JP2002264333A - Ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording method in which a high definition image can be formed stably even at the time of high speed driving. SOLUTION: In the ink jet recording method using a recording head having a nozzle for ejecting ink, the ink contains a color material, water and a water soluble organic solvent and has viscosity not lower than 5 mPa.s at 25 deg.C, the nozzle size is not larger than 30 μm, and the driving frequency of a voltage being applied to a recording head for ejection is not lower than 15 kHz.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording method for recording by discharging ink from a recording head.
In particular, the present invention relates to a high-speed inkjet recording method.

[0002]

2. Description of the Related Art Ink jet recording has become widespread as a method of obtaining a relatively inexpensive and high-quality output image. In recent years, in ink jet recording, high-speed printing has been desired from the market. For high-speed printing, it is necessary to drive the head at a high speed by applying a voltage at a high frequency such as 15 kHz. However, simply increasing the driving frequency has a problem in that a high-definition image cannot be stably formed due to a decrease in the flying speed of the ink, a variation in the ejection position of the ink, and the like.

[0003] JP-A-2000-351925 discloses that
A recording method using an ink containing a specific alkali-soluble resin, a nozzle diameter of 25 μm or less, and a driving frequency of 12 kHz or more has been disclosed. However, even if the ink disclosed herein is used, stability is still high. Is not enough.

The method disclosed in JP-A-5-64954 and the method disclosed in JP-A-5-119790 have a surface tension of 35 mN / m or less and a viscosity of 20 mP.
a.s or less ink, drive frequency 3kHz or more, 0.1
A method for ink-jet recording at μg / dot or less is described. However, these patents do not describe recording at a high frequency of 15 kHz or more, and these methods are insufficient for obtaining a high-speed and stable high-definition image.

[0005]

An object of the present invention is to provide an ink jet recording method capable of stably forming a high-definition image even at high speed driving.

[0006]

The above object of the present invention is achieved by the following constitution. (1) In an ink jet recording method for performing recording using a recording head having a nozzle for discharging ink, the ink contains a coloring material, water and a water-soluble organic solvent, and has a viscosity at 25 ° C of 5 mPa · s or more. , The nozzle diameter is 30μm
An ink jet recording method according to claim 1, wherein the driving frequency of the voltage applied to the recording head for discharging is 15 kHz or more. (2) The ink jet recording method according to (1), wherein the ink contains 35% by mass or more of a water-soluble organic solvent. (3) The ink contains 35 to 60 mass of a water-soluble organic solvent.
%. The inkjet recording method according to (2), wherein the content is in the range of 2%. (4) The inkjet recording method according to any one of (1) to (3), wherein the driving frequency is 20 kHz or more. (5) The inkjet recording method according to any one of (1) to (4), wherein the recording head is a piezo type recording head. (6) The ink jet recording method according to any one of (1) to (5), wherein the viscosity of the ink is 5 to 10 mPa · s. (7) The inkjet recording method according to any one of (1) to (6), wherein the drive frequency is 15 to 50 kHz. (8) The ink jet recording method according to any one of (1) to (7), wherein the amount of the discharged ink droplet is 9 pl / dot or less. (9) The ink jet recording method according to any one of (1) to (8), wherein the nozzle diameter is 25 μm or less. (10) The ink jet recording method according to any one of (1) to (9), wherein the coloring material is a water-soluble dye. (11) The color material is a pigment (1).
11. The ink jet recording method according to any one of claims 10 to 10. (12) The ink jet recording method according to any one of (1) to (11), wherein the ink contains ethylene glycol. (13) The inkjet recording method according to (12), wherein an ink containing 15% or more of ethylene glycol is used. (14) Ink jet recording according to (1) to (13), wherein at least three colors of ink of yellow, magenta, and cyan are used, and a plurality of inks of at least two colors having different dye concentrations are used. Method. (15) Printing is performed on paper or a recording medium having a void-type ink receiving layer on a support, (1) to (1).
4) The inkjet recording method according to the above. (16) The inkjet recording method according to any one of (1) to (15), wherein the water contained in the ink is ion-exchanged water. (17) The ink jet recording method according to any one of (1) to (16), wherein the nozzle has a diameter of 10 to 25 μm.

Hereinafter, the present invention will be described in detail. The ink used in the present invention contains a coloring material, a water-soluble organic solvent, and water,
Those having a viscosity at 25 ° C. of 5 mPa · s or more are used. If the viscosity is low, stable ejection cannot be performed during high-speed driving.

As the coloring material contained in the ink used in the present invention, conventionally known reactive dyes, acid dyes, direct dyes, disperse dyes and pigments can be used. Preferred reactive dyes for the present invention include C.I. I. Reactive Yellow 2, 3, 7, 15, 17, 18, 22, 23, 24, 2
5, 27, 37, 39, 42, 57, 69, 76, 8
1, 84, 85, 86, 87, 92, 95, 102, 1
05, 111, 125, 135, 136, 137, 14
2,143,145,151,160,161,16
5, 167, 168, 175, 176, C.I. I. Reactive Orange 1, 4, 5, 7, 11, 12, 13, 15, 16, 2,
0, 30, 35, 56, 64, 67, 69, 70, 7
2, 74, 82, 84, 86, 87, 91, 92, 9
3, 95, 107, C.I. I. Reactive Red 2,3,3: 1,5,8,11,21,22,23,2
4, 28, 29, 31, 33, 35, 43, 45, 4,
9, 55, 56, 58, 65, 66, 78, 83, 8
4, 106, 111, 112, 113, 114, 11
6, 120, 123, 124, 128, 130, 13
6, 141, 147, 158, 159, 171, 17
4, 180, 183, 184, 187, 190, 19
3, 194, 195, 198, 218, 220, 22
2, 223, 228, 235, C.I. I. Reactive Violet 1, 2, 4, 5, 6, 22, 23, 33, 36, 38, C.I. I. Reactive Blue 2,3,4,7,13,14,15,19,21,2
5, 27, 28, 29, 38, 39, 41, 49, 5,
0, 52, 63, 69, 71, 72, 77, 79, 8
9, 104, 109, 112, 113, 114, 11
6, 119, 120, 122, 137, 140, 14
3, 147, 160, 161, 162, 163, 16
8, 171, 176, 182, 184, 191, 19
4, 195, 198, 203, 204, 207, 20
9, 211, 214, 220, 221, 222, 23
1, 235, 236, C.I. I. Reactive Green 8, 12, 15, 19, 21, C.I. I. Reactive Brown 2, 7, 9, 10, 11, 17, 18, 19, 21, 2,
3, 31, 37, 43, 46, C.I. I. Reactive Black 5, 8, 13, 14, 31, 34, 39, and the like.

Preferred acid dyes for the present invention are C.I. I. Acid Yellow 1, 3, 11, 17, 18, 19, 23, 25, 36,
38, 40, 40: 1, 42, 44, 49, 59, 5
9: 1, 61, 65, 67, 72, 73, 79, 99,
104, 159, 169, 176, 184, 193, 2
00, 204, 207, 215, 219: 1, 220,
230, 232, 235, 241, 242, 246; I. Acid Orange 3, 7, 8, 10, 19, 24, 51, 51S, 56,
67, 74, 80, 86, 87, 88, 89, 94, 9
5, 107, 108, 116, 122, 127, 14
0, 142, 144, 149, 152, 156, 16
2, 166, 168, C.I. I. Acid Red 1, 6, 8, 9, 13, 18, 27, 35, 37, 5
2, 54, 57, 73, 82, 88, 97, 97: 1,
106, 111, 114, 118, 119, 127, 1
31, 138, 143, 145, 151, 183, 19
5, 198, 211, 215, 217, 225, 22
6, 249, 251, 254, 256, 257, 26
0, 261, 265, 266, 274, 276, 27
7,289,296,299,315,318,33
6, 337, 357, 359, 361, 362, 36
4, 366, 399, 407, 415; I. Acid Violet 17, 19, 21, 42, 43, 47, 48, 49, 5
4, 66, 78, 90, 97, 102, 109, 12
6, C.I. I. Acid Blue 1, 7, 9, 15, 23, 25, 40, 61: 1, 6
2, 72, 74, 80, 83, 90, 92, 103, 1,
04, 112, 113, 114, 120, 127, 12
7: 1, 128, 129, 138, 140, 142, 1
56, 158, 171, 182, 185, 193, 19
9, 201, 203, 204, 205, 207, 20
9, 220, 221, 224, 225, 229, 23
0, 239, 258, 260, 264, 277: 1, 2
78, 279, 280, 284, 290, 296, 29
8, 300, 317, 324, 333, 335, 33
8, 342, 350, C.I. I. Acid Green 9, 12, 16, 19, 20, 25, 27, 28, 4
0, 43, 56, 73, 81, 84, 104, 108,
109, C.I. I. Acid Brown 2, 4, 13, 14, 19, 28, 44, 123, 22
4, 226, 227, 248, 282, 283, 28
9, 294, 297, 298, 301, 355, 35
7, 413, C.I. I. Acid Black 1,2,3,24,24: 1,26,31,50,5
2, 52: 1, 58, 60, 63, 63S, 107, 1
09, 112, 119, 132, 140, 155, 17
2, 187, 188, 194, 207, 222 and the like.

Preferred direct dyes for the present invention are C.I. I. Direct Yellow 8, 9, 10, 11, 12, 22, 27, 28, 39,
44, 50, 58, 86, 87, 98, 105, 10
6, 130, 137, 142, 147, 153, C.I. I. Direct Orange 6, 26, 27, 34, 39, 40, 46, 102, 1
05, 107, 118, C.I. I. Direct Red 2, 4, 9, 23, 24, 31, 54, 62, 69, 7
9,80,81,83,84,89,95,212,2
24, 225, 226, 227, 239, 242, 24
3, 254, C.I. I. Direct Violet 9, 35, 51, 66, 94, 95, C.I. I. Direct Blue 1, 15, 71, 76, 77, 78, 80, 86, 8
7, 90, 98, 106, 108, 160, 168, 1
89, 192, 193, 199, 200, 201, 20
2, 203, 218, 225, 229, 237, 24
4,248,251,270,273,274,29
0, 291, C.I. I. Direct Green 26, 28, 59, 80, 85, C.I. I. Direct Brown 44, 44: 1, 106, 115, 195, 209, 2
10, 212: 1, 222, 223, C.I. I. Direct Black 17, 19, 22, 32, 51, 62, 108, 11
2, 113, 117, 118, 132, 146, 15
4, 159, 169 and the like.

The disperse dyes preferred in the present invention include C.I. I. Disperse Yellow 3, 4, 5, 7, 9, 13, 23, 24, 30, 33,
34, 42, 44, 49, 50, 51, 54, 56, 5
8, 60, 63, 64, 66, 68, 71, 74, 7
6, 79, 82, 83, 85, 86, 88, 90, 9
1, 93, 98, 99, 100, 104, 108, 11
4, 116, 118, 119, 122, 124, 12
6, 135, 140, 141, 149, 160, 16
2,163,164,165,179,180,18
2,183,184,186,192,198,19
9, 202, 204, 210, 211, 215, 21
6, 218, 224, 227, 231, 232; I. Disperse Orange 1,3,5,7,11,13,17,20,21,2
5, 29, 30, 31, 32, 33, 37, 38, 4
2, 43, 44, 45, 47, 48, 49, 50, 5,
3, 54, 55, 56, 57, 58, 59, 61, 6
6, 71, 73, 76, 78, 80, 89, 90, 9
1, 93, 96, 97, 119, 127, 130, 13
9, 142, C.I. I. Disperse Red 1, 4, 5, 7, 11, 12, 13, 15, 17, 2
7, 43, 44, 50, 52, 53, 54, 55, 5,
6, 58, 59, 60, 65, 72, 73, 74, 7
5, 76, 78, 81, 82, 86, 88, 90, 9
1, 92, 93, 96, 103, 105, 106, 10
7, 108, 110, 111, 113, 117, 11
8, 121, 122, 126, 127, 128, 13
1, 132, 134, 135, 137, 143, 14
5, 146, 151, 152, 153, 154, 15
7, 159, 164, 167, 169, 177, 17
9, 181, 183, 184, 185, 188, 18
9, 190, 191, 192, 200, 201, 20
2, 203, 205, 206, 207, 210, 22
1, 224, 225, 227, 229, 239, 24
0, 257, 258, 277, 278, 279, 28
1,288,298,302,303,310,31
1, 312, 320, 324, 328; I. Disperse Violet 1, 4, 8, 23, 26, 27, 28, 31, 33, 3
5, 36, 38, 40, 43, 46, 48, 50, 5
1, 52, 56, 57, 59, 61, 63, 69, 7
7, C.I. I. Disperse Green 9, C.I. I. Disperse Brown 1, 2, 4, 9, 13, 19, C.I. I. Disperse Blue 3, 7, 9, 14, 16, 19, 20, 26, 27, 3
5, 43, 44, 54, 55, 56, 58, 60, 6
2, 64, 71, 72, 73, 75, 79, 81, 8
2,83,87,91,93,94,95,96,10
2, 106, 108, 112, 113, 115, 11
8, 120, 122, 125, 128, 130, 13
9, 141, 142, 143, 146, 148, 14
9,153,154,158,165,167,17
1,173,174,176,181,183,18
5, 186, 187, 189, 197, 198, 20
0, 201, 205, 207, 211, 214, 22
4, 225, 257, 259, 267, 268, 27
0, 284, 285, 287, 288, 291, 29
3, 295, 297, 301, 315, 330, 33
3, C.I. I. Disperse Black 1, 3, 10, 24 and the like.

The pigments preferred in the present invention include carbon black and C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 16, 17, 43, 55,
74, 81, 83, 109, 110, 128 C.I. I. Pigment Orange 13, 16, 34, 43, C.I. I. Pigment Red 2, 5, 8, 12, 17, 22, 23, 41, 112,
114, 122, 123, 146, 148, 150, 1
66, 170, 220, 238, 245, 258, C.I. I. Pigment Violet 19, 23, C.I. I. Pigment Blue 15, 15: 1, 15: 3, 15: 5, 29, C.I. I. Pigment Green 7, 8, C.I. I. Pigment Brown 22, C.I. I. Pigment Black 1, 7, C.I. I. Pigment White 6 and the like.

The pigment used in the coloring material of the present invention includes:
Conventionally known organic and inorganic pigments can be used. For example, azo pigments such as azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc .; phthalocyanine pigments, perylene and perylene pigments; Cyclic pigments,
Dye lakes such as basic dye lakes and acid dye lakes; organic pigments such as nitro pigments, nitroso pigments, aniline black and daylight fluorescent pigments; and inorganic pigments such as carbon black.

The water-soluble organic solvent used in the present invention has a solubility in water of not less than 0.1% by mass (25 ° C.), preferably not less than 1%, particularly preferably not less than 5%.

The ink used in the present invention contains a water-soluble organic solvent, but preferably contains 35% by weight or more, and preferably contains 35% to 60% by weight of the ink when clogging of nozzles and after printing occur. It is preferable from the viewpoint of drying properties, bleeding, and the like.

The water-soluble organic solvent that can be used in the present invention includes alcohols (eg, methanol, ethanol,
1-propanol, 2-propanol, n-butanol, i-butanol, sec-butanol, tert-
Butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol, etc.), 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, etc.), polyhydric alcohol ethers (for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol mono) Phenyl 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, triethylene glycol monomethyl ether, triethylene glycol Monoethyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, dipropylene glycol monopropyl ether, tripropylene glycol dimethyl ether, etc.), amines (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-dimethylformamide, 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), sulfones (eg, sulfolane), sulfonates (For example, 1-butanesulfonic acid sodium salt), urea, acetonitrile, acetone and the like. Among the above-mentioned organic solvents, preferred ones as a result of various studies are ethylene glycol,
Diethylene glycol, triethylene glycol, glycerin, triethylene glycol mono-n-butyl ether, propylene glycol, ethylene glycol monobutyl ether, triethylene glycol mono-n-methyl ether, triethylene glycol mono-n-ethyl ether, triethylene glycol mono- n-isopropyl ether. Two or more of these organic solvents may be used in combination. Among these organic solvents, those containing ethylene glycol are particularly preferable, and those containing 15% by mass or more are particularly preferable. Further, those containing ethylene glycol and propylene glycol are more preferable.

To adjust the viscosity of the ink to 5 mPa · s or more, a viscosity modifier is added to adjust the viscosity. Examples of the viscosity modifier include a polymer and an organic solvent. Examples of the polymer include polyvinyl alcohol, polyvinyl pyrrolidone, polystyrene, and polyethylene glycol (# 20).
0) and the like, but are not limited thereto. As the organic solvent, those listed above can be used. Preferred examples include polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, and diethylene glycol.

The ink may be a known inorganic salt, a surfactant,
A pH adjuster, a hydrotrope, a dispersant, and the like may be included as necessary. An inorganic salt may be added to the ink in order to stabilize the viscosity and dye of the ink and improve the color development. Examples of the inorganic salt include sodium chloride, sodium sulfate, magnesium chloride, magnesium sulfide and the like.

As the surfactant, any of cationic, anionic, amphoteric and nonionic can be used.
Examples of the cationic surfactant include an aliphatic amine salt, an aliphatic quaternary ammonium salt, a benzalkonium salt, a benzethonium chloride, a pyridinium salt, an imidazolinium salt and the like.

Examples of the anionic surfactant include fatty acid soap, N-acyl-N-methylglycine salt, N-acyl-
N-methyl-β-alanine salt, N-acyl glutamate, alkyl ether carboxylate, acylated peptide, alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, dialkyl sulfosuccinate, alkyl sulfo Acetate, α-olefin sulfonate, N-acylmethyltaurine, sulfated oil, higher alcohol sulfate, secondary higher alcohol sulfate, alkyl ether sulfate, secondary higher alcohol ethoxy sulfate, polyoxy Examples include ethylene alkyl phenyl ether sulfate, monoglycol sulfate, fatty acid alkylolamide sulfate, alkyl ether phosphate, alkyl phosphate, and the like.

Examples of the amphoteric surfactant include a carboxybetaine type, a sulfobetaine type, an aminocarboxylate, and imidazolinium betaine. Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene secondary alcohol ether, polyoxyethylene alkyl phenyl ether (for example, Emulgen 911), polyoxyethylene sterol ether, polyoxyethylene lanolin derivative, polyoxyethylene Polyoxypropylene alkyl ether (for example, Newpol PE-62), polyoxyethylene glycerin fatty acid ester, polyoxyethylene castor oil, hydrogenated castor oil, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyethylene glycol fatty acid ester, Fatty acid monoglyceride, polyglycerin fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, ® sugar fatty acid esters, fatty acid alkanolamides, polyoxyethylene fatty acid amides, polyoxyethylene alkyl amines, alkyl amine oxides, acetylene glycol, acetylene alcohol, and the like.

When these surfactants are used, they can be used alone or as a mixture of two or more kinds. By adding in the range of 0.001 to 1.0% with respect to the total amount of the ink, the The surface tension can be adjusted arbitrarily.

In order to maintain the long-term storage stability of the ink, a preservative and a fungicide may be added to the ink. As preservatives and fungicides, aromatic halogen compounds (for example, Preven)
tol CMK (manufactured by Bayer AG)), methylene dithiocyanate, a halogen-containing sulfur compound, 1,2-benzisothiazolin-3-one (for example, PROXEL GX
L (manufactured by Zeneca)) and the like. The present invention is not limited to these embodiments.

To keep the dye in the ink stable, a pH adjuster may be added to the ink. As the pH adjuster, hydrochloric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide, or the like can be diluted with water or the like, or used as it is. The present invention is not limited to these embodiments.

A hydrotrope may be added to the ink so that the ink near the nozzle does not dry. Urea and urea derivatives are preferred as the hydrotrope agent. In the ink used in the present invention, for example, a water-insoluble dye such as a disperse dye or a pigment can be dispersed by mixing a dye, a dispersant, a medium, and optional additives and using a disperser. As the disperser, a conventionally known ball mill, sand mill, line mill, high-pressure homogenizer and the like can be used.

Preferred examples of the dispersant include, for example, a formalin condensate of sodium creosote oil sulfonate (eg, Demol C), a formalin condensate of sodium cresol sulfonate and sodium 2-naphthol-6-sulfonate, Formalin condensate of sodium cresolsulfonate, formalin condensate of sodium phenolsulfonate, formalin condensate of sodium β-naphtholsulfonate, formalin condensate of sodium β-naphthalenesulfonate (eg, Demol N) and lignin Sulfonates (for example, Vanillex RN) and the like. As a polymer dispersant, styrene / acrylic acid copolymer,
Styrene / acrylic acid / acrylate copolymer,
Styrene / methacrylic acid copolymer, styrene / methacrylic acid / acrylic acid ester copolymer, styrene / maleic acid copolymer, styrene / maleic acid / acrylic acid ester copolymer, polyvinyl alcohol and the like can be mentioned.

The use amount of the dispersant is preferably 20 to 200% based on the disperse dye or pigment. If the amount of the dispersing agent is too small, the particle size and the dispersion stability are poor. These dispersants may be used alone or in combination.

Preferred wetting agents for the dispersion of the present invention include sodium dodecylbenzenesulfonate, sodium 2-ethylhexylsulfosuccinate, sodium alkylnaphthalenesulfonate, ethylene oxide adduct of phenol, and ethylene oxide adduct of acetylene diol. It is.

Depending on the structure of the disperse dye or pigment to be used, foaming, gelling, or poor fluidity may occur during dispersion. In addition to the properties, it is necessary to select in consideration of foaming during dispersion, gelation of the dispersion, fluidity of the dispersion, and the like.

The nozzle of the recording head used in the present invention has a nozzle diameter of 25 μm or less. The nozzle diameter means the diameter when the cross section of the nozzle hole is circular, and the diameter when the cross section area of the nozzle hole is circular when the cross section is not circular. The nozzle surface is preferably subjected to a water-repellent treatment.

In the present invention, the frequency of the voltage applied to the recording head (hereinafter also referred to as the driving frequency) is 15 kHz,
20 kHz or more is preferable. Particularly, a range of 20 to 50 kHz is preferable, and a range of 20 to 35 kHz is particularly preferable.

The ink jet system is roughly classified into a continuous system and a drop-on-demand system. The present invention can be applied to the drop-on-demand system. Further, the drop-on-demand method includes an electric-heat conversion method, an electro-mechanical conversion method, and the like as a method of discharging ink. The present invention may be any method, but is effective for the electro-mechanical conversion method. The piezo type recording head means a recording head using an electro-mechanical conversion element (piezo element). In the present invention, the effect of the present invention is particularly great when a piezo type recording head is used.

[0033]

EXAMPLES Specific examples of the present invention will be described below, but the present invention is not limited to these examples.

<Manufacture of Head> A recording head used in the present invention shown in FIGS. 1 and 2 will be described. Lower substrate 1b and upper substrate 1 made of lead zirconate titanate which is a piezoelectric material
c is formed by bonding with an adhesive 6. Lower Substrate The lower substrate and the upper substrate are polarized in opposite directions as indicated by the arrows in FIG. A plurality of elongated grooves are formed over the upper substrate and the lower substrate. This forms a plurality of parallel partitions and grooves.

The electrodes 3 are provided on the inner surfaces of the plurality of grooves by plating. After the electrode 3 is attached to the groove 2, a part of the upper surface of the substrate 1 is stepped to form a stepped portion 35. The surface of the electrode film 3 is coated with an insulating film 17 such as parylene,
Is subjected to a hydrophilic treatment by an oxygen plasma treatment.

The lid 8 is adhered to the upper surface of the partition wall 4 with the adhesive 6, and the sealing piece 25 is attached to the end surface of the partition wall 4 with the adhesive. A nozzle plate 10 having a nozzle hole 11 (nozzle diameter shown in the following example) is bonded to the end face of the groove 2 with the same adhesive 6, and the ink chambers 9 are provided every other groove 2. To form The nozzle holes are provided corresponding to each ink chamber, that is, provided every other nozzle corresponding to the groove 2. The common groove 5 is carved in the upper part of the lid 8, and a hole 12 for communicating with each ink chamber is provided. Every other groove 2 has both a nozzle hole 11 and a communication hole 12. An upper plate 14 having an ink supply hole 15 is bonded to the upper portion of the lid 8 with an adhesive 6 so as to cover the upper portion of the common groove 5.

Each of the electrode films is connected to the lead wiring 7 exposed at the step 35 of the lid 8. A lid plate is adhered to the upper part of the partition wall with an adhesive.

The ink is supplied from the ink supply holes 15 to fill the ink chambers 2a formed in every other one of the parallel grooves 2 in FIGS. No ink is supplied to the adjacent dummy grooves 9 '.

When an electric signal is sent to the lead line 7 and a driving voltage is applied between the electrode film of the ink chamber 2a and the electrode films of the dummy grooves on both sides thereof so that the potential of the electrode film of the ink chamber becomes high, the ink is applied. When the partition walls on both sides of the chamber 2a are deformed inward, the ink chamber contracts and discharges ink, and subsequently the ink chamber electrode film is grounded, there is no deformation and the ink chamber is filled with ink again. The adhesive used was a combination of an epoxy resin and a curing agent.

Example 1 An ink having the following composition was prepared. Ink A CI Direct Yellow 86 3 parts by weight Ethylene glycol 20 parts by weight Propylene glycol 20 parts by weight Glycerin 3 parts by weight Proxel GXL (manufactured by Zeneca) 0.2 parts by weight Deionized water 54 parts by weight The viscosity of this ink at 25 ° C is 5.5 mPa.・ It was s.

The ink prepared as described above is used at a driving frequency of 20.
A continuous discharge test and an intermittent discharge test are performed using the piezo-type recording head with a nozzle diameter of 25 μm at a driving voltage of 8 V at kHz,
The ink ejection was evaluated for bending (displacement in the ink ejection direction) and ejection failure (no ink was ejected). Table 1 shows the results. Regarding the bending of the ink ejection, the ejection state was observed by synchronizing the ejection and the emission with an observation device of a strobe light emission system. At this time, those having a deviation of 3 degrees or more from the perpendicular direction with respect to the nozzle plate were determined to be bent. In addition, observation was performed 1 after the start of continuous ejection.
Minutes later. A sample with a bend was evaluated as x, and a sample with no bend was evaluated as ○. Regarding the ejection failure, the ejection was continued under the above conditions and observed one hour later.

Examples 2 to 7 Inks B to G having the following compositions were prepared. Table 1 shows the results of continuous discharge and intermittent discharge tests performed under the discharge conditions shown in Table 1.

Ink B CI Direct Blue 199 2.0 parts by weight Ethylene glycol 20 parts by weight Diethylene glycol 15 parts by weight Surfynol 465 0.2 parts by weight Preventol CMK 0.2 parts by weight (manufactured by Bayer) Ion-exchange water 63 parts by weight (viscosity 5.6 mPa · s) Ink C CI Direct Black 154 2.5 parts by weight Ethylene glycol 16 parts by weight Triethylene glycol monobutyl ether 10 parts by weight 2-pyrrolidone 20 parts by weight Surfynol 465 0.3 parts by weight Proxel GXL 0.2 parts by weight Ion exchange water 51.5 parts by weight (viscosity 5.1 mPa)・ S) Ink D CI Acid Red 52 3.0 parts by weight Ethylene glycol 20 parts by weight 2-Pyrrolidone 30 parts by weight Preventol CMK 0.2 parts by weight Ion-exchanged water 47 parts by weight (viscosity 6.1 mPa · s) Ink E CI Acid Yellow 23 3.0 parts by weight Parts ethylene glycol 25 parts by weight glycerin 10 parts by weight N-methylpyrrolide 8 parts by weight Proxel GXL 0.2 parts by weight Deionized water 54 parts by weight (viscosity 5.9 mPa · s) Ink F Food Black 2 3.0 parts by weight Diethylene glycol 35 parts by weight Glycerin 13 parts by weight Proxel GXL 0.2 parts by weight Deionized water 49 parts by weight (viscosity 7.3 mPa · s) Ink G CI Pigment Yellow 74 3.5 parts by weight Ethylene glycol 30 parts by weight Glycerin 14 parts by weight Proxel GXL 0.2 parts by weight Deionized water 53.5 parts by weight (viscosity 5.9 mPa · s) Comparative Example 1 An ink having the following composition was used. Created. (Ink described in Example 2-6 of JP-A-5-64954) Ink H Direct Black 154 2.0% Polyethylene glycol 1500 10.0% Surfynol 465 1.0% Urea 1.0% Deionized water 86.0% (viscosity 4.9 mPa · s) Ejection was performed at a drive frequency of 25 kHz using a head having a nozzle diameter of 20 μm. Table 1 shows the results.

Comparative Example 2 Evaluation was performed in the same manner as in Example 6 except that a recording head having a nozzle diameter of 60 μm was used. Table 1 shows the results.

[0045]

[Table 1]

Example 8 Preparation of Pigment Dispersion (Dispersion 1) CI Pigment Yellow 128 150 g Styrene-acrylic acid-acrylate copolymer (molecular weight 9000, acid value 150) 70 g ethylene glycol 200 g glycerin 80 g ion-exchanged water 300 g Was mixed and dispersed using a horizontal bead mill (System Zeta Mini manufactured by Ashizawa Co., Ltd.) filled with 0.3 mm zirconia beads at a volume ratio of 70%, and then centrifuged at 20,000 rpm for 30 minutes to obtain a pigment having an average particle size of 85 nm. A dispersion was obtained. (Adjustment of Dispersions 2 to 5) Dispersions 2 to 5 were prepared in the same manner as in the preparation of Dispersion 1 except that the pigment was replaced with the following. Dispersion 2: CI Pigment Yellow 74 Dispersion 3: CI Pigment Red 122 Dispersion 4: CI Pigment Blue 15: 3 Dispersion 5: Carbon Black Ink Preparation Ink J (Yellow Ink 1) Dispersion 1 (Pigment concentration 19% 18 parts by weight Ethylene glycol 30 parts by weight Glycerin 14 parts by weight Proxel GXL 0.2 parts by weight Deionized water 38 parts by weight (viscosity 5.9 mPa · s) Ink K (yellow ink 2) Dispersion 2 (pigment concentration 19%) 18 parts by weight Ethylene glycol 30 parts by weight Glycerin 14 parts by weight Proxel GXL 0.2 parts by weight Ion-exchanged water 38 parts by weight (viscosity 6.0 mPa · s) Ink L (magenta ink 1) Dispersion 3 (pigment concentration 19%) 18 parts by weight Ethylene glycol 30 parts by weight Parts Glycerin 14 parts by weight Proxel GXL 0.2 parts by weight Deionized water 38 parts by weight (viscosity 5.8 mPa · s) Ink M (magenta ink 2) Dispersion 3 (pigment concentration 19%) 4 parts by weight Ethylene glycol 35 parts by weight Glycerin 16 parts by weight Proxel GXL 0.2 parts by weight Deionized water 45 parts by weight (viscosity 5.7 mPa · s) Ink N (cyan ink 1) Dispersion 4 (pigment concentration 19%) 18 parts by weight Ethylene Glycol 30 parts by weight Glycerin 14 parts by weight Proxel GXL 0.2 parts by weight Deionized water 38 parts by weight (viscosity 5.7 mPa · s) Ink O (cyan ink 2) Dispersion 4 (pigment concentration 19%) 4 parts by weight Ethylene glycol 35 parts by weight Glycerin 16 parts by weight Proxel GXL 0.2 parts by weight Deionized water 45 parts by weight (viscosity 5.6 mPa · s) Ink P (black ink) Dispersion 4 (pigment concentration 19%) 18 parts by weight Ethylene glycol 30 parts by weight Glycerin 14 parts by weight Proxel GXL 0.2 parts by weight Deionized water 38 parts by weight (viscosity 5.8 mPa · s) Nozzle diameter 25 μm, driving frequency 35 with 256 nozzle head for each color
As a result of performing a printing test on PhotoJet Paper QP-PRO manufactured by Konica Corporation with the above-mentioned inks J to P installed in a printer of kHz, the ink ejection of each color was the same as in the above embodiment, and the ink ejection did not bend and the ejection failure did not occur. An image of high quality was obtained.

[0047]

As is clear from the above, according to the present invention,
High-definition images can be formed stably even at high speed driving.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a part of a recording head used in the present invention.

FIG. 2 is a schematic view showing a part of a recording head used in the present invention.

[Explanation of symbols]

 1 substrate 2 groove 2a ink chamber 3 electrode 6 adhesive 8 lid 9 'dummy groove 14 upper plate 15 ink supply hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 11/00 F-term (Reference) 2C056 EA01 EC07 EC42 FA04 FC02 HA05 2C057 AF01 AG12 AG45 AM16 AP02 AP25 AP59 AP60 BA03 BA14 2H086 BA02 BA03 BA52 BA53 BA59 BA61 BA62 4J039 AD03 AD06 AD23 AE07 BA04 BC07 BC09 BC10 BC11 BC13 BC14 BC15 BC33 BC35 BC36 BC53 BE01 BE03 BE04 BE06 BE08 BE12 BE23 CA03 CA06 EA44 EA48 GA24

Claims (13)

[Claims] An ink jet recording method for performing recording using a recording head having a nozzle for discharging ink, wherein the ink contains a coloring material, water and a water-soluble organic solvent,
An ink jet recording method, wherein the viscosity at 25 ° C. is 5 mPa · s or more, the diameter of the nozzle is 30 μm or less, and the driving frequency of the voltage applied to the recording head for discharging is 15 kHz or more. 2. The ink jet recording method according to claim 1, wherein the ink contains a water-soluble organic solvent in an amount of 35% by mass or more. 3. The ink according to claim 1, wherein the water-soluble organic solvent is 35 to 6 times.
3. The ink jet recording method according to claim 2, wherein the content is in the range of 0% by mass. 4. The ink jet recording method according to claim 1, wherein said driving frequency is 20 kHz or more. 5. The ink jet recording method according to claim 1, wherein said recording head is a piezo type recording head. 6. The ink jet recording method according to claim 1, wherein the viscosity of the ink is 5 to 10 mPa · s. 7. The ink jet recording method according to claim 1, wherein said driving frequency is 15 to 50 kHz. 8. The ink jet recording method according to claim 1, wherein the amount of the ejected ink droplet is 9 pl / dot or less. 9. The ink jet recording method according to claim 1, wherein said nozzle diameter is 25 μm or less. 10. The ink jet recording method according to claim 1, wherein said color material is a water-soluble dye. 11. The ink jet recording method according to claim 1, wherein said color material is a pigment. 12. The ink jet recording method according to claim 1, wherein said ink contains ethylene glycol. 13. The ink jet recording method according to claim 12, wherein an ink containing 15% or more of ethylene glycol is used.