JP2003127533A - Ink jet recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet which is excellent in image- printing density of an image without reducing other ink accepting performances. SOLUTION: This ink jet recording sheet has a coloring matter-accepting layer containing a cation polymer and an inorganic pigment particle, on a supporting body. In this case, the cation polymer has a group which is selected from a 4-36C alkyl group, an aryl group or an aralkyl group at the terminal end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material suitable for ink jet recording using a liquid ink such as an aqueous ink or an oil ink, or a solid ink which is solid at room temperature and is melted and liquefied to be used for printing. More specifically, the present invention relates to an inkjet recording sheet having excellent ink receiving performance.

[0002]

2. Description of the Related Art In recent years, along with the rapid development of the information industry, various information processing systems have been developed, and recording methods and apparatuses suitable for the information systems have also been developed and put into practical use. Among the above recording methods, the inkjet recording method is capable of recording on various recording materials, hardware (device)
Has been widely used not only in offices but also in so-called home use because it is relatively inexpensive, compact, and excellent in quietness.

With the recent increase in resolution of ink jet printers, it has become possible to obtain so-called photograph-like high-quality recorded matter. Further, with the development of hardware (device), various recording sheets for inkjet recording have been developed. The properties required of the recording sheet for inkjet recording are generally:
(1) quick drying (high ink absorption speed), (2) proper and uniform ink dot diameter (no bleeding), (3) good graininess, (4) High circularity of dots, (5) High color density, (6) High saturation (no dullness), (7) Good light resistance and water resistance of the printed area thing,
(8) The whiteness of the recording sheet is high, (9) the storage stability of the recording sheet is good (no yellowing coloring occurs during long-term storage), (10) deformation is difficult, and dimensional stability is good. (11) The curl is sufficiently small, and (11) the hard running property is good. In addition to the above characteristics, the photo glossy paper used for the purpose of obtaining a so-called photograph-like high-quality recorded matter may have glossiness, surface smoothness, and a photographic paper-like texture similar to silver salt photographs. Required.

For the purpose of improving these characteristics, an ink jet recording sheet having a porous structure in the coloring material receiving layer, excellent ink absorbability (quick drying) and high gloss has been developed and put into practical use.

Japanese Unexamined Patent Publication (Kokai) No. 62-178384 and Japanese Examined Patent Publication (Kokoku) No. 3-24905 propose a recording material having a coloring material receiving layer containing silica particles surface-treated with a silane coupling agent. However, although the surface activity of these silica particles is reduced and the weather resistance is improved, the cohesive force between silica particles is also reduced and the film strength of the colorant receiving layer is weakened.

Further, when the silica dispersion is mixed with a binder such as PVA, the silica dispersion agglomerates, resulting in a high viscosity and poor stability. For this reason, the particle size of silica particles in the dispersion becomes large, which adversely affects the glossiness, coating strength, ink absorption speed, water resistance, print density and the like.
Among them, the print density is particularly affected, and the print density is significantly reduced.

Japanese Unexamined Patent Publication No. 2001-10209 proposes an ink jet recording paper containing inorganic pigment fine particles, a silane coupling agent having an ammonia structure, and a cationic resin. However, the above-mentioned ink jet recording sheet is one in which the inorganic fine particles and the cationic resin are applied to the surface of the support, and agglomeration occurs between the fine inorganic particles and the inorganic fine particles having an anionic charge, resulting in various performances of the ink jet recording paper. Can not be fully exerted.

Japanese Unexamined Patent Publication Nos. 8-39927 and 200
0-309159, JP-A-2000-313164
The publication describes an ink jet recording sheet using a chain transfer agent at the time of polymerizing a cationic polymer. However, all of these use a chain transfer agent for adjusting the degree of polymerization, and do not enhance the dispersibility of the inorganic pigment fine particles.

[0009]

As described above, the color material receiving layer is strong without cracks and the like, while it has good ink absorbency and can form a high resolution image, and its formation. At present, an ink jet recording sheet which is excellent in image printing density, sharpness and glossiness while having an ink receptive property such as an image having excellent water resistance and aging blur resistance is not yet provided.

An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, the first object of the present invention is to provide an inkjet recording sheet having a high image print density. Secondly, the present invention is strong without occurrence of cracks and the like, forms a high-resolution image having good ink absorbability, and is excellent in glossiness, water resistance and bleeding with time after printing, and can be exposed to sunlight or sunlight. It is an object of the present invention to provide an inkjet recording sheet that exhibits high light resistance even under irradiation with light from a fluorescent lamp or the like.

[0011]

Means for solving the problems Means for solving the above problems are as follows. That is,

<1> A coloring material receiving layer containing a cationic polymer having a group selected from an alkyl group, an aryl group or an aralkyl group having a total carbon number of 4 to 36 at its terminal, and inorganic pigment fine particles is provided on a support. It is an inkjet recording sheet characterized by having.

<2> The cationic polymer is represented by the following general formula (1), and is the ink jet recording sheet of <1>.

[0014]

[Chemical 6] [In the formula, X represents a single bond or a divalent linking group, and R is a total of 4 to 3 carbon atoms which may have a branched structure or a cyclic structure.
6 represents an alkyl group, an aryl group and an aralkyl group.
A represents at least one repeating unit having a cation, and B represents at least one repeating unit copolymerizable with A. m and n represent the molar ratios of the A component and the B component, respectively, 0.2 ≦ m ≦ 1.0, 0 ≦ n ≦ 0.8 (m +
n = 1.0). ]

<3> R in the general formula (1) is
Total carbon number which may have branched structure or cyclic structure 8 to 1
<8> The inkjet recording sheet according to <2>, which is selected from an alkyl group, an aryl group, and an aralkyl group.

<4> For inkjet recording of <2> or <3>, the repeating unit A in the general formula (1) is at least one selected from the following (I) to (IV). It is a sheet.

(I) Repeating unit represented by the following general formula (2)

[Chemical 7] [In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ² , R ³ and R ⁴ each independently have a hydrogen atom or a substituent, and , May combine to form a saturated or unsaturated cyclic structure,
It represents an alkyl group having 1 to 18 carbon atoms, an aryl group or an aralkyl group. Z represents -O- or -NH-,
Y ² represents a divalent linking group having a total of 1 to 8 carbon atoms, which may have a heteroatom. X ⁻ represents an anion. ]

(II) Repeating unit represented by the following general formula (3)

[Chemical 8] [In the formula, R ⁵ represents a hydrogen atom or a methyl group. R ² ,
R ³ , R ⁴ and X ⁻ have the same meaning as in formula (2). ]

(III) A repeating unit represented by the following general formula (4) and / or general formula (5)

[Chemical 9] IN FORMULA, R < ² >, R < ³ >, X < ^- > IS SYNTHESIS OF GENERAL FORMULA (2). ]

(IV) Repeating unit represented by the following general formula (6) and / or general formula (7)

[Chemical 10] [In the formula, n represents 0 or 1, and R ² , R ³ , R ⁴ , and X ⁻
Is synonymous with general formula (2). ]

<5> The ink jet recording sheet according to <1> to <4>, wherein the cationic polymer has a number average molecular weight of 1,000 to 20,000.

<6> The mass ratio (x: y) of the inorganic pigment fine particles (x) and the cationic polymer (y) is 1:
The inkjet recording sheet of <1> to <5>, which is in the range of 0.001 to 1: 0.2.

<7> The inorganic pigment fine particles are silica fine particles having an average primary particle diameter of 20 nm or less, or pseudoboehmite having an average pore radius of 1 to 10 nm <1> to <6> Is a sheet for inkjet recording.

<8> The coloring material receiving layer is formed by applying a dispersion liquid containing the inorganic pigment fine particles and a water-soluble resin on the support. 7>
Is a sheet for inkjet recording.

<9> The water-soluble resin is polyvinyl alcohol or its derivative <8.
The inkjet recording sheet of <>.

<10> The colorant receiving layer contains a crosslinking agent capable of crosslinking the water-soluble resin <8>
Alternatively, the inkjet recording sheet of <9>.

<11> The inkjet recording sheet according to <10>, wherein the crosslinking agent is a boron compound.

<12> The ink jet recording sheet according to <1> to <11>, wherein the coloring material receiving layer contains an organic mordant.

<13> The organic mordant is polyallylamine or its derivative <12.
The inkjet recording sheet of <>.

<14> The colorant receiving layer has a porosity of 5
It has a three-dimensional network structure of 0 to 80%, and the mass ratio (i: p) of the inorganic pigment fine particles (i) and the water-soluble resin (p) is 1.5: 1 to 10: 1. The inkjet recording sheet of <8> to <13>.

<15> The color material receiving layer is formed by applying a first coating solution containing the inorganic pigment fine particles and a cationic polymer onto the surface of the support, and (1) simultaneously with the application,
(2) Either during the drying of the coating layer formed by the coating and before the coating layer exhibits a decreasing rate of drying, or (3) after the coating layer is dried to form a coating film. The inkjet recording sheet of <12> to <14>, further comprising a coloring material receiving layer obtained by applying the second coating liquid containing at least the organic mordant.

<16> The coloring material receiving layer is provided by adding the cross-linking agent to at least one of the first and second coating liquids, or is provided separately from the first and second coating liquids. The inkjet recording sheet of <15>, which is obtained by applying a coating liquid containing a crosslinking agent.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION << Inkjet recording sheet >>
The ink jet recording sheet of the present invention is a cationic polymer having inorganic pigment fine particles and a group having a total number of carbon atoms of 4 to 36 selected from an alkyl group, an aryl group or an aralkyl group (hereinafter referred to as “cationic polymer in the present invention”). And a coloring material receiving layer containing When forming the colorant receiving layer, the cationic polymer of the present invention may be added to the dispersion during dispersion of the inorganic pigment to prevent its aggregation, for example, when it is mixed with a water-soluble resin such as polyvinyl alcohol described later. It is possible to prepare a coating liquid having a low viscosity and a small dispersed particle size. Use of a low-viscosity and small-particle size dispersion can improve various properties such as the glossiness of the inkjet recording sheet, cracking of the colorant receiving layer, ink absorption speed, water resistance, and bleeding resistance over time. An ink jet recording sheet with high density can be provided. Further, when the cationic polymer of the present invention is used to disperse the inorganic pigment fine particles, the print density can be improved by adding a small amount as compared with the case where the inorganic pigment fine particles are simply dispersed using a known cationic polymer. Therefore, coloring of the coloring material receiving layer, which occurs when a large amount of a known cationic polymer is used, can be prevented, and deterioration of light resistance and film strength of the coloring material receiving layer and generation of blurring with time can be prevented.

<Coloring Material Receiving Layer> First, each material contained in the coloring material receiving layer will be described. The colorant receiving layer in the present invention contains at least the cationic polymer in the present invention and inorganic pigment fine particles, and preferably further contains a water-soluble resin, a crosslinking agent capable of crosslinking the water-soluble resin and an organic mordant, and other necessary. Depending on the requirement, various additives may be included.

(Cationic Polymer According to the Present Invention) The cationic polymer according to the present invention has a total carbon number of 4 to 3 at the terminal.
6 has a group selected from an alkyl group, an aryl group and an aralkyl group. The cationic polymer in the present invention may have these groups at least at one end, or may have both groups at both ends, but from the viewpoint of improving the dispersibility and fluidity of the inorganic pigment fine particles, It is preferable to have it at the end. Further, the alkyl group, aryl group and aralkyl group may have a branched structure or a cyclic structure.

The total number of carbon atoms in the above alkyl group is 4 to 36, preferably 8 to 18. When the carbon number is less than 4,
In some cases, it may not be possible to prevent the aggregation of the inorganic pigment fine particles,
When it exceeds 18, the solubility of the cationic polymer in water or alcohol decreases, and the production suitability may not be obtained. Examples of the alkyl group include 1-butyl group and 1
-Pentyl group, 1-hexyl group, 1-heptyl group, 1-
Octyl group, 1-nonyl group, 1-decyl group, 1-undecyl group, 1-dodecyl group, 1-tridecyl group, 1-tetradecyl group, 1-pentadecyl group, 1-hexadecyl group, 1-heptadecyl group, 1- Octadecyl group, 1-nonadecyl group, 1-eicosyl group, 1-docosyl group, 1-
Hexacosyl group, 1-triacontyl group, 1-hexatriacontyl group, sec-butyl group, iso-butyl group, tert-butyl group, neopentyl group, 2-methyl-1-butyl group, 3-methyl-1-butyl group Group, 2-ethyl-1-butyl group, 3,3-dimethyl-1-butyl group,
2-methyl-1-pentyl group, 3-methyl-1-pentyl group, 4-methyl-1-pentyl group, 2-propyl-1
-Pentyl group, 2,4,4-trimethyl-1-pentyl group, 2-ethyl-1-hexyl group, 3,5,5-trimethyl-1-hexyl group, 3,7-dimethyl-1-octyl group Group, 2-pentyl group, 3-pentyl group, 2-hexyl group, 3-hexyl group, 2-heptyl group, 2-octyl group, 3-octyl group, 2-nonyl group, 2-decyl group, Four
-Decyl group, 2-undecyl group, 2-dodecyl group, 2-
Tetradecyl group, 2-hexadecyl group, 3-methyl-2
-Butyl group, 3,3-dimethyl-2-butyl group, 3-methyl-2-pentyl group, 4-methyl-2-pentyl group,
2-methyl-3-pentyl group, 4,4-dimethyl-2-
Pentyl group, 4,4-dimethyl-2-methyl-2-pentyl group, 2,2-dimethyl-3-pentyl group, 2,4-
Dimethyl-3-pentyl group, 5-methyl-2-hexyl group, 2-methyl-3-hexyl group, 6-methyl-2-heptyl group, 4-methyl-3-heptyl group, 2,6 -Dimethyl-4-heptyl group, tert-amyl group, 2,3-
Dimethyl-2-butyl group, 2-methyl-2-pentyl group, 3-methyl-3-pentyl group, 3-ethyl-3-pentyl group, 2,3-dimethyl-3-pentyl group, 3-ethyl-2 , 2-dimethyl-3-pentyl group, 2-methyl-2-hexyl group, 3,7-dimethyl-3-octyl group, cyclohexyl group, and the following compound (A).

[0037]

[Chemical 11]

The aryl group preferably has 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms. Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenyl group, and an alkylphenyl group.

The aralkyl group preferably has 7 to 15 carbon atoms, and more preferably 7 to 11 carbon atoms. Examples of the aralkyl group include a benzyl group, a phenethyl group, a diphenylmethyl group, a triphenylmethyl group, and an α- or β-styryl group.

As the cationic polymer in the present invention, those represented by the following general formula (1) are particularly preferable.

[0041]

[Chemical 12] [In the formula, X represents a single bond or a divalent linking group, and R is a total of 4 to 3 carbon atoms which may have a branched structure or a cyclic structure.
6 represents an alkyl group, an aryl group and an aralkyl group.
A represents at least one repeating unit having a cation, and B represents at least one repeating unit copolymerizable with A. m and n represent the molar ratios of the A component and the B component, respectively, 0.2 ≦ m ≦ 1.0, 0 ≦ n ≦ 0.8 (m +
n = 1.0). ]

In the general formula (1), X represents a single bond or a divalent linking group. The divalent linking group is not particularly limited, but for example, a divalent linking group represented by the following general formula (8) is preferable.

[0043]

[Chemical 13]

In the general formula (8), R ⁸ represents a single bond or an alkylene group having 1 to 8 carbon atoms which may have a side chain, and Y represents a divalent linking group. The alkylene group has 1 to 8 carbon atoms, and preferably 1 to 4 carbon atoms. The alkylene group may have a side chain, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group, a methoxy group, an ethoxy group, a phenoxy group, a methyl group,
Ethyl group and methoxy group are preferred. The above Y represents a divalent linking group, and specifically, ether, thioether,
Amino, ester, amide, thioester, carbonate, urea, thiocarbonate, dithiocarbonate,
Examples thereof include aromatic rings and heterocycles. The above X is preferably a single bond or a divalent linking group represented by the general formula (8), wherein Y has an ether, a thioether, an ester or an amide, and a single bond or
The divalent linking group represented by the general formula (8), which has ether or ester as Y, is particularly preferable.

Specific examples of the divalent linking group represented by X are shown below, but the present invention is not limited thereto.

[0046]

[Chemical 14]

In the general formula (1), R is a branched structure,
It represents an alkyl group, an aryl group or an aralkyl group having a total carbon number of 4 to 36, which may have a cyclic structure.

The total number of carbon atoms in the alkyl group is 4 to 36, preferably 8 to 18. When the carbon number is less than 4,
In some cases, it may not be possible to prevent the aggregation of the inorganic pigment fine particles,
When it exceeds 18, the solubility of the cationic polymer in water or alcohol decreases, and the production suitability may not be obtained. Examples of the alkyl group include 1-butyl group and 1
-Pentyl group, 1-hexyl group, 1-heptyl group, 1-
Octyl group, 1-nonyl group, 1-decyl group, 1-undecyl group, 1-dodecyl group, 1-tridecyl group, 1-tetradecyl group, 1-pentadecyl group, 1-hexadecyl group, 1-heptadecyl group, 1- Octadecyl group, 1-nonadecyl group, 1-eicosyl group, 1-docosyl group, 1-
Hexacosyl group, 1-triacontyl group, 1-hexatriacontyl group, sec-butyl group, iso-butyl group, tert-butyl group, neopentyl group, 2-methyl-1-butyl group, 3-methyl-1-butyl group Group, 2-ethyl-1-butyl group, 3,3-dimethyl-1-butyl group,
2-methyl-1-pentyl group, 3-methyl-1-pentyl group, 4-methyl-1-pentyl group, 2-propyl-1
-Pentyl group, 2,4,4-trimethyl-1-pentyl group, 2-ethyl-1-hexyl group, 3,5,5-trimethyl-1-hexyl group, 3,7-dimethyl-1-octyl group Group, 2-pentyl group, 3-pentyl group, 2-hexyl group, 3-hexyl group, 2-heptyl group, 2-octyl group, 3-octyl group, 2-nonyl group, 2-decyl group, Four
-Decyl group, 2-undecyl group, 2-dodecyl group, 2-
Tetradecyl group, 2-hexadecyl group, 3-methyl-2
-Butyl group, 3,3-dimethyl-2-butyl group, 3-methyl-2-pentyl group, 4-methyl-2-pentyl group,
2-methyl-3-pentyl group, 4,4-dimethyl-2-
Pentyl group, 4,4-dimethyl-2-methyl-2-pentyl group, 2,2-dimethyl-3-pentyl group, 2,4-
Dimethyl-3-pentyl group, 5-methyl-2-hexyl group, 2-methyl-3-hexyl group, 6-methyl-2-heptyl group, 4-methyl-3-heptyl group, 2,6 -Dimethyl-4-heptyl group, tert-amyl group, 2,3-
Dimethyl-2-butyl group, 2-methyl-2-pentyl group, 3-methyl-3-pentyl group, 3-ethyl-3-pentyl group, 2,3-dimethyl-3-pentyl group, 3-ethyl-2 , 2-dimethyl-3-pentyl group, 2-methyl-2-hexyl group, 3,7-dimethyl-3-octyl group, cyclohexyl group and the above compound (A).

The aryl group preferably has 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms. Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenyl group, and an alkylphenyl group.

The aralkyl group preferably has 7 to 15 carbon atoms, and more preferably 7 to 11 carbon atoms. Examples of the aralkyl group include a benzyl group, a phenethyl group, a diphenylmethyl group, a triphenylmethyl group, and an α- or β-styryl group.

The aralkyl group preferably has 7 to 15 carbon atoms, more preferably 7 to 11 carbon atoms. Examples of the aralkyl group include a benzyl group, a phenethyl group, a diphenylmethyl group, a triphenylmethyl group, and an α- or β-styryl group.

Preferred specific examples of R in the general formula (1) are as follows: 1-butyl group, 1-pentyl group, 1-
Hexyl group, 1-heptyl group, 1-octyl group, 1-nonyl group, 1-decyl group, 1-undecyl group, 1-dodecyl group, 1-tridecyl group, 1-tetradecyl group, 1-pentadecyl group, 1-hexadecyl group, 1-heptadecyl group, 1-octadecyl group, 1-nonadecyl group, 1-eicosyl group, 1-docosyl group, 1-hexacosyl group, 1-
Triacontyl group, 1-hexatriacontyl group, se
c-butyl group, iso-butyl group, tert-butyl group, neopentyl group, 2-methyl-1-butyl group, 3-
Methyl-1-butyl group, 2-ethyl-1-butyl group,
3,3-dimethyl-1-butyl group, 2-methyl-1-pentyl group, 3-methyl-1-pentyl group, 4-methyl-
1-pentyl group, 2-propyl-1-pentyl group, 2,
4,4-trimethyl-1-pentyl group, 2-ethyl-1
-Hexyl group, 3,5,5-trimethyl-1-hexyl group, 3,7-dimethyl-1-octyl group, 2-pentyl group, 3-pentyl group, 2-hexyl group, 3-hexyl group Group, 2-heptyl group, 2-octyl group, 3-octyl group, 2-nonyl group, 2-decyl group, 4-decyl group, 2-
Undecyl group, 2-dodecyl group, 2-tetradecyl group,
2-hexadecyl group, 3-methyl-2-butyl group, 3,
3-dimethyl-2-butyl group, 3-methyl-2-pentyl group, 4-methyl-2-pentyl group, 2-methyl-3-
Pentyl group, 4,4-dimethyl-2-pentyl group, 4,
4-dimethyl-2-methyl-2-pentyl group, 2,2-
Dimethyl-3-pentyl group, 2,4-dimethyl-3-pentyl group, 5-methyl-2-hexyl group, 2-methyl-
3-hexyl group, 6-methyl-2-heptyl group, 4-methyl-3-heptyl group, 2,6-dimethyl-4-heptyl group, tert-amyl group, 2,3-dimethyl-2 -Butyl group, 2-methyl-2-pentyl group, 3-methyl-3
-Pentyl group, 3-ethyl-3-pentyl group, 2,3-
Dimethyl-3-pentyl group, 3-ethyl-2,2-dimethyl-3-pentyl group, 2-methyl-2-hexyl group,
3,7-dimethyl-3-octyl group, cyclohexyl group, phenyl group, naphthyl group, tolyl group, benzyl group,
Examples thereof include a phenethyl group and the above compound (A).

In the general formula (1), A represents at least one repeating unit having a cation. The above A is not particularly limited as long as it is a repeating unit having a cation, but repeating units represented by the following (I) to (IV) are particularly preferable.

(I) Repeating unit represented by the following general formula (2)

[Chemical 15] [In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ² , R ³ and R ⁴ each independently have a hydrogen atom or a substituent, and , May combine to form a saturated or unsaturated cyclic structure,
It represents an alkyl group having 1 to 18 carbon atoms, an aryl group or an aralkyl group. Z represents -O- or -NH-,
Y ² represents a divalent linking group having a total of 1 to 8 carbon atoms, which may have a heteroatom. X ⁻ represents an anion. ]

In the general formula (2), R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. When the carbon number exceeds 4, it may be difficult to obtain a polymer. The alkyl group preferably has 1 to 2 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-butyl group and an n-butyl group. R ¹ is preferably a hydrogen atom or a methyl group. R in the general formula (2)
² , R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, an aryl group or an aralkyl group. The alkyl group, aryl group and aralkyl group may have a substituent. As the substituent, a halogen atom, a hydroxyl group, an amino group, an ester group,
Examples thereof include ether group and amide group.

The alkyl group has 1 to 18 carbon atoms, preferably 1 to 8 carbon atoms. The carbon number is 1
When it exceeds 8, the solubility in water and alcohol is lowered, and sufficient performance may not be obtained in some cases. Examples of the alkyl include methyl group, ethyl group, propyl group, butyl group, hexyl group, cyclohexyl group, octyl group, decyl group, dodecyl group, tetradecyl group, octadecyl group, methyl group, ethyl group, butyl group. A group, a hexyl group and a cyclohexyl group are preferred.

The aryl group preferably has 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms. Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group, and a phenyl group and a tolyl group are preferable.

The aralkyl group preferably has 7 to 15 carbon atoms, and more preferably 7 to 11 carbon atoms. Examples of the aralkyl group include a benzyl group, a phenethyl group, a diphenylmethyl group, a triphenylmethyl group, an α- or β-styryl group, and benzyl is preferable.

In the general formula (2), Z is --O-- or --NH.
Represents-. In the general formula (2), Y ² represents a divalent linking group having a total of 1 to 8 carbon atoms, which may have a heteroatom. Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, a phosphorus atom and the like, an oxygen atom, a nitrogen atom,
A sulfur atom is preferred. The total number of carbon atoms in Y ² is 2 to 6
Is preferred. Examples of the divalent linking group include a methylene group, an ethylene group, a propylene group, a tetramethylene group, a hexamethylene group, a xylylene group, and 3-oxapentamethylene.

In the general formula (2), X^-Represents anion
You The anion is not particularly limited, but for example,
F^-, Cl^-, Br^-, I^-, AcO^-, NO₃ ^-, SO_Four ^2-,
HSO _Four ^-, MeSO_Four ^-, PO_Four ^3-, HPO_Four ^2-, H₂PO_Four
^-, TsO^-, CH₃SO₃ ^-, ClO_Four ^-, BF_Four ^-, P
F₆ ^-, CH₃CH₂CO₂ ^-, Ph-CO₂ ^-, (C
O₂)₂ ^2-, (Meth) acrylate anions
It

Specific examples of the repeating unit represented by the general formula (2) are shown below, but the invention is not limited thereto.

[0062]

[Chemical 16]

[0063]

[Chemical 17]

(II) Repeating unit represented by the following general formula (3)

[Chemical 18]

In formula (3), R ⁵ represents a hydrogen atom or a methyl group, preferably a hydrogen atom. R ² , R ³ ,
R ⁴ and X ⁻ have the same meaning as in the general formula (2).

Specific examples of the repeating unit represented by formula (3) are shown below, but the invention is not limited thereto.

[0067]

[Chemical 19]

[0068]

[Chemical 20]

(III) A repeating unit represented by the following general formula (4) and / or general formula (5)

[Chemical 21]

In the general formulas (4) and (5), R ² , R ³ ,
X ⁻ has the same meaning as in formula (2).

Specific examples of the repeating units represented by formulas (4) and (5) are shown below, but the invention is not limited thereto.

[0072]

[Chemical formula 22]

[0073]

[Chemical formula 23]

[0074]

[Chemical formula 24]

(IV) Repeating unit represented by the following general formula (6) and / or general formula (7)

[Chemical 25]

In the general formula (6) and n, n is 0 or 1.
Representation 1 is preferred, R², R³, R ^Four, X^-Is the general formula
It is synonymous with (2).

Specific examples of the repeating units represented by the general formulas (6) and (7) are shown below, but the invention is not limited thereto.

[0078]

[Chemical formula 26]

[0079]

[Chemical 27]

In the general formula (1), B represents at least one repeating unit copolymerizable with A. As the above B,
There is no particular limitation as long as it is a repeating unit copolymerizable with A, but it is an aromatic vinyl compound (eg, styrene, α-methylstyrene, p-hydroxystyrene, chloromethylstyrene and vinyltoluene), alkyl (meth) acrylate. Ester (eg, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate), (meth) acrylic acid alkylaryl ester ( Examples: benzyl (meth) acrylate, (meth) acrylic acid-substituted alkyl ester (eg, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate) ), Rutile (meth) acrylamide (eg, (meth) acrylamide, dimethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, n-butyl (meth) acrylamide, tert-butyl (meth) acrylamide and tert-octyl (meth) acrylamide) ), A substituted alkyl (meth) acrylamide (eg, dimethylaminoethyl (meth) acrylamide and dimethylaminopropyl (meth) acrylamide), vinyl cyanide (eg, (meth) acrylonitrile and α-chloroacrylonitrile), a carboxylic acid vinyl ester ( Examples, vinyl acetate, vinyl benzoate, vinyl formate), aliphatic conjugated dienes (eg, 1,3-butadiene and isoprene) and polymerizable oligomers (eg, one-end methacryloylated polymethylmethacrylate ori). Ma,
One-terminal methacryloylated polystyrene oligomer and one-terminal methacryloylated polyethylene glycol) and the like.

In the general formula (1), m and n each represent a molar ratio of the A component and the B component, and m is 0.2≤m≤1.0.
And n is 0.0 ≦ n ≦ 0.8. However, m +
n = 1. As m: n, preferably 0.4:
0.6-1.0: 0 and 0.5: 0.5-1.0:
0 is more preferable.

The number average molecular weight of the cationic polymer in the present invention is preferably 1,000 to 20,000, more preferably 1,000 to 10,000, and most preferably 1,500 to 10,000. The above molecular weight is less than 1000, or 200
If it exceeds 00, the aggregation of the inorganic pigment fine particles may not be prevented in some cases.

The mass ratio of the inorganic pigment fine particles in the invention to the cationic polymer in the colorant receiving layer is 1: 0.001.
Is preferably in the range of 1 to 0.2.
More preferably within the range of 1: 0.001:
It is particularly preferable that it is in the range of 5 to 0.05. If the addition amount of the cationic polymer in the present invention is less than 0.001% by mass of the addition amount of the inorganic pigment fine particles, it may not be possible to prevent the aggregation of the inorganic pigment fine particles, and if it exceeds 0.2% by mass, the inorganic pigment fine particles may be prevented. Cause agglomeration of
The coating solution may thicken and the coating suitability may be lost.

The cationic polymer in the present invention comprises a cationic group-containing monomer and a monomer copolymerizable therewith in the presence of a chain transfer agent having a total number of carbon atoms of 4 to 36 and a mercapto group. It can be obtained by co-polymerization. As the chain transfer agent, 1-butyl mercaptan, 1-pentyl mercaptan, 1-hexyl mercaptan, 1-heptyl mercaptan, 1-octyl mercaptan, 1-nonyl mercaptan, 1-decyl mercaptan, 1-undecyl mercaptan, 1- Dodecyl mercaptan, 1-tridecyl mercaptan, 1-tetradecyl mercaptan, 1-pentadecyl mercaptan, 1-hexadecyl mercaptan, 1-heptadecyl mercaptan, 1-octadecyl mercaptan, 1-nonadecyl mercaptan, 1-eicosyl mercaptan, 1-docosyl mercaptan, 1-
Hexacosyl mercaptan, 1-triacontyl mercaptan, 1-hexatriacontyl mercaptan, se
c-Butyl mercaptan, iso-butyl mercaptan, tert-butyl mercaptan, neopentyl mercaptan, 2-methyl-1-butyl mercaptan, 3-
Methyl-1-butyl mercaptan, 2-ethyl-1-butyl mercaptan, 3,3-dimethyl-1-butyl mercaptan, 2-methyl-1-pentyl mercaptan, 3
-Methyl-1-pentyl mercaptan, 4-methyl-1
-Pentyl mercaptan, 2-propyl-1-pentyl mercaptan, 2,4,4-trimethyl-1-pentyl mercaptan, 2-ethyl-1-hexyl mercaptan, 3,5,5-trimethyl-1-hexyl mercaptan, 3, 7-dimethyl-1-octyl mercaptan, 2
-Pentyl mercaptan, 3-pentyl mercaptan,
2-hexyl mercaptan, 3-hexyl mercaptan, 2-heptyl mercaptan, 2-octyl mercaptan, 3-octyl mercaptan, 2-nonyl mercaptan, 2-decyl mercaptan, 4-decyl mercaptan, 2-undecyl mercaptan, 2-dodecyl mercaptan , 2-tetradecyl mercaptan, 2-hexadecyl mercaptan, 3-methyl-2-butyl mercaptan, 3,3-dimethyl-2-butyl mercaptan, 3-
Methyl-2-pentyl mercaptan, 4-methyl-2-
Pentyl mercaptan, 2-methyl-3-pentyl mercaptan, 4,4-Dimethyl-2-pentyl mercaptan, 4,4-Dimethyl-2-methyl-2-pentyl mercaptan, 2,2-Dimethyl-3-pentyl mercaptan, 2 , 4-dimethyl-3-pentyl mercaptan, 5
-Methyl-2-hexyl mercaptan, 2-methyl-3
-Hexyl mercaptan, 6-methyl-2-heptyl mercaptan, 4-methyl-3-heptyl mercaptan,
2,6-dimethyl-4-heptyl mercaptan, ter
t-amyl mercaptan, 2,3-dimethyl-2-butyl mercaptan, 2-methyl-2-pentyl mercaptan, 3-methyl-3-pentyl mercaptan, 3-ethyl-3-pentyl mercaptan, 2,3-dimethyl-3
-Pentyl mercaptan, 3-ethyl-2,2-dimethyl-3-pentyl mercaptan, 2-methyl-2-hexyl mercaptan, 3,7-dimethyl-3-octyl mercaptan, cyclohexyl mercaptan, phenyl mercaptan, naphthyl mercaptan, tolyl mercaptan , Benzyl mercaptan, phenethyl mercaptan,
Thioglycolic acid 1-octyl, thioglycolic acid 1-
Decyl, 1-octadecyl thioglycolate, 2-ethylhexyl thioglycolate, isooctyl thioglycolate, 1-octyl mercaptopropionate, 1-decyl mercaptopropionate, 1-octadecyl mercaptopropionate, 2-ethylhexyl mercaptopropionate, mercapto. Examples include isooctyl propionate, octyloxyethyl mercaptan, octyloxyethyl thioglycolate, octyloxyethyl mercaptopropionate, and the following compounds (B) to (D).

[0085]

[Chemical 28]

Specific examples of the above-mentioned cationic polymers (cationic polymers 1 to 45) are shown below, but the present invention is not limited thereto.

[0087]

[Chemical 29]

[0088]

[Chemical 30]

[0089]

[Chemical 31]

[0090]

[Chemical 32]

[0091]

[Chemical 33]

[0092]

[Chemical 34]

[0093]

[Chemical 35]

[0094]

[Chemical 36]

[0095]

[Chemical 37]

[0096]

[Chemical 38]

[0097]

[Chemical Formula 39]

(Inorganic pigment fine particles) Examples of the inorganic pigment fine particles include silica fine particles, colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate and sulfuric acid. Examples thereof include calcium, boehmite, pseudo-boehmite and the like. Among them, silica fine particles and pseudo-boehmite are particularly preferable.

Since the above silica fine particles have a particularly large specific surface area, they have high ink absorption and retention efficiency, and also have a low refractive index. Therefore, if they are dispersed to an appropriate particle size, they are transparent to the colorant receiving layer. Is provided, and high color density and good color developability are obtained. The fact that the colorant receiving layer is transparent is not only for applications requiring transparency such as OHP, but also for obtaining high color density and good colorability when applied to recording sheets such as photo glossy paper. Is important in.

The average primary particle diameter of the inorganic pigment fine particles is preferably 20 nm or less, more preferably 10 nm or less, and particularly preferably 3 to 10 nm.

The silica fine particles have silanol groups on the surface thereof, and particles are easily attached to each other by hydrogen bonds due to the silanol groups. Therefore, as described above, when the average primary particle diameter is 10 nm or less, the void ratio is large. The structure can be formed. Thereby, the ink absorption characteristics can be effectively improved.

The silica fine particles are roughly classified into wet method particles and dry method particles according to the manufacturing method. In the above wet method, activated silica is generated by acid decomposition of silicate,
The mainstream method is to obtain water-containing silica by appropriately polymerizing this and coagulating and precipitating it. On the other hand, the dry method is a method by high-temperature gas phase hydrolysis of silicon halide (flame hydrolysis method) or a method in which silica sand and coke are heated and reduced and vaporized by an arc in an electric furnace, and this is oxidized by air. The main method is to obtain anhydrous silica by the (arc method).

The hydrous silica and anhydrous silica obtained by these methods have different properties because of the difference in the density of silanol groups on the surface, the presence or absence of vacancies, and the like. In particular, anhydrous silica (silicic acid anhydride) is preferable because it easily forms a three-dimensional structure having a high porosity. Although the reason for this is not clear, in the case of hydrous silica, the density of silanol groups on the surface of the fine particles is as high as 5 to 8 / nm ^2, and the silica fine particles are likely to densely aggregate (aggregate). On the other hand, in the case of anhydrous silica, since the density of silanol groups on the surface of the fine particles is as small as 2-3 / nm ^2, it causes sparse soft flocculation. As a result, it is estimated that the structure has a high porosity. Therefore, in the present invention, the density of silanol groups on the surface of the fine particles is 2-3 / nm.
It is preferable to use silica (fine silica particles) of ² .

Pseudo-boehmite is also preferable as the inorganic pigment fine particles. Pseudo-boehmite is boehmite (compositional formula A
10OOH) crystal colloidal aggregates, preferably containing a binder. As the pore characteristics, the average pore radius is preferably 1 to 10 nm, more preferably 3 to 10 nm. The pore volume is 0.5 to 1.0 ml /
It is preferably in the range of g. The coating amount of the pseudo-boehmite is preferably in the range of 5 to 30 g / m ² . If the coating amount is less than 5 g / m ² , the absorptivity of the ink may be lowered or the glossiness may be deteriorated due to the influence of the unevenness of the substrate, which is not preferable. Coating amount is 3
If it exceeds 0 g / m ² , not only is pseudoboehmite consumed unnecessarily, but the strength of the pseudoboehmite may be reduced, which is not preferable.

The composition of the pseudo-boehmite coating solution contains the binder in an amount of preferably 5 to 50 parts by mass based on 100 parts by mass of the pseudo-boehmite solid content, and the total solid content concentration is 5 to 3 parts.
Those of 0 mass% can be preferably used. The solvent of the coating liquid is preferably an aqueous system from the viewpoint of handleability. As the binder, an organic binder composed of a high molecular compound such as starch or a modified product thereof, polyvinyl alcohol and a modified product thereof, SBR latex, NBR latex, carboxymethyl cellulose, hydroxymethyl cellulose, polyvinylpyrrolidone can be preferably used.

(Water-Soluble Resin) The colorant-receiving layer in the present invention is preferably a layer formed by coating a dispersion containing fine inorganic pigment particles and a water-soluble resin on a support. Examples of the water-soluble resin include polyvinyl alcohol (PVA), cation-modified polyvinyl alcohol, which is a resin having a hydroxyl group as a hydrophilic structural unit,
Anion-modified polyvinyl alcohol, silanol-modified polyvinyl alcohol, polyvinyl acetal, cellulose resin [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC),
Carboxymethyl cellulose (CMC), etc.], chitins, chitosans, starch; polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG), polyvinyl ether (PVE) which are resins having an ether bond; amide group or Examples include resins having an amide bond, such as polyacrylamide (PAAM) and polyvinylpyrrolidone (PVP). Further, polyacrylic acid salts, maleic acid resins, alginates and gelatins having a carboxyl group as a dissociative group can be mentioned. Among the above,
Polyvinyl alcohols are particularly preferable.

The content of the water-soluble resin is preferably 9 to 40% by mass, and more preferably 16 to 33% by mass, based on the total mass of the solid content of the colorant receiving layer. If the content is less than 9% by mass, the film strength may be lowered and cracks may easily occur during drying, and if it exceeds 40% by mass, the voids may be easily clogged with a resin, resulting in a void ratio. May decrease and the ink absorbency may decrease.

The inorganic pigment fine particles and the water-soluble resin, which mainly constitute the colorant receiving layer, may be a single material or a mixed material of a plurality of materials.

From the viewpoint of transparency, the type of resin to be combined with the inorganic pigment fine particles is important. When the above anhydrous silica is used, polyvinyl alcohol (PVA) is preferable as the water-soluble resin, and the saponification degree is 70 to 70%.
99% PVA is more preferred, saponification degree 70-90%
Is particularly preferred.

The PVA has a hydroxyl group in its structural unit, and this hydroxyl group and a silanol group on the surface of the silica fine particles form a hydrogen bond to form a three-dimensional network structure having secondary particles of the silica fine particles as chain units. Make it easier to form. It is considered that the formation of the above-mentioned three-dimensional network structure makes it possible to form a coloring material receiving layer having a porous structure with a high porosity. In inkjet recording, the porous coloring material-receiving layer obtained as described above can rapidly absorb ink by a capillary phenomenon and form dots with good circularity without ink blurring.

-Content Ratio of Inorganic Pigment Fine Particles to Water-Soluble Resin-Content ratio of inorganic pigment fine particles (preferably silica fine particles or pseudo-boehmite; i) to water-soluble resin [PB ratio (i: p), The mass of all inorganic pigment fine particles relative to 1 part by mass of the water-soluble resin] has a great influence on the film structure of the colorant receiving layer. That is, as the PB ratio increases, the porosity, pore volume, and surface area (per unit mass) increase. Specifically, the PB ratio (i: p) is 1.5: 1 to 1
0: 1 is preferred. If the PB ratio exceeds 10: 1, that is, if the PB ratio becomes too large, the film strength may decrease and cracks may easily occur during drying.
If it is less than 1, that is, if the PB ratio is too small, the voids are likely to be blocked by the resin, and as a result, the void ratio may decrease and the ink absorbability may decrease.

When passing through the transport system of an ink jet printer, stress may be applied to the recording sheet, so that the coloring material receiving layer must have sufficient film strength. Further, in the case of cutting into a sheet shape, it is necessary that the coloring material receiving layer has sufficient film strength in order to prevent cracking or peeling of the coloring material receiving layer. In this case, the PB ratio is preferably 5: 1 or less, and is preferably 2: 1 or more from the viewpoint of ensuring high-speed ink absorbency in an inkjet printer.

For example, the inorganic pigment fine particles having an average primary particle diameter of 20 nm or less and the water-soluble resin have a PB ratio of 2: 1 to 1: 1.
When a coating solution completely dispersed in an aqueous solution at a ratio of 5: 1 was coated on a support and the coating layer was dried, a three-dimensional network structure having secondary particles of inorganic pigment fine particles as chain units was formed, Pore size 30 nm or less, porosity 50% to 80%, pore specific volume 0.5 ml / g or more, specific surface area 100 m ² / g
The above-mentioned translucent porous film can be easily formed.

(Crosslinking Agent) The colorant-receiving layer of the ink jet recording sheet of the present invention is a crosslinking agent capable of further crosslinking the above water-soluble resin to the coating layer (porous layer) containing the inorganic pigment fine particles and the water-soluble resin. And a layer cured by a crosslinking reaction between the crosslinking agent and the water-soluble resin.

The above-mentioned cross-linking agent is applied at the same time as the coating liquid (first coating liquid) for forming the porous color material receiving layer is applied, or by applying the first coating liquid. It is preferable to add the second coating solution to the second coating solution before the coating layer shows a decreasing rate of drying. By this operation, it is possible to effectively prevent the generation of cracks that occur during the drying of the coating layer. That is, at the same time when the coating liquid is applied, or before the coating layer shows a decreasing rate of drying, the crosslinking agent solution penetrates into the coating layer and reacts rapidly with the water-soluble resin in the coating layer, By gelling (curing) the water-soluble resin, the film strength of the coating layer is immediately and significantly improved. The cross-linking agent may be contained in the first and / or second coating liquid, or may be added and applied to a coating liquid different from the first and second coating liquids.

As the cross-linking agent capable of cross-linking the above water-soluble resin, a suitable one may be appropriately selected in relation to the water-soluble resin used in the colorant receiving layer, but among them, the crosslinking reaction is rapid. From the above, a boron compound is preferable, and examples thereof include borax, boric acid, borate (eg, orthoborate, In
_{BO 3, ScBO 3, YBO 3} , LaBO 3, Mg 3 (B
O ₃ ) ₂ , Co ₃ (BO ₃ ) ₂ , diborate (eg Mg _{2
B 2 O 5, Co 2 B} 2 O 5), metaborate (e.g., Li
_{BO 2, Ca (BO 2)} 2, NaBO 2, KBO 2), tetraborates _{(eg, Na 2 B 4 O 7 ·} 10H 2 O), pentaborate (e.g., KB ₅ O ₈ · 4H _{2 O, Ca 2 B 6 O 11} · 7H 2
O, CsB ₅ O ₅ ), glyoxal, melamine / formaldehyde (eg, methylol melamine, alkylated methylol melamine), methylol urea, resole resin, polyisocyanate, and epoxy resin. Among them, borax, boric acid, and borate are preferable in that they rapidly cause a crosslinking reaction,
In particular, it is more preferable to use it in combination with polyvinyl alcohol as the water-soluble resin.

When gelatin is used as the water-soluble resin, the following compounds known as a hardening agent for gelatin can be used as a crosslinking agent. For example, aldehyde compounds such as formaldehyde, glyoxal, and glutaraldehyde; ketone compounds such as diacetyl and cyclopentanedione; bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1,3.
Active halogen compounds such as 5-triazine and 2,4-dichloro-6-S-triazine sodium salt; divinyl sulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N'-ethylenebis (vinylsulfonyl acetate) Cetamide), active vinyl compounds such as 1,3,5-triacryloyl-hexahydro-S-triazine; N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin;

Isocyanate compounds such as 1,6-hexamethylene diisocyanate; US Pat. No. 301
Nos. 7280 and 2983611; aziridine compounds; carboximide compounds described in U.S. Pat. No. 3,100,704; epoxy compounds such as glycerol triglycidyl ether; 1,6-hexamethylene-N, N '. -Ethyleneimino compounds such as bisethyleneurea; halogenated carboxaldehyde compounds such as mucochloric acid and mucophenoxycyclo acid; dioxane compounds such as 2,3-dihydroxydioxane; chromium alum, potassium alum, zirconium sulfate, Chromium acetate and the like. The cross-linking agents may be used alone or in combination of two or more.

The above crosslinking agent solution is prepared by dissolving the crosslinking agent in water and / or an organic solvent. The concentration of the cross-linking agent in the cross-linking agent solution is 0.
05-10 mass% is preferable and 0.1-7 mass% is especially preferable. Water is generally used as the solvent constituting the crosslinking agent solution, and may be an aqueous mixed solvent containing an organic solvent miscible with the water. Any organic solvent can be used as long as it can dissolve the crosslinking agent, and examples thereof include alcohols such as methanol, ethanol, isopropyl alcohol, and glycerin; ketones such as acetone and methyl ethyl ketone; methyl acetate, ethyl acetate, and the like. And the like; aromatic solvents such as toluene; ethers such as tetrahydrofuran; and halogenated carbon solvents such as dichloromethane.

(Organic mordant) In the present invention, in order to further improve the water resistance of the formed image and the bleeding resistance with time,
It is preferable that the colorant receiving layer contains an organic mordant (hereinafter, may be simply referred to as “mordant”). As the mordant, a cationic polymer (cationic mordant) is preferable, and by allowing the mordant to be present in the colorant receiving layer,
It can interact with a liquid ink having an anionic dye as a coloring material to stabilize the coloring material and improve water resistance and blurring over time.

However, if this is directly added to the first coating liquid for forming the colorant-receptive layer, there is a concern that aggregation may occur with the inorganic pigment fine particles having an anion charge.
If the method of preparing and applying as an independent separate solution is used, there is no need to worry about the aggregation of the inorganic pigment fine particles. Therefore, in the present invention, it is used by being contained in the second coating liquid different from the above-mentioned inorganic pigment fine particles.

As the cationic mordant, a polymer mordant having a primary to tertiary amino group or a quaternary ammonium base as a cationic group is preferably used, but a cationic non-polymer mordant is also used. can do. As the polymer mordant, first to third
A homopolymer of a monomer (mordant monomer) having a primary amino group and a salt thereof, or a quaternary ammonium salt group, and a copolymerization weight of the mordant monomer and another monomer (hereinafter, referred to as "non-mordant monomer"). Those obtained as a polymer or a condensation polymer are preferable. Further, these polymer mordants can be used in the form of either a water-soluble polymer or water-dispersible latex particles.

Examples of the above-mentioned monomer (mordanting monomer) include trimethyl-p-vinylbenzylammonium chloride, trimethyl-m-vinylbenzylammonium chloride, triethyl-p-vinylbenzylammonium chloride and triethyl-m-vinylbenzylammonium. Chloride, N, N-dimethyl-N-ethyl-N-p-vinylbenzylammonium chloride,
N, N-diethyl-N-methyl-N-p-vinylbenzylammonium chloride, N, N-dimethyl-Nn
-Propyl-N-p-vinylbenzyl ammonium chloride, N, N-dimethyl-Nn-octyl-N-p
-Vinylbenzylammonium chloride, N, N-dimethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-benzyl-
N-p-vinylbenzylammonium chloride, N,
N-dimethyl-N- (4-methyl) benzyl-Np-
Vinylbenzylammonium chloride, N, N-dimethyl-N-phenyl-Np-vinylbenzylammonium chloride,

Trimethyl-p-vinylbenzylammonium bromide, trimethyl-m-vinylbenzylammonium bromide, trimethyl-p-vinylbenzylammonium sulfonate, trimethyl-m-vinylbenzylammonium sulfonate, trimethyl-p-vinylbenzylammonium acetate, trimethyl- m
-Vinylbenzyl ammonium acetate, N, N, N
-Triethyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N, N-triethyl-N
-2- (3-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- (4
-Vinylphenyl) ethylammonium chloride,
N, N-diethyl-N-methyl-N-2- (4-vinylphenyl) ethylammonium acetate,

N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth)
Acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, Methyl chloride of N-diethylaminopropyl (meth) acrylamide,
Examples thereof include ethyl chloride, methyl bromide, ethyl bromide, quaternary compounds of methyl iodide or ethyl iodide, and sulfonates, alkylsulfonates, acetates or alkylcarboxylates of which anions are substituted.

Specifically, for example, monomethyldiallylammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium chloride, triethyl-2- (methacryloyloxy) ethylammonium chloride, trimethyl-2- (acryloyloxy) ethylammonium chloride. , Triethyl-2-
(Acryloyloxy) ethylammonium chloride, trimethyl-3- (methacryloyloxy) propylammonium chloride, triethyl-3- (methacryloyloxy) propylammonium chloride, trimethyl-2- (methacryloylamino) ethylammonium chloride, triethyl-2- (methacryloyl) Amino) ethylammonium chloride, trimethyl-
2- (acryloylamino) ethylammonium chloride, triethyl-2- (acryloylamino) ethylammonium chloride, trimethyl-3- (methacryloylamino) propylammonium chloride, triethyl-3- (methacryloylamino) propylammonium chloride, trimethyl-3- (Acryloylamino) propyl ammonium chloride, triethyl-
3- (acryloylamino) propylammonium chloride,

N, N-dimethyl-N-ethyl-2- (methacryloyloxy) ethylammonium chloride,
N, N-diethyl-N-methyl-2- (methacryloyloxy) ethylammonium chloride, N, N-dimethyl-N-ethyl-3- (acryloylamino) propylammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium Bromide, trimethyl-3- (acryloylamino) propylammonium bromide, trimethyl-2- (methacryloyloxy) ethylammonium sulfonate, trimethyl-
3- (acryloylamino) propyl ammonium acetate etc. can be mentioned. In addition, examples of copolymerizable monomers include N-vinylimidazole and N-vinyl-2-methylimidazole.

The non-mordanting monomer does not contain a basic or cationic moiety such as a primary to tertiary amino group and its salt, or a quaternary ammonium salt group, and interacts with the dye in the ink jet ink. A monomer that does not show or has a substantially small interaction. Examples of the non-mordanting monomer include (meth) acrylic acid alkyl ester; (meth) acrylic acid cycloalkyl ester such as cyclohexyl (meth) acrylate; (meth)
(Meth) acrylic acid aryl ester such as phenyl acrylate; aralkyl ester such as benzyl (meth) acrylate; aromatic vinyls such as styrene, vinyltoluene, α-methylstyrene; vinyl acetate, vinyl propionate, vinyl versatate And vinyl esters such as allyl acetate; halogen-containing monomers such as vinylidene chloride and vinyl chloride; vinyl cyanide such as (meth) acrylonitrile; olefins such as ethylene and propylene.

The above-mentioned (meth) acrylic acid alkyl ester has a (meth) alkyl group having 1 to 18 carbon atoms in the alkyl moiety.
Acrylic acid alkyl esters are preferable, for example, methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate,
Examples include hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate. Among them, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate and hydroxyethyl methacrylate are preferable. The non-mordant monomers can be used alone or in combination of two or more.

Further, as a polymer mordant, polydiallyldimethylammonium chloride, polymethacryloyloxyethyl-β-hydroxyethyldimethylammonium chloride, polyethyleneimine, polyallylamine and its modified products, polyallylamine hydrochloride, polyamide-polyamine resin, cationization Starch, dicyandiamide formalin condensate, dimethyl-2-hydroxypropylammonium salt polymer, polyamidine, polyvinylamine and the like can be mentioned as preferable examples, and polyallylamine and its derivatives are particularly preferable.

The polyallylamine derivative is prepared by adding acrylonitrile, chloromethylstyrene, TEMPO, epoxyhexane, sorbic acid, etc. to polyallylamine in an amount of 2-5.
0 mol% added, preferably 5 to 10 mol% of acrylonitrile and chloromethylstyrene, particularly 5 to 10 mol% of polyallylamine.
Acrylonitrile adducts are preferable from the viewpoint of exerting the effect of preventing ozone fading.

The mordant preferably has a weight average molecular weight of 5,000 to 200,000. When the molecular weight is in the range of 5,000 to 200,000, water resistance and bleeding resistance over time can be improved.

(Other Components) The color material receiving layer may contain the following components, if necessary. For the purpose of suppressing the deterioration of the coloring material, various kinds of ultraviolet absorbers, antioxidants, and fading inhibitors such as singlet oxygen quencher may be contained. Examples of the ultraviolet absorber include cinnamic acid derivatives, benzophenone derivatives, benzotriazolylphenol derivatives and the like. For example, α-cyano-phenyl butyl cinnamate, o
-Benzotriazole phenol, o-benzotriazole-p-chlorophenol, o-benzotriazole-2,4-di-t-butylphenol, o-benzotriazole-2,4-di-t-octylphenol and the like can be mentioned. A hindered phenol compound can also be used as an ultraviolet absorber, and specifically, a phenol derivative in which at least one of 2-position or 6-position is substituted with a branched alkyl group is preferable.

Further, benzotriazole type ultraviolet absorbers, salicylic acid type ultraviolet absorbers, cyanoacrylate type ultraviolet absorbers, oxalic acid anilide type ultraviolet absorbers and the like can also be used. For example, JP-A-47-1053
No. 7, gazette 58-111942 gazette, gazette 58-21.
No. 2844, No. 59-19945, No. 59-
46646, 59-109055, and 6
No. 3-53544, Japanese Patent Publication No. 36-10466, No. 42-26187, No. 48-30492, No. 48-31255, No. 48-41572.
JP-A-48-54965 and JP-A-50-1072.
No. 6, gazettes, US Pat. Nos. 2,719,086, 3,707,375, 3,754,919, 4,220,711, etc. There is.

A fluorescent whitening agent can also be used as an ultraviolet absorber, and examples thereof include a coumarin-based fluorescent whitening agent. Specifically, JP-B-45-4699 and 54-53.
No. 24, etc.

Examples of the above-mentioned antioxidant include European Patent Nos. 223739, 309401, 309402, 310551 and 31.
No. 0552, No. 459416, German Published Patent No. 3435443, and Japanese Patent Laid-Open No. 54-48535.
No. 60-107384 and No. 60-107.
No. 383, No. 60-125470, No. 60-
No. 125471, No. 60-125472, No. 60-287485, No. 60-287486, No. 60-287487, and No. 60-28748.
8 gazette, the same 61-160287 gazette, the same 61-18.
5483, 61-211079 and 62.
No. 146678, No. 62-146680,
62-146679, 62-282885, 62-262047, 63-0511.
74, 63-89877, 63-88.
No. 380, No. 66-88381, No. 63-1.
No. 13536,

63-163351 and 63-2.
No. 03372, No. 63-224989, No. 6
No. 3-251282, No. 63-267594, No. 63-182484, Japanese Patent Laid-Open No. 1-2392.
82, JP-A-2-262654, and 2-7.
No. 1262, No. 3-121449, and No. 4-2.
No. 91685, No. 4-291684, No. 5-
No. 61166, No. 5-119449, No. 5-
No. 188687, No. 5-188686, No. 5
-110490 gazette, the same 5-1108437 gazette,
No. 5-170361, Japanese Patent Publication No. 48-43295, No. 48-33212, and U.S. Pat. No. 4,814.
No. 262, No. 4980275, etc. are mentioned.

Specifically, 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2 -Dihydroquinoline, 6-ethoxy-1-
Phenyl-2,2,4-trimethyl-1,2,3,4-
Tetrahydroquinoline, 6-ethoxy-1-octyl-
2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline, nickel cyclohexanoate, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2 -Ethylhexane, 2
-Methyl-4-methoxy-diphenylamine, 1-methyl-2-phenylindole and the like can be mentioned.

The anti-fading agents may be used alone or in combination of two or more kinds. This anti-fading agent is water-soluble,
It may be dispersed or emulsified, or may be contained in microcapsules. The amount of the anti-fading agent added is preferably 0.01 to 10% by mass of the coating material for the colorant receiving layer.

Further, for the purpose of enhancing the dispersibility of the fine particles of the inorganic pigment, various inorganic salts and an acid, an alkali or the like as a pH adjusting agent may be contained. Further, metal oxide fine particles having electronic conductivity may be included for the purpose of suppressing frictional electrification and peeling electrification on the surface, and various matting agents may be included for the purpose of reducing the frictional property of the surface.

<Method for Forming Color Material Receiving Layer> Next, a method for forming the color material receiving layer will be described. The coloring material receiving layer in the present invention is formed by applying a first coating liquid (coating liquid for a coloring material receiving layer) containing at least the inorganic pigment fine particles and the cationic polymer in the present invention, and (1) simultaneously with the coating, or
(2) Either during the drying of the coating layer formed by the coating and before the coating layer exhibits a decreasing rate of drying, or (3) after drying the coating layer to form a coating film. In addition, it is preferable that the second coating liquid (crosslinking agent solution) containing at least the organic mordant is applied to the coating layer, and the coating layer is cured and dried.

As described above, a mordant is secondarily added together with a crosslinking agent.
The water resistance of the coloring material-receptive layer can be improved by adding it to the coating liquid and applying it simultaneously. That is, when the mordant is added to the first coating liquid, since the mordant is cationic, coagulation may occur in the presence of the inorganic pigment fine particles having an anionic charge on the surface. If the coating solution and the first coating solution are prepared independently and applied individually, it is not necessary to consider the aggregation of the inorganic pigment fine particles, and the selection range of the mordant is expanded.

In the present invention, the above-mentioned first coating liquid for a colorant receiving layer containing at least inorganic pigment fine particles (eg silica fine particles) and the cationic polymer of the present invention, and further containing a water-soluble resin (eg PVA). Can be prepared, for example, as follows. That is, silica fine particles are added to water (for example, 10 to 20% by mass), and the cationic polymer-containing solution of the present invention (for example, 3
The amount of the 0% methanol solution added to the cationic polymer of the present invention is 0.005 to the content of the above vapor phase silica.
0.05 mass%), and using a high-speed rotating wet colloid mill (for example, CLEARMIX (manufactured by M Technique Co., Ltd.)), for example, 10,000 rpm
After dispersing for 20 minutes (preferably 10 to 30 minutes) under the condition of high-speed rotation (preferably 5000 to 20000 rpm), an aqueous polyvinyl alcohol solution (for example, PVA having a mass about 1/3 of silica) is dispersed. In addition, it can be prepared by further performing dispersion under the same rotation conditions as above. The obtained first coating liquid is a uniform sol, and a porous coloring material-receptive layer having a three-dimensional network structure can be formed by coating and forming this on a support by the following coating method. . If necessary, a surfactant, a pH adjusting agent, an antistatic agent, etc. may be added to the first coating liquid.

The first coating solution can be applied by a known application method such as an extrusion die coater, an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, a bar coater and the like. .

The above "before the coating layer starts to exhibit the rate of decrease in drying rate" usually means a few minutes immediately after coating the first coating liquid, and during this period, the coating layer The constant drying rate, which is a phenomenon in which the content of the solvent decreases in proportion to time, is shown. For the time showing the constant rate of drying, see Chemical Engineering Handbook (p.707-712, Maruzen Co., Ltd.).
Published, October 25, 1980).

As described above, after applying the first coating solution,
The coating layer is dried until it exhibits a rate of dry reduction, which is generally 0.5-10 at 50-180 ° C.
It is performed for a minute (preferably 0.5 to 5 minutes). As the drying time, it naturally depends on the coating amount, but the above range is suitable.

As a method of applying the coating solution containing the organic solvent solution (second coating solution) before the above-mentioned coating layer shows a decreasing rate of drying, (1) applying the second coating solution Method of further coating on the layer, (2) Method of spraying the second coating solution by a method such as spraying, (3) Immersion of the support on which the coating layer is formed in the solution of the second coating solution how to,
Etc.

As the coating method for coating the second coating liquid in the above method (1), for example, curtain flow coater, extrusion die coater, air doctor coater, bread coater, rod coater, knife coater, squeeze coater, reverse roll A known coating method such as a coater or a bar coater can be used. However, it is preferable to use a method such as an extrusion die coater, a curtain flow coater, or a bar coater in which the coater does not directly contact the already-formed coating layer. Further, in these coatings, two or more kinds of coating liquids may be simultaneously coated in a multilayer manner.

The above simultaneous coating (multilayer coating) can be carried out by a coating method using an extrusion die coater or a curtain flow coater. After the simultaneous coating, the formed coating layer is dried. In this case, the drying is generally performed at 40 to 150 ° C. for 0.5 to 1
Heating for 0 minutes, preferably
It is carried out by heating at 40 to 100 ° C. for 0.5 to 5 minutes. For example, when borax or boric acid is used as the crosslinking agent contained in the second coating liquid, 60 to 100 ° C.
It is preferable to heat for 5 to 20 minutes.

When the second coating solution is applied after the coating layer has been dried to form a coating film, the coating layer is dried at 4
It is carried out by heating at 0 to 150 ° C for 0.5 to 10 minutes, preferably at 0.5 to 5 at 40 to 100 ° C.
It is done by heating for a minute.

The above-mentioned cross-linking agent can be added to either of the above-mentioned first and second coating solutions to give the cross-linking agent on the support or the like. The cross-linking agent can also be applied at any stage of the coating process by preparing a solution containing the cross-linking agent separately from the above-mentioned first and second coating solutions.

In each step of the above-mentioned coating, water, an organic solvent, or a mixed solvent thereof can be used as a solvent. Examples of the organic solvent that can be used for this coating include alcohols such as methanol, ethanol, n-propanol, i-propanol and methoxypropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, acetonitrile, ethyl acetate, toluene and the like. To be

After the color material receiving layer is formed on the support, the surface of the color material receiving layer is smoothed by subjecting the color material receiving layer to calendering through a roll nip under heat and pressure using, for example, a super calender or a gloss calender. Sex, glossiness,
It is possible to improve transparency and coating film strength.
However, the calendering process may cause a decrease in the porosity (that is, the ink absorbency may decrease), so it is necessary to set conditions under which the decrease in the porosity is small.

The roll temperature for calendering treatment is preferably 30 to 150 ° C., and 40 to 100 ° C.
C is even more preferred. The linear pressure between the rolls during the calendering treatment is preferably 50 to 400 kg / cm, more preferably 100 to 200 kg / cm.

In the case of an ink jet recording sheet, the layer thickness of the color material receiving layer needs to have an absorption capacity enough to absorb all the liquid droplets, so it must be determined in relation to the porosity in the layer. There is. For example, if the ink amount is 8 nL / mm
² and the porosity is 60%, the layer thickness is about 15μ.
A film having a thickness of m or more is required. Considering this point, in the case of inkjet recording, the layer thickness of the colorant receiving layer is
10 to 50 μm is preferable.

The pore diameter of the color material receiving layer is preferably 0.005 to 0.030 μm in terms of median diameter, and 0.01 to
0.025 μm is more preferable. The porosity and the median pore diameter can be measured using a mercury porosimeter (trade name: Boasizer 9320-PC2, manufactured by Shimadzu Corporation).

The colorant-receiving layer preferably has excellent transparency. As a guideline, the haze value when the colorant-receiving layer is formed on a transparent film support is 30.
% Or less, and more preferably 20% or less. The haze value is a haze meter (H
GM-2DP: can be measured using Suga Test Instruments Co., Ltd.

<Support> As the support, any of a transparent support made of a transparent material such as plastic and an opaque support made of an opaque material such as paper can be used. In order to make the most of the transparency of the colorant receiving layer, it is preferable to use a transparent support or a highly glossy opaque support.

As a material that can be used for the transparent support, a material that is transparent and has the property of withstanding radiant heat when used in an OHP or backlight display is preferable. Examples of the material include polyesters such as polyethylene terephthalate (PET); polysulfone,
Examples thereof include polyphenylene oxide, polyimide, polycarbonate and polyamide. Among them, polyesters are preferable, and polyethylene terephthalate is particularly preferable. The thickness of the transparent support is not particularly limited, but is preferably 50 to 200 μm from the viewpoint of handleability.

As the highly glossy 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 JIS P-814.
It is a value determined according to the method described in 2 (75 degree specular gloss test method for paper and board). Specific examples include the following supports.

For example, high gloss paper supports such as art papers, coated papers, cast coated papers, and baryta papers used for silver salt photographic supports; polyesters such as polyethylene terephthalate (PET); nitrocellulose. , Cellulose acetate, cellulose acetate such as cellulose acetate butyrate, plastic film such as polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide, etc. were made opaque by containing a white pigment etc. (may be subjected to surface calendering treatment) High-gloss film; or a high-gloss film containing the above various paper supports, the above-mentioned transparent supports, or white pigments, etc., provided with a polyolefin coating layer containing or not containing a white pigment. Support. Further, a white pigment-containing expanded polyester film (for example, expanded PET in which polyolefin fine particles are contained and voids are formed by stretching) can also be preferably mentioned.

The thickness of the opaque support is not particularly limited, but is preferably 50 to 300 μm from the viewpoint of handleability.

Further, a corona discharge treatment,
Those subjected to glow discharge treatment, flame treatment, ultraviolet irradiation treatment and the like may be used.

Next, the base paper used for the paper support will be described in detail. The base paper 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 the wood pulp, LBKP, LBSP, NBKP, NBSP, LD
Any of P, NDP, LUKP and NUKP can be used, but LBKP, NBSP, LB with a large amount of short fibers
It is preferable to use more SP, NDP, and LDP. However, the ratio of LBSP and / or LDP is preferably 10% by mass or more and 70% by mass or less.

As the above-mentioned pulp, chemical pulp containing few impurities (sulfate pulp or sulfite pulp) is preferably used,
Pulp that has been bleached to improve its whiteness is also useful.

In the base paper, 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, fluorescent whitening agents, A water retention agent such as polyethylene glycol, a dispersant, and a softening agent such as quaternary ammonium can be appropriately added.

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

The basis weight of the base paper is preferably 30 to 250 g, particularly preferably 50 to 200 g. The thickness of the base paper is preferably 40 to 250 μm. The base paper can be given a high smoothness by calendering at the papermaking stage or after the papermaking. The base paper density is 0.7 to 1.2 g / m ² (J
ISP-8118) is common. Furthermore, the stiffness of the base paper is 2 under the conditions specified in JIS P-8143.
0 to 200 g is preferable.

A surface sizing agent may be applied to the surface of the base paper, 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 base paper is JI
It is preferably 5 to 9 when measured by the hot water extraction method specified in SP-8113.

The polyethylene for covering the front and back surfaces of the base paper is mainly low-density polyethylene (LDPE) and / or high-density polyethylene (HDPE), but other LLDPE, polypropylene and the like can be partially used.

In particular, the polyethylene layer on the side of forming the colorant-receiving layer is formed by adding rutile or anatase type titanium oxide into polyethylene, as is commonly used in photographic printing paper, to obtain opacity and whiteness. Those improved are preferable. Here, the content of titanium oxide is preferably about 3 to 20 mass% with respect to polyethylene, and 4
-13 mass% is more preferable.

The polyethylene-coated paper can be used as a glossy paper, or when a polyethylene is melt-extruded on the surface of a base paper for coating, a so-called patterning treatment is performed to obtain a matte surface or a matte surface which can be obtained by ordinary photographic printing paper. It is also possible to use those having a silk surface.

As described above, according to the present invention, it is possible to improve the print density of an image without deteriorating the performance of other inks. Moreover, when the colorant receiving layer has the three-dimensional network structure containing the inorganic pigment fine particles and the porosity of 50 to 80%, the ink exhibits good ink absorbency and can form a high resolution image, and also in a high temperature and high humidity environment. It is possible to simultaneously secure excellent ink receiving performance such that the bleeding with time is suppressed and the formed image also has high light resistance and water resistance.

[0174]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. still,
Unless otherwise specified, "parts" and "%" in the examples represent "parts by mass" and "mass%", the number following "WM" represents "weight average molecular weight", and the "degree of polymerization" is ""Weight average degree of polymerization".

<< Synthesis Example of Cationic Polymer in the Present Invention >> [Synthesis Example 1] N- [2- (methacryloyloxy) ethyl] -N, N, N-trimethylammonium chloride 3
0 parts and 1.6 parts of 2-ethylhexyl 3-mercaptopropionate were dissolved in 70 parts of methanol and heated to 65 ° C. under a nitrogen stream, and V-50 (polymerization initiator; manufactured by Wako Pure Chemical Industries, Ltd.) 0.16 parts of the above and further heated for 4 hours to obtain a cationic polymer 1 (a cationic polymer represented by the general formula (1) containing a repeating unit represented by the general formula (2)).
To obtain a 30% methanol solution.

[Synthesis Example 2] The same procedure as in Synthesis Example 1 was repeated except that the addition amount of 2-ethylhexyl 3-mercaptopropionate in Synthesis Example 1 was changed from 1.6 parts to 3.3 parts. A 30% methanol solution of the cationic polymer represented by the general formula (1) containing the repeating unit represented by the formula (2) was obtained.

[Synthesis Example 3] 30 parts of N- [2- (methacryloyloxy) ethyl] -N, N, N-trimethylammonium chloride of Synthesis Example 1 was added to N- [3- (methacryloylamino) 2-hydroxypropyl. ] -N, N, N
30% methanol solution of cationic polymer 3 (cationic polymer represented by general formula (1) containing a repeating unit represented by general formula (2)) in the same manner as in Synthesis Example 1 except that 30 parts of trimethylammonium chloride was used. Got

[Synthesis Example 4] 30 parts of N- [2- (methacryloyloxy) ethyl] -N, N, N-trimethylammonium chloride of Synthesis Example 1 was added to N- [2- (methacryloyloxy) ethyl] -N. -Chemical polymer 4 (cationic polymer represented by the general formula (1) containing the repeating unit represented by the general formula (2)) in the same manner as in Synthesis Example 1 except that 30 parts of -benzyl-N, N-dimethylammonium chloride was used. ) Was obtained as a 30% methanol solution.

[Synthesis Example 5] 30 parts of N- [2- (methacryloyloxy) ethyl] -N, N, N-trimethylammonium chloride of Synthesis Example 1 was added to N- [2- (methacryloyloxy) ethyl] -N. , N, N-trimethylammonium chloride 20 parts and methyl acrylate 10 parts, except that the cationic polymer 5 (in the general formula (1) containing a repeating unit represented by the general formula (2)) in the same manner as in Synthesis Example 1. A 30% solution of the indicated cationic polymer) in methanol was obtained.

[Synthesis Example 6] A cationic polymer 6 (was prepared in the same manner as in Synthesis Example 1 except that 1.6 parts of 2-ethylhexyl 3-mercaptopropionate in Synthesis Example 1 was changed to 1.5 parts of n-dodecanethiol. A 30% methanol solution of the cationic polymer represented by the general formula (1) containing the repeating unit represented by the general formula (2) was obtained.

[Synthesis Example 7] A cationic polymer 7 (was prepared in the same manner as in Synthesis Example 1 except that 1.6 parts of 2-ethylhexyl 3-mercaptopropionate of Synthesis Example 1 was changed to 2.1 parts of n-octadecanethiol. A 30% methanol solution of the cationic polymer represented by the general formula (1) containing the repeating unit represented by the general formula (2) was obtained.

[Synthesis Example 8] Synthesis Example 1 except that 1.6 parts of 2-ethylhexyl 3-mercaptopropionate of Synthesis Example 1 was changed to 0.84 parts of cyclohexyl mercaptan.
A 30% methanol solution of a cationic polymer 8 (a cationic polymer represented by the general formula (1) containing a repeating unit represented by the general formula (2)) was obtained in the same manner as in.

[Synthesis Example 9] Synthesis Example 1 except that 1.6 parts of 2-ethylhexyl 3-mercaptopropionate in Synthesis Example 1 was changed to 2.5 parts of octadecyl thioglycolate.
A 30% methanol solution of a cationic polymer 9 (a cationic polymer represented by the general formula (1) containing a repeating unit represented by the general formula (2)) was obtained in the same manner as in.

Comparative Synthesis Example 1 Cationic polymer 1 was prepared in the same manner as in Synthesis Example 1 except that 1.6 parts of 2-ethylhexyl 3-mercaptopropionate in Synthesis Example 1 was not added.
A 30% methanol solution of 0 (comparative cationic polymer) was obtained.

Comparative Synthetic Example 2 Cationic polymer 11 (comparative example 1) was prepared in the same manner as in Synthetic Example 1 except that 1.6 part of 2-ethylhexyl 3-mercaptopropionate in Synthetic Example 1 was changed to 0.45 part of ethanethiol. Cationic polymer)
To obtain a 30% methanol solution.

<< Preparation of Inkjet Recording Sheet >> [Example 1] -Preparation of Support-After performing corona discharge treatment on art paper (OK Kinfuji; manufactured by Oji Paper Co., Ltd.) with a basis weight of 186 g / m ² . High-density polyethylene was coated to a thickness of 19 μm using a melt extruder to form a resin layer composed of a matte surface (hereinafter, the resin layer surface is referred to as “rear surface”). The resin layer on the back surface side is further subjected to corona discharge treatment, and thereafter, aluminum oxide (alumina sol 10 is used as an antistatic agent).
0, Nissan Chemical Industries, Ltd.) and silicon dioxide (Snowtex O, Nissan Chemical Industries, Ltd.) were dispersed in water at a ratio of 1: 2 (mass ratio) to obtain a dry mass of 0. .2 g /
It was applied so as to be m ² .

Further, after the corona discharge treatment was applied to the felt surface (front surface) side where the resin layer was not provided, anatase type titanium dioxide 10%, a trace amount of ultramarine blue, and a fluorescent whitening agent 0.01% ( To polyethylene), MFR
(Melt flow rate) 3.8 low-density polyethylene was melt-extruded to a thickness of 24 μm using a melt extruder to form a high-gloss thermoplastic resin layer on the surface side of the base paper (hereinafter, This high-gloss surface is referred to as the "front surface"), and was used as a support. The front surface of the support was used after being subjected to corona discharge treatment before applying the coating liquid.

-Preparation of Coating Solution for Coloring Material Receiving Layer (First Coating Solution)-(2) Ion-exchanged water in the following composition was mixed with (1) fine particles of vapor phase method silica, and (3) the above cationic polymer. 30 of 1
% Methanol solution is further mixed, and Nanomizer LA3
1 (manufactured by Nanomizer Co., Ltd.), 500 kg / m
After performing the twice treated with ² pressure, further subjected to stirring for 60 minutes, added with stirring (4) Polyvinyl alcohol 8% aqueous solution in the following composition, and (5) Emulgen 109P (10%) solution and ( 6) Diethylene glycol monobutyl ether was added to prepare coating solution A (first coating solution) for the colorant receiving layer. The mass ratio of the silica fine particles to the water-soluble resin (PB ratio / (1) :( 4)) is 4.
It was 5: 1.

[Composition of Coating Liquid A for Coloring Material Receiving Layer] (1) Fine particles of vapor-phase method silica (fine particles of inorganic pigment) 7.7 parts (Specific surface area by BET method: 300 m ² / g, average primary particle diameter 7 nm, QS-30, manufactured by Tokuyama Corp. (2) Ion-exchanged water 72.1 parts (3) 30% methanol solution of the above cationic polymer 1 0.51 part (4) Polyvinyl alcohol 8% aqueous solution 21.3 parts (PVA124 , Manufactured by Kuraray Co., Ltd., saponification degree 98.5%, polymerization degree 2400) (5) Polyoxyethylene lauryl ether 1.0 part (nonionic surfactant; Emulgen 109P (10%), manufactured by Kao Corporation) (6) Diethylene glycol monobutyl ether (DEGMBE) 0.6 part (high boiling organic solvent)

-Production of Inkjet Recording Sheet- The coating material A for the colorant receiving layer obtained above was applied to the front side of the support at 200 m by using an extrusion die coater.
A coating amount of 1 / m ² was applied (coating step), and the coating layer was dried at 80 ° C. (air velocity of 3 to 8 m / sec) until the solid content concentration of the coating layer became 20%. The coating layer showed a constant drying rate during this period. Immediately thereafter, it is immersed in a cross-linking agent solution A (second coating solution) having the following composition for 30 seconds to adhere 20 g / m ² thereof onto the coating layer (step of applying the cross-linking agent solution), and further at 80 ° C. And dried for 10 minutes (drying step). From this, an inkjet recording sheet (1) of the present invention provided with a color material receiving layer having a dry film thickness of 32 μm was produced. .

[0191] [Composition of Crosslinking Agent Solution A] ・ Boric acid (crosslinking agent) 2.5 parts ・ Ion-exchanged water 69.5 parts ・ Polyallylamine (10%) aqueous solution (organic mordant; WM: 10,000) 25 parts ・ Polyoxyethylene lauryl ether (nonionic surfactant) 2 parts (Emulgen 109P (10%), manufactured by Kao Corporation) ・ Ammonium chloride 1 part

-Evaluation method-1. Evaluation of Coating Liquid for Coloring Material Receiving Layer (1-1) 500 g of the above coating liquid A for coloring material receiving layer
After being collected in a ml container and immersed in a high temperature tank at 30 ° C. for 10 minutes, the viscosity was measured using a B-type viscometer (manufactured by Tokimec) at 60 rpm, and the coating solution A for colorant receiving layer was obtained according to the following criteria. The dispersion state of was evaluated. The results are shown in Table 1. [Criteria] AA: The viscosity was less than 100 mPa · s, the dispersion state was good, and coating was possible. BB: Viscosity was 100 or more and less than 1000 mPa · s, and it was in a dispersed state in which some hindrance was caused in coating. CC: Viscosity was 1000 mPa · s or more, and it was in a dispersed state in which coating was impossible.

(1-2) Average Particle Size Light Scattering Diffraction Type Particle Size Distribution Measuring Device (LA910, Co., Ltd.)
HORIBA, Ltd.) was used to measure the volume-based median particle diameter D50 of the fine particles in the coating liquid A for the colorant receiving layer, and this value was adopted as the average particle diameter, and evaluated according to the following criteria. The results are shown in Table 1. The refractive index of 1.10 was input as a parameter during the measurement. [Standard] AA: less than 0.2 μm BB: 0.2 or more and less than 5.0 μm CC: 5 μm or more

(1-3) Coarse Particles In (1-2) above, evaluation was made by the ratio of particles having a size of 5 μm or more to the whole. The results are shown in Table 1. [Standard] AA: less than 2% BB: 2 or more and less than 10% CC: 10% or more

2. Evaluation of Inkjet Recording Sheet (2-1) Glossiness The 60 ° glossiness on the surface of the color material receiving layer of the recording sheet before printing was measured by a digital variable angle glossmeter (UGV-50DP, manufactured by Suga Test Instruments Co., Ltd.). And evaluated according to the following criteria. The results are shown in Table 2. [Standard] AA: The glossiness was 40 or more. BB: The glossiness was 30 or more and less than 40. CC: The glossiness was less than 30.

(2-2) Ink Absorption Rate Using an inkjet printer (PM-900C, manufactured by Seiko Epson Corporation), Y (yellow), M (magenta), C (cyan), K
Solid images of (black), B (blue), G (green) and R (red) are printed, and immediately (after about 10 seconds), the paper is contact-pressed on the image to transfer the ink to the paper. The presence or absence of each of these was evaluated according to the following criteria. The results are shown in Table 2. [Standard] AA: Ink transfer onto paper was not observed at all.
It shows that the ink absorption rate is good. BB: A part of the ink was transferred onto the paper, but there was no problem in practical use. CC: A large amount of ink transfer was recognized on the paper.

(2-3) Generation of Cracks The presence or absence of cracks on the surface of the ink jet recording sheet and the size thereof were visually observed and evaluated according to the following criteria. The results are shown in Table 2. [Standard] AA: No cracks were observed on the surface. BB: A crack having a length of 1 to 2 mm was recognized. CC: A crack having a length of 3 mm or more was recognized.

(2-4) Water resistance Using the same printer as in the above (2-2), the same printing pattern is formed on an ink jet recording sheet, left for 3 hours, and then immersed in water for 1 minute to form an ink. The degree of outflow into water was visually observed and evaluated according to the following criteria. The results are shown in Table 2. [Standard] AA: No dye outflow was observed. BB: A portion where the dye flowed out was recognized, and the color density was lowered. CC: The dye has run out into the water almost completely.

(2-5) Blurring with Time Using the same printer as in (2-2) above, a grid-like linear pattern (line width 0. Two
8 mm) was printed, and the visual density was measured by X-light 310TR (manufactured by X-light). After printing for 3 hours, store in a thermo-hygrostat at 40 ° C and 90% relative humidity for 1 day, measure the visual density again, calculate the density difference (ΔOD), and evaluate according to the following criteria. did. The smaller the value of the density difference (ΔOD), the more the generation of bleeding with time is suppressed. The results are shown in Table 2. [Reference] AA: The density difference was less than 0.36. BB: The density difference was 0.36 or more and less than 0.5. CC: The density difference was 0.5 or more.

(2-6) Lightfastness Using the same printer as in (2-2) above, solid Y (yellow), M (magenta), C (cyan) and K (black) inks are formed on an ink jet recording sheet. Print the image, X light 3
The visual density of each color was measured by 10TR (manufactured by X-Light Co., Ltd.). After that, 365n for the printed image
Xenon weather-ometer Ci through a film that blocks ultraviolet rays in the wavelength range of m or less
Using 65A (manufactured by ATLAS), the lamp was lit for 3.8 hours under the environmental conditions of 25 ° C. and relative humidity of 32%, and then the lamp was extinguished at 20 ° C. and relative humidity of 91%. A cycle of standing underneath for 1 hour was carried out for 11 days. After that, the visual density of each color was measured again to calculate the residual rate (rate of change in density before and after the test) of the fading of each color, and the evaluation was performed according to the following criteria. The results are shown in Table 2. [Standard] AA: Almost no fading occurred. BB: Slightly fading. CC: It was very fading.

(2-7) Image Density (Printing Density) Using the same printer as in (2-2) above, a K (black) solid image is printed on an ink jet recording sheet and left for 3 hours, and then the printing is performed. The reflection density of the surface was measured with a Macbeth reflection densitometer and evaluated according to the following criteria. The results are shown in Table 2. AA: The reflection density was 2.0 or more. BB: The reflection density was 1.8 or more and less than 2.0. CC: The reflection density was less than 1.8.

[Examples 2-9, Comparative Examples 1-5] Example 1
Coating Material B for Coloring Material Receiving Layer is the same as in Example 1 except that the cationic polymer 1 and the addition amount of the coating material A for Coloring Material Receiving Layer are changed to the cationic polymer and the addition amount shown in Table 1.
N was prepared, and the inkjet recording sheets (2) to (9) of the present invention and the comparative inkjet recording sheets (1) to (5) were prepared and evaluated. The results are shown in Table 2. In Comparative Examples 1, 2, 4 and 5, the coating liquid for the colorant receiving layer was too high in viscosity to be applied onto the support.

[0203]

[Table 1]

From Table 1 above, the coating liquid for the colorant receiving layer to which the cationic polymer of the present invention was added was able to suppress aggregation of vapor-phase method silica fine particles to each other and to obtain a dispersion having good fluidity. . On the other hand, the total number of carbon atoms at the end is 4 to 36.
Using a cationic polymer having no group selected from the alkyl group, aryl group or aralkyl group of, or
The coating liquids J, K, M and N (Comparative Examples 1, 2, 4 and 5) for the colorant receiving layer which did not use the cationic polymer (anti-aggregation agent) were all evaluated in the evaluation of viscosity, average particle size and coarse particles. The result was low, and the viscosity was high and it was impossible to apply it to the surface of the support. Further, coating liquids L and M for the colorant receiving layer which did not use the cationic polymer of the present invention
In Comparative Examples 3 and 4, it was necessary to add a large amount of cationic polymer.

[0205]

[Table 2]

From the results shown in Table 2 above, the cationic recording polymer of the present invention was added to the coating liquid for the colorant-receiving layer, and the ink jet recording sheets (1) to (9) of the present invention containing fine particles of the inorganic pigment showed glossiness. , Ink absorption speed, cracking, water resistance, bleeding resistance over time, light resistance, and print density were excellent.

On the other hand, in Comparative Example 3 in which the cationic polymer of the present invention was not used, bleeding with time occurred and the light resistance was low. Further, in Comparative Examples 1, 2, 4 and 5, the coating liquid for the colorant receiving layer had a high viscosity, so that an ink jet recording sheet could not be prepared and evaluation was impossible.

[0208]

INDUSTRIAL APPLICABILITY The present invention can provide an ink jet recording sheet having a high image printing density without deteriorating other ink receiving performance. Further, the present invention can provide an inkjet recording sheet which is strong without cracks and the like, has good ink absorbability and can form a high resolution image. Furthermore, the present invention can provide an ink jet recording sheet which is extremely excellent in bleeding resistance over time after printing and has excellent water resistance, and which exhibits high light resistance even under irradiation with light such as sunlight and fluorescent lamps.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C056 EA04 EA13 FC06                 2H086 BA15 BA31 BA33 BA34 BA35                       BA37

Claims (16)

[Claims] 1. An alkyl group having a total carbon number of 4 to 36 at the end,
An ink jet recording sheet, comprising a support and a colorant receiving layer containing a cationic polymer having a group selected from an aryl group or an aralkyl group and inorganic pigment fine particles. 2. The inkjet recording sheet according to claim 1, wherein the cationic polymer is represented by the following general formula (1). [Chemical 1] [In the formula, X represents a single bond or a divalent linking group, and R is a total of 4 to 3 carbon atoms which may have a branched structure or a cyclic structure.
6 represents an alkyl group, an aryl group and an aralkyl group.
A represents at least one repeating unit having a cation, and B represents at least one repeating unit copolymerizable with A. m and n represent the molar ratios of the A component and the B component, respectively, 0.2 ≦ m ≦ 1.0, 0 ≦ n ≦ 0.8 (m +
n = 1.0). ] 3. R in the general formula (1) is selected from an alkyl group having 8 to 18 carbon atoms, which may have a branched structure and a cyclic structure, an aryl group, and an aralkyl group. The inkjet recording sheet according to claim 2. 4. The inkjet recording sheet according to claim 2, wherein the repeating unit A in the general formula (1) is at least one selected from the following (I) to (IV). . (I) A repeating unit represented by the following general formula (2): [In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ² , R ³ and R ⁴ each independently have a hydrogen atom or a substituent, and , May combine to form a saturated or unsaturated cyclic structure,
It represents an alkyl group having 1 to 18 carbon atoms, an aryl group or an aralkyl group. Z represents -O- or -NH-,
Y ² represents a divalent linking group having a total of 1 to 8 carbon atoms, which may have a heteroatom. X ⁻ represents an anion. ] (II) A repeating unit represented by the following general formula (3): [In the formula, R ⁵ represents a hydrogen atom or a methyl group. R ² ,
R ³ , R ⁴ and X ⁻ have the same meaning as in formula (2). ] (III) The following general formula (4) and / or general formula (5)
Repeating unit represented by IN FORMULA, R < ² >, R < ³ >, X < ^- > IS SYNTHESIS OF GENERAL FORMULA (2). ] (IV) A repeating unit represented by the following general formula (6) and / or general formula (7): [In the formula, n represents 0 or 1, and R ² , R ³ , R ⁴ , and X ⁻
Is synonymous with general formula (2). ] 5. The inkjet recording sheet according to claim 1, wherein the cationic polymer has a number average molecular weight of 1,000 to 20,000. 6. The mass ratio (x: y) of the inorganic pigment fine particles (x) and the cationic polymer (y) is 1: 0.0.
The inkjet recording sheet according to any one of claims 1 to 5, which is in the range of 01 to 1: 0.2. 7. The inorganic pigment fine particles are silica fine particles having an average primary particle diameter of 20 nm or less, or pseudoboehmite having an average pore radius of 1 to 10 nm. The ink jet recording sheet according to [1]. 8. The color material receiving layer is formed by applying a dispersion liquid containing the inorganic pigment fine particles and a water-soluble resin on the support. The ink jet recording sheet according to any one of claims. 9. The ink jet recording sheet according to claim 8, wherein the water-soluble resin is polyvinyl alcohol or a derivative thereof. 10. The ink jet recording sheet according to claim 8, wherein the color material receiving layer contains a crosslinking agent capable of crosslinking the water-soluble resin. 11. The inkjet recording sheet according to claim 10, wherein the crosslinking agent is a boron compound. 12. The inkjet recording sheet according to claim 1, wherein the color material receiving layer contains an organic mordant. 13. The ink jet recording sheet according to claim 12, wherein the organic mordant is polyallylamine or a derivative thereof. 14. The coloring material receiving layer has a porosity of 50 to 8
It has a three-dimensional network structure of 0% and the mass ratio (i: p) of the inorganic pigment fine particles (i) and the water-soluble resin (p).
Is 1.5: 1 to 10: 1, The inkjet recording sheet according to any one of claims 8 to 13, wherein. 15. The coloring material receiving layer is formed by applying a first coating liquid containing the inorganic pigment fine particles and the cationic polymer onto the surface of the support, and (1) simultaneously with the coating, and (2).
At least during the drying of the coating layer formed by the coating and before the coating layer exhibits a rate of reduction drying, or (3) after the coating layer is dried to form a coating film, at least 2. A color material receiving layer obtained by applying a second coating liquid containing the organic mordant.
The inkjet recording sheet according to any one of 2 to 14. 16. The color material receiving layer is provided by adding the cross-linking agent to at least one of the first and second coating liquids, or the cross-linking is performed separately from the first and second coating liquids. The inkjet recording sheet according to claim 15, which is obtained by applying a coating liquid containing an agent.