JP2002355958A - Ink jet recording method and ink set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording method in which ejection stability can be improved without shortening the lifetime of a head in a high speed printer. SOLUTION: The ink jet recording method uses an aqueous ink containing 10-50% by mass of a coloring agent and a water soluble organic solvent, more specifically, containing 0-15% by mass of a water soluble organic solvent having the inorganic/organic ratio of 0.5-2.4 and a water soluble organic solvent having the inorganic/organic ratio of 2.5-5.0 for all liquid media wherein the driving frequency of a recording head is not lower than 15 kHz and epoxy resin is used as the adhesive of the ink channel and the nozzle plate of the recording head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink jet recording method (hereinafter, also simply referred to as a recording method) and an ink set.

[0002]

2. Description of the Related Art In recent years, the progress of ink jet recording technology has been remarkable, and high-definition images very similar to photographs have been obtained.

As a result, ink jet recording has come to be used in many fields.

Accordingly, it has been desired to improve the printing speed in addition to obtaining a high-definition image. In order to improve the printing speed, there are a method of increasing the number of nozzles of the head and a method of discharging a large number of ink droplets per unit time of one head. However, simply increasing the number of nozzles increases the cost of the printer. It is undesired to increase. In order to increase the printing speed without increasing the cost, a large number of ink droplets must be ejected per unit time.

Therefore, a driving frequency of 15 kHz or more is desired. With the high-frequency driving and the improvement of the scanning speed of the carriage accompanying such high-speed printing, ink ejection tends to be unstable. When the ejection of the ink becomes unstable, the image density is reduced, and streak-like unevenness is caused, thereby deteriorating the image quality.

Various reasons can be considered as causes of unstable ejection. First, defective refilling, drying of nozzles, secondly, presence of bubbles in the head, non-uniformity of ink, and deterioration of bonded portions. It is difficult to specify because of such factors.

As a method for improving the light fastness and bleeding of an ink jet image, an ink using a pigment instead of an ink using a dye attracts attention. If a large amount of undissolved components such as pigments are contained in the ink, the ejection of the ink becomes unstable. It has been found that these insolubles become resistance at the time of ink ejection and deteriorate the bonding portion of the head.

It is known that the adhesive portion of the head swells with water. Therefore, the use of a material that does not easily swell in water has been studied for the adhesive. On the other hand, it is effective to add a high-boiling water-soluble organic solvent to the ink in order to improve the instability of ejection by drying the nozzle. However, it has been found that, even with an adhesive that does not easily swell in water, a water-soluble solvent having a high organic property tends to swell the adhesive of the head more than water, and deteriorates the adhesive portion of the head. Furthermore, by driving the head at a high frequency,
It has been found that the force applied to the head also increases, and in particular, deteriorates the bonded portion.

When the adhesive of the head is deteriorated, the ink leaks out of the head and printing cannot be performed, thereby shortening the life of the head.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording method capable of improving ejection stability without shortening the life of a head in a high-speed printer, and an ink set suitable for the method. is there.

[0011]

The above object of the present invention is attained by the following constitutions.

(1) An aqueous ink containing 10 to 50% by mass of a coloring agent and a water-soluble organic solvent in the ink,
The inorganic / organic ratio is 0.5 to 2.4 with respect to the total liquid medium.
0 to 15% by mass of a water-soluble organic solvent having an inorganic / organic ratio of 2.5 to 5.0.
An ink-jet recording method using an ink containing 1% by mass, a driving frequency of a recording head is 15 kHz or more, and an adhesive for an ink flow path of the recording head and a nozzle plate is an epoxy resin.

(2) The content of the water-soluble organic solvent having an inorganic / organic ratio of 0.5 to 2.4 with respect to the whole liquid medium is 1
The ink jet recording method according to (1), wherein the amount is from 8 to 8% by mass.

(3) The ink jet recording method according to (1) or (2), wherein the colorant is a pigment.

(4) The surface tension of the ink is 3.0 × 10 ^-4
The ink-jet recording method according to any one of (1) to (3), wherein the ink-jet recording method is from 4.0 to 10 × 10 ⁻⁴ N / cm.

(5) The pigment has an average particle size of 10 to 200 nm.
The inkjet recording method according to (3) or (4), wherein

(6) 400 nm in the particle size distribution of the pigment
The ink jet recording method according to any one of (1) to (5), wherein the mass of the particles having the above particle diameters is 2% or less of the whole pigment.

(7) Any one of (1) to (6), wherein the aqueous ink contains an anionic surfactant.
Item 6. The ink jet recording method according to item 1.

(8) The method according to any one of (3) to (6), wherein the water-soluble polymer dispersant is contained in an amount of 0.1 to 1.0 part by mass based on 1 part by mass of the pigment. The ink-jet recording method as described above.

(9) The ink jet recording method according to any one of (1) to (9), wherein the water absorption of the adhesive is 2% or less.

(10) An ink set, wherein a multicolor set is formed by combining an ink and a recording head used in the ink jet recording method according to any one of (1) to (9).

(11) The ink set according to (10), wherein the multicolor set is a combination including three colors of yellow, magenta and cyan.

Hereinafter, the present invention will be described in more detail. In the present invention, the member that comes into contact with the ink refers to all members that come into contact with the ink, such as a path through which the ink flows (an ink flow path) and a member that forms an ink ejection port (eg, a nozzle plate). In the case where at least a part of the members in contact with these inks is a recording head having a laminated structure, when an epoxy resin is used as the adhesive, the properties and the amount of the organic solvent in the ink composition are determined. By using a specific combination, it is possible to obtain ejection stability without shortening the life of the head in a high-speed printer.

That is, the ink jet recording method of the present invention is an aqueous ink containing 1 to 20% by mass of a coloring agent and 10 to 50% by mass of a water-soluble organic solvent in the ink, and , The inorganic / organic ratio is 0.5 to
The content of the water-soluble organic solvent of 2.4 is 0 to 15% by mass, and the content of the water-soluble organic solvent having an inorganic / organic ratio of 2.5 to 5.0 is 5 to 50% by mass. Using ink, the driving frequency of the recording head is 15 kHz or more,
The adhesive for the ink flow path of the recording head and the nozzle plate is an epoxy resin.

Further, the present invention is preferably an ink wherein the content of a water-soluble organic solvent having an inorganic / organic ratio of 0.5 to 2.4 is 1 to 8% by mass. It is preferable that the content of the water-soluble organic solvent having a water / organic ratio of 2.5 to 5.0 is 5 to 30% by mass.

Here, the organic value is the sum of the values of the individual substituents calculated on the basis of carbon, with the value of one carbon atom being set to 20, and is obtained as follows.

Organic value = 20 × (number of carbon atoms constituting a molecule) + sum of organic values of substituents Inorganicity is defined as the individual substitution calculated on the basis of OH with OH being 100. It is the sum of the values of the bases and is obtained as follows.

Inorganic value = sum of the inorganic values of the substituents The ratio of the inorganic value and the organic value obtained in this manner is expressed as the inorganic / organic ratio in the present invention.

These inorganic and organic properties are specifically defined in "Organic Conceptual Diagram" by Yoshio Koda, Sankyo Shuppan 1985, and the calculation method is also described in the Sankyo Shuppan 1985.
It is described in.

The following are examples of the water-soluble organic solvent of the present invention. Inorganic / organic ratio Glycerin (GR) 5.0 Ethylene glycol (EG) 5.0 Propylene glycol (PG) 3.3 Diethylene glycol (DEG) 2.8 1,2-pentanediol (PD) 2.0 Dipropylene Glycol (DPG) 1.8 ethylene glycol monomethyl ether (EGMM) 2.0 ethylene glycol monoethyl ether (EGME) 1.5 diethylene glycol monobutyl ether (DGBE) 0.9 triethylene glycol monobutyl ether (TGBE) 0.8 In the present invention, alcohols (e.g., methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol, cyclo Xanol, benzyl alcohol, etc.), polyhydric alcohols (eg, thiodiglycol), polyhydric alcohol ethers (eg, ethylene glycol monoethyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol) Dimethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether,
Triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, tripropylene glycol dimethyl ether, etc.), amines (for example, 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) , Heterocycles (for example, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, 2-oxazolidone, 1,3-
Dimethyl-2-imidazolidinone), sulfoxides (eg, dimethyl sulfoxide), acetonitrile, acetone and the like can also be used.

The adhesive for the ink flow path and the nozzle plate of the recording head of the present invention is an epoxy adhesive, and a combination of an epoxy resin and a curing agent is preferably used in terms of adhesive strength.

Preferred examples of the epoxy resin include the following specific examples.

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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Preferred specific examples of the curing agent include the following.

[0040]

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[0041]

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[0042]

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[0043]

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In the present invention, the ink contains a colorant that can be dispersed or dissolved in water. Examples of such coloring agents include pigments, acid dyes, direct dyes, basic dyes, reactive dyes, and food dyes.
Among these, pigments or acidic dyes are preferred from the viewpoint of gloss and image storability, and pigments are particularly preferred.

As the dye that can be used in the present invention, conventionally known dyes can be used. The following are representative dyes, but the present invention is not limited thereto.

<Direct Dye> C.I. I. Direct Yellow 1, 4, 8, 11, 12, 24, 26, 27, 28, 3
3, 39, 44, 50, 58, 85, 86, 100, 1,
10, 120, 132, 142, 144, C.I. I. Direct Red 1,2,4,9,11,13,17,2
0, 23, 24, 28, 31, 33, 37, 39, 4
4, 47, 48, 51, 62, 63, 75, 79, 8
0, 81, 83, 89, 90, 94, 95, 99, 22
0, 224, 227, 243, C.I. I. Direct Blue 1, 2, 6, 8, 15, 22, 25, 71, 76, 7
8, 80, 86, 87, 90, 98, 106, 108,
120, 123, 163, 165, 192, 193, 1
94, 195, 196, 199, 200, 201, 20
2, 203, 207, 236, 237, C.I. I. Direct Black 2, 3, 7, 17, 19, 22, 32, 3
8, 51, 56, 62, 71, 74, 75, 77, 10
5, 108, 112, 117, 154, <Acid dye> C.I. I. Acid Yellow 2, 3, 7, 1
7, 19, 23, 25, 29, 38, 42, 49, 5
9, 61, 72, 99, C.I. I. Acid Orange 5
6, 64, C.I. I. Acid Red 1, 8, 14, 1
8, 26, 32, 37, 42, 52, 57, 72, 7
4, 80, 87, 115, 119, 131, 133, 1
34, 143, 154, 186, 249, 254, 25
6, C.I. I. Acid Violet 11, 34, 75,
C. I. Acid Blue 1, 7, 9, 29, 87, 12
6, 138, 171, 175, 183, 234, 23
6, 249, C.I. I. Acid Green 9, 12, 1
9, 27, 41, C.I. I. Acid Black 1, 2,
7, 24, 26, 48, 52, 58, 60, 94, 10
7, 109, 110, 119, 131, 155, <Reactive dye> I. Reactive Yellow 1, 2, 3, 13, 1
4, 15, 17, 37, 42, 76, 95, 168, 1
75, C.I. I. Reactive Red 2, 6, 11, 2
1, 22, 23, 24, 33, 45, 111, 112,
114, 180, 218, 226, 228, 235,
C. I. Reactive Blue 7, 14, 15, 18, 1
9, 21, 25, 38, 49, 72, 77, 176, 2
03, 220, 230, 235, C.I. I. Reactive Orange 5, 12, 13, 35, 95, C.I. I. Reactive Brown 7, 11, 33, 37, 46, C.I. I.
Reactive Green 8, 19, C.I. I. Reactive violet 2, 4, 6, 8, 21, 22, 25, C.I.
I. Reactive Black 5, 8, 31, 39 <Basic dye> C.I. I. Basic Yellow 11, 14, 21, 32 C.I. I. Basic Red 1, 2, 9, 12, 13 C.I. I. Basic violet 3, 7, 14 C.I. I. Basic Blue 3, 9, 24, 25 Other dyes that can be used in the ink of the present invention include chelate dyes and azo dyes used in so-called silver dye bleaching light-sensitive materials (for example, Cibachrome manufactured by Ciba Geigy). I can do it.

Chelating dyes are described, for example, in British Patent 1,077,484.

Regarding the azo dye of the silver dye bleaching photosensitive material, for example, British Patents 1,039,458 and 1.00
Nos. 4,957 and 1,077,628; U.S. Pat.
No. 612,448.

As the pigment that can be used in the present invention, 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, phthalocyanine pigments, perylene and perylene pigments, anthraquinone pigments, quinacridone pigments,
Polycyclic pigments such as dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthaloni pigments, dye lakes such as basic dye lakes and acid dye lakes, nitro pigments, nitroso pigments, aniline black, daylight fluorescent Organic pigments such as pigments and inorganic pigments such as carbon black are exemplified.

Specific examples of the organic pigment are shown below. Pigments for magenta or red include C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I.
I. Pigment Red 7, C.I. I. Pigment Red 1
5, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 53:
1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 12
3, C.I. I. Pigment Red 139, C.I. I. Pigment red 144, C.I. I. Pigment Red 149,
C. I. Pigment Red 166, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I.
I. Pigment Red 222 and the like.

Examples of orange or yellow pigments include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 12,
C. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I.
I. Pigment Yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment Yellow 93, C.I. I.
Pigment Yellow 94, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 138 and the like.

Examples of the green or cyan pigments include:
C. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3,
C. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

In order to disperse these pigments in the ink solvent, it is preferable to use a water-soluble polymer dispersant. As the water-soluble polymer dispersant, the following water-soluble resins can be used. Preferred from a viewpoint.

As the water-soluble resin, styrene-acrylic acid-alkyl acrylate copolymer, styrene-acrylic acid copolymer, styrene-maleic acid copolymer, styrene-maleic acid-alkyl acrylate are preferably used. Ester copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid It is a water-soluble resin such as a copolymer.

The content of the water-soluble resin with respect to the total amount of the ink is preferably from 0.1 to 10% by mass, and more preferably from 0.3 to 5% by mass.

These water-soluble resins can be used in combination of two or more. The content of the colorant that can be dispersed or dissolved in water used in the ink of the present invention is preferably 1 to 10% by mass based on the total mass of the ink.

As a method for dispersing the pigment, various methods such as a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, and a paint shaker can be used.

It is also preferable to use a centrifugal separator or a filter for the purpose of removing coarse particles of the pigment dispersion of the present invention.

The average particle size of the pigment in the present invention represents a number average particle size. The particle size distribution was determined by observing an electron micrograph.

The mass% of the particles having a particle diameter of 400 nm or more was determined by multiplying the frequency of the particle diameter distribution by the cube of the particle diameter.

In the present invention, the ink may contain a surfactant. Surfactants preferably used in the ink of the present invention include anionic surfactants such as dialkyl sulfosuccinates, alkyl naphthalene sulfonates, and fatty acid salts, polyoxyethylene alkyl ethers, and polyoxyethylene alkyl allyl ethers. ,
Examples include nonionic surfactants such as acetylene glycols and polyoxyethylene / polyoxypropylene block copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. In particular, an anionic surfactant can be preferably used.

The surface tension of the ink used in the present invention is:
CBVP at 25 ° C, manufactured by Kyowa Interface Science
Measurement can be performed using Surfactimeter A3 or the like.

The water absorption of the adhesive was measured by taking a predetermined amount of the cured adhesive, immersing it in water at 60 ° C. for 7 days, and calculating from the increase. In the present invention, the water absorption of the adhesive is preferably 5% or less, more preferably 2% or less, and it is preferably as small as possible and the lower limit is not particularly limited.

When the ink jet recording method of the present invention is used as a color print, the ink is combined with a head to form a multicolor set, and usually an ink set containing three colors of yellow, magenta and cyan is formed. Is preferably a combination of the ink and the head of the present invention.

[0065]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these embodiments.

<Manufacture of Head> The head of the ink jet printer used in the present invention shown in FIGS. 1 and 2 will be described. FIG. 1 is a schematic perspective view of a head used in the present invention having a partially broken surface, and FIG. 2 is a schematic cross-sectional view showing an example of an ink chamber portion of the head used in the present invention.

A lower substrate 1b and an upper substrate 1c made of lead zirconate titanate, which is a piezoelectric material, are formed by bonding with an adhesive 6. The lower substrate 1b and the upper substrate 1c are polarized in opposite directions as shown by arrows in FIG. A plurality of elongated grooves 2 are formed over the upper substrate and the lower substrate. Thereby, a plurality of parallel partition walls 4 and grooves 2 are formed.

An electrode film 3 is provided on the inner surface of the plurality of grooves by vapor deposition. After the electrode film 3 is attached to the groove 2, a part of the upper surface of the substrate 1 is stepped to form a step 35. The lid 8 is adhered to the upper surface of the partition 4 with the adhesive 6, and the groove 25 is attached to the end surface of the partition 4 with the adhesive. The surface of the electrode film 3 formed on the inner surface of the plurality of grooves is coated with an insulating film 17 such as parylene, and the surface of the insulating film 17 is hydrophilized by oxygen plasma processing. This hydrophilic treatment makes it difficult for bubbles to remain in the head, and improves ejection stability. A nozzle plate 10 having a nozzle hole 11 is bonded to the open end surface of the groove 2 with the same adhesive 6 to form an ink chamber 9 for every other groove 2. 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 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.

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

When a drive signal is applied between the electrode film of the ink chamber 2a and the electrode films of the dummy grooves on both sides thereof by applying an electric signal to the lead line 7, a drive voltage is applied so that the potential of the electrode film of the ink chamber becomes high. The partition walls on both sides of the chamber 2a are deformed inward, the ink chamber contracts, and the ink is ejected as small droplets. Subsequently, when the ink chamber electrode film is grounded, the deformation is eliminated and the ink is sucked into the ink chamber.

As the adhesive 6, the head 1 is a combination of the epoxy resin S-6 and the curing agent H-11, and the head 2 is a combination of the epoxy resin S-9 and the curing agents H-11 and H-16. Using.

<Preparation of Ink> (Yellow Pigment Dispersion) I. Pigment Yellow 74 95 g Demol C (manufactured by Kao Corporation) 65 g Ethylene glycol 100 g Deionized water 120 g is mixed, and 0.5 mm zirconia beads are mixed at a volume ratio of 5%.
The mixture was dispersed using a sand grinder filled with 0% to obtain a yellow pigment dispersion.

The sediment was removed by a centrifuge. (Magenta pigment dispersion) C.I. I. Pigment Red 122 105 g Joncryl 61 (acrylic-styrene-based resin, manufactured by Johnson) 60 g Glycerin 100 g Ion-exchanged water 130 g is mixed, and 0.5 mm zirconia beads are mixed at a volume ratio of 5%.
The mixture was dispersed using a sand grinder filled with 0% to obtain a magenta pigment dispersion.

The sediment was removed by a centrifuge. (Cyan pigment dispersion) I. Pigment Blue 15: 3 100 g Demol C 68 g Diethylene glycol 100 g Deionized water 125 g was mixed, and 0.5 mm zirconia beads were mixed in a volume ratio of 5%.
The mixture was dispersed using a sand grinder filled with 0% to obtain a cyan pigment dispersion.

The sediment was removed by a centrifuge. (Cyan Pigment Dispersion Liquid 2) In the production process of the above-mentioned cyan pigment dispersion liquid, centrifugation was not performed.

(Ink 1) Yellow pigment dispersion liquid 110 g Nipol LX844B (manufactured by Nippon Zeon Co., Ltd .; solid content: 40%) 50 g ethylene glycol 200 g propylene glycol 150 g Olfin 1010 (manufactured by Nissin Chemical Co., Ltd.) 4 g Proxel GXL (Zeneca) 2 g dioctyl sodium sulfosuccinate 0.1 g sodium chloride 0.6 g These were made up to 1000 g with ion-exchanged water, stirred sufficiently, and then passed twice through a 1 micron pore size Millipore filter to obtain ink 1. Was.

The average particle size of the pigment was 122 nm. 4
Particles having a particle size of 00 nm or more were 0.2%.

The particle size was measured using a Zetasizer 1000 manufactured by Malvern. (Ink 2) Magenta pigment dispersion 140 g Nipol SX1105 (manufactured by Zeon Corporation; solid content: 45%) 56 g ethylene glycol 150 g diethylene glycol 120 g Perex OT-P (manufactured by Kao Corporation) 4 g Proxel GXL 2 g sodium hydroxide 1 g Sodium dioctyl sulfosuccinate 0.1 g 1.8 g potassium nitrate This was made up to 1,000 g with ion-exchanged water, stirred sufficiently, and then passed twice through a millipore filter having a pore diameter of 1 micron to obtain ink 2.

The average particle size of the pigment in the obtained ink 2 was 8
It was 5 nm. Particles having a particle diameter of 400 nm or more are 0.1
%Met.

(Ink 3) Cyan pigment dispersion liquid 110 g Takerac W-605 (manufactured by Takeda Pharmaceutical Co., Ltd .; solid content: 30%) 267 g ethylene glycol 100 g diethylene glycol 140 g emulgen 913 4 g proxel GXL 2 g sodium dioctyl sulfosuccinate 0.1 g sodium chloride 0.8 g Potassium chloride 0.3 g This was made up to 1,000 g with ion-exchanged water, stirred sufficiently, and then passed twice through a millipore filter having a pore diameter of 1 micron to obtain ink 3.

The average particle size of the pigment of the obtained ink 3 is 10
It was 5 nm. Particles having a particle diameter of 400 nm or more were 0.5% by mass.

(Ink 4, Ink 5, Ink 6) The inks were prepared in the same manner as Ink 1, Ink 2, and Ink 3 except that the water-soluble organic solvents were changed as shown in Tables 1 and 2.

(Ink 7, Ink 8, Ink 9) The inks were prepared in the same manner as Ink 1, Ink 2, and Ink 3 except that the water-soluble organic solvents were changed as shown in Tables 1 and 2.

(Ink 10, Ink 11, Ink 12)
Ink 1, Ink 2 and Ink 3 were prepared in the same manner as in Ink 1, Ink 2, and Ink except that the water-soluble organic solvent was changed as shown in Tables 1 and 2.

(Ink 13) An ink 13 was prepared in the same manner as the ink 12, except that the cyan pigment dispersion was not filtered.

The average particle size of the obtained pigment dispersion is 110 n.
m. Particles having a particle size of 400 nm or more accounted for 2.5% by mass of the entire pigment.

(Ink 14) An ink was prepared in the same manner as Ink 12, except that sodium dioctylsulfosuccinate was not added.

(Ink 15) Tables 1 and 2
The ink was produced in the same manner as in the ink 12, except that the above was changed.

(Head endurance test method) Inks 1 to 1
4 is the head 1 and the ink 15 is the head 2
It was left at 60 ° C. for 3 days in a sealed state.

Thereafter, a solid printing test was performed on QP paper (manufactured by Konica Corporation) for 8 hours at a driving frequency of 30 kHz with a discharge amount of 6 picoliters using the same combination of ink and head.

X: Damage of the head adhesion was found before printing. Δ: Damage was found in the head after printing. ○: No damage was seen after printing.

(Image unevenness) The printing results were evaluated as follows. X: Streaks were continuously observed at a plurality of nozzle positions. Δ: Streaks were continuously observed at one nozzle position. Or, streaks were discontinuously observed at one or more nozzle positions. ：: A uniform image was obtained.

[0094]

[Table 1]

[0095]

[Table 2]

[0096]

[Table 3]

[0097]

As demonstrated in the examples, the ink jet recording method according to the present invention can improve the ejection stability without shortening the life of the head in a high-speed printer, and has an excellent effect.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a head used in the present invention having a partially broken surface.

FIG. 2 is a schematic sectional view showing an example of an ink chamber portion of a head used in the present invention.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 groove 2a ink chamber 3 electrode film 6 adhesive 8 lid 9 ink chamber 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) B41M 5/00 B41J 3/04 101Y C09D 11/00 103H F term (reference) 2C056 EA26 FC01 HA05 HA16 HA17 2C057 AF72 AF93 AG45 AP02 AP25 2H086 BA52 BA53 BA55 BA60 BA62 4J039 BA12 BC06 BC07 BC08 BC09 BC10 BC11 BC13 BC14 BC15 BC16 BC32 BC34 BC35 BC36 BC50 BC52 BC53 BC54 BE01 BE03 BE04 BE05 BE12 BE22 BE28 CA03 CA06 EA15 EA16 EA17 EA24 EA48 GA24

Claims (11)

[Claims] 1. An aqueous ink containing a colorant and a water-soluble organic solvent in an amount of 10 to 50% by mass in the ink, wherein the inorganic / organic ratio is 0.5 to 2. Using an ink containing 0 to 15% by mass of a water-soluble organic solvent of No. 4 and 5 to 50% by mass of a water-soluble organic solvent having an inorganic / organic ratio of 2.5 to 5.0, An ink jet recording method, wherein the driving frequency is 15 kHz or more, and the adhesive for the ink flow path of the recording head and the nozzle plate is an epoxy resin. 2. The content of a water-soluble organic solvent having an inorganic / organic ratio of 0.5 to 2.4 with respect to the whole liquid medium is 1 to 8
2. The ink jet recording method according to claim 1, wherein the content is% by mass. 3. The ink jet recording method according to claim 1, wherein the colorant is a pigment. 4. The ink has a surface tension of 3.0 × 10 ⁻⁴ or more.
The ink jet recording method according to any one of claims 1 to 3, wherein the pressure is 4.0 x ^10-4 N / cm. 5. The ink jet recording method according to claim 3, wherein the pigment has an average particle size of 10 to 200 nm. 6. The ink jet recording method according to claim 1, wherein the mass of particles having a particle diameter of 400 nm or more in the particle diameter distribution of the pigment is 2% or less of the whole pigment. . 7. The ink jet recording method according to claim 1, wherein the aqueous ink contains an anionic surfactant. 8. The ink jet according to claim 3, wherein the water-soluble polymer dispersant is contained in an amount of 0.1 to 1.0 part by mass based on 1 part by mass of the pigment. Recording method. 9. The ink jet recording method according to claim 1, wherein a water absorption rate of the adhesive is 2% or less. 10. An ink set, wherein a multicolor set is formed by combining an ink and a recording head used in the ink jet recording method according to any one of claims 1 to 9. 11. The ink set according to claim 10, wherein the multicolor set is a combination including three colors of yellow, magenta, and cyan.