JP2018058935A - Ink and inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous ink containing a water-insoluble colorant and having excellent storage stability.SOLUTION: An ink contains a water-insoluble colorant, a polymer, a polyalkylene wax, and water. Monomers constituting the polymer comprise at least one monomer selected from methacrylic acid derivatives and at least one monomer selected from acrylic acid derivatives. Thus, it is possible to provide an aqueous ink containing a water-insoluble colorant and having excellent storage stability.SELECTED DRAWING: None

Description

  The present invention relates to an ink containing a water-insoluble colorant and an ink jet recording method using the ink.

  A recording method using an ink jet printer (ink jet recording method) is one of typical recording methods. In this method, ink droplets are generated and recorded on various recording media (paper, film, fabric, etc.) for recording. Due to the advancement of inkjet technology, inkjet recording methods have come to be used in the field of high-definition printing that has been realized by silver salt photography and offset printing. Furthermore, in recent years, the demand for industrial applications has increased, and this application requires performance for high-speed printing.

  One of the performances required for industrial inkjet inks is storage stability. That is, the environment in which an industrial inkjet printer is used is often exposed to more severe temperature changes than the home or office environment. For this reason, the storage stability of ink with respect to changes in temperature is regarded as important. Among the inks, the dispersed ink containing a water-insoluble colorant is likely to cause a phenomenon that the dispersed state is broken due to a temperature change and clogs a filter in an inkjet head or a printer. When such a phenomenon occurs, productivity is extremely deteriorated and expensive ink jet heads need to be replaced. For these reasons, the storage stability of ink with respect to temperature changes is a big problem. For this reason, there is a strong demand for the development of inks that have good storage stability, particularly filterability, even when temperature changes occur.

Patent Documents 1 and 2 disclose inks that have good scuffing properties and high-quality images by controlling the permeability to paper with a surfactant and a penetrating agent.
Patent Documents 3 and 4 disclose a technique for improving the friction resistance by adding a resin to the ink so as to provide adhesion to a recording medium.
Patent Document 5 discloses a polymer, and Patent Document 6 discloses an ink containing a wax.

International Publication No. 2008/105289 JP 2003-253167 A JP 2013-166844 A JP 2013-199605 A International Publication No. 2015/152291 International Publication No. 2015/147192

  An object of the present invention is to provide a water-based ink containing a water-insoluble colorant and having good storage stability against temperature change, particularly good filterability.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a water-insoluble colorant, a polymer, a polyalkylene wax, and an ink containing water, thereby completing the present invention. I let you. That is, the present invention relates to the following 1) to 10).
1)
An ink containing a water-insoluble colorant, a polymer, a polyalkylene wax, and water, wherein the monomer constituting the polymer contains a monomer selected from at least one of a methacrylic acid derivative and an acrylic acid derivative. Ink.
2)
The ink according to 1) above, wherein the polyalkylene wax is a wax selected from polyethylene wax and polypropylene wax.
3)
The ink according to 1), wherein the monomers constituting the polymer are three types of monomers selected from methacrylic acid derivatives and one type of monomer selected from acrylic acid derivatives.
4)
The ink according to 1) or 3), wherein the monomer constituting the polymer is two types of alkyl methacrylate, methacrylic acid, and alkyl acrylate.
5)
An ink jet recording method for performing recording by ejecting the ink droplets according to any one of 1) to 4) from an ink jet printer and attaching the ink droplets to a recording medium.
6)
A recording medium to which the ink according to any one of 1) to 4) is attached.
7)
6. The recording medium as described in 6) above, wherein the recording medium is a medium having an ink receiving layer.
8)
The recording medium according to 6) above, wherein the recording medium is a medium having no ink receiving layer.
9)
An ink tank filled with the ink according to any one of 1) to 4).
10)
An inkjet printer loaded with the ink tank described in 9) above.

  According to the present invention, it is possible to provide a water-based ink containing a water-insoluble colorant and having good storage stability against temperature change, particularly good filterability.

Hereinafter, the ink of the present invention will be described in detail.
In this specification, “CI” is an abbreviation for color index.
Further, in the present specification, “%” and “part” are described on a mass basis unless otherwise specified, including examples.

[Water-insoluble colorant]
Examples of the water-insoluble colorant include known pigments, disperse dyes, solvent dyes, and the like. In the present specification, a water-insoluble colorant means a colorant having a solubility in 1 liter of water at 25 ° C. of usually 5 g or less, preferably 3 g or less, more preferably 1 g or less, and even more preferably 0.5 g or less. The lower limit of solubility includes 0 g.
Unless otherwise specified, “water-insoluble colorant” is hereinafter referred to as “colorant”.
A colorant can be used in combination. The type of the colorant contained in the ink is preferably 3 to 5 when it is black ink, and is usually 3 or preferably 2 or 1 when it is color ink other than black ink. However, when the black ink contains carbon black as a colorant, two or one kind of colorant is preferable. In this specification, color ink means colored ink other than black ink (for example, ink of each color such as yellow, magenta, cyan, red, orange, brown, violet, blue, and green).
Of the pigments, disperse dyes, and solvent dyes, pigments are preferred. Examples of the pigment include inorganic pigments, organic pigments and extender pigments.

  Examples of the inorganic pigment include carbon black, metal oxide, hydroxide, sulfide, ferrocyanide, and metal chloride.

  Examples of carbon black include thermal black, acetylene black, oil furnace black, gas furnace black, lamp black, gas black, and channel black. Specific examples thereof include, for example, the Raven series manufactured by Columbia Carbon; the Monarch series, Regal series, and Mogul series manufactured by Cabot; ColorBlack series, Printex series, SpecIalBlack series, and Nerox manufactured by Orion Engineered Carbons. Series: MA series, MCF series, No. 25, no. 33, no. 40, no. 47, no. 52, no. 900, and no. 2300 and the like.

  Examples of the organic pigment include various pigments such as azo, diazo, phthalocyanine, quinacridone, isoindolinone, dioxazine, perylene, perinone, thioindigo, anthoraquinone, and quinophthalone.

  Specific examples of the organic pigment include C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 24, 55, 73, 74, 75, 83, 93, 94, 95, 97, 98, 108, 114, 128, 129, 138, 139, 150, 151, 154, 180, 185, 193, 199, 202, 213; I. Pigment Red 5, 7, 12, 48, 48: 1, 57, 88, 112, 122, 123, 146, 149, 150, 166, 168, 177, 178, 179, 184, 185, 202, 206, 207, 254, 255, 257, 260, 264, 272; I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 25, 60, 66, 80; C.I. I. Pigment Violet 19, 23, 29, 37, 38, 50; C.I. I. Pigment Orange 13, 16, 68, 69, 71, 73; C.I. I. Pigment Green 7, 36, 54; C.I. I. And pigments of each color such as Pigment Black 1.

  Examples of extender pigments include silica, calcium carbonate, talc, clay, barium sulfate, and white carbon. The extender is preferably used in combination with other colorants.

Examples of the disperse dye include known disperse dyes. Among them, C.I. I. Dyes selected from Dispers are preferred. Specific examples thereof include C.I. I. Dispers Yellow 9, 23, 33, 42, 49, 54, 58, 60, 64, 66, 71, 76, 79, 83, 86, 90, 93, 99, 114, 116, 119, 122, 126, 149, 160, 163, 165, 180, 183, 186, 198, 200, 211, 224, 226, 227, 231, 237; I. Dispers Red 60, 73, 88, 91, 92, 111, 127, 131, 143, 145, 146, 152, 153, 154, 167, 179, 191, 192, 206, 221, 258, 283; I. Dispers Orange 9, 25, 29, 30, 31, 32, 37, 38, 42, 44, 45, 53, 54, 55, 56, 61, 71, 73, 76, 80, 96, 97; C.I. I. Dispers Violet 25, 27, 28, 54, 57, 60, 73, 77, 79, 79: 1; I. Dispers Blue 27, 56, 60, 79: 1, 87, 143, 165, 165: 1, 165: 2, 181, 185, 197, 202, 225, 257, 266, 267, 281, 341, 353, 354, Examples thereof include disperse dyes of respective colors such as 358, 364, 365, and 368.
As solvent dyes, C.I. I. Preference is given to dyes selected from Solvent.

  The total content of the colorant contained in the ink is usually 0.5% to 10%, preferably 0.5% to 8%, more preferably 1% to 8%, and further preferably 2% to 7%. . When the content is 0.5% or more, sufficient color developability of the recorded image is obtained, and when it is 10% or less, the discharge property is good.

[polymer]
The monomer constituting the polymer is preferably a monomer selected from at least one of each of a methacrylic acid derivative and an acrylic acid derivative;
3 types of monomers selected from methacrylic acid derivatives and 1 type of monomer selected from acrylic acid derivatives are more preferred;
Two types of alkyl methacrylate, methacrylic acid, and alkyl acrylate are more preferable.
The two types of alkyl methacrylate are preferably selected from linear alkyl methacrylate and unsaturated alkyl methacrylate.
As the linear alkyl methacrylate, linear C1-C3 alkyl methacrylate is preferable, and methyl methacrylate is more preferable.
As the unsaturated alkyl methacrylate, unsaturated C2-C4 alkyl methacrylate is preferable, and allyl methacrylate is more preferable.
The alkyl acrylate is preferably a branched alkyl acrylate, more preferably a branched C3-C8 alkyl acrylate, and even more preferably 2-ethylhexyl acrylate.
The polymer can be obtained, for example, by a synthetic method disclosed in International Publication No. 2015/147192 Gazette.

The average particle size of the polymer is usually 10 nm to 1 μm, preferably 30 nm to 500 nm. When the average particle size is such, the inkjet head is hardly clogged.
The glass transition point (Tg) of the polymer is usually −10 ° C. to 20 ° C., preferably −5 ° C. to 15 ° C.
The acid value of the polymer is usually 0 to 25 mg KOH / g, preferably 5 to 15 mg KOH / g.
The insolubility of the polymer in tetrahydrofuran is usually 80 to 100%, preferably 100%, that is, insoluble. Thereby, the average molecular weight of the resin can be controlled, and a resin containing no free monomer can be obtained.
The content of the polymer with respect to the total mass of the ink is usually 0.1% to 10%, preferably 0.2% to 8%, more preferably 0.3% to 8%. When the content is such, the scuffing property, the redispersibility, and the discharge property are good.

The monomer composition of the polymer is summarized in Table 1 below as “normal”, “preferred”, and “more preferable” configurations. In the range of the number of parts shown in Table 1 below, the total amount of monomers can be adjusted to 100 parts. The abbreviations in Table 1 below have the following meanings.
MA: Methacrylic acid.
ScMA: linear alkyl methacrylate.
BcAA: branched chain alkyl acrylate.
UsMA: unsaturated alkyl methacrylate.

[Polyalkylene wax]
The polyalkylene wax is preferably a wax selected from polyethylene wax and polypropylene wax. The polyalkylene wax may include a modified polyalkylene wax (for example, an oxidized polyalkylene wax), but preferably does not contain a paraffin wax. These waxes can be used as emulsions in aqueous media.
Specific examples of the polyethylene wax include, for example, CERAFLOUR 925, 929, 950, 991 manufactured by Big Chemie; AQUACER 507, 513, 515, 552, 1547 manufactured by Big Chemie; AQUAMAT 208, 263, 272 manufactured by Big Chemie; MINEPOL 221 manufactured by Mitsui Chemicals Co., Ltd .; Mitsui High Wax NL100, NL200, NL500 manufactured by Mitsui Chemicals, Inc .; HYTEC-6400, 6500 manufactured by Toho Chemicals Co., Ltd., and the like.
Examples of the polypropylene wax include AQUACER 593 manufactured by Big Chemie; Mitsui High Wax NP055 and NP505 manufactured by Mitsui Chemicals.
The particle size of the wax emulsion is preferably 5 μm or less and more preferably 1 μm or less in order to prevent clogging of the inkjet head.

  The wax content with respect to the total mass of the ink is preferably 0.1% to 5%, and more preferably 0.1% to 2%. When the content is such, the scuffing property, the redispersibility, and the discharge property are improved.

[Dispersant]
The ink may contain a dispersant. In addition, part or all of the colorant can be coated with a dispersant.
Examples of the dispersant include nonionic dispersants, anionic dispersants, and polymer dispersants, which can be appropriately selected according to the purpose.
The amount of the dispersant used is usually 1% to 100%, preferably 5% to 90%, more preferably 10% to 80% with respect to the total mass of the colorant. By setting it as such usage-amount, a colorant can fully be refined | miniaturized. In addition, it is possible to suppress bleeding of an image recorded with the ink containing this dispersion and to obtain good water resistance and scratch resistance.

  Nonionic dispersants include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester, sucrose ester, glycerin ester polyoxyethylene ether, sorbitan ester polyoxy Ethylene ether, polyoxyethylene ether of sorbitol ester, fatty acid alkanolamide, polyoxyethylene fatty acid amide, amine oxide, polyoxyethylene alkylamine, polyoxyethylene-β-naphthyl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene di And styryl phenyl ether.

  Anionic dispersants include alkyl sulfates, alkyl ether sulfates, alkyl ester sulfates, alkyl aryl ether sulfates, alkyl sulfonates, sulfosuccinates, alkyl aryl and alkyl naphthalene sulfonates, alkyl phosphates, polyphosphates Examples thereof include oxyethylene alkyl ether phosphate ester salts, alkyl allyl ether phosphate salts, polyoxyethylene alkyl ether sulfate salts, polyoxyethylene styryl phenyl ether sulfate salts, and polyoxyethylene distyryl phenyl ether sulfate salts.

Examples of the polymer dispersant include styrene and derivatives thereof; vinyl naphthalene and derivatives thereof; aliphatic alcohol esters of α, β-ethylenically unsaturated carboxylic acid and the like; (meth) acrylic acid and derivatives thereof; maleic acid and derivatives thereof; At least two monomers selected from the group consisting of itaconic acid and its derivatives; fumaric acid and its derivatives; vinyl acetate, vinyl alcohol, vinylpyrrolidone, acrylamide and its derivatives; Among these, a copolymer comprising at least one hydrophilic monomer), for example, a block copolymer, a random copolymer and a graft copolymer, and / or a salt thereof, can be mentioned. In the present specification, (meth) acrylic acid means both methacrylic acid and acrylic acid.
As a weight average molecular weight of a dispersing agent, it is about 1000-60000, Preferably it is 2000-50000, More preferably, it is about 2500-50000. Moreover, as an acid value, it is about 10-300 mgKOH / g, Preferably it is 10-275 mgKOH / g, More preferably, it is about 20-250 mgKOH / g.
As specific examples of commercially available dispersants, all of them are Jonkrill 61J, 67, 68, 450, 55, 555, 586, 678, 680, 682, 683, 690, B-36, etc. manufactured by BASF. Can be mentioned.

As a method for preparing an aqueous dispersion containing a colorant, all known methods can be used. For example, a known method of mixing a colorant and a dispersant and performing a dispersion treatment using a sand mill (also referred to as a bead mill), a roll mill, a ball mill, a paint shaker, an ultrasonic disperser, a microfluidizer, or the like. . For the preparation of the dispersion using a sand mill, it is preferable to use a bead having a diameter of about 0.01 mm to 1 mm and to increase the filling rate of the bead to prepare the dispersion under conditions that increase the dispersion efficiency.
After preparation of the dispersion, it is also preferable to remove beads and the like by filtration and / or centrifugation and to remove particle components having a large deviation from the target average particle diameter.
When foaming occurs during the preparation of the dispersion, a very small amount of a known antifoaming agent such as silicone or acetylene glycol can be added.
Other methods include acid precipitation method, phase inversion emulsification method, interfacial polymerization method, in-situ polymerization method, submerged cured coating method, coacervation (phase separation) method, submerged drying method, melt dispersion cooling method, Examples thereof include an air suspension coating method and a spray drying method. Among these, a phase inversion emulsification method, an acid precipitation method, and an interfacial polymerization method are preferable.

  Instead of using the above-mentioned dispersant, a surface-treated pigment (self-dispersed pigment) in which a dispersibility-imparting group is chemically introduced on the surface of the colorant can also be used as the colorant.

The average particle diameter (D50) of the colorant in the dispersion is usually 300 nm or less, preferably 30 to 280 nm, more preferably 40 to 270 nm, and still more preferably 50 to 250 nm.
Similarly, D90 is usually 300 nm or less, preferably 280 nm or less, more preferably 270 nm or less. The lower limit is preferably 100 nm or more.
Similarly, D10 is usually 10 nm or more, preferably 20 nm or more, more preferably 30 nm or more, and the upper limit is 100 nm or less.

  The water is preferably water having a pH of 6.5 to 7.5, such as distilled water, ion exchange water, pure water, or ultrapure water, and low free ion content such as various metal ions.

  The ink is composed of a water-soluble organic solvent, a binder, a water-soluble polymer compound, a surfactant, a fungicide, a preservative, a pH adjuster, a chelating reagent, a rust inhibitor, a water-soluble UV absorber, An ink preparation agent such as an antioxidant can be contained as required.

[Water-soluble organic solvent]
The water-soluble organic solvent contained in the ink is not particularly limited. For example, C1-C6 alcohol such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol or tert-butanol; N, N-dimethyl Carboxylic acid amides such as formamide or N, N-dimethylacetamide; Lactams such as 2-pyrrolidone and N-methyl-2-pyrrolidone; 1,3-dimethylimidazolidin-2-one or 1,3-dimethylhexahydropyrimido Cyclic ureas such as 2-one; ketones or ketoalcohols such as acetone, 2-methyl-2-hydroxypentan-4-one, ethylene carbonate; cyclic ethers such as tetrahydrofuran and dioxane; ethylene glycol, diethylene glycol, 1, 2-prop Diol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol (preferably having a molecular weight of 400, 800, 1540 or more Above), mono-, oligo- or polyalkylene glycols or thioglycols having C2-C6 alkylene units such as polypropylene glycol, thiodiglycol or dithiodiglycol; glycerin, diglycerin, hexane-1,2,6-triol, C3-C9 polyol (triol) such as trimethylolpropane; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoallyl ether, Lenglycol monoisopropyl 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, propylene glycol monopropyl ether, pro Glycol ethers such as lenglycol monobutyl ether and dipropylene glycol monomethyl ether (preferably selected from the group consisting of C3-C10 mono-, di- or triethylene glycol ethers and C4-C13 mono-, di- or tripropylene glycol ethers) Glycol ether); 1,2-pentanediol, 1, 5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, 2,4-diethyl-1,5 -C5-C9 alkanediols such as pentanediol; γ-butyrolactone or dimethyl sulfoxide.
The total content of the water-soluble organic solvent with respect to the total mass of the ink is usually 0% to 60%, preferably 5% to 60%, more preferably 10% to 50%.

[binder]
Examples of the binder include urethane type, polyester type, acrylic type, vinyl acetate type, vinyl chloride type, styrene-acrylic type, acrylic-silicone type, styrene-butadiene type resins or emulsions containing the same. Of these, resins selected from urethane, acrylic, and styrene-butadiene are preferred.
Specific examples of commercially available products include, for example, Superflex 126, 130, 150, 170, 210, 420, 470, 820, 830, 890 (urethane resin emulsion manufactured by Daiichi Kogyo Seiyaku Co., Ltd.); Hydran HW-350 , HW-178, HW-163, HW-171, AP-20, AP-30, WLS-201, WLS-210 (urethane resin emulsion manufactured by DIC Corporation); 0569, 0850Z, 2108 (manufactured by JSR Corporation) Styrene-butadiene resin emulsion); AE980, AE981A, AE982, AE986B, AE104 (acrylic resin emulsion manufactured by Etec Co., Ltd.) and the like.

[Water-soluble polymer]
Examples of the water-soluble polymer compound include anionic and nonionic polymer compounds. Examples of the anionic polymer compound include cellulose derivatives such as carboxymethyl cellulose, acrylic acid derivatives such as polyacrylic acid, and polystyrene derivatives such as polystyrene sulfonate. Examples of nonionic polymer compounds include polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, and gelatin.

[Surfactant]
Examples of the surfactant include anionic, cationic, nonionic, amphoteric, silicone-based, and fluorine-based surfactants. Among these, at least one surfactant selected from the group consisting of an anionic surfactant and a nonionic surfactant is preferable.
When the ink contains a surfactant, the total content of the surfactant with respect to the total mass of the ink is usually 0.1% to 3%, preferably 0.2% to 2.5%. If it is 0.1% or more, the effect as a surfactant is obtained, and if it is 3% or less, the dispersion stability of the pigment becomes good.

  Anionic surfactants include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, polyoxyethylene alkyl ether sulfates, polyoxyethylene dinonyl phenyl ether sulfates, polyoxyethylene lauryl ethers. Sulfate, N-acyl amino acid or salt thereof, N-acylmethyl taurate, alkyl sulfate polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl Alcohol sulfates, alkylphenol phosphates, alkyl phosphates, alkylaryl sulfonates, diethyl sulfonates, diethyl hexyl sulfonates, dioctyl sulfonates, etc. It is. Specific examples of commercially available products include, for example, Hightenol LA-10, LA-12, LA-16, NE-05, NE-15, NF-13, NF-17, Neohightenol ECL-30S, ECL-45. (Daiichi Kogyo Seiyaku Co., Ltd.), Adeka Coal EC-8600 (Adeka Co., Ltd.), Perex OT-P (Kao Co., Ltd.) and the like.

  Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.

  Examples of amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, and imidazoline derivatives. Can be mentioned.

  Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, and other ethers ( For example, Sobutanol EP-5035, 7085, 9050 manufactured by Nippon Shokubai Co., Ltd .; Pluronic L-31, L-34, L-44 manufactured by Adeka Co., Ltd.); polyoxyethylene oleate, polyoxyethylene distearate Sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl- Acetylene glycol (alcohol) type such as 1-hexyn-3-ol; polyoxyethylene acetylene glycol ether; polyoxyethylene distyrenated phenyl ether; polyoxyethylene tribenzylated phenyl ether; Surfynol manufactured by Nissin Chemical Co., Ltd. 104, 104PG50, 105PG50, 82, 420, 440, 465, 485; Orphine STG; Polyglycol ether type (for example, TargItol 15-S-7 manufactured by SIGMA-ALDRICH) and the like.

  Examples of the silicone surfactant include polyether-modified siloxane and polyether-modified polydimethylsiloxane. Specific examples of commercially available products include BYK-347 (polyether-modified siloxane); BYK-345, BYK-348, BYK-349 (polyether-modified polydimethylsiloxane) manufactured by BYK Chemie.

  Examples of fluorosurfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate compounds, perfluoroalkyl ethylene oxide adducts, and perfluoroalkyl ether groups in the side chain. The polyoxyalkylene ether polymer compound etc. which have are mentioned. Specific examples of commercially available products include, for example, Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300 (manufactured by DuPont); Capstone FS-30, FS-31 (manufactured by DuPont) PF-151N, PF-154N (Omnova);

[Antidepressant]
Specific examples of the antifungal agent include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzisothiazolin-3-one, and salts thereof. .

[Preservative]
Examples of preservatives include, for example, organic sulfur, organic nitrogen sulfur, organic halogen, haloaryl sulfone, iodopropargyl, haloalkylthio, nitrile, pyridine, 8-oxyquinoline, benzothiazole , Isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane, dithiocarbamate, brominated indanone, benzyl Examples thereof include bromoacetate-based or inorganic salt-based compounds.
Specific examples of the organic halogen compound include, for example, sodium pentachlorophenol.
Specific examples of the pyridine oxide compound include sodium 2-pyridinethiol-1-oxide.
Examples of isothiazoline compounds include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 5- Chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride and the like It is done.
Specific examples of the other antiseptic / antifungal agents include anhydrous sodium acetate, sodium sorbate, sodium benzoate, trade names Proxel GXL (S), LV, and XL-2 (S) manufactured by Arch Chemical Co., Ltd.

[PH adjuster]
Specific examples of the pH adjusting agent include alkanolamines such as diethanolamine, triethanolamine and N-methyldiethanolamine; hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide; ammonium hydroxide (ammonia Water); alkali metal carbonates such as lithium carbonate, sodium carbonate, sodium bicarbonate, potassium carbonate; alkali metal salts of organic acids such as sodium silicate and potassium acetate; and phosphates such as disodium phosphate Is mentioned.

[Chelating reagent]
Specific examples of the chelating reagent include, for example, disodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, and sodium uracil diacetate.

[Rust preventive]
Specific examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

[Water-soluble UV absorber]
Examples of water-soluble ultraviolet absorbers include sulfonated benzophenone compounds, benzotriazole compounds, salicylic acid compounds, cinnamic acid compounds, and triazine compounds.

[Antioxidant]
As examples of the antioxidant, for example, various organic and metal complex anti-fading agents can be used. Examples of organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocyclic rings. .

[Defoamer]
Examples of the antifoaming agent include silicone-based, silica mineral oil-based, olefin-based, and acetylene-based. Examples of commercially available products include Surfinol DF37, DF58, DF110D, DF220, MD-20, and Orphin SK-14, all manufactured by Shin-Etsu Chemical Co., Ltd.
When using an antifoamer, the addition amount is 0.01 to 5% normally, Preferably it is 0.03 to 3%, More preferably, it is 0.05 to 1%. When it is 0.01% or more, an effect as an antifoaming agent is obtained, and when it is 5% or less, the dispersion stability is good.

  All the above-mentioned components can be used alone or in combination of two or more.

When the ink is used as an inkjet ink, it is preferable to use an ink containing a small amount of inorganic impurities such as metal cation chloride (for example, sodium chloride) and sulfate (for example, sodium sulfate). The standard of the content of the inorganic impurities is about 1% or less with respect to the total mass of the colorant, and the lower limit includes the detection limit of the analytical instrument, that is, 0%.
Inorganic impurities are often mixed in the colorant. For this reason, an inorganic impurity can be removed as needed. As a purification method, for example, a method of suspending and purifying a solid colorant with a mixed solvent of C1-C4 alcohol such as methanol and water, or the like; And the like.

The pH of the ink is usually 7 to 11, preferably 8 to 10.
The surface tension of the ink is usually 10 to 50 mN / m, preferably 20 to 40 mN / m.
The viscosity of the ink is usually 2 mPa · s to 30 mPa · s, preferably 3 mPa · s to 20 mPa · s.
The pH, surface tension, and viscosity of the ink can be appropriately adjusted with a pH adjuster, a surfactant, a water-soluble organic solvent, or the like.

  The ink can be used for various recordings. For example, it is suitable for writing instruments, water-based printing, information recording, textile printing, etc., and particularly preferably used for ink jet recording.

The ink jet recording method is a method of recording by ejecting the ink droplets according to a recording signal and attaching them to a recording medium. There is no restriction | limiting in particular about the ink nozzle of an inkjet printer, an inkjet system, etc., It can select suitably according to the objective.
When recording by the inkjet recording method, a container containing the ink is loaded at a predetermined position of the inkjet printer, and recording is performed on a recording medium by the recording method.

As the ink jet method, a known method can be used. Specific examples of the ink jet method include a charge control method, a drop-on-demand (pressure pulse) method, an acoustic ink jet method, a thermal ink jet method, and the like.
In addition, a method of improving the image quality by ejecting a large amount of ink with a small colorant content in the ink in a small volume; using a plurality of inks having substantially the same hue and different concentrations of the colorant in the ink And a method for improving the fixing property of the colorant by using a colorless and transparent ink.

The recording medium means a substance to which the ink can adhere. Examples of the recording medium include, for example, sheet-like materials such as paper and film; fibers and cloth (cellulose, nylon, wool, etc.); leathers; base materials for color filters. The recording medium to which the ink is attached is included in the scope of the present invention.
Recording media can be broadly classified into those having an ink receiving layer and those having no ink receiving layer.
The ink receiving layer can be applied to the recording medium by a known method. It is also possible to purchase a recording medium that already has an ink receiving layer. Typical examples of the recording medium having an ink receiving layer include sheet-like recording media generally referred to as ink jet exclusive paper, ink jet exclusive film, glossy paper, and the like. Typical examples include professional photo paper manufactured by Canon Inc., super photo paper, glossy gold and matte photo paper; photo paper Krispia (high gloss), photo paper (gloss), photo matte manufactured by Seiko Epson Corporation. Paper: Advanced Photo Paper (Glossy) manufactured by Hewlett-Packard Japan, Inc., and Photographic Finishing Pro Pro manufactured by Fuji Film Co., Ltd.

Examples of the recording medium having no ink receiving layer include various papers such as coated paper and art paper used for gravure printing, offset printing, and cast coated paper used for label printing.
When using a recording medium that does not have an ink receiving layer, it is also preferable to subject the recording medium to a surface modification treatment for the purpose of improving the fixability of the colorant.

The surface modification treatment is preferably at least one treatment selected from corona discharge treatment, plasma treatment, and flame treatment. As these treatments, known methods can be used. In addition, it is generally known that the effects of these treatments decrease with time. For this reason, when the surface modification treatment is performed on the recording medium, it is preferable to perform ink jet recording without taking time.
In the surface modification treatment, the number of treatments, time, voltage to be applied, and the like can be appropriately adjusted so as to obtain a desired effect.

The ink of the present invention contains a water-insoluble colorant and has good storage stability, particularly filterability.
In addition, various scratch properties, in particular, excellent scratch properties and good color developability even in a wet state as in a dry state. Further, the ink of the present invention is excellent in redispersibility and marker resistance, and has good chroma.
Furthermore, an image recorded with the ink of the present invention is excellent in various fastness properties such as water resistance, light resistance, heat resistance, and oxidation gas resistance (for example, ozone gas resistance).

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to a following example.
In addition, content of the coloring agent in a dispersion liquid was calculated | required by the dry weight method using A & D Co., Ltd. make and MS-70. The average particle size of the colorant was measured using Nanotrac Wave-EX150 manufactured by Microtrack Bell.

[Preparation Example 1]: Preparation of dispersion 1.
The block copolymer A of Synthesis Example 3 was obtained by trying Synthesis Example 3 of International Publication No. 2013/115071. The resulting block copolymer A (6 parts) was added to 2-butanone (30 parts) to give a solution. To this solution, a solution of sodium hydroxide (0.44 g) in ion exchanged water (41 parts) was added and stirred for 1 hour to prepare an emulsion. In this emulsion, C.I. I. Pigment Red 122 (20 parts) and dispersed beads were added, and dispersion treatment was performed with a sand grinder (1500 rpm, 15 hours) to obtain a liquid. After 100 parts of ion-exchanged water was dropped into the obtained liquid, dispersion beads were separated from this liquid to obtain a filtrate. From the obtained filtrate, 2-butanone and a part of water were distilled off under reduced pressure by an evaporator to obtain a dispersion having a colorant content of 12.0% as “Dispersion 1”.

[Preparation Example 2]: Preparation of dispersion 2.
Joncryl 68 (11.3 parts) and triethanolamine (6 parts) were added to ion-exchanged water (95.2 parts) and stirred for 1 hour to obtain a solution. To the resulting solution, C.I. I. Pigment Red 122 (37.5 parts) and dispersed beads were added, and dispersion treatment was performed with a sand grinder (1500 rpm, 20 hours) to obtain a liquid. After dropping 150 parts of ion-exchanged water into the obtained liquid, the dispersion beads were separated from the liquid by filtration to obtain a dispersion having a colorant content of 15.8% as “Dispersion 2”. .

[Preparation Example 3] Preparation of dispersion 3.
C. I. Pigment Red 122 (20 parts) instead of C.I. I. A dispersion having a colorant content of 12.0% was obtained as “Dispersion 3” in the same manner as in “Preparation Example 1” except that Pigment Blue 15: 4 (20 parts) was used.

[Preparation Example 4]: Preparation of dispersion 4.
C. I. Pigment Red 122 (20 parts) instead of C.I. I. A dispersion having a colorant content of 12.0% was obtained as “Dispersion 4” in the same manner as in “Preparation Example 1” except that Pigment Yellow 74 (20 parts) was used.

[Preparation Example 5]: Preparation of polymer 1.
By pursuing “[Preparation Example 4] Preparation of polymer emulsion 3” in Patent Document 6, a polymer emulsion having an acid value of 6 mgKOH / g, Tg of 0 ° C., and a solid content of 24.9% was white suspension. Got as. This is designated as “Polymer 1”.

[Examples 1-8 and Comparative Examples 1-2]: Preparation of ink.
Each component described in Table 2 below was mixed, stirred for about 1 hour, and then filtered through a 3 μm membrane filter to obtain each ink of Examples and Comparative Examples. Each ink was prepared such that the content of the colorant contained in the total mass was 5%.
Abbreviations and the like in the following Table 2 represent the following meanings.
TEG: Triethylene glycol.
SF465: Surfynol 465.
AQ: AQUACER (As an example, “AQ515” means “AQUACER 515”).
H6400: HYTEC-6400.

[Storage stability]
Each of the inks of Examples and Comparative Examples was put in a sealed container to give a test sample, which was allowed to stand for 4 days in a thermostatic chamber at 60 ° C. and then left for one day in a thermostatic chamber at −5 ° C. After returning the sampled sealed container to room temperature, the time required to filter each ink (80 g) with a 1 μm membrane filter was measured and evaluated according to the following three criteria. The evaluation results are shown in Table 2 below.
A: The entire amount of ink could be filtered within 45 seconds.
B: The entire amount of ink could be filtered within 60 seconds.
C: The entire amount of ink could not be filtered within 60 seconds.

  As is clear from Table 3, the ink of each example had very good filterability.

  Since the ink of the present invention contains a water-insoluble colorant and has good storage stability against temperature changes, particularly good filterability, it is extremely useful as various recording inks, particularly industrial inkjet inks.

Claims (10)

  An ink containing a water-insoluble colorant, a polymer, a polyalkylene wax, and water, wherein the monomer constituting the polymer contains a monomer selected from at least one of a methacrylic acid derivative and an acrylic acid derivative. Ink.   The ink according to claim 1, wherein the polyalkylene wax is a wax selected from polyethylene wax and polypropylene wax.   The ink according to claim 1, wherein the monomers constituting the polymer are three types of monomers selected from methacrylic acid derivatives and one type of monomer selected from acrylic acid derivatives.   The ink according to claim 1 or 3, wherein the monomers constituting the polymer are two types of alkyl methacrylate, methacrylic acid, and alkyl acrylate.   An ink jet recording method for performing recording by ejecting the ink droplets according to claim 1 from an ink jet printer and attaching them to a recording medium.   A recording medium to which the ink according to claim 1 is attached.   The recording medium according to claim 6, wherein the recording medium is a medium having an ink receiving layer.   The recording medium according to claim 6, wherein the recording medium is a medium having no ink receiving layer.   An ink tank filled with the ink according to claim 1.   An ink jet printer loaded with the ink tank according to claim 9.