JP2022070811A - Ink set, image formation method, and image formation unit - Google Patents

Abstract

To provide an inkjet ink set excellent in bleeding resistance, wettability and fixability even for an impermeable substrate.SOLUTION: An ink set comprises an ink and a pretreatment liquid. The ink contains a color material, an organic solvent and a resin. The pretreatment liquid contains a polyvalent metal salt, a resin having a glass transition temperature (Tg) of 0°C or less, a silicone-based surfactant, and two or more organic solvents having a boiling point of 220°C or less.SELECTED DRAWING: None

Description

The present invention relates to an ink set, an image forming method and an image forming apparatus.

In recent years, it has been able to meet the demand for decoration of various designs, and compared to other recording methods, the process is simple, full-color conversion is easy, and even if the device has a simple configuration, acrylic plates and The inkjet method is increasing because it can be applied to various printed matter including a non-permeable substrate such as glass and a high-resolution image can be obtained.

As the ink used in the inkjet method, solvent ink, ultraviolet curable ink (UV ink), latex ink and the like are generally used.

Solvent ink may have an impact on the environment due to solvent evaporation. In the ultraviolet curable ink, the choice of the polymerizable monomer used may be limited from the viewpoint of safety. Latex ink has a problem that the image is easily peeled off when an external force is applied to the ink coating film as compared with UV ink. Further, when the ink is applied to the substrate without applying the pretreatment liquid, there is a problem that the image of the impermeable substrate is blurred.
Therefore, water-based inks that have a low environmental load and can record on a wide variety of substrates including non-permeable substrates have been proposed (see, for example, Patent Documents 1 and 2).

An object of the present invention is to provide an inkjet ink set having excellent bleeding resistance and fixability even for a non-permeable substrate.

The ink set of the present invention as a means for solving the above-mentioned problems is as described below.
An ink set consisting of ink and pretreatment liquid,
The ink contains a coloring material, an organic solvent, and a resin.
The pretreatment liquid contains a polyvalent metal salt, a resin having a glass transition point (Tg) of 0 ° C. or lower, a silicone-based surfactant, and two or more organic solvents having a boiling point of 220 ° C. or lower.
An ink set that features that.

According to the present invention, it is possible to provide an ink set having excellent bleeding resistance and fixability even for a non-permeable substrate.

FIG. 1 is a perspective explanatory view showing an example of the image forming apparatus of the present invention. FIG. 2 is a schematic diagram of an image having bleeding.

(Ink set)
The ink set of the present invention is a combination of ink and a pretreatment liquid.
The ink set of the present invention comprises an ink described later and a pretreatment liquid.
When recording is performed using an ink set that uses two or more types of ink containing different color materials, a multicolor image can be recorded, and an ink set that uses all colors of yellow, magenta, and cyan together. When used for recording, full-color images can be recorded. White ink is suitable as a base for color images.
(ink)
The ink in the present invention contains a coloring material, an organic solvent, and a resin, and further contains other components as needed.
The color of the ink is not particularly limited and may be appropriately selected depending on the intended purpose, and examples thereof include yellow, magenta, cyan, black, and white.

(Pretreatment liquid)
The pretreatment liquid in the present invention contains a polyvalent metal salt, a resin having a glass transition point (Tg) of 0 ° C. or less, a silicone-based surfactant, and an organic solvent having a boiling point of 220 ° C. or less, and further contains, if necessary. And other ingredients. The pretreatment liquid in the present invention may or may not contain a coloring material.

<Color material>
The coloring material used for the ink in the present invention is not particularly limited, and pigments and dyes can be used.
As the pigment, an inorganic pigment or an organic pigment can be used. These may be used alone or in combination of two or more. Further, a mixed crystal may be used.
As the pigment, for example, black pigment, yellow pigment, magenta pigment, cyan pigment, white pigment, green pigment, orange pigment, glossy color pigment such as gold or silver, metallic pigment and the like can be used.
As inorganic pigments, 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, and chrome yellow. Can be used.
Examples of organic pigments include azo pigments and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.). , Dye chelate (for example, basic dye type chelate, acid dye type chelate, etc.), nitro pigment, nitroso pigment, aniline black and the like can be used. Among these pigments, those having a good affinity with a solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
As a specific example of the pigment, for black, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11) , Metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).
Further, for color, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmin 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 Greens 1, 4, 7, 8, 10, 17, 18, 36 and the like.
The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used, and one type may be used alone or two or more types may be used in combination. As the dye, for example, 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. Hood 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. Dilekdo 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 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 as follows.

In order to disperse the pigment to obtain an ink, a method of introducing a hydrophilic functional group into the pigment to obtain a self-dispersing pigment, a method of coating the surface of the pigment with a resin and dispersing it, and a method of dispersing using a dispersant are used. The method, etc. can be mentioned.
As a method of introducing a hydrophilic functional group into a pigment to obtain a self-dispersing pigment, for example, a method of adding a functional group such as a sulfone group or a carboxyl group to a pigment (for example, carbon) so that the pigment can be dispersed in water. Can be mentioned.
Examples of the method of coating the surface of the pigment with a resin and dispersing the pigment include a method of encapsulating the pigment in microcapsules so that the pigment can be dispersed in water. This can be rephrased as a resin-coated pigment. In this case, it is not necessary that all the pigments blended in the ink are coated with the resin, and the uncoated pigments and the partially coated pigments are dispersed in the ink as long as the effect of the present invention is not impaired. May be. Resin-coated pigments are preferable from the viewpoint of ink storage stability and ejection reliability.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular-weight dispersant and high-molecular-weight dispersant represented by a surfactant.
As the dispersant, for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant and the like can be used depending on the pigment.
RT-100 (nonionic surfactant) manufactured by Takemoto Oil & Fat Co., Ltd. and a naphthalene sulfonic acid Na formalin condensate can also be suitably used as a dispersant.
The dispersant may be used alone or in combination of two or more.

<Pigment dispersion>
It is possible to obtain an ink by mixing a material such as water or an organic solvent with the pigment. It is also possible to produce an ink by mixing a material such as water or an organic solvent with a pigment dispersion obtained by mixing a pigment and other water or a dispersant.
The pigment dispersion is obtained by mixing and dispersing water, a pigment, a pigment dispersant, and other components as necessary, and adjusting the particle size. It is good to use a disperser for dispersion.
The particle size of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency is 20 nm or more in terms of the maximum number because the dispersion stability of the pigment is good and the image quality such as ejection stability and image density is also high. It is preferably 500 nm or less, and 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 Microtrac 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, good ejection stability can be obtained and the image density is increased by 0.1 mass. % Or more and 50% by mass or less are preferable, and 0.1% by mass or more and 30% by mass or less are more preferable.
It is preferable that the pigment dispersion is degassed by filtering coarse particles with a filter, a centrifuge, or the like, if necessary.

<Organic solvent>
The organic solvent used for the ink and the pretreatment liquid 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. In particular, when it is used as a pretreatment liquid, it is preferable to contain two or more compounds having a boiling point of 220 ° C. or lower from the viewpoint of drying property on the substrate to which the pretreatment liquid is applied.
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-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 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. , 1,3-Dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone and other nitrogen-containing heterocyclic compounds, formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, N- Amidos such as dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane and thiodiethanol, propylene carbonate and ethylene carbonate. And so on.

Polyol compounds having 8 or more carbon atoms and glycol ether compounds 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 the glycol ether compound 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; Examples thereof include polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

<Resin>
The type of resin contained in the ink and the pretreatment liquid is not particularly limited and may be appropriately selected depending on the intended purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, etc. Examples thereof include resins, butadiene resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.
Resin particles made of these resins may be used. It is possible to obtain ink by mixing resin particles with a material such as a coloring material or an organic solvent in the state of a resin emulsion in which water is used as a dispersion medium. As the resin particles, those synthesized as appropriate may be used, or commercially available products may be used. Further, these may be used alone or in combination of two or more kinds of resin particles.

The resin contained in the ink and the pretreatment liquid preferably contains a urethane resin or an acrylic resin from the viewpoint of fixability to the impermeable substrate.

The resin contained in the pretreatment liquid is a resin having a glass transition point of 0 ° C. or lower. By satisfying the above, the adhesion to the base material is improved. Further, from the viewpoint of dispersion stability in the mixture of polyvalent metal salts, a nonionic or cationic resin is preferable.

The content of the resin in the ink and the pretreatment liquid is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of fixability and storage stability of the ink, the content of the resin is 1 with respect to the total amount of the ink. It is preferably 3% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less from the viewpoint of discharge reliability and fixability.

The particle size of the solid content in the ink is not particularly limited and can be appropriately selected according to the purpose, but from the viewpoint of improving image quality such as ejection stability and image density, the maximum frequency in terms of the maximum number of inks. 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, pigment particles, and the like. The particle size can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

<Additives>
Water, a surfactant, an antifoaming agent, an antiseptic antifungal agent, a rust preventive agent, a pH adjuster and the like may be added to the ink and the pretreatment liquid, if necessary.

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

<Surfactant>
As the surfactant in the ink in the present invention, any of a silicone-based surfactant, a fluorine-based surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant can be used. From the viewpoint of the wet spread of the ink, a silicone-based surfactant is more preferable.
As the surfactant in the pretreatment liquid in the present invention, a silicone-based surfactant is used.
The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Of these, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, single-ended modified polydimethylsiloxane, side chain double-ended modified polydimethylsiloxane, and the like. Those having an oxyethylene group and 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 also be used, and examples thereof include compounds in which a polyalkylene oxide structure is introduced into the Si portion 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. Polyoxyalkylene ether polymer compounds are particularly preferred because they have low foaming properties. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonic acid salt. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt. The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes 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. The counter ions of the salts in these fluorine-based surfactants include Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , and NH (CH ₂ CH ₂ OH). ₃ etc. can be mentioned.
Examples of the amphoteric tenside include laurylaminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Examples of the nonionic surfactant include polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, and polyoxyethylene sorbitan. Examples thereof include fatty acid esters and ethylene oxide adducts of acetylene alcohols.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, polyoxyethylene alkyl ether sulfate salt and the like.
These may be used alone or in combination of two or more.

（但し、一般式（Ｓ－１）式中、ｍ、ｎ、ａ、及びｂは、それぞれ独立に、整数を表わし、Ｒは、アルキレン基を表し、Ｒ’は、アルキル基を表す。）
上記のポリエーテル変性シリコーン系界面活性剤としては、市販品を用いることができ、例えば、ＫＦ－６１８、ＫＦ－６４２、ＫＦ－６４３（信越化学工業株式会社）、ＥＭＡＬＥＸ－ＳＳ－５６０２、ＳＳ－１９０６ＥＸ（日本エマルジョン株式会社）、ＦＺ－２１０５、ＦＺ－２１１８、ＦＺ－２１５４、ＦＺ－２１６１、ＦＺ－２１６２、ＦＺ－２１６３、ＦＺ－２１６４（東レ・ダウコーニング・シリコーン株式会社）、ＢＹＫ－３３、ＢＹＫ－３８７（ビックケミー株式会社）、ＴＳＦ４４４０、ＴＳＦ４４５２、ＴＳＦ４４５３（東芝シリコン株式会社）などが挙げられる。 The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain-modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, one-ended modified polydimethylsiloxane, side. Examples thereof include polydimethylsiloxane modified at both ends of the chain, and a polyether-modified silicone-based surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group exhibits good properties as an aqueous surfactant, and is particularly effective. preferable.
As such a surfactant, an appropriately synthesized one may be used, or a commercially available product may be used. As commercially available products, for example, they can be obtained from Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Chemical Co., Ltd. and the like.
The above-mentioned polyether-modified silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a polyalkylene oxide structure represented by the general formula (S-1) may be dimethylpoly. Examples thereof include those introduced into the Si part side chain of siloxane.

(However, in the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R'represents an alkyl group.)
Commercially available products can be used as the above-mentioned polyether-modified silicone-based surfactant, for example, KF-618, KF-642, KF-643 (Shinetsu Chemical Industry 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.) and the like can be mentioned.

上記一般式（Ｆ－１）で表される化合物において、水溶性を付与するためにｍは０～１０の整数が好ましく、ｎは０～４０の整数が好ましい。
一般式（Ｆ－２）
ＣｎＦ_２ｎ＋１－ＣＨ_２ＣＨ（ＯＨ）ＣＨ_２－Ｏ－（ＣＨ_２ＣＨ_２Ｏ）_ａ－Ｙ
上記一般式（Ｆ－２）で表される化合物において、ＹはＨ、又はＣ_ｍＦ_２ｍ＋１でｍは１～６の整数、又はＣＨ_２ＣＨ（ＯＨ）ＣＨ_２－Ｃ_ｍＦ_２ｍ＋１でｍは４～６の整数、又はＣ_ｐＨ_２ｐ＋１でｐは１～１９の整数である。ｎは１～６の整数である。ａは４～１４の整数である。
上記のフッ素系界面活性剤としては市販品を使用してもよい。 この市販品としては、例えば、サーフロンＳ－１１１、Ｓ－１１２、Ｓ－１１３、Ｓ－１２１、Ｓ－１３１、Ｓ－１３２、Ｓ－１４１、Ｓ－１４５（いずれも、旭硝子株式会社製）；フルラードＦＣ－９３、ＦＣ－９５、ＦＣ－９８、ＦＣ－１２９、ＦＣ－１３５、ＦＣ－１７０Ｃ、ＦＣ－４３０、ＦＣ－４３１（いずれも、住友スリーエム株式会社製）；メガファックＦ－４７０、Ｆ－１４０５、Ｆ－４７４（いずれも、ＤＩＣ株式会社製）；ゾニール（Ｚｏｎｙｌ）ＴＢＳ、ＦＳＰ、ＦＳＡ、ＦＳＮ－１００、ＦＳＮ、ＦＳＯ－１００、ＦＳＯ、ＦＳ－３００、ＵＲ、キャプストーンＦＳ－３０、ＦＳ－３１、ＦＳ－３１００、ＦＳ－３４、ＦＳ－３５（いずれも、Ｃｈｅｍｏｕｒｓ社製）；ＦＴ－１１０、ＦＴ－２５０、ＦＴ－２５１、ＦＴ－４００Ｓ、ＦＴ－１５０、ＦＴ－４００ＳＷ（いずれも、株式会社ネオス社製）、ポリフォックスＰＦ－１３６Ａ，ＰＦ－１５６Ａ、ＰＦ－１５１Ｎ、ＰＦ－１５４、ＰＦ－１５９（オムノバ社製）、ユニダインＤＳＮ-４０３Ｎ（ダイキン工業株式会社製）などが挙げられ、これらの中でも、良好な印字品質、特に発色性、紙に対する浸透性、濡れ性、均染性が著しく向上する点から、Ｃｈｅｍｏｕｒｓ社製のＦＳ－３１００、ＦＳ－３４、ＦＳ－３００、株式会社ネオス製のＦＴ－１１０、ＦＴ－２５０、ＦＴ－２５１、ＦＴ－４００Ｓ、ＦＴ－１５０、ＦＴ－４００ＳＷ、オムノバ社製のポリフォックスＰＦ－１５１Ｎ及びダイキン工業株式会社製のユニダインＤＳＮ-４０３Ｎが特に好ましい。 As the fluorine-based surfactant, a compound having 2 to 16 carbon atoms substituted with fluorine is preferable, and a compound having 4 to 16 carbon atoms substituted with fluorine is more preferable.
Examples of the fluorosurfactant include a perfluoroalkyl phosphate ester compound, a perfluoroalkyl ethylene oxide adduct, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain. Among these, the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because it has less foaming property, and is particularly a fluorine-based compound represented by the general formula (F-1) and the general formula (F-2). Surfactants are preferred.

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)
CnF _{2n + 1} -CH ₂ CH (OH) CH ₂ -O- (CH ₂ CH ₂ O) _a -Y
In the compound represented by the above general formula (F-2), Y is H or C _m F _{2 m + 1} and m is an integer of 1 to 6, or CH ₂ CH (OH) CH ₂ -C _m F _{2 m + 1} and m is An integer of 4 to 6 or an integer of C _p H _{2p + 1} and p is an integer of 1 to 19. n is an integer of 1 to 6. a is an integer of 4 to 14.
Commercially available products may be used as the above-mentioned fluorine-based surfactant. Examples of this commercially available product include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Full Lard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Co., Ltd.); Megafuck F-470, F -1405, F-474 (all manufactured by DIC Co., Ltd.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by The Chemours Company); FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by The Chemours Company). , Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omniova), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.), etc. Among these, FS-3100, FS-34, FS-300, manufactured by The Chemours Company, Inc., from the viewpoint of remarkably improving good print quality, especially color development, permeability to paper, wettability, and leveling property. FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by Neos, Polyfox PF-151N manufactured by Omninova, and Unidyne DSN-403N manufactured by Daikin Industries Co., Ltd. are particularly preferable. ..

The content of the surfactant in the ink and the pretreatment liquid is not particularly limited and may be appropriately selected depending on the intended purpose. However, it is excellent in wettability and ejection stability, and the image quality is improved. It is preferably 0.001% by mass or more and 5% by mass or less, and more preferably 0.05% by mass or more and 5% by mass or less.

<Defoamer>
The defoaming agent is not particularly limited, and examples thereof include a silicone-based defoaming agent, a polyether-based defoaming agent, and a fatty acid ester-based defoaming agent. These may be used alone or in combination of two or more. Among these, a silicone-based defoaming agent is preferable because it has an excellent defoaming effect.

<Preservatives and fungicides>
The antiseptic and antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one and the like.

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

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

The physical properties of the ink and the pretreatment liquid are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the viscosity, surface tension, pH and the like are preferably in the following ranges.
The viscosities of the ink and the pretreatment liquid at 25 ° C. are preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa, from the viewpoint of improving the print density and character quality and obtaining good ejection properties. -S or less is more preferable. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. As the measurement conditions, it is possible to measure at 25 ° C. with a standard cone rotor (1 ° 34'× R24), a sample liquid volume of 1.2 mL, a rotation speed of 50 rpm, and 3 minutes.
The surface tension of the ink and the pretreatment liquid is preferably 35 mN / m or less, 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. preferable.
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 that comes into contact with the liquid.

<Multivalent metal salt>
The polyvalent metal salt contained in the pretreatment liquid promptly aggregates the pigment in the recording liquid after being dropped, suppresses color bleeding, and improves color development.
The polyvalent metal compound is not limited to the following, and is, for example, a titanium compound, a chromium compound, a copper compound, a cobalt compound, a strontium compound, a barium compound, an iron compound, an aluminum compound, a calcium compound, and a magnesium compound, and salts thereof. (Polyvalent metal salt) can be mentioned.
Among these polyvalent metal compounds, one or more selected from the group consisting of calcium compounds, magnesium compounds, and nickel compounds is preferable because pigments can be effectively aggregated, and alkaline earth metals such as calcium and magnesium are preferable. Is more preferable.
The polyvalent metal compound is preferably ionic. In particular, when the polyvalent metal compound is a calcium salt, the stability of the reaction solution becomes better.
Specific examples of the above polyvalent metal compounds include calcium carbonate, calcium nitrate, calcium chloride, calcium acetate, calcium sulfate, magnesium chloride, magnesium acetate, magnesium sulfate, barium sulfate, zinc sulfide, zinc carbonate, aluminum silicate, and calcium silicate. , Magnesium silicate, aluminum hydroxide and the like.
Among these, a calcium salt or a magnesium salt is preferable from the viewpoint of solubility in the pretreatment liquid and whitening of the pretreatment liquid film at the time of application to the impermeable substrate.

(Image formation method)
The image forming method of the present invention is an image forming method using an ink set composed of a pretreatment liquid and ink, and includes a pretreatment liquid application step of applying the pretreatment liquid in the ink set of the present invention to a recording medium, and the above-mentioned. It has an ink applying step of applying the ink in the ink set of the present invention on a recording medium having the pretreatment liquid applied to the surface.
Further, after the ink applying step, there may be a step of drying the pretreatment liquid and the impermeable substrate to which the ink is applied.
A non-permeable base material can be used as the recording medium, and leather can be used as the non-permeable base material.

(Image forming device)
The image forming apparatus of the present invention is an image forming apparatus using an ink set composed of a pretreatment liquid and ink, and the pretreatment liquid in the ink set of the present invention, the ink in the ink set of the present invention, and the pretreatment. The ink ejection means for ejecting the ink onto the recording medium is provided on the recording medium to which the liquid is applied.
As the ejection means, ink ejection means is used in which ink is applied by at least one stimulus selected from heat, pressure, vibration and light to eject the ink and record an image.

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

The recording medium is not limited to that used as a general recording medium, and wallpaper, flooring, building materials such as tiles, cloth for clothing such as T-shirts, textiles, leather and the like can be appropriately used. Further, ceramics, glass, metal, or the like can be used by adjusting the configuration of the path for transporting the recording medium.

The method for applying the ink and the pretreatment liquid is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an inkjet method, a blade coating method, a gravure coating method, a bar coating method, a roll coating method, or a dip. Examples include a coating method, a curtain coating method, a slide coating method, a die coating method, and a spray coating method. Among these, the inkjet method is preferable.

<Recording device, recording method>
The ink of the present invention can be suitably used for various recording devices by an inkjet recording method, for example, a printer, a facsimile device, a copying device, a printer / fax / copier multifunction device, a three-dimensional modeling device, and the like.
In the present invention, the recording device and the recording method are devices capable of ejecting ink, various processing liquids, and the like to a recording medium, and a method for recording using the device. The recording medium means a medium to which ink and various treatment liquids can adhere even temporarily.
This recording device can include not only a head portion for ejecting ink, but also means related to feeding, transporting, and discharging paper of a recording medium, a pretreatment device, a device called a posttreatment device, and the like. ..
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 printed surface and the back surface of the recording medium. The heating means and the drying means are not particularly limited, but for example, a hot 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 device and the recording method are not limited to those in which significant images such as characters and figures are visualized by ink. For example, those that form patterns such as geometric patterns and those that form three-dimensional images are also included.
Further, the recording device includes both a serial type device that moves the discharge head and a line type device that does not move the discharge head, unless otherwise specified.
Further, as this recording device, it is possible to use not only a desktop type but also a wide recording device capable of printing on an A0 size recording medium, or, for example, continuous paper wound in a roll shape as a recording medium. A continuous book printer is also included.

<< First Embodiment of Image Forming Device >>
FIG. 1 shows an example of an image forming apparatus.
The step of applying the ink and the step of applying the pretreatment liquid in the image forming method of the present invention may be performed by the same printing device or may be performed by different printing devices.

The image forming apparatus 100 includes a pretreatment liquid application unit 110, an ink ejection unit 120, a posttreatment liquid ejection unit 130, a drying unit 140, and a transport unit 150.
The pretreatment liquid application unit 110 applies the pretreatment liquid to the recording medium M.

The method for applying the pretreatment liquid is not particularly limited, but is limited to an inkjet method, a blade coating method, a gravure coating method, a gravure offset coating method, a bar coating method, a roll coating method, a knife coating method, an air knife coating method, and a comma coating method. , U comma coat method, AKKU coat method, smoothing coat method, micro gravure coat method, reverse roll coat method, 4 to 5 roll coat method, dip coat method, curtain coat method, slide coat method, die coat method, etc. Be done.
The pretreatment liquid application unit 110 may be omitted.

The recording medium M 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.
When a coated paper for commercial printing is used as the recording medium M, if an image is formed without applying the pretreatment liquid, the image may be double-fed during transportation in a subsequent step. In this case, by applying the pretreatment liquid, it is possible to suppress double feeding during transportation without lowering the blocking resistance.

The ink ejection unit 120 ejects inkjet ink onto the surface of the recording medium M coated with the pretreatment liquid.
A known inkjet head can be used as the ink ejection unit 120.

The post-treatment liquid ejection unit 130 ejects the post-treatment liquid to the area of the recording medium M on which the inkjet ink is applied and which is coated with the inkjet ink.
A known inkjet head can be used as the post-treatment liquid discharge unit 130.
Instead of the post-treatment liquid ejection unit 130, a post-treatment liquid application unit for applying the post-treatment liquid may be provided on substantially the entire surface of the recording medium M on which the inkjet ink is applied.

The method for applying the post-treatment liquid is not particularly limited, but is limited to an inkjet method, a blade coating method, a gravure coating method, a gravure offset coating method, a bar coating method, a roll coating method, a knife coating method, an air knife coating method, and a comma coating method. , U comma coat method, AKKU coat method, smoothing coat method, micro gravure coat method, reverse roll coat method, 4 to 5 roll coat method, dip coat method, curtain coat method, slide coat method, die coat method, etc. Be done.
The post-treatment liquid discharge unit 130 may be omitted.

The drying unit 140 dries the recording medium M coated with the post-treatment liquid with warm air.
If there is no post-treatment liquid discharge section, the drying section 140 may be omitted.
The drying unit 140 may use infrared rays, microwaves, a roll heater, or the like instead of warm air to heat-dry the recording medium M to which the post-treatment liquid is applied, or the recording medium to which the post-treatment liquid is applied may be heated and dried. The medium M may be naturally dried.

The transport unit 150 transports the recording medium M.
The transport unit 150 is not particularly limited as long as it can transport the recording medium M, and examples thereof include a transport belt.

The image forming apparatus 100 may further have a fixing portion for heating and fixing the image formed on the recording medium M.
The fixing portion is not particularly limited, and examples thereof include a fixing roller.
The temperature at which the image formed on the recording medium M is heated and fixed is usually 50 to 150 ° C, preferably 100 to 150 ° C.

Further, in the terms of the present invention, image formation, recording, printing, printing, etc. are all synonymous.

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

(Preparation Example 1 of Pigment Dispersion Liquid)
<Preparation of black pigment dispersion liquid A>
After premixing the following raw materials, a black pigment dispersion liquid A was obtained by circulating and dispersing for 7 hours in a disc-type bead mill (manufactured by Simmal Enterprises, KDL type, media: using zirconia balls having a diameter of 0.3 mm).
[composition]
-Carbon black pigment: 15 parts by mass (Product name: Monarch800, manufactured by Cabot)
-Anionic surfactant: 2 parts by mass (Pionin A-51-B, manufactured by Takemoto Oil & Fat Co., Ltd.)
・ Ion-exchanged water: 83 parts by mass

(Preparation Example 2 of Pigment Dispersion Liquid)
<Preparation of cyan pigment dispersion liquid A>
Same as Preparation Example 1 of Pigment Dispersion Liquid except that the carbon black pigment was changed to Pigment Blue 15: 3 (trade name: LIONOL BLUE FG-7351, manufactured by Toyo Ink Co., Ltd.) in Preparation Example 1 of the pigment dispersion liquid. A cyan pigment dispersion liquid A was obtained.

(Preparation Example 3 of Pigment Dispersion Liquid)
<Preparation of black pigment dispersion liquid B>
11.2 g of styrene, 2.8 g of acrylic acid, 12 g of lauryl methacrylate, 4 g of polyethylene glycol methacrylate, 4 g of styrene macromer, and 0.4 g of mercaptoethanol were mixed and heated to 65 ° C. Next, 100.8 g of styrene, 25.2 g of acrylic acid, 108 g of lauryl methacrylate, 36 g of polyethylene glycol methacrylate, 60 g of hydroxylethyl methacrylate, 36 g of styrene macromer, 3.6 g of mercaptoethanol, 2.4 g of azobismethylvaleronitrile, and 18 g of methyl ethyl ketone. The mixed solution of the above was added dropwise into the flask over 2.5 hours. After the dropping, a mixed solution of 0.8 g of azobismethylvaleronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hours. After aging at 65 ° C. for 1 hour, 0.8 g of azobismethylvaleronitrile was added, and the mixture was further aged for 1 hour. After completion of the reaction, 364 g of methyl ethyl ketone was added into the flask to obtain 800 g of the polymer solution A having a solid content concentration of 50%.
Then, 28 g of the polymer solution A, 42 g of carbon black (Black Pearls 1000 manufactured by Cabot Corporation), 13.6 g of a 1 mol / L potassium hydroxide aqueous solution, 20 g of methyl ethyl ketone, and 13.6 g of water were sufficiently stirred, and then a roll mill was used. Kneaded with. The obtained paste is placed in 200 g of pure water and sufficiently stirred, then the methyl ethyl ketone is removed by an evaporator, and pressure-filtered with a polyvinylidene fluoride membrane filter having an average pore size of 5 μm, so that the solid content concentration becomes 20%. The water content was adjusted to obtain a styrene-acrylic resin-coated black pigment dispersion B having a solid content concentration of 20%.

(Preparation Example 4 of Pigment Dispersion Liquid)
<Preparation of cyan pigment dispersion liquid B>
In the preparation of the styrene-acrylic resin-coated black pigment dispersion B, a styrene having a solid content concentration of 20% is similarly used except that Pigment Blue 15: 4 (SMART Cyan 3154BA manufactured by SENSIENT) is used instead of carbon black. An acrylic resin-coated type cyan pigment dispersion B was obtained.

(Preparation Example 1 of Polyurethane Resin Emulsion)
<Preparation of polyester urethane resin emulsion>
Double the amount of polyester polyol (trade name: Polylite OD-X-2251, manufactured by DIC Co., Ltd., average molecular weight 2,000) 200 in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube, and a stirrer. The reaction was carried out using 0.4 g, 15.7 g of 2,2-dimethylol propionic acid, 48.0 g of isophorone diisocyanate, 77.1 g of methyl ethyl ketone as an organic solvent, and 0.06 g of DMTDL (dibutyltin dilaurate) as a catalyst. After continuing the reaction for 4 hours, 30.7 g of methyl ethyl ketone was supplied as a diluting solvent, and the reaction was further continued. When the average molecular weight of the reaction product reached the range of 20,000 to 60,000, 1.4 g of methanol was added to complete the reaction to obtain an organic solvent solution of urethane resin. The carboxyl group of the urethane resin is neutralized by adding 13.4 g of a 48 mass% potassium hydroxide aqueous solution to the organic solvent solution of the urethane resin, then 715.3 g of water is added and the mixture is sufficiently stirred, and then aging and By removing the solvent, a polyester-based urethane resin emulsion having a solid content concentration of 30% by mass was obtained. Using the polyester-based urethane emulsion, the minimum film-forming temperature (MFT) measured by a "film-forming temperature test device" (manufactured by Imoto Seisakusho Co., Ltd.) was 74 ° C.

(Ink manufacturing example 1)
<Manufacturing of ink a>
Ion-exchanged water was added to the following ink formulation so that the total amount was 100 parts by mass, and after mixing, the mixture was mixed and stirred, and filtered through a filter (Made by Sartorius, Minisart) having an average pore size of 5 μm to prepare ink a. ..
[Ink prescription]
・ Black pigment dispersion B or cyan dispersion B: 20 parts by mass ・ Reester urethane resin emulsion: 6 parts by mass ・ Acrylic resin mobile 6750: 2 parts by mass (manufactured by Japan Coating Resin Co., Ltd.)
SAG503A: 1 part by mass (manufactured by Nissin Chemical Industry Co., Ltd., silicone surfactant)
・ 1,2-Propane diol: 9 parts by mass (trade name: propylene glycol, manufactured by ADEKA CORPORATION)
・ 1,3-Propanediol (manufactured by Dupont): 1 part by mass ・ 3-Methyl-1,3-butanediol: 10 parts by mass (trade name: isoprene glycol, manufactured by Kuraray Co., Ltd.)
・ 3-Methoxy-3-methyl-1-butanol: 3 parts by mass (trade name: Solfit, manufactured by Kuraray Co., Ltd.)
-3-Methoxy-N, N-dimethylpropionamide: 5 parts by mass (trade name: Equamid M100, manufactured by Idemitsu Kosan Co., Ltd.)
・ Proxel LV (Abyssia, antiseptic and antifungal agent): 0.1 parts by mass ・ Ion-exchanged water: Remaining amount
(Total: 100 parts by mass)

(Ink production examples 2 to 5, pretreatment liquid production examples 1 to 8)
<Manufacturing of inks b to e and pretreatment liquids A to H>
Ink production examples 1 produced inks b to e and pretreatment liquids A to H in the same manner as in ink production example 1 except that the ink formulations shown in Table 1 were changed. The content of the resin in Table 1 is the amount of solid content.

In Tables 1 and 2, the detailed contents of each component are as follows.

(Resin-ink component)
・ Superflex 300 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., polyurethane resin, solid content concentration: 30% by mass)
-W6110 polyurethane resin (manufactured by Mitsui Chemicals, Inc., solid content concentration 35% by mass)
-Mobile 6810 (manufactured by Japan Coating Resin Co., Ltd., acrylic resin, solid content concentration: 42% by mass)
・ Movinyl 6800 (manufactured by Japan Coating Resin Co., Ltd., acrylic resin, solid content concentration: 45% by mass)
・ Movinyl 6750 (manufactured by Japan Coating Resin Co., Ltd., acrylic resin, solid content concentration: 50% by mass)
-Solvine TA3 (manufactured by Nissin Chemical Co., Ltd., vinyl chloride-vinyl acetate copolymer resin, Tg: 65 ° C)

(Surfactant)
-FS-300 (DuPont, fluorine-based surfactant)
SAG002 (Silicone-based surfactant manufactured by Nissin Chemical Industry Co., Ltd.)
-BYK348 (Silicone-based surfactant manufactured by BYK)

(Organic solvent)
-1,3-Butanediol (trade name: 1,3-butanediol, manufactured by Daicel Chemical Co., Ltd.) (boiling point 207 ° C)
-3-Methyl-1,5-pentanediol (trade name: MPD, manufactured by Kuraray Co., Ltd.): (boiling point 250 ° C)
-2-Ethyl-1,3-hexanediol (trade name: octanediol, manufactured by KH Neochem Co., Ltd.) (boiling point 244 ° C)
-3-Butoxy-N, N-dimethylpropionamide (trade name: Equamid B100, manufactured by Idemitsu Kosan Co., Ltd.) (boiling point 252 ° C)

(Coagulant)
・ Calcium acetate ・ Magnesium acetate ・ Magnesium sulfate ・ Sodium acetate

(Resin-preparation liquid component)
・ XW-Um7 (Mitsui Chemicals, urethane resin, Tg: -4 ° C)
・ Movinyl 6940 (manufactured by Japan Coating Resin Co., Ltd., acrylic resin, Tg: -2 ° C)
・ Movinyl 6950 (manufactured by Japan Coating Resin Co., Ltd., acrylic resin, Tg: 0 ° C)
・ Movinyl 6951 (manufactured by Japan Coating Resin Co., Ltd., acrylic resin, Tg: -25 ° C)
-Sumikaflex 951HQ (manufactured by Sumika Chemtex, ethylene-vinyl acetate resin, Tg: -25 ° C)
-Sumikaflex 408HQE (manufactured by Sumika Chemtex, ethylene-vinyl acetate resin, Tg: -30 ° C)
-Acryt UW-550CS (manufactured by Taisei Fine Chemical Co., Ltd., core shell type acrylic resin, core part Tg: 50 ° C, shell part Tg: 40 ° C)

(Examples 1 to 7 and Comparative Examples 1 to 5)
Next, using each ink, "bleeding resistance" and "fixability" were evaluated as follows. The results are shown in Table 3.

<Image formation>
The ink (black and cyan) of each ink set was filled in the black portion and the cyan portion of an inkjet printer (device name: Ri100, manufactured by Ricoh Corporation), and the pretreatment liquid was filled in the magenta portion. Print 80% gradation pretreatment liquid (magenta) solid image on polystyrene (STYREX [registered trademark] 500), acrylic (Acrylite EX clear), polycarbonate (Iupilon white NF-2000C) in fast mode. Subsequently, a 100% gradation color solid image was printed, and the printed matter was passed through a hot air drying unit at 80 ° C., dried, and fixed.

<Bleeding resistance>
The bleeding at the color boundary between the black solid and the cyan solid in the obtained image was visually evaluated. In addition, B or more is the actual usable range.
FIG. 2 shows a schematic diagram of an image having bleeding. L in FIG. 2 indicates the boundary line of the color boundary portion when there is no bleeding.
[Evaluation criteria]
A: No color boundary bleeding B: Slight color bleeding is seen in 5 or less places C: Slight color bleeding is seen in 10 or less places D: Severe bleeding is seen and image quality is degraded ing

<Fixability>
The solid part of the image was evaluated by counting the number of remaining squares of 100 test squares by a grid peeling test using a cloth adhesive tape (123LW-50 manufactured by Nichiban).
In addition, B or more is the actual usable range.
[Evaluation criteria]
AA: The number of remaining cells was 100.
A: The number of remaining cells was 90 or more and less than 100.
B: The number of remaining cells was 80 or more and less than 90.
C: The number of remaining cells was 70 or more and less than 80.
D: The number of remaining cells was less than 70.

Japanese Unexamined Patent Publication No. 2005-220352 Japanese Unexamined Patent Publication No. 2011-094082

The present invention relates to the ink set of the following (1), but as an embodiment, it is an ink set including (1) ink containing the following (2) to (12) and a pretreatment liquid.
The ink contains a coloring material, an organic solvent, and a resin.
The pretreatment liquid contains a polyvalent metal salt, a resin having a glass transition point (Tg) of 0 ° C. or lower, a silicone-based surfactant, and two or more organic solvents having a boiling point of 220 ° C. or lower.
An ink set that features that.
(2) The ink set according to (1) above, which contains a urethane resin or an acrylic resin as the resin in the pretreatment liquid.
(3) The ink set according to (1) or (2) above, which contains a magnesium salt or a calcium salt as the polyvalent metal salt in the pretreatment liquid.
(4) The ink set according to any one of (1) to (3) above, which contains urethane resin or acrylic resin as the resin in the ink.
(5) The ink set according to any one of (1) to (4) above, wherein the pretreatment liquid contains three or more kinds of organic solvents having a boiling point of 220 ° C. or lower.
(6) The ink set according to any one of (1) to (5) above, which has a resin-coated pigment as a coloring material in the ink.
(7) An image forming method using an ink set consisting of a pretreatment liquid and ink.
The pretreatment liquid application step of applying the pretreatment liquid in the ink set according to any one of (1) to (6) above to the recording medium, and the pretreatment liquid application step.
The ink applying step of applying the ink in the ink set according to any one of (1) to (6) above onto a recording medium having the pretreatment liquid applied to the surface thereof.
An image forming method characterized by having.
(8) The image forming method according to (7) above, wherein the pretreatment liquid application step and / or the ink application step is performed by inkjet.
(9) The image forming method according to (7) or (8) above, which comprises a step of drying the pretreatment liquid and the impermeable substrate to which the ink is applied after the ink application step.
(10) The image forming method according to any one of (7) to (9) above, wherein the recording medium is a non-permeable substrate.
(11) An image forming apparatus using an ink set composed of a pretreatment liquid and ink.
The pretreatment liquid in the ink set according to any one of (1) to (6) above, and
With the ink in the ink set according to any one of (1) to (6) above,
The pretreatment liquid applying means for applying the pretreatment liquid to the recording medium,
An ink applying means for ejecting the ink onto the recording medium onto the recording medium to which the pretreatment liquid is applied,
An image forming apparatus characterized by having.
(12) The image forming apparatus according to (11) above, wherein the pretreatment liquid applying means and / or the ink applying means is an inkjet.

100 Image forming device 110 Pretreatment liquid application part 120 Ink discharge part 130 Post-treatment liquid discharge part 140 Drying part 150 Transport part M Recording medium L Boundary line of color boundary part when there is no bleeding

Claims (12)

An ink set consisting of ink and pretreatment liquid,
The ink contains a coloring material, an organic solvent, and a resin.
The pretreatment liquid contains a polyvalent metal salt, a resin having a glass transition point (Tg) of 0 ° C. or lower, a silicone-based surfactant, and two or more organic solvents having a boiling point of 220 ° C. or lower.
An ink set that features that. The ink set according to claim 1, which contains a urethane resin or an acrylic resin as the resin in the pretreatment liquid. The ink set according to claim 1 or 2, which contains a magnesium salt or a calcium salt as the polyvalent metal salt in the pretreatment liquid. The ink set according to any one of claims 1 to 3, which contains a urethane resin or an acrylic resin as the resin in the ink. The ink set according to any one of claims 1 to 4, wherein the pretreatment liquid contains three or more kinds of organic solvents having a boiling point of 220 ° C. or lower. The ink set according to any one of claims 1 to 5, which has a resin-coated pigment as a coloring material in the ink. An image forming method using an ink set consisting of a pretreatment liquid and ink.
A pretreatment liquid application step of applying the pretreatment liquid in the ink set according to any one of claims 1 to 6 to a recording medium, and a pretreatment liquid application step.
An ink applying step of applying the ink in the ink set according to any one of claims 1 to 6 onto a recording medium having the pretreatment liquid applied to the surface thereof.
An image forming method characterized by having. The image forming method according to claim 7, wherein the pretreatment liquid applying step and / or the ink applying step is performed by inkjet. The image forming method according to claim 7, further comprising a step of drying the pretreatment liquid and the impermeable substrate to which the ink is applied after the ink applying step. The image forming method according to any one of claims 7 to 9, wherein the recording medium is a non-permeable substrate. An image forming apparatus that uses an ink set consisting of a pretreatment liquid and ink.
The pretreatment liquid in the ink set according to any one of claims 1 to 6 and the pretreatment liquid.
The ink in the ink set according to any one of claims 1 to 6 and the ink.
The pretreatment liquid applying means for applying the pretreatment liquid to the recording medium,
An ink applying means for ejecting the ink onto the recording medium onto the recording medium to which the pretreatment liquid is applied,
An image forming apparatus characterized by having. The image forming apparatus according to claim 11, wherein the pretreatment liquid applying means and / or the ink applying means is an inkjet.

Images