JP2019019315A - Ink set, and manufacturing method of printed material - Google Patents

Abstract

To provide an ink set comprising an inkjet ink and a treatment liquid, the ink set capable of forming high image quality printed matter with excellent coat durability and drying properties without image defects such as color mixing or insufficient filling, regardless of printing conditions, such as printing speed and recording resolution, and recording media.SOLUTION: The ink set comprises an inkjet ink and a treatment liquid used together with the inkjet ink. The inkjet ink contains a pigment, a water-soluble organic solvent, a surfactant, and water. The water-soluble organic solvent contains a glycol ether-based organic solvent having a specific structure, and the processing liquid contains a flocculant. The flocculant contains 6.8-20.8 mass% of calcium nitrate relative to the total amount of the treatment liquid, and the amount of compounds contained in the treatment liquid that have three or more hydroxyl groups is less than or equal to 15 mass% relative to the total amount of the treatment liquid.SELECTED DRAWING: None

Description

  The present invention relates to an ink set and a method for producing printed matter using the ink set.

  Inkjet printing is a recording method in which droplets of inkjet ink ejected from an inkjet head are directly applied to a recording medium to form characters and images. Compared to conventional plate-type printing such as offset printing and gravure printing, it is not necessary to make a plate and can support variable printing. It is easy to operate and adjust the printing device and has low noise during printing. In recent years, there has been an increase in demand for industrial use, including home use and household use.

  Ink jet inks used for ink jet printing are classified into solvent type, aqueous type, UV curable type and the like according to the composition. On the other hand, in recent years, the movement to regulate the use of organic solvents and photosensitive monomers, which are harmful to humans and the environment, has been accelerating, and from solvent-based inks and UV curable inks using these materials to water-based inks. There is a growing demand for replacements.

  The water-based (type) ink-jet ink contains water as a main component, and a water-soluble organic solvent such as glycerin or glycol is added to control wettability and dryability with respect to the recording medium. Further, when a character or image pattern is printed (applied) on a recording medium using an inkjet ink composed of these liquid components, the liquid components penetrate into the recording medium and / or evaporate from the recording medium. Dry and fix on the recording medium.

  On the other hand, recording media used in ink jet printing are roughly classified into paper base materials, cloth base materials, plastic base materials and the like. Among them, the paper base material has a large production volume and requires high-speed printing, and high image quality is required. There are various types of paper base materials, from those having high permeability such as high-quality paper and recycled paper to those having low (no) permeability such as coated paper and art paper. In order to further expand the demand for ink-jet printing, the development of water-based ink-jet inks that can be applied to various recording media has become a major challenge for those skilled in the art.

  However, in conventional water-based inkjet inks, when printed on a highly permeable paper substrate, the inkjet ink penetrates into the paper substrate due to its low viscosity and high surface tension derived from water. Thus, there is a possibility that feathering (a bleeding phenomenon that occurs along the base fiber) may occur. In addition, when printing is performed on a paper base material having low permeability, ink jet ink droplets mix with each other, causing coalescence and color mixing. As described above, it has been difficult to obtain high-quality printed matter regardless of the recording medium.

  As a measure against the above problem, a treatment liquid treatment for a recording medium is known. In general, as a treatment liquid for ink-jet ink, one that forms a layer (ink receiving layer) that absorbs liquid components in the ink-jet ink and improves the drying property (see Patent Documents 1 to 4), a color material, a resin, and the like There are two types (see Patent Documents 5 to 6) that form a layer (ink aggregation layer) that prevents image blurring and improves image quality by intentionally aggregating solid components contained in inkjet ink. Are known.

  However, in the case of an ink receiving layer, the texture of the recording medium is reduced due to the necessity of increasing the thickness of the layer, the density / color gamut is decreased due to the ink being absorbed by the receiving layer, and the absorption is uneven. Bleeding or color mixing may occur due to this. On the other hand, in the case of an ink agglomerated layer, although the ability to accept liquid components is inferior, the ink is fixed on the surface of the agglomerated layer without greatly impairing the texture of the recording medium. If the layer can be applied uniformly, dot fusion of the ink-jet ink can be suppressed and the dots can be in an ideal perfect circle.

  On the other hand, another problem exists in the processing liquids disclosed in Patent Documents 5 to 6. Patent Document 5 discloses a treatment liquid (reaction liquid) containing a copolymer composed of a hydrophilic monomer and a hydrophobic monomer. In the examples, a treatment liquid containing 6% by mass of magnesium nitrate, and a water-soluble substance are disclosed. As an organic solvent, a set of ink jet ink containing glycerin and diethylene glycol has been evaluated. However, a treatment liquid containing magnesium nitrate as a flocculant cannot exhibit a sufficient agglomeration (color mixing suppression) effect when printing at high speed. Although it is conceivable to increase the coating amount of the treatment liquid in order to develop the cohesive effect, the coating amount of water or an organic solvent contained in the treatment liquid also increases. There is a possibility that the drying property of the printed ink-jet ink and the coating film resistance deteriorate, or the print image quality deteriorates due to the coalescence of the ink-jet ink droplets. In addition, a measure to increase the amount of the flocculant in the treatment liquid in order to further develop the coagulation effect is conceivable, but in that case, excessive wetting and spreading of the ink-jet ink may cause insufficient filling of the solid part. It will occur and the print quality will deteriorate.

  Patent Document 6 discloses a recording method using an ink set comprising a treatment liquid containing a polyvalent metal salt or a polyether-modified polysiloxane compound and an inkjet ink containing resin fine particles. There is a description that a printed matter having excellent coating film resistance and print image quality can be obtained by using. However, as described in the literature, the ink set is used for a recording medium having a specific absorption layer. For example, when printing on a paper substrate having high permeability, Image defects such as color mixing may occur. In addition, the polyvalent metal salt used in Examples of Patent Document 6 is magnesium nitrate, magnesium sulfate, and calcium acetate. As in Patent Document 5, sufficient aggregation (when printed at high speed) There is a possibility that the effect of suppressing color mixing) cannot be exhibited.

  As described above, conventionally, a processing liquid that can produce a high-quality printed material that is excellent in coating film resistance and drying property and has no image defects such as color mixing or insufficient filling, regardless of printing conditions such as recording media and printing speed. There was no ink set containing inkjet ink.

JP 2000-238422 A JP 2000-335084 A JP 2012-131108 A JP 2009-241304 A JP 2013-188958 A JP 2009-262549 A

  The present invention has been made in order to solve the above-mentioned problems, and is excellent in coating film resistance and drying properties regardless of the recording medium and printing conditions such as printing speed and recording resolution, and has an image such as color mixing or insufficient filling. An object of the present invention is to provide an ink set including a treatment liquid and an inkjet ink, which can produce a high-quality printed product without defects. In addition to the above, another object of the present invention is to provide the ink set which is excellent in storage stability and can maintain the above-mentioned quality even after a long period of time. Still another object of the present invention is to provide a production method effective for solving the above-described problems in producing printed matter using the ink set.

  As a result of intensive studies to solve the above problems, the present inventors have found that an inkjet ink containing an organic solvent having a specific structure and a surfactant, a specific amount of calcium nitrate as a flocculant, and a specific The inventors have found that the above problem can be solved only by an ink set with a treatment liquid in which the amount of the compound having a structure is a certain value or less, and the present invention has been completed.

  That is, the present invention is an ink set comprising an inkjet ink and a treatment liquid used together with the inkjet ink, wherein the inkjet ink contains a pigment, a water-soluble organic solvent, a surfactant, and water, and the water-soluble The organic solvent contains a glycol ether organic solvent (A) represented by the following general formula (1), the treatment liquid contains a flocculant, and the flocculant contains calcium nitrate with respect to the total amount of the treatment liquid. It is related with the ink set which contains 0.8-20.8 mass% and the said process liquid contains 15 mass% or less of compounds which have 3 or more of hydroxyl groups with respect to the process liquid whole quantity.

General formula (1):
R1-(— O—CH ₂ CH ₂ —) n—OH

  In the general formula (1), R1 represents an alkyl group having 2 to 4 carbon atoms, which may have a branched structure. N is 2 or 3.

  Moreover, this invention relates to the said ink set whose pH of the said process liquid is 3.5-11.

  The present invention also relates to the above ink set, wherein the treatment liquid further contains a pH adjuster.

  In the present invention, the treatment liquid further contains a nonionic surfactant, and the nonionic surfactant contains one or more compounds selected from an acetylene surfactant and a siloxane surfactant. Including the ink set.

  The present invention also relates to the above ink set, wherein the inkjet ink further contains a pigment dispersion resin.

  The present invention also relates to the above ink set, wherein the glycol ether organic solvent (A) represented by the general formula (1) includes a glycol ether organic solvent in which n is 2.

  The present invention also relates to the above ink set, wherein the water-soluble organic solvent further comprises a diol solvent (B) having a surface tension at 25 ° C. of 30 to 50 mN / m.

  Further, the present invention provides a diol solvent (B) having a surface tension of 30 to 50 mN / m at 25 ° C. with respect to the blending amount of the glycol ether organic solvent (A) represented by the general formula (1). It is related with the said ink set whose mass ratio of a compounding quantity is 1: 0.5-1: 7.5.

  The present invention is also a method for producing an inkjet ink print using the ink set described above, the step of applying the treatment liquid to a recording medium that is a paper base or a synthetic paper base, and the treatment liquid. The present invention relates to a method for producing an ink-jet ink print, comprising a step of applying the ink-jet ink to the applied portion by a one-pass printing method.

The present invention also relates to the method for producing an inkjet ink printed material, wherein the treatment liquid is applied to the recording medium so that the amount of calcium ions on the surface of the recording medium is 0.5 to 5.0 mmol / m ² .

  The present invention also relates to a printed matter obtained by printing the ink set described above on a recording medium.

  According to the present invention, a processing liquid capable of producing a high-quality printed matter having excellent coating film resistance and drying property and having no image defects such as color mixing and insufficient filling, regardless of printing conditions such as a recording medium and printing speed and recording resolution. And ink set containing inkjet ink can be provided. In addition to the above, it is possible to provide the ink set which is excellent in storage stability and can maintain the above-mentioned quality even after a long period of time. Furthermore, when manufacturing a printed matter using the said ink set, the manufacturing method effective in the solution of the said subject came to be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail. In addition, embodiment described below demonstrates an example of this invention. The present invention is not limited to the following embodiments, and includes modifications that are implemented without departing from the scope of the present invention.

  The ink set of the present invention includes an inkjet ink (hereinafter also simply referred to as “ink”) containing a pigment, a water-soluble organic solvent, a surfactant, and water, and a treatment liquid containing a flocculant. In addition, the water-soluble organic solvent contains the glycol ether organic solvent (A) represented by the general formula (1), and the flocculant contains calcium nitrate in the amount of 6.8 to 20. In addition to 8% by mass, the treatment liquid contains 15% by mass or less (or 0% by mass) of a compound having 3 or more hydroxyl groups based on the total amount of the treatment liquid. As described in the prior art, in inkjet printing, it has been conventionally performed to use a treatment liquid and an inkjet ink together. However, in the present invention, a treatment liquid containing a specific amount of a specific material is combined with an inkjet ink. In particular, it has its characteristics.

  The treatment liquid of the present invention is applied onto a recording medium before printing inkjet ink, and forms an ink aggregation layer on the recording medium. Calcium nitrate contained in the ink agglomeration layer formed by the treatment liquid of the present invention (hereinafter also simply referred to as “(treatment liquid layer) of the present invention”) is dissolved when an aqueous medium is applied later. It ionizes into ions and calcium ions. Therefore, when the ink-jet ink droplets of the present invention containing water or a water-soluble organic solvent come into contact with the treatment liquid layer, nitrate ions and calcium ions are ionized and eluted in the ink-jet ink droplets. It is done. The eluted calcium ions diffuse into the ink droplets and exist in a dissolved and / or dispersed state, and have solid components such as pigments and resins having anion charge, and cation-anion interactions and adsorption states. Cause changes. As a result, it is considered that aggregation / precipitation of the solid component and local thickening occur due to a decrease in the dissolution and / or dispersion function.

  In the present specification, the “aqueous medium” means a medium composed of a liquid containing at least water.

  In addition to calcium nitrate, cationic resins, acidic compounds, and inorganic metal salts other than calcium nitrate are known as flocculants that exhibit the above-described aggregation mechanism. The reason why calcium nitrate is selected in the present invention is the characteristics of calcium ions having a small ion size, such as high diffusion / penetration rate and high coagulation ability, and also the endotherm when dissolved in an aqueous medium, which is characteristic of nitrate. The magnitude of energy can be mentioned. That is, when calcium nitrate is ionized, it is necessary to absorb heat energy from the aqueous medium, so that it takes some time for ionization / elution and the manifestation of the aggregation function compared to the other flocculants described above. This is considered to be the case.

  On the other hand, the inkjet ink of the present invention comprises a glycol ether organic solvent (A) represented by the general formula (1) (hereinafter also referred to as “specific glycol ether organic solvent (A)”), a surfactant, including. The present inventors diligently studied the influence of the water-soluble organic solvent contained in the inkjet ink on the permeability to the recording medium. As a result, it has been found that the ink containing the specific glycol ether organic solvent (A) is particularly excellent in permeability, and that the effect is further enhanced when used in combination with a surfactant. In other words, inks using a specific glycol ether organic solvent (A) and a surfactant in combination are difficult not only for easily absorbent base materials such as fine paper and liner paper, but also for coated paper, art paper, cast paper and the like. It can permeate suitably also to an absorptive base material.

  Here, when a treatment liquid layer containing calcium nitrate is present on the recording medium to which the inkjet ink is applied, it is considered that the calcium nitrate also penetrates into the recording medium as the inkjet ink penetrates. As described above, since it takes some time for calcium nitrate to exhibit the function as a flocculant, it is considered that the ink is aggregated and thickened inside the recording medium. As a result, the amount of ink remaining on the surface of the recording medium is reduced, and a printed matter having both coating film resistance and drying property and print image quality can be obtained.

  Moreover, when an easily absorbable base material is used, penetration | infiltration progresses until an ink aggregates and thickens, and it is also considered that feathering and coalescence and mixing of droplets generate | occur | produce. On the other hand, in the case of the present invention, due to the endothermic reaction that occurs during the ionization of calcium nitrate, the liquid temperature of the ink droplets decreases, thereby increasing the viscosity and surface tension and suppressing excessive penetration and bleeding. Furthermore, it is thought that coalescence of the ink droplets can be suppressed by the surfactant contained in the ink being quickly oriented at the ink droplet interface.

  Furthermore, as a result of investigations by the present inventors, the amount of calcium nitrate present in the treatment liquid is set to 6.8 to 20.8% by mass with respect to the total amount of the treatment liquid, thereby synergistic with the ink having the above-described configuration. It has been found that the effect is further enhanced, and a printed matter having high image quality and excellent coating film resistance and drying properties can be stably obtained regardless of the recording medium and the printing speed.

  Further, the treatment liquid of the present invention may contain a compound having 3 or more hydroxyl groups, but when it is contained, it is preferably 15% by mass or less and not contained with respect to the total amount of the treatment liquid. High-quality paper and some coated papers have functional groups such as hydroxyl groups and carboxyl groups on the surface and inside thereof, so if they contain compounds having 3 or more hydroxyl groups, compounds having 3 or more hydroxyl groups It is thought to cause interactions such as hydrogen bonding. As a result, even if heat energy is applied to the treatment liquid, the compound having three or more hydroxyl groups tends to remain on the recording medium. When the ink jet ink of the present invention is applied to a recording medium having a treatment liquid layer in such a state, the hydroxyl group present in the compound having three or more hydroxyl groups interacts with calcium ions, There exists a possibility that the effect expression as a flocculant may become inadequate. As described above, in the present invention, by limiting the amount of the compound having three or more hydroxyl groups in the treatment liquid, it is possible to produce a printed material with excellent image quality that does not depend on the recording medium.

  As described above, by combining the above-described processing liquid and ink, the coating film resistance and drying properties are excellent regardless of printing conditions such as the recording medium and printing speed, and there is no image defect such as color mixing. It is thought that printed matter with high image quality can be created. In addition, said mechanism is inference and does not limit this invention at all.

  Subsequently, components of the treatment liquid of the present invention will be described in detail below.

<Calcium nitrate>
As described above, the treatment liquid of the present invention contains calcium nitrate. In the present invention, calcium nitrate lowers the dissolution and / or dispersion function of the solid components present in the ink-jet ink, and causes aggregation and precipitation of the solid components and local thickening, thereby combining the ink droplets. This is used to improve the color mixture by 1 and obtain a high-quality image regardless of printing conditions. In addition, as described above, calcium ions generated by ionization of calcium nitrate have a small ion size, are easy to move and diffuse in ink droplets and inside the recording medium, and have a valence of two. Aggregation function and insolubilization ability are high compared to monovalent cations. Therefore, calcium ions once ionized in the ink droplet move instantly to every corner of the ink droplet, and have a function of dissolving and / or dispersing solid components having anion charge such as pigment and resin. Can be reduced. As a result, color mixing does not occur even in high-speed printing, and a high-quality printed matter can be obtained. Furthermore, due to the large endothermic energy at the time of dissolution in an aqueous medium, which is a feature of nitrate, a printed matter excellent in coating film resistance and drying property can be obtained when combined with the ink of the present invention.

  In addition, as described above, the blending amount of calcium nitrate in the treatment liquid of the present invention increases the synergistic effect with the inkjet ink, and there is no embedding or bleeding, and from the viewpoint of obtaining a printed material with excellent coating film resistance and drying property, It is 6.8-20.8 mass% with respect to the processing liquid whole quantity. Further, even in printing at a very high speed, in order to develop an excellent image quality equivalent to offset printing, it is preferably 7.0 to 20.5% by mass, and 7.5 to 20% by mass. Is particularly preferred. In addition, the quantity of calcium nitrate shown above is a compounding quantity as calcium nitrate anhydrous.

<Compound having 3 or more hydroxyl groups>
Furthermore, as described above, in the present invention, the amount of the compound having 3 or more hydroxyl groups in the treatment liquid is 15% by mass or less with respect to the total amount of the treatment liquid, from the viewpoint of sufficiently expressing the effect of calcium ions as a flocculant. is there. Since it is considered that the function of calcium ions is inhibited as the amount of the compound having three or more hydroxyl groups in the treatment liquid increases, the amount of the compound having three or more hydroxyl groups in the treatment liquid is better. it is conceivable that. From the above viewpoint, the amount of the compound having 3 or more hydroxyl groups in the treatment liquid is more preferably 12% by mass or less, further preferably 9% by mass or less, more preferably 5% by mass with respect to the total amount of the treatment liquid. It is particularly preferred that it is as follows, and it is very particularly preferred that it is substantially free of it. “Substantially free” means that the compound is not intentionally added, and does not deny the presence of a small amount of by-products or impurities contained in other materials. In, it shall represent that content of the said compound is 1 mass% or less.

  The compound having 3 or more hydroxyl groups may be liquid or solid at room temperature (25 ° C.). Specific examples include glycerin, trimethylolpropane, 1,2,4-butanetriol, 1,2,6-hexanetriol, diglycerin, erythritol, threitol, ribitol, xylitol, sorbitol, mannitol, galactitol. A chain polyol compound such as, and an alkylene oxide adduct of the above compound; a polyol compound having a cyclic structure such as glucose, sucrose, maltose, lactose, cellobiose, trehalose, fructose, isomalt, lactitol, maltitol, etc .; Cyclitol compounds such as bornecitol, ononitol, pinitol, inositol, quinic acid, shikimic acid, and the like. When using the said compound, only 1 type may be used independently and 2 or more types may be used together.

<Organic solvent>
The treatment liquid of the present invention can further contain an organic solvent. By using an organic solvent in combination, the moisture retention / drying property and wettability of the treatment liquid can be adjusted to a more suitable one. Although there is no restriction | limiting in particular as an organic solvent which can be used for the processing liquid of this invention, It is preferable that a water-soluble organic solvent is included. The organic solvent does not contain the above pH adjuster. In the present specification, the “organic solvent” contained in the treatment liquid does not include a compound having three or more hydroxyl groups.

The organic solvent contained in the treatment liquid of the present invention is a water-soluble organic solvent containing at least one or two hydroxyl groups in the molecular structure from the viewpoint of affinity with water and calcium nitrate and solubility of calcium nitrate. It is preferable to use it.
Examples of the water-soluble organic solvent having one or two hydroxyl groups in the molecular structure, which are preferably used in the treatment liquid of the present invention, include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2- Monohydric alcohols such as butanol, 3-methoxy-1-butanol, 3-methoxy-3-methyl-1-butanol;
1,2-ethanediol, 1,2-propanediol (propylene glycol), 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2- Pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,2-heptanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1, 3-propanediol, 2-ethyl-2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-2-propyl- 1,3-propanediol, 2-methylpentane-2,4-diol, 2-ethyl-1,3-hexanediol, 1,2-octanediol, ethyl Glycol, diethylene glycol, triethylene glycol, dipropylene glycol, dihydric alcohols (glycols) such as butylene glycol, dibutylene glycol;
Ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monopentyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether Ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, dipropylene glycol monopropyl ether Tripropylene glycol monomethyl ether, glycol monoalkyl ethers such as tripropylene glycol monoethyl ether; and the like.
Among the exemplified compounds, monohydric alcohols such as ethanol, 1-propanol, 2-propanol, 3-methoxy-1-butanol, and 3-methoxy-3-methyl-1-butanol are particularly used in the present invention. preferable. The water-soluble organic solvent containing one or two hydroxyl groups in the molecular structure may be used alone or in combination of two or more.

  The amount of the water-soluble organic solvent containing one or two hydroxyl groups in the molecular structure contained in the treatment liquid of the present invention is preferably 0.1 to 30% by mass or less based on the total amount of the treatment liquid. More preferably, it is 1-25 mass%, and it is especially preferable that it is 1-20 mass%. By keeping the blending amount of the water-soluble organic solvent within the above range, it is possible to obtain a treatment liquid in which moisture retention, coating film resistance, dryness and wettability are compatible, and for a long time regardless of the printing method of the treatment liquid. Stable printing is possible.

In the treatment liquid of the present invention, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol butyl methyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol methyl ethyl ether, triethylene glycol butyl methyl ether, triethylene glycol Glycol dialkyl ethers such as diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol methyl ethyl ether, tetraethylene glycol butyl methyl ether, tetraethylene glycol diethyl ether;
2-pyrrolidone, N-methylpyrrolidone, N-ethylpyrrolidone, ε-caprolactam, 3-methyl-2-oxazolidinone, 3-ethyl-2-oxazolidinone, N, N-dimethyl-β-methoxypropionamide, N, N- Dimethyl-β-ethoxypropionamide, N, N-dimethyl-β-butoxypropionamide, N, N-dimethyl-β-pentoxypropionamide, N, N-dimethyl-β-hexoxypropionamide, N, N- Dimethyl-β-heptoxypropionamide, N, N-dimethyl-β-2-ethylhexoxypropionamide, N, N-dimethyl-β-octoxypropionamide, N, N-diethyl-β-butoxypropionamide, N, N-diethyl-β-pentoxypropionamide, N, N-diethyl-β-he Sokishi propionamide, N, N- diethyl -β- heptene Toki Cipro propionamide, N, nitrogen-containing solvents such as N- diethyl -β- octoxynol propionamide;
and heterocyclic compounds such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, and ε-caprolactone can be used. Said organic solvent may be used independently and may use 2 or more types together.

  The total amount of the organic solvent contained in the treatment liquid of the present invention is preferably 0.1 to 50% by mass or less, more preferably 0.15 to 30% by mass, based on the total amount of the treatment liquid. It is especially preferable that it is 0.2-25 mass%. By keeping the blending amount of the organic solvent within the above range, it is possible to achieve both drying property, moisture retention and wettability of the treatment liquid and to prevent deterioration of coating film resistance due to the residual organic solvent. Become.

  Moreover, it is preferable that content of the organic solvent whose boiling point is 240 degreeC or more is less than 10 mass% with respect to the said processing liquid whole quantity (it may be 0 mass%). Even if it does not contain an organic solvent at 240 ° C. or higher, the amount of the preparation is adjusted to be within the above range, so that the drying property of the treatment liquid at the time of high-speed printing becomes sufficient, and it penetrates into the recording medium. Since it does not remain, the aggregation performance and coating film resistance of calcium nitrate can be improved. In calculating the content of the organic solvent having a boiling point of 240 ° C. or higher, the content of a compound having a boiling point of 240 ° C. or higher among compounds having three or more hydroxyl groups (however, liquid at 25 ° C.), The content of a water-soluble organic solvent having one or two hydroxyl groups in the molecular structure and having a boiling point of 240 ° C. or higher is also included in the calculation.

<Surfactant>
The treatment liquid of the present invention preferably uses a surfactant in order to adjust the surface tension and improve the wettability on the recording medium. There are various types of surfactants such as nonionic surfactants, anionic surfactants, and cationic surfactants, but when used in the treatment liquid of the present invention, the aggregation function of calcium nitrate is inhibited. It is preferable to select a nonionic surfactant from the viewpoint of improving the wettability of the treatment liquid without doing so.

  Various types of nonionic surfactants such as acetylene-based, siloxane-based, acrylic-based, and fluorine-based surfactants are known. Wetability of treatment liquid and wetness of inkjet ink applied later Therefore, it is preferable to use an acetylene surfactant and / or a siloxane surfactant, and it is particularly preferable that at least an acetylene surfactant is included.

  The surfactant used in the present invention may be synthesized by a known method, or a commercially available product may be used. When the surfactant is selected from commercially available products, for example, BY16-201, FZ-77, FZ-2104, FZ-2110, FZ-2162, F-2123, L-7001, L-7002 as siloxane surfactants. SF8427, SF8428, SH3749, SH8400,8032ADDITIVE, SH3773M (manufactured by Dow Corning Toray Co., Ltd.), Tegoglide410, Tegoglide432, Tegoglide435, Tegoglide440, Tegoglide450, Tegotwin4000, Tegotwin4100, Tegowet250, Tegowet260, Tegowet270, Tegowet280 (manufactured by Evonik Degussa), SAG- 002, SAG-503A (manufactured by Nissin Chemical Industry Co., Ltd.), B K-331, BYK-333, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYKUV3500, BYK-UV3510 (manufactured by BYK Chemie), KF-351A, KF-352A, KF-353 KF-354L, KF355A, KF-615A, KF-640, KF-642, KF-643 (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like, and Surfynol 61, 104E, 104H, 104A, 104BC as acetylene surfactants , 104 DPM, 104 PA, 104 PG-50, 420, 440, 465, 485, SE, SE-F, Dinol 604, 607 (Air Products), Olphin E1004, E1010, E1020, PD-001, PD-002W, PD -004, PD-0 5, EXP. 4001, EXP. 4200, EXP. 4123, EXP. 4300 (manufactured by Nissin Chemical Industry Co., Ltd.). Said surfactant may be used independently and may use 2 or more types together.

  In particular, in order to obtain a uniform aggregated layer by various coating methods described later, it is necessary to orient the surfactant promptly on the surface and to reduce and stabilize the surface tension. From the said viewpoint, it is especially preferable that the compound represented by following General formula (2) is included as an acetylene type surfactant.

General formula (2):

  In general formula (2), s is an integer of 1 to 3, t is an integer of 0 or more, u is an integer of 0 or more, and t + u is an integer of 1 to 30. Et represents an ethylene group. Especially, in General formula (2), it is preferable that s is 1 or 2, and t + u is an integer of 5-20.

  Among the commercially available products exemplified above, examples of the compound represented by the general formula (2) include Surfinol 420, 440, 465, 485, Dinol 604, 607, Orphine E1004, E1010. Among these, there are Surfinol 465, Dinol 607, and Olphine E1010 as compounds in which s is 1 or 2 and t + u is an integer of 2 to 20 in the general formula (2).

  When a siloxane-based surfactant is used, it is preferable to use a modified siloxane-based surfactant into which various organic groups are introduced in order to adjust the function as a surfactant and the solubility characteristics in an aqueous medium. Among these, polyether-modified siloxane-based surfactants that use polyether groups as the organic groups are used to adjust the number of ethylene oxide groups and propylene oxide groups that make up the polyether groups. Since the hydrophobicity can be arbitrarily controlled and the surfactant can be made excellent in the orientation speed to the interface, it is preferably used in the treatment liquid of the present invention.

  When the treatment liquid of the present invention contains a surfactant, the addition amount is preferably 0.1 to 3.0% by mass, and 0.15 to 2.0% by mass with respect to the total amount of the treatment liquid. It is particularly preferred. By adding a surfactant within the above range, sufficient wettability with respect to the recording medium can be expressed regardless of the application method and even during high-speed printing, and coating quality such as repellency is deteriorated. Will not wake up. However, the blending amount of the surfactant is preferably determined in consideration of the surface tension of the inkjet ink described later.

  In the present invention, it is preferable that the surface tension of the treatment liquid is equal to or higher than the surface tension of the inkjet ink from the viewpoint of preventing bleeding of the printed matter. By making the surface tension of the treatment liquid larger than the surface tension of the inkjet ink, the amount of the surfactant that is oriented on the coating film surface when the treatment liquid is applied to the recording medium can be reduced, and the surface of the treatment liquid layer Since the energy does not decrease excessively, the wettability of the inkjet ink that is printed later becomes suitable, and a high-quality printed matter that does not bleed can be obtained.

<Binder resin>
The treatment liquid of the present invention can further contain a binder resin. The binder resin is a resin that does not participate in the reaction between the inkjet ink and the treatment liquid. By using the binder resin in combination, the water resistance of the printed material can be improved, so the printed material can be used for various purposes. Can do. In general, water-soluble resins and resin fine particles are known as binder resins, and either one can be used in the present invention. From the viewpoint of more effective expression, it is preferable to select a water-soluble resin.

  The content of the binder resin is preferably determined according to the amount of metal ions. Specifically, the mass ratio of the binder resin content to the metal ion content contained in the treatment liquid is such that the binder resin content is greater than 0 and less than 50 with respect to the metal ion content 1. It is particularly preferred that it is greater than 0 and less than 30. In the case of the above range, the water resistance of the printed matter is improved, and further, waviness (a phenomenon in which a part of the recording medium absorbs moisture partially stretches and becomes wavy) and curl (curving of the recording medium due to moisture). A high-quality printed matter without generation can be obtained.

  In the present invention, any binder resin can be used. Among these, a nonionic water-soluble resin is preferable because it is effective for improving water resistance and suppressing waving and curling. Note that a resin obtained by adding an anion unit or a cation unit to a nonionic water-soluble resin may be used as long as the basic performance of the treatment liquid can be maintained. Specific examples of the binder resin that can be used in the present invention include polyethyleneimine, polyamide, various quaternary ammonium base-containing water-soluble resins, polyacrylamide, polyvinylpyrrolidone, polyalkylene oxide, starch, methylcellulose, hydroxycellulose, carboxymethylcellulose, Examples thereof include water-soluble celluloses such as hydroxymethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, polyvinyl methyl ether, polyvinyl acetal and polyvinyl alcohol, and modified products thereof. In addition, an acrylic resin, a styrene acrylic resin, a maleic acid resin, a styrene maleic acid resin, a urethane resin, an ester resin, and the like can be used within a stable range with respect to calcium nitrate, but it goes without saying that the present invention is not limited thereto.

  Among these, the liquid component in the inkjet ink printed later is absorbed, and in high-speed printing, from the point that drying properties can be particularly improved, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl acetal, polyalkylene oxide, cellulose derivatives, It is preferable to select at least one selected from an acrylic resin and a styrene acrylic resin. In particular, at least one resin selected from polyvinyl alcohol, acrylic resin, and styrene acrylic resin has physical properties necessary for a processing liquid for ink-jet ink, such as transparency, coating film resistance, and binder power to pigments. Moreover, it is preferable from the viewpoints of easy availability and abundant types including modified products.

  Among the above, regarding polyvinyl alcohol, it is most preferable to use one having a degree of saponification of 95% or more (completely saponified product) because the pH drop of the treatment solution over time can be suppressed. That is, by using polyvinyl alcohol having a saponification degree of 95% or more, a treatment liquid layer having excellent glossiness, transparency, and ink jet ink absorbability can be obtained in addition to water resistance, rippling and curling suppression, and pH. Thus, it is possible to obtain a treatment solution having excellent stability over time. In addition, regarding acrylic resins and / or styrene acrylic resins, it is possible to prevent reaction with calcium nitrate in the treatment liquid, and to make the treatment liquid excellent in stability over time, such as pH and viscosity, and agglomeration effect. It is most preferable to select one having an acid value of 100 or less from the viewpoint of excellent properties, glossiness, undulation and curling suppression. The acid value can be measured by the same method as in the case of the pigment dispersion resin described later.

  When the treatment liquid of the present invention contains a binder resin, the number average molecular weight (Mn) is preferably 3,000 to 90,000, and particularly preferably 4,000 to 86,000. When the binder resin is in the above range, the water resistance and the curling of the recording medium due to the swelling of the treatment liquid layer do not occur while the water resistance required in general is fully expressed, and the movement of calcium ions is not hindered. For this reason, the aggregation effect is not deteriorated. Furthermore, the viscosity of a process liquid can also be contained in a suitable range by using the binder resin of the said number average molecular weight range.

  In addition, the number average molecular weight in this invention can be measured by a conventional method. As an example, using a TSKgel column (manufactured by Tosoh Corp.), GPC (manufactured by Tosoh Corp., HLC-8120GPC) equipped with an RI detector was measured as a polystyrene-equivalent number average molecular weight measured using THF as a developing solvent. can do.

<PH adjuster>
The treatment liquid of the present invention may contain a pH adjusting agent in order to make the pH range. The pH adjuster refers to a material having a function of keeping pH of a liquid constant by suppressing pH fluctuation due to environmental changes such as a pH drop due to absorption of carbon dioxide in the atmosphere. In the present invention, a material having pH adjusting ability can be arbitrarily selected, and in the case of basification, alkanolamines such as dimethylethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine; and other primary amines Secondary amine, tertiary amine, quaternary ammonium salt; ammonia water; alkali metal hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide; lithium carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, etc. Alkali metal carbonates can be used. When acidifying, various inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid; various organic acids such as acetic acid, citric acid, succinic acid, tartaric acid, malic acid, fumaric acid, malonic acid, ascorbic acid, glutamic acid Acids: alkali metal acetates such as lithium acetate and sodium acetate can be used, but are not limited thereto. Said pH adjuster may be used independently and may use 2 or more types together. Among these, a pH adjuster that does not contain a metal ion component is preferable because it does not affect the aggregation performance of calcium nitrate.

  As a compounding quantity of a pH adjuster, it is preferable that it is 0.01-5 mass% with respect to the process liquid whole quantity. By adjusting the blending amount of the pH adjuster within the above range, not only the function of calcium nitrate in the treatment liquid is inhibited, but the pH of the treatment liquid can be adjusted, and from the viewpoint of safety and odor. Is also suitable. Furthermore, the blending amount is 0 from the point that the treatment solution can be kept dry even at the time of high-speed coating while maintaining the pH stably even during long-term / continuous anchor coating. More preferably, it is 15-3 mass%.

  In the treatment liquid of the present invention, the boiling point of the pH adjuster is preferably 50 ° C. or higher from the viewpoint of preventing drying and fixing on the coating apparatus during coating of the treatment liquid. From the viewpoint of preventing deterioration of drying properties, the temperature is preferably 400 ° C. or lower.

  The molecular weight of the pH adjuster in the treatment liquid of the present invention is preferably 500 or less in terms of weight average molecular weight (Mw). By using the pH adjuster having the above molecular weight, in addition to improving the coating unevenness of the treatment liquid during high-speed printing, the viscosity of the treatment liquid can be within a suitable range. In addition, when a pH adjuster is a single substance, the said weight average molecular weight shall be read as the molecular weight of the said single substance.

<Water>
As content of the water contained in the process liquid of this invention, it is preferable that it is the range of 10-90 mass% with respect to the process liquid whole quantity.

<Other ingredients>
Further, the treatment liquid of the present invention can be appropriately added with additives such as an antifoaming agent and an antiseptic agent as necessary in order to obtain desired physical property values. When using these additives, it is preferable that the compounding quantity shall be 0.01 mass% or more and 10 mass% or less with respect to the process liquid whole quantity.

<Processing liquid production method>
The treatment liquid of the present invention comprising the above components is selected as appropriate, for example, calcium nitrate, water, and, if necessary, an organic solvent, a surfactant, a binder resin, a pH adjuster, and the above. It is manufactured by adding an additive component, stirring and mixing, and then filtering as necessary. However, the method for producing the treatment liquid of the present invention is not limited to the above.

  In addition, you may heat the said mixture in the range of 40-100 degreeC as needed in the case of stirring and mixing. However, when resin fine particles are used as the binder resin, it is preferable to heat at a temperature equal to or lower than the MFT of the resin fine particles.

  Moreover, when filtering, a filter opening diameter will not be restrict | limited especially if a coarse particle and dust can be removed, However, Preferably it is 0.3-100 micrometers, More preferably, it is 0.5-50 micrometers. Moreover, when filtering, a filter may use single type or may use multiple types together.

<Characteristics of treatment liquid>
The pH of the treatment liquid of the present invention is preferably 3.5-11. If the pH is within the above range, the processing solution is strongly acidic or strongly basic, thereby suppressing excessive speeding up of the coagulation action, suppressing streaks due to insufficient filling, and coagulation / precipitation of solid components and local It is possible to obtain a printed material that is compatible with high image quality due to thickening. Further, it is possible to suppress damage such as corrosion to a member used in a printing apparatus on which the treatment liquid is mounted, particularly a metal member. The pH range is preferably 3.5 to 9.5, and particularly preferably 4 to 8, from the viewpoint of further improving the above effects and obtaining a high-quality printed material for a wider ink composition. . If pH is 4-8, while being excellent in the corrosive control with respect to various metals, when applying a processing liquid to a recording medium over a long time, the coating material which does not have a nonuniformity can be obtained stably.

  The pH can be measured by a known method, for example, a desktop pH meter F-72 manufactured by HORIBA, Ltd. using a standard ToupH electrode or a sleeve ToupH electrode.

  Moreover, it is preferable that the process liquid of this invention adjusts the viscosity in 25 degreeC to 5-100 mPa * s. As long as the treatment liquid satisfies the above viscosity range, the treatment liquid can be applied without unevenness and can be applied to various printing methods described below. In addition, even during high-speed printing, the treatment liquid can be uniformly applied to the recording medium regardless of the treatment liquid application method, and 25% of the treatment liquid can be obtained from the viewpoint of obtaining a high-quality printed matter. The viscosity at 5 ° C. is more preferably 5 to 80 mPa · s, further preferably 5 to 60 mPa · s, and most preferably 5 to 30 mPa · s.

  The viscosity of the treatment liquid in the present invention is, for example, an E type viscometer (TVE25L type viscometer manufactured by Toki Sangyo Co., Ltd.) or a B type viscometer (TVB10 type viscometer manufactured by Toki Sangyo Co., Ltd.). Can be measured.

  Further, the surface tension at 25 ° C. of the treatment liquid of the present invention is preferably 20 to 75 mN / m, preferably 21 to 65 mN / m, from the viewpoint that sufficient wettability can be expressed with respect to various recording media. Is more preferable, and it is especially preferable that it is 22-45 mN / m. As will be described later, the surface tension of the treatment liquid is preferably equal to or higher than the surface tension of the inkjet ink.

  The surface tension of the treatment liquid in the present invention can be measured by a platinum plate method in a 25 ° C. environment using, for example, a surface tension meter (CBVPZ manufactured by Kyowa Interface Science Co., Ltd.).

  Subsequently, components of the inkjet ink of the present invention will be described in detail below.

<Pigment>
In addition to the viewpoint of having water resistance, light resistance, weather resistance, gas resistance, and the like, the inkjet ink of the present invention has a viewpoint that the aggregation speed is higher than that of a dye when the treatment liquid of the present invention is used in high speed printing. Therefore, a pigment is included as a color material. In the present invention, any of known organic pigments and inorganic pigments can be used. These pigments are preferably contained in the range of 2% by mass to 15% by mass with respect to the total amount of the ink-jet ink, more preferably in the range of 2.5% by mass to 12% by mass, and more preferably 3% by mass. It is particularly preferable that it is contained in the range of from 10% to 10% by mass. By setting the pigment content in the above range, the viscosity of the inkjet ink can be kept in a range suitable for inkjet printing while obtaining sufficient color development even in one-pass printing, resulting in long-term printing stability. Sex can be secured.

  Examples of the cyan organic pigment that can be used in the present invention include C.I. I. Pigment blue 1, 2, 3, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, 66, and the like. In particular, C.I. I. One or more selected from CI Pigment Blue 15: 3 and / or 15: 4 are preferred. For the purpose of improving color reproducibility, C.I. I. You may mix green pigments, such as pigment green 7,36,43,58.

  Examples of magenta organic pigments that can be used in the present invention include C.I. I. Pigment Red 5, 7, 12, 22, 23, 31, 48 (Ca), 48 (Mn), 49, 52, 53, 57 (Ca), 57: 1, 112, 122, 146, 147, 150, 185 238, 242, 254, 255, 266, 269, 282, C.I. I. Pigment Bio Red 19, 23, 29, 30, 37, 40, 43, 50 and the like. In particular, C.I. I. Pigment red 122, 146, 150, 185, 202, 209, 254, 266, 269, 282 and / or C.I. I. One or more pigments selected from the group consisting of CI Pigment Bio Red 19 are preferred. In particular, C.I. I. Pigment red 122, 202, 209, 282, C.I. I. A quinacridone pigment such as CI Pigment Bio Red 19 is particularly preferable because it exhibits high colorability when used in combination with the treatment liquid of the present invention, and a printed matter having excellent weather resistance can be obtained.

  From the viewpoint of further improving the color developability, it is also preferable to use a solid solution pigment containing a quinacridone pigment as the magenta organic pigment. Specifically, C.I. I. Pigment red 122 and C.I. I. Pigment Bio Red 19 and a solid solution pigment, C.I. I. Pigment red 202 and C.I. I. Pigment Bio Red 19 and a solid solution pigment, C.I. I. Pigment red 209 and C.I. I. Pigment Bio Red 19 and a solid solution pigment, C.I. I. Pigment red 282 and C.I. I. Pigment Bio Red 19 and a solid solution pigment, C.I. I. Pigment red 122 and C.I. I. Pigment Red 146, a solid solution pigment, C.I. I. Pigment red 122 and C.I. I. Pigment Red 150, a solid solution pigment, C.I. I. Pigment red 122 and C.I. I. Pigment Red 254, a solid solution pigment, C.I. I. Pigment red 122 and C.I. I. And a solid solution pigment containing CI Pigment Red 269.

  Examples of the yellow organic pigment that can be used in the present invention include C.I. I. Pigment Yellow 10, 11, 12, 13, 14, 17, 20, 24, 74, 83, 86, 93, 94, 95, 109, 110, 117, 120, 125, 128, 137, 138, 139, 147, 148, 150, 151, 154, 155, 166, 168, 180, 185, 213 and the like. In particular, C.I. I. One or more selected from the group consisting of CI Pigment Yellow 13, 14, 74, 120, 139, 180, 185, and 213 is preferably selected.

  Examples of the black organic pigment that can be used in the present invention include aniline black, lumogen black, and azomethine azo black. Further, a plurality of chromatic color pigments such as the above-mentioned cyan pigments, magenta pigments, yellow pigments, and the following orange pigments, green pigments, brown pigments can be used to form black pigments.

  Special colors such as orange pigments, green pigments and brown pigments can also be used in the inkjet ink of the present invention. Specifically, C.I. I. Pigment orange 16, 36, 43, 51, 55, 59, 61, 64, 71, C.I. I. Pigment green 7, 36, 43, 58, pigment brown 23, 25, 26, and the like. By using the above-mentioned special color pigment, it becomes possible to produce a printed material with a wider color rendering.

  Although it does not specifically limit as an inorganic pigment used by this invention, For example, a carbon black and iron oxide can be mentioned as a black pigment, and a titanium oxide can be mentioned as a white pigment.

Examples of the carbon black pigment that can be used in the present invention include carbon black produced by a furnace method or a channel method. Among these, these carbon blacks have a primary particle size of 11 to 50 nm, a specific surface area of 50 to 400 m ² / g by BET method, a volatile content of 0.5 to 10% by mass, a pH of 2 to 10 and the like. Those having the following are preferred. As a commercial product having such characteristics, for example, No. 25, 30, 33, 40, 44, 45, 52, 850, 900, 950, 960, 970, 980, 1000, 2200B, 2300, 2350, 2600; MA7, MA8, MA77, MA100, MA230 (Mitsubishi Chemical Corporation) Manufactured), RAVEN 760UP, 780UP, 860UP, 900P, 1000P, 1060UP, 1080UP, 1255 (manufactured by Colombian Carbon), REGAL330R, 400R, 660R, MOGUL L (manufactured by Cabot), Nexex 160IQ, 170IQ, 35, 75; PrintX30, 35, 40, 45, 55, 75, 80, 85, 90, 95, 300; Special Black 350, 550; Nerox 305, 500, 505, 600, 605 (Orion Engineered Carbon Etc.) and any of them can be preferably used.

  Moreover, as a titanium oxide used suitably as a white inorganic pigment, both an anatase type and a rutile type can be used, but it is preferable to use a rutile type in order to improve the concealability of printed matter. Moreover, although what was manufactured by any methods, such as a chlorine method and a sulfuric acid method, it is preferable to use the titanium oxide manufactured by the chlorine method from whiteness high.

  The surface of the titanium oxide pigment that can be used in the present invention is preferably treated with an inorganic compound and / or an organic compound. Examples of inorganic compounds include silicon, aluminum, zirconium, tin, antimony, titanium compounds, and hydrated oxides thereof. Examples of organic compounds include polyhydric alcohols, alkanolamines or derivatives thereof, higher fatty acids or metal salts thereof, organometallic compounds, and the like. Among them, polyhydric alcohols or derivatives thereof highly enhance the surface of titanium oxide. It can be hydrophobized to improve dispersion stability and is preferably used.

  In the present invention, in order to keep the hue and color developability of the printed matter within a suitable range, a plurality of the above pigments can be mixed and used. For example, a small amount of one or more pigments selected from a cyan organic pigment, a magenta organic pigment, an orange organic pigment, and a brown organic pigment is used to improve the color tone at a low printing rate with respect to black ink using a carbon black pigment. Can be added.

<Resin for pigment dispersion>
As a method of stably dispersing and holding the pigment in the ink-jet ink, (1) a method of adsorbing and dispersing a water-soluble pigment dispersion resin on the pigment surface, and (2) a water-soluble and / or water-dispersible surfactant. (3) A method in which a hydrophilic functional group is chemically and physically introduced on the pigment surface and dispersed in the ink without a dispersion resin or surfactant (self-dispersing pigment), ( 4) A method of coating a pigment with a water-insoluble resin and dispersing it in ink using another water-soluble pigment dispersion resin or a surfactant as required.

  The ink-jet ink used in the present invention preferably uses a pigment dispersed by a method other than the pigment produced by the method (3) (that is, a self-dispersing pigment). The present invention suppresses image defects such as color mixing by insolubilization of the treatment liquid with calcium ions, and calcium ions and high molecular weight components such as resins and surfactants interact with anions and cations. This is because causing the adsorption equilibrium transfer reaction has a greater effect of increasing the viscosity and lowering the fluidity due to the pigment component, and the image defects can be suppressed even during high-speed printing.

  Further, among the above, the method (1) or (4) is selected, that is, the pigment is more preferably dispersed using a pigment dispersing resin, and the method (1) using the pigment dispersing resin is used. It is particularly preferred to select. By selecting and examining the monomer composition and molecular weight constituting the resin, the resin adsorption capacity to the pigment and the charge of the pigment dispersion resin can be easily adjusted. As a result, dispersion stability can be imparted to fine pigments and treatment liquid This is because the ability to lower the dispersion function of the pigment can be controlled. The “pigment dispersing resin” is defined as a generic term for the water-soluble pigment dispersing resin used in the methods (1) and (4) and the water-insoluble resin used in the method (4). The

  The kind of resin for pigment dispersion used in the present invention is not particularly limited, and for example, acrylic resin, styrene acrylic resin, maleic resin, styrene maleic resin, urethane resin, ester resin, and the like can be used. In the present invention, in addition to the material selectivity and ease of synthesis, the use of an acrylic resin or styrene acrylic resin is preferable because the charge neutralization to calcium nitrate and the rate of aggregation by insolubilization are suitable. Is particularly preferred. The pigment-dispersing resin used in the present invention can be synthesized by a known method, or a commercially available product can be used.

  In the present invention, it is preferable to introduce an alkyl group having 8 to 36 carbon atoms into the pigment dispersing resin. This is because when the carbon number of the alkyl group is 8 to 36, the viscosity of the pigment dispersion can be lowered and further dispersion stabilization and viscosity stabilization can be realized, and the interaction reaction between calcium ions and anions and cations can be achieved. This is because the effect of increasing the viscosity and lowering the fluidity due to the pigment component after causing the adsorption equilibrium transfer reaction is extremely large. In addition, as carbon number of an alkyl group, Preferably it is C10-C34, More preferably, it is 12-30, More preferably, it is C18-C24. Moreover, as long as an alkyl group is C8-C36, even if it is linear or branched, both can be used, However, A linear thing is preferable. Examples of linear alkyl groups include octyl group (C8), decyl group (C10), lauryl group (C12), myristyl group (C14), cetyl group (C16), stearyl group (C18), aralkyl group (C20), and behenyl. Group (C22), lignoceryl group (C24), serotoyl group (C26), montanyl group (C28), melysyl group (C30), dotriacontanoyl group (C32), tetratriacontanoyl group (C34), hexatriaconta And a noyl group (C36).

  The content of the monomer containing an alkyl chain having 8 to 36 carbon atoms contained in the resin for pigment dispersion used in the present invention in the copolymer is reduced in the viscosity of the pigment dispersion and the coating film of the printed matter. From the viewpoint of achieving both resistance and gloss, the content is preferably 5% by mass to 60% by mass, more preferably 10% by mass to 55% by mass, and particularly preferably 20% by mass to 50% by mass. .

  Further, in the present invention, it is particularly preferable to introduce an aromatic group into the pigment dispersion resin because the adsorption ability to the pigment is improved and the dispersion function of the pigment can be quickly reduced when mixed with the treatment liquid. . This is because when the treatment liquid and inkjet ink are mixed, a strong intermolecular force called cation-π interaction works between the calcium ion contained in the treatment liquid and the pigment dispersion resin having an aromatic group. This is because both are preferentially adsorbed. Examples of aromatic groups include phenyl, naphthyl, anthryl, tolyl, xylyl, mesityl, and anisyl groups. Of these, a phenyl group and a tolyl group are preferable from the viewpoint of ensuring sufficient dispersion stability.

  From the viewpoint of coexistence of the dispersion stability of the pigment and the adsorption performance with the treatment liquid, the content of the monomer containing the aromatic ring is preferably 5 to 65 mass% with respect to the total amount of the resin for dispersing the pigment, More preferably, it is 10-50 mass%.

  In the present invention, the acid value of the pigment dispersing resin is preferably 20 to 300 mgKOH / g, and more preferably 50 to 250 mgKOH / g. By keeping the acid value within the above range, the effect of lowering the dispersion function when mixed with calcium ions in the treatment liquid is sufficiently enhanced, and an extremely high quality image can be obtained. In addition, because the storage stability of the ink is good, it is possible to maintain the same dispersion state as the initial state after storing the ink for a long time, and obtain a printed matter having the same cohesiveness and filling as the initial stage. Ink ejection stability is also improved.

  The acid value can be measured by a potentiometric titration method using a known apparatus, for example, “potentiometric automatic titration apparatus AT-610” manufactured by Kyoto Electronics Industry Co., Ltd.

  Further, the weight average molecular weight of the pigment dispersing resin is preferably in the range of 1,000 to 100,000. When the molecular weight is in the above range, the pigment is stably dispersed in water and the viscosity of the ink can be easily adjusted. Further, by setting the weight average molecular weight to 1,000 or more, it is possible to prevent the pigment dispersing resin adsorbed on the pigment or coated with the pigment from being removed, so that the dispersion stability can be suitably maintained. If the weight average molecular weight is 100,000 or less, the viscosity at the time of dispersion can be kept within a suitable range, and the discharge stability from the ink jet head is prevented from being deteriorated, so that the ink has suitable printing stability. Can do.

  Furthermore, the weight average molecular weight of the water-soluble pigment-dispersed resin is more preferably in the range of 5,000 to 50,000. When the molecular weight is in the above range, the ink thickens during insolubilization with calcium ions, and even during high-speed printing, color mixing is suppressed and high-quality images can be obtained, and continuous high-speed printing is possible. The discharge stability can also be kept good.

  In the present invention, the method (1) is selected as a method for stably dispersing and holding the pigment in the ink. That is, when a water-soluble pigment dispersion resin is used as the pigment dispersion resin, the solubility in the ink is increased. In order to increase, it is preferable that the acid group in the pigment-dispersed resin is neutralized with a base. On the other hand, if an excessive amount of base is added for neutralization, the calcium ions contained in the treatment solution are neutralized, and a sufficient effect cannot be exhibited. I need to pay. Whether or not the amount of the base added is excessive can be confirmed, for example, by preparing a 10% by mass aqueous solution of a water-soluble pigment-dispersed resin and measuring the pH of the aqueous solution. In this invention, in order to fully express the function of a process liquid, it is preferable that the pH of the said aqueous solution is 7-11, and it is more preferable that it is 7.5-10.5.

  Examples of the base for neutralizing the water-soluble pigment dispersion resin used in the present invention include alkanolamines such as diethanolamine, triethanolamine and N-methyldiethanolamine; ammonia water; lithium hydroxide, sodium hydroxide and potassium hydroxide. And alkali metal hydroxides such as lithium carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate and the like.

  Moreover, when selecting the method of said (1), it is preferable that the compounding quantity of the water-soluble pigment dispersion resin with respect to a pigment is 1-50 mass%. The blending amount of the pigment dispersion resin is 1 to 50% by mass with respect to the pigment, thereby suppressing the viscosity of the pigment dispersion and improving the viscosity stability and dispersion stability of the pigment dispersion and inkjet ink. It is preferable because it can cause a rapid decrease in the dispersion function when mixed with the treatment liquid. The ratio of the pigment to the pigment dispersion resin is more preferably 2 to 45% by mass, further preferably 4 to 40% by mass, and most preferably 5 to 35% by mass.

<Water-soluble organic solvent>
<Specific glycol ether organic solvent (A)>
The inkjet ink of the present invention contains a specific glycol ether organic solvent (A) represented by the following general formula (1) as a water-soluble organic solvent. As described above, the ink containing the specific glycol ether-based organic solvent (A) has particularly excellent permeability, and has a coating film resistance, a drying property, and a printing image quality regardless of the recording medium and printing conditions. It is thought that both can be achieved.

General formula (1):

R1-(— O—CH ₂ CH ₂ —) n—OH

  In the general formula (1), R1 represents an alkyl group having 2 to 4 carbon atoms, which may have a branched structure. N is 2 or 3.

  In the present invention, as the specific glycol ether organic solvent (A), R1 in the general formula (1) is an alkyl group having a branched structure and / or an alkyl group having 4 carbon atoms. Can be suitably used. The specific glycol ether organic solvent (A) in which R1 in the general formula (1) is an alkyl group having a branched structure and / or is an alkyl group having 4 carbon atoms has a low surface tension. This is because, regardless of the type of recording medium, it easily penetrates into the inside of the recording medium, resulting in a printed matter having excellent coating film resistance, drying property, and print image quality.

Moreover, in this invention, the specific glycol ether type | system | group organic solvent (A) whose n in General formula (1) is 2 is selected preferably. If it is a specific glycol ether organic solvent (A) with few ethylene oxide groups (-O-CH ₂ CH _2- ) having hydrophilicity, it can be applied to hardly absorbable substrates such as coated paper, art paper and cast paper. Therefore, it is possible to obtain a printed material that can easily penetrate and has excellent coating film resistance and drying property. Further, it is preferable because the viscosity of the ink can be kept low and the ejection stability can be improved.

  Specific examples of the specific glycol ether organic solvent (A) include diethylene glycol monoethyl ether, diethylene glycol mononormal propyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mononormal butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monotertiary butyl ether, triethylene. Examples include glycol monoethyl ether, triethylene glycol mononormal propyl ether, triethylene glycol monoisopropyl ether, triethylene glycol mononormal butyl ether, triethylene glycol monoisobutyl ether, and triethylene glycol monotertiary butyl ether. The specific glycol ether organic solvent (A) used in the present invention may be used alone or in combination of two or more.

  As described above, among the enumerated above, the specific glycol ether organic solvent (A) in which R1 in the general formula (1) is an alkyl group having a branched structure and / or an alkyl group having 4 carbon atoms. Or a specific glycol ether organic solvent (A) in which n in the general formula (1) is 2 can be preferably used. Specifically, it is preferable to select one or more organic solvents selected from diethylene glycol monoisopropyl ether, diethylene glycol mononormal butyl ether, diethylene glycol monoisobutyl ether, and diethylene glycol monotertiary butyl ether. Among them, diethylene glycol monoisobutyl ether and / or diethylene glycol monotertiary butyl ether that satisfies all of the preferable conditions described above are most preferably selected.

  In the inkjet ink of the present invention, the total amount of the specific glycol ether organic solvent (A) blended from the viewpoint of obtaining a high-quality printed material while ensuring the penetration into the recording and improving the coating film resistance. The total amount of the inkjet ink is preferably 2 to 35% by mass, more preferably 3 to 30% by mass, particularly preferably 4 to 25% by mass, and 5 to 20% by mass. Most preferred.

<Diol solvent (B) having a surface tension of 30 to 50 mN / m>
In addition to the specific glycol ether organic solvent (A) described above, the inkjet ink of the present invention further includes a diol solvent (B) (hereinafter referred to as “specific surface”) having a surface tension at 25 ° C. of 30 to 50 mN / m. It is preferable to contain a tension diol solvent (B) ”.

  The specific glycol ether organic solvent (A) has a small surface tension. Therefore, when printing on a recording medium with particularly high absorbability, or when the time interval from printing to drying is long, even if the ink set of the present invention is used, image defects such as feathering may not be suppressed. is there. Therefore, by using the specific surface tension diol solvent (B) in combination, the surface tension of the microscopic ink droplets is increased and hydrogen is added between the specific glycol ether organic solvent (A) and the ethylene oxide group. It is thought that a bond is formed. As a result, regardless of the recording medium and printing conditions, the printed matter has a particularly excellent print image quality. Furthermore, it is possible to improve the discharge stability, which is considered to be caused by the hydrogen bond.

  Examples of the specific surface tension diol solvent (B) used in the present invention include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, , 4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-pentanediol, 2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol, 2 , 2-dimethyl-1,3-propanediol, diethylene glycol, triethylene glycol, dipropylene glycol and the like, but are not limited thereto. The specific surface tension diol solvent (B) may be used alone or in combination of two or more.

  In the present invention, when the specific surface tension diol solvent (B) is used, it is preferable to use a solvent having a boiling point of 180 to 235 ° C under 1 atm, and a solvent having the boiling point of 180 to 225 ° C. It is more preferable to use one having a temperature of 180 to 210 ° C. By using the specific surface tension diol solvent (B) included in the boiling point range, the solid components in the ink cause agglomeration / precipitation and local thickening, and then quickly volatilize, resulting in a print image quality and a coating film. A printed matter having excellent resistance and drying properties can be obtained. Among the specific surface tension diol solvents (B) exemplified above, those having a boiling point of 180 to 235 ° C. under 1 atm are ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2 -Butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol, 2,2 -Dimethyl-1,3-propanediol, dipropylene glycol and the like.

  In addition, the boiling point under 1 atmosphere in this invention can be measured by using thermal analyzers, such as DSC (differential scanning calorimetry).

  In addition, the specific surface tension diol solvent (B) exemplified above is one selected from ethylene glycol, 1,2-propanediol, and 1,3-propanediol, which are alkanediols having 3 or less carbon atoms. It is also preferable to select the above water-soluble organic solvent. The alkanediol having 3 or less carbon atoms has a low boiling point at 1 atm and a relatively high surface tension of 35 to 50 mN / m, and when combined with the specific glycol ether organic solvent (A). The effect of improving the printing image quality is most excellent.

  Furthermore, it is also preferable to select diethylene glycol and / or triethylene glycol as the specific surface tension diol solvent (B). Diethylene glycol and triethylene glycol have an ethylene oxide group in the molecular structure, and have a high affinity with the specific glycol ether organic solvent (A) having an ethylene oxide group. Therefore, it is possible to stably obtain a printed matter excellent in coating film resistance, drying property, and print image quality.

  When the ink of the present invention contains the specific surface tension diol-based solvent (B), the blending amount thereof is preferably 3 with respect to the total amount of the ink from the viewpoint of suitably exhibiting the above effects and obtaining a printed matter with excellent print image quality. It is preferably ˜45% by mass, more preferably 4 to 40% by mass, and particularly preferably 5 to 35% by mass.

  In addition, as described above, the specific surface tension diol solvent (B) is a material that improves the print image quality and ejection stability of the printed matter by interacting with the specific glycol ether organic solvent (A). The blending amount is particularly preferably determined based on the blending amount of the specific glycol ether organic solvent (A). As a result of intensive studies by the present inventors, when the blending amount of the specific glycol ether organic solvent (A) is 1, the mass ratio of the blending amount of the specific surface tension diol solvent (B) is 0.5-7. It was found that the ink was excellent in print image quality and ejection stability. Moreover, from the viewpoint of further improving the above effects, the mass ratio of the blending amounts is more preferably 0.7 to 5, and particularly preferably 1 to 3.

<Other water-soluble organic solvents>
In the present invention, water-soluble organic solvents other than the specific glycol ether organic solvent (A) and the specific surface tension diol solvent (B) are used alone or in combination as the water-soluble organic solvent used in the ink-jet ink. It is possible. However, it is preferable to adjust the content so that the desired effect is not reduced.

Specifically, polyol solvents such as 1,2-pentanediol, 1,2-hexanediol, 4-methyl-1,2-pentanediol, 3,3-dimethyl-1,2-butanediol, and glycerin. ;
Monohydric alcohol solvents such as 2-propanol, 1-butanol, 2-butanol, 3-methoxy-1-butanol, 3-methoxy-3-methylbutanol;
Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene Propylene glycol monoether solvents such as glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, tripropylene glycol monobutyl ether;
Propylene glycol diether solvents such as propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and tripropylene glycol dimethyl ether;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol-2-ethylhexyl ether, diethylene glycol monomethyl ether, diethylene glycol monopentyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether Ethylene glycol monoether solvents such as
Diethylene glycol methyl ethyl ether, diethylene glycol methyl butyl ether, triethylene glycol methyl ethyl ether, triethylene glycol methyl butyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol methyl ethyl ether, Ethylene glycol diether solvents such as tetraethylene glycol methyl butyl ether;
Nitrogen-containing solvents such as 2-pyrrolidone, N-methyloxazolidinone, and ε-caprolactone;
Etc. However, it is not limited to these. These solvents may be used alone or in combination.

  The total amount of the water-soluble organic solvent in the ink-jet ink of the present invention is preferably 6% by mass or more and 70% by mass or less based on the total amount of the ink-jet ink from the viewpoint of achieving both moisture retention, drying property and wettability of the ink-jet ink. It is more preferably 10% by mass or more and 60% by mass or less, and particularly preferably 15% by mass or more and 50% by mass or less.

<Boiling point of water-soluble organic solvent>
In the inkjet ink of the present invention, the content of the water-soluble organic solvent having a boiling point of 245 ° C. or higher under 1 atm is preferably 0% by mass or more and less than 10% by mass with respect to the total amount of the inkjet ink. By controlling the amount of the organic solvent within the above range, it is excellent in coating film resistance and drying property even in high-speed printing, and blocking (when the printed matter is stacked or wound up, the back surface of the recording medium is ink The printed matter is free from the occurrence of smudges). In addition, when combined with the treatment liquid of the present invention, a blending amount of a water-soluble organic solvent having a boiling point of less than 245 ° C. under 1 atm from the viewpoint of obtaining a printed material with excellent image quality even at high speed printing. Is particularly preferably 0% by mass or more and 9% by mass or less based on the total amount of the ink-jet ink. In the above, “0 mass%” means that a water-soluble organic solvent having a boiling point of 240 ° C. or higher under 1 atm is not included. In calculating the content of the water-soluble organic solvent having a boiling point of 240 ° C. or higher at 1 atm, the specific glycol ether organic solvent (A) and the specific surface tension diol solvent (B) are also taken into consideration. Shall.

  Furthermore, the weighted boiling point average value of the water-soluble organic solvent contained in the inkjet ink of the present invention under 1 atm is preferably 175 to 245 ° C, more preferably 180 to 235 ° C, and more preferably 185 to 220. More preferably, it is 190 degreeC, and it is especially preferable that it is 190-210 degreeC. By keeping the weighted boiling point average value of the water-soluble organic solvent within the above range, when combined with the treatment liquid of the present invention, high-quality images can be obtained even at high-speed printing, and ejection stability is also excellent. It will be. In calculating the weighted boiling point average, the specific glycol ether organic solvent (A) and the specific surface tension diol solvent (B) are also taken into consideration. The weighted boiling point average value at 1 atm is obtained by adding the product of the boiling point at 1 atm and the mass ratio with respect to the total water-soluble organic solvent calculated for each water-soluble organic solvent. Value.

<Binder resin>
You may add binder resin to the inkjet ink of this invention as needed. As the binder resin, resin fine particles and water-soluble resins are generally known, and either or both of them can be used in the present invention.

  Among the above, the resin fine particles can have a high molecular weight compared to the water-soluble resin, can lower the viscosity of the inkjet ink, and can contain a larger amount of resin in the inkjet ink. It is suitable for particularly improving the coating film resistance. Types of resins used as resin fine particles include (meth) acrylic, styrene- (meth) acrylic, urethane, styrene-maleic acid, styrene-butadiene, vinyl chloride, vinyl chloride-vinyl acetate, There are ethylene-vinyl acetate type, polyolefin type, etc., ink storage stability, printed film resistance, wide range of material selection, and good compatibility when mixed with calcium nitrate, no whitening Considering that a printed material is obtained, one or more kinds of resin fine particles selected from (meth) acrylic, styrene- (meth) acrylic, urethane, and polyolefin are preferably used. In the present specification, “(meth) acryl” means “acryl” and / or “methacryl”.

  When the binder resin in the ink-jet ink is resin fine particles, it is necessary to consider the MFT of the resin fine particles. When resin fine particles having a low MFT are used, depending on the water-soluble organic solvent added to the ink-jet ink, the MFT of the resin fine particles is further lowered, and the resin fine particles are fused and aggregated even at room temperature. Nozzle clogging may occur. In order to avoid the problem, it is preferable to adjust the monomer constituting the resin fine particles so that the MFT of the resin fine particles is 50 ° C. or higher.

  Further, as the binder resin, core-shell type resin fine particles in which a resin having a low MFT is a core component and a resin fine particle having a high MFT is a shell component may be used. As a method for producing the core-shell type resin fine particles, a known method such as an interfacial polymerization method, a suspension polymerization method, an in-situ polymerization method, a phase inversion emulsification method, a coacervation method, or a submerged drying method is arbitrarily selected. it can.

  The MFT can be measured by, for example, an MFT tester manufactured by Tester Sangyo Co., Ltd. Specifically, a 25% by mass aqueous solution of resin fine particles is applied on a metal plate that is installed in the MFT tester and can be applied with a temperature gradient so as to have a WET film thickness of 300 μm. After applying a temperature gradient to the metal plate to completely form the resin fine particles, the temperature at the boundary between the whitened area without film formation and the area where the transparent resin film is formed is read to obtain MFT. .

  On the other hand, when a water-soluble resin is used as the binder resin, the resin fine particles are not fused or agglomerated as seen in the resin fine particles. Therefore, the resin is preferably selected for improving the maintenance performance of the ink jet printer. . When selecting a water-soluble resin, its weight average molecular weight is preferably in the range of 3,000 to 50,000, more preferably in the range of 4,000 to 40,000, and 5,000 to A range of 35,000 is particularly preferred. When the weight average molecular weight is 10,000 or more, the coating film resistance of the printed matter can be improved, and when the weight average molecular weight is 50,000 or less, the ejection stability and maintenance from the inkjet head can be improved. Ink jet ink having excellent properties can be obtained.

  When a water-soluble resin is used as the binder resin, the types of resins used as the water-soluble resin are (meth) acrylic, styrene- (meth) acrylic, urethane, styrene-maleic acid, styrene-butadiene. , Vinyl alcohol, cellulose, polyolefin, etc., ink storage stability, compatibility with the above water-soluble organic solvents, wide range of material selection, and good compatibility when mixed with calcium nitrate In view of obtaining a printed matter without whitening, at least one resin fine particle selected from (meth) acrylic, styrene- (meth) acrylic, and urethane is preferably used.

  When using binder resin with the inkjet ink of this invention, it is preferable that the content is the range of 1-20 mass% in the said inkjet ink whole quantity in conversion of solid content, More preferably, it is the range of 2-15 mass%. Especially preferably, it is the range of 3-10 mass%.

<Surfactant>
<Acetylene diol-based surfactant>
The ink-jet ink of the present invention contains a surfactant. Conventionally known surfactants can be arbitrarily used as the surfactant, and among them, an acetylene surfactant is preferably included. As described above, since the acetylene-based surfactant orients at the interface in a short time, even if the viscosity or surface tension of the ink slightly changes due to heat absorption when calcium nitrate is ionized, the orientation speed to the ink droplet interface In addition, it does not affect the penetration rate into the recording medium. Further, it is considered that by quickly orienting at the ink droplet interface, coalescence of the ink droplets can be suppressed, and a printed matter having no print and excellent print image quality can be obtained.

  In particular, in the present invention, it is preferable to select the acetylene surfactant having an HLB value of 3 or less by the Griffin method. The HLB (Hydrophile-Lipophile Balance) value is a parameter representing the hydrophilicity / hydrophobicity of the material, and the smaller the value, the higher the hydrophobicity. That is, it is considered that the smaller the HLB value, the higher the orientation speed on the ink droplet surface, and a printed matter with excellent print image quality can be obtained.

  In addition, the HLB value by the Griffin method is calculated | required like following formula (3) using the molecular weight of object material.

Formula (3):

HLB value = 20 × (sum of molecular weight of hydrophilic portion) ÷ (molecular weight of material)

  In another embodiment, it is also preferable to select the acetylene surfactant used in the ink jet ink of the present invention represented by the above general formula (2). The acetylene surfactant represented by the general formula (2) has an ethylene oxide group, and is considered to have high compatibility with the specific glycol ether organic solvent (A) which also has an ethylene oxide group. It is done. As a result, the acetylene surfactant is not unevenly distributed in the ink, and a high-quality printed matter can be obtained stably.

  In the present invention, acetylenic diol surfactants may be used alone or in combination of two or more. For example, an acetylenic diol surfactant having an HLB value of 3 or less by the Griffin method and an acetylenic diol surfactant represented by the general formula (2) can be used in combination. Moreover, what was synthesize | combined by the well-known method may be used for acetylene diol type surfactant, and the commercial item illustrated above may be used.

  When the inkjet ink of the present invention contains an acetylene surfactant, the blending amount is 0.2 to 2.5% by mass with respect to the total amount of the ink from the viewpoint of making the print image quality of the printed matter suitable. Is more preferable, 0.4 to 2.0 mass% is more preferable, and 0.5 to 1.5 mass% is particularly preferable.

<Other surfactants>
Furthermore, the inkjet ink of the present invention is added with a surfactant other than the acetylene surfactant (hereinafter also simply referred to as “other surfactant”) as long as the aggregation performance of the treatment liquid containing calcium nitrate is not impaired. Also good. Other surfactants may be used alone or in combination of two or more. Moreover, it is not necessary to use an acetylene type surfactant together or to use together.

  From the viewpoint of ensuring optimal wettability and realizing suitable ejection stability, it is preferable to use a siloxane-based surfactant and / or a fluorine-based surfactant as other surfactants. It is particularly preferred to use an activator.

  In addition, when a siloxane-based surfactant is used as a surfactant, a polyether-modified siloxane-based surfactant using a polyether group as an organic group from the viewpoint of improving the orientation speed to the ink interface and ejection stability. Is preferably selected. Further, from the viewpoint of the orientation speed to the ink interface, the HLB value by the Griffin method of the polyether-modified siloxane surfactant calculated by the above formula (3) is preferably 2 to 12, Is more preferably ˜11, and particularly preferably 3˜10.

  In addition, the molecular weight of the surfactant is also important in terms of controlling wettability in the process of evaporating the inkjet ink and improving the quality of the printed matter such as coating film resistance and solvent resistance. The molecular weight of the other surfactant is preferably 1,000 or more and 50,000 or less, more preferably 1,500 or more and 40,000 or less in terms of weight average molecular weight. By setting it to 1,000 or more, the effect of controlling the wettability with respect to the recording medium can be enhanced.

  Other surfactants that can be used in the present invention can be synthesized by known methods, or commercially available products can be used. When the surfactant is selected from commercially available products, for example, as the siloxane-based surfactant, those listed above as the surfactant that can be used in the treatment liquid, and as the fluorine-based surfactant, Zonyl TBS, FSP, FSA, Examples thereof include FSN-100, FSN, FSO-100, FSO, FS-300, Capstone FS-30, FS-31 (DuPont), PF-151N, and PF-154N (Omnova).

  When the inkjet ink of the present invention contains other surfactants, the addition amount is preferably 0.01% by mass or more and 3.0% by mass or less, and 0.05% by mass or more and 2% by mass or less with respect to the total amount of the inkjet ink. More preferably, it is 5 mass% or less.

  The surfactant used for the ink-jet ink and the surfactant used for the treatment liquid may be the same or different. When using different surfactants, it is better to determine the blending amount after paying attention to the surface tension of both as described above.

<Water>
As water contained in the ink-jet ink of the present invention, it is preferable to use ion-exchanged water (deionized water) instead of general water containing various ions.

  As content of the water which can be used by this invention, it is preferable that it is the range of 20-90 mass% with respect to the ink whole quantity.

<Other ingredients>
In addition to the above components, the ink-jet ink of the present invention is a pH adjuster, an antifoaming agent, an antiseptic, an infrared absorber, an ultraviolet absorber, etc., in order to obtain an ink having desired physical properties as required. These additives can be appropriately added. The addition amount is preferably 0.01% by mass or more and 10% by mass or less with respect to the total mass of the ink. In addition, what can be used with the said process liquid can be utilized suitably as said pH adjuster.

  In addition, it is preferable that the inkjet ink of this invention does not contain a polymerizable monomer substantially. Here, “substantially does not contain” means that the ink is not intentionally added, and does not exclude a slight amount of mixing or generation when the ink-jet ink is manufactured and stored. Specifically, the amount of the polymerizable monomer is preferably 1% by mass or less and more preferably 0.5% by mass or less with respect to the total amount of the inkjet ink.

<Inkjet ink set>
The ink-jet ink of the present invention may be used in a single color, but it can also be used as an ink-jet ink set in which a plurality of colors are combined according to the application. The combination is not particularly limited, but a full color image can be obtained by using three colors of cyan, yellow, and magenta. Moreover, the black feeling can be improved by adding black ink, and the visibility of characters and the like can be improved. Furthermore, color reproducibility can be improved by adding colors such as orange and green. When printing on a print medium other than white, a clear image can be obtained by using white ink together. When the inkjet ink has magenta ink, as described above, the magenta ink preferably contains a quinacridone pigment and / or a solid solution pigment containing a quinacridone pigment as a magenta pigment.

<Method for producing inkjet ink>
The ink-jet ink of the present invention comprising the above-described components is produced, for example, through the following process. However, the manufacturing method of the inkjet ink of the present invention is not limited to the following.

<(1) Production of pigment dispersion (when using pigment dispersion resin)>
When a water-soluble pigment dispersion resin is used as the pigment dispersion resin, the water-soluble pigment dispersion resin, water, and a water-soluble organic solvent as necessary are mixed and stirred to prepare a water-soluble pigment dispersion resin mixture. . A pigment is added to the water-soluble pigment-dispersed resin mixture, mixed and stirred (premixed), and then dispersed using a disperser. Thereafter, centrifugation, filtration, and adjustment of the solid content concentration are performed as necessary to obtain a pigment dispersion.

  In the case of producing a pigment dispersion coated with a water-insoluble resin, a water-insoluble resin solution is prepared by previously dissolving a water-insoluble resin in an organic solvent such as methyl ethyl ketone and neutralizing the water-insoluble resin as necessary. Is made. A pigment and water are added to the water-insoluble resin solution, mixed and stirred (premixed), and then dispersed using a disperser. Then, the said organic solvent is distilled off by reduced pressure distillation, Centrifugation, filtration, and adjustment of solid content concentration are performed as needed, and a pigment dispersion liquid is obtained.

  The disperser used in the pigment dispersion treatment may be any commonly used disperser. For example, a ball mill, a roll mill, a sand mill, a bead mill, a nanomizer, a paint shaker, a microfluidizer, and the like can be used.

  As a method for controlling the particle size distribution of the pigment contained in the pigment dispersion, mention is made of the amount of electric power given to the pigment dispersion during dispersion, the shape of the stirring member (agitator) is changed, and centrifugation and filtration are performed after the dispersion treatment. And so on. Further, when a media dispersing machine such as a ball mill or a bead mill is used as the dispersing machine, the media size can be reduced, the media material can be changed, the media filling rate can be increased, and the like. When a media disperser is used in the present invention, the media size is preferably 0.1 to 3 mm in diameter in order to keep the pigment within a suitable particle size range. Further, glass, zircon, zirconia, and titania are preferably used as the material for the media. Note that two or more of the above methods may be combined.

<(2) Adjustment of inkjet ink>
Next, a water-soluble organic solvent, a surfactant, water, and, if necessary, the binder resin and other additives mentioned above are added to the pigment dispersion and mixed and stirred.

  In addition, you may stir and mix the said mixture, heating in the range of 40-100 degreeC as needed. However, when resin fine particles are used as the binder resin, the heating temperature is preferably set to be equal to or lower than the MFT of the resin fine particles.

<(3) Removal of coarse particles>
Coarse particles contained in the mixture are removed by a technique such as filtration or centrifugation to obtain an inkjet ink. As a filtration method, a known method can be appropriately used. The filter pore diameter is not particularly limited as long as coarse particles and dust can be removed, but is preferably 0.3 to 5 μm, more preferably 0.5 to 3 μm. Moreover, when filtering, a filter may use single type or may use multiple types together.

<Characteristics of inkjet ink>
The inkjet ink of the present invention preferably has a viscosity at 25 ° C. adjusted to 3 to 20 mPa · s. If it is this viscosity area | region, the stable discharge characteristic will be shown also in the high frequency head of 10-70 KHz especially from the head which has a frequency of normal 4-10 KHz. In particular, by setting the viscosity at 25 ° C. to 3 to 14 mPa · s, even if it is used for an inkjet head having a design resolution of 600 dpi or more, it can be stably discharged.

  The viscosity at 25 ° C. of the inkjet ink in the present invention can be measured by a conventional method. Specifically, an E type viscometer (TVE25L type viscometer manufactured by Toki Sangyo Co., Ltd.) can be used and measured using 1 mL of ink.

  The inkjet ink of the present invention preferably has an average secondary particle diameter (D50) of the pigment of 40 nm to 500 nm, more preferably 50 nm to 400 nm, and particularly preferably in order to obtain a printed matter having excellent color developability. Is 60 nm to 300 nm. In order to keep the average secondary particle diameter within the preferable range, the pigment dispersion treatment step may be controlled as described above.

<Method for producing printed matter>
As a method for producing a printed matter using an ink set comprising the treatment liquid of the present invention and an inkjet ink, a step of applying the treatment liquid to a recording medium which is a paper base or a synthetic paper base, and the treatment liquid are provided. A method including a step of applying the ink-jet ink to the portion by a one-pass printing method is preferably used.

  The “one-pass printing method” is a printing method in which an ink jet head is scanned once with respect to a stopped recording medium, or a recording medium is passed only once under a fixed ink jet head. Ink is not printed on the top again. The one-pass printing method has fewer scans than the conventional ink-jet printing method (multi-pass printing method) in which the ink-jet head is scanned a plurality of times, and can increase the printing speed. Preferred. In particular, the adoption of this method is indispensable for realizing inkjet printing as an alternative to offset printing and gravure printing, which has been actively studied in recent years.

  Below, the manufacturing method of the printed matter using the ink set of this invention is demonstrated.

<Method of applying treatment liquid>
In the present invention, before printing the inkjet ink, the treatment liquid is applied on the recording medium conveyed at a speed of 40 m / min or more. As a method of applying the treatment liquid onto the recording medium, either a method of printing without contact with the recording medium such as ink jet printing or a method of printing with the treatment liquid in contact with the recording medium is adopted. Also good.

  In recent years, inkjet heads capable of discharging even a liquid composition having a viscosity of about 100 mPa · s at 25 ° C. have been developed by adopting a heater in the head and optimizing the flow path and nozzle structure in the head. The preferable viscosity range at 25 ° C. of the treatment liquid of the present invention is 5 to 100 mPa · s, and the treatment liquid can be printed without any problem even by ink jet printing. In addition, when adopting inkjet printing as a method for applying the treatment liquid, it is preferable to apply the treatment liquid only to a portion to which the inkjet ink is applied, from the viewpoint of leaving a texture unique to the recording medium in the non-printing portion.

  On the other hand, from the viewpoint of preventing damage to members constituting the ink jet head and ensuring ink jet printing suitability, a printing method in which a treatment liquid is brought into contact with the recording medium is preferably used in the present invention. As a printing method for contacting the treatment liquid, a conventionally known printing method can be arbitrarily selected, but a roller type is adopted from the viewpoint of simplicity of the device, uniform coating property, work efficiency, economy, etc. It is preferable to do. The “roller form” refers to a printing form in which a treatment liquid is applied to a rotating roll in advance and then the treatment liquid is transferred to a recording medium. Examples of the roller type coating machine preferably used in the present invention include an offset gravure coater, a gravure coater, a doctor coater, a bar coater, a blade coater, a flexo coater, and a roll coater.

  In the present invention, the coating film thickness of the treatment liquid on the recording medium is preferably 0.5 to 10 μm, more preferably 0.5 to 8.5 μm in terms of WET film thickness, and 0.6 It is particularly preferable that the thickness is ˜6 μm. By making the coating film thickness within the above range, the original texture of the recording medium is not impaired even in the portion where the treatment liquid is applied and the inkjet ink is not applied, and a sufficient color mixing suppressing effect is exhibited even during high-speed printing. The solvent component in the treatment liquid can be sufficiently dried. The coating thickness of the treatment liquid is preferably determined in consideration of the application amount of inkjet ink described later and the residual amount of the treatment liquid on the recording medium.

<Application of thermal energy after application of treatment liquid>
In the present invention, after applying the treatment liquid to the recording medium, it is preferable to apply thermal energy to the recording medium and dry the treatment liquid on the recording medium before applying the inkjet ink. In particular, it is preferable that the treatment liquid is completely dried before applying the ink jet ink, that is, the liquid component of the treatment liquid is completely removed. If the inkjet ink is applied before the treatment liquid is completely dried, the dissolution and / or dispersion function of the solid component in the inkjet ink can be further promoted, while the liquid component on the recording medium becomes excessive and the inkjet is performed. If the thermal energy applied after printing is insufficient, image defects such as waviness and blurring of the recording medium may occur.

  There is no restriction | limiting in particular in the application method of the heat energy used by this invention, For example, a heat drying method, a hot-air drying method, an infrared drying method, a microwave drying method, a drum drying method etc. can be mentioned. The above drying methods may be used alone or in combination. For example, by using a heat drying method and a hot air drying method in combination, the treatment liquid can be dried more quickly than when each of them is used alone.

  In the present invention, from the viewpoint of preventing damage to the recording medium and bumping of the liquid components in the processing liquid, when employing the heat drying method, the drying temperature is set to 35 to 100 ° C., and hot air drying is performed. When employing the method, the hot air temperature is preferably 50 to 250 ° C. From the same point of view, when the infrared drying method is employed, it is preferable that 50% or more of the integrated value of all infrared output used for infrared irradiation exists in the wavelength region of 700 nm or more and 1500 nm or less.

<Processing liquid application / drying device>
The treatment liquid application / drying apparatus of the present invention is equipped in-line or off-line with respect to an ink jet printing apparatus described later, but is preferably equipped in-line from the viewpoint of convenience during printing.

<Inkjet ink application method>
As described above, the inkjet ink is applied to the recording medium by a one-pass printing method. As described above, there are two types of one-pass printing methods: a method in which the inkjet head is scanned once with respect to the recording medium that is stopped, and a method in which the recording medium is passed only once under the fixed inkjet head. However, when the inkjet head is scanned, it is necessary to adjust the ejection timing in consideration of the movement of the inkjet head, and the landing position is likely to shift. Therefore, in the present invention, the inkjet head is fixed and the recording medium is fixed. A method of scanning is preferably used. At that time, the conveyance speed of the recording medium is preferably 40 m / min or more. In particular, when the processing liquid application device is installed in-line with respect to the ink jet printing apparatus, the processing liquid application device to the ink jet printing device are continuously arranged, and the recording medium to which the processing liquid is applied is directly used in the ink jet printing unit. It is preferable to be transported to.

  Further, as described above, by using the ink set of the present invention, a high-quality image can be produced even at a recording speed of 600 dpi or higher, but the same as offset printing or gravure printing. The recording resolution of the printed material is particularly preferably 1200 dpi or more from the viewpoint that a printed material having image quality can be provided.

<Inkjet head>
When a method of passing the recording medium only once under the fixed inkjet head as the one-pass printing method, the recording resolution in the recording width direction is determined by the design resolution of the inkjet head. As described above, in the present invention, since the recording resolution in the recording width direction is preferably 600 dpi or more, inevitably, the design resolution of the inkjet head is preferably 600 dpi or more, and particularly 1200 dpi or more. preferable. If the design resolution of the inkjet head is 600 dpi or more, printing can be performed with one inkjet head for each color, which is preferable from the viewpoint of miniaturization of the apparatus and economy. When an inkjet head having a design resolution lower than 600 dpi is used, a plurality of inkjet heads for each color are arranged in the transport direction of the recording medium, so that the recording resolution in the recording width direction can be achieved even in one-pass printing. 600 dpi or more can be realized.

  The print resolution in the recording medium conveyance direction depends not only on the design resolution of the inkjet head, but also on the drive frequency and print speed of the inkjet head. For example, the print speed is halved or the drive frequency is doubled. By doing so, the recording resolution in the transport direction is doubled. If the inkjet head design cannot achieve a print resolution of 600 dpi or more in the transport direction at a printing speed of 40 m / min or more, printing can be performed by arranging a plurality of ink-jet heads for each color in the transport direction of the recording medium. Both speed and print resolution can be achieved.

  In the ink jet one-pass printing of the present invention, the drop volume of the ink jet ink largely depends on the performance of the ink jet head, but is preferably in the range of 1 to 30 pL in order to realize a high quality image. In order to obtain a high-quality image, it is particularly preferable to use an ink jet head having a gradation specification capable of changing the drop volume.

<Application of thermal energy after application of inkjet ink>
It is preferable to apply thermal energy to the recording medium in order to dry the inkjet ink and the undried processing liquid after applying the ink jet ink onto the recording medium to which the processing liquid has been applied. The application method and conditions of heat energy preferably used in the present invention are the same as those used for drying the treatment liquid.

<Inkjet ink dryer>
The ink-jet ink drying apparatus is equipped inline or offline with respect to the ink-jet printing apparatus, but is preferably equipped inline from the viewpoint of convenience during printing. In the present invention, in order to prevent bleeding, color unevenness, curling of the recording medium, the thermal energy is preferably applied within 30 seconds after printing, more preferably within 20 seconds, and within 10 seconds. It is particularly preferable to apply.

<Amount of treatment liquid and inkjet ink applied>
In the present invention, it is preferable that the ratio of the applied amount of the inkjet ink to the applied amount of the treatment liquid is 0.1 or more and 10 or less. The ratio of the applied amounts is more preferably 0.5 or more and 9 or less, and particularly preferably 1 or more and 8 or less. By keeping the ratio of the applied amount within the above range, the change in the texture of the recording medium caused by the excessive amount of the processing liquid, or the blurring that occurs when the amount of inkjet ink becomes excessive and the effect of the processing liquid becomes insufficient. A high-quality printed matter can be obtained without color unevenness.

<Print speed>
As described above, when a printed matter is produced using the ink set of the present invention, the printing speed is preferably 40 m / min or more, more preferably 60 m / min or more, and 80 m / min or more. It is particularly preferred.

<Recording medium>
In the present invention, in order to sufficiently express the function of the processing liquid, it is necessary for high-speed and high-quality printing that calcium nitrate in the processing liquid is present within a certain range on the recording medium. Therefore, the formation state of the treatment liquid layer on the recording medium at the time of inkjet ink printing is important, and the porosity and permeability of the recording medium that affect the formation of the treatment liquid layer are important. When printing using the ink set of the present invention, a known recording medium can be arbitrarily used, but a paper base or a synthetic paper base is preferably selected from the above viewpoint.

  In the present invention, the “paper substrate” means a recording medium obtained by papermaking a material containing pulp. The paper making may be single layer paper making or multilayer paper making. Moreover, you may have a coating layer on the surface. Specific examples include high-quality paper, recycled paper, finely coated paper, coated paper, art paper, cast paper, liner paper, Manila cardboard, and coated cardboard. The “synthetic paper base material” is a recording medium using synthetic resin as a main raw material, and has the same printing processing characteristics as the paper base material.

  In addition to the recording medium described above, the ink set of the present invention includes, for example, a cloth base material such as cotton and silk; a paper base material; a synthetic paper base material; a polyvinyl chloride sheet, a PET film, a polypropylene film, and a polyethylene film. Can be used for various plastic substrates.

  The recording medium described above may have a smooth surface or an uneven surface, and may be transparent, translucent, or opaque. Further, two or more of these print media may be bonded to each other. Furthermore, a peeling adhesive layer or the like may be provided on the opposite side of the printing surface, and an adhesive layer or the like may be provided on the printing surface after printing. Further, the shape of the recording medium used in the present invention may be a roll or a sheet.

From the treatment solution, the concentration of calcium ions in the recording medium surface is preferably from 0.5~5mmol / m ^2, and more preferably 1~4mmol / m ^2. Thereby, cohesion by calcium and burying can be achieved, and furthermore, coating film resistance can be achieved.

<Printed matter>
The printed matter of the present invention is printed on a recording medium using the above ink set. The printed matter of the present invention has the characteristics that it is excellent in coating film resistance and drying property, and has high image quality without image defects such as color mixing and underfilling, regardless of the recording medium and printing conditions such as printing speed and recording resolution. .

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In the following description, “parts” and “%” represent “parts by mass” and “% by mass”, respectively, unless otherwise specified.

<I. Preparation of treatment solution>
<(1) Preparation example of PVA103 varnish>
The following materials were mixed with stirring at room temperature for 1 hour, then heated to 90 ° C., and further mixed for 1 hour. Then, the PVA103 varnish was obtained by allowing the mixture to cool to room temperature.
PVA103 (polyvinyl alcohol manufactured by Kuraray Co., Ltd. (degree of saponification 98-99% (complete saponification), degree of polymerization 300)) 25 parts Ion-exchanged water 75 parts

<(2) Preparation example of treatment liquid 1>
A mixing vessel equipped with a stirrer was prepared, and the following materials were sequentially added. While gently stirring, the mixture was mixed at room temperature for 1 hour, heated to 60 ° C., and further mixed for 1 hour. Thereafter, the mixture was allowed to cool to room temperature and then filtered through a membrane filter having a pore size of 1 μm to obtain a treatment liquid 1.
Calcium nitrate tetrahydrate (made by Yoneyama Chemical Co., Ltd.) 9.8 parts Triethanolamine (TEA) 1 part 35% hydrochloric acid (35% HCl) 0.62 parts PVA103 varnish 20 parts 2-propanol (iPrOH) 4 parts Dynol 607 (acetylene-based surfactant manufactured by Air Products) 0.4 part Proxel GXL (preservative, 1,2-benzisothiazol-3-one solution manufactured by Arch Chemicals) 0.05 part Ion-exchanged water 64.13 parts

<(3) Preparation examples of treatment liquids 2 to 40>
Treatment liquids 2 to 40 were obtained in the same manner as the treatment liquid 1 except that the materials shown in Table 1 were used.

The details of the abbreviations and trade names of the materials listed in Table 1 are as follows.
<1> Metal salt Ca (NO ₃ ) ₂ .4H ₂ O: Calcium nitrate tetrahydrate CaCl ₂ .2H ₂ O: Calcium chloride dihydrate NaCl: Sodium chloride <2> A compound having 3 or more hydroxyl groups
SANNICS GP-250: Sanyo Chemical Industries, glycerin propylene oxide adduct, number average molecular weight 250
<3> pH adjuster TEA: triethanolamine 35% HCl: 35% hydrochloric acid CH ₃ COOH: acetic acid CH ₃ COONa: sodium acetate <4> Binder resin BYK190: Styrene maleic acid resin aqueous solution (solid content 40 manufactured by BYK Japan) %)
<5> Organic solvent iPrOH: 2-propanol (boiling point 82 ° C., surface tension 20.9 mN / m)
MB: 3-methoxy-1-butanol (boiling point 158 ° C., surface tension 29.3 mN / m)
1,2-PD: 1,2-propanediol (boiling point 188 ° C., surface tension 35.1 m N / m)
1,2-HexD: 1,2-hexanediol (boiling point 224 ° C., surface tension 25.9 mN / m)
DEG: Diethylene glycol (boiling point 244 ° C., surface tension 44.2 mN / m)
<6> Surfactant Dinol 607: Acetylene-based surfactant manufactured by Air Products (HLB value by Griffin method = 8)
Surfynol 440: Acetylene-based surfactant manufactured by Air Products (HLB value by Griffin method = 8)
Surfynol 104E: Acetylene-based surfactant manufactured by Air Products (HLB value by Griffin method = 3)
BYK348: Siloxane-based surfactant manufactured by BYK Japan (HLB value by Griffin method = 10)
<7> Preservative Proxel GXL: 1,2-Benzisothiazol-3-one solution manufactured by Arch Chemicals

<II. Preparation of inkjet ink>
<Example of production of aqueous solution of pigment dispersion resin 1>
A reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer was charged with 93.4 parts of butanol and replaced with nitrogen gas. The inside of the reaction vessel was heated to 110 ° C., and a mixture of 20 parts of styrene as a polymerizable monomer, 40 parts of acrylic acid, 40 parts of behenyl acrylate, and 6 parts of V-601 (manufactured by Wako Pure Chemical) as a polymerization initiator. The polymerization reaction was carried out dropwise over 2 hours. After completion of the dropwise addition, the mixture was further reacted at 110 ° C. for 3 hours, then 0.6 part of V-601 (manufactured by Wako Pure Chemical Industries) was added, and the reaction was further continued at 110 ° C. for 1 hour to obtain a dispersion resin 1 solution. It was. Further, after cooling to room temperature, 37.1 parts of dimethylaminoethanol was added for neutralization, and then 100 parts of water was added to make it aqueous. Then, it heated to 100 degreeC or more, butanol was azeotroped with water, butanol was distilled off, and it adjusted so that solid content might be 30%. As a result, an aqueous solution having a solid content of 50% of the pigment dispersion resin 1 was obtained. It was 9.7 when pH of the aqueous solution (solid content 30%) of the said pigment dispersion resin 1 was measured using the desktop type pH meter F-72 by Horiba Ltd. In addition, the acid value of the pigment-dispersed resin was 250 mgKOH / g and the weight average molecular weight was measured by using the above-described method using HLC-8120GPC manufactured by Tosoh Corporation.

<Example of production of aqueous solution of pigment dispersion resins 2-7>
As shown in Table 2 below, the aqueous dispersions of the pigment dispersion resins 2 to 7 were the same as in the case of the pigment dispersion resin 1 except that the type and amount of the polymerizable monomer and the amount of the polymerization initiator were changed. Solution (solid content 30%) was obtained.

  Table 2 also shows the pH of the aqueous solution (solid content 30%) of each pigment dispersion resin, the acid value of the pigment dispersion resin, and the weight average molecular weight of the pigment dispersion resin.

<Production Example of Pigment Dispersing Resin 8>
In a reaction vessel equipped with a gas inlet tube, a thermometer, a condenser, and a stirrer, 45 parts of methyl ethyl ketone; 6.0 parts of acrylic acid, 30.0 parts of methyl methacrylate, and 14 parts of lauryl methacrylate as polymerizable monomers 0.05 part: 0.15 part of 2,2′-azobisisobutyronitrile; 0.65 part of 2- (dodecylthiocarbonothioylthio) -isobutyric acid were respectively added as polymerization initiators. After replacing the inside of the reaction vessel with nitrogen gas, the temperature was raised to 75 ° C. and the polymerization reaction was carried out for 3 hours to obtain a copolymer (hydrophilic block) composed of acrylic acid, methyl methacrylate, and lauryl methacrylate.
In addition, acrylic acid, methyl methacrylate, and lauryl methacrylate, which were used as raw materials, were analyzed with a gas chromatography mass spectrometer for the mixed solution in the reaction vessel before substitution with nitrogen gas and the mixed solution after the polymerization reaction. The detection peaks derived from were compared. As a result, in the mixed solution after the polymerization reaction, almost no peaks derived from acrylic acid, methyl methacrylate, or lauryl methacrylate were observed. From this result, it is considered that almost all of the charged polymerizable monomer was polymerized. Moreover, the weight average molecular weight of the said hydrophilic block measured using Tosoh Corporation HLC-8120GPC was about 23,000.

After completion of the above polymerization reaction, the reaction system was cooled to room temperature, and then 45 parts of methyl ethyl ketone; 10 parts of methyl methacrylate and 40 parts of benzyl methacrylate as polymerizable monomers were charged into the reaction vessel, respectively. After replacing the inside of the reaction vessel with nitrogen gas, the temperature is raised to 75 ° C. and the polymerization reaction is carried out for 3 hours, whereby a copolymer (hydrophobic block) composed of methyl methacrylate and benzyl methacrylate is added to the hydrophilic block. The added pigment dispersion resin 8 which is a block polymer was obtained.
As in the case of the hydrophilic block, detection peaks derived from polymerizable monomers were compared with a gas chromatography mass spectrometer. As a result, it was confirmed that almost all of the charged methyl methacrylate and benzyl methacrylate were polymerized to form hydrophobic blocks. Moreover, the weight average molecular weight of the said resin 8 for pigment dispersion measured using HLC-8120GPC by Tosoh Corporation was about 54,000. Moreover, the acid value of the said resin 8 for pigment dispersion measured by the method shown above using HLC-8120GPC by Tosoh Corporation was 45 mgKOH / g.

  Then, after cooling a reaction system to normal temperature, the mixed solution was taken out from the reaction container, and the methyl ethyl ketone solution of the resin 8 for pigment dispersion was obtained by adjusting with methyl ethyl ketone so that solid content might be 40.3%.

<Production Example of Pigment Dispersing Resin 9>
As a polymerizable monomer, 12.0 parts of methacrylic acid and 12.0 parts of methyl methacrylate; as a polymerization initiator, 0.2 part of 2,2′-azobisisobutyronitrile; 2- (dodecylthiocarbo Copolymer of methacrylic acid and methyl methacrylate (hydrophilic block) in the same manner as in the case of the hydrophilic block of the pigment-dispersing resin 8 except that 0.85 part of each is used in the form of nochioylthio) -isobutyric acid. B) was obtained.
As in the case of the hydrophilic block of the pigment-dispersing resin 8, the mixed liquid in the reaction vessel before being replaced with nitrogen gas and the mixed liquid after the polymerization reaction are analyzed with a gas chromatography mass spectrometer. -As a result of comparison, it is considered that almost all of the charged polymerizable monomers were polymerized. Moreover, the weight average molecular weight of the said hydrophilic block B measured using Tosoh HLC-8120GPC was about 12,000.

The pigment dispersion resin 8 is used except that the reaction system including the hydrophilic block B is used, and 56 parts of methyl methacrylate, 10 parts of 2-ethylhexyl methacrylate, and 10 parts of styrene are used as polymerizable monomers. Similarly to the case, a pigment dispersion resin 9 which is a block polymer in which a copolymer (hydrophobic block B) composed of methyl methacrylate, 2-ethylhexyl methacrylate and styrene is added to the hydrophilic block B. Got.
As in the case of the hydrophilic block, as a result of comparison of detection peaks derived from the polymerizable monomer with a gas chromatography mass spectrometer, almost all of the charged methyl methacrylate, 2-ethylhexyl methacrylate, and styrene were found. It was confirmed that the hydrophobic block B was formed by polymerization. Moreover, the weight average molecular weight of the pigment dispersing resin 9 measured using HLC-8120GPC manufactured by Tosoh Corporation was about 41,000. Moreover, the acid value of the said resin 9 for pigment dispersion measured by the method shown above using HLC-8120GPC by Tosoh Corporation was 92 mgKOH / g.

  Then, after cooling a reaction system to normal temperature, the mixed solution was taken out from the reaction container, and the methyl ethyl ketone solution of the resin 9 for pigment dispersion was obtained by adjusting with methyl ethyl ketone so that solid content might be 40.3%.

<Preparation examples of cyan pigment dispersions 1 to 7>
20 parts of LIONOL BLUE 7358G (CI Pigment Blue 15: 3) manufactured by Toyocolor Co., 20 parts of an aqueous solution of pigment dispersion resin 1 (solid content concentration 30%) and 60 parts of water are mixed and stirred. After preliminary dispersion, main dispersion was carried out for 2 hours using a 0.6 L dyno mill filled with 1800 g of zirconia beads having a diameter of 0.5 mm to obtain cyan pigment dispersion 1. Further, in the above, cyan pigment dispersions 2 to 8 were obtained in the same manner as in the case of the cyan pigment dispersion 1 except that the pigment dispersion resin 1 was replaced with the pigment dispersion resins 2 to 8.

<Preparation examples of magenta pigment dispersions 1 to 7>
Except that the pigment to be used is replaced with FASTGEN SUPER MAGENTA RG (CI Pigment Red 122) manufactured by DIC, magenta pigment dispersion 1 7 was obtained.

<Preparation example of yellow pigment dispersions 1-7>
By changing the pigment to be used to FAST YELLOW 7413 (CI Pigment Yellow 74) manufactured by Sanyo Color Co., Ltd., in the same manner as in the preparation examples of the above-mentioned cyan pigment dispersions 1 to 7, 8 was obtained.

<Preparation examples of black pigment dispersions 1-7>
Black pigment dispersions 1 to 7 were obtained in the same manner as in the preparation examples of cyan pigment dispersions 1 to 8, except that the pigment used was PrinteX85 (carbon black) manufactured by Orion Engineered Carbons. .

<Preparation Examples of Cyan Pigment Dispersions 8-9>
To a mixing vessel equipped with a stirrer, 14.9 parts of a methyl ethyl ketone solution (solid content concentration 40.3%) of pigment dispersing resin 8 and 14 parts of methyl ethyl ketone were added, and then 50 parts of water was stirred while stirring. 0.45 part of dimethylaminoethanol was added, and the mixture was further stirred for 30 minutes. Thereafter, 20 parts of LIONOL BLUE 7358G (CI Pigment Blue 15: 3) manufactured by Toyocolor Co., Ltd. was added, stirred well (preliminarily dispersed), and then filled with 1800 g of zirconia beads having a diameter of 0.5 mm. This dispersion was performed for 2 hours using a dyno mill. Subsequently, the obtained dispersion was taken out, 15 parts of water was added, and methyl ethyl ketone was distilled off under reduced pressure using an evaporator. Then, the cyan pigment dispersion liquid 8 was obtained by adjusting so that solid content concentration might be 20%.
Further, except that the methyl ethyl ketone solution of the pigment dispersing resin 8 is replaced with the methyl ethyl ketone solution of the pigment dispersing resin 9 and the addition amount of dimethylaminoethanol is 0.9 parts, the same as the preparation example of the cyan pigment dispersion 8 described above. As a result, a cyan pigment dispersion 9 was obtained.

<Preparation Examples of Magenta Pigment Dispersions 8-9>
Furthermore, a magenta pigment dispersion liquid is obtained in the same manner as in the preparation examples of the cyan pigment dispersion liquids 8 to 9, except that the pigment used is FASTGEN SUPER MAGENTA RG (CI Pigment Red 122) manufactured by DIC. 8-9 were obtained.

<Preparation example of yellow pigment dispersions 8-9>
Furthermore, a yellow pigment dispersion liquid is obtained in the same manner as in the preparation examples of the cyan pigment dispersion liquids 8 to 9 except that the pigment used is FAST YELLOW 7413 (CI Pigment Yellow 74) manufactured by Sanyo Dyeing Co., Ltd. 8-9 were obtained.

<Preparation Examples of Black Pigment Dispersions 8-9>
Further, except that the pigment to be used is replaced with PrinteX85 (carbon black) manufactured by Orion Engineered Carbons, the black pigment dispersions 8 to 9 were prepared in the same manner as in the preparation examples of the cyan pigment dispersions 8 to 9. Obtained.

<Preparation example of cyan pigment dispersion 10>
20 parts of LIONOL BLUE 7358G (CI Pigment Blue 15: 3) manufactured by Toyocolor Co., Ltd., plus coat Z-730 (carboxyl group-containing polyester resin manufactured by Kyoyo Chemical Industry Co., Ltd., weight average molecular weight 3,000, acid value 50 mgKOH / g, solid content concentration 25%) and 56 parts of water were added and mixed, respectively, pre-dispersed with a stirrer, and then used with a 0.6 L capacity dyno mill filled with 1800 g of zirconia beads having a diameter of 0.5 mm. The main dispersion was performed for 2 hours to obtain a cyan pigment dispersion liquid 10.

<Preparation Example of Magenta Pigment Dispersion Liquid 10, Yellow Pigment Dispersion Liquid 10, and Black Pigment Dispersion Liquid 10>
The pigments used were FASTGEN SUPER MAGENTA RG (CI Pigment Red 122) manufactured by DIC, FAST YELLOW 7413 (CI Pigment Yellow 74) manufactured by Sanyo Dye, and PrinteX85 manufactured by Orion Engineered Carbons. A magenta pigment dispersion 10, a yellow pigment dispersion 10, and a black pigment dispersion 10 were obtained in the same manner as in the preparation example of the cyan pigment dispersion 10 except that (carbon black) was used.

<Example of manufacturing JONCRYL 690 varnish>
The following materials were mixed for 30 minutes at room temperature with stirring, then heated to 60 ° C., and further mixed for 3 hours. Then, JONCRYL690 varnish was obtained by allowing the mixture to cool to room temperature.
JONCRYL 690 (acrylic resin manufactured by BASF, weight average molecular weight 16,500, acid value 240 mgKOH / g) 20 parts ion-exchanged water 80 parts

<Production example of CMYK inkjet ink set 1>
The materials described below were sequentially added to a mixing container while stirring with a stirrer, and stirred until it was sufficiently uniform. Thereafter, filtration was carried out with a membrane filter having a pore diameter of 1 μm, and coarse particles causing clogging of the head were removed to obtain ink. By performing the above steps with each of cyan pigment dispersion 1, magenta pigment dispersion 1, yellow pigment dispersion 1, and black pigment dispersion 1, cyan ink, magenta ink, yellow ink, and black ink were obtained. The color ink was CMYK inkjet ink set 1.
30 parts of pigment dispersion 1 (Ink was produced with cyan, magenta, yellow, and black)
Joncryl 8211 (BASF acrylic resin emulsion, solid content 44%) 13 parts Diethylene glycol monoisopropyl ether (DEMiPE) 17 parts Diethylene glycol monobutyl ether (DEMBE) 10 parts Triethanolamine (TEA) 0.5 parts Surfynol 465 (Air Products) Acetylene-based surfactant, HLB value by Griffin method = 13) 1 part Proxel GXL 0.05 part Ion-exchanged water 28.45 parts

<Production example of CMYK inkjet ink sets 2 to 45>
CMYK inkjet ink sets 2 to 45 (four colors of C, Y, M, and K, respectively) were obtained by the same method as inkjet ink set 1 except that the materials listed in Table 3 below were used.

Of the materials listed in Table 3, the details of the materials not used in Table 1 and above, and the abbreviations are as follows.
<1> Pigment dispersion CABOJET: Cyan: Cabojet 250C (self-dispersed copper phthalocyanine pigment dispersion manufactured by Cabot Corporation, pigment concentration 10%),
Magenta: Cabojet 265M (Cabot Corporation self-dispersing magenta pigment dispersion, pigment concentration 10%),
Yellow: Cabojet 270 (Cabot's self-dispersing yellow pigment dispersion, pigment concentration 10%),
Black: A solution obtained by diluting Cabojet 200 (self-dispersing carbon black aqueous solution manufactured by Cabot, pigment concentration 20%) with an equal mass of water to a pigment concentration of 10%.
<2> Specific glycol ether organic solvent (A)
DEMEE: Diethylene glycol monoethyl ether (boiling point 196 ° C.)
DEMiPE: Diethylene glycol monoisopropyl ether (boiling point 207 ° C.)
DEMBE: Diethylene glycol monobutyl ether (boiling point 230 ° C.)
DEMiBE: Diethylene glycol monoisobutyl ether (boiling point 241 ° C.)
TEMBE: Triethylene glycol monobutyl ether (boiling point 278 ° C.)
<3> Specific surface tension diol solvent (B)
1,3-PD: 1,3-propanediol (boiling point 214 ° C., surface tension 47.1 m N / m)
1,3-BuD: 1,3-butanediol (boiling point 207 ° C., surface tension 37.1 m N / m)
1,5-PenD: 1,5-pentanediol (boiling point 239 ° C., surface tension 42.2 mN / m)
<4> Other organic solvents TEMME: Triethylene glycol monomethyl ether (boiling point 249 ° C.)
EMBE: ethylene glycol monobutyl ether (boiling point 171 ° C.)
<5> Surfactant Zonyl FS-300: Fluorosurfactant manufactured by DuPont (solid content concentration 40%, HLB value by Griffin method = 14)

<III. Evaluation of treatment liquid and inkjet ink>
<Example of production of recording medium 1a to which treatment liquid is applied>
Using the printing test machine flexiproof 100 (manufactured by Matsuo Sangyo Co., Ltd.), the treatment liquid 1 prepared above was prepared as UPM Finessed Gloss paper (manufactured by UPM, basis weight 115 g / m ² , in the following description and Tables 4-6. “Recording medium A”) was applied uniformly. At this time, a ceramic roller having 140 wires / inch was used as the roller, and coating was performed at 80 m / min so that the coating film thickness of the treatment liquid 1 was 3.0 ± 0.3 μm. After applying the treatment liquid 1, the OK top coat + paper was placed in an air oven at 50 ° C. and dried for 3 minutes to produce a recording medium 1a to which the treatment liquid was applied.

<Preparation examples of recording media 2a to 35a and 48a to 53a to which treatment liquid is applied>
Recording media 2a to 25a and 32a to 37a to which the treatment liquid was applied were produced in the same manner as the recording medium 1 to which the treatment liquid was applied, using the treatment liquid described in Table 4.

<Example of production of recording medium 36a to which treatment liquid is applied>
The coating film thickness of the treatment liquid 3 is 0.4 ± 0 by using the treatment liquid 3 created above and using a ceramic roller having 1000 lines / inch as the ceramic roller used in the flexiproof 100 of the printing test machine. A recording medium 36a to which the treatment liquid was applied was produced in the same manner as the recording medium 1 to which the treatment liquid was applied, except that the thickness was 1 μm.

<Example of production of recording medium 37a to which treatment liquid is applied>
After producing the recording medium 3 to which the treatment liquid has been applied, the above-described treatment is performed using the printing test machine flexiproof 100 provided with a ceramic roller having a number of lines of 140 lines / inch on the surface to which the treatment liquid 3 has been applied. Liquid 3 was applied and dried in an air oven at 50 ° C. for 3 minutes. By repeating the above process two more times, a recording medium 37a to which the treatment liquid was applied, in which the total wet coating thickness of the treatment liquid 3 was 12.0 ± 1.2 μm, was produced.

<Preparation example of recording media 38a to 42a and 54a to which treatment liquid is applied>
Using treatment liquids 2-3, 5, 8, 19, 36, Npi fine quality 45 (manufactured by Nippon Paper Industries Co., Ltd., basis weight 52.3 g / m ² , “Recording medium” in the following description and Tables 4-6) The recording media 38a to 42a and 54a to which the treatment liquid was applied were prepared in the same manner as in the recording medium 1 to which the treatment liquid was applied, except that B) was used.

<Example of production of recording media 43a to 47a to which treatment liquid is applied>
Using processing liquids 2, 3, 5, 8, and 19, kraft repro liner paper (manufactured by Oji F-Tex Co., Ltd., continuous quantity 146 kg, “recording medium C” in the following description and Tables 4 to 6) Recording media 43a to 47a to which the treatment liquid was applied were produced in the same manner as recording medium 1 to which the treatment liquid was applied, except that it was used.

<Evaluation of coating unevenness (initial) of treatment liquid>
In order to improve visibility, 9.9 g of the treatment liquids 1 to 35 prepared above are separated, and 0.1 g of KayfectRed Pliquid (a dye made by Nippon Kayaku Co., Ltd.) is added, mixed and dissolved well, and then the coloring treatment is performed. Liquids 1 to 35 were prepared. The coloring treatment liquid was uniformly applied to the recording medium shown in Table 5 below using Flexiproof 100 (manufactured by Matsuo Sangyo Co., Ltd.). At this time, a 140-wire / inch ceramic roller was used as the roller, and coating was performed at a coating speed of 80 m / min so that the coating film thickness was 3.0 ± 0.3 μm. After the treatment liquid was applied, the recording media 1b to 45b to which the color treatment liquid was applied were prepared by drying in an air oven at 50 ° C. for 3 minutes.

According to the above method, when 10 recording media to which the color processing liquid is applied are continuously formed, the degree of color unevenness in each recording medium is visually observed, whereby the processing liquid is coated unevenly (initial coating suitability). Evaluated. The evaluation criteria were as follows, and ○ and Δ were good coating unevenness of the treatment liquid.
○: Coating unevenness was not seen at all on all 10 sheets.
Δ: Coating unevenness was observed on 1 to 2 out of 10 sheets.
X: Coating unevenness was observed in 3 or more of 10 sheets.

<Evaluation of coating unevenness of treatment liquid (after time)>
10 kg of each of the treatment solutions 1 to 35 was put into a can, and left to stand at room temperature for 1 week in an open state without closing the lid. Then, measure the solid content concentration of each treatment liquid, and for those whose solid content is larger than before standing, add water and prepare so that the solid content is the same as before standing Then, post-treatment liquids 1 to 35 were produced over time.

  The recording medium 1c to which the colored treatment liquids 1 to 35 after the passage of time and the colored treatment liquid after the passage of time are applied in the same manner as the evaluation method of the coating unevenness of the treatment liquid using the aftertreatment liquids 1 to 35 of the passage of time. ˜45c was prepared, and coating unevenness (coating suitability after aging) of the after-treatment liquid was evaluated. The evaluation criteria were the same as above.

  The evaluation results of the coating unevenness were as shown in Table 5 below.

[Examples 1-87, Comparative Examples 1-12]
<Preparation of inkjet ink set printer>
Four inkjet heads KJ4B-1200 (manufactured by Kyocera Corporation) were installed on the upper part of the conveyor that can convey the recording medium, and each of the K, C, M, and Y inkjet inks constituting the inkjet ink set was filled from the upstream side. The inkjet head has a design resolution of 1200 dpi and a maximum driving frequency of 64 kHz. When printing is performed at the maximum driving frequency and a printing speed of 80 m / min, the recording resolution in the recording medium conveyance direction is 1200 dpi.

<Printing printed bicycle images>
After fixing the recording medium provided with the treatment liquid prepared above on the conveyor of the inkjet ink set printing apparatus, the conveyor was driven at a constant speed shown below. When the recording medium to which the treatment liquid is applied passes through the installation part of the inkjet head, the inkjet ink is ejected in a drop volume of 3 pL in the order of KCMY, and the natural color of JIS X 9201 high-definition color digital standard image data (CMYK / SCID) The image N5 (bicycle) was printed. Within 10 seconds after printing, the printed material was placed in a 50 ° C. air oven and dried for 3 minutes to prepare a printed bicycle image. In addition, the conveyor speed was set to three types of 40 m / min, 60 m / min, and 80 m / min, and printing was performed under each condition to create a printed matter.

<Printing solid prints>
After fixing the recording medium provided with the treatment liquid on the conveyor of the inkjet ink set printing apparatus, the conveyor was driven at a constant speed shown below. When the recording medium to which the treatment liquid is applied passes through the installation portion of the inkjet head, each of the KCMY inkjet inks is ejected with a drop volume of 3 pL, and solid printing with a printing rate of 100% of 3 cm × 3 cm is performed in the order of CMYK. An adjacent image was printed. Within 10 seconds after printing, the printed material was placed in a 50 ° C. air oven and dried for a certain period of time to produce a solid printed material. In the embedding evaluation shown below, a printed matter was used in which the conveyor speed was set to three types of 40 m / min, 60 m / min, and 80 m / min, and the drying time in a 50 ° C. air oven was set to 3 minutes. In the drying evaluation, a solid printed matter was used which was printed at a conveyor speed of 60 m / min and taken out every 30 seconds after being put into a 50 ° C. air oven.

  The combinations of the recording medium and the ink jet ink evaluated above were as shown in Table 6 below.

  The following evaluation was performed on the bicycle image printed matter and the solid printed matter created above. The obtained evaluation results are shown in Table 6 below.

<Evaluation of cohesiveness (color mixing)>
Using a microscope, the dot shape of the 4C (CMYK) printed portion of the printed bicycle image was observed at a magnification of 200 times to evaluate the cohesiveness. The evaluation results were as follows, and ◎, ○, and Δ were considered good cohesiveness.
A: At all three printing speeds, the dots in the 4C printing part were independent, and no color mixing was observed.
○: The dots in the 4C printing part were independent at 40 m / min and 60 m / min, and no color mixture was seen, but at 80 m / min, the color mixture of dots was seen.
Δ: The dots in the 4C printing part were independent at 40 m / min, and no mixed color was seen, but at 60 m / min and 80 m / min, the mixed color of dots was seen.
X: A mixed color of dots in the 4C printing portion was observed at all three printing speeds.

<Evaluation of filling (initial)>
Using a microscope, the solid printed material was observed at a magnification of 200 times, and it was evaluated for each color whether there was no missing or streak. The evaluation results were as follows, and ◎, ○, and Δ were filled and considered good. In Table 6 above, among the four colors, those with the worst evaluation results are listed.
A: No omissions or streaks were observed at all three printing speeds.
○: No omission or streaking was observed at 40 m / min and 60 m / min, but omission or streaking was observed at 80 m / min.
Δ: No omission or streaking was observed at 40 m / min, but omission or streaking was observed at 60 m / min and 80 m / min.
X: Missing or streaks were observed at all three printing speeds.

<Evaluation of dryness>
The solid printed material after printing was put into a 50 ° C. air oven, and then taken out every 30 seconds. The printed material was touched with a finger to evaluate the drying property of the printed material. The evaluation criteria are as follows, and 、, ○, and Δ are considered to have good drying properties.
(Double-circle): Ink did not adhere even if it touched with the finger 30 seconds after oven putting.
○: Ink adhered to the finger 30 seconds after the oven was put in, but did not adhere after 1 minute.
Δ: Ink adhered to the finger after 1 minute from the introduction of the oven, but did not adhere after 1 minute 30 seconds.
X: The ink adhered to the finger even in the printed matter after 1 minute 30 seconds from the introduction of the oven.

<Evaluation of coating film resistance>
The above-mentioned printed bicycle image was set on a Southerland Love Tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) on which friction paper (NPI-70 manufactured by Nippon Paper Industries Co., Ltd.) was set. The coating film resistance was evaluated by visually confirming whether the substrate was peeled off. The evaluation criteria are as follows, and ◎, ○, and Δ are regarded as practical areas.
A: The ink did not peel off even after 20 reciprocations, and the ground was not visible.
○: The ink was peeled off after 20 reciprocations and the base was visible, but the base was not visible after 15 reciprocations.
Δ: After 15 round trips, the ink was peeled off and the base was visible, but after 10 round trips, the base was not visible.
X: The ink was peeled off even after 10 reciprocations, and the base was visible.

<Evaluation of ink set after time>
The treatment liquids 1 to 41 and the CMYK ink jet ink sets 1 to 45 were put in 10 kg each in a can, and allowed to stand at room temperature for 1 week in an open state without closing the lid. Thereafter, the solid content concentration of each ink-jet ink was measured, and for those that were larger than the initial value, water was added and the solid content was adjusted to be the same as that of the ink before aging. Post-treatment liquids 1 to 41 and CMYK inkjet ink sets 1 to 45 were produced after the passage of time.

<Evaluation of filling (after time)>
Using the above time-treated post-treatment liquids 1 to 41, recording media 1d to 54d provided with the time-treated post-treatment liquid were produced in the same manner as described above. Using the recording media 1d to 54d to which the post-aging treatment liquid was applied and the post-aging CMYK inkjet ink sets 1 to 45, the filling after the aging was evaluated by the same method as the above-described filling evaluation method. The evaluation criteria were the same as above.

<Evaluation of ejection stability of inkjet ink>
With respect to the CMYK ink jet ink sets 1 to 41 produced over time as described above, the discharge stability was evaluated by assuming the long-term running after the following method. The obtained evaluation results are shown in Table 7 below.

An ink jet discharge device equipped with four ink jet heads KJ4B-1200 (manufactured by Kyocera Corporation) was prepared, and after the lapse of time, K, C, M, and Y ink jet inks constituting the CMYK ink jet ink set were filled from the upstream side. Next, after discharging from all the nozzles for 2 hours continuously under the conditions of a drop volume of 3 pl and a driving frequency of 64 kHz, the discharge stability was evaluated by printing a nozzle check pattern and counting the number of missing nozzles. . The evaluation criteria are as follows, and 、, ○, and Δ indicate good discharge stability.
A: No nozzle omission in the nozzle check pattern 2 hours after the start of printing.
A: Nozzle missing was 1 to 2 in the nozzle check pattern 2 hours after the start of printing.
Δ: Nozzle missing was 3 to 4 in the nozzle check pattern 2 hours after the start of printing.
×: Nozzle missing was 5 or more in the nozzle check pattern 2 hours after the start of printing.

  From the above, by using the ink set of the present invention, regardless of the printing conditions such as the recording medium and the printing speed / recording resolution, the coating film resistance and drying properties are excellent, and there is no image defect such as color mixing or insufficient filling. It was found that high-quality printed material can be created.

Claims (11)

An ink set comprising an inkjet ink and a treatment liquid used with the inkjet ink,
The inkjet ink includes a pigment, a water-soluble organic solvent, a surfactant, and water,
The water-soluble organic solvent includes a glycol ether organic solvent (A) represented by the following general formula (1),
The treatment liquid contains a flocculant;
The flocculant contains 6.8 to 20.8% by mass of calcium nitrate based on the total amount of the treatment liquid,
An ink set, wherein the treatment liquid contains a compound having 3 or more hydroxyl groups in an amount of 15% by mass or less based on the total amount of the treatment liquid.

General formula (1):
R1-(— O—CH ₂ CH ₂ —) n—OH

(In the general formula (1), R1 represents an alkyl group having 2 to 4 carbon atoms, which may have a branched structure, and n is 2 or 3.)   The ink set according to claim 1, wherein the pH of the treatment liquid is 3.5 to 11.   The ink set according to claim 1, wherein the treatment liquid further contains a pH adjuster. The treatment liquid further contains a nonionic surfactant,
The ink set according to any one of claims 1 to 3, wherein the nonionic surfactant includes one or more compounds selected from an acetylene surfactant and a siloxane surfactant.   The ink set according to any one of claims 1 to 4, wherein the inkjet ink further contains a pigment dispersing resin.   The ink set according to any one of claims 1 to 5, wherein the glycol ether organic solvent (A) represented by the general formula (1) includes a glycol ether organic solvent in which n is 2.   The ink set according to any one of claims 1 to 6, wherein the water-soluble organic solvent further contains a diol solvent (B) having a surface tension at 25 ° C of 30 to 50 mN / m.   Mass ratio of the blending amount of the diol solvent (B) having a surface tension of 30 to 50 mN / m at 25 ° C. with respect to the blending amount of the glycol ether organic solvent (A) represented by the general formula (1). Is an ink set according to claim 7, wherein the ratio is 1: 0.5 to 1: 7.5. A method for producing an inkjet ink print using the ink set according to claim 1,
Applying the treatment liquid to a recording medium that is a paper base or a synthetic paper base;
And a step of applying the inkjet ink to the portion to which the treatment liquid has been applied by a one-pass printing method. The method for producing an ink-jet ink print according to claim 9, wherein the treatment liquid is applied to the recording medium such that the amount of calcium ions on the surface of the recording medium is 0.5 to 5.0 mmol / m ² .   A printed matter obtained by printing the ink set according to claim 1 on a recording medium.