JP2018069723A - Cleaning liquid, set of ink and cleaning liquid, cleaning method, cleaning device, printing method, and printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning liquid which has sufficient detergency and can secure good discharge reliability.SOLUTION: A cleaning liquid is used for cleaning ink containing water and a resin, where the cleaning liquid is a cleaning liquid containing water and a solvent, the solvent contains a glycol ether compound represented by general expression 1, and a swelling ratio calculated based on expression 1 from the mass before and after an ink membrane obtained by drying the ink is immersed in the cleaning liquid at 25°C for 24 hours is 20% or more and 150% or less. R(OR)OR...general expression 1. In general expression 1, Rand Reach represent either one of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms; Rrepresents an alkyl group having 2 to 3 carbon atoms; and X represents an integer of 1 to 4. Swelling ratio (%)=100×[(B-A)/A]...Expression 1. In expression 1, A represents a mass of the ink membrane before immersion; and B represents a mass of the ink membrane after immersion.SELECTED DRAWING: None

Description

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

  Conventionally, as ink-jet inks, dye inks have been mainstream from the viewpoints of good color developability and high reliability, but dye inks have the disadvantage of poor water resistance and light resistance. Therefore, in recent years, pigment ink has been increasingly used.

Inkjet recording using the pigment ink has been used for commercial printing applications such as a high-speed continuous book machine. In such commercial printing applications, it is required to obtain an image quality equivalent to that of conventional offset printing even for a coated paper having a low ink absorption as a printing medium.
In order to ensure the high-speed drying property (high-speed fixing property) required for the high-speed continuous book machine and the fixing property to a low ink-absorbing medium, the ink needs to contain a resin.
However, since the ink containing the resin adheres firmly to the ink discharge head, the conventional cleaning liquid has insufficient cleaning power, and it is difficult to ensure ink discharge reliability.

For this reason, for example, a cleaning liquid has been proposed in the case of using an ink having resin particles of 0.1% by mass or more and 50% by mass or less in the ink (see, for example, Patent Document 1).
In addition, a technique has been proposed in which a resin having high Martens hardness is included as resin particles in the ink to obtain a coating film having excellent scratch resistance (see, for example, Patent Document 2).
In order to improve maintainability, a maintenance method has been proposed in which the ejection surface of the ink head is cleaned with a cloth containing a cleaning liquid (see, for example, Patent Document 3).
Furthermore, a maintenance liquid for ink jet printers has been proposed that contains at least one of glycol ethers and glycol esters in an amount of 80% by mass or more in the maintenance liquid (for example, see Patent Document 4).

  An object of this invention is to provide the washing | cleaning liquid which has sufficient cleaning power and can ensure favorable discharge reliability.

The cleaning liquid of the present invention as a means for solving the above problems is a cleaning liquid used for cleaning ink containing water and resin.
The cleaning liquid is a cleaning liquid containing water and a solvent,
The solvent contains a glycol ether compound represented by the following general formula 1,
The swelling ratio calculated based on the following formula 1 from the mass before and after immersion of the ink film obtained by drying the ink in the cleaning liquid at 25 ° C. for 24 hours is 20% or more and 150% or less.
R ¹ (OR ² ) _X OR ³ ... General formula 1
However, in the general formula 1, ^{R 1} and ^{R 3} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, ^{R 2} represents an alkyl group having 2 to 3 carbon atoms, X is 1 Represents an integer of 4.
Swell rate (%) = 100 × [(BA) / A] Formula 1
In Formula 1, A represents the mass of the ink film before immersion, and B represents the mass of the ink film after immersion.

  According to the present invention, it is possible to provide a cleaning liquid that has a sufficient cleaning power and can ensure good ejection reliability.

FIG. 1 is a schematic view showing an example of the cleaning apparatus of the present invention. FIG. 2 is a perspective explanatory view showing an example of a serial type image forming apparatus. FIG. 3 is a perspective explanatory view showing an example of a main tank of the apparatus of FIG.

(Cleaning solution)
The cleaning liquid of the present invention is a cleaning liquid used for cleaning ink containing water and resin.
The cleaning liquid is a cleaning liquid containing water and a solvent,
The solvent contains a glycol ether compound represented by the following general formula 1,
The swelling ratio calculated based on the following formula 1 from the mass before and after immersion of the ink film in the cleaning liquid at 25 ° C. for 24 hours is 20% or more and 150% or less, and further if necessary And other ingredients.
R ¹ (OR ² ) _X OR ³ ... General formula 1
However, in the general formula 1, ^{R 1} and ^{R 3} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, ^{R 2} represents an alkyl group having 2 to 3 carbon atoms, X is 1 Represents an integer of 4.
Swell rate (%) = 100 × [(BA) / A] Formula 1
In Formula 1, A represents the mass of the ink film before immersion, and B represents the mass of the ink film after immersion.

The cleaning liquid of the present invention is an ink that is improved in drying and fixing properties, but is particularly difficult to remove stains, as in the ink described in Patent Document 2 in the cleaning liquid and maintenance method described in Patent Documents 1 and 3. On the other hand, it is based on the knowledge that sufficient detergency cannot be secured.
In the maintenance liquid for inkjet printers containing at least one of the glycol ethers and glycol esters described in Patent Document 4 in an amount of 80% by mass or more in the maintenance liquid, the ink adhered to the ejection surface of the head This is based on the knowledge that the ink remaining after washing is more firmly fixed to the nozzle surface.

The swelling ratio calculated based on the following formula 1 from the mass before and after immersion of the ink film obtained by drying the ink in the cleaning liquid at 25 ° C. for 24 hours is 20% or more and 150% or less. The lower limit is preferably 50% or more, and more preferably 58% or more.
When the degree of swelling with respect to the cleaning liquid is 20% or more and 150% or less, the ink film can be swollen.
Swell rate (%) = 100 × [(BA) / A] Formula 1
In Formula 1, A represents the mass of the ink film before immersion, and B represents the mass of the ink film after immersion.
Here, the film swelling degree of the ink film with respect to the cleaning liquid can be obtained as follows.
Ink is dropped onto a Teflon (registered trademark) petri dish (diameter 30 mm) and dried in a thermostatic bath at 50 ° C. for 1 day to produce an ink film having an average thickness of 1 mm after drying.
The prepared ink film is cut into a size of 5 mm × 5 mm, and then mass measurement is performed. The cut ink film is put into a 5 mL glass bottle, and further 1 g of a cleaning solution is put into the glass bottle so as to be immersed, and left in a sealed state at 25 ° C. for 24 hours.
After leaving at 25 ° C. for 24 hours, the ink film is taken out from the glass bottle, wiped with Kimwipe to such an extent that the surface cleaning liquid cannot be visually confirmed, mass measurement is performed, and the swelling ratio can be calculated from Equation 1 above. .

  The cleaning liquid of the present invention contains water and a solvent, preferably contains a surfactant, and further contains other components as necessary.

<Solvent>
The said solvent contains the glycol ether compound represented by following General formula 1, and also contains another solvent as needed.
Since the glycol ether compound represented by the general formula 1 has a stronger force acting on the ink film than other solvents, the cleaning property can be improved.
R ¹ (OR ² ) _X OR ³ ... General formula 1
In Formula 1, R ¹ and R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, wherein the alkyl group having 1 to 4 carbon atoms, such as methyl group, ethyl group, A propyl group, a butyl group, etc. are mentioned.
In Formula 1, R ² represents an alkyl group having 2 to 3 carbon atoms, for example, an ethyl group, a propyl group.
X represents an integer of 1 to 4.

Examples of the glycol ether compound represented by the general formula (1) include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol; ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol. Monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, propylene glycol n-pro Ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, etc. glycol ethers such as tetraethylene glycol diethyl ether. These may be used individually by 1 type and may use 2 or more types together.
Among these, diethylene glycol monobutyl ether, diethylene glycol diethyl ether, triethylene glycol monobutyl ether, and tripropylene glycol monomethyl ether are preferable.

  30 mass% or more and 70 mass% or less are preferable with respect to the whole quantity of the said washing | cleaning liquid, and, as for content of the glycol ether compound represented by the said General formula (1), 45 mass% or more and 60 mass% or less are more preferable. When the content is 30% by mass or more, it is possible to swell the ink film to a wiping level, and when the content is 70% by mass or less, the ink surface does not swell excessively. And can be wiped clean from the ink stain interface.

<Other solvents>
There is no restriction | limiting in particular as said other solvent, According to the objective, it can select suitably, For example, a water-soluble organic solvent, a C8-C11 polyol compound, etc. are mentioned.
Examples of the water-soluble organic solvent include polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds. Is mentioned.
Examples of the water-soluble organic solvent 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, 2 , 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-hexa Polyhydric alcohols such as diol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, and petriol; 2-pyrrolidone, Nitrogen-containing heterocyclic compounds such as N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone; formamide, N-methylformamide Amides such as N, N-dimethylformamide, 3-methoxy-N, N-dimethylpropionamide and 3-butoxy-N, N-dimethylpropionamide; amines such as monoethanolamine, diethanolamine and triethylamine; dimethyl sulfoxide , Sulfolane, thiodiethanol and other sulfur-containing compounds; Ren carbonate, and the like ethylene carbonate. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the polyol compound having 8 to 11 carbon atoms include 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and the like.

<Water>
There is no restriction | limiting in particular as said water, According to the objective, it can select suitably, For example, pure water, such as ion-exchange water, ultrafiltration water, reverse osmosis water, distilled water, ultrapure water, etc. are mentioned. .
The content of water is not particularly limited and may be appropriately selected depending on the intended purpose. preferable. When the content is 20% by mass or more and 80% by mass or less, it can be wiped cleanly from the interface between the nozzle surface and the ink stain.

<Surfactant>
As the surfactant, any of a silicone surfactant, a fluorine surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant can be used.
There is no restriction | limiting in particular in the said silicone type surfactant, According to the objective, it can select suitably. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, and side chain both terminal modified polydimethylsiloxane. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene group are particularly preferred because they exhibit good properties as an aqueous surfactant. As the silicone-based surfactant, a polyether-modified silicone-based surfactant can also be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the Si part side chain of dimethylsiloxane.
Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate ester compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. The polyoxyalkylene ether polymer compound is particularly preferred because of its low foamability. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylate. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a perfluoroalkyl ether group in the side chain. Examples thereof include salts of polyoxyalkylene ether polymers. As counter ions of salts in these fluorosurfactants, 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 etc. are mentioned.
Examples of the amphoteric surfactant include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Examples of the nonionic surfactant include polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene. Examples include sorbitan fatty acid esters and ethylene oxide adducts of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.
These may be used alone or in combination of two or more.

The silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, side Since both ends of the chain are modified with polydimethylsiloxane, a polyether-modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group exhibits good properties as an aqueous surfactant. preferable.
As such a surfactant, an appropriately synthesized product or a commercially available product may be used. Commercially available products can be obtained from, for example, Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., and Kyoeisha Chemical Co., Ltd.
There is no restriction | limiting in particular as said polyether modified silicone surfactant, According to the objective, it can select suitably, For example, the polyalkylene oxide structure represented by a general formula (S-1) type | formula is dimethylpolyethylene. Examples thereof include those introduced into the side chain of Si part of siloxane.
[General Formula (S-1)]
(In the general formula (S-1), m, n, a, and b represent integers. R and R ′ represent an alkyl group and an alkylene group.)
A commercial item can be used as said polyether modified silicone type surfactant, For example, KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Japan Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Bic Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.), etc. are mentioned.

<Other ingredients>
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, an antifoamer, antiseptic / antifungal agent, a rust preventive agent, a pH adjuster etc. are mentioned.

<Antifoaming agent>
There is no restriction | limiting in particular as an antifoamer, For example, a silicone type antifoamer, a polyether type | system | group antifoamer, a fatty-acid ester type | system | group antifoamer etc. are mentioned. These may be used alone or in combination of two or more. Among these, a silicone type antifoaming agent is preferable from the viewpoint of excellent foam breaking effect.

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

<Rust preventive>
There is no restriction | limiting in particular as a rust preventive agent, For example, acidic sulfite, sodium thiosulfate, etc. are mentioned.

<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.

(Set of ink and cleaning liquid)
The set of ink and cleaning liquid of the present invention is a set of ink and cleaning liquid having ink and cleaning liquid,
The ink contains water and a resin;
The cleaning liquid contains water and a solvent;
The solvent contains a glycol ether compound represented by the following general formula 1,
The swelling ratio calculated based on the following formula 1 from the mass before and after immersion of the ink film obtained by drying the ink in the cleaning liquid at 25 ° C. for 24 hours is 20% or more and 150% or less.
R ¹ (OR ² ) _X OR ³ ... General formula 1
However, in the general formula 1, ^{R 1} and ^{R 3} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, ^{R 2} represents an alkyl group having 2 to 3 carbon atoms, X is 1 Represents an integer of 4.
Swell rate (%) = 100 × [(BA) / A] Formula 1
In Formula 1, A represents the mass of the ink film before immersion, and B represents the mass of the ink film after immersion.

  The cleaning liquid of the present invention is used as the cleaning liquid in the ink and cleaning liquid set of the present invention.

  The ink in the ink and cleaning liquid set of the present invention contains water and a resin, preferably contains an organic solvent and a coloring material, and further contains other components as necessary.

<Resin>
The type of resin contained in the ink is not particularly limited and can be appropriately selected according to the purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene type Examples thereof include resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.
Resin particles made of these resins may be used. An ink can be obtained by mixing resin particles with a material such as a colorant or an organic solvent in a resin emulsion state in which water is dispersed as a dispersion medium. As said resin particle, what was synthesize | combined suitably may be used and a commercial item may be used. Moreover, these may be used individually by 1 type, or may be used in combination of 2 or more types of resin particles.

The volume average particle diameter of the resin particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 nm or more and 1,000 nm or less from the viewpoint of obtaining good fixability and high image hardness. It is more preferably 200 nm or less and particularly preferably 10 nm or more and 100 nm or less.
The volume average particle diameter can be measured using, for example, a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

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

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

<Organic solvent>
The organic solvent used in the present invention is not particularly limited, and a water-soluble organic solvent can be used. Examples thereof include ethers such as polyhydric alcohols, polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds.
Specific examples of the water-soluble organic solvent include, for example, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol 2,4-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-he Polyhydric alcohols such as sundiol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, petriol, ethylene glycol mono Polyhydric alcohol alkyl ethers such as ethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monophenyl ether, ethylene glycol mono Polyhydric alcohol aryl ethers such as benzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl- -N-containing heterocyclic compounds such as pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone, formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, Amides such as N-dimethylpropionamide and 3-butoxy-N, N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane and thiodiethanol, propylene carbonate, Examples thereof include ethylene carbonate.
In addition to functioning as a wetting agent, it is preferable to use an organic solvent having a boiling point of 250 ° C. or lower because good drying properties can be obtained.

<Color material>
The color material is not particularly limited, and pigments and dyes can be used.
An inorganic pigment or an organic pigment can be used as the pigment. These may be used alone or in combination of two or more. A mixed crystal may be used.
As the pigment, for example, a black pigment, a yellow pigment, a magenta pigment, a cyan pigment, a white pigment, a green pigment, an orange pigment, a glossy pigment such as gold or silver, a metallic pigment, or the like can be used.
Carbon black produced by known methods such as contact method, furnace method, thermal method in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow as inorganic pigments Can be used.
Organic pigments include azo pigments, polycyclic pigments (eg, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinofullerone pigments). Dye chelates (for example, basic dye type chelates, acidic dye type chelates), nitro pigments, nitroso pigments, aniline black, and the like can be used. Of these pigments, those having good affinity with the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
Specific examples of pigments include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11). And organic pigments such as metals such as titanium oxide and aniline black (CI Pigment Black 1).
Further, for color use, 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 (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 acid dye, a direct dye, a reactive dye, and a basic dye can be used. One kind may be used alone, or two or more kinds 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, and 35 are mentioned.

  The content of the color 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 dispersing the pigment surface by coating with a resin, a method of dispersing using a dispersant, Etc.
Examples of a method for introducing a hydrophilic functional group into a pigment to form a self-dispersing pigment include a self-dispersing pigment that can be dispersed in water by adding a functional group such as a sulfone group or a carboxyl group to the pigment (for example, carbon). Can be used.
As a method for coating the surface of the pigment with a resin and dispersing it, a method in which the pigment is included in microcapsules and can be dispersed in water can be used. This can be paraphrased as a resin-coated pigment. In this case, it is not necessary that all pigments blended in the ink are coated with a resin, and within a range where the effects of the present invention are not impaired, uncoated pigments and partially coated pigments are dispersed in the ink. It may be.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular type dispersant or 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 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and naphthalenesulfonic acid Na formalin condensate can also be suitably used as a dispersant.
A dispersing agent may be used individually by 1 type, or may use 2 or more types together.

<Pigment dispersion>
An ink can be obtained by mixing a material such as water or an organic solvent with a color material. Further, it is also possible to produce an ink by mixing a pigment, other water, a dispersant, and the like into a pigment dispersion and mixing a material such as water or an organic solvent.
The pigment dispersion is obtained by dispersing water, a pigment, a pigment dispersant, and other components as required, and adjusting the particle size. For dispersion, a disperser is preferably used.
The particle diameter of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency is 20 nm or more in terms of maximum number because the pigment dispersion stability is good and the image quality such as ejection stability and image density is also high. 500 nm or less is preferable and 20 nm or more and 150 nm or less are more preferable. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).
The content of the pigment in the pigment dispersion is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good ejection stability and increasing the image density, 0.1% by mass. % To 50% by mass is preferable, and 0.1% to 30% by mass is more preferable.
The pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifugal separator or the like, if necessary.

<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>
As the surfactant, any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants and anionic surfactants can be used.
There is no restriction | limiting in particular as a silicone type surfactant, According to the objective, it can select suitably. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, and side chain both terminal modified polydimethylsiloxane. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene group are particularly preferred because they exhibit good properties as an aqueous surfactant. In addition, as the silicone surfactant, a polyether-modified silicone surfactant can be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the side chain of the Si portion of dimethylsiloxane.
Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. Polyoxyalkylene ether polymer compounds are particularly preferred because of their low foaming properties. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylate. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a perfluoroalkyl ether group in the side chain. Examples thereof include salts of polyoxyalkylene ether polymers. As counter ions of salts in these fluorosurfactants, 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 etc. are mentioned.
Examples of amphoteric surfactants include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Nonionic surfactants include, for example, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan Examples include fatty acid esters and ethylene oxide adducts of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.
These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as content of surfactant in an ink, Although it can select suitably according to the objective, From the point which is excellent in wettability and discharge stability, and image quality improves, it is 0.001 mass. % To 5% by mass is preferable, and 0.05% to 5% by mass is more preferable.

<Antifoaming agent>
There is no restriction | limiting in particular as an antifoamer, For example, a silicone type antifoamer, a polyether type | system | group antifoamer, a fatty-acid ester type | system | group antifoamer etc. are mentioned. These may be used alone or in combination of two or more. Among these, a silicone type antifoaming agent is preferable from the viewpoint of excellent foam breaking effect.

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

<Rust preventive>
There is no restriction | limiting in particular as a rust preventive agent, For example, acidic sulfite, sodium thiosulfate, etc. are mentioned.

<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.

There is no restriction | limiting in particular as a physical property of an ink, According to the objective, it can select suitably, For example, it is preferable that a viscosity, surface tension, pH, etc. are the following ranges.
The viscosity at 25 ° C. of the ink is preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa · s or less from the viewpoint of improving the printing density and character quality and obtaining good discharge properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. Measurement conditions are 25 ° C., standard cone rotor (1 ° 34 ′ × R24), sample liquid amount 1.2 mL, rotation speed 50 rpm, and measurement is possible for 3 minutes.
The surface tension of the ink is preferably 35 mN / m or less and 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 7 to 12 and more preferably 8 to 11 from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

<Recording medium>
The recording medium used for recording is not particularly limited, and examples thereof include plain paper, glossy paper, special paper, cloth, film, OHP sheet, and general-purpose printing paper.

(Cleaning method and cleaning device)
The cleaning method of the present invention is a cleaning method for cleaning the nozzle surface of the ink discharge head,
A step of applying a cleaning liquid to the wiping member on the pressing member (hereinafter sometimes referred to as a “cleaning liquid applying step”);
A step of wiping the nozzle surface with the wiping member to which the cleaning liquid has been applied (hereinafter also referred to as “wiping step”), and further including other steps as necessary.
The cleaning liquid is the cleaning liquid of the present invention.

The cleaning device of the present invention is a cleaning device for cleaning the nozzle surface of the ink discharge head,
Means for applying a cleaning liquid to the wiping member on the pressing member (hereinafter sometimes referred to as “cleaning liquid applying means”);
Means for wiping the nozzle surface with the wiping member to which the cleaning liquid is applied (hereinafter also referred to as “wiping means”), and further includes other means as necessary.
The cleaning liquid is the cleaning liquid of the present invention.

<Cleaning liquid application process and cleaning liquid application means>
The pressing member is not particularly limited as long as it is a member capable of pressing the nozzle surface via the wiping member, and can be appropriately selected according to the purpose. For example, a pressing roller, a pressing roller, and a pressing belt A combination, a wiper, a blade, etc. are mentioned. Among these, a pressure roller is preferable.
The application means is not particularly limited as long as a certain amount of cleaning liquid can be applied, and can be appropriately selected according to the purpose. Examples thereof include application using a dropper, nozzle, spray, dispenser, and coating device.
There is no restriction | limiting in particular as said wiping member, According to the objective, it can select suitably, For example, a nonwoven fabric, cloth, etc. are mentioned. These are preferably wound in a roll shape, and a roll-shaped non-woven fabric is preferable from the viewpoint that dust generation is difficult and reliability is high.

The application amount of the cleaning liquid is preferably controlled by the recording time. In this case, it is more preferable that the application amount of the cleaning liquid is selected from a plurality of set values. Examples of the plurality of set values include a cleaning liquid application method (for example, “pressure”, “number of times of application”, “number of application nozzles”).
The application amount of the cleaning liquid is preferably controlled by a pressure applied to a cleaning liquid application nozzle as a cleaning liquid application unit. When the cleaning liquid is applied from a plurality of cleaning liquid application nozzles, it is preferable that the application amount of the cleaning liquid to the wiping member is controlled by the number of the cleaning liquid application nozzles. The amount of the cleaning liquid applied to the wiping member is preferably controlled by the number of times the cleaning liquid is applied from the cleaning liquid application nozzle.

<Wiping process and wiping means>
The wiping step is a step of wiping the nozzle surface with a wiping member to which a cleaning liquid is applied, and is preferably carried out by wiping means.
The method for wiping the nozzle surface with the wiping member to which the cleaning liquid has been applied is not particularly limited and can be appropriately selected according to the purpose. For example, a nonwoven fabric as the wiping member to which the cleaning liquid has been applied is used as the pressing member. For example, a method of pressing the nozzle surface of the ink discharge head with a pressing roller may be used.

<Other processes and other means>
Examples of the other steps and the other means include a control step and a control means.
Examples of the control means include devices such as sequencers and computers.

Here, FIG. 1 is a schematic view showing an example of the cleaning apparatus of the present invention. The cleaning device 300 in FIG. 1 is a device that cleans the nozzle surface 301a on the ink discharge side of the nozzle plate 301 of the ink discharge head.
The cleaning apparatus 300 includes a nonwoven fabric 303 as a wiping member, a cleaning liquid application nozzle 302 as a cleaning liquid application unit, a pressing roller 305 as a pressing member, and a take-up roller 304 that winds up the nonwoven fabric after the wiping process. Yes.
The cleaning liquid is supplied from the cleaning liquid tank via a cleaning liquid supply tube (not shown). By driving a pump provided in the middle of the cleaning liquid supply tube, the cleaning liquid is applied from the cleaning liquid application nozzle 302 to the non-woven fabric 303 as the wiping member in an application amount of the cleaning liquid according to the recording time. The nonwoven fabric 303 is wound in a roll shape.
As shown in FIG. 1, the non-woven fabric 303 to which the cleaning liquid is applied is brought into contact with and pressed against the nozzle surface 301a of the nozzle plate 301 by a pressing roller 305 as a pressing member, thereby cleaning the nozzle surface 301a. After the wiping process is completed, the nonwoven fabric 303 is taken up by the take-up roller 304.
A plurality of cleaning liquid application nozzles 302 as cleaning liquid application means can be provided, and pressure is applied based on control of a control means (not shown), and the application amount of the cleaning liquid can be changed by appropriately changing the pressure. Can be adjusted. Further, the amount of the cleaning liquid applied can be adjusted by changing the number of nozzles to which the cleaning liquid is applied based on the control of the control means (not shown). Furthermore, the application amount of the cleaning liquid can be adjusted by changing the number of times of applying the cleaning liquid based on the control of the control means (not shown).

(Printing method and printing apparatus)
The printing method of the present invention includes a discharge step of discharging ink from a nozzle of an ink discharge head;
A cleaning process for cleaning the nozzle surface of the ink discharge head, and further includes other processes as necessary.
The cleaning step is performed by the cleaning method of the present invention.

The printing apparatus of the present invention includes an ink discharge head having a nozzle for discharging ink,
Cleaning means for cleaning the nozzle surface of the ink discharge head, and further includes other means as necessary.
The cleaning means is the cleaning device of the present invention.

The ink used in the present invention can be suitably used in various recording apparatuses using an ink jet recording method, such as a printer, a facsimile apparatus, a copying apparatus, a printer / fax / copier complex machine, and a three-dimensional modeling apparatus.
In the present invention, the recording apparatus and the recording method are an apparatus capable of ejecting ink, various treatment liquids, and the like to a recording medium, and a method of performing recording using the apparatus. The recording medium means a medium on which ink or various processing liquids can be temporarily attached.
The recording apparatus can include not only a head portion that ejects ink but also means for feeding, transporting, and discharging a recording medium, and other devices called pre-processing devices and post-processing devices. .
The recording apparatus and the recording method may include a heating unit used in the heating step and a drying unit used in the drying step. The heating means and the drying means include, for example, a means for heating and drying the printing surface and the back surface of the recording medium. Although it does not specifically limit as a heating means and a drying means, For example, a warm air heater and an infrared heater can be used. Heating and drying can be performed before printing, during printing, after printing, and the like.
Further, the recording apparatus and the recording method are not limited to those in which significant images such as characters and figures are visualized by ink. For example, what forms patterns, such as a geometric pattern, etc. includes what forms a three-dimensional image.
Further, the recording apparatus includes both a serial type apparatus that moves the ejection head and a line type apparatus that does not move the ejection head, unless otherwise specified.
Furthermore, this recording apparatus can use not only a desktop type but also a wide recording apparatus that can print on an A0 size recording medium, for example, a continuous paper wound up in a roll shape as a recording medium. Also included are continuous paper printers.

An example of the recording apparatus will be described with reference to FIGS. FIG. 2 is a perspective view of the apparatus. FIG. 3 is a perspective view of the main tank. An image forming apparatus 400 as an example of a recording apparatus is a serial type image forming apparatus. A mechanism unit 420 is provided in the exterior 401 of the image forming apparatus 400. Each ink storage portion 411 of the main tank 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is, for example, an aluminum laminate film or the like. It is formed of a packaging member. The ink storage unit 411 is stored in, for example, a plastic container case 414. As a result, the main tank 410 is used as an ink cartridge for each color.
On the other hand, a cartridge holder 404 is provided on the inner side of the opening when the cover 401c of the apparatus main body is opened. A main tank 410 is detachably attached to the cartridge holder 404. Thus, 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 ink can be discharged from the discharge heads 434 to the recording medium.

The use of the ink used in the present invention is not particularly limited and can be appropriately selected according to the purpose. For example, it can be applied to printed matter, paint, coating material, base material and the like. Furthermore, it can be used not only to form two-dimensional characters and images using ink, but also as a three-dimensional modeling material for forming a three-dimensional three-dimensional image (three-dimensional modeled object).
A known three-dimensional modeling apparatus for modeling a three-dimensional model can be used, and is not particularly limited. For example, a three-dimensional modeling apparatus including an ink storage unit, a supply unit, a discharge unit, a drying unit, or the like is used. be able to. The three-dimensional structure includes a three-dimensional structure obtained by repeatedly applying ink. Further, a molded product obtained by processing a structure provided with ink on a substrate such as a recording medium is also included. The molded product is obtained by subjecting a recorded material or a structure formed in a sheet shape or a film shape to a molding process such as heat stretching or punching, for example, an automobile, an OA device, an electric -It is suitably used for applications in which surfaces are decorated after decorating, such as meters for electronic devices, cameras, etc., and panels for operation units.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

(Ink Preparation Example 1)
<Preparation of ink 1>
-Preparation of white pigment dispersion-
In a beaker, 5 g of polyoxyethylene styrenated phenyl ether (Neugen EA-177, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., HLB = 15.6, solid content 100% by mass) is dissolved in 200.0 g of high-purity water, and an organic white pigment Add 50.0 g of particles (Shigenox OWP, manufactured by Hackol Chemical Co., Ltd.), disperse to a state free of lumps while stirring for 30 minutes at 5000 rpm with an excel auto homogenizer manufactured by Nippon Seiki Seisakusho, and gradually rotate The mixture was stirred for 30 minutes at 10,000 rpm.
The obtained organic white pigment particle dispersion was treated with an ultrasonic homogenizer US-300T manufactured by Nippon Seiki Seisakusho Co., Ltd. (chip diameter 26 mm) for 1 hour while cooling with water. Advanced NanoTechnology Co., Ltd. uses DYNO-Mil multi-lab type manufactured by Maruenterprise, Inc., using zirconia beads with a diameter of 2 mm as media particles, a bead filling rate of 70% by volume, a stirring blade peripheral speed of 8 m / s, and batch processing for 30 minutes. A 20-pass dispersion process was performed at a pressure of 100 MPa using a nanomaker.
Then, it filtered with the membrane filter (cellulose acetate membrane) with an average hole diameter of 5 micrometers, and obtained the organic white pigment particle dispersion whose organic white pigment particle | grains were 19.6 mass%.

Next, 1,3-butanediol 15.0 mass%, 1,2-propanediol 15.0 mass%, acrylic resin emulsion (trade name: Boncoat R-3380-E, manufactured by DIC Corporation, solid content concentration: 45 mass%) 6.7 mass% (solid content 3 mass%), and fluorosurfactant (trade name: Zonyl (registered trademark) FSO-100, manufactured by DuPont) 1.0 mass% were added and stirred. After mixing, 20.0% by mass of the organic white pigment particle dispersion and the remaining amount of ion-exchanged water were added and stirred for 1 hour.
Next, pressure filtration was performed using a polypropylene filter having an average pore size of 1.5 μm to remove coarse particles, whereby ink 1 was prepared.

(Ink Preparation Example 2)
-Preparation of ink 2-
In Ink Preparation Example 1, the content of acrylic resin emulsion (manufactured by DIC Corporation, trade name: Boncoat R-3380-E, solid content concentration: 45 mass%) is 11.1 mass% (solid content 5 mass%). Ink 2 was prepared in the same manner as Ink Preparation Example 1 except that

(Ink Preparation Example 3)
-Preparation of ink 3-
In Ink Preparation Example 1, the content of the organic white pigment particle dispersion was 30% by mass, and an acrylic resin emulsion (manufactured by DIC Corporation, trade name: Boncoat R-3380-E, solid content concentration: 45% by mass). Ink 3 was prepared in the same manner as Ink Preparation Example 1, except that the content was changed to 17.8% by mass (solid content 8% by mass).

(Ink Preparation Example 4)
As ink 4, LX100 / LX101 latex ink cartridge white ink (manufactured by MIMAKI ENGINEERING CO., LTD., Product number: LX100-W-22), which is a resin-containing ink, was prepared.

(Ink Preparation Example 5)
As the ink 5, HP 831B 775-ml magenta Latex ink cartridge (manufactured by HP, product number: CZ690A), which is a resin-containing ink, was prepared.

* In Table 1, the content of the acrylic resin emulsion is a numerical value in terms of solid content.

In Table 1, 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 Co., Ltd.-Acrylic resin emulsion: manufactured by DIC Corporation, trade name: Boncoat R-3380-E, solid content concentration : 45% by mass
Surfactant: manufactured by DuPont, trade name: Zonyl (registered trademark) FSO-100

(Examples 1-14 and Comparative Examples 1-7)
<Preparation of cleaning solutions 1-16>
According to the composition and content of the following Table 2 to Table 5, each component was mixed in order from the top to prepare cleaning liquids 1-16.

<Preparation of cleaning liquid 17>
A commercially available MIMAKI01 (manufactured by MIMAKI ENGINEERING CO., LTD.) Was used as the cleaning liquid 17. The composition and content of this cleaning liquid 17 are shown in Table 5.

In addition, about the brand name of a component in the said Table 2-Table 5, and a manufacturer's name, it is as follows.
<Solvent>
・ Diethylene glycol monobutyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ Diethylene glycol diethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ Triethylene glycol monobutyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ Tripropylene glycol monomethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ 2-Pyrrolidone (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ 2,2,4-Trimethyl-1,3-pentanediol (manufactured by Wako Pure Chemical Industries, Ltd.)
・ 2-ethyl-1,3-hexanediol (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Surfactant>
・ LS-106 (manufactured by Kao Corporation) higher alcohol ether type nonionic surfactant ・ WET-240 (manufactured by Nissin Chemical) silicone surfactant ・ BYK-349 (manufactured by BYK) silicone interface Activator

Next, as shown in Table 6 below, the ink and the cleaning liquid were combined to form ink and cleaning liquid sets of Examples 1 to 14 and Comparative Examples 1 to 7.
Various characteristics were evaluated as follows using the obtained sets of ink and cleaning liquid. The results are shown in Table 6.

<Swelling rate>
Ink was dropped onto a Teflon (registered trademark) petri dish (diameter: 30 mm) and dried in a thermostatic bath at 50 ° C. for 1 day to prepare an ink film having an average thickness of 1 mm after drying.
The prepared ink film was cut into a size of 5 mm × 5 mm, and then mass measurement was performed. The cut ink film was put into a 5 mL glass bottle, and further 1 g of a cleaning solution was put into the bottle and immersed therein, and left in a sealed state at 25 ° C. for 24 hours.
After leaving at 25 ° C. for 24 hours, the ink film is taken out of the glass bottle, wiped with Kimwipe (manufactured by Nippon Paper Crecia Co., Ltd.) to the extent that the surface cleaning liquid cannot be visually confirmed, and mass measurement is performed. The swelling rate was calculated.
Swell rate (%) = 100 × [(BA) / A] Formula 1
In Formula 1, A represents the mass of the ink film before immersion, and B represents the mass of the ink film after immersion.

<Discharge reliability>
Using the printer shown in FIG. 1, the ink in each ink and cleaning liquid set shown in Table 6 was continuously discharged for 45 minutes, and after stopping the discharge, the nozzle surface of the discharge head was dried for 30 minutes, and then a dropper was used. Apply 3 mL of each cleaning solution to Anticon (clean wiper Anticon GOLD, polyester long fiber), wipe the nozzle surface, and then discharge again using the ink. Evaluated.
[Evaluation criteria]
◎: Discharge turbulence or non-discharge is not observed at all ○: Discharge turbulence or non-discharge of 2 nozzles or less, but immediately recovers △: Discharge turbulence exceeding 2 nozzles and 5 nozzles or less, non-discharge immediately Recovered ×: Discharge disturbance and non-discharge exceeding 2 nozzles and 5 nozzles or less XX: Discharge disturbance and non-discharge exceeding 5 nozzles

<Ink fixability>
An ink jet printer (IPSiO GX5000, manufactured by Ricoh Co., Ltd.) was filled with ink in a set of each ink and cleaning liquid shown in Table 6, and recording was performed on Type 6200 paper (NBS Ricoh Co., Ltd.) at a resolution of 600 dpi.
Subsequently, the filter paper was pressed against the recording portion, the transfer condition onto the filter paper was visually observed, and the “ink fixability” was evaluated according to the following criteria.
〔Evaluation criteria〕
◎: No pigment transfer to filter paper is observed ○: No pigment transfer to filter paper is observed △: Partial pigment transfer is observed ×: Most pigment transfer is observed

Aspects of the present invention are as follows, for example.
<1> In a cleaning liquid used for cleaning ink containing water and resin,
The cleaning liquid is a cleaning liquid containing water and a solvent,
The solvent contains a glycol ether compound represented by the following general formula 1,
The swelling ratio calculated from the mass before and after immersion of the ink film obtained by drying the ink in the cleaning liquid at 25 ° C. for 24 hours is 20% or more and 150% or less. It is a cleaning solution.
R ¹ (OR ² ) _X OR ³ ... General formula 1
However, in the general formula 1, ^{R 1} and ^{R 3} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, ^{R 2} represents an alkyl group having 2 to 3 carbon atoms, X is 1 Represents an integer of 4.
Swell rate (%) = 100 × [(BA) / A] Formula 1
In Formula 1, A represents the mass of the ink film before immersion, and B represents the mass of the ink film after immersion.
<2> In the above <1>, the glycol ether compound represented by the general formula 1 is at least one selected from diethylene glycol monobutyl ether, diethylene glycol diethyl ether, triethylene glycol monobutyl ether, and tripropylene glycol monomethyl ether. It is a washing | cleaning liquid of description.
<3> The cleaning liquid according to any one of <1> to <2>, wherein a content of the glycol ether compound represented by the general formula (1) in the cleaning liquid is 30% by mass or more and 70% by mass or less. is there.
<4> The cleaning liquid according to any one of <1> to <3>, wherein a content of the glycol ether compound represented by the general formula (1) in the cleaning liquid is 45% by mass or more and 60% by mass or less. is there.
<5> The cleaning liquid according to any one of <1> to <4>, wherein the cleaning liquid contains a surfactant.
<6> The cleaning liquid according to <5>, wherein the surfactant is a silicone-based surfactant.
<7> The cleaning liquid according to <6>, wherein the silicone surfactant is a polyether-modified silicone surfactant.
<8> The cleaning liquid according to any one of <1> to <7>, wherein the cleaning liquid contains a polyol compound having 8 to 11 carbon atoms.
<9> In the above <8>, the polyol compound having 8 to 11 carbon atoms is any of 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol. It is a washing | cleaning liquid of description.
<10> The cleaning liquid according to any one of <1> to <9>, wherein a content of the resin in the ink is 5% by mass or more.
<11> The cleaning liquid according to any one of <1> to <10>, wherein a content of the resin in the ink is 5% by mass or more and 30% by mass or less.
<12> A set of ink and cleaning liquid having ink and cleaning liquid,
The ink contains water and a resin;
The cleaning liquid contains water and a solvent;
The solvent contains a glycol ether compound represented by the following general formula 1,
The swelling ratio calculated from the mass before and after immersion of the ink film obtained by drying the ink in the cleaning liquid at 25 ° C. for 24 hours is 20% or more and 150% or less. A set of ink and cleaning liquid.
R ¹ (OR ² ) _X OR ³ ... General formula 1
However, in the general formula 1, ^{R 1} and ^{R 3} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, ^{R 2} represents an alkyl group having 2 to 3 carbon atoms, X is 1 Represents an integer of 4.
Swell rate (%) = 100 × [(BA) / A] Formula 1
In Formula 1, A represents the mass of the ink film before immersion, and B represents the mass of the ink film after immersion.
<13> In the above <12>, the glycol ether compound represented by the general formula 1 is at least one selected from diethylene glycol monobutyl ether, diethylene glycol diethyl ether, triethylene glycol monobutyl ether, and tripropylene glycol monomethyl ether. It is a set of the described ink and cleaning liquid.
<14> The ink according to any one of <12> to <13>, wherein a content of the glycol ether compound represented by the general formula (1) in the cleaning liquid is 30% by mass or more and 70% by mass or less. A set of cleaning solutions.
<15> The ink according to any one of <12> to <14>, wherein a content of the glycol ether compound represented by the general formula (1) in the cleaning liquid is 45% by mass or more and 60% by mass or less. A set of cleaning solutions.
<16> The ink and cleaning liquid set according to any one of <12> to <15>, wherein the cleaning liquid contains a surfactant.
<17> The set of the ink and the cleaning liquid according to <16>, wherein the surfactant is a silicone-based surfactant.
<18> The ink and cleaning liquid set according to <17>, wherein the silicone surfactant is a polyether-modified silicone surfactant.
<19> The set of the ink and the cleaning liquid according to any one of <12> to <18>, wherein the cleaning liquid contains a polyol compound having 8 to 11 carbon atoms.
<20> In the above <19>, the polyol compound having 8 to 11 carbon atoms is any one of 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol. It is a set of the described ink and cleaning liquid.
<21> The set of the ink and the cleaning liquid according to any one of <12> to <20>, wherein a content of the resin in the ink is 5% by mass or more.
<22> The set of the ink and the cleaning liquid according to any one of <12> to <21>, wherein a content of the resin in the ink is 5% by mass or more and 30% by mass or less.
<23> A cleaning method for cleaning a nozzle surface of an ink discharge head,
Applying a cleaning liquid to the wiping member on the pressing member;
Wiping the nozzle surface with the wiping member provided with a cleaning liquid,
The cleaning method is a cleaning method according to any one of <1> to <11>.
<24> a discharge step of discharging ink from the nozzles of the ink discharge head;
Cleaning a nozzle surface of the ink discharge head,
The printing method is characterized in that the cleaning step is performed by the cleaning method according to <23>.
<25> A cleaning device for cleaning the nozzle surface of the ink discharge head,
Means for applying a cleaning liquid to the wiping member on the pressing member;
A means for wiping the nozzle surface with the wiping member provided with a cleaning liquid,
The cleaning apparatus is a cleaning apparatus according to any one of <1> to <11>.
<26> an ink discharge head having a nozzle for discharging ink;
Cleaning means for cleaning the nozzle surface of the ink discharge head,
The printing device is characterized in that the cleaning means is the cleaning device according to <25>.

  The cleaning liquid according to any one of <1> to <11>, the set of the ink and the cleaning liquid according to any one of <12> to <22>, the cleaning method according to <23>, and the <24> According to the printing method described in <5>, the cleaning device described in <25>, and the printing device described in <26>, the conventional problems can be solved and the object of the present invention can be achieved. .

400 Image forming apparatus 401 Exterior of image forming apparatus 401c Cover of apparatus main body 404 Cartridge holder 410 Main tank 410k, 410c, 410m, 410y For each color of black (K), cyan (C), magenta (M), yellow (Y) Main tank 411 Ink storage section 413 Ink discharge port 414 Storage container case 420 Mechanism section 434 Discharge head 436 Supply tube

JP2013-158918A JP 2014-198824 A JP 2013-132753 A Japanese Patent No. 4872781

Claims (11)

In the cleaning liquid used for cleaning ink containing water and resin,
The cleaning liquid is a cleaning liquid containing water and a solvent,
The solvent contains a glycol ether compound represented by the following general formula 1,
The swelling ratio calculated from the mass before and after immersion of the ink film obtained by drying the ink in the cleaning liquid at 25 ° C. for 24 hours is 20% or more and 150% or less. Cleaning liquid.
R ¹ (OR ² ) _X OR ³ ... General formula 1
However, in the general formula 1, ^{R 1} and ^{R 3} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, ^{R 2} represents an alkyl group having 2 to 3 carbon atoms, X is 1 Represents an integer of 4.
Swell rate (%) = 100 × [(BA) / A] Formula 1
In Formula 1, A represents the mass of the ink film before immersion, and B represents the mass of the ink film after immersion.   The cleaning liquid according to claim 1, wherein a content of the glycol ether compound represented by the general formula (1) in the cleaning liquid is 30% by mass or more and 70% by mass or less.   The cleaning liquid according to claim 1, wherein the cleaning liquid contains a surfactant.   The cleaning liquid according to claim 3, wherein the surfactant is a silicone-based surfactant.   The cleaning liquid according to any one of claims 1 to 4, wherein the cleaning liquid contains a polyol compound having 8 to 11 carbon atoms.   The cleaning liquid according to claim 1, wherein a content of the resin in the ink is 5% by mass or more. A set of ink and cleaning liquid having ink and cleaning liquid,
The ink contains water and a resin;
The cleaning liquid contains water and a solvent;
The solvent contains a glycol ether compound represented by the following general formula 1,
The swelling ratio calculated from the mass before and after immersion of the ink film obtained by drying the ink in the cleaning liquid at 25 ° C. for 24 hours is 20% or more and 150% or less. A set of ink and cleaning fluid.
R ¹ (OR ² ) _X OR ³ ... General formula 1
However, in the general formula 1, ^{R 1} and ^{R 3} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, ^{R 2} represents an alkyl group having 2 to 3 carbon atoms, X is 1 Represents an integer of 4.
Swell rate (%) = 100 × [(BA) / A] Formula 1
In Formula 1, A represents the mass of the ink film before immersion, and B represents the mass of the ink film after immersion. A cleaning method for cleaning the nozzle surface of the ink discharge head,
Applying a cleaning liquid to the wiping member on the pressing member;
Wiping the nozzle surface with the wiping member provided with a cleaning liquid,
A cleaning method, wherein the cleaning liquid is the cleaning liquid according to claim 1. An ejection process for ejecting ink from the nozzles of the ink ejection head;
Cleaning a nozzle surface of the ink discharge head,
The printing method, wherein the cleaning step is performed by the cleaning method according to claim 8. A cleaning device for cleaning the nozzle surface of an ink discharge head,
Means for applying a cleaning liquid to the wiping member on the pressing member;
A means for wiping the nozzle surface with the wiping member provided with a cleaning liquid,
The cleaning apparatus according to claim 1, wherein the cleaning liquid is the cleaning liquid according to claim 1. An ink discharge head having nozzles for discharging ink;
Cleaning means for cleaning the nozzle surface of the ink discharge head,
The printing apparatus according to claim 10, wherein the cleaning unit is the cleaning apparatus according to claim 10.