JP2003291510A - Inkjet recording paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide inkjet recording paper which has good ink absorption, excellent bleeding resistance and excellent light resistance. <P>SOLUTION: In this inkjet recording paper, a porous layer, which contains fine silica particles, alumina or hydrated alumina, and a cationic polymer, is provided as an ink receiving layer on a nonhydrophilic support. The inkjet recording paper is characterized in that at least one of the cationic polymer is a polymer having a constitutional repeating unit which is expressed by general formula (1), wherein R indicates a hydrogen atom or an alkyl group, R<SB>1</SB>, R<SB>2</SB>and R<SB>3</SB>each indicate an alkyl group or a benzyl group, J indicates a mere bonding link or a divalent organic group, and X<SP>-</SP>indicates an anionic group. <P>COPYRIGHT: (C)2004,JPO

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 paper, and more particularly to an ink jet recording paper which has good ink absorbency and excellent bleeding resistance and light resistance.

[0002]

2. Description of the Related Art In recent years, the quality of ink jet recording materials has been rapidly improved, and the quality of photographs has been approaching. In particular, in order to achieve image quality comparable to photographic image quality with inkjet recording, improvements have been made from the aspect of inkjet recording paper (hereinafter, also simply referred to as recording paper), and especially on a support having high smoothness. A void-type recording paper provided with a constituent layer having fine voids composed of fine particles and a hydrophilic polymer (hereinafter, also referred to as void layer or porous layer) has high gloss and exhibits vivid color, and ink Due to its excellent absorbency and dryness, it is becoming one of the ones closest to photographic quality. Among them, the recording paper using the non-water-absorbent support, cockling after printing as seen in the water-absorbent support, there is no occurrence of so-called "wrinkle",
Since a highly smooth surface can be maintained, a higher quality print can be obtained.

Ink jet recording is generally classified into the case of using a water-soluble dye ink and the case of using a pigment ink. The pigment ink has a high durability of the image, but the glossiness is likely to change like an image, and as a result, it is difficult to obtain a print close to a photographic quality. On the other hand, when the water-soluble dye ink is used, the sharpness of the image is high, A color print having a uniform surface gloss and comparable to photographic quality can be obtained.

However, since this water-soluble dye has high hydrophilicity, it has a weak point that bleeding occurs. That is, when the image is stored in high humidity for a long time after recording, or when water droplets are attached to the print surface, the image tends to bleed.

In order to solve this problem, it is generally practiced to add a dye-fixing substance such as a cationic substance to the porous layer. For example, a method in which a cationic polymer is used to bind an anionic dye to strongly immobilize the dye is preferably used. Examples of such a cationic polymer include polymers of quaternary ammonium salts and the like. For example, “inkjet printer technology and materials” (published by CMC Co., Ltd. 1998 7
Mon.) and Japanese Patent Application Laid-Open No. 9-193532. Further, the water-soluble dye has a problem of light resistance that it is deteriorated by light when storing an image after printing.

Japanese Patent Laid-Open No. 10-193776 discloses that an ink absorption layer containing fine silica particles, a binder and a water-soluble cationic polymer provides high glossiness, high ink absorption, water resistance, light resistance and moisture resistance. Although it has been proposed to improve, the printing speed of printers has recently become faster and higher, and the demand for high-quality images has increased the amount of ink printed, resulting in high ink absorption, bleed resistance, and light resistance. There is a need for further improvement.

In Japanese Patent Laid-Open No. 2001-1630, 50
It has been proposed to increase the ink absorbability by containing synthetic silica fine particles and alumina fine particles each having a particle size of not more than nm, but it was insufficient for the above problems.

On the other hand, in an ink jet absorption layer using silica fine particles and a binder, the dye fixing property is insufficient, so that a cationic polymer having a strong mordant power is required.
In WO99 / 64248, dye fixing property is improved by adjusting the film surface pH of an ink absorbing layer composed of a cationic polymer containing at least a part of a specific structure having a strong mordant power and inorganic fine particles to improve the dye fixing property. Although it has been proposed to improve bleeding, it has been found that bleeding resistance, ink absorption and light resistance are still insufficient.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide an ink jet recording sheet having good ink absorbability, bleeding resistance and light resistance. That is.

[0010]

The above object of the present invention can be achieved by the following constitutions.

1. In an inkjet recording paper having a porous layer containing silica fine particles, alumina or alumina hydrate, and a cationic polymer as an ink receiving layer on a non-water-absorbing support, at least one of the cationic polymers is An ink jet recording sheet comprising a polymer having a repeating unit represented by the general formula (1).

2. 2. The inkjet recording paper according to item 1, wherein the mass ratio of the silica fine particles to alumina or alumina hydrate is 99: 1 to 50:50.

3. 3. The inkjet recording paper as described in 1 or 2 above, wherein the average particle diameter of primary particles of the silica fine particles is 3 to 100 nm.

4. The inkjet recording paper according to any one of items 1 to 3, wherein the alumina or the alumina hydrate has an average particle size of 1 to 300 nm.

5. The inkjet recording paper according to any one of items 1 to 4, wherein the alumina is vapor grown alumina.

6. The inkjet recording paper according to any one of items 1 to 4, wherein the alumina hydrate has a pseudo-boehmite structure.

7. 7. The inkjet recording paper according to any one of items 1 to 6 above, wherein the silica fine particles are fumed silica.

As a result of intensive studies on the above problems, the present inventors have found that a cationic polymer and a silica fine particle having a repeating unit represented by the general formula (1), which has a strong mordant power, and alumina or an aqueous alumina solution. It has been found that the combined use of the Japanese products makes it possible to obtain an ink jet recording paper having an ink absorbing layer which is excellent in ink absorbency and has good light resistance and bleeding resistance.

The present inventors presume as follows as the reason why the above object was achieved. That is, although the bleeding resistance is improved by the silica fine particles and the cationic polymer having the repeating unit represented by the general formula (1), the cationic polymer is likely to swell, so that the absorbability is lowered. It has the property of Therefore, by using alumina or alumina hydrate having a composition and crystal structure different from that of the silica fine particles together, the void ratio formed is increased and the ink absorbency is increased as compared with the case where each is used alone. I guess it was possible.
Further, since alumina or alumina hydrate is also excellent in ink fixability, when used in combination with a cationic polymer which also has ink fixability, dye inks having a wide range of properties with different types and amounts of dyes and solvents can be obtained. On the other hand, it was possible to improve the bleeding resistance and the light resistance.

The present invention will be described in detail below. (Silica Fine Particles) First, the silica fine particles used in the inkjet recording paper of the present invention will be described.

The silica used in the present invention more preferably has an average primary particle size of 3 to 100 nm.
When the average particle diameter of the primary particles is 100 nm or less, high glossiness of the recording paper can be achieved, and reduction of the maximum density due to irregular reflection on the surface can be prevented to obtain a clear image.

There are two types of silica, one is a wet method and the other is a gas phase method. The wet method silica is produced by a precipitation method using sodium silicate as a main raw material, and the gas phase silica is tetrachloride. It can be made by the hydrolysis method of burning silicon with hydrogen and oxygen. Among them, from the viewpoint of high reflection density and low cost, vapor-phase method silica is preferable, and examples of vapor-phase method silica are commercially available from Nippon Aerosil Co., Ltd. under the product name of Aerosil and from Tokuyama Corporation under the product name of Reorosil. ing. Further, vapor-phase-process silica having a cation surface treated can also be used.

(Alumina or alumina hydrate)
The alumina or alumina hydrate used in the inkjet recording paper of the invention will be described.

The alumina or alumina hydrate used in the present invention has an average particle size of 1 to 30 from the viewpoint of ink absorbability.
It is preferably 0 nm.

As the alumina used in the present invention, from the viewpoint of glossiness of the recording paper, vapor phase alumina having a high purity and a large specific surface area is preferable.

Further, the alumina hydrate used in the present invention may be porous, and the shape thereof is amorphous, needle-like,
Any shape such as a sphere can be used. Alumina hydrate, hydrazyllite, bayerite, norstrandite, boehmite,
Although classified into pseudo-boehmite and amorphous, the pseudo-boehmite having porosity is particularly preferable.

In the present invention, the layer containing fine silica particles and alumina or alumina hydrate may be composed of a plurality of layers having different ratios, and in the case of a multilayer structure of two or more layers. More preferably, at least the uppermost layer is a layer containing fine silica particles and alumina or alumina hydrate.

Further, the ratio of silica fine particles to alumina or alumina hydrate is 99: 1 to 50: from the viewpoint of void formation.
The range is preferably 50, and further 80:20.
It is preferably about 60:40.

(Cationic Polymer) The present invention is characterized in that at least one kind of the cationic polymer is a cationic polymer having a repeating unit represented by the general formula (1).

In the general formula (1), the alkyl group represented by R is preferably a methyl group. The alkyl group represented by R ₁ , R ₂ and R ₃ is preferably a methyl group,
It is an ethyl group or a benzyl group. The divalent organic group represented by J preferably represents -CON (R ')-. R'represents a hydrogen atom or an alkyl group.

Examples of the anionic group represented by X include a halogen ion, an acetate ion, a methylsulfate ion, and p-toluenesulfonate.

The preferred cationic polymer may be a homopolymer composed of the repeating unit represented by the above general formula (1) or a copolymer with another copolymerizable monomer. Examples of the copolymerizable repeating unit include a cationic monomer other than the general formula (1) and a monomer having no cationic group.

Examples of the monomer having a cationic group include the following repeating units.

[0034]

[Chemical 2]

Examples of the copolymerizable repeating unit having no cationic group include ethylene, styrene, butadiene, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate,
Octyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, hydroxyl ethyl methacrylate, acrylamide, vinyl acetate, vinyl methyl ether, vinyl chloride, 4-vinyl pyridine, N-vinyl pyrrolidone, N-vinyl imidazole, acrylic Nitrile etc. can be mentioned.

When the cationic polymer according to the present invention has the repeating unit represented by the general formula (1), the repeating unit represented by the general formula (1) is preferably 20 mol% or more, particularly preferably It is preferably 40 to 100 mol%.

Specific examples of the cationic polymer having the repeating unit represented by the general formula (1) according to the present invention are shown below, but the present invention is not limited thereto.

[0038]

[Chemical 3]

[0039]

[Chemical 4]

[0040]

[Chemical 5]

The above-mentioned cationic polymer has a number average molecular weight of about 3,000 to 200,000, preferably 5,000.
It is 100,000. The average molecular weight is represented by a value in terms of polyethylene glycol obtained by gel permeation chromatography.

In addition to the cationic polymer having the repeating unit represented by the general formula (1) according to the present invention, it is particularly preferable to use another cationic polymer in the ink absorbing layer of the recording paper of the present invention. There is no limitation, and conventionally known cationic polymers for ink jet recording paper can be mentioned. Among them, cationic polymers having a quaternary ammonium salt group are preferable. For example, cationic polymers having a guanidyl group described in JP-A-57-64591, dimethyldiallylammonium chloride described in JP-A-59-20696, polyamine sulfones described in JP-A-59-33176, and Alkyl (meth) acrylate quaternary ammonium salts or (meth) acrylamidoalkyl quaternary ammonium salt type cationic polymers described in JP-A No. 63-115780, described in JP-A Nos. 64-9776 and 64-75281. A copolymer of dimethylallyl ammonium chloride and acrylamide, a cationic polymer containing two or more quaternary nitrogen atoms in the repeating unit described in JP-A-3-133686, and a fourth polymer described in JP-A-4-288283. Polyvinylpyrrolidone with primary ammonium base JP-A-6-9
Cationic polymers obtained by reacting a secondary amine with epihalohydrin described in 2010 and 6-234268, polystyrene type cationic polymers described in International Patent Publication No. 99-64248, JP-A No. 11-3.
Examples thereof include cationic polymers composed of repeating units having two or more kinds of cationic groups described in No. 48409.

The amount of the cationic polymer according to the present invention to be used is generally 0.1 to 10 g, preferably 0.2 to 5 g per 1 m ^{2 of} recording paper.

(Binder) As a binder used in the ink absorbing layer, a hydrophobic binder or a hydrophilic binder is used, and a hydrophilic binder is preferable.

Examples of the hydrophilic binder include gelatin (alkali-treated gelatin, acid-treated gelatin, derivative gelatin in which amino group is blocked with phenylisocyanate, phthalic anhydride, etc.), polyvinyl alcohol (average degree of polymerization of 300 to 4500, Saponification degree is 70-100%
Preferred)), polyvinylpyrrolidone, polyethiylene oxide, hydroxylethyl cellulose, agar, pullulan, dextran, acrylic acid, carboxymethyl cellulose, casein, alginic acid, and the like, and two or more kinds can be used in combination. Of these, the preferred hydrophilic polymer is polyvinyl alcohol.

Polyvinyl alcohol is obtained by hydrolyzing vinyl acetate. In the present invention, those having an average degree of polymerization of 300 or more are preferably used, and particularly, the average degree of polymerization is 1000.
Those of up to 4500 are preferably used. The saponification degree is preferably 70 to 100%, and 80 to 99.5.
% Is particularly preferable.

This polyvinyl alcohol includes, in addition to usual polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate, modified polyvinyl alcohol such as cation-modified polyvinyl alcohol having terminals and anion-modified polyvinyl alcohol having an anionic group. Is also included.

Polyvinyl alcohol may be used in combination of two or more types such as different degree of polymerization or modification.

The amount of the hydrophilic binder used is about 1.5 to 12 times, preferably 2 to 10 times, and particularly preferably 3 to 8 times the mass ratio of the inorganic fine particles.

(Crosslinking Agent) When polyvinyl alcohol is used as the hydrophilic binder, a crosslinking agent should be contained in the void layer in order to improve the film-forming property of the film and enhance the water resistance and strength of the film. Is preferred.

Examples of such cross-linking agents include boric acid or salts thereof, epoxy cross-linking agents (for example, diglycidyl ethyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6). -Diglycidyl cyclohexane, N, N-diglycidyl-4-glycidyloxyaniline, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, etc.), aldehyde-based cross-linking agents (eg, formaldehyde, glyoxal, etc.), active halogen-based cross-linking agents (eg, 2,4-dichloro-4-hydroxy-
1,3,5-s-triazine, etc.), active vinyl compounds (eg, 1,3,5-trisacryloyl-hexahydro-s-triazine, bisvinylsulfonylmethyl ether, etc.), aluminum alum, isocyanate compounds, etc. Among them, boric acid or a salt thereof is preferable.

Boric acid or a salt thereof means an oxygen acid having a boron atom as a central atom and a salt thereof, and specifically, orthoboric acid, metaboric acid, hypoboric acid, tetraboric acid, pentaboric acid and These salts are included.

The amount of boric acid or its salt to be used can vary widely depending on the amount of the inorganic fine particles and the hydrophilic binder in the coating solution, but is generally 1 to 60% by mass, preferably 5 to 40% by mass relative to the hydrophilic binder. %.

The cross-linking agent such as boric acid or a salt thereof may be added to the coating solution when the water-soluble coating solution for forming the porous layer used in the present invention is applied, or the cross-linking agent may be added. It can be supplied by applying a water-soluble coating liquid for forming a porous layer that does not contain it, drying it, and then overcoating a solution containing a crosslinking agent.

In the present invention, in addition to the above boric acid, the above-mentioned other cross-linking agent may be used in combination.

The amount of the cross-linking agent used varies depending on the kind of hydrophilic binder, the kind of cross-linking agent, the kind of inorganic fine particles and the ratio to the hydrophilic binder. For example, when polyvinyl alcohol is used as the hydrophilic binder. , Usually 5 to 500 per 1 g of polyvinyl alcohol
mg, preferably 10 to 300 mg.

Various additives other than those mentioned above can be added to the ink absorbing layer of the ink jet recording paper of the present invention. For example, polystyrene, polyacrylic acid esters, polymethacrylic acid esters, polyacrylamides, polyethylene. , Polypropylene, polyvinyl chloride,
Polyvinylidene chloride, or copolymers thereof, fine particles of organic latex such as urea resin or melamine resin, various surfactants of cation or nonion, JP-A-57-
74193, 57-87988 and 62-26.
The ultraviolet absorber described in 1476, JP-A-57-741
No. 92, No. 57-87989, No. 60-72785.
No. 61-146591, JP-A-1-95091 and JP-A-3-13376, and JP-A-59-42493 and JP-A-59-52689.
No. 62-280069, No. 61-242871, and JP-A No. 4-219266, and the like, fluorescent whitening agents, sulfuric acid, phosphoric acid, citric acid, sodium hydroxide,
Various known additives such as pH adjusting agents such as potassium hydroxide and potassium carbonate, antifoaming agents, preservatives, thickeners, antistatic agents, matting agents and the like may be contained.

(Support) Next, the support used in the ink jet recording paper of the present invention will be described.

The support of the ink jet recording paper of the present invention is a non-water-absorbing support. When a water-absorbent support is used, the compound containing a zirconium or aluminum atom cannot diffuse the effect of the present invention when forming the ink absorbing layer or diffusing into the support during storage.

Examples of the non-water-absorptive support used in the present invention include a plastic resin film support or a support in which both surfaces of paper are coated with a plastic resin film. Examples of the plastic resin film support include a polyester film, a polyvinyl chloride film, a polypropylene film, a cellulose triacetate film, a polystyrene film, and a film support obtained by laminating these films. These plastic resin films may be transparent or translucent.

In the present invention, a non-water-absorbent support which does not cause cockling (wrinkle) during printing is preferred.
A particularly preferred support is a support in which both sides of paper are coated with a plastic resin, and most preferred is a support in which both sides of paper are coated with a polyolefin resin.

Hereinafter, a support in which both surfaces of paper, which is a particularly preferred support in the present invention, are coated with a polyolefin resin will be described.

The paper used in the support according to the present invention is made from wood pulp as a main raw material, and if necessary, synthetic paper such as polypropylene or synthetic fiber such as nylon or polyester is used in addition to wood pulp. . As wood pulp, LBKP, LBSP, NBKP, NBSP,
Any of LDP, NDP, LUKP and NUKP can be used, but LBKP, NBSP, L having a large amount of short fibers
It is preferable to use more BSP, NDP, and LDP. However, the ratio of LBSP and / or LDP is 10
~ 70% is preferred. As the above-mentioned pulp, a chemical pulp containing few impurities (sulfate pulp or sulfite pulp) is preferably used, and a pulp whose whiteness is improved by bleaching is also useful.

In the paper, for example, sizing agents such as higher fatty acids and alkyl ketene dimers, white pigments such as calcium carbonate, talc and titanium oxide, paper strength enhancers such as starch, polyacrylamide and polyvinyl alcohol, and fluorescent whitening. Agents, water retention agents such as polyethylene glycols, dispersants, and softening agents such as quaternary ammonium can be added as appropriate.

The freeness of pulp used for papermaking is CSF.
Is preferably 200 to 500 ml, and the fiber length after beating is preferably 30 to 70% of the sum of 24 mesh residue and 42 mesh residue defined in JIS P 8207. The 4-mesh residue is preferably 20% or less.

The basis weight of the paper is preferably 50 to 250 g, and particularly preferably 70 to 200 g. Paper thickness is 50-21
0 μm is preferable.

The paper can be given a high smoothness by calendering at the papermaking stage or after the papermaking. Paper density is 0.
7 to 1.2 g / m ² (JIS P 8118) is common. Further, the stiffness of the base paper is preferably 20 to 200 g under the conditions specified in JIS P 8143.

A surface sizing agent may be applied to the paper surface, and as the surface sizing agent, the same sizing agent as that which can be added to the base paper can be used.

The pH of the paper is preferably 5 to 9 when measured by the hot water extraction method specified in JIS P8113.

Next, the polyolefin resin coating both sides of this paper will be described. Examples of the polyolefin resin used for this purpose include polyethylene, polypropylene, polyisobutylene, and polyethylene.
Polyolefins such as propylene-based copolymers are preferred, and polyethylene is particularly preferred.

The particularly preferred polyethylene will be described below. The polyethylene that covers the front and back of the paper is
Mainly low density polyethylene (LDPE) and / or high density polyethylene (HDPE), but other L
LDPE, polypropylene, etc. can be partially used.

In particular, the polyolefin layer on the coating layer side is preferably one in which rutile or anatase type titanium oxide is added to improve the opacity and whiteness. Titanium oxide content is about 1 to 20 relative to polyolefin
%, Preferably 2 to 15%.

In the polyolefin layer, a coloring pigment having a high heat resistance or a fluorescent whitening agent for adjusting a white background can be added.

Examples of color pigments include ultramarine blue, navy blue,
Examples include cobalt blue, phthalocyanine blue, manganese blue, cerulean, tungsten blue, molybdenum blue, and anthraquinone blue.

Examples of the fluorescent whitening agent include dialkylaminocoumarin, bisdimethylaminostilbene, bismethylaminostilbene, 4-alkoxy-1,8-naphthalenedicarboxylic acid-N-alkylimide, bisbenzoxazolylethylene, and the like. Dialkyl stilbene etc. are mentioned.

The amount of polyethylene used on the front and back of the paper is selected so as to optimize the film thickness of the ink absorption layer and the curl at low and high humidity after providing the back layer, but generally the polyethylene layer is used. Is 15 to 50 μm on the ink absorption layer side.
m and 10 to 40 μm on the back layer side. The ratio of polyethylene on the front and back sides is preferably set so as to adjust the curl that changes depending on the type and thickness of the ink receiving layer, the thickness of the inner paper, etc. Usually, the ratio of polyethylene on the front and back sides is about the thickness. It is 3/1 to 1/3.

Furthermore, the polyethylene-coated paper support preferably has the following characteristics (1) to (7).

(1) Tensile strength: JIS P 811
The strength defined by 3 is preferably 19.6 to 294N in the vertical direction and 9.8 to 196N in the horizontal direction.

(2) Tear strength: JIS P 811
0.20 to 2.94N in the longitudinal direction with the strength specified by 6.
The lateral direction is preferably 0.098 to 2.45N.

(3) Compressive elastic modulus: 9.8 kN / cm ² is preferable. (4) Opacity: 80% or more, particularly 85 to 98% is preferable when measured by the method defined in JIS P 8138.

(5) Whiteness: L ^* , a ^* , and b ^* defined by JIS Z 8727 are L ^* = 80 to 96, a ^* =-3.
˜ + 5, b ^* = − 7 to +2 are preferable.

[0082] (6) Clark stiffness: support Clark stiffness in the carrying direction is 50~300cm ^3/100 of the recording paper is preferred.

(7) The water content of the base paper is 4 to 4 times that of the base paper.
10% is preferable. (8) The glossiness (75-degree specular glossiness) of providing the ink receiving layer is preferably 10 to 90%.

The ink absorbing layer of the ink jet recording sheet of the present invention may be an ink absorbing layer having a single layer structure or an ink absorbing layer having a multi-layer structure. The separated ink absorbing layer preferably contains at least one cationic polymer having the repeating unit represented by the general formula (1).

(Other Constituent Factors of Inkjet Recording Paper) In the inkjet recording paper of the present invention, a method for coating various layers, such as a porous ink absorbing layer and an undercoat layer, which are appropriately provided as necessary, on a support is The method can be appropriately selected from known methods. A preferred method is obtained by applying a coating solution forming each layer on a support and drying. In this case, two or more layers can be coated at the same time, and in particular, simultaneous coating is preferable since all hydrophilic binder layers need only be coated once.

The coating method is preferably a roll coating method, a rod bar coating method, an air knife coating method, a spray coating method, a curtain coating method or an extrusion coating method using a hopper described in US Pat. No. 2,681,294. Used.

The film surface pH of the recording surface of the ink jet recording paper of the present invention is preferably 3.0 to 7.5. When the film surface pH is 3.0 or more, so-called bronzing in which the dye is deposited and the gloss changes to a metallic state can be prevented when recording with an inkjet, and when the film surface pH is 7.5 or less, Sufficient bleeding resistance can be exhibited.

The film surface pH of the recording surface of the ink jet recording paper of the present invention is measured according to J. TAPPI paper pulp test method No. 30 using distilled water according to the method described in 49.
It can be obtained by a method of measuring after a second.

In the present invention, the film surface pH of the recording surface can be set within a predetermined range by adjusting the pH of the coating liquid forming the recording surface. In addition, after forming the recording surface, it is also possible to bring it into a predetermined range by overcoating with a suitable pH adjusting agent. As the pH adjuster, an aqueous solution of an appropriate acid or alkali can be used. In this case, the kind and concentration of the acid or alkali used are adjusted by the p
It can be appropriately selected depending on the width of H.

The ink jet recording paper of the present invention is particularly preferable because it is particularly effective in ink jet recording using a water-soluble dye ink, but can also be used in ink jet recording using pigment ink.

When an image is recorded using the ink jet recording paper of the present invention, a recording method using a water-based ink is preferably used.

The above-mentioned aqueous ink is a recording liquid containing the following colorant, solvent and other additives. As the colorant, a direct dye, an acid dye, which is known in the inkjet,
Water-soluble dyes such as basic dyes, reactive dyes or food dyes or water-dispersible pigments can be used.

As the solvent for the aqueous ink, water and various water-soluble organic solvents, for example, alcohols such as methyl alcohol, isopropyl alcohol, butyl alcohol, tert-butyl alcohol, isobutyl alcohol and the like;
Amides such as dimethylformamide and dimethylacetamide; ketones and ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol and butylene Polyhydric alcohols such as glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol, glycerin, triethanolamine; ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether, Examples thereof include lower alkyl ethers of polyhydric alcohols such as triethylene glycol monobutyl ether. Of these, polyhydric alcohols such as diethylene glycol, triethanolamine and glycerin, and lower alkyl ethers of polyhydric alcohol such as triethylene glycol monobutyl ether are preferable.

Examples of other water-based ink additives include, for example, pH adjusters, sequestering agents, antifungal agents, viscosity modifiers, surface tension modifiers, wetting agents, surfactants and rust preventives.
Etc.

The aqueous ink liquid is usually 0.02 at 20 ° C. in order to improve the wettability to the recording paper.
5 to 0.06 N / m, preferably 0.03 to 0.05 N
It is preferred to have a surface tension in the range of / m. The pH of the above ink is preferably 5 to 10, and particularly preferably 6 to 9.

[0096]

EXAMPLES The present invention will be specifically described below with reference to examples, but the embodiments of the present invention are not limited thereto. In addition, "%" described in the examples represents mass% unless otherwise specified.

<< Preparation of Inkjet Recording Paper >> [Preparation of Recording Paper 1 (Comparative Example)] (Preparation of Coating Solution) Pure water whose pH was adjusted to 2.5 with nitric acid was mixed with vapor phase silica (trade name: QS). -20, manufactured by Tokuyama Corp., primary average particle diameter 13 nm) was dispersed to prepare 400 g of a silica dispersion liquid 1 having a silica content of 25%.
To this silica dispersion liquid 1, 8% of a 20% aqueous solution of a cationic polymer (Exemplified Compound P-1) whose pH was adjusted to 2.5 was used.
0 g, 2.1 g of boric acid, and 75 ml of an aqueous solution in which 1.5 g of borax were dissolved were added and dispersed with a high-pressure homogenizer. While stirring the obtained dispersion liquid at 40 ° C., 278 ml of a 6% aqueous solution of polyvinyl alcohol (trade name: PVA235, manufactured by Kuraray Co., Ltd., saponification degree 88%, average polymerization degree 3500) was added, and a surfactant ( 1.5 ml of a 4% aqueous solution of S-1) was added, and pure water was added so that the total liquid became 1000 ml, to obtain a semi-transparent coating liquid 1.

(Preparation of recording paper) Next, the basis weight is 190 g /
^On the recording surface side of a support (thickness: 260 μm, containing 6% by mass of anatase type titanium dioxide in the polyethylene layer on the recording surface side) of polyethylene coated on both sides of m ² base paper, the above coating solution 1 was wetted to form a film. Ink jet recording paper 1 was obtained by applying the solution so as to have a thickness of 150 μm, cooling at 2 ° C. for 10 seconds, and then drying with a wind at 50 ° C.

[Preparation of Recording Paper 2 (Comparative Example)] (Preparation of coating liquid) Pure water was mixed with vapor-phase method alumina (trade name: aluminum oxide C, manufactured by Degussa, primary average particle diameter 13n).
m) was dispersed to prepare 400 g of an alumina dispersion liquid 1 having an alumina content of 25%. This alumina dispersion 1
20% of the cationic polymer (Exemplary compound P-1)
80 g of aqueous solution, 2.1 g of boric acid and 1.5 of borax
75 ml of an aqueous solution in which g was dissolved was added and dispersed with a high-pressure homogenizer. While stirring the obtained dispersion at 40 ° C., polyvinyl alcohol (trade name: PVA235,
Kuraray Co., Ltd., saponification degree 88%, average degree of polymerization 350
278 ml of a 6% aqueous solution of 0) was added, and the surfactant (S-
1.5 ml of 4% aqueous solution of 1) was added, and the whole solution was 10
Pure water was added so that the amount became 00 ml to obtain a semi-transparent coating liquid 2.

(Preparation of recording paper) Next, the basis weight is 190 g /
^On the recording surface side of a support (thickness: 260 μm, containing 6% by mass of anatase type titanium dioxide in the polyethylene layer on the recording surface side) having polyethylene coated on both sides of m ² base paper, the above coating solution 2 was wetted to form a film. Ink jet recording paper 2 was obtained by applying the solution to a thickness of 150 μm, cooling it at 2 ° C. for 10 seconds, and then drying it with air at 50 ° C.

[Preparation of Recording Paper 3 (Invention)] (Preparation of Coating Solution) 280 g of the above-mentioned silica dispersion 1 having a silica content of 25% was added to 280 g of a cationic polymer (example: 8% of 20% aqueous solution of compound P-1)
0 g, 2.1 g of boric acid, and 75 ml of an aqueous solution in which 1.5 g of borax were dissolved were added and dispersed with a high-pressure homogenizer. In the obtained dispersion liquid, the content of alumina is 25
% Of alumina dispersion 1 was added, and polyvinyl alcohol (trade name: PVA23) was added while stirring at 40 ° C.
5, manufactured by Kuraray Co., Ltd., saponification degree 88%, average degree of polymerization 35
00) 6% aqueous solution 278 ml, surfactant (S-1) 4% aqueous solution 1.5 ml, pure water is added so that the total liquid becomes 1000 ml, and semi-transparent coating Liquid 3 was obtained.

(Preparation of recording paper) Next, the basis weight is 180 g /
The coating liquid 3 was wetted on the recording surface side of a support (thickness 220 μm, containing 6% by mass of anatase type titanium dioxide in the polyethylene layer on the recording surface side) of polyethylene having m ² of both sides coated with polyethylene. The ink-jet recording paper 3 was obtained by applying it to a thickness of 150 μm, cooling it at 2 ° C. for 10 seconds, and then drying it with air at 50 ° C.

[Preparation of Recording Paper 4 (Invention)] Inkjet was prepared in the same manner as in the preparation of Recording Paper 3 except that the cationic polymer (P-1) in the coating liquid 3 was changed to Exemplified Compound P-8. Recording paper 4 was prepared.

[Preparation of Recording Paper 5 (Comparative Example)] Inkjet recording was carried out in the same manner as in preparation of the recording paper 3 except that the cationic polymer (P-1) in the coating liquid 3 was changed to the cationic polymer 1. Paper 5 was prepared.

[0105]

[Chemical 6]

[Preparation of Recording Paper 6 (Invention)] Basis Weight 19
The coating solution 1 was wetted on the recording surface side of a support (thickness 260 μm, containing 6% by mass of anatase type titanium dioxide in the polyethylene layer on the recording surface side) of which both sides of 0 g / m ² base paper were coated with polyethylene. An inkjet recording paper 6 was obtained by coating the coating solution 3 as a lower layer with a film thickness of 75 μm and simultaneously with the wet film thickness of 75 μm as an upper layer, cooling at 2 ° C. for 10 seconds, and drying with a wind at 50 ° C.

[Preparation of Recording Paper 7 (Invention)] (Preparation of Coating Solution) 120 g of the above-mentioned silica dispersion 1 having a silica content of 25% was added to 120 g of a cationic polymer (example: 8% of 20% aqueous solution of compound P-1)
0 g, 2.1 g of boric acid, and 75 ml of an aqueous solution in which 1.5 g of borax were dissolved were added and dispersed with a high-pressure homogenizer. In the obtained dispersion liquid, the content of alumina is 25
% Alumina dispersion 1 was added, and polyvinyl alcohol (trade name: PVA23) was added while stirring at 40 ° C.
5, manufactured by Kuraray Co., Ltd., saponification degree 88%, average degree of polymerization 35
00) 6% aqueous solution 278 ml, surfactant (S-1) 4% aqueous solution 1.5 ml, pure water is added so that the total liquid becomes 1000 ml, and semi-transparent coating Liquid 7 was obtained.

(Preparation of recording paper) Next, the basis weight is 190 g /
The coating liquid 7 was wetted on the recording surface side of a support (thickness: 260 μm, containing 6% by mass of anatase titanium dioxide in the polyethylene layer on the recording surface side) of polyethylene having m ² of both sides coated with polyethylene. The ink-jet recording paper 7 was obtained by applying the solution to a thickness of 150 μm, cooling at 2 ° C. for 10 seconds, and drying with a 45 ° C. air.

[Preparation of Recording Paper 8 (Invention)] (Preparation of Coating Solution) 350 g of the above-mentioned silica dispersion 1 having a silica content of 25% was added to 350 g of a cationic polymer (example: 8% of 20% aqueous solution of compound P-1)
0 g, 2.1 g of boric acid, and 75 ml of an aqueous solution in which 1.5 g of borax were dissolved were added and dispersed with a high-pressure homogenizer.

The obtained dispersion liquid was mixed with 8% alumina hydrate (trade name: Cataloid AS-1, Catalysts & Chemicals Co., Ltd.).
156 g of pseudo boehmite manufactured by Mitsui Chemical Co., Ltd. was added, and polyvinyl alcohol (product name: PVA235,
Kuraray Co., Ltd., saponification degree 88%, average degree of polymerization 350
278 ml of 6% aqueous solution of 0) and 1.5 ml of 4% aqueous solution of surfactant (S-1) were added, and then pure water was added so that the total amount became 1000 ml, and semitransparent coating was performed. Liquid 8 was obtained.

(Preparation of recording paper) Next, the basis weight is 190 g /
^On the recording surface side of a support (thickness: 260 μm, containing 6% by mass of anatase type titanium dioxide in the polyethylene layer on the recording surface side) of polyethylene coated on both sides of m ² base paper, a coating film 8 was wetted. The ink-jet recording paper 8 was obtained by applying the solution to a thickness of 150 μm, cooling it at 2 ° C. for 10 seconds, and then drying it with air at 50 ° C.

<< Evaluation of Various Properties of Recording Paper >> The following evaluations were carried out on the recording papers 1 to 8 produced above.

(Evaluation of ink absorbency) Each record prepared above
Regarding paper, a Bristow trial manufactured by Kumagai Riki Kogyo Co., Ltd.
Using a tester type II (pressure type), contact time 0.04 seconds
Liquid transfer rate (ml / m ²) Is measured according to the following criteria
Therefore, the ink absorbency was evaluated.

[0114] ◎: Liquid dislocation amount is 12 ml / m ² or more ○: Liquid dislocation amount is less than 10~12ml / m ² △: × Liquid dislocation amount is less than 8~10ml / m ^2: Liquid dislocation Volume is less than 8 ml / m ² (bleed resistance 1
Evaluation) On each recording paper, a black line having a line width of about 0.3 mm was printed on a solid print of magenta with an inkjet printer PM950C manufactured by Seiko Epson Corporation, and stored at 50 ° C. and a relative humidity of 85% for 3 days. Before and after storage, measure the line width with a microdensitometer (the width of the reflection density is 50% of the maximum density is taken as the line width), measure the bleeding rate expressed by the following formula, and bleed according to the following criteria. The resistance was evaluated. The smaller the bleeding rate, the better the bleeding resistance.

Bleeding rate = (line width after image storage) / (line width before image storage) ⊚: Bleeding rate is 1 to 1.20 times ◯: Bleeding rate is 1.21 to 1.4 times A: The bleeding rate is 1.41 to 1.6 times ×: The bleeding rate is 1.61 times or more (evaluation of bleeding resistance 2) In the above evaluation of bleeding resistance 1,
Bleeding resistance 2 was evaluated in the same manner except that the inkjet printer BJF900 manufactured by Canon Inc. was used as the printer.

(Evaluation of light resistance) Solid color black (Bk), yellow (Y), magenta (M), and cyan (C) single-color solid printing was performed on each recording paper with an inkjet printer PM900C manufactured by Seiko Epson Corporation. The optical density before and after light irradiation for 24 hours was measured with a xenon fade meter, the residual density ratio was measured according to the following formula, and the light resistance was evaluated according to the following criteria. Note that the residual concentration rate is 1.
The closer to 0, the better the light resistance. In addition, the concentration measurement was performed by evaluating the concentration of the untreated sample at 1.0.
In Table 1, the judgment was made by the average value of the residual density ratio of each single color.

[0117] Concentration residual rate = (concentration after light irradiation) / (concentration before light irradiation) ⊚: Concentration residual ratio is 0.95 or more ◯: Concentration residual rate is 0.85 or more and less than 0.95 Δ: residual concentration ratio is 0.75 or more and less than 0.85 X: Concentration residual rate is less than 0.75 Table 1 shows the results obtained as described above.

[0118]

[Table 1]

As is clear from Table 1, for the comparative sample,
It can be seen that the recording paper of the present invention has excellent ink absorbency, good bleeding resistance, and good light resistance.

[0120]

According to the present invention, the ink absorption is good,
In addition, it was possible to provide an inkjet recording paper having excellent bleeding resistance and light resistance.

Claims (7)

[Claims] 1. Silica fine particles on a non-water-absorbing support,
In an inkjet recording paper having a porous layer containing alumina or an alumina hydrate and a cationic polymer as an ink receiving layer, at least one of the cationic polymers is repeatedly represented by the following general formula (1). An ink jet recording paper, which is a polymer having units. [Chemical 1] [In the formula, R represents a hydrogen atom or an alkyl group, and R ₁ ,
R ₂ and R ₃ each represent an alkyl group or a benzyl group, and J
Represents a simple bond or a divalent organic group. X ⁻ represents an anion group. ] 2. The ink jet recording paper according to claim 1, wherein the mass ratio of the fine silica particles to alumina or alumina hydrate is 99: 1 to 50:50. 3. The inkjet recording paper according to claim 1, wherein the average particle diameter of primary particles of the silica fine particles is 3 to 100 nm. 4. The ink jet recording paper according to claim 1, wherein the alumina or the alumina hydrate has an average particle diameter of 1 to 300 nm. 5. The ink jet recording paper according to claim 1, wherein the alumina is vapor grown alumina. 6. The alumina hydrate has a pseudo-boehmite structure, according to any one of claims 1 to 4.
Ink jet recording paper according to item. 7. The ink jet recording paper according to claim 1, wherein the silica fine particles are fumed silica.