of particles in, for example, 5 cm square is measured and averaged. "Fine Particle Handbook", Asakura Shoten , P5
2, 1991).

In this case, the weight ratio of the solid content of the pigment and the hydrophilic resin is not limited, but is adjusted in the range of 100/2 to 100/200, preferably 100/5 to 100/100.
If the amount of the hydrophilic resin added is large, the pores between the particles become small, and it is difficult to obtain the ink absorption rate. On the other hand, if the amount of the binder is too small, large cracks occur in the recording layer, and the image quality and print density may be reduced. Because there is.

By providing an ink-receiving layer mainly composed of a resin such as the water-soluble resin or the water-dispersible resin, a recording medium having excellent gloss can be obtained. An embodiment containing a large amount of pigment is excellent. A pigment may be added to the resin-based ink receiving layer, but in this embodiment, 10% by weight or less,
Or about 5% by weight or less. Thereby, blocking can be prevented and glossiness can be adjusted.

The ink receiving layer can have a multilayer structure of two or more layers. An ink jet recording excellent in glossiness and recording density by (1) using the water-soluble resin or water-dispersible resin-containing layer or (2) using a fine pigment having a pigment particle size of 1 μm or less as the upper receiving layer. You can get the body. The lower layer can be made of, for example, the resin described above. Further, it may be composed of a pigment and a resin having the specific particle size or other than the specific particle size. In addition, a cationic resin can be added.

A high quality paper type recording paper or a coated paper type recording paper can also be added with a cationic resin for the purpose of improving ink fixability. The cationic resin may be contained in the support itself as in the above-mentioned materials (support in high-quality paper-type recording paper, coating-type recording paper), but preferably provided with an ink-receiving layer on the support. Is contained in the upper layer of the receiving layer (coating type recording paper). The kind of the cationic resin to be added is not particularly limited, but various resins forming an insoluble salt with a sulfone group, a carboxyl group, and the like of an ink jet dye, a secondary amine, a tertiary amine, and a quaternary amine A cationic resin containing an ammonium salt or the like can be used. Specific examples include polyethyleneimine, polyvinylpyridine, polyvinylamine, a polymer of monoallylamine hydrochloride, a polymer of diallylamine hydrochloride, a copolymer of monoallylamine hydrochloride-diallylamine hydrochloride, and a (meth) acrylamidoalkyl quaternary ammonium salt. Polymer, polyalkylene polyamine / dicyandiamide condensate, secondary amine /
Examples thereof include compounds such as epichlorohydrin addition polymer and polyepoxyamine. The amount of the cationic resin added was 0.01 to 10 g / m ^2.
m ² , more preferably in the range of 0.1 to 5 g / m ² .

In addition, various auxiliaries such as a dispersant, a thickener, an antifoaming agent, a coloring agent, an antistatic agent and a preservative used in the production of general coated paper are appropriately added. In the present invention, the support is not particularly limited, and may be transparent or opaque. For example, high quality paper, art paper, coated paper,
Papers such as cast coated paper, foil paper, kraft paper, polyethylene laminated paper, impregnated paper, vapor-deposited paper, water-soluble paper, etc., plastic films such as cellophane, polyethylene, polypropylene, soft polyvinyl chloride, rigid polyvinyl chloride, polyester etc. , Metal foil, synthetic paper, etc. are used as appropriate. When the receiving layer is provided on the support, the coating amount is not particularly limited, but is preferably 3 to 60 g / m ² ,
More preferably, it is 10 to 50 g / m ² . Examples of the coater for coating the receiving layer include various known coaters such as a die coater, a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, and a curtain coater. . In order to improve the gloss, a receiving layer can be provided by a cast coating method.

In the present invention, at least one recording layer (preferably, an upper layer, that is, a layer to which ink is applied) is provided on the molding surface, and a support (when the support has another recording layer, an additional layer). Transfer to the recording layer) and peeling off the molding surface, it is possible to obtain high gloss equivalent to that of a silver halide photograph. Materials used for the molding surface include plastic films such as cellophane with high surface smoothness, polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, and polyester, polyethylene laminated paper, glassine paper, impregnated paper, and vapor deposition. Flexible sheets such as paper such as paper, metal foil, and synthetic paper, and drums and plates having a highly smooth surface such as inorganic glass, metal, and plastic are appropriately used. In particular, a polymer film (polyethylene, polypropylene, polyester, or the like) or a metal drum having a highly smooth surface is preferable from the viewpoints of the manufacturing process and the suitability of the recording layer from the recording layer. The molded surface is preferably smooth for the purpose of obtaining high gloss, and the surface roughness (JIS B-0601) of the molded surface is preferably such that Ra is 0.5 μm or less, more preferably Ra is 0.05 μm. It is as follows. In addition, it is also possible to give a texture such as a semi-gloss tone by controlling the surface roughness.

The molding surface may be left untreated. However, the adhesion between the receiving layer and the support (or another receiving layer when another receiving layer is previously provided on the support) is less than the adhesive strength between the receiving surface and the support. In order to control the adhesive strength of the layer to be small, it is possible to apply a compound having releasability such as silicone or fluororesin to the coating surface of the molding surface and use it.

When transferring the recording surface to the support, the bonding method is not particularly limited as long as the receiving layer coated on the molding surface can be bonded to the support (or another receiving layer). Bonding is under pressure (5-150Kg / cm) and heat (30-100 ° C)
However, it is more preferable to apply steam to the upper and / or lower layers so that the water content of the upper layer and / or the lower layer is 50 to 350% based on the absolute dry weight, or to apply water and apply pressure by using a calender or the like. It is possible. Of course, it is possible to provide an intermediate layer (adhesive, pressure-sensitive adhesive, etc.) on the support in advance and to adhere, but as a more effective method,
The purpose of the present invention is to make the intermediate layer a receiving layer excellent in ink absorption. For example, a receiving layer is applied to a support, and the substrate is bonded in a wet state by using this adhesive force, and then dried and bonded.

The ink used in the ink jet recording method of the present invention comprises a dye for forming an image and a liquid medium for dissolving or dispersing the dye as essential components, and if necessary, various dispersants and an interface. It is adjusted by adding an activator, a viscosity adjuster, a specific resistance adjuster, a pH adjuster, a fungicide, a stabilizer for dissolving or dispersing the recording agent, and the like. The recording agents used in the ink include direct dyes, acid dyes, basic dyes,
Examples thereof include reactive dyes, food dyes, disperse dyes, oil dyes, and various pigments, and conventionally known dyes can be used without any particular limitation. The content of such a dye is determined depending on the type of the liquid medium component, the characteristics required for the ink, and the like, but in the case of the ink of the present invention, the composition as in the conventional ink, that is, There is no particular problem in use at a ratio of about 0.1 to 20% by weight. As the solvent of the ink used in the present invention, water and various water-soluble organic solvents, for example, having 1 carbon atom such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol and isobutyl alcohol isobutyl alcohol To 4, alkyl alcohols, ketones or ketone alcohols such as acetone and diacetone alcohol, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, thiodiglycol, Alkylene glycols having 2 to 6 alkylene groups such as hexylene glycol and diethylene glycol; amides such as dimethylformamide; ethers such as tetrahydrofuran S, glycerin, ethylene glycol methyl ether, diethylene glycol methyl (ethyl) ether, such as lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether.

[0025]

The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto.
Unless otherwise specified, parts and% in the examples are solid contents excluding water, and represent parts by weight and% by weight, respectively. Example 1 The following size press coating liquid was applied in a dry weight of 0.5 g / m ^2.
Then, a commercially available PPC paper (high quality paper electrophotographic paper) was subjected to size press coating, impregnated and dried to obtain a high quality paper type recording medium. (Size Press Coating Solution) 40 parts of sodium pyrocatechol-3,5-disulfonate (also referred to as Tyrone, manufactured by Kanto Chemical Co., Ltd.) and 60 parts of calcium chloride (Kanto Chemical Co., reagent). 5% concentration.

Example 2 The following coating solution for an ink receiving layer was dried at a weight of 20 g / m 2.
² so that commercial coated paper (made by Oji Paper Co., Ltd., trade name:
OK coat, 127.9 g / m ² ) was applied by a die coater and dried to obtain a coated paper type ink jet recording material. (Coating Solution for Receptive Layer) 100 parts of amorphous silica (4.5 μm average particle size, manufactured by Tokuyama, trade name: Fine Seal X-45), silyl-modified polyvinyl alcohol (Kuraray, trade name: PVA-)
R-1130) 35 parts, a cationic resin polydiallyldimethylammonium chloride (manufactured by Nitto Boseki Co., Ltd.
Brand name: PAS-H-10L) 15 parts, sodium p-hydroxybenzenesulfonate (Kanto Chemical, reagent) 2
Department. 2 parts of calcium chloride (Kanto Chemical, reagent). Coating solution concentration 7%.

Example 3 The following coating liquid for an ink receiving layer was dried at a weight of 20 g / m 2.
² so that commercial coated paper (made by Oji Paper Co., Ltd., trade name:
OK coat, 127.9 g / m ² ) was applied by a die coater and dried to obtain a coated paper type ink jet recording material. (Coating liquid for receiving layer) Silica sol A 100 parts, polyvinyl alcohol (manufactured by Kuraray Co., trade name: PVA-135H) 35 parts, sodium p-hydroxybenzenesulfonate (manufactured by Kanto Chemical, reagent) 8 parts, calcium chloride (Kanto) Chemical, reagent) 8 parts.
Coating solution concentration 7%. [Silica sol A] The average particle size of the aggregated particles (secondary particles) is 3
μm synthetic amorphous silica (manufactured by Nippon Silica Co., Ltd., trade name: Nipsil, HD-2, primary particle diameter: 11 nm)
Is pulverized and dispersed by a sand grinder, further pulverized and dispersed by a pressure homogenizer, and the pulverization and dispersion operation of the sand grinder and the pressure homogenizer is repeated until the average particle diameter of the aggregated particles (secondary particles) becomes 70 nm.
An aqueous dispersion having a concentration of 8% was produced as a trial. To 100 parts of the solid content of the aqueous dispersion, polydiallyldimethylammonium chloride (a product of Nitto Boseki Co., trade name: P
AS-H-10L) was added, and the mixture was thickened and aggregated, pulverized and dispersed by a sand grinder, and further pulverized and dispersed by a pressure homogenizer to obtain an average particle diameter of 49.
The dispersion operation of the pulverized amount of the sand grinder and the pressure homogenizer is repeated until the thickness becomes 0 nm, and the concentration of the coating liquid is 9%.
Was prepared as an aqueous dispersion.

Example 4 Commercially coated paper (manufactured by Oji Paper Co., Ltd., trade name: OK Coat, 12
7.9 g / m ² ) A PET film (manufactured by Toray Industries, trade name: Lumirror T50 μm) using a substrate as a molding surface,
An ink-jet receiving layer (upper layer) was obtained in the same manner as in Example 3, except that 8 parts of sodium p-hydroxybenzenesulfonate and 8 parts of calcium chloride in the receiving layer coating liquid were each changed to 6 parts. Then, the same coating solution for the receiving layer,
A commercially available coated paper (manufactured by Oji Paper Co., Ltd., trade name: OK coat, 127.9 g) such that the dry coating amount of the lower layer is 10 g / m ^2.
/ M ² ) with a bar coater, immediately bonded to the receiving layer (upper layer) and dried, and the PET film was peeled off to produce an ink jet recording medium having two receiving layers.

Example 5 A receiving layer was coated in the same manner as in Example 3 except that sodium p-hydroxybenzenesulfonate and calcium chloride in the coating solution for the receiving layer were removed. Next, the following coating solution was applied so as to be 1.0 g / m ² in dry weight, and dried. (Coating liquid) 50 parts of sulfosalicylic acid (manufactured by Kanto Chemical, reagent) and 50 parts of magnesium sulfate (manufactured by Kanto Chemical, reagent). Coating liquid concentration 2
0%. Example 6 An ink jet recording material of the present invention was produced in the same manner as in Example 3 except that sodium p-hydroxybenzenesulfonate was changed to hydroquinone (manufactured by Kanto Chemical Co., Inc., reagent).

Example 7 The following coating solution for an ink receiving layer was dried at a weight of 20 g / m 2.
² was coated on the following resin-coated paper with a die coater and dried to obtain a coated paper type ink jet recording material. (Coating liquid for receiving layer) Polyvinyl alcohol (Kuraray Co., Ltd., trade name PVA42)
0) 100 parts, silyl-modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name: PVA-R-1130) 35 parts, polydiallyldimethylammonium chloride as a cationic resin (manufactured by Nitto Boseki Co., trade name: PAS-H-10)
L) 15 parts, 2 parts of sodium p-hydroxybenzenesulfonate (manufactured by Kanto Chemical, reagent), 2 parts of sodium dihydrogen phosphate (manufactured by Kanto Chemical, reagent). Coating solution concentration 7%.

(Resin-coated paper for support) CSF (JIS
P-8121) was beaten to 300 ml softwood bleached kraft pulp (NBKP) and CSF was beaten to 350 ml hardwood bleached kraft pulp (LBKP) at a weight ratio of 2: 8, and a concentration of 0.5%. Was prepared. In this pulp slurry, cationized starch 2.0%, alkyl ketene dimer 0.4%, anionized polyacrylamide resin 0.1 based on the absolute dry weight of pulp.
%, Polyamide polyamine epichlorohydrin resin 0.
7% was added and dispersed sufficiently by stirring. Paper making the pulp slurry of the above composition with a fourdrinier machine, a drier,
180g basis weight through size press and machine calendar
/ Cm ² , and a base paper having a strength of 1.0 g / cm ³ . The size press liquid used in the size press step was prepared by mixing carboxyl-modified polyvinyl alcohol and sodium chloride at a weight ratio of 2: 1, adding the mixture to water, and heating and dissolving to a concentration of 5%. 25 on both sides of the paper
cc was applied. After performing corona discharge treatment on both sides of the base paper, the following polyolefin resin composition 1 mixed and dispersed with a Banbury mixer was applied to the felt side of the base paper so that the coating amount was 25 g / m ^2. Polyolefin resin composition 2 (back side resin composition) was applied to the wire side by a melt extruder (melting temperature of 320 ° C.) having a T-type die so that the coating amount was 25 g / m ² ,
The surface was cooled and solidified by a cooling roll having a mirror surface to produce a sheet-like support. The antioxidant in the polyolefin resin composition 1 prevents the polyethylene from being oxidized in the melt extrusion step, and the ultramarine and the fluorescent whitening agent give the polyolefin resin-containing layer a bluish and apparent whiteness. This is to improve visual perception.

(Polyolefin resin composition 1) Long chain type low density polyethylene resin (density 0.926 g / c
m ³ , melt index 20 g / 10 min) 35 parts by weight, low density polyethylene resin (density 0.919 g / cm)
³ , melt index 2 g / 10 min) 50 parts by weight, anatase type titanium dioxide (A-220; manufactured by Ishihara Sangyo) 1
5 parts by weight, zinc stearate 0.1 part by weight, antioxidant (Irganox 1010; manufactured by Ciba-Geigy) 0.03
Parts by weight, ultramarine (Blue mouth ultramarine No. 2000; manufactured by Daiichi Kasei)
0.09 parts by weight, 0.3 parts by weight of optical brightener (UVITEX OB; manufactured by Ciba-Geigy) (polyolefin resin composition 2) High-density polyethylene resin (density 0.954 g / cm ³ ,
Melt index 20 g / 10 min) 65 parts by weight, low-density polyethylene resin (density 0.924 g / cm ³ , melt index 4 g / 10 min) 35 parts by weight

Example 8 Same as Example 3 except that sodium p-hydroxybenzenesulfonate was changed to sodium salicylate (manufactured by Kanto Kagaku) and calcium chloride was changed to sodium dihydrogen phosphate (manufactured by Kanto Kagaku). The ink jet recording medium of the present invention was manufactured.

Comparative Example 1 A recording medium was produced in the same manner as in Example 3 except that sodium p-hydroxybenzenesulfonate and calcium chloride were omitted. Comparative Example 2 A recording medium was produced in the same manner as in Example 3, except that calcium chloride was used and sodium p-hydroxybenzenesulfonate was used in 16 parts.

Comparative Example 3 Except for sodium p-hydroxybenzenesulfonate,
A recording medium was produced in the same manner as in Example 3 except that the amount of calcium chloride was changed to 16 parts. Comparative Example 4 A recording medium was produced in the same manner as in Example 3, except that the hindered amine light stabilizer (trade name: Tinuvin 144, manufactured by Ciba Geigy) was changed to 16 parts except for sodium p-hydroxybenzenesulfonate and calcium chloride. did.

[Evaluation Method] The print density, image light fastness, and image water fastness of the ink jet recording materials obtained in Examples and Comparative Examples were evaluated by the following methods. In addition, EPS is used for printing.
An ON company printer (trademark: PM-750C) was used. [Print Density] The print density of the solid black portion was measured using a Macbeth reflection densitometer (Macbeth, RD-920).
The numbers shown in the table are the average values of three measurements. [Image light fastness] ISO-400 image (“High-definition color digital standard image data ISO / JIS-SCI
D ", p13, image name: fruit basket, p14, image name: candle, issued by the Japan Standards Association) in glossy paper mode, and a xenon lamp type FADE-OMETE
R (ATLAS ELECTRIC DEVICES
Co. (Model: CI35F), 63
The print sample was continuously processed at 50 ° C. and 50% for 50 hours. The two images were compared to the unprocessed image and the lightfastness level was evaluated as follows. A: Almost no fading occurred. ：: Slight fading, but good level. Δ: Discolored, the color balance is lost, but usable level. ×: Discolored and color balance was lost. XX: The degree of fading is large, and the color balance is significantly lost. Unusable level.

[Water resistance to printing] After printing on the ink jet recording medium, after leaving it for 24 hours, water droplets are dropped. One minute later, the water droplets are wiped off, and the state of the part immersed in the water droplets is observed. A: Almost no ink was removed. ：: Good level although some of the ink was removed. X: Ink was completely removed.

[0038]

[Table 1]

As is clear from Table 1, the recording media of Examples 1 to 8 containing at least an inorganic salt and a phenolic compound had good light fastness. Particularly, Examples 1 to 7 in which the phenolic compound containing a sulfone group and / or the inorganic salt contained a divalent or higher valent metal salt were particularly excellent. Examples 2 to 8 using a pigment and a cationic resin together
Were also good in print density and image water resistance. Among them, Examples 3 to 8 using fine silica having a particle size of 1 μm or less as a pigment had higher recording density and excellent image quality.
On the other hand, Comparative Example 1 containing no lightfastness improver was remarkably inferior in lightfastness, and Comparative Examples 2 and 3 containing only either an inorganic salt or a phenolic compound exhibited an effect of improving lightfastness but were insufficient. there were. The hindered amine-based light stabilizer (Comparative Example 4) provided an effect of improving light resistance, but was insufficient.

[0040]

The present invention relates to an ink jet recording medium, and particularly, an ink jet recording medium having excellent light resistance was obtained.

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Claims (8)

[Claims] 1. An ink jet recording medium containing at least an inorganic salt and a phenolic compound. 2. The ink-jet recording material according to claim 1, wherein the phenolic compound contains a sulfone group. 3. The phenolic compound having a sulfone group is at least one selected from the group consisting of sulfosalicylate, hydroxybenzenesulfonate and pyrocatechol-3,5-disulfonate. Inkjet recording medium. 4. The ink jet recording medium according to claim 1, wherein the inorganic salt is a divalent or higher valent metal salt. 5. The ink jet recording medium according to claim 4, wherein the divalent or higher valent metal salt is an alkaline earth metal salt. 6. A receiving layer provided by impregnating a support with a coating liquid containing an inorganic salt and a phenolic compound, or applying and drying a coating liquid containing an inorganic salt and a phenolic compound. 6. The ink jet recording material according to any one of items 1 to 5, 7. The ink jet recording medium according to claim 6, wherein said coating liquid contains a porous inorganic pigment and / or a cationic compound. 8. The ink jet recording medium according to claim 7, wherein the average particle size of the porous inorganic pigment is 1 μm or less.