JP2003253179A - Ink for inkjet recording, ink set for inkjet recording and method for inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ink for inkjet recording with which clogging of a nozzle is suppressed and spreading of an image is suppressed and the inkjet image with a high quality can be formed, an ink set for inkjet recording, and a method for inkjet recording using the ink for inkjet recording or the ink set for inkjet recording. <P>SOLUTION: In the ink for inkjet recording comprising a water-soluble dye, water, a water-soluble organic solvent, a content of the water-soluble organic solvent being 5-20 mass% and 25-100 mass% of the water-soluble organic solvent being tripropylene glycol. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording ink, an inkjet recording ink set, and an inkjet recording method.

[0002]

2. Description of the Related Art Ink jet recording methods have been widely used as methods for easily obtaining high quality images, and high image quality has been advanced.

In the conventional ink for ink jet recording, the ink is apt to evaporate in the nozzle, whereby the coloring material is deposited and the nozzle is clogged, or the viscosity of the ink changes and the ejection becomes unstable. Had problems such as.

In order to solve these problems, there is known a technique in which a water-soluble organic solvent containing a large amount of glycerin or the like having a high boiling point is added to the ink to suppress the evaporation of the ink and prevent the nozzle from clogging. Has been.

[0005]

However, the conventional ink has a problem that bleeding easily occurs in the formed inkjet image. Bleeding is a phenomenon in which, when an inkjet image formed by inkjet recording is stored for a long period of time, the coloring material on the inkjet image diffuses due to the influence of humidity, temperature, etc., and the image bleeds.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent ink from clogging the nozzles and to prevent bleeding to form an ink jet image of high quality. The present invention also provides an inkjet recording ink set and an inkjet recording method using the inkjet recording ink or the inkjet recording ink set.

[0007]

The object of the present invention has been achieved by the following constitution.

(1) In an ink jet recording ink containing a water-soluble dye, water and a water-soluble organic solvent, the content of the water-soluble organic solvent is 5 to 20% by mass, and the content of the water-soluble organic solvent is 25 to 20% by weight. An ink for inkjet recording, wherein 100% by mass is tripropylene glycol.

(2) In an ink jet recording ink containing a water-soluble dye, water and a water-soluble organic solvent, the content of the water-soluble organic solvent is 5 to 20% by mass, and tripropylene is used as the water-soluble organic solvent. An inkjet recording ink comprising glycol and propylene glycol.

(3) The ink for ink jet recording according to (2), wherein the total content of the tripropylene glycol and the propylene glycol in the water-soluble organic solvent is 50 to 100% by mass.

(4) The ink jet recording ink according to any one of (1) to (3), wherein the glycerin content in the water-soluble organic solvent is 25% by mass or less.

(5) In an ink jet recording ink set having at least a yellow ink jet recording ink, a magenta ink jet recording ink, a cyan ink jet recording ink, and a black ink jet recording ink, all of the ink jet recording inks An inkjet recording ink set comprising the inkjet recording ink according to any one of (1) to (4).

(6) In an ink jet recording method for recording with an ink on a recording medium having an ink receiving layer containing a water-soluble binder, the ink comprises (1) to
An ink jet recording ink according to any one of (4) or the ink set for ink jet recording according to (5).

(7) The ink jet recording method according to (6), wherein the ink receiving layer has a porous structure.

(8) The ink jet recording method according to (6) or (7), characterized in that a fixing process is performed on the recorded recording medium.

(9) The ink jet recording method described in any one of (6) to (8), wherein the recording is performed by an on-demand method.

(10) Recording is performed by ejecting the ink by an electromechanical conversion method.
The inkjet recording method according to any one of (9).

(11) Recording is performed by ejecting the ink by an electric / heat conversion system (6).
The inkjet recording method according to any one of (9).

The present invention will be described in detail below. As a result of intensive studies, the present inventors have found that the water-soluble dye,
In an ink jet recording ink containing water and a water-soluble organic solvent, the water-soluble organic solvent in the ink is
20% by mass, and further 25 to 10 of the water-soluble organic solvent
It has been found that the ink for inkjet recording in which 0% by mass is tripropylene glycol suppresses clogging of the nozzle, and the ink jet image formed using this ink has suppressed bleeding.

Furthermore, the present inventors set the amount of the water-soluble organic solvent in the ink in the ink for ink jet recording containing the water-soluble dye, water and the water-soluble organic solvent to 5 to 20% by mass, and further to the water-soluble organic solvent. It was also found that the ink for inkjet recording containing tripropylene glycol and propylene glycol as described above suppressed the clogging of the nozzle, and the ink jet image formed using this ink had suppressed bleeding.

The ink jet recording ink of the present invention comprises
The water-soluble organic solvent in the ink is 5 to 20% by mass, and 25 to 100% by mass of the water-soluble organic solvent is tripropylene glycol, which is a water-soluble organic solvent having a high boiling point. Therefore, the occurrence of nozzle clogging can be suppressed.

Further, the ink jet recording ink of the present invention contains the water-soluble organic solvent in the ink in an amount of 5 to 20% by mass, and the water-soluble organic solvent further contains tripropylene glycol and propylene glycol. It is possible to suppress the evaporation of water and to prevent the occurrence of nozzle clogging.

The ink jet recording ink of the present invention comprises
The content of tripropylene glycol in the water-soluble organic solvent is preferably 50 to 100%. This allows
Bleeding can be further suppressed, and nozzle clogging can be further suppressed.

The ink jet recording ink of the present invention comprises
It is also preferable that the total amount of tripropylene glycol and propylene glycol in the water-soluble organic solvent is 50 to 100% by mass because bleeding can be further suppressed and nozzle clogging can be further suppressed.

The ink jet recording ink of the present invention comprises
The glycerin content in the water-soluble organic solvent is preferably 25% by mass or less, and most preferably glycerin is not contained in the water-soluble organic solvent. This can further suppress bleeding.

The water-soluble organic solvent in the present invention means alcohols (for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol, etc.). , Polyhydric alcohols (for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiene Glycol, etc.), polyhydric alcohol ethers (eg ethylene glycol monomethyl ether) Ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, tri Ethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, dipropylene glycol monopropyl ether, tripropylene glycol dimethyl ether, etc.), amine (E.g., ethanolamine, diethanolamine, triethanolamine, N- methyldiethanolamine, N-
Ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine, etc., amides (eg formamide, N, N-dimethyl) Formamide, N, N-dimethylacetamide, etc.), heterocycles (eg, 2-pyrrolidone, N-methyl-2-pyrrolidone,
N-cyclohexyl-2-pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, etc.),
Sulfoxides (eg, dimethyl sulfoxide, etc.),
Examples thereof include sulfones (eg, sulfolane).

The water-soluble organic solvent used in the ink jet recording ink of the present invention preferably has a high boiling point in order to further suppress nozzle clogging.

Examples of the water-soluble dye that can be used in the present invention include azo dyes, methine dyes, azomethine dyes, xanthene dyes, quinone dyes, phthalocyanine dyes, triphenylmethane dyes and diphenylmethane dyes. The specific compound is shown below.
However, the compounds are not limited to these exemplified compounds.

[C. I. Acid Yellow] 1, 3, 1
1, 17, 18, 19, 23, 25, 36, 38, 4
0, 42, 44, 49, 59, 61, 65, 67, 7
2, 73, 79, 99, 104, 110, 114, 11
6, 118, 121, 127, 129, 135, 13
7, 141, 143, 151, 155, 158, 15
9, 169, 176, 184, 193, 200, 20
4, 207, 215, 219, 220, 230, 23
2, 235, 241, 242, 246 [C. I. Acid Orange] 3, 7, 8, 10, 1
9, 24, 51, 56, 67, 74, 80, 86, 8
7, 88, 89, 94, 95, 107, 108, 11
6, 122, 127, 140, 142, 144, 14
9, 152, 156, 162, 166, 168 [C. I. Acid Red] 88, 97, 106, 11
1, 114, 118, 119, 127, 131, 13
8, 143, 145, 151, 183, 195, 19
8, 211, 215, 217, 225, 226, 24
9, 251, 254, 256, 257, 260, 26
1, 265, 266, 274, 276, 277, 28
9, 296, 299, 315, 318, 336, 33
7, 357, 359, 361, 362, 364, 36
6, 399, 407, 415 [C. I. Acid Violet] 17, 19, 21,
42, 43, 47, 48, 49, 54, 66, 78, 9
0, 97, 102, 109, 126 [C. I. Acid Blue] 1, 7, 9, 15, 23,
25, 40, 62, 72, 74, 80, 83, 90, 9
2, 103, 104, 112, 113, 114, 12
0, 127, 128, 129, 138, 140, 14
2, 156, 158, 171, 182, 185, 19
3, 199, 201, 203, 204, 205, 20
7,209,220,221,224,225,22
9, 230, 239, 249, 258, 260, 26
4, 278, 279, 280, 284, 290, 29
6, 298, 300, 317, 324, 333, 33
5, 338, 342, 350 [C. I. Acid Green] 9, 12, 16, 19,
20, 25, 27, 28, 40, 43, 56, 73, 8
1, 84, 104, 108, 109 [C. I. Acid Brown] 2, 4, 13, 14, 1
9, 28, 44, 123, 224, 226, 227, 2
48, 282, 283, 289, 294, 297, 29
8, 301, 355, 357, 413 [C. I. Acid Black] 1, 2, 3, 24, 2
6, 31, 50, 52, 58, 60, 63, 107, 1
09, 112, 119, 132, 140, 155, 17
2, 187, 188, 194, 207, 222 [C. I. Direct Yellow] 8, 9, 10, 11,
12, 22, 27, 28, 39, 44, 50, 58, 7
9, 86, 87, 98, 105, 106, 130, 13
2, 137, 142, 147, 153 [C. I. Direct Orange] 6, 26, 27, 3
4, 39, 40, 46, 102, 105, 107, 11
8 [C. I. Direct Red] 2, 4, 9, 23, 2
4, 31, 54, 62, 69, 79, 80, 81, 8
3, 84, 89, 95, 212, 224, 225, 22
6, 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, 1
99, 200, 201, 202, 203, 218, 22
5,229,237,244,248,251,27
0, 273, 274, 290, 291 [C. I. Direct Green] 26, 28, 59, 8
0,85 [C. I. Direct Brown] 44, 106, 11
5, 195, 209, 210, 222, 223 [C. I. Direct Black] 17, 19, 22, 3
2, 51, 62, 108, 112, 113, 117, 1
18, 132, 146, 154, 159, 169 [C. I. Basic Yellow] 1, 2, 11, 13,
15, 19, 21, 28, 29, 32, 36, 40, 4
1, 45, 51, 63, 67, 70, 73, 91 [C. I. Basic orange] 2, 21, 22 [C. I. Basic Red] 1, 2, 12, 13, 1
4, 15, 18, 23, 24, 27, 29, 35, 3
6, 39, 46, 51, 52, 69, 70, 73, 8
2, 109 [C. I. Basic Violet] 1, 3, 7, 1
0, 11, 15, 16, 21, 27, 39 [C. I. Basic blue] 1, 3, 7, 9, 21,
22, 26, 41, 45, 47, 52, 54, 65, 6
9, 75, 77, 92, 100, 105, 117, 12
4, 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, 3
9, 42, 57, 69, 76, 81, 84, 85, 8
6, 87, 92, 95, 102, 105, 111, 12
5, 135, 136, 137, 142, 143, 14
5, 151, 160, 161, 165, 167, 16
8, 175, 176 [C. I. Reactive orange] 1, 4, 5, 7, 1
1, 12, 13, 15, 16, 20, 30, 35, 5
6, 64, 67, 69, 70, 72, 74, 82, 8
4, 86, 87, 91, 92, 93, 95, 107 [C. I. Reactive Red] 2, 3, 5, 8, 1
1, 21, 22, 23, 24, 28, 29, 31, 3
3, 35, 43, 45, 49, 55, 56, 58, 6
5, 66, 78, 83, 84, 106, 111, 11
2, 113, 114, 116, 120, 123, 12
4, 128, 130, 136, 141, 147, 15
8, 159, 171, 174, 180, 183, 18
4, 187, 190, 193, 194, 195, 19
8, 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, 2
9, 38, 39, 41, 49, 50, 52, 63, 6
9, 71, 72, 77, 79, 89, 104, 109,
112, 113, 114, 116, 119, 120, 1
22, 137, 140, 143, 147, 160, 16
1, 162, 163, 168, 171, 176, 18
2, 184, 191, 194, 195, 198, 20
3, 204, 207, 209, 211, 214, 22
0, 221, 222, 231, 235, 236 [C. I. Reactive Green] 8, 12, 15, 1
9, 21 [C. I. Reactive Brown] 2, 7, 9, 10,
11, 17, 18, 19, 21, 23, 31, 37, 4
3, 46 [C. I. Reactive Black] 5, 8, 13, 1
4, 31, 34, 39 [C. I. Food Black] 1, 2 Examples include compounds represented by the general formula (1) and compounds represented by the general formula (2).

[0030]

[Chemical 1]

[0031]

[Chemical 2]

The dyes listed above are described in "Dyeing Note 21st Edition" (published by Shikiso Co., Ltd.) and the like.

In the present invention, C.I. I.
Direct Yellow 132, a compound represented by the general formula (1) as a magenta dye, a compound represented by the general formula (2), and a cyan dye such as C.I. I. Direct Blue 199, C.I. as a black dye. I. It is preferable to use Food Black 2. The light resistance of the inkjet image thus formed can be improved, and the quality of the inkjet image can be improved.

The compound represented by the general formula (1) will be described. In the formula, R ₁ represents a hydrogen atom or a substitutable substituent, preferably a hydrogen atom or a phenylcarbonyl group. R ₂ may be different and represents a hydrogen atom or a substitutable substituent, preferably a hydrogen atom. R ₃ represents a hydrogen atom or a substitutable substituent, preferably a hydrogen atom or an alkyl group. R ₄ represents a hydrogen atom or a substitutable substituent, preferably a hydrogen atom or an aryloxy group. R ₅ may be different and represents a hydrogen atom or a substitutable substituent, and a sulfonic acid group is preferable. n represents an integer of 1 to 4. m represents an integer of 1 to 5.

The compound represented by the general formula (2) will be described. In the formula, X represents a phenyl group or a naphthyl group, which may be substituted with a substitutable substituent, and is preferably substituted with a sulfonic acid group or a carboxyl group. Y represents a hydrogen ion, a sodium ion, a potassium ion, a lithium ion, an ammonium ion, or an alkylammonium ion. R ₆ may be different and represents a hydrogen atom or a substituent capable of substituting on the naphthalene ring. q represents an integer of 1 or 2. p represents an integer of 1 to 4. q
+ P = 5. Z represents a substitutable substituent, represents a carbonyl group, a sulfonyl group or a group represented by the general formula (3), and a group represented by the general formula (3) is preferable.

[0036]

[Chemical 3]

In the formula (3), W ₁ and W ₂ may represent different halogen atoms, amino groups, hydroxyl groups, alkylamino groups and arylamino groups, and halogen atoms, hydroxyl groups or alkylamino groups. Is preferred.

In the present invention, among the compounds represented by the general formula (1), the following compounds are particularly preferably used, and the light resistance of the ink jet image formed thereby can be further improved, and the ink jet The image quality can be improved.

[0039]

[Chemical 4]

In the present invention, it is preferable to use the following compounds among the compounds represented by the general formula (2), which can further improve the light resistance of an ink jet image formed.

[0041]

[Chemical 5]

[0042]

[Chemical 6]

The dye represented by the general formula (1) may be used alone or in combination with a plurality of dyes.
The dye having a different structure represented by or the dye represented by the general formula (2) may be used in combination.

The ink jet recording ink of the present invention comprises
The content of the water-soluble dye can be selected in the range of 0.1 to 20% by mass, and in order to form a photographic image with an inkjet image, a so-called dark and light ink in which the content of the water-soluble dye is changed is used. It is preferably prepared and used. Also,
If necessary, it is also preferable in terms of color reproduction that special color inks such as red, green and blue are used.

The ink jet recording ink set in the present invention is an ink jet recording ink set having at least a yellow ink jet recording ink, a magenta ink jet recording ink, a cyan ink jet recording ink, and a black ink jet recording ink. , Refers to an ink set that includes a plurality of inks that are generally used for so-called color inkjet printing.

In the ink jet recording ink set of the present invention, all the ink jet recording inks of the ink jet recording ink set are the ink jet recording ink of the present invention, and when an ink jet image is formed using this ink set, bleeding occurs. Can be suppressed.

The ink jet recording method of the present invention is an ink jet recording in which the ink for ink jet recording of the present invention or the ink set for ink jet recording of the present invention is used for recording on a recording medium having an ink receiving layer containing a water-soluble binder. Ink jet images formed by this recording method are suppressed in bleeding.

The ink receiving layer of the recording medium used in the present invention includes a void type image receiving layer having voids and a so-called swelling type image receiving layer having no voids. In the case of the swelling type image receiving layer, the ink receiving layer is made of a water absorbing resin, and the water absorbing resin absorbs the ink solvent and the dye by incorporating them between the molecules of the resin. Such an ink receiving layer is preferable in that it is more advantageous than the void type because the dye does not come into direct contact with air for fading of the image.

The water-absorbent resin is, for example, polyvinyl alcohol, gelatin, polyethylene oxide, polyvinylpyrrolidone, casein, starch, agar, carrageenan,
Polyacrylic acid, polymethacrylic acid, polyacrylamide, polymethacrylamide, polystyrene sulfonic acid,
Hydrophilic polymers such as cellulose, hydroxylethyl cellulose, carboxymethyl cellulose, hydroxylethyl cellulose, dextran, dextrin, pullulan, and water-soluble polyvinyl butyral can be mentioned.
These hydrophilic polymers can be used in combination of two or more.

The hydrophilic polymer preferably used in the present invention is polyvinyl alcohol.

The ink receiving layer preferably contains a curing agent and a surfactant in addition to the hydrophilic binder. To prevent blocking, a filler such as a matting agent can be added to the extent that voids are not generated.

On the other hand, the use of the void type ink receiving layer according to the present invention is preferable in that the color bleeding can be further improved.

The void type ink receiving layer of the recording medium used in the present invention is preferably formed mainly of fine particles and a hydrophilic binder.

As the fine particles that can be used in the present invention, inorganic fine particles and organic fine particles can be used.
In particular, inorganic fine particles are preferable because they have high gloss, high color density, and easily obtain fine particles. Examples of such inorganic fine particles include light calcium carbonate, heavy calcium carbonate, magnesium carbonate, kaolin, clay, talc, calcium sulfate, barium sulfate,
Titanium dioxide, zinc oxide, zinc hydroxide, zinc sulfide, zinc carbonate, hydrotalcite, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, alumina, colloidal alumina, pseudoboehmite, water Aluminum oxide, lithopone,
Examples thereof include white inorganic pigments such as zeolite and magnesium hydroxide. The above-mentioned inorganic fine particles can be used as primary particles as they are, or can be used in the state of forming secondary aggregated particles.

In the present invention, from the viewpoint of obtaining a high quality print on an ink jet recording medium, alumina, pseudo-boehmite, colloidal silica or fine particle silica synthesized by a vapor phase method is preferable as the inorganic fine particles.

Of these, pseudo-boehmite alumina hydrate is preferable from the viewpoint of preventing bleeding of a printed image in a high humidity environment. As a typical example of this pseudo-boehmite, Japanese Patent Laid-Open No. 7-8
Alumina hydrate A described in Examples of 9221
Is mentioned. This alumina hydrate A was first produced into aluminum alkoxide by the method described in US Pat. No. 4,242,271, and the method described in US Pat. No. 4,202,870. Then hydrolyze the aluminum alkoxide with 30% in an oven.
Aging at 2 ° C. for 2 hours gives a colloidal sol of alumina. The alumina hydrate A is amorphous and has a flat plate shape, a BET specific surface area of 76 g / m, and a BET pore volume of 0.5.
It is 7 ml / g.

The reason why such pseudo-boehmite has a high ink receptivity is considered to be the fact that its pore radius and pore size distribution are in a range very suitable for ink receptivity. The pore size distribution of pseudo-boehmite has two or more maximums. The relatively large pores absorb the solvent component in the ink, and the relatively small pores adsorb the dye in the ink. One of the maximum pore size distributions of pseudo-boehmite has a pore radius of preferably 10 nm or less, more preferably 1 to 6 nm. The other maximum preferably has a pore radius of 10 to 20 nm.

In the present invention, the most preferable of the above-mentioned inorganic fine particles is fine particle silica synthesized by a gas phase method. It is preferable in terms of color bleed, gloss, image density, and cost. The silica synthesized by this vapor phase method may have a surface modified with Al. The Al content of the vapor grown silica whose surface is modified with Al is preferably 0.05 to 5% by mass with respect to silica.

The inorganic fine particles may have any particle diameter, but the average particle diameter is preferably 1 μm or less. If it is 1 μm or less, the glossiness and color developability are better, and therefore, in particular, 0.2 μm
The following is preferable, and 0.1 μm or less is most preferable. The lower limit of the particle size is not particularly limited, but from the viewpoint of manufacturing the inorganic fine particles, it is generally 0.003 μm or more, and particularly 0.005 μm.
The above is preferable.

The average particle size of the above-mentioned inorganic fine particles is obtained by observing the cross section and the surface of the void type ink receiving layer with an electron microscope to obtain the particle size of 100 arbitrary particles, and taking as a simple average value (number average). Desired. Here, each grain size is represented by a diameter assuming a circle having the same projected area.

The dispersity of the fine particles is preferably 0.5 or less from the viewpoint of glossiness and color developability. When it is 0.5 or less, gloss and color developability at the time of printing are better. Particularly, 0.3 or less is preferable. Here, the dispersity of the fine particles is represented by a value obtained by observing the fine particles in the void-type ink receiving layer with an electron microscope and determining the standard deviation by the average particle diameter. .

The fine particles may be primary particles as they are or may be present in the porous film as secondary particles or higher-order aggregated particles, but the average particle diameter is observed by an electron microscope. The particle size of the independent particles that are formed in the void-type ink receiving layer.

The content of the fine particles in the water-soluble coating liquid is 5 to 40% by mass, and particularly preferably 7 to 30% by mass.

The water-soluble binder contained in the void-type ink receiving layer is not particularly limited, and conventionally known water-soluble binders can be used. For example, gelatin, polyvinylpyrrolidone, polyethylene oxide, polyacrylamide, polyvinyl alcohol. Etc. can be used, but polyvinyl alcohol is particularly preferable.

Polyvinyl alcohol is a polymer that has an interaction with inorganic fine particles, has a particularly high holding power for inorganic fine particles, and has a relatively small humidity dependency of hygroscopicity. Is relatively small, the suitability for cracking during coating and drying, which is the subject of the present invention, is excellent. As the polyvinyl alcohol preferably used in the present invention, in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate, modified polyvinyl alcohol having a cation-modified terminal or anion-modified polyvinyl alcohol having an anionic group, etc. Polyvinyl alcohol is also included.

The polyvinyl alcohol obtained by hydrolyzing vinyl acetate preferably has an average degree of polymerization of 300 or more, and particularly preferably an average degree of polymerization of 1,000 to 5,000.
Those of are preferably used. Degree of saponification is 70 to 10
0% is preferable, and 80 to 99.5% is particularly preferable.

Examples of the cation-modified polyvinyl alcohol include primary to tertiary amino groups and quaternary ammonium groups as described in JP-A-61-10483, which are main chains or side chains of the polyvinyl alcohol. The polyvinyl alcohols contained therein are obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate.

Examples of the ethylenically unsaturated monomer having a cationic group include trimethyl- (2-acrylamido-2,2-dimethylethyl) ammonium chloride and trimethyl- (3-acrylamido-3,3-dimethylpropyl). ) Ammonium chloride, N-vinylimidazole, N-vinyl-2-methylimidazole, N
-(3-dimethylaminopropyl) methacrylamide,
Hydroxylethyltrimethylammonium chloride, trimethyl- (methacrylamidopropyl) ammonium chloride, N- (1,1-dimethyl-3-dimethylaminopropyl) acrylamide and the like can be mentioned.

The ratio of the cation-modified group-containing monomer of the cation-modified polyvinyl alcohol is 0.1 to 10 mol%, preferably 0.2 to 5 mol% with respect to vinyl acetate.

Polyvinyl alcohol can be used in combination of two or more types such as different degree of polymerization or modification. In particular, when polyvinyl alcohol having a degree of polymerization of 2000 or more is used, the degree of polymerization is set in advance in the inorganic fine particle dispersion liquid.
5,000 or less polyvinyl alcohol is 0.05 to 10% by mass, preferably 0.1 to 5% by mass with respect to the inorganic fine particles.
It is preferable to add polyvinyl alcohol having a degree of polymerization of 2000 or more after the addition because there is no significant increase in viscosity.

The ratio of the fine particles to the water-soluble binder in the void type ink receiving layer is preferably 2 to 20 times by mass. If the mass ratio is less than 2 times, not only the void ratio of the void-type ink receiving layer is lowered and it becomes difficult to obtain a sufficient void volume, but also an excessive amount of the water-soluble binder swells during inkjet recording to form voids. It becomes a factor to block the ink absorption speed. On the other hand, if this ratio exceeds 20 times, cracking tends to occur when the void-type ink receiving layer is applied as a thick film, which is not preferable. Particularly preferred ratio of fine particles to water-soluble binder is 2.5.
˜12 times, most preferably 3 to 10 times.

It is preferable to add a compound containing a zirconium atom or an aluminum atom in the molecule to the void type ink receiving layer using the above vapor phase method silica because the color bleeding and the bleeding are improved.

The compound having a zirconium atom in the molecule which can be used in the recording medium used in the present invention does not include zirconium oxide. Specific examples thereof include zirconium difluoride, zirconium trifluoride and zirconium tetrafluoride. , Hexafluorozirconate (eg potassium salt), heptafluorozirconate (eg sodium salt, potassium salt), heptafluorozirconate (eg sodium salt, potassium salt, ammonium salt), octafluorozirconate (eg Lithium salt), zirconium fluoride oxide, zirconium dichloride, zirconium trichloride, zirconium tetrachloride, hexachlorozirconate (eg sodium salt, potassium salt), zirconium oxychloride (zirconyl chloride), zirconium dibromide, Zirconium bromide, zirconium tetrabromide, bromide, zirconium oxide, a three-iodide zirconium,
Zirconium tetraiodide, zirconium peroxide, zirconium hydroxide, zirconium sulfate, zirconium p-toluenesulfonate, zirconyl sulfate, sodium zirconyl sulfate, zirconyl acid sulfate trihydrate, potassium zirconium sulfate, zirconium selenate, zirconium nitrate, nitric acid Zirconyl, zirconium phosphate, zirconyl carbonate, zirconyl ammonium carbonate, zirconium acetate, zirconyl acetate, zirconyl acetate acetate, zirconyl lactate, zirconyl citrate, zirconyl stearate, zirconium phosphate, zirconyl phosphate, zirconium zirconium isopropylate, zirconium Butyrate, zirconium acetylacetonate, zirconium acetate, bis (acetylacetonate) dichlorozirco Um, tris (acetylacetonato) chloro zirconium, and the like.

Among these compounds, zirconyl carbonate, zirconyl ammonium carbonate, zirconyl acetate, zirconyl nitrate, zirconium acid chloride, zirconyl lactate,
Zirconyl citrate is preferred, with ammonium zirconyl carbonate and zirconyl acetate being most preferred.

The compound containing an aluminum atom in the molecule which can be used in the present invention does not include aluminum oxide, and specific examples thereof include aluminum fluoride, hexafluoroaluminic acid (eg potassium salt), aluminum chloride, Basic aluminum chloride (eg, polyaluminum chloride), tetrachloroaluminate (eg,
Sodium salt), aluminum bromide, tetrabromoaluminate (eg potassium salt), aluminum iodide, aluminate (eg sodium salt, potassium salt, calcium salt), aluminum chlorate, aluminum perchlorate, thiocyan Aluminum acid sulfate, aluminum sulfate, basic aluminum sulfate, aluminum potassium sulfate (alum), ammonium aluminum sulfate (ammonium alum), sodium aluminum sulfate, aluminum phosphate, aluminum nitrate, aluminum hydrogen phosphate, aluminum carbonate, aluminum polysulfate silicate, aluminum formate, Aluminum acetate, aluminum lactate, aluminum oxalate, aluminum isopropylate, aluminum butyrate, ethyl acetate aluminum diisopropylate Rate, aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), aluminum monoacetylacetonate bis (ethyl acetoacetonate) and the like.

Among these, aluminum chloride, basic aluminum chloride, aluminum sulfate, basic aluminum sulfate and basic aluminum sulfate silicate are preferable,
Most preferred are basic aluminum chloride and basic aluminum sulfate.

The above compound is used as an ink jet recording paper 1.
Per m ² , usually 0.05 to 25 mmol, preferably 0.25 to 10 mmol, particularly preferably 0.5 to 5 m
Used in the mol range.

In the void type ink receiving layer using silica, it is preferable to add a silane coupling agent because it has an effect of reducing color bleed.

The silane coupling agent is preferably a compound having a quaternary ammonium salt and a di- or trialkoxysilanyl group. Examples of preferable silane coupling agents include (a) 3- (trimethoxysilyl) propyldimethyloctadecyl ammonium chloride,
(B) N-β- (N-vinylbenzylaminoethyl)-
γ-aminopropyltrimethoxysilane, (C) 3-
Examples thereof include (trimethoxysilyl) propyldimethylhydroxyethylammonium chloride and a silane coupling agent having a (d) imidazole group. These chemical formulas are shown below.

[0080]

[Chemical 7]

The curing of the silane coupling agent is carried out by converting a plurality of alkoxysilanyl groups into silanol groups in the presence of water (which can be caused by moisture in the air), and the silane coupling agents are heated (preferably by heating). ) It is carried out by binding by a condensation reaction between silanol groups to form a crosslinked structure.

When these cationic substances are added to the coating liquid for the transparent porous layer, they may interact with the anionic charge on the surface of the inorganic fine particles such as silica to cause aggregation, but they are contained in the coating liquid for the crosslinking agent. In that case, there is no problem, and an effective amount can be added to improve the film quality of the transparent porous layer. The addition amount of the cationic substance is 0.0
It is preferably ¹ to 3.6 g / m ² , and 0.05 to
More preferably, it is about 2 g / m ² .

As the support used for the recording medium that can be used in the present invention, a water-absorbent support (for example, paper) or a non-water-absorbent support can be used, but a higher quality print can be obtained. From the viewpoint of the above, a non-water absorbent support is preferred.

In the water-absorbent support, not only it is difficult to obtain a high-quality print, but also each overcoated additive component diffuses in the paper after coating, resulting in a loss of the original effect of the additive.

Examples of non-water-absorbing supports that are preferably used include polyester films, diacetate films, triate sate films, polyolefin films, acrylic films, polycarbonate films, polyvinyl chloride films, polyimide films. A transparent or opaque film made of a material such as cellophane or celluloid, or resin-coated paper in which both sides of a base paper are coated with a polyolefin resin coating layer, so-called RC
Paper or the like is used.

Various additives can be added to the water-soluble coating liquid for forming the void type ink receiving layer.
Examples of such an additive include a cationic mordant, a cross-linking agent, a surfactant (cation, nonion, anion, amphoteric), a white background color tone adjusting agent, a fluorescent whitening agent, a mildew proofing agent, a viscosity adjusting agent, a low boiling point. Examples include organic solvents, high-boiling organic solvents, latex emulsions, anti-fading agents, ultraviolet absorbers, polyvalent metal compounds (water-soluble or water-insoluble), matting agents, silicone oils, etc. Among them, cationic mordants are
It is preferable in order to improve water resistance and moisture resistance after printing.

As the cation mordant, a polymer mordant having a primary to tertiary amino group and a quaternary ammonium base is used, but it is less likely to undergo discoloration or deterioration in light resistance during long-term storage. Polymer mordants having a quaternary ammonium salt group are preferred.

A preferred polymer mordant is obtained as a homopolymer of the above-mentioned monomer having a quaternary ammonium salt group, a copolymer with other monomer or a condensation polymer.

It is also particularly preferable to include a crosslinking agent for the water-soluble binder. The cross-linking agent improves the water resistance of the void-type ink receiving layer, and suppresses the swelling of the water-soluble binder during inkjet recording, thereby improving the ink absorption rate.

As the cross-linking agent, conventionally known cross-linking agents can be used, and inorganic cross-linking agents (eg, chromium compounds, aluminum compounds, zirconium compounds, boric acids, etc.) and organic cross-linking agents (eg, epoxy-based cross-linking agents). Cross-linking agent,
Isocyanate crosslinking agent, aldehyde crosslinking agent, N-methylol crosslinking agent, acryloyl crosslinking agent, vinylsulfone crosslinking agent, active halogen crosslinking agent, carbodiimide crosslinking agent, ethyleneimino crosslinking agent, etc.) are used. be able to.

The amount of these cross-linking agents is about 1 to 50% by weight, preferably 2 to 40% by weight based on the water-soluble binder.
It is% by mass.

When the water-soluble binder is polyvinyl alcohol and the fine particles are silica, the crosslinking agent is preferably an inorganic crosslinking agent such as boric acid or a zirconium compound and an epoxy crosslinking agent.

The coating method that can be used in the preparation of the recording medium that can be used in the present invention can be appropriately selected from known methods, for example, gravure coating method, roll coating method, rod bar coating method. The air knife coating method, the spray coating method, the extrusion coating method, the curtain coating method or the extrusion coating method using a hopper described in US Pat. No. 2,681,294 is preferably used.

The void-type ink receiving layer of the recording medium that can be used in the present invention may be a single layer or a multi-layer. In the case of a multi-layer structure, it is necessary to apply all layers at the same time. It is preferable from the viewpoint of manufacturing cost reduction.

The ink jet recording method of the present invention is preferably an on-demand method. In the ink jet recording method of the present invention, it is preferable to perform fixing processing after recording with ink on a recording medium.

In the present invention, the fixing method means (1) a method of recording by inkjet onto a recording medium containing thermoplastic fine particles on the surface of the void type ink receiving layer and then heating to close the voids on the surface, (2) A method of forming a transparent protective layer (overcoat layer) on the surface of the ink receiving layer by thermal transfer after recording on the recording medium by inkjet, (3) forming a resin layer by coating on the surface of the ink receiving layer after recording on the recording medium by inkjet Methods and the like. In either method, it is preferable to evaporate the solvent as much as possible by heating after recording and then perform fixing in order to further suppress the bleeding.

(1), (2) and (3) will be described in detail below. It is preferable that the surface layer of the recording medium containing the thermoplastic fine particles on the surface of the void type ink receiving layer (1) contains the inorganic pigment and the thermoplastic fine particles. The light resistance or water resistance of the recording medium is improved depending on the presence or absence of heat treatment after image recording.

Examples of the thermoplastic fine particles which can be used in the fixing treatment include polycarbonate, polyacrylonitrile, polystyrene, polyacrylic acid, polymethacrylic acid, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyester, polyamide, Examples thereof include polyethers, copolymers thereof and salts thereof. Among them, styrene-acrylic acid ester copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-acrylic acid ester copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, SBR latex preferable. Further, the thermoplastic fine particles may be a mixture of a plurality of polymers having different monomer compositions, particle sizes, and degrees of polymerization.

In selecting the thermoplastic fine particles, ink receptivity, glossiness of an image after fixing by heating and pressurization, image fastness and releasability should be taken into consideration.

The diameter of the thermoplastic fine particles is preferably 0.
The thickness is from 05 to 10 μm, more preferably from 0.1 to 5 μm. More preferably, it is 0.1 to 1 μm.

The glass transition point (Tg) is a criterion for selecting the thermoplastic fine particles. When Tg is lower than the coating drying temperature, for example, the coating drying temperature at the time of manufacturing the recording medium is already higher than Tg and the ink solvent permeates, so that the voids due to the thermoplastic fine particles disappear. The Tg of the thermoplastic fine particles is preferably 50 to 150 ° C. from the viewpoint of the load on the device and the thermal stability of the support.

As the minimum film forming temperature (MFT),
It is preferably 50 to 150 ° C. The thermoplastic particles are
From the viewpoint of environmental suitability, those dispersed in an aqueous system are preferred, and an aqueous latex obtained by emulsion polymerization is particularly preferred. At this time, the type obtained by emulsion polymerization using a nonionic dispersant as an emulsifier is a form that can be preferably used. From the viewpoint of odor and safety, the thermoplastic fine particles to be used preferably have a small amount of remaining monomer components, preferably 3% by mass or less, more preferably 1% by mass or less, based on the solid content of the polymer. It is preferably 0.1% by mass or less.

The surface layer containing the inorganic pigment and the thermoplastic fine particles has a solid content of 2 g / m ² to
The range of 50 g / m ² is preferable and 3 g / m ^{2 to} 30 g / m
The range of ² is more preferable.

[0104] recording medium used in the present invention the ink jet recording method, the solid content of the thermoplastic fine particles contained in the surface layer is preferably in the range of ^{0.5g / m 2 ~15g / m 2} , 1g / m 2 ~ A range of 7 g / m ² is particularly preferred.
If the solid content of the thermoplastic fine particles is too small, a sufficient film cannot be formed and the pigment cannot be sufficiently dispersed in the film. Therefore, the image quality, gloss, and light resistance are not sufficiently improved. If the solid content of the thermoplastic fine particles is too large,
In a short heating step, the thermoplastic fine particles cannot be completely formed into a film, and the fine particles remain as they are, resulting in opacity and thus deterioration in image quality. In addition, the ink absorption speed is also reduced, causing bleeding at the boundary, which is a problem.

The surface layer coating liquid containing the inorganic pigment and the thermoplastic fine particles may have the inorganic pigment and the thermoplastic fine particles dispersed at the same time, or may be prepared by dispersing them and mixing them at the time of preparing the coating liquid.

A preferable mode of the ink jet recording method of the present invention is to melt and form the thermoplastic fine particles contained in the surface layer by heat treatment after image recording. In order to give the required amount of heat in a short time, it is desirable to heat using a heat source that is as hot as possible, but if the temperature is excessively high, damage to the support, severe curling, or
Roughness of image surface and roller contamination may occur. 1
The range of 00 to 200 ° C is preferable, and the range of 100 to 150 ° C is more preferable.

The heating method may be performed by a heater built in the printer or by another heater. The surface of the roller or belt is preferably coated with a fluororesin or a silicone resin in order to prevent contamination. At that time, it is preferable to use a silicon rubber roller or belt coated with heat resistant silicon.

In the ink jet recording method of the present invention, it is preferable to perform recording by ejecting ink by the electromechanical conversion method. Examples of the electromechanical conversion method include an electromechanical conversion method using a piezoelectric element. Examples of the piezoelectric element include a piezo element.

In the ink jet recording method of the present invention, it is also preferable to perform recording by ejecting ink by an electric / heat conversion system. Examples of the electricity / heat conversion method include an electricity / heat conversion method using a heating element.

[0110]

EXAMPLES Examples of the present invention will be described below.
The invention is not limited to these examples.

Example 1 [Preparation of Recording Medium 1] [Preparation of Silica Dispersions D1 and D2] Vapor phase silica (Nippon Aerosil) in which the average particle diameter of the primary particles dispersed in advance is 0.012 μm. 400L of silica dispersion B1 (pH = 2.3, containing 1% by mass of ethanol) containing 25% of A200) and 0.3% of water-soluble fluorescent whitening agent UVITENXFW LIQUID (manufactured by Ciba Specialty Chemicals). To the cationic polymer P-1
%, N-propanol 10% and ethanol 2%
To 110 L of the contained aqueous solution C1 (pH = 2.5, containing 2 g of antifoaming agent SN381 manufactured by Sannobuco), 3
It was added with stirring at 000 rpm. Next, 54 L of a mixed aqueous solution A1 of boric acid and borax at a 1: 1 mass ratio (concentration of 3% each) was gradually added while stirring.

Then, the mixture was dispersed with a high-pressure homogenizer manufactured by Sanwa Kogyo Co., Ltd. at a pressure of 3000 N / cm ² , and the whole amount was made up to 630 L with pure water to obtain a substantially transparent silica dispersion D1.

On the other hand, 400 L of the above silica dispersion B1
Is an aqueous solution C2 containing 12% of the cationic polymer P-2, 10% of n-propanol and 2% of ethanol.
3000L at room temperature to 120L (pH = 2.5)
Was added with stirring, and then 52 L of the mixed aqueous solution A1 was gradually added with stirring.

Then, the mixture was dispersed with a high-pressure homogenizer manufactured by Sanwa Kogyo Co., Ltd. at a pressure of 3000 N / cm ² , and the whole amount was made up to 630 L with pure water to obtain a substantially transparent silica dispersion D.
Got 2.

The above silica dispersions D1 and D2 were mixed with each other at 30 μm.
TCP-manufactured by Advantec Toyo Co., Ltd.
Filtration was performed using a 30 type filter.

[Preparation of Oil Dispersion] 20 kg of diisodecyl phthalate and 20 kg of antioxidant (AO-1) were dissolved by heating in 45 kg of ethyl acetate, and 8 kg of acid-treated gelatin and 2.9 kg of cationic polymer P-1 were prepared. Gelatin aqueous solution 21 containing 10.5 kg of saponin
After mixing with 0 L at 55 ° C., emulsifying and dispersing with a high pressure homogenizer, the total amount was made up to 300 L with pure water to prepare an oil dispersion.

[0117]

[Chemical 8]

[Preparation of Coating Solution] Using each of the dispersions prepared above, the following additives were sequentially mixed to prepare a coating solution. In addition, each added amount is shown as an amount per 1 L of the coating liquid.

[0119]   (Coating liquid for first layer: bottom layer)   Silica dispersion D1 580 ml   Polyvinyl alcohol (Kuraray: PVA203) 10% aqueous solution 5 ml   Polyvinyl alcohol (average degree of polymerization: 3800, saponification degree 88%)     290 ml of 6.5% aqueous solution   Oil dispersion 30ml   Latex dispersion (Showa High Polymer Co., AE803) 42ml   8.5 ml of ethanol   Finish with 1000ml of pure water   (Coating liquid for second layer)   Silica dispersion D1 600ml   Polyvinyl alcohol (Kuraray: PVA203) 10% aqueous solution 5 ml   Polyvinyl alcohol (average degree of polymerization: 3800, saponification degree 88%)     270 ml of 6.5% aqueous solution   Oil dispersion 20ml   Latex dispersion (Showa High Polymer Co., Ltd .: AE803) 22 ml   8 ml of ethanol   Finish with 1000ml of pure water   (Coating liquid for third layer)   Silica dispersion D2 630ml   Polyvinyl alcohol (Kuraray: PVA203) 10% aqueous solution 5 ml   Polyvinyl alcohol (average degree of polymerization: 3800, saponification degree 88%)     270 ml of 6.5% aqueous solution   Oil dispersion 10ml   Latex dispersion (Showa High Polymer AE803) 5 ml   3 ml of ethanol   Finish with 1000ml of pure water   (4th layer coating liquid: top layer)   Silica dispersion D2 660 ml   Polyvinyl alcohol (Kuraray: PVA203) 10% aqueous solution 5 ml   Polyvinyl alcohol (average degree of polymerization: 3800, saponification degree 88%)     250% 6.5% aqueous solution   Betaine type surfactant-1 4% aqueous solution 3 ml   2 ml of a 25% aqueous solution of saponin   3 ml of ethanol   Finish with 1000ml of pure water

[0120]

[Chemical 9]

20% of each coating solution prepared as described above was used.
TCP manufactured by Advantech Toyo Co., Ltd. with filtration accuracy of μm
After filtering with a D-30 filter, it was filtered with a TCPD-10 filter.

[Coating of Recording Medium] Next, a slide hopper type coater was used to coat each of the above coating solutions on a paper support coated with polyethylene on both sides at 40 ° C. so that the wet film thickness described below was obtained. 4 layers were applied simultaneously.

<Wet Film Thickness> First layer: 42 μm Second layer: 39 μm Third layer: 44 μm Fourth layer: 38 μm The above paper support has a width of about 1.5 m and a length of about 40 μm.
The following support wound in a roll of 00 m was used.

The paper support used had a water content of 8% and a grammage of 170 g, and the surface of the photographic base paper was extruded with a thickness of 35 μm of polyethylene containing 6% of anatase-type titanium oxide and melt-coated on the back surface. Was extruded and melt-coated with polyethylene having a thickness of 40 μm. The surface side is polyvinyl alcohol (PVA23 manufactured by Kuraray Co., Ltd.) after corona discharge.
5) was coated with an undercoating layer so that the amount of 0.05 g per 1 m ² of the recording medium, and the back side was subjected to corona discharge machining.
A back layer containing about 0.4 g of a styrene-acrylic acid ester latex binder having a g of about 80 ° C., 0.1 g of an antistatic agent (cationic polymer) and 0.1 g of silica of about 2 μm as a matting agent was applied.

Drying after applying the coating liquid for the ink receiving layer is as follows.
After passing through a cooling zone kept at 5 ° C for 15 seconds to reduce the temperature of the film surface to 13 ° C, the temperature of a plurality of drying zones is appropriately set and dried, and then wound into a roll shape. A comparative recording medium 1 was obtained. The center line average surface roughness (Ra value A) of the recording medium 1 was measured by the method described below, and was 0.21 μm. [Preparation of Yellow Ink-1] The following components were mixed and sufficiently stirred, and then filtered using a membrane filter having a pore size of 0.45 µm to prepare Yellow Ink 1.

C. I. Direct Yellow 132 2.5 mass% tripropylene glycol 5.0 mass% propylene glycol 10.0 mass% 2-propanol 2.0 mass% Olphin E1010 (manufactured by Nisshin Chemical Co., Ltd.) 1.0 mass% ion-exchanged water 79 0.5% by mass [Preparation of magenta ink-1] Yellow ink-1
In the preparation of C. I. Yellow Ink-1 except that an equal mixture of Compound M-1 and Compound M-4 was used instead of Direct Yellow 132.
Magenta Ink-1 was prepared in the same manner as in. [Preparation of Cyan Ink-1] In the preparation of Yellow Ink-1, the water-soluble dye was replaced with C.I. I. C. instead of Direct Yellow 132. I. Similar to the preparation of Yellow Ink-1, except that Direct Blue 199 was used,
Cyan ink-1 was prepared. [Preparation of Black Ink-1] Yellow Ink-1 above
In the preparation of C. I. C. instead of Direct Yellow 132. I. Black Ink-1 was prepared in the same manner as in Yellow Ink-1, except that Food Black 2 was used. [Preparation of Ink Sets-1 to 8] An ink set 1 having the above-mentioned yellow ink 1, magenta ink 1, cyan ink 1, and black ink 1 as one unit was prepared. Further, the content of the water-soluble dye contained in each of the yellow ink, the magenta ink 1, the cyan ink 1, and the black ink 1 of the ink set 1, the type of the water-soluble organic solvent contained in the ink, and Table 1
Ink sets 2 to 8 were prepared by changing the ink as shown in FIG.

[0127]

[Table 1]

[Production of Image Recording Samples 1 to 8] Nozzle diameter 23 μm, driving frequency 10 kHz, number of nozzles per color 128, nozzle density of the same color 90 dpi (hereinafter, dpi represents the number of dots per 2.54 cm). The ink set 1 is set in the on-demand type ink jet printer having the maximum recording density of 720 × 720 dpi, and the recording medium 1 is set as the recording medium, and each of yellow, magenta, cyan, and black single color, And an image recording sample 1 which is a solid image of 10 cm × 10 cm in which two to four colors are overprinted. Similarly, the ink set 1 was changed to the ink sets 2 to 8 to prepare image recording samples 2 to 8. [Evaluation of Bleeding of Image Recording Samples 1 to 8] Image Forming Samples 1 to 1
The following bleeding evaluation was performed for No. 8. The results are shown in Table 2. <Evaluation of bleeding> After the image recording sample was left in an environment of 30 ° C. and 80% relative humidity for 2 days, the boundary between the printed portion and the non-printed portion was observed, and the bleeding was evaluated according to the following visual evaluation criteria. ◎: The boundary between the printed area and the non-printed area is clear even in the 4-color overprinted area. ○: The boundary between the printed area and the non-printed area is clear in the single-color printed area, but some blurring is observed in the overprinted area. Bleeding is observed in the department

[0129]

[Table 2]

Further, with respect to the ink sets 1 to 8, the following clogging evaluation of nozzles was performed. [Evaluation of nozzle clogging] After printing with the printer in which the above ink set 1 is set and confirming the ejection of ink from each nozzle, the head is capped at 25 ° C without capping.
It was left in a 30% environment for 3 days. Ejection was performed again after standing, and the cleaning operation (suction operation) required until ejection from all nozzles was possible was evaluated according to the following criteria. Similarly, the ink set 1 was changed to the ink sets 2 to 8 and evaluated according to the following criteria. The results are shown in Table 3. ◯: All nozzles ejected within 3 cleaning operations ×: All nozzles ejected within 4 cleaning operations

[0131]

[Table 3]

From the results of Tables 2 and 3, it was found that the ink jet recording ink of the present invention suppressed the nozzle clogging. Further, it was found that the image recording sample produced by using the ink for inkjet recording of the present invention has suppressed bleeding. In particular, it was found that the image recording samples 1 and 4 were suppressed in bleeding. Further, the image recording sample produced using the inkjet recording ink of the present invention had no image bronzing and had good light resistance.

Example 2 [Preparation of recording medium 2]
Instead of the layer coating solution, the fourth coating solution was further purified with pure water to further add 13.1 mmol of zirconyl acetate (molecular weight 2
20% aqueous solution of 15) was gradually added to 0.01 mmo.
A recording medium was prepared in the same manner as the recording medium 1 except that a translucent coating solution was prepared by adding 1 l of an aqueous solution of zirconyl nitrate and finally adding pure water so that the volume of the entire solution was 1000 ml. 2 was produced. [Production of Recording Medium 3] In the production of the recording medium 1,
Instead of the layer coating liquid, 3 g of basic polyaluminum hydroxide (Purachem WT manufactured by Riken Green Co., Ltd.) was added before finishing the fourth coating liquid with pure water, and finally the total volume of the liquid was 1
A recording medium 3 was prepared in the same manner as the recording medium 1 except that a coating solution containing pure water was used so that the amount became 000 ml. [Preparation of Recording Medium 4] Recording medium 4 was prepared by applying the following overcoat liquid on the surface of the ink receiving layer of recording medium 1 at 20 g / m ² and then drying. (Overcoat liquid) 17.8 parts of shelf sand, 97.8 parts of water, 0.2 surfactant (Dainippon Ink and Chemicals, F-144D) 0.2
Parts and 1 part of POLON-MF-50 manufactured by Shin-Etsu Chemical Co., Ltd. as a cationic silane coupling agent and stirred to obtain an overcoat liquid. [Preparation and Evaluation of Image Recording Sample] An image recording sample was prepared in the same manner as in Example 1 except that the recording medium 1 was changed to recording media 2 to 4, and bleeding was evaluated. The image recording sample recorded using the inkjet recording ink of the present invention had no bleeding and had no problem.

Example 3 In Example 1, the printer was an inkjet printer BJ S700 manufactured by Canon, the recording medium 1 was PICTORICOPRO manufactured by PICTORICO, and the compound M-1 and the compound M which were water-soluble dyes of the magenta ink 1 were used. Nozzle clogging was evaluated and image recording samples were formed in the same manner as in Example 1 except that the equal mixture of the compound M-1 and the compound M-9 was used instead of the equal mixture of -4. When the bleeding was evaluated, it was found that the ink jet recording ink of the present invention suppressed the nozzle clogging and further suppressed the bleeding of the image recording sample. Furthermore, no kogation (burning of the head) was observed even after continuous emission for a long time.

Example 4 In the same manner as in Example 1, except that the printer was an inkjet printer hp pc1160 manufactured by Hewlett Packard Co., and the recording medium 1 was a light-resistant premium photo paper (thick) manufactured by Hewlett Packard Co., Ltd. The nozzle clogging was evaluated, and the image recording sample was further formed to evaluate the bleeding. However, the ink jet recording ink of the present invention has suppressed nozzle clogging,
Further, it was found that the bleeding of the image recording sample was suppressed.

Example 5 In Example 1, the printer was an inkjet printer CL-750 manufactured by Seiko Epson Corporation, and the recording medium 1 was used.
Nozzle clogging was evaluated in the same manner as in Example 1 except that the photoprint paper 2 manufactured by Seiko Epson Corporation was used, and an ink jet recording ink of the present invention was evaluated by forming an image recording sample. It was found that the nozzle clogging was suppressed and the bleeding of the image recording sample was also suppressed.

Example 6 Light magenta ink-1 and light cyan ink-1 in which the total dye concentrations of magenta ink-1 and cyan ink-1 prepared in Example 1 were each 0.5% by mass were prepared. An ink set 9 composed of yellow ink-1, magenta ink-1, cyan ink-1, black ink-1, light magenta ink-1, and light cyan ink-1 was prepared, and an ink jet printer PM-890C manufactured by Seiko Epson Corporation and The ink jet printer BJ F900 manufactured by Canon Inc. was set. Further, an image recording sample was prepared by using Photoike QP Photo Gloss Paper Thick DX manufactured by Konica as a recording medium, and the bleeding was evaluated, but it was found that almost no bleeding occurred.

Example 7 [Production of Recording Medium 5] In the production of recording medium 1,
Instead of the layer coating liquid, a mixed liquid of the fourth layer coating liquid and the following thermoplastic fine particle dispersion liquid (thermoplastic fine particles: inorganic pigment, after being mixed so that the solid content mass ratio is 45:55, the viscosity is A recording medium 5 was prepared in the same manner as the recording medium 1 except that (diluted with pure water so as to give 45 mPa · s) was used.

(Thermoplastic Fine Particle Dispersion) Styrene-acrylic latex polymer (Tg 78 ° C., average particle size 250 n) emulsion-polymerized using a nonionic surfactant as an emulsifier.
m, solid content concentration 40%) with a 6% nitric acid aqueous solution to a pH of 4.
It was adjusted to 7, and this was used as a thermoplastic fine particle dispersion. [Preparation of Image Recording Sample and Evaluation of Bleeding] In Example 1, the recording medium 1 was used as the recording medium 5, and the recording medium 5 after image recording was coated with silicone (KS-830E; Shin-Etsu Chemical Co., Ltd.) nickel belt. An image-recording sample was formed and bleeding was evaluated in the same manner as in Example 1 except that heating and pressing was performed by (heating roller temperature: 120 ° C.). It was found that bleeding was suppressed in the image recording sample formed using the ink for inkjet recording of the present invention.

Example 8 [Preparation of image recording samples 1'to 8 '] The ink receiving layer of image recording samples 1 to 8 prepared in Example 1 and the overcoat resin layer surface of the overcoat transfer sheet described below are overlaid and heated. Image recording samples 1'to 8'having a glossy overcoat layer surface by passing a pressure device to transfer the overcoat resin onto the image receiving sheet and peeling off the heat resistant film.
Was produced.

(Overcoat Transfer Sheet) A polyethylene glycol terephthalate film (E150 made by Diamond Foil) having a smooth surface with a thickness of 12 μm was used as a heat-resistant film, and Chemipearl (made by Mitsui Petrochemical, polyethylene aqueous solution) was used as a thermoplastic overcoat resin layer. Dispersion) 20 parts (solid content mass), polyvinyl alcohol adhesive 7 parts (solid content mass), 40 parts of water is applied to a coating liquid of 5 g / m ² (solid content mass) and dried. It was made. Bleeding Evaluation of Image Recording Samples 1 ′ to 8 ′ The bleeding evaluation was performed on the obtained image forming samples, and the bleeding was suppressed in the image recording samples formed using the inkjet recording ink of the present invention. I understood. This shows that the occurrence of bleeding can be suppressed by using the inkjet recording ink of the present invention even in the case where bleeding-prone processing such as laminating is performed on the image of the image recording sample. There is.

[0142]

INDUSTRIAL APPLICABILITY According to the present invention, an ink jet recording ink, an ink jet recording ink set and an ink jet recording ink or ink jet which can suppress nozzle clogging and further suppress bleeding to form a high quality ink jet image It was possible to provide an inkjet recording method using the recording ink set.

Continued front page    F-term (reference) 2C056 EA26 FC01                 2H086 BA05 BA15 BA35 BA52 BA62                 4J039 BC07 BC09 BC10 BE06 BE12                       CA03 EA15 EA16 EA17 EA19                       EA41 EA47 FA02 GA24

Claims (11)

[Claims] 1. An ink jet recording ink containing a water-soluble dye, water and a water-soluble organic solvent, wherein the content of the water-soluble organic solvent is 5 to 20% by mass, and 25 to 100% of the water-soluble organic solvent. An ink jet recording ink, characterized in that mass% is tripropylene glycol. 2. An inkjet recording ink containing a water-soluble dye, water and a water-soluble organic solvent, wherein the content of the water-soluble organic solvent is 5 to 20% by mass, and tripropylene glycol is used as the water-soluble organic solvent. An ink for inkjet recording comprising: and propylene glycol. 3. The ink for ink jet recording according to claim 2, wherein the total content of the tripropylene glycol and the propylene glycol in the water-soluble organic solvent is 50 to 100% by mass. 4. The glycerin content in the water-soluble organic solvent is 25% by mass or less.
4. The inkjet recording ink according to any one of 3 above. 5. At least a yellow ink jet recording ink, a magenta ink jet recording ink,
In an ink jet recording ink set having a cyan ink jet recording ink and a black ink jet recording ink, all of the ink jet recording inks are the ink jet recording inks according to any one of claims 1 to 4. Characteristic inkjet recording ink set. 6. An ink jet recording method according to claim 1, wherein the ink is used for recording on a recording medium having an ink receiving layer containing a water-soluble binder. An ink jet recording method comprising the ink set for ink jet recording according to claim 5. 7. The ink jet recording method according to claim 6, wherein the ink receiving layer has a porous structure. 8. The inkjet recording method according to claim 6, wherein a fixing process is performed on the recorded recording medium. 9. The ink jet recording method according to claim 6, wherein the recording is performed by an on-demand method. 10. The ink jet recording method according to claim 6, wherein recording is performed by ejecting the ink by an electromechanical conversion method. 11. The ink jet recording method according to claim 6, wherein recording is performed by ejecting the ink by an electric / heat conversion method.