Ink composition, ink set, recorded matter, recording method, and method for producing recorded matter

Abstract

Provided is an ink composition with which it is possible to obtain recorded matter having excellent glossiness and to effectively suppress bleeding of printing even when using any base material (recording medium) including low-absorbent base materials such as vinyl chloride resins.　This ink composition contains an organic solvent, wherein the organic solvent contains the following organic solvent A, and further contains a polysiloxane surfactant in the range of 0.01–2.0% by mass (inclusive) based on the total amount of the ink composition.　Organic solvent A: at least one substance selected from the group consisting of alkylamide-based solvents (a1) and cyclic amide-based solvents (a2).

Description

Ink composition, ink set, recorded matter, recording method, and method for producing recorded matter

[0001] The present invention relates to an ink composition, an ink set, a recorded matter, a recording method, and a method for producing a recorded matter.

[0002] As ink compositions, aqueous ink compositions in which a colorant is dissolved or dispersed in water or a mixture of water and an organic solvent, and non-aqueous ink compositions in which a colorant is dissolved or dispersed in a water-free organic solvent are widely used. These ink compositions are applied to a substrate such as paper directly or through another layer by an inkjet system or the like, and characters or images can be obtained by adhering the non-aqueous ink composition and allowing it to dry.

[0003] For example, Patent Document 1 describes a technology related to a non-aqueous ink composition containing a cyclic ester (lactone solvent) and an organic solvent having a predetermined flash point. Patent Document 1 describes that by containing the cyclic ester (lactone solvent) as a solvent, this non-aqueous ink composition can dissolve part of the recording surface, allowing the ink composition to penetrate into the interior of the recording medium and improving the abrasion resistance of the image.

[0004] Furthermore, when an ink composition is ejected onto the surface of a substrate by an inkjet method, additives contained in the ink composition may interfere with the opening and closing action of a pressure regulating valve. Patent Document 2 describes an ink composition for use in a recording device that adjusts the pressure inside a recording head by opening and closing the pressure regulating valve and has a pressure regulating valve covered with an elastic member, the ink composition comprising a slip agent and a lactone-based solvent. Patent Document 2 also describes that this ink composition prevents deterioration of elastic members such as the pressure regulating valve and is capable of recording images with excellent abrasion resistance.

[0005] Japanese Patent No. 6256039 Japanese Patent Application Laid-Open No. 2013-249463

[0006] Lactone-based solvents reduce the effect of additives contained in the ink composition on the pressure regulating valve and the like, and also have high permeability and are easily permeable into resin substrates.

[0007] However, the present inventors have found that if the ink composition penetrates into the resin substrate to a large extent, the glossiness of the recorded surface of the resulting recorded matter decreases.

[0008] Furthermore, lactone-based solvents are difficult to dry. Furthermore, if the drying property of the ink composition decreases, bleeding may occur due to the undried ink composition that has landed on the substrate (recording medium), depending on the type of substrate (recording medium).

[0009] An object of the present invention is to provide an ink composition that can provide a recorded product with excellent glossiness and can effectively suppress bleeding of printed characters even when using any substrate (recording medium) including a low-absorbency substrate such as a vinyl chloride resin.

[0010] The present inventors have conducted extensive research to solve the above problems, and as a result have found that an ink composition containing a predetermined amount of a polysiloxane surfactant together with a predetermined organic solvent can solve the above problems, leading to the completion of the present invention. Specifically, the present invention provides the following.

[0011] (1) An ink composition containing an organic solvent, the organic solvent containing the following organic solvent A, and further containing a polysiloxane surfactant in an amount of 0.01% by mass or more and 2.0% by mass or less based on the total amount of the ink composition: Organic solvent A: at least one selected from the group consisting of alkylamide solvents (a1) and cyclic amide solvents (a2).

[0012] (2) The ink composition according to (1), wherein the organic solvent A contains the alkylamide solvent (a1).

[0013] (3) The ink composition according to (2), wherein the alkylamide solvent (a1) is represented by the following formula (1): (In formula (1), R １ is hydrogen or an alkyl group having 1 to 4 carbon atoms, and R ２ R ３ each independently represents hydrogen or an alkyl group having 1 to 4 carbon atoms.

[0014] (4) The ink composition according to (3), wherein the alkylamide solvent (a1) contains at least one selected from the group consisting of N,N-diethylformamide, N,N-diethylpropanamide, and N,N-diethylacetamide.

[0015] (5) The ink composition according to (1), wherein the organic solvent A contains a cyclic amide solvent (a2).

[0016] (6) The ink composition according to (5), wherein the cyclic amide solvent (a2) is represented by the following formula (2): (In formula (2), R ４ is an alkylene group having 3 to 5 carbon atoms, and R ５ represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an unsaturated hydrocarbon group.

[0017] (7) The ink composition according to (6), wherein the cyclic amide solvent (a2) contains at least one selected from the group consisting of ε-caprolactam, N-methyl-ε-caprolactam, and N-vinylcaprolactam.

[0018] (8) The ink composition according to any one of (1) to (7), wherein the content of the organic solvent A is in the range of 1% by mass to 90% by mass of the total amount of the ink composition.

[0019] (9) The ink composition according to any one of (1) to (8), wherein the polysiloxane surfactant contains a repeating unit represented by the following formula (3) and a polyester and / or polyether-modified polydialkylsiloxane containing repeating units represented by the following formulas (3) and (4): (In formula (3), R ６ is an alkyl group having 1 to 3 carbon atoms, R ７ is an alkyl group having 1 to 15 carbon atoms. (In formula (4), R ８ is an alkyl group having 1 to 3 carbon atoms, and X is a polyester modified group or a polyether modified group.

[0020] (10) The ink composition according to any one of (1) to (9), which is ejected by an inkjet method.

[0021] (11) The ink composition according to any one of (1) to (10), which is used on a resin substrate.

[0022] (12) An ink set comprising the ink composition according to any one of (1) to (11).

[0023] (13) A recording method comprising ejecting the ink composition according to any one of (1) to (11) onto the surface of a substrate by an inkjet system.

[0024] (14) A method for producing a recorded matter, comprising ejecting the ink composition according to any one of (1) to (11) onto a surface of a substrate by an inkjet system.

[0025] (15) A recorded matter, in which a recording layer of the ink composition according to any one of (1) to (11) is formed on the surface of a substrate.

[0026] The ink composition of the present invention can provide a recorded matter having excellent glossiness and can effectively prevent bleeding of the print on the resulting recorded matter.

[0027] Specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be practiced with appropriate modifications within the scope of the object of the present invention. In addition, in this specification, the expression "to" means "or more" or "less than."

[0028] 1. Overview of the Invention The ink composition of the invention is an ink composition containing an organic solvent, and the organic solvent contains organic solvent A described below.

[0029] Organic solvent A: at least one selected from the group consisting of alkylamide solvents (a1) and cyclic amide solvents (a2).

[0030] The ink composition of the present invention is characterized by containing, together with the organic solvent A, a polysiloxane surfactant in an amount of 0.01% by mass or more and 2.0% by mass or less based on the total amount of the ink composition.

[0031] By using an ink composition containing a predetermined amount of a polysiloxane-based surfactant together with organic solvent A, it is possible to obtain a recorded matter having excellent gloss and to effectively suppress bleeding of the print on the obtained recorded matter.

[0032] The ink composition of the present invention may be a colored ink composition containing a colorant (including a colored colorant or a black-and-white colorant), an ink composition containing a glittering pigment (scale-like metal particles) for giving a metallic finish to a recorded material (substrate), or a clear ink composition that does not contain a colorant. Clear inks that do not contain a colorant include inks for forming layers with desired functions. Examples of such inks include overcoat ink compositions for forming an overcoat layer that protects a recorded material (substrate), matte ink compositions that matte the gloss of a recorded material (substrate), and inks containing an ultraviolet absorber, a light stabilizer, or the like for forming a weather-resistant layer.

[0033] <2-1. Non-aqueous ink composition> Hereinafter, a non-aqueous ink composition will be described as an example of a specific embodiment of the present invention (hereinafter referred to as "the present embodiment").

[0034] Here, the term "non-aqueous ink composition" refers to an ink composition (oil-based ink composition) that does not intentionally contain water, excluding water that is inevitably contained therein, such as water contained in atmospheric moisture or additives, and is different from an aqueous ink composition in which a colorant is dissolved or dispersed in water or a mixture of water and an organic solvent.

[0035] The water content in the non-aqueous ink composition according to this embodiment is preferably 1.0% by mass or less, and more preferably 0.5% by mass or less, of the total amount of the non-aqueous ink composition. If moisture from raw materials or atmospheric moisture is mixed in during the manufacturing process, the storage stability of the non-aqueous ink composition may deteriorate, and solids may be generated due to components contained in the non-aqueous ink composition. By reducing the water content in the non-aqueous ink composition to minimize the amount of moisture (intentionally eliminating moisture), it is possible to more effectively improve storage stability, etc.

[0036] Each component contained in the non-aqueous ink composition according to this embodiment will be described below.

[0037] [Organic Solvent] The organic solvent is capable of dissolving or dispersing each component contained in the non-aqueous ink composition according to this embodiment. The organic solvent includes organic solvent A (at least one selected from the group consisting of alkylamide solvents (a1) and cyclic amide solvents (a2)).

[0038] (1) Alkylamide-based solvent (a1) The alkylamide-based solvent (a1) is an alkylamide-based solvent having an alkyl group (C ｎ H ２ｎ＋１ It is a compound having a -C(=O)-N- group (amide bond) and a -C(=O)-N- group, and is an organic solvent consisting of a compound composed of hydrogen or an alkyl group and a -C(=O)-N- group.

[0039] The alkylamide solvent (a1) is a solvent that penetrates into the substrate to a certain extent, similar to the lactone solvent. The alkylamide solvent (a1) is more volatile than the lactone solvent, and as a result, the amount of penetration into the substrate can be reduced compared to a non-aqueous ink composition containing a lactone solvent. Therefore, it is possible to improve the glossiness of the recorded surface of the resulting recorded matter while enjoying the benefits of a non-aqueous ink composition containing a lactone solvent.

[0040] Furthermore, since the alkylamide solvent (a1) dries easily, the non-aqueous ink composition that has landed on a substrate (recording medium) can dry quickly, resulting in less bleeding of the print.

[0041] The alkylamide solvent (a1) is preferably an organic solvent composed only of hydrogen or an alkyl group and a —C(═O)—N— group, and does not contain an alkoxy group, and for example, one having the following structure can be preferably used.

[0042] (In formula (1), R １ is hydrogen or an alkyl group having 1 to 4 carbon atoms, and R ２ , R ３each independently represents hydrogen or an alkyl group having 1 to 4 carbon atoms.

[0043] In addition, R in formula (1) ２ and R ３ is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably an alkyl group having 2 to 4 carbon atoms.

[0044] Specific examples of the alkylamide solvent (a1) include N,N-diethylformamide, N,N-diethylacetamide, N,N-dipropylformamide, N,N-dibutylformamide, N,N-diethylpropanamide, N,N-dipropylpropanamide, N-ethylformamide, N-ethylacetamide, etc. Among these, from the viewpoint of particularly achieving the effects of the present invention, it is preferable to contain at least one selected from the group consisting of N,N-diethylformamide, N,N-diethylpropanamide, and N,N-diethylacetamide.

[0045] The content of the alkylamide solvent (a1) is not particularly limited, but the lower limit of the content of the alkylamide solvent (a1) is preferably 1 mass % or more, more preferably 5 mass % or more, and even more preferably 8 mass % or more, of the total amount of the non-aqueous ink composition.

[0046] The upper limit of the content of the alkylamide solvent (a1) is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less, of the total amount of the non-aqueous ink composition.

[0047] (2) Cyclic Amide Solvent (a2) The cyclic amide solvent (a2) is a solvent having a cyclic structure and a —C(═O)—N— group in the cyclic structure.

[0048] The cyclic amide solvent (a2) is a solvent that penetrates into the substrate to a certain extent, similar to the lactone solvent, but penetrates less into the substrate than the lactone solvent, and as a result, the cyclic amide solvent (a2) can penetrate into the substrate to a lesser extent than the non-aqueous ink composition containing the lactone solvent. This makes it possible to improve the gloss of the recorded surface of the resulting recorded matter while enjoying the benefits of the non-aqueous ink composition containing the lactone solvent.

[0049] As the cyclic amide solvent (a2), for example, those having the following structure can be preferably used.

[0050] (In formula (2), R ４ is an alkylene group having 3 to 5 carbon atoms, and R ５ represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an unsaturated hydrocarbon group.

[0051] The unsaturated hydrocarbon group means a hydrocarbon group containing at least one multiple bond, such as a vinyl group.

[0052] In addition, R ５ is preferably hydrogen, an alkyl group having 1 to 3 carbon atoms, or an unsaturated hydrocarbon group, and more preferably hydrogen, an alkyl group having 1 to 2 carbon atoms, or an unsaturated hydrocarbon group.

[0053] Specific examples of the cyclic amide solvent (a2) include N-methylcaprolactam, N-acetylcaprolactam, ε-caprolactam, N-vinylcaprolactam, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-ethyl-ε-caprolactam, N-propyl-ε-caprolactam, N-methyl-ε-caprolactam, etc. Among these, it is preferable to contain at least one selected from the group consisting of ε-caprolactam, N-methylcaprolactam, and N-vinylcaprolactam.

[0054] The content of the cyclic amide solvent (a2) is not particularly limited, but the lower limit of the content of the cyclic amide solvent (a2) is preferably 1 mass % or more, more preferably 3 mass % or more, and even more preferably 10 mass % or more, of the total amount of the non-aqueous ink composition.

[0055] The upper limit of the content of the cyclic amide solvent (a2) is preferably 90% by mass or less, more preferably 60% by mass or less, and even more preferably 40% by mass or less, of the total amount of the non-aqueous ink composition.

[0056] Among the organic solvents A, "one containing an alkylamide solvent (a1)" is more preferred. Because the alkylamide solvent (a1) dries easily, "one containing an alkylamide solvent (a1)" can obtain a recorded matter with excellent gloss, can enhance the drying properties of the non-aqueous ink composition that has landed on the substrate (recording medium), and can effectively suppress bleeding of the print in the obtained recorded matter.

[0057] The organic solvent A sufficiently exhibits the effects of the present invention when it contains at least one of an alkylamide solvent (a1) and a cyclic amide solvent (a2), but two or more of the organic solvents A may also be mixed. By mixing two or more, it is possible to achieve any balance between the glossiness of the resulting recorded material and the effect of suppressing print bleeding. When two or more organic solvents A are mixed, the lower limit of the total content of the organic solvents A is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, of the total amount of the non-aqueous ink composition. The upper limit of the total content of the organic solvents A is preferably 90% by mass or less, of the total amount of the non-aqueous ink composition.

[0058] [Other Organic Solvents] The organic solvent may contain an organic solvent other than the organic solvent A. Specifically, examples thereof include ethylene glycol mono-n-butyl ether, ethylene glycol mono-isobutyl ether, ethylene glycol mono-t-butyl ether, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl ether), triethylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl) ether, tetra ... alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, propylene glycol mono-n-butyl ether, propylene glycol mono-isobutyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-2-ethylhexyl ether, dipropylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl) ether, tripropylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl) ether, tetrapropylene glycol monomethyl ether (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl); ethylene glycol dibutyl ether; ethylene glycol dipropyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dipropyl ether, diethylene glycol propyl methyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, diethylene glycol butyl ethyl ether, diethylene glycol methyl-2-ethylhexyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol ethyl methyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol ethyl methyl ether, propylene glycol diethyl ether,Propylene glycol ethyl methyl ether, propylene glycol methyl propyl ether, propylene glycol methyl butyl ether, propylene glycol methyl-2-ethylhexyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol ethyl methyl ether, dipropylene glycol methyl propyl ether, dipropylene glycol dipropyl ether, dipropylene glycol methyl butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol Dialkyl ethers of polyhydric alcohols such as glycol diethyl ether and tripropylene glycol ethyl methyl ether; lactones such as γ-butyrolactone, δ-valerolactone, δ-hexanolactone, ε-caprolactone, γ-valerolactone, γ-hexalactone, γ-heptalactone, γ-octalactone, γ-nonalactone, γ-decalactone, γ-undecalactone, δ-heptalactone, δ-octalactone, δ-nonalactone, δ-decalactone, and δ-undecalactone; carbonates such as propylene carbonate and ethylene carbonate. oxazolidinone solvents such as 3-methyl-2-oxazolidinone, 3-ethyl-2-oxazolidinone, and N-vinylmethyloxazolidinone; triethylene glycol butyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, 1-methoxy-2-propyl acetate; Acetate solvents such as 2-methylbutyl acetate, 3-methoxybutyl ether acetate, and cyclohexyl acetate; amide solvents such as 3-methoxypropanamide, 3-butoxypropanamide, N,N-dimethyl-3-methoxypropanamide, N,N-dibutyl-3-methoxypropanamide, N,N-dibutyl-3-butoxypropanamide, and N,N-dimethyl-3-butoxypropanamide; methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, and sec-butyl alcohol;Alkyl alcohols having 1 to 5 carbon atoms such as tert-butyl alcohol, isobutyl alcohol, and n-pentanol; monohydric alcohols such as 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-propanol, 1-methoxy-2-propanol, and 3-methoxy-n-butanol; acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl isopropyl ketone, methyl n-butyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, methyl hexyl ketone, methyl isoamyl ketone, diethyl ketone, ethyl n- Ketones or ketoalcohols such as propyl ketone, ethyl isopropyl ketone, ethyl-n-butyl ketone, ethyl isobutyl ketone, di-n-propyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, isophorone, and acetyl ketone; ethers such as tetrahydrofuran and dioxane; oxyethylene or oxypropylene copolymers such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-propanediol, hexanediol, isobutylene glycol, triethylene glycol, tripropylene glycol, tetraethylene glycol, 1,3-propanediol, 2-methyl-1,2-propanediol, 2-methyl-1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol diols such as glycerin, trimethylolethane, trimethylolpropane, 1,2,6-hexanetriol, etc.; triols such as mesoerythritol, pentaerythritol, etc.; tetrahydric alcohols such as monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine, etc.; methyl acetate,Acetate esters such as ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, hexyl acetate, and octyl acetate; lactic acid esters such as methyl lactate, ethyl lactate, butyl lactate, propyl lactate, ethylhexyl lactate, amyl lactate, and isoamyl lactate; dibasic acid esters such as dimethyl oxalate, diethyl oxalate, dimethyl malonate, diethyl malonate, dipropyl malonate, dimethyl succinate, diethyl succinate, dimethyl glutarate, and diethyl glutarate; saturated carbohydrates such as n-hexane, isohexane, n-nonane, isononane, dodecane, and isododecane. Examples of the organic solvent include general organic solvents that do not fall under the category of organic solvent A, such as unsaturated hydrocarbons such as 1-hexene, 1-heptene, and 1-octene, saturated cyclic hydrocarbons such as cyclohexane, cycloheptane, cyclooctane, cyclodecane, and decalin, unsaturated cyclic hydrocarbons such as cyclohexene, cycloheptene, cyclooctene, 1,1,3,5,7-cyclooctatetraene, and cyclododecene, aromatic hydrocarbons such as benzene, toluene, and xylene, morpholines such as N-methylmorpholine, N-ethylmorpholine, and N-formylmorpholine, and terpene solvents. It is preferable to select a solvent with an appropriate HLB value depending on the resin and dispersant to be combined with it.

[0059] [Surfactant] The non-aqueous ink composition according to this embodiment contains a polysiloxane surfactant. A polysiloxane surfactant is a surfactant having a siloxane skeleton. By using an ink composition containing a predetermined amount of a polysiloxane surfactant together with organic solvent A, it is possible to obtain a recorded matter having excellent gloss and to effectively suppress bleeding of the print on the obtained recorded matter.

[0060] The reason for this is not entirely clear. Areas on the substrate (recording medium) where the non-aqueous ink composition is applied in a low amount dry faster than areas where the ink composition is applied in a high amount, so the concentration of the polysiloxane surfactant is temporarily increased locally in areas where the non-aqueous ink composition is applied in a low amount. This results in the polysiloxane surfactant in areas where the ink composition is applied in a low amount moving to areas where the ink composition is applied in a high amount. This is thought to reduce the fluidity of areas on the substrate (recording medium) where the non-aqueous ink composition is applied in a high amount toward areas where the ink composition is applied in a low amount, thereby suppressing bleeding of the print on the recorded material.

[0061] Furthermore, bleeding of the print may occur due to local differences in the surface tension of the non-aqueous ink composition on the substrate (recording medium), but it is thought that by incorporating a polysiloxane-based surfactant, it is possible to reduce the differences in the surface tension of the non-aqueous ink composition on the substrate (recording medium) and thereby suppress bleeding of the print in the recorded matter.

[0062] Furthermore, by including a polysiloxane surfactant, it is possible to suppress a decrease in glossiness due to the non-aqueous ink composition penetrating into the substrate, and also to impart slip properties to the resulting recorded matter.

[0063] Furthermore, as described above, the alkylamide solvent (a1) dries easily. Therefore, in the case of an ink composition containing the alkylamide solvent (a1), the drying property of the ink composition that has landed on a substrate (recording medium) can be improved, and bleeding of the print can be further suppressed.

[0064] The polysiloxane surfactant may be a modified polysiloxane surfactant. Examples of modified polysiloxane surfactants include polyether-modified, polyester-modified, aralkyl-modified, and polyacrylic-modified surfactants. Among these, it is preferable to use a polyester- and / or polyether-modified polydialkylsiloxane.

[0065] Examples of polyester- and / or polyether-modified polydialkylsiloxanes include those containing repeating units represented by the following formula (3) and the following formula (4).

[0066] (In formula (3), R ６ is an alkyl group having 1 to 3 carbon atoms, R ７ is an alkyl group having 1 to 15 carbon atoms.

[0067] (In formula (4), R ８ is an alkyl group having 1 to 3 carbon atoms, and X is a polyester modified group or a polyether modified group.

[0068] The polyester and / or polyether-modified polydialkylsiloxane may also be a co-modified compound containing an organic group such as an epoxy group, an amino group, or a (meth)acryloyl group.

[0069] Specific examples of polyester and / or polyether-modified polydialkylsiloxanes include FZ-2122, FZ-2110, FZ-7006, FZ-2166, FZ-2164, FZ-7001, FZ-2120, SH8400, FZ-7002, FZ-2104, 8029 ADDITIVE, 8032 ADDITIVE, 57 ADDITIVE, 67 ADDITIVE, and 8616 ADDITIVE (all of which are substituted by methyl methyl acrylate). , manufactured by Dow Corning Toray Co., Ltd.), KF-6012, KF-6015, KF-6004, KF-6013, KF-6011, KF-6043, KP-104, 110, 112, 323, 341 (all manufactured by Shin-Etsu Chemical Co., Ltd.), BYK-300 / 302, BYK-301, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315N, BYK-320, BYK-322, BYK-323, B YK-325, BYK-326, BYK-330, BYK-331, BYK-333, BYK-337, BYK-341, BYK-342, BYK-344, BYK-345 / 346, BYK-347, BY K-348, BYK-349, BYK-370, BYK-375, BYK-377, BYK-378, BYK-UV3500, BYK-3451, BYK-UV3510, BYK-3530, BYK-UV35 70, BYK-3455, BYK-Silclean 3700 (all manufactured by BYK-Chemie), Silface SAG503A, Silface SJM-002, Silface SJM-003 (all manufactured by Nissin Chemical Industry Co., Ltd.), TEGOTwin 4000, TEGOTwin 4100, TEGOWet 240, TEGOWet 250, TEGOWet 240 (all manufactured by Evonik).

[0070] The content of the polysiloxane surfactant is not particularly limited as long as it is in the range of 0.01% by mass or more and 2.0% by mass or less of the total amount of the non-aqueous ink composition, but the lower limit of the content of the polysiloxane surfactant is preferably 0.03% by mass or more, and more preferably 0.05% by mass or more, of the total amount of the non-aqueous ink composition, and the upper limit of the content of the polysiloxane surfactant is preferably 1.5% by mass or less, and more preferably 1.0% by mass or less.

[0071] The non-aqueous ink composition according to this embodiment may also contain a surfactant other than the surfactant having a siloxane skeleton. For example, polyoxyalkylene alkyl ethers such as Nonion P-208, P-210, P-213, E-202S, E-205S, E-215, K-204, K-220, S-207, S-215, A-10R, A-13P, NC-203, NC-207 (manufactured by Nippon Oil & Fats Co., Ltd.), Emulgen 106, 108, 707, 709, A-90, A-60 (manufactured by Kao Corporation), Floren G-70, D-90, TG-740W (manufactured by Kyoeisha Chemical Co., Ltd.), Poem J-0081HV (manufactured by Riken Vitamin Co., Ltd.), Adekatall NP-620, NP-650, NP-660, NP-675, NP-683, NP-6 86, ADEKACOL CS-141E, TS-230E (manufactured by ADEKA Corporation), SOLGEN 30V, 40, TW-20, TW-80, NOIGEN CX-100 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), etc. As the fluorine-based surfactant, it is preferable to use a fluorine-modified polymer, specific examples of which include BYK-340 (manufactured by BYK Japan), etc. As the acetylene glycol-based surfactant, specific examples include Surfynol (registered trademark) 82, 104, 465, 485, TG (all manufactured by Air Products Japan), Olfine (registered trademark) STG, E1010 (all manufactured by Nissin Chemical Industry Co., Ltd.), etc. The surfactant is not limited to the above, and any of anionic, cationic, amphoteric, or nonionic surfactants can be used.

[0072] [Resin] The non-aqueous ink composition according to this embodiment does not need to contain a resin, but may contain a resin. By containing a resin, the fixability, water resistance, and stretchability of the recording layer formed using the non-aqueous ink composition can be improved. Furthermore, the glossiness of the resulting recorded matter can be improved.

[0073] The resin is not particularly limited, but examples thereof include acrylic resins, polystyrene resins, polyester resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, polyethylene resins, polyurethane resins, rosin-modified resins, phenolic resins, terpene resins, polyamide resins, vinyltoluene-α-methylstyrene copolymers, ethylene-vinyl acetate copolymers, cellulose resins, silicone resins, acrylamide resins, epoxy resins, and copolymer resins or mixtures thereof. Among these, those containing acrylic resins, vinyl chloride-vinyl acetate copolymer resins, cellulose resins, polyester resins, or polyurethane resins are preferred.

[0074] The acrylic resin is not particularly limited as long as it contains a (meth)acrylic acid ester monomer as the main monomer component. The acrylic resin may be a homopolymer of one type of radically polymerizable monomer or a copolymer of two or more selected radically polymerizable monomers. In particular, a preferred acrylic resin for the non-aqueous ink composition according to this embodiment is a homopolymer of methyl methacrylate or a copolymer of methyl methacrylate and at least one compound selected from the group consisting of butyl methacrylate, ethoxyethyl methacrylate, and benzyl methacrylate. Examples of commercially available acrylic resins include Rohm and Haas's "Paraloid B99N," "Paraloid B60," "Paraloid B66," and "Paraloid B82."

[0075] The vinyl chloride resin may be either a homopolymer of vinyl chloride monomer or a copolymer using two or more selected polymerizable monomers. Examples of vinyl chloride resin copolymers include vinyl chloride-vinyl acetate copolymer resins. Vinyl chloride-vinyl acetate copolymer resins are polymers of vinyl chloride monomer and vinyl acetate monomer. Examples of vinyl chloride-vinyl acetate copolymer resins include vinyl chloride-vinyl acetate copolymer, vinyl chloride / vinyl acetate / maleic acid copolymer, vinyl chloride / vinyl acetate / vinyl alcohol copolymer, vinyl chloride / vinyl acetate / hydroxyalkyl acrylate copolymer, and mixtures thereof. Examples of the vinyl chloride-vinyl acetate copolymer resins are available from Nissin Chemical Industry Co., Ltd. under the trade names "Solvin C," "Solvin CL," "Solvin CNL," "Solvin CLL," "Solvin CLL2," "Solvin C5R," "Solvin TA2," "Solvin TA3," "Solvin A," "Solvin AL," "Solvin TA5R," and "Solvin M5," and can be used in the present invention.

[0076] Vinyl chloride-vinyl acetate copolymer resin can be obtained by polymerizing vinyl chloride monomer and vinyl acetate monomer. The polymerization method may be any conventionally known polymerization method. The polymerization method is preferably emulsion polymerization or suspension polymerization, and more preferably suspension polymerization.

[0077] A cellulose-based resin is a resin having a cellulose skeleton obtained by biologically or chemically introducing functional groups into cellulose as a raw material. Examples of cellulose-based resins include cellulose acetate alkylate resins such as cellulose acetate butyrate resin, cellulose acetate propionate resin, and cellulose acetate propionate butyrate resin, cellulose acetate resin, nitrocellulose resin, and mixtures thereof. The cellulose resins are available from EASTMAN under the trade names "CAB551-0.01", "CAB551-0.2", "CAB553-0.4", "CAB531-1", "CAB381-0.1", "CAB381-0.5", "CAB381-2", "CAB381-20", "CAP504", "CAP482-0.5", and the like.

[0078] The polyester resin contains at least a structural unit obtained by polycondensation of an alcohol component and a carboxylic acid component. The polyester resin may contain a modified polyester resin. Examples of the polyester resin include those available under the trade names "VYLON226," "VYLON270," "VYLON560," "VYLON600," "VYLON630," "VYLON660," "VYLON885," "VYLONGK250," "VYLONGK810," and "VYLON GK890" from Toyobo Co., Ltd., and those available under the trade names "eliteUE-3200," "eliteUE-3285," "eliteUE-3320," "eliteUE-9800," and "eliteUE-9885" from Unitika Co., Ltd.

[0079] The polyurethane resin contains at least a structural unit obtained by copolymerizing an alcohol component and an isocyanate component. The polyurethane resin may include a polyurethane resin modified with polyester, polyether, or caprolactone. Examples of the polyurethane resin include those available from Arakawa Chemical Industries, Ltd. under the trade names "Uriano KL-424," "Uriano KL-564," "Uriano KL-593," and "Uriano 3262," and those available from DIC Corporation under the trade names "Pandex 372E," "Pandex 390E," "Pandex 394E," "Pandex 304," "Pandex 305E," "Pandex P-870," "Pandex P-910," "Pandex P-895," "Pandex 4030," and "Pandex 4110."

[0080] Furthermore, these acrylic resins, vinyl chloride-vinyl acetate copolymer resins, cellulose resins, polyester resins, and polyurethane resins may be used alone, but it is preferable to use a mixture of two of them, and it is more preferable to use a resin mixture of an acrylic resin and a vinyl chloride-vinyl acetate copolymer resin. Depending on the content ratio of the acrylic resin and the vinyl chloride-vinyl acetate copolymer resin, it is possible to control so as to satisfy the requirements for the non-aqueous ink, such as color development, drying properties, coating film properties, and printability. When an acrylic resin and a vinyl chloride-vinyl acetate copolymer resin are mixed, the mixing ratio is not particularly limited and can be changed as appropriate.

[0081] The weight-average molecular weight (relative molecular mass) of the resin is not particularly limited, but the lower limit of the weight-average molecular weight (relative molecular mass) of the resin is preferably 15,000 or more, and more preferably 20,000 or more. A weight-average molecular weight (relative molecular mass) of the resin of 15,000 or more can improve the coating abrasion resistance of the recording layer (coating) of the resulting recorded matter. The upper limit of the weight-average molecular weight (relative molecular mass) is preferably 80,000 or less, and more preferably 50,000 or less. A weight-average molecular weight (relative molecular mass) of the resin of 80,000 or less can result in a recorded matter with superior gloss. The relative molecular weight of the resin can be measured by conventional GPC (gel permeation chromatography).

[0082] The resin contained in the non-aqueous ink composition is preferably contained in an amount of 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, based on the total amount of the non-aqueous ink composition. The resin contained in the non-aqueous ink composition is preferably contained in an amount of 20.0% by mass or less, more preferably 15.0% by mass or less, and even more preferably 10.0% by mass or less, based on the total amount of the non-aqueous ink composition.

[0083] [Colorant] The non-aqueous ink composition according to this embodiment may contain a colorant. The colorant is not particularly limited and may be a dye-based or pigment-based colorant. However, it is preferable to use a pigment (pigment-based colorant) from the viewpoint of providing good resistance to water resistance, light resistance, and the like of the recorded matter. The pigment that can be used in the non-aqueous ink composition according to this embodiment is not particularly limited, and examples thereof include organic pigments and inorganic pigments that are used in conventional ink compositions. These may be used alone or in combination of two or more types. It is noted that the non-aqueous ink composition according to this embodiment does not necessarily contain a colorant.

[0084] When a pigment is used in the non-aqueous ink composition according to this embodiment, the dispersion stability of the pigment can be improved by using a dispersant or a dispersion aid (pigment derivative) described below.

[0085] Specific examples of organic pigments include insoluble azo pigments, soluble azo pigments, dye derivatives, phthalocyanine organic pigments, quinacridone organic pigments, perylene organic pigments, perinone organic pigments, azomethine organic pigments, anthraquinone organic pigments (anthrone organic pigments), xanthene organic pigments, diketopyrrolopyrrole organic pigments, dioxazine organic pigments, nickel azo pigments, isoindolinone organic pigments, pyranthrone organic pigments, thioindigo organic pigments, condensed azo organic pigments, benzimidazolone organic pigments, quinophthalone organic pigments, isoindoline organic pigments, quinacridone solid solution pigments, and organic solid solution pigments such as perylene solid solution pigments. Other pigments include lake pigments and carbon black.

[0086] Examples of organic pigments by Color Index (C.I.) number include C.I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 20, 24, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 117, 120, 125, 128, 129, 130, 137, 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 180, 185, 213, 214, C.I. C.I. Pigment Red 5, 7, 9, 12, 48, 49, 52, 53, 57:1, 97, 112, 122, 123, 146, 149, 150, 168, 177, 180, 184, 192, 202, 206, 208, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 254, 255, 269, 291, C.I. Pigment Orange 16, 36, 43, 51, 55, 59, 61, 64, 71, 73, C.I. Pigment Violet 19, 23, 29, 30, 37, 40, 50, C.I. Examples of suitable pigments include C.I. Pigment Blue 15, 15:1, 15:3, 15:4, 15:6, 16, 22, 60, 64, C.I. Pigment Green 7, 36, 58, 59, 62, 63, C.I. Pigment Brown 23, 25, 26, C.I. Pigment Black 7, and the like.

[0087] Specific examples of dyes that can be used in the non-aqueous ink composition according to this embodiment include azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, cyanine dyes, squarylium dyes, croconium dyes, merocyanine dyes, stilbene dyes, diarylmethane dyes, triarylmethane dyes, fluoran dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes such as indigoids, fulgide dyes, nickel complex dyes, and azulene dyes.

[0088] Specific examples of inorganic pigments that can be used in the non-aqueous ink composition according to this embodiment include titanium oxide, barium sulfate, calcium carbonate, zinc oxide, barium carbonate, silica, talc, clay, synthetic mica, alumina, zinc white, lead sulfate, yellow lead, zinc yellow, red iron oxide (red iron (III) oxide), cadmium red, ultramarine, Prussian blue, chromium oxide green, cobalt green, umber, titanium black, aluminum, titanium, indium, synthetic iron black, and inorganic solid solution pigments.

[0089] In the non-aqueous ink composition according to this embodiment, the average dispersed particle size of the pigment that can be contained is not particularly limited as long as it can produce the desired color. While this varies depending on the type of pigment used, in order to obtain good pigment dispersibility and dispersion stability and sufficient coloring power, the volume average particle size is preferably 5 nm or more, more preferably 20 nm or more, and even more preferably 30 nm or more. Having a volume average particle size equal to or greater than the above-mentioned lower limit can improve the lightfastness of the non-aqueous ink composition. Having a volume average particle size equal to or less than 300 nm, more preferably 200 nm or less, and even more preferably 150 nm or less. Having a volume average particle size equal to or less than the above-mentioned upper limit can improve the inkjet ejection stability when the non-aqueous ink composition is an inkjet ink composition that is ejected onto the surface of a substrate by an inkjet method. In this embodiment, the volume average particle size of the pigment is the volume-based cumulative 50% particle size (D50) measured at 25°C using a particle size distribution measuring device (NANOTRACWAVE particle size analyzer manufactured by Microtrackbell Corporation). In this specification, the term "volume-based cumulative 50% particle diameter (D50)" refers to the particle diameter at which the cumulative volume calculated from the smallest diameter side is 50%. The "volume-based cumulative 50% particle diameter (D50)" may also be referred to as the "volume average particle diameter D50" or the "median diameter."

[0090] Furthermore, in an ink set including a plurality of non-aqueous ink compositions according to this embodiment, the volume average particle diameters of the pigments included in the respective non-aqueous ink compositions may be the same or may have different relationships. For example, in an ink set including a cyan ink and a magenta ink, which are non-aqueous ink compositions according to this embodiment, the volume average particle diameter of the pigment included in the cyan ink and the volume average particle diameter of the pigment included in the magenta ink may be the same or may be different.

[0091] In the non-aqueous ink composition according to this embodiment, the pigment content is not particularly limited as long as the desired image can be formed, and can be adjusted as appropriate. Specifically, although this varies depending on the type of pigment, it is preferably in the range of 0.05% by mass or more, and more preferably 0.1% by mass or more, of the total amount of the non-aqueous ink composition. It is preferably in the range of 20% by mass or less, and more preferably 10% by mass or less, of the total amount of the non-aqueous ink composition. By having the pigment content in the range of 0.05% by mass or more or 20% by mass or less, an excellent balance between the dispersion stability and coloring power of the pigment can be achieved.

[0092] Furthermore, the non-aqueous ink composition according to this embodiment is not particularly limited in the color to be recorded (printed), and coloring materials may be selected and combined according to the intended color. Colors include inks of various colors such as yellow, magenta, cyan, and black, as well as light magenta, light cyan, light black, orange, green, red, and white. In this case, coloring materials of the same color may be selected in an ink set containing the non-aqueous ink composition according to this embodiment.

[0093] [Dispersant] A dispersant may be used in the non-aqueous ink composition according to this embodiment, if necessary. Any dispersant used in non-aqueous ink compositions may be used as the dispersant. A polymer dispersant is preferably used as the dispersant. Such dispersants have a main chain made of a polyester, polyacrylic, polyurethane, polyamine, polycaprolactone, or the like, and have polar groups such as amino groups, carboxyl groups, sulfone groups, or hydroxyl groups as side chains. Examples of polyacrylic dispersants include Disperbyk-2000, 2001, 2008, 2009, 2010, 2020, 2020N, ​​2022, 2025, 2050, 2070, 2095, 2150, 2151, 2155, 2163, 2164, BYKJET-9130, 9131, 9132, 9133, 9151 (manufactured by BYK-Chemie), EfkaPX4310, PX4320, PX4330, PA4401, 4402, PA4403, 4570, 7411, 7477, PX4700, PX4701 (manufactured by BASF), and TREPLUS D-1200, D-1410, D-1420, MD-1000 (manufactured by Otsuka Chemical Co., Ltd.), FLOWRENE DOPA-15BHFS, 17HF, 22, G-700, 900, NC-500, GW-1500 (manufactured by Kyoeisha Chemical Co., Ltd.), and the like can be used. Examples of polycaprolactone-based dispersants include Ajisper PB821, PB822, and PB881 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), Hinoact KF-1000, T-6000, T-7000, T-8000, T-8000E, and T-9050 (manufactured by Kawaken Fine Chemicals Co., Ltd.), Solsperse 20000, 24000, 32000, 32500, 32550, 32600, 33000, 33500, 34000, 35200, 36000, 37500, 39000, 71000, 76400, 76500, 86000, 88000, J180, and J200 (manufactured by Lubrizol Corporation), and TEGO Dispers 652, 655, 685, 688, 690 (manufactured by Evonik Japan Co., Ltd.), etc. are used.Preferred dispersants include BYKJET-9130, 9131, 9132, 9133, 9151, Efka PX4310, PX4320, PX4330, PX4700, PX4701, Solsperse 20000, 24000, 32000, 33000, 33500, 34000, 35200, 39000, 71000, 76500, 86000, 88000, J180, J200, and TEGO Dispers 655, 685, 688, and 690. These can be used alone or in combination.

[0094] The content of the dispersant is not particularly limited, but the lower limit of the content of the dispersant is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 0.8% by mass or more, based on the total amount of the non-aqueous ink composition. The content of the dispersant is not particularly limited, but the lower limit of the content of the dispersant is preferably 5.0% by mass or more, more preferably 4.0% by mass or more, and even more preferably 3.0% by mass or more, based on the total amount of the non-aqueous ink composition.

[0095] [Dispersion Aid] A dispersion aid may be used in the non-aqueous ink composition according to this embodiment, if necessary. The dispersion aid adsorbs to the surface of the colorant (pigment), and the functional group enhances the affinity with the organic solvent and dispersant in the non-aqueous ink composition, thereby improving dispersion stability. As the dispersion aid, a known pigment derivative having a functional group such as an acidic group, a basic group, or a neutral group in the organic pigment residue can be used.

[0096] [Other Components] The non-aqueous ink composition according to this embodiment may optionally contain known additives such as stabilizers, such as antioxidants and UV absorbers, epoxidized compounds, polycarboxylic acids, surface conditioners, slip agents, leveling agents (acrylic, silicone, etc.), antifoaming agents, pH adjusters, disinfectants, preservatives, deodorizers, charge control agents, and wetting agents. Specific examples of antioxidants include hindered phenol-based antioxidants, amine-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, and hydrazine-based antioxidants. Specific examples include BHA (2,3-butyl-4-oxyanisole) and BHT (2,6-di-t-butyl-p-cresol). Furthermore, benzophenone-based compounds or benzotriazole-based compounds can be used as UV absorbers. Specific examples of the epoxidized product include epoxy glyceride, epoxy fatty acid monoester, and epoxy hexahydrophthalate, and specific examples include Adeka Cizer O-130P and Adeka Cizer O-180A (manufactured by ADEKA Corporation).Specific examples of the polycarboxylic acid include citric acid and maleic acid.

[0097] 2-2. Aqueous Ink Composition As another embodiment of the present invention (hereinafter referred to as "this embodiment"), an aqueous ink composition will be described as an example of the present invention. The aqueous ink composition is characterized by containing water and an organic solvent, the organic solvent containing organic solvent A, and further containing a polysiloxane surfactant in a range of 0.01% by mass or more and 2.0% by mass or less of the total amount of the non-aqueous ink composition.

[0098] [Organic Solvent] The organic solvent contains an organic solvent A. As the organic solvent A (at least one selected from the group consisting of alkylamide solvents (a1) and cyclic amide solvents (a2)), those contained in the non-aqueous ink composition described above can be used.

[0099] The content of the alkylamide solvent (a1) is not particularly limited, but the lower limit of the content of the alkylamide solvent (a1) is preferably 0.1 mass % or more, more preferably 1.0 mass % or more, and even more preferably 3.0 mass % or more, of the total amount of the non-aqueous ink composition.

[0100] The upper limit of the content of the alkylamide solvent (a1) is preferably 40.0 mass % or less, more preferably 35.0 mass % or less, and even more preferably 30.0 mass % or less, of the total amount of the non-aqueous ink composition.

[0101] The content of the cyclic amide solvent (a2) is not particularly limited, but the lower limit of the content of the cyclic amide solvent (a2) is preferably 0.1 mass % or more, more preferably 1.0 mass % or more, and even more preferably 3.0 mass % or more, of the total amount of the non-aqueous ink composition.

[0102] The upper limit of the content of the cyclic amide solvent (a2) is preferably 40.0 mass % or less, more preferably 35.0 mass % or less, and even more preferably 30.0 mass % or less, of the total amount of the non-aqueous ink composition.

[0103] The organic solvent A sufficiently exhibits the effects of the present invention when it contains at least one of an alkylamide solvent (a1) and a cyclic amide solvent (a2), but two or more of the organic solvents A may also be mixed. By mixing two or more, it is possible to achieve any balance between the glossiness of the resulting recorded material and the effect of suppressing print bleeding. When two or more organic solvents A are mixed, the lower limit of the total content of the organic solvents A is preferably 1.0% by mass or more, more preferably 3.0% by mass or more, and even more preferably 5.0% by mass or more, of the total amount of the non-aqueous ink composition. The upper limit of the total content of the organic solvents A is preferably 30.0% by mass or less, of the total amount of the non-aqueous ink composition.

[0104] The organic solvent may contain other organic solvents. As the other organic solvent, a water-soluble organic solvent can be used. The water-soluble organic solvent is preferably soluble in 100 parts by mass of water at 25°C at 1 atmosphere at 50 parts by mass or more. The water-soluble organic solvent is more preferably soluble in 100 parts by mass of water at 25°C at 1 atmosphere at 70 parts by mass or more, and even more preferably soluble in 100 parts by mass of water at 25°C at 1 atmosphere at 90 parts by mass or more.

[0105] Examples of such water-soluble organic solvents include alkyl alcohols having 1 to 5 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, and n-pentanol; monohydric alcohols, such as 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-propanol, 1-methoxy-2-propanol, and 3-methoxy-n-butanol; amides, such as 1-dimethylformamide, dimethylacetamide, 3-methoxypropanamide, 3-butoxypropanamide, N,N-dimethyl-3-methoxypropanamide, N,N-dibutyl-3-methoxypropanamide, N,N-dibutyl-3-butoxypropanamide, and N,N-dimethyl-3-butoxypropanamide; ketones or ketoalcohols, such as acetone and diacetone alcohol; ethers, such as tetrahydrofuran and dioxane; polyethylene glycol, polypropylene glycol, and the like. oxyethylene or oxypropylene copolymers such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-propanediol, isobutylene glycol, triethylene glycol, tripropylene glycol, tetraethylene glycol, 1,3-propanediol, 2-methyl-1,2-propanediol, 2-methyl-1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol diols such as 1,2-pentanediol, 1,2-hexanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol, and 2-methyl-2,4-pentanediol; triols such as glycerin, trimethylolethane, trimethylolpropane, and 1,2,6-hexanetriol; tetrahydric alcohols such as mesoerythritol and pentaerythritol;Monoalkyl ethers such as ethylene glycol monomethyl (or ethyl, isopropyl, n-butyl, isobutyl, n-hexyl, 2-ethylhexyl) ether, diethylene glycol monomethyl (or ethyl, isopropyl, n-butyl, isobutyl, n-hexyl, 2-ethylhexyl) ether, triethylene glycol monomethyl (or ethyl, isopropyl, n-butyl, isobutyl) ether, propylene glycol monomethyl (or ethyl, isopropyl, n-butyl, isobutyl) ether, dipropylene glycol monomethyl (or ethyl, isopropyl, n-butyl, isobutyl) ether; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol Examples of the dialkyl ethers of polyhydric alcohols include ethanol diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, and dipropylene glycol diethyl ether; alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, and N-butyldiethanolamine; nitrogen-containing heterocyclic compounds such as N-methyl-2-pyrrolidone, 2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone; and cyclic compounds such as γ-butyrolactone and sulfolane.

[0106] [Water] The aqueous ink composition according to this embodiment may contain water. It is preferable to use deionized water as the water, rather than water containing various ions. The amount of water contained is not particularly limited as long as it can disperse or dissolve each component.

[0107] [Surfactant] The aqueous ink composition according to this embodiment contains a polysiloxane surfactant. The polysiloxane surfactant may be the same as that contained in the non-aqueous ink composition.

[0108] The content of the polysiloxane surfactant is not particularly limited as long as it is in the range of 0.01% by mass or more and 2.0% by mass or less of the total amount of the aqueous ink composition, but the lower limit of the content of the polysiloxane surfactant is preferably 0.03% by mass or more, and more preferably 0.05% by mass or more, of the total amount of the aqueous ink composition, and the upper limit of the content of the polysiloxane surfactant is preferably 1.5% by mass or less, and more preferably 1.0% by mass or less, of the total amount of the aqueous ink composition.

[0109] The aqueous ink composition according to this embodiment may also contain a surfactant other than the surfactant having a siloxane skeleton, such as an anionic surfactant, a nonionic surfactant, a fluorine-based surfactant, an alkylene oxide-modified acetylene glycol-based surfactant, or an alkylene oxide-unmodified acetylene glycol-based surfactant.

[0110] [Resin] The aqueous ink composition according to this embodiment may contain a resin. As the resin, a resin emulsion is preferred because it provides excellent fixation and water resistance of printed matter. Furthermore, by forming a resin emulsion, the resin can be dispersed in the ink composition as resin fine particles due to electrostatic repulsion and steric repulsion.

[0111] Specifically, acrylic resin, polystyrene resin, polyester resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, polyethylene resin, urethane resin, silicone resin, acrylamide resin, epoxy resin, or copolymer resin or mixture thereof can be used. These are preferred because they can improve not only water resistance but also solvent resistance. Among them, those containing acrylic resin are preferred because they can provide excellent discharge stability, water resistance, and solvent resistance.

[0112] The acrylic resin is not particularly limited as long as it contains a (meth)acrylic acid ester monomer as the main component of the monomer constituting the (meth)acrylic acid ester. Known compounds can be used as the (meth)acrylic acid ester monomer, and monofunctional (meth)acrylic acid esters are preferably used. Examples thereof include (meth)acrylic acid alkyl esters, (meth)acrylic acid aralkyl esters, and (meth)acrylic acid alkoxyalkyl esters. Specific examples include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, neopentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, and dicyclopentanyl (meth)acrylate. Dicyclopentenyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclohexyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, allyl (meth)acrylate, propargyl (meth)acrylate, phenyl (meth)acrylate, naphthyl (meth)acrylate, anthracenyl (meth)acrylate, anthraninonyl (meth)acrylate, piperonyl (meth)acrylate, salicylic (meth)acrylate, furyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, pyranyl (meth)acrylate, benzyl (meth)acrylate, phenethyl (meth)acrylate, cresyl (meth)acrylate, glycidyl (meth)acrylate, (meth)acrylic acid-3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxycyclohexylethyl (meth)acrylate, 1,1,1-trifluoroethyl (meth)acrylate, perfluoroethyl (meth)acrylate, perfluoro-n-propyl (meth)acrylate, perfluoro-isopropyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, triphenylmethyl (meth)acrylate, cumyl (meth)acrylate, 3-(N,N-dimethylamino)propyl (meth)acrylate, ) (meth)acrylic acid esters such as methoxyethyl acrylate, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, 2-cyanoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, trimethoxysilylpropyl (meth)acrylate, triethoxysilylpropyl (meth)acrylate, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropylmethyldimethoxysilane.

[0113] The monomers constituting the acrylic resin may include an acid group-containing monomer having an acid group, a hydroxyl group-containing monomer having a hydroxyl group, and an amino group-containing monomer having an amino group. Examples of the acid group-containing monomer having an acid group include carboxyl group-containing monomers having an ethylenically unsaturated double bond and a carboxyl group, such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, crotonic acid, citraconic acid, maleic anhydride, maleic acid monomethyl ester, maleic acid monobutyl ester, itaconic acid monomethyl ester, itaconic acid monobutyl ester, vinylbenzoic acid, oxalic acid monohydroxyethyl (meth)acrylate, and carboxyl group-terminated caprolactone-modified (meth)acrylate. The hydroxyl group-containing monomer containing a hydroxyl group is not particularly limited as long as it has an unsaturated double bond and a hydroxyl group, and examples thereof include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, caprolactone-modified hydroxy(meth)acrylate, methyl α-(hydroxymethyl)(meth)acrylate, ethyl α-(hydroxymethyl)(meth)acrylate, n-butyl α-(hydroxymethyl)(meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, and 4-hydroxybutyl (meth)acrylate.The amino group-containing monomer is not particularly limited as long as it has an unsaturated double bond and an amino group, and examples thereof include (meth)acrylamide N-monomethyl(meth)acrylamide, N-monoethyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-n-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, methylenebis(meth)acrylamide, N-methylol(meth)acrylamide, N-butoxymethyl(meth)acrylamide, dimethylaminoethyl(meth)acrylamide, Examples of the vinyl monomer include acrylamide compounds such as N,N-dimethylaminopropylacrylamide and diacetoneacrylamide; nitrogen atom-containing (meth)acrylate compounds such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate and ethylene oxide adduct (meth)acrylate of morpholine; N-vinylpyrrolidone, N-vinylpyridine, N-vinylimidazole, N-vinylpyrrole, N-vinyloxazolidone, N-vinylsuccinimide, N-vinylmethylcarbamate, N,N-methylvinylacetamide, (meth)acryloyloxyethyltrimethylammonium chloride, 2-isopropenyl-2-oxazoline, 2-vinyl-2-oxazoline, and (meth)acrylonitrile.

[0114] Furthermore, the monomers constituting the acrylic resin may contain other monomers as needed in addition to the (meth)acrylic acid ester monomers. Such other monomers are not particularly limited as long as they are copolymerizable with the (meth)acrylic acid ester monomers and can provide the desired water resistance and solvent resistance. They may be monofunctional monomers having one ethylenically unsaturated double bond or polyfunctional monomers having two or more ethylenically unsaturated double bonds. For example, vinyl monomers such as vinyl acetate, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, N-vinylpyrrolidone, vinylpyridine, N-vinylcarbazole, vinylimidazole, vinyl ether, vinyl ketone, and vinylpyrrolidone; aromatic vinyl monomers such as styrene, α-, o-, m-, and p-alkyl, nitro, cyano, amide, and ester derivatives of styrene, vinyltoluene, and chlorostyrene; olefin monomers such as ethylene, propylene, and isopropylene; diene monomers such as butadiene and chloroprene; and vinyl cyanide compound monomers such as acrylonitrile and methacrylonitrile. Other examples that can be used include diacrylate compounds such as polyethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3-butylene glycol diacrylate; triacrylate compounds such as trimethylolpropane triacrylate, trimethylolethane triacrylate, and tetramethylolmethane triacrylate; dimethacrylate compounds such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and triethylene glycol dimethacrylate; trimethacrylate compounds such as trimethylolpropane trimethacrylate and trimethylolethane trimethacrylate; and divinylbenzene. Acrylic resins can be formed using these monomers, but the form of copolymerization of the monomers is not particularly limited and can be, for example, a block copolymer, a random copolymer, a graft copolymer, or the like. Resin emulsions can be produced, for example, by emulsion polymerization followed by neutralization after the reaction.As the emulsifier, a conventional polymer surfactant may be used, or a reactive surfactant having an unsaturated bond may be used. The synthesis method is not particularly limited, but for example, emulsion polymerization can be performed by mixing water, a monomer, an emulsifier, and a polymerization initiator in the presence of a reactive surfactant, a non-reactive surfactant, polyvinyl alcohol, a cellulose derivative, etc. Alternatively, the resin emulsion can be obtained by mixing resin fine particles with water together with a surfactant without performing an emulsion polymerization reaction. For example, the resin emulsion can be obtained by adding and mixing resin fine particles composed of a (meth)acrylic acid ester or styrene and a (meth)acrylic acid ester, and a surfactant, into water.

[0115] Examples of commercially available resin emulsions include ACRYL WEM-031U, WEM-200U, WEM-321, WEM-3000, WEM-202U, and WEM-3008 (acrylic-urethane resin emulsions manufactured by Taisei Fine Chemical Co., Ltd.), ACRYL UW-550CS, UW-223SX, AKW107, and RKW-500 (acrylic resin emulsions manufactured by Taisei Fine Chemical Co., Ltd.), and LUBRIJET N240 (manufactured by Lubrizol, acrylic resin emulsion), Superflex 150, 210, 470, 500M, 620, 650, E2000, E4800, R5002 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., urethane resin emulsion), Vinyblanc 701FE35, 701FE50, 701FE65, 700, 701, 711, 737, 747 (manufactured by Nissin Chemical Industry Co., Ltd., vinyl chloride-acrylic resin emulsion), Vinyblanc 2706, 2685 (manufactured by Nissin Chemical Industry Co., Ltd., acrylic resin emulsion), Movinyl 743N, 6600, 7470, 7720 (manufactured by Japan Coating Resins Co., Ltd., acrylic resin emulsion), PRIMAL AC-261P, AC-818 (manufactured by The Dow Chemical Company) Acrylic resin particle emulsion) and the like can be exemplified, but are not limited to these.

[0116] The content of the resin (resin emulsion) contained in the aqueous ink composition according to this embodiment is not particularly limited, but the lower limit of the resin content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, and more preferably 2.0% by mass or more, of the total amount of the aqueous ink. The upper limit of the resin content is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, of the total amount of the aqueous ink.

[0117] From the viewpoints of dispersion stability in the ink composition and ejection stability during inkjet ejection, the average particle diameter of the resin emulsion is preferably 30 nm or more, more preferably 40 nm or more, and even more preferably 50 nm or more. From the viewpoints of dispersion stability in the ink composition and ejection stability during inkjet ejection, the average particle diameter of the resin emulsion is preferably 300 nm or less, more preferably 270 nm or less, and even more preferably 250 nm or less. In this embodiment, the number average particle diameter of the pigment can be measured at a measurement temperature of 25°C using a concentrated particle size analyzer (manufactured by Otsuka Electronics Co., Ltd., model: FPAR-1000).

[0118] [Colorant] The aqueous ink composition according to this embodiment may contain a colorant. The colorant may be one contained in the non-aqueous ink composition described above. The colorant is not particularly limited and may be either a dye-based or pigment-based colorant. However, it is preferable to use a pigment (pigment-based colorant) from the viewpoint of providing good resistance to water and light in the recorded material. The pigment may be a pigment dispersion in which the pigment is dispersed in an aqueous solvent using a pigment dispersant, or a self-dispersing pigment in which hydrophilic groups are directly modified on the pigment surface. In this embodiment, the pigment that can be used in the inkjet recording ink may be a combination of two or more of the organic pigments or inorganic pigments described above, or may be a combination of a pigment dispersion dispersed in an aqueous solvent using the pigment dispersant described above and a self-dispersing pigment described below.

[0119] Examples of self-dispersing pigments include those modified with a hydrophilic group such as a carbonyl group, a carboxyl group, a hydroxyl group, a sulfonic acid group, or a phosphorus-containing group. Commercially available products include, for example, CAB-O-JET200, CAB-O-JET250C, CAB-O-JET260M, CAB-O-JET270Y, CAB-O-JET740Y, CAB-O-JET300, CAB-O-JET400, CAB-O-JET450C, CAB-O-JET465M, CAB-O-JET470Y, CAB-O-JET480V, CAB-O-JET352K, CAB-O-JET554B, and CAB-O-JET1027R manufactured by Cabot Corporation; Co., Ltd., "Microjetblack162, Aqua-Black001, BONJETBLACKCW-1, BONJETBLACKCW-2, BONJETBLACKCW-3," Tokai Carbon Co., Ltd., "Aqua-Black162, Aqua-Black001," Toyo Ink Mfg. Co., Ltd., LIOJETWDBLACK002C, Sanyo Dye Co., Ltd., "SFColor," Fuji SPColor, Clariant, and "Hostajet."

[0120] In the aqueous ink composition according to this embodiment, the pigment content is not particularly limited as long as the desired image can be formed, and can be adjusted as appropriate. Specifically, although this varies depending on the type of pigment, it is preferably in the range of 0.05% by mass or more, and more preferably 0.1% by mass or more, of the total amount of the aqueous ink composition. It is preferably in the range of 20% by mass or less, and more preferably 10% by mass or less, of the total amount of the aqueous ink composition. By having the pigment content in the range of 0.05% by mass or more or 20% by mass or less, an excellent balance between the dispersion stability and coloring power of the pigment can be achieved.

[0121] [Pigment Dispersant] The aqueous ink composition according to this embodiment may contain a pigment dispersant. Here, the pigment dispersant refers to a resin or surfactant that has the function of improving the dispersibility of the pigment in the ink by adhering to part of the pigment surface.

[0122] There are no particular restrictions on the pigment dispersant that can be used in the aqueous ink composition according to this embodiment. For example, cationic, anionic, nonionic, amphoteric, silicone (silicon), fluorine-based surfactants, and the like can be used. Among surfactants, polymer surfactants (polymer dispersants) such as those exemplified below are preferred.

[0123] The pigment dispersant that can be preferably used in the aqueous ink composition according to this embodiment is a water-soluble polymer dispersant, such as a polyester-based, polyacrylic-based, polyurethane-based, polyamine-based, or polycaprolactone-based dispersant having a main chain and a polar group such as an amino group, a carboxy group, a sulfo group, or a hydroxy group on the side chain. Examples of such dispersants include (co)polymers of unsaturated carboxylic acid esters such as polyacrylic acid esters; copolymers of aromatic vinyl compounds such as styrene and α-methylstyrene with unsaturated carboxylic acid esters such as acrylic acid esters; (partial) amine salts, (partial) ammonium salts, and (partial) alkylamine salts of (co)polymers of unsaturated carboxylic acids such as polyacrylic acid; (co)polymers of hydroxyl group-containing unsaturated carboxylic acid esters such as hydroxyl group-containing polyacrylic acid esters and modified products thereof; polyurethanes; unsaturated polyamides; polysiloxanes; long-chain polyaminoamidophosphate salts; polyethyleneimine derivatives (amides obtained by reacting poly(lower alkyleneimine) with polyesters containing free carboxyl groups or bases thereof); polyallylamine derivatives (reaction products obtained by reacting polyallylamine with one or more compounds selected from the three types of compounds: polyesters having free carboxyl groups, polyamides, or co-condensates of esters and amides (polyesteramides)). Among these, water-soluble polymer dispersants containing a (meth)acrylic resin are preferred from the viewpoints of ink dispersion stability and image clarity of printed matter.

[0124] Specific examples of water-soluble polymer dispersants include SMA1440, SMA2625, SMA17352, SMA3840, SMA1000, SMA2000, and SMA3000 manufactured by SARTOMER Corporation; JONCRYL67, JONCRYL678, JONCRYL586, JONCRYL611, JONCRYL680, JONCRYL682, JONCRYL690, JONCRYL819, JONCRYL-JDX5050, EFKA4550, EFKA4560, EFKA4585, EFKA5220, and EFKA6230 manufactured by BASF Japan Ltd.; and SOLSPERSE20 manufactured by The Lubrizol Corporation. 000, SOLSPERSE 27000, SOLSPERSE 41000, SOLSPERSE 41090, SOLSPERSE 43000, SOLSPERSE 44000, SOLSPERSE 46000, SOLSPERSE 47000, SOLSPERSE 54000, and BYK-Chemie BYKJET-9150, BYKJET-9151, BYKJET-9170, DISPERBYK-168, DISPERBYK-190, DISPERBYK-198, DISPERBYK-2010, DISPERBYK-2012, DISPERBYK-2015, and the like.

[0125] In the aqueous ink composition according to this embodiment, the pigment that can be used may be a pigment dispersion in which a pigment is dispersed in an aqueous solvent using a pigment dispersant, or a pigment dispersion in which a hydrophilic group is directly modified on the surface of the pigment to form a self-dispersing pigment. In this embodiment, the pigment that can be used in the aqueous ink composition may be a combination of two or more of the organic pigments or inorganic pigments described above, or may be a combination of a pigment dispersion dispersed in an aqueous solvent using the pigment dispersant described above and a self-dispersing pigment described below.

[0126] [Other Components] The aqueous ink composition according to this embodiment may further contain other components as needed, as long as the effects of the present disclosure are not impaired. Examples of other components include antioxidants, pigments, resins, and defoaming agents.

[0127] 3. Method for Producing Ink Composition The ink composition according to this embodiment can be produced by mixing organic solvent A, a polysiloxane surfactant, and various components (e.g., resin, colorant, etc.) using a paint shaker. At this time, the components may be dispersed using zirconia beads. If necessary, a dispersion in which a colorant is dispersed in a specific solvent may be prepared, and then other components may be added to prepare the ink composition. If necessary, the non-aqueous ink composition according to this embodiment may be subjected to a degassing treatment or the like to adjust the dissolved oxygen and nitrogen contents to the desired levels.

[0128] Furthermore, when producing a non-aqueous ink composition, it is preferable to dry the organic solvent in advance. By drying the organic solvent in advance, the amount of water contained in the non-aqueous ink composition can be reduced. Examples of methods for drying the organic solvent include a method of spraying an inert gas (e.g., nitrogen gas) dried under an inert gas atmosphere such as nitrogen for a predetermined period of time, a method of purifying the organic solvent by distillation, a method of passing the organic solvent through a semi-permeable membrane that selectively allows water to pass through, and a method of selectively adsorbing water mixed in the organic solvent onto a water adsorbent that adsorbs water.

[0129]

[0043] The ink set according to the present embodiment is an ink set that includes the ink composition described above. The ink composition can provide a recorded matter with excellent glossiness and can effectively suppress bleeding of the print in the resulting recorded matter. The ink set according to the present embodiment also suppresses bleeding of the print and can provide a recorded matter that exhibits excellent glossiness.

[0130]

[0033] In particular, when an ink composition is applied on top of a wet ink composition, the amount of ink composition applied on the substrate (recording medium) inevitably increases, making bleeding more likely to occur. For this reason, the problems of the present invention are particularly likely to occur with ink sets that include a plurality of ink compositions, and among these, the problems of the present invention are particularly pronounced with, for example, ink sets that include a plurality of colored ink compositions that are ejected by an inkjet method to form a desired image (or ink sets that include colored ink compositions, and that also include a white ink composition that contains a white colorant, an ink composition that contains a glitter pigment, and a clear ink composition that does not contain a colorant, as well as ink sets that further include a primer agent, an overcoat agent, a receiving solution, etc.).

[0131] An ink set containing an ink composition containing an organic solvent A (at least one selected from the group consisting of alkylamide solvents (a1) and cyclic amide solvents (a2)) and a polysiloxane surfactant in an amount of 0.01 mass % or more and 2.0 mass % or less relative to the total amount of the ink composition can effectively suppress bleeding in printing that occurs when multiple ink compositions are used.

[0132]

[0043] Note that by applying a further ink composition onto the wet ink composition that has been applied to the substrate, the organic solvent A and the polysiloxane surfactant will inevitably be contained in the mixture of ink compositions that has been applied to the substrate. Thus, the ink set according to this embodiment will achieve the effects of the present invention if it contains at least one ink composition that contains a predetermined amount of polysiloxane surfactant together with organic solvent A. Among these, it is preferable to include at least two or more ink compositions that contain a predetermined amount of polysiloxane surfactant together with organic solvent A, and it is even more preferable that all of the ink compositions included in the ink set contain a predetermined amount of polysiloxane surfactant together with organic solvent A.

[0133] In order to obtain an ink set that achieves the effects of the present invention, the proportion of the above-mentioned ink composition (an ink composition that contains organic solvent A and a polysiloxane-based surfactant in an amount ranging from 0.01% by mass to 2.0% by mass of the total amount of the ink composition) in the mixture of ink compositions on the substrate is preferably 25% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more.

[0134] Examples of ink compositions contained in the ink set according to this embodiment include black ink compositions containing a black pigment, white ink compositions containing a white pigment, colored ink compositions such as yellow, magenta, cyan, light magenta, light cyan, light black, orange, green, and red, glitter ink compositions containing glitter pigments, and clear ink compositions that do not contain coloring materials.

[0135] The ink set according to the present embodiment is not limited to a usage form in which an ink composition is applied on top of a wet ink composition, but may also be used in a usage form in which, for example, the ink composition on a substrate (recording medium) is dried, and then a further ink composition is applied on top of the dried ink composition.

[0136]

[0042] 5. Recording method using ink composition The recording method according to this embodiment is a recording method in which the ink composition described above is applied to the surface of a substrate. The ink composition described above can provide a recorded matter having excellent glossiness and can effectively suppress bleeding of the print in the obtained recorded matter. The recording method according to this embodiment also suppresses bleeding of the print and can provide a recorded matter having excellent glossiness.

[0137] The method for applying the ink composition to the surface of a substrate is not particularly limited, and examples thereof include inkjet printing, gravure printing, flexography, spray printing, screen printing, and coater printing. Among these, inkjet printing is preferred. With the inkjet printing, a desired image can be formed by ejecting the desired image electronically onto any location on the substrate. In particular, when recording at high speed using the inkjet printing, additional ink composition may be ejected onto an undried ink composition, making the print more susceptible to bleeding. An ink composition containing an organic solvent A (at least one selected from the group consisting of alkylamide solvents (a1) and cyclic amide solvents (a2)) and a polysiloxane surfactant in an amount of 0.01% by mass or more and 2.0% by mass or less based on the total amount of the ink composition can effectively suppress bleeding of the print when using such an inkjet printing method.

[0138] When applying the composition to the surface of the substrate by an inkjet method, the method of discharging the composition by the inkjet method may be a piezoelectric method using a piezoelectric element or a thermal method using a heating element, and is not particularly limited.

[0139] 6. Method for producing a recorded material The recording method using the ink composition described above can also be defined as a method for producing a recorded material. In the method for producing a recorded material according to this embodiment, bleeding of the print is suppressed and a recorded material exhibiting excellent gloss can be obtained.

[0140] 7. Recorded Matter Each layer constituting the recorded matter produced by the method for producing a recorded matter according to the embodiment described above will be described.

[0141] [Medium (Recording Medium)] The substrate (recording medium) that can be used in the recording method according to the present embodiment is not particularly limited, and may be a non-absorbent substrate such as a resin substrate or a metal plate glass, an absorbent substrate such as paper or fabric, or a surface-coated substrate such as a substrate having a receiving layer, and various substrates can be used.

[0142] When using a non-aqueous ink composition that is substantially free of water, it is preferable for the surface to be primarily made of resin. In particular, since the ink composition contains an organic solvent A that exhibits permeability into resin substrates, bleeding of prints on media (recording media) with a resin surface is reduced, resulting in clearer prints. Examples of resins include polyvinyl chloride polymers, acrylic, PET, polycarbonate, PE, PP, etc. Furthermore, the ink composition may be used for resin substrates that are intended to have a film laminated to the recording surface of a recorded material (so-called resin substrates for lamination). In particular, substrates (recording media) with a surface made of a hard or soft polyvinyl chloride polymer are preferred. Examples of substrates (recording media) with a surface made of a polyvinyl chloride polymer include polyvinyl chloride substrates (films or sheets).

[0143] When using an aqueous ink composition containing water as the main component, absorbent substrates such as paper and fabric, and substrates with a surface coating such as substrates with a receiving layer are preferred.

[0144] [Recording Layer] The recording layer is a layer formed by volatilization of the solvent contained in the ink composition, and is a layer on which a desired image is formed. By applying the ink composition, a recorded matter with excellent gloss can be obtained, and bleeding of the print in the obtained recorded matter can be effectively suppressed.

[0145] The layer formed by the evaporation of the solvent contained in the ink composition may be formed from a plurality of layers. For example, a layer of a color ink (e.g., yellow, magenta, cyan, or black) of the ink composition may be formed on a layer of a white ink of the ink composition.

[0146] [Other Layers] The recorded matter according to the present embodiment may further include a layer having a desired function on the upper surface of the decorative layer. For example, an overcoat layer containing at least one of a resin and a wax may be formed to further impart abrasion resistance and gloss to the recorded matter. Furthermore, a layer expressing a textured (matte) surface may be formed by adding a filler or varying the film thickness on a pixel-by-pixel basis. Furthermore, a weather-resistant layer containing an ultraviolet absorber, a light stabilizer, or the like, or a glittering layer containing a glittering pigment may be formed to impart weather resistance to the recorded matter.

[0147] Although the recorded matter according to the present embodiment includes a recording layer formed from the ink composition, for example, the ink composition may be ejected onto a recording layer formed from a conventionally known ink composition to form a layer having a desired function. Also, the ink composition may be ejected onto a recording layer formed from the ink composition to form a layer having a desired function.

[0148] 8. Inkjet Recording Apparatus> As the inkjet recording apparatus for ejecting the ink composition by an inkjet method, a conventionally known inkjet recording apparatus can be used, such as an inkjet printer such as the VersaArt RE-640 manufactured by Roland DG Corporation.

[0149] As an example of the configuration of the inkjet recording device, it may be an on-carriage type, serial printer type inkjet recording device, an off-carriage type inkjet recording device in which the ink cartridge is fixed externally, or a line printer type inkjet recording device in which the ink composition is ejected onto a recording medium (substrate) without moving the inkjet head.

[0150] The inkjet recording apparatus preferably includes a heating mechanism and a fixing mechanism for fixing the substrate. The heating mechanism included in the inkjet recording apparatus controls the surface temperature of the substrate, and the ink composition that has landed on the substrate (recording medium) is dried, thereby making it possible to volatilize the solvent contained in the ink composition.

[0151] Furthermore, the fixing mechanism for fixing the substrate makes it possible to dry the ink composition while keeping the substrate (recording medium) fixed, thereby preventing the substrate from warping due to heating, which would otherwise cause uneven heating.

[0152] The heating mechanism provided in the inkjet recording apparatus may be a preheater, platen heater, afterheater, etc., or may be a mechanism for blowing hot air onto the recorded material, or a mechanism for heating the recorded material by infrared rays, etc. Furthermore, a combination of these heating mechanisms may also be used.

[0153] The fixing mechanism for fixing the substrate is not particularly limited and may be a fixing mechanism for fixing the substrate with a predetermined jig or a fixing mechanism for sucking and adsorbing the substrate by negative pressure.

[0154] The inkjet head for ejecting the ink composition is not particularly limited and may be a piezoelectric inkjet head using a piezoelectric element or a thermal inkjet head using a heating element.

[0155] Furthermore, the inkjet recording apparatus according to the present embodiment can be used with inks of various colors, such as yellow, magenta, cyan, and black, as described above, or with inks of light magenta, light cyan, light black, orange, green, red, and white, and there are no particular limitations on the order of colors to be printed or the position and configuration of the head. Furthermore, the inkjet recording apparatus according to the present embodiment may or may not be equipped with a winding mechanism for the recording medium (substrate), a drying mechanism for drying the surface of the substrate, and an ink circulation mechanism.

[0156] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these descriptions in any way.

[0157] 1. Resin Preparation (1) Acrylic Resin A mixture of 150 g of methyl methacrylate, 50 g of butyl methacrylate, and a predetermined amount of t-butylperoxy-2-ethylhexanoate (polymerization initiator) was added dropwise over 1.5 hours to 300 g of diethylene glycol diethyl ether maintained at 100°C. After completion of the addition, the mixture was allowed to react at 100°C for 2 hours and then cooled to obtain a colorless, transparent methyl methacrylate polymer solution. The solvent was then thoroughly distilled off from the polymer solution to obtain a methyl methacrylate polymer. The amount of t-butylperoxy-2-ethylhexanoate, the polymerization initiator, was varied to control the weight average molecular weight of the methyl methacrylate (acrylic resin) to 10,000 to 105,000 (the mass of the polymerization initiator used is listed in Table 1 below, and is denoted as "initiator amount" in Table 1).

[0158] (2) Vinyl chloride-vinyl acetate copolymer resin After nitrogen substitution, an autoclave equipped with a stirrer was charged with 100 parts by mass of deionized water, 40 parts by mass of methanol, 32 parts by mass of vinyl chloride, 5 parts by mass of vinyl acetate, 0.2 parts by mass of glycidyl methacrylate, 3.55 parts by mass of hydroxypropyl acrylate, 0.1 parts by mass of hydroxypropyl methylcellulose (suspending agent), 0.026 parts by mass of di-2-ethylhexyl peroxydicarbonate (polymerization initiator), and a predetermined amount of di-3,5,5-trimethylhexanol peroxide (polymerization initiator), and the temperature was raised to 63°C with stirring under a nitrogen gas atmosphere. Immediately after the temperature reached 63°C, 48 parts by mass of vinyl chloride was added over 6 hours, and a mixture of 0.6 parts by mass of glycidyl methacrylate and 10.65 parts of hydroxypropyl acrylate was continuously added under pressure over 5.4 hours to carry out a copolymerization reaction. When the internal pressure of the autoclave reached 0.3 MPa, the residual pressure was released, the autoclave was cooled, and the resin slurry was removed, filtered, and dried to obtain a vinyl chloride copolymer resin. The amount of di-3,5,5-trimethylhexanol peroxide used as a polymerization initiator was varied to control the weight average molecular weight of the vinyl chloride-vinyl acetate copolymer resin to 40,000 to 90,000 (the mass of the polymerization initiator used is shown in Table 1 below, and is indicated as "initiator amount" in Table 1).

[0159]

[0160] 2. Preparation of Ink Compositions Ink compositions for Examples and Comparative Examples were prepared using the organic solvents, resins, dispersants, and pigments in the proportions shown in the table below. Specifically, each component was dispersed with zirconia beads using a paint shaker to prepare a non-aqueous ink composition. The units are % by mass.

[0161] 3. Evaluation 1 (Bleeding) The bleeding properties of the ink compositions of the Examples and Comparative Examples were evaluated. Specifically, the ink compositions of the Examples and Comparative Examples were printed using an inkjet method with an inkjet printer (product name VersaArt RE-640, manufactured by Roland DG Corporation)) on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R, manufactured by MACtac)) in high-quality print mode (1440 x 720 dpi) at a substrate surface temperature of 40°C, with an image having 6 pt text in a different color in a solid area of ​​each color. The image was then dried in an oven at 60°C for 5 minutes, and the bleeding of the printed matter was observed visually and with a magnifying glass (10x) (referred to as "Bleeding" in the table). Evaluation Criteria Evaluation 5: No bleeding of the ink was observed with a magnifying glass. Evaluation 4: No bleeding of the ink was observed visually, and the 6 pt text was clear. Rating 3: Slight ink bleeding was observed with the naked eye, but the design was not impaired. Rating 2: Ink bleeding was observed with the naked eye, but 6 pt letters were still legible. Rating 1: Ink bleeding was significantly observed with the naked eye, and 6 pt letters were not visible.

[0162] (Glossiness) The glossiness of the ink compositions of the Examples and Comparative Examples was evaluated. Specifically, in the same manner as in the bleeding evaluation described above, a solid portion was printed on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) in high quality print mode (1440 x 720 dpi) at a substrate surface temperature of 40°C, and the print was dried in a 60°C oven for 5 minutes, after which the 20° glossiness of the printed matter was measured. The glossiness was measured using a handy glossmeter, Phopoint IQ-S (manufactured by Konica Minolta) (referred to as "glossiness" in the table). Evaluation criteria Rating 5: 20° glossiness of 70 or more Rating 4: 20° glossiness of 65 or more but less than 70 Rating 3: 20° glossiness of 55 or more but less than 65 Rating 2: 20° glossiness of 50 or more but less than 55 Rating 1: 20° glossiness less than 50

[0163] (Surface Drying Property) The surface drying property of the ink compositions of the Examples and Comparative Examples was evaluated. Specifically, in the same manner as in the bleeding property evaluation above, a solid image was printed in high quality print mode (1440 x 720 dpi) on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)), and the time until drying at 40°C was measured (referred to as "Surface Drying Property" in the table). Evaluation Criteria Rating 5: Dries in less than 2 minutes. Rating 4: Dries in 2 minutes or more but less than 4 minutes. Rating 3: Dries in 4 minutes or more but less than 6 minutes. Rating 2: Dries in 6 minutes or more but less than 8 minutes. Rating 1: Dries in 8 minutes or more.

[0164] (Coating Film Abrasion Resistance) The coating film abrasion resistance of the ink compositions of the Examples and Comparative Examples was evaluated. Specifically, in the same manner as in the bleeding evaluation above, a solid image was printed in high-quality printing mode (1440 x 720 dpi) on a recording medium (glued polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) and dried at 40°C. The printed surface of the print was rubbed with a test cloth at a load of 200 g 50 times, and the abrasion resistance was evaluated visually. (In the table, this is indicated as coating film abrasion resistance.) Evaluation Criteria Rating 5: The ink film did not peel off, and no ink adhered to the test cloth. Rating 4: The ink film did not peel off, but ink adhered to the test cloth. Rating 3: The ink film peeled slightly, and the ink film adhered to the test cloth. Rating 2: The ink film peeled slightly, and the ink film adhered to the test cloth. Rating 1: Most of the ink film peeled off, and the ink film adhered to the test cloth piece.

[0165] (Suitability for Components) The ink compositions of the Examples and Comparative Examples were evaluated for suitability for components (suitability for inkjet head components). Specifically, 0.2 g of a cured product of an epoxy adhesive (two-component curing epoxy adhesive "1500", manufactured by Cemedine Co., Ltd.) used in inkjet head components was dried at 60°C for one day. The cured product was immersed in the ink compositions of the Examples and Comparative Examples and left at 60°C for one week. An immersion test was then performed to measure the weight change of the cured product (referred to as "suitability for components" in the table). Evaluation Criteria Rating 5: Weight change rate is less than 3%, and there is no deterioration in the epoxy adhesive material. Rating 4: Weight change rate is 3% or more but less than 5%, and there is no deterioration in the epoxy adhesive material. Rating 3: Weight change rate is 5% or more but less than 10%, and there is no deterioration in the epoxy adhesive material. Rating 2: Weight change rate is 10% or more but less than 15%, and there is no deterioration in the epoxy adhesive material. Rating 1: Weight change rate is 15% or more and / or there is deterioration in the epoxy adhesive material.

[0166]

[0167]

[0168]

[0169]

[0170]

[0171]

[0172]

[0173]

[0174] In the table, "DEF" means "N,N-diethylformamide."

[0175] In the table, "DEPA" means "N,N-diethylpropanamide."

[0176] In the table, "DEAA" means "N,N-diethylacetamide."

[0177] In the table, "DMF" means "N,N-dimethylformamide."

[0178] In the table, "EC" means "ε-caprolactam."

[0179] In the table, "MEC" means "N-methyl-ε-caprolactam."

[0180] In the table, "NVC" means "N-vinylcaprolactam."

[0181] In the table, "NMP" means "N-methyl-2-pyrrolidone."

[0182] In the table, "DBDG" means "diethylene glycol dibutyl ether."

[0183] In the table, "MEDG" means "diethylene glycol methyl ethyl ether."

[0184] In the table, "DEDG" means "diethylene glycol diethyl ether."

[0185] In the table, "DMFDG" means "dipropylene glycol dimethyl ether."

[0186] In the table, "BTG" means "triethylene glycol mono-n-butyl ether."

[0187] In the table, "MFTG" means "tripropylene glycol monomethyl ether."

[0188] In the table, "MFDG" means "dipropylene glycol monomethyl ether."

[0189] In the table, "GBL" means "γ-butyrolactone."

[0190] In the table, "DVL" means "δ-valerolactone."

[0191] In the table, "ECL" means "ε-caprolactone."

[0192] In the table, "PC" means "propylene carbonate."

[0193] In the table, "DEGmEEA" means "diethylene glycol monoethyl ether acetate."

[0194] In the table, "EL" means "ethyl lactate."

[0195] As can be seen from the above table, the ink compositions of the examples, which contain organic solvent A and further contain a polysiloxane surfactant in a range of 0.01% by mass or more and 2.0% by mass or less of the total amount of the non-aqueous ink composition, can produce recorded materials with excellent gloss and can effectively suppress bleeding of the print in the resulting recorded materials.

[0196] In particular, among the ink compositions of Examples 2 and 29 to 39 in which the type of surfactant was changed, the ink compositions of Examples 2 and 29 to 37 containing polyester and / or polyether-modified polydialkylsiloxane showed improved glossiness even compared to the ink compositions of Examples 38 and 39.

[0197] Furthermore, among the ink compositions of Examples 47 to 52 in which the polymerization average molecular weight of the resin contained was changed, the ink compositions of Examples 47, 48, 50 to 51 in which the polymerization average molecular weight was 80,000 or less had good glossiness even when compared to the ink compositions of Examples 49 and 52.

[0198] Furthermore, the ink compositions of Examples 53 to 71, in which the type of pigment was changed, and the ink compositions of Examples 72 to 86, in which the type of other organic solvent was changed, all exhibited the effects of the present invention.

[0199] On the other hand, the ink compositions of Comparative Examples 8 and 9, which contained an acrylic copolymer surfactant instead of a polysiloxane surfactant, caused bleeding in the resulting recorded matter and also reduced gloss and coating film abrasion resistance, and did not achieve the effects of the present invention.

[0200] Furthermore, the ink composition of Comparative Example 1, which does not contain a polysiloxane-based surfactant, the ink composition of Comparative Example 2, which contains a polysiloxane-based surfactant in an amount of less than 0.01% by mass relative to the total amount of the ink composition, and the ink composition of Comparative Example 5, which contains a polysiloxane-based surfactant in an amount of more than 2.0% by mass relative to the total amount of the ink composition, did not provide recorded materials with excellent gloss.

[0201] Furthermore, the ink composition of Comparative Example 6, which does not contain organic solvent A, does not provide a recorded matter having excellent surface drying properties, and is unable to suppress bleeding of the print in the resulting recorded matter.

[0202] 4. Evaluation 2 The bleeding properties of ink sets containing the above ink compositions were evaluated. Specifically, the bleeding properties of ink sets were evaluated for ink compositions containing the cyan pigment (PB15:4) of the Examples and Comparative Examples, and ink compositions in which the pigment type was changed to a magenta pigment (PR122) in the ink compositions of the Examples and Comparative Examples.

[0203] An image of 6 pt text at 100% density in cyan was printed on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) using an inkjet printer in high quality print mode (1440 x 720 dpi) with a substrate surface temperature of 50°C, in a solid area of ​​200% density in cyan and magenta. The resulting print was dried in an oven at 60°C for 5 minutes, and then the print was inspected visually and with a magnifying glass (x10) for bleeding. Evaluation criteria Rating 5: No ink bleeding was observed with a magnifying glass. Rating 4: No ink bleeding was observed visually, and the 6 pt text was clear. Rating 3: Slight ink bleeding was observed visually, but the design was not impaired. Rating 2: Ink bleeding was observed visually, but the 6 pt text was distinguishable. Rating 1: Significant ink bleeding was visually observed, and 6 pt characters were not visible.

[0204]

[0205] As can be seen from the above table, an ink set containing ink compositions that contain organic solvent A and further contain a polysiloxane surfactant in an amount ranging from 0.01% by mass to 2.0% by mass of the total amount of the non-aqueous ink composition can effectively suppress bleeding of the print in the resulting recorded matter.

[0206] Furthermore, print bleeding was suppressed even when the ink composition of Comparative Example 1, which did not contain a polysiloxane surfactant, was combined with the ink compositions of Examples 2, 31, 36, and 38, which contained organic solvent A and further contained a polysiloxane surfactant in an amount of 0.01% by mass or more and 2.0% by mass or less relative to the total amount of the non-aqueous ink composition, or when the ink composition of Comparative Example 6, which did not contain organic solvent A, was combined with the ink compositions of Examples 2, 31, 36, and 38, which contained organic solvent A and further contained a polysiloxane surfactant in an amount of 0.01% by mass or more and 2.0% by mass or less relative to the total amount of the non-aqueous ink composition. This shows that an ink set that includes at least one ink composition containing a predetermined amount of polysiloxane surfactant together with organic solvent A will be an ink set that can suppress print bleeding.

[0207] 5. Preparation of Water-Based Ink Compositions Water-based ink compositions of Examples and Comparative Examples were prepared using a colorant (pigment dispersion), a resin (resin emulsion), an organic solvent (a), other solvents, and water (ion-exchanged water) in the proportions shown in the table below. The methods for preparing the pigment dispersion and resin (resin emulsion) are described below.

[0208] (1) Preparation of pigment dispersant A mixture of 63 g of methyl methacrylate, 27 g of butyl acrylate, 30 g of butyl methacrylate, 15 g of acrylic acid, 15 g of methacrylic acid, and 3.6 g of tert-butylperoxy-2-ethylhexanoate was added dropwise over 1.5 hours to 200 g of toluene maintained at 100°C. After completion of the addition, the mixture was reacted at 100°C for 2 hours and then cooled to obtain a resin solution. The resin was purified from the resin solution with hexane to obtain a pigment dispersant resin with a weight average molecular weight (polystyrene equivalent) of 20,000 and an acid value of 143 mgKOH / g.

[0209] 2.5 g of the pigment dispersion resin obtained above and 0.6 g of N,N-dimethylaminoethanol were dissolved in 80 g of water (ion-exchanged water), and 15 g of C.I. Pigment 122 and 0.05 g of an antifoaming agent ("Surfynol 104PG" manufactured by Air Products Co., Ltd.) were added, and the mixture was dispersed using zirconia beads in a paint shaker to obtain a pigment dispersion.

[0210] (2) Preparation of Resin Emulsion After thoroughly replacing the air inside a flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet tube, reflux condenser, and dropping funnel with nitrogen gas, 0.75 g of a reactive surfactant (manufactured by Kao Corporation, trade name: Latemul PD-104), 0.04 g of potassium persulfate, 1.5 g of methacrylic acid, and 150 g of pure water were charged and stirred and mixed at 25 ° C. A mixture of 115.5 g of methyl methacrylate, 18 g of 2-ethylhexyl acrylate, and 15 g of butyl acrylate was added dropwise to prepare a pre-emulsion. Furthermore, after thoroughly replacing the air inside a flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet tube, reflux condenser, and dropping funnel with nitrogen gas, 3 g of a reactive surfactant (manufactured by Kao Corporation, trade name: Latemul PD-104), 0.01 g of potassium persulfate, and 200 g of pure water were stirred and mixed at 70 ° C. The prepared pre-emulsion was then added dropwise to the flask over 3 hours. After heating and aging for another 3 hours at 70°C, the mixture was cooled, the pH was adjusted to 8 with N,N-dimethylethanolamine, and filtered through a #150 mesh (manufactured by Nippon Orimono Co., Ltd.) to obtain 500 g of a resin emulsion with a solid content of 30% by mass (glass transition temperature: 64°C, acid value: 7 mgKOH / g, volume-based cumulative 50% particle size (D50): 90 nm). The volume-based cumulative 50% particle size (D50) of the resin emulsion was measured at 25°C using a concentrated particle size analyzer (manufactured by Otsuka Electronics Co., Ltd., model: FPAR-1000).

[0211] 6. Evaluation 3 The above aqueous ink compositions were evaluated in the same manner as above for bleeding resistance, gloss, surface drying property, coating film abrasion resistance, and component suitability.

[0212]

[0213] As can be seen from the above table, even in the case of aqueous ink compositions containing water, if the ink compositions of the examples contain organic solvent A and further contain a polysiloxane surfactant in a range of 0.01 mass % or more and 2.0 mass % or less of the total amount of the non-aqueous ink composition, it is possible to obtain recorded materials with excellent gloss and to effectively suppress bleeding of the print in the obtained recorded materials.

[0214] In particular, among the ink compositions of Examples 2-1 to 2-3 in which the type of organic solvent A was changed, the ink composition of Example 1, which contained an alkylamide solvent, was able to more effectively suppress bleeding of the print in the resulting recorded matter, even compared to the ink compositions of Examples 2-2 and 2-3, which contained a cyclic amide solvent.

[0215] Furthermore, among the ink compositions of Examples 2-5 to 2-8 in which the content of organic solvent A was changed, the ink compositions of Examples 2-6 to 2-7 in which the content of organic solvent A was in the range of 3.0 mass % or more and 30.0 mass % or less produced recorded materials with superior glossiness, even compared to the ink composition of Example 2-5, and were able to more effectively suppress bleeding of the print in the resulting recorded materials.

[0216] On the other hand, the ink composition of Comparative Example 2-1, which did not contain organic solvent A, and the ink compositions of Comparative Examples 2-2 and 2-3, which contained a polysiloxane surfactant outside the range of 0.01% by mass or more and 2.0% by mass or less of the total amount of the non-aqueous ink composition, and Comparative Examples 2-4 to 2-6, which did not contain a polysiloxane surfactant, caused bleeding in the resulting recorded matter and also reduced gloss, and did not achieve the effects of the present invention.

[0217] 7. Evaluation 4 The bleeding property of an ink set containing the above aqueous ink composition was evaluated. Specifically, the bleeding property was evaluated for an ink set containing an ink composition in which the magenta dispersion of the Examples and Comparative Examples was replaced with a cyan dispersion prepared in the same manner.

[0218] (Evaluation of inter-color bleeding) An image having 6 pt text at 100% density of cyan in a solid area of ​​200% density of cyan and magenta was printed on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) using an inkjet printer in high quality print mode (1440 x 720 dpi) with a substrate surface temperature of 50°C. The resulting print was dried in an oven at 60°C for 5 minutes, and then the print was observed visually and with a magnifying glass (10x) for bleeding. Evaluation criteria Rating 5: No ink bleeding was observed with a magnifying glass. Rating 4: No ink bleeding was observed visually, and the 6 pt text was clear. Rating 3: Slight ink bleeding was observed visually, but the design was not impaired. Rating 2: Ink bleeding was observed visually, but the 6 pt text was distinguishable. Rating 1: Significant ink bleeding was visually observed, and 6 pt characters were not visible.

[0219]

[0220] As can be seen from the above table, even an ink set of an aqueous ink composition that contains organic solvent A and further contains a polysiloxane surfactant in a range of 0.01 mass % or more and 2.0 mass % or less of the total amount of the aqueous ink composition can effectively suppress bleeding of the print in the resulting recorded matter.

[0221] Furthermore, print bleeding was suppressed even when the ink composition of Comparative Example 2-1, which does not contain organic solvent A, was combined with the ink composition of Example 2-1, which contained organic solvent A and further contained a polysiloxane-based surfactant in a range of 0.01% by mass to 2.0% by mass of the total amount of the aqueous ink composition, or when the ink compositions of Comparative Examples 2-4 and 2-5, which do not contain a polysiloxane-based surfactant, were combined with the ink composition of Example 2-1, which contained organic solvent A and further contained a polysiloxane-based surfactant in a range of 0.01% by mass to 2.0% by mass of the total amount of the aqueous ink composition. This shows that an ink set containing at least one aqueous ink composition containing a predetermined amount of polysiloxane-based surfactant as well as organic solvent A is an ink set that can suppress print bleeding in the same way as an ink set containing at least one aqueous ink composition.

Claims

1. An ink composition containing an organic solvent, The water content is 1.0% by mass or less based on the total amount of the non-aqueous ink composition, The organic solvent contains the following organic solvent A, The ink composition further contains a polysiloxane surfactant in an amount of 0.01% by mass to 2.0% by mass. An ink composition (excluding active energy ray-curable ink compositions that are cured by irradiation with active energy rays). Organic solvent A: at least one selected from the group consisting of alkylamide solvents (a1) and cyclic amide solvents (a2), the alkylamide solvent (a1) being represented by the following general formula (1), and the cyclic amide solvent (a2) containing at least one selected from the group consisting of ε-caprolactam, N-methyl-ε-caprolactam, and N-vinylcaprolactam. 【Chemistry 1】 (In formula (1), R 1 represents hydrogen or an alkyl group having 1 to 4 carbon atoms, and R 2 and R 3 each independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms.)

2. The organic solvent A contains the alkylamide solvent (a1). The ink composition according to claim 1 .

3. The alkylamide solvent (a1) contains at least one selected from the group consisting of N,N-diethylformamide, N,N-diethylpropanamide, and N,N-diethylacetamide. The ink composition according to claim 2.

4. An ink composition containing an organic solvent, The organic solvent contains the following organic solvent A, The organic solvent A contains a cyclic amide solvent (a2), The ink composition further contains a polysiloxane surfactant in an amount of 0.01% by mass to 2.0% by mass. An ink composition (excluding active energy ray-curable ink compositions that are cured by irradiation with active energy rays). Organic solvent A: a cyclic amide solvent (a2), which contains at least one selected from the group consisting of ε-caprolactam, N-methyl-ε-caprolactam, and N-vinylcaprolactam.

5. The content of the organic solvent A is in the range of 1% by mass to 90% by mass of the total amount of the ink composition. The ink composition according to claim 1 .

6. The polysiloxane-based surfactant contains a polyester and / or a polyether-modified polydialkylsiloxane having a repeating unit represented by the following formula (3) and a repeating unit represented by the following formula (4): The ink composition according to claim 1 . 【Chemistry 2】 (In formula (3), R ６ is an alkyl group having 1 to 3 carbon atoms; R ７ is an alkyl group having 1 to 15 carbon atoms. 【Chemistry 3】 (In formula (4), R ８ is an alkyl group having 1 to 3 carbon atoms, and X is a polyester modified group or a polyether modified group.

7. Discharged by the inkjet method The ink composition according to claim 1 .

8. Used for resin substrates The ink composition according to claim 1 .

9. An ink set comprising the ink composition according to any one of claims 1 to 8.

10. The ink composition according to any one of claims 1 to 8 is ejected onto a surface of a substrate by an inkjet method. Recording method.

11. The ink composition according to any one of claims 1 to 8 is ejected onto a surface of a substrate by an inkjet method. A method for producing recorded matter.

12. A recording layer of the ink composition according to any one of claims 1 to 8 is formed on the surface of a substrate. Recorded material.

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