Non-aqueous ink composition, non-aqueous ink set, and printing method

Abstract

The present invention relates to a non-aqueous ink composition for inkjet printing, which is unlikely to cause bleeding of an image on a printed object, gives excellent image glossiness, is unlikely to cause media blocking when printed on roll media and wound, and is unlikely to cause corrosion of a printing head. More specifically, the present invention relates to a non-aqueous ink composition for inkjet printing, which contains an organic solvent (A) and a resin (B) and which is characterized in that the organic solvent (A) contains (A-1) a glycol ether-based solvent having a boiling point of lower than 200°C and (A-2) an amide bond-containing or urea bond-containing compound for which a specific mixed liquid has a pH of 7.0 or more, the amount of the glycol ether-based solvent (A-1) having a boiling point of lower than 200°C in the organic solvent (A) is within a range of 60 to 95 mass%, and the amount of the amide bond-containing or urea bond-containing compound (A-2) for which a specific mixed liquid has a pH of 7.0 or more in the organic solvent (A) is within a range of 4.0 to 30 mass% (here, in the case of an orange ink, the amount of the amide bond-containing or urea bond-containing compound (A-2) for which a specific mixed liquid has a pH of 7.0 or more in the organic solvent (A) is within a range of 1.0 to 30 mass%).

Description

[Technical Field]

[0001] The present invention relates to a non-aqueous ink composition, a non-aqueous ink set including the non-aqueous ink composition, and a printing method using the non-aqueous ink composition, and in particular to a non-aqueous ink composition for inkjet printing that produces printed images that are resistant to bleeding and have excellent image gloss, and that is resistant to media blocking when printed on and wound up roll media, and is resistant to corrosion of the print head. [Background technology]

[0002] Conventionally, when printing on PVC sheets and the like, methods have been considered for obtaining printed matter with excellent adhesion between the substrate and the image by using a combination of a solvent that does not dissolve polyvinyl chloride resin and a solvent that does.

[0003] For example, Japanese Patent Laid-Open Publication No. 2005-15672 (Patent Document 1) describes a non-aqueous inkjet ink for polyvinyl chloride resin sheets, which is composed of an organic solvent, a pigment, and a resin, and which contains 1 to 30 wt% of an organic solvent in which the polyvinyl chloride resin is soluble, while the organic solvent does not dissolve the polyvinyl chloride resin at all or barely dissolves the polyvinyl chloride resin. Japanese Patent Laid-Open Publication No. 2005-200469 (Patent Document 2) describes an oil-based ink for a piezoelectric inkjet printer, which contains a fixing resin, a pigment, and a solvent, and which contains a compound represented by general formula (1) and a cyclic ester, with the amount of the cyclic ester being 1 to 60 parts by mass per 100 parts by mass of the compound represented by general formula (1).

[0004] Lactone solvents, especially gamma-butyrolactone, are often used to dissolve polyvinyl chloride resin, but inks containing gamma-butyrolactone have the problem of easily corroding printer heads. To address this issue, methods are being investigated that add anti-rust components to the ink to prevent head corrosion while still taking advantage of the benefits of using lactone solvents.

[0005] For example, Japanese Patent Laid-Open Publication No. 2008-247967 (Patent Document 3) describes that in a non-aqueous inkjet ink composition containing a pigment, a resin, a pigment dispersant, and an organic solvent such as γ-butyrolactone, by using an amino group-containing alcohol, and preferably by further adjusting the pH of the aqueous extract of the ink to 6.0 to 10.0, clogging of the nozzles of the printer head when printing with an inkjet printer does not occur, and printed matter of excellent print quality can be obtained. Japanese Patent Laid-Open Publication No. 2009-235383 (Patent Document 4) describes that in a non-aqueous inkjet ink composition containing a pigment, a resin, a pigment dispersant, and an organic solvent such as γ-butyrolactone, by using an imidazole compound, and preferably by further adjusting the pH of the aqueous extract of the ink to 6.0 to 10.0, clogging of the nozzles of the printer head when printing with an inkjet printer does not occur, and printed matter of excellent print quality can be obtained. Japanese Patent Application Laid-Open No. 2009-242649 (Patent Document 5) describes that by using a volatile rust inhibitor in a non-aqueous inkjet ink composition containing a pigment, a resin, a pigment dispersant, and an organic solvent such as γ-butyrolactone, and preferably further adjusting the pH of the water extract of the ink to 6.0 to 10.0, clogging of the nozzles in the printer head when printing with an inkjet printer does not occur, and printed matter of excellent print quality can be obtained. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-15672 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-200469 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-247967 [Patent Document 4] Japanese Patent Application Laid-Open No. 2009-235383 [Patent Document 5] Japanese Patent Application Laid-Open No. 2009-242649 Summary of the Invention [Problem to be solved by the invention]

[0007] In light of these circumstances, an object of the present invention is to provide a non-aqueous ink composition for inkjet printing that produces printed images that are resistant to bleeding and have excellent image gloss, and that is resistant to media blocking when printed on roll media and then wound up, and that is resistant to print head corrosion. Another object of the present invention is to provide a non-aqueous ink set that includes such a non-aqueous ink composition, and a printing method that uses such a non-aqueous ink composition. [Means for solving the problem]

[0008] To achieve the above-mentioned objectives, the present inventors first investigated the use of a glycol ether-based solvent, which has low viscosity and excellent drying properties, in combination with a lactone-based solvent as a solvent for a non-aqueous ink composition for inkjet printing. They found that γ-butyrolactone, a suitable lactone-based solvent, has an acidic pH of 5.4 when mixed with, for example, 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of γ-butyrolactone. Therefore, even when used in a non-aqueous ink composition, γ-butyrolactone can cause head corrosion due to moisture in the surrounding environment. Therefore, they focused on an amide bond- or urea bond-containing compound, which, when mixed with such a compound, has a pH of 7.0 or higher and is a solvent that does not fall into the acidic range and has a high ability to dissolve resins such as polyvinyl chloride resin (in other words, has excellent resin solubility). Amide bond- or urea bond-containing compounds, when mixed with such a compound, have a pH of 7.0 or higher, and are capable of preventing head corrosion. Furthermore, the inventors have discovered that an amide bond- or urea bond-containing compound has a high ability to dissolve resins used in substrates and resins contained in inks, and that by using the compound in a specific ratio together with a glycol ether-based solvent having a boiling point of less than 200°C, it is possible to obtain printed matter that is resistant to bleeding of images, has excellent image gloss, and is resistant to media blocking when printed on and wound up on roll media, and have thus completed the present invention.

[0009] Therefore, a first non-aqueous ink composition of the present invention is a non-aqueous ink composition for inkjet printing comprising (A) an organic solvent and (B) a resin, (A) The organic solvent is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher, The amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in (A) the organic solvent is within a range of 60 to 95 mass %, and The non-aqueous ink composition is characterized in that the amount of the amide bond or urea bond-containing compound (A-2) in the organic solvent (A) is within a range of 4.0 to 30% by mass.

[0010] A second non-aqueous ink composition of the present invention is a non-aqueous ink composition for inkjet printing, comprising (A) an organic solvent and (B) a resin, the non-aqueous ink composition is an orange ink, (A) The organic solvent is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher, The amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in (A) the organic solvent is within a range of 60 to 95 mass %, and The non-aqueous ink composition is characterized in that the amount of (A-2) the amide bond or urea bond-containing compound in (A) the organic solvent is within the range of 1.0 to 30% by mass.

[0011] In a preferred embodiment of the first and second non-aqueous ink compositions of the present invention, the (A) organic solvent further contains (A-3) a glycol or glycol ether solvent having a boiling point of 220°C or higher and lower than 300°C.

[0012] In another preferred embodiment of the first and second non-aqueous ink compositions of the present invention, the (A-2) amide bond or urea bond-containing compound includes at least one solvent selected from alkylamide solvents, cyclic amide solvents, aromatic amide solvents, alkylurea solvents, and cyclic urea solvents.

[0013] In another preferable embodiment of the first non-aqueous ink composition of the present invention, the non-aqueous ink composition is a black ink, The pH of the water extract of the non-aqueous ink composition is within the range of 3.0 to 7.0.

[0014] In another preferred embodiment of the first non-aqueous ink composition of the present invention, the non-aqueous ink composition is a white ink, The amount of water contained in the non-aqueous ink composition is less than 10,000 ppm by mass.

[0015] The non-aqueous ink set of the present invention is a non-aqueous ink set for inkjet printing comprising at least a cyan ink, a magenta ink, and a yellow ink, the cyan ink, the magenta ink, and the yellow ink comprise (A) an organic solvent, (B) a resin, and (C) a pigment; (A) The organic solvent is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher, The amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in (A) the organic solvent is within a range of 60 to 95 mass %, and The non-aqueous ink set is characterized in that the amount of (A-2) the amide bond or urea bond-containing compound in (A) the organic solvent is within the range of 4.0 to 30% by mass.

[0016] In a preferred embodiment of the non-aqueous ink set of the present invention, the non-aqueous ink set comprises an orange ink, the orange ink comprises (A) an organic solvent, (B) a resin, and (C) a pigment; (A) The organic solvent is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher, The amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in (A) the organic solvent is within a range of 60 to 95 mass %, and The amount of the amide bond or urea bond-containing compound (A-2) in the organic solvent (A) is within a range of 1.0 to 30% by mass.

[0017] A first printing method of the present invention is a printing method for forming a printed layer using a non-aqueous ink composition for inkjet printing, which comprises (A) an organic solvent and (B) a resin, (A) The organic solvent is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher, The amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in (A) the organic solvent is within a range of 60 to 95 mass %, and The printing method is characterized in that the amount of the amide bond- or urea bond-containing compound (A-2) in the organic solvent (A) is within a range of 4.0 to 30% by mass.

[0018] A second printing method of the present invention is a printing method for forming a printing layer using a non-aqueous ink composition for inkjet printing, which comprises (A) an organic solvent and (B) a resin, the non-aqueous ink composition is an orange ink, (A) The organic solvent is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher, The amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in (A) the organic solvent is within a range of 60 to 95 mass %, and The printing method is characterized in that the amount of the amide bond- or urea bond-containing compound (A-2) in the organic solvent (A) is within a range of 1.0 to 30% by mass. [Effects of the Invention]

[0019] The non-aqueous ink composition of the present invention can provide a non-aqueous ink composition for inkjet printing that produces printed images that are resistant to bleeding and have excellent image gloss, and that is resistant to media blocking and print head corrosion when printed on roll media and then wound up. Furthermore, the non-aqueous ink set of the present invention can provide a non-aqueous ink set that includes the non-aqueous ink composition. The printing method of the present invention can provide a printing method that uses the non-aqueous ink composition. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention relates to a non-aqueous ink composition, a non-aqueous ink set, and a printing method.

[0021] The non-aqueous ink composition of the present invention is a non-aqueous ink composition for inkjet printing that contains an organic solvent and a resin. In this specification, the organic solvent is referred to as component (A) and is also referred to as "(A) organic solvent." The resin is referred to as component (B) and is also referred to as "(B) resin."

[0022] In this specification, a non-aqueous ink composition means an ink composition that does not contain water as a solvent and is not miscible with water in any proportion.

[0023] In this specification, an ink composition for inkjet printing means an ink composition that can be used for printing with an inkjet printer.

[0024] The non-aqueous ink composition of the present invention contains an organic solvent (A), and the amount of the organic solvent (A) in the non-aqueous ink composition of the present invention is preferably 80 to 99 mass %, more preferably 90 to 95 mass %.

[0025] In the non-aqueous ink composition of the present invention, the organic solvent (A) is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher. Includes.

[0026] In this specification, the "glycol ether-based solvent having a boiling point of less than 200°C" is referred to as component (A-1), and as described above, is also referred to as "(A-1) glycol ether-based solvent having a boiling point of less than 200°C." Additionally, the "amide bond- or urea bond-containing compound, such that a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of an amide bond- or urea bond-containing compound has a pH of 7.0 or higher" is referred to as component (A-2), and as described above, is also referred to as "(A-2) amide bond- or urea bond-containing compound."

[0027] The glycol ether solvent of component (A-1) is an organic solvent that has low viscosity, a relatively high tag closed-circuit flash point, and good drying properties, and is preferably used as the main solvent for the non-aqueous ink composition of the present invention. The glycol ether solvent of component (A-1) preferably has a flash point of 50°C or higher and 75°C or lower. In this specification, the flash point is the flash point measured by the tag closed-circuit flash point.

[0028] In this specification, glycol ether solvents refer to compounds having an alkyl ether structure based on glycols such as ethylene glycol, propylene glycol, etc. Glycol ether solvents include those in which both terminals of the molecule are hydroxyl groups, and those in which the hydrogen atoms of the hydroxyl groups at one or both terminals of the molecule are substituted with a substituent such as an alkyl group or an acyl group.

[0029] The glycol ether solvent of component (A-1) has a boiling point of less than 200°C, preferably 150 to 200°C, and more preferably 160 to 190°C. In this specification, the boiling point refers to the boiling point at 1 atmosphere. When the glycol ether solvent of component (A-1) has a boiling point of less than 200°C, the drying properties of the ink are improved, making it easier to obtain printed matter with excellent blocking resistance.

[0030] The glycol ether solvent of the component (A-1) preferably contains a glycol ether solvent represented by the following general formula (1). R1-(OR2)nO-R3 (1) In formula (1), n is an integer between 1 and 4, R1 is an alkyl group having 1 to 8 carbon atoms which may be branched or an acyl group having 1 to 4 carbon atoms, R2 is an alkylene group having 1 to 4 carbon atoms which may be branched, R3 is hydrogen, an alkyl group having 1 to 4 carbon atoms which may be branched, or an acyl group having 1 to 4 carbon atoms.

[0031] The glycol ether solvent of component (A-1) preferably contains a dialkylene glycol dialkyl ether or a dialkylene glycol monoalkyl ether acetate, and more preferably contains at least one selected from diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, and propylene glycol monomethyl ether acetate.

[0032] In the non-aqueous ink composition of the present invention, the amount of component (A-1) in the organic solvent (A) is preferably within a range of 60 to 95% by mass, and more preferably within a range of 75 to 95% by mass. The component (A-1) may be used alone or in combination of two or more types.

[0033] The amide bond- or urea bond-containing compound (A-2) is an organic solvent that does not corrode the head because the pH of a mixture consisting of 50 parts by weight of water, 47.5 parts by weight of diethylene glycol ethyl methyl ether, and 12.5 parts by weight of the amide bond- or urea bond-containing compound (A-2) is higher than 7.0, which is not in the acidic range, and has a high ability to dissolve resins such as polyvinyl chloride resin (in other words, excellent resin solubility). Using the (A-2) component as a solvent has the effect of allowing the ink on the substrate to penetrate without spreading. Therefore, when used in combination with the glycol ether-based solvent (A-1) described above, the amide bond- or urea bond-containing compound (A-2) can provide printed materials that are resistant to image bleeding and to media blocking when printed on and wound up on roll media. The reason for setting the pH of the mixture consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of a compound containing an amide bond or a urea bond at 7.0 or higher is based on the idea that not making the ink pH acidic would protect the head from corrosion. Diethylene glycol ethyl methyl ether is the glycol ether solvent of component (A-1), and in the present invention, it is considered important that the pH of an aqueous solution containing this glycol ether (A-1), water, and the compound containing an amide bond or a urea bond (A-2) does not fall into a strongly acidic range, and the pH of the aqueous solution at a specific mixing ratio that approximates the blending ratio of an actual ink is specified as 7.0 or higher.

[0034] The amide bond- or urea bond-containing compound of component (A-2) has a pH of 7.0 or higher, preferably 7.0 to 10.0, and more preferably 7.0 to 9.5, when mixed with 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of the amide bond- or urea bond-containing compound.

[0035] The amide bond or urea bond-containing compound of component (A-2) preferably contains at least one solvent selected from alkylamide solvents, cyclic amide solvents, aromatic amide solvents, alkylurea solvents, and cyclic urea solvents.

[0036] Specific examples of alkylamide solvents include 3-methoxy-N,N-dimethylpropanamide, etc. Specific examples of cyclic amide solvents include 2-pyrrolidone and ε-caprolactam, etc. Specific examples of aromatic amide solvents include benzamide, etc. Specific examples of alkylurea solvents include N-methylurea, etc. Specific examples of cyclic urea solvents include 1,3-dimethyl-2-imidazolidinone, etc.

[0037] As the amide bond or urea bond-containing compound of component (A-2), cyclic urea solvents are preferred, imidazolidinone solvents are more preferred, and 1,3-dimethyl-2-imidazolidinone is most preferred.

[0038] In the non-aqueous ink composition of the present invention, the amount of component (A-2) in the organic solvent (A) is preferably within a range of 4.0 to 30% by mass, more preferably within a range of 5 to 30% by mass, and even more preferably within a range of 5 to 15% by mass. The component (A-2) may be used alone or in combination of two or more. When the amount of component (A-2) in the organic solvent (A) is 30% by mass or less, the glossiness of the image can be improved.

[0039] Furthermore, the present inventors have found that when the non-aqueous ink composition of the present invention is an orange ink, the effects of component (A-2) can be fully exhibited even when the amount of component (A-2) in organic solvent (A) is less than 4.0% by mass. That is, when the non-aqueous ink composition of the present invention is an orange ink, the amount of component (A-2) in organic solvent (A) is preferably within the range of 1.0 to 30% by mass, more preferably within the range of 1.5 to 20% by mass, even more preferably within the range of 2.0 to 15% by mass, and particularly preferably within the range of 2.0 to 12% by mass.

[0040] In the non-aqueous ink composition of the present invention, the ratio of the amount of component (A-1) in organic solvent (A) to the amount of component (A-2) in organic solvent (A) is preferably 2 to 10, and more preferably 4 to 8. In this specification, the ratio of the amount of component (A-1) in organic solvent (A) to the amount of component (A-2) in organic solvent (A) may be expressed as "(A-1) / (A-2)". Here, the ratio of the amount of component (A-1) in organic solvent (A) to the amount of component (A-2) in organic solvent (A) is based on mass.

[0041] In the non-aqueous ink composition of the present invention, the organic solvent (A) further contains, in addition to the components (A-1) and (A-2) described above, (A-3) Glycol or glycol ether solvent with a boiling point of 220°C or higher but lower than 300°C From the viewpoint of safety, it is particularly preferred that component (A-3) be a glycol having a boiling point of 220°C or higher and lower than 300°C, with hydroxyl groups at both ends.

[0042] In this specification, the "glycol or glycol ether-based solvent having a boiling point of 220°C or higher but lower than 300°C" is defined as component (A-3), and is also referred to as "(A-3) glycol or glycol ether-based solvent having a boiling point of 220°C or higher but lower than 300°C" as described above.

[0043] The glycol or glycol ether solvent of component (A-3) prevents the ink from drying out in the head and improves re-ejection properties, while also contributing to improving the gloss of printed matter.

[0044] Examples of component (A-3) include diethylene glycol, triethylene glycol, tripropylene glycol, polypropylene glycol, diethylene glycol-2-ethylhexyl ether, diethylene glycol monohexyl ether, diethylene glycol monobutyl ether, dipropylene glycol, ethylene glycol monophenyl ether, triethylene glycol monomethyl ether, diethylene glycol dibutyl ether, etc. Component (A-3) preferably has excellent compatibility with components (A-1) and (A-2).

[0045] If the amount of component (A-3) is too large, the blocking resistance of the printed matter may decrease, and therefore, in the non-aqueous ink composition of the present invention, the amount of component (A-3) in the organic solvent (A) is preferably within the range of 0.1 to 5.0 mass%, more preferably 0.1 to 2.0 mass%, even more preferably 0.1 to 1.0 mass%, and most preferably 0.1 to 0.7 mass%. The component (A-3) may be used alone or in combination of two or more types.

[0046] In the non-aqueous ink composition of the present invention, the organic solvent (A) further comprises (A-4) An organic solvent with a boiling point of less than 150°C that does not fall under component (A-1) or component (A-2) may include:

[0047] In this specification, an organic solvent having a boiling point of less than 150°C and not corresponding to either component (A-1) or component (A-2) is referred to as component (A-4), and is also referred to as "(A-4) an organic solvent having a boiling point of less than 150°C and not corresponding to component (A-1) or component (A-2)" as described above.

[0048] The organic solvent of component (A-4) has a low boiling point, which can improve the drying properties of the ink.

[0049] Examples of the component (A-4) include propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclopentanone, etc. The component (A-4) preferably has excellent compatibility with the components (A-1) and (A-2).

[0050] In the non-aqueous ink composition of the present invention, the amount of component (A-4) in the organic solvent (A) is preferably within a range of 0.5 to 2.0% by mass, and more preferably within a range of 0.5 to 1.0% by mass. Component (A-2) may be used singly or in combination of two or more.

[0051] The non-aqueous ink composition of the present invention preferably does not contain γ-butyrolactone.

[0052] The non-aqueous ink composition of the present invention contains a (B) resin, and the amount of the (B) resin in the non-aqueous ink composition of the present invention is preferably 1 to 5 mass %, more preferably 1 to 3 mass %. The (B) resin may be used alone or in combination of two or more types.

[0053] Examples of (B) resins include polyvinyl chloride (vinyl chloride resin), polyvinyl acetate, vinyl chloride-vinyl acetate copolymer (vinyl chloride / vinyl acetate copolymer resin), vinyl chloride resin, chlorinated rubber, chlorinated polyethylene resin, chlorinated polypropylene resin, chlorinated ethylene-vinyl acetate resin, acrylic resin, acrylic silicone resin, styrene-acrylic copolymer resin, polystyrene resin, polyamide resin, polyurethane resin, polyolefin resin, silicone resin, fluororesin, epoxy resin, polyester resin, ketone resin, phenolic resin, polyvinyl alcohol, polyvinyl alcohol derivatives (anion-modified polyvinyl alcohol, etc.), cellulose, cellulose derivatives (hydroxymethyl cellulose, hydroxyethyl cellulose, cellulose acetate, etc.), rosin resin, oil-based resin, petroleum resin, alkyd resin, alginic acid, alginic acid derivatives (propylene glycol alginate, etc.), etc. Modified versions of these resins are also included, such as hydroxyalkyl etherified versions and carboxylic acid versions. Of these, acrylic resins, vinyl chloride resins, and vinyl chloride / vinyl acetate copolymer resins are preferred from the standpoint of adhesion to substrates and durability of printed films.

[0054] The non-aqueous ink composition of the present invention may contain a colorant such as a dye or pigment, but in this case, it is preferable to contain a pigment from the viewpoint of weather resistance. For example, a metallic ink can be made using a metal pigment. The content of the colorant in the ink composition is, for example, 0.1 to 15 mass %. The colorant may be used alone or in combination of two or more types. In this specification, the pigment is referred to as component (C), and is also referred to as "pigment (C)."

[0055] Specific examples of colorants include: C.I.Pigment Yellow 1、2、3、4、5、6、7、9、10、12、13、14、15、16、17、24、32、34、35、36、37、41、42、43、49、53、55、60、61、62、63、65、73、74、75、77、81、83、87、93、94、95、97、98、99、100、101、104、105、106、108、109、110、111、113、114、116、117、119、120、123、124、126、127、128、129、130、133、138、139、150、151、152、153、154、155、165、167、168、169、170、172、173、174、175、176、179、180、181、182、183、184、185、191、193、194、199、205、206、209、212、213、214、215、219、 C.I.Pigment Orange 1、2、3、4、5、13、15、16、17、19、20、21、24、31、34、36、38、40、43、46、48、49、51、60、61、62、64、65、66、67、68、69、71、72、73、74、81、 C.I.Pigment Red 1、2、3、4、5、6、7、8、9、10、11、12、14、15、16、17、18、21、22、23、31、32、38、41、48、48:1、48:2、48:3、48:4、48:5、49、52、52:1、52:2、53:1、54、57:1、58、60:1、63、64:1、68、81:1、83、88、89、95、101、104、105、108、112、114、119、122、123、136、144、146、147、149、150、164、166、168、169、170、171、172、175、176、177、178、179、180、181、182、183、184、185、187、188、190、193、194、200、202、206、207、208、209、210、211、213、214、216、220、220、221、224、226、237、238、239、242、245、247、248、251、253、254、255、256、257、258、260、262、263、264、266、268、269、270、271、272、279、 C.I.Pigment Violet 1、2、3、3:1、3:3、5:1、13、15、16、17、19、23、25、27、29、31、32、36、37、38、42、50、 C.I.Pigment Blue 1、15、15:1、15:2、15:3、15:4、15:5、15:6、16、17:1、24、24:1、25、26、27、28、29、36、56、60、61、62、63、75、79、80、 C.I.Pigment Green 1、4、7、8、10、15、17、26、36、50、 C.I.Pigment Brown 5、6、23、24、25、32、41、42、 C.I.Pigment Black 1、6、7、9、10、11、20、26、28、31、32、34、 C.I.Pigment White 1、2、4、5、6、7、11、12、18、19、21、22、23、26、27、28、 Examples include aluminum flakes, glass flakes, pearl pigments, and hollow particles.

[0056] Among these, from the viewpoint of weather resistance and color reproducibility of the obtained film, CIPigment Black 7, CIPigment Blue 15:3, 15:4, 28, CIPigment Red 101, 122, 202, 254, 282, CIPigment Violet 19, CIPigment White 6, CI Pigment Yellow 42, 120, 138, 139, 150, 151, 155, 213, and CI Pigment Orange 43, 64, 71, 73, 83 are preferred.

[0057] From the viewpoint of ejection stability, the pigment particles dispersed in the ink composition preferably have a volume average particle diameter of 0.05 to 0.4 μm and a volume maximum particle diameter of 0.2 to 1 μm. If the volume average particle diameter is greater than 0.4 μm and the volume maximum particle diameter is greater than 1 μm, it tends to be difficult to eject the ink composition stably. The volume average particle diameter and volume maximum particle diameter can be measured using a measuring device that uses dynamic light scattering.

[0058] The non-aqueous ink composition of the present invention may further contain a pigment dispersant as needed to disperse the pigment. The content of the pigment dispersant in the ink composition is, for example, 0.1 to 5% by mass. The pigment dispersants may be used alone or in combination of two or more.

[0059] Specific examples of pigment dispersants include: ANTI-TERRA-U, ANTI-TERRA-U100, ANTI-TERRA-204, ANTI-TERRA-205, DISPERBYK-101, DISPERBYK-102, DISPERBYK-103, DISPERBYK-106, DISPERBYK-108, DISPERBYK-109, DISPERBYK-110, DISPERBYK-111, DISPERBYK-112, DISPERBYK-116, DISPERBYK-130, DISPERBYK-140, DISPERBYK-142, DISPERBYK-145, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-164, DISPERBYK-166, DISPERBYK-167, DISPERBYK-168, DISPERBYK-170, DISPERBYK-171, DISPERBYK-174, DISPERBYK-180, DISPERBYK-182, DISPERBYK-183, DISPERBYK-184, DISPERBYK-185, DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2008, DISPERBYK-2009, DISPERBYK-2020, DISPERBYK-2025, DISPERBYK-2050, DISPERBYK-2070, DISPERBYK-2096, DISPERBYK-2150, DISPERBYK-2155, DISPERBYK-2163, DISPERBYK-2164, BYK-P104, BYK-P104S, BYK-P105, BYK-9076, BYK-9077, BYK-220S, BYKJET-9150, BYKJET-9151 (all manufactured by BYK Japan), Solsperse3000, Solsperse5000, Solsperse9000, Solsperse11200, Solsperse13240, Solsperse13650, Solsperse13940, Solsperse16000, Solsperse17000, Solsperse18000, Solsperse20000, Solsperse21000, Solsperse24000SC, Solsperse24000GR, Solsperse26000, Solsperse27000, Solsperse28000, Solsperse32000, Solsperse32500, Solsperse32550, Solsperse32600, Solsperse33000, Solsperse34750, Solsperse35100, Solsperse35200, Solsperse36000, Solsperse36600, Solsperse37500, Solsperse38500, Solsperse39000, Solsperse41000, Solsperse54000, Solsperse55000, Solsperse56000, Solsperse71000, Solsperse76500, SolsperseX300 (all manufactured by Lubrizol), Disparlon DA-7301, Disparlon DA-325, Disparlon DA-375, Disparlon DA-234 (all manufactured by Kusumoto Chemicals Co., Ltd.), FLORENE AF-1000, FLORENE DOPA-15B, FLORENE DOPA-15BHFS, FLORENE DOPA-17HF, FLORENE DOPA-22, FLORENE DOPA-33, FLORENE G-600, FLORENE G-700, FLORENE G-700AMP, FLORENE G-700DMEA, FLORENE G-820, FLORENE G-900, FLORENE GW-1500, FLORENE KDG-2400, FLORENE NC-500, FLORENE WK-13E (all manufactured by Kyoeisha Chemical Co., Ltd.), TEGO Dispers610, TEGO Dispers610S, TEGO Dispers630, TEGO Dispers650, TEGO Dispers652, TEGO Dispers655, TEGO Dispers662C, TEGO Dispers670, TEGO Dispers685, TEGO Dispers700, TEGO Dispers710, TEGO Dispers740W, LIPOTIN A, LIPOTIN BL, LIPOTIN DB, LIPOTIN SB (both manufactured by Evonik Degussa), PB821, PB822, PN411, PA111 (all manufactured by Ajinomoto Fine-Techno Co., Ltd.), Texahall 963, Texahall 964, Texahall 987, Texahall P60, Texahall P61, Texahall P63, Texahall 3250, Texahall SF71, Texahall UV20, Texahall UV21 (all manufactured by Cognis), Examples include BorchiGenSN88 and BorchiGen0451 (both manufactured by Borchias).

[0060] The non-aqueous ink composition of the present invention may contain, as other components, additives such as ultraviolet absorbers, radical scavengers, surface conditioners, antioxidants, plasticizers, rust inhibitors, solvents, fillers, antifoaming agents, charge control agents, stress relaxation agents, penetrating agents, light-guiding materials, glittering materials, magnetic materials, fluorescent materials, antibacterial agents, antiviral agents, and anti-algae agents, as needed.

[0061] The non-aqueous ink composition of the present invention can be used as inks of various colors, such as basic color inks such as cyan ink, magenta ink, yellow ink, and black ink, as well as light cyan ink, light magenta ink, light yellow ink, light black ink, orange ink, and white ink.

[0062] When the non-aqueous ink composition of the present invention is a black ink, the pH of the aqueous extract of the non-aqueous ink composition is preferably in the range of 3.0 to 7.0. When using acidic carbon black pigments in conventional non-aqueous inks, it is preferable to adjust the pH using a basic compound such as an amino-group-containing alcohol to prevent head corrosion. However, the non-aqueous ink composition of the present invention contains a specific amount of component (A-2) that ensures that a mixture consisting of 50 parts by weight of water, 47.5 parts by weight of diethylene glycol ethyl methyl ether, and 12.5 parts by weight of an amide bond- or urea bond-containing compound has a pH of 7.0 or higher, thereby preventing head corrosion. Furthermore, by adjusting the pH of the aqueous extract of the non-aqueous ink composition to a range of 3.0 to 7.0, the resolubility of the ink in the ejection head can be improved. The pH of the aqueous extract of the black ink can be adjusted by the type of pigment and the amount of solvent. From the perspective of maintaining the pH of the aqueous extract of the non-aqueous ink composition in the range of 3.0 to 7.0, it is preferable that the black ink does not contain an amino-group-containing alcohol.

[0063] Amino-group-containing alcohols are compounds that contain an amino group and a hydroxyl group in the molecule and are sometimes used to prevent nozzle clogging in the ejection head of a printer. Examples of amino-group-containing alcohols include 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, and tris(hydroxymethyl)aminomethane.

[0064] When the non-aqueous ink composition of the present invention is a white ink, the amount of water contained in the non-aqueous ink composition is preferably less than 10,000 ppm by mass. By controlling the water content of the white ink within the above-specified range, the stability of the ink can be improved. Methods for reducing the water content of the ink to less than 10,000 ppm by mass include reducing the water content of the materials before preparing the ink or reducing the water content of the ink after preparation. From the perspective of suppressing an increase in the viscosity of the ink, it is preferable to prepare the ink after reducing the water content of the pigment beforehand. Conventional methods such as using a dehydrating agent or heating can be used to reduce the water content. The water content of the white ink is preferably less than 9,000 ppm by mass, more preferably less than 8,000 ppm by mass. The amount of pigment contained in the white ink is preferably 1 to 20% by mass, and more preferably 5 to 18% by mass. White inks often contain a larger amount of pigment than other pigment inks in order to increase the hiding power when printed on transparent substrates, and because inorganic pigments such as titanium oxide readily absorb water, keeping the moisture content in the white ink below 10,000 ppm by mass is particularly important in terms of improving the storage stability of the ink.

[0065] The non-aqueous ink composition of the present invention can be prepared by mixing various components appropriately selected as needed, and, if necessary, filtering the resulting mixture using a filter having a pore size of not more than about 1 / 10 of the nozzle diameter of the inkjet printhead to be used.

[0066] The viscosity of the non-aqueous ink composition of the present invention at 25°C is preferably 2.5 mPa·s or more and less than 7.0 mPa·s, more preferably 2.8 to 6.5 mPa·s, and even more preferably 3.0 to 6.0 mPa·s. When the viscosity of the ink composition at 25°C is within the above-specified range, good ejection stability can be obtained. The viscosity of the ink can be measured using a cone-plate viscometer. In this specification, the viscosity of the ink is also referred to as "viscosity (R)".

[0067] The non-aqueous ink composition of the present invention preferably has a surface tension at 25°C of 20 to 35 mN / m, more preferably 23 to 33 mN / m, and even more preferably 25 to 30 mN / m. If the surface tension of the ink at 25°C is within the above-specified range, good ejection stability is obtained, and the ink has good wettability on the printing surface, which leads to improved ink drying properties and glossiness of the printed material. The surface tension of the ink can be measured by a plate method.

[0068] Next, the non-aqueous ink set of the present invention will be described.

[0069] The non-aqueous ink set of the present invention is a non-aqueous ink set for inkjet printing comprising at least a cyan ink, a magenta ink, and a yellow ink, the cyan ink, the magenta ink, and the yellow ink comprise (A) an organic solvent, (B) a resin, and (C) a pigment; (A) The organic solvent is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher. The non-aqueous ink set comprises: Here, the amount of (A-1) glycol ether solvent having a boiling point of less than 200°C in (A) the organic solvent is within a range of 60 to 95 mass %, and the amount of (A-2) the amide bond- or urea bond-containing compound in (A) the organic solvent is within a range of 4.0 to 30 mass %.

[0070] In the non-aqueous ink set of the present invention, the "(A) organic solvent," "(A-1) glycol ether solvent with a boiling point of less than 200°C," "(A-2) amide bond or urea bond-containing compound," "(B) resin," and "(C) pigment" are as described in the description of the non-aqueous ink set of the present invention.

[0071] In this specification, a non-aqueous ink set for inkjet printing refers to a non-aqueous ink set that can be used for printing with an inkjet printer, and a non-aqueous ink set refers to an ink set that is composed of non-aqueous ink compositions. In other words, the inks that constitute the non-aqueous ink set of the present invention are non-aqueous ink compositions.

[0072] The inks constituting the non-aqueous ink set of the present invention consist of at least cyan ink, magenta ink, and yellow ink, but it is also possible to include an ink that emits a color different from these, such as black ink. In addition to the basic color inks such as cyan ink, magenta ink, yellow ink, and black ink, examples of inks constituting the non-aqueous ink set of the present invention include light cyan ink, light magenta ink, light yellow ink, light black ink, orange ink, and white ink.

[0073] It is preferable that all of the inks constituting the non-aqueous ink set of the present invention be the non-aqueous ink composition of the present invention described above.

[0074] When the non-aqueous ink set of the present invention includes an orange ink in addition to a cyan ink, a magenta ink, and a yellow ink, the orange ink contains (A) an organic solvent, (B) a resin, and (C) a pigment, (A) The organic solvent is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher, The amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in (A) the organic solvent is within a range of 60 to 95 mass %, and The amount of the amide bond- or urea bond-containing compound (A-2) in the organic solvent (A) is preferably within a range of 1.0 to 30% by mass. The orange ink is preferably the non-aqueous ink composition of the present invention described above.

[0075] When the non-aqueous ink set of the present invention includes an additional ink (excluding the orange ink) in addition to the cyan ink, magenta ink, and yellow ink, the additional ink contains (A) an organic solvent, (B) a resin, and (C) a pigment, (A) The organic solvent is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher, The amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in (A) the organic solvent is within a range of 60 to 95 mass %, and The amount of the amide bond- or urea bond-containing compound (A-2) in the organic solvent (A) is preferably within a range of 4.0 to 30% by mass. The additional ink is preferably the non-aqueous ink composition of the present invention described above.

[0076] In the ink set, each color ink contains (A-1) a glycol-based solvent with a boiling point below 200°C and (A-2) an amide or urea bond-containing compound. A mixture of 50 parts by weight of water, 47.5 parts by weight of diethylene glycol ethyl methyl ether, and 12.5 parts by weight of the (A-2) amide or urea bond-containing compound has a pH of 7.0 or higher. The proportions of the (A-2) amide or urea bond-containing compound are preferably similar. Maintaining the same blend ratio of (A-1) and (A-2), particularly at approximately 10% or less, and even at approximately 5% or less, facilitates control of the drying speed and gloss of printed materials, thereby further improving the blocking resistance and gloss of the resulting printed materials. Furthermore, it is also preferable to maintain the same viscosity for each color ink. The difference in viscosity (R) at 25°C is preferably 0.5 mPa·s or less, and the viscosity (R) of each ink at 25°C is preferably within the range of 3.0 to 6.0 mPa·s. By adjusting the viscosity of each color ink to fall within this range, it becomes easier to obtain printed matter that is excellent in blocking resistance and gloss.

[0077] Next, the printing method of the present invention will be described.

[0078] The printing method of the present invention is a printing method for forming a printed layer using a non-aqueous ink composition for inkjet printing, which comprises (A) an organic solvent and (B) a resin, and includes the steps of: (A) The organic solvent is (A-1) a glycol ether solvent with a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher, The proportion of (A-1) glycol ether solvent with a boiling point of less than 200°C in (A) the organic solvent is within a range of 60 to 95 mass %, and The printing method is characterized in that the ratio of the amide bond- or urea bond-containing compound (A-2) in the organic solvent (A) is within the range of 4.0 to 30% by mass.

[0079] Furthermore, the present inventors have found that in the printing method of the present invention, when the non-aqueous ink composition is an orange ink, the effects of component (A-2) can be fully exhibited even when the amount of component (A-2) in organic solvent (A) is less than 4.0% by mass. That is, in the printing method of the present invention, when the non-aqueous ink composition is an orange ink, the amount of component (A-2) in organic solvent (A) is preferably within the range of 1.0 to 30% by mass.

[0080] In the printing method of the present invention, the "non-aqueous ink composition for inkjet printing," "(A) organic solvent," "(A-1) glycol ether solvent with a boiling point of less than 200°C," "(A-2) amide bond- or urea bond-containing compound having an aqueous solution with a pH of 7.0 or higher," and "(B) resin" are as described in the description of the non-aqueous ink composition of the present invention.

[0081] In this specification, the printed layer means a layer formed by printing with ink.

[0082] In the printing method of the present invention, the non-aqueous ink composition is preferably the non-aqueous ink composition of the present invention described above. Furthermore, when a printed layer is formed from a plurality of non-aqueous ink compositions, the printed layer is preferably formed using the non-aqueous ink set of the present invention described above.

[0083] In the printing method of the present invention, the substrate on which the printed layer is formed is not particularly limited, but suitable examples include substrates used in industrial lines. The substrate may be in the form of, for example, a film, a sheet, or a plate. Examples of substrate materials include plastics such as epoxy resin, ABS resin, polycarbonate, polyvinyl chloride, polystyrene, and acrylic resin, particularly polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and polypropylene (PP); metals such as iron, stainless steel, and aluminum; wood; cement; concrete; gypsum; calcium silicate; calcium carbonate; and glass. Specific examples of substrates include vinyl chloride sheets, tarpaulin, plastic cardboard, acrylic boards, flexible boards, calcium silicate boards, gypsum slag barite boards, calcium carbonate boards, wood chip cement boards, precast concrete boards, lightweight foamed concrete (ALC) boards, gypsum boards, tiles, and glass plates. Among these, polyvinyl chloride and tarpaulin substrates are preferred. Component (A-2) has high penetration into polyvinyl chloride substrates and tarpaulin substrates, and produces a printed layer that is less likely to bleed and has excellent blocking resistance.

[0084] In the printing method of the present invention, printing is performed by an inkjet printing method. Various inkjet printers can be used for inkjet printing. Examples of inkjet printers include inkjet printers that eject ink compositions using a charge control method or a piezoelectric method. Large-format inkjet printers, specifically inkjet printers designed for printing on products produced on industrial lines, can also be suitably used. [Example]

[0085] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0086] <<Examples 1 to 19 and Comparative Examples 1 to 7>> Mixtures containing the components in the amounts (parts by mass) shown in Tables 1 to 13 were kneaded in a bead mill for 3 hours to prepare inks 1 to 104.

[0087] The pigments used were a yellow pigment: Comalix Yellow 150 (Zeya Chemicals), a cyan pigment: Chromophie Blue A-220JC (Dainichiseika Color & Chemicals Mfg. Co., Ltd.), a black pigment: Monarch 1000 (Cabot Corporation), and a magenta pigment: Fastogen Super Magenta RG (DIC Corporation). The dispersants used were DISPERBYK-2150 (BYK) or SOLSPERSE 32000 (Lubrizol), and the resins used were VINNOL H15 / 42 (vinyl chloride-vinyl acetate copolymer resin, Wacker Chemie) or Dianal BR-87 (acrylic resin, Mitsubishi Chemical Corporation).

[0088] <Head corrosion resistance> The printer head was filled with inks 1 to 104 and immersed at room temperature for 100 hours. The presence or absence of rust around the nozzles was then observed using a digital microscope and evaluated according to the following criteria. The results are shown in Table 14. (standard) ◯: No rust was observed in any of the magenta ink, yellow ink, cyan ink, and black ink. ×: Rust occurred in the case of one or more of magenta ink, yellow ink, cyan ink, and black ink.

[0089] <Discharge stability> The black inks listed in Table 14 were filled into a large-format inkjet printer. After printing a test pattern image, a 100% solid image was printed for 1,000 hours. After printing, the test pattern was printed again and evaluated according to the following criteria. The results are shown in Table 14. (standard) ◎: Test pattern defects and test pattern distortion are less than 1%. ○: Missing or distorted test pattern is less than 5%. △: Test pattern missing or distorted 5% to 10%. ×: Missing or distorted test pattern exceeds 10%.

[0090] <Blocking resistance> The black inks listed in Table 14 were applied to a glossy PVC sheet heated to 45°C using bar coater #7. After application, a 200g weight was placed on the ink film every 10 seconds to evaluate whether the weight left an imprint. The evaluation results, based on the following criteria, are shown in Table 14. Inks rated as ⊚ or ◯ are inks that can produce printed matter that is less likely to block when printed on roll media and then wound up. (standard) ◎: No traces of the weight remain on the coating within 2 minutes. 〇: No traces of the weight remain on the coating within 3 minutes. ×: Traces of the weight remain on the coating even after 3 minutes.

[0091] <Resistance to inter-color bleeding> Using the various ink sets in Table 14, a solid image of a 300% mixture of CMY colors and a solid image of a 200% mixture of MY colors were printed adjacent to each other. The evaluation results, based on the following criteria, are shown in Table 14. Images using inks rated as ◯ are less likely to bleed. (standard) ◯: No bleeding was observed between adjacent colors. ×: Bleeding was observed between adjacent colors.

[0092] <Dot diameter> A test pattern was printed using a large-format inkjet printer with the black ink listed in Table 14, and the dot diameter was observed using a digital microscope. The evaluation results according to the following criteria are shown in Table 14. Printed images with dot diameters of 80 μm or more have a high gloss. (standard) 〇: Dot diameter is 80μm or more ×: Dot diameter is less than 80 μm

[0093] <Gloss of printed matter> A 100% solid image was printed using a large-format inkjet printer with the black ink listed in Table 14. The resulting print was dried at 60°C for 1 hour, and then the 20° gloss was measured using a BYK gloss meter. The evaluation results, based on the following criteria, are shown in Table 14. (standard) ◎: Gloss value is 40 or more 〇: Gloss value is 30 or more ×: Gloss value less than 30

[0094] [Table 1]

[0095] [Table 2]

[0096] [Table 3]

[0097] [Table 4]

[0098] [Table 5]

[0099] [Table 6]

[0100] [Table 7]

[0101] [Table 8]

[0102] [Table 9]

[0103] [Table 10]

[0104] [Table 11]

[0105] [Table 12]

[0106] [Table 13]

[0107] In the table, "(A-1) / organic solvent" indicates the amount (% by mass) of (A-1) glycol ether-based solvent with a boiling point of less than 200°C in (A) organic solvent, "(A-2) / organic solvent" indicates the amount (% by mass) of (A-2) amide bond- or urea bond-containing compound in (A) organic solvent, "(A-3) / organic solvent" indicates the amount (% by mass) of (A-3) glycol or glycol ether-based solvent with a boiling point of 220°C or higher and lower than 300°C in (A) organic solvent, and "(A-1) / (A-2)" indicates the mass ratio of the amount of (A-1) component in (A) organic solvent to the amount of (A-2) component in (A) organic solvent.

[0108] [Table 14]

[0109] In addition, the pH of the water extract was measured for black inks 5, 45, 49, 53, 57, and 77, and the head corrosion resistance and continuous ejection stability were evaluated. The results are shown in Table 15.

[0110] <pH of water extract> Using a separatory funnel, 1 g of black ink was added dropwise to 100 g of distilled water, and after the addition was complete, the mixture was thoroughly mixed and stirred, and then allowed to stand for 30 minutes at 20°C. After that, the aqueous phase (i.e., the aqueous extract) located at the bottom of the separatory funnel was removed, and the pH of the aqueous extract was measured at 20°C using a pH meter.

[0111] <Head corrosion resistance> The printer head was filled with black ink and immersed at room temperature for 100 hours, after which the presence or absence of rust around the nozzle was observed with a digital microscope and evaluated according to the following criteria. (standard) ○: No rust has occurred. ×: Rust is present.

[0112] <Continuous ejection stability evaluation> The continuous ejection stability when a 100% solid image was printed for 5 m was evaluated based on the following criteria. ○: Even after printing 5 m, the ink droplets were ejected without any change in droplet shape or deflection in flight. △: After printing 5 m, slight changes in droplet shape and deflection in flight were observed in the flight state of the ejected ink droplets, but this was at a level that would not cause any problems in practical use. ×: After printing 5 m, significant changes in droplet shape and deflection of flight path were observed in the flight state of the ejected ink droplets, which is problematic for practical use.

[0113] [Table 15]

[0114] <<Examples 20 to 24 and Comparative Examples 8 to 11>> Mixtures containing the components in the amounts (parts by mass) shown in Table 16 were kneaded in a bead mill for 3 hours to prepare orange inks O1 to O9.

[0115] <Head corrosion resistance> The printer head was filled with inks O1 to O9 and immersed at room temperature for 100 hours. The presence or absence of rust around the nozzles was then observed using a digital microscope and evaluated according to the following criteria. The results are shown in Table 16. (standard) ○: No rust has occurred. ×: Rust is present.

[0116] <Discharge stability> The orange inks listed in Table 16 were filled into a large-format inkjet printer. After printing a test pattern image, a 100% solid image was printed for 1,000 hours. After printing, the test pattern was printed again and evaluated according to the following criteria. The results are shown in Table 16. (standard) ◎: Test pattern defects and test pattern distortion are less than 1%. ○: Missing or distorted test pattern is less than 5%. △: Test pattern missing or distorted 5% to 10%. ×: Missing or distorted test pattern exceeds 10%.

[0117] <Blocking resistance> The orange inks listed in Table 16 were applied to a glossy PVC sheet heated to 45°C using bar coater #7. After application, a 200g weight was placed on the ink film every 10 seconds to evaluate whether the weight left an imprint. The evaluation results, based on the following criteria, are shown in Table 16. Inks rated as ⊚ or ◯ are inks that can produce printed matter that is less likely to block when printed on roll media and then wound up. (standard) ◎: No traces of the weight remain on the coating within 2 minutes. 〇: No traces of the weight remain on the coating within 3 minutes. ×: Traces of the weight remain on the coating even after 3 minutes.

[0118] <Resistance to inter-color bleeding> Using an ink set consisting of the various orange inks in Table 16 and inks 6, 7, and 8 prepared above, a solid image of 300% CMY mixed colors was printed next to a solid image of 100% orange mixed color. The evaluation results, based on the following criteria, are shown in Table 16. Images using inks rated ○ were less likely to bleed. (standard) ◯: No bleeding was observed between adjacent colors. ×: Bleeding was observed between adjacent colors.

[0119] <Gloss of printed matter> A 100% solid image was printed using a large-format inkjet printer with the orange ink shown in Table 16. The resulting print was dried at 60°C for 1 hour, and then the 20° gloss was measured using a BYK gloss meter. The evaluation results, based on the following criteria, are shown in Table 16. (standard) ◎: Gloss value is 40 or more 〇: Gloss value is 30 or more ×: Gloss value less than 30

[0120] [Table 16]

[0121] In the table, "(A-1) / organic solvent" indicates the amount (% by mass) of (A-1) glycol ether-based solvent with a boiling point of less than 200°C in (A) organic solvent, "(A-2) / organic solvent" indicates the amount (% by mass) of (A-2) amide bond- or urea bond-containing compound in (A) organic solvent, "(A-3) / organic solvent" indicates the amount (% by mass) of (A-3) glycol or glycol ether-based solvent with a boiling point of 220°C or higher and lower than 300°C in (A) organic solvent, and "(A-1) / (A-2)" indicates the mass ratio of the amount of (A-1) component in (A) organic solvent to the amount of (A-2) component in (A) organic solvent.

[0122] <<Examples 25 to 30>> <Preparation of White Inks W1 to W6> Using titanium oxide pigment that had been dehydrated in advance using a dehydrating agent, mixtures containing the components shown in Table 17 were kneaded in a bead mill for 3 hours to prepare white inks W1 to W6. The viscosity of the resulting inks at 25°C was measured using a cone-plate viscometer, and this was taken as the initial viscosity. The water content of inks W1 to W6 was also measured using a moisture meter (Karl Fischer method).

[0123] <Head corrosion resistance> The printer head was filled with white inks W1 to W6 and immersed at room temperature for 100 hours. The presence or absence of rust around the nozzles was then observed using a digital microscope and evaluated according to the following criteria. The results are shown in Table 17. (standard) ○: No rust has occurred. ×: Rust is present.

[0124] <Discharge stability> White inks W1 to W6 were filled into a large-format inkjet printer. After printing a test pattern image, a 100% solid image was printed for 1,000 hours. After printing, the test pattern was printed again and evaluated according to the following criteria. The results are shown in Table 17. (standard) ◎: Test pattern defects and test pattern distortion are less than 1%. ○: Missing or distorted test pattern is less than 5%. △: Test pattern missing or distorted 5% to 10%. ×: Missing or distorted test pattern exceeds 10%.

[0125] <Blocking resistance> White inks W1 to W6 listed in Table 17 were applied to a glossy PVC sheet heated to 45°C using bar coater #7. After application, a 200g weight was placed on the ink film every 10 seconds to evaluate whether the weight left an imprint. The evaluation results, based on the following criteria, are shown in Table 17. Inks rated as ⊚ or ◯ are inks that can produce printed matter that is less likely to block when printed on roll media and then wound up. (standard) ◎: No traces of the weight remain on the coating within 2 minutes. 〇: No traces of the weight remain on the coating within 3 minutes. ×: Traces of the weight remain on the coating even after 3 minutes.

[0126] <Resistance to inter-color bleeding> Using an ink set consisting of the various white inks in Table 17 and inks 6, 7, and 8 prepared above, a solid image of 300% CMY mixed color and a solid image of 100% white mixed color were printed adjacent to each other. The evaluation results, based on the following criteria, are shown in Table 17. Images using inks rated ○ were less likely to bleed. (standard) ◯: No bleeding was observed between adjacent colors. ×: Bleeding was observed between adjacent colors.

[0127] <Gloss of printed matter> A 100% solid image was printed using a large-format inkjet printer with the white ink listed in Table 17. The resulting print was dried at 60°C for 1 hour, and then the 20° gloss was measured using a BYK gloss meter. The evaluation results, based on the following criteria, are shown in Table 17. (standard) ◎: Gloss value is 40 or more 〇: Gloss value is 30 or more ×: Gloss value less than 30

[0128] <Storage stability> The white inks W1 to W6 were stored at 50°C for 28 days, and the viscosity of the inks was measured before and after storage to determine the rate of change in viscosity from the initial viscosity, and the storage stability was evaluated according to the following criteria. The results are shown in Table 17. (standard) ◎: Viscosity change rate is 0-0.9% ○: Viscosity change rate is 1.0% to 2.9% △: Viscosity change rate is 3.0% to 14.9% ×: Viscosity change rate is 15.0% or more

[0129] [Table 17]

[0130] In the table, "(A-1) / organic solvent" indicates the amount (% by mass) of (A-1) glycol ether-based solvent with a boiling point of less than 200°C in (A) organic solvent, "(A-2) / organic solvent" indicates the amount (% by mass) of (A-2) amide bond- or urea bond-containing compound in (A) organic solvent, "(A-3) / organic solvent" indicates the amount (% by mass) of (A-3) glycol or glycol ether-based solvent with a boiling point of 220°C or higher and lower than 300°C in (A) organic solvent, and "(A-1) / (A-2)" indicates the mass ratio of the amount of (A-1) component in (A) organic solvent to the amount of (A-2) component in (A) organic solvent.

Claims

1. A non-aqueous ink composition for inkjet printing, comprising (A) an organic solvent and (B) a resin, (A) The organic solvent is (A-1) a glycol ether solvent having a boiling point of less than 200°C, (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher; and (A-3) contains a glycol or glycol ether solvent having a boiling point of 220°C or higher but lower than 300°C, the amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in the organic solvent (A) is within a range of 60 to 95% by mass, the amount of the amide bond- or urea bond-containing compound (A-2) in the organic solvent (A) is within a range of 4.0 to 30% by mass, A non-aqueous ink composition, characterized in that the amount of (A-3) a glycol or glycol ether solvent having a boiling point of 220°C or higher and lower than 300°C in the organic solvent (A) is 0.1 to 2.0 mass%.

2. A non-aqueous ink composition for inkjet printing, comprising (A) an organic solvent and (B) a resin, the non-aqueous ink composition is an orange ink, (A) The organic solvent is (A-1) a glycol ether solvent having a boiling point of less than 200°C, (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher; and (A-3) contains a glycol or glycol ether solvent having a boiling point of 220°C or higher but lower than 300°C, the amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in the organic solvent (A) is within a range of 60 to 95% by mass, the amount of the amide bond- or urea bond-containing compound (A-2) in the organic solvent (A) is within a range of 1.0 to 30% by mass, A non-aqueous ink composition, characterized in that the amount of (A-3) a glycol or glycol ether solvent having a boiling point of 220°C or higher and lower than 300°C in the organic solvent (A) is 0.1 to 2.0 mass%.

3. 3. The ink composition according to claim 1, wherein the amide bond- or urea bond-containing compound (A-2) includes at least one solvent selected from the group consisting of alkylamide solvents, cyclic amide solvents, aromatic amide solvents, alkylurea solvents, and cyclic urea solvents.

4. the non-aqueous ink composition is a black ink, 2. The ink composition according to claim 1, wherein the pH of the aqueous extract of the non-aqueous ink composition is in the range of 3.0 to 7.

0.

5. the non-aqueous ink composition is a white ink, The ink composition according to claim 1 , wherein the amount of water contained in the non-aqueous ink composition is less than 10,000 ppm by mass.

6. A non-aqueous ink set for inkjet printing comprising at least a cyan ink, a magenta ink, and a yellow ink, the cyan ink, the magenta ink, and the yellow ink each contain (A) an organic solvent, (B) a resin, and (C) a pigment; (A) The organic solvent is (A-1) a glycol ether solvent having a boiling point of less than 200°C, (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher; and (A-3) contains a glycol or glycol ether solvent having a boiling point of 220°C or higher but lower than 300°C, the amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in the organic solvent (A) is within a range of 60 to 95% by mass, the amount of the amide bond- or urea bond-containing compound (A-2) in the organic solvent (A) is within a range of 4.0 to 30% by mass, A non-aqueous ink set, characterized in that the amount of (A-3) glycol or glycol ether solvent having a boiling point of 220°C or higher but lower than 300°C in the organic solvent (A) is 0.1 to 2.0% by mass.

7. the non-aqueous ink set comprises an orange ink, the orange ink comprises (A) an organic solvent, (B) a resin, and (C) a pigment; (A) The organic solvent is (A-1) a glycol ether solvent having a boiling point of less than 200°C, and (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher, the amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in the organic solvent (A) is within a range of 60 to 95% by mass, 7. The non-aqueous ink set according to claim 6, wherein the amount of (A-2) the amide bond or urea bond-containing compound in (A) the organic solvent is within the range of 1.0 to 30% by mass.

8. A printing method for forming a print layer using a non-aqueous ink composition for inkjet printing, the non-aqueous ink composition comprising (A) an organic solvent and (B) a resin, the method comprising: (A) The organic solvent is (A-1) a glycol ether solvent having a boiling point of less than 200°C, (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher; and (A-3) contains a glycol or glycol ether solvent having a boiling point of 220°C or higher but lower than 300°C, the amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in the organic solvent (A) is within a range of 60 to 95% by mass, the amount of the amide bond- or urea bond-containing compound (A-2) in the organic solvent (A) is within a range of 4.0 to 30% by mass, A printing method, characterized in that the amount of (A-3) glycol or glycol ether solvent having a boiling point of 220°C or higher but lower than 300°C in the organic solvent (A) is 0.1 to 2.0 mass%.

9. A printing method for forming a print layer using a non-aqueous ink composition for inkjet printing, the non-aqueous ink composition comprising (A) an organic solvent and (B) a resin, the method comprising: the non-aqueous ink composition is an orange ink, (A) The organic solvent is (A-1) a glycol ether solvent having a boiling point of less than 200°C, (A-2) an amide bond- or urea bond-containing compound, wherein a mixed solution consisting of 50 parts by mass of water, 47.5 parts by mass of diethylene glycol ethyl methyl ether, and 12.5 parts by mass of (A-2) the amide bond- or urea bond-containing compound has a pH of 7.0 or higher; and (A-3) contains a glycol or glycol ether solvent having a boiling point of 220°C or higher but lower than 300°C, the amount of (A-1) glycol ether solvent with a boiling point of less than 200°C in the organic solvent (A) is within a range of 60 to 95% by mass, the amount of the amide bond- or urea bond-containing compound (A-2) in the organic solvent (A) is within a range of 1.0 to 30% by mass, A printing method, characterized in that the amount of (A-3) glycol or glycol ether solvent having a boiling point of 220°C or higher but lower than 300°C in the organic solvent (A) is 0.1 to 2.0 mass%.

Images