JP6893404B2 - How to improve scratchability - Google Patents

Description

The present invention relates to a method for improving scratchability.

There are two major colorants contained in inkjet inks: water-soluble colorants (eg acid dyes, direct dyes, etc.) and water-insoluble or sparingly soluble colorants (eg disperse dyes, solvent dyes, and pigments). Can be separated. Of these, various types of fastness are excellent, and in recent years, inks containing water-insoluble or sparingly soluble colorants, particularly pigments (pigment inks), have been mainly used for industrial purposes.
In the inkjet recording method, various recording media are used. One of them is an inkjet paper (glossy paper) having an ink receiving layer. On the other hand, plain paper and non-absorbent recording media with low ink absorption capacity are often used. These recording media do not have an ink receiving layer. Therefore, when recording on these recording media with water-based ink, the scratch resistance of the recorded image is weakened, which is a big problem. In particular, when recording with a water-based pigment ink, the ink may be easily transferred or peeled off due to friction.
Also, in industrial applications, images recorded with ink are often used outdoors. In the outdoor use of this recorded image, there may be a large difference in the scratchability of the recorded image between sunny weather and rainy weather, which is a problem. That is, it is recognized that the scratchability of the recorded image in the rainy weather is significantly deteriorated in the sunny weather, which is a problem.
Therefore, there is a strong demand for a method for improving the scrapability under wet conditions corresponding to rainy weather as well as dry conditions corresponding to sunny weather.

Patent Documents 1 and 2 disclose inks that are said to have good scratchability and high-quality images by controlling the permeability to paper with a surfactant and a penetrant.
Patent Documents 3 and 4 disclose a method of adding a resin to an ink to impart adhesion to a recording medium and improve friction resistance.
Patent Document 5 discloses an ink composition containing a polymer, and Patent Document 6 discloses an ink composition containing a wax.

International Publication No. 2008/105289 Japanese Unexamined Patent Publication No. 2003-253167 Japanese Unexamined Patent Publication No. 2013-166844 Japanese Unexamined Patent Publication No. 2013-199605 International Publication No. 2015/152291 International Publication No. 2015/147192

An object of the present invention is to provide various methods for improving scratch resistance, particularly wet scratch resistance.

As a result of intensive research to solve the above-mentioned problems, the present inventors have solved the above-mentioned problems with an ink containing a quinacridone pigment and an azo pigment as colorants, and further containing a polymer, wax, and water. We found what we could do and completed the present invention. That is, the present invention relates to the following 1) to 6).
1)
A method for improving scratchability, which comprises an ink containing a quinacridone pigment and an azo pigment as a colorant, and further containing a polymer, a wax, and water.
However, the monomer constituting the polymer contains at least one monomer selected from each of the methacrylic acid derivative and the acrylic acid derivative.
2)
The method for improving scratchability according to 1) above, wherein the wax contains at least one selected from polyethylene wax, polypropylene wax, polyethylene oxide wax, polypropylene oxide wax and paraffin wax.
3)
The quinacridone pigment is C.I. I. Pigment Red 122, 202, and C.I. I. The method for improving scratchability according to 1) above, which is a pigment selected from Pigment Violet 19.
4)
The method for improving scratchability according to 1) above, wherein the monomers constituting the polymer are three types of monomers selected from methacrylic acid derivatives and one type of monomers selected from acrylic acid derivatives.
5)
The method for improving scratchability according to 1) or 4) above, wherein the monomers constituting the polymer are two types of alkyl methacrylate, methacrylic acid, and alkyl acrylate.
6)
The azo pigment is C.I. I. The method for improving scratchability according to 1) above, which is Pigment Red 150.

INDUSTRIAL APPLICABILITY According to the present invention, various methods for improving scratch resistance, particularly wet scratch resistance, can be provided.

Hereinafter, the ink of the present invention will be described in detail.
As used herein, "CI" is an abbreviation for Color Index.
Further, in the present specification, “%” and “part” are described in terms of mass, including examples, unless otherwise specified.

[Quinacridone pigment]
Examples of the quinacridone pigment include C.I. I. Pigment Red and C.I. I. Examples include quinacridone pigments selected from pigment violet. Such quinacridone pigments can be easily searched, for example, from the online search screen of Color Index International. Among them, C.I. I. Pigment Red 122, 202 and C.I. I. Pigment Violet 19 is preferred and C.I. I. Pigment Red 122 and C.I. I. Pigment Violet 19 is more preferred. In the following specification, "CI Pigment Red" is referred to as "PR" and "CI Pigment Violet" is referred to as "PV".

[Azo pigment]
Examples of the azo pigment include C.I. I. Examples include azo pigments selected from Pigment Red. Such azo pigments can be easily searched, for example, from the online search screen of Color Index International. Among them, PR150 is preferable.

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%, still more preferably 2% to 7%. .. When the content is 0.5% or more, sufficient color development of the recorded image is obtained, and when the content is 10% or less, the ejection property is good.

The content ratio of the quinacridone pigment to the azo pigment with respect to the total mass of the colorant is usually 95/5 to 5/95, preferably 90/10 to 10/90, more preferably 80/20 to 20/80, still more preferably 70. It is / 30 to 30/70. By setting such a ratio, a recorded image having a good balance between color development and saturation can be obtained.

[polymer]
As the monomer constituting the polymer, at least one monomer selected from each of the methacrylic acid derivative and the acrylic acid derivative is preferable;
Three types of monomers selected from methacrylic acid derivatives and one type of monomer selected from acrylic acid derivatives are more preferred;
Two types of alkyl methacrylate, methacrylic acid, and alkyl acrylate are more preferred.
As the two types of alkyl methacrylates constituting the polymer, a monomer selected from each of a linear alkyl methacrylate and an unsaturated alkyl methacrylate is preferable.
As the linear alkyl methacrylate, the linear C1-C3 alkyl methacrylate is more preferable, and the methyl methacrylate is further preferable.
As the unsaturated alkyl methacrylate, unsaturated C1-C4 alkyl methacrylate is more preferable, and allyl methacrylate is further preferable.
Further, as the alkyl acrylate constituting the polymer, a branched chain alkyl acrylate is preferable, a branched chain C1-C8 alkyl acrylate is more preferable, and a 2-ethylhexyl acrylate is further preferable.
The polymer can be obtained, for example, by the synthetic method disclosed in WO 2015/147192 Gazette. The third polymer can also be used as an emulsion.

The average particle size of the polymer is usually 10 nm to 1 μm, preferably 30 nm to 500 nm. With such an average particle size, the inkjet head is less likely to be clogged or occur.
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 0-25 mgKOH / g, preferably 5-15 mgKOH / g.
The insolubility of the polymer in tetrahydrofuran is usually 80-100%, preferably 100%, i.e. insoluble. Thereby, the average molecular weight of the resin can be controlled, and a resin containing no free monomer or the like can be obtained.
The polymer content 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%. With such a content, scratchability, redispersibility, and ejection property are good.

The monomer composition of the polymer is summarized in Table 1 below as "normal", "favorable", and "more preferable" configurations. Within the range of each monomer in Table 1 below, the total amount of the 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.

[wax]
The wax contained in the ink is preferably a wax emulsion, more preferably an aqueous wax emulsion. As the wax, natural wax and chemically synthesized wax can be used.
Natural waxes include petroleum-based waxes such as paraffin wax and microcrystallin wax, brown charcoal-based waxes such as Montan wax, plant-based waxes such as carnauba wax and canderia wax, and animal and plant-based waxes such as beeswax and lanolin. Examples thereof include an emulsion in which wax is dispersed in an aqueous medium.

As the wax emulsion, at least one wax preferably selected from polyethylene wax, polypropylene wax, polyethylene oxide wax, polypropylene oxide wax and paraffin wax, or a mixed wax thereof is dispersed in an aqueous medium. Emulsion is mentioned.

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.

Commercially available products as wax emulsions include, for example, CERAFLOUR 925, 929, 950, 991, AQUACER 498, 515, 526, 513, 537, 538, 552, 1547, AQUAMAT 208, 263, 272, manufactured by Big Chemie. MINERPOL221 and the like; Mitsui High Wax NL100, NL200, NL500, 4202E, 1105A, 2203A, NP550, NP055, NP505, etc. manufactured by Mitsui Chemicals Co., Ltd .; KUE-100, 11 and the like manufactured by Sanyo Chemicals Co., Ltd. can be mentioned.
Of these, AQUACER 515, 513, 537, 539, 1547 are preferred; AQUACER 515, 531, 537, 1547 are more preferred.

The wax content 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%. With such a content, scratchability, redispersibility, and ejection property are improved.

The content ratio of the polymer and the wax in the total mass of the polymer and the wax contained in the ink is usually 95/5 to 5/95, preferably 90/10 to 10/90, and more preferably 80/20 to 20/90. It is 80. By setting such a ratio, a recorded image having a good balance between redispersibility and fixability can be obtained.

The ink can be used as magenta ink. For the purpose of obtaining a full-color recorded image, it can be used as an ink set including, for example, cyan ink, yellow ink, and black ink. At this time, the colorants contained in the cyan, yellow, and black inks are not particularly limited, and known pigments can be arbitrarily used. In addition to these four-color ink sets, for the purpose of obtaining recorded images with higher-definition hues, for example, with four or more color ink sets in which inks such as violet, orange to brown, and green are arbitrarily added. You can also do it.

[Dispersant]
The ink can contain a dispersant. It is also possible to coat a part or all of the pigment with a dispersant.
Examples of the dispersant include a nonionic dispersant, an anion dispersant, and a polymer dispersant, which can be appropriately selected depending on the intended purpose. Among these, at least one selected from the group consisting of a nonionic dispersant, an anion dispersant and a polymer dispersant is preferable.
The amount of the dispersant used is usually 1 to 100%, preferably 5 to 90%, more preferably 10 to 80%, based on the total mass of the pigment, as a mass ratio in terms of solid content when preparing the dispersion liquid. %. By using such an amount, the pigment can be sufficiently miniaturized. Further, it is possible to suppress bleeding of an image recorded with an ink containing this dispersion liquid, and to obtain good water resistance and scratch resistance.

Nonionic dispersants include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyalkylene glycols, glycerin esters, sorbitan esters, sucrose esters, glycerin ester polyoxyalkylene ethers, and sorbitan ester polyoxyalkylene ethers. Polyoxyalkylene ether of sorbitol ester, fatty acid alkanolamide, polyoxyalkylene fatty acid amide, amine oxide, polyoxyalkylene alkylamine, polyoxyalkylene-β-naphthyl ether, polyoxyalkylene styrylphenyl ether, polyoxyalkylene distyryl phenyl ether And so on.

Anionic dispersants include alkyl sulfates, alkyl ether sulfates, alkyl ester sulfates, alkylaryl ether sulfates, alkyl sulfonates, sulfosuccinates, alkylaryl and alkylnaphthalene sulfonates, alkyl phosphates, Examples thereof include polyoxyalkylene alkyl ether phosphate, alkylallyl ether phosphate, polyoxyalkylene alkyl ether sulfate, polyoxyalkylene styrylphenyl ether sulfate, and polyoxyalkylene distyryl phenyl ether sulfate.

Examples of the polymer dispersant include styrene and its derivatives; vinylnaphthalene and its derivatives; aliphatic alcohol esters of α, β-ethylenically unsaturated carboxylic acids, etc .; acrylic acids and their derivatives; maleic acid and its derivatives; itaconic acid and At least two monomers (preferably at least one of them) selected from the group of monomers consisting of derivatives thereof; fumaric acid and derivatives thereof; vinyl acetate, vinyl alcohol, vinylpyrrolidone, acrylamide, derivatives thereof and the like. Examples thereof include copolymers composed of (one of which is a hydrophilic monomer), such as block copolymers, random copolymers and graft copolymers, and / or salts thereof.
The weight average molecular weight of the dispersant is approximately 1,000 to 60,000, preferably 2,000 to 50,000, and more preferably 2,500 to 50,000. The acid value is about 10 to 300, preferably 10 to 275, and more preferably about 20 to 250, as mgKOH / g.
Specific examples of commercially available products include, for example, John Krill 61J, 67, 68, 450, 55, 555, 586, 678, 680, 682, 683, 690, and B-36 manufactured by BASF. ..

As a method for preparing the aqueous dispersion containing the colorant, all known methods can be used. An example of this is a known method in which a colorant and a dispersant are mixed and dispersed 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. .. Of these, a sand mill (bead mill) is preferable. For the preparation of the dispersion liquid using a sand mill, it is preferable to prepare the dispersion liquid under the condition that the dispersion efficiency is improved by using beads having a diameter of about 0.01 mm to 1 mm and increasing the filling rate of the beads.
After preparing 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 size.
When foaming occurs during the preparation of the dispersion liquid, a very small amount of a known antifoaming agent such as silicone-based or acetylene glycol-based can be added.
Other methods include acid analysis method, phase inversion emulsification method, interfacial polymerization method, in-situ polymerization method, in-liquid curing coating method, core selvation (phase separation) method, in-liquid drying method, melting dispersion cooling method, and the like. Examples include an aerial suspension coating method and a spray drying method. Among these, the phase inversion emulsification method, the acid analysis method and the interfacial polymerization method are preferable.

Instead of using the above-mentioned dispersant, a surface-treated pigment (self-dispersing 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 size (D50) of the colorant in the dispersion is usually 300 nm or less, preferably 30 to 280 nm, more preferably 40 to 270 nm, still more preferably 50 to 250 nm.
Similarly, D90 is usually 300 nm or less, preferably 280 nm or less, and 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.

As the water, for example, distilled water, ion-exchanged water, pure water, ultrapure water and the like having a pH of 6.5 to 7.5 and having a low free ion content such as various metal ions are preferable.

The ink contains 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 preventive, and a water-soluble ultraviolet absorber as components other than the above. An ink preparation agent such as an antioxidant can be contained as required. One type of ink preparation may be used, or two or more types may be used in combination.

[Water-soluble organic solvent]
The water-soluble organic solvent contained in the ink is not particularly limited, and is, for example, C1-C6 alkanol such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, second butanol or third butanol; N, N-dimethyl. Formamides or carboxylic acid amides such as N, N-dimethylacetamide; lactams such as 2-pyrrolidone, N-methyl-2-pyrrolidone or N-methylpyrrolidin-2-one; 1,3-dimethylimidazolidine-2-one or Cyclic ureas such as 1,3-dimethylhexahydropyrimido-2-one; ketones or keto alcohols such as acetone, 2-methyl-2-hydroxypentane-4-one, ethylene carbonate; cyclics such as tetrahydrofuran and dioxane. Ether; ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene Monos, oligos or polyalkylene glycols or thioglycols having C2-C6 alkylene units such as glycols (preferably those having a molecular weight of 400, 800, 1540 or higher), polypropylene glycols, thiodiglycols or dithiodiglycols; glycerin, di C3-C9 polyols (triols) such as glycerin, hexane-1,2,6-triol, trimethylpropane, etc .; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoallyl ether, ethylene glycol 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, prolen glycol monobutyl ether, dipropylene glycol A glycol ether selected from the group consisting of glycol ethers such as monomethyl ethers (preferably C3-C10 mono, di or triethylene glycol ethers, and C4-C13 mono, di or tripropylene glycol ethers. Le); 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3- Examples thereof include C5-C9 alkanediol such as hexanediol, 2,4-diethyl-1,5-pentanediol; γ-butyrolactone, dimethylsulfoxide and the like; and the like.
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%, and more preferably 10% to 50%.

[binder]
Examples of the binder include urethane-based, polyester, acrylic-based, vinyl acetate-based, vinyl chloride-based, acrylic styrene-based, acrylic silicone-based, and styrene-butadiene-based resins, or emulsions containing them. Among these, resins selected from urethane-based, acrylic-based, and styrene-butadiene-based resins are preferable.
Specific examples of commercially available products include, for example, Superflex 126, 130, 150, 170, 210, 420, 470, 820, 830, 890 (urethane-based 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 Co., Ltd.); 0569, 0850Z, 2108 (manufactured by JSR Co., Ltd.) AE980, AE981A, AE982, AE986B, AE104 (acrylic resin emulsion manufactured by E-Tech 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 the nonionic polymer compound include polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, gelatin and the like.

[Surfactant]
Examples of the surfactant include anion, cation, nonionic, amphoteric, silicone-based, and fluorine-based surfactants. Among these, at least one type of surfactant selected from the group consisting of anionic surfactants and nonionic surfactants 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%. At 0.1% or more, the effect as a surfactant is obtained, and at 3% or less, the dispersion stability of the pigment is good.

Anionic surfactants include alkyl sulfocarboxylic acid salt, α-olefin sulfonate, polyoxyethylene alkyl ether acetate, polyoxyethylene alkyl ether sulfate, polyoxyethylene dinonylphenyl ether sulfate, and polyoxyethylene lauryl ether. Sulfate, N-acylamino acid or salt thereof, N-acylmethyl taurine salt, alkyl sulfate polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, sulphonic acid soap, castor oil sulfate, lauryl Examples thereof include alcohol sulfate, alkylphenol-type phosphoric acid ester, alkyl-type phosphoric acid ester, alkylaryl sulfonate, diethyl sulfo sulphate, diethyl hexyl sulfo sulphate, and dioctyl sulfo sulphate. Specific examples of commercially available products include, for example, High Tenor LA-10, LA-12, LA-16, NE-05, NE-15, NF-13, NF-17, Neo High Tenor ECL-30S, ECL-45. (Manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Adecacol EC-8600 (manufactured by Adeka Corporation), Perex OT-P (manufactured by Kao Corporation) and the like.

Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly4-vinylpyridine derivatives.

Examples of amphoteric surfactants include betaine lauryldimethylaminoacetate, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, betaine coconut oil fatty acid amide propyldimethylaminoacetate, polyoctylpolyaminoethylglycine, and imidazoline derivatives. Can be mentioned.

Examples of the nonionic surfactant include ethers such as polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, and polyoxyethylene alkyl ether. For example, Sophanol EP-5035, 7085, 9050 manufactured by Nippon Catalyst Co., Ltd .; Pluronic L-31, L-34, L-44, etc. manufactured by Adeca Co., Ltd.); Polyoxyethylene oleic acid ester, polyoxyethylene distearate , Solbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate and other ester systems; 2,4,7,9-tetramethyl-5- Acetylene glycol (alcohol) such as decine-4,7-diol, 3,6-dimethyl-4-octin-3,6-diol, 3,5-dimethyl-1-hexin-3-ol; polyoxyethylene acetylene Glycol ether; Polyoxyethylene distyrene phenyl ether; Polyoxyethylene tribenzylated phenyl ether; Surfinol 104, 104PG50, 105PG50, 82, 420, 440, 465, 485; Orphine STG; Poly Glycol ether type (for example, TergItol 15-S-7 manufactured by SIGMA-ALDRICH) and the like can be mentioned.

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

Examples of the fluorine-based surfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate ester compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group as side chains. Examples thereof include a polyoxyalkylene ether polymer compound contained in. Specific examples of commercially available products include, for example, ZonylTBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, Capstone FS-30, FS-31 (manufactured by DuPont); PF-151N, PF. -154N (manufactured by Omniova); etc.

[Antifungal agent]
Specific examples of the fungicide 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 organic sulfur-based, organic nitrogen-sulfur-based, organic halogen-based, haloarylsulfone-based, iodopropagil-based, haloalkylthio-based, nitrile-based, pyridine-based, 8-oxyquinolin-based, and benzothiazole-based. , Isothiazolin-based, dithiol-based, pyridine oxide-based, nitropropane-based, organotin-based, phenol-based, tetraammonium salt-based, triazine-based, thiazine-based, anilide-based, adamantan-based, dithiocarbamate-based, brominated indanone-based, benzyl Examples thereof include bromacetate-based or inorganic salt-based compounds.
Specific examples of the organic halogen-based compound include sodium pentachlorophenol.
Specific examples of the pyridine oxide compound include 2-pyridinethiol-1-oxide sodium.
Examples of isothiazolin-based compounds include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, and 5-one. Chloro-2-methyl-4-isothiazolin-3-onemagnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-onecalcium chloride, 2-methyl-4-isothiazolin-3-onecalcium chloride and the like. Be done.
Specific examples of other antiseptic and fungicides include anhydrous sodium acetate, sodium sorbate, sodium benzoate, trade names Proxel GXL (S), Proxel LV, Proxel XL-2 (S) manufactured by Arch Chemical Co., Ltd., and the like. ..

[PH regulator]
Specific examples of the pH adjuster 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 hydrogen carbonate, potassium carbonate; Alkali metal salts of organic acids such as sodium silicate and potassium acetate; and phosphates such as disodium phosphate, etc. Can be mentioned.

[Chelating reagent]
Specific examples of the chelating reagent include disodium ethylenediaminetetraacetate, sodium nitrilotriacetic acid, sodium hydroxyethylethylenediamine triacetate, sodium diethylenetriamine pentaacetate, and sodium uracil diacetate.

[anti-rust]
Specific examples of the rust preventive include acidic sulfites, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrate, pentaerythritol tetranitrate, dicyclohexylammonium nitrate and the like.

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

[Antioxidant]
As an example of the antioxidant, for example, various organic and metal complex-based anti-fading agents can be used. Examples of the organic anti-fading agent include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indans, chromanes, alkoxyanilines, heterocyclics and the like. Be done.

[Defoamer]
Examples of the defoaming agent include silicone-based, silica-mineral oil-based, olefin-based, and acetylene-based. Examples of commercially available antifoaming agents include Surfinol DF37, DF58, DF110D, DF220, MD-20, and Orphine SK-14 manufactured by Shin-Etsu Chemical Co., Ltd.
When an antifoaming agent is used, the amount added is usually 0.01 to 5%, preferably 0.03 to 3%, and more preferably 0.05 to 1%. At 0.01% or more, the effect as an antifoaming agent is obtained, and at 5% or less, the dispersion stability is good.

When the ink is used as an ink for inkjet recording, it is recommended to use an ink having a low content of inorganic impurities such as chloride (for example, sodium chloride) and sulfate (for example, sodium sulfate) of metal cations in the ink. preferable. The guideline for 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 or less, that is, 0%.
Inorganic impurities are often mixed in colorants. Therefore, inorganic impurities can be removed as needed. As a purification method thereof, for example, a method of suspending and purifying a solid colorant with a mixed solvent of (C1 to C4) alcohol such as methanol and water; or, after preparing an ink, an inorganic impurity is removed with an ion exchange resin. Examples thereof include a method of exchange adsorption.

The pH of the ink is usually preferably 7 to 11, 8 to 10.
The surface tension of the ink is usually preferably 10 to 50 mN / m and 20 to 40 mN / m.
The viscosity of the ink is usually preferably 2 mPa · s to 30 mPa · s, 3 mPa · s to 20 mPa · s.
The pH and surface tension 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 in various recordings. For example, it is suitable for writing tools, water-based printing, information recording, printing, etc., and is particularly preferably used for inkjet recording.

The inkjet recording method is a method of recording by ejecting droplets of the ink in response to a recording signal and adhering them to a recording medium. The ink nozzle of the inkjet printer, the inkjet method, and the like are not particularly limited and may be appropriately selected depending on the intended purpose.
When recording is performed 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 inkjet method, a known method can be used. Specific examples of the inkjet method include a charge control method, a drop-on-demand (pressure pulse) method, an acoustic inkjet method, a thermal inkjet method, and the like.
In addition, a method of improving the image quality by ejecting a large number of inks with a low content of colorant in the ink in a small volume; image quality using multiple inks having substantially the same hue but different concentrations of the colorant in the ink. A method of improving the fixability of the colorant by using a colorless and transparent ink; and the like are also included.

The recording medium means a substance to which the ink can adhere. Examples of recording media include sheet-like substances such as paper and film; fibers and cloths (cellulose, nylon, wool, etc.); leathers; base materials for color filters, and the like. The recording medium to which the ink is attached is included in the scope of the present invention.
Recording media can be roughly 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 recording media having an ink receiving layer include sheet-shaped recording media usually called inkjet paper, inkjet film, glossy paper, and the like. Typical examples are professional photo paper, super photo paper, glossy gold and matte photo paper manufactured by Canon Corporation; photo paper Crispia (high gloss), photo paper (glossy), photo matte manufactured by Seiko Epson Corporation. Paper: Advanced photo paper (glossy) manufactured by Nippon Hulett Packard Co., Ltd .; Colored photo finishing Pro manufactured by Fuji Film Co., Ltd. and the like.

Examples of the recording medium having no ink receiving layer include various types of paper such as coated paper and art paper used for gravure printing and offset printing; cast coated paper used for label printing and the like.
When a recording medium having no ink receiving layer is used, it is also preferable to perform a surface modification treatment on the recording medium for the purpose of improving the fixability of the colorant.

As the surface modification treatment, it is preferable to perform at least one treatment selected from corona discharge treatment, plasma treatment and frame treatment. As these treatments, known methods can be used. It is also generally known that the effects of these treatments diminish over time. For this reason, when the information transmission sheet is subjected to the surface modification treatment, it is preferable to continuously perform inkjet recording without a delay.
The surface modification treatment can be performed by appropriately adjusting the number of treatments, the time, the voltage to be applied, and the like so that a desired effect can be obtained.

According to the present invention, an ink having various scratch properties, particularly excellent scratch properties even in a wet state as in a dry state, and good color development can be obtained. Further, the ink of the present invention is excellent in redispersibility, marker resistance, and saturation.
Further, the image recorded with the ink of the present invention is excellent in various fastnesses such as water resistance, light resistance, heat resistance, and oxidation gas resistance (for example, ozone gas resistance).

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following Examples.
The content of the pigment solid content in the dispersion was determined by the dry mass spectrometry method using MS-70 manufactured by A & D Co., Ltd. The average pigment particle size in the dispersion solution was determined using Nanotrac Wave-EX150 manufactured by Microtrac Bell.

[Preparation Example 1]: Preparation of an aqueous solution of a dispersant.
John Krill 678 (20 parts) and triethanolamine (11.4 parts) were added to ion-exchanged water (68.6 parts), and the mixture was stirred for 1 hour to obtain an aqueous solution of the dispersant. “John Krill 678” in Table 2 below means this aqueous solution.

[Preparation Example 2]: Preparation of dispersions 1 to 4.
Each component shown in Table 2 below was mixed and subjected to a dispersion treatment for 15 hours under a condition of 1500 rpm with a sand grinder to obtain a liquid. After 100 parts of ion-exchanged water was added dropwise to the obtained liquid, dispersion beads 1 to 4 were obtained by filtering and separating the dispersion beads from this liquid.
In Tables 2 and 3 below, the numerical values indicating the amounts of the components are all "parts", and those with "-" mean that the components are not included. In addition, ion-exchanged water was used as "water". In addition, "Orphine SK-14" is an antifoaming agent. This component is removed at the same time as the dispersion beads are filtered and separated in the preparation of the dispersion liquid, and is not contained in the dispersion liquids 1 to 4.
The abbreviations and the like in Table 2 have the following meanings.
PR122: C.I. I. Pigment Red 122, Cinquasia Magenta D4550J manufactured by BASF.
PV19: C.I. I. Pigment Violet 19, Cinquasia Magenta E05B manufactured by BASF.
PR122 + PR19: C.I. I. Pigment Red 122 and C.I. I. Pigment Red 19 solid solution, Clariant Inkjet Magenta E-02.
PR150: C.I. I. Pigment Red 150, FUJI FAST CARMINE 522-1D manufactured by Fuji Dye Co., Ltd.
SK-14: Orfin SK-14.

[Preparation Example 3] Preparation of polymer 1.
By retesting "[Preparation Example 4] Preparation of Polymer Emulsion 3" in Patent Document 6, a white suspension of a polymer emulsion having an acid value of 6 mgKOH / g, a Tg of 0 ° C., and a solid content of 24.9%. Obtained as. This is referred to as "polymer 1".

[Examples 1 to 3] and [Comparative Examples 1 to 4]: Preparation of ink for evaluation test.
After mixing each component shown in Table 3 below, the inks of Examples 1 to 3 and Comparative Examples 1 to 4 for evaluation test were obtained by filtering with a 3 μm membrane filter, respectively.
In Table 1 below, the solid content conversion values for the polymer 1 and the wax are listed below. That is, the inks of Examples 1 to 3 each contain 1 part of polymer 1 and 1 part of wax as solid content conversion values. The inks of Comparative Examples 1 and 3 contain 2 parts of polymer 1 as a solid content conversion value and do not contain wax. The inks of Comparative Examples 2 and 4 contain 2 parts of wax as a solid content conversion value and do not contain polymer 1.
The abbreviations and the like in Table 3 below represent the following meanings.
GLY: Glycerin.
DEG: Diethylene glycol.
2-PY: 2-pyrrolidone.
SF465: Surfinol 465, an acetylene-based surfactant manufactured by Nissin Chemical Industry Co., Ltd.
GXL (s): Proxel GXL (s).
Wax: AQUACER515, a wax manufactured by BYK (solid content 35.0%).

[Inkjet recording]
The inks obtained in each Example and Comparative Example were filled in a cartridge of an inkjet printer manufactured by Seiko Epson Corporation and PX204, and inkjet recording was performed on coated paper manufactured by Oji Paper Co., Ltd. and OK top coat.
Inkjet recording was performed so as to obtain a solid image of 100% duty, and a recorded image recorded with the ink of each example or comparative example was obtained. Using this as a test piece, the following evaluation test was conducted.
The color of each test piece obtained as described above was measured using a colorimeter manufactured by X-rite, SpectroEye. The color measurement conditions are ANSIA, a viewing angle of 2 °, and a light source D50 based on the density.

[Dry scraping test]
The scratch resistance of each test piece was determined by No. 1 manufactured by Yasuda Seiki Seisakusho. 428 Gakushin Dyeing Friction fastness tester was used for evaluation. That is, with a load of 500 g applied to the test piece, the inkjet-recorded portion was rubbed 20 times, and the degree of deterioration of the image was evaluated according to the following four-step evaluation criteria. The results are shown in Table 4 below.
Dry scratchability evaluation criteria:
A: Color transfer to a blank surface and / or scratches on the image on the recording surface are hardly confirmed.
B: Color transfer to a blank surface and / or slight scratches on the image on the recording surface are observed.
C: Color transfer to a blank surface and / or scratches on the image on the recording surface are clearly observed.
D: Color transfer to a blank surface and scratches on the image on the recording surface are very large.

[Wet scraping test]
Wet scraping property of each test piece was determined by No. 1 manufactured by Yasuda Seiki Seisakusho. 428 Gakushin Dyeing Friction fastness tester was used for evaluation. As an evaluation standard, the portion recorded by inkjet was rubbed twice with a cloth moistened with water under a load of 500 g, and the degree of deterioration of the image was evaluated according to the following evaluation criteria. The results are shown in Table 4 below.
Wet scraping criteria:
A: Color transfer to the cloth and / or slight scratches on the image on the recording surface are observed.
C: Color transfer to the cloth and / or scratches on the image on the recording surface are clearly observed.

[Color development test 1]
The reflection density Dm value (OD value) of each test piece obtained as described above was measured in color. The results are shown in Table 4 below.
[Color development test 2]
The reflection concentration Dm value (OD value) of each test piece after the wet scraping test obtained as described above was measured and evaluated according to the following four-step evaluation criteria. The results are shown in Table 4 below.
Color development evaluation criteria:
A: OD value is 1.4 or more.
B: OD value is 1.2 or more and less than 1.4.
C: OD value is 1.0 or more and less than 1.2.
D: OD value is less than 1.0.

From the results in Table 4, the inks of Examples 1 to 3 containing both the polymer and the wax were dry-scratch-resistant and wet-scratch-resistant, as compared with Comparative Examples 1 to 4 containing only one of them in a double amount. And it was confirmed that it has an excellent effect on color development.

The method for improving scratchability of the present invention is extremely excellent in various scratchiness, particularly in a wet state as well as in a dry state, and can improve color development. Therefore, it is extremely useful as a method for improving the scratchability of various recorded images.

Claims (3)

Quinacridone pigments and C.I. I. A method for improving scratchability using an ink containing Pigment Red 150 and further containing a polymer, wax, and water.
However, the monomers constituting the polymer are two types of alkyl methacrylate, methacrylic acid, and alkyl acrylate, two types of alkyl methacrylate are selected from each of linear alkyl methacrylate and unsaturated alkyl methacrylate, and the alkyl acrylate is a branched chain. An ink that is an alkyl acrylate. The method for improving scratchability according to claim 1, wherein the wax contains at least one selected from polyethylene wax, polypropylene wax, polyethylene oxide wax, polypropylene oxide wax and paraffin wax. The quinacridone pigment is C.I. I. Pigment Red 122, 202, and C.I. I. The method for improving scratchability according to claim 1, which is a pigment selected from Pigment Violet 19.