Treatment liquid, inkjet ink set, and method for producing printed matter

Abstract

To provide a process liquid applicable by an inkjet system, excellent in discharge recovery performance after standing of an inkjet head, and applicable to various base materials with an aqueous ink to form a high-quality image.SOLUTION: A process liquid applicable to a base material by an inkjet system contains water, a coagulant and a surfactant. The coagulant contains a polycondensation product of an aliphatic amine and epihalohydrin and a diallyl dialkyl ammonium halide-based polymer at a mass ratio of 20:80 to 90:10. The surfactant contains a fluorine-based surfactant and a silicone-based surfactant.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a treatment liquid, an inkjet ink set, and a method for producing a printed matter. [Background technology]

[0002] An inkjet recording system is a printing system that performs printing by ejecting highly fluid liquid ink from fine nozzles and depositing it on a substrate. This system is characterized by the ability to print high-resolution, high-quality images at high speed and with low noise using relatively inexpensive equipment, and has recently become rapidly popular. Water-based inks are widely used because they can produce high-quality prints at low cost. Water-based inks have an increased drying rate due to the inclusion of moisture, and also have the advantage of being environmentally friendly.

[0003] In a printing method using an aqueous ink containing a binder resin, the binder resin forms a film by drying the printed matter, thereby obtaining fixability of the image and enabling printing on various substrates. Patent Document 1 proposes a method for adapting the ink to media with different water absorbencies, such as fabrics and non-water-absorbent recording media, by printing an aqueous inkjet ink containing a soluble resin having a specific acidic group, a solvent with a surface tension of 25 mN / m or more and 40 mN / m or less, and a silicone-based or fluorine-based surfactant while heating the medium.

[0004] There is a method of pretreating a substrate before printing with an aqueous ink. Well-known methods of pretreating a substrate include applying a pretreatment liquid to a certain area of ​​the substrate by roller coating, spray coating, wire bar coater, etc. In recent years, a method of applying a pretreatment liquid to a substrate by an inkjet method has been researched.

[0005] Patent Document 2 proposes a method of inkjet recording by ejecting a reaction liquid and an aqueous ink from respective nozzle rows mounted on the same recording head, in which the amount of reaction liquid ejected relative to the aqueous ink is changed depending on the position in the scanning direction within a specified band, thereby controlling the reaction amounts of the reaction liquid and the aqueous ink to be greater in positions where the reaction liquid penetrates more into the recording medium due to differences in landing time, thereby reducing color unevenness within the band.

[0006] Patent Document 3 proposes a method of depositing a reaction liquid and an aqueous ink on a recording medium by an inkjet method, in which the reaction liquid contains a flocculant, water, and a surfactant, the surfactant content is 2 to 10 mass% relative to the total mass of the reaction liquid, and the ratio on the recording medium of the surfactant content in the reaction liquid and the surfactant content in the aqueous ink is specified, thereby making it easier for the reaction liquid and the aqueous ink to wet and spread on the recording medium and suppressing the occurrence of pinholes in the printed matter. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Republished Publication No. 2008-102722 [Patent Document 2] JP 2005-119115 A [Patent Document 3] JP 2019-65087 A Summary of the Invention [Problem to be solved by the invention]

[0008] Water-based inks have high surface tension because they contain water, and when they contain water-soluble organic solvents, they tend to take longer to dry due to hydrogen bonding. Therefore, when water-based inks are applied to a substrate with low surface free energy, the substrate repels the ink, which requires a long drying time. Furthermore, when adjusting the components of the water-based ink to suit such a substrate, it becomes difficult to print on substrates with different permeability while maintaining image quality. In the method disclosed in Patent Document 1, since ensuring wetting and spreading on non-water-absorbent recording media while preventing deterioration of image quality due to ink mixing are contradictory actions, uniform coating on substrates with poorer wettability is not sufficient, and image unevenness occurs, especially in solid images.

[0009] When applying a pretreatment liquid by an inkjet method, it is difficult to apply the pretreatment liquid uniformly to a substrate, and printing with aqueous ink on a substrate that has been unevenly pretreated can result in reduced image quality. Although the method disclosed in Patent Document 2 can suppress image unevenness in the band direction, not only does it complicate the control of the printing system, but image unevenness may not be sufficiently suppressed depending on the material of the substrate. Furthermore, in order to promote the aggregation of the ink components on the substrate and improve image quality such as fine print reproducibility, it is desirable to carefully select the flocculant in the pretreatment liquid. In the method disclosed in Patent Document 3, the type and amount of surfactant used are considered to make it easier for the reaction liquid and the aqueous ink to wet and spread on the recording medium, but the ejection recovery performance of an inkjet head filled with the pretreatment agent after being left alone when a stronger flocculant is used in the pretreatment agent is not considered. When the pretreatment liquid contains a polymer with strong cationic properties, the polymer may crystallize and cause nozzle clogging. This crystallization of the polymer may also be caused by an interaction with the surfactant, so it is desirable to select a flocculant that improves the wetting and spreading of the pretreatment liquid on the substrate as well as the ejection recovery performance after being left alone.

[0010] One object of the present invention is to provide a treatment liquid that can be applied by an inkjet system, has excellent ejection recovery performance after an inkjet head is left unused, and is further applicable to various substrates so as to enable the formation of high-quality images with aqueous ink; an inkjet ink set comprising this treatment liquid and aqueous ink; and a method for producing printed matter using this treatment liquid and aqueous ink. [Means for solving the problem]

[0011] One aspect of the present invention is a treatment liquid applied to a substrate by an inkjet system, the treatment liquid comprising water, a flocculant, and a surfactant, the flocculant comprising a polycondensate of an aliphatic amine and an epihalohydrin, and a diallyldialkylammonium halide-based polymer in a mass ratio of 20:80 to 90:10, and the surfactant comprising a fluorine-based surfactant and a silicone-based surfactant. Another aspect of the present invention is an inkjet ink set comprising the above-mentioned treatment liquid and an aqueous inkjet ink. Yet another aspect of the present invention is a method for producing a printed matter, comprising the steps of applying the treatment liquid to a substrate by an inkjet system, and applying an aqueous inkjet ink by a wet-on-wet method to the substrate to which the treatment liquid has been applied by the inkjet system. Effect of the Invention

[0012] According to one embodiment of the present invention, it is possible to provide a treatment liquid that can be applied by an inkjet method, has excellent ejection recovery performance after an inkjet head is left unused, and is applicable to various substrates so as to enable the formation of high-quality images with aqueous ink; an inkjet ink set comprising this treatment liquid and aqueous ink; and a method for producing printed matter using this treatment liquid and aqueous ink. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will be described below using an embodiment. The following embodiment is not intended to limit the present invention.

[0014] A treatment liquid according to one embodiment is a treatment liquid applied to a substrate by an inkjet system, and is characterized in that it contains water, a flocculant, and a surfactant, the flocculant contains a polycondensate of an aliphatic amine and an epihalohydrin, and a diallyldialkylammonium halide-based polymer in a mass ratio of 20:80 to 90:10, and the surfactant contains a fluorine-based surfactant and a silicone-based surfactant. This makes it possible to provide a treatment liquid that can be applied by an inkjet method, has excellent ejection recovery performance after the inkjet head is left unused, and can be applied to various substrates to enable the formation of high-quality images using aqueous ink.

[0015] In aqueous ink, pigments and the like are dispersed by electrostatic repulsion and steric hindrance, but by applying an aggregating agent to the substrate before or after applying the aqueous ink, the electrostatic repulsion of the pigments and the like in the aqueous ink on the substrate is suppressed, causing the pigments and the like to aggregate, resulting in a loss of fluidity of the ink. This makes it possible to suppress the coalescence of ink droplets on the substrate, excessive penetration of the ink, and the like. By applying the treatment liquid by the inkjet method, it is possible to apply the treatment liquid only to the printing area, and further, it is also possible to apply the treatment liquid only to the portion overlapping the printed image. In addition, the printing system can be simplified by applying both the treatment liquid and the aqueous ink to the substrate by the inkjet method.

[0016] Diallyldialkylammonium halide polymers are a type of cationic polymer that aggregates aqueous inks on a substrate and functions as an aggregating agent. Diallyldialkylammonium halide polymers are highly hydrophobic, which is one of the factors that causes crystallization when the head is left unattended and water or a neutralizing agent evaporates, which can cause non-ejection of the treatment liquid. This tendency becomes particularly pronounced when a component with low polarity, such as a fluorine-based surfactant, is present in the treatment liquid. In the present disclosure, a method has been found that uses the aggregation action of diallyldialkylammonium halide polymers while preventing crystallization that causes non-ejection. By using a polycondensate of aliphatic amine and epihalohydrin and a diallyldialkylammonium halide polymer in a mass ratio of 20:80 or more, with a higher proportion of the polycondensate of aliphatic amine and epihalohydrin, crystallization caused by the diallyldialkylammonium halide polymer is suppressed, and ejection recovery performance after standing can be improved. Although the principle is unclear, it is speculated as follows. The polycondensate of aliphatic amine and epihalohydrin is highly hydrophilic, and precipitation is unlikely to occur even if water or the neutralizing agent evaporates to a certain extent. In addition, the polycondensate of aliphatic amine and epihalohydrin has a nitrogen atom in the molecular skeleton like the diallyldialkylammonium halide polymer, so it is thought that the polymers easily interact with each other and the distance between the molecules is likely to be close. Therefore, when a polycondensation product of an aliphatic amine and epihalohydrin and a diallyldialkylammonium halide-based polymer are contained in a mixed state in the treatment liquid, even if water or the neutralizing agent derived from the diallyldialkylammonium halide-based polymer volatilizes, it is considered that the polycondensation product of an aliphatic amine and epihalohydrin supplies the neutralizing agent to the diallyldialkylammonium halide-based polymer, thereby preventing a decrease in solubility, or enters into the gaps between the diallyldialkylammonium halide-based polymer molecules, thereby suppressing crystallization caused by the diallyldialkylammonium halide-based polymer.

[0017] The treatment liquid according to one embodiment can be applied to various substrates, and can provide high-quality printed matter using aqueous ink. The key to image quality is, first, uniform application of the treatment liquid to the substrate and uniform aggregation of the ink components on the substrate, and, second, an appropriate reaction speed with the ink components. This makes it possible to prevent image cracking and obtain a high-quality image with little image unevenness, and also to obtain a high-quality image with high image density.

[0018] The polycondensate of aliphatic amine and epihalohydrin contained in the treatment liquid and the diallyldialkylammonium halide polymer each act as an aggregating agent. In particular, the diallyldimethylammonium halide polymer can cause uniform aggregation of the ink components by aggregating the ink components after the treatment liquid and the aqueous ink are sufficiently mixed on the substrate. In a state in which the treatment liquid and the aqueous ink are not sufficiently mixed on the substrate and aggregate, a part in which the ink components react excessively with the aggregating agent and aggregate, and a part in which the ink components hardly react with the aggregating agent and do not aggregate are mixed. This may cause image unevenness due to the mixture of the aggregated and non-aggregated parts of the ink components on the substrate. Furthermore, in an ink containing a water-dispersible resin as a binder resin, a part in which the resin particles are close to each other (aggregated part) and a part in which the resin particles are far apart (non-aggregated part) are mixed on the substrate, so that the film formation becomes non-uniform in the drying process after the application of the aqueous ink, and cracks in the image may be caused. The cyclic amine skeleton of the diallyldialkylammonium halide polymer has the ability to disperse coloring materials, etc. This, combined with the aggregation performance of the cationic group, is thought to make the aggregation performance of the ink relatively gentle. In addition, with only the diallyldialkylammonium halide polymer, the aggregation of the ink components on the substrate is gentle, and fine print reproducibility may be poor. On the other hand, the polycondensation product of the aliphatic amine and epihalohydrin has a property of being highly hydrophilic and easily spreading in an aqueous solution, so that the amino group, which is the reaction site with the ink components, is easily in contact with the particles in the ink, and as a result, the reaction between the ink components and the aggregating agent is promoted. Therefore, by using the polycondensation product of the aliphatic amine and epihalohydrin in combination with the diallyldimethylammonium halide polymer, the image quality, especially the fine print reproducibility, can be further improved.

[0019] By including a fluorine-based surfactant and a silicone-based surfactant in the treatment liquid, after the treatment liquid is applied to the substrate, the treatment liquid quickly wets and spreads over the substrate, making it possible to apply the treatment liquid uniformly to the substrate. Since the fluorosurfactant tends to be oriented at the gas-liquid interface, and the silicone surfactant tends to be oriented at the interface with the substrate, it is believed that the contact angle of the treatment liquid to the substrate can be significantly reduced. Furthermore, by including a fluorosurfactant and a silicone surfactant, the fluorosurfactant and the silicone surfactant form an association, which is believed to be able to efficiently reduce the contact angle with the substrate. For example, even if the fluorosurfactant is difficult to be oriented at the interface with the substrate, the fluorosurfactant forms an association with the silicone surfactant, which makes it easy to be oriented at the interface with the substrate, and the surfactant is uniformly distributed at the interface with the substrate, which is believed to increase the wettability with the substrate.

[0020] The substrate to which the treatment liquid is applied may be either a permeable substrate or a non-permeable substrate. In the case of a non-permeable substrate, according to one embodiment, the treatment liquid is easily spread on the substrate, and the ink components and the coagulant are easily coagulated uniformly on the substrate, so that the image has a uniform image quality without cracks and less image unevenness, and furthermore, the coagulation action is sufficiently obtained on the substrate, so that an image quality with excellent fine character reproducibility can be obtained. The permeable substrate can also obtain excellent image quality. In the case of a permeable substrate, it is desired that the reaction rate between the ink components and the treatment liquid on the substrate is higher. If the reaction rate between the ink components and the treatment liquid on the substrate is slow, the ink may over-penetrate into the substrate, resulting in a decrease in image density. As described above, the polycondensate of an aliphatic amine and an epihalohydrin has high hydrophilicity, so that the reaction rate with the ink components on the substrate in a wet state is fast, and the image density can be increased on the permeable substrate.

[0021] "Processing liquid" The treatment liquid is applied to the substrate by the inkjet method and can contain water, a flocculant, and a surfactant. This treatment liquid can be applied to the substrate before printing with aqueous ink, and more specifically, can be applied to the substrate before printing with aqueous inkjet ink.

[0022] The treatment liquid contains a polycondensate of an aliphatic amine and an epihalohydrin, and a diallyldialkylammonium halide polymer as an aggregating agent. The treatment liquid is applied to a substrate, whereby the aggregating agent is applied onto the substrate, and the aggregating agent on the substrate aggregates components such as coloring materials of the aqueous ink that is applied thereafter, thereby forming a high-quality image.

[0023] The polycondensation product of an aliphatic amine and an epihalohydrin can be obtained by polycondensing a mixture containing an aliphatic amine and an epihalohydrin. Examples of the aliphatic amine include an aliphatic monoamine and an aliphatic polyamine. Examples of the aliphatic amine include monoalkyl monoamines, dialkyl monoamines, alkylenediamines, alkanolamines, polyalkylene glycol amines, and glycol ether amines. Specific examples include alkyl monoamines such as monomethylamine, monoethylamine, dimethylamine, diethylamine, and methylethylamine; alkylenediamines such as ethylenediamine and propylenediamine; alkanolamines such as monoethanolamine, dimethylethanolamine, 1-amino-2-propanol, di-2-propanolamine, diethanolamine, and triethanolamine; polyalkylene glycol amines such as diethylene glycol amine and triethylene glycol amine; and glycol ether amines such as 2-(2-methoxyethoxy)ethylamine and 2-methoxyethylamine. The aliphatic amine is preferably an alkyl amine, and more preferably an alkyl monoamine. Examples of epihalohydrin include epichlorohydrin and epibromohydrin. Furthermore, the polycondensation product of an aliphatic amine and an epihalohydrin also includes a polycondensation product of an aliphatic amine, an epihalohydrin, and ammonia. The polycondensation product of an aliphatic amine and an epihalohydrin may be a product obtained by polycondensing an aliphatic amine and an epihalohydrin, but may also be a product in which a halogen atom has been substituted with an organic acid or the like.

[0024] The polycondensation product of aliphatic amine and epihalohydrin is preferably a quaternary ammonium salt, the ratio of secondary or tertiary ammonium salt in the constituent unit of the polycondensation product of aliphatic amine and epihalohydrin is preferably low, and it is more preferable that all the constituent units of cationic groups in the constituent unit of the polycondensation product of aliphatic amine and epihalohydrin are quaternary ammonium salts. This further prevents the generation of foreign matter due to the interaction between the polycondensation product of aliphatic amine and epihalohydrin and the diallyldialkylammonium halide polymer, and further improves the ejection recovery performance after being left alone. The polycondensation product of aliphatic amine and epihalohydrin is preferably a polycondensation product of dialkyl monoamine and epihalohydrin, and may be a polycondensation product containing ammonia or alkylenediamine in addition to dialkyl monoamine and epihalohydrin. Dimethylamine is preferable as the dialkyl monoamine, and ethylenediamine is preferable as the alkylenediamine. As the epihalohydrin, epichlorohydrin is preferred, which enhances the interaction with the diallyldialkylammonium halide polymer, and can further prevent crystallization caused by the diallyldialkylammonium halide polymer, thereby improving the ejection recovery performance after standing. Specifically, the polycondensation product of an aliphatic amine and epihalohydrin is preferably an aliphatic amine-epihalohydrin polycondensation product, an aliphatic amine-ammonia-epihalohydrin polycondensation product, more preferably an aliphatic amine-epihalohydrin polycondensation product. More specifically, the polycondensation product of an aliphatic amine and epihalohydrin is preferably a dimethylamine-epichlorohydrin polycondensation product, a dimethylamine-ammonia-epichlorohydrin polycondensation product, or a dimethylamine-ethylenediamine-epichlorohydrin polycondensation product, more preferably a dimethylamine-epichlorohydrin polycondensation product.

[0025] The weight average molecular weight (Mw) of the polycondensation product of an aliphatic amine and epihalohydrin is preferably 1,000 to 200,000, and more preferably 2,000 to 100,000. From the viewpoint of ejection property, the weight average molecular weight (Mw) of the polycondensation product of an aliphatic amine and epihalohydrin is preferably 50,000 or less, and more preferably 10,000 or less. In the present disclosure, the weight average molecular weight of a polymer is a value determined by a GPC method in terms of standard polystyrene. The same applies hereinafter.

[0026] Commercially available examples of polycondensates of aliphatic amines and epihalohydrin include dimethylamine-ammonia-epichlorohydrin polycondensates such as "Unisense KHE1000L, Unisense KHE100L, Unisense KHE101L, Unisense KHE102L, Unisense KHE105L" manufactured by Senka Corporation, dimethylamine-epihalohydrin polycondensates such as "Unisense KHE104L" manufactured by Senka Corporation, and dimethylamine-ethylenediamine-epichlorohydrin polycondensates such as "Catiomaster PE-30" manufactured by Yokkaichi Synthetic Co., Ltd.

[0027] Examples of the diallyldialkylammonium halide polymer include homopolymers of diallyldialkylammonium halide, copolymers of diallyldialkylammonium halide and monomers polymerizable therewith, etc. Examples of the monomers polymerizable with diallyldialkylammonium halide include acrylamide, sulfur dioxide, and alkyldiallylamine such as methyldiallylamine, etc. Examples of the diallyldialkylammonium halide include diallyldimethylammonium halide and diallyldiethylammonium halide, and diallyldimethylammonium halide is preferred.The diallyldialkylammonium halide is more preferably diallyldimethylammonium chloride. The diallyldialkylammonium halide polymer may be a polymer in which diallyldialkylammonium halide is homopolymerized or copolymerized with other monomers, and may also be a polymer in which the halogen atom is substituted with an organic acid or the like. In addition, since the polycondensate of an aliphatic amine and epihalohydrin and the diallyldimethylammonium halide-based polymer can further enhance their interaction in an aqueous medium by using a common neutralizing agent, if one is a halogen, the other is preferably a halogen, and if one is an organic acid, the other is preferably an organic acid. More preferably, both neutralizing agents are chlorine.

[0028] Specific examples of diallyldialkylammonium halide polymers include diallyldimethylammonium chloride homopolymer, diallyldimethylammonium chloride-acrylamide copolymer, diallyldimethylammonium chloride-sulfur dioxide copolymer, and diallyldimethylammonium chloride-methyldiallylamine copolymer.

[0029] The weight average molecular weight (Mw) of the diallyldialkylammonium halide polymer is preferably 1,000 to 200,000, more preferably 3,000 to 100,000, and even more preferably 5,000 to 10,000. From the viewpoint of dischargeability, the weight average molecular weight (Mw) of the diallyldialkylammonium halide polymer is preferably 50,000 or less, and even more preferably 10,000 or less.

[0030] Commercially available examples of diallyldialkylammonium halide polymers include diallyldimethylammonium chloride polymers such as "PAS-H-1L, PAS-H-5L, PAS-H-10L" manufactured by Nittobo Chemical Co., Ltd. and "Unisense FPA100L" manufactured by Senka Corporation, and diallyldimethylammonium chloride-sulfur dioxide copolymers such as "PAS-A-1, PAS-A-5" manufactured by Nittobo Chemical Co., Ltd.

[0031] The mass ratio (E:D) of the polycondensate of an aliphatic amine and an epihalohydrin (E) to the diallyldialkylammonium halide polymer (D) is preferably from 20:80 to 90:10, more preferably from 30:70 to 80:20, and still more preferably from 35:65 to 50:50. By having a high ratio of the polycondensate of aliphatic amine and epihalohydrin within this mass ratio (E:D) range, the ejection recovery performance after leaving the ink for a long time can be improved, and the image quality of printed matter, particularly the image density on permeable substrates, can be further increased. By using a high ratio of the diallyldialkylammonium halide polymer within this range of mass ratio (E:D), the image quality of the printed matter, particularly the uniform image quality and fine print reproducibility on non-permeable substrates, can be improved.

[0032] The content of the polycondensate of an aliphatic amine and epihalohydrin is preferably 0.5 to 15 mass %, more preferably 1 to 10 mass %, and further preferably 1 to 5 mass %, in terms of the amount of active ingredient, relative to the total amount of the treatment liquid. The content of the diallyldialkylammonium halide polymer is preferably from 0.5 to 15 mass %, more preferably from 1 to 10 mass %, and even more preferably from 1 to 5 mass %, in terms of the amount of active ingredient, relative to the total amount of the treatment liquid. The total amount of the polycondensate of an aliphatic amine and epihalohydrin and the diallyldialkylammonium halide polymer is preferably 1 to 20% by mass, more preferably 5 to 10% by mass, in terms of the amount of active ingredients, based on the total amount of the treatment liquid. The treatment liquid may contain flocculants other than those mentioned above, as long as the effects of the present invention are not impaired.

[0033] The treatment liquid may contain a fluorine-based surfactant and a silicone-based surfactant as a surfactant. By containing such a surfactant in the treatment liquid, the affinity between the substrate and the treatment liquid is further increased, allowing the treatment liquid to be applied more uniformly to the substrate, and improving the uniformity of an image formed by the aqueous ink applied thereafter.

[0034] Examples of fluorine-based surfactants include perfluoroalkyl alkylene oxide adducts, perfluoroalkyl group-containing oligomers, perfluoroalkyl phosphates, perfluoroalkyl carboxylates, perfluoroalkyl quaternary ammonium salts, perfluoroalkyl amine oxide compounds, and perfluoroalkyl betaines. The fluorosurfactant is preferably a nonionic fluorosurfactant, more preferably a perfluoroalkyl alkylene oxide adduct or a perfluoroalkyl group-containing oligomer. The perfluoroalkyl alkylene oxide adduct is more preferably a perfluoroalkyl ethylene oxide adduct. The nonionic fluorosurfactant is easy to form the above-mentioned association, and can apply the treatment liquid more uniformly to the substrate.

[0035] Examples of commercially available fluorine-based surfactants include perfluoroalkyl ethylene oxide adducts such as "Surflon S-242" and "Surflon S-243," and perfluoroalkyl group-containing oligomers such as "Surflon S-386."

[0036] The fluorosurfactant may be used alone or in combination of two or more kinds. The amount of the fluorosurfactant in terms of the active ingredient is preferably 0.1 to 5 mass %, more preferably 0.5 to 3 mass %, based on the total amount of the treatment liquid.

[0037] The silicone surfactant may be a compound in which a modified group is introduced into a polysiloxane skeleton. The modified group may be introduced into one or both of the terminal position and the side chain position of the polysiloxane skeleton, but a side chain type modified silicone surfactant in which a modified group is introduced into the side chain position of the polysiloxane skeleton is preferred. By using a side chain type modified silicone surfactant, it becomes easier to form an association with the above-mentioned fluorine-based surfactant, and the treatment liquid can be applied more uniformly to the substrate. Specific examples of silicone surfactants include polyether-modified silicone surfactants, alkyl-modified silicone surfactants, phenyl-modified silicone surfactants, alkyl-aralkyl-co-modified silicone surfactants, and acrylic-modified silicone surfactants. Among these, polyether-modified silicone surfactants are preferred. Furthermore, the silicone surfactant is preferably a nonionic surfactant.

[0038] As the polyether-modified silicone surfactant, for example, a compound having a polyalkylene glycol chain in a polysiloxane skeleton can be used. In this compound, the polyalkylene glycol chain may be a polyethylene glycol chain, a polypropylene glycol chain, a polyethylene propylene glycol chain, a polytrimethylene glycol chain, etc., and is preferably a polyethylene glycol chain. The number of moles of the polyalkylene oxide added is preferably 5 to 20, more preferably 8 to 15.

[0039] The polyether-modified silicone surfactant is preferably a compound in which a polyalkylene glycol chain is introduced to at least one silicon atom of a trisiloxane skeleton or a tetrasiloxane skeleton. In this surfactant, the methyl group bonded to the siloxane skeleton may be substituted with other hydrophobic groups such as an alkyl group having 2 or more carbon atoms. Preferred examples include a compound in which one or two polyalkylene glycol chains are introduced to the silicon atom at the 3rd position of the trisiloxane skeleton, and a compound in which a total of 1 to 4 polyalkylene glycol chains are introduced to one or both of the silicon atoms at the 3rd and 5th positions of the tetrasiloxane skeleton. More specifically, examples include heptamethyltrisiloxane in which an alkylene glycol chain is introduced to the 3rd position, nonamethyltetrasiloxane in which an alkylene glycol chain is introduced to the 3rd or 5th position, and octamethyltetrasiloxane in which an alkylene glycol chain is introduced to the 3rd and 5th positions.

[0040] Examples of commercially available silicone surfactants include "BYK-302, BYK-307, BYK-325, BYK-331, BYK-333, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, and BYK-378" (all from BYK Japan Co., Ltd.), and "L-7001, L-7002, L-7604, FZ-2105, and 8032" from the DOWSIL (registered trademark) series. ADDITIVE" (all from Dow Corning Toray Co., Ltd.), "KF-6011, KF-6011P, KF-6013, KF-6004, KF-6043" (all from Shin-Etsu Chemical Co., Ltd.), "Disparlon AQ-7120, Disparlon AQ-7130, Disparlon AQ-7180" (all from Kusumoto Chemical Co., Ltd.), and "Silface SAG503A, Silface SAG001, Silface SAG002, Silface SAG003, Silface SAG005, Silface SAG008" (all from Nissin Chemical Industry Co., Ltd.) (all product names).

[0041] The silicone surfactant may be used alone or in combination of two or more kinds. The silicone surfactant is preferably contained in an amount of 0.1 to 5 mass %, more preferably 0.5 to 3 mass %, in terms of the amount of active ingredient relative to the total amount of the treatment liquid. The total amount of the fluorosurfactant and the silicone surfactant is preferably 0.1 to 10 mass %, more preferably 1 to 3 mass %, in terms of the amount of active ingredients relative to the total amount of the treatment liquid. By making this total amount 10 mass % or less, particularly 3 mass % or less, the discharge performance of the treatment liquid can be further improved. The mass ratio of the fluorosurfactant and the silicone surfactant is preferably 1:10 to 10:1, more preferably 1:5 to 2:1, in terms of the amount of active ingredients.

[0042] It is preferable that either the fluorine-based surfactant or the silicone-based surfactant is water-soluble, and it is more preferable that both are water-soluble. The treatment liquid may contain surfactants other than those mentioned above, as long as the effects of the present invention are not impaired.

[0043] The treatment liquid preferably contains water as an aqueous solvent, and the main solvent may be water. The water is not particularly limited, but is preferably one that contains as few ionic components as possible. Examples of the water that can be used include ion-exchanged water, distilled water, and ultrapure water. From the viewpoint of adjusting the viscosity, the water content is preferably 20 to 90% by mass, more preferably 30 to 80% by mass, and even more preferably 40 to 70% by mass, based on the total amount of the treatment liquid.

[0044] The treatment liquid may contain a water-soluble organic solvent. The water-soluble organic solvent is preferably compatible with water. As the water-soluble organic solvent, an organic compound that is liquid at room temperature and can be dissolved or mixed with water can be used from the viewpoint of wettability and moisture retention, and it is preferable to use a water-soluble organic solvent that can be uniformly mixed with the same volume of water at 20°C under 1 atmosphere. The boiling point of the water-soluble organic solvent is preferably 180 to 270°C. When the boiling point of the water-soluble organic solvent is 180°C or higher, more preferably 200°C or higher, evaporation of the water-soluble organic solvent from the treatment liquid can be suppressed, and on-machine stability can be further improved. When the boiling point of the water-soluble organic solvent is 270°C or lower, the amount of solvent remaining in the printed matter after application of the water-based ink can be reduced, and the durability of the image can be further improved. From this viewpoint, it is preferable to limit the amount of the water-soluble organic solvent having a boiling point exceeding 270°C to less than 5 mass% of the total amount of the treatment liquid.

[0045] Examples of the water-soluble organic solvent include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,2-butanediol, and 1,2-hexanediol; glycerins such as glycerin, diglycerin, triglycerin, and polyglycerin; acetins such as monoacetin and diacetin; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, di ... Examples of glycol ethers that can be used include tetraethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, dipropylene glycol monomethyl ether, and diethylene glycol benzyl ether; and 1-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, β-thiodiglycol, and sulfolane. The water-soluble organic solvent may be used alone or in combination of two or more kinds as long as a single phase is formed.

[0046] From the viewpoints of wettability, moisturizing effect, viscosity adjustment, etc., the water-soluble organic solvent may be contained in an amount of 1 to 80 mass % relative to the total amount of the treatment liquid, more preferably 10 to 50 mass %, and even more preferably 20 to 40 mass %. The water-soluble organic solvent preferably contains glycols having a boiling point of 200 to 270° C. The content of the glycols having a boiling point of 200 to 270° C. is preferably 10 to 60% by mass, and more preferably 20 to 40% by mass, based on the total amount of the treatment liquid.

[0047] The treatment liquid may further include an amine compound. When the treatment liquid contains an amine compound, the amine compound functions as a rust inhibitor, and rust generation can be prevented while the treatment liquid is loaded into the printing device. The polycondensate of aliphatic amine and epihalohydrin, which is an aggregating agent, and the diallyldialkylammonium halide-based polymer both contain acid as a neutralizing agent, and therefore may cause rust on the metal members of the inkjet head. When the treatment liquid further contains an amine compound, the amine compound is oriented on the surface of the metal member, and rust generation on the metal member due to acid can be suppressed. Furthermore, by using an amine compound instead of a general rust inhibitor such as benzotriazole or alkylnaphthalenesulfonate, a reaction with the diallyldialkylammonium halide-based polymer is not caused, and the generation of foreign matter from the treatment liquid can be suppressed. For these reasons, the ejection recovery performance of the treatment liquid after being left in the head can be further improved.

[0048] The boiling point of the amine compound is preferably not more than 250° C., more preferably not more than 150° C., and even more preferably not more than 100° C. A volatile amine compound having a boiling point in this range is volatilized and removed from the surface of the printed material after being applied to the substrate, and interaction with the ink components on the printed material is prevented, thereby further improving the durability of the image. The boiling point of the amine compound is preferably 70° C. or higher, which prevents the amine compound from volatilizing from the inkjet nozzle, maintains a state in which an appropriate amount of the amine compound is contained in the treatment liquid inside the inkjet nozzle, and ensures a sufficient rust prevention effect. For example, the boiling point of the amine compound is preferably from 70 to 250°C, more preferably from 70 to 150°C, and even more preferably from 70 to 100°C.

[0049] The amine compound may be any of primary amines, secondary amines, and tertiary amines, but tertiary amines are more preferred. Tertiary amines have the advantage of being highly adsorbable to metals and being volatile, which makes it less likely to cause a decrease in image durability. The amine compound is preferably an aliphatic amine compound, and specific examples thereof include alkylamines, alkanolamines, and alkylenediamines. The number of carbon atoms in one molecule of the aliphatic amine is preferably 4 to 20, and more preferably 6 to 10. Examples of the amine compound include primary amines such as methylamine, ethylamine, aminomethylpropanol, aminoethylpropanol, ethylenediamine, and hexamethylenediamine; secondary amines such as dimethylamine, diethylamine, and ethylmethylamine; and tertiary amines such as trimethylamine, triethylamine, triethanolamine, dimethylaminoethanol, diethylaminoethanol, dimethylaminopropanol, triethanolamine, and tetramethylethylenediamine. Of these, triethylamine and dimethylaminoethanol are preferred, and triethylamine is more preferred. The amine compounds may be used alone or in combination of two or more.

[0050] The content of the amine compound is preferably 0.1 to 2% by mass, more preferably 0.5 to 1% by mass, based on the total amount of the treatment liquid. When the amine compound is contained in an amount of 0.1% by mass or more based on the total amount of the treatment liquid, the ejection recovery performance after leaving the treatment liquid can be further improved. When the amine compound is contained in an amount of 2% by mass or less based on the total amount of the treatment liquid, the ejection recovery performance after leaving the treatment liquid can be further improved, the amount of the amine compound remaining on the printed matter can be reduced, and the effect on the ink components on the printed matter can be suppressed, thereby further improving the durability of the image.

[0051] In addition to the components described above, the treatment liquid may optionally contain various additives such as rust inhibitors, preservatives, antioxidants, UV absorbers, infrared absorbers, crosslinking agents, pH adjusters, defoamers, wetting agents (moisturizing agents), surface tension adjusters (penetrating agents), and fixing agents.

[0052] In order to obtain ejection properties suitable for the inkjet method, the viscosity of the treatment liquid at 23° C. is preferably 1 to 30 mPa·s, more preferably 3 to 20 mPa·s, and even more preferably 4 to 12 mPa·s.

[0053] The method for preparing the treatment liquid is not particularly limited, but the desired treatment liquid can be obtained by appropriately mixing each component. The obtained composition may be filtered using a filter or the like. In addition, various additives may be added as appropriate.

[0054] "Ink set" According to one embodiment, it is possible to provide an inkjet ink set that includes a treatment liquid and an aqueous inkjet ink, the treatment liquid being the treatment liquid according to the embodiment described above. This ink set can be used in a printing method in which the treatment liquid and the aqueous inkjet ink are each applied to a substrate by an inkjet system. It is preferable that the treatment liquid is applied to the substrate before the aqueous inkjet ink is applied, and then the aqueous inkjet ink is applied. Hereinafter, the aqueous inkjet ink is also simply referred to as aqueous ink.

[0055] The water-based ink may contain a coloring material and water. The coloring material may contain a pigment, a dye, or a combination thereof. In terms of weather resistance and water resistance of the image, a pigment may be preferably used.

[0056] The pigment may be preferably incorporated into the ink as a pigment dispersion. The pigment dispersion may be any one in which the pigment can be dispersed in a solvent and in which the pigment is in a dispersed state in the ink. For example, a pigment dispersed in water using a pigment dispersant, a self-dispersing pigment dispersed in water, or a microencapsulated pigment in which the pigment is coated with a resin dispersed in water may be used.

[0057] As the pigment, organic pigments such as azo pigments, phthalocyanine pigments, polycyclic pigments, and dye lake pigments, and inorganic pigments such as carbon black and metal oxides can be used. As the azo pigment, soluble azo lake pigments, insoluble azo pigments, and condensed azo pigments can be used. As the phthalocyanine pigment, metal phthalocyanine pigments and metal-free phthalocyanine pigments can be used. As the polycyclic pigment, quinacridone pigments, perylene pigments, perinone pigments, isoindoline pigments, isoindolinone pigments, dioxazine pigments, thioindigo pigments, anthraquinone pigments, quinophthalone pigments, metal complex pigments, and diketopyrrolopyrrole (DPP) can be used. As the carbon black, furnace carbon black, lamp black, acetylene black, channel black, and the like can be used. As the metal oxide, titanium oxide, zinc oxide, and the like can be used. These pigments may be used alone or in combination of two or more.

[0058] The average particle size of the pigment is preferably 10 to 500 nm, and more preferably 10 to 200 nm. The average particle size of these pigments is preferably 10 nm or more from the viewpoint of color development, and is preferably 500 nm or less from the viewpoint of dispersion stability. In the case of inkjet ink, it is preferably 500 nm or less from the viewpoint of ejection properties.

[0059] In order to stably disperse the pigment in the ink, a pigment dispersant such as a polymer dispersant or a surfactant can be preferably used. Examples of commercially available polymer dispersants include the TEGO Disperse series (TEGO Disperse 740W, 750W, 755W, 760W) manufactured by Evonik Japan Co., Ltd., the Solsperse series (Solsperse 20000, 27000, 41000, 43000, 44000, 46000) manufactured by Lubrizol Japan Co., Ltd., the Joncryl series (Joncryl 57J, 60J, 63J) manufactured by BASF Japan Co., Ltd., and the DISPERBYK-102, 185, 190, 193, 199 and BYKJET-9152 manufactured by BYK-Chemie Japan Co., Ltd. (all trade names).

[0060] As the surfactant-type dispersant, a non-ionic surfactant can be used in consideration of the dispersion stability of the pigment in the ink. Commercially available surfactant-type dispersants include, for example, nonionic surfactants such as the Emulgen series manufactured by Kao Corporation, "Emulgen A-60, A-90, A-500, 420" (all trade names).

[0061] The pigment dispersants can be used alone or in combination of two or more. When a pigment dispersant is used, the amount of pigment dispersant added varies depending on the type of pigment dispersant and is not particularly limited. For example, the pigment dispersant can be added in an amount of 0.005 to 2.0 parts by mass of the active ingredient per 1 part pigment.

[0062] A self-dispersing pigment may be blended as a coloring material. A self-dispersing pigment is a pigment in which a hydrophilic functional group has been introduced to the surface of the pigment by chemical or physical treatment. The hydrophilic functional group introduced to the self-dispersing pigment is preferably ionic, and by charging the pigment surface anionically or cationic, the pigment particles can be stably dispersed in water by electrostatic repulsion. As the anionic functional group, a carboxy group, a sulfo group, a sulfino group, a sulfate ester group, a phosphoric acid group, a phosphoric acid ester group, a phosphorous acid group, a phosphorous acid ester group, and the like are preferred. As the cationic functional group, a quaternary ammonium group, a quaternary phosphonium group, and the like are preferred.

[0063] These hydrophilic functional groups may be bonded directly to the pigment surface or via other atomic groups. Examples of the other atomic groups include, but are not limited to, alkylene groups, phenylene groups, naphthylene groups, etc. Methods for treating the pigment surface include diazotization treatment, sulfonation treatment, hypochlorous acid treatment, humic acid treatment, vacuum plasma treatment, etc.

[0064] As the self-dispersing pigment, for example, CAB-O-JET series "CAB-O-JET200, 300, 400, 250C, 260M, 270" manufactured by Cabot Corporation, and "BONJET BLACK CW-1, CW-2, CW-4" manufactured by Orient Chemical Industries Co., Ltd. can be preferably used (all are product names).

[0065] A pigment dispersion in which the pigment is previously dispersed with a pigment dispersant may be used. Commercially available pigment dispersions dispersed with a pigment dispersant include, for example, the HOSTAJET series manufactured by Clariant and the FUJI SP series manufactured by Fuji Pigment Co., Ltd. (both are trade names). A pigment dispersion dispersed with the above-mentioned pigment dispersant may be used. A dispersion of a microencapsulated pigment in which the pigment is coated with a resin may also be used.

[0066] A dye may be blended as a coloring material. As the dye, those generally used in the technical field of printing can be used, and are not particularly limited. Specific examples include basic dyes, acid dyes, direct dyes, soluble vat dyes, acid mordant dyes, mordant dyes, reactive dyes, vat dyes, and sulfur dyes. Of these, those that are water-soluble and those that become water-soluble by reduction or the like can be preferably used. More specific examples include azo dyes, rhodamine dyes, methine dyes, azomethine dyes, xanthene dyes, quinone dyes, triphenylmethane dyes, diphenylmethane dyes, and methylene blue.

[0067] The coloring materials can be used alone or in combination of two or more. The coloring material preferably has an active ingredient content of 0.1 to 20% by mass, more preferably 1 to 10% by mass, and even more preferably 2 to 5% by mass, based on the total amount of the ink.

[0068] The aqueous ink may further contain a surfactant, which can enhance the permeability or wetting and spreading of the ink into a substrate and improve the coatability of the ink. As the surfactant, a nonionic surfactant, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a combination of these can be preferably used, and it is more preferable that the surfactant contains a nonionic surfactant.

[0069] Examples of nonionic surfactants include silicone surfactants, acetylene glycol surfactants, fluorine surfactants, polyoxyethylene alkyl ether surfactants, polyoxypropylene alkyl ether surfactants, polyoxyethylene alkyl phenyl ether surfactants, polyoxypropylene alkyl phenyl ether surfactants, polyoxyethylene fatty acid ester surfactants, polyoxypropylene fatty acid ester surfactants, sorbitan fatty acid ester surfactants, polyoxyethylene sorbitan fatty acid ester surfactants, polyoxyethylene sorbitol fatty acid ester surfactants, glycerin fatty acid ester surfactants, etc. The nonionic surfactants may be used alone or in combination of two or more.

[0070] The nonionic surfactant preferably includes a silicone surfactant, an acetylene glycol surfactant, or a combination thereof. Commercially available silicone surfactants include, for example, "Silface SAG014" and "Silface SAG002" (trade names, manufactured by Nissin Chemical Industry Co., Ltd.). Commercially available acetylene glycol surfactants include, for example, acetylene glycol "Olfine E1010" and "Olfine E1020" (both trade names, manufactured by Nissin Chemical Industry Co., Ltd.).

[0071] The amount of the active ingredient of the surfactant is preferably 0.1 to 5 mass %, and more preferably 0.2 to 2 mass %, relative to the total amount of the ink.

[0072] The water-based ink may further contain a binder resin. The binder resin may be a water-dispersible resin, a water-soluble resin, or a combination thereof.

[0073] Examples of the water-dispersible resin include conjugated diene resins such as styrene-butadiene copolymers and methyl methacrylate-butadiene copolymers; acrylic resins such as polymers or copolymers of acrylic acid esters, methacrylic acid esters, or combinations thereof, or copolymers of these with styrene or the like; vinyl resins such as vinyl chloride-vinyl acetate copolymers and ethylene-vinyl acetate copolymers; functional group-modified resins of these various resins with functional group-containing monomers such as carboxyl groups; urethane resins, melamine resins, urea resins, polyester resins, polyolefin resins, silicone resins, polyvinyl butyral resins, alkyd resins, and the like. These water-dispersible resins may be used alone or in combination of two or more. These water-dispersible resins may be in the form of aqueous resin emulsions (O / W type emulsions). The aqueous resin emulsion may be a resin emulsion of the above resin alone, or a hybrid type resin emulsion consisting of two or more of the above resins. The average particle size of the water-dispersible resin is preferably from 0.01 to 0.50 μm, and more preferably from 0.05 to 0.30 μm. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, neutralized polyacrylic acid, acrylic acid / maleic acid copolymer, acrylic acid / sulfonic acid copolymer, styrene / maleic acid copolymer, etc. In addition, anionic water-soluble resins obtained by introducing an anionic functional group into these resins can be used. From the viewpoint of ink fixation, the binder resin preferably contains a water-dispersible resin, and more preferably contains a water-dispersible urethane resin, a water-dispersible polyolefin resin, a water-dispersible acrylic resin, or a combination thereof.

[0074] Specific examples of water-dispersible urethane resins include anionic resins having a urethane skeleton. Specific examples include "Superflex 150, Superflex 300, Superflex 460, Superflex 470, Superflex 740, Superflex 840" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "Takelac WS-6021, Takelac W-512-A-6, Takelac W-6110" manufactured by Mitsui Chemicals Polyurethanes, Inc., "ADEKA BONTITOR HUX-370, ADEKA BONTITOR HUX-380" manufactured by Adeka Corporation, and "NeoRez R-9660, NeoRez R-966, NeoRez R-967, NeoRez R-986, NeoRez R-2170" manufactured by DSM (all trade names).

[0075] Commercially available examples of water-dispersible polyolefin resins include the Arrowbase series manufactured by Unitika Ltd. (such as "Arrowbase SB-1010, Arrowbase SE-1010, and Arrowbase DC1010"), the Hardlen series manufactured by Toyobo Co., Ltd. (such as "NZ1004, EW5250, and EH801J"), and the AQUACER series manufactured by BYK Corporation (such as "272, 497, 515, 531, and 537") (all of which are product names).

[0076] Examples of the water-dispersible acrylic resin include water-dispersible styrene (meth)acrylic resin, water-dispersible (meth)acrylic resin, etc. The styrene (meth)acrylic resin and the water-dispersible (meth)acrylic resin are not particularly limited, and commercially available products can be used. Examples of commercially available water-dispersible styrene (meth)acrylic resins or water-dispersible (meth)acrylic resins include "Mowinyl 966A, Mowinyl 6750, Mowinyl 6751D, Mowinyl 6960, Mowinyl 6718, Mowinyl 7320" manufactured by Nippon Synthetic Chemical Industry Co., Ltd., "Microgel E-1002, Microgel E-5002" manufactured by Nippon Paint Co., Ltd., "Boncoat 4001, Boncoat 5454" manufactured by DIC Corporation, "SAE1014" manufactured by Zeon Corporation, "Sybinol SK-200" manufactured by Saiden Chemical Industry Co., Ltd., "Neocryl BT-62, Neocryl SA-1094" manufactured by DSM, and "Joncryl 7100, Joncryl 390, Joncryl 711, Joncryl 511, Joncryl 7001, Joncryl 632, Joncryl 741, Joncryl 751" manufactured by BASF. 450, Johncryl 840, Johncryl 74J, Johncryl HRC-1645J, Johncryl 734, Johncryl 852, Johncryl 7600, Johncryl 775, Johncryl 537J, Johncryl 1535, Johncryl PDX-7630A, Johncryl 352J, Johncryl 352D, Johncryl PDX-7145, Johncryl 538J, Johncryl 7640, Examples of binders include Joncryl 7641, Joncryl 631, Joncryl 790, Joncryl 780, and Joncryl 7610 manufactured by Nissin Chemical Industry Co., Ltd., Vinyblan 2580, Vinyblan 2585, Vinyblan 2682, Vinyblan 2680, Vinyblan 2684, Vinyblan 2685, and Vinyblan 2687 manufactured by Nissin Chemical Industry Co., Ltd., and NK Binder R-5HN manufactured by Shin-Nakamura Chemical Co., Ltd. (all trade names).

[0077] The binder resins can be used alone or in combination of two or more. The content of the binder resin is preferably from 1 to 20% by mass, and more preferably from 5 to 10% by mass, based on the total amount of the ink.

[0078] The aqueous ink preferably contains water as an aqueous solvent, and the main solvent may be water. The water is not particularly limited, but is preferably one that contains as few ionic components as possible. In particular, from the viewpoint of the pigment dispersion stability of the ink, it is preferable that the content of polyvalent metal ions such as calcium is small. As the water, for example, ion-exchanged water, distilled water, ultrapure water, etc. may be used. From the viewpoint of adjusting the viscosity, the water content is preferably 20 to 90% by mass, more preferably 30 to 80% by mass, and even more preferably 40 to 70% by mass, based on the total amount of the ink.

[0079] The water-based ink may contain a water-soluble organic solvent, which may be any of those described above for the treatment liquid. From the viewpoints of wettability, moisturizing effect, viscosity adjustment, and the like, the water-soluble organic solvent is preferably contained in an amount of 1 to 80 mass % relative to the total amount of the ink, more preferably 10 to 50 mass %, and even more preferably 20 to 40 mass %.

[0080] In addition to the components described above, the aqueous ink may optionally contain various additives such as rust inhibitors, preservatives, antioxidants, UV absorbers, infrared absorbers, crosslinking agents, pH adjusters, defoamers, wetting agents (moisturizing agents), surface tension adjusters (penetrating agents), and fixing agents.

[0081] In order to obtain ejection properties suitable for an inkjet ink, the viscosity of the aqueous ink is preferably 1 to 40 mPa·s at 23° C., more preferably 3 to 20 mPa·s, and even more preferably 4 to 12 mPa·s.

[0082] The method for preparing the ink is not particularly limited, but the desired ink can be obtained by appropriately mixing each component. For example, a dispersing machine such as a bead mill may be used to improve the dispersibility of the pigment. The obtained composition may be filtered using a filter or the like. Various additives may also be added as appropriate.

[0083] "Method of manufacturing printed matter" According to one embodiment, it is possible to provide a method for producing a printed matter, the method including the steps of applying a treatment liquid to a substrate by an inkjet method, and applying an aqueous inkjet ink by an inkjet method to the substrate to which the treatment liquid has been applied, using a wet-on-wet method. The treatment liquid and aqueous inkjet ink may be the treatment liquid and aqueous inkjet ink according to the embodiment described above.

[0084] The treatment liquid and the water-based ink are each preferably applied to the substrate by an inkjet method. The inkjet method is a printing method that can easily and freely form an image on demand without contacting the substrate. The inkjet method is not particularly limited, and may be any of a piezo method, an electrostatic method, a thermal method, etc. When an inkjet printing device is used, it is preferable to eject a treatment liquid or an aqueous ink from an inkjet head based on a digital signal, and to cause droplets of the ejected treatment liquid or ink to adhere to the substrate.

[0085] First, the process of applying the treatment liquid to the substrate by the inkjet method will be described. As described above, the treatment liquid has excellent ejection recovery performance after being left standing, and therefore can be applied to the substrate by adopting the inkjet method. The region to which the treatment liquid is applied to the substrate may be a region having the same shape as the image formed by the water-based ink, a wider region including the shape of the image formed by the water-based ink, or the entire surface of the substrate. Since the treatment liquid can be applied on demand by the inkjet method, the application region can be adjusted to match the shape of the image formed by the water-based ink. The amount of the treatment liquid applied is 0.1 to 200 g / m 2 is preferable, and 2 to 20 g / m 2 is more preferred.

[0086] Next, a process of applying the aqueous ink to the substrate to which the treatment liquid has been applied by a wet-on-wet method using an inkjet method will be described. The aqueous ink is preferably applied to the substrate to which the treatment liquid has been applied by a wet-on-wet method. That is, the aqueous ink is applied in a state in which moisture is not completely removed from the substrate to which the treatment liquid has been applied, preferably in a state in which the substrate to which the treatment liquid has been applied is kept wet. Specifically, after the treatment liquid is applied, the aqueous ink is preferably applied in a state in which the remaining amount of the volatile matter of the treatment liquid on the substrate is 60 mass% or more. For example, after the treatment liquid is applied to the substrate, the aqueous ink is preferably applied without going through a drying process such as heat drying. By applying the aqueous ink while the treatment liquid is in a wet state on the substrate, the treatment liquid and the aqueous ink are sufficiently mixed on the substrate, the ink components are uniformly aggregated, and excellent image quality can be obtained.

[0087] After the treatment liquid is applied, the temperature of the substrate surface until the aqueous ink is applied is preferably 40° C. or less, and preferably 35° C. or less. In addition, as long as the substrate can be kept wet between the application of the treatment liquid and the application of the aqueous ink, it is also preferable to apply the treatment liquid while heating the substrate, regardless of the above temperature. Furthermore, the aqueous ink may be applied while heating the substrate to which the treatment liquid has been applied. For example, the treatment liquid and the aqueous ink may be applied while heating the substrate to 30 to 60° C., preferably 35 to 45° C. In particular, when a non-permeable substrate is used as the substrate, it is preferable to apply the treatment liquid and the aqueous ink while heating. The time from the application of the treatment liquid to the substrate until the application of the aqueous ink is preferably 0.1 to 200 seconds. By setting this temperature or time, when the substrate is a non-permeable substrate, the treatment liquid is appropriately leveled on the substrate before the aqueous ink is applied, and when the substrate is a permeable substrate, the aqueous ink is easily applied without the treatment liquid excessively penetrating the substrate.

[0088] The amount of water-based ink applied is 0.1 to 400 g / m 2 is preferable, and 2 to 40 g / m 2 is more preferred. In the case of monochrome printing, one type of water-based ink may be used, and in the case of color printing, two or more types of water-based ink may be used. When two or more types of water-based inks are used, it is preferable to apply the first water-based ink by a wet-on-wet method after applying the treatment liquid to the substrate, and then apply the next water-based ink by a wet-on-wet method.

[0089] The step of applying the treatment liquid and the step of applying the aqueous ink may be performed in separate devices, or may be performed using one device. In the method for producing a printed matter according to one embodiment, the aqueous ink is applied by a wet-on-wet method, which makes it possible to eliminate the need for a drying step after applying the treatment liquid, and therefore the application of the treatment liquid and the aqueous ink can be easily performed in-line within one printing device.

[0090] A step of heat treating the substrate after application of the aqueous ink can be further provided. By heat treating the substrate to which the treatment liquid and the aqueous ink have been applied, moisture can be removed from the substrate. Furthermore, the component of the aggregating agent in the treatment liquid is concentrated on the substrate, which further strengthens the effect of aggregating the coloring material of the aqueous ink, and a printed matter of higher image quality can be obtained. When an aqueous ink containing a binder resin is used, the formation of a resin film on the substrate can be promoted.

[0091] The substrate may be heated by contact or non-contact. Examples of the heating device include a hot air dryer, a heating wire, a hot plate, a heat roller, and an IR heater. These heating devices may be integrated with the printing device. The heat treatment temperature is preferably 40 to 200°C, more preferably 60 to 180°C, and even more preferably 80 to 120°C. By setting the temperature at 40°C or higher, heating can be efficiently performed and the heating time can be shortened. By setting the temperature at 200°C or lower, deterioration of the image quality and deterioration of the substrate due to excessive heating can be prevented. The heat treatment time may be appropriately set according to the type of substrate, heat treatment temperature, heat treatment method, etc., as well as the components and contents of the treatment liquid and the aqueous ink.

[0092] A step of forming an overcoat layer by post-treating the substrate after applying the aqueous ink may be further provided. The method of post-treating the substrate may be performed by applying an overcoat liquid to the substrate. For example, an overcoat liquid containing a resin capable of forming a film and an aqueous medium or an oil-based medium may be used as the overcoat liquid. Note that, since the method for producing a printed matter using the treatment liquid and aqueous ink according to one embodiment provides excellent image quality, it is not necessary to provide an overcoat layer.

[0093] The above-mentioned method for producing a printed matter can be applied to both permeable and non-permeable substrates. A non-permeable substrate is one in which liquid does not penetrate into the substrate, specifically, a substrate in which most of the liquid in the treatment liquid or ink remains on the surface of the substrate. Examples of non-permeable substrates include metal substrates such as metal plates of aluminum, iron, copper, titanium, tin, chromium, cadmium, and alloys (e.g., stainless steel, steel, etc.); glass substrates such as plate glass such as borosilicate glass, quartz glass, and soda lime glass; resin substrates such as resin sheets such as PET films, PP films, OHT sheets, polyester sheets, and polypropylene sheets, acrylic plates, and polyvinyl chloride plates; and ceramic substrates such as molded bodies of alumina, zirconia, steatite, and silicon nitride. These substrates may have a plating layer, a metal oxide layer, a resin layer, or the like formed thereon, or may have been surface-treated using a corona treatment or the like.

[0094] Examples of permeable substrates include printing paper such as plain paper, coated paper, and special paper; fabrics such as woven fabrics, knitted fabrics, and nonwoven fabrics; porous building materials for humidity control, sound absorption, and heat insulation; wood, concrete, and porous materials. Here, plain paper is paper on which no ink receiving layer or film layer is formed on the normal paper. Examples of plain paper include fine paper, medium-quality paper, PPC paper, wood paper, recycled paper, etc. As the coated paper, inkjet coated paper such as matte paper, glossy paper, and semi-glossy paper, and so-called coated printing paper can be preferably used. Here, coated printing paper is printing paper that has been used in letterpress printing, offset printing, gravure printing, etc., and is printing paper in which a coating layer is provided on the surface of fine paper or medium-quality paper with a paint containing an inorganic pigment such as clay or calcium carbonate and a binder such as starch. Coated printing paper is classified into lightly coated paper, fine lightweight coated paper, medium lightweight coated paper, fine coated paper, medium coated paper, art paper, cast coated paper, etc., depending on the coating amount of the paint and the coating method.

[0095] Examples of fibers that make up the fabric include at least one type selected from various fibers such as inorganic fibers such as metal fibers, glass fibers, rock fibers, and silicic fibers; regenerated fibers such as cellulose-based and protein-based fibers; semi-synthetic fibers such as cellulose-based fibers; synthetic fibers such as polyamide, polyester, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyvinyl alcohol, polyurethane, polyethylene, polypropylene, polystyrene, and polyethylene fluoride; and natural fibers such as cotton, hemp, silk, and wool. EXAMPLES

[0096] The present invention will be described in detail below with reference to examples. The present invention is not limited to the following examples. In the following description, "%" means "% by mass" unless otherwise specified. Raw materials for which no particular description is given regarding the manufacturer are available from Tokyo Chemical Industry Co., Ltd., Fujifilm Wako Pure Chemical Industries, Ltd., etc. The content shown in each table indicates the total amount of the components blended as a solution or dispersion, and also indicates the proportion of the resin content or active ingredient, etc.

[0097] (Preparation of water-based ink) The raw materials were mixed according to the recipe shown below, stirred at 100 rpm for 30 minutes using a mix rotor, and filtered through a 5 μm nylon syringe filter to obtain an ink. Water dispersion of self-dispersing pigment (Cabot Corporation's "CAB-O-JET 400" (solid content 15%)): 20% by mass Urethane resin emulsion (DSM "NeoRezR-967" (resin content 40%)): 22.5% by mass Glycerin: 1% by weight Diethylene glycol: 30% by mass Surfactant (Nissin Chemical Industry Co., Ltd. "Silface SAG002" (non-volatile content > 95%)): 1% by mass Ion-exchanged water: 25.5% by mass

[0098] (Synthesis of silicone surfactants) The synthesis recipe for the silicone surfactant used in the treatment liquid is shown in Table 1, and it was synthesized according to the following procedure. The raw materials for liquid A shown in the table were placed in a flask and heated and stirred at 70°C under a nitrogen atmosphere. The raw materials for liquid B shown in the table were mixed to prepare liquid B, which was then added dropwise to the flask over 1 hour and heated and stirred for 5 hours. The product was filtered and toluene was removed from the filtrate under reduced pressure. By-products were separated by column chromatography. The structural formulas of the obtained activators 1 to 3 are shown in the following formulas (1) to (3), respectively. In the following formulas, R 1 ~R 3 are respectively (CH2)3-(OC2H4) 10 It is a group represented by —OH.

[0099] [ka]

[0100] [Table 1]

[0101] (Preparation of processing solution) Tables 2 to 4 show the formulations of the pretreatment liquid. According to the formulations shown in the tables, the raw materials were mixed so that the total amount was 100 mass%, and the mixture was stirred at 100 rpm for 30 minutes using a mix rotor and filtered through a 5 μm nylon syringe filter to obtain a treatment liquid. The components used are as follows. The ratio of the contents of DMA / ECH polycondensate and DMA / NH3 / ECH polycondensate to the contents of DADMAC polymer and DADMAC / SO2 copolymer, "ECH:DADMAC", is shown in the tables.

[0102] DMA / ECH polycondensate "Unisense KHE104L" (product name): manufactured by Senka Corporation, dimethylamine-epichlorohydrin polycondensate, resin content 20%. DMA / NH3 / ECH polycondensate "Unisense KHE101L" (product name): manufactured by Senka Corporation, dimethylamine-ammonia-epichlorohydrin polycondensate, resin content 41%. DADMAC polymer "PAS-H-1L" (product name): manufactured by Nittobo Medical Co., Ltd., diallyldimethylammonium chloride polymer (molecular weight: 8,500), resin content 28%. DADMAC / SO2 copolymer "PAS-A-1" (product name): manufactured by Nittobo Medical Co., Ltd., diallyldimethylammonium chloride-sulfur dioxide copolymer (molecular weight: 5000), resin content 24%. Fluorosurfactants "Surflon S-243" (product name) and "Surflon S-386" (product name): Manufactured by AGC Seimi Chemical Co., Ltd. Both are nonionic fluorosurfactants, 100% active ingredient. Silicone-based surfactants: Activator 1 (side-chain modified), Activator 2 (side-chain modified), and Activator 3 (end modified): synthesized according to the above recipe.

[0103] (Manufacturing method of printed matter) Two inkjet printers, "MMP-8130" (product name) manufactured by Mastermind, Inc., were used as printing devices. The first printer applied the treatment liquid to the substrate, and the second printer applied the water-based ink to the substrate to which the treatment liquid had been applied, using a wet-on-wet method. After application of the water-based ink, the substrate was dried at 90°C using a hot air dryer to produce a printed matter.

[0104] The conditions for applying the treatment liquid are as follows. Setting density: Set to "8" in the printing device settings. Processing solution application area: A solid image of 20 cm x 10 cm square is applied. Processing fluid printing rate: 25%.

[0105] The conditions for applying the water-based ink are as follows. Setting density: Set to "8" in the printing device settings. Ink image: The word “Beauty” is printed in 12-point white letters within a 20cm x 10cm solid image so that it overlaps with the area to which the treatment liquid is applied. Ink coverage rate: 100%.

[0106] The following two types of substrates were used for the printed materials. Non-permeable substrate: polyvinyl chloride substrate ("MPI3002P WPE" (product name) manufactured by Avery Dennison), referred to as PVC substrate in the following explanation. Permeable substrate: 100% polyester fabric (Toromatt), referred to as fabric substrate in the following explanation.

[0107] (Evaluation method) The image quality of the printed matter and the ejection recovery performance after standing were evaluated as follows. The results are shown in Tables 2 to 4. "Image quality of prints" The treatment liquid was applied to the PVC substrate and the cloth substrate under the above-mentioned treatment liquid application conditions, and 50 seconds after the application of the treatment liquid, the substrate was wetted with the treatment liquid and the water-based ink was applied under the above-mentioned water-based ink application conditions. After the application of the water-based ink, the substrate was dried at 90°C using a hot air dryer to obtain a printed matter.

[0108] The image quality of the prints on the PVC substrate was evaluated according to the following criteria. A: A uniform solid image is formed, and no blurring is observed in the white characters. B: Image unevenness or cracks that can be seen from a distance of 30 cm from the printed surface are observed, or some of the white letters are crushed, but still legible. C: Clear image unevenness or cracks are observed on the printed surface, or the outline characters are difficult to read.

[0109] The image quality of the prints on the fabric substrate was evaluated by measuring the OD value of the printed surface using a Videojet X-Rite eXact colorimeter and using the following criteria: A:OD value is 1.4 or higher. B: OD value is 1.3 or more and less than 1.4. C:OD value is less than 1.3.

[0110] Based on the evaluation of the image quality of the prints on the PVC substrate and the cloth substrate, the image quality of the prints was comprehensively evaluated according to the following criteria. A: The image quality of both the PVC substrate and the cloth substrate is A. B: The image quality of the PVC substrate and the cloth substrate is A and B, B and A, or B and B, respectively. C: At least one of the image quality of the PVC substrate and the cloth substrate is C.

[0111] "Recovery of treatment liquid ejection after the head is left unused" The ejection recovery performance of the ink-jet head filled with the treatment liquid after it was left standing was evaluated by the following procedure. The treatment liquid was loaded into an inkjet printer "MMP-8130" (product name) manufactured by Mastermind Co., Ltd., and after confirming that the treatment liquid was ejected normally without missing nozzles, the printer was left in a capped state at room temperature for one month, and then a cleaning operation was performed. After the cleaning operation, the treatment liquid was applied to a PET (polyethylene terephthalate) film under the same conditions as those for applying the treatment liquid described above. The number of white streaks observed on the substrate to which the treatment liquid was applied was counted as the number of missing nozzles, and the occurrence rate of missing nozzles was calculated from the number of missing nozzles relative to the total number of nozzles, and evaluated according to the following criteria. A: The rate of nozzle clog after cleaning is less than 1%. B: The rate of nozzle missing after the cleaning operation is 1% or more and less than 3%. C: Missing nozzles after cleaning operation are 3% or more.

[0112] [Table 2]

[0113] [Table 3]

[0114] [Table 4]

[0115] As shown in the table, good image quality was obtained for both non-permeable and permeable substrates by printing using the substrate to which the treatment liquid of each Example was applied. In addition, the ejection recovery performance of the treatment liquid of each Example after the head was left standing was good.

[0116] In Examples 1 to 4, compared to Example 5, a treatment liquid containing a side-chain modified silicone surfactant was used, and therefore the treatment liquid was able to sufficiently spread on the PVC substrate, resulting in more uniform solid images. In Examples 1 to 4, 7, and 8, the ratio of the diallyldialkylammonium halide polymer was higher than in Example 6, so the aqueous ink and the treatment liquid on the PVC base material were thoroughly mixed before coagulation, resulting in better uniformity of solid images. In Examples 1 to 6, since the amine compound was included, the ejection recovery performance of the treatment liquid after it was left in the head was superior to that of Example 7. This is believed to be because the amine compound functioned as a rust inhibitor, suppressing the generation of rust in the head and also suppressing the generation of foreign matter. In comparison with Example 8, Examples 1 to 6 use a treatment liquid containing an aliphatic amine-epihalohydrin polycondensate of a quaternary ammonium salt that does not contain a secondary or tertiary ammonium salt as a constituent unit. This not only suppresses the generation of crystals in the treatment liquid when the head is left standing, but also prevents the generation of foreign matter due to the interaction between the polycondensate of an aliphatic amine and epihalohydrin and the diallyldialkylammonium halide polymer, and further improves the ejection recovery performance of the treatment liquid after the head is left standing.

[0117] In Examples 1 to 8, the ratio of the polycondensate of aliphatic amine and epihalohydrin was higher than in Example 9, so the reaction rate of the ink components and the treatment liquid on the cloth substrate was faster, and the image density on the cloth substrate was improved. In addition, in Examples 1 to 4, 7, and 8, the ratio of the polycondensate of aliphatic amine and epihalohydrin was higher than in Example 9, so the reaction of the ink components and the coagulant on the PVC substrate was promoted, and the fine character reproducibility on the PVC substrate was improved. In addition, in Examples 1 to 6, the ratio of the polycondensate of aliphatic amine and epihalohydrin was higher than in Example 9, so the generation of crystals in the treatment liquid due to the head being left unattended was more suppressed, and the discharge recovery performance of the treatment liquid after the head being left unattended was more improved.

[0118] In Comparative Example 1, the treatment liquid did not contain a diallyldialkylammonium halide polymer, and the ink and treatment liquid aggregated on the PVC substrate before they were sufficiently mixed, resulting in non-uniform film formation during the drying process after application of the water-based ink, and cracks in the image. In Comparative Example 2, the treatment liquid does not contain a polycondensate of an aliphatic amine and epihalohydrin, and in Comparative Example 3, the ratio of the polycondensate of an aliphatic amine and epihalohydrin is low. In these Comparative Examples, a large amount of crystals was generated by leaving the treatment liquid on the head, and the ejection recovery performance of the treatment liquid after leaving it on the head was reduced. Furthermore, in Comparative Example 2, the reaction speed of the ink components and the treatment liquid on the cloth substrate was slow, and sufficient image density was not obtained on the cloth substrate. In Comparative Examples 4 and 5, the treatment liquid did not contain a combination of a fluorine-based surfactant and a silicone-based surfactant as surfactants, and the wettability of the treatment liquid on the PVC substrate decreased, the treatment liquid was not applied uniformly, and image unevenness was observed.

Claims

1. A treatment liquid applied to a substrate by an inkjet method, Water, a flocculant, and a surfactant; The flocculant contains a polycondensate of an aliphatic amine and an epihalohydrin and a diallyldialkylammonium halide polymer in a mass ratio of 20:80 to 90:10; The surfactant in the treatment liquid includes a fluorine-based surfactant and a silicone-based surfactant.

2. 2. The treatment liquid according to claim 1, wherein the polycondensate of the aliphatic amine and the epihalohydrin and the diallyldialkylammonium halide polymer are present in a mass ratio of 35:65 to 50:

50.

3. 3. The treatment liquid according to claim 1, further comprising an amine compound having a boiling point of 70 to 250°C.

4. The treatment liquid according to claim 1 , wherein the silicone surfactant includes a side-chain-modified silicone surfactant.

5. An inkjet ink set comprising the treatment liquid according to claim 1 and an aqueous inkjet ink.

6. 5. A method for producing a printed matter, comprising: a step of applying the treatment liquid according to claim 1 to a substrate by an inkjet system; and a step of applying an aqueous inkjet ink by a wet-on-wet method to the substrate to which the treatment liquid has been applied by the inkjet system.

7. The method for producing a printed matter according to claim 6 , wherein the substrate is a non-permeable substrate.

8. The method for producing a printed matter according to claim 6 , wherein the substrate is a permeable substrate.

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