Processing liquid

Abstract

To provide: a pretreatment solution for water-based pigment inkjet printing, which has excellent adhesion to ink non-absorbent media and can form a printed material with good print image quality without blotting between inkjet ink droplets; and an ink set comprising the pretreatment solution and a water-based inkjet ink.SOLUTION: A treatment solution for use in a recording method implemented with a water-based inkjet ink at least contains water, an aggregating agent that aggregates components of the ink, and an organic compound. The organic compound contains a compound selected from compounds represented by the shown or other specific chemical formulas, satisfying prescribed conditions.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a processing solution for inkjet printing. [Background technology]

[0002] Inkjet printing, one of the most representative color recording methods, works by generating tiny droplets of ink and depositing them onto a recording medium such as paper. In recent years, demand for inks that can print on various recording media has increased in commercial and industrial applications.

[0003] In commercial fields such as catalogs and brochures, recording media with lower ink absorption than plain paper, such as coated paper and art paper (hereinafter also referred to as "low-ink-absorbing media"), are often used. In industrial fields such as outdoor signage and flexible food packaging, non-ink-absorbing recording media such as polyvinyl chloride film, PET (polyethylene terephthalate) film, and polyolefin film (hereinafter also referred to as "non-ink-absorbing media") are often used.

[0004] For media that do not absorb ink well or do not absorb ink at all, development has progressed on solvent-based inks using organic solvents as the main solvent, and curable inks containing polymerizable monomers. However, these inks have many safety concerns regarding the natural environment and human health. Therefore, in recent years, the development of water-based inks using water as the main solvent has become increasingly popular.

[0005] Water-based inks do not penetrate non-absorbent media at all. Therefore, after impact, ink droplets do not penetrate the substrate, causing bleeding between droplets and degrading print quality. Furthermore, because the ink does not penetrate, achieving sufficient adhesion is difficult, leading to peeling of the ink film during post-processing, making practical use impractical. To fix water-based ink to non-absorbent media while minimizing bleeding, it is necessary to reduce the printing speed to allow the water and organic solvents in the ink to dry. However, reducing the printing speed leads to decreased productivity, leaving challenges for water-based inks. In recent years, when increasing the speed of inkjet recording, there is a growing demand for recording suitability in single-pass printing, rather than shuttle-scanning methods.

[0006] As a solution to the above problem, pretreatment solutions for recording media are known (Patent Documents 1-3).

[0007] However, for high-speed printing using a single-pass method, no pre-treatment solution is known that provides both wettability and drying properties for ink-non-absorbent media while also achieving good image quality. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 6866597 [Patent Document 2] Patent No. 5500409 [Patent Document 3] Patent No. 6541088 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The present invention aims to provide a pretreatment liquid for aqueous pigment inkjet printing, which has excellent adhesion to ink-nonabsorbent media, can prevent bleeding between inkjet ink droplets, and can obtain printed matter with good print quality, and an ink set containing the pretreatment liquid and aqueous inkjet ink.

Means for Solving the Problems

[0010] As a result of intensive studies to solve the above problems, the present inventors have found that a treatment liquid used in a recording method using aqueous inkjet ink, the treatment liquid contains at least water, a flocculant that aggregates the components of the ink, and an organic compound, and the organic compound satisfies the following condition (A), can solve the above problems, and completed the present invention.

[0011] That is, the present invention relates to the following 1) to 12). 1) A treatment liquid used in a recording method using aqueous inkjet ink, the treatment liquid contains at least water, a flocculant that aggregates the components of the ink, and an organic compound, and the organic compound satisfies the following condition (A). (A) Compound a: at least one compound selected from the compounds represented by the following formula (1) and the compounds represented by the following formula (2); Compound b: at least one compound selected from the compounds represented by the following formula (3) and the compounds represented by the following formula (4); Compound c: at least one compound selected from the group consisting of C4-C5 alkane diols, the compounds represented by the following formula (5), and the compounds represented by the following formula (6); is included.

[0012]

Chemical formula

[0013] (In formula (1), R 1represents a linear or branched C5-C10 hydrocarbon group.)

[0014] [Chemical formula]

[0015] (In formula (2), R 2 represents a linear or branched C6-C7 hydrocarbon group, and n1 represents 1 or 2.)

[0016] [Chemical formula]

[0017] (In formula (3), R 3 represents a linear or branched C7-C12 hydrocarbon group.)

[0018] [Chemical formula]

[0019] (In formula (4), R 4 represents a phenyl group or a benzyl group, and n2 represents 1 or 2.)

[0020] [Chemical formula]

[0021] (In formula (5), R 5 represents a hydrogen atom or a methyl group.)

[0022] [Chemical formula]

[0023] (In formula (6), R 6 represents a linear or branched C1-C4 hydrocarbon group, and n3 represents 1 or 2.) 2) The treatment solution described in 1), wherein, when the total content of compound a is A and the total content of compound c is C, the relationship C > A is satisfied. 3) The treatment liquid according to 1) or 2), wherein the flocculant comprises at least one selected from the group consisting of polyvalent metal salts, organic acids, and cationic resins. 4) A processed recording medium in which the processing solution described in any one of items 1) to 3) has been applied to the recording medium. 5) The processed recording media described in 4) is a recording medium that is paper or an ink-non-absorbent recording medium. 6) A method for manufacturing a processed recording medium, comprising applying a processing solution described in any one of items 1) to 3) to the recording medium. 7) A method for manufacturing a processed recording medium according to 6), wherein the recording medium is a paper substrate or a non-absorbent recording medium. 8) A method for manufacturing a processed recording medium according to item 6), wherein the processing solution described in any one of items 1) to 3) is applied by an inkjet or an anilox roller. 9) An ink set comprising a processing solution described in any one of items 1) to 3) and a water-based inkjet ink containing a coloring agent. 10) A step of applying the processing liquid described in any one of items 1) to 3) to the recording medium, An image forming method comprising the step of applying an aqueous color ink containing a coloring agent to the portion of the recording medium to which the processing liquid has been applied. 11) The amount of processing solution applied to the recording medium according to any one of items 1) to 3) is 0.05 to 4.0 g / m². 2 An image formation method. 12) Image forming method comprising the step of applying the processing liquid to the recording medium as described in 8), followed by drying, and then applying ink. [Effects of the Invention]

[0024] The present invention provides a pretreatment solution for aqueous pigment inkjet printing that exhibits excellent adhesion to non-ink-absorbing media, prevents bleeding between inkjet ink droplets, and allows for the production of printed materials with good print quality, as well as an ink set comprising the pretreatment solution and aqueous inkjet ink. [Modes for carrying out the invention]

[0025] The embodiments for carrying out the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below and can be implemented in various ways within the scope of its essence. In this specification, unless otherwise specified, "parts" and "%" in the examples, etc., are all expressed on a mass basis. Also, in this specification, the aqueous inkjet ink containing the above-mentioned colorant and the aqueous inkjet ink may be abbreviated as "ink".

[0026] <Processing solution used in recording methods using water-based inkjet inks> The processing solution (hereinafter also simply referred to as "processing solution") used in the recording method using the aqueous inkjet ink according to this embodiment contains at least water, a coagulant for coagulating the components of the ink, and an organic compound, wherein the organic compound satisfies the conditions of (A) above. The ink may also contain a coloring agent, and known coloring agents include pigments, disperse dyes, etc.

[0027] <Water> As for the water, water with a low content of impurities such as metal ions is preferred, i.e., ion-exchanged water, distilled water, etc. The water content is preferably 50 to 90% by mass, and more preferably 60 to 80% by mass, relative to the total mass of the treatment solution according to this embodiment. When the water content is within the above range, the solubility of the coagulant that aggregates the ink components in the treatment solution tends to be good.

[0028] The coagulant that aggregates the components of the above-mentioned ink (hereinafter also simply referred to as "coagulant") reacts with components such as colorants contained in the water-based ink composition and resin particles that may be contained in the water-based ink composition, thereby causing the colorants and resin particles to aggregate. However, the degree of aggregation of colorants and resin particles by the coagulant varies depending on the type of coagulant, colorant, and resin particles, and can be adjusted. Such aggregation can, for example, enhance the color development of the colorants, improve the fixation of resin particles, and / or increase the viscosity of the water-based ink composition on the recording medium.

[0029] While not particularly limited, examples of flocculants include metal salts, acids, and cationic compounds. Cationic compounds include cationic resins (cationic polymers) and cationic surfactants. Among these, polyvalent metal salts are preferred as metal salts. Cationic resins are preferred as cationic compounds. Examples of acids include organic acids and inorganic acids, with organic acids being preferred. Therefore, selecting a flocculant from cationic resins, organic acids, and polyvalent metal salts is preferable in terms of obtaining particularly excellent image quality and abrasion resistance.

[0030] Preferably, the metal salt is a polyvalent metal salt, but other metal salts can also be used. Among these flocculants, it is preferable to use at least one selected from metal salts and organic acids because of its excellent reactivity with the components contained in the ink. Furthermore, among cationic compounds, it is preferable to use a cationic resin because it dissolves easily in the treatment solution. It is also possible to use multiple types of flocculants in combination.

[0031] A polyvalent metal salt is a compound composed of a metal ion with two or more valencies and an anion. Examples of metal ions with two or more valencies include calcium, magnesium, copper, nickel, zinc, barium, aluminum, titanium, strontium, chromium, cobalt, and iron. Among the metal ions that make up these polyvalent metal salts, it is preferable that at least one of calcium ions and magnesium ions is present, given their excellent ability to aggregate the components of the ink.

[0032] The anions constituting the polyvalent metal salt are inorganic ions or organic ions. That is, the polyvalent metal salt in this invention consists of an inorganic ion or an organic ion and a polyvalent metal. Examples of such inorganic ions include chloride ions, bromide ions, iodide ions, nitrate ions, sulfate ions, hydroxide ions, etc. Examples of organic ions include organic acid ions, such as carboxylate ions. It is preferable that the polyvalent metal compound is an ionic polyvalent metal salt, and in particular, if the polyvalent metal salt is a magnesium salt or a calcium salt, the stability of the treatment solution will be better. Furthermore, the counterion of the polyvalent metal may be either an inorganic acid ion or an organic acid ion.

[0033] Specific examples of the polyvalent metal salts mentioned above include calcium carbonate (heavy calcium carbonate and light calcium carbonate), calcium nitrate, calcium chloride, calcium sulfate, magnesium sulfate, calcium hydroxide, magnesium chloride, magnesium carbonate, barium sulfate, barium chloride, zinc carbonate, zinc sulfide, aluminum silicate, calcium silicate, magnesium silicate, copper nitrate, calcium propionate, calcium acetate, magnesium acetate, and aluminum acetate. These polyvalent metal salts may be used individually or in combination of two or more. These metal salts may also contain water of hydration in their raw material form.

[0034] Examples of metal salts other than polyvalent metal salts include monovalent metal salts such as sodium salts and potassium salts, such as sodium sulfate and potassium sulfate. Suitable organic acids include, for example, poly(meth)acrylic acid, acetic acid, glycolic acid, malonic acid, malic acid, maleic acid, ascorbic acid, succinic acid, glutaric acid, fumaric acid, citric acid, tartaric acid, lactic acid, sulfonic acid, orthophosphate, pyrrolidone carboxylic acid, pyrrone carboxylic acid, pyrrole carboxylic acid, furanic acid, pyridine carboxylic acid, coumaric acid, thiophene carboxylic acid, nicotinic acid, or derivatives of these compounds, or salts thereof. Organic acids may be used individually or in combination of two or more.

[0035] Examples of inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid. Inorganic acids may be used individually or in combination of two or more.

[0036] Examples of cationic resins include cationic urethane resins, cationic olefin resins, cationic amine resins, and cationic surfactants. Cationic polymers are preferably water-soluble.

[0037] As cationic urethane resins, commercially available products can be used, such as Hydran CP-7010, CP-7020, CP-7030, CP-7040, CP-7050, CP-7060, CP-7610 (product names, manufactured by Dainippon Ink & Chemicals Co., Ltd.), Superflex 600, 610, 620, 630, 640, 650 (product names, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and Urethane Emulsion WBR-2120C, WBR-2122C (product names, manufactured by Taisei Fine Chemical Co., Ltd.).

[0038] Cationic olefin resins have olefins such as ethylene and propylene as their structural framework, and known ones can be appropriately selected and used. Cationic olefin resins may also be in an emulsion state dispersed in a solvent such as water or an organic solvent. Commercially available cationic olefin resins can be used, such as Arrowbase CB-1200 and CD-1200 (trade names, manufactured by Unitika Ltd.).

[0039] Cationic amine resins can be any resin having an amino group in its structure, and known resins can be appropriately selected and used. Examples include polyamine resins, polyamide resins, and polyallylamine resins. Polyamine resins are resins that have an amino group in the main skeleton of the resin. Polyamide resins are resins that have an amide group in the main skeleton of the resin. Polyallylamine resins are resins that have a structure derived from an allyl group in the main skeleton of the resin.

[0040] Examples of the polyamine resins mentioned above include Unisense KHE103L (hexamethylenediamine / epichlorohydrin resin, aqueous solution with a solid content of 50% by mass) and Unisense KHE104L (dimethylamine / epichlorohydrin resin, aqueous solution with a solid content of 20% by mass), both manufactured by Senka Co., Ltd. Furthermore, specific examples of commercially available cationic polyamine resins include Arafix 100, 251S, 255, 255LOX (trade names, manufactured by Arakawa Chemical Co., Ltd.), DK-6810, 6853, 6885 (trade names, manufactured by Seikoh PMC Co., Ltd.), and Catiomaster (registered trademark) PD-1, 7, 30, A, PDT-2, PE-10, PE-30, DT-EH, EPA-SK01, TMHMDA-E (trade names, manufactured by Yokkaichi Gosei Co., Ltd.).

[0041] Examples of the polyamide resins mentioned above include Sepolion NE205 (trade name, manufactured by Sumitomo Seika Co., Ltd.).

[0042] Examples of polyallylamine resins include polyallylamine hydrochloride, polyallylamine amide sulfate, allylamine hydrochloride / diallylamine hydrochloride copolymer, allylamine acetate / diallylamine acetate copolymer, allylamine acetate / diallylamine acetate copolymer, allylamine hydrochloride / dimethylallylamine hydrochloride copolymer, allylamine / dimethylallylamine copolymer, polydiallylamine hydrochloride, polymethyldiallylamine hydrochloride, polymethyldiallylamine amide sulfate, polymethyldiallylamine acetate, polydiallyldimethylammonium chloride, diallylamine acetate / sulfur dioxide copolymer, diallylmethylethylammonium ethyl sulfate / sulfur dioxide copolymer, methyldiallylamine hydrochloride / sulfur dioxide copolymer, diallyldimethylammonium chloride / sulfur dioxide copolymer, and diallyldimethylammonium chloride / acrylamide copolymer. Furthermore, the content ratio of the above flocculant in the above treatment liquid is preferably 0.5 to 20% by mass, and more preferably 3 to 10% by mass. Furthermore, even when the flocculant is shared in a solution or dispersion, it is preferable that the solid content is within the above range.

[0043] Examples of cationic surfactants that can be used include primary, secondary, and tertiary amine salt compounds, alkylamine salts, quaternary alkylammonium salts, alkylpyridinium salts, sulfonium salts, phosphonium salts, etc. Specifically, examples include hydrochloride salts and acetate salts of laurylamine, coconutamine, rosinamine, etc., lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, benzyltributylammonium chloride, benzalkonium chloride, cetylpyridinium chloride, cetylpyridinium bromide, dihydroxyethyllaurylamine, etc. These can be used individually or in combination of two or more.

[0044] <Organic compounds> The above treatment solution contains an organic compound that satisfies the conditions of (A) above.

[0045] In the above equation (1), R1 represents a linear or branched C5-C10 hydrocarbon group. Examples of the linear or branched C5-C10 hydrocarbon group include, for example, n-pentyl group, isopentyl group, neopentyl group, sec-pentyl group, tert-pentyl group, 2-methylbutyl group, 1-ethylpropyl group, 1,2-dimethylpropyl group, n-hexyl group, isohexyl group, neohexyl group, sec-hexyl group, tert-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 2,2-dimethylbutyl group, 2-ethylbutyl group, n-heptyl group, isoheptyl group, sec-heptyl group, tert-heptyl group, n-octyl group, isooctyl group, n-nonyl group, isononyl group, sec-nonyl group, n-decyl group, etc., and R 1 is preferably a linear or branched C5-C7 hydrocarbon group. As the organic compound represented by the above formula (1), 1,2-heptanediol, 1,2-octanediol, and 1,2-nonanediol are preferred.

[0046] In the above formula (2), R 2 represents a linear or branched C6-C7 hydrocarbon group. Examples of the linear or branched C6-C7 hydrocarbon group include, for example, n-hexyl group, isohexyl group, neohexyl group, sec-hexyl group, tert-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 2,2-dimethylbutyl group, 2-ethylbutyl group, n-heptyl group, isoheptyl group, sec-heptyl group, tert-heptyl group, etc., and R 2 is preferably a linear or branched C6 hydrocarbon group, etc. As the organic compound represented by the above formula (2), diethylene glycol monohexyl ether and ethylene glycol monohexyl ether are preferred. Also, n1 represents 1 or 2, and 2 is preferred.

[0047] In the above formula (3), R 3This represents a linear or branched C7-C12 hydrocarbon group. Examples of linear or branched C7-C12 hydrocarbon groups include n-heptylene group, 1-methylhexylene group, 2-methylhexylene group, 3-methylhexylene group, 1,5-dimethylpentylene group, 2,4-dimethylpentylene group, n-octylene group, 1-methylheptylene group, 2-methylheptylene group, 3-methylheptylene group, 4-methylheptylene group, 1,6-dimethylhexylene group, 2,5-dimethylhexylene group, 2-ethylpentylene group, 2-ethyl-1-propylpropylene group, n-nonylene group, 1-methyl Examples of such groups include methyloctylene group, 2-methyloctylene group, 3-methyloctylene group, 4-methyloctylene group, 1,7-dimethylheptylene group, 2,6-dimethylheptylene group, 3,5-dimethylheptylene group, 2-butyl-2-ethylpropylene group, n-decylene group, n-undecylene group, n-dodecylene group, etc., and the organic compound represented by formula (3) above is preferably 1,8-octanediol, 1,7-heptanediol, 1,9-nonanediol, or 2-butyl-2-ethyl-1,3-propanediol.

[0048] In the above equation (4), R 4 n2 represents a phenyl group or a benzyl group, and is preferably a phenyl group. Also, n2 represents 1 or 2, and is preferably 2. The organic compound represented by the above formula (4) is preferably ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monophenyl ether, or diethylene glycol monobenzyl ether.

[0049] The C4-C5 alkanediols mentioned above are preferably 1,5-pentanediol and 1,4-butanediol.

[0050] In the above equation (5), R 5 This represents a hydrogen atom or a methyl group.

[0051] In the above formula (6), R 6This represents a linear or branched C1-C4 hydrocarbon group. Examples of linear or branched C1-C4 hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups. Furthermore, n3 represents 1 or 2, and is preferably 2.

[0052] In the above-mentioned treatment solution, if the total content of compound a is A and the total content of compound c is C, it is preferable that the relationship C > A is satisfied, more preferably that the value obtained by C / A is in the range of 2 to 100, even more preferably in the range of 3 to 30, and particularly preferably in the range of 4 to 20.

[0053] In the above-mentioned treatment solution, if the total content of compound b is B and the total content of compound c is C, it is preferable that the relationship C > B is satisfied, more preferably that the value obtained by C / B is in the range of 2 to 1000, even more preferably in the range of 3 to 100, particularly preferably in the range of 5 to 30, and especially preferably in the range of 8 to 20.

[0054] In the above-mentioned treatment solution, the total mass content of compound b is preferably 0.01 to 2% by mass, more preferably 0.05 to 1% by mass, and even more preferably 0.3 to 0.8% by mass. Compound a is a highly hydrophobic compound and has the property of easily orienting at the interface between the processing liquid and air (the surface of the processing liquid) after the processing liquid has landed on the recording medium. This property is thought to reduce the surface tension of the processing liquid and promote the wetting spread of the processing liquid on the recording medium, thereby exhibiting excellent wettability. Compound b is a compound that is easily orienting at the interface between the processing liquid and the recording medium after the processing liquid has landed on the recording medium. This property is thought to reduce the interfacial tension generated at the interface between the processing liquid and the recording medium and promote the wetting spread of the processing liquid on the recording medium, thereby exhibiting excellent wettability. Compound c is a compound with a balanced hydrophilicity and hydrophobicity and is soluble in water, compounds a, and b contained in the processing liquid. This property is thought to enable the stable dissolution of compounds a and b even in processing liquids where water accounts for the majority of the total mass of the processing liquid, thereby preventing phase separation of the processing liquid. It is also thought to have the property of improving the solubility of the coagulant in the processing liquid.

[0055] The pH of the above-mentioned treatment solution is preferably 1.0 to 10.0, more preferably 2.0 to 9.0, and even more preferably 3.0 to 9.0.

[0056] The treatment solution according to this embodiment may contain additives such as surfactants, fungicides, preservatives, pH adjusters, chelating reagents, rust inhibitors, defoaming agents, water-soluble ultraviolet absorbers, antioxidants, and resin emulsions, as needed. The content of each additive can be arbitrarily set depending on the application of the treatment solution.

[0057] Examples of surfactants include anionic, nonionic, silicone, and fluorine-based surfactants. Among these, surfactants selected from silicone-based and fluorine-based surfactants are preferred, and silicone-based surfactants are more preferred from the viewpoint of safety for living organisms and the environment.

[0058] Examples of anionic surfactants include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, polyoxyethylene alkyl ether sulfates, N-acyl amino acids or their salts, N-acyl methyl taurates, alkyl sulfates, polyoxyalkyl ether sulfates, alkyl sulfates, polyoxyethylene alkyl ether phosphates, rosinic acid soaps, castor oil sulfates, lauryl alcohol sulfates, alkylphenol type phosphates, alkyl type phosphates, alkylaryl sulfonates, diethyl sulfosulfate, diethylhexyl sulfosulfate, and dioctyl sulfosulfate.

[0059] Nonionic surfactants include, for example, ether-based surfactants such as polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, and polyoxyethylene distyrenated phenyl ether (e.g., Emulgen A-60, A-90, A-500 manufactured by Kao Corporation); polyoxyethylene oleate ester, polyoxyethylene distearate ester, sorbitan laurate, and sorbitan monostearate. Examples include ester-based compounds such as sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, and polyoxyethylene stearate; acetylene glycol (or acetylene alcohol)-based compounds such as 2,4,7,9-tetramethyl-5-decine-4,7-diol, 3,6-dimethyl-4-octin-3,6-diol, and 3,5-dimethyl-1-hexyn-3-ol (for example, Surfinol 104, 104PG50, 82, 420, 440, 465, 485; Olfin STG; etc., manufactured by Evonik Japan Co., Ltd.); and polyglycol ether-based compounds.

[0060] Examples of silicone-based surfactants include polyether-modified siloxanes and polyether-modified polydimethylsiloxanes. Examples include Dynol 960 and 980 from Air Products Inc.; Silface SAG001, SAG002, SAG003, SAG005, SAG503A, SAG008, SAG009, and SAG010 from Nisshin Chemical Industry Co., Ltd.; BYK-345, 347, 348, 349, 3450 (also known as BYKLPX 23289), 3451 (also known as BYKLPX 23347), 3455, LP-X23288, and LP G20726 from BIC Chemie Japan Inc.; and TEGO® Twin 4000, TEGO® Wet KL 245, 250, 260, 265, 270, and 280 from Evonic Tego Chemie Inc.

[0061] Examples of fluorinated surfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in their side chains. Examples of commercially available products include Capstone FS-30 and FS-31 manufactured by Chemors.

[0062] Examples of antifungal agents include sodium dehydroacetate, sodium benzoate, sodium pyridinethion-1-oxide, ethyl p-hydroxybenzoate, 1,2-benzisothiazolin-3-one, and their salts.

[0063] Examples of preservatives include compounds such as organic sulfur, organic nitrogen sulfur, organic halogen, haloaryl sulfone, iodopropagyl, haloalkylthio, nitrile, pyridine, 8-oxyquinoline, benzothiazole, isothiazolin, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane, dithiocarbamate, brominated indanone, benzyl bromacetate, and inorganic salts. Specific examples of organic halogen compounds include, for example, sodium pentachlorophenol. Specific examples of pyridine oxide compounds include, for example, sodium 2-pyridinethiol-1-oxide. Specific examples of isothiazolin compounds include, for example, 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, and 2-methyl-4-isothiazolin-3-one calcium chloride. Specific examples of other preservatives and fungicides include, for example, anhydrous sodium acetate, sodium sorbate, sodium benzoate, and Arch Chemical's trade names Proxel GXL(S), Proxel LV, and Proxel XL-2(S).

[0064] Examples of pH adjusting agents include alkanolamines such as diethanolamine, triethanolamine, and N-methyldiethanolamine; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; ammonium hydroxide (ammonia water); alkali metal carbonates such as lithium carbonate, sodium carbonate, sodium bicarbonate, and potassium carbonate; alkali metal salts of organic acids such as sodium silicate and potassium acetate; and inorganic bases such as disodium phosphate. However, if an excessive amount of pH adjusting agent is added, it may inhibit the function of cationic polymer compounds in the pretreatment solution, so it is necessary to adjust the amount added so that the pH of the pretreatment solution falls within the above-mentioned suitable range.

[0065] Examples of chelating reagents include disodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, and sodium uracildiacetate.

[0066] Examples of rust inhibitors include acidic sulfites, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitride, pentaerythritol tetranitrate, and dicyclohexylammonium nitride.

[0067] Examples of defoaming agents include silicone-based, silica mineral oil-based, olefin-based, and acetylene-based compounds. Examples of commercially available defoaming agents include Surfinol DF37, DF58, DF110D, DF220, MD-20, and Olfin SK-14, manufactured by Shin-Etsu Chemical Co., Ltd.

[0068] Examples of water-soluble ultraviolet absorbers include sulfonated benzophenone compounds, benzotriazol compounds, salicylic acid compounds, cinnamic acid compounds, and triazine compounds.

[0069] As antioxidants, for example, various organic and metal complex-based colorfastness inhibitors can be used. Examples of organic colorfastness inhibitors include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocyclic compounds.

[0070] The treatment solution according to this embodiment may contain a resin emulsion for the purpose of improving the durability of the printed material after ink deposition. The inclusion of a resin emulsion in the treatment solution according to this embodiment tends to improve water resistance, adhesion, tape peel resistance, and abrasion resistance. At least one of polymer emulsions and wax emulsions is preferred as the resin emulsion. Examples of the resin emulsion include cationic urethane polymers and cationic acrylic polymers.

[0071] When the processing solution according to this embodiment contains a resin emulsion, its solid content is preferably 1 to 20% by mass, and more preferably 3 to 15% by mass. A solid content of 1% by mass or more of the resin emulsion tends to exhibit water resistance, adhesion, tape peel resistance, and abrasion resistance. Furthermore, a solid content of 20% by mass or less of the resin emulsion tends to improve storage stability and, in the case of inkjet printing, ejection suitability.

[0072] The method for preparing the treatment solution according to this embodiment is not particularly limited, and known preparation methods can be employed. For example, one method is to prepare an aqueous solution or aqueous dispersion containing a flocculant, and then mix this aqueous solution or aqueous dispersion with water, organic compounds such as compounds a to c mentioned above, and additives as needed.

[0073] The recording medium is not particularly limited, but a recording medium that is poorly absorbent or non-absorbent is preferred, and a recording medium that is non-absorbent is more preferred. Examples of poorly absorbent recording media include plain paper without an ink-receiving layer, media used in gravure printing and offset printing, art paper, coated paper, matte paper, and cast paper. Examples of non-absorbent recording media include PET (polyethylene terephthalate) film, PP (polypropylene) film, vinyl chloride sheet, glass, and rubber, and paper or a non-absorbent recording medium is preferred.

[0074] An image forming method according to one embodiment of the present invention involves recording on the above-mentioned recording medium using the above-mentioned processing liquid and inkjet recording ink.

[0075] One embodiment of such a recording method is, for example, a processing step in which a processing liquid and an ink composition for inkjet recording are applied to a recording medium, and an image is formed by bringing the processing liquid and ink into contact with the recording medium. In the application step, a processing liquid application step may be performed after an image recording step in which an image consisting of ink is recorded on the recording medium, in which the processing liquid is applied to the image. However, from the viewpoint of improving the image quality of the recorded image, it is preferable to perform the image recording step after the processing liquid application step. Preferably, the process includes a step of applying the processing liquid to the recording medium and a step of applying an aqueous color ink containing a coloring agent to the portion of the recording medium to which the processing liquid has been applied. The application step will be described in detail below, with the case in which the image recording step is performed after the processing liquid application step as an example.

[0076] <Processing solution application process> As described above, in the application step, it is preferable to perform a processing liquid application step in which the processing liquid is applied in advance to the area on the recording medium where the image will be formed, prior to the image recording step. Any of the following methods can be used to apply the processing liquid: spin coating, spray coating, gravure roll coating, reverse roll coating, bar coating, inkjet method, etc. Among these, the inkjet method (inkjet recording method) is preferred. When using the inkjet method, droplets of the processing liquid are ejected from the nozzle of the inkjet recording head and adhered to the recording medium. The processing liquid described above tends to have good ejection stability when ejecting the processing liquid from the nozzle because its surface tension can be easily set to a value suitable for the inkjet recording method due to the organic compounds it contains. In the processing liquid application step, it is preferable to coat the processing liquid using an inkjet or anilox roller. An anilox roller is a roller whose surface, which has been sprayed with ceramic, is processed with a laser to create shapes such as pyramids, diagonal lines, or hexagonal patterns. The anilox roller allows processing liquid to enter the recesses on its surface and transfer to the recording medium upon contact. In this case, the amount of processing liquid applied can be controlled according to the size of the recesses in the anilox roller. Examples of anilox rollers that can be used include ceramic anilox rollers with cell engraving and chrome-plated anilox rollers. Cell shapes can include honeycomb patterns, diamond patterns, helical patterns, etc., and any of these patterns can be used.

[0077] <Application amount> When the processing solution is applied to the recording medium, the amount of coagulant contained in the processing solution that adheres to it is 0.01 g / m². 2 More than 7.0g / m 2 It is preferable that it be applied in the following manner: 0.05 g / m 2 More than 5g / m 2 It is more preferable that the amount is applied as follows: 0.05 to 4.0 g / m² 2It is even more preferable that the amount of flocculant applied is 0.01 mmol / m 2 By applying the colorant in the above manner, the aggregation of the colorant can be promoted, resulting in good image quality. Furthermore, the amount of coagulant applied is 7.0 g / m². 2 By applying the solution as described below, the precipitation of the coagulant from the recording unit can be suppressed, and the amount of processing solution applied can be reduced, thereby shortening the drying time of the processing solution and enabling faster recording.

[0078] After the processing solution application step and before the image recording step, the process may include a step to dry the processing solution applied to the recording medium. In this case, it is preferable to dry the processing solution to the point where it is no longer sticky to the touch. The drying step of the processing solution may be performed by natural drying, but from the viewpoint of improving the drying speed, it is preferable to perform drying with heat. If the drying step of the processing solution involves heating, the heating method is not particularly limited, but examples include a print heater mechanism that heats the recording medium by bringing it into contact with a heat source, a mechanism that irradiates with infrared rays, or a hot air drying mechanism using a dryer. It is preferable to perform drying after the step of applying the processing solution to the recording medium, and then perform the step of applying ink.

[0079] <Image recording process> In the application process, it is preferable to perform the image recording process after the processing liquid application process described above. The image recording process is a process in which, after the processing liquid application process described above, droplets of inkjet recording ink are attached to the area to which the processing liquid has been applied, thereby recording an image. As a result, the colorants contained in the ink react with the flocculants contained in the processing liquid, improving the color development of the recorded image.

[0080] The image recording process involves ejecting the aforementioned ink droplets from the nozzles of an inkjet recording head and bringing them into contact with a processing solution applied to the recording medium to record an image.

[0081] The method for preparing the processing solution according to this embodiment is not particularly limited, and known preparation methods can be employed. One example is a method in which the appropriate additive components listed above are added, stirred and mixed, and then filtered as necessary.

[0082] The processing solution according to this embodiment is preferably microfiltered. A membrane filter, glass filter paper, or the like can be used for microfiltration. The pore size of the filter when performing microfiltration is usually 0.5 to 20 μm, preferably 0.5 to 10 μm.

[0083] The above processing solution also exhibits excellent drying properties, fixing properties, storage stability, and inkjet ejection stability on the media.

[0084] The present invention also includes a treated recording medium obtained by applying the above-mentioned processing solution to the recording medium, a method for manufacturing a treated recording medium by applying the above-mentioned processing solution to the recording medium, and a method for manufacturing a treated recording medium in which the recording medium is a paper substrate or a non-absorbent recording medium.

[0085] The present invention also includes a set of the above-mentioned processing liquid and ink, a set of the above-mentioned processing liquid and multiple inks, and a set of the above-mentioned processing liquid and ink or multiple inks and a recording medium.

[0086] For all the matters mentioned above, a combination of desirable items is more desirable, and a combination of more desirable items is even more desirable. The same applies to combinations of desirable items and more desirable items, and combinations of more desirable items and even more desirable items, and so on. [Examples]

[0087] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, unless otherwise specified, "parts" means parts by mass and "%" means mass percent.

[0088] [Examples 1-25] and [Comparative Examples 1-7]: Preparation of treatment solution. After mixing the components listed in Tables 1-3 below, the mixtures were filtered through a 5 μm membrane filter to obtain the treatment solutions for Examples 1-25 and Comparative Examples 1-7 for evaluation testing. The abbreviations in Tables 1-3 represent the following: DK-6850: Cationic polymer (manufactured by Seikoh PMC, solids content 50%) Hydran CP-7050: Cationic urethane polymer (manufactured by DIC Corporation, solids content 25%) MW6950: Movinyl 6950 Cationic Acrylic Polymer (manufactured by Japan Coating Resin Co., Ltd., solids content 45%)

[0089] [Table 1]

[0090] [Table 2]

[0091] [Table 3]

[0092] <Rating> [Solubility evaluation] The solubility of the mixed solutions with the compositions of Examples 1-27 and Comparative Examples 1-12 was evaluated. The results are shown in Table 4 below. If the solubility is insufficient, the uniformity of the treatment solution will decrease and the wettability effect will not be fully realized, so it is practically preferable that the evaluation criterion below is A. -Soluble Evaluation Criteria- A: A state that is uniform and completely mixed. B: There are no oil droplets on the surface of the liquid, but it is suspended and not completely dissolved. C: Oil droplets are floating on the surface of the mixture, indicating that it is not completely dissolved. D: The components in the mixture have separated and are not completely dissolved. [Contact angle evaluation] Using PET film (Toyobo Co., Ltd., E5102) as the substrate, the contact angle between each treatment solution obtained above and the PET film was measured and evaluated according to the evaluation criteria below. Specifically, a DM-501Hi (Kyowa Interface Science Co., Ltd.) was used as the contact angle meter, and with a droplet volume of 2 μL, the contact angle 10 seconds after the treatment solution hit the film was measured at 25°C. The results are shown in Tables 4 to 6 below. A lower contact angle value indicates that the treatment solution wets and spreads well over the PET film, so it is practically preferable that the evaluation criteria below are B or higher. In Table 6 below, "-" indicates that the materials of the treatment solution were not mixed, and therefore evaluation as a treatment solution was not possible. -Contact Angle Evaluation Criteria- A: Contact angle ≦18° B:18°<contact angle≦24° C:24°<contact angle≦30° D:30°<contact angle

[0093] [Table 4]

[0094] [Evaluation of treatment solution coating] Using PET film (manufactured by Toyobo Co., Ltd., E5102) as the substrate, the treatment solutions from examples 1 to 25 above were applied using a bar coater No. 0. Drying was performed at 70°C for 2 minutes. In all cases, a good coating film was formed.

[0095] <Preparation Example 1: Preparation of Magenta Dispersion> Joncyrl 68 (BASF, mass-average molecular weight: 13000) (11.3 parts) and triethanolamine (6 parts) were dissolved in deionized water (95.2 parts) and stirred for 1 hour. CIPigmentRed 122 (Clariant, InkjetMagentaE02) (37.5 parts) was added to the resulting solution and the mixture was dispersed using a sand grinder at 1500 rpm for 20 hours. After adding deionized water (150 parts) dropwise to the resulting dispersion, the solution was filtered to remove the dispersion beads, yielding a magenta dispersion with a solid content of 15.8%. <Preparation Example 2: Preparation of Cyanide Dispersion> Joncyrl 68 (BASF, mass-average molecular weight: 13000) (9 parts) and triethanolamine (6 parts) were dissolved in deionized water (75 parts) and stirred for 1 hour. To the resulting solution, CIPigment Blue 15:4 (Dainichi Seika Kogyo Co., Ltd., Chromofine blue 4851) (30 parts) was added, and the mixture was dispersed in a sand grinder at 1500 rpm for 15 hours. Deionized water (40 parts) was added dropwise to the resulting liquid, and the dispersion beads were removed by filtration to obtain a cyanide dispersion with a pigment solid content of 18.7%. <Ink preparation example> The cyanide and magenta dispersions obtained in Preparation Examples 1 and 2 were mixed with the components listed in Table 5 below, and then filtered through a 3 μm pore size membrane filter to obtain the inks of Preparation Examples 1 and 2. In the total mass of the ink, the numerical values ​​in the column for each component in Table X represent the amount (parts) of that component used, and "-" means that the component was not used. Details of the resin emulsions in Table X are as follows. DPnP: Dipropylene glycol monopropyl ether. BDG: Diethylene glycol monobutyl ether. BYK349: Silicone-based surfactant (manufactured by BIC Chemie Japan Co., Ltd., BYK-349). A-1127: NeoCryl A-1127 (Acrylic resin emulsion, manufactured by DSMCoatingResin, solids content 44.0%)

[0096] [Table 5]

[0097] [Print Image Evaluation] Images were formed on substrates coated with the processing solution using the inks obtained in Preparation Examples 1 and 2 with an inkjet head KJ4B-1200 (manufactured by Kyocera Corporation). The image was created by printing the ink from Preparation Example 1 in a 1 cm width (A), and then printing a 2 mm thick line in a cross shape on (A) using the ink from Preparation Example 2 (B). The obtained prints were evaluated by measuring the width of the line (B) on the print (A) and by measuring the width of the line (B) on the substrate, not on the print (A), to calculate the line width expansion rate. It was found that when printing on substrates coated with the processing solutions of Examples 1 to 25, a good printed image could be formed with a line width expansion rate of 10% or less. [Inkjet Printing Evaluation] When the inks obtained in Preparation Examples 1 and 2 were used to form images on paper and PET film, respectively, using an inkjet head KJ4B-1200 (manufactured by Kyocera Corporation), both showed good ink ejection and good image formation.

[0098] From the results in Tables 4 and 5 above, the treatment solution of the example is at least superior in wettability compared to the treatment solution of the comparative example, and its solubility is also equivalent to or better. In other words, the treatment solution of the example is an excellent treatment solution that combines solubility, wettability, and dischargeability. [Industrial applicability]

[0099] The ink of the present invention exhibits excellent solubility of processing solutions and wettability to media, making it extremely useful as a processing solution for various recording applications, particularly inkjet recording applications.

Claims

1. A processing solution used in a recording method using water-based inkjet ink, wherein the processing solution contains at least water, a coagulant for coagulating the components of the ink, and an organic compound, and the organic compound satisfies the following condition (A). (A) Compound a: At least one compound selected from the compound represented by the following formula (1) and the compound represented by the following formula (2); Compound b: At least one compound selected from the compounds represented by the following formula (3) and the compounds represented by the following formula (4); Compound c: At least one compound selected from the group consisting of C4-C5 alkanediols, compounds represented by the following formula (5), and compounds represented by the following formula (6); Includes. 【Chemistry 1】 (In formula (1), R １ (This represents a linear or branched C5-C10 hydrocarbon group.) 【Chemistry 2】 (In formula (2), R ２ (where n1 represents a linear or branched C6-C7 hydrocarbon group, and n1 represents 1 or 2.) 【Transformation 3】 (In formula (3), R ３ (This represents a linear or branched C7-C12 hydrocarbon group.) 【Chemistry 4】 (In formula (4), R ４ (where n2 represents a phenyl group or a benzyl group, and n2 represents 1 or 2.) 【Transformation 5】 (In formula (5), R ５ (This represents a hydrogen atom or a methyl group.) 【Transformation 6】 (In formula (6), R ６ (where n3 represents a linear or branched C1-C4 hydrocarbon group, and n3 represents 1 or 2.)

2. The treatment solution according to claim 1, wherein, when the total content of compound a in the treatment solution is A and the total content of compound c is C, the relationship C > A is satisfied.

3. The treatment liquid according to claim 1 or 2, wherein the flocculant comprises at least one selected from the group consisting of polyvalent metal salts, organic acids, and cationic resins.

4. A processed recording medium having been coated with the processing solution described in claim 1 or 2.

5. The processed recording medium according to claim 4, wherein the recording medium is paper or an ink-non-absorbent recording medium.

6. A method for manufacturing a processed recording medium, comprising applying the processing solution described in claim 1 or 2 to the recording medium.

7. The method for manufacturing a processed recording medium according to claim 6, wherein the recording medium is a paper substrate or a non-absorbent recording medium.

8. A method for manufacturing a processed recording medium according to claim 6, wherein the processing solution according to claim 1 or 2 is applied by an inkjet or an anilox roller.

9. An ink set comprising the processing solution described in claim 1 or 2 and an aqueous inkjet ink containing a coloring agent.

10. A step of applying the processing liquid according to claim 1 or 2 to a recording medium, An image forming method comprising the step of applying an aqueous color ink containing a coloring agent to the portion of the recording medium to which the processing liquid has been applied.

11. The amount of the processing solution applied to the recording medium according to claim 1 or 2 is 0.05 to 4.0 g / m². ２ An image formation method.

12. An image forming method according to claim 8, comprising the steps of applying a processing liquid to a recording medium, drying it, and then applying ink.

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