Coloring Liquid, Coloring Liquid Set, Recording Medium, and Coloring Method

Abstract

Provided is a coloring liquid containing: a pigment having a naphthalene skeleton in the molecule; at least one compound selected from compounds having two or more naphthalene skeletons in the molecule (excluding the pigment having a naphthalene skeleton in the molecule and compounds having a pyrazine skeleton in the molecule) and compounds having a pyrazine skeleton in the molecule (excluding the pigment having a naphthalene skeleton in the molecule); and water. Also provided are a coloring liquid set including the coloring liquid, a recording medium to which the coloring liquid or each coloring liquid included in the coloring liquid set is attached, and a coloring method using the coloring liquid or the coloring liquid set.

Description

Technical Field

[0001] The present invention relates to a coloring liquid, a coloring liquid set including the coloring liquid, a recording medium to which the coloring liquid or each coloring liquid included in the coloring liquid set is attached, and a coloring method using the coloring liquid or the coloring liquid set. Background Art

[0002] Heretofore, various dyes and pigments have been developed, and color index numbers have been assigned to some of them, and they have been commercially available. Taking azo pigments as an example, azo pigments synthesized by diazo coupling have long been known and are widely used industrially. In particular, in addition to printing books, they are also used for coloring various products indispensable for modern life such as clothes, food, furniture, and building materials. In addition, in recent years, the effective use of inks for inkjet printing and the like in a wide range of fields has been promoted (for example, see Patent Document 1).

[0003] On the other hand, in the case of being used in precision electronic devices such as inkjet printers, there are several important problems to be solved, such as ensuring the redissolubility when the coloring liquid is dried. Various methods for solving this problem have been studied, but it has not been known so far that the performance of the coloring liquid can be improved by adding a specific compound and the performance of the recording medium to be colored can also be improved.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-185201 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] An object of the present invention is to provide a coloring liquid having excellent redissolubility when dried and capable of obtaining a colored product having excellent fastness, a coloring liquid set including the coloring liquid, a recording medium to which the coloring liquid or each coloring liquid included in the coloring liquid set is attached, and a coloring method using the coloring liquid or the coloring liquid set.

[0009] Means for Solving the Problems

[0010] Specific means for solving the above problems include the following embodiments. 1)

[0012] A coloring solution containing: a pigment having a naphthalene skeleton in the molecule; at least one compound selected from compounds having two or more naphthalene skeletons in the molecule (wherein, the pigment having a naphthalene skeleton in the molecule and the compound having a pyrazine skeleton in the molecule are not included); and a compound having a pyrazine skeleton in the molecule (wherein, the pigment having a naphthalene skeleton in the molecule is not included); and water. 2)

[0014] The coloring solution according to 1), wherein the compound having two or more naphthalene skeletons in the molecule is a compound having a hydroxyl group in the molecule. 3)

[0016] The coloring solution according to 1) or 2), wherein the compound having two or more naphthalene skeletons in the molecule is a compound having a substituted binaphthyl skeleton. 4)

[0018] The coloring solution according to any one of 1) to 3), wherein the compound having two or more naphthalene skeletons in the molecule is 1,1'-binaphthalene-2,2'-diol. 5)

[0020] The coloring solution according to any one of 1) to 4), wherein the compound having a pyrazine skeleton in the molecule is a compound represented by the following formula (1).

[0021] [Chemical formula 1]

[0022]

[0023] (In formula (1), the rings Ar represented by the dashed lines 1 and Ar 2 each independently represent a benzene ring or a naphthalene ring. R 1 and R 2 represent substituents on the ring Ar 1 , and R 3 and R 4 represent substituents on the ring Ar 2 . R 1 , R 2 , R 3 , and R 4 each independently represent a hydrogen atom, a hydroxyl group, a carboxyl group, a halogenated group, an alkyl group, a phenyl group, a phenoxy group, a naphthyl group, a hydroxynaphthyl group, a naphthoxy group, an amino group, a nitro group, a sulfo group, a sulfamoyl group, an acetyl group, an acetamido group, a methylamino group, an ethylamino group, a cyano group, a methoxycarbonyl group, an ethoxycarbonyl group, a 3-methoxy-2-hydroxypropylamino group, a phenylamino group, a methoxyamino group, a hydroxyethylamino group, a hydroxypropylamino group, an N-acetyl-N-methylamino group, or an acetoxyethoxyethylamino group.) 6)

[0025] The coloring liquid according to any one of 1) to 5), wherein the compound having a pyrazine skeleton in the molecule is a compound represented by the following formula (1-1).

[0026] [Chemical formula 2]

[0027] 7)

[0029] The coloring liquid according to any one of 1) to 6), wherein the pigment having a naphthalene skeleton in the molecule is an azo pigment having an azo bond in the molecule. 8)

[0031] The coloring liquid according to any one of 1) to 7), wherein the pigment having a naphthalene skeleton in the molecule is an azo metal complex pigment. 9)

[0033] The coloring liquid according to 8), wherein the azo metal complex pigment is an azo metal complex pigment containing a metal selected from the group consisting of chromium, copper, iron, and cobalt. 10)

[0035] The coloring liquid according to any one of 1) to 9), wherein when the content of the pigment having a naphthalene skeleton in the molecule is 100 parts by mass, the content of the compound having two or more naphthalene skeletons in the molecule is less than 1.8 parts by mass. 11)

[0037] The coloring liquid according to any one of 1) to 10), wherein when the content of the pigment having a naphthalene skeleton in the molecule is 100 parts by mass, the content of the compound having a pyrazine skeleton in the molecule is less than 1.2 parts by mass. 12)

[0039] The coloring liquid according to any one of 1) to 11), wherein the pigment having a naphthalene skeleton in the molecule is at least one pigment selected from the group consisting of C.I. Acid Brown 298; C.I. Acid Blue 193; and C.I. Acid Black 52, 52:1, 172, 194,

[0040] the compound having two or more naphthalene skeletons in the molecule is 1,1'-binaphthalene-2,2'-diol,

[0041] the compound having a pyrazine skeleton in the molecule is a compound represented by the following formula (1-1).

[0042] [Chemical formula 3]

[0043] 13)

[0045] The coloring liquid according to any one of 1) to 12) contains both the compound having two or more naphthalene skeletons in the molecule and the compound having a pyrazine skeleton in the molecule. 14)

[0047] The coloring liquid according to any one of 1) to 13) further contains a water-soluble organic solvent. 15)

[0049] A coloring liquid set includes: the coloring liquid according to any one of 1) to 14); and at least one coloring liquid having a hue different from that of the coloring liquid. 16)

[0051] A recording medium is attached with the coloring liquid according to any one of 1) to 14) or each coloring liquid included in the coloring liquid set described in 15). 17)

[0053] In the recording medium according to 16), the recording medium is a fiber. 18)

[0055] A coloring method is to perform coloring by attaching the coloring liquid according to any one of 1) to 14) or each coloring liquid included in the coloring liquid set described in 15) to a recording medium.

[0056] Effects of the Invention

[0057] According to the present invention, it is possible to provide a coloring liquid having excellent redissolvability when dried and capable of obtaining a colored product with excellent fastness, a coloring liquid set including the coloring liquid, a recording medium attached with the coloring liquid or each coloring liquid included in the coloring liquid set, and a coloring method using the coloring liquid or the coloring liquid set. Detailed Description of the Invention

[0058] Hereinafter, the specific embodiments of applying the present invention will be described in detail. In this specification, "C.I." is an abbreviation for Color Index.

[0059] <Coloring Liquid>

[0060] The coloring liquid according to this embodiment contains: a pigment having a naphthalene skeleton in the molecule; at least one compound selected from a compound having two or more naphthalene skeletons in the molecule (wherein, the pigment having a naphthalene skeleton in the molecule and the compound having a pyrazine skeleton in the molecule are not included) and a compound having a pyrazine skeleton in the molecule (wherein, the pigment having a naphthalene skeleton in the molecule is not included); and water.

[0061] As described above, in addition to a pigment having a naphthalene skeleton in the molecule, a compound having two or more naphthalene skeletons in the molecule and / or a compound having a pyrazine skeleton in the molecule are contained, so that the performance of the coloring liquid is improved and the performance of the colored recording medium is also improved. The reason is not necessarily clear, and the inventors of the present application speculate as follows.

[0062] That is, it is considered that the compound having two or more naphthalene skeletons in the molecule and the compound having a pyrazine skeleton in the molecule contribute to the solubility and dissolution stability of the pigment having a naphthalene skeleton in the molecule. As a result, the filterability of the coloring liquid becomes good, clogging of the filter is suppressed, and precipitation of the pigment due to main reasons such as drying can be suppressed. In addition, it is considered that due to the above reasons, the dried coloring liquid is also easily redissolved. It is considered that by improving these performances, for example, when the coloring liquid is used as an ink for an inkjet printer, the occurrence of clogging of the head filter, nozzles, etc. can be effectively suppressed, and the ejection stability of the ink is improved.

[0063] In addition, it is considered that in the case of containing a compound having two or more naphthalene skeletons in the molecule and / or a compound having a pyrazine skeleton in the molecule, ultraviolet rays and oxidizing gases preferentially act on these compounds. As a result, the fastness of the colored recording medium is improved. For example, if the recording medium is cloth, the light resistance tends to be improved, and if the recording medium is paper such as photographic paper, the light resistance and ozone resistance tend to be improved.

[0064] Hereinafter, each component contained in the coloring liquid according to the present embodiment will be described in detail. It should be noted that each of the components described below can be used alone or in combination of two or more.

[0065] [Pigment having a naphthalene skeleton in the molecule]

[0066] The pigment having a naphthalene skeleton in the molecule (hereinafter, also referred to as "naphthalene skeleton-containing pigment") can be a dye or a pigment. As the dye, for example, direct dyes, acid dyes, reactive dyes, disperse dyes (sublimation dyes, solvent dyes, etc.), cationic dyes, azo dyes, sulfur dyes, mordant dyes, etc. can be cited. Among these dyes, disperse dyes, cationic dyes, direct dyes, acid dyes, and reactive dyes are preferred.

[0067] As the naphthalene skeleton-containing pigment, for example, azo pigments having an azo bond in the molecule, azine pigments, azomethine pigments, aminoketone pigments, xanthene pigments, quinoline pigments, nitro pigments, methylene pigments, stilbene pigments, styrene pigments, naphthalocyanine pigments, oxazole pigments, azomethine pigments, anthraquinone pigments, phthalocyanine pigments, coumarin pigments, triphenylmethane pigments, etc. can be cited. Among these, azo pigments are preferred.

[0068] When the naphthalene skeleton-containing pigment is an azo pigment, an azo metal complex pigment can be produced by incorporating a metal into the molecule.

[0069] The metal in the azo metal complex pigment is not particularly limited as long as it can form a complex with the azo pigment, and metals selected from the group consisting of chromium, copper, iron, and cobalt are preferred.

[0070] As azo dyes or azo metal complex dyes, for example, the following can be cited: C.I. Acid Yellow 33, 100; C.I. Acid Orange 7, 8, 9, 12, 16, 17, 19, 20, 23, 27, 30, 31, 41, 51, 55, 56, 127, 137, 159, 160; C.I. Acid Red 4, 6, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 25, 25:1, 27, 30, 31, 32, 37, 42, 44, 54, 56, 57, 60, 66, 68, 70, 71, 74, 86, 88, 89, 97, 99, 102, 116, 118, 119, 127, 133, 134, 135, 137, 141, 142, 144, 145, 148, 151, 154, 158, 163, 173, 182, 184, 186, 231, 256, 257, 266, 276, 301, 308, 337, 355, 366, 374, 440, 442, 444; C.I. Acid Brown 2, 3, 4, 5, 6, 7, 8, 14, 15, 16, 17, 20, 29, 32, 43, 44, 45, 46, 64, 86, 87, 88, 90, 91, 102, 105, 122, 146, 214, 282, 283, 294, 295, 296, 297, 298, 454, 469, 471; C.I. Acid Violet 1, 2, 14, 27, 56, 62, 67, 78, 90, 91, 117, 119; C.I. Acid Blue 36, 44, 70, 85, 92, 113, 116, 118, 120, 135, 155, 158, 158:1, 161, 171, 193, 194, 229, 234, 300, 328, 349; C.I. Acid Green 12, 19, 34, 35, 45, 73, 74, 75, 76, 77, 122, 125; C.I. Acid Black 3, 4, 5, 7, 16, 17, 18, 20, 21, 23, 24, 26, 16:1, 26:2, 27, 31, 32, 34, 35, 36, 43, 51, 52, 52:1, 63, 64, 107, 109, 112, 124, 155, 172, 194, 234; C.I. Reactive Yellow 16; C.I. Reactive Orange 1, 4, 5, 7, 13, 16, 17, 18, 20, 35, 44, 56, 64, 72, 78, 84, 95, 97, 124; C.I. Reactive Red 5, 7, 8, 9, 11, 13, 16, 22, 33, 43, 46, 55, 59, 65, 66, 84, 123, 136, 158, 159, 174, 180, 183, 186, 196, 206, 222, 224, 230, 236; C.I.Reactive Brown 1, 2, 7, 8, 9, 10, 17, 23, 33, 43, 45, 47; C.I. Reactive Violet 9; C.I. Reactive Blue 39, 40, 82, 112, 243; C.I. Reactive Black 1, 3, 9, 13; C.I. Mordant Brown 33; C.I. Mordant Black 7, 17; Kayacel Red CB Liquid, Kayacel Black CN Liquid, Kayacelon React Brown CN-AM; C.I. Direct Yellow 52, 87; C.I. Direct Orange 26, 29, 29:1, 102, 104, 108, 118; C.I. Direct Red 1, 2, 4, 6, 7, 8, 10, 13, 14, 15, 16, 17, 22, 23, 24, 26, 28, 29, 31, 32, 33, 34, 36, 42, 44, 45, 50, 52, 53, 54, 55, 57, 59, 60, 61, 62, 64, 65, 83:1, 88, 89, 90, 95, 99, 117, 118, 119, 120, 122, 123, 126, 127, 127:1, 130, 141, 142, 144, 145, 147, 148, 149, 150, 152, 153, 154, 155, 168, 169, 173, 174, 175, 181, 186, 189, 191, 194, 212, 224, 225, 226, 227, 239, 242, 243, 250, 254, 257, 258, 264; C.I. Direct Brown 2, 13, 14, 24, 25, 26, 46, 50, 56, 57, 58, 59, 60, 61, 63, 67, 68, 69, 70, 73, 74, 75, 86, 95, 99, 101, 112, 149, 151, 166, 167, 168, 171, 179, 186, 190, 202, 206, 208, 209, 210, 223, 224; C.I. Direct Violet 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17, 21, 22, 25, 26, 27, 28, 31, 32, 35, 36, 37, 38, 39, 40, 41, 42, 43, 46, 47, 48, 51, 53, 56, 57, 62, 63, 64, 66, 72, 77, 78, 79, 80, 81, 83, 85, 87, 100, 102, 103; C.I.Direct Blue 2, 3, 4, 8, 9, 12, 16, 19, 21, 22, 23, 26, 27, 29, 30, 31, 33, 34, 35, 36, 38, 39, 42, 43, 45, 48, 49, 50, 51, 54, 55, 58, 60, 63, 64, 65, 67, 69, 70, 71, 72, 74, 75, 78, 81, 82, 83, 90, 93, 96, 98, 110, 111, 116, 120, 120:1, 121, 122, 123, 124, 126, 127, 128, 129, 110, 131, 132, 133, 135, 136, 138, 140, 145, 148, 149, 150, 151, 152, 157, 158, 159, 162, 163, 164, 165, 166, 167, 168, 175, 176, 177, 183, 184, 185, 186, 200, 201, 203, 214, 215, 230, 231, 237, 239, 248, 258, 270, 273, 274, 278, 288, 289, 291, 295, 306, 308; C.I. Direct Green 3, 11, 13, 19, 20, 21, 22, 23, 33, 34, 36, 38, 39, 42, 443, 49, 50, 51, 57, 64; C.I. Direct Black 1, 2, 3, 9:1, 10, 14, 15, 17, 22, 24, 27, 29, 32, 36, 40, 48, 49, 51, 56, 71, 74, 75, 76, 77, 78, 80, 87, 91, 96, 97, 100, 101, 103, 112, 117, 118, 122, 131, 132, 141, 150, 151, 153, 156, 164, 173, 196, 197, 198, 199; Kayacelon Red C-HB, Kayacelon Rubin C-BL, Kayafect Red S Liquid, Kayafect Red H Liquid 50, Kayaku Direct Fast Red S Liquid 10BX; C.I. Disperse Yellow 97; C.I. Disperse Orange 13, 42, 125; C.I. Disperse Red 6, 44, 81, 141, 151, 200, 220, 271, 330, 334; C.I. Disperse Blue 15, 38, 85, 194, 260, 283, 294; C.I. Disperse Black 1; C.I. Basic Yellow 41; C.I. Basic Orange 47; C.I. Sulphur Green 6; C.I. Sulphur Black 6, 11; etc. Among these, pigments having a naphthol skeleton in the molecule are preferred, and more preferably C.I. Acid Brown 298; C.I. Acid Blue 193; and C.I.Acid Black 52, 52:1, 172, 194; more preferably C.I. Acid Brown 298, C.I. Acid Blue 193, and C.I. Acid Black 172.

[0071] The content rate of the naphthalene-skeleton-containing pigment is generally 0.5 to 25% by mass, preferably 1 to 20% by mass, more preferably 1 to 17% by mass, relative to the total mass of the coloring liquid. When the coloring liquid according to the present embodiment is used as a light-colored coloring liquid or ink (so-called light ink) in which the content rate of the naphthalene-skeleton-containing pigment is set low, the content rate of the naphthalene-skeleton-containing pigment is generally 0.025 to 5% by mass, preferably 0.05 to 2.5% by mass, more preferably 0.05 to 2% by mass, relative to the total mass of the coloring liquid.

[0072] [Compound having two or more naphthalene skeletons in the molecule]

[0073] As the compound having two or more naphthalene skeletons in the molecule (hereinafter, also referred to as "naphthalene-based compound"), it is not particularly limited as long as it does not contain the above-mentioned naphthalene-skeleton-containing pigment and the compound having a pyrazine skeleton in the molecule and has two or more naphthalene skeletons in the molecule.

[0074] Among the naphthalene-based compounds, compounds having a hydroxyl group in the molecule and compounds having a binaphthalene skeleton in the molecule are preferred, compounds having a substituted binaphthalene skeleton in the molecule are more preferred, compounds having both a hydroxyl group and a binaphthalene skeleton in the molecule are further preferred, and 1,1'-binaphthalene-2,2'-diol is particularly preferred. 1,1'-binaphthalene-2,2'-diol can be any of a racemate, an R-form, and an S-form.

[0075] When the content of the naphthalene-skeleton-containing pigment is 100 parts by mass, the content of the naphthalene-based compound is preferably less than 1.8 parts by mass, more preferably 0.0001 parts by mass or more and less than 1.8 parts by mass, further preferably 0.0002 parts by mass or more and less than 1.5 parts by mass, particularly preferably 0.0005 to 1.0 parts by mass, and extremely preferably 0.001 to 1.0 parts by mass.

[0076] [Compound having a pyrazine skeleton in the molecule]

[0077] As the compound having a pyrazine skeleton in the molecule (hereinafter, also referred to as "pyrazine-based compound"), it is not particularly limited as long as it does not contain the above-mentioned naphthalene-skeleton-containing pigment and has a pyrazine skeleton in the molecule.

[0078] Among the pyrazine-based compounds, the compound represented by the following formula (1) is preferred.

[0079] [Chemical formula 4]

[0080]

[0081] In the above formula (1), the ring Ar represented by a dashed line 1 and the ring A r2 each independently represent a benzene ring or a naphthalene ring. R 1 and R 2 represent substituents of the ring Ar 1 and R 3 and R 4 represent substituents of the ring Ar 2 and R 1 , R 2 , R 3 , and R 4 each independently represent a hydrogen atom, a hydroxyl group, a carboxyl group, a halogenated group, an alkyl group, a phenyl group, a phenoxy group, a naphthyl group, a hydroxynaphthyl group, a naphthoxy group, an amino group, a nitro group, a sulfo group, a sulfamoyl group, an acetyl group, an acetamido group, a methylamino group, an ethylamino group, a cyano group, a methoxycarbonyl group, an ethoxycarbonyl group, a 3-methoxy-2-hydroxypropylamino group, a phenylamino group, a methoxyamino group, a hydroxyethylamino group, a hydroxypropylamino group, an N-acetyl-N-methylamino group, or an acetoxyethoxyethylamino group.

[0082] As the halogenated group, for example, a fluorine group, a chlorine group, a bromine group, an iodine group, etc. can be mentioned.

[0083] As the alkyl group, for example, a linear or branched alkyl group having 1 to 20 carbon atoms can be mentioned. Specific examples of the alkyl group include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a tert-butyl group, etc., but are not limited to these.

[0084] When the ring Ar 1 and the ring Ar 2 represent a naphthalene ring, the naphthalene ring can arbitrarily select its ring bonding position with respect to the pyrazine ring. For example, when both the ring Ar 1 and the ring Ar 2 represent a naphthalene ring, the structures represented by the following formulas (A) to (D) can be taken.

[0085] [Chemical formula 5]

[0086]

[0087] As a particularly preferred compound among the compounds represented by the above formula (1), the compound represented by the following formula (1-1) can be mentioned.

[0088] [Chemical formula 6]

[0089]

[0090] The compound represented by the above formula (1) is a kind of azine dye well-known as C.I. Acid Black 2, etc., and is widely used for dyeing fibers, etc. Azine dyes include various dyes such as dyes having a phenazine ring and a naphthyridine ring. For example, they can be obtained based on Non-Patent Document [Hiroshi Horiguchi (1969). Review of Synthetic Dyes Sankyo Publishing].

[0091] In addition, the compound represented by the above formula (1-1) can be obtained, for example, by the following method: brominating the commercially available compound represented by the above formula (D), and then reacting the borated 2-naphthol by the Suzuki-Miyaura cross-coupling reaction.

[0092] When the content of the naphthalene skeleton pigment is set to 100, the content of the pyrazine-based compound is preferably less than 1.2 parts by mass, more preferably 0.0001 part by mass or more and less than 1.2 parts by mass, further preferably 0.0002 to 1.0 part by mass, particularly preferably 0.0005 to 0.5 part by mass, and extremely preferably 0.001 to 0.5 part by mass.

[0093] It should be noted that the coloring liquid according to this embodiment preferably contains both a naphthalene-based compound and a pyrazine-based compound, and more preferably contains both 1,1'-binaphthalene-2,2'-diol and the compound represented by the above formula (1-1).

[0094] [Water]

[0095] As water, water with few impurities such as ion-exchanged water and distilled water is preferred.

[0096] With respect to the total mass of the coloring liquid, the content rate of water is preferably 1 to 99% by mass, more preferably 5 to 95% by mass.

[0097] [Water-soluble organic solvent]

[0098] The coloring liquid according to this embodiment may further contain a water-soluble organic solvent. Examples of the water-soluble organic solvent include alcohols, pyrrolidones, polyoxyalkylene diglycerol ethers, and the like. Examples of the alcohols include C2-C6 alcohols having 2 to 3 hydroxyl groups such as glycerol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,3-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 2,4-diethyl-1,5-pentanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol; polyglycerol ethers such as dipropylene glycol and polypropylene glycol; polyoxy C2-C3 alkylene polyglycerol ethers such as polyoxyethylene polyglycerol ether and polyoxypropylene polyglycerol ether; mono-, di-, or tri-C2-C3 alkylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and polyethylene glycol; poly C2-C3 alkylene glycols having 4 or more repeating units and a molecular weight of about 20,000 or less (preferably liquid solvents); C1-C6 monoalkyl ethers of polyhydric alcohols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether (butyl carbitol), triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether (butyl triglycol), propylene glycol monomethyl ether, propylene glycol monoethyl ether (1-ethoxy-2-propanol), dipropylene glycol monopropyl ether (1-(1-methyl-2-propoxyethoxy)-2-propanol), dipropylene glycol monobutyl ether (1-(2-butoxy-1-methylethoxy)propane-2-ol), diethylene glycol monoethyl ether, diethylene glycol monohexyl ether (hexyl carbitol); C1-C6 dialkyl ethers of polyhydric alcohols such as diethylene glycol diethyl ether (diethyl carbitol); diol monoethers such as 3-methoxy-1-butanol and 3-methoxy-3-methylbutanol; diol phenyl ethers such as propylene glycol (mono)phenyl ether (1-phenoxy-2-propanol); and the like. Examples of the pyrrolidones include 2-pyrrolidone, N-methyl-2-pyrrolidone, 1-(2-hydroxyethyl)-2-pyrrolidone, and the like. Examples of the polyoxyalkylene diglycerol ethers include polyoxypropylene diglycerol ethers such as SC-P400, SC-P750, SC-P1000, SC-P1200, SC-P1600, etc., all of which are manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.; polyoxyethylene diglycerol ethers such as SC-E450, SC-E750, SC-E1000, SC-E1500, SC-E2000, etc.; and the like.Among these, glycerol, diglycerol, 1,3-propanediol, 1,5-pentanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, diethylene glycol monobutyl ether, 1,3-butanediol, 1,6-hexanediol, triethylene glycol, triethylene glycol monobutyl ether, 1-(2-hydroxyethyl)-2-pyrrolidone, and 2-pyrrolidone are preferred.

[0099] The content rate of the water-soluble organic solvent is usually 0 to 50% by mass, preferably 1 to 50% by mass, and more preferably 5 to 40% by mass, relative to the total mass of the coloring liquid.

[0100] [Additives]

[0101] The coloring liquid according to this embodiment may further contain other additives. Examples of the additives include surfactants, pH adjusters, antiseptics and fungicides, dye solubilizers, water-soluble aids, humectants, and the like.

[0102] The total content rate of the additives is usually 0 to 10% by mass, preferably about 0.05 to 5% by mass, relative to the total mass of the coloring liquid.

[0103] Examples of the surfactants include anionic, cationic, amphoteric, and nonionic surfactants. Among these, nonionic surfactants are preferred.

[0104] Examples of the anionic surfactants include alkylsulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids or their salts, N-acyl methyl taurates, alkyl sulfates, polyoxyalkylene ether sulfates, alkyl sulfate polyoxyethylene alkyl ether phosphates, rosin acid soaps, castor oil sulfate esters, lauryl sulfate esters, alkylphenol type phosphates, alkyl type phosphates, alkyl aryl sulfonates, diethyl sulfosuccinates, diethylhexyl sulfosuccinates, dioctyl sulfosuccinates, and the like.

[0105] Examples of the cationic surfactants include 2-vinylpyridine derivatives, poly-4-vinylpyridine derivatives, and the like.

[0106] Examples of the amphoteric surfactants include lauryl dimethylaminoacetate betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, coconut oil fatty acid amide propyl dimethylaminoacetate betaine, polyoctyl polyaminoethyl glycine, imidazoline derivatives, and the like.

[0107] As nonionic surfactants, for example, the following can be mentioned: ether-based ones such as polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether; ester-based ones such as polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate; alkynol-based ones such as 2,4,7,9-tetramethyl-5-decyn-4,7-diol, 3,6-dimethyl-4-octyn-3,6-diol, 3,5-dimethyl-1-hexyn-3-ol; products with trade names SURFYNOL 104E, 104H, 104A, 104PA, 104PG50, DF110D, 82, 420, 440, 465, 485, OLFINE STG manufactured by Nissin Chemical Industry Co., Ltd.; and so on. Among these, SURFYNOL is preferred, and SURFYNOL 104PG50, DF110D, 420, 440, 465 are more preferred.

[0108] When the coloring liquid according to this embodiment contains a surfactant, its content rate is usually 0.001 to 2% by mass, preferably 0.01 to 1.5% by mass, based on the total mass of the coloring liquid.

[0109] As the pH adjuster, any substance can be used as long as it can control the pH of the coloring liquid within the range of 6.0 to 11.0. As the pH adjuster, for example, the following can be mentioned: alkanolamines such as diethanolamine, dimethylethanolamine, diethylethanolamine, triethanolamine; hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide, potassium hydroxide; ammonium hydroxide (aqueous ammonia); carbonates of alkali metals such as lithium carbonate, sodium carbonate, potassium carbonate; tris(hydroxymethyl)aminomethane; and so on. Among these, triethanolamine is preferred.

[0110] When the coloring liquid according to this embodiment contains a pH adjuster, its content rate is usually 0.01 to 2% by mass, preferably 0.05 to 1% by mass, based on the total mass of the coloring liquid.

[0111] As an antiseptic and mildew-proof agent, for example, the following can be cited: sodium dehydroacetate, sodium benzoate, sodium 1-oxopyridinethione, zinc 1-oxopyridinethione, 1,2-benzisothiazolin-3-one, amine salts of 1-benzisothiazolin-3-one; Biox P520LP and Preventol BIT 20N manufactured by LANXESS Corporation; ROCIMA 640 manufactured by Dow Chemical Company; Mergal K-20 manufactured by TROY Corporation; Proxel GXL and Proxel XL2 manufactured by Lonza Corporation; etc. Among these, Proxel GXL and Proxel XL2 are preferred.

[0112] When the coloring liquid according to this embodiment contains an antiseptic and mildew-proof agent, its content rate is usually 0.001 to 2% by mass, preferably 0.01 to 1% by mass, based on the total mass of the coloring liquid.

[0113] As a dye solvent, for example, urea, ε-caprolactam, ethylene carbonate, etc. can be cited.

[0114] As a water-soluble auxiliary agent, for example, urea, thiourea, cyanoguanidine, guanidine phosphate, guanidine sulfamate, etc. can be cited.

[0115] As a humectant, for example, urea, glycerol, etc. can be cited.

[0116] [Method for preparing the coloring liquid]

[0117] The coloring liquid according to this embodiment can be obtained by dissolving a naphthalene skeleton pigment, a naphthalene-based compound, a pyrazine-based compound, and other additives added as needed in a solvent such as water.

[0118] The naphthalene skeleton pigment, naphthalene-based compound, and pyrazine-based compound can be purchased as commercial products or synthesized. Regarding the naphthalene-based compound and pyrazine-based compound, for example, they can also be obtained by separating and purifying the substances generated as by-products during the synthesis of the naphthalene skeleton pigment. The separation and purification can adopt commonly known pigment purification methods and chemical substance purification methods. As specific separation and purification methods, for example, in addition to the recrystallization method, sublimation method, dialysis method, salting-out method, ion exchange resin method, column chromatography method, thin layer chromatography method, and paper chromatography method described in Non-Patent Document [Journal of the Society of Synthetic Organic Chemistry, Japan, 1955, Vol. 13, No. 4, p. 106], methods based on adsorbents, ultrafiltration method, reverse osmosis membrane method, distillation method, etc. can also be cited.

[0119] As the ion exchange resin, cation exchange resins, anion exchange resins, etc. can be cited. As the adsorbent, for example, activated carbon, zeolite, diatomaceous earth, cellulose fiber, chelating fiber, synthetic adsorbent, etc. can be cited. In the ion exchange resin method and the method based on the adsorbent, the ion exchange resin and the adsorbent can also be mixed in the pigment solution (which is prepared by dissolving or dispersing the pigment in water or an appropriate organic solvent), stirred, and then subjected to filtration separation. Or, the pigment solution (which is prepared by dissolving or dispersing the pigment in water or an appropriate organic solvent) can also be passed through a column filled with the ion exchange resin and the adsorbent.

[0120] As a method for detecting or quantifying naphthalene compounds and pyrazine compounds, the usual analytical methods for organic compounds can be adopted. As specific analytical methods, for example, nuclear magnetic resonance analysis method, high performance liquid chromatography method, high performance liquid chromatography / mass spectrometry method, paper chromatography method, thin layer chromatography method, gas chromatography method, gas chromatography / mass spectrometry method, gel permeation chromatography method, elemental analysis method, infrared spectroscopic analysis method, infrared / visible spectroscopic analysis method, etc. can be cited.

[0121] [Use of the coloring solution]

[0122] The coloring solution according to the present embodiment can be used for various recording uses such as printing, copying, marking, writing, drawing, stamping, etc., and is particularly suitable for inkjet recording. When the coloring solution according to the present embodiment is used as an ink for inkjet recording, the coloring solution according to the present embodiment can be directly used, or other additives can also be contained as needed.

[0123] When the coloring solution according to the present embodiment is used as an ink for inkjet recording, it is preferably microfiltered using a membrane filter or the like. The pore diameter of the membrane filter is usually 0.1 to 1 μm, preferably 0.1 to 0.5 μm.

[0124] In addition, when the coloring solution according to the present embodiment is used as an ink for inkjet recording, regarding the viscosity of the coloring solution at 25°C, when measured using an E-type viscometer, it is preferably 3 to 20 mPa·s. In addition, regarding the surface tension of the coloring solution at 25°C, when measured using the plate method, it is preferably 20 to 45 mN / m. Regarding the viscosity and surface tension of the coloring solution, it is preferably adjusted to an appropriate value within the above ranges in consideration of the ejection amount, response speed, droplet flight characteristics, inkjet head characteristics, etc. of the inkjet printer.

[0125] <Coloring solution set>

[0126] The coloring liquid set according to this embodiment includes: the coloring liquid according to this embodiment; and at least one coloring liquid having a hue different from that of the coloring liquid. Examples of the coloring liquid that the coloring liquid set according to this embodiment may include are magenta coloring liquid, cyan coloring liquid, yellow coloring liquid, blue coloring liquid, green coloring liquid, orange coloring liquid, gray coloring liquid, black coloring liquid, and the like.

[0127] <Recording Medium and Coloring Method>

[0128] The recording medium according to this embodiment is attached with the coloring liquid according to this embodiment, or each coloring liquid included in the coloring liquid set according to this embodiment. In addition, the coloring method according to this embodiment is a method of performing coloring by attaching the coloring liquid according to this embodiment, or each coloring liquid included in the coloring liquid set according to this embodiment, to a recording medium.

[0129] Examples of the recording medium include: information transfer sheets such as plain paper, resin-coated paper, inkjet special paper, glossy paper, glossy film, electrophotographic common paper; fibers (such as cotton, linen, nylon, wool, silk), fabrics; glass; metal; ceramics; leather; substrates for color filters; and the like. As the recording medium, it is preferable to use a sheet-like recording medium, and it may have a three-dimensional shape such as a spherical or cubic shape other than a sheet shape.

[0130] The method of attaching the coloring liquid to the recording medium is not particularly limited. For example, an inkjet recording method can be preferably selected.

[0131] As a preferred recording medium used in inkjet recording, for example, a recording medium having an ink receiving layer provided on a substrate such as paper, synthetic paper, or film can be cited. The ink receiving layer is provided by the following methods: a method of impregnating or coating a cationic polymer in the above substrate; a method of coating inorganic fine particles such as porous silica, alumina sol, and special ceramics that can absorb pigments in the coloring liquid and hydrophilic polymers such as polyvinyl alcohol and polyvinylpyrrolidone on the surface of the substrate; and so on. A recording medium provided with such an ink receiving layer is generally called an inkjet special paper (film), a glossy paper (film), etc. Among them, the inkjet special paper of the type in which inorganic fine particles such as porous silica, alumina sol, and special ceramics that can absorb pigments in the coloring liquid are coated on the surface of the substrate is considered to be easily affected by oxidizing gases in the air such as ozone gas. Representative examples of special papers that can be obtained as commercial products include: Photo Paper / Glossy Pro "Platinum Grade", Photo Paper / Glossy Gold manufactured by Canon Inc.; Photo Paper Crispia (High Gloss), Photo Paper (Glossy), Matte Paper manufactured by SEIKO EPSON Corporation; Premium Photo Paper (Glossy) manufactured by Hewlett-Packard Japan, Ltd.; Super Premium Glossy Photo Paper (Premium Plus Glossy Photo paper) manufactured by Brother Industries, Ltd.; and so on. It should be noted that, of course, ordinary paper can also be used. Specifically, examples include: PB Paper GF500 manufactured by Canon Inc.; High Quality Double-Sided Plain Paper manufactured by SEIKO EPSON Corporation; PPC (plain paper copier) paper; and so on.

[0132] In addition, as a preferred recording medium used in inkjet recording, fibers can be cited. As the fibers, polyamide-based fibers, blended fibers containing polyamide-based fibers, cellulose-based fibers, blended fibers containing cellulose-based fibers, etc. can be preferably used. As polyamide-based fibers, silk, wool, nylon, etc. can be cited. As cellulose-based fibers, cotton, hemp, rayon, polynosic, etc. can be cited. As blended fibers, fibers obtained by blending polyamide-based fibers or cellulose-based fibers with other fibers can be cited. It should be noted that as the fibers, fiber structures (fabrics, etc.) are also included.

[0133] <Dyeing method of fibers>

[0134] The dyeing method of the fibers according to the present embodiment uses the coloring liquid according to the present embodiment as ink and includes at least the following steps performed in sequence.

[0135] [Step A]

[0136] The process of attaching ink to fibers using methods such as inkjet printing, screen printing, dip dyeing, continuous dyeing, etc.

[0137] [Process B]

[0138] The process of fixing the pigment of the ink attached to the fibers to the fibers.

[0139] [Process C]

[0140] The process of washing the unfixed pigment remaining on the fibers.

[0141] As the inkjet printer that can be used in Process A, for example, an inkjet printer using the following methods can be cited: the piezoelectric method using mechanical vibration; the bubble jet (BubbleJet, registered trademark) method using bubbles generated by heating; and so on.

[0142] As Process B, a method such as subjecting the fibers with attached ink to pre-drying by placing them at room temperature to 130 °C for about 0.5 to 30 minutes and then performing a steaming treatment to fix the pigment to the fibers under humid and hot conditions can be cited. As the steaming treatment, it is preferably placed in an environment with a relative humidity of 80 to 100% and a temperature of 95 to 105 °C for 5 to 30 minutes.

[0143] In Process C, it is preferable to wash the fibers with fixed pigment with water. At the time of this washing, it can be washed with water containing a surfactant. After performing Process C, the washed fibers are usually dried at 40 to 120 °C for 5 to 30 minutes, whereby a dried dyed product can be obtained.

[0144] [Pretreatment process]

[0145] For the purpose of preventing bleeding of the pigment, etc., a pretreatment process for the fibers may be included before the above Process A. In the case of printing polyamide fibers or cellulose fibers, a pretreatment process is preferably included.

[0146] As the pretreatment process, a process of applying an aqueous solution containing a paste and a pH regulator as a pretreatment liquid for the fibers to the fibers before Process A can be cited. The pretreatment liquid preferably further contains a water-soluble auxiliary agent.

[0147] Examples of the paste contained in the pretreatment liquid include natural gums such as guar gum and locust bean gum; starches; seaweeds such as sodium alginate and gloiopeltis; plant barks such as pectic acid; cellulose derivatives such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, and carboxymethyl cellulose; processed starches such as carboxymethyl starch; processed natural gums such as silicone gum (Japanese: シラツガム) and roasted bean gum (Japanese: ローストビーンガム); synthetic pastes such as polyvinyl alcohol and polyacrylate; and so on. Among these, natural gums such as guar gum and locust bean gum; processed natural gums such as silicone gum and roasted bean gum; etc. are preferred.

[0148] Examples of the pH adjuster contained in the pretreatment liquid include alkaline sodium salts such as sodium carbonate and sodium bicarbonate; acidic ammonium salts such as ammonium sulfate, ammonium tartrate, and ammonium acetate; and so on.

[0149] Examples of the water-soluble auxiliary contained in the pretreatment liquid include urea, dimethylurea, thiourea, monomethylthiourea, dimethylthiourea, and so on. Among these, urea is preferred.

[0150] Regarding the content ratio of each component in the pretreatment liquid, for example, when using blended fibers, it varies depending on the blend ratio of the blended fibers, etc., and thus it is difficult to generalize. As a reference, based on the total mass of the pretreatment liquid, the content ratio of the paste is 0.5 to 5% by mass, the content ratio of the pH adjuster is 0.5 to 5% by mass, and the balance is water. When the pretreatment liquid further contains a water-soluble auxiliary, based on the total mass of the pretreatment liquid, the content ratio of the water-soluble auxiliary is preferably 1 to 20% by mass. The pretreatment liquid is preferably acidic, and as the range of its pH, it is usually pH 7 or less, preferably pH 5 to 7.

[0151] Examples of the method for applying the pretreatment liquid to the fiber include the pad dyeing method. The liquor ratio of pad dyeing is preferably about 40 to 90%, more preferably about 60 to 80%.

[0152] [Post-treatment process]

[0153] If necessary, the dyed fabric can also be treated with a fixing agent, ultraviolet absorber, antioxidant, etc. for the purpose of improving light fastness, wet fastness, and chlorine fastness as a post-treatment.

[0154] Examples of the fixing agent used in the post-treatment include polyamine-based, polycationic-based, tannin-based, and synthetic tannin-based fixing agents.

[0155] As the ultraviolet absorber used in the post-treatment, for example, benzophenone compounds, benzotriazole compounds, cinnamic acid compounds, triazine compounds, stilbene compounds, etc. can be cited. In addition, compounds that absorb ultraviolet rays and emit fluorescence represented by benzoxazole compounds, so-called fluorescent brighteners, etc. can also be used.

[0156] As the antioxidant used in the post-treatment, for example, L-ascorbic acid (alias, vitamin C), isoascorbic acid, α-tocopherol (alias, vitamin E), etc. can be cited.

[0157] Regarding all the above matters, etc., the combination of preferred modes with each other is more preferred, and the combination of more preferred modes with each other is further preferred. The same applies to the combination of a preferred mode and a more preferred mode, the combination of a more preferred mode and a further preferred mode, etc.

[0158] Examples

[0159] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited by the examples. It should be noted that the inks in each example are all included in the above-mentioned coloring liquid.

[0160] <Examples 1 to 10 and Comparative Examples 1 to 3: Preparation of Coloring Liquid>

[0161] Commercially available C.I. Acid Blue 193, C.I. Acid Black 172, and C.I. Acid Brown 298 were purified by activated carbon filtration, microfiltration, and ultrafiltration. The purified C.I. Acid Blue 193, C.I. Acid Black 172, or C.I. Acid Brown 298, 1,1'-binaphthalene-2,2'-diol (naphthalene compound), the compound represented by the above formula (1-1) (pyrazine compound), and water were mixed in such a way as to have the compositions shown in Tables 1 to 3 below, to obtain the coloring liquids of Examples 1 to 10 and Comparative Examples 1 to 3. In Tables 1 to 3, the numerical values of each component represent parts by mass.

[0162] [Table 1]

[0163]

[0164] [Table 2]

[0165]

[0166] [Table 3]

[0167]

[0168] <Evaluation>

[0169] Using each of the coloring liquids prepared in the above-described manner, the following evaluation tests were conducted. The results are shown in Tables 4 and 5 below. It should be noted that for the coloring liquids of Examples 1 to 10, when filtering the entire amount using a mixed cellulose filter (manufactured by ADVANTEC Co., Ltd.) with a pore size of 0.2 μm, the filterability was good, and foreign matter and coloring were not likely to remain on the filter. When filtering the entire amount using a mixed cellulose filter (manufactured by ADVANTEC Co., Ltd.) with a pore size of 0.2 μm, the filterability was good, and foreign matter and coloring were not likely to remain on the filter.

[0170] [Evaluation of Drying Resistance]

[0171] After dropping 1 part by mass of each coloring liquid onto a glass petri dish with an outer diameter of 32 mm (manufactured by Tokyo Glass Kikai Co., Ltd., FINESchale), it was left standing in a dryer at 30°C and observed at regular intervals. The drying resistance was evaluated according to the following criteria. When the evaluation of drying resistance is "D", it lacks practicality.

[0172] -Evaluation Criteria-

[0173] A: The coloring liquid on the petri dish was not dry (had fluidity) after 6 hours.

[0174] B: The coloring liquid on the petri dish was not dry (had fluidity) after 4 hours.

[0175] C: The coloring liquid on the petri dish was not dry (had fluidity) after 2 hours.

[0176] D: The coloring liquid on the petri dish was not dry (had fluidity) after 1 hour.

[0177] [Evaluation of Redissolvability]

[0178] After dropping 0.5 part by mass of each coloring liquid onto a glass petri dish with an outer diameter of 32 mm (manufactured by Tokyo Glass Kikai Co., Ltd., FINESchale) and allowing it to dry naturally, 0.5 part of water was dropped, and the redissolvability was evaluated according to the following criteria. When the evaluation of redissolvability is "D", it lacks practicality.

[0179] -Evaluation Criteria-

[0180] A: Redissolved within 5 minutes.

[0181] B: Redissolved in more than 5 minutes and within 10 minutes.

[0182] C: Redissolved in more than 10 minutes and within 30 minutes.

[0183] D: There was an undissolved part even after 30 minutes and it could not be redissolved.

[0184] Note that "redissolvability" is considered to be the following criterion: when the solid component concentration increases (caused by evaporation of volatile components in the ink, etc.) and the dissolved or dispersed components become unstable and agglomerate or precipitate, resulting in clogging of the nozzle or the like, the function of the nozzle is restored by supplying new ink or the like to redissolve or redisperse it (see Journal of the Imaging Society of Japan, Vol. 41, No. 2 (2002), p. 182). The inability to redissolve when the ink dries means that the function of the nozzle cannot be restored, so such ink is not practical.

[0185] [Table 4]

[0186]

[0187] [Table 5]

[0188]

[0189] As shown in Tables 4 and 5, the coloring liquids of Examples 1 to 10 containing naphthalene-based compounds and / or pyrazine-based compounds have both practical dry resistance and redissolvability. In addition, the filterability of the coloring liquids of Examples 1 to 10 is also good.

[0190] <Examples 11 to 26 and Comparative Examples 4 to 6: Preparation of Ink>

[0191] Mix the respective components described in Tables 6 to 9 below to obtain the inks of Examples 11 to 26 and Comparative Examples 4 to 6. In Tables 6 to 9, the numerical values of the respective components represent parts by mass. In addition, in Tables 6 to 9, the respective abbreviations have the following meanings.

[0192] TEG: Triethylene glycol (manufactured by Mitsubishi Chemical Corporation)

[0193] TEGMBE: Triethylene glycol monobutyl ether (manufactured by Kanto Chemical Co., Inc.)

[0194] SURFYNOL 465: Surfactant (manufactured by Nissin Chemical Industry Co., Ltd.)

[0195] Proxel XL2: Antiseptic and mildew-proof agent (manufactured by Lonza)

[0196] TEA: Triethanolamine (manufactured by Mitsui Chemicals, Inc.)

[0197] 2Py: 2-Pyrrolidone (manufactured by Mitsubishi Chemical Corporation)

[0198] Gly: Glycerol (manufactured by Junsei Chemical Co., Ltd.)

[0199] [Table 6]

[0200]

[0201] [Table 7]

[0202]

[0203] [Table 8]

[0204]

[0205] [Table 9]

[0206]

[0207] [Evaluation]

[0208] For each of the inks prepared in the above-described manner, the same operations as in Example 1 were carried out, and various evaluation tests for dry resistance and redissolubility were conducted. Further, using each of the inks, the following various evaluation tests were carried out. The results are shown in Tables 10 to 12 below. It should be noted that for the inks of Examples 11 to 26, when filtering the entire amount using a mixed cellulose filter (manufactured by Advantech Co., Ltd.) with a pore size of 0.2 μm, the filterability was good, and foreign matters and coloring were not likely to remain on the filter. In addition, for the inks of Examples 11 to 26, when printing a nozzle check pattern using an inkjet printer PX-205 (manufactured by Seiko Epson Corporation), the occurrence of printing defects was small, and good printed materials could be obtained in all cases. For each of the inks prepared in the above-described manner, the same operations as in Example 1 were carried out, and various evaluation tests for dry resistance and redissolubility were conducted. Further, using each of the inks, the following various evaluation tests were carried out. The results are shown in Tables 10 to 12 below. It should be noted that for the inks of Examples 11 to 26, when filtering the entire amount using a mixed cellulose filter (manufactured by Advantech Co., Ltd.) with a pore size of 0.2 μm, the filterability was good, and foreign matters and coloring were not likely to remain on the filter. In addition, for the inks of Examples 11 to 26, when printing a nozzle check pattern using an inkjet printer PX-205 (manufactured by Seiko Epson Corporation), the occurrence of printing defects was small, and good printed materials could be obtained in all cases.

[0209] [Evaluation of Light Resistance of Dyed Cloth]

[0210] A pretreatment liquid containing guar gum (2 parts by mass), ammonium sulfate (2 parts by mass), urea (5 parts by mass), and water (91 parts by mass) was prepared, and silk cloth (silk habutai) was pretreated by the padding method. Specifically, the silk cloth was immersed in the pretreatment liquid, and after squeezing out the excess liquid with a rubber roller, it was dried at 60°C. A container filled with each ink was loaded into an inkjet printer PX-205 (manufactured by Seiko Epson Corporation), and a full-color pattern (solid pattern) was inkjet-printed on the pretreated silk cloth at 100% gray scale to obtain each dyed product. Next, each dyed product was pre-dried at 60 to 80°C and then subjected to a steaming treatment at 100 to 103°C for 30 minutes under the condition of a relative humidity of 90% or more. Each of the obtained dyed products was washed with cold water for 5 minutes and then dried to obtain each test dyed cloth.

[0211] For each of the test dyed fabrics obtained in the above manner, a light fastness test was conducted in accordance with the IS L0843 A method. That is, using a xenon lamp weather resistance tester SUGA NX75 (manufactured by Suga Test Instruments Co., Ltd.), each test dyed fabric was irradiated with light for 39.4 hours. The light irradiation conditions were set as follows: black panel temperature: 63 °C, chamber temperature: 38 °C, relative humidity: 50%, irradiance: 50 W / m 2 (wavelength 300 - 400 nm), internal filter: quartz, external filter: soda-lime glass. A colorimeter (SectroEye, manufactured by GretagMacbeth) was used to measure the color of each test dyed fabric before and after the test, and the color difference (ΔE) was calculated according to the following formula (1). In formula (1), ΔL*, Δa*, and Δb* respectively represent the differences in L*, a*, and b* before and after the test.

[0212] ΔE = [(ΔL*) 2 +(Δa*) 2 +(Δb*) 2 1 / 2 ···(1)

[0213] Then, based on the calculated value of the color difference (ΔE), the light fastness was evaluated according to the following criteria.

[0214] - Evaluation Criteria -

[0215] A: ΔE is less than 1.2

[0216] B: ΔE is 1.2 or more and less than 1.6

[0217] C: ΔE is 1.6 or more and less than 1.9

[0218] D: ΔE is 1.9 or more

[0219] [Evaluation of Light Fastness and Ozone Resistance of Photo Paper]

[0220] Containers filled with each ink were loaded into an inkjet printer PX-205 (manufactured by Seiko Epson Corporation), and full-page printing was performed on photo paper (manufactured by Seiko Epson Corporation) to obtain a recording. The obtained recording was used as a test piece for light fastness test and ozone resistance test.

[0221] As the light fastness test, a xenon lamp weather resistance tester XL75 (manufactured by Suga Test Instruments) was used to irradiate each test piece with light for 50 hours. The light irradiation conditions were set as follows: chamber temperature: 24 °C, relative humidity: 60%, irradiance: 0.36 W / m 2 ​Conditions. For the reflection concentration before and after the test, within the range where the reflection concentration (Dc or Dk) is 0.70 to 0.85, colorimetry was performed using a colorimeter (SectroEye, manufactured by GretagMacbeth), and the pigment residual rate was calculated according to the following formula (2).

[0222] Pigment residual rate = (reflection concentration after the test / reflection concentration before the test) × 100 (%) ··· (2)

[0223] Then, based on the calculated value of the pigment residual rate, the light resistance was evaluated according to the following criteria.

[0224] - Evaluation criteria -

[0225] A: The pigment residual rate is 90% or more

[0226] B: The pigment residual rate is 80% or more and less than 90%

[0227] C: The pigment residual rate is 70% or more and less than 80%

[0228] D: The pigment residual rate is less than 70%

[0229] As the ozone resistance test, an ozone weathering tester OMS-H (manufactured by Suga Test Instruments Co., Ltd.) was used. Under the conditions of an ozone concentration of 1 ppm, a chamber temperature of 23 °C, and a relative humidity of 50%, each test piece was placed for 16 hours. Then, the residual of the pigment in each test piece was visually confirmed, and the ozone resistance was evaluated according to the following criteria.

[0230] - Evaluation criteria -

[0231] a: The original pigment clearly remains.

[0232] b: A small amount of the original pigment remains.

[0233] c: The original pigment cannot be confirmed.

[0234] [Table 10]

[0235]

[0236] [Table 11]

[0237]

[0238] [Table 12]

[0239]

[0240] As shown in Tables 10 to 12, the inks of Examples 11 to 26 containing naphthalene compounds and / or pyrazine compounds have both practical dry resistance and redissolvability, and are excellent in preventing and recovering nozzle clogging of the print head. In addition, the inks of Examples 11 to 26 also have good filterability and ink ejection properties. Furthermore, the light resistance and ozone resistance of the recording media (silk cloth, photo paper) colored with the inks of Examples 11 to 26 are improved. It should be noted that when nylon 6,6 is dyed instead of silk cloth (silk spun silk), the light resistance of the obtained dyed cloth is also good.

Claims

1. A coloring liquid, comprising: a pigment having a naphthalene skeleton in the molecule; at least one compound selected from a compound having two or more naphthalene skeletons in the molecule and a compound having a pyrazine skeleton in the molecule; and water, Among them, The pigment having a naphthalene skeleton in the molecule is at least one pigment selected from the group consisting of C.I. Acid Brown 298, C.I. Acid Blue 193, C.I. Acid Black 52, C.I. Acid Black 52:1, C.I. Acid Black 172, and C.I. Acid Black 194, The compound having two or more naphthalene skeletons in the molecule is 1,1'-binaphthalene-2,2'-diol, The compound having a pyrazine skeleton in the molecule is a compound represented by the following formula (1-1), 2. The coloring liquid according to claim 1, wherein, When the content of the pigment having a naphthalene skeleton in the molecule is 100 parts by mass, the content of the compound having two or more naphthalene skeletons in the molecule is less than 1.8 parts by mass.

3. The coloring solution according to claim 1 or 2, wherein, When the content of the pigment having a naphthalene skeleton in the molecule is 100 parts by mass, the content of the compound having a pyrazine skeleton in the molecule is less than 1.2 parts by mass.

4. The coloring liquid according to claim 1 or 2, which contains both the compound having two or more naphthalene skeletons in the molecule and the compound having a pyrazine skeleton in the molecule.

5. The coloring liquid according to claim 1 or 2, which further contains a water-soluble organic solvent.

6. A coloring liquid set, comprising: the coloring liquid according to any one of claims 1 to 5; and at least one coloring liquid having a hue different from that of the coloring liquid.

7. A recording medium to which the coloring liquid according to any one of claims 1 to 5, or each coloring liquid included in the coloring liquid set according to claim 6 is attached.

8. The recording medium according to claim 7, wherein, The recording medium is a fiber.

9. A coloring method, wherein, Coloring is performed by attaching the coloring liquid according to any one of claims 1 to 5, or each coloring liquid included in the coloring liquid set according to claim 6 to the recording medium.

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