JP2000280601A - Ink jet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording body excellent in image light fastness and a method of manufacturing the same. An ink-jet recording body is obtained by recording with an ink-jet ink on a recording body provided with a recording layer including an upper recording layer and an optional lower recording layer provided on a support, and providing a protective layer on the recording surface. An ink jet recording medium wherein at least the upper layer of the recording layer contains an antioxidant and the protective layer contains an ultraviolet absorber.

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 medium having improved light fastness of an image and a method of manufacturing the same.

[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, since the ink used in this method requires conditions such as no clogging of the ink jet nozzle and a vivid color tone, it is necessary to always select a pigment ink or a dye ink excellent in light resistance. It is not possible at present. On the other hand, ink jet recording paper is generally high-quality paper devised so as to be rich in ink absorption or coated paper having a surface coated with a porous pigment. Is easily discolored and difficult to store for a long time.

[0003] In view of the above, there have been proposed a number of techniques for imparting light resistance to images by incorporating a light resistance improver into ink jet recording paper. For example, Japanese Patent Application Laid-Open No. 57-87988 discloses an ink jet recording sheet characterized by containing an ultraviolet absorber as at least one component.
No. 08755 describes an ink jet recording material in which an ink holding layer and a physically or chemically transparentizable porous ink transport layer are sequentially laminated on a support, wherein the porous ink transport layer has an ultraviolet absorber. An ink jet recording material characterized by containing is disclosed. Although these recording media can provide a certain effect of improving light fastness, they are not always satisfactory because of poor ink absorption and printing bleeding. In order to improve the light resistance efficiently, it is considered effective to distribute the light resistance improver around or above the layer where the dye component is fixed in the recording layer. The agent has a high hydrophobicity, is extremely difficult to be incorporated into a water-soluble paint, and tends to sink in the coating layer. That is, the former containing an ultraviolet absorber in the receiving layer requires a large amount of compounding to provide sufficient light resistance, and as a result, the absorbing property of the receiving layer decreases,
Printing bleeding occurs. The latter, in which a layer containing an ultraviolet absorber is provided on the receiving layer, has relatively good light fastness, but the ink transport layer has high hydrophobicity and the transport speed is slow, so that print blurring also occurs.

Japanese Patent Application Laid-Open No. 62-261476 discloses a recording material having an ink transporting layer and an ink holding layer, wherein the ink transporting layer and / or the ink holding layer contains an ultraviolet absorber. Is disclosed in Japanese Patent Laid-Open No. 9-169157.
In the gazette, a support layer, a release layer formed on the support layer, an ultraviolet cut layer containing an ultraviolet absorber formed on the release layer, and a heat-sealing property composed of glycols An image receiving layer, wherein the image receiving layer is printed with an aqueous ink by an inkjet printer, and then heat-sealed to a transfer receiving body, and the support layer is peeled off. ing. Since such a recording medium is recorded from the side opposite to the viewing side, that is, from the back side, Japanese Patent Laid-Open No.
There is no problem of print bleeding as described in JP-A-87988 and JP-A-7-108755, and since there is a layer containing an ultraviolet absorbent on the ink holding layer when viewed from the viewing surface side, the light resistance An improvement effect is also obtained. However,
Since the ink dye is fixed to the lower layer, the print density is low, and the desired image quality cannot be obtained.

As a method for solving the above-mentioned disadvantages, there has been proposed a method in which a light fastness improving agent is applied on a recording surface after recording. Japanese Patent Application Laid-Open No. 56-77154 discloses an ink jet recording method characterized in that after recording on an ink jet recording sheet having a porous structure, voids of the porous structure of the recording sheet are filled with a nonvolatile, colorless substance. Has been described. JP-A-61-230976 has a substrate and a peelable transfer layer provided on the substrate, the transfer layer comprising at least a layer containing an ultraviolet absorber, Japanese Patent Application Laid-Open No. H8-174989 discloses that a protective member having two layers including a light stabilizer is provided on an ink jet recording sheet on an ink receiving layer of an ink jet recording sheet on which an image is formed. Discloses an ink jet recording sheet having a transfer overcoat layer formed by thermally transferring an overcoat resin layer made of a thermoplastic resin as a main component via a heat-resistant film on the entire surface or a part of the sheet. JP-A-56-771
No. 54, Japanese Patent Application Laid-Open No. Hei 8-
Japanese Patent Publication No. 174989 discloses that an overcoat layer contains a light fastness improver such as an ultraviolet absorber or an antioxidant, and such a recording medium has an effect of improving light fastness. However, since it is impossible to completely block the light, since the image is viewed through the protective layer, even if the light resistance improver is contained only in the protective layer, a sufficient light resistance effect cannot be obtained in long-term storage. . Further, since the lightfastness improver is generally colored, it is easy to cause a problem that the color tone of a recorded image changes with an increase in the amount, and it has been difficult to improve the lightfastness only with the protective layer.

[0006]

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 excellent image light fastness and a method for producing the same.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, have at least one recording layer, and provided a protective layer on the recording surface after recording. In the ink-jet recording body, by containing a light resistance improver in at least the uppermost layer and the protective layer of the recording layer,
The present inventors have found a recording medium having excellent image quality and light fastness and completed the present invention. When a hindered amine light stabilizer is contained in at least the upper layer of the recording layer and a benzotriazole ultraviolet absorber or cerium oxide is contained in the protective layer, excellent light resistance can be obtained. In particular, when a hindered amine light stabilizer is contained in at least the upper layer of the recording layer and a benzotriazole ultraviolet absorber is contained in the protective layer, more excellent light resistance can be obtained.

[0008] The present invention includes, but is not limited to, the following embodiments. [1] An ink jet recording body in which an ink jet ink is recorded on an ink jet recording body provided on a support with a recording layer including an upper recording layer and an optional lower recording layer provided thereon, and a protective layer is provided on the recording layer. An ink jet recording medium wherein at least the upper layer of the recording layer contains an antioxidant and the protective layer contains an ultraviolet absorber. [2] The ink jet recording material according to [1], wherein the antioxidant contains a hindered amine light stabilizer and the ultraviolet absorber contains a benzotriazole ultraviolet absorber or cerium oxide. [3] The ink jet recording material according to [1] or [2], wherein the protective layer is a protective layer provided by bonding a transparent resin film. [4] The ink jet recording medium according to any one of [1] to [3], wherein the upper recording layer contains a pigment having an average particle size of 1 μm or less (in the case of an aggregated pigment, an aggregated particle size).

[5] The pigment according to [4], wherein the pigment having an average particle size of 1 μm or less is fine secondary particles having an average particle size of 500 nm or less formed by aggregating primary particles having an average particle size of 3 to 40 nm. Ink jet recording medium. [6] The ink jet recording material according to any one of the above, wherein the transparency of the protective layer is 15% or less. [7] The ink-jet recording material according to any one of the above, wherein the protective layer is a transparent resin film coated with an ultraviolet absorber. [8] The ink jet recording material according to any one of the above, wherein the protective layer is a transparent resin film kneaded with an ultraviolet absorbent. [9] The ink jet recording material according to any one of the above, wherein the protective layer is provided by a coating method.

[10] The ink jet recording medium according to any one of the above, wherein at least one recording layer contains a cationic resin. [11] The ink-jet recording material according to any one of the above, wherein the recording layer contains a water-soluble binder. [12] An inkjet recording method in which a recording medium including an upper recording layer and an optional lower recording layer provided on a support is recorded with an inkjet ink, and a protective layer is provided on the recording surface. An inkjet recording method wherein at least the upper layer of the recording layer contains an antioxidant and the protective layer contains an ultraviolet absorber.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to an ink jet recording medium having at least one recording layer and a protective layer provided on the recording surface after recording, wherein at least the recording layer contains an antioxidant, An object of the present invention is to provide an ink jet recording medium characterized in that an ultraviolet inhibitor is contained in a protective layer. The recording medium of the present invention comprises one or more recording layers and a protective layer provided on the recording surface after recording. The recording layer used in the present invention is not particularly limited, and may be a support itself mixed or kneaded with a light fastness improver, but is preferably provided on the support with various materials having ink absorbency. It has at least one recording layer. The resin used for the recording layer provided on the support is not particularly limited, for example, polyvinyl alcohol, cation-modified polyvinyl alcohol,
Polyvinyl alcohols such as modified polyvinyl alcohol such as silyl-modified polyvinyl alcohol, gelatin, casein, soy protein, starch, natural resins such as cationic starch,
Carboxymethylcellulose, methylcellulose, hydroxypropylcellulose, cellulose derivatives such as hydroxypropylmethylcellulose, polyvinylpyrrolidone, polyurethane, polyester, sodium polyacrylate, acrylic polymerization latex, vinyl copolymer latex such as styrene-vinyl acetate copolymer, etc. Various resins such as synthetic resins are exemplified.

Further, by using these resins as binders and using various pigments in combination, an absorbing layer having excellent water resistance, ink absorption speed, and ink drying property can be obtained. Examples of such pigments include inorganic pigments such as fine silica, alumina, hydrated alumina, calcined kaolin, calcium carbonate, and aluminosilicate, or organic pigments such as urea-formaldehyde resin fine particles, melamine-formaldehyde resin fine particles, and benzoguanamine resin fine particles. Is mentioned. Preferably, the pigment has a size of 1 μm or less, whereby a recording medium having excellent gloss and recording density can be obtained. More preferably, it is a pigment having a secondary particle average particle diameter of 500 nm or less formed by aggregating primary particles of 3 to 40 nm, and particularly, providing such secondary particles of fine silica in at least the upper layer of the ink recording layer. Thus, high gloss and high print density can be obtained. If the primary particles are smaller than 3 nm, the ink absorption may be inferior. On the other hand, if the primary particles are larger than 40 nm or the secondary particles are larger than 500 nm, the transparency of the recording layer is reduced, and it is difficult to obtain a high print density. It is possible.
The solid content weight ratio of the pigment and the adhesive (binder) is 100 /
2-100 / 200, preferably 100 / 5-100 /
Adjusted to a range of 100. If the amount of the adhesive (binder) is large, the pores between the particles become small, and it is difficult to obtain an ink absorption rate. On the other hand, if the amount of the adhesive (binder) is too small, large cracks may occur in the recording layer, and image quality and print density may be reduced.

Examples of the light resistance improver include an ultraviolet absorber and an antioxidant as shown below. The recording layer contains an antioxidant at least in the upper layer. As antioxidants, phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, which prevent oxidation by heat and oxygen, and HAL
A hindered amine light stabilizer called S (Hindered Amine LightStabilizer) is exemplified.

Examples of the phenolic antioxidant include monophenols: 2,6-di-t-butyl-p-cresol,
Butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5
-Di-t-butyl-4-hydroxyphenyl) propionate, bisphenol type: 2,2′-methylenebis (4-methyl-6-t-butylphenol), 2,2 ′
-Methylenebis (4-ethyl-6-t-butylphenol), 4,4'-thiobis (3-methyl-6-t-butylphenol), 4,4'-butylidenebis (3-methyl-6-t-butylphenol) and the like. Polymer type phenols: 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenol) butane, 1,3,5-trimethyl-2,4,6-tris (3,5- Di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis-
(Methylene-3- (3'5'-di-t-butyl-4'-
(Hydroxyphenyl) propionate) methane, bis (3,3′-bis- (4′-hydroxy-3′-tert-butylphenyl) butyric acid) glycol ester, 1,3,5-tris (3 ′, 5 ′) -Di-t-butyl-4'-hydroxybenzyl) -S-triazine-2,
4,6- (1H, 3H, 5H) trione, tocophenol (s) and the like.

As the sulfur-based antioxidant, dilauryl 3,3
3′-thiodipropionate, dimyristyl 3,3′-
Thiodipropionate, distearyl 3,3'-thiodipropionate and the like. Phosphorous antioxidants include triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite,
4,4'-butylidene-bis (3-methyl-6-t-butylphenylditridecyl) phosphite, cyclic neopentanetetraylbis (octadecylphosphite), tris (nonylphenyl) phosphite, tris (mono and / Or dinonylphenyl) phosphite, diisodecylpentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene = 10-oxide, 10- (3,5-
Di-tert-butyl-4-hydroxybenzyl) -9,10
-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-
Dihydro-9-oxa-10-phosphaphenanthrene, tris (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,4-di-t-butylphenyl) phosphite, Cyclic neopentanetetraylbis (2,6-di-
t-butyl-4-methylphenyl) phosphite, 2,
2-methylenebis (4,6-di-t-butylphenyl)
Known ones such as octyl phosphite are exemplified.

HALS (Hindered amine light stabilizer)
As bis (1,2,2,6,6-pentamethyl-4-piperidyl) 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate, phenyl -4-piperidinyl carbonate, bis (2,2,6,6-tetramethylpiperidinyl) -4-sebacate, bis (N-methyl-2,
2,6,6-tetramethyl-4-piperidyl-1,2,2
3,4-butanetetracarboxylate, 1,1′-
(1,2-ethanediyl) bis (3,3,5,5-tetramethylpiperidine) and the like.
LS-770, Geigy's Chimassorb 944LD, Asahi Denka's ADK STAB LA-57, etc. are available. In the present invention, HALS is particularly effective from the viewpoint of coating suitability and light resistance after printing. The recording layer may contain an ultraviolet absorbent described below.

The antioxidant and the ultraviolet absorber described below are used by being dispersed in a paint containing the above-mentioned various resins and pigments as main components. Of course, it is also possible to use an ultraviolet absorber and an antioxidant together in the recording layer (absorbing layer). Photodegradation is considered to be due to the initiation reaction of autoxidation by light (ultraviolet) energy. However, it is difficult to completely suppress the generation of radicals with an ultraviolet absorber. Is effective. Particularly when the protective layer contains an ultraviolet absorber and the recording layer contains an antioxidant, the light resistance is extremely excellent. Preferably, the protective layer is a benzotriazole ultraviolet absorber, and the recording layer is HAL.
S is contained. A cationic resin can be added to the recording layer for the purpose of improving the ink fixing property. It is preferable to add a cationic resin in the recording layer of the invention, particularly in the upper layer. The cationic resin to be added is not particularly limited, but various resins forming an insoluble salt with a sulfone group, a carboxyl group, etc. of an ink jet dye, secondary amine, tertiary amine, quaternary ammonium salt And the like. 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 is 1 to 3 with respect to 100 parts by weight of the pigment.
0 parts by weight, more preferably in the range of 5 to 20 parts by weight. 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.

The support is not particularly limited, and may be transparent or opaque. For example, cellophane, polyethylene, polypropylene, soft polyvinyl chloride, hard polyvinyl chloride, plastic films such as polyester, high quality paper, art paper, coated paper, cast coated paper,
Paper such as foil paper, kraft paper, polyethylene laminated paper, impregnated paper, vapor-deposited paper, and water-soluble paper, metal foil, and synthetic paper are appropriately used.

The recording layer may be composed of only one layer, but another recording layer (lower layer) may be used in order to increase the ink absorbency and the like.
May be provided. Other recording layers are generally commercially available pigments (eg, silica, alumina silicate, kaolin, clay,
Calcined clay, zinc oxide, tin oxide, magnesium sulfate, aluminum oxide, aluminum hydroxide, pseudo-boehmite,
Calcium carbonate, satin white, aluminum silicate,
Smectite, magnesium silicate, magnesium carbonate,
Magnesium oxide, diatomaceous earth, styrene-based plastic pigments, urea resin-based plastic pigments, benzoguanamine-based plastic pigments, etc., various publicly known and used pigments in the general coated paper field), the binder described above, etc., and the above-mentioned cationic resin is added. You can also. Preferably, the upper recording layer (the side to which the ink is applied) is made the fine pigment-containing layer so that the surface gloss and
By increasing the recording density, the lower recording layer (support side) can improve the absorbability of the ink solvent as a pigment-containing layer having a larger particle diameter than the fine pigment, and the lower recording layer (support side) can also be improved. By using the fine pigment, the surface gloss and the recording density can be further increased. The recording layer essentially includes at least one upper recording layer, and further includes one or more lower layers provided as necessary.

The coating amount of the recording layer is not particularly limited, but when the recording layer is composed of only one layer, the coating amount of the recording layer is 3 to 60 g / m ² , preferably 10 to 50 g / m ² . Adjust. When having another recording layer, the coating amount of the recording layer containing the antioxidant (at least the upper layer) is 2 to 30 g / g.
m ² , preferably 3 to 20 g / m ² . The coating amount of the other coating layer is 1 to 50 g / m ² , preferably 5 to 40 g.
/ M ² . Antioxidant content is 0.1-5
g / m ² range. Preferably 0.2 to 2.5
g / m ² . If less, it is difficult to obtain the effect,
If the amount is too large, ink absorbability is impaired. Various known coatings 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 are used as coating coaters for the upper recording layer and other recording layers. Engineering equipment. As the ink used in the inkjet recording method of the present invention, a dye for forming an image and a liquid medium for dissolving or dispersing the dye are essential components, and various dispersants, surfactants, if necessary,
It is adjusted by adding a viscosity adjusting agent, a specific resistance adjusting agent, a pH adjusting agent, a fungicide, a dissolution or dispersion stabilizer of the recording agent, and the like. Recording agents used in the ink include direct dyes, acid dyes, basic dyes, reactive dyes, food dyes, disperse dyes,
Examples include oil-based 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 such as methyl alcohol, ethyl alcohol, n-propyl alcohol,
C1-C4 alkyl alcohols such as isopropyl alcohol, n-butyl alcohol and isobutyl alcohol; ketone or ketone alcohols such as acetone and diacetone alcohol; polyethylene glycol, polyalkylene glycols such as polypropylene glycol, ethylene glycol; Alkylene groups such as propylene glycol, butylene glycol, butylene glycol, triethylene glycol, thiodiglycol, hexylene glycol, diethylene glycol having 2 to 6 alkylene glycols, amides such as dimethylformamide, ethers such as tetrahydrofuran, glycerin, Multivalent alcohols such as ethylene glycol methyl ether, diethylene glycol methyl (ethyl) ether, and triethylene glycol monomethyl ether Such as a lower alkyl ether of Le and the like.

In the present invention, a protective layer is provided on the recording layer after recording with the ink jet ink as described above. The protective layer must contain at least an ultraviolet absorber, and examples of such an ultraviolet absorber include organic and inorganic ones. Salicylic acids (phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, etc.) and benzophenones (2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2- Hydroxy-4-octoxybenzophenone,
2-hydroxy-4-dodecyloxybenzophenone,
2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-dihydroxy-4-methoxy-5
Sulfobenzophenone, etc.), benzotriazole type ｛2
-(2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-ter
t-butylphenyl) benzotriazole, 2- (2 ′
-Hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2-
(2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) benzotriazole, 2- [2 '-Hydroxy-3'-
(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl] benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6 -(2H-benzotriazol-2-yl) phenol], etc., cyanoacrylate (2-ethylhexyl-2-cyano-3,3′-diphenylacrylate, ethyl-2-cyano-3,3′-diphenylacrylate, etc.) ) And the like.

As the inorganic ultraviolet absorber, zinc oxide,
Transition metal oxides such as cerium oxide, titanium oxide, and yttrium oxide are appropriately used. In the present invention, a benzotriazole-based organic compound and a cerium oxide-based inorganic compound are particularly effective in terms of coating suitability and print light resistance.

As described above, the protective layer contains an ultraviolet absorber as a light resistance improving agent. In particular, if the benzotriazole-based ultraviolet absorber has a wide absorption wavelength range and a high absorption intensity, better light resistance can be obtained. The protective layer may contain an antioxidant. The content of the ultraviolet absorber is 0.1 to 5 g / m ² , preferably 0.2 to 2.5 g.
/ M ² range. If the amount is small, it is difficult to obtain the light resistance effect. On the other hand, if the amount is too large, it causes a change in the color tone of the image and a decrease in the print density, and deteriorates the image quality. This is because the recorded image is viewed through the protective layer, and the protective layer is required to have a certain degree of transparency. Such an ideal transparency has a haze value of 15% or less, preferably 10 or less.

The lightfastness improver such as an ultraviolet absorber or an antioxidant may be applied alone on the printed image, but may be incorporated into other protective layer materials by dispersion (kneading) or coating. Can be placed on the printed image. As the material used in combination with the light resistance improver in the protective layer, a material having high transparency is preferable for the above-mentioned reason. For example, when a plastic film containing a light resistance improver is used as the protective layer, examples of usable films include a polypropylene film, a polyester film, a polyvinyl chloride film,
Alternatively, a transparent resin film such as a fluorine film may be used. Various lamination methods, such as an extrusion lamination method, a wet lamination method, a hot melt lamination method, a dry lamination method, a hot lamination method, and a cold lamination method, can be applied to the recording layer. As described above, the light fastness improver such as an ultraviolet absorber may be kneaded in the film or may be applied on the film. Further, a lightfastness improver is dispersed in a liquid of a water-soluble resin or a water-dispersible resin as described above such as polyvinyl alcohols and various cellulose derivatives,
It can be installed by various coating methods.

[0026]

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 coating liquid for a recording layer was dried at a dry weight of 20
g / m 2 was coated on a commercially available coated paper (manufactured by Oji Paper Co., Ltd., trade name: OK coat, 127.9 g / m ² ) with a die coater and dried. (Coating liquid for recording layer) 100 parts of amorphous silica (trade name: Fine Seal X-45, manufactured by Tokuyama Corporation, secondary particle size: 4.5)
μm), 35 parts of silyl-modified polyvinyl alcohol (manufactured by Kuraray, trade name: PVA-R-1130), and polydiallyldimethylammonium chloride (trade name: PAS-H-10L, manufactured by Nitto Boseki Co., Ltd.), which is a cationic resin
Part, hindered amine light stabilizer 2- (3,5-
Bis (1,2,2,6,6-pentamethyl-4-piperidyl) di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate
(Ciba Geigy, product name: Tinuvin 144) 10
Department. Concentration 12%. Subsequently, an ink jet printer (trade name: PM-700, manufactured by EPSON) is provided on the obtained recording layer.
Printed in C). A transparent PET film substrate (Lumilar T25 μm, manufactured by Toray Industries, Inc.) is coated with a water-soluble benzotriazole-based ultraviolet absorber (trade name: Sunguard W-51, manufactured by SENKA CORPORATION) at a rate of 1 g / m ^{2 on} one surface of the substrate using a roll coater. Polyurethane adhesive (Dainichi Seika,
(Product name: WA-377) was applied at a rate of 2.5 g / m ² and laminated by a dry lamination method.

Comparative Example 1 The operation was performed in the same manner as in Example 1 except for the following points. On a recording layer obtained in the same manner as in Example 1, an ink jet printer (E
Printed by PSON, trademark: PM-700C). On top of this, a transparent PET film substrate (Lumilar T, manufactured by Toray Industries, Inc.)
25 μm), on one side, 1,3,5-trimethyl-2,4,6- which is an emulsion type hindered phenol.
Tris- (3,5-di-t-butyl-4-hydroxybenzyl) benzene (manufactured by Ciba-Geigy, trade name: Tinuvin 1130) was applied to the same surface of a protective layer coated with a roll coater at 1 g / m ² to form a polyurethane adhesive. An agent (Dainichi Seika, trade name: WA-377) was applied at a rate of 2.5 g / m ² and laminated by a dry lamination method. Otherwise, an ink jet recording medium was manufactured in the same manner as in Example 1.

Example 2 100 parts of amorphous silica (trade name: Fine Seal X-45, manufactured by Tokuyama Corporation) and 15 parts of a cationic resin for a recording layer were mixed with 115 parts of a silica sol B containing the following cationic resin.
And an ink jet recording medium of the present invention was produced in the same manner as in Example 1 except that the paint concentration was changed to 7%. [Silica Sol A] Synthetic amorphous silica having an average particle size of 3 μm (manufactured by Nippon Silica Industry Co., Ltd., trade name: Nipsil, HD-
(2, primary particle size: 11 nm) was pulverized and dispersed by a sand grinder, and further pulverized and dispersed by a pressure homogenizer. The pulverization and dispersion operation of the sand grinder and the pressure homogenizer was repeated until the average particle diameter became 70 nm, and 8%. Was prepared as an aqueous dispersion. [Silica sol B] Polydiallyldimethylammonium chloride (trade name: PAS-H-10L, manufactured by Nitto Boseki Co., Ltd.) 1 was added to 100 parts of silica sol A.
5 parts were added to thicken and aggregate. Next, after pulverizing and dispersing with a sand grinder, further pulverizing and dispersing with a pressure type homogenizer, and repeating the pulverizing and dispersing operations of the sand grinder and the pressure type homogenizer until the average particle diameter becomes 150 nm, thereby producing a 9% aqueous dispersion as a trial. did.

Example 3 The same procedure as in Example 1 was performed until the coating and printing of the recording layer.
After recording, the following UV absorber, Ruchi
Polyolefin resin composition containing titanium oxide
25g / m by melt extruder with T-die^TwoBecomes
Cooling law with a mirror surface
And solidified by cooling. (Polyolefin resin composition) Long chain type low density polyethylene
Resin (density 0.926g / m^Three, Melt index
20 g / 10 min) 35 parts by weight, low density polyethylene resin
(Density 0.919 g / m ^Three, Melt index 2g /
10 minutes) 50 parts by weight, rutile type titanium oxide (Kanto Chemical Co., Ltd.)
15 parts by weight, an antioxidant (Irganox1)
010; Ciba-Geigy) 0.03 parts by weight.

Example 4 In Example 1, polyvinyl alcohol (manufactured by Kuraray Co., trade name: PVA-420) was used instead of laminating a transparent PET film substrate coated with an ultraviolet absorbent after printing.
A coating liquid consisting of 100 parts and 20 parts of cerium oxide was coated and dried so that the dry coating amount was 10 g / m ^2, and a protective layer was provided.

Comparative Example 2 A recording layer was coated and printed in the same manner as in Example 1, but thereafter, no protective layer was provided. Comparative Example 3 A recording medium was obtained in the same manner as in Example 1, except that the hindered amine-based stabilizer was omitted from the composition of the recording layer coating liquid.

COMPARATIVE EXAMPLE 4 Before printing on the same recording layer as in Example 1,
10g / m of similar coating liquid ^TwoCoating so that it becomes a protective layer
Was provided. Thereafter, printing was performed on the protective layer. Comparative Example 5 The protective layer of Example 1, that is, a transparent layer containing an ultraviolet absorbent.
The recording coating layer of Example 1 was coated on a bright PET film,
After drying, printing was performed from the recording layer surface side. That
Thereafter, the recording layer and the commercial coated paper of Example 1 (Oji Paper, OK
Paper).

[Evaluation Method] The transparency of the protective layer obtained in the examples and comparative examples, and the ink absorbency, print density (after laminating the protective layer), and image light fastness of the ink jet recording material were evaluated by the following methods. did. Note that printing is performed as described above for EP.
A printer (trade name: PM-750C) manufactured by SON was used. [Transparency of protective layer (haze value)] The transparency of the protective layer was evaluated by the haze value. (The lower the haze, the higher the transparency.) According to JIS K 7105, it was measured using HR-100 manufactured by Murakami Color Research Laboratory. In Example 3,
4 and Comparative Example 4 were transparent PE for measuring the haze.
A sample coated on a T film substrate (Lumilar T25 μm, manufactured by Toray Industries, haze value: 1) was prepared and used for measurement. [Printing ink absorbency] The single color of yellow, magenta, and cyan is overprinted so that the printing portion is solid black, and high quality paper is overlaid on the printing surface every 5 seconds immediately after printing to determine whether or not the ink is transferred. Observed. The number of seconds that were not transferred at all was measured and evaluated according to the following steps. ：: less than 15 seconds Δ: 15 seconds to less than 60 seconds ×: 60 seconds or more [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 Lightfastness] Images of ISO-400 (“High-definition color digital standard image data ISO / 400
JIS-SCID ", p13, Image name: Fruit basket, p
14. Image name: Candle, issued by Japan Standards Association, printed in glossy paper mode and provided with a protective layer (Comparative Example 4 was bonded to a substrate). Next, a xenon lamp type FADE-OMETER (ATLAS ELE
CTRIC DEVICES Co. Made by MODE
L: CI35F), and the print sample was continuously processed for 72 hours at 63 ° C. and 50%. The two images were compared to the unprocessed image and the lightfastness level was evaluated as follows. A: Almost no fading occurred. ：: The image is faint and fading, but the color balance is not broken. Δ: The image has faded, and the color balance has been lost. X: Discolored considerably.

[0035]

[Table 1]

As is clear from Table 1, Examples 1-4 in which the recording layer and the protective layer contained a lightfastness improver were usable at all evaluation items, and the benzotriazole-based ultraviolet absorption was included in the protective layer. Examples in which a hindered amine-based light stabilizer was used as an agent for improving the light resistance of the recording layer were particularly excellent in light resistance. In the protective layer adjusted to a haze value of less than 15, almost no decrease in print density due to the provision of the protective layer was observed. On the other hand, Comparative Example 2 in which the protective layer was not provided, Comparative Example 3 in which the recording layer did not contain the light resistance improving agent, and the recording layer and the protective layer contained the light resistance improving agent even when the protective layer was coated with an ultraviolet absorber. Comparative Example 1 containing no antioxidant had poor light fastness. Comparative Example 4 in which printing was performed from above the protective layer was poor in absorbency, and Comparative Example 5 in which printing was performed from the surface opposite to the protective layer was significantly poor in print density.

[0037]

The present invention relates to an ink jet recording medium, and in particular, an ink jet recording medium having excellent light fastness and excellent image quality without deteriorating printing quality.

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Claims (4)

[Claims] 1. An ink-jet recording method comprising the steps of: recording on an ink-jet recording medium having a recording layer including an upper recording layer and an optional lower recording layer provided on a support with an ink-jet ink; and providing a protective layer on the recording layer. An ink jet recording material, wherein the recording material is at least the upper layer of the recording layer contains an antioxidant, and the protective layer contains an ultraviolet absorber. 2. The ink jet recording material according to claim 1, wherein the antioxidant contains a hindered amine light stabilizer and the ultraviolet absorber contains a benzotriazole ultraviolet absorber or cerium oxide. 3. The ink jet recording medium according to claim 1, wherein the protective layer is a protective layer provided by bonding a transparent resin film. 4. The ink jet recording medium according to claim 1, wherein the upper recording layer contains a pigment having an average particle diameter of 1 μm or less.