Nonaqueous ink composition, recording method using the same, method for producing recorded matter, and inkjet recording device

Abstract

To provide a nonaqueous ink composition that can give a recorded matter having excellent surface dryability and can also effectively suppress blurred printing.SOLUTION: A nonaqueous ink composition is ejected by the inkjet technique and contains an organic solvent, where the organic solvent contains an alkylamide solvent (a), and an organic solvent (b) with an enthalpy of evaporation (EOV) of 43.5 kJ / mol or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a non-aqueous ink composition, a recording method using the same, a method for producing a recorded matter, and an inkjet recording apparatus. [Background technology]

[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.

[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 also describes that by containing a 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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6256039 Summary of the Invention [Problem to be solved by the invention]

[0005] Lactone solvents are solvents that easily penetrate resin substrates, and non-aqueous ink compositions containing lactone solvents have high penetration into resin substrates. Patent Document 1 describes that the abrasion resistance and drying properties of recorded images and characters are good even when a low-absorbency recording medium is used.

[0006] However, lactone-based solvents are difficult to dry, and the surface drying property of the recorded material is reduced, especially when a resin substrate is used. As a result, the obtained recorded material needs to be dried thoroughly, which reduces the productivity of the recorded material. Furthermore, if the drying property of the non-aqueous ink composition is poor, depending on the type of substrate (recording medium), bleeding may occur due to the undried non-aqueous ink composition that has landed on the substrate (recording medium).

[0007] An object of the present invention is to provide a non-aqueous ink composition that can provide a recorded matter with excellent surface drying properties and can effectively suppress bleeding of printed characters on any substrate (recording medium), including low-absorbency substrates such as vinyl chloride resins. [Means for solving the problem]

[0008]

[0009] As a result of extensive investigations aimed at solving the above problems, the present inventors have found that a non-aqueous ink composition containing a specific organic solvent can solve the above problems, and have thus completed the present invention. Specifically, the present invention provides the following.

[0009] (1) A non-aqueous ink composition containing an organic solvent and ejected by an inkjet method, the organic solvent containing an alkylamide solvent (a) and an organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less.

[0010] (2) The non-aqueous ink composition according to (1), wherein the organic solvent (b) contains at least one selected from the group consisting of glycol ether dialkyls, glycol ether monoalkyls, acetates, carbonates, dibasic acid esters, amides, and ketones.

[0011] (3) The non-aqueous ink composition according to (1) or (2), wherein the content of the alkylamide solvent (a) is in the range of 1% by mass or more and 90% by mass or less of the total amount of the non-aqueous ink composition, and the total content of the alkylamide solvent (a) and the organic solvent (b) is in the range of 70% by mass or more and 95% by mass or less of the total amount of the non-aqueous ink composition.

[0012] (4) The non-aqueous ink composition according to any one of (1) to (3), wherein the alkylamide solvent (a) is represented by the following general formula (1):

[0013] [ka] (In formula (1), R1 is hydrogen or an alkyl group having 1 to 4 carbon atoms, and R2 and R3 each independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms.)

[0014] (5) The non-aqueous ink composition according to (4), wherein the alkylamide solvent (a) contains at least one selected from the group consisting of N,N-diethylformamide, N,N-diethylpropanamide, and N,N-diethylacetamide.

[0015] (6) The non-aqueous ink composition according to any one of (1) to (5), wherein the resin has an intrinsic viscosity of 90 mL / g or more at 25°C in an amount of 5 mass% or less of the total amount of resin.

[0016] (7) A non-aqueous ink composition according to any one of (1) to (6), which is ejected by an inkjet method using an inkjet recording device comprising: a storage mechanism for storing the non-aqueous ink composition; an inkjet ejection port; and a tube for circulating the non-aqueous ink composition, the tube being connected to the storage mechanism and the inkjet ejection port and comprising a valve mechanism for opening and closing a flow path for the non-aqueous ink composition.

[0017] (8) The non-aqueous ink composition according to any one of (1) to (7), which is ejected by an inkjet method through a plastic tube using an inkjet recording apparatus equipped with the plastic tube.

[0018] (9) The non-aqueous ink composition according to any one of (1) to (8), which is used on a resin substrate.

[0019] (10) A recording method comprising ejecting the non-aqueous ink composition according to any one of (1) to (9) onto the surface of a substrate by an inkjet method.

[0020] (11) A method for producing a recorded matter, comprising ejecting the non-aqueous ink composition according to any one of (1) to (9) onto the surface of a substrate by an inkjet method.

[0021] (12) An inkjet recording apparatus that ejects the non-aqueous ink composition according to any one of (1) to (9) by an inkjet method.

[0022] (13) a storage mechanism for storing the non-aqueous ink composition; and an inkjet ejection port. and a tube for circulating the non-aqueous ink composition, the tube being connected to the storage mechanism and the inkjet ejection port, and having a valve mechanism for opening and closing a flow path for the non-aqueous ink composition.

[0023] (14) The inkjet recording apparatus according to (12) or (13), further comprising an ink circulation mechanism for circulating the non-aqueous ink composition.

[0024] (15) The inkjet recording apparatus according to any one of (10) to (12), further comprising a heating mechanism and a fixing mechanism for fixing the substrate.

[0025] (16) A recorded matter having a recording layer of the non-aqueous ink composition according to any one of (1) to (9) formed on the surface of a substrate. [Effects of the Invention]

[0026] The non-aqueous ink composition of the present invention can provide a recorded matter having excellent surface drying properties, and can effectively prevent bleeding of the printed matter on the resulting recorded matter. DETAILED DESCRIPTION OF THE INVENTION

[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. Furthermore, in this specification, the notation "to" means "more than or equal to" or "less than or equal to," and the notation "X:Y~A:B" includes "X:Y" and "A:B" themselves and means the range between "X:Y" and "A:B."

[0028] 1. Non-aqueous ink composition The non-aqueous ink composition according to this embodiment is a non-aqueous ink composition that contains an organic solvent and is ejected by an inkjet method, and is characterized in that the organic solvents are an alkylamide solvent (a) and an organic solvent (b) having an enthalpy of evaporation (EOV) of 43.5 kJ / mol or less.

[0029] Such a non-aqueous ink composition provides excellent surface drying properties for recorded materials, and can effectively prevent bleeding of the print on the resulting recorded materials.

[0030] Here, "non-aqueous ink composition" means an ink composition that does not contain water (oil-based ink composition), 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. Note that, in this specification, the term "water-free" does not take into account water that is inevitably contained, such as moisture in the atmosphere or water that originates from additives, etc.

[0031] The non-aqueous ink composition according to this embodiment may be a colored ink containing a colorant (including a colored colorant or a black-and-white colorant), an ink containing a glittering pigment (scale-like metal particles) for giving a metallic finish to a recorded material (substrate), or a clear ink containing no colorant. Clear inks containing no 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 eliminate the gloss of a recorded material (substrate), and inks containing UV absorbers, light stabilizers, etc. for forming a weather-resistant layer.

[0032] Each component contained in the non-aqueous ink composition according to this embodiment will be described below.

[0033] [Organic solvents] The organic solvent contains an alkylamide solvent (a) and an organic solvent (b) having an enthalpy of vaporization (EOV) of 43.5 kJ / mol or less.

[0034] (Alkylamide solvent (a)) Alkylamide solvents are those containing alkyl groups (C n H 2n+1 -) and a -C(=O)-N- group (amide bond), and is an organic solvent consisting of a compound composed of hydrogen or an alkyl group and a -C(=O)-N- group.

[0035] Alkylamide solvents (a) dry more easily than lactone solvents and dry quickly on the substrate surface. Therefore, by containing alkylamide solvents (a) and an organic solvent (b) described below, a recorded material with excellent surface drying properties can be obtained. Furthermore, since alkylamide solvents (a) penetrate to a certain extent into substrates (recording media) whose surfaces are mainly made of resin, bleeding of the print is reduced and the print is clear. Furthermore, a non-aqueous ink composition containing alkylamide solvents (a) can also suppress the occurrence of offset (blocking resistance) to the back surface of the recorded material that overlaps the front surface.

[0036] Furthermore, although the alkylamide-based solvent (a) penetrates to some extent into substrates (recording media) whose surfaces are mainly made of resin, its penetration into components is lower and it dries faster than non-aqueous ink compositions containing lactone-based solvents. Therefore, non-aqueous ink compositions containing alkylamide-based solvent (a) can also suppress the occurrence of offset (blocking resistance) to the back surface of the recorded material that overlaps the front surface, and also have good compatibility with components used in inkjet recording devices.

[0037] The alkylamide solvent is preferably an organic solvent that does not contain an alkoxy group and is composed only of hydrogen or an alkyl group and a -C(=O)-N- group, and for example, one having the following structure can be preferably used.

[0038] [ka] (In formula (1), R1 is hydrogen or an alkyl group having 1 to 4 carbon atoms, and R2 and R3 each independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms.)

[0039] R2 and R3 in formula (1) are preferably alkyl groups having 1 to 4 carbon atoms, and more preferably alkyl groups having 2 to 4 carbon atoms.

[0040] Specific examples of alkylamide solvents 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, and among these, it is particularly preferable to contain N,N-diethylformamide.

[0041] The content of the alkylamide solvent (a) is not particularly limited, but the lower limit of the content of the alkylamide solvent (a) is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, even more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on the total amount of the non-aqueous ink composition. This makes it possible to obtain a recorded product with excellent surface drying properties, which further reduces bleeding of the print and makes the print clearer.

[0042] The upper limit of the content of the alkylamide solvent (a) is preferably 90% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less, even more preferably 50% by mass or less, and even more preferably 45% by mass or less, based on the total amount of the non-aqueous ink composition. This makes it possible to suppress the occurrence of blank areas in solid printed areas (improving solid filling). Furthermore, it is possible to suppress the occurrence of offset (blocking resistance) to the back surface of the printed material that overlaps the front surface, and the component suitability for inkjet recording devices is also improved.

[0043] (organic solvent (b)) Organic solvent (b) is an organic solvent with an enthalpy of vaporization (EOV) of 43.5 kJ / mol or less. As used herein, the enthalpy of vaporization is a calculated value determined using Advanced Chemistry Development (ACD / Labs) software, version 11.02.

[0044] The higher the evaporation enthalpy value, the less volatile the organic solvent is, and organic solvents (b) with an evaporation enthalpy (EOV) of 43.5 kJ / mol or less are highly volatile solvents.

[0045] By incorporating such an organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less together with the alkylamide solvent (a), a recorded material with excellent surface drying properties can be obtained. Furthermore, the non-aqueous ink composition deposited on a substrate (recording medium) dries quickly, resulting in less bleeding and clearer prints. The evaporation enthalpy (EOV) of this organic solvent (b) is preferably 43.0 kJ / mol or less, more preferably 42.5 kJ / mol or less. The lower limit of the evaporation enthalpy (EOV) of this organic solvent (b) is not particularly limited, but is preferably 30 kJ / mol or more, more preferably 33 kJ / mol or more, and even more preferably 35 kJ / mol or more.

[0046] The type of organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less is not particularly limited, but it is preferably a glycol ether dialkyl, glycol ether monoalkyl, acetate, carbonate ester, dibasic acid ester, amide, or ketone, which has an evaporation enthalpy (EOV) of 43.5 kJ / mol or less. This provides excellent surface drying properties to the recorded material, and effectively suppresses bleeding of the print on the resulting recorded material.

[0047] Examples of glycol ether dialkyls include diethylene glycol dimethyl ether (38.0 kJ / mol), diethylene glycol methyl ethyl ether (38.8 kJ / mol), diethylene glycol diethyl ether (40.9 kJ / mol), diethylene glycol isopropyl methyl ether (40.4 kJ / mol), triethylene glycol dimethyl ether (43.4 kJ / mol), and dipropylene glycol dimethyl ether (39.8 kJ / mol).

[0048] Examples of glycol ether monoalkyl include ethylene glycol monomethyl ether (37.5 kJ / mol), ethylene glycol monoethyl ether (39.2 kJ / mol), propylene glycol monomethyl ether (41.6 kJ / mol), and propylene glycol monoethyl ether (43.0 kJ / mol).

[0049] Examples of acetates include ethylene glycol monobutyl ether acetate (42.8 kJ / mol), propylene glycol monomethyl ether acetate (39.2 kJ / mol), 2-methylbutyl acetate (37.3 kJ / mol), 3-methoxybutyl acetate (41.2 kJ / mol), and cyclohexyl acetate (40.9 kJ / mol).

[0050] Examples of carbonate esters include diethyl carbonate (36.0 kJ / mol).

[0051] Examples of dibasic acid esters include dimethyl malonate (41.3 kJ / mol) and dimethyl succinate (43.2 kJ / mol).

[0052] Examples of amides include N-N-dimethyl-β-methoxypropanamide (42.5 kJ / mol) and N-vinylmethyloxazolidinone (38.3 kJ / mol).

[0053] Examples of ketones include 2-octanone (39.0 kJ / mol).

[0054] The content of the organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less is not particularly limited, but the lower limit of the content of the organic solvent (b) is preferably 5.0 mass% or more, more preferably 20.0 mass% or more, and even more preferably 45.0 mass% or more, based on the total amount of the non-aqueous ink composition. This allows for a recorded product with superior surface drying properties, reduced print bleeding, and clearer prints. The upper limit of the content of the organic solvent (b) is preferably 95.0 mass% or less, more preferably 90.0 mass% or less, even more preferably 85.0 mass% or less, and even more preferably 80.0 mass% or less, based on the total amount of the non-aqueous ink composition. This relatively increases the content of the alkylamide solvent (a), allowing for a recorded product with superior surface drying properties, reduced print bleeding, and clearer prints.

[0055] (Total content of alkylamide solvent (a) and organic solvent (b)) The total content of the alkylamide solvent (a) and the organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less is not particularly limited, but the lower limit of the total content is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, based on the total amount of the non-aqueous ink composition. This allows for the production of recorded materials with superior surface drying properties, further reducing print bleeding and resulting in clearer prints. The upper limit of the total content of the alkylamide solvent (a) and the organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less, based on the total amount of the non-aqueous ink composition. Relatively increasing the content of the organic solvent having an evaporation enthalpy (EOV) of more than 43.5 kJ / mol results in excellent maintenance and improved inkjet ejection properties of the non-aqueous ink composition.

[0056] (Other organic solvents) The organic solvent may contain an organic solvent other than the alkylamide solvent (a) and the organic solvent (b) having an enthalpy of evaporation (EOV) of 43.5 kJ / mol or less. Specifically, an organic solvent having an enthalpy of evaporation (EOV) of more than 43.5 kJ / mol, different from the alkylamide solvent, may be used.

[0057] For example, glycol ether dialkyls, glycol ether monoalkyls, acetates, cyclic esters, carbonates, lactates, dibasic acid esters, alcohols, amides, and ketones each having an enthalpy of vaporization (EOV) of more than 43.5 kJ / mol may be mentioned.

[0058] Examples of glycol ether dialkyl include diethylene glycol dibutyl ether (47.2 kJ / mol), tetraethylene glycol dimethyl ether (49.3 kJ / mol), and tetraethylene glycol diethyl ether (51.9 kJ / mol).

[0059] Examples of glycol ether monoalkyl include ethylene glycol monopropyl ether (44.89 kJ / mol), diethylene glycol monomethyl ether (50.1 kJ / mol), diethylene glycol monoethyl ether (51.0 kJ / mol), diethylene glycol mono-n-butyl ether (54.3 kJ / mol), triethylene glycol monomethyl ether (54.7 kJ / mol), triethylene glycol mono-n-butyl ether (60.0 kJ / mol), tetraethylene glycol monobutyl ether (66.9 kJ / mol), pentaethylene glycol monobutyl ether (72.4 kJ / mol), hexaethylene glycol monobutyl ether (77.6 kJ / mol), dipropylene glycol monomethyl ether (51.1 kJ / mol), dipropylene glycol monopropyl ether (55.8 kJ / mol), and tripropylene glycol monomethyl ether (59.1 kJ / mol).

[0060] Examples of acetates include diethylene glycol mono-n-butyl ether acetate (48.2 kJ / mol) and diethylene glycol mono-n-ethyl ether acetate (45.8 kJ / mol).

[0061] Examples of carbonate esters include propylene carbonate (47.8 kJ / mol) and ethylene carbonate (49.0 kJ / mol).

[0062] Examples of dibasic acid esters include diethyl malonate (43.6 kJ / mol), dipropyl malonate (46.6 kJ / mol), diethyl succinate (45.5 kJ / mol), diethyl glutarate (47.3 kJ / mol), and dimethyl adipate (46.5 kJ / mol).

[0063] Examples of amide solvents include 3-methyl-2-oxazolidinone (50.4 kJ / mol), 3-ethyl-2-oxazolidinone (50.7 kJ / mol), N-methylcaprolactam (48.5 kJ / mol), N-acetylcaprolactam (47.9 kJ / mol), ε-caprolactam (51.1 kJ / mol), N-vinylcaprolactam (49.2 kJ / mol), and N,N-dimethyl-β-butoxypropanamide (48.5 kJ / mol).

[0064] Examples of lactate esters include methyl lactate (44.5 kJ / mol), ethyl lactate (45.6 kJ / mol), butyl lactate (49.5 kJ / mol), propyl lactate (47.8 kJ / mol), ethylhexyl lactate, amyl lactate (51.3 kJ / mol), and isoamyl lactate (51.0 kJ / mol).

[0065] Examples of alcohols include 3-methoxybutanol (46.5 kJ / mol), 3-methoxy-3-methylbutanol (46.7 kJ / mol), and diacetone alcohol (47.1 kJ / mol).

[0066] Examples of cyclic esters include γ-butyrolactone (44.0 kJ / mol), ε-caprolactone (46.2 kJ / mol), δ-valerolactone (45.4 kJ / mol), and δ-hexanolactone (45.2 kJ / mol).

[0067] The organic solvent contained in the non-aqueous ink composition according to this embodiment is preferably selected to have an appropriate HLB value depending on the resin and dispersant to be combined.

[0068] The non-aqueous ink composition according to this embodiment may contain a lactone solvent with an evaporation enthalpy (EOV) of greater than 43.5 kJ / mol, but if the lactone solvent is contained in a large amount, blocking resistance may not be obtained. The content of lactone solvents with an evaporation enthalpy (EOV) of greater than 43.5 kJ / mol is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 1.0% by mass or less, and even more preferably 0.5% by mass or less, of the total amount of the non-aqueous ink composition.

[0069] The organic solvent may contain organic solvents other than the above-mentioned organic solvents. Specific examples thereof include alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol; ketones such as 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-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; acetates such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, hexyl acetate, and octyl acetate; Examples of common organic solvents, regardless of their enthalpy of vaporization (EOV), include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol; saturated hydrocarbons such as n-hexane, isohexane, n-nonane, isononane, dodecane, and isododecane; 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; terpene solvents; and ether solvents. It is preferable to select a solvent with an appropriate HLB value depending on the resin and dispersant to be combined.

[0070] [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.

[0071] 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.

[0072] 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 radically polymerizable monomer or a copolymer of two or more selected radically polymerizable monomers. In particular, preferred acrylic resins for the non-aqueous ink composition of this embodiment are methyl methacrylate homopolymers or copolymers of methyl methacrylate with at least one compound selected from the group consisting of butyl methacrylate, ethoxyethyl methacrylate, and benzyl methacrylate. Commercially available acrylic resins include, for example, Rohm and Haas's "Paraloid B99N," "Paraloid B60," "Paraloid B66," and "Paraloid B82."

[0073] 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 that can be used in the present invention include those available from Nissin Chemical Industry Co., Ltd. under the trade names Solbin C, CL, CNL, CLL, CLL2, C5R, TA2, TA3, A, AL, TA5R, and M5.

[0074] The 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.

[0075] Cellulose-based resins are resins with a cellulose skeleton obtained by introducing functional groups biologically or chemically 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. These 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," and "CAP482-0.5."

[0076] 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 from Toyobo Co., Ltd. under the trade names "VYLON226," "VYLON270," "VYLON560," "VYLON600," "VYLON630," "VYLON660," "VYLON885," "VYLONGK250," "VYLONGK810," and "VYLON GK890," and those available from Unitika Co., Ltd. under the trade names "elitleUE-3200," "elitleUE-3285," "elitleUE-3320," "elitleUE-9800," and "elitleUE-9885."

[0077] 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 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."

[0078] Although these acrylic resins, vinyl chloride-vinyl acetate copolymer resins, cellulose resins, polyester resins, and polyurethane resins may be used alone, it is preferable to use a mixture of two of them, and it is even more preferable to use a resin mixture of an acrylic resin and a vinyl chloride-vinyl acetate copolymer resin. The content ratio of the acrylic resin and the vinyl chloride-vinyl acetate copolymer resin can be controlled to satisfy the requirements for non-aqueous inks, such as color development, drying properties, coating film properties, and printability. When mixing an acrylic resin and a vinyl chloride-vinyl acetate copolymer resin, the mixing ratio is not particularly limited and can be changed as appropriate.

[0079] The weight average molecular weight (relative molecular mass) of the resin is not particularly limited, but is preferably 5,000 or more, and more preferably 15,000 or more. The weight average molecular weight (relative molecular mass) is preferably 100,000 or less, and more preferably 50,000 or less. The relative molecular weight of the resin can be measured by ordinary GPC (gel permeation chromatography).

[0080] 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.

[0081] Furthermore, the resin contained in the non-aqueous ink composition according to this embodiment preferably has an intrinsic viscosity of 90 mL / g or more at 25° C., and the amount of resin contained in the non-aqueous ink composition according to this embodiment is preferably 5% by mass or less of the total amount of resin. This makes it possible to prevent blank areas from occurring in solid printed areas (improving solid printing).

[0082] In this specification, the intrinsic viscosity is the specific viscosity [η SP ]((η-η0) / η0 (η0: solvent viscosity, η: solution viscosity)) and concentration C are calculated using the formula Lim(〔η SP ] / C), the concentration C can be extrapolated to 0 (C→0). The developing solvent is not particularly limited, but tetrahydrofuran, for example, can be used.

[0083] The content of resins having an intrinsic viscosity of 90 mL / g or more at 25°C is preferably in the range of 4.0 mass% or less, more preferably 3.5 mass% or less, and even more preferably 2.5 mass% or less, of the total amount of resin.

[0084] [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 and light in the recorded material. The pigment that can be used in the non-aqueous ink composition according to this embodiment is not particularly limited, and examples include organic pigments and inorganic pigments used in conventional ink compositions. These may be used alone or in combination of two or more. The non-aqueous ink composition according to this embodiment does not have to contain a colorant.

[0085] 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) as described below.

[0086] 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.

[0087] Examples of organic pigments by Color Index (CI) number include CI 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, and 214; and CI Pigment Red 5, 7, 9, 12, 48, 49, 52, 53, 57:1, 97, 112, 122, 123, 146, 149, 150, 168, 177, 180, and 184. , 192, 202, 206, 208, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 254, 255, 269, 291, CI Pigment Orange 16, 36, 43, 51, 55, 59, 61, 64, 71, 73, CI Pigment Violet 19, 23, 29, 30, 37, 40, 50, CI Pigment Blue 15, 15:1, 15:3, 15:4, 15:6, 16, 22, 60, 64, CI Pigment Green 7, 36, 58, 59, 62, 63, CI Pigment Brown 23, 25, 26, CI Pigment Black 7, etc.

[0088] 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.

[0089] 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.

[0090] The average dispersed particle size of the pigment that can be contained in the non-aqueous ink composition according to this embodiment 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 greater, more preferably 20 nm or greater, and even more preferably 30 nm or greater. 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 average particle size (D50) measured at 25°C using a particle size distribution analyzer (NANOTRACWAVE particle size analyzer manufactured by Microtrackbell Corporation).

[0091] 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.

[0092] 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.

[0093] 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.

[0094] [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 a polar group such as an amino group, a carboxyl group, a sulfone group, or a hydroxyl group as a side chain. Examples of polyacrylic dispersants include Disperbyk-2000, 2001, 2008, 2009, 2010, 2020, 2020N, ​​2022, 2025, 2050, 2070, 2095, 2150, 2151, 2155, 2163, and 2164, BYKJET-9130, 9131, 9132, 9133, and 9151 (manufactured by BYK-Chemie), Efka PX4310, PX4320, and PX4330, PA4401, 4402, PA4403, 4570, 7411, and 7477, PX4700, and PX4701 (manufactured by BASF), and TREPLUS Examples of compounds that can be used include D-1200, D-1410, D-1420, MD-1000 (manufactured by Otsuka Chemical Co., Ltd.), Florene DOPA-15BHFS, 17HF, 22, G-700, 900, NC-500, and GW-1500 (manufactured by Kyoeisha Chemical Co., Ltd.). 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) and other products 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.

[0095] 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.

[0096] [Dispersion aid] A dispersing aid may be used as needed in the non-aqueous ink composition according to this embodiment. The dispersing aid adsorbs to the surface of the colorant (pigment), and its functional groups enhance the affinity with the organic solvent and dispersant in the non-aqueous ink composition, thereby improving dispersion stability. Known pigment derivatives having functional groups such as acidic, basic, or neutral groups in the organic pigment residue can be used as the dispersing aid.

[0097] [Surfactants] A surfactant may be added to the non-aqueous ink composition according to this embodiment for the purposes of suppressing evaporation of the ink composition in devices such as nozzles and tubes, preventing solidification, and resolubilizing the ink composition when solidified, as well as for the purposes of reducing surface tension and improving wettability with a recording medium (substrate). Examples of surfactants include 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, and NC-207 (manufactured by NOF Corporation), Emulgen 106, 108, 707, 709, A-90, and A-60 (manufactured by Kao Corporation), and Flo Other examples include: UREN G-70, D-90, TG-740W (manufactured by Kyoeisha Chemical Co., Ltd.), POEM J-0081HV (manufactured by Riken Vitamin Co., Ltd.), ADEKA TOR NP-620, NP-650, NP-660, NP-675, NP-683, NP-686, ADEKA COLL CS-141E, TS-230E (manufactured by Adeka Corporation), SOLGEN 30V, 40, TW-20, TW-80, NOIGEN CX-100 (manufactured by Adeka Corporation), etc. As the fluorine-based surfactant, it is preferable to use a fluorine-modified polymer, a specific example of which is BYK-340 (manufactured by BYK Japan KK), and as the silicone-based surfactant, it is preferable to use a polyester-modified silicone or a polyether-modified silicone, specific examples of which include BYK-313, 315N, 322, 326331, 347, 348, BYK-UV3500, 3510, 3530, and 3570 (all manufactured by BYK Japan KK). As the acetylene glycol-based surfactant, specific examples include Surfynol (registered trademark) 82, 104, 465, 485, and TG (all manufactured by Air Products Japan), Olfine (registered trademark) STG, and E1010 (all manufactured by Nissin Chemical Industry Co., Ltd.).

[0098] The surfactant is not limited to the above, and any of anionic, cationic, amphoteric, and nonionic surfactants can be used, and may be selected appropriately depending on the purpose of addition.

[0099] [Other ingredients] 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 or silicone-based), 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). Benzophenone-based compounds or benzotriazole-based compounds can also be used as UV absorbers. Specific examples of epoxidized products include epoxy glycerides, epoxy fatty acid monoesters, and epoxy hexahydrophthalates, and specific examples include Adeka Cizer O-130P and Adeka Cizer O-180A (manufactured by ADEKA Corporation).Specific examples of polycarboxylic acids include citric acid and maleic acid.

[0100] 2. Method for producing ink composition The ink composition according to this embodiment can be produced by mixing an alkylamide solvent (a), an organic solvent (b) having an enthalpy of evaporation (EOV) of 43.5 kJ / mol or less, and each of the main components (e.g., resin, colorant, etc.) using a paint shaker. At this time, each component may be dispersed using zirconia beads.

[0101] The non-aqueous ink composition according to this embodiment may be subjected to a degassing treatment, etc., as needed, to adjust the dissolved oxygen and nitrogen contents to the desired levels. Furthermore, since the non-aqueous ink composition according to this embodiment has a flash point of 60°C or higher, the volatilization of the organic solvent contained in the non-aqueous ink composition can be suppressed.

[0102] It is also 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.

[0103] 3. Recording method using ink composition The recording method according to the present embodiment is a recording method in which the non-aqueous ink composition described above is ejected onto the surface of a substrate by an inkjet method. The non-aqueous ink composition described above can produce a recorded matter having excellent surface dryness and can effectively suppress bleeding of the print in the resulting recorded matter, and the recording method according to the present embodiment can also produce a recorded matter having excellent surface dryness and suppressed bleeding of the print. The method for ejecting ink by the inkjet method is not particularly limited and may be a piezoelectric method using a piezoelectric element or a thermal method using a heating element.

[0104] In particular, the non-aqueous ink composition has extremely excellent surface drying properties, making it possible to transport a substrate (recording medium) at high speed and eject the ink onto the surface of the substrate using an inkjet method, thereby improving the production speed of recorded matter. The same applies to the production method of recorded matter described below.

[0105] Specifically, the recording speed in the recording method according to the present embodiment is 10 m / s, although it depends on the type of substrate. 2 / h or more is preferable, and 20m 2 / h or more is more preferable, and 30m 2 / h or more is more preferable.

[0106] It is preferable to heat the non-aqueous ink composition that has landed on the substrate (recording medium) using a heating mechanism provided in the inkjet recording apparatus. By doing so, the non-aqueous ink composition that has landed on the substrate (recording medium) is dried, thereby increasing the drying speed of the organic solvent contained in the non-aqueous ink composition, and further improving the production speed of recorded materials. It should be noted that the non-aqueous ink composition that has landed on the substrate (recording medium) is sufficiently dried even without heating by the heating mechanism, so it is not necessary to dry the non-aqueous ink composition using the heating mechanism.

[0107] ≪4. Manufacturing method of recorded materials≫ The recording method using the ink composition described above can also be defined as a method for producing a recorded matter. The method for producing a recorded matter according to the present embodiment also makes it possible to obtain a recorded matter that has excellent surface dryness and suppresses bleeding of the print.

[0108] 5. Records Each layer constituting the recorded matter produced by the method for producing a recorded matter according to the embodiment described above will now be described.

[0109] [Media (recording media)] 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 substrate with a surface coating such as a substrate having a receiving layer, and various substrates can be used.

[0110] Among these, the non-aqueous ink composition does not contain water, and therefore is preferably one whose surface is mainly made of resin. In particular, since the non-aqueous ink composition contains an alkylamide solvent (a) that exhibits permeability to resin substrates, bleeding of prints on media (recording media) whose surfaces are made of resin is reduced, resulting in clearer prints. Examples of resins include polyvinyl chloride polymers, acrylic, PET, polycarbonate, PE, and PP. The ink composition may also be used for resin substrates 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) whose surfaces are made of hard or soft polyvinyl chloride polymers are preferred. Examples of substrates (recording media) whose surfaces are made of polyvinyl chloride polymers include polyvinyl chloride substrates (films or sheets).

[0111] Furthermore, the non-aqueous ink composition contains an organic solvent (b) with an evaporation enthalpy (EOV) of 43.5 kJ / mol or less, and dries quickly on substrates impermeable to the alkylamide solvent (a). This reduces bleeding of prints and enables clear printing even on substrates impermeable to the alkylamide solvent (a). Therefore, bleeding of prints can be effectively suppressed even when using various substrates (recording media).

[0112] [Recording layer] The recording layer is a layer formed by volatilization of the solvent contained in the non-aqueous ink composition, and is a layer on which a desired image is formed. By ejecting the non-aqueous ink composition, a recorded matter having excellent surface drying properties and suppressed bleeding of the printed image can be obtained.

[0113] The layer formed by the evaporation of the solvent contained in the non-aqueous ink composition may be formed from multiple layers. For example, a layer of a color ink (e.g., yellow, magenta, cyan, black) of the non-aqueous ink composition may be formed on a layer of a white ink of the non-aqueous ink composition.

[0114] [Other layers] The recorded matter according to this embodiment may further include a layer having a desired function on the upper surface of the recording layer. For example, an overcoat layer containing at least one of resin and wax may be formed to further impart abrasion resistance and gloss to the recorded matter. A layer that expresses a textured surface (matte surface) may also be formed by incorporating 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 also be formed to impart weather resistance to the recorded matter.

[0115] Although the recorded matter according to the present embodiment includes a recording layer formed from the non-aqueous ink composition, for example, a layer having a desired function may be formed by ejecting the non-aqueous ink composition onto a recording layer formed from a conventionally known ink composition. Also, a layer having a desired function may be formed by ejecting the non-aqueous ink composition onto a recording layer formed from the non-aqueous ink composition.

[0116] 6. Inkjet recording device The inkjet recording device for ejecting the non-aqueous ink composition by an inkjet method may be a conventionally known inkjet recording device, such as an inkjet printer such as the VersaArt RE-640 manufactured by Roland DG Corporation.

[0117] As an example of the configuration of an inkjet recording device, an on-carriage type, serial printer type inkjet recording device will be described, but an inkjet recording device capable of carrying out the recording method according to this embodiment may also be 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 inkjet head does not move and ejects the ink composition onto a recording medium (substrate).

[0118] 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 substrate surface temperature to dry the non-aqueous ink composition that has landed on the substrate (recording medium), thereby improving the drying rate of the organic solvent contained in the non-aqueous ink composition. Furthermore, the fixing mechanism for fixing the substrate allows the non-aqueous ink composition to be dried while the substrate (recording medium) is fixed, thereby preventing uneven heating due to bending of the substrate caused by heating. This makes it possible to effectively dry the non-aqueous ink composition that has landed on the substrate (recording medium). Such drying and fixing mechanisms are particularly effective when transporting the substrate (recording medium) at high speed to improve the production speed of recorded materials.

[0119] The heating mechanism provided in the inkjet recording apparatus may be a preheater, a platen heater, an afterheater, or a mechanism for blowing hot air onto the recording material. In addition, a combination of these heating mechanisms may be used.

[0120] The surface temperature of the substrate heated by the heating mechanism is not particularly limited as long as it can volatilize the organic solvent contained in the non-aqueous ink composition, and the lower limit of the surface temperature of the substrate is preferably 20° C. or higher, more preferably 30° C. or higher, and even more preferably 40° C. or higher. The upper limit of the surface temperature of the substrate is preferably 70° C. or lower, more preferably 60° C. or lower, and even more preferably 50° C. or lower.

[0121] The fixing mechanism for fixing the substrate is not particularly limited and may be a fixing mechanism that fixes the substrate with a predetermined jig or a fixing mechanism that sucks and adsorbs the substrate by negative pressure.

[0122] Since the non-aqueous ink composition has a high drying property, such a mechanism is not an essential component of the inkjet recording apparatus according to this embodiment. For example, the inkjet recording apparatus may be made smaller without providing a heating mechanism, and the overall transport section may be shortened, thereby improving the production speed of recorded materials.

[0123] Furthermore, if the non-aqueous ink composition has too high a drying property, the amount of organic solvent contained in the non-aqueous ink composition may change during inkjet ejection, and the desired properties may not be obtained. Therefore, it is preferable that the flash point of the non-aqueous ink composition be 60°C or higher.

[0124] The inkjet head for ejecting the non-aqueous 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.

[0125] The inkjet recording apparatus may also be configured to include a plastic tube connecting a container (such as an ink cartridge or bottle) for storing the non-aqueous ink composition to an inkjet nozzle for ejecting the non-aqueous ink composition, and to supply the non-aqueous ink composition to an inkjet head through the plastic tube and eject the non-aqueous ink composition by an inkjet method. If the non-aqueous ink composition is present in the plastic tube, some of the organic solvent contained in the non-aqueous ink composition may volatilize. This may change the amount of organic solvent contained in the non-aqueous ink composition at the inkjet ejection stage, making it difficult to obtain desired properties.

[0126] In particular, the alkylamide solvent (a) contained in the above-mentioned non-aqueous ink composition volatilizes in a relatively small amount compared to other organic solvents, even when present in a plastic tube. The amount of evaporation of an organic solvent in a plastic tube does not necessarily correlate with the volatility parameters of the organic solvent itself, such as the boiling point, flash point, or evaporation enthalpy of the organic solvent. This is because the permeability of plastics varies depending on the type of organic solvent, and the evaporation rate in a sealed low-density polyethylene tube is rather due to the permeability of plastics, specifically, a parameter due to the chemical structure, molecular weight, compatibility, etc. of the organic solvent.

[0127] Alkylamide-based solvents are solvents that volatilize in a relatively small amount inside a plastic tube, and therefore, a non-aqueous ink composition containing an alkylamide-based solvent can be inkjet-ejected while maintaining the amount of organic solvent component contained in the non-aqueous ink composition.

[0128] The amount of evaporation of an organic solvent inside a plastic tube can be determined by filling a low-density polyethylene tube (a polyethylene tube hose (model number: 6-608-03, low-density polyethylene (PE-LD) with an inner diameter of 3 mm and an outer diameter of 5 mm, manufactured by AS ONE Corporation) with the organic solvent, sealing it, storing it at 50°C for one week, and measuring the amount of evaporation after storage. For example, the evaporation amounts of diethylene glycol dimethyl ether were 68% by mass, diethylene glycol methyl ethyl ether 58% by mass, diethylene glycol diethyl ether 54% by mass, and dipropylene glycol dimethyl ether 59% by mass, while N,N-diethylformamide was 11% by mass, N,N-diethylpropanamide was 12% by mass, and N,N-diethylacetamide was 13% by mass, indicating that alkylamide solvents have a low evaporation amount inside a plastic tube.

[0129] The material of the plastic tube is not particularly limited, but examples include polyolefin resins such as polyethylene resins, ethylene propylene diene rubber, nylon, polyurethane, PTFE, etc. Among these, polyethylene resins and ethylene propylene diene rubber are preferred.

[0130] When the organic solvent (b) and the like contained in the non-aqueous ink composition, which has an evaporation enthalpy (EOV) of 43.5 kJ / mol or less, volatilizes in an inkjet recording apparatus, some of the components of the non-aqueous ink composition may precipitate, causing nozzle clogging and reducing ejection stability. Therefore, the inkjet recording apparatus according to this embodiment is preferably provided with a mechanism capable of clearing nozzle clogging.

[0131] Specifically, the tube connected to the storage mechanism and the inkjet ejection orifice is preferably provided with a valve mechanism for opening and closing the flow path of the non-aqueous ink composition. By supplying the non-aqueous ink composition from the storage mechanism to the inkjet ejection orifice via the valve mechanism, the ejection stability of the non-aqueous ink composition containing a highly volatile solvent can be improved.

[0132] It is also preferable to provide an ink circulation mechanism that circulates the non-aqueous ink composition within the inkjet recording device, which can improve the ejection stability of the non-aqueous ink composition containing a highly volatile solvent.

[0133] In addition, when the inkjet recording device is a device capable of ejecting multiple non-aqueous ink compositions, these storage mechanisms, plastic tubes, and ink circulation mechanisms do not need to be provided for all mechanisms that eject multiple non-aqueous ink compositions, but rather they need to be provided for at least one non-aqueous ink composition.

[0134] 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. [Example]

[0135] 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.

[0136] 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 to 300 g of diethylene glycol diethyl ether maintained at 100°C over 1.5 hours. After the addition was completed, 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 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 30,000 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).

[0137] (2) Vinyl chloride-vinyl acetate copolymer resin An autoclave equipped with a stirrer was charged with 100 parts deionized water, 40 parts methanol, 32 parts vinyl chloride, 5 parts vinyl acetate, 0.2 parts glycidyl methacrylate, 3.55 parts hydroxypropyl acrylate, 0.1 parts hydroxypropyl methylcellulose (suspending agent), 0.026 parts di-2-ethylhexyl peroxydicarbonate (polymerization initiator), and a predetermined amount of di-3,5,5-trimethylhexanol peroxide (polymerization initiator) after nitrogen substitution. The mixture was heated to 63 ° C under a nitrogen gas atmosphere with stirring. Immediately after reaching 63 ° C, 48 parts vinyl chloride was added over 6 hours, and a mixture of 0.6 parts glycidyl methacrylate and 10.65 parts hydroxypropyl acrylate was continuously added over 5.4 hours to carry out the copolymerization reaction. When the internal pressure of the autoclave reached 0.3 MPa, the residual pressure was released, the mixture was cooled, and the resin slurry was removed, filtered, and dried to obtain a vinyl chloride copolymer resin. At this time, the amount of di-3,5,5-trimethylhexanol peroxide, which is a polymerization initiator, was changed to control the weight average molecular weight of the vinyl chloride-vinyl acetate copolymer resin to 40,000 to 75,000 (the mass of the polymerization initiator used at this time is shown in Table 1 below, and is represented as "amount of initiator" in Table 1).

[0138] Table 1 shows the weight-average molecular weight (relative molecular mass) of each resin (acrylic resin, vinyl chloride-vinyl acetate copolymer resin) and the percentage of resins with an intrinsic viscosity of 90 mL / g or more at 25°C. The weight-average molecular weight (relative molecular mass) was measured by GPC (gel permeation chromatography). The percentage of resins with an intrinsic viscosity of 90 mL / g or more was determined by connecting a viscosity detector (WYATT ViscoStar III) and a refractive index detector (WYATT Optilab T-rEX) to a Shimadzu SEC (GPC) system. Using tetrahydrofuran as the developing solvent, the sample was first passed through a column heated to 40°C, and then cooled to 25°C. The passed-through material was measured for specific viscosity [η SP ], and the concentration C is calculated using a refractive index detector. SP ] / C), the intrinsic viscosity was calculated by extrapolating the concentration C to 0.

[0139] [Table 1]

[0140] 2. Preparation of Non-Aqueous Ink Composition Non-aqueous ink compositions of Examples and Comparative Examples were prepared using the organic solvents, resins, dispersants, and pigments (colorants) in the proportions shown in the table below. Specifically, each component was dispersed with zirconia beads using a paint shaker to prepare the non-aqueous ink compositions. The units are % by mass.

[0141] 3. Rating 1 (Surface dryness) The surface drying properties of the non-aqueous ink compositions of the Examples and Comparative Examples were evaluated. Specifically, a solid image was printed using the non-aqueous ink compositions of the Examples and Comparative Examples on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) in high-quality print mode (1440 x 720 dpi) using an inkjet printer (product name VersaArt RE-640, manufactured by Roland DG Corporation)) using the inkjet method, and the time until the ink dried at 40°C was measured (referred to as "surface drying properties" in the table). Evaluation criteria Rating 5: Dries in less than 2 minutes. Rating 4: Dries in 2 to 4 minutes. Rating 3: Dries in 4 to 6 minutes. Rating 2: Dries in 6 to 8 minutes. Rating 1: Dries in 8 minutes or more.

[0142] (bleeding) The non-aqueous ink compositions of the Examples and Comparative Examples were evaluated for bleeding. Specifically, in the same manner as in the evaluation of surface drying property described above, an image with 6-point text of a different color in a solid area of ​​each color 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 resulting print was dried in an oven at 60°C for 5 minutes, after which bleeding of the print was observed visually and with a magnifying glass (x10) (referred to as "Bleeding" in the table). Evaluation criteria Rating 5: No ink bleeding is observed when observed with a magnifying glass. Rating 4: No ink bleeding was observed visually, and 6 pt characters were clear. Rating 3: Slight bleeding of ink was visually observed, but the design was not impaired. Rating 2: Ink bleeding was observed visually, but 6 pt characters were legible. Rating 1: Significant ink bleeding was visually observed, and 6 pt characters were not visible.

[0143] (Filled in completely) The non-aqueous ink compositions of the Examples and Comparative Examples were evaluated for solid printing. Specifically, printing was performed on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) in a bidirectional high-speed printing mode (360 x 720 dpi) at a substrate surface temperature of 40°C in the same manner as in the evaluation of surface drying property described above, and the filling (whiteout) of the solid printed area was confirmed (referred to as "solid printing" in the table). Evaluation criteria Rating 5: A uniform solid color is formed Rating 4: No white spots can be seen with the naked eye, but slight color unevenness can be seen, but the design is not impaired. Rating 3: No white spots can be seen with the naked eye, but color unevenness can be seen Rating 2: White spots can be seen Evaluation 1: Significant white spots are observed, and a decrease in density is observed.

[0144] (Cleaning recovery) For the non-aqueous ink compositions of Examples and Comparative Examples, whether nozzle clogging in the head could be resolved by the printer's cleaning operation was evaluated. Specifically, using the above printer equipped with a cleaning system, the ink compositions of Examples and Comparative Examples were filled and a solid image of 1.80 m2 was printed in high-quality print mode (1440 x 720 dpi), and the printer was left at room temperature of 25°C for one week. Thereafter, a nozzle check pattern was printed and cleaning was performed until no nozzle gaps remained (referred to as "cleaning recovery" in the table). Rating 5: No omissions Rating 4: Clears nozzle clogs with one cleaning. Rating 3: Nozzle clogging is cleared after 2-3 cleanings. Rating 2: Nozzle clogs are cleared after 4 to 5 cleanings. Rating 1: Nozzle clogs are not cleared even after cleaning six times.

[0145] (blocking resistance) The non-aqueous ink compositions of the Examples and Comparative Examples were evaluated for blocking resistance. Specifically, in the same manner as in the evaluation of surface drying property described above, a solid area was printed on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) in high-quality printing mode (1440 x 720 dpi) at a substrate surface temperature of 40°C, and the printed matter was left for 24 hours after being rolled up, and then unrolled, and the backside of the film that overlapped the printed matter surface and the printed matter surface were evaluated (referred to as "blocking resistance" in the table). Evaluation criteria Rating 5: No transfer to the back surface after winding, and no roughness on the surface of the recorded material. Rating 4: There is no bleed-through to the back side after winding, but slight roughness is observed on the surface of the printed matter, but the design is not impaired. Rating 3: After winding, slight transfer to the back side was observed, and slight marks were also observed on the surface of the recorded material. Rating 2: After winding, transfer to the back side is clearly observed, and marks are visible on the surface of the recorded material. Rating 1: After winding, significant ink transfer to the back surface was observed, and the design of the printed surface was significantly impaired.

[0146] (component suitability) The non-aqueous ink compositions of the Examples and Comparative Examples were evaluated for their suitability for components (suitability for inkjet head components). Specifically, an epoxy adhesive (two-component curing epoxy adhesive "1500", manufactured by Cemedine Co., Ltd.) used for inkjet head components was dried at 60°C for one day, and 0.2 g of the cured product was immersed in the ink compositions of the Examples and Comparative Examples and left at 60°C for one week, and an immersion test was performed to measure the change in weight 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 of the epoxy adhesive material. Rating 4: The weight change rate is between 3% and 5%, and there is no deterioration of the epoxy adhesive material. Rating 3: The weight change rate is 5% or more but less than 10%, and there is no deterioration of the epoxy adhesive material. Rating 2: The weight change rate is 10% or more but less than 15%, and there is no deterioration of the epoxy adhesive material. Rating 1: Weight change rate is 15% or more and / or there is deterioration of the epoxy adhesive material.

[0147] [Table 2]

[0148] [Table 3]

[0149] [Table 4]

[0150] [Table 5]

[0151] [Table 6]

[0152] [Table 7]

[0153] [Table 8]

[0154] [Table 9]

[0155] In the table, "MEDG" stands for diethylene glycol methyl ethyl ether.

[0156] In the table, "DEDG" stands for diethylene glycol diethyl ether.

[0157] In the table, "DMFDG" stands for dipropylene glycol dimethyl ether.

[0158] In the table, "EGMBEA" stands for ethylene glycol monobutyl ether acetate.

[0159] In the table, "PMA" stands for propylene glycol monomethyl ether acetate.

[0160] In the table, "3-MBA" stands for 3-methoxybutyl acetate.

[0161] In the table, "DEC" stands for diethyl carbonate.

[0162] In the table, "DMSU" stands for dimethyl succinate.

[0163] In the table, "EGmME" stands for ethylene glycol monomethyl ether.

[0164] In the table, "M100" is N,N-dimethyl-β-methoxypropanamide.

[0165] In the table, "DEF" stands for N,N-diethylformamide.

[0166] In the table, "DEPA" stands for N,N-diethylpropanamide.

[0167] In the table, "DEAA" stands for N,N-diethylacetamide.

[0168] In the table, "DMF" stands for N,N-dimethylformamide.

[0169] In the table, "MFDG" stands for dipropylene glycol monomethyl ether.

[0170] In the table, "MFTG" stands for tripropylene glycol monomethyl ether.

[0171] In the table, "ML" stands for methyl lactate.

[0172] In the table, "3-MBOH" stands for 3-methoxybutanol.

[0173] In the table, "GBL" stands for gamma-butyrolactone.

[0174] In the table, "Solsperse 32000" is a polycaprolactone-based dispersant manufactured by Lubrizol Corporation.

[0175] In the table, "Solsperse 33000" is a polycaprolactone-based dispersant manufactured by Lubrizol Corporation.

[0176] As can be seen from Tables 2 to 9, the non-aqueous ink compositions of the examples, which contain an alkylamide solvent (a) and an organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less, can produce recorded materials with excellent surface drying properties and can effectively suppress bleeding of the print on the resulting recorded materials.

[0177] In particular, among the non-aqueous ink compositions of Examples 1 to 13, in which the content of alkylamide solvent (a) was varied, Examples 2 to 7 and 9 to 13, in which the content of alkylamide solvent (a) was 3% by mass or more of the total amount of the non-aqueous ink composition, produced records with excellent surface drying properties and further reduced bleeding of the print. Furthermore, Examples 1 to 11 and 13, in which the content of alkylamide solvent (a) was 70% by mass or less of the total amount of the non-aqueous ink composition, also suppressed the occurrence of blocking resistance and had good component suitability.

[0178] Furthermore, in the non-aqueous ink compositions of Examples 14 to 24, in which the type of organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less was changed, the non-aqueous ink compositions containing glycol ether dialkyls, glycol ether monoalkyls, acetates, carbonates, dibasic acid esters, amides, and ketones as organic solvents (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less also suppressed the occurrence of blocking and reduced bleeding of the print.

[0179] Furthermore, in Examples 25 to 27 in which the type of alkylamide solvent (a) was changed, the non-aqueous ink compositions of Examples 25 and 26, which contained alkylamide solvent (a) (N,N-diethylformamide, N,N-diethylpropanamide, and N,N-diethylacetamide), had better component suitability than the non-aqueous ink composition of Example 27.

[0180] Furthermore, among the non-aqueous ink compositions of Examples 37 to 49, which varied the content of resin with an intrinsic viscosity of 90 mL / g or more at 25°C, the non-aqueous ink compositions of Examples in which the content of resin with an intrinsic viscosity of 90 mL / g or more at 25°C was in the range of 5 mass% or less of the total amount of resin showed improved solid filling, even compared to the non-aqueous ink compositions of Examples in which the content was in the range of more than 5 mass%.

[0181] On the other hand, the non-aqueous ink compositions of Comparative Examples 1 and 2, which did not contain an alkylamide-based solvent (a) and did not contain an organic solvent that penetrates into resin substrates, exhibited poor surface drying properties and even bleeding in the resulting printed matter. Furthermore, Comparative Example 3, which contained γ-butyrolactone (a lactone-based solvent) and an organic solvent (b) with an evaporation enthalpy (EOV) of 43.5 kJ / mol or less, exhibited offset (anti-blocking) to the back surface of the printed matter.

[0182] 4. Rating 2 The non-aqueous ink composition of Example 7 was ejected by an inkjet method, and the "bleeding" and "solid coverage" were evaluated in the same manner as above. The heating mechanism and the fixing mechanism for fixing the substrate, both of which were provided in the inkjet recording apparatus, were turned on and off as shown in Table 10 below.

[0183] [Table 10]

[0184] As can be seen from Table 10, by using an inkjet recording device equipped with a heating mechanism and a fixing mechanism for fixing the substrate, turning each mechanism "on," and drying the non-aqueous ink composition while the substrate (recording medium) is fixed by the fixing mechanism for fixing the substrate, and then ejecting the non-aqueous ink composition containing an alkylamide solvent (a) and an organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less by the inkjet method, it can be seen that the resulting recorded matter has good "bleed-through" and "solid coverage."

[0185] 5. Rating 3 For the non-aqueous ink composition of Example 14, an inkjet recording device equipped with a valve mechanism was used to evaluate whether nozzle clogging in the head could be cleared by the cleaning operation of the printer. Specifically, the printer equipped with a cleaning system was filled with the non-aqueous ink composition of Example 14 and a solid image was printed at 1.80 m in high quality print mode (1440 x 720 dpi). 2 After printing, the ink was left at room temperature of 25°C for one week, after which a nozzle check pattern was printed and cleaning was performed (shown as "cleaning recovery" in the table). When the valve mechanism was used at this time, the valve mechanism was closed during cleaning to apply negative pressure to the path, and the valve was opened to open and close the ink. Evaluation criteria Rating 2: Nozzle clogs are cleared with one cleaning. Rating 1: Nozzle clogs are not cleared with one cleaning.

[0186] [Table 11]

[0187] As can be seen from Table 11, the provision of a valve mechanism improved cleaning recovery. Therefore, when the nonaqueous ink composition of the present invention containing an alkylamide solvent (a) and an organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less is used in an inkjet recording device equipped with such a valve mechanism, it is possible to enjoy the benefit of being able to obtain recorded matter with excellent drying properties, while effectively overcoming the deterioration in cleaning recovery (maintenance) that is relatively likely to occur when an organic solvent (b) having an evaporation enthalpy (EOV) of 43.5 kJ / mol or less is contained.

[0188] 6. Rating 4 The non-aqueous ink compositions of Example 7 and Comparative Example 3 were ejected onto respective recording media by an inkjet method, and bleeding was confirmed. Specifically, the non-aqueous ink compositions of Example 7 and Comparative Example 3 were printed onto various recording media by the inkjet method using an inkjet printer (trade name MMP-F13, manufactured by Mastermind, Inc.) in high-quality print mode (1440 x 720 dpi) at a substrate surface temperature of 50°C, with images of 6-point text of a different color printed within a solid area of ​​each color. The resulting recorded matter was dried in an oven at 60°C for 5 minutes, and then the recorded matter was visually observed for bleeding using a magnifying glass (x10) (referred to as "Bleeding" in the table). Evaluation criteria Rating 5: No ink bleeding is observed when observed with a magnifying glass. Rating 4: No ink bleeding was observed visually, and 6 pt characters were clear. Rating 3: Slight bleeding of ink was visually observed, but the design was not impaired. Rating 2: Ink bleeding was observed visually, but 6 pt characters were legible. Rating 1: Significant ink bleeding was visually observed, and 6 pt characters were not visible. In the above-mentioned bleeding evaluation, the bleeding was confirmed using the recording media shown in Table 6 below.

[0189] [Table 12]

[0190] In Table 12, "Vinyl chloride" means that a vinyl chloride resin substrate (IMAGinJT5829R manufactured by MACtac) was used as the recording medium.

[0191] In Table 12, "PET1" means that a PET film (polyester film T4100 manufactured by Toyobo Co., Ltd.) was used as the recording medium.

[0192] In Table 12, "PET2" means that a PET film (Lumirror T60 manufactured by Toray Industries, Inc.) was used as the recording medium.

[0193] In Table 12, "acrylic" means that an acrylic plate (Acrylite EX manufactured by Mitsubishi Chemical Corporation) was used as the recording medium.

[0194] In Table 12, "glass" means that a glass plate (float plate glass manufactured by Asahi Glass Co., Ltd.) was used as the recording medium.

[0195] In Table 12, "metal (aluminum)" means that an aluminum composite plate (Color Ace C211FF manufactured by Fukuda Metal Foil and Powder Co., Ltd.) was used as the recording medium.

[0196] In Table 12, "coated paper" means that a paper substrate (OK Topcoat manufactured by Oji Paper Co., Ltd.) was used as the recording medium.

[0197] As can be seen from Table 12, the non-aqueous ink composition of Example 7, which contains an alkylamide solvent (a) and an organic solvent (b) with an evaporation enthalpy (EOV) of 43.5 kJ / mol or less, can effectively suppress bleeding of prints on all substrates, including resin substrates. On the other hand, the non-aqueous ink composition of Comparative Example 3, which contains a lactone solvent instead of the alkylamide solvent (a), caused bleeding of prints on a PET1 substrate.

Claims

1. A non-aqueous ink composition containing an organic solvent and ejected by an inkjet method, The organic solvent is an alkylamide solvent (a); an organic solvent (b) having an enthalpy of vaporization (EOV) of 43.5 kJ / mol or less; containing Non-aqueous ink compositions.

2. The organic solvent (b) contains at least one selected from the group consisting of glycol ether dialkyls, glycol ether monoalkyls, acetates, carbonates, dibasic acid esters, amides, and ketones. The non-aqueous ink composition of claim 1 .

3. the content of the alkylamide solvent (a) is in the range of 1% by mass or more and 90% by mass or less of the total amount of the non-aqueous ink composition; The total content of the alkylamide solvent (a) and the organic solvent (b) is in the range of 70% by mass or more and 95% by mass or less of the total amount of the non-aqueous ink composition. The non-aqueous ink composition according to claim 1 or 2.

4. The alkylamide solvent (a) is represented by the following general formula (1): The non-aqueous ink composition according to any one of claims 1 to 3. 【Chemistry 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.

5. The alkylamide solvent (a) contains at least one selected from the group consisting of N,N-diethylformamide, N,N-diethylpropanamide, and N,N-diethylacetamide. The non-aqueous ink composition according to claim 4.

6. Further containing resin, The resin has an intrinsic viscosity of 90 mL / g or more at 25°C in an amount of 5 mass% or less based on the total amount of resin. The non-aqueous ink composition according to any one of claims 1 to 5.

7. The non-aqueous ink composition is ejected by an inkjet method using an inkjet recording apparatus comprising: a storage mechanism for storing the non-aqueous ink composition; an inkjet ejection port; and a tube for circulating the non-aqueous ink composition, the tube being connected to the storage mechanism and the inkjet ejection port and comprising a valve mechanism for opening and closing a flow path for the non-aqueous ink composition. The non-aqueous ink composition according to any one of claims 1 to 6.

8. Using an inkjet recording device equipped with a plastic tube, ink is ejected through the plastic tube by an inkjet method. The non-aqueous ink composition according to any one of claims 1 to 7.

9. Used for resin substrates The non-aqueous ink composition according to any one of claims 1 to 8.

10. The non-aqueous ink composition according to any one of claims 1 to 9 is ejected onto the surface of a substrate by an inkjet method. Recording method.

11. The non-aqueous ink composition according to any one of claims 1 to 9 is ejected onto the surface of a substrate by an inkjet method. A method for producing recorded materials.

12. The non-aqueous ink composition according to any one of claims 1 to 9 is ejected by an inkjet method. Inkjet recording device.

13. a storage mechanism for storing the non-aqueous ink composition; an inkjet ejection port; a tube for distributing the non-aqueous ink composition; Equipped with the tube is connected to the storage mechanism and the inkjet ejection port, and includes a valve mechanism for opening and closing a flow path for the non-aqueous ink composition; The inkjet recording apparatus according to claim 12.

14. Equipped with an ink circulation mechanism that circulates the non-aqueous ink composition The inkjet recording apparatus according to claim 12 or 13.

15. The heating mechanism and the fixing mechanism for fixing the substrate are provided.

15. The inkjet recording apparatus according to claim 12.

16. A recording layer of the non-aqueous ink composition according to any one of claims 1 to 9 formed on the surface of a substrate. Recorded material.

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