Inkjet recording treatment liquid

Abstract

To provide an inkjet recording treatment liquid, an ink set for inkjet recording, a surface-treated recording medium, an inkjet recording method, and use as an inkjet recording pretreatment liquid, which can achieve high-quality printed matter combining favorable dot expandability and excellent image uniformity, even when the treatment liquid is applied to a low-permeability recording medium and then subjected to a thermal drying step.SOLUTION: An inkjet recording treatment liquid comprising a polyoxyethylene ether compound (A) having an aromatic ring, a flocculant (B'), and water, wherein the content of the compound (A) is 3 mass% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a treatment liquid for inkjet recording, an ink set for inkjet recording, a surface-treated recording medium, an inkjet recording method, and use as a pretreatment liquid for inkjet recording. [Background technology]

[0002] Inkjet recording methods have many advantages, such as not requiring plate making, being easily adaptable to variable printing, and not contacting the printed material, and therefore are becoming increasingly popular in a wide range of fields, including office and home use. In recent years, attempts have been made to expand the use of inkjet recording methods to commercial printing and industrial printing applications, which require significantly larger print volumes, and there is a demand for inkjet recording methods to print on a variety of recording media. In response to such demands, a method has been proposed in which a treatment liquid is applied to the recording medium in advance, before the ink is applied to the recording medium, to intentionally aggregate solid components contained in the ink, such as coloring materials and resins, thereby forming an ink aggregation layer on the recording medium.

[0003] For example, Patent Document 1 describes that by using a treatment liquid containing 1,4-cyclohexanedimethanol, a polyvalent metal salt, and water to treat a recording medium used in inkjet recording, it is possible to obtain high-quality printed matter that combines good dot expandability and excellent image uniformity when using a recording medium with low permeability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2023 / 199982 Summary of the Invention [Problem to be solved by the invention]

[0005] With the recent increase in printing speed, when forming an image using ink by inkjet recording on a recording medium whose surface has been treated with a treatment liquid, the treatment liquid can reduce the drying speed of the ink, and the image forming unit can transfer the ink to the transport roller of the printing press, resulting in ink staining of the transport roller. In order to prevent such ink staining of the transport roller and in response to demands for improved handling, such as storage, of recording media whose surface has been treated with a treatment liquid when the application of the treatment liquid to the recording medium and the printing process on the printing press are performed in separate processes, a heat-drying process may be performed after the application of the treatment liquid. However, the technology disclosed in Patent Document 1 provides insufficient performance when the heat-drying process is performed after the application of the treatment liquid to a low-permeability recording medium, and it has been found that there is room for improvement. An object of the present invention is to provide a treatment liquid for inkjet recording, an ink set for inkjet recording, a surface-treated recording medium, and an inkjet recording method that are capable of producing high-quality printed matter that combines good dot expandability and excellent image uniformity, even when a heat drying step is performed after the treatment liquid is applied to a low-permeability recording medium. [Means for solving the problem]

[0006] The present inventors have found that the above-mentioned problems can be solved by a treatment liquid for inkjet recording, which contains a polyoxyethylene ether compound having an aromatic ring, one or more compounds selected from the group consisting of a polyvalent metal salt, a polyvalent amine, and an organic acid, and water, and in which the content of the polyoxyethylene ether compound having an aromatic ring is a predetermined value or more. That is, the present invention provides the following [1] to [5]. [1] A method for producing a flocculant comprising: (A) a polyoxyethylene ether compound having an aromatic ring; (B') a flocculant; and (B') water; The treatment liquid for inkjet recording contains the compound (A) in an amount of 3% by mass or more. [2] An ink set for inkjet recording, comprising the treatment liquid for inkjet recording according to [1] above, and an ink containing a colorant and water. [3] A surface-treated recording medium that has been treated using the treatment liquid for inkjet recording described in [1] above. [4] An inkjet recording method using the inkjet recording treatment liquid according to [1] above, comprising the following steps 1 and 2: Step 1: A step of applying the treatment liquid to a recording medium and then heating and drying the same to obtain a surface-treated recording medium. Step 2: A step of forming an image on the treated surface of the surface-treated recording medium obtained in Step 1 by an inkjet recording method using an ink containing a colorant and water. [5] A composition comprising: (A) a polyoxyethylene ether compound having an aromatic ring; (B) one or more compounds selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids; and water; Use of a composition containing the compound (A) in an amount of 3% by mass or more as a pretreatment liquid for inkjet recording. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a treatment liquid for inkjet recording, an ink set for inkjet recording, a surface-treated recording medium, and an inkjet recording method that are capable of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, even when a heat drying step is performed after the treatment liquid is applied to a low-permeability recording medium. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Inkjet recording processing liquid] The treatment liquid for inkjet recording of the present invention (hereinafter also simply referred to as "treatment liquid") contains a polyoxyethylene ether compound (A) having an aromatic ring (hereinafter also referred to as "compound (A)"), a coagulant (B'), and water, and the content of compound (A) is 3 mass% or more. In the present invention, the term "aromatic ring-containing polyoxyethylene ether compound" refers to an ether compound having one or more aromatic rings and two or more ethylene oxide-derived units in one molecule. In the present invention, "containing a polyoxyethylene ether compound (A) having an aromatic ring, a flocculant (B'), and water" also means "comprised of a blend of a polyoxyethylene ether compound (A) having an aromatic ring, a flocculant (B'), and water."

[0042] From the viewpoint of being able to obtain printed matter of high print quality in image formation by an inkjet recording system, the treatment liquid of the present invention is preferably used for treating a recording medium to be used in inkjet recording, and more preferably for treating a low-permeability recording medium to be used in inkjet recording. In other words, the treatment liquid of the present invention is preferably used as a pretreatment liquid for inkjet recording.

[0009] According to the present invention, even when a treatment liquid is applied to a low-permeability recording medium and then a heat drying process is performed, it is possible to obtain high-quality printed matter that combines good dot spreadability and excellent image uniformity. The reason for this is not entirely clear, but is thought to be as follows. The polyoxyethylene ether compound having an aromatic ring contained in the treatment liquid of the present invention contains units derived from ethylene oxide, which have a high affinity with the solvent component in the ink. It is therefore thought that when an ink for inkjet recording lands on a recording medium that has been treated with the treatment liquid of the present invention, the units derived from ethylene oxide greatly improve the wettability of the ink with respect to the recording medium, thereby enabling the ink dots to expand. Furthermore, since the polyoxyethylene ether compound having an aromatic ring has a highly hydrophobic aromatic ring in the molecule, when a resin component is contained in the ink for inkjet recording, the compound has the effect of swelling the resin component in the ink when the ink that has landed on a recording medium treated with the treatment liquid of the present invention expands, thereby promoting uniform thickening of the entire ink dot and causing uniform aggregation, and is also able to suppress fluctuations in dot expansion behavior due to microscopic non-uniformities in the surface condition of the recording medium, which is thought to improve image uniformity. Furthermore, it is believed that the polyoxyethylene ether compound having the aromatic ring interacts with the resin components and cellulose fibers contained in the coating layer formed on the surface of the low-permeability recording medium because the compound has a highly hydrophobic aromatic ring in the molecule, and remains on the surface even when water and the like have evaporated due to heating and drying, thereby achieving the above-mentioned effects. Furthermore, it is believed that after the treatment liquid of the present invention is applied to a recording medium, the high surfactant effect of the polyoxyethylene ether compound having an aromatic ring causes precipitates of aggregating agents such as polyvalent metal salts, polyvalent amines, and organic acids to be present in small amounts and uniformly on the recording medium. Therefore, when ink is applied by inkjet recording to a recording medium that has been treated with the treatment liquid of the present invention, re-dissolution of the aggregating agents such as polyvalent metal salts, polyvalent amines, or organic acids into the aqueous medium contained in the ink occurs uniformly within the dots, resulting in a uniform aggregating effect and increased viscosity of the ink, which is believed to suppress distortion of the dots and color mixing, thereby further improving image uniformity. In the present invention, whether a recording medium has low or high permeability is determined by the amount of water absorbed by the recording medium when the recording medium is in contact with pure water for 100 ms. The amount of water absorbed can be measured as the amount of water transferred when the recording medium is in contact with pure water for 100 ms using an automatic scanning absorption meter (e.g., KM500win manufactured by Kumagai Riki Kogyo Co., Ltd.) under conditions of 23°C and 50% relative humidity. The term "low permeability" includes both low permeability and non-permeability, and the water absorption is 0 g / m 2 More than 7g / m 2 "High permeability" means that the water absorption is 7 g / m or less. 2 It means to be super.

[0010] <Compound (A)> The treatment liquid of the present invention contains a polyoxyethylene ether compound (A) having an aromatic ring. By containing compound (A), the treatment liquid of the present invention can control the wettability of the ink to a low-permeability recording medium, even when the treatment liquid is applied to the low-permeability recording medium and then subjected to a heat drying process, and can also produce a high-quality printed matter that combines good dot expandability and excellent image uniformity by exhibiting a specific interaction with the flocculant (B') such as a polyvalent metal salt, a polyvalent amine, or an organic acid. The compound (A) can be used alone or in combination of two or more.

[0011] Examples of compound (A) include polyoxyethylene alkylphenyl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene dodecylphenyl ether; polyoxyethylene styrenated phenyl ether (including various polyoxyethylene styrenated phenyl ethers such as polyoxyethylene monostyrenated phenyl ether, polyoxyethylene distyrenated phenyl ether, and polyoxyethylene tristyrenated phenyl ether); polyoxyethylene phenyl ethers such as polyoxyethylene phenyl ether, polyoxyethylene tribenzyl phenyl ether, polyoxyethylene naphthyl ether, polyoxyethylene bisphenol A ether, and polyoxyethylene bisphenol F ether; and polyoxyethylene benzyl ethers such as diethylene glycol monobenzyl ether, triethylene glycol monobenzyl ether, polyoxyethylene benzyl ether (polyoxyethylene monobenzyl ether, and polyoxyethylene dibenzyl ether. Among these, from the viewpoint of dot expandability and image uniformity on low-permeability recording media, polyoxyethylene phenyl ethers are preferred, and more preferred is at least one selected from the group consisting of polyoxyethylene phenyl ether and polyoxyethylene distyrenated phenyl ether.

[0012] The HLB value of compound (A) is the average value of the compounds contained in compound (A). From the viewpoint of dot expandability and image uniformity on a low-permeability recording medium, the HLB value of compound (A) is preferably 20 or less, more preferably 18 or less, even more preferably 16 or less, still more preferably 15 or less, and still more preferably 14 or less, and from the viewpoint of dot expandability and image uniformity on a low-permeability recording medium, it is preferably 10 or more, more preferably 11 or more, and still more preferably 12 or more. In the present invention, the HLB value is a value indicating the affinity of a surfactant for water and oil as a hydrophile-lipophile balance, and can be calculated by the Griffin method using the following formula: Alternatively, the catalog values for each product can be referenced as long as they comply with the Griffin method. HLB value = 20 × [(total formula weight of hydrophilic groups contained in surfactant) / (molecular weight of surfactant)] Examples of the hydrophilic group include a hydroxy group and an ethyleneoxy group.

[0013] Examples of commercially available products of compound (A) include Emulgen A-60, A-90, A-500, and B-66 manufactured by Kao Corporation; Noigen EA-87, EA-127, EA-137, EA-157, EA-167, EA-177, EA-197D, and EA-207D manufactured by Daiichi Kogyo Seiyaku Co., Ltd.; Braunon DSP-9, DSP-12.5, KTSP-16, TSP-50, and PH-5 manufactured by Aoki Oil & Fat Industries Co., Ltd.; and PhG-30 and PhG-55 manufactured by Nippon Nyukazai Co., Ltd.

[0014] <Flocculant (B')> The treatment liquid of the present invention contains a flocculant (B'). The treatment liquid of the present invention contains the aggregating agent (B'), which reduces the dispersibility of dispersoids present in the ink for inkjet recording, causing the dispersoids to aggregate and thereby increase in viscosity and precipitate, thereby suppressing color mixing due to coalescence of ink dots, and improving image uniformity, making it possible to obtain high-quality printed matter. In the present invention, the dispersoids present in the ink for inkjet recording include not only ink components such as pigments that are currently dispersed in the ink in a solid state, but also ink components that are in a dissolved state in the ink but lose their solubility when they come into contact with a recording medium that has been treated with the treatment liquid of the present invention, causing thickening or precipitation. Specific examples of ink components that are in a dissolved state in the ink for inkjet recording but lose their solubility when they come into contact with a recording medium that has been treated with the treatment liquid of the present invention, causing thickening or precipitation, include dyes, water-soluble resins, etc. The reason why the dispersibility or solubility of the dispersoids present in the ink for inkjet recording decreases when the ink comes into contact with a recording medium that has been treated with the treatment liquid of the present invention is thought to be that when the ink comes into contact with a recording medium that has been treated with the treatment liquid of the present invention, precipitates of the aggregating agent (B') present on the recording medium are redissolved in the ink, and the aggregating agent (B') acts to reduce the thickness of the electric double layer that stabilizes the dispersoids present in the ink, making it impossible to prevent the dispersoids from approaching each other. The aggregating agent (B') is not particularly limited as long as it is a component that reduces the dispersibility of dispersoids present in the inkjet recording ink and causes the dispersoids to aggregate, and examples thereof include polyvalent metal salts, polyvalent amines, organic acids, etc., and these may be used alone or in combination of two or more. From the viewpoint of dot expansion and image uniformity on a low-permeability recording medium, the aggregating agent (B') is preferably one or more selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids. That is, the treatment liquid of the present invention preferably contains one or more compounds (B) (hereinafter also referred to as "compound (B)") selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids. Furthermore, from the viewpoint of dot expansion and image uniformity on a low-permeability recording medium, compound (B) is more preferably a polyvalent metal salt. As described above, the treatment liquid of the present invention containing compound (A), aggregating agent (B'), and water is preferably used as a pretreatment liquid for inkjet recording from the viewpoints of dot spreadability and image uniformity on low-permeability recording media. Furthermore, from the same viewpoint, the aggregating agent (B') is preferably the above-mentioned compound (B). In other words, a composition containing a polyoxyethylene ether compound (A) having an aromatic ring, one or more compounds (B) selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids, and water, in which the content of compound (A) is 3% by mass or more, is suitable for use as a pretreatment liquid for inkjet recording.

[0015] [Polyvalent metal salts] Any polyvalent metal salt can be used as long as it is composed of a divalent or higher polyvalent metal ion and an anion (a counterion of the polyvalent metal ion). Examples of divalent or higher polyvalent metal ions include calcium, magnesium, copper, nickel, zinc, barium, aluminum, titanium, strontium, chromium, cobalt, and iron ions. Among these, the polyvalent metal ion constituting the polyvalent metal salt is preferably a divalent or trivalent metal ion, more preferably a divalent metal ion, from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity. Examples of divalent metal ions include ions of elements belonging to Group 2 of the periodic table of elements, such as magnesium ion, calcium ion, and iron(II) ion. Examples of trivalent metal ions include aluminum ion and iron(III) ion. Among these, from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the polyvalent metal ion constituting the polyvalent metal salt is more preferably one or more selected from the group consisting of magnesium ions, calcium ions, and aluminum ions, even more preferably one or more selected from the group consisting of magnesium ions and calcium ions, and even more preferably magnesium ions. The anions constituting the polyvalent metal salt include inorganic ions and organic ions. Examples of inorganic ions include monovalent anions such as nitrate ions and halide ions; and divalent anions such as sulfate ions. The organic ions include organic acid ions such as carboxylate ions. Among these, the anion constituting the polyvalent metal salt is preferably an inorganic ion, more preferably one or more selected from the group consisting of nitrate ion and sulfate ion, and even more preferably nitrate ion, from the viewpoints of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, and of availability and economy.

[0016] From the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the polyvalent metal salt is preferably one or more selected from the group consisting of magnesium nitrate, magnesium sulfate, calcium nitrate, and aluminum nitrate, more preferably one or more selected from the group consisting of magnesium nitrate, calcium nitrate, and aluminum nitrate, even more preferably one or more selected from the group consisting of magnesium nitrate and calcium nitrate, and still more preferably magnesium nitrate. The polyvalent metal salt may have water of hydration in the raw material form. The polyvalent metal salts can be used alone or in combination of two or more.

[0017] [Polyamine] A polyamine is a compound having multiple amino groups in the molecule. The amino group of the polyamine may be ammonia, a primary amine, or a monovalent functional group (-NH, -NHR, -NRR') formed by removing one hydrogen atom from a secondary amine. Here, R and R' represent hydrocarbon groups. The polyamine may also be in the form of a salt. Examples of the salts of polyvalent amines include inorganic acid salts or organic acid salts of polyvalent amines. Examples of inorganic acid salts of polyvalent amines include hydrochlorides, sulfates, nitrates, and phosphates. Examples of organic acid salts of polyvalent amines include carboxylates and sulfonates. Furthermore, the polyvalent amines may be quaternary ammonium salts in which the amino groups are quaternized with a quaternizing agent.

[0018] The polyvalent amine may be an alkanediamine. From the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the alkanediamine is preferably at least one selected from the group consisting of ethylenediamine (1,2-diaminoethane), 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, and 1,8-octamethylenediamine.

[0019] As the polyamine, a polymer having multiple amino groups in the molecule (hereinafter also referred to as "amino group-containing polymer") is preferred from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity. The amino group-containing polymer is preferably a polymer containing a constituent unit derived from a polymerizable monomer having at least one amino group. The amino group-containing polymer may be in the form of a salt or a quaternary ammonium salt in which the amino group is quaternized with a quaternizing agent.

[0020] As the amino group-containing polymer and salt thereof, from the viewpoints of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, and from the viewpoints of availability and economy, one or more types selected from the group consisting of polyethyleneimine, polyvinylamine, polyallylamine, polydiallylmethylamine, polydiallylethylamine, dimethylamine / epichlorohydrin copolymer, dimethylamine / ammonia / epichlorohydrin copolymer, and salts thereof are preferred. As the quaternary ammonium salt of an amino group-containing polymer, from the viewpoints of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, and from the viewpoints of availability and economy, a diallyl quaternized ammonium salt polymer is preferred, and more preferred is one or more selected from the group consisting of polydiallyldimethylammonium chloride, polydiallyldiethylammonium chloride, polydiallylmethylethylammonium ethyl sulfate, diallyldimethylammonium chloride / acrylic acid copolymer, diallyldimethylammonium chloride / acrylamide copolymer, and diallyldimethylammonium chloride / acrylic acid / acrylamide copolymer.

[0021] The polyvalent amine is preferably in the form of a polyvalent amine salt. From the viewpoint of increasing the density of the salt to significantly exhibit the effect of reducing the dispersibility or solubility of dispersoids present in the inkjet recording ink and obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the polyvalent amine salt is preferably a salt of an amino group-containing polymer, more preferably one or more selected from the group consisting of polydiallyldimethylammonium chloride, polydiallylmethylethylammonium ethyl sulfate, dimethylamine / epichlorohydrin copolymer, polyethyleneimine hydrochloride, and polyallylamine hydrochloride, and even more preferably one or more selected from the group consisting of polydiallyldimethylammonium chloride and dimethylamine / epichlorohydrin copolymer. As the salt of the amino group-containing polymer, from the same viewpoint, polydiallyldimethylammonium chloride and dimethylamine / epichlorohydrin copolymer are preferred, and from the viewpoint of dot expandability after drying, polydiallyldimethylammonium chloride is more preferred, and from the viewpoint of image quality uniformity after drying, dimethylamine / epichlorohydrin copolymer is more preferred. The weight-average molecular weight of the amino group-containing polymer salt is preferably 5,000 or more from the viewpoint of increasing the density of the salt and improving the image uniformity of printed matter when using a low-permeability recording medium, and is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 25,000 or less from the viewpoint of suppressing thickening of the treatment liquid, uniformly applying the treatment liquid to the recording medium, and improving the image uniformity of printed matter. The average molecular weight of the amino group-containing polymer salt can be measured by gel permeation chromatography (GPC). When a commercially available product is used as the amino group-containing polymer salt, the average molecular weight of the amino group-containing polymer salt can be determined by referring to the catalog value of each commercially available product. Suitable examples of commercially available salts of amino group-containing polymers include the "PAS" series manufactured by Nittobo Medical Co., Ltd. and the "Unisense" series manufactured by Senka Corporation. The polyamines can be used alone or in combination of two or more.

[0022] [Organic acid] The organic acid may be added to the processing solution in the form of an acid or a salt, but is preferably added in the form of a salt. Preferred examples of the organic acid include monocarboxylic acids such as acetic acid and propionic acid; polycarboxylic acids such as poly(meth)acrylic acid, oxalic acid, malonic acid, maleic acid, succinic acid, glutaric acid, and fumaric acid; hydroxycarboxylic acids such as ascorbic acid, glycolic acid, malic acid, citric acid, tartaric acid, and lactic acid; heterocyclic ring-containing carboxylic acids such as pyrrolidonecarboxylic acid, pyrronecarboxylic acid, pyrrolecarboxylic acid, furancarboxylic acid, pyridinecarboxylic acid, coumaric acid, thiophenecarboxylic acid, and nicotinic acid, and derivatives of these compounds. From the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the organic acid is preferably a hydroxycarboxylic acid, more preferably a hydroxypolycarboxylic acid, even more preferably one or more selected from citric acid, tartaric acid, and lactic acid, and even more preferably lactic acid. The organic acid may be in the form of a salt. However, when the organic acid forms a metal salt, it is included in the above-mentioned polyvalent metal salt. As the salt of the organic acid, an ammonium salt is preferred from the viewpoint of obtaining a high-quality printed matter that combines good dot expandability and excellent image uniformity. The organic acids may be used singly or in combination of two or more.

[0023] From the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the treatment liquid of the present invention preferably contains as compound (A) one or more compounds selected from the group consisting of polyoxyethylene phenyl ether and polyoxyethylene styrenated phenyl ether, and as compound (B) a polyvalent metal salt; more preferably contains as compound (A) one or more compounds selected from the group consisting of polyoxyethylene phenyl ether and polyoxyethylene styrenated phenyl ether, and as compound (B) one or more polyvalent metal salts selected from the group consisting of magnesium nitrate, calcium nitrate, and aluminum nitrate; still more preferably contains as compound (A) one or more compounds selected from the group consisting of polyoxyethylene phenyl ether and polyoxyethylene styrenated phenyl ether, and as compound (B) one or more polyvalent metal salts selected from the group consisting of magnesium nitrate and calcium nitrate; and still more preferably contains as compound (A) one or more compounds selected from the group consisting of polyoxyethylene phenyl ether and polyoxyethylene styrenated phenyl ether, and as compound (B) one or more polyvalent metal salts selected from the group consisting of magnesium nitrate and calcium nitrate.

[0024] <Water> The treatment liquid of the present invention contains water. The water used in the treatment solution of the present invention is preferably pure water or ion-exchanged water from the viewpoint of preventing the inclusion of unintended substances.

[0025] The treatment liquid of the present invention may further contain, as necessary, other components besides the compound (A) and the compound (B), such as a water-soluble organic solvent, a pH adjuster, a surfactant, a colorant, an antifoaming agent, an antiseptic / fungal agent, and a rust inhibitor.

[0026] (Water-soluble organic solvent) The treatment liquid of the present invention may further contain a water-soluble organic solvent, from the viewpoint of ensuring sufficient solubility of compound (A) in the treatment liquid and obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity. Examples of the water-soluble organic solvent include polyhydric alcohols; ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers; nitrogen-containing heterocyclic compounds; amides; amines; and sulfur-containing compounds.

[0027] Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol (1,2-propanediol), 1,3-propylene glycol, dipropylene glycol (isomer mixture), 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3- Examples of diols include pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanediol, 1,7-heptanediol, 1,8-octanediol, and 1,2-octanediol.

[0028] Examples of polyhydric alcohol alkyl ethers include (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, and dipropylene glycol monoethyl ether. Examples of polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether. Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and ε-caprolactam. Examples of amides include formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide. Examples of amines include monoethanolamine, diethanolamine, triethanolamine, and triethylamine. These compounds are also used as pH adjusters. Examples of sulfur-containing compounds include dimethyl sulfoxide, sulfolane, and thiodiethanol. Other examples of water-soluble organic solvents include propylene carbonate and ethylene carbonate.

[0029] Among these, when a water-soluble organic solvent is used, the water-soluble organic solvent is preferably at least one selected from the group consisting of polyhydric alcohols and polyhydric alcohol alkyl ethers, more preferably a polyhydric alcohol, from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity. From the same viewpoint as above, the polyhydric alcohol is preferably a diol, more preferably one or more selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol (1,2-propanediol), 1,3-propylene glycol, dipropylene glycol (mixture of isomers), 1,2-butanediol, 1,3-butanediol, and 1,4-butanediol, and even more preferably one or more selected from the group consisting of diethylene glycol, propylene glycol (1,2-propanediol), and dipropylene glycol (mixture of isomers). From the same viewpoint as above, the polyhydric alcohol alkyl ether is preferably a (poly)alkylene glycol monoalkyl ether, more preferably at least one selected from the group consisting of ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, and triethylene glycol monobutyl ether, and even more preferably at least one selected from the group consisting of diethylene glycol monobutyl ether and triethylene glycol monobutyl ether. The water-soluble organic solvents can be used alone or in combination of two or more.

[0030] (pH adjuster) The processing liquid of the present invention may contain a pH adjuster. The pH adjuster refers to an agent that suppresses pH fluctuations due to environmental changes and maintains the pH of the treatment solution constant. The pH adjuster can be selected arbitrarily depending on the pH of the treatment liquid of the present invention. Examples of basic compounds used as pH adjusters to basify the processing solution of the present invention include alkanolamines such as dimethylethanolamine, diethanolamine, triethanolamine, and N-methyldiethanolamine; primary amines, secondary amines, tertiary amines, and quaternary ammonium salts; aqueous ammonia; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; and alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, and sodium hydrogencarbonate. When the pH adjuster is an alkanolamine, a primary amine, a secondary amine, a tertiary amine, or a quaternary ammonium salt, it is preferable that the amine or quaternary ammonium salt is monovalent. Examples of acidic compounds used as pH adjusters to acidify the treatment solution of the present invention include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and boric acid; organic acids such as acetic acid, citric acid, succinic acid, tartaric acid, malic acid, fumaric acid, malonic acid, ascorbic acid, and glutamic acid; and alkali metal acetates such as lithium acetate and sodium acetate. The pH adjusters can be used alone or in combination of two or more.

[0031] (surfactant) The treatment liquid of the present invention may contain a surfactant. The surfactant is preferably a nonionic surfactant. Examples of nonionic surfactants include polyoxyalkylene alkyl ether surfactants, acetylene alcohol surfactants such as acetylene glycol surfactants, polyhydric alcohol surfactants, fatty acid alkanolamides, silicone surfactants, and fluorine surfactants. Among these, from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the surfactant is preferably an acetylene alcohol surfactant, and more preferably an acetylene glycol surfactant. Examples of acetylene glycol surfactants include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, and ethylene oxide adducts of these diols. Examples of acetylene alcohol surfactants other than acetylene glycol surfactants include 3,5-dimethyl-1-hexyn-3-ol, 2,4-dimethyl-5-hexyn-3-ol, and ethylene oxide adducts of these monools. The sum (n) of the average number of moles of ethyleneoxy groups (EO) added in the ethylene oxide adduct is preferably 0 or more, and is preferably 20 or less, more preferably 10 or less, from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity. Examples of commercially available nonionic surfactants include the "Surfynol" series manufactured by Nissin Chemical Industry Co., Ltd. and Air Products & Chemicals, and the "Acetylenol" series manufactured by Kawaken Fine Chemicals Co., Ltd. The surfactants can be used alone or in combination of two or more.

[0032] The treatment liquid of the present invention may contain a colorant, as described below, to the extent that the effects of the present invention are not impaired. When the treatment liquid of the present invention contains a colorant, the colorant is preferably a pigment or a hydrophobic dye from the viewpoint of water resistance, and is preferably a pigment from the viewpoint of achieving high weather resistance.

[0033] (Composition of Processing Solution) The content of compound (A) in the treatment liquid of the present invention is 3% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and even more preferably 20% by mass or more, from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity. From the same viewpoint as above and from the viewpoint of economy, it is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 45% by mass or less, and even more preferably 40% by mass or less. Furthermore, from the viewpoint of improving dot expandability, it is even more preferably 30% by mass or more, even more preferably 35% by mass or more. Furthermore, from the viewpoint of improving image uniformity, it is even more preferably 30% by mass or less, and even more preferably 25% by mass or less.

[0034] From the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the content of compound (B) in the treatment liquid of the present invention is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, still more preferably 10% by mass or more, and even more preferably 13% by mass or more, and from the same viewpoint as above, it is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, still more preferably 25% by mass or less, still more preferably 20% by mass or less, and even more preferably 17% by mass or less. When compound (B) is used in the form of a hydrate having water of hydration as the raw material form of the polyvalent metal salt, the content of the polyvalent metal salt in the treatment liquid of the present invention means the content of the anhydrous polyvalent metal salt.

[0035] From the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the water content in the treatment liquid of the present invention is preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, still more preferably 70% by mass or less, and even more preferably 65% by mass or less; and from the same viewpoint as above and from the viewpoint of economy, the water content is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, still more preferably 35% by mass or more, and even more preferably 40% by mass or more. When the polyvalent metal salt is used in the form of a hydrate having water of hydration as a raw material, the water content in the treatment liquid of the present invention means the amount including the water content from the hydrate of the polyvalent metal salt.

[0036] The mass ratio of the content of compound (B) to the content of compound (A) in the treatment liquid of the present invention [compound (B) / compound (A)] is preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.3 or more, and still more preferably 0.4 or more, from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, and from the same viewpoint as above, is preferably 15 or less, more preferably less than 15, even more preferably 8 or less, still more preferably 4 or less, still more preferably 3 or less, still more preferably 2 or less, still more preferably 1 or less, and still more preferably 0.80 or less.

[0037] The mass ratio of the content of compound (A) to the content of water in the treatment liquid of the present invention [compound (A) / water] is preferably 0.01 or more, more preferably 0.04 or more, even more preferably 0.06 or more, still more preferably 0.07 or more, even more preferably 0.10 or more, and even more preferably 0.15 or more from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, and from the same viewpoint as above and from the viewpoint of economy, it is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.0 or less. Furthermore, from the viewpoint of improving image uniformity, it is even more preferably 0.20 or more, even more preferably 0.25 or more, even more preferably 0.5 or more, and even more preferably 0.8 or more, and from the viewpoint of improving dot expandability, it is even more preferably 0.50 or less, even more preferably 0.40 or less, and even more preferably 0.20 or less.

[0038] When the treatment liquid of the present invention further contains a water-soluble organic solvent, the content of the water-soluble organic solvent in the treatment liquid is preferably 30% by mass or less, more preferably 15% by mass or less, even more preferably 5% by mass or less, and still more preferably 2% by mass or less, from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity. When two or more water-soluble organic solvents are used in the treatment liquid of the present invention, the content is the total content of the water-soluble organic solvents.

[0039] The content of coloring material in the treatment liquid of the present invention is preferably 1% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.01% by mass or less, and even more preferably 0% by mass, i.e., it is even more preferable that the treatment liquid of the present invention does not contain any coloring material. If the content of the colorant in the treatment liquid of the present invention is within the above range, when the treatment liquid is used together with an ink for ink-jet recording to perform ink-jet recording, an image can be formed without affecting the hue of the ink.

[0040] Although there are no particular restrictions on the viscosity of the treatment liquid of the present invention, from the viewpoint of obtaining high-quality prints that combine good dot expandability and excellent image uniformity, the viscosity of the treatment liquid at 25°C is preferably 1 mPa·s or more, more preferably 3 mPa·s or more, even more preferably 4 mPa·s or more, and preferably 100 mPa·s or less, more preferably 80 mPa·s or less, even more preferably 50 mPa·s or less, still more preferably 30 mPa·s or less, still more preferably 20 mPa·s or less, and still more preferably 10 mPa·s or less. The viscosity of the treatment liquid of the present invention is measured by the method described in the examples. From the viewpoint of preventing metal corrosion of members, the pH of the treatment solution of the present invention at 20°C is preferably 3.5 or higher, more preferably 4 or higher, even more preferably 4.5 or higher, still more preferably 5 or higher, even more preferably 6 or higher, even more preferably 7 or higher, and is preferably 11.0 or lower, more preferably 10.5 or lower, even more preferably 10.0 or lower. The pH of the treatment solution of the present invention is measured by the method described in the examples.

[0041] (Preparation of processing solution) The treatment liquid of the present invention is prepared by appropriately mixing Compound (A), Compound (B), water, and, if necessary, the other components described above. The pH of the treatment liquid can be appropriately adjusted with the pH adjuster described above.

[0042] [Inkjet recording ink set] <Inkjet recording ink> Hereinafter, an ink for ink jet recording that can be applied to a recording medium that has been treated with the treatment liquid of the present invention (hereinafter also referred to as a "surface-treated recording medium") will be described.

[0033] From the viewpoint of obtaining a high-quality printed matter that combines good dot spreadability and excellent image uniformity, the ink for inkjet recording preferably contains a colorant and water. That is, in the present invention, the treatment liquid can be used as an inkjet recording ink set together with an ink containing a colorant and water.

[0043] [Coloring material] The colorant used in the inkjet recording ink may be either a dye or a pigment, and among these, it is preferable to use a pigment as the colorant from the viewpoint of water resistance, light resistance, weather resistance, gas resistance, etc. The pigment may be any of known organic pigments and inorganic pigments, and may be used singly or in combination of two or more kinds, or may be a mixed crystal. Examples of inorganic pigments include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, etc. Carbon black produced by known methods such as a contact method, a furnace method, or a thermal method can also be used as the inorganic pigment. Examples of organic pigments include azo pigments, polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.), dye chelates (e.g., basic dye chelates, acid dye chelates, etc.), nitro pigments, nitroso pigments, and aniline black. As the pigment, hollow particles such as hollow resin particles and hollow inorganic particles can be used. Furthermore, glossy color pigments such as gold and silver pigments or metallic pigments can also be used. Specific examples of pigments for black inks include carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black; metals such as copper, iron (CI Pigment Black 11), and titanium oxide; and organic pigments such as aniline black (CI Pigment Black 1). Specific examples of pigments for chromatic inks include one or more product numbers selected from the group consisting of CI Pigment Yellow, CI Pigment Orange, CI Pigment Red, CI Pigment Violet, CI Pigment Blue, and CI Pigment Green.

[0044] The dye is not particularly limited, and examples thereof include acid dyes, basic dyes, direct dyes, reactive dyes, etc. The dyes may be used alone or in combination of two or more. Examples of the dye include product numbers selected from the group consisting of CI Acid Yellow, CI Acid Red, CI Acid Blue, CI Acid Black, CI Food Black, CI Direct Yellow, CI Direct Red, CI Direct Blue, CI Direct Black, CI Reactive Red, and CI Reactive Black.

[0045] When the inkjet recording ink contains a pigment, the pigment is dispersed in a medium in the ink. The form of the pigment in the inkjet recording ink may be a form in which the pigment is dispersed using a resin (hereinafter also referred to as a "pigment dispersion resin") or a surfactant as a dispersant, or a form of a self-dispersed pigment that is dispersed without using a dispersant. Among these, the form in which the pigment in the inkjet recording ink is dispersed using a pigment dispersion resin is preferred. The pigment dispersing resin may be either a water-soluble resin or a water-insoluble resin. Here, regarding the "water-soluble" and "water-insoluble" of a resin, when a resin that has been dried at 105°C for 2 hours and has reached a constant weight is dissolved in 100 g of water at 25°C until saturation is reached, if the dissolved amount exceeds 10 g it is judged to be "water-soluble," and if it is 10 g or less it is judged to be "water-insoluble." Furthermore, as will be described later, if the resin has anionic groups that have been neutralized with a neutralizing agent, the resin is judged to be "water-soluble" by the amount of dissolution measured in the presence of a neutralizing agent such that the mass ratio of the resin to the neutralizing agent is the same as that in the inkjet recording ink.

[0046] Specific examples of the form of the pigment in the inkjet recording ink, from the viewpoint of improving the dispersion stability of the pigment, include (a) a form in which a water-soluble resin is adsorbed onto the surface of the pigment, (b) a form in which a water-soluble surfactant or a water-dispersible surfactant is adsorbed onto the surface of the pigment, (c) a form of a self-dispersing pigment in which a hydrophilic functional group is chemically or physically introduced onto the surface of the pigment and dispersed without using a pigment dispersing resin or a surfactant, and (d) a form in which the pigment is coated with a water-insoluble resin.

[0047] The pigments having the aforementioned forms (a) to (d) preferably have anionic properties. This allows polyvalent metal ions derived from the polyvalent metal salt contained in the treatment liquid or ammonium cations derived from the amino groups of the polyvalent amine to electrostatically interact with the anionic properties of the pigment surface, reducing the dispersibility of the pigment present in the ink and causing it to aggregate. As a result, it is believed that high-quality printed matter that combines good dot spreadability and excellent image uniformity can be obtained when using a low-permeability recording medium. From this perspective, in form (a), the water-soluble resin preferably has an anionic group; in form (b), the water-soluble surfactant or water-dispersible surfactant preferably has an anionic group; in form (c), the hydrophilic functional group introduced onto the pigment surface preferably has an anionic group; and in form (d), the water-insoluble resin preferably has an anionic group. The anionic group may be a group that dissociates to release a hydrogen ion, such as a carboxyl group (-COOM), a sulfonic acid group (-SO3M), or a phosphate group (-OPO3M2), or a group in the form of a dissociated ion (-COO- , -SO3 - , -OPO3 2- , -OPO3 - In the above chemical formula, M represents a hydrogen atom, an alkali metal, ammonium, or an organic ammonium.

[0048] Among these, the form of the pigment in the inkjet recording ink is preferably one or more forms selected from the group consisting of form (c) and form (d), and more preferably form (d), from the viewpoint of reducing the dispersibility of dispersoids present in the ink by polyvalent metal ions and / or polyvalent amines, thereby exhibiting a good aggregation effect, and from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity when using a low-permeability recording medium. When the form of the pigment in the inkjet recording ink is form (d), the form in which the pigment is coated with the water-insoluble resin includes a form in which the water-insoluble resin encapsulates the pigment, a form in which the pigment is uniformly dispersed in the water-insoluble resin, a form in which the pigment is exposed from the surface of the water-insoluble resin particles, a form in which the water-insoluble resin is adsorbed to the pigment, and the like. When the pigment in the inkjet recording ink has the form (d), the pigment is preferably coated with a water-insoluble resin having a crosslinked structure. In the form in which the pigment is coated with a water-insoluble resin having a crosslinked structure, the water-insoluble resin preferably has a structure containing a polymer component having a linear two-dimensional structure, which may have branched chains, and a component derived from a crosslinking agent. It is believed that such a crosslinked structure is formed by a polymer having a linear two-dimensional structure, which may have branched chains, being converted into a three-dimensional structure by the component derived from the crosslinking agent.

[0049] When the inkjet recording ink is in the form (d), the type of water-insoluble resin used as the pigment dispersing resin for dispersing the pigment is not particularly limited. Specific examples of water-insoluble resins include (meth)acrylic resins, styrene / (meth)acrylic resins, maleic acid resins, styrene / maleic acid resins, urethane resins, and polyester resins. Among these, the water-insoluble resin is preferably at least one selected from the group consisting of (meth)acrylic resins, styrene / (meth)acrylic resins, urethane resins, and polyester resins, and more preferably at least one selected from the group consisting of (meth)acrylic resins and styrene / (meth)acrylic resins, from the viewpoint of reducing the dispersibility of dispersoids present in the ink due to polyvalent metal ions derived from polyvalent metal salts or ammonium cations derived from amino groups of polyvalent amines, thereby easily controlling the aggregation effect, and from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity when using a low-permeability recording medium. In this specification, "(meth)acrylic" means acrylic or methacrylic. The water-insoluble resin may be synthesized by a known method or may be a commercially available product. The water-insoluble resin may be used alone or in combination of two or more.

[0050] The number average molecular weight of the pigment dispersing resin is preferably 5,000 or more, more preferably 7,000 or more, even more preferably 10,000 or more, and is preferably 100,000 or less, more preferably 50,000 or less, even more preferably 30,000 or less. The number average molecular weight is measured by the method described in the Examples. The acid value of the pigment dispersing resin is preferably 5 mgKOH / g or more, more preferably 50 mgKOH / g or more, even more preferably 100 mgKOH / g or more, still more preferably 150 mgKOH / g or more, even more preferably 200 mgKOH / g or more, and is preferably 800 mgKOH / g or less, more preferably 500 mgKOH / g or less, even more preferably 300 mgKOH / g or less. The acid value of the pigment dispersing resin can be determined by the method described in the examples, but can also be calculated from the mass ratio of the constituent monomers.

[0051] [Fixing resin] The inkjet recording ink may contain a resin that functions as a fixing aid (hereinafter also referred to as a "fixing resin"). The fixing resin in the inkjet recording ink is preferably in the form of a resin that does not coat the pigment, and more preferably in the form of resin particles that do not contain a pigment. The fixing resin is not particularly limited and can be appropriately selected depending on the purpose. Specific examples of the fixing resin include urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, styrene / butadiene resin, vinyl chloride resin, styrene / acrylic resin, and acrylic silicone resin. The ink can be obtained by mixing a particulate fixing resin with a colorant, water, an organic solvent, etc. The fixing resin may be a synthesized resin or a commercially available product. The fixing resin may be used alone or in combination of two or more.

[0052] 〔wax〕 The inkjet recording ink may contain wax. As used herein, "wax" refers to an organic substance that is solid or semi-solid at room temperature (25°C) and becomes liquid when heated. Here, "semi-solid wax" means that the wax deforms and flows when force is applied to it, but can maintain a certain shape when no force is applied to it. Furthermore, the temperature at which wax becomes liquid when heated, known as the melting point of wax, is in the temperature range of 45°C or higher. The wax may be either a natural wax or a synthetic wax. Examples of natural waxes include petroleum waxes such as paraffin wax and microcrystalline wax; vegetable waxes such as carnauba wax, candelilla wax and rice wax; and animal waxes such as lanolin and beeswax. Examples of synthetic waxes include synthetic hydrocarbon waxes such as polyolefin wax and Fischer-Tropsch wax; silicone wax; and modified waxes such as paraffin wax derivatives, montan wax derivatives, and microcrystalline wax derivatives. Among these, polyolefin waxes containing an olefin monomer as the main component are preferred. The waxes can be used alone or in combination of two or more.

[0053] The inkjet recording ink preferably contains wax as a dispersion (hereinafter also referred to as "wax dispersion"). The wax dispersion is not particularly limited, and examples thereof include those prepared by emulsifying wax with a known surfactant, such as a nonionic surfactant or an anionic surfactant. Examples of nonionic surfactants include ethylene oxide adducts of higher alcohols and ethylene oxide adducts of alkylated phenols. Examples of anionic surfactants include sulfates and phosphates based on ethylene oxide adducts of higher alcohols; and alkylated benzenesulfonates. Among these, from the viewpoint of improving the ink ejection stability and the image fastness of printed matter, a nonionic wax dispersion obtained by emulsifying wax with a nonionic surfactant is preferred, and a nonionic polyolefin wax dispersion is more preferred. Suitable examples of commercially available wax dispersions include the "Hi-Tec E" series manufactured by Toho Chemical Industry Co., Ltd., the "AQUACER" series manufactured by BYK, the "Cellosol" series manufactured by Chukyo Yushi Co., Ltd., and the "Chemipearl" series manufactured by Mitsui Chemicals, Inc.

[0054] 〔water〕 The medium for the inkjet recording ink is preferably an aqueous medium, that is, the inkjet recording ink is preferably an aqueous ink containing water. Here, "water-based" means that water accounts for the largest proportion by mass of the ink-jet recording ink medium. When the medium of the inkjet recording ink is an aqueous medium, the aqueous medium contained in the ink is supplied to a recording medium that has been treated with the treatment liquid, and the polyvalent metal salt, polyvalent amine, or organic acid that has precipitated on the recording medium is redissolved, and it is thought that when a low-permeability recording medium is used, a high-quality printed matter that combines good dot expandability and excellent image uniformity can be obtained. The water contained in the inkjet recording ink is preferably ion-exchanged water, deionized water, or distilled water.

[0055] [Water-soluble organic solvent] The inkjet recording ink may further contain a water-soluble organic solvent as an aqueous medium. Examples of the water-soluble organic solvent contained in the ink include polyhydric alcohols exemplified as the water-soluble organic solvents used in the treatment liquid described above; ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers; nitrogen-containing heterocyclic compounds; amides; amines; and sulfur-containing compounds. Among these, from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the water-soluble organic solvent is preferably at least one selected from the group consisting of polyhydric alcohols and polyhydric alcohol alkyl ethers, and more preferably a combination of a polyhydric alcohol and a polyhydric alcohol alkyl ether. From the viewpoint of environmental friendliness, the water content in the aqueous medium of the inkjet recording ink is preferably 51% by mass or more, more preferably 55% by mass or more, even more preferably 60% by mass or more, still more preferably 65% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less, and still more preferably 80% by mass or less.

[0056] The inkjet recording ink may contain surfactants, antifoaming agents, antiseptics and antifungals, rust inhibitors, pH adjusters, and the like, as needed.

[0057] (Composition of inkjet recording ink) The content of the colorant in the inkjet recording ink is preferably 2% by mass or more, more preferably 3% by mass or more, and even more preferably 4% by mass or more from the viewpoint of improving the image density of the printed matter, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less from the viewpoint of obtaining a high-quality printed matter that combines good dot expandability and excellent image uniformity. When the inkjet recording ink contains a pigment dispersing resin, the content of the pigment dispersing resin in the ink is preferably 2% by mass or more, more preferably 4% by mass or more, and even more preferably 6% by mass or more, from the viewpoint of pigment dispersion stability and obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, from the viewpoint of improving the image density of the printed matter. When the inkjet recording ink contains a pigment dispersion resin, the mass ratio of the pigment content to the pigment dispersion resin content in the ink [pigment / pigment dispersion resin] is preferably 0.30 or more, more preferably 0.50 or more, and even more preferably 0.70 or more, from the viewpoint of improving the image density of the printed matter, and is preferably 1.00 or less, more preferably 0.90 or less, and even more preferably 0.80 or less, from the viewpoint of pigment dispersion stability and obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity. When the inkjet recording ink contains a fixing resin, the content of the fixing resin in the ink is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 1.5% by mass or more, from the viewpoint of obtaining a high-quality printed matter that combines good dot expandability and excellent image uniformity, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, from the viewpoint of improving the image density of the printed matter. When the inkjet recording ink contains a wax, the content of the wax in the ink is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.8% by mass or more, from the viewpoint of obtaining a high-quality printed matter that combines good dot expandability and excellent image uniformity, and is preferably 7% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less. When the inkjet recording ink contains a water-soluble organic solvent, the content of the water-soluble organic solvent in the ink is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, from the viewpoint of obtaining a high-quality printed matter that combines good dot expandability and excellent image uniformity, and is preferably 45% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less. When the inkjet recording ink contains a water-soluble organic solvent and a polyhydric alcohol and a polyhydric alcohol alkyl ether are used in combination as the water-soluble organic solvent, the mass ratio of the content of polyhydric alcohol alkyl ethers to the content of polyhydric alcohols in the ink [polyhydric alcohol alkyl ethers / polyhydric alcohols] is preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.3 or more, and is preferably 0.9 or less, more preferably 0.7 or less, even more preferably 0.5 or less, from the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity. From the viewpoint of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, the water content in the inkjet recording ink is preferably 40% by mass or more, more preferably 45% by mass or more, even more preferably 50% by mass or more, and still more preferably 55% by mass or more, and is preferably 75% by mass or less, more preferably 70% by mass or less, and even more preferably 65% by mass or less.

[0058] [Inkjet recording method] As an inkjet recording method using the treatment liquid of the present invention, a method of forming an image by an inkjet recording system using an ink for inkjet recording on the treated surface of a surface-treated recording medium that has been treated with the treatment liquid is preferred, and a method including the following steps 1 and 2 is more preferred. Step 1: A step of applying the treatment liquid to a recording medium and then heating and drying the same to obtain a surface-treated recording medium. Step 2: A step of forming an image on the treated surface of the surface-treated recording medium obtained in Step 1 by an inkjet recording method using an ink containing a colorant and water.

[0059] (Process 1) Step 1 is a step in which the treatment liquid is applied to a recording medium, and then the recording medium is heated and dried to obtain a surface-treated recording medium. In the present invention, the recording medium used in step 1 may be either a low-permeability recording medium or a high-permeability recording medium, but from the viewpoint of good dot expansion and excellent image uniformity, it is preferable to use a low-permeability recording medium. Examples of low-permeability recording media include low-water-absorbency coated paper and non-water-absorbency resin film. Examples of coated paper include general-purpose glossy paper and multicolor foam gloss paper. The resin film is preferably at least one selected from the group consisting of polyester film, polyvinyl chloride film, polypropylene film, and polyethylene film. These resin films may be surface-treated, such as by corona treatment. An example of a highly permeable recording medium is highly water-absorbent plain paper.

[0060] The method for applying the treatment liquid to the recording medium is not particularly limited, and examples of the method for applying the treatment liquid to the recording medium include immersion, roller coating, spray coating, brush coating, and coating by an inkjet recording method. Among these, application by a roller is preferred from the viewpoint of being able to apply the treatment liquid simply and uniformly. The roller application method refers to (i) a method in which the treatment liquid is held in the gap between the recording medium and a member that comes into contact with the recording medium, and one of the recording medium and the member that comes into contact with the recording medium is moved, and the treatment liquid applied to a portion of the recording medium is spread over the entire recording medium, thereby obtaining a surface-treated recording medium that has been treated with the treatment liquid, or (ii) a method in which the recording medium and a member that is in contact with the recording medium or is close to the recording medium while holding a small gap are rotated, and the treatment liquid is printed on the recording medium or the treatment liquid held in the small gap is absorbed into the recording medium. Specific examples of rollers used for roller application include offset gravure coaters, gravure coaters, doctor coaters, bar coaters, blade coaters, flexo coaters, and roll coaters. Among these, one or more types selected from the group consisting of doctor coaters, bar coaters, and roll coaters are preferred. Furthermore, from the viewpoint of being able to perform steps 1 and 2 continuously, the device used to apply the treatment liquid to the recording medium is preferably one that integrates a means for applying the treatment liquid used in step 1, a heat drying means used in step 1, and a means for applying the ink for inkjet recording used in step 2. In this case, for example, the means for applying the treatment liquid, such as a roller coater, may be incorporated into the inkjet recording device described below.

[0061] The amount of the treatment liquid applied to the recording medium is preferably 0.2 g / m from the viewpoint of obtaining a high-quality print that combines good dot spreadability and excellent image uniformity. 2 More preferably, 0.5 g / m 2 More preferably, 1 g / m 2 More preferably, 1.3 g / m 2 From the same viewpoint as above, it is preferably 5 g / m 2 Less than 2 g / m, more preferably 2 More preferably, 1.8 g / m or less 2 The following is the result.

[0062] In step 1, from the viewpoint of obtaining a high-quality printed matter that combines good dot expandability and excellent image uniformity, after the treatment liquid is applied to the recording medium, the treatment liquid on the recording medium may be dried at room temperature before being dried by heating. Examples of room temperature drying methods in step 1 include static drying, air drying, and reduced pressure drying. In the recording method of the present invention, application of active energy rays such as ultraviolet rays and radiation is not included in the drying of the present invention. The temperature during room temperature drying in step 1 is preferably 45°C or lower, more preferably 40°C or lower, even more preferably 38°C or lower, and even more preferably 30°C or lower, from the viewpoint of suppressing deformation of the recording medium, and is preferably 20°C or higher, more preferably 25°C or higher, from the viewpoint of drying in a short time. The time for drying at room temperature in step 1 is preferably 0.5 minutes or more, more preferably 1 minute or more, even more preferably 5 minutes or more, and preferably 30 minutes or less, more preferably 20 minutes or less, even more preferably 10 minutes or less.

[0063] The temperature during heat drying in step 1 is preferably 50° C. or higher, more preferably 70° C. or higher, and even more preferably 90° C. or higher, from the viewpoint of drying in a short time, and is preferably 125° C. or lower, more preferably 123° C. or lower, and even more preferably 120° C. or lower, from the viewpoint of suppressing deformation of the recording medium. As the temperature during heat drying in step 1, it is preferable to use the value obtained by measuring the temperature of the treated surface of the surface-treated recording medium with a non-contact thermometer, and the value obtained by measuring the temperature of the heat drying means may also be used. The heat drying time in step 1 is preferably 10 seconds or more, more preferably 20 seconds or more, and even more preferably 30 seconds or more, and from the viewpoint of suppressing deformation of the recording medium and improving the recording speed, it is preferably 180 seconds or less, more preferably 120 seconds or less, and even more preferably 100 seconds or less. Suitable means for heating and drying the surface-treated recording medium include a method of blowing gas adjusted to the above-mentioned temperature onto the surface-treated recording medium, a method of holding or passing the surface-treated recording medium through a gas atmosphere adjusted to the above-mentioned temperature, a method of irradiating the treated surface of the surface-treated recording medium with an infrared heater, and a method of heating with a platen heater.

[0064] (Process 2) Step 2 is a step of forming an image on the treated surface of the surface-treated recording medium obtained in step 1 by inkjet recording using inkjet recording ink. The ink for inkjet recording is loaded into a known inkjet recording apparatus, and is deposited as ink dots on the treated surface of the surface-treated recording medium obtained in step 1, thereby forming an image. Any type of inkjet recording apparatus, such as a thermal type or a piezo type, can be used.

[0065] The present invention may also include the following aspects. <1> The method comprises: (A) a polyoxyethylene ether compound having an aromatic ring; (B') a flocculant; and (B') water; The treatment liquid for inkjet recording contains the compound (A) in an amount of 3% by mass or more.

[0066] <2> The flocculant (B') is one or more compounds (B) selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids. <1> 1. The inkjet recording treatment liquid according to claim 1.

[0067] <3> the inkjet recording treatment liquid is a pretreatment liquid for inkjet recording, <1> or <2> 1. The inkjet recording treatment liquid according to claim 1.

[0068] <4> The polyvalent metal ion constituting the polyvalent metal salt is at least one selected from divalent metal ions and trivalent metal ions. <2> or <3> 1. The inkjet recording treatment liquid according to claim 1.

[0069] <5> The polyamine is a polymer containing a constitutional unit derived from a polymerizable monomer having at least one amino group. <2> ~ <4> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0070] <6> The organic acid is a hydroxycarboxylic acid. <2> ~ <5> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0071] <7> the mass ratio of the content of the compound (B) to the content of the compound (A) in the inkjet recording treatment liquid [compound (B) / compound (A)] is less than 15; <2> ~ <6> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0072] <8> The compound (B) is at least one selected from the group consisting of magnesium nitrate, calcium nitrate, and aluminum nitrate. <2> ~ <7> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0073] <9> The compound (A) has an HLB value of 10 or more and 20 or less according to the Griffin method. <1> ~ <8> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0074] <10> The compound (A) has an HLB value of 11 or more and 14 or less according to the Griffin method. <1> ~ <9> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0075] <11> the content of the compound (A) in the inkjet recording treatment liquid is 3% by mass or more and 60% by mass or less; <1> ~ <10> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0076] <12> the content of the compound (B) in the inkjet recording treatment liquid is 1% by mass or more and 40% by mass or less; <2> ~ <11> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0077] <13> the content of the compound (B) in the inkjet recording treatment liquid is 1% by mass or more and 40% by mass or less; <2> ~ <12> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0078] <14> The inkjet recording treatment liquid further contains a pH adjuster in an amount of 0.1% by mass or more and 1% by mass or less. <1> ~ <13> 10. The pretreatment liquid for inkjet recording according to any one of the above items.

[0079] <15> The method comprises: (A) a polyoxyethylene ether compound having an aromatic ring; (B') a flocculant; and (B') water; the compound (A) is a polyoxyethylene phenyl ether, the flocculant (B') is one or more compounds (B) selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids; the polyvalent metal salt is an inorganic acid salt of a divalent or trivalent metal, the polyamine is a polymer containing a constituent unit derived from a polymerizable monomer having at least one amino group, the organic acid is a hydroxycarboxylic acid, The content of the compound (A) is 3% by mass or more, the content of the compound (B) is 1% by mass or more and 40% by mass or less, the mass ratio of the content of the compound (B) to the content of the compound (A) [compound (B) / compound (A)] is less than 15;

[0080] <16> the compound (A) is a polyoxyethylene phenyl ether having an HLB value of 10 or more and 20 or less, the flocculant (B') is one or more compounds (B) selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids; the polyvalent metal salt is a nitrate of a divalent or trivalent metal, the polyamine is a diallyl quaternized ammonium salt polymer having a weight average molecular weight of 5,000 to 50,000, the organic acid is a hydroxy polycarboxylic acid, The content of the compound (A) is 3% by mass or more and 60% by mass or less, The content of the compound (B) is 5% by mass or more and 25% by mass or less, the mass ratio [compound (B) / compound (A)] is 0.1 or more and 8 or less, <15> 1. The inkjet recording treatment liquid according to claim 1.

[0081] <17> the compound (A) is at least one selected from the group consisting of polyoxyethylene phenyl ether and polyoxyethylene distyrenated phenyl ether having an HLB of 10 or more and 20 or less, the flocculant (B') is one or more compounds (B) selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids; the polyvalent metal salt is at least one selected from the group consisting of magnesium nitrate, calcium nitrate, and aluminum nitrate; the polyvalent amine is at least one selected from polydiallyldimethylammonium chloride and dimethylamine / epichlorohydrin copolymers having a weight average molecular weight of 5,000 to 50,000, the organic acid is at least one selected from citric acid, tartaric acid, and lactic acid; The content of the compound (A) is 5% by mass or more and 50% by mass or less, The content of the compound (B) is 10% by mass or more and 20% by mass or less, the mass ratio [compound (B) / compound (A)] is 0.3 or more and 4 or less, <15> or <16> 1. The inkjet recording treatment liquid according to claim 1.

[0082] <18> the inkjet recording treatment liquid is a pretreatment liquid for inkjet recording, <15> ~ <17> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0083] <19> The compound (A) is at least one selected from the group consisting of polyoxyethylene phenyl ether and polyoxyethylene distyrenated phenyl ether having an HLB of 11 or more and 15 or less. <15> ~ <18> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0084] <20> The flocculant (B') is a polyvalent metal salt, and the polyvalent metal salt is at least one selected from the group consisting of magnesium nitrate and calcium nitrate. <15> ~ <19> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0085] <21> The content of the compound (A) is 15% by mass or more and 45% by mass or less. <15> ~ <20> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0086] <22> the mass ratio [compound (B) / compound (A)] is 0.3 or more and 1 or less, <15> ~ <21> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0087] <23> The method for treating a recording medium used in inkjet recording, <1> ~ <122> 10. The inkjet recording treatment liquid according to claim 9, wherein the inkjet recording treatment liquid is a treatment liquid for inkjet recording.

[0088] <24> The aforementioned <1> ~ <23> 1. An ink set for inkjet recording, comprising the treatment liquid for inkjet recording according to any one of 1 to 3 above, and an ink containing a colorant and water.

[0089] <25> The ink is a water-based pigment ink. <24> 1. An ink set for ink jet recording according to claim 1.

[0090] <26> The aforementioned <1> ~ <23> 1. A surface-treated recording medium which has been treated with the treatment liquid for inkjet recording according to any one of 1 to 8.

[0091] <27> The aforementioned <1> ~ <23> 1. An inkjet recording method using the inkjet recording treatment liquid according to any one of the above items 1 to 2, comprising the following steps 1 and 2: Step 1: A step of applying the inkjet recording treatment liquid to a recording medium, and then heating and drying the recording medium to obtain a surface-treated recording medium. Step 2: A step of forming an image on the treated surface of the surface-treated recording medium obtained in Step 1 by an inkjet recording method using an ink containing a colorant and water.

[0092] <28> The composition contains a polyoxyethylene ether compound (A) having an aromatic ring, one or more compounds (B) selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids, and water, Use of a composition containing the compound (A) in an amount of 3% by mass or more as a pretreatment liquid for inkjet recording.

[0093] <29> the compound (B) is one or more selected from the group consisting of magnesium nitrate, calcium nitrate, and aluminum nitrate; the mass ratio of the content of the compound (B) to the content of the compound (A) in the composition [compound (B) / compound (A)] is 0.3 or more and less than 15, the compound (A) has an HLB value of 10 or more and 14 or less according to the Griffin method, the content of the compound (A) in the composition is 5% by mass or more and 60% by mass or less, the content of the compound (B) in the composition is 1% by mass or more and 40% by mass or less, The composition further contains 0.1% by mass or more and 1% by mass or less of triethanolamine in the composition. <28> 10. Use of the pretreatment liquid for inkjet recording according to claim 19 as a pretreatment liquid for inkjet recording.

[0094] <30> The composition is used together with an aqueous pigment ink. <28> or <29> 10. Use of the pretreatment liquid for inkjet recording according to claim 19 as a pretreatment liquid for inkjet recording. [Example]

[0095] In the following Production Examples, Examples and Comparative Examples, "parts" means "parts by mass" unless otherwise specified. Various physical properties were measured or calculated by the following methods.

[0096] (1) Number average molecular weight of pigment dispersing resin The content was determined by gel permeation chromatography. The measurement sample was prepared by mixing 0.1 g of resin with 10 mL of the eluent described below in a glass vial, stirring with a magnetic stirrer at 25°C for 10 hours, and filtering with a syringe filter "DISMIC-13HP" (PTFE, 0.2 μm, manufactured by Advantec Co., Ltd.). The measurement conditions are shown below. GPC equipment: Tosoh Corporation "HLC-8320GPC" Columns: "TSKgel SuperAWM-H", "TSKgel SuperAW3000", and "TSKgel guardcolumn Super AW-H" manufactured by Tosoh Corporation Eluent: N,N-dimethylformamide dissolved with phosphoric acid and lithium bromide at concentrations of 60mmol / L and 50mmol / L, respectively. Flow rate: 0.5mL / min Standard material: Monodisperse polystyrene kits with known molecular weights manufactured by Tosoh Corporation: "PStQuick b (F-550, F-80, F-10, F-1, a-1000)" and "PStQuick c (F-288, F-40, F-4, A-5000, A-500)"

[0097] (2) Acid value of pigment dispersing resin The acid value of the pigment dispersion resin was measured by dissolving the resin in a titration solvent (toluene:acetone = 2:1 (volume ratio)) made by mixing toluene and acetone in an automatic potentiometric titrator (Kyoto Electronics Manufacturing Co., Ltd., electric burette, model number: APB-610), and titrating it with a 0.1 N potassium hydroxide / ethanol solution by potentiometric titration, with the inflection point on the titration curve being the endpoint. The acid value (mg KOH / g) was calculated from the titration volume of the potassium hydroxide solution up to the endpoint.

[0098] (3) Solids concentration of pigment dispersion and wax dispersion A 30 mL polypropylene container (φ: 40 mm, height: 30 mm) was precisely weighed, and approximately 10.0 g of sodium sulfate (reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was weighed into the container and kept at a constant weight in a desiccator. Approximately 1 g of pigment dispersion or wax dispersion was added and mixed, and the mass of the pigment dispersion or wax dispersion was then precisely weighed. The container was then maintained at 105°C for 2 hours to remove volatiles, and the container was then left in the desiccator for an additional 15 minutes before the entire container was precisely weighed. The mass of the pigment dispersion or wax dispersion residue after devolatilization was calculated by subtracting the precisely weighed mass of the container and the precisely weighed mass of the sodium sulfate from the precisely weighed mass of the entire container. The mass of the pigment dispersion or wax dispersion residue after devolatilization was divided by the precisely weighed mass of the pigment dispersion or wax dispersion before devolatilization to obtain the solids concentration (% by mass).

[0099] (4) Melting point of wax The melting point of the wax was measured using an apparatus conforming to JIS K 0064:1992. Specifically, the wax dispersion was dried and used as a sample. The sample was heated to 200°C using a differential scanning calorimeter "DSC Q20" (manufactured by TA Instruments) and then cooled to 0°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min, and the calorific value was measured up to 200°C. The temperature of the peak with the largest peak area among the observed heat of fusion peaks was determined as the maximum peak temperature of melting, and this peak temperature was taken as the melting point of the wax.

[0100] (5) Average particle size of pigment dispersion Using a laser particle analysis system "ELS-8000" (Otsuka Electronics Co., Ltd.), particle size was measured by dynamic light scattering and calculated by cumulant analysis. The measurement conditions were a temperature of 25°C, an angle between the incident light and the detector of 90°, and 100 integration times. The refractive index of water (1.333) was input as the refractive index of the dispersion solvent. For the measurement sample, a pigment dispersion was weighed into a screw tube (Maruem Co., Ltd., No. 5) and the solids concentration was 2 × 10 -4Water was added to the mixture so that the concentration reached 5% by mass, and the mixture was stirred at 25°C for 1 hour using a magnetic stirrer.

[0101] (6) Viscosity of the treatment liquid The viscosity of the treatment liquid at 25° C. was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., model number: TV-25, using a standard cone rotor 1°34′×R24, rotation speed 50 rpm).

[0102] (7) pH of the treatment solution The pH at 20°C was measured using a tabletop pH meter "F-71" (manufactured by Horiba Ltd.) equipped with a pH electrode "6337-10D" (manufactured by Horiba Ltd.).

[0103] Production Example 1-1 (Production of pigment dispersing resin (1)) A monomer mixture was prepared by mixing 31 parts of acrylic acid (a reagent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 69 parts of styrene (a reagent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). Into a reaction vessel, 10 parts of methyl ethyl ketone (hereinafter also referred to as "MEK") (a reagent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.2 parts of a polymerization chain transfer agent (2-mercaptoethanol) (a reagent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 10 mass % of the monomer mixture were placed and mixed, and the atmosphere was thoroughly replaced with nitrogen gas. Separately, a mixture of the remainder of the monomer mixture (90% by mass of the monomer solution), 0.13 parts of the polymerization chain transfer agent, 30 parts of MEK, and 1.1 parts of a radical polymerization initiator (2,2'-azobis(2,4-dimethylvaleronitrile), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name "V-65") was placed in a dropping funnel. The monomer mixture in the reaction vessel was heated to 65°C under a nitrogen atmosphere while being stirred, and the mixture in the dropping funnel was added dropwise over 3 hours. After 2 hours at 65°C after the completion of the dropping, a solution of 0.1 parts of the polymerization initiator in 2 parts of MEK was added. The mixture was further aged at 65°C for 2 hours and then at 70°C for 2 hours, and then dried under reduced pressure to obtain an acrylic acid / styrene copolymer (number average molecular weight: 19,000, acid value: 240 mgKOH / g) as pigment dispersion resin (hereinafter also referred to as "pigment dispersion resin (1)").

[0104] Production Example 2-C1 (Production of cyan ink I-C1 for inkjet recording) 100 parts of the pigment dispersion resin (1) obtained in Production Example 1-1 and 78.6 parts of MEK were mixed, and 41.2 parts of a 5N aqueous sodium hydroxide solution (volumetric analysis grade, sodium hydroxide content: 16.9% by mass, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added as a neutralizer to neutralize (degree of neutralization: 40 mol%). Next, 800 parts of ion-exchanged water was added, and 100 parts of a cyan pigment (CI Pigment Blue 15:3, manufactured by DIC Corporation, product name "TGR-SD") was added. The mixture was stirred at 20°C for 60 minutes using a Disper (manufactured by Asada Iron Works Co., Ltd., product name "Ultra Disper") blade at 7,000 rpm to obtain a pigment mixture. The resulting pigment mixture was subjected to a dispersion treatment using a Microfluidizer (trade name, manufactured by Microfluidics) at a pressure of 200 MPa for 10 passes to obtain a cyan pigment dispersion. To the obtained cyan pigment dispersion, 250 parts of ion-exchanged water was added and the mixture was stirred. After that, the MEK was completely removed at 60°C under reduced pressure. After further removing some of the water, 35.7 parts of trimethylolpropane polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name "Denacol EX-321", epoxy equivalent: 140) was added as a crosslinking agent, the mixture was sealed, and heated at 70°C for 5 hours while stirring with a stirrer. The mixture was then cooled to room temperature, and ion-exchanged water was added to adjust the solids concentration to 24% by mass. The mixture was then filtered through a 5 μm pore size filter (acetyl cellulose membrane, outer diameter: 2.5 cm, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to obtain a cyan pigment dispersion (crosslinking rate 60 mol%, average particle size: 102 nm). 50 parts of the obtained cyan pigment dispersion, 2.9 parts of a polyethylene wax dispersion (manufactured by Toho Chemical Industry Co., Ltd., trade name "Hitec E-6500", ion type: nonionic, wax melting point: 140°C, solid content concentration: 35% by mass), 19 parts of 1,2-propanediol (reagent manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.), 8 parts of ethylene glycol monobutyl ether (reagent manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.), and 2,4,7,9-tetramethyl-5-decyne-4,7-diol (Air Products and The resulting mixture was mixed with 0.5 parts of a cellulose acetate solution (trade name "Surfynol 104" manufactured by Fujifilm Chemicals Co., Ltd.), ion-exchanged water was added so that the total amount became 100 parts, and the mixture was filtered through a filter with a pore size of 5 μm (acetyl cellulose membrane, outer diameter: 2.5 cm, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to obtain a cyan ink for inkjet recording I-C1 (solids concentration: 13 mass %, pigment content: 5 mass %, pigment dispersing resin content: 7 mass %, wax content: 1 mass %).

[0105] Production Example 2-C2 (Production of cyan ink I-C2 for inkjet recording) A cyan ink for inkjet recording I-C2 was obtained in the same manner as in Production Example 2-C1, except that the water-soluble organic solvent was changed to 19 parts of dipropylene glycol (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) and 8 parts of 1,2-hexanediol (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) instead of 1,2-propanediol and ethylene glycol monobutyl ether.

[0106] Production Example 2-M1 (Production of magenta ink I-M1 for inkjet recording) A magenta ink for inkjet recording I-M1 was obtained in the same manner as in Production Example 2-C1, except that a magenta pigment (CI Pigment Red 122, manufactured by DIC Corporation, trade name "FASTOGEN Super Magenta RGT") was used instead of the cyan pigment.

[0107] Production Example 2-M2 (Production of magenta ink I-M2 for inkjet recording) A magenta ink for inkjet recording I-M2 was obtained in the same manner as in Production Example 2-C2, except that a magenta pigment (CI Pigment Red 122, manufactured by DIC Corporation, trade name "FASTOGEN Super Magenta RGT") was used instead of the cyan pigment.

[0108] Preparation Example 1 (Preparation of Treatment Solution 1) The components of the treatment solution were added to a container equipped with a stirrer in the following formulation and mixed at 25°C for 1 hour, after which the mixture was filtered using a 25 mL needleless syringe (Terumo Corporation) fitted with a 5 μm pore size filter (acetyl cellulose membrane, outer diameter: 2.5 cm, Fujifilm Wako Pure Chemical Industries, Ltd.) to obtain treatment solution 1. The viscosity of treatment solution 1 at 25°C was 5.6 mPa·s, and the pH at 20°C was 5.1. [Composition of Treatment Solution 1] Polyoxyethylene phenyl ether (EO addition mole number: 5, HLB value: 14) (manufactured by Aoki Oil & Fat Industries Co., Ltd., product name "Brownon PH-5") 20.0 parts Magnesium nitrate hexahydrate (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) 25.9 parts Ion-exchanged water 53.6 parts Triethanolamine (Nippon Shokubai Co., Ltd.) 0.5 parts

[0109] Preparation Examples 2 to 12 and Comparative Preparation Examples 1 to 3 (Preparation of Treatment Solutions 2 to 12 and C1 to C3) Treatment solutions 2 to 12 and C1 to C3 were prepared in the same manner as in Preparation Example 1, except that the compounding composition of the treatment solution was changed according to Table 1. The components of the treatment liquid other than those used in Preparation Example 1 are shown below. [Polyoxyethylene ether compound (A) having an aromatic ring] Polyoxyethylene distyrenated phenyl ether (Kao Corporation, product name "Emulgen A-60", HLB value: 12.6, active ingredient: 100%) Polyoxyethylene styrenated phenyl ether (EO addition moles: 9, HLB value: 11.4) (manufactured by Aoki Oil & Fat Industries Co., Ltd., product name "Brownon DSP-9", active ingredient 100%) Diethylene glycol monobenzyl ether (manufactured by Nippon Nyukazai Co., Ltd., product name "Benzyl Diglycol", HLB value: 10.7, active ingredient 100%) Polyoxyethylene distyrenated phenyl ether (Kao Corporation, product name "Emulgen A-500", HLB value: 18, active ingredient: 100%) [Compound (A') other than the polyoxyethylene ether compound (A) having an aromatic ring] 1,4-Cyclohexanedimethanol (Eastman Chemical) Polyoxyethylene alkyl ether (Kao Corporation, product name "Emulgen 1108", HLB value: 13.5, active ingredient 100%) [Compound (B)] [Polyvalent metal salts] Calcium nitrate tetrahydrate (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) Aluminum nitrate nonahydrate (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) [Polyamine] PAS-H-1L (aqueous solution of polydiallyldimethylammonium chloride (solid content 28% by mass), manufactured by Nittobo Medical Co., Ltd., product name, weight-average molecular weight: 8,500 (catalog value)) Unisense KHE-107L (aqueous solution of dimethylamine / epichlorohydrin copolymer (solid content 52% by mass), Senka Corporation, product name, molecular weight converted to PEG by GPC: less than 20,000 (catalog value)) [Organic acid] 40% by weight ammonium lactate aqueous solution (40% by weight of active ingredient, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0110] Example 1 (Process 1) A wireless bar coater "A-Bar" (Mitsui Electric Seiki Co., Ltd., model: OSP-1.5, pitch: 0.08 mm, depth: 4 μm, film thickness: 1.5 μm / wet) was used, and coated paper "OK Topcoat+" (Oji Paper Co., Ltd., basis weight: 127.9 g / m) was used as a low-permeability recording medium. 2 , Pure water absorption amount at contact time of 100 msec: 4.9 g / m 2Treatment liquid 1 was uniformly applied to the substrate. The substrate was left to stand in an environment of 25°C and 50% RH for 10 minutes to dry at room temperature, and then heated and dried in a thermostatic chamber heated to 100°C for 60 seconds. The amount of treatment liquid 1 applied was 1.6±0.3 g / m 2 It was made to be like this.

[0111] (Process 2) Images were formed on the treated surface of the surface-treated recording medium obtained in step 1 by inkjet recording using the cyan ink for inkjet recording I-C1 and the magenta ink for inkjet recording I-M1 according to the methods (1) and (2) below, and the resulting prints were evaluated. The results are shown in Table 1.

[0112] Examples 2 to 12 and Comparative Examples 1 to 3 A surface-treated recording medium was obtained in the same manner as in Example 1, except that in step 1, treatment liquid 1 was replaced with each of the treatment liquids shown in Table 1. Thereafter, the same operation as in step 2 of Example 1 was carried out, and an image was formed by inkjet recording using the inkjet recording cyan ink I-C1 and the inkjet recording magenta ink I-M1 on the treated surface of the surface-treated recording medium obtained in step 1, according to the methods (1) and (2) below, and the resulting prints were evaluated. The results are shown in Table 1.

[0113] Example 13 An image was formed by inkjet recording in the same manner as in Example 1, except that the inkjet cyan ink I-C2 and the inkjet magenta ink I-M2 were used instead of the inkjet cyan ink I-C1 and the inkjet magenta ink I-M1 in step 2, and the resulting prints were evaluated. The results are shown in Table 1.

[0114] <Evaluation> (1) Evaluation of dot scalability An image was created and evaluated by the following inkjet recording method using a cyan ink for inkjet recording on each of the surface-treated recording media obtained in step 1 of the Examples and Comparative Examples. In addition, an image was also created and evaluated by the following inkjet recording method using a cyan ink for inkjet recording on each of the recording media after room temperature drying in step 1 of the Examples and Comparative Examples (not subjected to heat drying).

[0115] (Printing using inkjet recording method) In an environment of a temperature of 25±1°C and a relative humidity of 30±5%, a printing evaluation device (manufactured by Tritec Corporation) equipped with an inkjet head "KJ4B-HD06MHG-STDV" (manufactured by Kyocera Corporation, piezo type) was filled with cyan ink for inkjet recording. The head voltage was set to 26 V, the frequency to 20 kHz, the ejection liquid volume to 12 pL, the head temperature to 32°C, the resolution to 600 dpi, and the negative pressure to -4.0 kPa. The surface-treated recording medium or the recording medium after drying at room temperature in step 1 was fixed to the conveying table under reduced pressure so that the longitudinal direction of the surface-treated recording medium or the recording medium after drying at room temperature in step 1 was the same as the conveying direction. A print command was transferred to the print evaluation device, and an image using cyan ink with a duty of 2% was printed. The ink dot diameter was measured using a handheld image evaluation system "PIAS (registered trademark)-II" (manufactured by Quality Engineering Associates (QEA)) under conditions of a threshold of 50%, a minimum dot diameter of 10 μm, and a maximum dot diameter of 100 μm. The results are shown in Table 1. A larger dot diameter indicates better dot expandability and image quality. The evaluation criteria are shown below. A rating of C indicates no practical problems. (Evaluation criteria) A: Dot diameter is 60 μm or more B: Dot diameter is 58 μm or more and less than 60 μm C: Dot diameter is 55 μm or more and less than 58 μm D: Dot diameter less than 55 μm

[0116] (2) Evaluation of image uniformity On each of the surface-treated recording media obtained in step 1 of the examples and comparative examples, images were formed using the cyan ink for inkjet recording and the magenta ink for inkjet recording by the following inkjet recording method.

[0117] (Printing using inkjet recording method) In an environment of a temperature of 25±1°C and a relative humidity of 30±5%, a printing evaluation device (manufactured by Tritec Corporation) equipped with an inkjet head "KJ4B-HD06MHG-STDV" (manufactured by Kyocera Corporation, piezo type) was filled with the cyan ink for inkjet recording and the magenta ink for inkjet recording. The head voltage was set to 26 V, the frequency to 20 kHz, the amount of ejected liquid to be used to spit out 12 pL, the head temperature to 32°C, the resolution to 600 dpi, and the negative pressure to -4.0 kPa. The surface-treated recording medium was fixed to the conveying table under reduced pressure so that the longitudinal direction of the surface-treated recording medium was the same as the conveying direction. A print command was transferred to the print evaluation device, and an image was printed using inkjet recording cyan ink and inkjet recording magenta ink at a duty of 60% each, for a total duty of 120%. The image uniformity of the printed image was evaluated using a handheld image evaluation system "PIAS (registered trademark)-II" (manufactured by Quality Engineering Associates (QEA)). * The graininess value was measured, and the results are shown in Table 1. * The smaller the graininess value, the more suppressed the color mixing between dots and the better the image quality. The evaluation criteria are shown below. If the evaluation is C, there is no problem in practical use. (Evaluation criteria) A:L * Graininess value less than 1.6 B:L * Graininess value is 1.6 or more and less than 2.3 C:L * Graininess value is 2.3 or more and less than 3.0 D:L * Graininess value is 3.0 or more

[0118] [Table 1]

[0119] From Table 1, it can be seen that, compared to Comparative Examples 1 to 3, Examples 1 to 13 can produce high-quality prints that combine good dot expansion and image uniformity when printing on a low-permeability recording medium, even when a heat drying process is performed after applying the treatment liquid. [Industrial Applicability]

[0120] According to the present invention, it is possible to provide a treatment liquid for inkjet recording, an ink set for inkjet recording, a surface-treated recording medium, and an inkjet recording method that are capable of obtaining high-quality printed matter that combines good dot expandability and excellent image uniformity, even when a heat drying step is performed after the treatment liquid is applied to a low-permeability recording medium.

Claims

1. A method for producing a coagulant comprising the steps of: (A) a polyoxyethylene ether compound having an aromatic ring; (B') a flocculant; and (B') water; The inkjet recording treatment liquid has a content of the compound (A) of 3% by mass or more.

2. 2. The inkjet recording treatment liquid according to claim 1, wherein the aggregating agent (B') is one or more compounds (B) selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids.

3. 3. The inkjet recording treatment liquid according to claim 2, wherein the polyvalent metal ions constituting the polyvalent metal salt are divalent metal ions.

4. The inkjet recording treatment liquid according to claim 2, wherein the polyvalent amine is a polymer containing a structural unit derived from a polymerizable monomer having at least one amino group.

5. 3. The treatment liquid for inkjet recording according to claim 2, wherein a mass ratio of a content of the compound (B) to a content of the compound (A) in the treatment liquid for inkjet recording [compound (B) / compound (A)] is less than 15.

6. The inkjet recording treatment liquid according to claim 2, wherein the compound (B) is a polyvalent metal salt.

7. The treatment liquid for inkjet recording according to claim 2, wherein the compound (A) has an HLB value of 10 or more and 20 or less.

8. The treatment liquid for inkjet recording according to claim 2, wherein the content of the compound (A) in the treatment liquid is 5% by mass or more and 60% by mass or less.

9. The treatment liquid for inkjet recording according to claim 2, wherein the content of the compound (B) in the treatment liquid is 1% by mass or more and 40% by mass or less.

10. The inkjet recording treatment liquid according to claim 2, which is for treating a recording medium used in inkjet recording.

11. The treatment liquid for inkjet recording according to claim 2, wherein the treatment liquid is a pretreatment liquid for inkjet recording.

12. An ink set for inkjet recording, comprising the treatment liquid for inkjet recording according to any one of claims 1 to 11, and an ink containing a colorant and water.

13. A surface-treated recording medium which has been treated with the treatment liquid according to any one of claims 1 to 11.

14. An inkjet recording method using the inkjet recording treatment liquid according to any one of claims 1 to 11, comprising the following steps 1 and 2: Step 1: A step of applying the inkjet recording treatment liquid to a recording medium, and then heating and drying the recording medium to obtain a surface-treated recording medium. Step 2: A step of forming an image on the treated surface of the surface-treated recording medium obtained in Step 1 by an inkjet recording method using an ink containing a colorant and water.

15. The composition contains a polyoxyethylene ether compound (A) having an aromatic ring, one or more compounds (B) selected from the group consisting of polyvalent metal salts, polyvalent amines, and organic acids, and water, Use of a composition containing the compound (A) in an amount of 3% by mass or more as a pretreatment liquid for inkjet recording.

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