JP6701755B2 - Oil-based inkjet recording ink set and oil-based inkjet recording method - Google Patents

Description

  The present invention relates to a pretreatment liquid, an oil-based inkjet recording ink set, and an oil-based inkjet recording method.

  Inkjet printers for office use are being developed. Office-use printers are required to be capable of high-speed printing with high image quality on recording media such as plain paper, and to be capable of finishing such as bookbinding after printing. Therefore, as the properties required for the ink used in this printer, it is possible to secure a high print density at a high speed on plain paper, and to prevent strike-through in order to enable double-sided printing. Is required to prevent paper deformation such as cockling and curling after high-speed printing. When a water-based ink mixed with an aqueous medium is used as the ink, paper deformation such as cockling and curling may occur after plain paper high-speed printing, and thus paper deformation does not easily occur. Development is also in progress.

  When a volatile organic compound is used as a medium used in the oil-based ink, when the volatile organic compound is released into the environment, it may cause health hazards such as allergies. Therefore, a low-volatile organic compound is used as a medium for the oil-based ink. However, when printing with an oil-based ink that uses a low-volatile organic compound as a medium, the medium remains low inside the paper due to its low volatility and penetrates to cause strikethrough and bleeding. The print density may decrease. Also, when a recording medium printed with oil-based ink is sandwiched between polypropylene (PP) clear folders, the organic solvent moves to the clear folders, so that only the inside of the clear folders expands and the clear folders face outward. It may warp so that it may turn up, or it may be deformed by waviness. In particular, when a recorded matter recorded with a high duty on a recording medium is sandwiched between clear folders, there is a problem in that the clear folders are largely warped outward and a problem occurs in use.

  Therefore, to solve such problems, the viscosity of the ink is increased to limit the migration of the organic solvent from the recording medium to the clear folder, and by selecting a medium with a high polarity, the attackability to the clear folder is improved. It is being reduced to suppress the deformation (see, for example, Patent Document 1). Here, as the medium, a diester of a polyhydric alcohol and a branched aliphatic carboxylic acid or a diester of a branched aliphatic alcohol and a high aliphatic carboxylic acid is used.

JP, 2009-275211, A

  However, if the viscosity of the ink or the polarity of the medium is too high, problems may occur in the ejection property of the ink and the sticking when the recording materials are stacked and stored, and the deformation of the clear folder is suppressed for about 10 days at the shortest. It is limited in time and the suppression effect is not sufficient. As described above, it is difficult to suppress the deformation of the clear folder due to the recorded matter using the oil-based ink for a long period of time.

Therefore, some aspects according to the present invention, by solving at least a part of the above-mentioned problems, a pretreatment liquid capable of improving the storability of a recorded material in a clear folder over a long period of time, and this pretreatment liquid. An object of the present invention is to provide an oil-based inkjet recording ink set including the above and an oil-based inkjet recording method.

  The present invention has been made to solve at least a part of the above problems, and can be realized as the following aspects or application examples.

[Application example 1]
One aspect of the pretreatment liquid according to the present invention is
A pretreatment liquid for an oil-based ink containing an organic solvent,
The organic solvent of the oil-based ink contains at least one selected from the group consisting of alcohols, primary amines and secondary amines,
The pretreatment liquid contains a maleic anhydride resin derivative.

  According to the pretreatment liquid of the application example, the organic solvent of the oil-based ink contains at least one selected from the group consisting of alcohol, primary amine and secondary amine, and the pretreatment liquid is a maleic anhydride resin. By containing the derivative, it is possible to provide a pretreatment liquid capable of improving the storage property of recorded matter in a clear folder for a long period of time.

[Application example 2]
In the above application example,
The maleic anhydride resin derivative may be at least one selected from the group consisting of rosin-modified maleic anhydride resin, acrylic-modified maleic anhydride resin, and styrene-modified maleic anhydride resin.

[Application example 3]
In the above application example,
The organic solvent may have 12 or more carbon atoms.

[Application example 4]
One aspect of the oil-based inkjet recording ink set according to the present invention is
It is characterized by containing the pretreatment liquid described in the above application example.

[Application example 5]
One aspect of the oil-based inkjet recording method according to the present invention is
Recording is performed using the ink set described in the above application example.

The figure which shows typically an example of the inkjet recording device which performs the oil-based inkjet recording method which concerns on this embodiment.

  Hereinafter, preferred embodiments of the present invention will be described. The embodiment described below describes an example of the present invention. Further, the present invention is not limited to the following embodiments, and includes various modified examples implemented within a range that does not change the gist of the present invention.

1. Pretreatment Liquid A pretreatment liquid according to an embodiment of the present invention is a pretreatment liquid for an oil-based ink containing an organic solvent, and the organic solvent of the oil-based ink is an alcohol, a primary amine and a secondary amine. At least one selected from the group is included, and the pretreatment liquid contains a maleic anhydride resin derivative.

  The pretreatment liquid according to the present embodiment constitutes an oil-based inkjet recording ink set used in the oil-based inkjet recording method, and the organic solvent of the oil-based ink is at least selected from the group consisting of alcohols, primary amines and secondary amines. The pretreatment liquid contains one maleic anhydride resin derivative. As described above, the combination of the oil-based ink containing a highly polar organic solvent and the pretreatment liquid containing the maleic anhydride resin derivative can suppress the storability of the clear folder for a long period of time.

  Hereinafter, the components contained in the pretreatment liquid according to the present embodiment and the components that may be contained therein will be described.

1.1. Maleic Anhydride Resin Derivative The pretreatment liquid according to the present embodiment contains a maleic anhydride resin derivative. The maleic anhydride resin derivative is a kind of resin. In the pretreatment liquid according to the present embodiment, a maleic anhydride resin derivative is used as a resin, and pretreatment is performed by applying the maleic anhydride resin derivative onto a recording medium before recording with an oil-based ink described below. This prevents the acylation reaction of the maleic anhydride resin derivative from rapidly progressing on the surface of the recording medium, and prevents the clear folder from being attacked by the components contained in the oil-based ink.

  In addition, the maleic anhydride resin derivative resin is preferably in the form of an emulsion. In this case, it is possible to suppress an increase in the viscosity of the pretreatment liquid even when the same solid content concentration is added, as compared with the case where a solution type resin is used. In addition, since the pretreatment liquid has a low viscosity, it is possible to perform simple coating by the existing spray method, roller method, etc. in the coating process of the pretreatment liquid, and evenly coat it even with a high solid content. It will be easier.

  The maleic anhydride resin derivative is not particularly limited, and for example, rosin-modified maleic anhydride resin, acrylic-modified maleic anhydride resin, styrene-modified maleic anhydride resin, etc. can be used.

  The content of the maleic anhydride resin derivative in terms of solid content needs to be 1% by mass or more and 20% by mass or less with respect to the total mass (100% by mass) of the pretreatment liquid, but 1% by mass or more and 16% by mass. % Or less, and more preferably 3% by mass or more and 16% by mass or less. Within the above range, application of the pretreatment liquid is easy, and the effect of storage in a clear folder is high.

1.2. Liquid Medium The pretreatment liquid according to the present embodiment contains a liquid medium as a medium for dispersing the maleic anhydride resin derivative. Examples of the liquid medium include aqueous solvents and organic solvents. Water is included as the aqueous solvent, and examples of the aqueous solvent include water and water-soluble organic solvents. The water is not particularly limited, and deionized water, ultrafiltered water, reverse osmosis water, distilled water, or other pure water, or ultrapure water can be used. As the organic solvent, any of various known vegetable oils and/or petroleum-based solvents can be used, and both nonpolar organic solvents and polar organic solvents can be used. Among them, the liquid medium used is preferably a low-volatile organic solvent from the viewpoint of environmental consideration.

  The content of the liquid medium is not particularly limited and may be appropriately determined as needed, but is 70% by mass or more and 95% by mass or less with respect to the total mass (100% by mass) of the pretreatment liquid. Good.

1.3. Other Components The pretreatment liquid according to the present embodiment may further contain other additives contained in a normal pretreatment liquid. Examples of the other additives include, but are not limited to, a flocculant, a surfactant, a pH adjuster, an antiseptic/antifungal agent, a thickener, and a chelating agent.

<Flocculant>
The aggregating agent has a function of aggregating these components by reacting with a coloring material or resin contained in the oil-based ink. As a result, it is possible to improve the image quality of the image formed by the oil-based ink, suppress the occurrence of bleeding, and further improve the clear folder storability.

  The aggregating agent is not particularly limited, and examples thereof include organic acids (eg, acetic acid, propionic acid, lactic acid and the like and salts thereof), polyallylamine, polyallylamine derivatives, polyvalent metal compounds, and the like. Among them, a polyvalent metal compound and an organic acid can be preferably used, and a polyvalent metal compound can be more preferably used, because they are more excellent in the aggregation action of the coloring material. When a polyvalent metal compound is used, the content of metal ions contained in the polyvalent metal compound, that is, the concentration of metal ions derived from the polyvalent metal compound, is based on the total mass (100 mass%) of the pretreatment liquid. It is preferably 0.5% by mass or more and 5% by mass or less, and more preferably 1% by mass or more and 5% by mass or less.

<Surfactant>
As the surfactant, an acetylene glycol-based surfactant, a silicone-based surfactant, and a fluorine-based surfactant can be preferably used.

  The acetylene glycol-based surfactant is not particularly limited, but for example, Surfynol 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE- F, 504, 61, DF37, CT111, CT121, CT131, CT136, TG, GA, DF110D (all product names, manufactured by Air Products and Chemicals. Inc.), Olfin B, Y, P, A, STG, SPC. , E1004, E1010, PD-001, PD-002W, PD-003, PD-004, EXP. 4001, EXP. 4036, EXP. 4051, AF-103, AF-104, AK-02, SK-14, AE-3 (all above trade names, manufactured by Nissin Chemical Industry Co., Ltd.), acetylenol E00, E00P, E40, E100 (all above trade names, Kawa Ken Fine Chemical Co., Ltd.).

  The silicone surfactant is not particularly limited, and examples thereof include polysiloxane compounds. The polysiloxane compound is not particularly limited, and examples thereof include polyether-modified organosiloxane. Examples of commercially available products of the polyether-modified organosiloxane include BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, and BYK-348 (trade names, manufactured by BYK). , KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515. , KF-6011, KF-6012, KF-6015, KF-6017 (the above trade names, manufactured by Shin-Etsu Chemical Co., Ltd.).

  As the fluorine-based surfactant, a fluorine-modified polymer is preferably used, and specific examples thereof include BYK-340 (manufactured by BYK Japan KK).

When the surfactant is contained, its content is, for example, 0 with respect to the total mass of the pretreatment liquid.
． It can be set to 05 mass% or more and 2.0 mass% or less.

<pH adjuster>
Examples of the pH adjuster include potassium dihydrogen phosphate, disodium hydrogen phosphate, sodium hydroxide, lithium hydroxide, potassium hydroxide, ammonia, diethanolamine, triethanolamine, triisopropanolamine, potassium carbonate, sodium carbonate, Examples include sodium hydrogen carbonate.

<Antiseptic, antifungal, rust preventive>
Examples of the antiseptic/antifungal agent include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, and 1,2-dibenzisothiazolin-3-one. Etc. Examples of commercially available products include Proxel XL2 and Proxel GXL (trade names, manufactured by Avicia), Denise CSA, NS-500W (trade names, manufactured by Nagase Chemtex Co., Ltd.), and the like. Examples of the rust preventive agent include benzotriazole and the like.

<Thickener>
Examples of the thickener include polyvinyl alcohols, poly(meth)acrylic acids, polyethers, polyvinylpyrrolidones, polyvinylformals, proteins (eg gelatin, casein, glue etc.), polysaccharides (eg pullulan, Dextran, dextrin, cyclodextrin, carrageenan, pectin, glucomannan, sodium alginate, xanthan gum, arabic gum, locust bean gum, tragacanth gum, guar gum, tamarind gum, etc., starches (eg starch, oxidized starch, carboxyl starch, dialdehyde starch) Etc.), cellulose or a derivative thereof (eg, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, etc.), alginate (eg, sodium alginate, potassium alginate, ammonium alginate, etc.) alginate ester (eg, Propylene glycol alginate, etc.) and the like. When the thickening agent is contained, its content is not particularly limited, but may be, for example, 20% by mass or less based on the total mass of the pretreatment liquid.

<Chelating agent>
Examples of chelating agents include known aluminum chelating agents and the like.

1.4. Method for Producing Pretreatment Liquid The pretreatment liquid according to the present embodiment can be obtained by mixing the above-described components (materials) in any order, filtering the mixture as necessary, and removing impurities. it can. As a method of mixing the respective materials, a method of sequentially adding the materials to a container equipped with a stirring device such as a mechanical stirrer or a magnetic stirrer and stirring and mixing is preferably used. As a filtration method, for example, centrifugal filtration or filter filtration can be performed as necessary.

1.5. Physical Properties of Pretreatment Liquid The viscosity of the pretreatment liquid according to the present embodiment at 20° C. improves the dischargeability from a nozzle when an inkjet method or a spray method is used, and the coating property when a roll coater or the like is used. From the viewpoint of improvement, it is preferably 30 mPa·s or less, more preferably 25 mPa·s or less, further preferably 20 mPa·s or less, particularly preferably 15 mPa·s or less, and 10 mPa·s. It is more preferably s or less and even more preferably 5 mPa·s or less. Although the lower limit is not limited, it is preferably 1 mPa·s or more. The viscosity can be measured, for example, by using a viscoelasticity tester MCR-300 (trade name, manufactured by Physica) under the environment of 20°C.

1.6. Applications The pretreatment liquid used in the present embodiment is applied to a recording medium such as paper by coating or jetting before recording in a known inkjet recording device described later. This prevents the acylation reaction of the maleic anhydride resin derivative from rapidly progressing on the surface of the recording medium, and prevents the clear folder from being attacked by the components contained in the oil-based ink.

  Examples of the method of attaching the pretreatment liquid to the recording medium include a method of immersing the recording medium in the pretreatment liquid, a method of applying the pretreatment liquid with a roll coater, a method of spraying the pretreatment liquid, and the like. And any method can be used. The pretreatment liquid can be jetted by using a jetting device that employs a spray type, an inkjet type, or the like, which will be described later, and in any case, the pretreatment liquid is jetted without contact with the recording medium.

2. Oil-Based Ink The oil-based ink used in the present embodiment constitutes the oil-based inkjet recording ink set according to the present embodiment when used together with the above-mentioned pretreatment liquid. In the present invention, the oil-based inkjet recording ink set is one or more of the above-mentioned pretreatment liquid and a color ink composition (for example, white, cyan, magenta, yellow, black ink composition, etc.) as an oil-based ink. If it contains, the oil-based inkjet recording ink set according to the present embodiment is constituted. Further, the oil-based ink may be a clear ink containing no coloring material.

  The oil-based ink used in the present embodiment contains an organic solvent, and the organic solvent contains at least one selected from the group consisting of alcohols, primary amines and secondary amines. In this embodiment, the oil-based ink can be used as an oil paint, a paint, a writing tool such as a fountain pen, or an ink for printing without particular limitation.

  Here, the “oil-based ink” in the present specification is an ink containing an organic solvent as a main component, and means an ink containing substantially no water. Further, "substantially free of water" means that water is not intentionally added during the production of the ink, and it contains a trace amount of water which is inevitably mixed during production or storage of the ink. I don't care.

  The specific content of water in the "oil-based ink substantially free of water" is preferably 3% by mass or less, more preferably 1% by mass or less, in the oil-based ink. %, more preferably less than 0.05% by mass, even more preferably less than 0.01% by mass, even more preferably less than 0.005% by mass, most preferably less than 0.001% by mass.

  Hereinafter, in the present embodiment, examples in which the oil-based ink is used as an oil-based inkjet ink composition for inkjet recording (hereinafter, also simply referred to as ink) will be given, and components contained in the oil-based inkjet ink composition and components that may be contained explain.

2.1. Color Material The oil-based ink used in the present embodiment contains a color material. As the coloring material, an oily dye or a pigment such as a colored inorganic pigment or a colored organic pigment that is usually used in conventional oil-based inkjet ink compositions can be used. These coloring materials may be used alone or in combination of two or more.

When a pigment is used, the average particle size of the pigment dispersion in the ink is 20 nm or more and 200 n or more.
If it is m or less and the hue is white, black, yellow, magenta, cyan, red, green, blue or orange, conventionally known inorganic pigments and organic pigments can be used without particular limitation.

  Examples of such pigments include azo pigments such as azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments; phthalocyanine pigments, perylene and perylene pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone. Polycyclic pigments such as pigments and quinophthalone pigments; dye lakes such as basic dye type lakes and acid dye type lakes; organic pigments such as nitro pigments, nitroso pigments, aniline black, daylight fluorescent pigments; inorganic pigments such as carbon black Etc.

  More specifically, examples of pigments used when the oil-based inkjet ink composition according to the present embodiment is magenta or red ink include C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48:1, C.I. I. Pigment Red 53:1, C.I. I. Pigment Red 57:1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 139, C.I. I. Pigment Red 144, C.I. I. Pigment Red 149, C.I. I. Pigment Red 166, C.I. I. Pigment Red 170, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 194, C.I. I. Pigment Red 209, C.I. I. Pigment Red 222, C.I. I. Pigment Red 224, C.I. I. Pigment Violet 19 and the like.

  Examples of pigments used when the oil-based ink used in this embodiment is orange or yellow ink include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Orange 64, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 138, C.I. I. Pigment Yellow 150, C.I. I. Pigment Yellow 180 and the like.

  Examples of pigments when the oil-based ink used in this embodiment is green or cyan ink include C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15:2, C.I. I. Pigment Blue 15:3, C.I. I. Pigment Blue 15:4, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7, C.I. I. Pigment Green 36 and the like.

  When the oil-based ink used in this embodiment is a black ink, examples of the pigment include carbon black.

  Examples of pigments when the oil-based ink used in this embodiment is white ink include C.I. I. Pigment White 6, C.I. I. Pigment White 18, C.I. I. Pigment White 21 and the like.

As commercially available products, as black pigments, for example, carbon blacks MA11, MA100, MA220, MA600a, #40, #44 manufactured by Mitsubishi Chemical are preferred. Examples of pigments other than black include SYMULER Brilliant Carmine 6B, SYMULER Red, FASTOGENSuper M manufactured by Dainippon Ink Co., Ltd.
agenta, SYMULER Fast Yellow, FASTOGEN Blue
4RO-2, FASTOGEN Green, FASTOGEN SuperViolet and the like. These pigments may be used alone or in an appropriate combination.

  The content of the pigment in the oil-based ink used in the present embodiment can be appropriately selected depending on the application and printing characteristics, but since excellent hiding properties and color reproducibility can be obtained, the total mass of the ink (100% by mass) ), the content is preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 15% by mass or less, and particularly preferably 1% by mass or more and 10% by mass or less. Is.

  As described above, the average particle diameter of the pigment is preferably 20 nm or more and 200 nm or less. When the average particle diameter is 20 nm or more, the color developability becomes better, and thus it becomes easy to use as an inkjet ink. On the other hand, when the average particle diameter is 200 nm or less, it becomes easy to use in an inkjet system. Further, when the oil-based ink is used as an inkjet ink, the average particle diameter is more preferably 50 nm or more and 150 nm or less because it is excellent in storage stability, ejection stability and sedimentation property.

  Here, the “average particle diameter” in the present specification means a sphere-converted 50% average particle diameter (d50) obtained by a light scattering method for ink. The “sphere-converted 50% average particle diameter (d50) by light scattering method” is a value obtained as follows. The particles in the dispersion medium are irradiated with light, and the diffracted and scattered light generated is measured by the detectors arranged in front of, in the side of, and behind the dispersion medium. Using the measured values, the particles which are originally indefinite are assumed to be spherical, and the cumulative volume of the particle group converted into a sphere equal to the volume of the particles is calculated as 100% to obtain a cumulative curve. The point at which the cumulative value at that time is 50% is the 50% average particle diameter (d50).

  When a pigment is used as the coloring material, any dispersant used in ordinary oil-based inks can be used from the viewpoint of improving the dispersion stability of the pigment in the oil-based ink. The pigment dispersant that can be used in the present invention is not particularly limited as long as it can stably disperse a pigment in a solvent. For example, Nippon Lubrizol Solsperse 5000, Solsperse 13940, Solsperse 11200, Solsperse 21000, Solsperse 28000. Etc.

  In the oil-based ink used in the present embodiment, the content of the dispersant can be appropriately selected depending on the pigment to be dispersed, but is preferably 5 parts by mass with respect to 100 parts by mass of the content of the pigment in the oil-based ink. Parts to 200 parts by mass, more preferably 30 parts to 120 parts by mass.

  Preferable examples of commercially available dyes used in the oil-based ink used in the present embodiment include vaLifast Black 3810, elixa Black 846, OIL BLACK HBB, and OIL BLACK No. 5 manufactured by Orient Kagaku. For dyes other than black, OIL BLUE 2N, elixa Orange-240, VALIFAST BLUE 1603, elixa Green-502, VALIFAST ORANGE 1201, OIL GREEN 530, elixa Green-540, OIL YELLOWAWEL, WILA-IELAWEL, GLA-ELAWEL, GLEA-ELAWEL, LOWELAWEL, GIL 1101 and the like. These dyes may be used alone or in combination as appropriate.

2.2. Organic Solvent The oil-based ink used in the present embodiment contains an organic solvent, and the organic solvent contains at least one selected from the group consisting of alcohol, primary amine, and secondary amine. Here, the “organic solvent” in the present specification refers to a liquid medium in which a coloring material such as a pigment is dispersed and containing an organic solvent, and refers to a liquid medium at room temperature and normal pressure. Here, when the organic solvent contains an organic solvent and a mixture other than the organic solvent, the content of the organic solvent exceeds 5% by mass.

  The oil-based ink used in the present embodiment can suppress the deformation of the clear folder by containing at least one selected from the group consisting of alcohol, primary amine and secondary amine as the organic solvent, and By combining with the pretreatment with the pretreatment liquid of (3), the storability of the clear folder can be improved.

  The alcohol used as the organic solvent is not particularly limited, and any of primary to tertiary alcohols and monohydric to trihydric alcohols can be used. Further, the hydrocarbon group of the alcohol may be saturated or unsaturated, and may be linear or branched. Similarly, in the hydrocarbon groups of the primary amine and the secondary amine used as the organic solvent, the structure is not limited as long as the polarity of the organic solvent is high and the deformation of the clear folder can be suppressed.

  Among them, the organic solvent preferably has 12 or more carbon atoms, because the polarity of the organic solvent is further increased and the deformation of the clear folder can be suppressed. Examples of the organic solvent having 12 or more carbon atoms include 1-dodecanol, hexadecanol, and oleyl alcohol. These organic solvents may be used alone or in an appropriate combination.

  In the present embodiment, the content of the organic solvent is preferably 80% by mass or more, and more preferably 90% by mass or more, based on the total mass (100% by mass) of the ink composition.

2.3. Other Components The oil-based ink used in this embodiment may further contain other additives contained in ordinary oil-based inks. Examples of other additives include organic solvents other than the above organic solvents, stabilizers such as antioxidants and ultraviolet absorbers, binder resins, metal soaps, metal complexes, and the like.

<Other organic solvents>
Examples of other organic solvents include non-polar organic solvents or polar organic solvents, drying oils esters of fatty acids and alcohols, organic solvents having a high SP value and high iodine value, drying oils and the like.

  Examples of the non-polar organic solvent include naphthene-based, paraffin-based, isoparaffin-based hydrocarbon solvents, fluorine-based solvents, silicon-based solvents and the like. As these non-polar organic solvents, commercially available ones may be used, for example, aliphatic saturated hydrocarbons such as dodecane, ExxonMobil's Isopar, Exxol, and JX Nikko Nisseki Energy's AF solvent. , Normal Paraffin H, AS Sol manufactured by Wilvie Co., Dust Clean manufactured by Matsumura Oil Co., Ltd., Sun Sen manufactured by Sun Oil Co., Ltd., Sun Sun, Surflon manufactured by AGC Seimi Chemical Co., Ltd., and the like.

  Examples of polar organic solvents include ester solvents, alcohol solvents, amide solvents, fatty acid solvents, ether solvents and the like.

  Examples of the ester solvent include higher fatty acid esters having 5 or more carbon atoms in one molecule, preferably 9 or more carbon atoms in one molecule, and more preferably 12 to 32 carbon atoms in one molecule. For example, isodecyl isononanoate, isotridecyl isononanoate, isononyl isononanoate, methyl laurate, isopropyl laurate, isopropyl myristate, isopropyl palmitate, isooctyl palmitate, hexyl palmitate, isostearyl palmitate, isooctyl isopalmitate, olein. Methyl acidate, ethyl oleate, isopropyl oleate, butyl oleate, hexyl oleate, methyl linoleate, isobutyl linoleate, ethyl linoleate, butyl stearate, hexyl stearate, isooctyl stearate, isopropyl isostearate, pivalic acid 2 -Octyldodecyl, diisopropyl adipate, diisopropyl sebacate, diethyl sebacate, propylene glycol monocaprylate, trimethylolpropane tri-2-ethylhexanoate, glyceryl tri-2-ethylhexanoate and the like. Also, soybean oil fatty acid methyl, which is an ester of dry oil fatty acid and alcohol, soybean oil fatty acid isobutyl, linseed oil fatty acid methyl, linseed oil fatty acid butyl, linseed oil fatty acid propyl, linseed oil fatty acid 2-ethylhexyl, tung oil fatty acid methyl, tall oil fatty acid Methyl, tall oil fatty acid isobutyl, etc. are mentioned.

  Examples of the alcohol solvent include aliphatic higher alcohols having 12 or more carbon atoms in one molecule, and examples thereof include higher alcohols such as isomyristyl alcohol, isopalmityl alcohol, isostearyl alcohol, and oleyl alcohol. ..

  Examples of the amide-based solvent include acetamide, dimethylacetamide, N-methylpyrrolidinone and the like.

  Examples of the fatty acid solvent include fatty acids having 4 or more carbon atoms in one molecule, preferably 9 or more and 22 or less carbon atoms in one molecule. Examples thereof include isononanoic acid, isomyristic acid, hexadecanoic acid, and isopalmitin. Acid, oleic acid, isostearic acid and the like can be mentioned.

  Examples of the ether solvent include glycol ethers such as diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, propylene glycol monobutyl ether, and propylene glycol dibutyl ether, and acetates of glycol ethers.

  Ester of a dry oil fatty acid and alcohol has a low viscosity, and even if it is used in a large amount in ink for inkjet recording, there is no problem in ejection property. Further, PP, which is a material of the clear folder, has a low attack property and has a large number of double bonds, thereby promoting oxidative polymerization of the ink. Therefore, by using the ink as a component of the ink according to the present embodiment, even if the viscosity is low before recording, the ink after recording is rapidly cured to have high viscosity, and the organic solvent contained in the ink is a recorded matter. Fixed inside. As a result, even if the recorded matter is sandwiched between the clear folders, the organic solvent is prevented from transferring to the clear folders, and the storability of the clear folders is improved.

  The dry oil fatty acid, which is a raw material of the ester, is obtained by hydrolyzing the dry oil. Examples of the drying oil include flaxseed oil, tung oil, mustard oil, shiso oil, walnut oil, citrus oil, safflower oil, sunflower oil, and the like, as described below. The drying oil can be hydrolyzed by a known method.

The alcohol used as the raw material of the ester may be an unsaturated alcohol, and can be used without any limitation in the number of carbon atoms, but after recording, the ester is immediately hydrolyzed on the recording medium, and the decomposed alcohol is Since there is a possibility of shifting to a clear folder, it is necessary to adjust the ink composition according to the above carbon number.

  When the carbon number of the alcohol is 3 or less, the alcohol easily volatilizes, and even if the alcohol in the recording medium moves to a clear folder and is deformed, it tends to return to the original state. It is more preferable that the oxidative polymerization reaction of the ink is completed before the transfer of the organic solvent and the decomposed alcohol does not transfer to the clear folder. It is preferable to promote it.

  On the other hand, when the number of carbon atoms in the alcohol is 4 or more, the ester is less attacked on PP, but the decomposed alcohol is less likely to volatilize, and thus it is easier to move to a clear folder, which is a clear folder. It will transform. When the ink contains a metal soap or a metal complex, the hydrolysis reaction of the above ester is promoted. Therefore, it is preferable that the ink contains no metal soap or a metal complex.

  The method for producing an ester of a dry oil fatty acid and an alcohol is not particularly limited and can be produced by a known method. For example, JP-A-2005-53871, JP-A-2009-203343, and JP-A-2011-99009 are available. It can be manufactured by the method described in the publication.

  Here, the SP value is a solubility parameter and is obtained, for example, by the calculation method of Fedors described in “Paint Research No. 152 (2010) P.43”. The iodine value is, for example, a value calculated according to the method specified in “JIS K 3331:2009, hydrogenated oil/fatty acid for industrial use”.

  Since the above organic solvent has a high SP value, it has a low PP attack property, and since it has a large number of double bonds, oxidative polymerization of the ink is promoted. Therefore, when used as an organic solvent in the ink according to this embodiment, the ink after recording is rapidly cured, and the organic solvent contained in the ink is fixed in the recording medium. As a result, even if the recorded matter is sandwiched between the clear folders, the residual solvent is prevented from transferring to the clear folders, and the storability of the clear folders is improved.

  Examples of the organic solvent include linolenic acid monoglyceride (SP value 10.3, iodine value 216), the ester of the drying oil fatty acid and alcohol, and the compound represented by the general formula (2) described later ( SP value 12.6, iodine value 297) and the compound represented by the general formula (3) (SP value 11.5, iodine value 231) are also included. These may be used alone or in combination of two or more.

  Further, an allyl compound may be contained as an organic solvent having a high SP value and a high iodine value. The allyl compound is likely to undergo a crosslinking reaction at the α-carbon position. Therefore, when the allyl compound is contained as the organic solvent, the oxidative polymerization of the ink is promoted on the recording medium after recording. For this reason, by using the ink according to the present embodiment, even if the viscosity is low before recording, the ink after recording is rapidly cured to have high viscosity, and the organic solvent contained in the ink remains in the recording medium. It is fixed. As a result, even if the recorded matter is sandwiched between the clear folders, the organic solvent is prevented from transferring to the clear folders, and the storability of the clear folders is improved.

The allyl compound can be used without particular limitation, but a compound having a high reactivity and a low PP attack property is preferable. Among them, allyl ether is preferable from the viewpoint of reactivity.
Be done.

  Since drying oil has a high viscosity, it causes a problem in dischargeability when used in many inks for inkjet recording. However, since PP, which is a material for the clear folder, has low attack property and has many double bonds, The oxidative polymerization of is promoted. Therefore, by supplementarily using the ink according to the present embodiment, the ink after recording is rapidly cured and the organic solvent contained in the ink is fixed in the recording medium. As a result, even if the recorded matter is sandwiched between the clear folders, the organic solvent is prevented from migrating to the clear folders, and the storability of the clear folders is improved.

  Here, the drying oil refers to an oil that completely hardens in the air and has an iodine value of 130 or more, and examples thereof include flaxseed oil, tung oil, mustard oil, shiso oil, walnut oil, tallow oil, safflower oil, and sunflower oil. Etc. These drying oils may be used alone or in combination of two or more.

  When the drying oil is contained, the content thereof is preferably 0.05% by mass or more and 10% by mass or less with respect to the total mass of the oil-based ink from the viewpoint of the ejection property of the ink.

<Antioxidant>
Examples of the antioxidant include BHA (2,3-butyl-4-oxyanisole) and BHT (2,6-di-t-butyl-p-cresol).

<Ultraviolet absorber>
Examples of the ultraviolet absorber include benzophenone compounds and benzotriazole compounds.

<Binder resin>
A binder resin may be added to the oil-based ink used in this embodiment for the purpose of adjusting the viscosity of the ink. As the binder resin, for example, acrylic resin, styrene acrylic resin, rosin-modified resin, phenol resin, terpene resin, polyester resin, polyamide resin, epoxy resin, vinyl chloride vinyl acetate copolymer resin, cellulose acetate butyrate, or other fiber-based resin. Examples thereof include resins and vinyltoluene-α-methylstyrene copolymer resins. These binder resins may be used alone or in combination of two or more. The binder resin can further improve the fixability of the ink to the vinyl chloride resin depending on the amount added.

<Metal soap, metal complex>
The metal soap and the metal complex are also called a drier (curing accelerator), and act as an oxidizing agent that accelerates the oxidative polymerization of the organic compound contained in the organic solvent. Therefore, when recording is performed on a recording medium such as paper using the oil-based ink, the ink after recording is rapidly cured, and the organic solvent contained in the ink is fixed in the recording medium. As a result, even if the recorded matter is sandwiched between the clear folders, the organic solvent is prevented from moving to the clear folders, and the clear folders are prevented from being deformed.

In the present embodiment, the metal contained in the metal soap or metal complex is Co (cobalt), Mn (manganese), Pb (lead), Zr (zirconium), Ca (calcium), Ba (barium), K (potassium). And at least one selected from the group consisting of Fe (iron). In this embodiment, the metal soap or metal complex is an organic acid metal salt. As the organic acid used as a raw material for the organic acid metal salt, an organic acid conventionally used as a general raw material for dryers can be used without particular limitation. Specifically, for example, propionic acid, octylic acid, naphthenic acid, neodecanoic acid, tung oil acid, linseed oil acid, soybean oil acid, can be used organic acids such as resin acid, excellent drying acceleration effect From the viewpoint of obtaining, it is preferable to use an aliphatic monocarboxylic acid having 3 to 12 carbon atoms, and it is more preferable to use octylic acid, naphthenic acid, or neodecanoic acid. These may be used alone or in combination of two or more.

  Of the compounds (metal salts) containing these metals, cobalt, for example, promotes oxidation at the interface between the ink coating and the air, and other manganese, etc., are moderate and act on the inside as well as on the surface. Accelerate the polymerization of. Auxiliary driers such as zirconium and calcium improve the overall performance in combination with the previously mentioned driers, but have little effect on their own.

Examples of the organic acid metal salt used in the present embodiment include those represented by the general formula (A)
(OMR) Type ₃ (A)
(In the formula, M represents a cobalt atom or a manganese atom, R represents an organic acid group, and three Rs in the molecule may be the same or different.)
An organic acid metal salt represented by

  In the general formula (A), the organic acid group R is, for example, a carboxylate group of an organic acid such as propionic acid, octylic acid, naphthenic acid, neodecanoic acid, tung oil, flaxseed oil, soybean oil, and resin acid. It is preferably a carboxylate group of an aliphatic monocarboxylic acid having 3 to 12 carbon atoms, and more preferably a carboxylate group of octylic acid, naphthenic acid or neodecanoic acid.

  As described above, in the present embodiment, the metal soap and the metal complex include a cobalt drier and a manganese drier, but it is preferable to use the manganese drier from the viewpoint of use environment. Since manganese has a lower activity than cobalt, when a manganese drier is used, it is preferably used together with a ligand that activates the manganese drier. Examples of the ligand include 2,2′-bipyridine, 2-(aminomethyl)pyridine, 2-hydroxymethylpyridine and the like. The ligand may be used alone or in combination of two or more.

  It is preferable to use manganese neodecanoate as the manganese dryer, and examples of commercially available products include DICATE Mn 6.5% SB manufactured by DIC Corporation.

  Examples of the organic acid metal salt used as the dryer include organic acid cobalt boron metal salt and organic acid manganese boron metal salt. These may be used alone or in combination, but when they are used in combination, they are excellent in the drying property of a coating film in a thick film that is difficult to uniformly cure, and therefore their combination is preferable. Further, when the organic acid cobalt boron metal salt and the organic acid manganese boron metal salt are used in combination, the dryness of the coating film in a thick film is similarly excellent, and thus the combined use is preferable. Further, when the organic acid cobalt boron metal salt and the organic acid manganese metal salt are used in combination, a low-cost dryer having an excellent drying promoting effect can be obtained, so that the combination thereof is particularly preferable.

  The method for producing the organic acid metal salt used in the present invention is not particularly limited and can be produced by a known method. For example, it can be produced by the method described in Japanese Patent Publication No. 63-63551. .

Further, it is preferable to dilute these organic acid metal salts with an organic solvent in advance before adding them to the oil-based ink, from the viewpoint of easy handling and uniform mixing property. The diluting organic solvent is not particularly limited as long as it can uniformly dissolve the organic acid metal salt and is inert to the organic acid metal salt, for example, toluene, xylene, heptane, hexane, cyclohexane, Hydrocarbon solvents such as mineral spirits; alcohol solvents such as methanol, ethanol, propanol, cyclohexanol; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; propyl ether, methyl cellosolve, cellosolve, butyl cellosolve, methyl carbitol, An ether solvent such as butyl carbitol can be used, and these may be used alone or in combination of two or more kinds.

2.4. Method for producing oil-based ink The oil-based ink used in the present embodiment can be produced by a known conventional method. When a pigment is used as a coloring material, first, a pigment, a dispersant, and an organic solvent (a part) are mixed, and then a pigment dispersion is prepared by a ball mill, a bead mill, an ultrasonic wave, a jet mill or the like, Adjust to have ink properties. Then, an organic solvent (residual amount) and other additives (for example, a surfactant and a binder resin) can be added with stirring to obtain an oil-based ink.

2.5. Physical Properties The oil-based ink used in the present embodiment preferably has a surface tension at 20° C. of 20 mN/m or more and 50 mN/m from the viewpoint of a balance between recording quality and reliability as an inkjet ink composition. /M or more and 40 mN/m or less is more preferable. The surface tension is measured by using an automatic surface tension meter CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) and confirming the surface tension when the platinum plate is wetted with the ink in an environment of 20°C. be able to.

  From the same viewpoint, the viscosity of the oil-based ink used in this embodiment at 20° C. is preferably 2 mPa·s or more and 30 mPa·s or less, and more preferably 2 mPa·s or more and 20 mPa·s or less. .. The viscosity is measured by using a viscoelasticity tester MCR-300 (manufactured by Physica), increasing the Shear Rate to 10 to 1000 under an environment of 20° C., and reading the viscosity at Shear Rate 200. Can be measured.

2.6. Use The oil-based ink used in the present embodiment is contained in an ink cartridge of a known inkjet recording device, ejects ink droplets, and deposits the droplets on a recording medium such as paper to record an image. As the ink jet recording apparatus, an ink jet recording apparatus which is equipped with an electrostrictive element capable of vibrating based on an electric signal and configured to eject ink by vibration of the electrostrictive element is preferable. In the oil-based ink used in the present embodiment, the organic solvent contains at least one selected from the group consisting of alcohols, primary amines and secondary amines. Is suppressed from being deformed. In addition, the combination with the pretreatment using the pretreatment liquid makes it possible to suppress the deformation of the clear folder due to the recorded matter using this ink for a long period of time.

3. Oil-based inkjet recording method Next, the oil-based inkjet recording method according to the present embodiment will be described. The oil-based inkjet recording method according to the present embodiment records with an oil-based inkjet recording ink set containing the above-described pretreatment liquid and oil-based ink.

3.1. Inkjet Recording Device Next, an example of an inkjet recording device in which the oil-based inkjet recording method according to the present embodiment is implemented will be described with reference to the drawings. The inkjet recording device that can be used in the oil-based inkjet recording method according to the present embodiment is not limited to the following modes.

  Examples of the inkjet device include an inkjet printer (hereinafter, printer) equipped with the inkjet head shown in FIG. 1. As shown in FIG. 1, the printer 1 is a device that ejects liquid ink onto the surface of a recording medium 2 such as recording paper to record an image or the like. The printer 1 includes an inkjet head 3, a carriage 4 to which the inkjet head 3 is attached, a carriage moving mechanism 5 that moves the carriage 4 in the main scanning direction (the longitudinal direction of the printer 1, that is, the width direction of the recording medium 2), and recording. A transport mechanism 6 for transporting the medium 2 in the sub-scanning direction (direction orthogonal to the main scanning direction) is provided.

  Here, the pretreatment liquid and the oil-based ink used in the ink jet recording apparatus are stored in the ink cartridge 7. The ink cartridge 7 is detachably attached to the inkjet head 3. It is also possible to adopt a configuration in which the ink cartridge 7 is arranged on the main body side of the printer 1 and is supplied from the ink cartridge 7 to the inkjet head 3 through an ink supply tube.

  The carriage moving mechanism 5 includes a timing belt 8. The timing belt 8 is driven by a pulse motor 9 such as a DC motor. Therefore, when the pulse motor 9 is operated, the carriage 4 is guided by the guide rod 10 installed on the printer 1 and reciprocates in the main scanning direction.

  A platen 11 is arranged below the inkjet head 3 during the recording operation. The platen 11 is arranged at a distance from a nozzle forming surface (nozzle plate; not shown) of the inkjet head 3 when performing a recording operation, and supports the recording medium 2. Further, the flushing box 12 is provided in an end portion of the platen 11 in the main scanning direction, more specifically, in an area outside the area (recording area) where ink is ejected onto the recording medium 2 arranged on the platen 11. . The flushing box 12 is a member that collects the pretreatment liquid or the ink ejected from the inkjet head 3 in the preliminary ejection of the pretreatment liquid or the oil-based ink, for example. The flushing box 12 of the present embodiment is formed in a box shape that opens upward (to the inkjet head 3 side). An ink absorbing material (not shown) made of, for example, urethane sponge is provided on the bottom surface inside the flushing box 12. The flushing boxes 12 are preferably provided on both sides of the platen 11 in the main scanning direction, but may be provided on at least one side.

  The inkjet head 3 is a means for adhering the pretreatment liquid or the oil-based ink to the recording medium 2, and includes a nozzle (not shown) for ejecting the pretreatment liquid or the oil-based ink. As a method of ejecting the pretreatment liquid or the oil-based ink from the nozzle, for example, a strong electric field is applied between the nozzle and the acceleration electrode placed in front of the nozzle, and the droplet-shaped pretreatment liquid or the oil-based ink is continuously discharged from the nozzle. System (electrostatic suction method) in which the liquid droplets of the reaction liquid are ejected according to the recording information signal while the liquid droplets of the reaction liquid fly between the deflection electrodes; a pressure is applied to the reaction liquid by a small pump, and the nozzle vibrates. A method of forcibly ejecting droplets of pretreatment liquid or oil-based ink by mechanically vibrating it with a child or the like; A method of ejecting and recording liquid droplets of oily or oil-based ink (piezo method); The pretreatment liquid or oily ink is heated and foamed by microelectrodes according to the recording information signal, and the droplets of pretreatment liquid or oily ink are ejected and recorded. Examples include a method (thermal jet method).

  As the inkjet head 3, either a line type inkjet head or a serial type inkjet head can be used, but in the present embodiment, a serial type inkjet head is used.

  Here, an ink jet recording apparatus provided with a serial ink jet head is a recording apparatus that performs a scan (pass) for ejecting the ink composition multiple times while moving the recording head relative to a recording medium. Is to do. A specific example of the serial-type recording head is that the recording head is mounted on a carriage that moves in the width direction of the recording medium (direction intersecting the conveyance direction of the recording medium), and the recording head moves as the carriage moves. An example is one that ejects droplets onto the recording medium by moving the.

  On the other hand, an inkjet recording apparatus provided with a line type inkjet head performs recording by performing one scan (pass) for ejecting the ink composition while moving the recording head relative to a recording medium. Is. A specific example of the line-type recording head is one in which the recording head is formed wider than the width of the recording medium and the droplets are ejected onto the recording medium without the recording head moving.

  Although not shown, the inkjet device may be provided with a drying unit. By providing the drying means, the liquid medium can be quickly evaporated and scattered from the pretreatment liquid or the oil-based ink adhered to the recording medium, so that a recorded image or the like can be quickly formed. The drying means that can be used as the drying means is not particularly limited as long as it has a configuration that promotes evaporation and scattering of the liquid medium contained in the pretreatment liquid or the oil-based ink. For example, means for applying heat to the recording medium, means for blowing air onto the pretreatment liquid or oil-based ink, means for combining them, and the like can be mentioned. Specifically, forced air heating, radiant heating, conductive heating, high frequency drying, microwave drying and the like are preferably used.

  Further, the drying by the drying means is preferably drying accompanied by heating, and it is preferable that the inkjet recording apparatus performs recording by discharging the recording medium to a heated recording medium. The heating method is not particularly limited, and examples thereof include a heat press method, an atmospheric pressure steam method, a high pressure steam method, and a thermofix method. Examples of the heating means for the recording medium include infrared rays (lamp). Be done. In this case, the temperature of the heated recording medium is preferably 30° C. or higher and 50° C. or lower, and more preferably 30° C. or higher and 40° C. or lower. In this case, it is possible to accelerate the drying of the ink in the recording process.

3.2. Recording Medium In the present embodiment, the recording medium to be printed is not particularly limited, and can be used for any type of recording medium such as plain paper, coated paper, plastic film, cloth, and leather, and has low ink absorbency. Alternatively, it may be a non-absorbent recording medium.

In the present specification, the "ink low-absorption or non-absorptive recording medium" refers to a recording medium having a property of not absorbing or hardly absorbing an ink composition. Quantitatively, an ink non-absorbent or low-absorbent recording medium means "a recording medium having a water absorption amount of 10 mL/m ² or less from the start of contact to 30 msec ^1/2 in the Bristow method". Point to. The Bristow method is the most popular method for measuring the amount of liquid absorbed in a short time, and is also adopted by the Japan Pulp and Paper Technology Association (JAPAN TAPPI). For details of the test method, refer to “JAPAN TAPPI Paper Pulp Test Method 2000 Edition”, Standard No. 51, "Paper and Paperboard-Liquid Absorption Test Method-Bristow Method". On the other hand, an ink-absorbent recording medium refers to a recording medium that does not correspond to a non-ink-absorbing or low-ink-absorbing recording medium.

Examples of the non-ink-absorbent recording medium include a plastic film having no ink-absorbing layer, one coated with plastic on a substrate such as paper, and one having a plastic film bonded thereto. .. Examples of the plastic here include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene and polypropylene.

  Examples of the low-ink-absorbent recording medium include a recording medium having a coating layer for receiving ink on the surface. For example, the base material is paper, art paper, coated paper, matte Printed paper such as paper, and the like. When the substrate is a plastic film, polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc., the surface of which is coated with a hydrophilic polymer. , Silica, titanium and the like coated with a binder. These recording media may be transparent recording media.

3.3. Pretreatment Step The pretreatment step is a step in which the droplets of the pretreatment liquid according to the present embodiment are ejected from the inkjet head onto the recording medium to be attached. As described above, as a method of attaching the pretreatment liquid, a method of immersing the recording medium in the pretreatment liquid, a method of applying the pretreatment liquid with a roll coater, a method of spraying the pretreatment liquid, or the like. For example, the pretreatment liquid can be jetted by using a jetting device that adopts a spray type, an inkjet type, or the like. In this embodiment, the droplets of the pretreatment liquid are ejected and adhered from the inkjet head 3 to the recording medium 2.

The deposition amount of the pretreatment liquid is preferably 0.1 mg/cm ² or more and 30.0 mg/cm ² or less, and more preferably 0.4 mg/cm ² or more and 10 mg/cm ² or less. Within this range, the storability of the clear folder can be improved, and the drying time of the pretreatment liquid can be shortened, so that the recording speed can be increased.

  After the step of attaching the pretreatment liquid, a step of drying the pretreatment liquid may be provided before attaching the oil-based ink. In this case, the drying may be stopped while the pretreatment liquid is wet. The drying step of the pretreatment liquid may be carried out by natural drying, but from the viewpoint of improving the drying speed and accelerating the fusion of the resin component contained in the pretreatment liquid to the fabric, it is a drying process involving heating. Good. When the drying step of the pretreatment liquid involves heating, the heating method is not particularly limited, and examples thereof include a heat press method, a normal pressure steam method, a high pressure steam method, and a thermofix method. .. In addition, examples of the heat source for heating include infrared rays (lamps).

3.4. Oil-based ink adhesion process (recording process)
Next, an oil-based ink is made to adhere to the surface of the recording medium which has been subjected to the pretreatment, and an image is recorded. As a result, an image made of oil-based ink is formed on the surface of the recording medium.

  In the present invention, the "image" refers to a recording pattern formed from a dot group, and includes text printing and solid images. A "solid image" is a dot recorded on all pixels that are the minimum recording unit area defined by the recording resolution. Normally, the recording area of the recording medium is covered with ink and the background of the recording medium is covered. Means an image pattern which should be an image in which is not visible.

The maximum adhesion amount of the oil-based ink on the surface of the recording medium is preferably 5 mg/inch ² or more and 15 mg/inch ² or less. It is preferable that the maximum adhesion amount of the oil-based ink on the surface of the recording medium is within the above range, because the storability in the clear folder is improved and the recording speed can be increased.

After the recording step, a drying step of drying the oil-based ink attached to the recording medium may be provided. In this case, it is preferable to perform drying to the extent that stickiness is not felt when the oil-based ink attached to the surface of the recording medium is touched. The drying step of the oil-based ink may be carried out by natural drying, but from the same viewpoint as the drying step of the above-mentioned pretreatment step, drying accompanied by heating is preferable. The heating method of the oil-based ink is not particularly limited, but the same method as the heating method described above can be used.

  In the oil-based inkjet recording method used in the present embodiment, before recording with the oil-based ink used in the present embodiment, by performing a pretreatment step using the above pretreatment liquid, the organic solvent in the obtained image Due to the influence, deformation of the clear folder is suppressed. Further, it is possible to suppress the deformation of the clear folder due to the recorded matter using this ink for a long period of time.

4. EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Experimental Examples and Comparative Examples, but the present invention is not limited to these Examples.

4.1. Preparation of Pretreatment Liquids Premixed liquids 1 to 3 were obtained by mixing and stirring each material so that the composition (% by mass) shown in Table 1 below was obtained.

なお、表１中、ロジン変性マレイン酸樹脂１として、「マルキードＮｏ．３２」（荒川化学工業株式会社製）を、ロジン変性マレイン酸樹脂２として、「マルキードＮｏ．３３」（荒川化学工業株式会社製）を、スチレン変性マレイン酸樹脂として、「アラスター７００」（荒川化学工業株式会社製）を使用した。

In Table 1, as the rosin-modified maleic acid resin 1, “Marquid No. 32” (manufactured by Arakawa Chemical Industry Co., Ltd.) and as the rosin-modified maleic acid resin 2, “Marquid No. 33” (Arakawa Chemical Industry Co., Ltd.). Manufactured by Arakawa Chemical Industry Co., Ltd. was used as the styrene-modified maleic acid resin.

4.2. Preparation of oil-based ink composition Each material was mixed and stirred to completely dissolve it so that the composition (% by mass) shown in Table 2 below was obtained, and then filtered with a membrane filter having a pore size of 1 μm to obtain each oil-based ink composition. Got

  In Table 2, Neozapon Blue 807 (manufactured by BASF Japan Ltd.) was used as the oily dye.

4.3. Clear Folder Deformation Evaluation Test Each pretreatment liquid was applied on a monochrome copy/printer paper P (manufactured by Fuji Xerox Co., Ltd.) using a bar coater (No. 2) and dried by air drying for 12 hours. Next, each of the obtained oil-based ink compositions was filled in an ink cartridge of a modified machine of an inkjet printer PX-M7050F (manufactured by Seiko Epson Co., Ltd.), and solid printing (rectangular 20 cm) on double-sided fine plain paper (manufactured by Seiko Epson Co., Ltd.). X 28 cn) and the printed matter was inserted into a PP clear folder. Place the clear folder with the printed matter in it at 23°C/50% R.S. H. It was left standing sideways in the environment for 30 days. After that, the amount of the outwardly warped clear folder was measured using a ruler, and the value was evaluated as the amount of deformation. The evaluation results are ranked as follows.
5: Deformation amount less than 10 mm 4: Deformation amount 10 mm or more and less than 30 mm 3: Deformation amount 30 mm or more and less than 50 mm 2: Deformation amount 50 mm or more and less than 100 mm 1: Deformation amount 100 mm or more

4.4. Evaluation results The above evaluation results are shown in the bottom row of Table 3. In Comparative Example 1 in which the pretreatment liquid was not used, the amount of deformation of the clear folder was large and the storability of the clear folder was poor. In addition, even in the case of using the pretreatment liquid or Comparative Example 2 in which an organic solvent outside the scope of the present invention was used as the organic solvent, the amount of deformation of the clear folder was large, and the clear folder storability was poor. On the other hand, in Example, the use of the pretreatment liquid was combined with the oil-based ink containing the organic solvent containing at least one selected from the group consisting of alcohol, primary amine, and secondary amine, and Comparative Example 1 The deformation amount of the clear folder was smaller than that of No. 2 and the storage property was excellent.

  As described above, according to the present embodiment, the oil-based ink contains the organic solvent containing at least one selected from the group consisting of alcohol, primary amine and secondary amine, and contains the maleic anhydride resin derivative. By performing the pretreatment with the pretreatment liquid, the deformation of the clear folder can be dramatically suppressed, and the deformation of the clear folder due to the recorded matter using the oil-based ink can be suppressed for a long period of time.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations having the same function, method, and result, or configurations having the same object and effect). Further, the invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Further, the invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes configurations in which known techniques are added to the configurations described in the embodiments.

DESCRIPTION OF SYMBOLS 1... Printer (inkjet recording device), 2... Recording medium, 3... Inkjet head, 4... Carriage, 5... Carriage moving mechanism, 6... Conveying mechanism, 7... Ink cartridge, 8... Timing belt, 9... Pulse motor, 10 … Guide rod, 11… Platen, 1
2... Flushing box

Claims (4)

A pretreatment liquid, and an oil- based inkjet recording ink set containing an oil-based inkjet ink containing an organic solvent ,
The organic solvent of the oil-based ink-jet ink comprises at least one alcohol, selected from the group consisting of primary amines and secondary amines,
The pretreatment liquid contains maleic acid-modified resins anhydrous, oil-based inkjet recording ink set. The maleic anhydride-modified resins are rosin-modified maleic acid resin is at least one selected from the group consisting of acrylic-modified maleic acid resins and styrene-modified maleic acid resin, oil-based ink-jet according to claim 1 Recording ink set . The oil-based inkjet recording ink set according to claim 1 or 2, wherein the organic solvent has 12 or more carbon atoms. An oil- based inkjet recording method, wherein recording is performed using the oil-based inkjet recording ink set according to any one of claims 1 to 3 .

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