JP3910617B2 - Inkjet recording sheet - Google Patents

Description

  The present invention relates to an ink jet recording sheet for forming an image sheet by ink jet recording. In particular, the present invention relates to an ink jet recording sheet for forming a high gloss image sheet by ink jet recording.

  In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording methods and apparatuses suitable for each information system have been developed and adopted. Among such recording methods, in inkjet recording in which ink is jetted and thermal transfer recording using a melt type color material or a sublimation type color material, the apparatus used is light and compact, and noise is reduced. It is also excellent in operability and maintainability. Furthermore, devices used in ink jet recording have been widely used recently because they can be easily colored.

  Various types of ink jet recording methods have been developed. In terms of physical properties, a method using a dye solution (water-based ink) containing a water-soluble dye and a dye solution (oil-based ink) containing an oil-soluble dye are roughly used. There are three methods: a method and a method in which a low melting point solid wax (wax ink) containing a dye is heated and melted. The mainstream is a type that uses water-based ink. In any case, this is a method of forming an image by ejecting liquid fine droplets onto an ink jet recording sheet.

  The above-mentioned image formation by ink jet recording is performed on ordinary paper, and in the following applications, it is necessary to use a transparent sheet. In many cases, a transparent film having a colorant receiving (absorbing) layer on the surface is used. Is used to form a recording sheet as described above. For example, an OHP film that is increasingly used in place of slides in a meeting, a backlight display film that is increasingly used in place of a print poster or display board, and a second original film. be able to. In addition, a hard copy in which an image is formed on an ink jet recording sheet has a fine image and may require a glossiness higher than that formed on ordinary paper. That is, when considering a silver salt photograph that is an ideal hard copy, high glossiness is an important issue to be achieved.

Accordingly, in ink jet recording, a liquid ink is absorbed quickly in order to obtain a fine image, the ink image transferability is good, and a colorant receiving layer that does not cause ink bleeding or the like. In order to form an image sheet, a highly transparent colorant receiving layer is required.
A conventional colorant-receiving layer mainly composed of a resin is excellent in transparency, but easily swells or dissolves with ink and becomes sticky, so that the ink image (paper is pressed against the printed ink image) Sometimes the degree of density of ink transferred to paper is not good.

For example, in the case of ink jet recording, Japanese Patent Application Laid-Open No. 56-80489 proposes the use of a soluble or swellable substance, and many polymer systems (polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide ( PEO) and carboxymethyl cellulose (CMC)) have been proposed. However, although such a polymer colorant-receiving layer is excellent in transparency, ink absorbability and ink transfer properties are not satisfactory. That is, such a colorant receiving layer utilizes the penetrating effect of the aqueous ink due to the hydrophilic group or dissociable group of the polymer, and it can be said that sufficient ink absorption is sufficient even when the film is thickened. Of course, the ink transfer performance is not satisfactory.
Japanese Patent Laid-Open No. 3-104683 proposes the use of polyvinylpyrrolidone crosslinked to the material of the colorant receiving layer. By using such a colorant-receiving layer, the ink transfer property is somewhat improved, but it is not satisfactory. That is, if the crosslinking proceeds too much, the ink absorptivity is lowered and the ink transfer property is deteriorated.

In order to improve the ink absorptivity and ink transfer properties, a recording sheet comprising a transparent support, a colloidal silica provided thereon and a transparent layer of a water-soluble resin has been proposed. Since the above-mentioned transparent layer does not have a high porosity, the recording sheet has improved ink absorbability, but it cannot be said that it is sufficient. Also disclosed is a recording sheet comprising a colorant-receiving layer having pores formed from pseudoboehmite fine particles. Although this recording sheet has improved ink absorption and ink transfer properties, it has a high refractive index and does not provide sufficiently high transparency.
Japanese Patent Publication No. 61-53598 discloses a recording sheet comprising a support, a synthetic silica provided thereon, fine particles having a refractive index of 1.44 to 1.55, and a transparent layer made of a water-soluble resin. It is disclosed. Synthetic silica usually has a primary particle size exceeding 10 nm, and the secondary particles have a particle size of several hundred nm. Such secondary particles are likely to scatter light, and thus a recording sheet containing such particles does not exhibit a sufficiently high light transmittance.

On the other hand, Japanese Examined Patent Publication No. 62-11678 discloses an ink jet recording sheet using a specific basic latex polymer, which has excellent ink absorbability and excellent ink retention. This basic latex polymer is obtained from a monomer having a tertiary amino group or a quaternary ammonium group, a monomer containing two or more ethylenically unsaturated groups, and other monomers. The colorant-receiving layer containing this basic latex polymer is excellent in the ink absorbability and the like, but since the particle diameter is usually about 0.5 μm in the case of latex, sufficiently high transparency cannot be obtained. Further, in Examples, a sheet provided with a colorant receiving layer containing a basic latex polymer on ordinary paper, and a sheet provided with a colorant receiving layer containing a basic latex polymer and a large amount of calcium carbonate on a transparent film. No sheet with excellent transparency is disclosed.
Therefore, a recording sheet suitable for applications requiring transparency such as the above-described OHP sheet or applications requiring high gloss has not been obtained.

  The present invention provides an ink jet recording sheet which can form an image by ink jet recording, has a high glossiness, and does not cause ink transfer or ink bleeding under high humidity when the image is formed. The purpose is to provide.

The present invention relates to a recording sheet comprising an opaque support having a highly glossy surface and a colorant receiving layer provided thereon, wherein the colorant receiving layer is an acrylic having an average particle diameter of 1 to 200 nm. At least one monomer selected from the group consisting of acid alkyl esters, alkyl methacrylate esters, styrene and styrene derivatives has a cationic group containing a quaternary ammonium base, and one or two carbon-carbon double bonds in the molecule Cationic crosslinked polymer fine particles containing a quaternary ammonium base obtained by emulsion polymerization using the emulsifier having the above and a crosslinked water-soluble resin (the weight ratio of the former to the latter is 1: 1 to 1: Do because any) in the range of 10 Ri, further matting agent contain 0.01 to 5 wt%, and the glossiness of the recording sheet (JIS P-814 (75 degree specular gloss) described in 2 is 70% or more.
The glossiness is a value measured according to the method described in JIS P-8142 (75-degree specular gloss test method for paper and paperboard).

Preferred embodiments of the ink jet recording sheet of the present invention are as follows.
1) The average particle diameter of the crosslinked polymer fine particles is 1 to 100 nm .
2) The water-soluble resin is polyvinyl alcohol .
3) The weight ratio between the crosslinked polymer fine particles and the water-soluble resin is in the range of 1: 1 to 1:10 (polymer fine particles: water-soluble resin) .
4) Glossiness is 75% or more (particularly 80% or more) .
5) The ink used for inkjet recording is a water-based ink (50% by weight or more of the solvent is water) .

The ink jet recording sheet of the present invention is a cation having an average particle size of 1 to 200 nm and containing at least one monomer selected from the group consisting of alkyl acrylates, alkyl methacrylates, styrene and styrene derivatives, containing a quaternary ammonium base. Crosslinked with cationically crosslinked polymer fine particles containing a quaternary ammonium base obtained by emulsion polymerization using an emulsifier having an ionic group and having one or more carbon-carbon double bonds in the molecule water-soluble resins (where the former pair latter weight ratio of 1: 1 to 1: in the range of 10) Ri Do from the coloring material-receiving layer is provided which contains more 0.01-5% by weight of matting agent It has been. Since this colorant receiving layer has an excellent ink absorbing ability, it has good ink transfer properties. Moreover, even if inorganic fine particles are not used, good ink transfer properties are exhibited. When the highly transparent colorant-receiving layer of the present invention is provided on a support having high glossiness, a high-quality ink image can be formed without impairing the high gloss of the support.

The ink jet recording sheet of the present invention has a basic structure comprising a high-gloss opaque support and a colorant receiving layer provided on one surface of the support. The colorant receiving layer may be provided on both sides of the support.
The inkjet recording sheet of the present invention can be produced, for example, as follows.
In the present invention, a high-gloss opaque support is used as the support.

As the high-gloss opaque support, one having a glossiness of 40% or more on the surface on which the colorant-receiving layer is provided is preferable. The glossiness is a value determined by measurement according to the method described in JIS P-8142 (75-degree specular gloss test method for paper and paperboard).
Examples of high-gloss opaque supports include high-gloss papers such as art paper, coated paper, cast-coated paper, and baryta paper used for silver salt photographic supports; polyesters such as polyethylene terephthalate (PET) , Cellulose esters such as nitrocellulose, cellulose acetate and cellulose acetate butyrate, and plastic films such as polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide, etc. A support provided with a polyolefin coating layer containing or not containing a white pigment on the surface of a film (including surface calendar treatment) or the above-mentioned various papers, the above-mentioned transparent plastic film or a plastic containing white pigment, etc. All Rukoto can. Furthermore, a white pigment-containing foamed polyester film (eg, calcium carbonate-containing foamed PET containing polyolefin fine particles and forming voids by stretching) can also be mentioned.
Polyolefin-coated paper used as a silver salt photographic support (a kind of support having a polyolefin coating layer such as a paper support having a white pigment-containing polyolefin layer on its surface) or a metal vapor deposition layer The special paper etc. in which etc. were provided can be used conveniently. In particular, a paper support provided with a white pigment-containing polyolefin layer, a polyester (preferably PET) film provided with a white pigment-containing polyolefin layer, a white pigment-containing polyester film, or a white pigment-containing foamed polyester film is preferred.
Although there is no restriction | limiting in particular in the thickness of a support body, the thing of 50-200 micrometers is easy to handle and preferable.

The colorant receiving layer of the present invention can be formed as follows.
A colorant-receiving layer can be formed by applying a coating solution in which crosslinked polymer fine particles having an average particle size of 200 nm or less are dispersed in a water-soluble resin solution and drying the coating solution.
Examples of water-soluble resins include polyvinyl alcohol (PVA), cellulose resins (methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC) as resins having hydroxyl groups as hydrophilic structural units. Etc.), chitins and starch; polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG) and polyvinyl ether (PVE) as resins having an ether bond; and resins having an amide group or an amide bond Examples thereof include polyacrylamide (PAAM) and polyvinylpyrrolidone (PVP). In addition, polyacrylates having a carboxyl group as a dissociable group, maleic acid resin, alginate and gelatins; polystyrene sulfonates having a sulfone group, amino groups, imino groups, tertiary amines and quaternary ammonium salts Examples thereof include polyallylamine (PAA), polyethyleneimine (PEI), epoxidized polyamide (EPAm), polyvinylpyridine, and gelatins.

The water-soluble resin is preferably crosslinked with a crosslinking agent in order to improve the water resistance of the colorant receiving layer. That is, it is preferable to form a colorant receiving layer by adding a cross-linking agent to a coating solution containing polymer fine particles cross-linked with a water-soluble resin, coating the support, and drying by heating (cross-linking). .
Examples of the crosslinking agent include aldehydes (eg, formaldehyde, glyoxal and glutaraldehyde), N-methylol compounds (eg, dimethylolurea and methyloldimethylhydantoin), dioxane derivatives (eg, 2,3-dihydroxydioxane), carboxyl Compounds acting by activating groups (eg, carbenium, 2-naphthalenesulfonate, 1,1-bispyrrolidino-1-chloropyridinium and 1-morpholinocarbonyl-3- (sulfonatoaminomethyl)), active vinyl compounds (Eg, 1,3,5-triacroyl-hexahydro-s-triazine, bis (vinylsulfone) methane and N, N′-methylenebis- [β- (vinylsulfonyl) propionamide]), active halogen compounds (eg, 2 , 4-jiku B-6-hydroxy--S- triazine), isoxazole compounds, melamine resins, isocyanate compounds and dialdehyde starches, and the like. These can be used alone or in combination.
When productivity is considered, use of aldehydes, such as glutaraldehyde with high reaction activity, or a melamine resin is preferable.
As a preferable water-soluble resin used in combination with the crosslinking agent, polyvinyl alcohol can be exemplified.
The addition amount of the crosslinking agent is preferably from 0.1 to 20% by weight, particularly preferably from 0.5 to 15% by weight, based on the water-soluble resin.

The crosslinked polymer fine particles having an average particle diameter of 200 nm or less of the present invention are cationic containing a quaternary ammonium base . Such polymer fine particles usually contain at least one monomer selected from the group consisting of alkyl acrylates, alkyl methacrylates, styrene and styrene derivatives , a cationic group containing a quaternary ammonium base , and carbon in the molecule. It can be obtained by emulsion polymerization using an emulsifier having one or more carbon double bonds (preferably two or more). As such polymer fine particles, a microgel described in JP-A-5-254251 can be suitably used. In this publication, it is described that microgel is used for thermal recording paper. However, thermal recording is not performed by ejecting ink onto a recording sheet as in the present invention, but is performed by heating. And belong to different technical fields.

As an example of the alkyl acrylate ester and the alkyl methacrylate ester, an alkyl (meth) acrylate having 1 to 18 carbon atoms is preferable, for example, methyl (meth) acrylate, ethyl (meth) acrylate, ( N-propyl (meth) acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate Can be mentioned.
Examples of styrene and styrene derivatives include styrene, α-methylstyrene and vinyltoluene.

  In addition to the monomer, a monomer copolymerizable with the monomer may be used in an amount of 50% by weight or less of the total monomer amount. For example, anionic vinyl monomers such as acrylic acid, methacrylic acid, maleic anhydride, styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid; dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and quaternary ammonium And cationic vinyl monomers such as vinyl monomers having salts; and nonionic vinyl monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and (meth) acryloyloxyphosphate. it can.

  In addition to the above monomers, a crosslinkable vinyl monomer may be used in an amount of 5% by weight or less of the total monomer amount. For example, bifunctional monomers such as ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, hexamethylenebis (meth) acrylamide, divinylbenzene; 1,3,5-triacryloylhexahydro-S-triazine And trifunctional monomers such as triallyl isocyanurate; tetrafunctional monomers such as tetramethylolmethane tetraacrylate and N, N, N ′, N′-tetraallyl-1,4-diaminobutane.

Examples of the carbon-carbon double bond of the emulsifier having one or more carbon-carbon double bonds in the molecule include (meth) allyl group, 1-propenyl group, 2-methyl-1-propenyl group. , Vinyl group, isopropenyl group and (meth) acryloyl group. Of these, a (meth) acryloyl group is preferred.
The emulsifier has a cationic group (hydrophilic group) for exhibiting an emulsifying action together with a hydrophobic group. A cationic group is preferable because it has a large function of holding ink and thus improves the water resistance of the colorant-receiving layer. As the cationic group, —N (R ¹ ) (R ² ) (R ³ ) [R ¹ , R ² and R ³ each independently represents a hydrogen atom, alkyl or hydroxyalkyl, and at least one group is alkyl or A cationic group containing a quaternary ammonium base represented by [which is hydroxyalkyl].
The emulsifier plays the role of a normal emulsifier and the role of a polymerizable (crosslinkable) monomer, and thus the surface of the resulting crosslinked polymer fine particle has the above cationic groups. Of course, it may exist inside the polymer fine particles.

  Examples of emulsifiers include sulfooxysuccinic acid ester salts of polyoxyethylene alkyl ether having two or more carbon-carbon double bonds in the molecule, and polyoxyethylene alkyl ether having two or more carbon-carbon double bonds in the molecule. Sulfate ester salt of polyoxyethylene alkylphenyl ether having two or more carbon-carbon double bonds in the molecule, polyoxyethylene alkylphenyl ether having two or more carbon-carbon double bonds in the molecule Sulfate ester salt, acidic phosphoric acid (meth) acrylate ester dispersant, oligoester (meth) acrylate phosphate ester or alkali salt thereof, and polyalkylene glycol derivative oligoester poly ( Meth) acrylate Rukoto can. These commercially available products include KAYAMER PM-2 (manufactured by Nippon Kayaku Co., Ltd.), New Frontier A-229E (Daiichi Kogyo Seiyaku Co., Ltd.), New Frontier N-250Z (Daiichi Kogyo Seiyaku). For example).

When using an emulsifier having two or more carbon-carbon double bonds in the molecule, an emulsifier having one carbon-carbon double bond in the molecule may be contained in a proportion of 60% by weight or less of the total emulsifier. . The emulsifier having one or more carbon-carbon double bonds in the molecule may contain a normal anionic emulsifier, a cationic emulsifier, or a nonionic emulsifier.
The amount of the emulsifier having one or more carbon-carbon double bonds in the molecule is usually 1 to 20 parts by weight, preferably 3 to 10 parts by weight, based on 100 parts by weight of the total monomers. .

The crosslinked polymer fine particles of the present invention can be obtained by a known emulsion polymerization method using the above materials.
For example, the above emulsifier and water are added to a reaction vessel, and the above monomer is added to emulsify, and then a radical polymerization initiator is added, and the monomer is polymerized by heating with stirring and polymerizing the monomer. Can be obtained. Addition of the vinyl monomer may be either batch dropping or divided dropping. The concentration of such a material is such that the solid content concentration in the finally obtained reaction liquid (dispersion) is usually 20 to 50% by weight, preferably 30 to 45% by weight. Adjusted. The pH during the reaction is preferably in the range of 3 to 9, and the reaction temperature may be a temperature at which the polymerization initiator is activated, and is usually 40 to 90 ° C, preferably 50 to 80 ° C. The reaction time is usually 30 minutes to 2 hours.

Examples of the radical polymerization initiator include water-soluble radical polymerization initiators such as persulfates such as potassium persulfate and ammonium persulfate, hydrogen peroxide, and water-soluble azo initiators; or the above-mentioned persulfates and hydrogen sulfite. The redox polymerization initiator which combined reducing agents, such as sodium and sodium thiosulfate, can be mentioned. Redox polymerization initiators are preferred. The addition amount of the radical polymerization initiator is preferably 0.05 to 5% by weight, particularly preferably 0.1 to 3% by weight of the total monomer amount.
Further, in order to make the obtained polymer fine particles into transparent ultra fine particles, it is preferable to carry out the polymerization in the presence of a transition metal ion as a polymerization accelerator.
The polymer fine particles crosslinked with the emulsifier thus obtained have the above-mentioned emulsifier on the surface, and therefore there are anionic groups and cationic groups (hydrophilic groups) on the surface. Become. Therefore, the inkjet water-based ink can be easily adsorbed on the surface, and an anionic group, a cationic group, etc. can work effectively. Such a hydrophilic group is also present inside the polymer fine particles depending on the type, amount and reaction method of the emulsifier used.

  The resulting crosslinked polymer fine particle is a dispersion having a solid content concentration of usually 20 to 50% by weight, preferably 30 to 45% by weight, and the average particle size is 200 nm or less (preferably in the range of 1 to 100 nm). ). Moreover, the viscosity of the 40 weight% dispersion of polymer fine particles is usually 100 to 500 cps.

  The colorant receiving layer of the present invention is mainly composed of the crosslinked polymer fine particles and a water-soluble resin. The ratio of the crosslinked polymer fine particles and the water-soluble resin contained in the colorant receiving layer is preferably in the range of 1: 1 to 1:10 (polymer fine particles: water-soluble resin), particularly 1: 1. A range of ˜1: 5 is preferred.

  In addition to the polymer fine particles crosslinked with the water-soluble resin, the colorant-receiving layer of the present invention includes, as a matting agent, colloidal silica, calcium silicate, Inorganic fine particles such as zeolite, kaolinite, halloysite, muscovite, talc, calcium carbonate, calcium sulfate and boehmite, or organic fine particles such as polymethyl methacrylate fine particles, polystyrene fine particles and polyethylene fine particles may be contained. Silica is preferable as the inorganic fine particles, and polymethyl methacrylate fine particles are preferable as the organic fine particles. The content of the matting agent in the colorant receiving layer is preferably from 0.01 to 5% by weight.

  The crosslinked polymer fine particles and water-soluble resin mainly constituting the colorant receiving layer may be a single material or a mixed system of a plurality of materials. The colorant-receiving layer is mainly composed of the above-mentioned crosslinked polymer fine particles and a water-soluble resin, but may further contain various inorganic salts and an acid alkali as a pH adjusting agent in order to improve the dispersibility of the particles. Various surfactants may be used for the purpose of improving the coating suitability and the surface quality. Further, a mordant may be used for the purpose of fixing a dye and improving water resistance in ink jet recording. Various matting agents may be included for the purpose of reducing the frictional properties of the surface. In addition, various antioxidants and ultraviolet absorbers may be included for the purpose of suppressing deterioration of the color material. Further, it may contain a fluorescent brightening agent.

The colorant-receiving layer can be formed, for example, by applying an aqueous dispersion (coating liquid) containing the resin, polymer fine particles, etc. on a support (high gloss opaque support) and drying by heating. it can. The coating can be performed by a known coating method such as an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, or a bar coater.
The drying is usually performed at 50 to 180 ° C. for 1 to 20 minutes with a hot air dryer, but preferably at 90 to 150 ° C. for 2 to 15 minutes.
In addition, after application and drying, the surface smoothness, transparency and coating strength can be improved by passing between roll nips under heating and pressure, for example, with a super calender or gloss calender.

In the color material receiving layer of the present invention thus obtained, crosslinked polymer fine particles having an average particle diameter of 1 to 200 nm are uniformly dispersed in the water-soluble resin. For this reason, it is presumed that the ink ejected by ink jet recording is absorbed in the water-soluble resin and polymer fine particles and the gap between the water-soluble resin and polymer fine particles. Therefore, in the case of ink absorption only by the water-soluble resin, the color material receiving layer of the water-soluble resin swells or softens, so that the ink image onto the paper is large. The amount of ink to be absorbed is small, and almost no ink appears. Especially when the polymer particles is cationic improves ink show-through, etc. affinity is good with the ink. Further, since it is not necessary to use inorganic fine particles which are usually used for improving ink image transfer properties, the colorant receiving layer has high transparency. When the highly transparent colorant receiving layer of the present invention is provided on a support having a high glossiness, a high quality ink image can be formed without impairing the high gloss of the support. . Furthermore, since the average particle diameter of the crosslinked polymer fine particles contained in the colorant receiving layer of the present invention is as small as 1 to 200 nm, most of the light in the low wavelength region (about 400 nm) of visible light is scattered. Therefore, the transparency of the obtained image is improved and the image quality is excellent.
The inkjet recording sheet of the present invention in which the colorant-receiving layer is provided on a highly glossy opaque support has a glossiness of 70% or more, preferably 75% or more, particularly preferably 80% or more. .
Next, examples and comparative examples are shown. Examples 1 to 3 and Comparative Examples 1 to 2 are all reference examples. Examples 4 to 7 and Comparative Examples 3 to 4 are examples and comparative examples of the present invention, respectively.

[Example 1]
(1) Composition of coating solution for forming a colorant receiving layer 35 parts by weight of a 10% by weight aqueous solution of polyvinyl alcohol (PVA210, manufactured by Kuraray Co., Ltd.)
Anionic cross-linked polymer fine particles 10 wt% aqueous dispersion 15 parts by weight (average particle size: 80 nm,
Acrylic resin fine particles cross-linked by an emulsifier having two carbon-carbon double bonds and a phosphate group,
Arakawa Chemical Industries, Ltd.)
1 part by weight of matting agent (4% by weight aqueous dispersion of thyloid # 620,
Fuji Devison Chemical Co., Ltd.)
1 part by weight of surfactant (10% by weight aqueous dispersion of Megafac F-144D,
Dainippon Ink & Chemicals, Inc.)
A material having the above composition was mixed to obtain a coating material for forming a colorant receiving layer.

This coating solution was applied to the surface of a biaxially stretched polyethylene terephthalate film having a thickness of 100 μm whose surface had been subjected to corona discharge treatment using a bar coater and dried at 120 ° C. for 10 minutes using a hot air dryer. As a result, a colorant receiving layer having a dry film thickness of 8 μm was formed.
Thus, an inkjet recording sheet in which a colorant receiving layer was provided on polyethylene terephthalate was obtained.

[Example 2]
In Example 1, instead of the 10% by weight aqueous dispersion of anionic crosslinked polymer fine particles, a 10% by weight aqueous dispersion of cationic crosslinked polymer fine particles (average particle size: 73 nm, 2 carbon-carbon double bonds) This was carried out except that a coating solution for forming a colorant receiving layer was prepared using polystyrene fine particles crosslinked with an emulsifier having quaternary ammonium bases and a trade name “Mist Pearl C-100” manufactured by Arakawa Chemical Industries, Ltd. An ink jet recording sheet was prepared in the same manner as in Example 1.

[Example 3]
In Example 2, the following materials were added to the coating material composition for forming the colorant receiving layer of Example 2 as a PVA crosslinking agent:
4.5 parts by weight of melamine resin (10% by weight aqueous dispersion of Sumires # 613,
(Sumitomo Chemical Co., Ltd.)
0.45 parts by weight of amine hydrochloride (5% by weight aqueous dispersion of ACX-P,
(Sumitomo Chemical Co., Ltd.)
An ink jet recording sheet was prepared in the same manner as in Example 2 except that a coating material for forming a colorant receiving layer was prepared by adding

[Comparative Example 1]
In Example 1, an ink jet recording sheet was prepared in the same manner as in Example 1 except that the colorant-receiving layer-forming coating solution having the following composition was used.
(1) Composition of coating material for forming colorant receiving layer 150 parts by weight of 10% by weight aqueous solution of polyvinyl alcohol (PVA210 (manufactured by Kuraray Co., Ltd.))
80 parts by weight of synthetic silica (average particle size: 20 nm)
Fine powder glass powder 20 parts by weight Water 310 parts by weight Materials of the above composition were mixed to obtain a coating material for forming a colorant receiving layer.

[Comparative Example 2]
In Example 1, an ink jet recording sheet was prepared in the same manner as in Example 1 except that the colorant-receiving layer-forming coating solution having the following composition was used.
(1) Composition of a coating material for forming a colorant receiving layer 4.5 parts by weight of polyvinylpyrrolidone (PVPK-90 (manufactured by GAF))
Dibenzylidenesorbitol 4.5 parts by weight (Gelol D)
1.0 part by weight of cationic polymer (quaternary ammonium salt-containing acrylic resin,
PQ-10, manufactured by Soken Chemical Co., Ltd.)
90.0 parts by weight of DMF A material having the above composition was mixed and dissolved to obtain a coating material for forming a colorant receiving layer.

The inkjet suitability was evaluated by the following measuring method for the inkjet recording sheet in which the transparent material obtained above was provided with a colorant receiving layer.
(1) Ink transfer characteristics A blue solid image is printed on a recording sheet with an inkjet color printer (BJC-600J; manufactured by Canon Inc.), and after 10 seconds, copy paper (PPC (Electrophotographic Copier) paper WR, Fuji Xerox Co., Ltd.) was contact-pressed with a rubber roller (condition: 0.6 kg / cm linear pressure). Then, the amount of ink transferred to the copy paper was evaluated by measuring the reflection density of the ink image portion using a reflection densitometer (X-rite, manufactured by X-rite Incorporated). The higher the reflection density, the greater the amount of ink transferred.
(2) Parallel light transmittance The parallel light transmittance was measured using a haze meter (HGM-2DP: manufactured by Suga Test Instruments Co., Ltd.).
(3) Light transmittance at 400 nm The light transmittance at a wavelength of 400 nm was measured using a spectrophotometer (instant multiphotometry system MCPD-1000; manufactured by Otsuka Electronics Co., Ltd.).
(4) Bleeding of images under high humidity For printing, the same printer as (1) is used, and yellow, magenta, cyan, black, blue, green, and red solid images are printed on the recording sheet. The sheet was left in an environment of 28 ° C. and 85% RH for 3 days. The degree of bleeding in the solid image portion was evaluated as follows.
AA: There is no blur in the solid image area
BB: Bleeding in part of the solid image
CC: Bleeding is observed in a considerable part of the solid image

  The evaluation results are shown in Table 1 below.

Table 1
─────────────────────────────────────
Ink transmission 400nm transmission High humidity
Image clarity (%) Rate (%)
─────────────────────────────────────
Example 1 0.17 86 84 BB
Example 2 0.15 87 85 AA
Example 3 0.15 87 84 AA
─────────────────────────────────────
Comparative Example 1 0.20 14-CC
Comparative Example 2 0.65 82-AA
─────────────────────────────────────

Examples and comparative examples when a high-gloss opaque support is used as the support are described below.
[Example 4]
In Example 3, an inkjet recording sheet was prepared in the same manner as in Example 3 except that the following high-gloss opaque support was used as the support.

<High gloss opaque support>
A mixed pulp of 70 parts by weight of LBPK and 30 parts by weight of NBSP is beaten to 300 ml of Canadian freeness by a double disc refiner, and after adding the following materials to this pulp slurry, paper is made and dried to obtain a base paper having a basis weight of 180 g / m ^2. It was.

Pulp 100 parts by weight Epoxidized behenamide 0.3 part by weight Alkyl ketene dimer 0.4 part by weight Cationic starch 1.0 part by weight Polyamide polyamine epichlorohydrin 0.2 part by weight Cationic polyacrylamide 0.5 part by weight

The obtained base paper was impregnated with 30 g / m ² of a sizing agent (aqueous solution) having the following composition by sizing press treatment.
Polyvinyl alcohol 4 parts by weight γ-aminopropyltriethoxysilane 0.05 parts by weight Optical brightener 0.6 parts by weight Antifoaming agent 0.005 parts by weight

Next, the obtained sizing agent-attached paper was calendered with a soft calender so as to have a thickness of 200 μm, and then calendered with a machine calender to adjust the thickness to 175 μm. Thereafter, the back surface (wire surface) of the base paper is subjected to corona discharge treatment, coated with polyethylene having a density of 0.98 g / cm ³ to a thickness of 25 μm, and the front surface (felt surface) is subjected to corona discharge treatment, followed by 10 weights. An opaque support was obtained by coating polyethylene having a density of 0.94 g / cm ³ containing 30% of titanium oxide to a thickness of 30 μm.

[Example 5]
In Example 3, an inkjet recording sheet was prepared in the same manner as in Example 3 except that the following high-gloss opaque support was used as the support.

<High gloss opaque support>
A polyester resin (PET) containing 15% by weight of calcium carbonate having an average particle size of 0.9 μm was biaxially stretched to obtain a white polyester film having a density of 0.9 g / cm ³ and SRa of 0.17 μm. A polyester resin solvent solution kneaded with 50% by weight of tin oxide was applied to both sides of this white polyester film at a solid content of 0.3 g / m ² and dried, and then the surface electrical resistance was 5 × 10 ^{8 to} 5 × 10 ^9. An antistatic layer of Ω was formed.

After performing corona discharge treatment on both sides of the film, high-density polyethylene (density 0.960 g / cm ³ , MI = 13 g / 10 min) was melt-extruded with a resin thickness of 30 μm using a melt extruder, The antistatic layer was covered with a polyethylene resin layer (this surface is called the back surface).
Next, on the other antistatic layer not provided with the resin layer, a low-density polyethylene (density 0.923 g / cm ³ , containing 15% by weight of anatase-type titanium dioxide and a small amount of ultramarine using a melt extruder is used. MI = 7 g / 10 min) was melt-extruded with a resin thickness of 32 μm and coated with a resin layer having a glossy surface (this surface is called the front surface).

After corona discharge treatment of the back surface of the high-density polyethylene resin layer, aluminum oxide (Aluminazole-100, manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (Snowtex-0, manufactured by Nissan Chemical Industries, Ltd.) as antistatic agents ) Was dispersed in water at a weight ratio of 1/2 (Aluminazole-100 / Snowtex-0), and coated so that the weight after drying was 0.2 g / m ² .
An opaque support was obtained as described above.

[Example 6]
In Example 3, an inkjet recording sheet was prepared in the same manner as in Example 3 except that the following high-gloss opaque support was used as the support.

<High gloss opaque support>
A 25 μm-thick polyethylene terephthalate film filled with 2% by weight of silica having an average particle diameter of 3 μm is placed in the vacuum deposition and vacuum deposition is performed at a vacuum degree of 10 ⁻⁴ Torr. An aluminum vapor deposition film was formed.
On the surface of this vapor-deposited film, an adhesive having the following composition was diluted with ethyl acetate so that the coating amount after drying was 5 g / m ² and dried in an oven at 100 ° C. for 2 minutes. (Adhesive composition)
Vinyl chloride / vinylidene chloride / vinyl acetate / 56 parts by weight Maleic anhydride copolymer 37 parts by weight of tolylene diisocyanate Trimethylolpropane adduct Epoxylated fatty acid alkyl ester (molecular weight about 350) 7 parts by weight It was.

A mixed pulp of 80 parts by weight of LBPK and 20 parts by weight of NBSP is beaten to 300 ml of Canadian freeness with a double disc refiner, and after adding the following materials to this pulp slurry, paper is made and dried to obtain a base paper having a basis weight of 160 g / m ^2. It was. The density was adjusted to 1.0 g / cm ³ with an asyn calender.

Pulp 100 parts by weight Sodium stearate 1.0 part by weight Anionic polyacrylamide 0.5 part by weight Aluminum sulfate 1.5 part by weight Polyamide polyamine epichlorohydrin 0.5 part by weight Alkyl ketene dimer 0.5 part by weight

One side of the obtained base paper was subjected to corona discharge treatment, and then a low-density polyethylene (density 0.923 g / cm ³ , MI = 7 g / 10 min) was melt-extruded with a resin thickness of 30 μm using a melt extruder. One surface (front surface) was covered with a polyethylene resin layer.
Next, after corona discharge treatment was performed on the other surface on which the resin layer was not provided, high-density polyethylene (density 0.950 g / cm ³ , MI = 8 g / 10 min) was applied at a resin thickness of 30 μm using a melt extruder. It was melt extruded and coated with a resin layer (this surface is called the back surface). Thus, a paper having both surfaces laminated with polyethylene was prepared.

Next, a polyurethane-based two-component adhesive having the following composition is applied to the surface of the previously prepared film with a vapor deposition layer on which the vapor deposition layer is not provided so that the coating amount after drying is 3 g / m ^2. And dried in an oven at 100 ° C. for 2 minutes.
(Adhesive composition)
100 parts by weight of polybond AY-651A (manufactured by Sanyo Chemical Industries)
15 parts by weight of polybond AY-651C (manufactured by Sanyo Chemical Industries)
The coated surface and the low-density polyethylene surface of the paper laminated on both sides with polyethylene were combined and heat-pressed at a pressure of 20 kg / cm.
Was made.
An opaque support was obtained as described above. The surface having the vapor deposition layer is the front surface.

[Example 7]
In Example 3, a high gloss opaque support of a calcium carbonate-containing foamed polyethylene terephthalate film (trade name: E-68L; manufactured by Toray Industries, Inc.) having a layer thickness of 130 μm was used as the support. Similarly, an inkjet recording sheet was prepared.

[Comparative Example 3]
On the high-gloss opaque support of Example 6, the colorant-receiving layer-forming coating solution of Comparative Example 1 was applied in the same manner as in Example 1 to produce an inkjet recording sheet.

[Comparative Example 4]
On the high-gloss opaque support of Example 6, the colorant-receiving layer-forming coating solution of Comparative Example 2 was applied in the same manner as in Example 1 to produce an inkjet recording sheet.

The inkjet suitability of the inkjet recording sheet in which the colorant-receiving layer was provided on the high-gloss opaque support obtained above was evaluated by the following measurement method.
(1) Ink printability and (3) image bleeding under high humidity were evaluated in the same manner as described above.
(2) Glossiness For the highly glossy opaque support and recording sheet obtained in the above Examples and Comparative Examples, according to the method described in JIS P-8142 (75-degree specular gloss test method for paper and paperboard), Gloss was measured.
That is, six test pieces were prepared for each, and measured using a gloss meter (digital variable gloss meter, manufactured by Suga Test Instruments Co., Ltd.). The average value of the measured values obtained was defined as the glossiness.

  The evaluation results are shown in Table 2 below.

Table 2
─────────────────────────────────────
Ink glossiness (%) bleeding under high humidity
Reflective support Recording sheet
─────────────────────────────────────
Example 4 0.15 87 85 AA
Example 5 0.14 95 93 AA
Example 6 0.16 99 95 AA
Example 7 0.14 49 92 AA
─────────────────────────────────────
Comparative Example 3 0.21 99 21 CC
Comparative Example 4 0.67 99 92 AA
─────────────────────────────────────

Claims (3)

A recording sheet comprising an opaque support having a highly glossy surface and a colorant receiving layer provided thereon, wherein the colorant receiving layer has an average particle diameter of 1 to 200 nm , an alkyl acrylate, An emulsifier having at least one monomer selected from the group consisting of alkyl methacrylates, styrene and styrene derivatives having a cationic group containing a quaternary ammonium base and one or more carbon-carbon double bonds in the molecule Cationic crosslinked polymer fine particles containing a quaternary ammonium base obtained by emulsion polymerization and a water-soluble resin crosslinked (however, the weight ratio of the former to the latter is in the range of 1: 1 to 1:10. is described in Ri Do from there), further a matting agent contain 0.01 to 5 wt%, and the glossiness of the recording sheet (JIS P-8142 And a 75-degree specular gloss) of 70% or more.   2. The ink jet recording sheet according to claim 1, wherein the average particle diameter of the crosslinked polymer fine particles is in the range of 1 to 100 nm. The inkjet recording sheet according to claim 1, wherein the water-soluble resin is polyvinyl alcohol .