JP7161569B2 - Non-aqueous ink composition, recording method using the same, and method for producing recorded matter - Google Patents

Description

The present invention relates to a non-aqueous ink composition, a recording method using the same, and a method for producing a recorded matter.

As the ink composition, an aqueous ink composition in which a coloring material is dissolved or dispersed in water or a mixture of water and an organic solvent, or a non-aqueous ink composition in which a coloring material is dissolved or dispersed in an organic solvent that does not contain water. is widely used.

For example, Patent Literature 1 describes a technique relating to a non-aqueous ink composition containing multiple organic solvents having a predetermined flash point. In Patent Document 1, this non-aqueous ink composition contains a plurality of organic solvents with different flash points to partially dissolve the recording surface and penetrate the ink composition into the interior of the recording medium. It is described that the abrasion resistance of images can be improved.

Patent No. 6256039

As described in Patent Document 1, the flash point of an organic solvent affects the drying property of the organic solvent, and the lower the flash point of the organic solvent, the higher the volatility of the solvent. Therefore, in a non-aqueous ink composition containing a plurality of organic solvents, the organic solvent with a low flash point volatilizes first.

On the other hand, if such a highly volatile solvent with a low flash point evaporates first, the low volatile organic solvent with a high flash point wets and spreads over the substrate surface. The present inventor's research has revealed that when the ink spreads on the surface of the base material, bleeding of the print occurs.

In addition, if an organic solvent having a large static surface tension is contained in order to suppress such bleeding of the print, the ink jetting from the nozzle of the ink jet recording apparatus will be difficult to run off, making it difficult to perform stable jetting. There was a case.

SUMMARY OF THE INVENTION An object of the present invention is to provide a non-aqueous ink composition that has high ink jet ejection stability and that can effectively suppress bleeding in printing.

As a result of intensive studies to solve the above problems, the present inventors found that the above problems can be solved by a non-aqueous ink composition containing a plurality of organic solvents having a predetermined static surface tension. The present invention has been completed. Specifically, the present invention provides the following.

(1) A non-aqueous ink composition that contains an organic solvent and is ejected by an inkjet method, wherein the organic solvent has a static surface tension of less than 35 mN/m and a flash point of 80° C. or less ( A non-aqueous ink composition comprising a) and an organic solvent (b) having a static surface tension of 35 mN/m or higher and a flash point of 80° C. or higher.

(2) The mass ratio of the contents of the organic solvent (a) and the organic solvent (b) (organic solvent (a):organic solvent (b)) is in the range of 99:1 to 70:30 ( 1) The non-aqueous ink composition described in 1).

(3) The organic solvent (a) contains at least one selected from the group consisting of amide solvents, glycol ether dialkyls, glycol ether monoalkyls, acetates, dibasic acid esters and lactate esters (1) or The non-aqueous ink composition according to (2).

(4) The non-aqueous ink composition according to (3), wherein the organic solvent (a) contains an alkylamide solvent as the amide solvent.

(5) Any one of (1) to (4), wherein the organic solvent (b) contains at least one selected from the group consisting of carbonate ester, cyclic ester, amide solvent, and glycol ether monoalkyl. A non-aqueous ink composition of

(6) The resin according to any one of (1) to (5), which further contains a resin, and the resin has an intrinsic viscosity of 90 mL / g or more at 25 ° C. in a range of 5% by mass or less in the total amount of the resin. Non-aqueous ink composition.

(7) The non-aqueous ink composition according to any one of (1) to (6), which is ejected by an inkjet method using an inkjet recording apparatus comprising a heating mechanism and a fixing mechanism for fixing a substrate. .

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

(9) The non-aqueous ink composition according to any one of (1) to (8), which is used for resin substrates.

(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.

(11) A method for producing 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.

(12) A recorded matter in which a recording layer of the non-aqueous ink composition according to any one of (1) to (9) is formed on the surface of a substrate.

The non-aqueous ink composition of the present invention has high ink jet ejection stability, and can effectively suppress print bleeding.

Hereinafter, specific embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments at all, and can be implemented with appropriate modifications within the scope of the purpose of the present invention. can do. Further, in this specification, the notation "~" means "more than" and "less than", and the notation "X: Y to A: B" means "X: Y" and "A: B" themselves. and means a range between "X:Y" and "A:B".

<1. Non-Aqueous Ink Composition>
The non-aqueous ink composition according to the present embodiment is a non-aqueous ink composition that contains an organic solvent and is ejected by an inkjet method, wherein the organic solvent has a static surface tension of less than 35 mN/m and is flammable. It is characterized by containing an organic solvent (a) having a point of 80° C. or lower and an organic solvent (b) having a static surface tension of 35 mN/m or higher and a flash point of 80° C. or higher.

With such a non-aqueous ink composition, ink ejection stability is high, and blurring of printing can be effectively suppressed.

Here, the term “non-aqueous ink composition” means an ink composition that does not contain water (an oil-based ink composition), in which a coloring material is dissolved or dissolved in water or a mixture of water and an organic solvent. It differs from dispersed aqueous ink compositions. In the present specification, the phrase "water-free" does not take into account water that is unavoidably contained due to moisture in the air or additives.

The non-aqueous ink composition according to the present embodiment may be a colored ink containing a coloring material (including a colored coloring material and a black-white coloring material). It may be an ink containing a luster pigment (scale-like metal particles) for giving a metallic tone, or a clear ink containing no coloring material. In the case of a clear ink that does not contain a coloring material, inks for forming a layer having a desired function can be used. Such inks include, for example, an overcoat ink composition for forming an overcoat layer that protects a recorded article (substrate), a matting ink composition for matting a recorded article (substrate), and a weather resistant layer. Inks containing ultraviolet absorbers, light stabilizers, etc. for forming

In this specification, the flash point of the organic solvent is the flash point by the Cleveland open flash point tester if the flash point by the closed tag flash point tester is not 80 ° C. or less, and the closed tag flash point tester If the flash point is 80 ° C or less, if the dynamic viscosity of the solvent at the flash point is less than 10 cSt, the flash point is determined by the closed tag flash point tester, and if the dynamic viscosity of the solvent at the flash point is 10 cSt or more is the flash point determined by the Seta closed-type flash point tester.

Each component contained in the non-aqueous ink composition according to the present embodiment will be described below.

[Organic solvent]
The organic solvent includes an organic solvent (a) having a static surface tension of less than 35 mN/m and a flash point of 80°C or less, and an organic solvent (a) having a static surface tension of 35 mN/m or more and a flash point of 80°C or more ( b) and

(Organic solvent (a))
The organic solvent (a) is an organic solvent having a static surface tension of less than 35 mN/m and a flash point of 80° C. or lower. By containing such an organic solvent (a), the ejection stability of the non-aqueous ink composition can be improved.

Then, after the non-aqueous ink composition is ejected by inkjet and lands on the substrate (recording medium), the organic solvent (a) with a lower flash point evaporates first, so the organic solvent with a low static surface tension ( (a) does not affect the occurrence of print bleeding, and the organic solvent (b) described later, having a static surface tension of 35 mN/m or more and a flash point of 80° C. or more, effectively suppresses print bleeding. can be done.

The static surface tension of the organic solvent (a) is preferably less than 34 mN/m, more preferably less than 33 mN/m, even more preferably less than 32 mN/m. The lower limit of the static surface tension of the organic solvent (a) is not particularly limited, but is preferably in the range of 20 mN/m or more, more preferably in the range of 23 N/m or more, and 25 N/m or more. is more preferably in the range of

In this specification, the static surface tension is a value measured at a measurement temperature of 25° C. by the Wilhelmy method (manufactured by Kyowa Interface Science, model: DY-300).

Although the upper limit of the flash point of the organic solvent (a) depends on the type of the organic solvent (a), it is preferably in the range of 79°C or less, more preferably in the range of 78°C or less, and 75°C or less. is more preferably in the range of Although the lower limit of the flash point of the organic solvent (a) depends on the type of the organic solvent (a), it is preferably in the range of 40°C or higher, more preferably in the range of 45°C or higher, and 50°C or higher. is more preferably in the range of

As such an organic solvent (a), amide solvents, glycol ether dialkyls, glycol ether monoalkyls, acetates, dibasic acid esters and lactate esters are preferable, and among these, alkylamide solvents are contained as amide solvents. is particularly preferred. An alkylamide solvent is a compound having an alkyl group (C _n H _2n+1 -) and a -C(=O)-N- group (amide bond), wherein hydrogen or an alkyl group and -C(=O)- It is a solvent consisting of a compound composed of N-groups.

The alkylamide-based solvent dries quickly on the substrate surface. Therefore, by including an alkylamide solvent, it is possible to obtain recorded matter having excellent surface drying properties. Further, the alkylamide-based solvent (a) penetrates to some extent into the substrate (recording medium) whose surface is mainly made of resin. Therefore, by containing the alkylamide-based solvent (a) and the organic solvent (b) described later, it is possible to more effectively suppress the blurring of the print, resulting in clearer print.

As the alkylamide-based solvent, those having, for example, the following structures can be preferably used.

（式（１）中、Ｒ_１は、水素若しくは炭素数１以上４以下のアルキル基であり、Ｒ_２Ｒ_３は、それぞれ独立して、水素もしくは炭素数１以上４以下のアルキル基を表す。）

(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. )

R ₂ and R ₃ in formula (1) are preferably alkyl groups having 1 to 4 carbon atoms, and more preferably alkyl groups having 2 to 4 carbon atoms.

Specific examples of alkylamide solvents include N,N-dimethylacetamide (32.4 N/m), N,N-diethylformamide (31.7 mN/m), N,N-diethylacetamide (29.1 mN /m), N,N-diethylpropanamide (26.1 mN/m), and the like. Among these, from the viewpoint of particularly exhibiting 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. preferable.

Glycol ether dialkyl includes diethylene glycol methyl ethyl ether (27.7 mN/m), diethylene glycol diethyl ether (27.0 mN/m), dipropylene glycol dimethyl ether (21.0 mN/m), ethylene glycol dimethyl ether (23.5 mN/m ), ethylene glycol diethyl ether (24.5 mN/m), diethylene glycol dimethyl ether (25.6 mN/m), and the like.

Examples of glycol ether monoalkyl include dipropylene glycol monomethyl ether (29.0 mN/m), ethylene glycol monomethyl ether (27.7 mN/m), ethylene glycol monoisopropyl ether (27.8 mN/m), ethylene glycol monobutyl ether ( 27.7 mN/m) and the like.

Acetates include ethylene glycol monobutyl ether acetate (27.0 mN/m), propylene glycol monomethyl ether acetate (27.0 mN/m), 3-methoxybutyl acetate (28.0 mN/m), and the like.

Examples of dibasic acid ester include diethyl oxalate (32.2 mN/m).

Examples of lactate include methyl lactate (31.0 mN/m) and ethyl lactate (29.0 mN/m).

The content of the organic solvent (a) is not particularly limited, but the lower limit of the content of the organic solvent (a) is preferably 30% by mass or more based on the total amount of the non-aqueous ink composition, and preferably 60% by mass or more. is more preferable, and 75% by mass or more is even more preferable. The upper limit of the content of the organic solvent (a) is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 88% by mass or less in the total amount of the non-aqueous ink composition. .

(Organic solvent (b))
The organic solvent (b) is an organic solvent having a static surface tension of 35 mN/m or higher and a flash point of 80° C. or higher. By containing such an organic solvent (b), it is possible to effectively suppress bleeding of printing due to wetting and spreading on the substrate surface.

The lower limit of the static surface tension of the organic solvent (b) is preferably 37 mN/m or more, more preferably 38 mN/m or more, and even more preferably 40 mN/m or more. The upper limit of the static surface tension of the organic solvent (a) is not particularly limited, but is preferably 60 mN/m or less, more preferably 55 N/m or less, and 50 N/m or less. More preferred.

Although the lower limit of the flash point of the organic solvent (b) depends on the type of the organic solvent (b), it is preferably 90°C or higher, more preferably 95°C or higher, and further preferably 100°C or higher. preferable. The upper limit of the flash point of the organic solvent (b) depends on the type of the organic solvent (b), but is preferably 170° C. or less, more preferably 160° C. or less, and 150° C. or less. More preferred.

As such an organic solvent (b), carbonic acid esters, amide-based solvents, and glycol ether monoalkyls are preferred, and among these, it is particularly preferred to contain carbonic acid esters.

Specific examples of carbonate esters include propylene carbonate (41.6 mN/m) and the like.

Specific examples of cyclic esters include γ-butyrolactone (44.1 mN/m) and ε-caprolactone (42.0 mN/m).

Specific examples of amide solvents include 3-methyl-2-oxazolidinone (46.8 mN/m).

Examples of glycol ether monoalkyl include tetraethylene glycol monobutyl ether (39.0 mN/m) and diethylene glycol monophenyl ether (44.9 mN/m).

The content of the organic solvent (b) is not particularly limited. The range is more preferable, and the range of 3% by mass or more is even more preferable. The upper limit of the content of the organic solvent (b) is preferably 35% by mass or less, more preferably 30% by mass or less, and 25% by mass or less in the total amount of the non-aqueous ink composition. is more preferable.

(Mass ratio of content of organic solvent (a) and organic solvent (b))
The mass ratio of the contents of the organic solvent (a) and the organic solvent (b) (organic solvent (a):organic solvent (b)) is preferably in the range of 99:1 to 70:30, and 99: It is more preferably within the range of 1 to 75:25, more preferably within the range of 99:1 to 80:20. By setting the amount in such a range, the effect of the present invention that ink ejection stability is high and print bleeding can be effectively suppressed can be more effectively enjoyed.

(Other organic solvents)
The organic solvent may contain an organic solvent other than the above organic solvent (a) and organic solvent (b). The flash point and surface tension of these other organic solvents are not particularly limited.

Specifically, alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl isopropyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, methyl-n-amyl 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, ketones such as acetyl ketone, methyl acetate, ethyl acetate, -n-propyl acetate, isopropyl acetate, -n-butyl acetate, isobutyl acetate, hexyl acetate, acetic acid esters such as octyl acetate, Lactate esters such as butyl lactate, propyl lactate, ethylhexyl lactate, amyl lactate and isoamyl lactate; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and dipropylene glycol; Acetates, saturated hydrocarbons such as n-hexane, isohexane, n-nonane, isononane, dodecane and isododecane, unsaturated hydrocarbons such as 1-hexene, 1-heptene and 1-octene, cyclohexane, cycloheptane and cyclocyclohexane Cyclic saturated hydrocarbons such as octane, cyclodecane and decalin; cyclic unsaturated hydrocarbons such as cyclohexene, cycloheptene, cyclooctene, 1,1,3,5,7-cyclooctatetraene and cyclododecene; benzene, toluene, xylene morpholines such as N-methylmorpholine, N-ethylmorpholine and N-formylmorpholine; terpene solvents; ether solvents such as triethylene glycol mono-n-butyl ether; Common organic solvents such as amide solvents such as N-dimethyl-β-methoxypropanamide can be used. It is preferable to select a solvent with an appropriate HLB value according to the resin, dispersant, etc. to be combined.

When other organic solvent is contained, the content of the other organic solvent is not particularly limited, but the lower limit of the content of the other organic solvent is in the range of 1% by mass or more based on the total amount of the non-aqueous ink composition. is preferred, the range of 2% by mass or more is more preferred, and the range of 3% by mass or more is even more preferred. The upper limit of the content of other organic solvents is preferably 10% by mass or less, more preferably 9% by mass or less, and even more preferably 8% by mass or less.

[resin]
The non-aqueous ink composition according to the present embodiment may contain no resin, but may contain a resin. By containing the resin, the fixability, water resistance and stretchability of the recording layer formed from the non-aqueous ink composition can be improved. Furthermore, the glossiness of the obtained recorded matter can be improved.

Examples of resins include, but are not limited to, acrylic resins, polystyrene resins, polyester resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride vinyl acetate copolymer resins, polyethylene resins, polyurethane resins, and rosin. Modified resin, phenol resin, terpene resin, polyamide resin, vinyl toluene-α-methylstyrene copolymer, ethylene-vinyl acetate copolymer, cellulose resin, silicone (silicon) resin, acrylamide resin, Epoxy resins, or copolymer resins or mixtures thereof can be used. Among these, those containing acrylic resins, vinyl chloride-vinyl acetate copolymer resins, cellulose resins, polyester resins, or polyurethane resins are preferable.

The acrylic resin is not particularly limited as long as it is contained as a main component of the monomer constituting the (meth)acrylic acid ester monomer. The acrylic resin may be a homopolymer of one kind of radically polymerizable monomer, or may be a copolymer of two or more kinds of selected radically polymerizable monomers. A preferred acrylic resin for the oil-based ink composition according to the embodiment is a homopolymer of methyl methacrylate, or selected from the group consisting of methyl methacrylate, butyl methacrylate, ethoxyethyl methacrylate, and benzyl methacrylate. It is a copolymer with at least one compound. Examples of commercially available (meth)acrylic resins include "Paraloid B99N", "Paraloid B60", "Paraloid B66" and "Paraloid B82" manufactured by Rohm and Haas.

A vinyl chloride-vinyl acetate copolymer resin is a polymer of vinyl chloride monomer and vinyl acetate monomer. Vinyl chloride-vinyl acetate copolymer resins include, for example, 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 copolymers, etc., and mixtures thereof. Examples of the vinyl chloride-vinyl acetate copolymer resins include "SOLBIN C", "SOLBIN CL", "SOLBIN CNL", "SOLBIN CLL", "SOLBIN CLL2", and "SOLBIN C5R" from Nissin Chemical Industry Co., Ltd. ”, “SOLBIN TA2”, “SOLBIN TA3”, “SOLBIN A”, “SOLBIN AL”, “SOLBIN TA5R”, “SOLBIN M5” and the like, and used in the present invention.

A vinyl chloride-vinyl acetate copolymer resin can be obtained by polymerizing a vinyl chloride monomer and a vinyl acetate monomer. A conventionally known polymerization method may be used as the polymerization method. The polymerization method is preferably emulsion polymerization or suspension polymerization, more preferably suspension polymerization.

A cellulose-based resin is a resin having a cellulose skeleton obtained by biologically or chemically introducing a functional group using cellulose as a raw material. For example, cellulose-based resins include cellulose acetate butyrate resins, cellulose acetate propionate resins, cellulose acetate alkylate resins such as cellulose acetate propionate butyrate resins, cellulose acetate resins, nitrocellulose resins, and mixtures thereof. mentioned. Examples of the above cellulose resins include "CAB551-0.01", "CAB551-0.2", "CAB553-0.4", "CAB531-1", "CAB381-0.1", "CAB381-0.5", and "CAB381" available from EASTMAN. -2", "CAB381-20", "CAP504", "CAP482-0.5", and the like.

A polyester resin contains at least a structural unit obtained by polycondensation of an alcohol component and a carboxylic acid component. The polyester-based resin may include a modified polyester-based resin. Examples of the polyester-based resins include "VYLON226", "VYLON270", "VYLON560", "VYLON600", "VYLON630", "VYLON660", "VYLON885", "VYLONGK250", "VYLONGK810", and "VYLON GK890" manufactured by Toyobo Co., Ltd. etc., and Unitika's product names such as "elitleUE-3200", "elitleUE-3285", "elitleUE-3320", "elitleUE-9800" and "elitleUE-9885".

A polyurethane resin contains at least a structural unit obtained by copolymerizing an alcohol component and an isocyanate component. Polyurethane-based resins may include polyurethane-based resins modified with polyester, polyether, or caprolactone. Examples of the polyurethane-based resins include "Uriano KL-424", "Uriano KL-564", "Uriano KL-593", and "Uriano 3262" available from Arakawa Chemical Industries, Ltd., and "Pandex 372E" and "Uriano 372E" available from DIC. Pandex 390E”, “Pandex 394E”, “Pandex 304”, “Pandex 305E”, “Pandex P-870”, “Pandex P-910”, “Pandex P-895”, “Pandex 4030", "Pandex 4110", and the like.

These acrylic resins, vinyl chloride-vinyl acetate copolymer resins, cellulose resins, polyester resins, and polyurethane resins may be used alone, but they may be used in combination. is preferable, and it is more preferable to use a resin obtained by mixing 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 so as to meet the requirements for color development, drying properties, coating properties, printability, etc. required for non-aqueous inks. When the acrylic resin and the vinyl chloride-vinyl acetate copolymer resin are mixed, the mixing ratio is not particularly limited and can be changed as appropriate.

The weight average molecular weight (relative molecular mass) of the resin is not particularly limited, but is preferably 5,000 or more, more preferably 15,000 or more. The weight average molecular weight (relative molecular mass) is preferably 100,000 or less, more preferably 50,000 or less. Relative molecular weights of resins can be measured by conventional GPC (gel permeation chromatography).

The resin contained in the non-aqueous ink composition is preferably contained at a rate of 0.05% by mass or more, more preferably at a rate of 0.1% by mass or more, based on the total amount of the non-aqueous ink composition. It is more preferable to contain at a rate of 0.5% by mass or more. The resin contained in the non-aqueous ink composition is preferably contained at a ratio of 20.0% by mass or less, more preferably 15.0% by mass or less, based on the total amount of the non-aqueous ink composition. It is more preferable to contain at a rate of 10.0% by mass or less.

Further, the resin contained in the non-aqueous ink composition according to the present embodiment preferably has a resin having an intrinsic viscosity of 90 mL/g or more at 25° C. in a range of 5% by mass or less in the total amount of the resin. The non-aqueous ink composition according to the present embodiment contains a plurality of organic solvents having a predetermined static surface tension, so that the composition has high inkjet ejection stability, and has an intrinsic viscosity of 90 mL/g or more. When the resin is in the range of 5% by mass or less based on the total amount of the resin, the jetting stability of inkjet can be made extremely high.

In this specification, the intrinsic viscosity is the specific viscosity after the target resin is dispersed in a developing solvent and the molecules contained in the resin are separated by a column filled with granular gel in GPC (gel permeation chromatography) [ η _SP ]((η−η ₀ )/η ₀ (η ₀ : solvent viscosity, η: solution viscosity)) and concentration C are obtained, and the concentration C is set to 0 in the formula Lim ([η _SP ]/C). It can be obtained by interpolation (C→0). Although the developing solvent is not particularly limited, for example, tetrahydrofuran can be used.

The content of the resin having an intrinsic viscosity of 90 mL/g or more at 25° C. is preferably 4.0% by mass or less, more preferably 3.5% by mass or less, more preferably 2.5% by mass, based on the total amount of the resin. % or less is even more preferable.

[Color material]
The non-aqueous ink composition according to this embodiment may contain a coloring material. The coloring material is not particularly limited, and may be a dye-based or a pigment-based coloring material. pigment-based coloring materials) are preferably used. Pigments that can be used in the non-aqueous ink composition according to the present embodiment are not particularly limited, and include organic pigments or inorganic pigments that are used in conventional ink compositions. These may be used individually by 1 type, or may be used in combination of 2 or more type. Note that the non-aqueous ink composition according to the present embodiment may not contain a coloring material.

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 dispersing aid (pigment derivative), which will be described later.

Specific organic pigments include, for example, insoluble azo pigments, soluble azo pigments, derivatives from dyes, phthalocyanine-based organic pigments, quinacridone-based organic pigments, perylene-based organic pigments, perinone-based organic pigments, azomethine-based organic pigments, and anthraquinone-based pigments. Organic pigments (anthrone-based organic pigments), xanthene-based organic pigments, diketopyrrolopyrrole-based organic pigments, dioxazine-based organic pigments, nickel azo-based pigments, isoindolinone-based organic pigments, pyranthrone-based organic pigments, thioindigo-based organic pigments, condensed azo organic solid solution pigments such as organic pigments, benzimidazolone organic pigments, quinophthalone organic pigments, isoindoline organic pigments, quinacridone solid solution pigments, perylene solid solution pigments, and other pigments such as lake pigments and carbon black. be done.

When organic pigments are exemplified by color index (C.I.) numbers, C.I. 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. 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. I. Pigment Orange 16, 36, 43, 51, 55, 59, 61, 64, 71, 73, C.I. I. pigment violet 19, 23, 29, 30, 37, 40, 50, C.I. I. Pigment Blue 15, 15:1, 15:3, 15:4, 15:6, 16, 22, 60, 64, C.I. I. Pigment Green 7, 36, 58, 59, 62, 63, C.I. I. Pigment Brown 23, 25, 26, C.I. I. Pigment Black 7 and the like.

Specific examples of dyes that can be used in the non-aqueous ink composition according to the present embodiment include azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, cyanine dyes, squarylium dyes, and croconium dyes. Dyes, merocyanine dyes, stilbene dyes, diarylmethane dyes, triarylmethane dyes, fluorane dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes such as indigoids, fulgide dyes, nickel complex dyes, and Azulene dyes can be mentioned.

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

In the non-aqueous ink composition according to the present embodiment, the average dispersed particle size of the pigment that can be contained is not particularly limited as long as the desired color development is possible. Although it varies depending on the type of pigment used, the volume average particle diameter is preferably 5 nm or more, preferably 20 nm or more, from the viewpoint of good dispersibility and dispersion stability of the pigment and obtaining sufficient coloring power. is more preferable, and 30 nm or more is even more preferable. When the volume average particle size is at least the above lower limit, the light resistance of the non-aqueous ink composition can be improved. The volume average particle size is preferably 300 nm or less, more preferably 200 nm or less, and even more preferably 150 nm or less. The non-aqueous ink composition according to the present embodiment contains a plurality of organic solvents having a predetermined static surface tension, so that the ink jet ejection stability is high, and the volume average particle diameter of the pigment is is equal to or less than the upper limit of the ink jet ejection stability can be made extremely high. In the present embodiment, the volume average particle diameter of the pigment is the volume average particle diameter (D50 ).

In the ink set containing a plurality of non-aqueous ink compositions according to the present embodiment, the volume average particle diameters of the pigments contained in the respective non-aqueous ink compositions may be the same or different. may For example, in the case of an ink set containing the cyan ink and the magenta ink of the non-aqueous ink composition according to the present embodiment, the volume average particle diameter of the pigment contained in the cyan ink and the volume average particle diameter of the pigment contained in the magenta ink and may be the same or different.

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

In addition, the non-aqueous ink composition according to the present embodiment is not particularly limited in the color to be recorded (printed), and coloring materials may be selected and used in combination depending on the intended color. Colors can also be used for each color ink such as yellow, magenta, cyan, black, light magenta, light cyan, light black, orange, green, red, white, and the like. At this time, in the ink set containing the non-aqueous ink composition according to the present embodiment, coloring materials of the same color may be selected.

[Dispersant]
A dispersant may be used as necessary in the non-aqueous ink composition according to the present embodiment. Any dispersant used in non-aqueous ink compositions can be used as the dispersant. As the dispersant, a polymer dispersant is preferably used. Such a dispersant has a main chain of polyester, polyacrylic, polyurethane, polyamine, polycaprolactone, etc., and has a polar group such as an amino group, a carboxyl group, a sulfone group, or a hydroxyl group as a side chain. is. For polyacrylic dispersants, for example, 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 Vic Chemie), Efka PX4310, PX4320, PX4330, PA4401, 4402, PA4403, 4570, 7411, 7477, PX4700, PX4701 (manufactured by BASF), TREPLUS D-1200, D-1410, D-1420, MD-1000 (manufactured by Otsuka Chemical Co., Ltd.), Floren DOPA-15BHFS, 17HF, 22, G-700, 900, NC-500, GW-1500 (manufactured by Kyoeisha Chemical Co., Ltd.), and the like are used. Polycaprolactone-based dispersants include, for example, Ajisper PB821, PB822, PB881 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), Hinoact KF-1000, T-6000, T-7000, T-8000, T-8000E, T-9050 ( Kawaken Fine Chemicals Co., Ltd.), Solsperse 20000, 24000, 32000, 32500, 32550, 32600, 33000, 33500, 34000, 35200, 36000, 37500, 39000, 71000, 76400, 76500, 86000, 88000, J10 TEGO Dispers 652, 655, 685, 688, 690 (manufactured by Evonik Japan) and the like are used.好ましい分散剤としては、ＢＹＫＪＥＴ－９１３０、９１３１，９１３２，９１３３，９１５１、ＥｆｋａＰＸ４３１０、ＰＸ４３２０、ＰＸ４３３０、ＰＸ４７００、ＰＸ４７０１、Ｓｏｌｓｐｅｒｓｅ２００００、２４０００、３２０００、３３０００、３３５００、３４０００、３５２００、３９０００、７１０００、７６５００、８６０００、 88000, J180, J200, TEGO Dispers 655, 685, 688, 690, etc. are used. These individual or mixtures thereof can be used.

[Dispersing aid]
A dispersing aid may be used as necessary in the non-aqueous ink composition according to the present embodiment. The dispersing aid is adsorbed on the surface of the coloring material (pigment), and the functional group increases affinity with the organic solvent and dispersant in the non-aqueous ink composition, thereby improving dispersion stability. As the dispersing 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.

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

[Surfactant]
The non-aqueous ink composition according to this embodiment may contain a surfactant. In particular, the non-aqueous ink composition according to the present embodiment does not necessarily contain a surfactant, but contains a plurality of organic solvents having a predetermined static surface tension. By containing an activator, the ink composition can be prevented from volatilizing and solidifying in devices such as nozzles and tubes. can be done. In addition, by containing a surfactant, the surface tension can be lowered, and the wettability with the recording medium (substrate) can be moderately improved to the extent that bleeding does not occur in printing.

Examples of such surfactants include polyoxyalkylene alkyl ethers such as nonionic 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 NOF Corporation), 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.), Adekatol NP-620, NP-650 , NP-660, NP-675, NP-683, NP-686, Adekacol CS-141E, TS-230E (manufactured by Adeka Co., Ltd.), Solgen 30V, 40, TW-20, TW-80, Neugen CX- 100 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), it is preferable to use a fluorine-modified polymer as a fluorine-based surfactant, and as a specific example, BYK-340 (manufactured by BYK-Chemie Japan), etc., a silicon-based interface As the activator, it is preferable to use polyester-modified silicone or polyether-modified silicone. Specific examples include BYK-313, 315N, 322, 326, 331, 347, 348, BYK-UV3500, 3510, 3530, 3570 ( Specific examples of acetylene glycol-based surfactants include Surfynol (registered trademark) 82, 104, 465, 485, TG (all manufactured by Air Products Japan), Olfin ( (registered trademark) STG, E1010 (both manufactured by Nisshin Chemical Co., Ltd.), and the like.

Surfactants are not limited to those described above, and anionic, cationic, amphoteric or nonionic surfactants may be used, and may be appropriately selected according to the purpose of addition.

In the non-aqueous ink composition according to the present embodiment, the content of the surfactant is not particularly limited, but the lower limit of the content of the surfactant is 0.01% by mass in the total amount of the non-aqueous ink composition. The above range is preferable, the range of 0.05% by mass or more is more preferable, and the range of 0.1% by mass or more is even more preferable. When the content of the surfactant is 0.01% by mass or more based on the total amount of the non-aqueous ink composition, the ejection stability can be further improved. The lower limit of the surfactant content is preferably 5.0% by mass or less, more preferably 1.0% by mass or less, and 0.5% by mass of the total amount of the non-aqueous ink composition. More preferably, it is in the range of mass % or less. When the content of the surfactant is in the range of 5.0% by mass or less in the total amount of the non-aqueous ink composition, it is possible to suppress the bleeding of the print due to the non-aqueous ink composition spreading excessively, and the bleeding of the print can be suppressed. can be effectively suppressed.

[Other ingredients]
The non-aqueous ink composition according to the present embodiment contains stabilizers such as antioxidants and ultraviolet absorbers, epoxides and the like, polyvalent carboxylic acids, surface modifiers, slip agents, leveling agents (acrylic, silicone, etc.). ), antifoaming agents, pH adjusters, bactericides, preservatives, deodorants, charge control agents, wetting agents, and other known additives as optional components. Specific examples of antioxidants include hindered phenol-based antioxidants, amine-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, hydrazine-based antioxidants, and the like. Specific examples include BHA (2,3-butyl-4-oxyanisole) and BHT (2,6-di-t-butyl-p-cresol). Moreover, a benzophenone-based compound or a benzotriazole-based compound can be used as the ultraviolet absorber. 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). exemplified. Specific examples of polycarboxylic acids include citric acid and maleic acid.

<2. Method for producing ink composition>
The method for producing an ink composition according to the present embodiment comprises an organic solvent (a) having a static surface tension of less than 35 mN/m and a flash point of 80° C. or less, and a static surface tension of 35 mN/m or more, and It can be produced by mixing an organic solvent (b) having a flash point of 80° C. or higher and each main component (for example, a resin, a coloring material, etc.) using a paint shaker. At this time, each component may be dispersed with zirconia beads.

Note that the non-aqueous ink composition according to the present embodiment may be adjusted to a desired dissolved oxygen content and dissolved nitrogen content by performing a deaeration treatment or the like, if necessary. Further, since the non-aqueous ink composition according to the present embodiment has a flash point of 60° C. or higher, volatilization of the organic solvent contained in the non-aqueous ink composition can be suppressed.

Moreover, 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. As a method for drying the organic solvent, for example, a method of spraying an inert gas (e.g., nitrogen gas) dried in an inert gas atmosphere such as nitrogen for a predetermined time, a method of distilling and refining the organic solvent, and water are selected. Examples include a method of allowing the organic solvent to permeate through a semi-permeable membrane that selectively permeates the organic solvent, and a method of selectively adsorbing water mixed in the organic solvent with a water adsorbent that adsorbs water.

<3. Recording Method Using Ink Composition>
The recording method according to the present embodiment is a recording method in which the above non-aqueous ink composition is ejected onto the surface of a substrate by an inkjet method. The above non-aqueous ink composition has high ink jet ejection stability and can effectively suppress print bleeding. , printing blur can be effectively suppressed. A method of ejecting ink by an inkjet method may be a piezo method using a piezoelectric element or a thermal method using a heating element, and is not particularly limited.

Then, it is preferable to heat the non-aqueous ink composition that has landed on the substrate (recording medium) by a heating mechanism provided in the inkjet recording apparatus. This makes it possible to preferentially volatilize the organic solvent (a) contained in the non-aqueous ink composition by heating the non-aqueous ink composition that has landed on the substrate (recording medium). Since the organic solvent (b), which has a high static surface tension and does not spread easily, is slowly volatilized later, it is possible to more effectively suppress bleeding of the print. The same applies to the method of manufacturing a printed matter, which will be described later.

<4. Method for producing printed matter>
A recording method using the above ink composition can also be defined as a method for producing a printed matter. Also in the method for producing a printed matter according to the present embodiment, the ejection stability of the inkjet is high, and bleeding of the print can be effectively suppressed.

<5. Records>
Each layer constituting the recorded matter manufactured by the method for manufacturing the recorded matter of the above-described embodiment will be described.

[Medium (recording medium)]
The base material (recording medium) that can be used in the recording method according to the present embodiment is not particularly limited, and non-materials such as resin base materials (including those whose surface is mainly made of resin), metal plate glass, etc. It may be an absorbent substrate, an absorbent substrate such as paper or fabric, or a surface-coated substrate such as a substrate having a receiving layer. material can be used.

Among these, since the above non-aqueous ink composition is a non-aqueous ink composition that does not contain water, it is preferable that the surface is mainly made of a resin. In particular, when the non-aqueous ink composition wets and spreads on a non-absorbent substrate such as a substrate whose surface is mainly made of resin or a metal plate glass, bleeding of the print may occur, but it has a predetermined static surface tension. The above non-aqueous ink composition containing a plurality of organic solvents can effectively suppress print bleeding even on non-absorbent substrates such as resin substrates. Examples of resins constituting such non-absorbent base materials include polyvinyl chloride-based polymers, acryl, PET, polycarbonate, PE, and PP. Further, it may be used for a resin base material (so-called resin base material for lamination) on the premise that a film is attached to the recording surface of a recorded matter. In particular, a base material (recording medium) whose surface is made of a hard or soft polyvinyl chloride polymer is preferred. Examples of the substrate (recording medium) whose surface is made of a polyvinyl chloride polymer include polyvinyl chloride substrates (films or sheets).

[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 that forms a desired image. By ejecting the above non-aqueous ink composition, it is possible to obtain a recorded matter having excellent surface drying property and showing a clear image without blurring.

The layer formed by evaporating the solvent contained in the non-aqueous ink composition may be formed from a plurality of layers. A layer of color ink (for example, yellow, magenta, cyan, black) of the above non-aqueous ink composition may be formed on the substrate.

[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 for the purpose of further imparting abrasion resistance and glossiness to the recorded matter. Further, a layer having an uneven surface (a matte surface) may be formed by adding a filler or changing the film thickness for each pixel. Moreover, in order to impart weather resistance to the recorded matter, a weather resistant layer containing an ultraviolet absorber, a light stabilizer, etc., a glittering layer containing a glittering pigment, or the like may be formed.

In the recorded matter according to the present embodiment, the recorded matter including the recording layer formed with the above non-aqueous ink composition has been described. Alternatively, the above non-aqueous ink composition may be ejected to form a layer having a desired function. Further, a layer having a desired function may be formed by ejecting the above non-aqueous ink composition on the recording layer formed with the above non-aqueous ink composition.

<6. Inkjet recording device>
A conventionally known inkjet recording apparatus that ejects the above non-aqueous ink composition by an inkjet method can be used. For example, an inkjet printer such as VersaArt RE-640 manufactured by Roland DG Co., etc. can be used.

As an example of the configuration of the inkjet recording apparatus, an on-carriage type and serial printer type inkjet recording apparatus will be described. It may be an off-carriage type inkjet recording device fixed to the head, or a line printer type inkjet recording device in which the ink composition is ejected onto the recording medium (substrate) without moving the inkjet head. good.

Also, the inkjet recording apparatus preferably includes a heating mechanism and a fixing mechanism for fixing the substrate. The organic solvent contained in the non-aqueous ink composition is dried by controlling the substrate surface temperature with a heating mechanism provided in the inkjet recording apparatus and drying the non-aqueous ink composition that has landed on the substrate (recording medium). It is possible to preferentially evaporate (a), and the organic solvent (b), which has a high static surface tension and is difficult to spread, is slowly volatilized later, so that the bleeding of the print can be more effectively prevented. can be suppressed.

Furthermore, the fixing mechanism for fixing the base material makes it possible to dry the non-aqueous ink composition while the base material (recording medium) is fixed. Uniformity can be suppressed. This makes it possible to effectively dry the non-aqueous ink composition that has landed on the substrate (recording medium). This makes it possible to more effectively suppress print bleeding.

The heating mechanism provided in the inkjet recording apparatus may be a pre-heater, a platen heater, an after-heater, or the like, or may be a mechanism for blowing warm air onto the recorded matter. Also, a plurality of these heating mechanisms may be combined.

The surface temperature of the substrate heated by the heating mechanism is not particularly limited as long as the organic solvent contained in the non-aqueous ink composition can be volatilized, and the lower limit of the surface temperature of the substrate is 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.

A fixing mechanism for fixing the substrate 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, and is not particularly limited.

If the non-aqueous ink composition has excessively high drying properties, the amount of the organic solvent contained in the non-aqueous ink composition changes during the inkjet ejection stage, and desired characteristics may not be obtained. Therefore, it is preferable that the non-aqueous ink composition has a flash point of 60° C. or higher.

The inkjet head for ejecting the non-aqueous ink composition may be a piezoelectric inkjet head using piezoelectric elements or a thermal inkjet head using a heating element, and is not particularly limited.

Further, the inkjet recording apparatus comprises a plastic tube connecting a container (ink cartridge, bottle, etc.) for storing the non-aqueous ink composition and an inkjet head for ejecting the non-aqueous ink composition. The water-based ink composition may be supplied to the inkjet head through this plastic tube and ejected by the inkjet method. When the non-aqueous ink composition is present in the plastic tube, part of the organic solvent contained in the non-aqueous ink composition may volatilize. As a result, the amount of the organic solvent contained in the non-aqueous ink composition changes during the inkjet ejection stage, and desired characteristics may not be obtained.

In particular, the amount of alkylamide-based solvents, even if present in the plastic tube, is relatively small compared to other organic solvents. The amount of volatilization of the organic solvent in the plastic tube does not necessarily correlate with the volatility parameters of the organic solvent itself, such as the boiling point, flash point, and vaporization enthalpy of the organic solvent. This is because the permeability to plastic varies depending on the type of organic solvent, and the volatilization rate in a closed low-density polyethylene tube is rather due to the permeability to plastic. Specifically, the chemical structure and molecular weight of the organic solvent , compatibility and the like.

Alkylamide solvents are solvents that volatilize in a plastic tube in a relatively small amount, so if the nonaqueous ink composition contains an alkylamide solvent, the organic solvent Ink jetting can be performed while maintaining the amount of the component.

A low-density polyethylene tube (a tube made by cutting a low-density polyethylene (PE-LD) with an inner diameter of 3 mm and an outer diameter of 5 mm) to 12 cm) was filled with an organic solvent. It can be obtained by sealing the container, storing it at 50°C for 1 week, and measuring the amount of volatilization after storage. For example, the volatilization amount of diethylene glycol dimethyl ether is 68% by mass, diethylene glycol methyl ethyl ether is 58% by mass, diethylene glycol diethyl ether is 54% by mass, and dipropylene glycol dimethyl ether is 59% by mass. 11% by mass, 12% by mass of N,N-diethylpropanamide, and 13% by mass of N,N-diethylacetamide, indicating that the alkylamide-based solvent is a solvent with a small amount of volatilization in the plastic tube.

The material of the plastic tube is not particularly limited, but examples thereof include polyethylene resin, ethylene propylene diene rubber, etc. Among them, it is preferable to use polyethylene resin, and among these, it is particularly preferable to use low density polyethylene resin. .

The material of the plastic tube is not particularly limited, but includes polyolefin resin such as polyethylene resin, ethylene propylene diene rubber, nylon, polyurethane, PTFE, and the like. Among these, polyethylene resins and ethylene propylene diene rubbers are preferred.

In addition, the ink jet recording apparatus according to the present embodiment can be used for each color ink such as yellow, magenta, cyan, and black, as well as for light magenta, light cyan, light black, orange, green, red, and white, as described above. There are no particular restrictions on the order of colors to be printed, the position of the head, or the configuration. Further, the inkjet recording apparatus according to the present embodiment may or may not have a winding mechanism for the recording medium (base material), a drying mechanism for drying the surface of the base material, and an ink circulation mechanism.

The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these descriptions.

1. Preparation of resin (1) Acrylic resin In 300 g of diethylene glycol diethyl ether kept at 100 ° C., 150 g of methyl methacrylate and 50 g of butyl methacrylate and a predetermined amount of t-butyl peroxy-2-ethylhexanoate (polymerization initiation agent) was added dropwise over 1.5 hours. After completion of the dropwise addition, the mixture was allowed to react at 100° C. for 2 hours and then cooled to obtain a colorless and transparent polymer solution of methyl methacrylate. Thereafter, the solvent was distilled off from the polymer solution to obtain a polymer of methyl methacrylate. At this time, the amount of t-butylperoxy-2-ethylhexanoate, which is a polymerization initiator, was changed to control the polymerization average molecular weight of methyl methacrylate (acrylic resin) to be 30,000 to 105,000 (this The mass of the polymerization initiator used is shown in the following Table 1. In Table 1, it is described as "initiator amount").

(2) Vinyl chloride-vinyl acetate copolymer resin In an autoclave equipped with a stirrer, after purging with nitrogen, 100 parts of deionized water, 40 parts of methanol, 32 parts of vinyl chloride, 5 parts of vinyl acetate, and 0.2 parts of glycidyl methacrylate. , 3.55 parts of hydroxypropyl acrylate, 0.1 part of hydroxypropyl methylcellulose (suspending agent), 0.026 parts of di-2-ethylhexylperoxydicarbonate (polymerization initiator), di-3,5,5 - A predetermined amount of trimethylhexanol peroxide (polymerization initiator) was charged, and the temperature was raised to 63°C while stirring in a nitrogen gas atmosphere. and 10.65 parts of hydroxypropyl acrylate were continuously injected for 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 taken out, 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 polymerization 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 the following Table 1. In Table 1, it is described as "initiator amount".).

Table 1 shows the weight-average molecular weight (relative molecular mass) of each resin (acrylic resin, vinyl chloride-vinyl acetate copolymer resin) and the ratio of resins having 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). In addition, the ratio of the resin with an intrinsic viscosity of 90 mL / g or more is determined by connecting a viscosity detector (ViscoStar III manufactured by WYATT) and a refractive index detector (Optilab T-rEX manufactured by WYATT) to a Shimadzu SEC (GPC) system, Using tetrahydrofuran as a developing solvent, the sample was first passed through a column heated to 40°C in the Shimadzu SEC (GPC) system, and then cooled to 25°C. η _SP ] was determined, the concentration C was determined by a refractive index detector, and the intrinsic viscosity was determined by extrapolating the concentration C to 0 in Lim ([η _SP ]/C).

2. Preparation of non-aqueous ink composition Organic solvent, resin, dispersant, pigment (coloring material) Non-aqueous ink compositions of Examples and Comparative Examples were prepared according to the proportions of each component 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 unit is % by mass.

3. Rating 1
(Bleeding)
Bleeding properties were evaluated for the non-aqueous ink compositions of Examples and Comparative Examples. Specifically, the non-aqueous ink compositions of Examples and Comparative Examples were applied to a recording medium (glued poly Vinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) in high-quality print mode (1440 x 720 dpi) at a substrate surface temperature of 40 ° C. Prints an image with 6pt characters in the solid part of each color in a color different from the solid part, After drying the resulting printed matter in an oven at 60° C. for 5 minutes, bleeding of the printed matter was visually observed with a loupe (x10) (denoted as “bleeding property” in the table).
Evaluation Criteria Evaluation 5: No bleeding of the ink was observed by observation with a magnifying glass.
Evaluation 4: No bleeding of the ink was visually observed, and 6 pt characters were clear.
Evaluation 3: Slight bleeding of the ink was visually observed, but the design was not damaged.
Evaluation 2: Bleeding of the ink was visually observed, but the 6pt characters were recognizable.
Evaluation 1: Remarkable bleeding of the ink was visually observed, and 6 pt characters were not visually recognized.

(Surface drying property)
Surface drying properties were evaluated for the non-aqueous ink compositions of Examples and Comparative Examples. Specifically, a solid image was printed on a recording medium (polyvinyl chloride film with glue (IMAGin JT5829R: manufactured by MACtac)) in a high-quality print mode (1440 x 720 dpi) in the same manner as in the bleeding evaluation above, and the image was printed at 40°C. The time until drying was measured (indicated as "surface dryness" in the table).
Rating Criteria Rating 5: Dries in less than 2 minutes.
Evaluation 4: Dry in 2 minutes or more and less than 4 minutes.
Evaluation 3: Dry in 4 minutes or more and less than 6 minutes.
Evaluation 2: Dry in 6 minutes or more and less than 8 minutes.
Evaluation 1: It dries in 8 minutes or more.

(Ejection stability)
Ejection stability was evaluated for the non-aqueous ink compositions of Examples and Comparative Examples. Specifically, in the same manner as the bleeding evaluation, a recording medium (polyvinyl chloride film with glue (IMAGin JT5829R: manufactured by MACtac)) was continuously printed in a bidirectional high-speed printing mode (360 x 720 dpi) at a substrate surface temperature of 40 ° C. Solids and fine lines were printed, and the presence or absence of missing dots, flight deflection, and ink scattering was visually observed, and the number of occurrences was counted (referred to as "discharge stability" in the table).
Evaluation 5: Less than 10 occurrences of missing dots, flight deflection, or ink scattering within the 24-hour test period.
Evaluation 4: During the test period of 24 hours, dot missing, flight deflection, or ink scattering occurred 10 times or more and less than 20 times.
Evaluation 3: During the test period of 24 hours, dot missing, flight deflection, or ink scattering occurred 20 times or more and less than 30 times.
Evaluation 2: During the test period of 24 hours, dot missing, flight deflection, or ink scattering occurred 30 times or more and less than 40 times.
Evaluation 1: During the test period of 24 hours, dot missing, flight deflection, or ink scattering occurred 40 times or more.

In the table, "MEDG" is diethylene glycol methyl ethyl ether.

In the table, "DEDG" is diethylene glycol diethyl ether.

In the table, "DMFDG" is dipropylene glycol dimethyl ether.

In the table, "MFDG" is dipropylene glycol monomethyl ether.

In the table, "DEF" is N,N-diethylformamide.

In the table, "DEPA" is N,N-diethylpropanamide.

In the table, "DEAA" is N,N-diethylacetamide.

In the table, "EGMBEA" is ethylene glycol monobutyl ether acetate.

In the table, "PMA" is propylene glycol monomethyl ether acetate.

In the table, "3-MBA" is 3-methoxybutyl acetate.

In the table, "DEOX" is diethyl oxalate.

In the table, "ML" is methyl lactate.

In the table, "EL" is ethyl lactate.

In the table, "PC" is propylene carbonate.

In the table, "GBL" is γ-butyrolactone.

In the table, "ECL" is ε-caprolactone.

In the table, "MOZ" is 3-methyl-2-oxazolidinone.

In the table, "PhDG" is diethylene glycol monophenyl ether.

In the table, "BTeG" is tetraethylene glycol mono-n-butyl ether.

In the table, "BTG" is triethylene glycol mono-n-butyl ether.

In the table, "M100" means N.O. N-dimethyl-β-methoxypropanamide.

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

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

As can be seen from Tables 2 to 9, an organic solvent (a) having a static surface tension of less than 35 mN / m and a flash point of 80 ° C. or less and a static surface tension of 35 mN / m or more and a flash point of 80 ° C. It can be seen that the non-aqueous ink compositions of Examples containing the above organic solvent (b) have high ink jet ejection stability and can effectively suppress print bleeding.

In particular, in the non-aqueous ink compositions of Examples 1 to 5 in which the mass ratio of the content of the organic solvent (a) and the organic solvent (b) was changed, the content of the organic solvent (a) and the organic solvent (b) was The non-aqueous ink compositions of Examples 1 to 4 in which the mass ratio (organic solvent (a):organic solvent (b)) is in the range of 99:1 to 70:30 more effectively suppresses bleeding of printing. We were able to. In addition, the non-aqueous ink compositions of Examples 2 to 5 had particularly high ink ejection stability.

Further, in the non-aqueous ink compositions of Examples 3 and 6 to 10 in which the type of the organic solvent (b) having a static surface tension of 35 mN/m or higher and a flash point of 80° C. or higher was changed, the non-aqueous ink compositions of Example 3 It can be seen that the effect of the present invention is exhibited even when the carbonic acid ester of the water-based ink composition is replaced with an amide-based solvent or glycol ether monoalkyl.

Further, in the non-aqueous ink compositions of Examples 3 and 11 to 22 in which the type of the organic solvent (a) was changed, the effects of the present invention were obtained. The non-aqueous ink compositions of Examples 14 to 16 containing could particularly effectively suppress bleeding of printing.

Further, in the non-aqueous ink compositions of Examples 33 to 44 in which the content of the resin having an intrinsic viscosity of 90 mL/g or more at 25°C was changed, 5 resins having an intrinsic viscosity of 90 mL/g or more at 25°C were included in the total amount of the resin. The non-aqueous ink compositions of Examples in the range of less than or equal to 5% by mass exhibited particularly high inkjet ejection stability even compared to the non-aqueous ink compositions of Examples in the range of more than 5% by mass. .

On the other hand, the non-aqueous ink compositions of Comparative Examples 1 and 2, which do not contain the organic solvent (b) having a static surface tension of 35 mN/m or more and a flash point of 80° C. or more, or a static surface tension of less than 35 mN/m, Moreover, the non-aqueous ink composition of Comparative Example 3, which does not contain the organic solvent (a) having a flash point of 80° C. or lower, does not exhibit the effects of the present invention.

4. Evaluation 2
The non-aqueous ink composition of Example 14 was ejected by an ink jet method, and "bleeding" and "solid filling" were evaluated in the same manner as described above. At this time, the heating mechanism provided in the inkjet recording apparatus and the fixing mechanism for fixing the substrate were switched on/off as shown in Table 4 below. When the heating device was not used, printing was performed at room temperature (23° C. to 25° C.), and when the adsorption mechanism was not used, printing was performed with air suction turned off.

(filled solid)
In the same manner as in the bleeding evaluation, a recording medium (polyvinyl chloride film with glue (IMAGin JT5829R: manufactured by MACtac)) was subjected to bidirectional high-speed printing mode (360 x 720 dpi), and solid printing was performed. It was confirmed (indicated as "filled solid" in the table).
Evaluation Criteria Evaluation 4: Uniform solid is formed Evaluation 3: Slight color unevenness can be visually confirmed, but the design is not impaired Evaluation 2: Color unevenness can be visually confirmed Evaluation 1: Unevenness occurs Significant loss of design

As can be seen from Table 10, using an inkjet recording apparatus comprising a warming mechanism and a fixing mechanism for fixing the substrate, turning each mechanism "on", the fixing mechanism for fixing the substrate, By drying the non-aqueous ink composition while fixing the substrate (recording medium) and ejecting the non-aqueous ink composition containing the organic solvent (a) and the organic solvent (b) by an inkjet method, It can be seen that the "bleeding property" and "solid filling" of the obtained recorded matter are improved.

Claims (11)

A non-aqueous ink composition containing an organic solvent and ejected by an inkjet method,
The organic solvent is
an organic solvent (a) having a static surface tension of less than 35 mN/m and a flash point of 80° C. or less;
an organic solvent (b) having a static surface tension of 35 mN/m or higher and a flash point of 80° C. or higher;
contains
The organic solvent (a) contains an alkylamide solvent as an amide solvent.
Non-aqueous ink composition. The mass ratio of the contents of the organic solvent (a) and the organic solvent (b) (organic solvent (a):organic solvent (b)) is in the range of 99:1 to 70:30. A non-aqueous ink composition as described. 3. The organic solvent (a) according to claim 1 or 2, containing at least one selected from the group consisting of amide solvents, glycol ether dialkyls, glycol ether monoalkyls, acetates, dibasic acid esters and lactate esters. A non-aqueous ink composition of 4. The non-aqueous ink composition according to any one of claims 1 to 3 , wherein the organic solvent (b) contains at least one selected from the group consisting of carbonate ester, cyclic ester, amide solvent, and glycol ether monoalkyl. thing. Furthermore, it contains a resin,
The non-aqueous ink composition according to any one of claims 1 to 4 , wherein the resin has an intrinsic viscosity of 90 mL/g or more at 25°C in a range of 5% by mass or less in the total amount of the resin. 6. The non-aqueous ink composition according to any one of claims 1 to 5 , which is ejected by an inkjet method using an inkjet recording apparatus comprising a heating mechanism and a fixing mechanism for fixing a substrate. 7. The non-aqueous ink composition according to any one of claims 1 to 6 , which is ejected through an inkjet recording apparatus having a plastic tube by an inkjet method through the plastic tube. The non-aqueous ink composition according to any one of claims 1 to 7 , which is used for a resin substrate. A recording method, wherein the non-aqueous ink composition according to any one of claims 1 to 8 is ejected onto the surface of a substrate by an inkjet method. A method for producing recorded matter, comprising ejecting the non-aqueous ink composition according to any one of claims 1 to 8 onto the surface of a substrate by an inkjet method. A recorded matter having a recording layer of the non-aqueous ink composition according to any one of claims 1 to 8 formed on the surface of a substrate.