WO2010013528A1 - Ink-jet recording method - Google Patents

Abstract

Disclosed is an ink-jet recording method.  In the method, the recording is carried out on an ink-jet recording medium which comprises a support and an ink-receiving layer arranged on the support and comprising at least inorganic microparticles, a water-soluble resin and a cross-linking agent.  In the method, the recording is carried out by using an ink which comprises at least a dye, water and a water-soluble organic solvent component.  In the ink, the water-soluble organic solvent component contains a water-soluble organic solvent at a ratio of 40 mass% or more relative to the total quantity of the water-soluble organic solvent component.  The water-soluble organic solvent has such a property that, when applied on the ink-receiving layer at a rate of 6.6 g/m², the ratio of the total volume of pores having a median diameter of 40 to 100 nm to the total volume of pores having a median diameter of 100 nm or smaller in the ink-receiving layer is 11% or less, wherein the median diameters are measured by mercury intrusion porosimetry.

Description

Inkjet recording method

The present invention relates to an inkjet recording method.

With the rapid development of the information technology industry in recent years, various information processing systems have been developed, and recording methods and recording apparatuses suitable for each information processing system have been put into practical use. Among these, the ink jet recording method is widely used because it can record on various recording materials, the hardware (device) is relatively inexpensive and compact, and has excellent quietness. ing. In the recording using the ink jet recording method, it has become possible to obtain a so-called photographic-like high quality recorded matter.

In recent years, recording media in which the ink receiving layer has a porous structure have been put into practical use. According to this, it is said that it is excellent in quick-drying and high gloss is obtained.
However, there is an increasing demand for image quality, and there is a demand for an inkjet recording medium that can obtain a clearer and higher quality image (high density) and is excellent in storage stability.

As a printing method for obtaining a high-density image, a method for obtaining a high-density recorded image by defining the pore diameter of the receiving layer is disclosed (for example, see Patent Documents 1 and 2).
However, all refer only to the receiving layer pore diameter before performing the printing process, and do not mention any recording method for controlling the receiving layer pore diameter after the printing process.

Further, as another method for obtaining a high density image, various studies have been made on inkjet ink. There is a description of increasing the density of a printed image depending on the content and type of a water-soluble organic solvent contained in ink (see, for example, Patent Document 3).
As described above, various studies have been made on the ink jet recording method capable of obtaining a high-density recorded image. However, in recent years, the demand for image quality is increasing, and a higher-density image quality is required. ing.

Japanese Patent Laid-Open No. 2000-247022 JP 2006-181954 A JP-A-2005-336489

Furthermore, in addition to the performance with respect to image quality, another problem specific to the ink jet recording method is that the hue changes over time immediately after printing, so that it takes time to stabilize the image. In particular, when the recorded image is not sufficiently dried, when an object such as another recording material is superimposed on a part of the recorded image, the hue of the recorded image differs between the overlapping portion and the non-overlapping portion. It became clear that there was a case (that is, a case where an overlay was generated).

It is an object of the present invention to provide an ink jet recording method capable of obtaining a clear and high density recorded image and highly suppressing hue change immediately after printing.

As a result of intensive studies on the above problems by the present inventors, a recording process is performed using an inkjet ink containing a specific amount of a specific water-soluble organic solvent in the ink, and the ink receiving layer pore diameter after recording is controlled. As a result, a clear and high density recorded image was obtained, and a remarkable improvement effect of suppressing hue change immediately after printing was found.

<1>
An ink containing at least a dye, water, and a water-soluble organic solvent on an ink jet recording medium having an ink receiving layer containing at least an inorganic fine particle, a water-soluble resin, and a crosslinking agent on a support, wherein the ink is a water-soluble organic solvent. Volume ratio of pores having a median diameter of 40 to 100 nm in pores having a median diameter of 100 nm or less measured by mercury intrusion of the ink receiving layer after applying 6.6 g / m ² to the ink receiving layer. An ink jet recording method, wherein recording is performed using an ink having a water-soluble organic solvent content of 40% by mass or more.

<2>
The inkjet recording method according to <1>, wherein the water-soluble resin is polyvinyl alcohol.

<3>
The water-soluble organic solvent in the ink is ethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, dipropylene glycol monoalkyl ether, 1,2-alkyl diol, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether. Inkjet recording according to <1> or <2>, wherein the inkjet recording is at least one selected from triethylene glycol dialkyl ether, propylene glycol dialkyl ether, dipropylene glycol dialkyl ether, and tripropylene glycol dialkyl ether Method.

According to the present invention, it is possible to provide an ink jet recording method capable of obtaining a clear and high density recorded image and highly suppressing a hue change immediately after printing.

Hereinafter, the ink jet recording method of the present invention will be described in detail.
In the inkjet recording method of the present invention, an inkjet recording medium having an ink receiving layer containing at least inorganic fine particles, a water-soluble resin, and a crosslinking agent on a support, a dye, water, and 6.6 g / m in the ink receiving layer. ⁽²⁾ at least a water-soluble organic solvent in which the volume ratio of pores having a median diameter of 40 to 100 nm is 11% or less in pores having a median diameter of 100 nm or less as measured by a mercury intrusion method of the ink receiving layer after the application. In addition, recording is performed using an ink in which the content ratio of the water-soluble organic solvent in the total water-soluble organic solvent is 40% by mass or more.
According to the ink jet recording method of the present invention, a clear and high density recorded image can be obtained, and a recorded image capable of highly suppressing a hue change immediately after printing can be provided.

<Ink>
The ink in the present invention contains at least a dye, water, and a water-soluble organic solvent, and may contain other components as necessary.
The ink in the present invention may be at least one selected from the group consisting of yellow ink, magenta ink, cyan ink, and black ink, and may be configured as an ink set in which these inks are combined. Below, each component contained in the ink in this invention is demonstrated.

(Water-soluble organic solvent)
The ink contains a water-soluble organic solvent, and the content ratio of the water-soluble organic solvent (hereinafter also referred to as “specific water-soluble organic solvent”) in the total water-soluble organic solvent needs to be 40% by mass or more. is there.
The water-soluble organic solvent is a water-soluble compound that dissolves in water by 1% by mass or more.
The specific water-soluble organic solvent, median diameter 40 in the ink-receiving layer to 6.6 g / m ² applied to the ink-receiving layer of mercury intrusion median diameter 100nm in the following the pores as measured by method at after ~ The solvent has a volume ratio of pores of 100 nm of 11% or less.

Here, the “mercury intrusion method” refers to the fact that the surface tension of mercury is large and pressure is applied to cause mercury to enter the fine pores of the powder. This is a method for obtaining the pore distribution. If the change in the surface of the mercury liquid surface (that is, the amount of mercury entering the pores) is detected while continuously increasing the applied pressure, The size and its volume can be measured.

The median diameter of the ink receiving layer gap measured by this mercury intrusion method is synonymous with the capillary diameter (double of r in Formula 1) of (Formula 1) basic formula of liquid penetration (Lucas-washburn formula). Increasing the median diameter shortens the ink absorption time.
t = (2h ² × η) / (γ × r × cos θ) (Equation 1)
t; penetration time h; liquid penetration depth η; liquid viscosity γ; liquid surface tension r; capillary radius θ;

As a result of investigations by the present inventors, the pore median diameter after recording and the volume ratio of the pores after recording are “pore median diameter” before recording and “water-soluble” contained in the ink used for recording. The effect of “organic solvent and water” is almost all. Therefore, the measurement of the pore median diameter and the pore volume after recording is performed on a sample in which an aqueous solution obtained by diluting a water-soluble organic solvent with water is applied to the ink receiving layer.
In addition, pores larger than the median diameter of 100 nm are not considered because pores derived from the support exist for pores larger than the median diameter of 100 nm.

The application of the water-soluble organic solvent in the measurement by the mercury intrusion method of the ink receiving layer should be performed at an application amount of 5 to 8 g / m ^{2 in view} of the print density and the performance of hue change immediately after printing. In the present invention, a value obtained by setting the applied amount of the water-soluble organic solvent to 6.6 g / m ² is adopted. In order to set the application amount of the water-soluble organic solvent to the above value, the water-soluble organic solvent is preferably applied by diluting with water to 15 to 40% by mass.
For mercury intrusion measurement, drying was insufficient immediately after applying the water-soluble organic solvent (including water) to the ink receiving layer, so a water-soluble organic solvent (including water) was applied at 25 ° C. and 50 ° C. It is necessary to carry out after standing for 24 hours at% RH. Although it may be 24 hours or more, in the present invention, the standing 24 hours at 25 ° C. and 50% RH is adopted.

From the above, the pore median diameter and pore volume of the ink receiving layer before application of the water-soluble organic solvent were measured by the mercury intrusion method of the ink receiving layer before application of the water-soluble organic solvent to the ink receiving layer. The pore median diameter is the value of the pore diameter and the pore volume. The pore median diameter of the ink receiving layer after application of the water-soluble organic solvent is a water-soluble 15% to 40% by weight aqueous solution of the water-soluble organic solvent in the ink receiving layer. These are values of pore diameter and pore volume measured by the mercury intrusion method of the ink receiving layer after application of 6.6 g / m ² as an organic solvent and 24 hours later.

The pore median diameter before recording is preferably 5 to 40 nm, more preferably 8 to 35 nm, in order to obtain a recorded image excellent in print density and hue change without deteriorating bronzing. More preferably, it is ˜30 nm.

It is necessary to use a specific water-soluble organic solvent in which the volume ratio of pores having a median diameter of 40 to 100 nm of the ink receiving layer after application measured by the mercury intrusion method is 0% or more and 11.0% or less. Is from 0% to 10.0%, more preferably from 0% to 9%, still more preferably from 0% to 8%.

Thus, by using a specific water-soluble organic solvent in which the volume ratio of the pores after recording is in the above range, it is possible to obtain an excellent recorded image with high image density and small hue change immediately after printing. it can.

In the present invention, the median diameter, pore volume, and pore volume ratio of the ink receiving layer voids (pores) are determined as follows.
1) An aqueous solution diluted with water to 15 to 40% by mass so that the water-soluble organic solvent becomes 6.6 g / m ² is applied on the ink receiving layer of the inkjet recording medium.
2) The inkjet recording medium after the application is stored for 24 hours in an environment of 25 ° C. and 50% RH.
3) After storage, the pore-median diameter distribution and the pore volume of the ink-jet recording medium after application are measured using a Shimadzu Autobore 9200 at an initial pressure of about 20 kPa.
-After application: pore median diameter L2 and pore volume V2
4) Separately, the pore median size distribution and the pore volume are measured in the same manner as in the above 3) for only the support without the ink receiving layer.
・ No application (support only): pore median diameter L1 and pore volume V1
5) From the above, the volume ratio (%) of pores with a median diameter of 40 to 100 nm in pores with a median diameter of 100 nm or less after application is
(V2 _{40 to 100 nm} −V1 _{40 to 100 nm} ) / (V2 _{100 nm or less−} V1 _{100 nm or less} ) × 100
Can be expressed as

V2 _{40 to 100 nm} : Volume of pores with a median diameter of 40 to 100 nm after application V2 _{100 nm or less} : Volume of pores with a median diameter of 100 nm or less after application V1 _{40 to 100 nm} : Median diameter 40 without application (support only) Volume of pores of ˜100 _nm V1 _{100 nm or less} : Volume of pores with a median diameter of 100 nm or less without application (support only)

Examples of water-soluble organic solvents include alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, t-butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol),
Polyhydric alcohols (for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol),
Glycol derivatives (for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, triethylene glycol Monomethyl ether, ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethylene glycol monophenyl ether), amines (eg, ethanolamine, diethanolamine, triethanolamine, -Methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimine, tetramethylpropylenediamine) and other polar solvents (eg formamide, N, N-dimethylformamide, N , N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, acetonitrile, acetone ).
The water-soluble organic solvent may be used alone or in combination of two or more.

Examples of the water-soluble organic solvent (specific water-soluble organic solvent) include 1,2-alkyl diol, (mono, di) ethylene glycol monoalkyl ether, among the above water-soluble organic solvents in terms of print density and hue change. One or more selected from (mono, di) propylene glycol monoalkyl ether, (mono, di, tri) ethylene glycol dialkyl ether, and (mono, di, tri) propylene glycol dialkyl ether are preferred.
The content of the specific water-soluble organic solvent in the total water-soluble organic solvent needs to be 40% by mass or more, but more preferably 60% by mass to 100% by mass in terms of print density and hue change. Preferably, 70 mass% or more and 100 mass% or less are more preferable, and 85 mass% or more and 100 mass% or less are especially preferable.

As the 1,2-alkyldiol, the alkyl group preferably has 2 to 6 carbon atoms, and more preferably 2 to 3 carbon atoms in terms of printing density, and specific examples include ethylene glycol and 1,2-propanediol. It is done.
As the (mono, di) ethylene glycol monoalkyl ether and the (mono, di) propylene glycol monoalkyl ether, the alkyl group preferably has 1 to 5 carbon atoms, and more preferably 1 to 4 carbon atoms in terms of printing density.
As (mono, di, tri) ethylene glycol dialkyl ether and (mono, di, tri) propylene glycol dialkyl ether, an alkyl group has 1 carbon atom in order to realize a high printing density without impairing solubility in ink. To 3 are more preferable, and one carbon atom is more preferable.
Among the above water-soluble organic solvents, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, (mono, di, tri) ethylene glycol dimethyl ether , (Mono, di, tri) propylene glycol dimethyl ether is particularly preferred.

The content of the water-soluble organic solvent in the ink of the present invention is preferably 3% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 40% by mass or less from the viewpoint of suppressing hue change and obtaining a clear and high concentration. Preferably, 5 mass% or more and 30 mass% or less are more preferable, and 7 mass% or more and 25 mass% or less are especially preferable.

(dye)
The ink in the invention further contains at least one dye in addition to the water-soluble organic solvent.
As the dye, a general dye that can be used for inkjet can be used. For example, in addition to those classified as acid dyes, direct dyes, reactive dyes, vat dyes, sulfur dyes or food dyes in the color index, use dyes classified as oil-soluble dyes, basic dyes, etc. You can also.

Examples of the dye in the present invention include azo dyes, azomethine dyes, xanthene dyes, and quinone dyes.
The dye in the present invention is preferably a water-soluble dye from the viewpoint of suppressing ink viscosity and forming a clear image. The water-soluble dye refers to a dye that dissolves 0.2 g or more in 100 ml of an aqueous solvent (25 ° C.).
Specific compounds of the dye are shown below. However, it is not limited to these exemplified compounds.

[C. I. Acid Yellow]
1, 3, 11, 17, 18, 19, 23, 25, 36, 38, 40, 42, 44, 49, 59, 61, 65, 67, 72, 73, 79, 99, 104, 110, 114, 116, 118, 121, 127, 129, 135, 137, 141, 143, 151, 155, 158, 159, 169, 176, 184, 193, 200, 204, 207, 215, 219, 220, 230, 232, 235, 241, 242, 246
[C. I. Acid Orange]
3, 7, 8, 10, 19, 24, 51, 56, 67, 74, 80, 86, 87, 88, 89, 94, 95, 107, 108, 116, 122, 127, 140, 142, 144, 149, 152, 156, 162, 166, 168

[C. I. Acid Red]
1, 6, 8, 9, 13, 18, 27, 35, 37, 52, 54, 57, 73, 88, 97, 106, 111, 114, 118, 119, 127, 131, 138, 143, 145, 151, 183, 195, 198, 211, 215, 217, 225, 226, 249, 251, 254, 256, 257, 260, 261, 265, 266, 274, 276, 277, 289, 296, 299, 315, 318, 336, 337, 357, 359, 361, 362, 364, 366, 399, 407, 415
[C. I. Acid Violet]
17, 19, 21, 42, 43, 47, 48, 49, 54, 66, 78, 90, 97, 102, 109, 126
[C. I. Acid Blue]
1, 7, 9, 15, 23, 25, 40, 62, 72, 74, 80, 83, 90, 92, 103, 104, 112, 113, 114, 120, 127, 128, 129, 138, 140, 142, 156, 158, 171, 182, 185, 193, 199, 201, 203, 204, 205, 207, 209, 220, 221, 224, 225, 229, 230, 239, 249, 258, 260, 264, 278, 279, 280, 284, 290, 296, 298, 300, 317, 324, 333, 335, 338, 342, 350

[C. I. Acid Green]
9, 12, 16, 19, 20, 25, 27, 28, 40, 43, 56, 73, 81, 84, 104, 108, 109
[C. I. Acid Brown]
2, 4, 13, 14, 19, 28, 44, 123, 224, 226, 227, 248, 282, 283, 289, 294, 297, 298, 301, 355, 357, 413
[C. I. Acid Black]
1, 2, 3, 24, 26, 31, 50, 52, 58, 60, 63, 107, 109, 112, 119, 132, 140, 155, 172, 187, 188, 194, 207, 222

[C. I. Direct yellow]
8, 9, 10, 11, 12, 22, 27, 28, 39, 44, 50, 58, 79, 86, 87, 98, 105, 106, 130, 132, 137, 142, 147, 153
[C. I. Direct orange]
6, 26, 27, 34, 39, 40, 46, 102, 105, 107, 118
[C. I. Direct red]
2, 4, 9, 23, 24, 31, 54, 62, 69, 79, 80, 81, 83, 84, 89, 95, 212, 224, 225, 226, 227, 239, 242, 243, 254
[C. I. Direct violet]
9, 35, 51, 66, 94, 95

[C. I. Direct blue]
1, 15, 71, 76, 77, 78, 80, 86, 87, 90, 98, 106, 108, 160, 168, 189, 192, 193, 199, 200, 201, 202, 203, 218, 225, 229, 237, 244, 248, 251, 270, 273, 274, 290, 291
[C. I. Direct green]
26, 28, 59, 80, 85
[C. I. Direct brown]
44, 106, 115, 195, 209, 210, 222, 223
[C. I. Direct black]
17, 19, 22, 32, 51, 62, 108, 112, 113, 117, 118, 132, 146, 154, 159, 169

[C. I. Basic yellow]
1, 2, 11, 13, 15, 19, 21, 28, 29, 32, 36, 40, 41, 45, 51, 63, 67, 70, 73, 91
[C. I. Basic orange]
2, 21, 22
[C. I. Basic Red]
1, 2, 12, 13, 14, 15, 18, 23, 24, 27, 29, 35, 36, 39, 46, 51, 52, 69, 70, 73, 82, 109
[C. I. Basic violet]
1, 3, 7, 10, 11, 15, 16, 21, 27, 39
[C. I. Basic blue]
1, 3, 7, 9, 21, 22, 26, 41, 45, 47, 52, 54, 65, 69, 75, 77, 92, 100, 105, 117, 124, 129, 147, 151
[C. I. Basic green]
1, 4
[C. I. Basic brown]
1

[C. I. Reactive Yellow]
2, 3, 7, 15, 17, 18, 22, 23, 24, 25, 27, 37, 39, 42, 57, 69, 76, 81, 84, 85, 86, 87, 92, 95, 102, 105, 111, 125, 135, 136, 137, 142, 143, 145, 151, 160, 161, 165, 167, 168, 175, 176
[C. I. Reactive orange]
1, 4, 5, 7, 11, 12, 13, 15, 16, 20, 30, 35, 56, 64, 67, 69, 70, 72, 74, 82, 84, 86, 87, 91, 92, 93, 95, 107
[C. I. Reactive Red]
2, 3, 5, 8, 11, 21, 22, 23, 24, 28, 29, 31, 33, 35, 43, 45, 49, 55, 56, 58, 65, 66, 78, 83, 84, 106, 111, 112, 113, 114, 116, 120, 123, 124, 128, 130, 136, 141, 147, 158, 159, 171, 174, 180, 183, 184, 187, 190, 193, 194, 195, 198, 218, 220, 222, 223, 228, 235

[C. I. Reactive violet]
1, 2, 4, 5, 6, 22, 23, 33, 36, 38
[C. I. Reactive Blue]
2, 3, 4, 5, 7, 13, 14, 15, 19, 21, 25, 27, 28, 29, 38, 39, 41, 49, 50, 52, 63, 69, 71, 72, 77, 79, 89, 104, 109, 112, 113, 114, 116, 119, 120, 122, 137, 140, 143, 147, 160, 161, 162, 163, 168, 171, 176, 182, 184, 191, 194, 195, 198, 203, 204, 207, 209, 211, 214, 220, 221, 222, 231, 235, 236
[C. I. Reactive Green]
8, 12, 15, 19, 21
[C. I. Reactive Brown]
2, 7, 9, 10, 11, 17, 18, 19, 21, 23, 31, 37, 43, 46
[C. I. Reactive Black]
5, 8, 13, 14, 31, 34, 39
[C. I. Food Black]
1, 2

The following dyes are also suitable as magenta dyes, cyan dyes, black dyes, and yellow dyes that can be used in the ink of the present invention.
That is, the magenta dye that can be used in the ink of the present invention includes, for example, aryl or heteryl azo dyes having phenols, naphthols, anilines, etc. as coupler components; for example, pyrazolones, pyrazolotriazoles, etc. as coupler components. Azomethine dyes; methine dyes such as arylidene dyes, styryl dyes, merocyanine dyes, cyanine dyes, oxonol dyes, etc .; carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, etc., such as naphthoquinones, anthraquinones, anthrapyridones, etc. Examples thereof include, but are not limited to, quinone dyes such as condensed polycyclic dyes such as dioxazine dyes.
As the magenta dye, a heterocyclic azo dye is preferable. International Patent Publication No. 2002/83795 (pages 35 to 55), 2002-83661 (pages 27 to 42), JP-A-2004-149560 (paragraph number [0046]) To [0059]) and 2004-149561 (paragraph numbers [0047] to [0060]) are more preferable in terms of ozone resistance.

Cyan dyes that can be used in the ink of the present invention include, for example, aryl or heteryl azo dyes having phenols, naphthols, anilines, etc. as coupler components; for example, heterocycles such as phenols, naphthols, pyrrolotriazole as coupler components. Azomethine dyes having rings, etc .; polymethine dyes such as cyanine dyes, oxonol dyes, merocyanine dyes; carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes; phthalocyanine dyes; anthraquinone dyes; indigo thioindigo dyes However, it is not limited to these.
As the associative phthalocyanine dyes, International Publication Nos. 2002/60994, 2003/811, 2003/62324, JP-A-2003-213167, 2004-75986, 2004-323605, 2004 Nos. 315758, 2004-315807, and 2005-179469 are preferable in terms of ozone resistance.

Examples of the black dye that can be used in the ink of the present invention include disazo, trisazo, and tetraazo dyes. These black dyes may be used in combination with a pigment such as a carbon black dispersion.
Preferred examples of black dyes having excellent ozone resistance are described in detail in JP-A-2005-307177.

Examples of the yellow dye that can be used in the ink of the present invention include International Patent Publication WO2005 / 075753, JP-A-2004-83903 (paragraph numbers [0024] to [0062]), and 2003-277661 (paragraph number [0021]). [0050]), 2003-277262 (paragraph numbers [0042] to [0047]), 2003-128953 (paragraph numbers [0025] to [0076]), 2003-41160 (paragraph number [0028] ] To [0064]), those described in US Application Publication No. US2003 / 0213405 (paragraph number [0108]), and C.I. I. Direct yellow 8, 9, 11, 12, 27, 28, 29, 33, 35, 39, 41, 44, 50, 53, 59, 68, 86, 87, 93, 95, 96, 98, 100, 106, 108, 109, 110, 130, 132, 142, 144, 161, 163, C.I. I. Acid Yellow 17, 19, 23, 25, 39, 40, 42, 44, 49, 50, 61, 64, 76, 79, 110, 127, 135, 143, 151, 159, 169, 174, 190, 195 196, 197, 199, 218, 219, 222, 227, C.I. I. Reactive Yellow 2, 3, 13, 14, 15, 17, 18, 23, 24, 25, 26, 27, 29, 35, 37, 41, 42, C.I. I. Basic yellow 1, 2, 4, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 39, 40, and the like. Further, yellow dyes described in paragraph numbers [0013] to [0112] and [0114] to [0121] of JP-A No. 2007-191650 are also preferable from the viewpoint of ozone resistance.

The content of the dye contained in the ink of the present invention is preferably 0.5 to 30% by mass, more preferably 1.0 to 15% by mass. By setting the content to 0.5% by mass or more, the print density is improved. Moreover, by setting it as a content rate of 30 mass% or less, it can suppress that the viscosity rise of an ink and structural viscosity arise in a viscosity characteristic, and the discharge stability of the ink from an inkjet head becomes favorable.

In addition to the above components, other components can be appropriately used as necessary in the ink of the present invention. Examples of components that can be contained in general inks are within the range not impeding the effects of the present invention. it can.

In the ink of the present invention, the water-soluble organic solvent is ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, (mono, di, tri) One or more types selected from ethylene glycol dimethyl ether and (mono, di, tri) propylene glycol dimethyl ether, and the content (%) thereof is 85% by mass or more and 100% by mass or less in the total water-soluble organic solvent. A combination is most preferred.

<Inkjet recording medium>
The ink jet recording medium in the present invention includes an ink receiving layer containing at least inorganic fine particles, a water-soluble resin, and a crosslinking agent on a support, and may include other layers as necessary.

(Water-soluble resin)
The ink receiving layer according to the present invention contains a water-soluble resin.
In the present invention, the “water-soluble resin” means a resin having a solubility in water of 10 g / 100 g or more at room temperature (25 ° C.).
Examples of the water-soluble resin include a polyvinyl alcohol resin that is a resin having a hydroxy group as a hydrophilic structural unit [polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified. Polyvinyl alcohol, polyvinyl acetal, etc.], cellulosic resins [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, etc.] , Chitins, chitosans, starch, resins having ether bonds [polyethylene oxide (PEO), poly B pyrene oxide (PPO), polyethylene glycol (PEG), poly ether (PVE)], and resins having carbamoyl groups [polyacrylamide (PAAM), polyvinyl pyrrolidone (PVP), polyacrylic acid hydrazide, etc.] and the like. Moreover, the polyacrylic acid salt which has a carboxyl group as a dissociable group, a maleic acid resin, an alginate, gelatins etc. can also be mentioned Among these, polyvinyl alcohol-type resin is preferable and especially polyvinyl alcohol is preferable.

As the content of the water-soluble resin, the decrease in the film strength and cracking at the time of drying due to the insufficient content, and the excessive content makes the voids easily blocked by the resin, From the viewpoint of preventing the ink absorbency from being lowered due to the decrease in the porosity, the amount is preferably 9 to 40% by mass, more preferably 12 to 33% by mass with respect to the total solid content of the ink receiving layer.
The water-soluble resin mainly constituting the ink receiving layer and the fine particles described later may be a single material or a mixed system of a plurality of materials.

The number average polymerization degree of the polyvinyl alcohol resin is preferably 1800 or more, more preferably 2000 or more, from the viewpoint of preventing cracks. When combined with silica fine particles, the type of water-soluble resin is important from the viewpoint of transparency. In particular, when anhydrous silica is used, it is preferable to use a polyvinyl alcohol-based resin as the water-soluble resin, and more preferable is a polyvinyl alcohol-based resin having a saponification degree of 70 to 99%.

The polyvinyl alcohol resin includes the derivatives of the above specific examples, and the polyvinyl alcohol resin may be used alone or in combination of two or more.

The polyvinyl alcohol-based resin has a hydroxyl group in its structural unit, and this hydroxyl group and a silanol group on the surface of the silica fine particle form a hydrogen bond to form a three-dimensional network structure in which the secondary particle of the silica fine particle is a chain unit. Easy to form. By forming such a three-dimensional network structure, it is considered that an ink receiving layer having a porous structure with a high porosity can be formed.
In the ink jet recording medium, the porous ink receiving layer obtained as described above can rapidly absorb ink by capillary action and form dots with good roundness without ink bleeding.

(Inorganic fine particles)
The ink receiving layer in the invention contains inorganic fine particles (hereinafter also referred to as “fine particles”).
Examples of the inorganic fine particles include silica fine particles, colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate, calcium sulfate, alumina fine particles, boehmite, pseudoboehmite. Etc. Among these, silica fine particles, colloidal silica, alumina fine particles, and pseudoboehmite are preferable, and vapor phase method silica fine particles are particularly preferable.

Since the silica fine particles have a particularly large specific surface area, the ink absorption and retention efficiency is high, and the refractive index is low. Therefore, if the dispersion is carried out to an appropriate fine particle diameter, transparency can be imparted to the ink receiving layer, There is an advantage that high color density and good color developability can be obtained. Thus, the fact that the receiving layer is transparent means that not only for applications that require transparency such as OHP, but also when applied to recording media such as photo glossy paper, high color density and good color developability and This is important from the viewpoint of obtaining glossiness.

The average primary particle diameter of the inorganic fine particles is preferably 20 nm or less, more preferably 15 nm or less, and particularly preferably 10 nm or less. When the average primary particle diameter is 20 nm or less, the ink absorption characteristics can be effectively improved, and at the same time, the glossiness of the ink receiving layer surface can be enhanced.

In particular, the silica fine particle has a silanol group on the surface thereof, and the particles are likely to adhere to each other due to the hydrogen bond of the silanol group, and because of the adhesion effect between the particles via the silanol group and the water-soluble resin, Similarly, when the average primary particle size is 20 nm or less, the ink-receiving layer has a high porosity and a highly transparent structure can be formed, and the ink absorption characteristics can be effectively improved.

Generally, silica fine particles are generally roughly classified into wet method particles and dry method (gas phase method) particles according to the production method. In the above wet method, a method is mainly used in which activated silica is produced by acid decomposition of a silicate, and this is appropriately polymerized and agglomerated and precipitated to obtain hydrous silica. On the other hand, the gas phase method is a method by high-temperature gas phase hydrolysis of silicon halide (flame hydrolysis method), a method in which silica sand and coke are heated and reduced by an arc in an electric furnace and oxidized with air. A method of obtaining anhydrous silica by the (arc method) is the mainstream.

Vapor phase silica (anhydrous silica fine particles obtained by vapor phase method) is different from the above hydrous silica in the density of silanol groups on the surface, presence or absence of vacancies, etc., and shows different properties but high porosity. Suitable for forming a three-dimensional structure. The reason for this is not clear, but 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 tend to aggregate (aggregate) easily. In the case of the method silica, the density of silanol groups on the surface of the fine particles is as small as 2 to 3 / nm ² , so that it becomes sparse soft aggregation (flocculate), and as a result, it is estimated that the structure has a high porosity. The
In the present invention, vapor phase silica fine particles (anhydrous silica) obtained by the dry method are preferred, and silica fine particles having a density of silanol groups on the fine particle surface of 2 to 3 / nm ² are preferred.

≪Content ratio of fine particles and water-soluble resin (PB ratio) ≫
The content ratio of the fine particles (preferably silica fine particles; x) to the water-soluble resin (y) [PB ratio (x / y), the mass of the fine particles with respect to 1 part by mass of the water-soluble resin] also depends on the film structure of the ink receiving layer. It has a big impact. That is, as the PB ratio increases, the porosity, pore volume, and surface area (per unit mass) increase.

Specifically, the ink jet recording medium may be stressed when passing through the transport system of the ink jet printer, the ink receiving layer needs to have sufficient film strength, and is further cut into a sheet shape. In the case of processing, since the ink receiving layer needs to have sufficient film strength in order to prevent cracking and peeling of the ink receiving layer, the PB ratio (x / y) is the hardness of the ink receiving layer. From the viewpoint of increasing it, it is preferably 4.5 or less. Furthermore, it is more preferably 4.3 or less, and particularly preferably 4.15 or less.
In addition, although not particularly limited, the PB ratio is 1.5 or more from the viewpoint of preventing the gap from being easily blocked by the resin and preventing the ink absorbability from being lowered due to the decrease in the porosity. Further, it is preferably 2 or more from the viewpoint of securing high-speed ink absorbability with an inkjet printer.

For example, a coating solution in which anhydrous silica fine particles having an average primary particle size of 20 nm or less and a water-soluble resin are completely dispersed in an aqueous solution with a PB ratio (x / y) of 2 to 4.5 is applied on a support. When the coating layer is dried, a three-dimensional network structure is formed with the secondary particles of silica fine particles as a chain unit, the average pore diameter is 30 nm or less, the porosity is 50% to 80%, and the pore specific volume is 0.5 ml. / G or more, and a translucent porous film having a specific surface area of 100 m ² / g or more can be easily formed.

(Crosslinking agent)
The ink receiving layer according to the present invention is a porous layer in which a layer containing a water-soluble resin or the like further contains a cross-linking agent capable of cross-linking the water-soluble resin, and is cured by a cross-linking reaction of the water-soluble resin with the cross-linking agent. Some embodiments are preferred. By adding a cross-linking agent, the water-soluble resin is cross-linked, and a high hardness ink receiving layer can be obtained.

As the cross-linking agent, a suitable one may be appropriately selected in relation to the water-soluble resin contained in the ink-receiving layer. Among them, a boron compound is preferable in that the cross-linking reaction is rapid, and examples thereof include borax and boric acid. , borates (eg, _{orthoborate, InBO 3, ScBO 3, YBO} 3, LaBO 3, Mg 3 (BO 3) 2, Co 3 (BO 3) 2, two borates _(e.g., Mg ₂ B _{2 O 5} , Co ₂ B ₂ O ₅ ), metaborate (eg, LiBO ₂ , Ca (BO ₂ ) ₂ , NaBO ₂ , KBO ₂ ), tetraborate (eg, Na ₂ B ₄ O ₇ · 10H ₂ O), Examples include pentaborate (for example, KB ₅ O ₈ · 4H ₂ O, Ca ₂ B ₆ O ₁₁ · 7H ₂ O, CsB ₅ O ₅ ), etc. And borax Boric acid, boric acid salts are preferable, and boric acid is particularly preferred, it is most preferable to use this in combination with polyvinyl alcohol as the water-soluble resin.

Moreover, as a crosslinking agent of polyvinyl alcohol, the following compound can be mentioned as a suitable thing besides the said boron compound.
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-1,3,5- Active halogen compounds such as triazine and 2,4-dichloro-6-S-triazine sodium salt; divinylsulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N′-ethylenebis (vinylsulfonylacetamide) ), Active vinyl compounds such as 1,3,5-triacryloyl-hexahydro-S-triazine; N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin; melamine resins (eg, methylolmelamine, alkylated methylolmelamine) ;Epoxy resin;

Isocyanate compounds such as 1,6-hexamethylene diisocyanate; Aziridine compounds described in US Pat. Nos. 3,017,280 and 2,983611; Carboximide compounds described in US Pat. No. 3,100,704; Glycerol triglycidyl Epoxy compounds such as ethers; Ethyleneimino compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea; Halogenated carboxaldehyde compounds such as mucochloric acid and mucophenoxycyclolic acid; 2,3-dihydroxy Dioxane compounds such as dioxane; metal-containing compounds such as titanium lactate, aluminum sulfate, chromium alum, potash alum, zirconyl acetate and chromium acetate, polyamine compounds such as tetraethylenepentamine, and hydrazide compounds such as adipic acid dihydrazide A low molecular or polymer such as having two or more oxazoline groups.

Furthermore, as the crosslinking agent for the water-soluble resin in the present invention, polyvalent metal compounds listed below are also preferable. By using a polyvalent metal compound, not only acts as a cross-linking agent, but ozone resistance, image blurring, and glossiness can be further improved.
The polyvalent metal compound is preferably water-soluble, for example, calcium acetate, calcium chloride, calcium formate, calcium sulfate, barium acetate, barium sulfate, barium phosphate, manganese chloride, manganese acetate, manganese formate dihydrate. , Ammonium manganese sulfate hexahydrate, cupric chloride, ammonium copper (II) chloride dihydrate, copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, nickel chloride hexahydrate Japanese, nickel acetate tetrahydrate, nickel ammonium sulfate hexahydrate, nickel amidosulfate tetrahydrate, aluminum sulfate, aluminum alum, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, aluminum nitrate nonahydrate, Aluminum chloride hexahydrate, ferrous bromide, ferrous chloride, Ferric chloride, ferrous sulfate, ferric sulfate, zinc phenolsulfonate, zinc bromide, zinc chloride, zinc nitrate hexahydrate, zinc sulfate, titanium tetrachloride, tetraisopropyl titanate, titanium acetylacetonate, Titanium lactate, zirconyl acetylacetonate, zirconyl acetate, zirconyl sulfate, zirconyl ammonium carbonate, zirconyl stearate, zirconyl octylate, zirconyl nitrate, zirconyl oxychloride, zirconyl hydroxychloride, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate Japanese hydrate, magnesium citrate nonahydrate, sodium phosphotungstate, sodium tungsten citrate, 12 tungstophosphoric acid n hydrate, 12 tungstosilicic acid 26 hydrate, molybdenum chloride, 12 molybdophosphate n hydrate ,nitric acid Lithium, germanium nitrate, strontium nitrate, yttrium acetate, yttrium chloride, yttrium nitrate, indium nitrate, lanthanum nitrate, lanthanum chloride, lanthanum acetate, lanthanum benzoate, cerium chloride, cerium sulfate, cerium octylate, praseodymium nitrate, neodymium nitrate, nitric acid Examples include samarium, europium nitrate, gadolinium nitrate, dysprosium nitrate, erbium nitrate, ytterbium nitrate, hafnium chloride, and bismuth nitrate.

Among these, aluminum-containing compounds (water-soluble aluminum compounds) such as aluminum sulfate, aluminum alum, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate; zirconyl acetylacetonate , Zirconyl acetate, zirconyl sulfate, zirconyl ammonium carbonate, zirconyl stearate, zirconyl octylate, zirconyl nitrate, zirconyl oxychloride, zirconyl hydroxychloride and the like (water-soluble zirconyl compound); and titanium tetrachloride, tetraisopropyl titanate, Titanium-containing compounds such as titanium acetylacetonate and titanium lactate are preferred, especially polyaluminum chloride, zirconyl acetate, zirconyl carbonate ammonium , Oxychloride is preferable.

As the cross-linking agent in the present invention, boron compounds and zirconyl compounds are particularly preferable among those listed above.

In the present invention, the cross-linking agent is preferably contained in an amount of 5 to 50% by mass, more preferably 8 to 30% by mass with respect to the water-soluble resin. When the content of the cross-linking agent is within the above range, the water-soluble resin is effectively cross-linked to increase the hardness of the ink receiving layer, prevent cracks and the like, and obtain excellent scratch resistance.

In addition, although said crosslinking agent may be used individually by 1 type or in combination of 2 or more types, while acting as a suitable crosslinking agent, from the viewpoint of further improving ozone resistance, image blurring, and glossiness,
The polyvalent metal compound (particularly preferably, a zirconyl compound) is preferably contained in an amount of 0.1% by mass or more, more preferably 0.5% by mass or more, based on at least the water-soluble resin. It is particularly preferably 0% by mass or more. Further, although not particularly limited, the upper limit of the content of the polyvalent metal compound is preferably 50% by mass or less from the viewpoints of image density, ink absorbability, curling of the recording medium, and the like.

In the present invention, the cross-linking agent may be added to the ink receiving layer coating solution and / or the coating solution for forming the adjacent layer of the ink receiving layer when forming the ink receiving layer, or The above-mentioned coating solution for ink-receiving layer is coated on a support on which a coating solution containing a crosslinking agent has been applied in advance, or a coating solution for ink-receiving layer that does not contain a crosslinking agent is coated and dried, and then the coating solution is overcoated. For example, a crosslinking agent can be supplied to the ink receiving layer. Preferably, from the viewpoint of production efficiency, it is preferable to add a crosslinking agent to the ink receiving layer coating solution or the coating solution for forming the adjacent layer, and supply the crosslinking agent simultaneously with the formation of the ink receiving layer. In particular, it is preferably contained in the ink receiving layer coating solution from the viewpoint of improving the image printing density and glossiness. Further, the concentration of the crosslinking agent in the ink receiving layer coating solution is preferably 0.05 to 10% by mass, more preferably 0.1 to 7% by mass.

For example, a crosslinking agent can be suitably applied as follows. Here, a boron compound will be described as an example. That is, when the ink receiving layer is a layer obtained by crosslinking and curing the coating layer coated with the ink receiving layer coating liquid (first coating liquid), the crosslinking curing is performed by (1) coating the coating layer by applying the coating liquid. (2) During the dry coating of the coating layer formed by coating the coating solution and before the coating layer exhibits a reduced rate of drying, the pH is 8 or more. This is performed by applying a basic solution (second coating solution) to the coating layer. The boron compound as the crosslinking agent may be contained in either the first coating liquid or the second coating liquid, or may be contained in both the first coating liquid and the second coating liquid.

(Ammonium carbonate)
The ink receiving layer according to the present invention preferably further contains ammonium carbonate. By containing ammonium carbonate in the ink receiving layer, an ink receiving layer having high hardness can be obtained.
As content of the said ammonium carbonate, it is preferable that it is 8 mass% or more with respect to the said water-soluble resin, It is more preferable that it is 9 mass% or more, It is especially preferable that it is 11 mass% or more. The upper limit is not particularly limited, but is preferably 20% by mass or less from the viewpoint of image density, ink absorbability, curling of the recording medium, and the like.

(Water-dispersible cationic resin)
Moreover, a water-dispersible cationic resin can be contained as a component of the ink receiving layer according to the present invention. The water-dispersible cationic resin is preferably a urethane resin that is a cationically modified self-emulsifying polymer, and preferably has a glass transition temperature of less than 50 ° C.
This “cation-modified self-emulsifying polymer” means a highly stable emulsified dispersion that can be naturally stabilized in an aqueous dispersion medium without using an emulsifier or a surfactant, or even if used in a very small amount. Means a molecular compound. Quantitatively, the “cation-modified self-emulsifying polymer” means a polymer substance having stable emulsification and dispersion at a concentration of 0.5% by mass or more with respect to the aqueous dispersion medium at room temperature of 25 ° C. The concentration is preferably 1% by mass or more, and more preferably 3% by mass or more.

More specifically, the “cation-modified self-emulsifying polymer” of the present invention is, for example, a polyaddition system or polycondensation having a cationic group such as a primary to tertiary amino group or a quaternary ammonium group. Based polymer compounds.

Examples of the vinyl polymer that is effective as the polymer include polymers obtained by polymerizing the following vinyl monomers. That is, acrylic acid esters and methacrylic acid esters (the ester group is an alkyl group or aryl group which may have a substituent, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n- Butyl, sec-butyl, tert-butyl, hexyl, 2-ethylhexyl, tert-octyl, 2-chloroethyl, cyanoethyl, 2-acetoxyethyl, tetrahydrofurfuryl, 5-hydroxypentyl Cyclohexyl group, benzyl group, hydroxyethyl group, 3-methoxybutyl group, 2- (2-methoxyethoxy) ethyl group, 2,2,2-tetrafluoroethyl group, 1H, 1H, 2H, 2H-perfluorodecyl Group, phenyl group, 2,4,5-tetramethylphenyl group, 4-chlorophenyl group, etc.);

Vinyl esters, specifically, aliphatic carboxylic acid vinyl esters which may have a substituent (for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl Chloroacetate, etc.), optionally substituted aromatic carboxylic acid vinyl ester (for example, vinyl benzoate, vinyl 4-methylbenzoate, vinyl salicylate, etc.);

Acrylamides, specifically, acrylamide, N-monosubstituted acrylamide, N-disubstituted acrylamide (substituents are optionally substituted alkyl groups, aryl groups, silyl groups, such as methyl groups, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, tert-octyl group, cyclohexyl group, benzyl group, hydroxymethyl group, alkoxymethyl group, phenyl group, 2,4,5-tetramethylphenyl group , 4-chlorophenyl group, trimethylsilyl group, etc.);

Methacrylamide, specifically, methacrylamide, N-monosubstituted methacrylamide, N-disubstituted methacrylamide (substituent is an optionally substituted alkyl group, aryl group, silyl group, for example , Methyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, tert-octyl group, cyclohexyl group, benzyl group, hydroxymethyl group, alkoxymethyl group, phenyl group, 2,4,5- Tetramethylphenyl group, 4-chlorophenyl group, trimethylsilyl group, etc.);

Olefins (eg, ethylene, propylene, 1-pentene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, butadiene, etc.), styrenes (eg, styrene, methylstyrene, isopropylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, etc.) Vinyl ethers (for example, methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxyethyl vinyl ether, etc.);

Other vinyl monomers include crotonic acid ester, itaconic acid ester, maleic acid diester, fumaric acid diester, methyl vinyl ketone, phenyl vinyl ketone, methoxyethyl vinyl ketone, N-vinyl oxazolidone, N-vinyl pyrrolidone, methylenemalon nitrile, diphenyl Examples include -2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, dibutyl-2-acryloyloxyethyl phosphate, dioctyl-2-methacryloyloxyethyl phosphate, and the like.

Examples of the monomer having a cationic group include monomers having a tertiary amino group such as dialkylaminoethyl methacrylate and dialkylaminoethyl acrylate.

Examples of the polyurethane applicable to the cationic group-containing polymer include polyurethanes synthesized by a polyaddition reaction using various combinations of the following diol compounds and diisocyanate compounds.
Specific examples of the diol compound include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 2,2 -Dimethyl-1,3-propanediol, 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 3,3-dimethyl-1,2-butanediol 2-ethyl-2-methyl-1,3-propanediol, 1,2-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-2, 4-pentanediol, 2,2-diethyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 1,7-heptane All, 2-methyl-2-propyl-1,3-propanediol, 2,5-dimethyl-2,5-hexanediol, 2-ethyl-1,3-hexanediol, 1,2-octanediol, 1, 8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, hydroquinone, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol (average molecular weight = 200,300,400,600,1000,1500,4000), polypropylene glycol (average molecular weight = 200,400,1000), polyester polyol, 4,4′-dihydroxy-diphenyl-2,2-propane, 4,4 ′ -Dihydroxyphenyls Luhon etc. are mentioned.

Examples of the diisocyanate compound include methylene diisocyanate, ethylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylylene diisocyanate, 1, 5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethylbiphenylene diisocyanate, 4,4'-biphenylene diisocyanate, dicyclohexylmethane diisocyanate And methylenebis (4-cyclohexylisocyanate).

Examples of the cationic group contained in the cationic group-containing polyurethane include cationic groups such as primary to tertiary amines and quaternary ammonium salts. As the self-emulsifying polymer used in the aqueous dispersion in the invention, a urethane resin having a cationic group such as a tertiary amine and a quaternary ammonium salt is preferable.
The cationic group-containing polyurethane can be obtained, for example, by using a product obtained by introducing a cationic group into a diol as described above during the synthesis of polyurethane. In the case of a quaternary ammonium salt, a polyurethane containing a tertiary amino group may be quaternized with a quaternizing agent.

The diol compound and diisocyanate compound that can be used for the synthesis of the polyurethane may be used alone or in various ways (for example, adjustment of the glass transition temperature (Tg) of the polymer and improvement of solubility, Depending on the compatibility with the binder, improvement in the stability of the dispersion, etc., one type may be used alone, or two or more types may be used in any desired ratio.

(mordant)
The ink receiving layer according to the present invention preferably contains the following mordant for the purpose of further improving the bleeding and water resistance of the image. As the mordant, an organic mordant such as a cationic polymer (cationic mordant) and an inorganic mordant such as a water-soluble metal compound are preferable. As the cationic mordant, a polymer mordant having a primary to tertiary amino group or a quaternary ammonium base as a cationic functional group is preferably used, but a cationic non-polymer mordant may also be used. Can do.

Examples of the polymer mordant include a homopolymer of a monomer having a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base (a mordant monomer), the mordant monomer and another monomer ( Those obtained as copolymers or condensation polymers with non-mordant monomers) are preferred. Moreover, these polymer mordants can be used in any form of a water-soluble polymer or water-dispersible latex particles.

Examples of the mordant monomer include trimethyl-p-vinylbenzylammonium chloride, trimethyl-m-vinylbenzylammonium chloride, triethyl-p-vinylbenzylammonium chloride, triethyl-m-vinylbenzylammonium chloride, N, N-dimethyl- N-ethyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-methyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-Nn-propyl-Np-vinylbenzyl Ammonium chloride, N, N-dimethyl-Nn-octyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N-diethyl- -Benzyl-Np-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-vinyl Benzylammonium 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 chloride Tate;

N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N- Methyl chloride, ethyl chloride, methyl bromide of dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide , Quaternized products of ethyl bromide, methyl iodide or ethyl iodide, or sulfonates, alkyl sulfonates, acetates or alkyl carboxylates substituted with their anions.

Specific examples of the compound include monomethyl diallylammonium 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- (Methacryloylamino) ethylammonium chloride, trimethyl-2- (acryloyl) Mino) ethylammonium chloride, triethyl-2- (acryloylamino) ethylammonium chloride, trimethyl-3- (methacryloylamino) propylammonium chloride, triethyl-3- (methacryloylamino) propylammonium chloride, trimethyl-3- (acryloylamino) Propylammonium 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- And (acryloylamino) propylammonium acetate. Other examples of copolymerizable monomers include N-vinylimidazole and N-vinyl-2-methylimidazole. Further, it is also possible to use a polymerization unit such as N-vinylacetamide or N-vinylformamide, which is converted into a vinylamine unit by hydrolysis after polymerization and a salt thereof.

The non-mordant monomer does not contain a basic or cationic moiety such as a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base, and does not interact with a dye in an inkjet ink. Or the monomer which interaction is substantially small is said. For example, (meth) acrylic acid alkyl ester; (meth) acrylic acid cycloalkyl ester such as cyclohexyl (meth) acrylic acid; (meth) acrylic acid aryl ester such as phenyl (meth) acrylate; benzyl (meth) acrylic acid Aralkyl esters of styrene; vinyl aromatics such as styrene, vinyl toluene and α-methyl styrene; vinyl esters such as vinyl acetate, vinyl propionate and vinyl versatate; allyl esters such as allyl acetate; vinylidene chloride, vinyl chloride, etc. Halogen-containing monomers, vinyl cyanides such as (meth) acrylonitrile, olefins such as ethylene and propylene, and the like.

The (meth) acrylic acid alkyl ester is preferably a (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl moiety, specifically, 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, hexyl (meth) acrylate, (meth) Examples include octyl acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and the like. Among these, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, and hydroxyethyl methacrylate are preferable. The non-mordant monomer can also be used alone or in combination of two or more.

Further, as the polymer mordant, polydiallyldimethylammonium chloride, polymethacryloyloxyethyl-β-hydroxyethyldimethylammonium chloride, polyethyleneimine, polyamide-polyamine resin, cationized starch, dicyandiamide formalin condensate, dimethyl-2-hydroxypropylammonium Salt polymers, polyamidines, polyvinylamines, dicyan diamide-formalin polycondensates represented by dicyan chaotic resins, dicyanamide-diethylene triamine polycondensates represented by polyamine chaotic resins, epichlorohydrin-dimethylamine addition polymers, dimethyl dialine Ammonium chloride-SO ₂ copolymer, diallylamine salt-SO ₂ copolymer and the like are also preferable. Can do.

Specific examples of the polymer mordant include JP-A Nos. 48-28325, 54-74430, 54-124726, 55-22766, 55-142339, 60-23850, and 60. -23851, 60-23852, 60-23853, 60-57836, 60-60643, 60-118834, 60-122940, 60-122941, 60-122294 No. 60-235134, JP-A-1-161236, U.S. Pat.No. 2,484,430, No. 2,548,564, No. 3,148,061, No. 3,309,690, No. 4,115,124, No. 4,124,386, No. 4,193,800, No. 4,427,853, No. 4,282,305 No. 4,450,224, JP-A-1-161236 10-81064, 10-119423, 10-157277, 10-217601, 11-348409, JP-A-2001-138621, 2000-43401, 2000-21235, 2000-309157, 2001-96897, 2001-138627, JP-A-11-91242, 8-2087, 8-2090, 8-2091, 8-2093, 8 And those described in JP-A Nos. -174992, 11-192777, and JP-A No. 2001-301314.

Examples of the inorganic mordant include polyvalent water-soluble metal salts and hydrophobic metal salt compounds other than those described above. For example, magnesium, aluminum, calcium, scandium, titanium, vanadium, manganese, iron, nickel, copper, zinc, gallium, germanium, strontium, yttrium, zirconium, molybdenum, indium, barium, lanthanum, cerium, praseodymium, neodymium, samarium, Examples include salts or complexes of metals selected from europium, gadolinium, dysproprosium, erbium, ytterbium, hafnium, tungsten, bismuth.

Specific examples include calcium acetate, calcium chloride, calcium formate, calcium sulfate, barium acetate, barium sulfate, barium phosphate, manganese chloride, manganese acetate, manganese formate dihydrate, manganese ammonium sulfate hexahydrate, chloride chloride Dicopper, ammonium copper (II) chloride dihydrate, copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel sulfate Ammonium hexahydrate, nickel amidosulfate tetrahydrate, alumina sulfate, alumina alum, basic polyaluminum hydroxide, sulfite alumina, thiosulfate alumina, polychlorinated alumina, alumina nitrate nonahydrate, alumina chloride hexahydrate , Ferrous bromide, ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, pheno Zinc sulfonate, zinc bromide, zinc chloride, zinc nitrate hexahydrate, zinc sulfate, titanium tetrachloride, tetraisopropyl titanate, titanium acetylacetonate, titanium lactate, zirconium acetylacetonate, zirconyl acetate, zirconyl sulfate, zirconyl carbonate Ammonium, zirconyl stearate, zirconyl octylate, zirconyl nitrate, zirconium oxychloride, zirconium hydroxychloride, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, magnesium citrate nonahydrate, sodium phosphotungstate, Sodium tungsten citrate, 12 tungstophosphoric acid n hydrate, 12 tungstosilicic acid 26 hydrate, molybdenum chloride, 12 molybdophosphoric acid n hydrate, potassium nitrate, manganese acetate, germanium nitrate Strontium nitrate, yttrium acetate, yttrium chloride, yttrium nitrate, indium nitrate, lanthanum nitrate, lanthanum chloride, lanthanum acetate, lanthanum benzoate, cerium chloride, cerium sulfate, cerium octylate, praseodymium nitrate, neodymium nitrate, samarium nitrate, nitric acid Examples include europium, gadolinium nitrate, dysprosium nitrate, erbium nitrate, ytterbium nitrate, hafnium chloride, and bismuth nitrate. Among these, alumina-containing compounds, titanium-containing compounds, zirconium-containing compounds, and group IIIB series metal compounds (salts or complexes) are preferable.

In addition, the “polyvalent metal compounds” listed in the above section (Crosslinking agent) can also be suitably used as a mordant.
The addition amount when the mordant is added to the ink receiving layer is preferably 0.01 to 5 g / m ² .

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

Also, benzotriazole ultraviolet absorbers, salicylic acid ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, oxalic acid anilide ultraviolet absorbers, and the like can be used. For example, JP-A-47-10537, 58-111942, 58-21284, 59-19945, 59-46646, 59-109055, 63-53544. No. 36, Japanese Patent Publication No. 36-10466, No. 42-26187, No. 48-30492, No. 48-31255, No. 48-41572, No. 48-54965, No. 50-10726. No. 2,719,086, US Pat. No. 3,707,375, US Pat. No. 3,754,919, US Pat. No. 4,220,711, etc. Has been.

Fluorescent brighteners can also be used as ultraviolet absorbers, and examples include coumarin fluorescent brighteners. Specific examples are described in Japanese Patent Publication Nos. 45-4699 and 54-5324.

Examples of the antioxidant include European Patent Nos. 223739, 309401, 309402, 310551, 310552, 3594416, and German Patent No. 3435443. Publication No. 54-85535, No. 60-107384, No. 60-107383, No. 60-125470, No. 60-125471, No. 60-125472, No. 60- No. 287485, No. 60-287486, No. 60-287487, No. 60-287488, No. 61-160287, No. 61-185483, No. 61-2111079, No. 62-146678. Publication No. 62-146680 Publication No. 62-146679 Publication No. 62-146679 Gazette, 62-28285 gazette, 62-262207 gazette, 63-051174 gazette, 63-898877 gazette, 63-88380 gazette, 66-88381 gazette, 63-113536 gazette. ;

JP-A-63-163351, JP-A-63-203372, JP-A-63-224989, JP-A-63-251282, JP-A-63-267594, JP-A-63-182484, JP-A-1-239282, JP-A-2-262654, JP-A-2-71262, JP-A-3-121449, JP-A-4-29185, JP-A-4-291684, JP-A-5-61166, JP-A-5-119449, No. 5-188687, No. 5-188686, No. 5-110490, No. 5-110437, No. 5-170361, No. 48-43295, No. 48-33212, US Those described in Japanese Patent Nos. 4814262 and 4980275 are exemplified.

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 cyclohexane acid, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2-ethylhexane, 2-methyl-4-methoxy-diphenylamine, Examples include 1-methyl-2-phenylindole.

These anti-fading agents may be used alone or in combination of two or more. The anti-fading agent may be water-solubilized, dispersed, emulsified, or contained in microcapsules. The addition amount of the anti-fading agent is preferably 0.01 to 10% by mass of the coating solution for the ink receiving layer.

In the present invention, the ink receiving layer preferably contains a high boiling point organic solvent for curling prevention. The high-boiling organic solvent is preferably a water-soluble one, and examples of the water-soluble high-boiling organic solvent include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, glycerin, diethylene glycol monobutyl ether (DEGMBE), and triglyceride. Ethylene glycol monobutyl ether, glycerin monomethyl ether, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,4-pentanetriol, 1,2,6-hexanetriol, thiodiglycol, tri Examples include alcohols such as ethanolamine and polyethylene glycol (weight average molecular weight of 400 or less). Diethylene glycol monobutyl ether (DEGMBE) is preferred.

The content of the high boiling point organic solvent in the ink receiving layer coating solution is preferably 0.05 to 1% by mass, particularly preferably 0.1 to 0.6% by mass.
Further, for the purpose of enhancing the dispersibility of the fine particles, various inorganic salts and acid, alkali or the like may be contained as a pH adjuster.
Further, for the purpose of suppressing surface frictional charge and peeling charge, the metal oxide fine particles having electronic conductivity may contain various matting agents for the purpose of reducing the surface frictional characteristics.

In a preferred combination aspect of the present invention, the water-soluble organic solvent of the ink is ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, ( Mono, di, tri) ethylene glycol dimethyl ether, (mono, di, tri) propylene glycol dimethyl ether, and the content (%) thereof is 85% by mass or more and 100% by mass or less in the total water-soluble organic solvent. Most preferred is a combination of embodiments in which the water-soluble resin of the layer is polyvinyl alcohol.

(Support)
As the support used in the present invention, either a transparent support made of a transparent material such as plastic or an opaque support made of an opaque material such as paper can be used, but polyethylene or the like is used as the outermost layer on the side where the ink receiving layer is provided. It is preferable to have a resin layer (hereinafter, simply referred to as a “thermoplastic resin-containing layer”) comprising the above thermoplastic resin. In addition, the said thermoplastic resin content layer can also be provided in the both sides of a paper base material according to the objective.

Next, the thermoplastic resin will be described.
The thermoplastic resin is not particularly limited, and may be a finely divided known thermoplastic resin such as a polyolefin resin (for example, a homopolymer of α-olefin such as polyethylene or polypropylene or a mixture thereof) or a latex thereof. It can be appropriately selected and used. Especially, as said thermoplastic resin, polyolefin resin (especially polyethylene resin) is preferable.

The polyolefin resin is not particularly limited in molecular weight as long as it can be extrusion coated, and can be appropriately selected according to the purpose. Usually, a polyolefin resin having a molecular weight of 20,000 to 200,000 is used. It is done.
The polyethylene resin is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include high density polyethylene (HDPE), low density polyethylene (LDPE), and linear low density polyethylene (L-LDPE). Can be mentioned.

In the thermoplastic resin-containing layer, a stabilizer such as a white pigment, a colored pigment or a fluorescent brightening agent, phenol, bisphenol, thiobisphenol, amines, benzophenone, salicylate, benzotriazole, and an organometallic compound should be added. Is preferred.

Examples of the method for forming the thermoplastic resin-containing layer include melt extrusion, wet lamination, dry lamination and the like, and melt extrusion is most preferable. When the thermoplastic resin-containing layer is formed by the melt extrusion, the coating is performed for the purpose of strengthening the adhesion between the thermoplastic resin-containing layer and the lower layer (hereinafter sometimes referred to as “coating layer”). It is preferable to pre-treat the layer surface.
Examples of the pretreatment include an acid etching treatment using a mixed solution of chromic sulfate, a flame treatment using a gas flame, an ultraviolet irradiation treatment, a corona discharge treatment, a glow discharge treatment, and an anchor coat treatment such as an alkyl titanate. However, the corona discharge treatment is particularly preferable from the viewpoint of simplicity. In the case of corona discharge treatment, it is necessary to perform treatment so that the contact angle with water is 70 ° or less.

-Paper base-
As the support in the present invention, a paper substrate which is an opaque support can be used.
Examples of the paper base include natural pulp paper mainly composed of normal natural pulp, mixed paper composed of natural pulp and synthetic fiber, synthetic fiber paper mainly composed of synthetic fiber, polystyrene, polyethylene terephthalate, polypropylene, etc. Any of the so-called synthetic papers obtained by converting the synthetic resin film into pseudo paper may be used, but natural pulp paper (hereinafter simply referred to as “base paper”) is particularly preferable. As the base paper, neutral paper (pH 5 to 9) and acidic paper can be used, but neutral paper is more preferable.

The above-mentioned base paper is made from natural pulp selected from conifers, hardwoods, etc., as necessary, fillers such as clay, talc, calcium carbonate, urea resin fine particles, rosin, alkyl ketene dimer, higher fatty acid, epoxidized fatty acid amide, A sizing agent such as paraffin wax and alkenyl succinic acid, a starch, a polyamide polyamine epichlorohydrin, a paper strength enhancer such as polyacrylamide, a fixing agent such as a sulfuric acid band and a cationic polymer can be used. Moreover, you may add softening agents, such as surfactant. Furthermore, synthetic paper using synthetic pulp may be used in place of the natural pulp, or a mixture of natural pulp and synthetic pulp in an arbitrary ratio may be used. Among them, it is preferable to use hardwood pulp having short fibers and high smoothness. The water content of the pulp material used is preferably in the range of 200 to 500 ml (C.S.F.), more preferably in the range of 300 to 400 ml.

The paper base material may contain other components such as a sizing agent, a softening agent, a paper strength agent, and a fixing agent. Examples of the sizing agent include rosin, paraffin wax, higher fatty acid salt, alkenyl succinate, fatty acid anhydride, styrene maleic anhydride copolymer, alkyl ketene dimer, epoxidized fatty acid amide, etc. Includes a reaction product of a maleic anhydride copolymer and a polyalkylene polyamine, a quaternary ammonium salt of a higher fatty acid, and the paper strength agent includes polyacrylamide, starch, polyvinyl alcohol, melamine formaldehyde condensate, gelatin In addition, examples of the fixing agent include a sulfuric acid band and a polyamide polyamine epichlorohydrin. In addition, dyes, fluorescent dyes, antistatic agents and the like can be added as necessary.

The paper substrate is preferably subjected to activation treatment such as corona discharge treatment, flame treatment, glow discharge treatment, plasma treatment and the like before the formation of the above-described thermoplastic resin-containing layer.

-Calendar processing-
The support in the present invention can be subjected to calendar treatment.
After providing the thermoplastic resin-containing layer on the paper base material, the planarity of the thermoplastic resin-containing layer can be obtained by applying a calender treatment under specific conditions, and further through the thermoplastic resin-containing layer. High glossiness, high flatness, and high image quality image formation on the surface of the ink receiving layer formed in this manner can be ensured.

The calendering is performed by using a soft calender or super calender in which at least one of the roll pair is composed of a metal roll (preferably composed of a metal roll and a resin roll), or both, and the surface temperature of the metal roll. Is set to be equal to or higher than the glass transition temperature of the thermoplastic resin described above, and the nip pressure between the roll nips of the roll pair is preferably set to 50 to 400 kg / cm.

Hereinafter, a soft calendar having a metal roll and a resin roll and a super calendar will be described in detail. The metal roll is a cylindrical or columnar roll having a smooth surface, and is appropriately selected from known metal rolls without being limited to the material and the like as long as it has a heating means inside. Can be used. Further, since the metal roll is in contact with the recording surface side, that is, the surface on the side where the ink receiving layer is formed, of both sides of the support during calendering, the surface roughness is preferably as smooth as possible. Specifically, the surface roughness is preferably 0.3 s or less, more preferably 0.2 s or less in terms of the surface roughness specified by JIS B0601.

Further, the surface temperature during the treatment of the metal roll is generally preferably 70 to 250 ° C. when the paper substrate is treated. On the other hand, when the paper substrate provided with the above-described thermoplastic resin-containing layer is treated, the glass transition temperature Tg or higher of the thermoplastic resin contained in the thermoplastic resin-containing layer is not less than It is more preferable that it is Tg or more and + 40 ° C. or less.

The resin roll can be appropriately selected from synthetic resin rolls made of polyurethane resin, polyamide resin or the like, and those having a Jore D hardness of 60 to 90 are suitable.
The nip pressure of the roll pair having the metal roll is appropriately 50 to 400 kg / cm, preferably 100 to 300 kg / cm. In the case of a process using a soft calendar and / or a super calendar in which a pair of rolls configured as described above is arranged, it is desirable that the process be performed once or twice.

In addition, the support body used for an inkjet recording medium is not specifically limited, The transparent support body which consists of transparent materials, such as a plastics, can also be used. A material that can be used for the transparent support is preferably a material that is transparent and can withstand radiant heat when used in an OHP or a backlight display. Examples of such materials include polyesters such as polyethylene terephthalate (PET); polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide, and the like. Of these, polyesters are preferable, and polyethylene terephthalate is particularly preferable.
Also, a read-only optical disk such as CD-ROM or DVD-ROM, a write-once optical disk such as CD-R or DVD-R, or a rewritable optical disk is used as a support, and an ink receiving layer and a gloss imparting layer are provided on the label side. Can also be given.

A polymer fine particle dispersion may be added to the constituent layer (for example, ink receiving layer) of the ink jet recording medium of the present invention. The polymer fine particle dispersion is used for the purpose of improving film properties such as dimensional stabilization, curling prevention, adhesion prevention, film cracking prevention and the like. The polymer fine particle dispersion is described in JP-A Nos. 62-245258, 62-1316648, and 62-110066. When a polymer fine particle dispersion having a low glass transition temperature (40 ° C. or lower) is added to the ink receiving layer, cracking and curling of the layer can be prevented. Further, even when a polymer fine particle dispersion having a high glass transition temperature is added to the back layer, curling can be prevented.

The layer thickness of the ink receiving layer of the present invention needs to be determined in relation to the porosity in the layer since it needs to have an absorption capacity sufficient to absorb all droplets in the case of inkjet recording. For example, if the ink amount is 8 nl / mm ² and the porosity is 60%, a film having a layer thickness of about 15 μm or more is required. Considering this point, in the case of inkjet recording, the thickness of the ink receiving layer is preferably 10 to 50 μm.

The porosity of the ink receiving layer can be measured using a mercury porosimeter “Bore Sizer 9320-PC2” manufactured by Shimadzu Corporation.

In addition, the ink receiving layer is preferably excellent in transparency, as a guide, the haze value when the ink receiving layer is formed on a transparent film support is preferably 30% or less, More preferably, it is 20% or less. The haze value can be measured using a haze meter “HGM-2DP” manufactured by Suga Test Instruments Co., Ltd.

-Inkjet recording system-
In the ink jet recording method of the present invention, the ink jet recording method is not limited, and a known method, for example, a charge control method in which ink is ejected using electrostatic attraction, or a drop-on-demand method using vibration pressure of a piezo element. Method (pressure pulse method), acoustic ink method that converts electrical signals into acoustic beams, irradiates ink, and ejects ink using radiation pressure, and forms bubbles by heating ink and uses generated pressure A thermal ink jet method is used. Inkjet recording methods use a method of ejecting a large number of low-density inks called photo inks in a small volume, a method of improving image quality using a plurality of inks having substantially the same hue and different concentrations, and colorless and transparent inks. The method is included.

(Drying process)
In the ink jet recording method of the present invention, drying can be performed after printing (preferably within 10 minutes after printing). The drying device is installed in the ink jet recording apparatus inline or offline.
As the drying method, a heat drying method is preferable, and the heating method is performed by a normal method such as warm air or hot air heating by a heated blast dryer, infrared drying by an infrared lamp, hot roll heating, dielectric heating or the like. In order to obtain a recorded image excellent in density and hue change immediately after printing without causing problems such as curling due to overheating, drying is preferably performed within 1 minute immediately after printing, and drying is performed at 50 ° C. to 200 ° C. It is preferably carried out for 1 second to 5 minutes at 50 ° C. to 150 ° C. for 1 second to 5 minutes.

The ink jet recording method uses the combination of the above (2), which is a preferred combination mode of the ink and the ink jet recording medium, and is performed at 50 ° C. to 150 ° C. for 1 second to 5 minutes within 1 minute immediately after the printing. A drying process can be performed.

Hereinafter, the present invention will be described more specifically with reference to examples. The scope of the present invention is not limited to the specific examples shown below. Unless otherwise specified, “part” and “%” are based on mass.

[Example 1]
(Production of support)
50 parts of LBKP made of acacia and 50 parts of LBKP made of aspen were beaten to 300 ml of Canadian freeness by a disc refiner to prepare a pulp slurry.
Then, the pulp slurry obtained above was cation modified starch (CAT 0304L manufactured by NSC Japan) 1.3%, 0.15% anionic polyacrylamide (DA4104 manufactured by Seiko PMC), alkyl ketene dimer (Arakawa Chemical Co., Ltd.) per pulp. Sizepine K) 0.29%, epoxidized behenamide 0.29%, polyamide polyamine epichlorohydrin (Arakawa Chemical Co., Ltd .: Arafix 100) 0.32% was added, followed by defoaming agent 0.12% Was added.

In the process of making the pulp slurry prepared as described above with a long paper machine and pressing the felt surface of the web against the drum dryer cylinder through the dryer canvas for drying, the tensile force of the dryer canvas is 1.6 kg / After drying at a setting of cm, 1 g / m ² of polyvinyl alcohol (manufactured by Kuraray Co., Ltd .: KL-118) was applied to both sides of the base paper with a size press and dried to perform calendar treatment. The base paper was made with a basis weight of 166 g / m ² to obtain a base paper (base paper) having a thickness of 160 μm.

After the corona discharge treatment is performed on the wire surface (back surface) side of the obtained base paper, a high-density polyethylene is coated to a thickness of 25 g / m ² using a melt extruder, and thermoplasticity comprising a mat surface. A resin layer was formed. The thermoplastic resin layer on the back side is further subjected to corona discharge treatment, and then, as an antistatic agent, aluminum oxide (“Alumina Zil 100” manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (manufactured by Nissan Chemical Industries, Ltd.) Of “Snowtex O”) was dispersed in water at a mass ratio of 1: 2 so that the dry mass was 0.2 g / m ² . Then polyethylene having a density of 0.93 g / ^{m 2} with a corona treated 10 wt% of titanium oxide on the surface was coated using a melt extruder so that 24 g / ^{m 2.}

(Preparation of coating liquid A (first liquid) for ink receiving layer)
(1) Gas phase method silica fine particles, (2) ion-exchanged water, (3) “Charol DC-902P”, and (4) “ZA-30” shown in the following composition were mixed to bead mill ( After dispersion using KD-P (produced by Jinmaru Enterprises Co., Ltd.), the dispersion was heated to 45 ° C. and held for 20 hours. Then, the following (5) boric acid aqueous solution, (6) dimethylamine / epichlorohydrin / polyalkylene polyamine polycondensate, (7) polyvinyl alcohol solution, (8) “Superflex 650”, (9 ) Ethanol water was added at 30 ° C. to prepare an ink-receiving layer coating solution A (first solution).

(1) Gas phase method silica fine particles 100 parts (AEROSlL300SF75, manufactured by Nippon Aerosil Co., Ltd.)
(2) 555 parts of ion-exchanged water (3) 8.7 parts of “Charol DC-902P” (dispersing agent, 51.5% aqueous solution manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
(4) 2.7 parts of zirconyl acetate (“ZA-30”, manufactured by Daiichi Rare Element Chemical Co., Ltd., 50% aqueous solution)
(5) Boric acid (crosslinking agent) aqueous solution (7.5%) 50 parts (6) Dimethylamine / epichlorohydrin / polyalkylene polyamine polycondensate (“SC-505”, Hymo Co., Ltd., 50% aqueous solution) 77 parts (7) Polyvinyl alcohol (water-soluble resin) solution having the following composition 290 parts (8) "Superflex 650" 25 parts (cation-modified polyurethane, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
(9) Ethanol water (ethanol content 59%) 75 parts

-Composition of polyvinyl alcohol solution-
・ Polyvinyl alcohol 20.3 parts ("JM-33", saponification degree 94.5%, polymerization degree 3300, manufactured by Nippon Binpo-Poval Co., Ltd.)
・ Diethylene glycol monobutyl ether 6.0 parts ("Butizenol 20P", manufactured by Kyowa Hakko Co., Ltd.)
・ Ion-exchanged water 263.7 parts

(Preparation of basic solution B (second solution))
The composition shown below was mixed and stirred to obtain a basic solution B.
(1) Boric acid 0.65 parts (2) Zirconyl ammonium carbonate 2.5 parts (Zircosol AC-7 (13% aqueous solution), manufactured by Daiichi Rare Element Chemical Co., Ltd.)
(3) Ammonium carbonate (first grade: manufactured by Kanto Chemical Co., Inc.) 4.0 parts (4) 92.85 parts ion-exchanged water (5) 0.6 parts polyoxyethylene isodecyl ether (Neugen SD-70, Daiichi Manufactured by Kogyo Seiyaku Co., Ltd.

(Preparation of polyvalent metal salt aqueous solution C for in-line blending)
The composition shown below was mixed and stirred to obtain an aqueous polyvalent metal salt solution C for in-line blending.
(1) Alphain 83 20.0 parts (polyaluminum chloride: manufactured by Daimei Chemical Industry Co., Ltd.)
(2) Neugen SD-60 4.4 parts (polyoxyethylene isodecyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
(3) 75.6 parts of ion exchange water

(Preparation of inkjet recording sheet)
After the corona discharge treatment is performed on the front surface of the support, the aqueous solution of the polyvalent metal salt for in-line blending is applied to the coating solution A (first solution) for the ink-receiving layer that is flowed to a coating amount of 173 ml / m ^2. C was inline mixing at a rate of 10.8 ml / ^{m 2} of the ink-receiving layer coating liquid a-2 was prepared and subjected to coating. Thereafter, it was dried with a hot air dryer at 80 ° C. (wind speed 3 to 8 m / sec) until the solid content concentration of the coating layer became 20%. This coating layer showed constant rate drying during this period. Then, before showing the rate-decreasing drying, it was immersed in the basic solution B (second liquid) for 3 seconds to adhere 13 g / m ² on the coating layer, and further dried at 80 ° C. for 10 minutes. (Curing process). This produced the inkjet recording sheet of Example 1 provided with an ink receiving layer having a dry film thickness of 32 μm.

<Preparation of ink>
(Preparation of magenta ink)
Deionized water was added to the following components to make 1 liter, and the mixture was stirred for 1 hour while heating at 30 to 40 ° C. Thereafter, the pH was adjusted to 9 with KOH 10 mol / l and filtered under reduced pressure through a microfilter having an average pore size of 0.25 μm to prepare magenta ink M-101.

・ Dye M-1 (see below) 35.0g
・ Triethylene glycol 20.0g
・ 1,5-pentanediol 40.0g
・ 2-pyrrolidone 40.0g
・ Ethylene glycol 75.5g
・ Urea 19.0g
・ PROXEL XL2 (Avecia Co., Ltd.) 1.1g

<Performance evaluation>
(Ink receiving layer pore median diameter and pore volume measurement)
A water-soluble organic solvent (described in Table 1) was diluted with water and applied to the inkjet recording sheet using a bar coater so that the amount of the water-soluble organic solvent applied was 6.6 g / m ² . .
The coated inkjet recording sheet is stored in an environment of 25 ° C. and 50% RH for 24 hours, cut into a size of 20 × 100 mm, and pore size distribution and fineness at an initial pressure of about 20 kPa using a Shimadzu Autobore 9220. The pore volume was measured (pore median diameter L2 and pore volume V2 after coating).
In addition, the pore diameter distribution was similarly measured (pore median diameter L1 and pore volume V1 of the support) only for the support on which the ink receiving layer was not applied, and the pore volume ratio was determined as follows. Asked. The obtained results are shown in Table 1.

The volume ratio (%) of pores with a median diameter of 40 to 100 nm in pores with a median diameter of 100 nm or less is:
(V2 _{40 to 100 nm} −V1 _{40 to 100 nm} ) / (V2 _{100 nm or less−} V1 _{100 nm or less} ) × 100
I asked for it.
V2 _{40 to 100 nm} : Volume of pores with a median diameter of 40 to 100 nm after coating V2 _{100 nm or less} : Volume of pores with a median diameter of 100 nm or less after coating V1 _{40 to 100 nm} : Median diameter of a support only _{40 to 40 nm} Volume of pores of 100 nm · V1 _{100 nm or less} : Volume of pores having a median diameter of 100 nm or less of the support alone

(Concentration measurement)
The ink jet recording sheet obtained above was stored at 25 ° C. and 50% RH for one day, and then the ink receiving layer was loaded with the above-mentioned magenta ink using a printer PM-A950 manufactured by Seiko Epson. In the same environment, a magenta solid image was printed with color adjustment set to no color correction, and stored in the same environment for 24 hours.
After storage, the magenta concentration was measured with X-rite 310 (manufactured by X-rite) and evaluated according to the following evaluation criteria. The obtained results are shown in Table 1.

-Evaluation criteria-
A: Concentration is 2.6 or more B: Concentration is 2.5 or more and less than 2.6 C: Concentration is 2.4 or more and less than 2.5 D: Concentration is less than 2.4

(Hue change measurement)
The ink jet recording sheet obtained above was stored at 25 ° C. and 50% RH for one day, and then the ink receiving layer was loaded with the above-mentioned magenta ink using a printer PM-A950 manufactured by Seiko Epson. In the same environment, a magenta solid image was printed by adjusting the magenta density to 1.3.
Immediately after printing (within 2 minutes after printing) and 24 hours after printing, the hue of the magenta solid part is measured, and the difference between the hue immediately after printing and the hue after 24 hours after printing is the color difference (ΔE) It was.
Here, the hue was measured by measuring L ^* a ^* b ^* using a spectrophotometer (Spectrolino, manufactured by Gretag Macbeth Co., Ltd.) under the conditions of a light source F8 and a viewing angle of 2 degrees.
From the obtained color difference (ΔE), color change was evaluated according to the following evaluation criteria. The obtained results are shown in Table 1.

-Evaluation criteria-
A... ΔE <1: Color change is hardly recognized B... 1 ≦ ΔE <2: Color change is noticeable but not so noticeable C... 2 ≦ ΔE <4: Color change is noticeable but acceptable level D .. 4 ≦ ΔE: Level where color change is a big problem

[Examples 2 to 20]
A magenta ink was prepared, printed and evaluated in the same manner as in Example 1 except that ethylene glycol was replaced with the water-soluble organic solvent shown in Table 1 in Example 1.
Here, the abbreviations in the column of the water-soluble organic solvent in Tables 1 and 2 are as follows.
EGMME: ethylene glycol monomethyl ether EGDME: ethylene glycol dimethyl ether DEGMME: diethylene glycol monomethyl ether DEGMBE: diethylene glycol monobutyl ether DEGDME: diethylene glycol dimethyl ether DPGMME: dipropylene glycol monomethyl ether DPGMBE: dipropylene glycol monobutyl ether EGMMEA: ethylene glycol monomethyl ether acetate TEGMBE: triethylene Glycol monobutyl ether

[Example 21]
In Example 1, a magenta ink was prepared, printed and evaluated in the same manner as in Example 1 except that the composition of the magenta ink was changed as follows.
・ Dye M-1 (see above) 35.0 g
・ Triethylene glycol 14.7g
・ 1,5-pentanediol 29.5g
・ 2-pyrrolidone 29.5g
・ DEGMBE 101.8g
・ Urea 19.0g
・ PROXEL XL2 (Avecia Co., Ltd.) 1.1g

[Example 22]
In Example 1, a magenta ink was prepared, printed and evaluated in the same manner as in Example 1 except that the composition of the magenta ink was changed as follows.
・ Dye M-1 (see above) 35.0 g
・ Triethylene glycol 9.1g
・ 1,5-pentanediol 18.3g
・ 2-pyrrolidone 18.3g
・ DEGMBE 129.9g
・ Urea 19.0g
・ PROXEL XL2 (Avecia Co., Ltd.) 1.1g

[Example 23]
In Example 1, a magenta ink was prepared, printed and evaluated in the same manner as in Example 1 except that the composition of the magenta ink was changed as follows.
・ Dye M-1 (see above) 35.0 g
・ 5.6 g of triethylene glycol
・ 1,5-pentanediol 11.2g
・ 2-pyrrolidone 11.2g
・ DEGMBE 147.4g
・ Urea 19.0g
・ PROXEL XL2 (Avecia Co., Ltd.) 1.1g

[Example 24]
In Example 1, a magenta ink was prepared, printed and evaluated in the same manner as in Example 2 except that the composition of the magenta ink was changed as follows.
・ Dye M-1 (see above) 35.0 g
・ Triethylene glycol 2.5g
・ 1,5-pentanediol 4.9g
・ 4.9g 2-pyrrolidone
・ DEGMBE 163.2g
・ Urea 19.0g
・ PROXEL XL2 (Avecia Co., Ltd.) 1.1g

[Example 25]
An ink jet recording sheet was obtained in the same manner as in Example 1, except that the polyvinyl alcohol JM-33 in the ink receiving layer was changed to PVA235 (saponification degree 88%, polymerization degree 3500, manufactured by Kuraray Co., Ltd.). . Printing was performed in the same manner as in Example 1 except that this ink jet recording sheet was used.

[Example 26]
In Example 1, a magenta ink was produced, printed and evaluated in the same manner as in Example 1 except that the aqueous dye of the magenta ink was changed to M-5.

[Comparative Example 1]
In Example 1, a magenta ink was prepared, printed and evaluated in the same manner as in Example 1 except that the composition of the magenta ink was changed as follows.
・ Dye M-1 (see above) 35.0 g
・ Triethylene glycol 22.1g
・ 1,5-pentanediol 44.2g
・ 2-pyrrolidone 44.2g
・ DEGMBE 64.9g
・ Urea 19.0g
・ PROXEL XL2 (Avecia Co., Ltd.) 1.1g

[Comparative Example 2]
In Example 1, a magenta ink was prepared, printed and evaluated in the same manner as in Example 1 except that the composition of the magenta ink was changed as follows.
・ Dye M-1 (see above) 35.0 g
・ Triethylene glycol 24.9g
・ 1,5-pentanediol 49.8g
・ 2-pyrrolidone 49.8g
・ DEGMBE 50.9g
・ Urea 19.0g
・ PROXEL XL2 (Avecia Co., Ltd.) 1.1g

[Comparative Example 3]
In Example 1, a magenta ink was prepared, printed and evaluated in the same manner as in Example 1 except that the composition of the magenta ink was changed as follows.
・ Dye M-1 (see above) 35.0 g
・ Triethylene glycol 30.5g
・ 1,5-pentanediol 61.1g
・ 2-pyrrolidone 61.1g
・ DEGMBE 22.8g
・ Urea 19.0g
・ PROXEL XL2 (Avecia Co., Ltd.) 1.1g

[Comparative Examples 4 to 8]
A magenta ink was prepared, printed and evaluated in the same manner as in Example 1 except that ethylene glycol was replaced with the water-soluble organic solvent shown in Table 1 in Example 1.

As is clear from Table 1, the comparative example not having the constitution of the present invention had a low density, and the hue change immediately after printing was greatly inferior.
On the other hand, in the example having the configuration of the present invention, the density after printing was high, and the hue change immediately after printing was also good.

[Examples 27 to 29, Comparative Examples 9 to 11]
<Production of various color inks>
In Example 1, yellow ink, cyan ink, and black ink were prepared as shown in Table 2 by changing the dye species and additives.

The structure of the dyes in Table 2 is as follows.

<Printing and performance evaluation of yellow, cyan and black images>
Example 1 is the same as Example 1 except that the yellow inks Y-101 and Y-102, cyan inks C-101 and C-102, black inks Bk-101 and Bk-102 are used instead of the magenta ink. Similarly, solid images of yellow, cyan, and black were printed, and performance evaluation was performed.

As is clear from Table 3, the comparative example not having the configuration of the present invention was poor in density and hue change immediately after printing.
On the other hand, in the example having the configuration of the present invention, not only high density but also a change in hue immediately after printing was obtained.

Claims (4)

1. An ink containing at least a dye, water, and a water-soluble organic solvent on an ink jet recording medium having an ink receiving layer containing at least an inorganic fine particle, a water-soluble resin, and a crosslinking agent on a support, wherein the ink is a water-soluble organic solvent. in volume ratio of the pore median diameter 40 ~ 100nm in the ink-receiving layer to 6.6 g / m ² applied to the ink-receiving layer of mercury intrusion median diameter 100nm in the following the pores as measured by method after the An ink jet recording method, wherein recording is performed using an ink having a water-soluble organic solvent content of 40% by mass or more.
   
2. The inkjet recording method according to claim 1, wherein the water-soluble resin is polyvinyl alcohol.
   
3. The water-soluble organic solvent in the ink is ethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, dipropylene glycol monoalkyl ether, 1,2-alkyl diol, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether. The inkjet recording method according to claim 1, wherein the inkjet recording method is at least one selected from triethylene glycol dialkyl ether, propylene glycol dialkyl ether, dipropylene glycol dialkyl ether, and tripropylene glycol dialkyl ether.
   
4. The water-soluble organic solvent in the ink is ethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, dipropylene glycol monoalkyl ether, 1,2-alkyl diol, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether. The inkjet recording method according to claim 2, wherein the inkjet recording method is at least one selected from triethylene glycol dialkyl ether, propylene glycol dialkyl ether, dipropylene glycol dialkyl ether, and tripropylene glycol dialkyl ether.