JP2017132048A - Pretreatment liquid, ink set for oily inkjet recording and oily inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide pretreatment liquid for oily ink which can improve clear folder storage properties of a recorded matter for a long period of time, and an ink set for inkjet recording, and an oily inkjet recording method.SOLUTION: A pretreatment liquid according to the invention is pretreatment liquid for oily ink. The pretreatment liquid contains an aluminum chelating agent.SELECTED DRAWING: None

Description

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

  Development of office-use inkjet printers is ongoing. An office use printer is required to be capable of high-speed printing with high image quality on a recording medium such as plain paper, and to be able to handle a finisher such as bookbinding after printing. For this reason, the characteristics required for the ink used in this printer are that a high print density can be secured at high speed for plain paper, and that show-through is suppressed to enable double-sided printing, However, it is required that paper deformation such as cockling and curling does not occur after high-speed printing. When water-based ink containing an aqueous medium is used as the ink, paper deformation such as cockling and curling may occur after high-speed printing on plain paper, so paper deformation is unlikely to occur. Development is also underway.

  When a volatile organic compound is used as a medium used for oil-based ink, there is a risk of causing health damage such as allergies when the volatile organic compound is released into the environment. Therefore, a low-volatile organic compound is used as a medium used for oil-based ink. However, when printing with oil-based inks that use low-volatile organic compounds as the medium, the medium is low-volatile, so it remains inside the paper and penetrates to cause penetration and bleeding. The print density may decrease. When a recording medium printed with oil-based ink is sandwiched between clear folders made of polypropylene (PP), the organic solvent moves to the clear folder, so that only the inside of the clear folder expands and the clear folder faces outward. It may be deformed by turning back or wavy to turn up. In particular, when a recorded matter recorded at a high duty on a recording medium is sandwiched between clear folders, the clear folder largely warps outward, which causes a problem in use.

  Therefore, in response to such problems, the viscosity of the ink is increased to limit the transfer of the organic solvent from the recording medium to the clear folder, and by selecting a highly polar medium, the attack property to the clear folder is improved. Reduction is performed by reducing the deformation (for example, see Patent Document 1). Here, 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 as a medium.

JP 2009-275211 A

  However, if the ink viscosity or the polarity of the medium is too high, there will be problems with ink ejection properties and sticking when the recorded material is stored in layers, and the deformation of the clear folder will be as short as about 10 days. 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 over a long period of time.

Accordingly, some aspects according to the present invention provide a pretreatment liquid that can improve the clear folder storability of recorded matter over a long period of time by solving at least a part of the above-described problems, and the pretreatment liquid. An oil-based ink jet recording ink set and an oil-based ink jet recording method are provided.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented 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 oil-based ink,
The pretreatment liquid contains an aluminum chelating agent.

  According to the pretreatment liquid according to the above application example, the pretreatment liquid contains an aluminum chelating agent, thereby providing a pretreatment liquid capable of improving the clear folder storability of recorded matter over a long period of time. Can do.

（式（１）中、Ｒ^１Ｏは揮発性アルコキシ基を表し、Ｒ^２、Ｒ^３およびＲ^４は、各々独立してアルキル基を表し、Ｒ^５はメチル基またはＲ^１Ｏを表す。）

（式（２）中、Ｒ^６Ｏは揮発性アルコキシ基を表し、Ｒ^７は、アルキル基を表す。） [Application Example 2]
In the above application example,
The aluminum chelating agent may be a compound represented by the following formula (1) or the following formula (2).

(In formula (1), R ¹ O represents a volatile alkoxy group, R ² , R ³ and R ⁴ each independently represents an alkyl group, and R ⁵ represents a methyl group or R ¹ O.)

(In formula (2), R ⁶ O represents a volatile alkoxy group, and R ⁷ represents an alkyl group.)

[Application Example 3]
In the above application example,
The organic solvent of the oil-based ink can be a higher alcohol having 12 or more carbon atoms.

[Application Example 4]
One aspect of the ink set for oil-based inkjet recording according to the present invention is:
It contains 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 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. In addition, the present invention is not limited to the following embodiments, and includes various modifications that are implemented within a range that does not change the gist of the present invention.

1. Pretreatment liquid The pretreatment liquid according to an embodiment of the present invention is a pretreatment liquid for oil-based ink, and the pretreatment liquid contains an aluminum chelating agent.

  The pretreatment liquid according to the present embodiment constitutes an ink set for oil-based ink jet recording used in the oil-based ink jet recording method, and the pretreatment liquid contains an aluminum chelating agent, thereby suppressing the clear folder storage property for a long period of time. can do.

  Hereinafter, components included in the pretreatment liquid according to the present embodiment and components that can be included will be described.

1.1. Aluminum chelating agent The pretreatment liquid according to this embodiment contains an aluminum chelating agent. When the pretreatment liquid contains an aluminum chelating agent, an exchange reaction occurs with an organic solvent that has an attacking property against the clear folder contained in the oil-based ink used for recording, and is converted to a solvent with a low attacking property. To do. For this reason, when the pretreatment liquid contains an aluminum chelating agent, it is possible to provide a pretreatment liquid that can improve the clear folder storability of recorded matter over a long period of time.

（式（１）中、Ｒ^１Ｏは揮発性アルコキシ基を表し、Ｒ^２、Ｒ^３およびＲ^４は、各々独立してアルキル基を表し、Ｒ^５はメチル基またはＲ^１Ｏを表す。）

（式（２）中、Ｒ^６Ｏは揮発性アルコキシ基を表し、Ｒ^７は、アルキル基を表す。） The aluminum chelating agent can be, for example, a compound represented by the following formula (1) or the following formula (2).

(In formula (1), R ¹ O represents a volatile alkoxy group, R ² , R ³ and R ⁴ each independently represents an alkyl group, and R ⁵ represents a methyl group or R ¹ O.)

(In formula (2), R ⁶ O represents a volatile alkoxy group, and R ⁷ represents an alkyl group.)

In the compound represented by the above formula (1) or the above formula (2), the carbon number of the volatile alkoxy group of R ¹ O and R ⁶ O is not particularly limited, and for example, the carbon number is 1 or more and 5 or less, Preferably it has 2 or 3 carbon atoms.

Moreover, in the compound represented by the above formula (1) or the above formula (2), the carbon number of the alkyl group of R ² , R ³ , R ^4, and R ⁷ is not particularly limited. Or less, preferably 2 or 3 carbon atoms.

Examples of the compound represented by the above formula (1) include a compound represented by the following formula (3).

As a compound represented by the said Formula (2), the compound represented by following formula (4) is mentioned, for example.

The content of the aluminum chelating agent needs to be 1% by mass to 20% by mass with respect to the total mass (100% by mass) of the pretreatment liquid, but may be 1% by mass to 16% by mass. Preferably, the content is 3% by mass or more and 16% by mass or less. By being in the said range, application | coating of a pretreatment liquid is easy and the effect of clear folder storage property is high.

  In addition, as a chelating agent other than the aluminum chelating agent, for example, a similar effect is also exhibited by a group 13 element such as B (boron), Ga (gallium), In (indium), or the like. However, an aluminum chelating agent using Al is the most efficient from the viewpoint of cost and safety, and is preferably used.

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-soluble organic solvents. As the organic solvent, any of various known vegetable oils and / or petroleum solvents can be used, and any of a nonpolar organic solvent and a polar organic solvent can be used.

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

1.3. Other Components The pretreatment liquid according to this embodiment may further contain other additives contained in a normal pretreatment liquid. Examples of the other additives include, but are not limited to, flocculants, resins, surfactants, pH adjusters, preservatives and fungicides, and thickeners.

<Flocculant>
The flocculant has a function of aggregating these components by reacting with a color material or resin contained in the oil-based ink. Thereby, the image quality of the image formed with the oil-based ink can be improved, the occurrence of bleeding can be suppressed, and further, the clear folder storage property can be improved.

  The flocculant is not particularly limited, and examples thereof include organic acids (for example, acetic acid, propionic acid, lactic acid, and salts thereof), polyallylamine, polyallylamine derivatives, polyvalent metal compounds, and the like. Among these, a polyvalent metal compound and an organic acid can be preferably used, and a polyvalent metal compound can be more preferably used from the viewpoint that the color material is more excellent in aggregating action. When a polyvalent metal compound is used, the content of metal ions contained in the polyvalent metal compound, that is, the metal ion concentration derived from the polyvalent metal compound is based on the total mass (100% by 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.

<Resin>
The pretreatment liquid according to the present embodiment may contain a resin. By containing the resin, the fixability of the pretreatment liquid to the recording medium can be improved. The resin is preferably added in the form of an emulsion. The resin emulsion can 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.

As the resin, acrylic resin, styrene acrylic resin, fluorene resin, urethane resin, polyolefin resin, rosin modified resin, terpene resin, polyester resin, polyamide resin, epoxy resin, vinyl chloride resin, Known resins such as vinyl chloride-vinyl acetate copolymer, ethylene vinyl acetate resin, maleic anhydride resin derivative, polyolefin wax and the like can be mentioned. These resins can be used singly or in combination of two or more.

  Among the resins exemplified above, styrene acrylic resins, polyester resins, polyolefin waxes, and maleic anhydride resin derivatives can be preferably used.

  When the resin is contained, the content thereof is preferably 1% by mass or more and 20% by mass or less in terms of solid content with respect to the total mass of the pretreatment liquid, and is 1% by mass or more and 16% by mass or less. It is preferable that the content is 3% by mass or more and 16% by mass or less. When the resin content is within the above range, the white image obtained can be further improved in abrasion resistance.

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

  Although it does not specifically limit as acetylene glycol type surfactant, 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 are trade names, manufactured by Air Products and Chemicals. Inc.), Olphin 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 trade names, manufactured by Nissin Chemical Industry Co., Ltd.), acetylenol E00, E00P, E40, E100 (all trade names, river Ken Fine Chemical Co., Ltd.).

  Although it does not specifically limit as a silicone type surfactant, A polysiloxane type compound is mentioned. Although it does not specifically limit as the said polysiloxane type compound, For example, polyether modified organosiloxane is mentioned. Commercially available products of the polyether-modified organosiloxane include, for example, BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-348 (above 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 (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).

  When the surfactant is contained, the content thereof can be, for example, 0.05% by mass or more and 2.0% by mass or less with respect to the total mass of the pretreatment liquid.

<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 thereof include sodium hydrogen carbonate.

<Preservatives, fungicides, rust inhibitors>
Examples of preservatives and fungicides include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate,
Examples include sodium dehydroacetate and 1,2-dibenzisothiazolin-3-one. Examples of commercially available products include Proxel XL2, Proxel GXL (above trade name, manufactured by Avicia), Denside CSA, NS-500W (above trade name, manufactured by Nagase ChemteX Corporation), and the like. Examples of the rust inhibitor include benzotriazole.

<Thickener>
Examples of the thickener include polyvinyl alcohols, poly (meth) acrylic acids, polyethers, polyvinyl pyrrolidones, polyvinyl formals, proteins (for example, gelatin, casein, and glue), polysaccharides (for example, 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 derivatives thereof (for example, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropyl) Pills methyl cellulose), alginates (e.g., sodium alginate, potassium alginate, ammonium alginate, etc.) alginates (e.g., propylene glycol alginate, etc.) and the like. In the case of containing a thickener, the content is not particularly limited, but can be, for example, 20% by mass or less with respect to the total mass of the pretreatment liquid.

1.4. Method for Producing Pretreatment Liquid Each of the pretreatment liquids according to the present embodiment can be obtained by mixing the above-described components (materials) in an arbitrary order, performing filtration or the like as necessary, and removing impurities. it can. As a method for mixing each material, a method in which materials are sequentially added to a container equipped with a stirring device such as a mechanical stirrer or a magnetic stirrer and stirred and mixed 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 Viscosity at 20 ° C. of the pretreatment liquid according to the present embodiment is improved in dischargeability from a nozzle when using an ink jet method or a spray method, or applicability when using a roll coater or the like. 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 or less. s or less is more preferable, and 5 mPa · s or less is even more preferable. The lower limit is not limited, but 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 Pysica) under a 20 ° C. environment.

1.6. Applications The pretreatment liquid used in this embodiment is attached to a recording medium such as paper by coating or jetting before recording in a known inkjet recording apparatus described later. Thereby, in the recording process, the alcohol exchange reaction in the ink by the aluminum chelating agent rapidly proceeds on the surface of the recording medium, and the clear folder is prevented from being attacked by the components contained in the oil-based ink.

  Examples of the method for 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. Any method can be used. The pretreatment liquid can be ejected by using an ejecting apparatus that employs a spray method, an ink jet method, which will be described later, and the like, and is performed in a non-contact manner on the recording medium in any case.

2. Oil-based ink The oil-based ink used in the present embodiment constitutes the oil-based ink jet recording ink set according to the present embodiment when used with the pretreatment liquid. In the present invention, the oil-based ink set for ink-jet recording includes at least one of the pretreatment liquid and a color ink composition (for example, white, cyan, magenta, yellow, black ink composition) as the oil-based ink. If it contains, the oil-based inkjet recording ink set which concerns on this embodiment shall be comprised. The oil-based ink may be a clear ink that does not include a color material.

  The oil-based ink used in this embodiment contains an organic solvent. In the present embodiment, the oil-based ink can be used without particular limitation as a writing instrument such as an oil paint, a paint, and a fountain pen, or a printing ink.

  Here, the “oil-based ink” in the present specification is an ink containing an organic solvent as a main component and means an ink that does not substantially contain water. In addition, “substantially free of water” means that water is not intentionally added when the ink is produced, and contains a minute amount of water that is inevitably mixed during the production or storage of the ink. It does not matter.

  The specific water content of the “oil-based ink substantially free of water” is preferably such that the water content in the oil-based ink is 3% by mass or less, more preferably 1% by mass or less. More preferably, it is less than 0.05% by mass, more preferably less than 0.01% by mass, still more preferably less than 0.005% by mass, and most preferably less than 0.001% by mass.

  Hereinafter, in this embodiment, an example in which an oil-based ink is used as an oil-based ink-jet ink composition for ink-jet recording (hereinafter, also simply referred to as ink) will be given, and components included in the oil-based ink-jet ink composition and components that can be included explain.

2.1. Coloring material The oil-based ink used in the present embodiment contains a coloring material. As the color material, pigments such as oily dyes, colored inorganic pigments, and colored organic pigments that are 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 using a pigment, if the average particle size of the pigment dispersion in the ink is 20 nm or more and 200 nm or less and the hue is white, black, yellow, magenta, cyan, red, green, blue or orange, There is no particular limitation, and conventionally known inorganic pigments and organic pigments can be used.

  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, isoindolinones. 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, and daylight fluorescent pigments; inorganic pigments such as carbon black Etc.

More specifically, examples of the pigment when the oil-based inkjet ink composition according to this 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 the present 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. And CI Pigment Yellow 180.

  Examples of pigments used when the oil-based ink used in the present 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. And CI Pigment Green 36.

  Examples of the pigment when the oil-based ink used in the present embodiment is a black ink include carbon black.

  Examples of the pigment when the oil-based ink used in the present embodiment is white ink include C.I. I. Pigment white 6, C.I. I. Pigment white 18, C.I. I. And CI Pigment White 21.

As a commercially available product, for example, carbon black MA11, MA100, MA220, MA600a, # 40, and # 44 manufactured by Mitsubishi Chemical are preferably cited as black pigments. Examples of pigments other than black include SYMULERBrilliant Carmine 6B, SYMULER Red, FASTOGENSuper Magenta, SYMULER Fast Yellow, and FASTOGEN Blue manufactured by Dainippon Ink, Inc.
4RO-2, FASTOGEN Green, FASTOGEN SuperViolet, etc. are mentioned. These pigments may be used alone or in appropriate combination.

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

As described above, the average particle size of the pigment is preferably 20 nm or more and 200 nm or less. When the average particle size is 20 nm or more, the color developability becomes better, so that it is easy to use as an inkjet ink. On the other hand, when the average particle size is 200 nm or less, it becomes easy to use the ink jet method. In addition, 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 of excellent storage stability, ejection stability, and sedimentation.

  Here, the “average particle diameter” in the present specification means a 50% average particle diameter (d50) in terms of a sphere obtained by a light scattering method for ink. “50% average particle diameter in terms of sphere by light scattering method (d50)” is a value obtained as follows. The particles in the dispersion medium are irradiated with light, and the generated diffracted scattered light is measured by detectors arranged in front, side, and rear of the dispersion medium. Using the measurement value, assuming that the particles that are originally indefinite are spherical, the total volume of the particle population converted to a sphere equal to the volume of the particles is 100%, and a cumulative curve is obtained. The point at which the cumulative value becomes 50% is defined as the 50% average particle diameter (d50).

  When a pigment is used as the color material, any dispersant used in a normal oil-based ink 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 the pigment is stably dispersed in the solvent. For example, Solsperse 5000, Solsperse 13940, Solsperse 11200, Solsperse 21000, Solsperse 28000 manufactured by Nippon Lubrizol are available. 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 masses with respect to 100 mass parts of the pigment content in the oil-based ink. Part to 200 parts by mass, more preferably 30 parts to 120 parts by mass.

  Preferred 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 Chemical. In addition, as 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 IF-YL LOW iG LOW iGLOW iGLOW iGLOW iGLOW iGLOW iGLOW iGLOW iGlWelGlS 1101 etc. are mentioned. These dyes may be used alone or in appropriate combination.

2.2. Organic solvent The oil-based ink used in the present embodiment contains an organic solvent. Here, the “organic solvent” in this specification refers to a liquid medium in which a coloring material such as a pigment is dispersed contains an organic solvent, and refers to a liquid medium at normal temperature and pressure. Here, when the organic solvent is an organic solvent-containing material composed of a mixture other than the organic solvent and the organic solvent, the organic solvent content exceeds 5% by mass.

  The oil-based ink used in the present embodiment can use alcohol as the organic solvent. Since alcohol has a high polarity, it is possible to suppress the deformation of the clear folder, and the clear folder storability can be improved by combining with the pretreatment with the pretreatment liquid described above.

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 either saturated or unsaturated, and may be linear or branched. Similarly, in the primary amine and secondary amine hydrocarbon groups used as the organic solvent, the structure is not limited as long as the polarity of the organic solvent becomes high and the deformation of the clear folder can be suppressed.

  Among them, the organic solvent is preferably a higher alcohol having 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 higher alcohol having 12 or more carbon atoms include 1-dodecanol, hexadecanol, and oleyl alcohol. These organic solvents may be used alone or in 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 with respect to the total mass (100% by mass) of the ink composition.

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

<Other organic solvents>
Examples of other organic solvents include nonpolar organic solvents or polar organic solvents, drying oil fatty acid and alcohol esters, high SP value and high iodine value organic solvents, drying oils, and the like.

  Examples of the nonpolar organic solvent include hydrocarbon solvents such as naphthenic, paraffinic, and isoparaffinic solvents, fluorine-based solvents, and silicon-based solvents. As these nonpolar organic solvents, commercially available ones may be used, for example, aliphatic saturated hydrocarbons such as dodecane, Expar Mobil Isopar, Exsol, JX Nippon Oil & Energy Corporation AF solvent. Normal paraffin H, AS Sol manufactured by Wilvie Co., Ltd., Dust Clean manufactured by Matsumura Oil Co., Ltd., Sansen manufactured by Sun Oil Co., Ltd., the same sampler, Surflon manufactured by AGC Seimi Chemical Co., Ltd., and the like.

  Examples of the polar organic solvent 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, 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 acid, ethyl oleate, isopropyl oleate, butyl oleate, hexyl oleate, methyl linoleate, isobutyl linoleate, ethyl linoleate, butyl stearate, hexyl stearate, isotearic acid Octyl, isopropyl isostearate, 2-octyldodecyl pivalate, diisopropyl adipate, diisopropyl sebacate, diethyl sebacate, propylene glycol monocaprylate, trimethylolpropane tri-2-ethylhexanoate, glyceryl tri-2-ethylhexanoate, etc. Can be mentioned. In addition, soybean oil fatty acid methyl, 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 which are esters of drying oil fatty acid and alcohol Examples include methyl and tall oil fatty acid isobutyl.

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

  Examples of the amide 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 to 22 carbon atoms in one molecule. For example, isononanoic acid, isomyristic acid, hexadecanoic acid, 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, propylene glycol dibutyl ether, and acetates of glycol ethers.

  Dry oil fatty acid and alcohol ester have a low viscosity, and even if they are used in many inks for ink jet recording, there is no problem in ejection properties. In addition, PP, which is a material of the clear folder, has a low attack property and has many double bonds, thereby promoting oxidative polymerization of the ink. Therefore, by using it as a component of the ink according to the present embodiment, even after the viscosity is low before recording, the ink after recording is quickly cured to become high viscosity, and the organic solvent contained in the ink is recorded matter. Immobilized in. Thereby, even if the recorded matter is sandwiched between the clear folders, the organic solvent is prevented from moving to the clear folder, and the clear folder storage property is improved.

  The drying oil fatty acid used as the raw material of the ester is obtained by hydrolyzing drying oil. Examples of the dry oil include linseed oil, tung oil, coconut oil, shiso oil, walnut oil, cocoon oil, safflower oil, and sunflower oil, as will be described later. The drying oil can be produced by a known method.

  The alcohol used as the raw material of the ester may be an unsaturated alcohol, and can be used without limitation on the number of carbons. 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 carbon number.

  When the carbon number of the alcohol is 3 or less, the alcohol tends to volatilize, and even if the alcohol in the recording medium moves to the clear folder and is deformed, it tends to return to the PP of the ester. It is more preferable that the ink oxidative polymerization reaction is completed before the organic solvent migrates and the decomposed alcohol does not migrate to the clear folder. It is preferable to promote.

  On the other hand, when the carbon number of the alcohol is 4 or more, the attacking property of the ester to PP is low, but the decomposed alcohol is less likely to volatilize, so it is easy to move to the clear folder. It will be deformed. When the metal soap or metal complex is contained in the ink, the hydrolysis reaction of the ester is promoted. Therefore, it is preferable that the metal soap or metal complex is not contained in the ink.

The production method of the ester of the drying oil fatty acid and the alcohol is not particularly limited and can be produced by a known method. For example, JP 2005-35871 A, JP 2009-203 A
It can be manufactured by the methods described in Japanese Patent Application Laid-Open No. 343 and Japanese Patent Application Laid-Open No. 2011-99009.

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

  Since the organic solvent has a high SP value, the attack property of PP is low, and the oxidative polymerization of the ink is promoted by having many double bonds. For this reason, when used as an organic solvent in 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 remaining solvent is prevented from moving to the clear folder, and the clear folder storage property 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 a compound represented by the general formula (2) described later ( SP value 12.6, iodine value 297), and a compound represented by general formula (3) (SP value 11.5, iodine value 231) are also included. These can be used individually by 1 type or in mixture of 2 or more types.

  Further, an allyl compound may be included as an organic solvent having a high SP value and a high iodine value. Allyl compounds are susceptible to crosslinking reactions at the α-carbon position. For this reason, when an allyl compound is included as the organic solvent, 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 rapidly cures to become high viscosity, and the organic solvent contained in the ink is contained in the recording medium. Fixed. Thereby, even if the recorded matter is sandwiched between the clear folders, the organic solvent is prevented from moving to the clear folder, and the clear folder storage property is improved.

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

  Dry oil has a high viscosity, so if it is used in many inks for ink jet recording, there will be a problem in ejection properties. However, the attack property of PP, which is a material of clear folder, is low, and the ink has many double bonds. The oxidative polymerization of is promoted. For this reason, by using supplementarily in the ink according to the present embodiment, the ink after recording is quickly cured, and the organic solvent contained in the ink is fixed in the recording medium. Thereby, even if the recorded matter is sandwiched between the clear folders, the organic solvent is prevented from moving to the clear folder, and the clear folder storage property is improved.

  Here, the dry oil is an oil that is completely solidified in the air and has an iodine value of 130 or more. For example, flaxseed oil, tung oil, coconut oil, shiso oil, walnut oil, coconut oil, safflower oil, sunflower oil Etc. These drying oils can 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 ink dischargeability.

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

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

<Binder resin>
The oil-based ink used in the present embodiment may be added with a binder resin for the purpose of adjusting the viscosity of the ink. Examples of the binder resin include acrylic resins, styrene acrylic resins, rosin modified resins, phenol resins, terpene resins, polyester resins, polyamide resins, epoxy resins, vinyl chloride vinyl acetate copolymer resins, cellulose acetate butyrate, and the like. Resin, vinyltoluene-α-methylstyrene copolymer resin, and the like. 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 of the binder resin added.

<Metal soap, metal complex>
Metal soaps and metal complexes are also called dryers (curing accelerators) and act as oxidizing agents that promote the oxidative polymerization of organic compounds contained in the organic solvent. For this reason, when recording on a recording medium such as paper using oil-based ink, the ink after recording is quickly cured, and the organic solvent contained in the ink is fixed in the recording medium. As a result, even when the recorded matter is sandwiched between the clear folders, the organic solvent is prevented from moving to the clear folder, and the clear folder is prevented from being deformed.

  In this 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 the raw material for the organic acid metal salt, an organic acid that has been conventionally used as a general raw material for dryers can be used without any particular limitation. Specifically, for example, an organic acid such as propionic acid, octylic acid, naphthenic acid, neodecanoic acid, tung oil acid, linseed oil acid, soybean oil acid, resin acid, etc. can be used. From the point obtained, 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.

  Among these metal-containing compounds (metal salts), for example, cobalt promotes oxidation at the interface between the ink coating and air, and other manganese is moderate and works inside as well as surface oxidation. Accelerate polymerization of Auxiliary driers such as zirconium and calcium improve overall performance in combination with the previously described driers, but have little effect when used alone.

As an organic acid metal salt used in the present embodiment, for example, the general formula (A)
(OMR) Formula 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.)
The organic acid metal salt represented by these is mentioned.

  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 acid, linseed oil acid, soybean oil acid, or resin acid. Yes, preferably a carboxylate group of an aliphatic monocarboxylic acid having 3 to 12 carbon atoms, more preferably a carboxylate group of octylic acid, naphthenic acid, or neodecanoic acid.

  As described above, in this embodiment, cobalt drier and manganese drier can be used as the metal soap and metal complex, but it is preferable to use a manganese drier from the viewpoint of the use environment. In addition, since manganese is inferior in activity to cobalt, when a manganese dryer is used, it is preferably used together with a ligand that activates the manganese dryer. Examples of the ligand include 2,2′-bipyridine, 2- (aminomethyl) pyridine, 2-hydroxymethylpyridine, and the like. A ligand can be used individually by 1 type or in mixture of 2 or more types.

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

  Examples of organic acid metal salts used as other dryers include organic acid cobalt boron metal salts and organic acid manganese boron metal salts. These may be used singly or in combination, but when used together, they are excellent in the drying property of the coating film with a thick film that is difficult to be uniformly cured, so that the combined use is preferable. Furthermore, when the organic acid cobalt boron metal salt and the organic acid manganese boron metal salt are used in combination with the organic acid manganese boron metal salt, the combined use of the organic acid cobalt boron metal salt and the organic acid manganese boron metal salt is preferable because the coating film is excellent in dryness. In addition, when the organic acid cobalt boron metal salt and the organic acid manganese metal salt are used in combination, a low-cost dryer excellent in drying acceleration effect can be obtained, and the combined use 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 JP-B-63-63551. .

  In addition, it is preferable from the viewpoint of easy handling and uniform mixing that these organic acid metal salts are previously diluted with an organic solvent before being added to the oil-based ink. The diluted organic solvent is not 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 and cyclohexanol; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; propyl ether, methyl cellosolve, cellosolve, butyl cellosolve, methylcarbitol, Ether solvents such as butyl carbitol can be used, and these may be used alone or in combination of two or more.

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. In the case of using a pigment as a colorant, first, a pigment, a dispersant, and an organic solvent (partial) 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 characteristics. Subsequently, an organic solvent (remaining amount) and other additives (for example, a surfactant or a binder resin) can be added with stirring to obtain an oil-based ink.

2.5. Physical Properties The oil-based ink used in this embodiment preferably has a surface tension at 20 ° C. of 20 mN / m or more and 50 mN / m from the viewpoint of the balance between recording quality and reliability as an inkjet ink composition, and 25 mN. More preferably, it is at least 40 mN / m. The surface tension is measured by using an automatic surface tension meter CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) by confirming the surface tension when the platinum plate is wetted with ink in an environment of 20 ° C. be able to.

  From the same viewpoint, the viscosity of the oil-based ink used in the present 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 Pysica), increasing the Shear Rate to 10 to 1000 in an environment of 20 ° C., and reading the viscosity at Shear Rate 200. Can be measured.

2.6. Application The oil-based ink used in this embodiment is stored in an ink cartridge of a known ink jet recording apparatus, ejects ink droplets, and attaches the droplets to a recording medium such as paper to record an image. The ink jet recording apparatus is preferably an ink jet recording apparatus that is equipped with an electrostrictive element that can vibrate based on an electrical signal and that can eject ink by the vibration of the electrostrictive element. The oil-based ink used in the present embodiment can suppress the deformation of the clear folder due to the recorded matter using the ink for a long period of time by combining with the pretreatment using the pretreatment liquid.

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 performs recording using the above-described pretreatment liquid and oil-based ink set for oil-based inkjet recording including oil-based ink.

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

  Examples of the ink jet apparatus include an ink jet printer (hereinafter referred to as a printer) equipped with the ink jet head shown in FIG. As shown in FIG. 1, the printer 1 is a device that records an image or the like by ejecting liquid ink onto the surface of a recording medium 2 such as recording paper. 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 (a direction orthogonal to the main scanning direction) is provided.

  Here, the pretreatment liquid and 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. A configuration in which the ink cartridge 7 is disposed 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 may be employed.

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. Accordingly, 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 formation surface (nozzle plate; not shown) of the inkjet head 3 when performing a recording operation, and supports the recording medium 2. Further, a flushing box 12 is provided at an end portion of the platen 11 in the main scanning direction, specifically, an area outside the area (recording area) where ink is ejected to the recording medium 2 disposed on the platen 11. . The flushing box 12 is a member that collects the pretreatment liquid and ink ejected from the inkjet head 3 in the preliminary discharge of the pretreatment liquid and 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 disposed 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 ink-jet head 3 is means for attaching a pretreatment liquid and oil-based ink to the recording medium 2 and includes a nozzle (not shown) that discharges the pretreatment liquid and oil-based ink. As a method of discharging the pretreatment liquid or 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 droplet-shaped pretreatment liquid or oil-based ink is continuously applied from the nozzle. System that discharges the liquid in response to the recording information signal while the liquid droplets of the reaction liquid fly between the deflection electrodes (electrostatic suction system); pressure is applied to the reaction liquid with a small pump, and the nozzle vibrates. A method of forcibly ejecting droplets of pretreatment liquid or oil-based ink by mechanically vibrating with a child or the like; pressure and recording information signal are simultaneously applied to the pretreatment liquid or oil-based ink with a piezoelectric element, and the pretreatment liquid Or a method for ejecting and recording droplets of oil-based ink (piezo method); pretreatment liquid or oil-based ink is heated and foamed with a microelectrode according to a recording information signal, and droplets of the pretreatment liquid or oil-based ink are ejected and recorded Method (thermal Tsu door method), and the like.

  As the ink-jet head 3, either a line-type ink-jet head or a serial-type ink-jet head can be used, but in this embodiment, a serial-type ink-jet head is used.

  Here, the ink jet recording apparatus provided with the serial ink jet head refers to recording by performing a plurality of scans (passes) for discharging the ink composition while moving the recording head relative to the recording medium. Is to do. In a specific example of the serial type recording head, a recording head is mounted on a carriage that moves in the width direction of the recording medium (a direction that intersects the conveyance direction of the recording medium), and the recording head accompanies the movement of the carriage. In which liquid droplets are ejected onto the recording medium by moving.

  On the other hand, an ink jet recording apparatus equipped with a line type ink jet head performs recording by performing a scan (pass) for discharging the ink composition once while moving the recording head relative to the recording medium. It 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 droplets are ejected onto the recording medium without moving the recording head.

Although not shown, the ink jet apparatus may be provided with a drying means. By providing the drying means, it is possible to quickly evaporate and disperse the liquid medium from the pretreatment liquid or oil-based ink attached to the recording medium, thereby forming a recorded image or the like quickly. The drying means that can be employed 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 and the oil-based ink. For example, there are means for applying heat to the recording medium, means for blowing air on the pretreatment liquid and oil-based ink, and means for combining them. Specifically, forced air heating, radiation 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 ink jet recording apparatus perform recording by discharging to a heated recording medium. 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. Examples of the heating means for the recording medium include infrared rays (lamps). It is 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, drying of the ink in the recording process can be promoted.

3.2. Recording medium In this 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, fabric, leather, etc., and has low ink absorption. Alternatively, a non-absorbable recording medium may be used.

In the present specification, the “ink-absorbing or non-absorbing recording medium” refers to a recording medium having a property of not absorbing or hardly absorbing an ink composition. Quantitatively, a non-ink-absorbing or low-absorbing recording medium is a “recording medium 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”. Point to. This 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 Paper Pulp Technology Association (JAPAN TAPPI). For details of the test method, refer to Standard No. of “JAPAN TAPPI Paper Pulp Test Method 2000”. 51 "Paper and paperboard-Liquid absorbency test method-Bristow method". On the other hand, an ink-absorbing recording medium refers to a recording medium that does not correspond to a non-ink-absorbing or low-absorbing recording medium.

  Examples of non-ink-absorbing recording media include plastic films that do not have an ink absorbing layer, those that are coated with plastic on a substrate such as paper, and those that have a plastic film adhered thereto. . Examples of the plastic here include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

  Examples of the recording medium with low ink absorption include a recording medium provided with a coating layer for receiving ink on the surface. For example, as the base material is paper, art paper, coated paper, mat For example, when the base material is a plastic film, a hydrophilic polymer is applied to the surface of polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc. , Silica and titanium particles are 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 and attached. As described above, as a method of attaching the pretreatment liquid, there are 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. For example, the spraying of the pretreatment liquid can be performed using a spraying apparatus such as a spray type or an ink jet type. In the present embodiment, droplets of the pretreatment liquid are ejected from the inkjet head 3 to the recording medium 2 and attached.

The adhesion 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. By being in this range, the clear folder storage property can be improved, and the drying time of the pretreatment liquid can be shortened, so that the recording speed can be increased.

  A step of drying the pretreatment liquid may be provided after attaching the pretreatment liquid and before attaching the oil-based ink. In this case, in the recording step to be described later, it is preferable to stop the drying in a state where the pretreatment liquid is wet from the viewpoint of the progress of the alcohol exchange reaction in the ink by the aluminum chelating agent. The drying process of the pretreatment liquid may be performed by natural drying, but is a drying with heating from the viewpoint of improving the drying speed and promoting the fusion of the resin component contained in the pretreatment liquid to the fabric. Also 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. . Moreover, as a heat source for heating, for example, infrared rays (lamp) can be cited.

3.4. Oil-based ink adhesion process (recording process)
Next, an oil-based ink is attached to the surface of the pretreated recording medium to record an image. As a result, an image made of oil-based ink is formed on the surface of the recording medium.

  In the present invention, “image” refers to a recording pattern formed from a group of dots, and includes text printing and solid images. Note that a “solid image” means that dots are recorded for all of the 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 ground of the recording medium is recorded. This means an image pattern that should be an image that cannot be seen.

The maximum amount of oil-based ink attached to 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 in the above range because the clear folder storage property is improved and the recording speed can be increased.

  In addition, you may provide the drying process which dries the oil-based ink adhering to the recording medium after the recording process. In this case, it is preferable to perform drying to such an extent that no stickiness is felt when the oil-based ink adhered to the surface of the recording medium is touched. The drying step of the oil-based ink may be performed by natural drying, but is preferably drying accompanied by heating from the same viewpoint as the drying step of the above-described pretreatment step. The method for heating the oil-based ink is not particularly limited, and examples thereof include the same methods as those mentioned in the above heating method.

  In the oil-based inkjet recording method used in the present embodiment, the organic solvent in the obtained image is obtained by performing a pretreatment step using the pretreatment liquid before recording with the oil-based ink used in the present embodiment. Due to the influence, the deformation of the clear folder is suppressed. In addition, it is possible to suppress the deformation of the clear folder due to the recorded matter using this ink over 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 Each material was mixed and stirred so that the composition (mass%) shown in Table 1 below was obtained, to obtain pretreatment liquids 1 and 2.

なお、表１中、アルミキレート剤１としては下記化学式（３）の化合物を、アルミキレート剤２としては下記化学式（４）の化合物を使用した。

In Table 1, a compound represented by the following chemical formula (3) was used as the aluminum chelating agent 1, and a compound represented by the following chemical formula (4) was used as the aluminum chelating agent 2.

4.2. Preparation of oil-based ink composition Each material was mixed and stirred to be completely dissolved so as to have the composition (mass%) shown in Table 2 below, and then filtered through 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 oil-based dye.

4.3. Clear Folder Deformation Evaluation Test Each pretreatment liquid was applied to 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 obtained oil-based ink composition was filled in an ink cartridge of a remodeling machine of an ink jet printer PX-M7050F (manufactured by Seiko Epson Corporation), and solid printing (rectangular 20 cm) on double-sided fine plain paper (manufactured by Seiko Epson Corporation). X28 cn), and the printed matter was inserted into a clear folder made of PP. Set the clear folder with the printed material into it at 23 ° C / 50% R. H. It was left to stand in the environment for 30 days. Thereafter, the amount of the clear folder that had been allowed to warp outward was measured using a ruler, and the value was evaluated as the amount of deformation. The evaluation results were 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 Examples 1 and 2 in which the pretreatment liquid was not used, the amount of deformation of the clear folder was large and the clear folder storage property was poor. On the other hand, in the Example, by using the pretreatment liquid containing an aluminum chelating agent, the amount of deformation of the clear folder was small compared to Comparative Examples 1 and 2, and the storage property was excellent. As described above, according to the present embodiment, by performing the pretreatment with the pretreatment liquid containing the aluminum chelating agent, the deformation of the clear folder can be remarkably suppressed, and the recorded matter using the oil-based ink is used. It becomes possible to suppress the deformation of the clear folder over a long period of time.

  The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present 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. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 1 ... Printer (inkjet recording device), 2 ... Recording medium, 3 ... Inkjet head, 4 ... Carriage, 5 ... Carriage moving mechanism, 6 ... Conveyance mechanism, 7 ... Ink cartridge, 8 ... Timing belt, 9 ... Pulse motor, 10 ... guide rod, 11 ... platen, 12 ... flushing box

Claims (5)

A pretreatment liquid for oil-based ink,
The pretreatment liquid, wherein the pretreatment liquid contains an aluminum chelating agent. The pretreatment liquid according to claim 1, wherein the aluminum chelating agent is a compound represented by the following formula (1) or the following formula (2).

(In formula (1), R ¹ O represents a volatile alkoxy group, R ² , R ³ and R ⁴ each independently represents an alkyl group, and R ⁵ represents a methyl group or R ¹ O.)

(In formula (2), R ⁶ O represents a volatile alkoxy group, and R ⁷ represents an alkyl group.)   The pretreatment liquid according to claim 1 or 2, wherein the organic solvent of the oil-based ink is a higher alcohol having 12 or more carbon atoms.   An ink set for oil-based inkjet recording, comprising the pretreatment liquid according to any one of claims 1 to 3.   An oil-based inkjet recording method for recording with the ink set according to claim 4.

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