JP6743370B2 - Ink, ink container, inkjet recording method, inkjet recording device, and recorded matter - Google Patents

Description

The present invention relates to an ink, an ink container, an inkjet recording method, an inkjet recording device, and a recorded matter.

Conventionally, as inkjet inks, dye inks have been the mainstream from the viewpoint of good colorability and high reliability, but the dye inks have the drawback of being poor in water resistance and light resistance. Therefore, recently, pigment ink has been increasingly used.
However, the printed matter on which at least one of a character and an image is printed by the pigment ink has a problem that the pigment is easily peeled off because the pigment adheres to the outermost surface of the recording medium and the abrasion resistance is poor.

Further, in recent years, it has been required to obtain an image quality comparable to that of conventional offset printing even with a printing coated paper having a low ink absorbency used for commercial printing applications, by an inkjet recording method. Since the above-mentioned coated paper for printing has a surface structure that hardly absorbs ink, there is a problem that the scratch resistance of an image is lowered and a so-called blocking phenomenon in which contact surfaces of recording media stick to each other occurs.
In particular, in a high-speed printing system, the image quality is deteriorated due to transfer stains on the transfer rollers, etc., and since the recording medium for continuous ledger paper is rewound on a roll after printing, the blocking phenomenon is remarkable. is there.
As described above, in the high-speed printing system using the coated paper for printing, it is required that the scratch resistance and the blocking resistance of the image are dramatically improved as well as the high image quality equivalent to the offset printing.

In order to solve the above problems, for example, an ink using resin particles having no hydrolyzable silyl group obtained by polymerizing an acrylic monomer and a silane compound has been proposed (see, for example, Patent Document 1).
Further, an ink containing resin particles obtained by polymerizing a mixture containing a monomer having an alkoxysilyl group has been proposed (see, for example, Patent Document 2).

It is an object of the present invention to provide an ink having good scratch resistance and blocking property of an image and excellent in gloss and image density of the image.

The ink of the present invention as a means for solving the above problems is an ink containing water, an organic solvent, a coloring material, and a resin,
The content of the tetrahydrofuran (THF) soluble component of the resin in the ink film obtained by drying the ink is 20% by mass or more and 50% by mass or less, and the THF soluble component of the resin is measured by a differential scanning calorimeter ( The glass transition temperature by DSC is -20°C or higher and 20°C or lower.

According to the present invention, it is possible to provide an ink having excellent scratch resistance and blocking property of an image and excellent in gloss and image density of the image.

FIG. 1 is a perspective explanatory view showing an example of an inkjet recording apparatus. FIG. 2 is a perspective explanatory view showing an example of a main tank in the inkjet recording apparatus.

The ink of the present invention contains water, an organic solvent, a coloring material, and a resin, and the content of the tetrahydrofuran (THF) soluble component of the resin in the ink film obtained by drying the ink is 20% by mass or more and 50% by mass or more. The glass transition temperature by the differential scanning calorimetry (DSC) of the THF-soluble component of the resin is -20°C or higher and 20°C or lower, and further contains other components as necessary. ..

The content of the THF-soluble component of the resin in the ink film is 20% by mass or more and 50% by mass or less, and preferably 25% by mass or more and 40% by mass or less. When the content of the THF-soluble component is 20% by mass or more, smear fixing property is improved, and when it is 50% by mass or less, glossiness is improved and image density is improved.

The content of pre-Symbol T HF soluble component in the ink film can be measured as follows.
First, an ink film having a film thickness of about 0.3 mm obtained by drying the ink for 1 day with a hot air circulation dryer set at 100° C. is cut into a size of about 50 mm in length and about 10 mm in width. The cut out ink film G1 (mg) is dipped in 50 g of THF and kept at 50° C. for 1 day, then taken out from THF and dried at 50° C. for 1 day. From the dried ink film weight G 2 (mg), the content R (% by mass) of the THF soluble component in the ink film can be calculated from the following formula.
R=(G1-G2)/G1×100

The glass transition temperature by DSC of the THF-soluble component is -20°C or higher and 20°C or lower, preferably -10°C or higher and 10°C or lower. When the glass transition temperature is −20° C. or higher and 20° C. or lower, blocking resistance is good and smear fixability and glossiness are improved.

The glass transition temperature can be measured using DSC system Q-2000 (manufactured by TA Instruments). Specifically, first, about 5.0 mg of resin placed in a sample container made of aluminum was set in the apparatus, and measurement was performed under a nitrogen stream under the following measurement conditions. The DSC curve at the time of the second heating was selected and the glass transition temperature was determined by the midpoint method.
-Hold for 5 minutes after cooling to -70°C-Raise to 120°C at 10°C/min-Hold for 5 minutes after cooling to -70°C-Raise to 120°C at 10°C/min

The weight average molecular weight of the THF-soluble component by GPC is preferably 200,000 or more and 900,000 or less, and more preferably 300,000 or more and 700,000 or less. When the weight average molecular weight is 200,000 or more and 900,000 or less, blocking resistance is good, and smear fixing property and glossiness are improved.

The weight average molecular weight can be measured using a gel permeation chromatography (GPC) measuring device (for example, HLC-8220GPC, manufactured by Tosoh Corporation). As the column, TSKgel Super HZM-H 15 cm triplet (manufactured by Tosoh Corporation) is used. The resin to be measured was made into a 0.15 mass% solution with tetrahydrofuran (THF) (containing a stabilizer, manufactured by Wako Pure Chemical Industries, Ltd.), filtered through a 0.2 μm filter, and the filtrate was used as a sample. 100 μL of the THF sample solution is injected into the measuring device, and measurement is performed at a flow rate of 0.35 mL/min in an environment of a temperature of 40° C.
The weight average molecular weight was calculated using a calibration curve prepared from a monodisperse polystyrene standard sample. As the standard polystyrene sample, Showdex STANDARD series manufactured by Showa Denko KK and toluene are used. A THF solution of the following three kinds of monodisperse polystyrene standard samples is prepared and measured under the above-mentioned conditions, and a calibration curve is prepared with the retention time of the peak top as the light scattering molecular weight of the monodisperse polystyrene standard sample.
-Solution A: S-7450 2.5 mg, S-678 2.5 mg, S-46.5 2.5 mg, S-2.90 2.5 mg, THF 50 mL.
-Solution B: S-3730 2.5 mg, S-257 2.5 mg, S-19.8 2.5 mg, S-0.580 2.5 mg, THF 50 mL.
-Solution C: S-1470 2.5 mg, S-112 2.5 mg, S-6.93 2.5 mg, toluene 2.5 mg, THF 50 mL.
An RI (refractive index) detector was used as the detector.

From the viewpoint of blocking resistance, it is preferable that the THF-insoluble component of the resin contained in the ink film be crosslinked with a polyfunctional monomer or the like.

As the polyfunctional monomer, in the case of a resin obtained from a radically polymerizable monomer, divinyl monomers such as divinylbenzene and ethylene glycol dimethacrylate, and monomers having a reactive functional group such as glycidyl methacrylate and vinyltrimethoxysilane. In the case of polyester and polyurethane, monomers such as trimethylolpropane are listed.

(ink)
Hereinafter, the organic solvent, water, coloring material, resin, additive and the like used in the ink will be described.

<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 polyhydric alcohols, ethers such as 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, 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-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl- Polyhydric alcohols such as 1,3-pentanediol and petriol, ethylene glycol monoethyl 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 Polyhydric alcohol alkyl ethers such as ethers, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone , Nitrogen-containing heterocyclic compounds such as 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone, formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N- Amides such as dimethylpropionamide and 3-butoxy-N,N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethyl sulfoxide, sulfolane and thiodiethanol, propylene carbonate and ethylene carbonate. And so on.
It is preferable to use an organic solvent having a boiling point of 250° C. or less because it not only functions as a wetting agent but also obtains good drying properties.

A polyol compound having 8 or more carbon atoms and a glycol ether compound are also preferably used. Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.
Specific examples of glycol ether compounds include polyhydric alcohol alkyls such as 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. Ethers; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

The polyol compound having 8 or more carbon atoms and the glycol ether compound can improve the ink permeability when paper is used as the recording medium.

The content of the organic solvent in the ink is not particularly limited and can be appropriately selected according to the purpose, but from the viewpoint of the drying property of the ink and the ejection reliability, 10% by mass or more and 60% by mass or less is preferable, 20 mass% or more and 60 mass% or less are more preferable.

<Water>
The content of water in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% by mass or more and 90% by mass or less and 20% by mass or less from the viewpoint of the drying property of the ink and the ejection reliability. % Or more and 60 mass% or less is more preferable.

<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. Also, mixed crystals may be used.
Examples of pigments that can be used include black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, luster color pigments such as gold and silver, and metallic pigments.
As an inorganic pigment, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method. Can be used.
Further, as the organic pigment, an azo pigment, a polycyclic pigment (for example, a phthalocyanine pigment, a perylene pigment, a perinone pigment, an anthraquinone pigment, a quinacridone pigment, a dioxazine pigment, an indigo pigment, a thioindigo pigment, an isoindolinone pigment, a quinofuraron pigment, etc.) , Dye chelates (for example, basic dye chelates, acid dye chelates, etc.), nitro pigments, nitroso pigments, aniline black, etc. can be used. Among these pigments, those having a good affinity with the solvent are preferably used. In addition, hollow resin particles and hollow inorganic particles can also be used.
Specific examples of the pigment include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black and channel black, or copper and iron (CI pigment black 11) for black. , Metal oxides 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 acid dye, a direct dye, a reactive dye, and a basic dye can be used, and 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. Dilectd 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 and the like can be mentioned.

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 viewpoint of improving the image density, good fixing property and ejection stability. It is the following.

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 the surface of the pigment with a resin to disperse, a method of dispersing using a dispersant, And so on.
Examples of a method for introducing a hydrophilic functional group into a pigment to give a self-dispersing pigment include, for example, a self-dispersing pigment that is dispersible 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 for coating the surface of the pigment with a resin to disperse the pigment, a method in which the pigment is contained 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 for all the pigments mixed in the ink to be coated with the resin, and as long as the effect of the present invention is not impaired, uncoated pigments and partially coated pigments are dispersed in the ink. May be.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low molecular type dispersant or polymer 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.
Takemoto Yushi Co., Ltd.'s RT-100 (nonionic surfactant) and naphthalenesulfonic acid Na formalin condensate can also be suitably used as the dispersant.
The dispersants may be used alone or in combination of two or more.

<Pigment dispersion>
It is possible to obtain ink by mixing a color material with a material such as water or an organic solvent. Further, it is also possible to manufacture an ink by mixing a pigment and other materials such as water and a dispersant to form a pigment dispersion, and mixing materials such as water and an organic solvent.
The pigment dispersion is obtained by dispersing water, a pigment, a pigment dispersant, and other components as necessary, and adjusting the particle size. A disperser may be used for dispersion.
There is no particular limitation on the particle size of the pigment in the pigment dispersion, but since the dispersion stability of the pigment is good and the image quality such as ejection stability and image density is high, the maximum frequency is 20 nm or more in terms of maximum number. It is preferably 500 nm or less, more preferably 20 nm or more and 150 nm or less. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell KK).
The content of the pigment in the pigment dispersion is not particularly limited and may be appropriately selected depending on the purpose, but from the viewpoint of obtaining good ejection stability and increasing the image density, it is 0.1 mass. % Or more and 50% by mass or less is preferable, and 0.1% by mass or more and 30% by mass or less is more preferable.
The pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifugal separator or the like, if necessary.

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

It is preferable that the resin contains resin particles made of a (meth)acrylic resin from the viewpoint of scratch resistance of an image and long-term storage and storage stability of an ink.

The resin preferably has a structure derived from a reactive emulsifier. The use of the reactive emulsifier improves the storage stability of the ink.
The reactive emulsifier is appropriately selected depending on the intended purpose without any limitation, but it is particularly preferable to use an emulsifier having a radical-polymerizable double bond. A commercially available product can be used as the reactive emulsifier. Examples of the commercially available product include Latemur S-180 (manufactured by Kao Corporation), Eleminol JS-2 (manufactured by Sanyo Chemical Industry Co., Ltd.), Aqualon RN-20 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and the like.

The volume average particle diameter of the resin particles is not particularly limited and may be appropriately selected depending on the 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 more and more preferably 10 nm or more and 100 nm or less.
The volume average particle size can be measured using, for example, a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell KK).

The content of the resin is not particularly limited and may be appropriately selected depending on the intended purpose, but from the viewpoint of fixability and storage stability of the ink, 1% by mass or more and 30% by mass or less based on the total amount of the ink. Is preferable and 5 mass% or more and 20 mass% or less is more preferable.

The particle size of the solid content in the ink is not particularly limited and can be appropriately selected according to the purpose. However, from the viewpoint of improving the image quality such as ejection stability and image density, the maximum number of times converted to the maximum number Is preferably 20 nm or more and 1000 nm or less, and more preferably 20 nm or more and 150 nm or less. The solid content includes resin particles and pigment particles. The particle size can be measured using a particle size analyzer (Nanotrack Wave-UT 151, manufactured by Microtrack Bell KK).

<Additive>
If necessary, a surfactant, an antifoaming agent, an antiseptic/antifungal agent, an anticorrosive agent, a pH adjusting agent, etc. may be added to the ink.

-Surfactant-
As the surfactant, any of silicone-based surfactants, fluorine-based surfactants, amphoteric surfactants, nonionic surfactants, and anionic surfactants can be used.
The silicone surfactant is not particularly limited and can be appropriately selected according to the purpose. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and side-chain both-end modified polydimethylsiloxane. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene group are particularly preferable because they exhibit good properties as an aqueous surfactant. Further, as the silicone-based surfactant, a polyether-modified silicone-based surfactant can be used, and examples thereof include a compound having a polyalkylene oxide structure introduced into the side chain of the Si moiety of dimethylsiloxane.
Examples of the fluorinated surfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphoric acid ester compound, a perfluoroalkyl ethylene oxide adduct and a perfluoroalkyl ether group in the side chain. A polyoxyalkylene ether polymer compound is particularly preferable because it has a low foaming property. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonate. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salts. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in its side chain include a sulfuric acid ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in its side chain and a perfluoroalkyl ether group in its side chain. Examples thereof include salts of polyoxyalkylene ether polymers. As counter ions of salts in these fluorine-based surfactants, 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) are used. _{3 and the} like.
Examples of the amphoteric surfactant include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Examples of nonionic surfactants include polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, polyoxyethylene propylene block polymers, sorbitan fatty acid esters, polyoxyethylene sorbitan. Examples thereof include fatty acid esters and ethylene oxide adducts of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, and salt of polyoxyethylene alkyl ether sulfate.
These may be used alone or in combination of two or more.

The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and side-modified polydimethylsiloxane. Examples thereof include polydimethyl siloxane modified at both chain ends, and a polyether modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group exhibits excellent properties as an aqueous surfactant. preferable.
As such a surfactant, those synthesized appropriately may be used, or commercially available products 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., Kyoeisha Kagaku Co., Ltd.
The polyether-modified silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the polyalkylene oxide structure represented by the general formula (S-1) is represented by dimethylpolyethylene. Examples thereof include those introduced into the side chain of the Si portion of siloxane.
General formula (S-1)
(However, in the general formula (S-1), m, n, a, and b represent an integer. R and R′ represent an alkyl group or an alkylene group.)
As the above polyether-modified silicone surfactant, commercially available products can be used, and examples thereof include KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS-. 1906EX (Nippon 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 (Big Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.), etc. are mentioned.

As the fluorine-based surfactant, a fluorine-substituted compound having 2 to 16 carbon atoms is preferable, and a fluorine-substituted compound having 4 to 16 carbon atoms is more preferable.
Examples of the fluorine-based surfactant include a perfluoroalkyl phosphate ester compound, a perfluoroalkylethylene oxide adduct, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in its side chain.
Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because it has a low foaming property, and particularly fluorine represented by the general formula (F-1) and the general formula (F-2) A system surfactant is preferable.
General formula (F-1)
In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10 and n is preferably an integer of 0 to 40 in order to impart water solubility.
General formula (F-2)
_{C n F 2n + 1- CH 2} CH (OH) CH 2 -O- (CH 2 CH 2 O) a -Y
In the compound represented by the general formula (F-2), Y is H, or CnF _2n+1 and n is an integer of 1 to 6, or CH ₂ CH(OH)CH ₂ -CnF _2n+1 and n is 4 to 6. An integer or CpH _2p+1 and p is an integer of 1 to 19. a is an integer of 4-14.
A commercial item may be used as the above-mentioned fluorine-based surfactant. Examples of the commercially available product include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F -1405, F-474 (all manufactured by DIC Corporation); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all manufactured by DuPont) ); FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omnova Co., Ltd.), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.) and the like can be mentioned. Among these, FS-300 manufactured by DuPont, FT-110 manufactured by Neos Co., Ltd., and FT-, from which good printing quality, particularly color developability, penetrability to paper, wettability, and level dyeability are remarkably improved. 250, FT-251, FT-400S, FT-150, FT-400SW, Polyfox PF-151N manufactured by Omnova Co., Ltd. and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferable.

The content of the surfactant in the ink is appropriately selected depending on the intended purpose without any limitation, but it is 0.001% by mass from the viewpoint of excellent wettability and ejection stability and improving image quality. % Or more and 5 mass% or less is preferable, and 0.05 mass% or more and 5 mass% or less is more preferable.

-Antifoam-
The defoaming agent is not particularly limited, and examples thereof include a silicone defoaming agent, a polyether defoaming agent, and a fatty acid ester defoaming agent. These may be used alone or in combination of two or more. Among these, a silicone-based defoaming agent is preferable because of its 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-
The rust preventive agent is not particularly limited, and examples thereof include acid sulfite and sodium thiosulfate.

-PH adjuster-
The pH adjuster is not particularly limited as long as it can adjust the pH to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

The physical properties of the ink are not particularly limited and may 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, from the viewpoint that the printing density and character quality are improved and good ejection properties are obtained, and 5 mPa·s or more and 25 mPa·s or less are preferable. More preferable. Here, as the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. The measurement conditions are 25° C., standard cone rotor (1°34′×R24), sample liquid volume 1.2 mL, rotation speed 50 rpm, and 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 preferably 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 the corrosion of the metal member with which the ink comes into contact.

<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.

(Recorded material)
The recorded matter of the present invention has an image formed by using the ink of the present invention on a recording medium.
A recorded matter can be obtained by recording with an inkjet recording apparatus and an inkjet recording method.

(Ink container)
The ink container of the present invention contains the ink of the present invention in a container, and further has other members appropriately selected as necessary.
The container is not particularly limited, and its shape, structure, size, material and the like can be appropriately selected according to the purpose, and for example, an aluminum laminate film, an ink bag formed of a resin film or the like can be used at least. Preferable ones have.

(Inkjet recording device, inkjet recording method)
The inkjet recording method of the present invention is an inkjet recording method in which ink is ejected from nozzles of a recording head and applied to a recording medium for recording.
The ink is the ink of the present invention.
An inkjet recording apparatus of the present invention has the ink container of the present invention and a recording head for ejecting ink droplets, and further has other members as necessary.

The ink of the present invention can be suitably used for various recording apparatuses using an inkjet recording method, such as a printer, a facsimile apparatus, a copying apparatus, a printer/fax/copier compound machine, and a three-dimensional modeling apparatus.
In the present invention, the recording device and the recording method are a device capable of ejecting ink, various treatment liquids, and the like onto a recording medium, and a method of recording using the device. The recording medium means a medium to which ink or various treatment liquids can be attached even temporarily.
This recording device can include not only a head portion for ejecting ink, but also means for feeding, conveying, and discharging a recording medium, and other devices such as a pre-processing device and a post-processing device. ..
The recording device and the recording method may have a heating means used in the heating step and a drying means used in the drying step. The heating means and the drying means include, for example, means 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, but, 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 recording device and the recording method are not limited to those in which a significant image such as a character or a figure is visualized by ink. For example, it also includes one that forms a pattern such as a geometric pattern and one that models 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 limited.
Further, this recording device is not limited to a desktop type, and can be used as a wide recording device capable of printing on an A0 size recording medium or, for example, a continuous paper wound in a roll as a recording medium. It also includes a continuous form printer.
An example of the recording device will be described with reference to FIGS. FIG. 1 is a perspective explanatory view of the device. FIG. 2 is a perspective 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 mechanical section 420 is provided inside 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 packed with, for example, an aluminum laminate film. It is formed of a member. The ink container 411 is housed in a container case 414 made of plastics, for example. 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 body is opened. The main tank 410 is detachably attached to the cartridge holder 404. As a result, the ink discharge ports 413 of the main tank 410 communicate with the ejection heads 434 for each color via the supply tubes 436 for each color, and ink can be ejected from the ejection head 434 to the recording medium.

This recording device can include not only a portion for ejecting ink, but also a device called a pre-processing device, a post-processing device, or the like.
As one mode of the pretreatment device and the posttreatment device, as in the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y), a pretreatment liquid and a posttreatment liquid are included. There is a mode in which a liquid storage section and a liquid ejection head are added and a pretreatment liquid and a posttreatment liquid are ejected by an inkjet recording method.
As another aspect of the pretreatment apparatus and the posttreatment apparatus, there is an aspect in which a pretreatment apparatus and a posttreatment apparatus other than the ink jet recording method are provided, for example, by a blade coating method, a roll coating method, a spray coating method.

The method of using the ink is not limited to the ink jet recording method and can be widely used. In addition to the inkjet recording method, for example, a blade coating method, a gravure coating method, a bar coating method, a roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, a spray coating method and the like can be mentioned.

The use of the ink of the present invention is not particularly limited and can be appropriately selected according to the purpose. For example, the ink can be applied to printed matter, paints, coating materials, substrates and the like. Furthermore, it can be used not only for forming 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 model).
As a three-dimensional modeling device for modeling a three-dimensional molded item, a known one can be used, and it is not particularly limited, but for example, one provided with an ink containing means, a supplying means, a discharging means, a drying means, etc. is used. be able to. The three-dimensional molded item includes a three-dimensional molded item obtained by overcoating with ink. Further, it also includes a molded product obtained by processing a structure to which ink is applied on a substrate such as a recording medium. The molded product is, for example, a recording product or a structure formed in a sheet shape or a film shape, which has been subjected to molding processing such as heat drawing and punching processing. -It is suitable for applications such as electronic devices, meters for cameras, panels for operation parts, etc., where the surface is molded after decoration.

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

(Preparation example 1)
-Preparation of Pigment Dispersion 1-
2 mol/liter of sodium persulfate was added to 100 g of carbon black (manufactured by Mitsubishi Chemical Corporation, #44, nitrogen adsorption specific surface area 110 m ² /g, DBP oil absorption 78 cm ³ /100 g), and the mixture was stirred at 75° C. for 10 hours for oxidation. Processed. Then, after washing with pure water and drying, it was dispersed again in water, neutralized with sodium hydroxide, and the residual salt was separated with an ultrafiltration membrane. The water content was adjusted so that the pigment concentration was 20% by mass, and coarse particles were removed by filtering with a membrane filter having an average pore size of 1.5 μm.
The obtained pigment dispersion had an electric conductivity of 1.35 mS/cm, a pH of 5.6, an acid value of 50 mgKOH/g, and an amount of Na contained in the 20% by mass dispersion of 2,200 ppm. When it was measured degradation products were separated from the dispersion with concentrated FT-IR, a peak derived from -COO- around 1590 cm ^-1 and 1384cm ^-1 were observed.

(Synthesis example 1)
-Synthesis of dispersion liquid of resin particles 1-
A mixture of 133 parts by mass of methyl methacrylate, 184 parts by mass of 2-ethylhexyl acrylate, 2.2 parts by mass of Aqualon HS-10 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) as a reactive emulsifier, and 166 parts by mass of ion-exchanged water. , Using a homomixer to obtain a uniform milky white emulsion.
Next, in a 1 L flask equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, and a reflux tube, 287 parts by mass of ion-exchanged water and water of pH 3 adjusted with sulfuric acid in advance were charged to introduce nitrogen. Then, the temperature was raised to 70°C. Then, after adding 12.7 parts by mass of a 10 mass% aqueous solution of Aqualon HS-10 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) as a reactive emulsifier, 8.7 parts by mass of a 5 mass% ammonium persulfate aqueous solution, it was adjusted in advance. The prepared emulsion was continuously added dropwise over 2.5 hours. In addition, 1.8 parts by mass of a 5% by mass ammonium persulfate aqueous solution was added every hour until 3 hours passed after the start of dropping. After completion of the dropping, the mixture was aged at 70° C. for 2 hours and then cooled, and the pH was adjusted to 7 to 8 with an aqueous sodium hydroxide solution to obtain a dispersion liquid of resin particles 1.

(Synthesis example 2)
-Synthesis of dispersion liquid of resin particles 2-
120 parts by mass of methyl methacrylate, 165 parts by mass of 2-ethylhexyl acrylate, 32 parts by mass of vinyltriethoxysilane, 2.2 parts by mass of Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a reactive emulsifier, and ion exchange. A mixture consisting of 166 parts by mass of water was emulsified using a homomixer to obtain a uniform milky white emulsion.
Next, in a 1 L flask equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, and a reflux tube, 287 parts by mass of water of pH 3 which had been adjusted with ion-exchanged water and sulfuric acid in advance was charged, and nitrogen was introduced. While raising the temperature to 70°C. Then, after adding 9.4 parts by mass of 10% by mass Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) aqueous solution as a reactive emulsifier and 8.7 parts by mass of 5% by mass aqueous ammonium persulfate solution, it was adjusted in advance. The prepared emulsion was continuously added dropwise over 2.5 hours. In addition, 1.8 parts by mass of a 5% by mass ammonium persulfate aqueous solution was added every hour until 3 hours passed after the start of dropping. After completion of the dropping, the mixture was aged at 70° C. for 2 hours and then cooled, and the pH was adjusted to 7 to 8 with an aqueous sodium hydroxide solution to obtain a dispersion liquid of resin particles 2.

(Synthesis example 3)
-Synthesis of dispersion liquid of resin particles 3-
A dispersion of resin particles 3 was obtained in the same manner as in Synthesis Example 1, except that in Synthesis Example 1, 79 parts by mass of methyl methacrylate and 237 parts by mass of 2-ethylhexyl acrylate were used.

(Synthesis example 4)
-Synthesis of dispersion liquid of resin particles 4-
A dispersion of resin particles 4 was obtained in the same manner as in Synthesis Example 1 except that in Synthesis Example 1, 95 parts by mass of methyl methacrylate and 222 parts by mass of 2-ethylhexyl acrylate were used.

(Synthesis example 5)
-Synthesis of dispersion liquid of resin particles 5-
A dispersion of resin particles 5 was obtained in the same manner as in Synthesis Example 1 except that 177 parts by mass of methyl methacrylate and 139 parts by mass of 2-ethylhexyl acrylate were used in Synthesis Example 1.

(Synthesis example 6)
-Synthesis of dispersion liquid of resin particles 6-
A dispersion of resin particles 6 was obtained in the same manner as in Synthesis Example 1 except that 187 parts by mass of methyl methacrylate and 130 parts by mass of 2-ethylhexyl acrylate were used in Synthesis Example 1.

(Synthesis example 7)
-Preparation example of dispersion of resin particles 7-
A mixture of 133 parts by mass of methyl methacrylate, 184 parts by mass of 2-ethylhexyl acrylate, 2.2 parts by mass of Aqualon HS-10 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) as a reactive emulsifier, and 166 parts by mass of ion-exchanged water. , Using a homomixer to obtain a uniform milky white emulsion.
Next, in a 1 L flask equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, and a reflux tube, 264 parts by mass of water of pH 3 prepared in advance with ion-exchanged water and sulfuric acid was charged, and nitrogen was introduced. While raising the temperature to 70°C. Then, after adding 12.7 parts by mass of a 10% by mass Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) aqueous solution as a reactive emulsifier, 17.8 parts by mass of a 5% by mass aqueous ammonium persulfate solution, it was prepared in advance. The placed emulsion was continuously added dropwise over 5 hours. In addition, 3.8 parts by mass of a 5% by mass aqueous ammonium persulfate solution was added every one hour until 3 hours passed from the start of dropping. After completion of the dropping, the mixture was aged at 70° C. for 2 hours and then cooled, and the pH was adjusted to 7 to 8 with an aqueous sodium hydroxide solution to obtain a dispersion liquid of resin particles 7.

(Synthesis example 8)
-Preparation of dispersion liquid of resin particles 8-
133 parts by mass of methyl methacrylate, 183 parts by mass of 2-ethylhexyl acrylate, 0.35 parts by mass of n-octanethiol, 2.2 parts by mass of Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a reactive emulsifier, and A mixture of 166 parts by mass of ion-exchanged water was emulsified using a homomixer to obtain a uniform milky white emulsion.
Next, in a 1 L flask equipped with a stirrer, a thermometer, a nitrogen gas introducing tube, and a reflux tube, 264 parts by mass of ion-exchanged water and water of pH 3 prepared in advance with sulfuric acid were charged to introduce nitrogen. Then, the temperature was raised to 70°C. Then, after adding 12.7 parts by mass of a 10% by mass Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) aqueous solution as a reactive emulsifier, 17.8 parts by mass of a 5% by mass ammonium persulfate aqueous solution, it was adjusted in advance. The placed emulsion was continuously added dropwise over 5 hours. In addition, 3.8 parts by mass of a 5% by mass aqueous ammonium persulfate solution was added every one hour until 3 hours passed from the start of dropping. After the dropping was completed, the mixture was aged at 70° C. for 2 hours and then cooled, and the pH was adjusted to 7 to 8 with an aqueous sodium hydroxide solution to obtain a dispersion liquid of resin particles 8.

(Synthesis example 9)
-Preparation of dispersion liquid of resin particles 9-
A mixture of 133 parts by mass of methyl methacrylate, 184 parts by mass of 2-ethylhexyl acrylate, 2.2 parts by mass of Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a reactive emulsifier, and 166 parts by mass of ion-exchanged water. Was emulsified using a homomixer to obtain a uniform milky white emulsion.
Next, in a 1 L flask equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, and a reflux tube, 288 parts by mass of water of pH 3 prepared in advance with ion-exchanged water and sulfuric acid was charged, and nitrogen was introduced. While raising the temperature to 70°C. Next, after adding 12.7 parts by mass of a 10% by mass Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) aqueous solution as a reactive emulsifier and 9.6 parts by mass of a 5% by mass ammonium persulfate aqueous solution, it was adjusted in advance. The stored emulsion was continuously added dropwise over 2 hours. Also, 2.2 parts by mass of a 5% by mass ammonium persulfate aqueous solution was added every hour. After completion of the dropping, the mixture was aged at 70° C. for 2 hours and then cooled, and the pH was adjusted to 7 to 8 with an aqueous sodium hydroxide solution to obtain a dispersion liquid of resin particles 9.

Next, Table 1 shows the solid content concentration and the volume average particle diameter of the obtained dispersion liquid of the respective resin particles. The volume average particle diameter was measured by Nanotrac Wave-UT151 (manufactured by Microtrac Bell Co., Ltd.).

(Example 1)
-Preparation of ink-
The liquid mixture having the following formulation was stirred for 1 hour and uniformly mixed. Thereafter, pressure filtration was performed with a cellulose acetate membrane filter having an average pore diameter of 0.8 μm to remove coarse particles, and thus an ink 2 was obtained.
[Ink prescription]
・Pigment dispersion 1... 5.0% by mass (solid content)
Resin particles 1... 1.5% by mass (solid content)
・Resin particles 2... 4.5% by mass (solid content)
・Propylene glycol...30% by mass
・1,3-Butanediol: 5 mass%
・2-Pyrrolidone: 2.0 mass%
・Surfactant (Softanol EP7025, manufactured by Nippon Shokubai Co., Ltd.)... 1.0% by mass
-2,2,4-trimethyl-1,3-pentanediol: 2.0 mass%
・Ion-exchanged water...remaining amount (total: 100% by mass)

(Examples 2-8 and Comparative Examples 1-4)
-Preparation of ink-
Inks 1, 3 to 12 were prepared in the same manner as in Example 1 except that the resin particles 1 and 2 in Example 1 were changed to the types and blending amounts of the resin particles shown in Table 2.

Next, the obtained inks 1 to 12 were filled in an ink cartridge, and an image was formed using an inkjet printer (IPSiO GX e5500, manufactured by Ricoh Co., Ltd.) equipped with the ink cartridge.
The images prepared by the above method were evaluated as follows. Tables 3 and 4 show the evaluation results and the measurement results of the content of the THF soluble component in the ink film, the weight average molecular weight, and the glass transition temperature.

<Content of T HF-soluble matter in the ink film>
The content of the THF soluble component in the ink film is determined by first drying each ink in a hot air circulation dryer set at 100° C. for 1 day to obtain an ink film having a film thickness of about 0.3 mm. It was cut into a size of about 50 mm and a width of about 10 mm. The cut out ink film G1 (mg) was dipped in 50 g of THF , held at 50° C. for 1 day, taken out from THF and dried at 50° C. for 1 day. From the dried ink film weight G 2 (mg), the content of T HF solubles that put the ink film R (mass%) was calculated from the following equation.
R=(G1-G2)/G1×100

<Weight average molecular weight of THF-soluble component>
The weight average molecular weight of the THF-soluble component was measured using a gel permeation chromatography (GPC) measuring device (HLC-8220GPC, manufactured by Tosoh Corporation). As the column, TSKgel Super HZM-H 15 cm triplet (manufactured by Tosoh Corporation) was used. The resin to be measured was made into a 0.15 mass% solution with tetrahydrofuran (THF) (containing a stabilizer, manufactured by Wako Pure Chemical Industries, Ltd.), filtered through a 0.2 μm filter, and the filtrate was used as a sample. 100 μL of the THF sample solution was injected into the measuring device, and measurement was performed at a flow rate of 0.35 mL/min in an environment of a temperature of 40° C.
The weight average molecular weight of the THF-soluble component was calculated using a calibration curve prepared from a monodisperse polystyrene standard sample. As the standard polystyrene sample, Showdex STANDARD series manufactured by Showa Denko KK and toluene were used. A THF solution of the following three types of monodisperse polystyrene standard samples was prepared and measured under the above conditions, and a calibration curve was prepared using the retention time of the peak top as the light scattering molecular weight of the monodisperse polystyrene standard sample.
-Solution A: S-7450 2.5 mg, S-678 2.5 mg, S-46.5 2.5 mg, S-2.90 2.5 mg, THF 50 mL.
-Solution B: S-3730 2.5 mg, S-257 2.5 mg, S-19.8 2.5 mg, S-0.580 2.5 mg, THF 50 mL.
-Solution C: S-1470 2.5 mg, S-112 2.5 mg, S-6.93 2.5 mg, toluene 2.5 mg, THF 50 mL.
An RI (refractive index) detector was used as the detector.

<Glass transition temperature of THF-soluble component>
The glass transition temperature of the THF soluble component was measured using DSC system Q-2000 (TA Instruments). Specifically, first, about 5.0 mg of the THF-soluble content of the resin contained in the aluminum sample container was set in the apparatus, and the measurement was performed under a nitrogen stream under the following measurement conditions. The DSC curve at the time of the second heating was selected and the glass transition temperature was determined by the midpoint method.
-Hold for 5 minutes after cooling to -70°C-Raise to 120°C at 10°C/min-Hold for 5 minutes after cooling to -70°C-Raise to 120°C at 10°C/min

<Image density>
A solid chart (10% duty) of 10 points was used as an image chart on a glossy printing paper (LumiArtGross having a basis weight of 90 g/m ² manufactured by Store Enso) and an ink adhesion amount of 10,000 mg/ A solid image was printed at m ² . With respect to the obtained solid image, the image density was measured using a reflection type color spectrophotometric densitometer (manufactured by X-Rite) and evaluated according to the following criteria.
[Evaluation criteria]
○: 1.5 or more △: 1.2 or more and less than 1.5 ×: less than 1.2

<Glossiness of image>
Printing gloss paper (basis weight 90g / ^{m 2} LumiArtGross, Store Enso Corporation) the inkjet printer used, gloss meter for the black solid image printed by the ink deposition amount 10,000mg / ^{m 2} (manufactured by BYK Japan KK Manufactured, 4501-microgloss 60°) and 60 degree glossiness (image glossiness) measured using the glossiness of the background of the printed gloss paper (background glossiness) are compared, and evaluated according to the following criteria. did.
The 60 degree glossiness of the background of the printed gloss paper was 25.
[Evaluation criteria]
◯: Background glossiness +2 <image glossiness △: Background glossiness ≦ image glossiness ≦ background glossiness +2
×: Image gloss <background gloss

<Smear fixability>
After printing a solid image printed on glossy paper for printing (LumiArtGross having a basis weight of 90 g/m ² manufactured by Store Enso) using the inkjet printer at a duty of 6 cm and a duty of 10,000 mg/m ^2. After 3 hours, the solid image part printed on the white cotton cloth (made by Toyo Seiki Co., Ltd.) attached to the clock meter (made by Toyo Seiki Co., Ltd.) was made to reciprocate 10 times, and the stain of the ink adhering to the white cotton cloth was visually observed. Then, the evaluation was made according to the following criteria.
[Evaluation criteria]
◯: There is no stain Δ: There is stain, but there is no problem in practical use X: Marked stain is noticeable

<Blocking resistance>
Blocking resistance was evaluated with reference to the TAPPI T477 test method issued by Japan Pulp and Paper Technology Association. After printing a solid image on a 6 cm square on a glossy paper for printing (LumiArtGross having a basis weight of 90 g/m ² manufactured by Store Enso) with an ink adhesion amount of 10,000 mg/m ² , the solid image Gloss paper for printing, which is not printed on the printed surface, is stacked on top of this, sandwiched between two 10 cm square glass plates, and a load of 1 kg/m ² is applied from above, at 40°C, 90% RH. It was allowed to stand for 24 hours under the above environmental conditions. After that, it was left at room temperature (25° C.) for 2 hours, and the degree of sticking of the gloss papers for printing to each other when peeled off was visually observed and evaluated according to the following evaluation criteria.
[Evaluation criteria]
○: No blocking (adhesion or adhesion does not occur on the adjacent surface, and the surface of the sample is not damaged)
Δ: Slight blocking (slightly sticking, slight scratch on sample surface)
X: Remarkably blocked (adhesion or adhesion occurs on the adjacent surface. There is a scratch on the surface of the sample)

Aspects of the present invention are as follows, for example.
<1> An ink containing water, an organic solvent, a coloring material, and a resin,
The content of the tetrahydrofuran (THF) soluble component of the resin in the ink film obtained by drying the ink is 20% by mass or more and 50% by mass or less, and the THF soluble component of the resin is measured by a differential scanning calorimeter ( The ink has a glass transition temperature of -20°C or higher and 20°C or lower according to (DSC).
<2> The ink according to <1>, wherein the content of the tetrahydrofuran (THF)-soluble component in the resin is 25% by mass or more and 40% by mass or less.
<3> The ink according to any one of <1> to <2>, wherein the THF-soluble component of the resin has a glass transition temperature of -5°C or higher and 5°C or lower.
<4> The THF-soluble component of the resin according to any one of <1> to <3>, which has a weight average molecular weight of 200,000 or more and 900,000 or less as determined by gel permeation chromatography (GPC). It is ink.
<5> The weight-average molecular weight of the THF-soluble component of the resin measured by gel permeation chromatography (GPC) is 300,000 or more and 700,000 or less, according to any one of <1> to <4>. It is ink.
<6> The ink according to any one of <1> to <5>, in which the THF-insoluble matter of the resin is crosslinked.
<7> The ink according to any one of <1> to <6>, in which the resin contains resin particles made of a (meth)acrylic resin.
<8> The ink according to any one of <1> to <7>, wherein the resin has a structure derived from a reactive emulsifier.
<9> An ink container including an ink container that contains the ink according to any one of <1> to <8>.
<10> In an inkjet recording method in which ink is ejected from a nozzle of a recording head and applied to a recording medium to record,
The inkjet recording method is characterized in that the ink is the ink according to any one of <1> to <8>.
<11> An ink jet recording apparatus including the ink container according to <9> and a recording head for ejecting ink droplets.
<12> A recorded matter, which comprises an image formed using the ink according to any one of <1> to <8> on a recording medium.

The ink according to any one of the items <1> to <8>, the ink container according to the item <9>, the inkjet recording method according to the item <10>, the inkjet recording device according to the item <11>, and The recorded matter according to <12> can solve the problems of the related art and achieve the object of the invention.

Japanese Patent No. 4921753 Japanese Patent No. 4462379

Claims (11)

An ink containing water, an organic solvent, a coloring material, and a resin,
The content of the tetrahydrofuran (THF) soluble component of the resin in the ink film obtained by drying the ink is 20% by mass or more and 50% by mass or less, and the THF soluble component of the resin is measured by a differential scanning calorimeter ( An ink having a glass transition temperature of −20° C. or higher and 20° C. or lower by DSC). The ink according to claim 1, wherein the THF-soluble component of the resin has a weight average molecular weight of 200,000 or more and 900,000 or less as determined by gel permeation chromatography (GPC). The ink according to claim 1, wherein the THF-insoluble matter of the resin is crosslinked. The ink according to claim 1, wherein the resin contains resin particles made of a (meth)acrylic resin. The ink according to any one of claims 1 to 4, wherein the resin has a structure derived from a reactive emulsifier. An ink container comprising an ink container that contains the ink according to claim 1. In an ink jet recording method in which ink is ejected from a nozzle of a recording head and applied to a recording medium for recording,
An ink jet recording method, wherein the ink is the ink according to any one of claims 1 to 5. An ink jet recording apparatus comprising: the ink container according to claim 6; and a recording head for ejecting ink droplets. A recorded matter, which comprises an image formed by using the ink according to any one of claims 1 to 5 on a recording medium. An ink containing water, an organic solvent, a coloring material, and a crosslinked acrylic resin,
The content of the tetrahydrofuran (THF)-soluble component of the crosslinked acrylic resin in the ink film obtained by drying the ink is 20 mass% or more and 50 mass% or less, and the crosslinked acrylic resin THF is An ink having a glass transition temperature of −20° C. or higher and 20° C. or lower by a differential scanning calorimetry (DSC), which is a soluble component. An ink containing water, an organic solvent, a coloring material, and a resin,
The resin is a crosslinked acrylic resin and a non-crosslinked acrylic resin,
The content of the tetrahydrofuran (THF) soluble component of the resin in the ink film obtained by drying the ink is 20% by mass or more and 50% by mass or less, and the THF soluble component of the resin is measured by a differential scanning calorimeter ( An ink having a glass transition temperature of −20° C. or higher and 20° C. or lower by DSC).