JP6658133B2 - Cleaning liquid for cleaning ink, set of ink and cleaning liquid for cleaning ink, cleaning method, inkjet recording apparatus, and inkjet recording method - Google Patents

Description

The present invention relates to a cleaning liquid, a set of ink and a cleaning liquid, a cleaning method, an inkjet recording apparatus, and an inkjet recording method.

  Conventionally, dye inks have been the mainstream ink jet inks in terms of good color developability, high reliability, and the like.However, in recent years, the dye inks are poor in water resistance and light resistance. Inks are increasingly being used.

The pigment ink has come to be used for commercial printing applications such as a high-speed serial printing machine. The high-speed drying property (high-speed fixing property) required for the high-speed serial printing machine and the fixing property to a low ink absorption recording medium are required. In order to ensure the above, a resin is contained. However, when a resin is contained in the pigment ink, during continuous recording, the ink adheres to a recording head or the like, agglomerates, and dries, whereby the ejection stability of the ink may be reduced. In order to ensure the ejection stability of the ink, it is necessary to wash the ink attached to the recording head or the like.
However, since the ink containing the resin strongly adheres to the recording head, there is a problem that the cleaning power of the conventional cleaning liquid is insufficient.

  Therefore, a maintenance liquid for inkjet recording containing 1,2-propanediol and a surfactant having an HLB value of 14 or less has been proposed (for example, see Patent Document 1).

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a cleaning liquid capable of efficiently cleaning ink fixed on a nozzle plate or the like.

  The cleaning solution of the present invention as a means for solving the above-mentioned problem is a cleaning solution containing water, an organic solvent, and a surfactant, wherein the organic solvent is 3-methoxy-3-methyl-1-butanol. And the surfactant contains a silicone surfactant.

  ADVANTAGE OF THE INVENTION According to this invention, the washing | cleaning liquid which can wash the ink stuck to the nozzle plate etc. efficiently can be provided.

FIG. 1 is a perspective explanatory view showing an example of a serial type image forming apparatus. FIG. 2 is a perspective explanatory view showing an example of a main tank of the apparatus of FIG.

(Washing liquid)
The cleaning liquid of the present invention is a cleaning liquid containing water, an organic solvent, and a surfactant, wherein the organic solvent contains 3-methoxy-3-methyl-1-butanol, and the surfactant is silicone. It contains a surfactant and, if necessary, other components.
The cleaning liquid of the present invention is based on the finding that the conventional cleaning liquid for inkjet recording has insufficient cleaning power in recent years for cleaning ink having high-speed fixability.

The present inventors have also found the following.
In recent years, an ink composition that achieves high-speed fixing adheres to the surface of an inkjet discharge head, and when dried, solidifies and firmly adheres so that it is difficult to remove it by washing. In particular, when the ink composition contains 5% by mass or more of resin particles, a nozzle plate having a nozzle hole having a feature of being excellent in fixability to a recording medium, and further excellent in image strength and blocking resistance is provided. Alternatively, there is a problem that the cleaning property of the ink remaining in the ink flow path is further reduced and the ejection stability is deteriorated. Therefore, if a cleaning liquid containing 3-methyl-3-methoxy-1-butanol is used, the ink fixed on the nozzle plate surface can be easily peeled off as a film. That is, the action of the cleaning liquid of the present invention is basically different from the conventional method of dissolving or redispersing and removing in that the ink is peeled off as a film. It has been found that the detergency can be significantly improved by a new mechanism of action.

<Organic solvent>
The organic solvent contains 3-methoxy-3-methyl-1-butanol, and further contains other organic solvents as needed.

<< Other organic solvents >>
The other organic solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a water-soluble organic solvent.
Examples of the water-soluble organic solvent include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, and carbonic acid. Ethylene and the like. These may be used alone or in combination of two or more.

  Examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, , 4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexyl Njioru, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, etc. Petri ol. These may be used alone or in combination of two or more.

  Examples of the polyhydric alcohol alkyl ethers include, for example, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Can be These may be used alone or in combination of two or more.

  Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether. These may be used alone or in combination of two or more.

  Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, γ- Butyrolactone and the like. These may be used alone or in combination of two or more.

  Examples of the amides include formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, N-dimethylpropionamide, and 3-butoxy-N, N-dimethylpropionamide. These may be used alone or in combination of two or more.

Examples of the amines include monoethanolamine, diethanolamine, and triethylamine. These may be used alone or in combination of two or more.
Examples of the sulfur-containing compound include dimethyl sulfoxide, sulfolane, and thiodiethanol.

  The content of the organic solvent is preferably from 10% by mass to 60% by mass, more preferably from 20% by mass to 60% by mass, based on the total amount of the cleaning liquid.

  The content of the 3-methoxy-3-methyl-1-butanol is preferably 10% by mass or more, more preferably 20% by mass or more, based on the total amount of the washing liquid, from the viewpoint of improving the washability of the fixed matter of the ink. .

<Surfactant>
The surfactant contains a silicone surfactant and, if necessary, other surfactants. The silicone surfactant only needs to have a skeleton formed by a siloxane bond in its structure, and it includes a silicone surfactant.

The silicone surfactant is not particularly limited and may be appropriately selected depending on the purpose. However, a silicone surfactant that does not decompose even at a high pH is preferable.
The silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a side-chain modified polydimethylsiloxane, a polydimethylsiloxane modified at both ends, a polydimethylsiloxane modified at one end, and a polydimethylsiloxane modified at both ends. Terminal-modified polydimethylsiloxane; Among them, a polyether-modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group is preferable from the viewpoint of exhibiting good properties as an aqueous surfactant. When the polyether-modified silicone surfactant is used, there are portions where the polyether-modified silicone surfactant is electrically positively polarized or charged, and the substrate or dirt is electrically negatively polarized or charged. Since it is easy to be adsorbed to the part where it is, the cleaning property can be improved.

  As such a surfactant, an appropriately synthesized one may be used, or a commercially available product may be used. The commercially available products can be obtained, for example, from Big Chemie Japan Co., Ltd., Shin-Etsu Chemical Co., Ltd., Dow Corning Toray Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Chemical Co., Ltd., etc.

The polyether-modified silicone surfactant is not particularly limited and may be appropriately selected depending on the purpose. For example, a polyalkylene oxide structure represented by the following general formula (S-1) may be a dimethylpolysiloxane And the like introduced into the side chain of the Si portion.
(General formula (S-1))
However, in the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R ′ represents an alkyl group.

  As the polyether-modified silicone surfactant, a commercial product can be used. Examples of the commercial product include KF-618, KF-642, and KF-643 (all manufactured by Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS-1906EX (all manufactured by Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (all Toray) -Dow Corning Silicone Co., Ltd.), BYK-33, BYK-348, BYK-387 (both from Big Chemie Japan KK), TSF4440, TSF4452, TSF4453 (both from Momentive Performance Materials Japan GK) Manufactured), WET270 (Evonik de Sa Japan Co., Ltd.), and the like.

<< other surfactants >>
Other surfactants are not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include a fluorine-based surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant. No. These may be used alone or in combination of two or more.

  Examples of the fluorine-based surfactant include perfluoroalkylsulfonic acid compounds, perfluoroalkylcarboxylic acid compounds, perfluoroalkylphosphate ester compounds, perfluoroalkylethylene oxide adducts, perfluoroalkyl Polyoxyalkylene ether polymer compounds having an ether group in the side chain are preferred.

Examples of the perfluoroalkylsulfonic acid compound include perfluoroalkylsulfonic acid, perfluoroalkylsulfonic acid salt, and the like.
Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt.
Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in a side chain include, for example, a sulfate salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in a side chain, and a side chain having a perfluoroalkyl ether group. And a salt of a polyoxyalkylene ether polymer.
These may be used alone or in combination of two or more.
As the counter ion of the salt in the fluorine-based surfactant, for example, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂₎ OH) _{3 and the} like.

  Examples of the amphoteric surfactant include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, lauryl dihydroxyethyl betaine, and the like. These may be used alone or in combination of two or more.

  Examples of the nonionic surfactant include polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, and polyoxyethylene. Examples thereof include sorbitan fatty acid esters and ethylene oxide adducts of acetylene alcohol. These may be used alone or in combination of two or more.

  Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurylate, and polyoxyethylene alkyl ether sulfate. These may be used alone or in combination of two or more.

  The content of the surfactant is preferably from 0.0010% by mass to 5% by mass, and more preferably from 0.05% by mass to 5% by mass with respect to the total amount of the cleaning liquid, from the viewpoint of excellent wettability and ejection stability. The following is more preferred.

<Water>
The water is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include ion-exchanged water, ultrafiltration water, reverse osmosis water, pure water such as distilled water, and ultrapure water. . These may be used alone or in combination of two or more.

  The water content is not particularly limited and may be appropriately selected depending on the intended purpose. However, the content is preferably 10% by mass or more and 95% by mass or less, and more preferably 20% by mass or more and 80% by mass or less based on the total amount of the washing liquid. Is more preferred.

[Dynamic surface tension]
The dynamic surface tension of the cleaning solution at 25 ° C. with a life time of 15 ms according to the maximum bubble pressure method is preferably 35 mN / m or less, and more preferably 30 mN / m or less. When the dynamic surface tension at 25 ° C. for the life time of 15 ms is 35 mN / m or less, the wettability of the cleaning liquid when coming into contact with dirt can be increased, and the ink film fixed to the nozzle plate or the like can be removed. The film can be peeled off, and the cleanability can be improved by a new action mechanism which is basically different from the conventional method of dissolving or redispersing and removing.
The dynamic surface tension of the cleaning solution at 25 ° C. at a life time of 150 msec according to the maximum bubble pressure method is preferably 35 mN / m or less, more preferably 30 mN / m or less. When the dynamic surface tension at 25 ° C. during the life time of 150 msec is 35 mN / m or less, it is possible to sufficiently secure the spread of wetness necessary for cleaning.
The dynamic surface tension can be measured at 25 ° C. by a maximum bubble pressure method using, for example, a dynamic surface tensiometer (device name: SITA DynoTester, manufactured by SITA Messtechnik).
The lifetime refers to the lifetime of bubbles generated in the maximum bubble pressure method, also referred to as bubble lifetime, from the time when a new interface is generated in the probe tip of the dynamic surface tensiometer to the maximum bubble pressure. Means time.

The ratio at which the dynamic surface tension at 25 ° C. in lifetime 15m sec determined by a maximum bubble pressure method of the washing liquid and F _15, the dynamic surface tension at 25 ° C. in lifetime 150m sec determined by a maximum bubble pressure method was F _0.99 (F ₁₅ / F ₁₅₀ ) is preferably 1.10 or more, more preferably 1.20 or more, and particularly preferably 1.25 or more. When the ratio (F ₁₅ / F ₁₅₀ ) is 1.10 or more, the speed of spread of wetness to dirt increases, and the ink fixed on the recording head can be instantaneously cleaned, and the cleaning property can be improved. .

<Other ingredients>
The other components are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include an antifoaming agent, an antiseptic / antifungal agent, a rust inhibitor, and a pH adjuster.

<Defoaming agent>
The defoaming agent is not particularly limited, and examples thereof include a silicone-based defoaming agent, a polyether-based defoaming agent, and a fatty acid ester-based defoaming agent. These may be used alone or in combination of two or more. Among these, silicone-based antifoaming agents are preferred because of their excellent foam breaking effect.

<Antiseptic / antifungal agent>
The preservative / antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

<Rust inhibitor>
The rust inhibitor is not particularly limited, and examples thereof include acidic sulfites and sodium thiosulfate.

<PH adjuster>
The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

  The cleaning liquid of the present invention is not particularly limited and may be appropriately selected depending on the purpose. However, it is preferable that the cleaning liquid is for inkjet.

(Set of ink and cleaning liquid)
The set of the ink of the present invention and the cleaning liquid includes the cleaning liquid of the present invention and an ink containing resin particles, and further includes other components as necessary. When the ink contains resin particles, the fixability of the ink to the recording medium is improved, but the ejection stability is not easily maintained. Therefore, the ink is used as a set that is a combination of the cleaning liquid and the ink of the present invention. Can be.

  The set of the ink and the cleaning liquid of the present invention can be suitably used for various cleaning methods, recording methods, and recording apparatuses. The cleaning method of the present invention, the inkjet recording method of the present invention, and the inkjet recording apparatus of the present invention described below. Can be particularly preferably used.

<Ink>
The ink preferably contains resin particles, an organic solvent, and a coloring material, and further contains other components as necessary.

<Resin>
The type of the resin contained in the ink is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a urethane resin, a polyester resin, an acrylic resin, a vinyl acetate resin, a styrene resin, and a butadiene resin. Resin, styrene-butadiene-based resin, vinyl chloride-based resin, acrylic styrene-based resin, acrylic silicone-based resin, and the like.
Resin particles made of these resins may be used. Ink can be obtained by mixing resin particles with a material such as a coloring material or an organic solvent in a state of a resin emulsion in which water is used as a dispersion medium. As the resin particles, appropriately synthesized ones or commercially available ones may be used. These may be used alone or in combination of two or more resin particles.

The volume average particle size of the resin particles is not particularly limited and may be appropriately selected depending on the intended purpose; however, from the viewpoint of obtaining good fixability and high image hardness, it is preferably from 10 nm to 1,000 nm, and preferably from 10 nm to 1,000 nm. The thickness is more preferably from 200 nm to 200 nm, and particularly preferably from 10 nm to 100 nm.
The volume average particle size can be measured, for example, using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Inc.).

  The particle size of the solid content in the ink is not particularly limited and can be appropriately selected depending on the purpose.However, from the viewpoint of improving image quality such as ejection stability and image density, the maximum frequency in terms of the maximum number is considered. Is preferably from 20 nm to 1000 nm, more preferably from 20 nm to 150 nm. The solid content includes resin particles and pigment particles. The particle size can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Inc.).

  The content of the resin particles is 5% by mass or more, preferably 5% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass with respect to the total amount of the ink, from the viewpoint of fixability and storage stability of the ink. % By mass or less is more preferable.

<< Organic solvent >>
The organic solvent is not particularly limited and can be appropriately selected depending on the intended purpose. The same organic solvent as the solvent in the cleaning liquid can be used.

<Color material>
The coloring material is not particularly limited, and pigments and dyes can be used.
As the pigment, an inorganic pigment or an organic pigment can be used. These may be used alone or in combination of two or more. Further, a mixed crystal may be used.
As the pigment, for example, black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, luster pigments such as gold and silver, and metallic pigments can be used.
As inorganic pigments, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, carbon black produced by a known method such as a contact method, a furnace method, and a thermal method Can be used.
Examples of the organic pigment include azo pigments and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinoflurone pigments). And dye chelates (eg, basic dye chelates and acid dye chelates), nitro pigments, nitroso pigments, aniline black, and the like. Among these pigments, those having good affinity for the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can be used.
Specific examples of the pigment include carbon black (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, or copper or iron (CI pigment black 11) for black. And metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).
Further, for color, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, C.I. I. Pigment Violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3, 15: 4 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment Green 1, 4, 7, 8, 10, 17, 18, 36, and the like.
The dye is not particularly limited, and an acidic dye, a direct dye, a reactive dye, and a basic dye can be used. One type of dye may be used alone, or two or more types may be used in combination.
Examples of the dye include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52, 80, 82, 249, 254, 289, C.I. I. Acid blue 9, 45, 249, C.I. I. Acid Black 1, 2, 24, 94, C.I. I. Food black 1, 2, C.I. I. Direct Yellow 1,12,24,33,50,55,58,86,132,142,144,173, C.I. I. Direct Red 1,4,9,80,81,225,227, C.I. I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, C.I. I. Directed Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive Black 3, 4, 35.

  The content of the coloring material in the ink is preferably 0.1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass from the viewpoints of improvement in image density, good fixability and ejection stability. It is as follows.

In order to disperse the pigment in the ink, a method of introducing a hydrophilic functional group into the pigment to form a self-dispersing pigment, a method of coating and dispersing the surface of the pigment with a resin, a method of dispersing using a dispersant, And the like.
As a method of introducing a hydrophilic functional group into a pigment to obtain a self-dispersible pigment, for example, a self-dispersible pigment which can be dispersed in water by adding a functional group such as a sulfone group or a carboxyl group to a pigment (for example, carbon). Can be used.
As a method of coating and dispersing the surface of the pigment with a resin, a method in which the pigment is included in microcapsules and can be dispersed in water can be used. This can be rephrased as a resin-coated pigment. In this case, it is not necessary that all the pigments incorporated in the ink be coated on the resin, and as long as the effects of the present invention are not impaired, uncoated pigments or partially coated pigments are dispersed in the ink. May be.
Examples of a method of dispersing using a dispersant include a method of dispersing using a known low-molecular type dispersant and a high-molecular type dispersant represented by a surfactant.
As the dispersant, for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, or the like can be used depending on the pigment.
RT-100 (a nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd., and Na formalin condensate of naphthalenesulfonic acid can also be suitably used as the dispersant.
One type of dispersant may be used alone, or two or more types may be used in combination.

<Additives>
If necessary, a surfactant, an antifoaming agent, an antiseptic / antifungal agent, a rust inhibitor, a pH adjuster and the like may be added to the ink.

<Surfactant>
The surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a silicone surfactant, a fluorine-based surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant. Activators and the like. As these surfactants, those similar to the surfactants in the cleaning liquid can be used.

  The content of the surfactant in the ink is not particularly limited and may be appropriately selected depending on the purpose. However, from the viewpoint of excellent wettability and ejection stability and improved image quality, 0.001 mass % To 5% by mass, more preferably 0.05% to 5% by mass.

<Defoaming agent>
As the defoaming agent, the same defoaming agents as other components in the cleaning liquid can be used.

<Antiseptic / antifungal agent>
As the antiseptic / antifungal agent, the same antiseptic / antifungal agent as other components in the washing liquid can be used.

<Rust inhibitor>
As the rust preventive, the same rust preventives as other components in the cleaning liquid can be used.

<PH adjuster>
As the pH adjuster, the same pH adjusters as other components in the cleaning liquid can be used.

The physical properties of the ink are not particularly limited and can be appropriately selected depending on the purpose. For example, the viscosity, surface tension, pH, and the like are preferably in the following ranges.
The viscosity of the ink at 25 ° C. is preferably 5 mPa · s or more and 30 mPa · s or less, and more preferably 5 mPa · s or more and 25 mPa · s or less, from the viewpoint of improving print density and character quality, and obtaining good ejection properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. As measurement conditions, measurement can be performed at 25 ° C. with a standard cone rotor (1 ° 34 ′ × R24), a sample liquid amount of 1.2 mL, a rotation speed of 50 rpm, and 3 minutes.
The surface tension of the ink is preferably 35 mN / m or less, more preferably 32 mN / m or less at 25 ° C., from the viewpoint that the ink is suitably leveled on the recording medium and the drying time of the ink is shortened.
The pH of the ink is preferably from 7 to 12, and more preferably from 8 to 11, from the viewpoint of preventing corrosion of the metal member that comes into contact with the ink.

  The ink is preferably for ink jet.

<Recording medium>
The recording medium is not particularly limited, and plain paper, glossy paper, special paper, cloth, and the like can be used. However, good image formation can be performed using a non-permeable base material.
The non-permeable substrate is a substrate having a surface having low water permeability and low absorptivity, and includes a material that does not open to the outside even if there are many cavities inside, and more quantitatively. And a base material having a water absorption amount of 10 mL / m ² or less from the start of contact to 30 msec ^1/2 in the Bristow method.
As the non-permeable substrate, for example, a plastic film such as a vinyl chloride resin film, a polyethylene terephthalate (PET) film, a polypropylene, a polyethylene, or a polycarbonate film can be suitably used.

(Composition container)
The composition containing container contains the cleaning solution of the present invention in a container, and further has other members as necessary.
Further, the composition containing container contains the ink used in the set of the ink and the cleaning liquid of the present invention, and the cleaning liquid used in the set of the ink and the cleaning liquid of the present invention in a container. And other members.

  The container is not particularly limited and, depending on the purpose, its shape, structure, size, material, and the like can be appropriately selected.For example, an aluminum laminated film, an ink bag formed of a resin film, or the like can be used. Those having at least are mentioned.

<Washing method>
The cleaning method of the present invention is a method for cleaning an ink jet recording apparatus having a nozzle plate having a nozzle hole and an ink flow path, wherein the ink remaining in the nozzle plate or the ink flow path is cleaned with the cleaning liquid of the present invention. Cleaning step, and further includes other steps as necessary.

<< Cleaning process >>
The cleaning step is a step of cleaning the ink remaining in the nozzle plate having the nozzle holes or the ink flow path with the cleaning liquid of the present invention.
Examples of the washing include spraying the washing liquid onto a nozzle plate having nozzle holes or the like, and wiping the ink with a cloth or the like impregnated with the washing liquid. When the cleaning portion is the ink flow path, the cleaning can be performed by replacing the cleaning liquid with ink and discharging the ink from the nozzle. This makes it possible to clean the nozzle plate having the nozzle holes, the ink flow path, and its surroundings.

(Inkjet recording apparatus and inkjet recording method)
The ink jet recording apparatus of the present invention includes the ink and the cleaning liquid in the set of the ink of the present invention and the cleaning liquid.
Further, an ink jet recording apparatus of the present invention is an ink jetting means for applying a stimulus to the ink in a set of the ink and the cleaning liquid of the present invention, causing the ink to fly, and recording an image on a recording medium, and a nozzle having a nozzle hole. Cleaning means for cleaning the ink remaining in the plate or the ink flow path with the cleaning liquid, and further including other means as necessary.
The ink jet recording method of the present invention is a nozzle plate having a nozzle hole, in which a stimulus is applied to the ink in the set of the ink and the cleaning liquid of the present invention, an ink flying step of recording an image on a recording medium by flying the ink. Or a cleaning step of cleaning the ink remaining in the ink flow path with the cleaning liquid, and further includes other steps as necessary.

The ink flying step in the inkjet recording method can be suitably performed by the ink flying means.
The storage means in the inkjet recording apparatus is not particularly limited as long as it can store the cleaning liquid and the ink, and can be appropriately selected according to the purpose.
The cleaning step can be suitably performed by the cleaning means, and is performed by applying the cleaning liquid to a nozzle plate having a nozzle hole of a recording head to which ink is attached, an ink flow path, or the like using a dropper or the like. Cleaning with a wiping member impregnated with the cleaning liquid.
The wiping member is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a nonwoven fabric and a cloth. These are preferably wound in a roll shape, and a roll-shaped nonwoven fabric is preferable in terms of low dust generation and high reliability.

The ink used in the set of the ink and the cleaning liquid of the present invention is suitably used for various recording apparatuses using an ink jet recording method, for example, a printer, a facsimile apparatus, a copying apparatus, a combined printer / fax / copier machine, and a three-dimensional printing apparatus. Can be.
In the present invention, an inkjet recording apparatus is an apparatus capable of discharging ink, various kinds of processing liquids, and the like onto a recording medium, and a method of performing recording using the apparatus. The recording medium means a medium to which ink and various processing liquids can be temporarily attached.
The inkjet recording apparatus may include not only a head portion for discharging ink, but also means for feeding, transporting, and discharging a recording medium, and other devices such as a pre-processing device and a post-processing device. it can.

  The inkjet recording device may include a heating unit and a drying unit. The heating unit and the drying unit include, for example, a unit for heating and drying the printing surface or the back surface of the recording medium. The heating means and the drying means are not particularly limited, and for example, a warm air heater or an infrared heater can be used. Heating and drying can be performed before printing, during printing, after printing, and the like.

  Further, the ink jet recording apparatus is not limited to the one in which a significant image such as a character or a figure is visualized by ink. For example, those that form a pattern such as a geometric pattern and the like that form a three-dimensional image are also included.

Further, the ink jet recording apparatus includes, unless otherwise limited, a serial type apparatus that moves the ejection head and a line type apparatus that does not move the ejection head.
Further, the ink jet recording apparatus is not limited to a desktop type, and a wide recording apparatus capable of printing on a recording medium of A0 size or a continuous paper wound in a roll shape is used as a recording medium. Possible continuous printers are also included.

  An example of the inkjet recording apparatus will be described with reference to FIGS. FIG. 1 is a perspective explanatory view of the device. FIG. 2 is a perspective explanatory view of the main tank. The image forming apparatus 400 as an example of the recording apparatus is a serial type image forming apparatus. A mechanism section 420 is provided inside an exterior 401 of the image forming apparatus 400. Each ink storage section 411 of the main tank 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is packaged with, for example, an aluminum laminated film. It is formed by a member. The ink storage unit 411 is stored in a storage container case 414 made of, for example, plastics. Thus, the main tank 410 is used as an ink cartridge for each color.

  On the other hand, a cartridge holder 404 is provided behind the opening when the cover 401c of the apparatus main body is opened. The main tank 410 is detachably mounted on the cartridge holder 404. Accordingly, the ink discharge ports 413 of the main tank 410 and the discharge heads 434 for the respective colors communicate with each other via the supply tubes 436 for the respective colors, and the ink can be discharged from the discharge heads 434 to the recording medium.

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.
In addition, the dynamic surface tension of the cleaning liquid was measured as follows.
(Dynamic surface tension)
The dynamic surface tension is obtained by calculating the dynamic surface tension F ₁₅ at 25 ° C. with a lifetime of 15 ms and the dynamic surface tension F ₁₅₀ at 25 ° C. with a lifetime of 150 ms at 25 ° C. by the maximum bubble pressure method. The measurement was performed using a surface tensiometer (device name: SITA DynoTester, manufactured by SITA Messtechnik).

(Example 1)
2-Methoxy-3-methyl-1-butanol (manufactured by Kuraray Co., Ltd.) 20.0% by mass, polyether-modified silicone surfactant 1 (trade name: BYK-348, manufactured by BYK Japan KK) 0.5% by mass %, And the remaining amount of ion-exchanged water was added so that the total was 100% by mass, and the mixture was stirred for 1 hour to obtain a washing liquid 1.

(Examples 2 to 10 and Comparative Examples 1 to 3)
Cleaning liquids 2 to 13 were obtained in the same manner as in Example 1, except that the compositions were changed to those shown in Tables 1 and 2 below. The compositions are shown in Tables 1 and 2 below.

In Tables 1 and 2, the trade names of the components and the names of the manufacturers are as follows.
・ 3-methoxy-3-methyl-1-butanol: manufactured by Kuraray Co., Ltd. ・ 1,3-butanediol: manufactured by Tokyo Chemical Industry Co., Ltd. ・ Polyether-modified silicone surfactant 1: manufactured by BYK Japan KK, trade name : BYK-348
-Polyether-modified silicone surfactant 2: Evonik Degussa Japan Co., Ltd., trade name: WET270
・ Polyglycerin-modified silicone surfactant: manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-6106
・ Polyoxyalkylene alkyl ether: manufactured by Kao Corporation, trade name: LS106
-Fluorosurfactant: DuPont, trade name: FS-34

(Preparation example of yellow pigment dispersion)
<Preparation of yellow pigment dispersion>
After replacing the inside of a 1 L flask equipped with a mechanical stirrer, a thermometer, a nitrogen gas inlet tube, a reflux tube, and a dropping funnel with nitrogen gas, 11.2 g of styrene, 2.8 g of acrylic acid, 12 g of lauryl methacrylate, polyethylene 4 g of glycol methacrylate, 4 g of styrene macromer, 0.4 g of mercaptoethanol and 40 g of methyl ethyl ketone were added, and the temperature was raised to 65 ° C. Next, styrene 100.8 g, acrylic acid 25.2 g, lauryl methacrylate 108 g, polyethylene glycol methacrylate 36 g, hydroxylethyl methacrylate 60 g, styrene macromer 36 g, mercaptoethanol 3.6 g, azobismethylvaleronitrile 2.4 g, and methyl ethyl ketone 342 g Was dropped into the flask over 2.5 hours. Further, a mixed solution of 0.8 g of azobismethyl valeronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hour, and the mixture was aged for 1 hour. Next, after adding 0.8 g of azobismethyl valeronitrile, the mixture was aged for 1 hour to obtain 800 g of a 50% by mass polymer solution.

  28 g of the obtained polymer solution, C.I. I. Pigment Yellow 74 (trade name: Yellow No. 43, manufactured by Dainichi Seika Kogyo Co., Ltd.) 26 g, 13.6 g of a 1 mol / L aqueous potassium hydroxide solution, 20 g of methyl ethyl ketone, and 13.6 g of water were stirred, and then a roll mill was used. And kneaded to obtain a paste. The obtained paste was poured into 200 g of water and stirred, and then methyl ethyl ketone and water were distilled off using an evaporator. A yellow pigment dispersion having a pigment content of 15% by mass and a solid content of 20% by mass was used. I got

(Ink Preparation Example 1)
<Preparation of Ink 1>
15.0% by mass of 1,3-butanediol (manufactured by Tokyo Chemical Industry Co., Ltd.), 15.0% by mass of 1,2-propanediol (manufactured by Mitsui Chemicals, Inc.), acrylic resin particles (trade name: Boncoat R-3380) -E, DIC Corporation, solid content concentration: 45% by mass) 6.7% by mass, and 1.0% by mass of a fluorine-based surfactant (trade name: Zonyl (registered trademark) FSO-100, manufactured by DuPont) Was added, and the mixture was stirred and mixed. Then, 20.0% by mass of the yellow pigment dispersion and the remaining amount of ion-exchanged water were added so that the total was 100% by mass, and the mixture was stirred for 1 hour. Next, ink 1 was prepared by filtering under pressure using a polypropylene filter (trade name: Profile Star, manufactured by Nippon Pall Co., Ltd.) having an average pore diameter of 1.5 μm to remove coarse particles.

(Ink Preparation Example 2)
<Preparation of Ink 2>
In Preparation Example 1 of the ink, the amount of acrylic resin particles (trade name: Boncoat R-3380-E, manufactured by DIC Corporation, solid content concentration: 45% by mass) was changed from 6.7% by mass to 11.1% by mass. An ink 2 was prepared in the same manner as in the preparation example 1 of the ink except that it was performed. The composition is shown in Table 3 below.

In Table 3, the trade names of the components and the names of the manufacturing companies are as follows.
-1,3-butanediol: manufactured by Tokyo Chemical Industry Co., Ltd.-1,2-propanediol: manufactured by Mitsui Chemicals, Inc.-Acrylic resin particles: manufactured by DIC Corporation, trade name: Boncoat R-3380-E, solid content concentration : 45% by mass
-Fluorinated surfactant: manufactured by DuPont, trade name: Zonyl (registered trademark) FSO-100

(Example 11)
The ink 1 and the cleaning liquid 1 were combined to form a set 1 of ink and cleaning liquid.

(Examples 12 to 21 and Comparative Examples 4 to 7)
In Example 11, sets 2 to 15 of the ink and the cleaning liquid were prepared in the same manner as in Example 11, except that the combination was changed to the combination shown in Table 4 below.

  Using the set of the obtained ink and the cleaning liquid, “cleanability”, “ejection stability”, and “fixing property” were evaluated as follows. The results are shown in Table 4 below.

(Cleanability)
An SUS316 plate (3 cm × 4 cm) was immersed in the ink in each ink and cleaning liquid set for 60 minutes. Thereafter, the substrate was allowed to stand at room temperature (25 ° C.) for 2 hours under a pressurized condition of 0.1 MPa in the atmosphere and dried to obtain a SUS316 plate to which the dried ink was adhered.

The SUS316 plate to which the obtained dried ink was adhered was repeatedly washed for 3 minutes using 30 mL of the cleaning liquid in the set of each ink and the cleaning liquid. After completion of the washing, the SUS316 plate was visually observed, and "cleanability" was evaluated based on the following evaluation criteria.
[Evaluation criteria]
：: Repeated washing was not observed at all in the initial stage (within 1 minute). ○: After repeated washing, dried ink was not observed at all. △: Slightly dried ink was not observed. ×: No change was observed in the dried ink before and after washing.

(Discharge stability)
Using the printer shown in FIG. 1, the ink in the set of each ink and the cleaning liquid was continuously discharged for 45 minutes, and the surface of the recording head was dried for 30 minutes after the discharge was stopped. Then, after applying 3 mL of the cleaning liquid to the nozzle surface of the recording head using a dropper, wiping was performed and ink was discharged again, and "discharge stability" was evaluated based on the following evaluation criteria.
[Evaluation criteria]
◎: Discharge turbulence or non-discharge not found at all ○: Discharge turbulence of 5 nozzles or less, or non-discharge, but recovers immediately △: Discharge turbulence of 5 nozzles or less, non-discharge, there is no recovery ×: Discharge turbulence exceeding 5 nozzles or non-discharge

(Fixing)
An ink jet printer (apparatus name: IPSiO GX5000, manufactured by Ricoh Co., Ltd.) was filled with the ink in the set of each ink and the cleaning liquid, and recording was performed on Type 6200 paper (manufactured by NBS Ricoh Co., Ltd.) at 600 dpi resolution. Next, a filter paper (trade name: circular quantitative filter paper No. 6, manufactured by ADVANTEC) is pressed against the recording unit, the state of ink transfer to the filter paper is visually observed, and “fixing” is performed based on the following evaluation criteria. Sex "was evaluated.
[Evaluation criteria]
：: Almost no ink transfer ○: Some ink is transferred △: Many ink is transferred ×: Most ink is transferred

Aspects of the present invention are, for example, as follows.
<1> A cleaning liquid containing water, an organic solvent, and a surfactant,
The organic solvent contains 3-methoxy-3-methyl-1-butanol,
The cleaning liquid is characterized in that the surfactant contains a silicone surfactant.
<2> The cleaning liquid according to <1>, wherein the silicone surfactant is a polyether-modified silicone surfactant.
<3> The cleaning liquid according to any one of <1> to <2>, wherein a dynamic surface tension at 25 ° C. with a life time of 15 ms by a maximum bubble pressure method is 30 mN / m or less.
<4> the dynamic surface tension at 25 ° C. in lifetime 15m sec determined by the maximum bubble pressure method and _{F 15,} the ratio at which the dynamic surface tension at 25 ° C. in lifetime 150m sec determined by a maximum bubble pressure method was _{F 0.99} The cleaning liquid according to any one of <1> to <3>, wherein (F ₁₅ / F ₁₅₀ ) is 1.25 or more.
<5> The cleaning liquid according to any one of <1> to <4>, wherein the content of the 3-methoxy-3-methyl-1-butanol is 10% by mass or more.
<6> The cleaning liquid according to any one of <1> to <5>, wherein the content of the organic solvent is 10% by mass or more and 60% by mass or less.
<7> The cleaning liquid according to any one of <2> to <6>, wherein the polyether-modified silicone surfactant is a compound represented by the following general formula (S-1).
(General formula (S-1))
However, in the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R ′ represents an alkyl group.
<8> The cleaning liquid according to any one of <1> to <7>, wherein the content of the surfactant is 0.0010% by mass or more and 5% by mass or less.
<9> The cleaning liquid according to any one of <1> to <8>, wherein the organic solvent further includes 1,2-butanediol.
<10> The cleaning liquid according to any one of <1> to <9>, which is used for inkjet.
<11> The cleaning liquid according to any one of <1> to <10>,
And an ink containing resin particles,
A set of an ink and a cleaning liquid, wherein the content of the resin particles in the ink is 5% by mass or more.
<12> The set according to the item <11>, wherein the resin particles are acrylic resin particles.
<13> The set of the ink and the cleaning liquid according to any one of <11> to <12>, wherein the resin particles have a volume average particle diameter of 10 nm or more and 1,000 nm or less.
<14> The set of the ink and the cleaning liquid according to any one of <11> to <13>, wherein the content of the resin particles is 5% by mass or more and 30% by mass or less.
<15> The ink according to any one of <11> to <14>, wherein the ink further includes an organic solvent, and a cleaning liquid.
<16> The set of the ink and the cleaning liquid according to <15>, wherein the organic solvent in the ink is at least one of 1,3-butanediol and 1,2-propanediol.
<17> The set of the ink and the cleaning liquid according to any one of <11> to <16>, wherein the ink further contains a fluorine-based surfactant.
<18> A method for cleaning an ink jet recording apparatus having a nozzle plate having a nozzle hole and an ink flow path,
A cleaning method including a cleaning step of cleaning the ink remaining in the nozzle plate or the ink flow path with the cleaning liquid according to any one of <1> to <10>.
<19> An ink jet recording apparatus, comprising the ink and the cleaning liquid in the set of the ink and the cleaning liquid according to any one of <11> to <17>.
<20> an ink flying unit that applies a stimulus to the ink in the set of the ink and the cleaning liquid according to any one of <11> to <17>, causes the ink to fly, and records an image on a recording medium;
Cleaning means for cleaning the nozzle plate having a nozzle hole or the ink remaining in the ink flow path with the cleaning liquid in the set of the ink and the cleaning liquid according to any one of <11> to <18>. An ink jet recording apparatus characterized in that:
<21> an ink flying step of applying a stimulus to the ink in the set of the ink and the cleaning liquid according to any one of <11> to <17>, causing the ink to fly, and recording an image on a recording medium;
A cleaning step of cleaning the nozzle plate having nozzle holes or the ink remaining in the ink flow path with the cleaning liquid.

  The cleaning liquid according to any one of <1> to <10>, the set of the ink and the cleaning liquid according to <11> to <17>, the cleaning method according to <18>, and the cleaning method according to <19> to <20. According to the inkjet recording apparatus described in any one of <1> and <2>, the various problems in the related art can be solved and the object of the present invention can be achieved.

Japanese Patent No. 5593366

Claims (9)

Water, an organic solvent, and a cleaning liquid for ink cleaning containing a surfactant,
The organic solvent contains 3-methoxy-3-methyl-1-butanol,
The cleaning liquid for ink cleaning , wherein the surfactant contains a silicone surfactant. The cleaning liquid for ink cleaning according to claim 1, wherein the silicone surfactant is a polyether-modified silicone surfactant. The cleaning liquid for ink cleaning according to any one of claims 1 to 2, wherein a dynamic surface tension at 25 ° C for a life time of 15 msec by a maximum bubble pressure method is 30 mN / m or less. The ratio (F ₁₅ ) when the dynamic surface tension at 25 ° C. with a life time of ₁₅ msec according to the maximum foam pressure method is F ₁₅ and the dynamic surface tension at 25 ° C. with a life time of 150 msec according to the maximum foam pressure method is F ₁₅₀ / F ₁₅₀ ) is 1.25 or more, the cleaning liquid for ink cleaning according to any one of claims 1 to 3. A cleaning liquid for cleaning ink according to any one of claims 1 to 4,
And an ink containing resin particles,
A set of an ink and a cleaning liquid for cleaning an ink, wherein the content of the resin particles in the ink is 5% by mass or more. A nozzle plate having a nozzle hole, and a method of cleaning an ink jet recording apparatus having an ink flow path,
A cleaning method comprising a cleaning step of cleaning the ink remaining in the nozzle plate or the ink flow path with the cleaning liquid for ink cleaning according to any one of claims 1 to 4. Ink jet recording apparatus of the ink and the ink set of the cleaning the cleaning solution according to claim 5, characterized in that it has the ink, and a said ink cleaning washing liquid. An ink flying means for applying a stimulus to the ink in the set of the ink and the cleaning liquid for cleaning the ink according to claim 5, causing the ink to fly, and recording an image on a recording medium,
An ink jet recording apparatus comprising: a nozzle plate having a nozzle hole; or a cleaning unit for cleaning the ink remaining in the ink flow path with the cleaning liquid for ink cleaning . An ink flying step of applying a stimulus to the ink in the set of the ink and the cleaning liquid for ink cleaning according to claim 5, causing the ink to fly, and recording an image on a recording medium;
A cleaning step of cleaning the ink remaining in the nozzle plate having the nozzle holes or the ink flow path with the cleaning liquid for ink cleaning .