JP2015227003A - Inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording method capable of providing clear images by suppressing bleeding or white-out, excellent in long term storage property of an obtained printed matter and suppressing deterioration of a device.SOLUTION: There is provided an inkjet recording method of printing by adhering an acceptance solution to a printing surface of a material to be recorded, and adhering an inkjet ink to an adhesion part of the acceptance solution. The acceptance solution contains a metal salt having a valance of 2 or more and a solvent, the solvent contains at least water, where the solvent having the boiling point of 280°C or more is 5 pts.mass or less based on 100 pts.mass of the acceptance solution and pH is 6.0 to 10.0. The inkjet ink contains a pigment, a resin, a surfactant and a solvent, the solvent contains at least aqueous solvent and printing is performed by adhering the inkjet ink after adhering the acceptance solution to the printing surface and before drying the acceptance solution.

Description

  The present invention relates to an ink jet recording method and an ink set for ink jet recording.

In the printing field, ink-jet printing methods have been developed and widely used.
When printing using an ink jet printer, the ink droplets ejected from the print head land on the printing paper, and then penetrate and fix to form dots, and an image is formed by collecting a large number of these dots. This dot formation process is important for forming a clear image.

As the recording material, various materials such as non-coated paper, coated paper, and cloth, as well as polyester resin and vinyl chloride resin are used.
Non-coated paper is a hydrophilic substance in which a large number of hydroxyl groups of cellulose are present, has a property of being easily adapted to water, and has ink absorbability. When water-based ink is used for such an absorbent recording material, since the ink easily penetrates into the recording material, bleeding called feathering is likely to occur along the fibers of the recording material. However, since the color material density on the surface of the recording material is low, a clear image cannot be obtained, and the blur is further increased, there is a problem in that the color material falls through.

The coated paper is coated with a solution (coating liquid) in which a pigment mainly composed of kaolin or calcium carbonate having a particle system of about 0.1 to 0.3 μm and a binder are dispersed in water on the surface of the recording material. The coating layer is formed and smoothed on the surface, and the binder such as synthetic latex used to fix the pigment fills the gap between the pigment particles and makes the surface hydrophobic. Low ink absorbency. Examples of the coated paper include coated paper and art paper, and are used for printed materials that require high reproducibility such as calendars, posters, and magazine color pages. In recent years, printing lots are becoming more and more small, and as an alternative to conventional offset printing, inkjet printing, which is on-demand printing that is easy to handle high-speed printing, has attracted attention. Printing on inkjet paper using inkjet ink is expected.
If a recording material such as coated paper is used as the recording material, the water-based ink does not easily penetrate into the recording material. The resulting feathering is less likely to occur.
On the other hand, the water-based ink landed on the low-absorbency recording material by the ink jet method has a problem that the dots do not spread sufficiently and the dot diameter is small. When the dot diameter is small, the color material cannot be uniformly applied to the surface of the recording material, and thus printing unevenness may occur or an excessive gap may be generated between dots, resulting in white spots. Also, since the water-based ink droplets remain on the surface of the recording material, the coloring material is difficult to fix, uneven color mixing occurs in the boundary area of different colors, and bleeding called color bleeding occurs. There was a problem that it was easy.

  As a technique for improving the fixing property of the ink pigment on the printing surface of the recording material, an ink jet is applied in which a receiving solution is applied in advance to the printing surface of the recording material, and the ink is attached to the receiving surface of the receiving solution for printing. Recording methods are being studied.

Patent Document 1 discloses an ink jet recording method for improving the bleeding when recording an image of a secondary color, improving the color developability, and solving the problem of ink back-through in the recording medium. When the reaction liquid, the first ink, and the second ink are applied in this order, the first ink is applied after applying the wetting time Tw1 of the reaction liquid to the recording medium and the previous reaction liquid. The time Td1 until the filling satisfies the relationship of Td1 <Tw1, the wetting time Tw2 of the mixture of the first ink and the reaction liquid with respect to the recording medium, and the first ink after the first ink is applied. An ink jet recording method is disclosed in which the time Td2 until the second ink is applied satisfies the relationship Td2 <Tw2.
In the method of Patent Document 1, the first ink and the second ink are applied and mixed with the reaction liquid before the reaction liquid wets and spreads on the recording medium, that is, while the reaction liquid remains on the surface of the recording medium. In this way, a secondary color is generated. In Patent Document 1, it is necessary to increase the surface tension in order for the reaction liquid to remain on the surface of the recording medium. For this reason, the surface of the recording medium, particularly coated paper, has a poor wettability in the hydrophobic recording medium, and the reaction liquid cannot be uniformly applied, resulting in unevenness and white spots. However, unevenness and white spots may occur.

  In Patent Document 2, as a method of digitally printing a fabric, a step of pretreating the fabric with an aqueous pretreatment solution containing a nonionic latex polymer and a high cation salt solution, a step of drying the pretreated fabric, and the drying A specific method is disclosed which comprises the step of digitally printing the resulting fabric with a color inkjet ink. As disclosed in Patent Document 2, when a dye is contained as a color material and a fabric is used as a recording material, bleeding is likely to occur, and printing is usually performed after the pretreatment solution is dried. Met.

  As an ink jet recording method in which Patent Document 3 is not affected by a recording medium, there is no color unevenness or white spot, feathering and color bleeding can be suppressed, and a clear image can be obtained. A receiving solution containing a divalent or higher metal salt is attached to the printing surface of the recording medium, and an ink-jet ink containing a pigment, a resin, a surfactant, and an aqueous solvent is attached to the receiving solution attaching portion for printing. Disclosed is an inkjet recording method, wherein a surface tension of the receiving solution and the inkjet ink is 32 mN / m or less, and a difference in surface tension between the receiving solution and the inkjet ink is 5 mN / m or less. .

JP 2007-168252 A JP 2010-503779 gazette JP 2013-188958 A

  In the conventional ink jet recording method, the time required for drying may be long, and sufficient image sharpness may not be obtained. In addition, the present inventors have obtained knowledge that the conventional receiving solution may have insufficient reactivity with the ink jet ink or may affect the deterioration of the printed matter or the substrate.

  The present invention has been made in view of the above circumstances, can suppress bleeding and white spots, can obtain a clear image, is excellent in long-term storage of the obtained printed matter, and suppresses deterioration of the apparatus. Provided is an ink jet recording method and an ink set for ink jet recording capable of obtaining a clear image with suppressed bleeding and white spots, having excellent long-term storage stability of printed matter, and capable of suppressing deterioration of the apparatus. For the purpose.

An ink jet recording method according to the present invention is an ink jet recording method in which a receiving solution is attached to a printing surface of a recording material, and an ink jet ink is attached to a receiving portion of the receiving solution for printing.
The receiving solution contains a divalent or higher metal salt and a solvent, the solvent contains at least water, and the solvent having a boiling point of 280 ° C. or higher is 5 parts by mass or less with respect to 100 parts by mass of the receiving solution. A receiving solution having a pH of 6.0 to 10.0,
The inkjet ink contains a pigment, a resin, a surfactant, and a solvent, and the solvent is an inkjet ink containing at least an aqueous solvent,
After the receiving solution is attached to the printing surface, the ink-jet ink is attached and printed before the receiving solution is dried.

  In the inkjet recording method of the present invention, the application amount (Vp) per unit area of the receiving solution and the application amount (Vi) per unit area of the inkjet ink on the printing surface of the recording material are Vp ≦ Vi. It is preferable that the above relationship is satisfied from the viewpoint that the solid filling property is improved and a printed matter having excellent gloss and texture can be obtained.

  In the ink jet recording method of the present invention, the method of attaching the receiving solution may be coating by a coater method, and the method of attaching the ink jet ink may be printing by an ink jet method.

  In the ink jet recording method of the present invention, the method of attaching the receiving solution and the method of attaching the ink jet ink can be printing by a serial head ink jet method.

  Further, in the ink jet recording method of the present invention, the method of attaching the receiving solution and the method of attaching the ink jet ink can be printing by a line head type ink jet method.

An ink set for ink jet recording according to the present invention has a receiving solution and an ink jet ink used for an ink jet recording method in which a receiving solution is attached to a printing surface of a recording material and ink jet ink is attached to a receiving portion of the receiving solution for printing. An ink set that combines
The receiving solution contains a divalent or higher metal salt and a solvent, the solvent contains at least water, and the solvent having a boiling point of 280 ° C. or higher is 5 parts by mass or less with respect to 100 parts by mass of the receiving solution. A receiving solution having a pH of 6.0 to 10.0;
The inkjet ink is an inkjet ink containing a pigment, a resin, a surfactant, and a solvent, wherein the solvent contains at least an aqueous solvent, and the pH of the inkjet ink is 6.0 to 10.0. It is characterized by that.

  According to the present invention, an ink jet recording method capable of obtaining a clear image with suppressed bleeding and white spots, having excellent long-term storability of the obtained printed matter, and suppressing deterioration of the apparatus, and bleeding In addition, it is possible to provide an ink set for ink-jet recording that can obtain clear images with suppressed white spots and has excellent long-term storability of printed matter and can suppress deterioration of the apparatus.

Hereinafter, an ink jet recording method and an ink set for ink jet recording according to the present invention will be described.
[Inkjet recording method]
An ink jet recording method according to the present invention is an ink jet recording method in which a receiving solution is attached to a printing surface of a recording material, and an ink jet ink is attached to a receiving portion of the receiving solution for printing.
The receiving solution contains a divalent or higher metal salt and a solvent, the solvent contains at least water, and the solvent having a boiling point of 280 ° C. or higher is 5 parts by mass or less with respect to 100 parts by mass of the receiving solution. A receiving solution having a pH of 6.0 to 10.0,
The inkjet ink contains a pigment, a resin, a surfactant, and a solvent, and the solvent is an inkjet ink containing at least an aqueous solvent,
After the receiving solution is attached to the printing surface, the ink-jet ink is attached and printed before the receiving solution is dried.

According to the ink jet recording method of the present invention, it is possible to obtain a clear image with suppressed bleeding and white spots, and excellent long-term storability of the obtained printed matter, thereby suppressing deterioration of the apparatus.
The ink jet recording method of the present invention can suppress feathering and back-through which are particularly problematic when an absorbent base material is used as a recording material. Since white spots and color bleed, which are particularly problematic when using a conductive substrate, can be suppressed, bleeding and white spots are suppressed regardless of the recording material.

Although there is an unclear part as an effect | action which exhibits the above effects by the inkjet recording method of the said invention, it is estimated as follows.
Conventionally, as a technique for improving the fixability of the ink pigment on the printing surface of the recording material, a receiving solution is applied in advance to the printing surface of the recording material, and the ink is applied to the receiving surface of the receiving solution. Inkjet recording methods for printing have been studied. As such a receiving solution, a receiving solution containing a divalent or higher metal salt has been known. For example, when an absorptive substrate such as non-coated paper is used as a recording material, water-based ink easily penetrates into the recording material, so that the pigment does not stay on the surface of the recording material and the back side of the substrate There is a problem that the ink reaches the ink surface, the color material density on the surface of the base material is lowered, and a problem that the ink easily spreads along the fiber of the paper and feathering easily occurs and a clear image cannot be obtained. By applying a receiving solution containing a metal salt having a valence of 2 or more in advance to the printing surface of such an absorbent substrate, the pigment in the water-based ink adhered by the ink jet method is a metal salt having a valence of 2 or more. It is presumed that the dispersion state is changed by the interaction of the above, and is fixed on the surface of the recording medium to suppress the feathering.
On the other hand, when a low-absorbing substrate or a non-absorbing substrate is used as the recording material, the ink hardly permeates and is repelled on the substrate surface. For this reason, there is a problem that the dots are not sufficiently spread, the printing surface is not sufficiently filled with ink, and printing unevenness and white spots are likely to occur. Further, when a non-absorbing substrate is used as a recording material, there is a problem that the time required for drying becomes long and the ink droplets that are repelled are irregularly connected, so that unevenness tends to occur.

As a result of intensive studies, the present inventors have attached a receiving solution containing a divalent or higher valent metal salt to the printing surface, and then attached an inkjet ink before the receiving solution is dried, thereby reducing the low-absorbency substrate. And non-absorbent substrates were found to be able to suppress printing unevenness and white spots. By adhering the inkjet ink before the receiving solution dries, the inkjet ink on the surface of the recording material is likely to get wet and spread, and the dot diameter of the inkjet ink is increased to eliminate printing unevenness and white spots. Are immediately mixed to rapidly change the dispersion state of the pigment, and it is presumed that the ink is fixed without causing color bleeding.
On the other hand, when the ink-jet ink is attached after the receiving solution is dried, after the receiving solution is attached to the low-absorbing substrate or the non-absorbing substrate, the droplet of the receiving solution is repelled, and the central portion of the droplet While the vicinity is raised, the peripheral edge tends to shrink. When such droplets are dried, it is presumed that a difference in the amount of metal salt tends to occur on the surface of the recording material, thereby causing bleeding and unevenness.

  As a result of further studies, the present inventors have found that when a printed material obtained by such an ink jet recording method is stored for a long period of time, the printed material may turn yellow. Further, it has been found that the apparatus used in such an ink jet recording method may corrode metal parts or resin parts in the flow path of the receiving solution after long-term operation. The present inventors have found that such a problem occurs when a receiving solution having an acidity with a pH of less than 6 is used. For these reasons, the present inventors have found that the deterioration of the recording material and the corrosion of the metal can be suppressed by adjusting the pH of the receiving solution to 6.0 to 10.0.

  Furthermore, the present inventors have found that the fixing property of the ink on the recording material is improved by adjusting the pH of the receiving solution containing a divalent or higher valent metal salt to 6.0 to 10.0. It was. Therefore, the amount of the metal salt on the recording material can be reduced as compared with the conventional receiving solution, and the gloss and texture of the printed matter can be improved. Since the receiving solution having a pH of 6.0 to 10.0 has excellent ink fixing properties, it is possible to reduce the concentration of the metal salt in the receiving solution or to reduce the amount of the receiving solution applied to the recording material. it can. When the concentration of the metal salt in the receiving solution is lowered, precipitation and sedimentation of the metal salt in the receiving solution are suppressed, and the storage stability of the receiving solution itself can be improved. Further, the adhesion of the metal salt is suppressed in the receiving solution coating apparatus, such as an ink jet nozzle, and the occurrence of problems in the apparatus can be suppressed.

  In printing by an ink jet method, there has been known a problem that solid contents such as pigments in ink adhere to ink jet nozzles. For this reason, high-boiling solvents having a boiling point of 280 ° C. or higher have been widely used in order to suppress precipitation of solids in the ink. In the receiving solution used in combination with such an ink-jet ink, the solvent is usually the same as that of the ink-jet ink. For this reason, it has not been surprisingly known that a receiving solution containing a metal salt having a valence of 2 or more tends to suppress the volatilization of the solvent by the metal salt. Thus, even if the content rate of the high boiling point solvent having a boiling point of 280 ° C. or higher is 5 parts by mass or less, the problem of metal salt precipitation in the inkjet nozzle is suppressed. Therefore, in the present invention, when the content of the high boiling point solvent having a boiling point of 280 ° C. or higher is set to 5 parts by mass or less, the receiving solution and the ink-jet ink are applied onto the recording material, and recording is performed. Even when the amount of adhering liquid on the material increases, it is possible to suppress a decrease in drying property. On the other hand, when the amount of the receiving solution applied to the recording material is reduced, the drying time of the printed material can be shortened, the recording material is less likely to curl and cockling, and printing speed and cost are reduced. Can also be achieved.

<Recording material>
In the inkjet recording method of the present invention, the recording material is not particularly limited, and any of an absorptive substrate, a low-absorbing substrate, and a non-absorbing substrate can be suitably used. As an absorptive base material, uncoated paper, such as re-paper, medium quality paper, high quality paper, and copy paper (PCC); Fabrics, such as cotton, a synthetic fabric, silk, hemp, a nonwoven fabric, etc. are mentioned, for example. In particular, the recording method of the present invention is preferably applied to non-coated paper because it is easy to suppress feathering and back-through. In addition, the absorbency of a base material is JAPAN TAPPI paper pulp test method No., for example. The test can be performed with 51-87 or the like. Non-coated paper has high absorbency because it is not coated with a coating liquid that reduces ink penetration and absorption.
Examples of the low-absorbency substrate include coated paper such as finely coated paper, lightweight coated paper, coated paper, art paper, cast paper, and the like. Coated paper is a sheet of paper coated with a white pigment or binder component to improve surface smoothness, and it is difficult for ink to be absorbed and penetrated. Examples of the non-absorbable substrate include plastic films such as polyester resins, polypropylene resins, vinyl chloride resins and polyimide resins; metals, metallized paper, glass, synthetic rubber, natural rubber, leather, and the like. It is done. The ink jet recording method of the present invention can be suitably used even when a low-absorbing substrate or a non-absorbing substrate with low ink permeability is used, and there is no color unevenness and a clear color bleed is suppressed. An image can be obtained.

<Accepted solution>
In the present invention, the receiving solution contains a divalent or higher metal salt and a solvent, and the solvent contains at least water, and the solvent having a boiling point of 280 ° C. or higher is 5 parts by mass or less with respect to 100 parts by mass of the receiving solution. A receiving solution having a pH of 6.0 to 10.0 is used. By using such a receiving solution, it is possible to suppress feathering and back-through which are particularly problematic when an absorbent base material is used as the recording material, and a low-absorbing base material or White spots and color bleed, which are particularly problematic when using non-absorbent base materials, can be suppressed. In addition to being able to suppress deterioration of the apparatus, it is also excellent in drying properties.
In the present invention, the receiving solution is an ink that is applied to the printing surface before the ink-jet ink is attached to the printing surface of the recording medium in order to improve the printing quality when printing is performed by the inkjet recording method. is there.

  The receiving solution used in the inkjet recording method of the present invention contains at least a divalent or higher metal salt and a solvent, and further contains other components as necessary within the range not impairing the effects of the present invention. It may be a thing. Hereinafter, each component contained in the receiving solution of the present invention will be described.

(1) Bivalent or higher metal salt In the present invention, the bivalent or higher metal salt improves the fixability of the ink on the recording material.
The divalent or higher metal salt can be appropriately selected from known metal salts composed of polyvalent metal ions and anions. Examples of the polyvalent metal ions include calcium ions, magnesium ions, aluminum ions, titanium ions, iron (II) ions, iron (III) ions, cobalt ions, nickel ions, copper ions, zinc ions, barium ions, and strontium. And ions. Especially, it is preferable that it is 1 or more types selected from calcium ion, magnesium ion, nickel ion, and zinc ion from the point of the magnitude | size of interaction with the pigment in the inkjet ink mentioned later.

The anion may be an inorganic anion or an organic anion. Among them, it is preferable to use an organic anion from the viewpoint of excellent long-term storability of the printed matter and suppressing deterioration of the apparatus.
Specific examples of inorganic anions include, but are not limited to, chloride ions, bromide ions, nitrate ions, and sulfate ions. Specific examples of organic anions include pantothenic acid ions, pantoic acid ions, propionic acid ions, ascorbic acid ions, acetate ions, malic acid ions, o-benzoic acid sulfimide ions, lactate ions, benzoic acid ions, glucones. Preferred examples include, but are not limited to, organic acid ions such as acid ions, salicylic acid ions, oxalate ions, and citrate ions.
Among them, one having at least one selected from calcium salts, magnesium salts, nickel salts, aluminum salts and zinc salts having a solubility in water of 0.1 mol / liter or more is preferable. More preferred are one or more selected from nickel salts and zinc salts. This is because a metal salt having a solubility in water of 0.1 mol / liter or more has a large interaction with the pigment or resin in the ink.

In the present invention, the metal salt having a valence of 2 or more can be any combination of the polyvalent metal ion and the anion, and is an organic acid salt having an organic anion even if it is an inorganic salt having an inorganic anion. There may be.
Specific examples of inorganic salts include calcium salts, magnesium salts such as calcium chloride, magnesium chloride, calcium bromide, magnesium bromide, calcium nitrate, magnesium nitrate, magnesium sulfate, but are not limited thereto. Absent. Among these inorganic salts, chlorides, nitrates, and sulfates that are generally highly soluble in water are more preferred, and nitrates and sulfates are more preferred.
Specific examples of organic acid salts include pantothenic acid, pantoic acid, propionic acid, ascorbic acid, acetic acid, malic acid, o-benzoic acid sulfimide, lactic acid, benzoic acid, gluconic acid, salicylic acid, oxalic acid, and citric acid calcium salt , Magnesium salts, nickel salts, and zinc salts, but are not limited thereto. Among these organic acid salts, calcium salt or magnesium salt of pantothenic acid, propionic acid, or acetic acid is more preferable from the viewpoint of suppressing feathering and bleeding. In the present invention, the divalent or higher valent metal salt can be used alone or in combination of two or more.

The concentration of the divalent or higher metal salt in the receiving solution is not particularly limited. Among these, from the viewpoint of fixability, the concentration of the divalent or higher metal salt is preferably 0.005 to 0.5 mol / liter. When the concentration of the divalent or higher metal salt is 0.005 mol / liter or higher, feathering and color bleeding can be sufficiently suppressed. On the other hand, if the concentration of the metal salt having a valence of 2 or more is 0.5 mol / liter or less, the gloss and texture of the printed matter are improved, and the precipitation of the metal salt is suppressed during storage of the receiving solution. The storage stability of the solution itself is also excellent.
Further, the concentration of the divalent or higher metal salt in the receiving solution is preferably adjusted as appropriate according to the type of the recording material. Specifically, when the recording material is a non-absorbing substrate, the concentration of the divalent or higher metal salt in the receiving solution is preferably 0.005 to 0.2 mol / liter, and the recording material is In the case of a low-absorption substrate, the concentration of the metal salt having a valence of 2 or more is preferably 0.05 to 0.5 mol / liter, and when the recording material is an absorbent substrate, 2 It is preferable that the concentration of the metal salt of the valence or higher is 0.1 to 0.5 mol / liter.

(2) Solvent The solvent of the receiving solution contains at least water and, if necessary, an organic solvent. What is necessary is just to select suitably from the solvent which can melt | dissolve the said metal salt as the said organic solvent. In the present invention, it is preferable to include an aqueous solvent. In the present invention, the aqueous solvent refers to a solvent that dissolves 3 parts by mass or more at 1 atm in 100 parts by mass of water at 25 ° C.
In the present invention, from the viewpoint of the solubility of the metal salt, the total content of water and the aqueous solvent is preferably 50% by mass or more, more preferably 70% by mass or more based on the total solvent. Preferably, it is still more preferably 80% by mass or more, and still more preferably 95% by mass or more.

Specific examples of the aqueous solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, and n-pentanol. 5 alkyl alcohols; monovalent alcohols such as 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-propanol, 1-methoxy-2-propanol, 3-methoxy-n-butanol; 1 -Dimethylformamide, dimethylacetamide, 3-methoxypropanamide, 3-butoxypropanamide, N, N-dimethyl-3-methoxypropanamide, N, N-dibutyl-3-methoxypropanamide, N, N-dibutyl-3 -Butoxypropanamide, N Amides such as N-dimethyl-3-butoxypropanamide; Ketones or ketoalcohols such as acetone and diacetone alcohol; Ethers such as tetrahydrofuran and dioxane; Ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3 -Propanediol, isobutylene glycol, tripropylene glycol, tetraethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,2-hexanediol, Diols such as 1,5-pentanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol 1, 2, -Triols such as hexanetriol: tetrahydric alcohols such as mesoerythritol and pentaerythritol; ethylene glycol monomethyl (or ethyl, propyl, n-butyl, isobutyl,) ether, diethylene glycol monomethyl (or ethyl, propyl, n-butyl, Isobutyl,) ether, triethylene glycol monomethyl (or ethyl, propyl, n-butyl, isobutyl) ether, propylene glycol monomethyl (or ethyl, propyl, n-butyl,) ether, dipropylene glycol monomethyl (or ethyl, propyl, n -Monoalkyl ethers such as butyl, ether); diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl Dialkyl of polyhydric alcohols such as chill ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether Ethers: Alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine N-methyl-2-pyrrolidone, 2 Pyrrolidone, 1,3-dimethyl-2-imidazolidinone nitrogen-containing heterocyclic compounds such as non; .gamma.-butyrolactone, cyclic compounds such as sulfolane.
As the aqueous solvent in the present invention, those having a boiling point of less than 280 ° C are preferred.
In this invention, an aqueous solvent can be used individually by 1 type or in combination of 2 or more types.

  In the present invention, the solvent having a boiling point of 280 ° C. or higher can be used in a range of 5 parts by mass or less with respect to 100 parts by mass of the entire receiving solution. In the present invention, the receiving solution is excellent in drying properties by suppressing the amount of the solvent having a boiling point of 280 ° C. or higher. As specific examples of the solvent having a boiling point of 280 ° C. or higher, polyethylene glycol, polypropylene glycol, triethylene glycol, glycerin, trimethylolethane, trimethylolpropane, and diglycerin can be preferably exemplified.

When the receiving solution is adhered to the recording material by the ink jet method, it is preferable to use a solvent having a boiling point of 180 ° C. or higher and lower than 280 ° C. from the viewpoint that drying at the ink jet nozzle is suppressed and the dryness of the printed matter is excellent. Specific examples of the solvent having a boiling point of 180 ° C. or higher and lower than 280 ° C. include propylene glycol (187 ° C.), dipropylene glycol (232 ° C.), tripropylene glycol (268 ° C.), diethylene glycol (245 ° C.), 1,3-propane. Diol (214 ° C), 1,2-butanediol (193 ° C), 1,3-butanediol (208 ° C), 1,4-butanediol (230 ° C), 1,2-pentanediol (210 ° C), 1,2-hexanediol (223 degreeC) etc. are mentioned. The temperature in parentheses indicates the boiling point of the solvent.
Further, when an absorbent base material is used as the recording material, it is preferable to use water and an aqueous solvent together from the viewpoint of suppressing curling and cockling (waving) of the base material.

Moreover, in this invention, it is preferable to use the solvent from which the viscosity of the said dilution liquid will be 7 mPa * s or less when the said aqueous solvent is diluted to 50 mass% with water as an aqueous solvent.
Examples of the aqueous solvent in which the viscosity of the diluted solution becomes 7 mPa · s or less when diluted to 50% by mass with water are monovalent alcohols, diols, triols, monoalkyl ethers, dialkyl ethers Is preferred. Specific examples include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,2-butanediol, 1,2-hexanediol, 1,2-pentanediol, 1,3-propanediol, 1,3-butane. Examples include diol, 1,4-butanediol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, and glycerin.
The viscosity measurement method is not particularly limited as long as the viscosity can be accurately measured. For example, a method using a viscosity measuring device such as a rheometer, a B-type viscometer, a capillary viscometer, etc. Is mentioned. The capillary viscosity measurement method can be performed according to the method described in DIN 53015 or ISO / DIS 12058. More specifically, a capillary viscometer “AMVn” manufactured by Anton Paar can be used as a measurement apparatus, and measurement can be performed at a measurement temperature of 25 ° C.

The water contained in the solvent does not contain various ions, and it is preferable to use deionized water.
The water content in the solvent may be adjusted as appropriate as long as the above components can be dispersed or dissolved. Especially, it is preferable that it exists in the range of 10 mass%-95 mass% with respect to the solvent whole quantity, it is more preferable that it exists in the range of 20 mass%-95 mass%, and the range of 30 mass%-90 mass% is preferable. Even more preferably within.
Moreover, as content of the aqueous solvent in a solvent, it is preferable to exist in the range of 5 mass%-90 mass% with respect to the solvent whole quantity, and it is more preferable to exist in the range of 5 mass%-80 mass%. Preferably, it is still more preferably within the range of 10% by mass to 70% by mass.
This is because when the contents of the water and the aqueous solvent are within the above-mentioned ranges, the moisture retention is sufficient and nozzle clogging or the like can be reduced. Moreover, it is because it can make it easy to discharge by an inkjet head.

(3) Other components In this invention, the receiving solution may contain the other component further as needed. Other components include, for example, a basic compound for adjusting pH to 6.0 to 10.0, a surfactant for adjusting surface tension, and scratch resistance, water resistance, and solvent resistance for printed matter. Resins for imparting various resistances such as properties and blocking resistance, gloss, and improving optical density.

The basic compound can be appropriately selected and used from conventionally known basic compounds, and may be an inorganic basic compound or an organic basic compound, or a combination thereof. Good.
Specific examples of the inorganic basic compound include ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate and the like. Of the inorganic basic compounds, sodium salt or potassium salt is preferable from the viewpoint of storage stability and ejection stability. Specific examples of the organic basic compound include alkylamines such as dimethylamine, diethylamine, and triethylamine; triethanolamine, 1- (dimethylamino) -2-propanol, N, N-dimethyl-2-aminoethanol, N -Benzylethanolamine, N, N-dimethylisopropanolamine, 1-amino-2-propanol, N-methylethanolamine, N, N-diethyl-2-aminoethanol, 2- (dimethylamino) -2-methyl-1 -Propanol, 3- (dimethylamino) -1-propanol, 2-amino-2-methyl-1-propanol, 3- (methylamino) -1-propanol, N-ethylethanolamine, 2-aminoethanol, N- t-Butylethanolamine, 3-amino-1-propanol N-n-butylethanolamine, diethanolamine, 3- (dimethylamino) -1,2-propanediol, 2- (2-aminoethoxy) ethanol, N, N-dibutylethanolamine, 2- (2-aminoethylamino) Ethanol, N-methyldiethanolamine, hydroxyethylpiperazine, 3-methylamino-1,2-propanediol, N-ethyldiethanolamine, 2-phenyl-2-aminoethanol, Nnbutyldiethanolamine, N-phenyldiethanolamine, N- Examples thereof include amino alcohols such as t-butyldiethanolamine and 2-amino-1,3-propanediol. When an organic basic compound is used, an amino alcohol having a boiling point of 100 to 300 ° C. is preferable from the viewpoint of safety, storage stability, and ejection stability.
In this invention, a basic compound can be used individually by 1 type or in combination of 2 or more types.

  The content of the basic compound in the receiving solution is added so that the pH of the receiving solution is 6.0 to 10.0. Depending on the type of the basic compound, the type and concentration of the metal salt, etc. As a guideline for the content ratio of the basic compound in the receiving solution, 0.0001 to 0.1 parts by weight is preferable with respect to 100 parts by weight of the receiving solution, and 0.001 to 0. More preferably, the content is 0.05 parts by mass.

  The surfactant can be appropriately selected from conventionally known ones. Of these, anionic surfactants, nonionic surfactants, silicone (silicone) surfactants, fluorine surfactants, acetylene glycol surfactants, and the like are preferred because of their excellent surface tension adjustability. Used. Specific examples include Emar, Latem, Perex, Neoperex, and Demol (all anionic surfactants; manufactured by Kao Corporation), Sannole, Lipolane, Lipon, Lipar (all anionic surfactants; Lion shares) Company made), New Coal 290-A, 290-KS, New Coal 291-M, New Coal 291-PG, New Coal 291-GL, New Coal 292-PG, New Coal 293, New Coal 297 (both are anions) Surfactant, manufactured by Nippon Emulsifier Co., Ltd., Neugen, Epan, Sorgen (all nonionic surfactants; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Emulgen, Amit, Emazole (all nonionic surfactants) ; Manufactured by Kao Corporation, NAROACTY, EMALMIN, SANNONIC (all Nonionic surfactant; manufactured by Sanyo Chemical Industries, Ltd.), Surfinol 104, 82, 465, 485, TG, 2502, Dinol 604, Dinol 607 (all are acetylene glycol surfactants; manufactured by Air Products) Olfin E1004, E1010, PD-004, PD-501, PD-502, SPC, EXP4300, Surfynol MD-20 (all are acetylene glycol surfactants; manufactured by Nissin Chemical Industry Co., Ltd.), acetylenol EH, E40, E60, E81, E100, E200 (all manufactured by Kawaken Fine Chemicals Co., Ltd.), MegaFac (fluorine-based surfactant: manufactured by DIC Corporation), Surflon (fluorine-based surfactant: manufactured by AGC Seimi Chemical Co., Ltd.) ), BYK-330, BBYK-333, B K-348, BYK-381, BYK-3455, BYK-3410, BYK-3411, BYK-DYNWET800, BYK-3440 (all nonionic surfactants; manufactured by BYK Chemie), Sylface SAG503A, Sylface SJM-002 Silface SJM-003 (all are silicone (silicone) surfactants; manufactured by Nissin Chemical Industry Co., Ltd.), FZ-2122, FZ-2110, FZ-7006, FZ-2166, FZ-2164, FZ- 7001, FZ-2120, SH 8400, FZ-7002, FZ-2104, 8029 ADDITIVE, 8032 ADDITIVE, 57 ADDITIVE, 67 ADDITIVE, 8616 ADDITIVE (all are silicone (silicone) surfactants; (Made by Dow Corning), KF-6012, KF-6015, KF-6004, KF-6013, KF-6011, KF-6043, KP-104, 110, 112, 323, 341 (all are silicone (silicon)) System surfactants; manufactured by Shin-Etsu Chemical Co., Ltd.). The content of the surfactant is appropriately adjusted according to the solvent and other components. Among these, a silicone-based surfactant or an acetylene glycol-based surfactant is preferable from the viewpoints of dischargeability and wettability with respect to the substrate. In this invention, surfactant can be used individually by 1 type or in combination of 2 or more types. The content of the surfactant is preferably about 0.01 to 10.0 parts by mass, and more preferably 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the total amount of the receiving solution.

Examples of the resin contained in the receiving solution include a resin having a hydrophilic group and a cationic or nonionic resin emulsion. By using such a resin, it is possible to impart various resistances such as scratch resistance, water resistance, solvent resistance, and blocking resistance to the obtained printed matter, and to improve the gloss and printing density of the printed matter. In addition, when the resin emulsion is used, for example, when it is applied to a recording material, it suppresses the formation of lumps during storage of the receiving liquid from a bivalent or higher valent metal salt such as calcium chloride. In particular, the adhesion of a metal salt having low adhesion to a non-absorbent substrate can be improved.
Examples of the resin used for the resin emulsion include acrylic resin, polystyrene resin, polyester resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride vinyl acetate copolymer resin, urethane resin, silicone (silicon) resin, acrylamide resin, and epoxy resin. Or a copolymer resin thereof or the like. Among them, an acrylic resin is preferably used. These resins can be used alone or in combination of two or more.
As the monomer constituting the acrylic resin, one or more monomers can be appropriately selected from known (meth) acrylic acid ester monomers. In the present invention, it is particularly preferable to use a (meth) acrylic acid ester monomer having no acidic group as a main component, and appropriately combining monomers having an acidic group.
In the present invention, an acidic group refers to a group that exhibits acidity in water, and examples thereof include a carboxyl group, a sulfo group, a phosphoric acid group, and acid anhydrides and acid halides thereof. Among them, the monomer having no acidic group is preferably a monomer having no acidic group, amide group, imide group, or hydroxyl group. Examples of such a monomer include (meth) acrylic acid alkyl ester, (meth) acrylic acid aralkyl ester, (meth) acrylic acid alkoxyalkyl ester, and the like. Specifically, methyl (meth) acrylate, (meth) ) Ethyl acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, and the like.
In addition, in this invention, (meth) acryl represents each of acrylic or methacryl.

The acid value of the resin used for the receiving solution is not particularly limited. From the viewpoint of suppressing aggregation and sedimentation of the metal salt, the acid value of the resin is preferably 0 to 10 mgKOH / g.
In the present invention, the acid value represents the mass (mg) of potassium hydroxide required to neutralize the acidic component contained in 1 g of the sample (solid content of the resin), and the method described in JIS K 0070 It is a value measured by a similar method.

  In the receiving solution, the content ratio of the resin is not particularly limited, but 0.05 to 20 parts by mass with respect to 100 parts by mass of the receiving solution in terms of the stability of the resin in the receiving solution and various resistances of the printed matter. It is preferable that it is 0.1-15 mass parts, It is still more preferable that it is 1-10 mass parts.

In the present invention, the pH of the receiving solution is adjusted to 6.0 to 10.0. By setting the pH to 6.0 or more, the interaction between the metal salt and the pigment on the recording material is improved and the fixing property of the pigment is excellent. By setting the pH to 6.0 or more, it is possible to suppress the deterioration of cellulose of the recording material and the metal portion of the apparatus. Moreover, since the decomposition and aggregation of each component such as a solvent, a surfactant, and a resin contained in the receiving solution are suppressed by setting the pH to 6.0 or more, the storage stability of the receiving solution is excellent. On the other hand, if the pH is 10.0 or less, the reactivity between the metal salt and the pigment is sufficiently secured, and the safety of the operator is also secured because the pH is not too high.
In the present invention, the pH of the receiving solution is preferably 7.0 to 9.0.
In addition, pH of a receiving solution can be measured with the pH meter using the glass electrode based on JISZ8802. In the present invention, the pH of the receiving solution was measured at 25 ° C. with a pH meter HM-30R manufactured by Toa DKK Corporation.

What is necessary is just to adjust the surface tension of the said receiving solution suitably. Above all, from the point that the wettability of the receiving solution with respect to the printing surface of the recording material is sufficient, color unevenness and white spots of the printed matter can be suppressed, and a clear image can be obtained, the point is 32 mN / m or less. It is preferably 30 mN / m or less, more preferably 28 mN / m or less, and even more preferably 26 mN / m or less.
On the other hand, when the receiving solution is adhered to the substrate surface by the ink jet method, the surface tension of the receiving solution is preferably 20 mN / m or more from the viewpoint of improving the ejection stability of the ink from the ejection head.

Further, it is preferable to adjust the surface tension of the receiving solution according to the type of the recording material, and it is preferable to lower the surface tension of the receiving solution as the recording material has a lower absorbability. Specifically, when the absorbent base material is used as the recording material, the surface tension of the receiving solution is preferably 32 mN / m or less, and when the low absorbent base material is used, the receiving base material is acceptable. The surface tension of the solution is preferably 30 mN / m or less, and more preferably 28 mN / m or less. When a non-absorbable substrate is used as the recording material, the surface tension of the receiving solution is preferably 28 mN / m or less, more preferably 26 mN / m or less.
Furthermore, the surface tension of the receiving solution is preferably lower than the surface tension of the inkjet ink described later.
The surface tension of the receiving solution can be adjusted by appropriately selecting the composition of the solvent and the surfactant.
The surface tension in the present invention is a value measured by the Wilhelmy method (Kyowa Interface Science model: CBVP-Z) at a measurement temperature of 25 ° C.

<Inkjet ink>
In the present invention, the ink-jet ink contains a pigment, a resin, a surfactant, and a solvent, and the ink-jet ink containing an ink-jet ink containing at least an aqueous solvent is used, and the effect of the present invention is impaired. As long as it is not, other components may be contained as necessary.

(1) Pigment In the present invention, the pigment is not particularly limited and can be appropriately selected from known pigments conventionally used in inkjet inks, and may be an organic pigment or an inorganic pigment. .

Examples of organic pigments include insoluble azo pigments, soluble azo pigments, derivatives from dyes, phthalocyanine organic pigments, quinacridone organic pigments, perylene organic pigments, dioxazine organic pigments, nickel azo pigments, and isoindolinone organic pigments. Organic solid solution pigments such as pyranthrone organic pigments, thioindigo organic pigments, condensed azo organic pigments, benzimidazolone organic pigments, quinophthalone organic pigments, isoindoline organic pigments, quinacridone solid solution pigments, perylene solid solution pigments, Examples of other pigments include carbon black.
When organic pigments are exemplified by color index (CI) numbers, C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 20, 24, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 117, 120, 125, 128, 129, 130, 137, 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 180, 185, 213, 214; I. Pigment Red 5, 7, 9, 12, 48, 49, 52, 53, 57, 97, 112, 122, 123, 147, 149, 168, 177, 180, 184, 192, 202, 206, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 254; I. Pigment orange 16, 36, 43, 51, 55, 59, 61, 64, 71; C.I. I. Pigment violet 19, 23, 29, 30, 37, 40, 50; C.I. I. Pigment Blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64; C.I. I. Pigment green 7, 36, 58; I. Pigment brown 23, 25, 26, and the like.

  Specific examples of the inorganic pigment include barium sulfate, iron oxide, zinc oxide, barium carbonate, barium sulfate, silica, clay, talc, titanium oxide, calcium carbonate, synthetic mica, alumina, zinc white, lead sulfate, yellow lead, Examples include zinc yellow, red bean (red iron oxide (III)), cadmium red, ultramarine blue, bitumen, chromium oxide green, cobalt green, amber, titanium black, synthetic iron black, and inorganic solid solution pigments.

  The average dispersed particle diameter of the pigment is not particularly limited as long as the desired color can be developed. It varies depending on the type of pigment used, but the pigment has good dispersion stability and sufficient coloring power. From the point of obtaining, it is preferably in the range of 5 nm to 200 nm, and more preferably in the range of 30 nm to 150 nm. If the average dispersed particle size is not more than the above upper limit, nozzle clogging of the inkjet head is unlikely to occur, a homogeneous image with high reproducibility can be obtained, and the resulting printed matter can be of high quality. Because. It is because light resistance may fall when it is less than said lower limit.

  The content of the pigment is not particularly limited as long as a desired image can be formed, and is appropriately adjusted. Specifically, although it varies depending on the type of pigment, it is preferably in the range of 0.05 to 20 parts by mass, and 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the ink composition. More preferably within the range of parts. This is because, when the content is within the above-described range, it is possible to achieve an excellent balance between pigment dispersion stability and coloring power.

  Further, the pigment in the present invention may be a pigment dispersion in which the pigment is dispersed in an aqueous solvent by a surfactant or a dispersant described later for dispersing the pigment, and a hydrophilic group is formed on the pigment surface. It may be included as a modified self-dispersing pigment dispersion. In the present invention, it is preferable to use a self-dispersing pigment from the viewpoint of water resistance.

  Examples of such a self-dispersing pigment include, as a hydrophilic group, a carbonyl group, a carboxyl group, a hydroxyl group, a sulfonic acid group, and at least one P—O described in JP2012-51357A. Examples thereof include those modified with a phosphorus-containing group having a P═O bond. Examples of commercially available products include “CAB-O-JET (registered trademark) 200”, “CAB-O-JET (registered trademark) 250C”, and “CAB-O-JET (manufactured by Cabot Specialty Chemicals). Registered trademark) 260M "," CAB-O-JET (registered trademark) 270Y "," CAB-O-JET (registered trademark) 740Y "," CAB-O-JET (registered trademark) 300 "," CAB-O- " JET (registered trademark) 400 "," CAB-O-JET (registered trademark) 450C "," CAB-O-JET (registered trademark) 465M "," CAB-O-JET (registered trademark) 470Y "," CAB- "O-JET (registered trademark) 480V", "CAB-O-JET (registered trademark) 352K", "CAB-O-JET (registered trademark) 554B", "CAB-O-JET (registered trademark)" Standard) 1027R ”,“ CAB-O-JET (registered trademark) 740Y ”;“ Microjet black 162, Aqua-Black 001 ”,“ BONJET (registered trademark) BLACK CW-1 ”,“ BONJET ”manufactured by Orient Chemical Industries, Ltd. (Registered trademark) BLACK CW-2 "and" BONJET (registered trademark) BLACK CW-3 ";" LIOJET (registered trademark) WD BLACK 002C "manufactured by Toyo Ink Manufacturing Co., Ltd., and the like. Among these, a self-dispersing pigment modified with a phosphorus-containing group having at least one P—O or P═O bond is preferable because it has excellent ink fixing properties and water resistance. Self-dispersing pigments can be used alone or in combination of two or more. The self-dispersing pigment can obtain a clear image because the pigment component tends to stay on the surface even when printed on the absorbent base material due to the effect of the functional group modified to the pigment.

(2) Resin The resin used in the ink-jet ink suppresses the penetration of the pigment into the recording material and promotes the fixing of the pigment to the surface of the recording material. As the resin, a resin emulsion is preferable from the viewpoint of excellent fixability and excellent water resistance of printed matter.
In the present invention, the resin emulsion means an aqueous dispersion in which the continuous phase is water and the dispersed particles are resin fine particles. The resin emulsion generally has the property of thickening and aggregating when water, which is a continuous phase, decreases due to evaporation or penetration, and when the recording material is an absorbent substrate, it penetrates the pigment into the substrate. Inhibits and promotes fixing to the substrate. When the recording material is a low-absorbing substrate or a non-absorbing substrate, an ink film is formed on the surface of the substrate to fix the pigment on the surface of the recording material. Has the effect of

The resin emulsion can be produced by, for example, mixing water, a monomer, an emulsifier, and a polymerization initiator to cause an emulsion polymerization reaction and neutralizing the reaction after the reaction. As the emulsifier, a normal polymer surfactant may be used, or a reactive emulsifier having an unsaturated bond may be used. The resin emulsion can also be obtained by mixing resin fine particles with water together with a surfactant without causing an emulsion polymerization reaction. For example, it can be obtained by adding (meth) acrylic acid ester or resin fine particles comprising styrene and (meth) acrylic acid ester and a surfactant to water and mixing them. In this case, the mixing ratio (weight ratio) of the resin component and the surfactant is usually preferably about 10: 1 to 5: 1, and if the amount of the surfactant used is less than the range, it is difficult to form an emulsion. On the other hand, outside the above range, the water resistance and penetrability of the ink may decrease.
Specific examples of the resin component constituting the resin emulsion include, for example, (meth) acrylic resin, styrene resin, polyester resin, vinyl resin, polyethylene resin, urethane resin, silicone (silicon) resin, acrylamide resin, epoxy resin, (meta ) A resin containing an acid group such as acrylic acid or a mixed form thereof is preferable. In particular, it is preferable that the resin fine particles contain a (meth) acrylic resin. These resins are not particularly limited in the form of copolymerization, and can be, for example, block copolymers, random copolymers, and the like.
As these resin components, a polymer having both a hydrophilic part and a hydrophobic part is preferable, and the average particle diameter is not particularly limited as long as an emulsion can be formed, but is preferably 500 nm or less, more preferably 200 nm or less, and 150 nm. The following is more preferable, and further 100 nm or less is more preferable. When the particle size of the resin component constituting the resin emulsion is larger than 500 nm and the difference from the pigment particle size becomes large, the resin particles formed from the resin and emulsion particles come into contact with each other when forming dots by being ejected from the inkjet ink. As a result, pigment particles are present in the gaps, and a sea-island structure is formed, which may impair the fixing property of the pigment and may cause insufficient gloss and resistance of the printed matter.

(I) Emulsifier, polymerization initiator, chain transfer agent The emulsifier and polymerization initiator used in the emulsion polymerization will be described.
As the emulsifier, for example, an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant can be used. A reactive surfactant can also be used.
As polymerization initiators, potassium persulfate, ammonium persulfate, hydrogen persulfate, azobisisobutyronitrile, benzoyl peroxide, dibutyl peroxide, peracetic acid, cumene hydroperoxide, t-butylhydroxyperoxide, paramentanehydroxy A peroxide or the like can be used.
Examples of chain transfer agents for polymerization include t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, xanthogens dimethylxanthogen disulfide, diisobutylxanthogen disulfide, dipentene, indene, 1,4-cyclohexadiene, dihydrofuran. , Xanthene and the like can be used.

(Ii) Monomer component (ii-1) Monomer The monomer used in the emulsion polymerization is preferably an unsaturated vinyl monomer. Specific examples of unsaturated vinyl monomers include acrylic acid ester monomers, methacrylic acid ester monomers, aromatic vinyl monomers, vinyl ester monomers, vinyl cyanide monomers, halogenated monomers generally used in emulsion polymerization. Examples include monomers, olefin monomers, and diene monomers.
Specific examples thereof include acrylic esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, and isobutyl acrylate; methacrylic esters such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, and n-butyl methacrylate; Vinyl esters such as vinyl acetate; Vinyl cyanides such as acrylonitrile and methacrylonitrile; Halogenated monomers such as vinylidene chloride and vinyl chloride; Styrene, 2-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, etc. Aromatic vinyl monomers; olefins such as ethylene, propylene and isopropylene; dienes such as butadiene and chloroprene; vinyl ether, vinyl ketone and vinyl Vinyl monomers such as pyrrolidone and the like. For the monomer having no carboxyl group, the use of an unsaturated vinyl monomer having a carboxyl group is essential, but preferred examples thereof include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, The use of methacrylic acid is preferred.

(Ii-2) Crosslinkable monomer In addition, the resin fine particles forming the resin emulsion can have a structure crosslinked by a crosslinkable monomer having two or more polymerizable double bonds. Examples of the crosslinkable monomer having two or more polymerizable double bonds include diacrylate compounds such as polyethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3 monobutylene glycol diacrylate; trimethylolpropane triacrylate , Triacrylate compounds such as trimethylol ethane triacrylate, tetramethylol methane triacrylate; dimethacrylate compounds such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate; trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, etc. A trimethacrylate compound; divinylbenzene.
Furthermore, printing stability can be further improved by adding an acrylamide or a hydroxyl group-containing monomer in addition to the monomer. Specific examples of acrylamides include acrylamide and N, N-dimethylacrylamide. Specific examples of the hydroxyl group-containing monomer include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxyethyl methacrylate, and these can be used as one kind or a mixture of two or more kinds.

(Iii) Neutralizing agent As the neutralizing agent to be used after completion of the emulsion polymerization reaction, an acid or a base can be used depending on the type of the salt-forming group. Examples of the acid include inorganic acids such as hydrochloric acid and sulfuric acid, and organic acids such as acetic acid, propionic acid, lactic acid, succinic acid, glycolic acid, gluconic acid, and glyceric acid. As the base, those similar to the basic compound in the receiving solution can be used.
The degree of neutralization is not particularly limited. Among these, the pH of the resin emulsion is preferably 7 to 10, but the concentration of the ionic component needs to be adjusted so that the conductivity of the resin emulsion does not increase.

(Iv) Molecular weight of the resin emulsion The molecular weight of the resin emulsion is preferably 1,000 to 1,000,000. The content of the resin emulsion in the inkjet ink is not particularly limited, but the solid content of the resin emulsion is, for example, about 0.05 to 20% by mass with respect to the total amount of the inkjet ink. Can do.

(V) Conductivity of Resin Emulsion When using a pigment as a coloring material in the inkjet ink of the present invention, particularly when using the self-dispersing pigment, the conductivity of a 1% by weight aqueous solution of the resin emulsion. By being low, it can suppress that a dispersibility falls by interaction with a resin emulsion and a surface treatment pigment, and can improve the storage stability of an inkjet ink. The “resin emulsion having a solid content of 1% by mass” refers to a solution obtained by dissolving or dispersing the resin emulsion in water so that the solid content concentration is 1% by mass.
The electrical conductivity of the 1% by weight aqueous solution of the resin emulsion can be adjusted by, for example, the type of resin component, monomer type, reaction mechanism, type of emulsifier, presence or absence of addition of an emulsifier, type of neutralizing agent, and the like.
The low conductivity of a 1% by weight aqueous solution of the resin emulsion is considered to indicate that the resin emulsion itself has a small amount of ionic groups and counter ions of the ionic groups in the ink. . Moreover, it is thought that the low electrical conductivity of 1 mass% solid content aqueous solution of a resin emulsion shows that there exist few amounts in the ink of impurities, such as an ionic substance derived from manufacture of a resin emulsion. Moreover, it is thought that the low electrical conductivity of 1 mass% solid content aqueous solution of a resin emulsion shows that the polarity of a resin component is low or an acid value is low.

The electrical conductivity of a 1% by mass aqueous solution of the resin emulsion is preferably 300 μS / cm or less, more preferably 200 μS / cm or less, and even more preferably 150 μS / cm or less. If the conductivity is high, the ionic group and its counter ion or ionic impurity in the resin emulsion may affect the dispersion stability of the surface-treated pigment. Thus, since the influence on the dispersibility of the surface-treated pigment is suppressed by reducing the ions in the resin emulsion, the lower the electrical conductivity of the aqueous solution with a solid content of 1% by mass of the resin emulsion, the better. It is about 20 μS / cm. If the conductivity is too low, it is difficult to disperse the resin emulsion or to produce a resin emulsion with stable quality.
As a method for measuring the conductivity, first, the resin emulsion is diluted with ion exchange water to adjust the solid content to 1% by mass, and then a conductivity meter (Eutech Instruments, model: EC Testr 11+) is used. The method of measuring the electrical conductivity of an aqueous solution having a solid content of 1% by mass of the resin emulsion is adopted.

(3) Surfactant The surfactant in the inkjet ink is used for improving the ejection stability of the ink in the inkjet system and adjusting the surface tension of the inkjet ink. The surfactant is not particularly limited, but is an anionic surfactant, a nonionic surfactant, a silicone (silicone) surfactant, a fluorine-based interface because of excellent surface tension adjustment. An activator, an acetylene glycol surfactant and the like are preferably used. Specific examples include those similar to those used as the surfactant of the receiving solution. The content of the surfactant is appropriately adjusted according to the content of the water-soluble organic solvent or other surfactant. The content of the surfactant is preferably about 0.01 to 3.0% by mass and more preferably within the range of 0.1 to 2.0% by mass with respect to the total amount of the inkjet ink.

(4) Solvent In the present invention, the inkjet ink contains a solvent, and at least an aqueous solvent as the solvent.
The aqueous solvent does not react with each component in the ink composition and can be appropriately selected from solvents that can dissolve or disperse each component.
In the present invention, the inkjet ink is preferably an aqueous inkjet ink containing an aqueous solvent as a solvent and water from the viewpoint of dispersion stability of pigments and resins.
In the present invention, from the viewpoint of the dispersion stability of the pigment or resin, the total content of the aqueous solvent and water is preferably 50% by mass or more, more preferably 70% by mass or more based on the total solvent. More preferably, it is more preferably 80% by mass or more, and even more preferably 90% by mass or more. The aqueous solvent used in the inkjet ink is preferably a solvent that dissolves 5 parts by mass or more in 100 parts by mass of water at 25 ° C. under 1 atm.

  Specific examples of the aqueous solvent used in the inkjet ink include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-pentanol and the like. 1-carbon such as 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-propanol, 1-methoxy-2-propanol and 3-methoxy-n-butanol 1-dimethylformamide, dimethylacetamide, 3-methoxypropanamide, 3-butoxypropanamide, N, N-dimethyl-3-methoxypropanamide, N, N-dibutyl-3-methoxypropanamide, N, N-dibutyl Amides such as 3-butoxypropanamide and N, N-dimethyl-3-butoxypropanamide; Ketones or ketoalcohols such as acetone and diacetone alcohol; Ethers such as tetrahydrofuran and dioxane; Polyethylene glycol, polypropylene glycol and the like Oxyethylene or oxypropylene copolymer; ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-propanediol, isobutylene glycol, triethylene glycol, tripropylene glycol, tetraethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,5-pentanediol, 1,6 Diols such as hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol; glycerin, trimethylolethane, trimethylolpropane, Triols such as 1,2,6-hexanetriol: tetrahydric alcohols such as mesoerythritol and pentaerythritol; ethylene glycol monomethyl (or ethyl, propyl, n-butyl, isobutyl,) ether, diethylene glycol monomethyl (or ethyl, propyl) , N-butyl, isobutyl,) ether, triethylene glycol monomethyl (or ethyl, propyl, n-butyl, isobutyl) ether, propylene glycol monomethyl (or ethyl, propyl, n-butyl,) ether, Monoalkyl ethers such as dipropylene glycol monomethyl (or ethyl, propyl, n-butyl,) ether; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether Dialkyl ethers of polyhydric alcohols such as tetraethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether; monoethanolamine, diethanolamine, triethanolamine, N-methylethanol Alkanolamines such as ruamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine; N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3- And nitrogen-containing heterocyclic compounds such as dimethyl-2-imidazolidinone; cyclic compounds such as γ-butyrolactone and sulfolane.

  When using a low-absorbing substrate or a non-absorbing substrate as the recording material, from the viewpoint of improving the smoothness of the printed matter, as a solvent for inkjet ink, a glycol ether monoalkyl solvent, a glycol ether dialkyl solvent, a long solvent It is preferable to use an alcohol solvent having a chain alkyl group. When these solvents are used, the addition amount is preferably 1 to 10% by mass and more preferably 1 to 5% by mass with respect to the total amount of the inkjet ink.

Moreover, in this invention, ratio (V50 / V20) of the viscosity (V50) of 50 mass% aqueous solution of the said aqueous solvent and the viscosity (V20) of 20 mass% aqueous solution is 2.0-3 as an aqueous solvent. The aqueous solvent in the range of .6, especially the aqueous solvent in the range of 2.0 to 3.2 is included, and the aqueous solvent preferably contains 50% by mass or more of the total aqueous solvent. By containing 50% by mass or more of the aqueous solvent having a viscosity ratio within the above-mentioned range, it is possible to suppress the ink viscosity from rapidly increasing after the water in the ink adhering to the inkjet nozzle volatilizes. This is because it is possible to obtain an ink that has good fluidity and good continuous ejection properties and ejection properties after standing. The aqueous solvent having the viscosity ratio in the above range is preferably 70% by mass or more, more preferably 80% by mass or more of the total amount of the aqueous solvent.
The method for measuring the viscosity is the same as the method for measuring the viscosity in the receiving solution.

  As the water-soluble organic solvent satisfying V50 / V20 in the range of 2.0 to 3.6, monovalent alcohols, diols, triols, monoalkyl ethers, and dialkyl ethers are preferable. Monovalent alcohols, diols, and triols are more preferable. Further, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,2-butanediol, 1,2-hexanediol, 1,2-pentanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, and glycerin are more preferable.

  When a low-absorbing substrate or a non-absorbing substrate is used as the recording material, a solvent having a boiling point of 280 ° C. or higher is added to 100 parts by mass of the entire inkjet ink in order to improve the drying property of the recording surface. It is preferable to set it as the range below a mass part. In the present invention, the ink-jet ink is excellent in drying properties by suppressing the amount of the solvent having a boiling point of 280 ° C. or higher. As specific examples of the solvent having a boiling point of 280 ° C. or higher, polyethylene glycol, polypropylene glycol, triethylene glycol, glycerin, trimethylolethane, trimethylolpropane, and diglycerin can be preferably exemplified.

The water used in the inkjet ink does not contain various ions, and it is preferable to use deionized water.
The water content in the solvent may be adjusted as appropriate as long as the above components can be dispersed or dissolved. Especially, it is preferable that it exists in the range of 10 mass%-95 mass% with respect to the solvent whole quantity, it is more preferable that it exists in the range of 20 mass%-95 mass%, and the range of 30 mass%-90 mass% is preferable. Even more preferably within.
Moreover, as content of the aqueous solvent with respect to the solvent whole quantity containing water, it is preferable to exist in the range of 5 mass%-90 mass% with respect to the solvent whole quantity, and it exists in the range of 5 mass%-80 mass%. More preferably, it is still more preferably in the range of 10% by mass to 70% by mass.
This is because when the contents of the water and the aqueous solvent are within the above-mentioned ranges, the moisture retention is sufficient and nozzle clogging or the like can be reduced. Moreover, it is because it can make it easy to discharge by an inkjet head.

What is necessary is just to adjust suitably content of the said solvent from points, such as the dispersibility of each component in an inkjet ink, and the discharge property of an ink. Among them, the solvent is preferably contained so that the solid content concentration of the ink is 0.1% by mass to 30% by mass, more preferably 1% by mass to 20% by mass, and more preferably 1% by mass. It is still more preferable to contain so that it may become -15 mass%. This is because when the content is within the above-described range, the discharge property can be excellent.
In the present invention, the solid content means all components other than the solvent in the ink.

(5) Other components In the present invention, the inkjet ink may further contain other components as necessary. Examples of other components include a dispersant, a penetrating agent, a wetting agent, an antiseptic, an antioxidant, a conductivity adjusting agent, a pH adjusting agent, a viscosity adjusting agent, an antifoaming agent, and an oxygen scavenger.

(5-1) Dispersant In the present invention, a pigment dispersant can be used to disperse the pigment. In the present invention, the pigment dispersant is not particularly limited. For example, surfactants such as cationic, anionic, nonionic, amphoteric, silicone (silicon), and fluorine can be used.
Among these, a polymer surfactant (polymer dispersant) can be preferably used. Since the pigment dispersed with the polymer dispersant can form an ink film in a state where the pigment surface is covered with the polymer dispersant and the resin, a high gloss image can be obtained. The functional group preferably has an acidic group from the viewpoint of dispersion stability and compatibility.

Examples of the polymer dispersant include a polyester-based, polyacryl-based, polyurethane-based, polyamine-based, and polycaptolactone-based main chain, such as amino group, carboxy group, sulfo group, and hydroxy group in the side chain. Examples thereof include a dispersant having a polar group. Examples of such polymer dispersants include (co) polymers of unsaturated carboxylic acid esters such as polyacrylic acid esters; aromatic vinyl compounds such as styrene and α-methylstyrene and unsaturated acrylates and the like. Copolymers of carboxylic acid esters; (partial) amine salts, (partial) ammonium salts and (partial) alkylamine salts of (co) polymers of unsaturated carboxylic acids such as polyacrylic acid; hydroxyl group-containing polyacrylic acid esters Hydroxyl-containing unsaturated carboxylic acid ester (co) polymers and modified products thereof; polyurethanes; unsaturated polyamides; polysiloxanes; long-chain polyaminoamide phosphates; polyethyleneimine derivatives (poly (lower alkyleneimine) ) And free carboxyl group-containing polyesters to obtain amides and their bases); poly A lylamine derivative (obtained by reacting polyallylamine with one or more compounds selected from three compounds of polyester, polyamide or ester / amide co-condensate (polyesteramide) having a free carboxyl group) Reaction product) and the like.
Specific examples include “SMA1440” manufactured by SARTOMER (styrene-maleic acid-maleic acid ester polymer dispersant weight average molecular weight 7,000, acid value 185 mg KOH / g, Tg 60 ° C.), BASF Japan “John Crill 682”. (Styrene-acrylic acid- (meth) acrylic acid ester polymer dispersant, weight average molecular weight 1,700, acid value 238 mgKOH / g, Tg 56 ° C.), “JDX-C3000” (acrylic acid- (meth) acrylic acid ester polymer Dispersant Weight average molecular weight 9,500, acid value 85 mgKOH / g, Tg65 ° C., Lubrizol Solsperse 41000 (acid value 50 mgKOH / g), Solsperse 43000 (acid value 30 mgKOH / g), Solsperse 47000 (acid value 20 mgKOH / g) And the like.

  In the present invention, the above pigment dispersants can be used singly or in combination of two or more. In the present invention, when a pigment dispersant is used, its content is not particularly limited. Although depending on the type of pigment, the pigment dispersant is usually 3 to 80% by mass in terms of solid content with respect to 100% by mass of the pigment, and 5 to 60% by mass is preferable from the viewpoint of dispersibility and dispersion stability. 10 to 50% by mass is more preferable.

(5-2) Penetrant The inkjet ink of the present invention may further contain a penetrant for enhancing the penetrability with respect to the recording material, particularly the absorbent base and the low-absorbent base. In the present invention, the penetrant is not particularly limited, and any of the aqueous solvents having permeability can be used. Examples of penetrants include 1,2-alkyl diols and glycol ethers. Specific examples of 1,2-alkyldiol include 1,2-hexanediol, 1,2-pentanediol, and the like. Specific examples of the glycol ether include diethylene glycol monobutyl ether and diethylene glycol monopentyl ether. Examples include diethylene glycol monohexyl ether, 3-methoxy-3-methyl-1-butanol, and the like can be used alone or in combination of two or more.
When the penetrant is used, the amount of penetrant added is preferably 1 to 15% by mass and more preferably 1 to 10% by mass with respect to the total amount of the ink-jet ink.

(5-3) Wetting agent The inkjet ink of the present invention may further contain a wetting agent. The wetting agent is not particularly limited, but is preferably selected from aqueous solvents having a boiling point of 180 ° C. or higher and having water absorption and water retention, and the boiling point is 180 ° C. or higher and lower than 280 ° C. In addition, it is more preferable to select and use an aqueous solvent having water absorption and water retention. Examples of the aqueous solvent used as the wetting agent include amine solvents. When an amine solvent is used as the wetting agent, the amount added is preferably in the range of about 0.3 to 3.0% by mass, more preferably 0.5 to 1.0% by mass, based on the total amount of the inkjet ink. % Range.
In this invention, a wetting agent can be used individually by 1 type or in combination of 2 or more types.

  The solid content in the inkjet ink is preferably in the range of 0.1 to 30% by mass with respect to the entire inkjet ink. In addition, solid content represents components other than the water and aqueous solvent in inkjet ink.

<Method for preparing inkjet ink>
The method for preparing the inkjet ink is not particularly limited. For example, a method in which a self-dispersing pigment is added to an aqueous solvent and dispersed, and then a resin, a surfactant, and other components are added as necessary. After adding the resin, surfactant and other components as necessary, the pigment is dispersed in the aqueous solvent after adding the pigment, resin, surfactant and other components as necessary. And a method of preparing it.

In the present invention, the pH of the inkjet ink is preferably 6.0 to 10.0, and more preferably 7.0 to 9.0. By setting the pH to 6.0 or more, the interaction between the metal salt on the recording material and the pigment or resin is improved, and the fixing property of the pigment is excellent. By setting the pH to 6.0 or more, the dispersion stability of the pigment or resin can be maintained, aggregation and sedimentation hardly occur, and ink storage stability can be improved. On the other hand, if the pH is 10.0 or less, the interaction between the metal salt and the pigment is sufficiently ensured, and the safety of the operator is also ensured because the pH is not too high.
Ink-jet ink can adjust pH by adding a known acidic substance or basic substance.

Further, the surface tension of the inkjet ink is preferably 32 mN / m or less. Especially, it is preferable that it is 30 mN / m or less, and it is more preferable that it is 28 mN / m or less from the point which can suppress a color nonuniformity and white spot. On the other hand, the surface tension of the inkjet ink is preferably 20 mN / m or more from the viewpoint of improving the ejection stability of the ink from the ejection head.
Furthermore, the surface tension of the inkjet ink is preferably higher than that of the receiving solution. By using such an inkjet ink, feathering and color bleeding can be suppressed and a clear image can be obtained.
In addition, the difference between the surface tension of the ink-jet ink and the surface tension of the receiving solution is preferably 5 mN / m or less from the viewpoint that unevenness can be suppressed and a clear image can be obtained. It is preferable.
The surface tension of the inkjet ink can be adjusted by appropriately selecting the aqueous solvent, the surfactant, and the like.

In the inkjet recording method of the present invention,
It contains a metal salt having a valence of 2 or more and a solvent, the solvent contains at least water, the solvent having a boiling point of 280 ° C. or more with respect to 100 parts by mass of the receiving solution is 5 parts by mass or less, and the pH is A receiving solution that is 6.0 to 10.0;
For inkjet recording, comprising a pigment, a resin, a surfactant, and a solvent, the solvent including at least an aqueous solvent, and the inkjet ink having a pH of 6.0 to 10.0 It is particularly preferable to use an ink set.
With such a combination, it is possible to obtain a clear image in which bleeding and white spots are suppressed regardless of the type of recording material, improve the long-term storability of the printed matter, and cause troubles in the apparatus. Can be suppressed.

<Method of adhering the receiving solution to the recording material>
The method for adhering the receiving solution to the recording material is not particularly limited as long as it is an application method capable of adhering the receiving solution to only the printing portion or the entire printing surface, and a conventionally known method can be used. For example, a method of applying the receiving solution by a spray method, a coater method, an ink jet method, a gravure method, or a flexo method can be used, and among these, it is preferable to adhere by a coater method or an ink jet method.
According to the coater method, the receiving solution can be uniformly applied in a short time. In addition, according to the ink jet system, it is easy to apply to any place or to the entire printing surface.
The form of the inkjet head is not particularly limited, and may be a serial head type inkjet system or a line head type inkjet system. When the method for adhering the receiving solution is a serial head type ink jet method, the method for adhering the ink jet ink described later is also preferably a serial head type ink jet method, and the method for adhering the receiving solution is a line head type ink jet method. In this case, it is preferable to use a line head type ink jet method as a method of attaching the ink jet ink described later.

<Method of attaching inkjet ink>
The ink-jet ink is adhered to the portion of the recording material to which the first-order receiving solution is adhered by the ink-jet method. In the present invention, after depositing the receiving solution on the printing surface and before the receiving solution is dried, the ink is deposited, thereby preventing color unevenness and white spots and preventing feathering and color bleeding. Further, in the present invention, since the step of drying the receiving solution is not necessary, the process and time for drying the receiving solution adhering to the printing surface can be reduced, and it can be suitably used for mass printing and high-speed printing. it can.
The inkjet ink of the present invention can be applied to any inkjet recording apparatus such as a piezo system, a thermal system, and an electrostatic system, but among them, aggregates hardly occur and discharge stability is excellent. It is preferably used for an inkjet recording apparatus. A piezo-type recording head uses a piezoelectric vibrator as a pressure generating element, and discharges ink droplets by pressurizing and depressurizing a pressure chamber by deformation of the piezoelectric vibrator.
The format of the ink jet printing method is not particularly limited, and may be a serial head type ink jet method or a line head type ink jet method.

  In the present invention, the term “before the receiving solution is dried” refers to a state in which liquid is present on the surface of the recording material and no metal salt is deposited. Specifically, if the deposition of the metal salt is not visually confirmed or is stuck when the recording materials are superposed, it can be determined that the receiving solution is before drying. A pre-test is performed in advance by a combination of the recording material used in the ink jet recording method of the present invention and the receiving solution, and the time before the receiving solution is dried is determined by measuring the time before the receiving solution is dried. Can also be determined. When two or more ink-jet inks are used in combination, all the ink-jet inks are attached and printed before the receiving solution is dried.

  In the present invention, as a combination of the method of adhering the receiving solution and the method of adhering the inkjet ink, (1) the method of adhering the receiving solution is coating by a coater method, and the method of adhering the inkjet ink is an inkjet method (2) The method for adhering the receiving solution and the method for adhering the inkjet ink include printing by a serial head type ink jet method, and (3) the method of adhering the receiving solution, and the inkjet ink. It is preferable that the method of adhering is one of the printing by a line head type inkjet system. In the method (1), the ink jet method may be a serial head type ink jet method or a line head type ink jet method.

(1) The method of attaching the receiving solution is coating by a coater method, and the method of attaching the inkjet ink is printing by an inkjet method. The method of (1) is, for example, in a conveyance mechanism of a recording material. A printing apparatus in which a roll coater for adhering a receiving solution and an ink jet head for adhering ink jet ink are arranged in this order can be used.
By first applying the receiving solution onto the recording material to be conveyed by a roll coater, and then, without passing through the drying process, the inkjet ink is adhered to the receiving solution adhesion surface of the recording material by the inkjet method. Print.
Although it depends on various conditions, when a receiving solution is attached by a roll coater, as a guide, if ink jet ink is attached within 60 seconds after the receiving solution is attached, it is guaranteed that the receiving solution is not dried. The

(2) The method of adhering the receiving solution and the method of adhering the ink-jet ink are printed by a serial head type ink-jet method. The method of (2) includes, for example, a recording head that reciprocally scans a recording material. The printing apparatus provided can be used. The recording head includes a head that discharges the receiving solution and a head that discharges the inkjet ink.
Using a recording head that reciprocally scans the recording material, the receiving solution is first attached on the recording material, and then the inkjet ink is sequentially attached to the receiving solution adhesion surface of the recording material for printing. .
Although it depends on various conditions, when the receiving solution is attached by the serial head method, as a guide, if the inkjet ink is attached within 30 seconds after the receiving solution is attached, it is guaranteed that the receiving solution is before drying. Is done.

(3) The method for adhering the receiving solution and the method for adhering the inkjet ink In the method (3), for example, in a recording material transport mechanism, a line head for the receiving solution and an inkjet ink A printing apparatus in which line heads are arranged in this order can be used.
After the receiving solution is applied to the recording material to be conveyed by the line head, the inkjet ink is continuously attached to the receiving solution adhesion surface of the recording material by the line head for inkjet ink without passing through the drying process. To print.
Although it depends on various conditions, when the receiving solution is attached by the line method, as a guide, if the inkjet ink is attached within 10 seconds after the receiving solution is attached, it is guaranteed that the receiving solution is before drying. The

In the present invention, on the printing surface of the recording material, the application amount (Vp) per unit area of the receiving solution and the application amount (Vi) per unit area of the inkjet ink satisfy the relationship Vp ≦ Vi. It is preferable that Vp <Vi is satisfied. When the coating amount of the receiving solution and the coating amount of the inkjet ink satisfy the above relationship, the balance between the bleeding suppression effect and the wetting spread improvement effect becomes good, and the solid filling becomes better.
When the amount of the receiving solution applied is large, the reaction between the ink and the receiving solution tends to proceed, and the dot diameter of the ink may not be sufficiently widened. In addition, when the amount of the receiving solution applied is large, the amount of liquid on the recording material becomes too large, and drying may take time. If drying is slow, the image quality may deteriorate. By making the coating amount of the receiving solution smaller than the coating amount of the inkjet ink, the dot diameter of the ink is sufficiently widened, the solid filling is good, a high gloss printed matter is obtained and the drying property is also excellent.
In the present invention, since the reactivity of the metal salt and the ink in the receiving solution is excellent by setting the pH of the receiving solution to 6.0 to 10.0, even when the coating amount of the receiving solution is reduced, Since the fixability of the ink is good, the coating amount of the receiving solution can be made smaller than before.
In the present invention, the coating amount (Vp) per unit area of the receiving solution and the coating amount (Vi) per unit area of the inkjet ink are (0.10 × Vi) <Vp ≦ (1.00 × Vi). ) Is preferable. When the recording material is a non-absorbing substrate, (0.10 × Vi) <Vp <(0.85 × Vi) is more preferable, and (0.15 × Vi) <Vp <(0.75 × Vi). Is even more preferred.
In the case of the ink jet method, the receiving solution and the coating amount per unit area of the ink jet ink can be adjusted by changing the ink discharge amount and resolution.

The amount of the metal salt per unit area that adheres to the recording material may be appropriately adjusted within a range in which the ink fixing property and the gloss and texture of the printed matter to be obtained are compatible.
The amount of metal salt per unit area adhering to the recording material is preferably, for example, 0.001 to 10 mol / m ² , although it may vary depending on the type of recording material or the like. It is more preferable to set it as 01-1.0 mol / m < ² >.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

(Manufacture examples 1-7) Preparation of a receiving solution In order to become the composition shown in following Table 1, respectively, a metal salt and other components are added and dissolved in water, and a solvent is added to make the total amount 100 parts by mass. Receiving solutions A to G were prepared. The surface tension of the obtained receiving solution was measured by the Wilhelmy method at 25 ° C. Further, the pH of the receiving solution was measured at 25 ° C. with a pH meter HM-30R manufactured by Toa DKK Corporation. The results are shown in Table 1.

(Comparative Production Examples 1 to 4) Preparation of Comparative Receiving Solution In order to obtain the composition shown in Table 1 below, the metal salt and other components were added to water and dissolved, and the solvent was added to make the total amount 100 parts by mass. Comparative receiving solutions H to K were prepared.

[Evaluation of receiving solution]
<Evaluation 1: Resin corrosion evaluation>
An epoxy resin piece having a diameter of 10 mm and a thickness of 2 mm (a cured product obtained by drying a two-part curable epoxy adhesive “1500” made by Cemedine Co., Ltd. “1500” for 1 day at 60 ° C.) is immersed in each of the receiving solution and the comparative receiving solution. Then, it was allowed to stand at 60 ° C. for 4 weeks to evaluate the state change. The results are shown in Table 1.
(Resin Corrosion Evaluation Criteria)
A: The weight change of the epoxy resin piece was within ± 2% and there was almost no change in appearance.
B: The weight change of the epoxy resin piece exceeded ± 2%, or was swollen and dissolved.
If the resin corrosivity evaluation result is A, it can be used practically without any problem.

<Evaluation 2: Metal corrosivity evaluation>
A 10 mm × 20 mm × 0.05 mm metal (stainless steel piece) was immersed in each of the receiving solution and the comparative receiving solution and left at 60 ° C. for 4 weeks to evaluate the state change. The results are shown in Table 1.
(Metal corrosivity evaluation criteria)
A: There was almost no change in appearance, and the metal piece was not corroded.
B: The metal piece was discolored or was corroded or dissolved.
If the metal corrosion evaluation result is A, it can be used practically without any problem.

<Evaluation 3: Curl test>
The receiving solution and the comparative receiving solution were each applied to OK fine paper (made by Oji Paper Co., Ltd.) with Miyabar # 8 and allowed to stand at room temperature to evaluate the curl state. The results are shown in Table 1.
(Curl test evaluation criteria)
A: No warpage or unevenness of the paper was observed.
B: Paper warpage or unevenness was observed.
If the curl test result is A, it can be used practically without any problem.

<Evaluation 4: Storage stability test>
Each of the above receiving solution and comparative receiving solution was applied to OK fine paper (made by Oji Paper Co., Ltd.) with Miyabar # 8 and allowed to stand at 60 ° C. for 4 weeks to evaluate the state of discoloration and surface deterioration. The results are shown in Table 1.
(Evaluation criteria for storage stability test)
A: Discoloration and unevenness of paper were not observed.
B: Discoloration or unevenness of paper was observed.
If the storage stability test result is A, it can be used practically without any problem.

The abbreviations in Table 1 are as follows.
DEG: Diethylene glycol PD: 1,2-pentanediol PG: Propylene glycol DEGDE: Diethylene glycol diethyl ether DPGP: Dipropylene glycol monopropyl ether GLY: Glycerin TEG: Triethylene glycol MeOH: Methanol E1010: Acetylene manufactured by Nisshin Chemical Industry Co., Ltd. Glycol surfactant (modified ethylene oxide of acetylene glycol) Orphine E1010
SAG: Polyether-modified polysiloxane Silface SAG503A manufactured by Nissin Chemical Industry Co., Ltd.
EH: (made by Kawaken Fine Chemical Co., Ltd.) Acetylene glycol modified with ethylene oxide acetylenol EH
NaOH: sodium hydroxide DMAE: dimethylaminoethanol AcH: 1 mol / L acetic acid aqueous solution

(Production Examples 8 to 18) Preparation of Inkjet Ink In order to obtain the composition shown in Table 2 below, the pigment, resin, surfactant, and other components were added to an aqueous solvent and dissolved, and water was added to the total amount. Was 100 parts by mass, and inkjet inks A to H and J to L were prepared. The surface tension of the obtained inkjet ink was measured by the Wilhelmy method at 25 ° C. The pH of the inkjet ink was measured at 25 ° C. with a pH meter HM-30R manufactured by Toa DKK Corporation.

(Production Example 19) Preparation of inkjet ink In 80.7 g of ion-exchanged water, a styrene-maleic acid-maleic ester polymer dispersant (“SMA2625” manufactured by SARTOMER, weight average molecular weight 9,000, acid value 220 mgKOH / g, Tg 110 ° C.) 3.0 g and N, N-dimethyl-2-aminoethanol 1.2 g are dissolved in C.I. I. 15 g of Pigment Yellow 155 and 0.1 g of an antifoaming agent (“Surfinol 104E” manufactured by Air Products) were added and dispersed with a paint shaker using zirconia beads to obtain a yellow pigment dispersion Y2.
Subsequently, each component was added so that it might become a composition shown in following Table 2, and the inkjet ink I was obtained.

The abbreviations in Table 2 are as follows.
Y1: C.I. I. Self-dispersing pigment in which a functional group including a sulfonic acid group is bonded to the surface of the pigment yellow 155 particle (Cab-O-Jet 740Y, manufactured by Cabot)
M1: C.I. I. Self-dispersing pigment in which a functional group containing a phosphonic acid group is bonded to the particle surface of pigment magenta 122 (Cab-O-Jet 465M, manufactured by Cabot)
C1: C.I. I. Self-dispersing pigment in which a functional group containing a phosphonic acid group is bonded to the surface of pigment blue 15: 4 particles (Cab-O-Jet 450C, manufactured by Cabot)
K1: Self-dispersed pigment in which a functional group containing a phosphonic acid group is bonded to the surface of carbon black particles (Cab-O-Jet 400, manufactured by Cabot)
K2: Self-dispersing pigment in which a functional group containing a carboxylic acid group is bonded to the surface of carbon black particles (Cab-O-Jet 300, manufactured by Cabot)
Y2: Yellow pigment dispersion E-1 of Production Example 19: Acrylic resin emulsion (Tg 30 ° C., acid value 3 mgKOH / g)
E-2: Acrylic resin emulsion (Tg 50 ° C., acid value 0.5 mg KOH / g)
PG: Propylene glycol PrD: 1,3-propanediol DPGM: Dipropylene glycol monomethyl ether GLY: Glycerin D607: Acetylene glycol surfactant (modified ethylene oxide of acetylene glycol) DYNOL 607
SAG: Polyether-modified polysiloxane Silface SAG503A manufactured by Nissin Chemical Industry Co., Ltd.
N291: Nippon Emulsifier Co., Ltd. Dioctylsulfosuccinate New Coal 291-PG

  The acrylic resin emulsions E-1 and E-2 were prepared as follows.

(Preparation of resin emulsion E-1)
After fully replacing the inside of the flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet tube, reflux tube and dropping funnel with nitrogen gas, a phosphate ester type reactive surfactant (manufactured by ADEKA), product Name: ADEKA rear soap PP-70) 0.75 g, potassium persulfate 0.04 g, acrylic acid 3 g and pure water 150 g were charged and stirred at 25 ° C. and mixed. A pre-emulsion was prepared by adding dropwise a mixture of 22.5 g of styrene, 60 g of methyl methacrylate, 30 g of ethyl methacrylate, and 34.5 g of 2-ethylhexyl acrylate. Separately, after replacing the inside of the flask equipped with a mechanical stirrer, thermometer, nitrogen gas introduction, reflux tube and dropping funnel with nitrogen gas, 3 g of the above-mentioned Adeka Soap PP-703, potassium persulfate 0 0.01 g and 200 g of pure water were mixed by hand stirring at 70 ° C. Thereafter, the pre-emulsion was dropped into the flask over 3 hours. After further aging at 70 ° C. for 3 hours, the mixture was cooled, adjusted to pH 8 with aqueous ammonia solution, filtered through # 150 mesh (manufactured by Nippon Textile), and 500 g of resin emulsion E-1 (solid content 30) Mass%). The average particle diameter of the obtained resin was 90 nm.

(Preparation of resin emulsion E-2)
After fully replacing the inside of the flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet tube, reflux tube and dropping funnel with nitrogen gas, polyoxyalkylene alkenyl ether ammonium sulfate type reactive surfactant (Kao) Manufactured, trade name: Latemul PD-104) 1 g, potassium persulfate 0.04 g, acrylic acid 3 g and pure water 150 g were charged and stirred at 25 ° C. and mixed. A pre-emulsion was prepared by adding dropwise a mixture of 22.5 g of styrene, 60 g of methyl methacrylate, 30 g of ethyl methacrylate, and 34.5 g of 2-ethylhexyl acrylate. Separately from this, a mechanical stirrer, a thermometer, during introduction of nitrogen gas, the inside of a flask equipped with a reflux pipe and a dropping funnel was replaced with nitrogen gas, and then 2.75 g of the above-mentioned Adeka Soap PP-70, persulfuric acid 0.01 g of potassium and 200 g of pure water were mixed by hand stirring at 70 ° C. Thereafter, the pre-emulsion was dropped into the flask over 3 hours. The mixture was further heated and aged at 70 ° C. for 3 hours and then cooled, adjusted to pH 8 with an aqueous ammonia solution, filtered through # 150 mesh (manufactured by Nippon Textile), and 500 g of resin emulsion E-2 (solid content 30) Mass%). The average particle diameter of the obtained resin was 150 nm.

  Hereinafter, the inkjet inks A to D are referred to as an ink set 1, the inkjet inks E to H are referred to as an ink set 2, and the inkjet inks I to L are referred to as an ink set 3.

(Acceptance method of receiving solution)
Method A-1: Coater Method The receiving solution was applied with Miyabar # 4 so as to be uniform on the surface of the recording material.
Method A-2: Solid printing was performed at a serial head type ink jet method of 600 dpi × 600 dpi (droplet amount: 8 pl).
Method A-3: Line Head Inkjet Method Only a portion to be printed with an ink set was selected, and printing was performed at 600 dpi × 600 dpi (droplet amount 8 pl).
Method A-4: Solid printing was performed with a serial head type ink jet method of 600 dpi × 600 dpi (droplet amount: 12 pl).
Method A-5: Solid printing was performed at a serial head type ink jet method of 600 dpi × 600 dpi (droplet amount: 5 pl).
Method A-6: Line Head Type Inkjet Method Only a portion to be printed with an ink set was selected, and printing was performed at 600 dpi × 600 dpi (droplet amount 12 pl).
Method A-7: Line Head Inkjet Method Only a portion to be printed with an ink set was selected, and printing was performed at 600 dpi × 600 dpi (droplet amount 5 pl).

(Inkjet ink adhesion method)
Method B-1: Serial Head Type Inkjet System A serial head having discharge nozzles for each color was prepared, and printing was performed at 600 dpi × 600 dpi (droplet amount 10 pl).
Method B-2: Line Head Type Inkjet Printing was performed at 600 dpi × 600 dpi (droplet amount 10 pl) for all colors in one scan using a separate line head for each color.
The receiving solution and inkjet ink were printed and then dried at 70 ° C. for 5 minutes.
The image to be printed was 100% solid for each color and high-definition color digital image standard data conforming to JIS X 9201.

In addition, the application amount of the receiving solution and ink when printing 100% solid is
In the case of the coater method of Method A-1, it was 0.50 / m ² .
In the inkjet ink method,
In the case of 600 dpi × 600 dpi and a droplet amount of 5 pl, 0.28 / m ² ,
In the case of 600 dpi × 600 dpi and a droplet amount of 8 pl, 0.45 / m ² ,
In the case of 600 dpi × 600 dpi and a droplet amount of 10 pl, 0.56 / m ² ,
In the case of 600 dpi × 600 dpi and a droplet amount of 12 pl, it was 0.67 / m ² .

Example 1
The receiving solution A is applied onto the recording material (OK fine paper (highly absorbent base material); fine paper made by Oji Paper Co., Ltd.) by the above method A-1, and then the ink set 1 is sequentially applied by the method B-2. Printed. The maximum time difference from when the receiving solution was deposited to when the inkjet ink was printed was 30 seconds. In addition, the drying time after apply | coating the receiving solution A previously measured to the OK fine paper by the said method A-1 was 60 second.
The drying time was measured by overlapping the surface on which the receiving solution was applied with the surface on which the receiving solution was not applied, until the surface was not stuck.

(Example 2)
The receiving solution A is applied onto a recording material (OK fine paper (high-absorbent base material; uncoated paper manufactured by Oji Paper Co., Ltd.)) by the above method A-2, and then ink set 1 by the method B-1. Were printed sequentially. The maximum time difference from when the receiving solution was deposited to when the inkjet ink was printed was 5 seconds. In addition, the drying time after apply | coating the receiving solution A to OK quality paper by the said method A-2 measured in advance was 30 second. The drying time was measured in the same manner as in Example 1.

(Example 3)
After the receiving solution A was applied on the recording material (OK fine paper (high-absorbent substrate)) by the above method A-3, the ink set 1 was sequentially printed by the method B-2. The maximum time difference from when the receiving solution was adhered to when the inkjet ink was printed was 0.5 seconds. In addition, the drying time after apply | coating the receiving solution A to OK quality paper by the said method A-3 measured previously was 10 second. The drying time was measured in the same manner as in Example 1.

Example 4
In Example 1, except that the receiving solution B was used instead of the receiving solution A, and OK topcoat + (low-absorbent substrate; coated paper manufactured by Oji Paper Co., Ltd.) was used instead of OK fine paper. Printing was carried out in the same manner as in Example 1. In addition, the drying time after apply | coating the receiving solution B previously measured to OK topcoat + by the said method A-1 was 80 second. The drying time was measured in the same manner as in Example 1.

(Example 5)
In Example 2, except that the receiving solution B was used instead of the receiving solution A, OK topcoat + (low-absorbing substrate) was used instead of OK fine paper, and ink set 2 was used instead of ink set 1. In the same manner as in Example 2, printing was performed. In addition, the drying time after applying the receiving solution B to the OK topcoat + by the above method A-2, which was measured in advance, was 50 seconds. The drying time was measured in the same manner as in Example 1.

(Example 6)
In Example 3, except that receiving solution B was used instead of receiving solution A, OK topcoat + (low-absorbing substrate) was used instead of OK fine paper, and ink set 2 was used instead of ink set 1. In the same manner as in Example 3, printing was performed. In addition, the drying time after apply | coating the receiving solution B previously measured to OK topcoat + by the said method A-3 was 20 second. The drying time was measured in the same manner as in Example 1.

(Example 7)
In Example 1, the receiving solution C was used instead of the receiving solution A, and P-223RW (non-absorbent base material; soft polyvinyl chloride sheet manufactured by Lintec Corporation) was used instead of OK fine paper. Printing was performed in the same manner as in Example 1 except that the ink set 3 was used. In addition, the drying time after apply | coating the receiving solution C previously measured to P-223RW by the said method A-1 was 200 second. The drying time was measured in the same manner as in Example 1.

(Example 8)
In Example 2, except that the receiving solution C was used instead of the receiving solution A, P-223RW (non-absorbent substrate) was used instead of OK fine paper, and the ink set 3 was used instead of the ink set 1, Printing was performed in the same manner as in Example 2. In addition, the drying time after applying the receiving solution C to P-223RW by the method A-2 measured in advance was 120 seconds. The drying time was measured in the same manner as in Example 1.

Example 9
In Example 3, except that the receiving solution C was used instead of the receiving solution A, P-223RW (non-absorbent substrate) was used instead of OK fine paper, and the ink set 3 was used instead of the ink set 1, Printing was performed in the same manner as in Example 3. In addition, the drying time after apply | coating the receiving solution C previously measured to P-223RW by the said method A-3 was 120 second. The drying time was measured in the same manner as in Example 1.

(Examples 10 to 18)
In Examples 1 to 9, printing was performed in the same manner as in Examples 1 to 9 except that the time difference from the attachment of the receiving solution to the printing of the inkjet ink was changed as shown in Table 3 below.

(Comparative Examples 1-9)
In Examples 1 to 9, printing was performed in the same manner as in Examples 1 to 9 except that the receiving solution was attached and the inkjet solution was printed after the receiving solution was dried.

(Comparative Example 10)
Without accepting the receiving solution, the ink set 1 was sequentially adhered and printed on OK fine paper by Method B-2.

(Comparative Example 11)
Without accepting the receiving solution, the ink set 2 was sequentially attached to the OK topcoat + by the method B-2 and printed.

(Comparative Example 12)
Without accepting the receiving solution, the ink set 3 was sequentially adhered to P-223RW by the method B-2 and printed.

(Examples 19 to 25)
Using the ink set 2, printing was performed on the OK topcoat + by the receiving solution and ink adhesion method described in Table 6.

(Comparative Example 13)
Printing was performed in the same manner as in Example 24, except that after receiving the receiving solution in Example 24, the receiving solution was dried and then the inkjet ink was printed.

(Examples 26 to 32)
Using ink set 3, printing was performed on P-223RW by the receiving solution and ink adhesion method described in Table 7.

(Comparative Example 14)
Printing was performed in the same manner as in Example 26, except that after receiving the receiving solution in Example 26, the receiving solution was dried and then the inkjet ink was printed.

(Comparative Examples 15-18)
Using ink set 3, printing was performed on P-223RW by the receiving solution and ink adhesion method described in Table 7.
Examples 19 to 32 and Comparative Examples 15 to 18 were adjusted so that the maximum time difference from when the receiving solution was attached to when the inkjet ink was printed was shorter than the drying time of the receiving solution measured in advance. And printing.

[Print evaluation]
About the printed matter obtained by the Example and the comparative example, it evaluated from the following three viewpoints, respectively. The results are shown in Tables 3-7.

<Evaluation 1: Evaluation of bleeding from printed part to non-printed part>
A: No blur was observed and the image was clear.
B: Slight bleeding was observed, but the image was clear.
C: Bleeding was observed and the image was slightly inferior in sharpness.
D: Bleeding was observed and the ink spread to the non-printing area was clear.
E: Remarkable bleeding was observed and the image was unclear.
If the blur evaluation from the print portion to the non-print portion is A or B evaluation, it is within the practical range.

<Evaluation 2: Bleeding of color boundary (bleeding in which inks of different colors adjoining irregularly)>
A: No blur was observed and the image was clear.
B: Slight bleeding was observed, but the image was clear.
C: Slight bleeding was observed, and the color boundary was slightly inferior.
D: Bleeding was observed and the color boundary was unclear.
E: Remarkable bleeding was observed and the image was unclear.
If the color boundary blur evaluation is A or B evaluation, it is within the practical range.

<Evaluation 3: Evaluation of solid filling (filling of solid printed portions (white spots))>
A: Printing unevenness and white spots were not observed, and the solid portion was sufficiently filled with ink (the dot diameter was sufficiently widened).
B: Although there was slight unevenness, the solid part was buried.
C: Filling of the solid part was slightly insufficient.
D: The solid portion was not sufficiently filled, and the image was uneven.
E: The substrate surface was remarkably exposed and the image was unclear.
If the solid filling evaluation is A or B evaluation, it is within the practical range.

[Summary of results]
As shown in Examples 1 to 32, according to the printing method of the present invention, there is no blur from the printed part to the non-printed part, the blur of the color boundary, and the white spot regardless of the type of the recording material. I was able to get a good image. In addition, the receiving solutions A to G whose pH was adjusted to 6 to 10 did not corrode the resin and the metal, curled the base material, and were excellent in the storage stability of the receiving solution itself.
Table 3 summarizes the results of Examples and Comparative Examples using an absorbent base material as a recording material. As shown in Comparative Example 10, when ink-jet printing was performed on the absorbent base material without using the receiving solution, the image was unclear particularly due to bleeding from the printed area to the non-printed area or color boundary. Even when the receiving solution was used, Comparative Examples 1 to 3 in which inkjet printing was performed after the receiving solution was dried had insufficient results although these bleedings were improved. In Examples 1 to 3 and Examples 10 to 12 in which ink jet printing was performed before the receiving solution was dried, these bleedings were improved. Among the examples, it was clarified that in Examples 1 to 3 in which inkjet printing was performed without taking much time after the receiving solution was adhered, the occurrence of bleeding and white spots was further suppressed.
Table 4 summarizes the results of Examples and Comparative Examples using low-absorbance substrates as recording materials. Table 5 summarizes the results of Examples and Comparative Examples using a non-absorbent substrate as the recording material. As shown in Comparative Examples 11 and 12, when ink-jet printing was performed on a low-absorbency substrate or a non-absorbent substrate in the receiving solution, significant blurring and white spots occurred and the image became unclear. As shown in Comparative Examples 4 to 6 and Comparative Examples 7 to 9, even when a receiving solution is used, when ink-jet printing is performed after the receiving solution is dried, bleeding and white spots are improved but insufficient. It was a result. In Examples 4 to 9 and Examples 13 to 18 in which ink jet printing was performed before the receiving solution was dried, bleeding and white spots were improved.
Further, when Examples 19 to 21, Examples 22 to 24, Examples 26 to 28, and Examples 30 to 32 are compared, the coating amount per unit area (Vp) of the receiving solution and the unit area of the inkjet ink are compared. The solid filling was better when the coating amount (Vi) satisfies Vp <Vi. This is because when Vp <Vi when the recording material has low absorptivity, the balance between the bleeding suppression effect and the wetting spread improvement effect is good from the viewpoint of the magnitude of the interaction between the receiving solution and the ink. It is guessed that.
In Comparative Examples 15 to 18 using a receiving solution having a pH of 5.0 or less, bleeding and white spots were not sufficiently improved even when inkjet printing was performed before the receiving solution was dried. It was speculated that this was because the metal salt was difficult to interact with the pigment because of its low pH.

An ink jet recording method according to the present invention is an ink jet recording method in which a receiving solution is attached to a printing surface of a recording material, and an ink jet ink is attached to a receiving portion of the receiving solution for printing.
The recording material is a low-absorbing substrate or a non-absorbing substrate,
The receiving solution contains a divalent or higher metal salt and a solvent, the solvent contains at least water, and the solvent having a boiling point of 280 ° C. or higher is 5 parts by mass or less with respect to 100 parts by mass of the receiving solution. A receiving solution having a pH of 6.0 to 10.0,
The inkjet ink contains a pigment, a resin, a surfactant, and a solvent, and the solvent is an inkjet ink containing at least an aqueous solvent,
After the receiving solution is attached to the printing surface, before the receiving solution is dried, the inkjet ink is attached and printed ,
On the printing surface of the recording material, the application amount (Vp) per unit area of the receiving solution and the application amount (Vi) per unit area of the inkjet ink are (0.5 × Vi) ≦ Vp ≦ (0 .50 / 0.56 × Vi) .

( Reference Example 1)
The receiving solution A is applied onto the recording material (OK fine paper (highly absorbent base material); fine paper made by Oji Paper Co., Ltd.) by the above method A-1, and then the ink set 1 is sequentially applied by the method B-2. Printed. The maximum time difference from when the receiving solution was deposited to when the inkjet ink was printed was 30 seconds. In addition, the drying time after apply | coating the receiving solution A previously measured to the OK fine paper by the said method A-1 was 60 second.
The drying time was measured by overlapping the surface on which the receiving solution was applied with the surface on which the receiving solution was not applied, until the surface was not stuck.

( Reference Example 2)
The receiving solution A is applied onto a recording material (OK fine paper (high-absorbent base material; uncoated paper manufactured by Oji Paper Co., Ltd.)) by the above method A-2, and then ink set 1 by the method B-1. Were printed sequentially. The maximum time difference from when the receiving solution was deposited to when the inkjet ink was printed was 5 seconds. In addition, the drying time after apply | coating the receiving solution A to OK quality paper by the said method A-2 measured in advance was 30 second. The drying time was measured in the same manner as in Reference Example 1.

( Reference Example 3)
After the receiving solution A was applied on the recording material (OK fine paper (high-absorbent substrate)) by the above method A-3, the ink set 1 was sequentially printed by the method B-2. The maximum time difference from when the receiving solution was adhered to when the inkjet ink was printed was 0.5 seconds. In addition, the drying time after apply | coating the receiving solution A to OK quality paper by the said method A-3 measured previously was 10 second. The drying time was measured in the same manner as in Reference Example 1.

Example 4
Implementation was carried out except that the receiving solution B was used instead of the receiving solution A in Reference Example 1 and OK topcoat + (low-absorbent substrate; coated paper manufactured by Oji Paper Co., Ltd.) was used instead of OK fine paper. Printing was carried out in the same manner as in Example 1. In addition, the drying time after apply | coating the receiving solution B previously measured to OK topcoat + by the said method A-1 was 80 second. The drying time was measured in the same manner as in Reference Example 1.

(Example 5)
In Reference Example 2, accepting solution B was used instead of accepting solution A, OK topcoat + (low-absorbent substrate) was used instead of OK fine paper, and ink set 2 was used instead of ink set 1. Then, printing was performed in the same manner as in Reference Example 2. In addition, the drying time after applying the receiving solution B to the OK topcoat + by the above method A-2, which was measured in advance, was 50 seconds. The drying time was measured in the same manner as in Reference Example 1.

(Example 6)
In Reference Example 3, accepting solution B was used instead of accepting solution A, OK topcoat + (low-absorbent substrate) was used instead of OK fine paper, and ink set 2 was used instead of ink set 1. In the same manner as in Reference Example 3, printing was performed. In addition, the drying time after apply | coating the receiving solution B previously measured to OK topcoat + by the said method A-3 was 20 second. The drying time was measured in the same manner as in Reference Example 1.

(Example 7)
In Reference Example 1, the receiving solution C was used instead of the receiving solution A, and P-223RW (non-absorbent base material; manufactured by Lintec Corporation, soft polyvinyl chloride sheet) was used instead of OK fine paper, and instead of the ink set 1 Printing was performed in the same manner as in Reference Example 1 except that ink set 3 was used. In addition, the drying time after apply | coating the receiving solution C previously measured to P-223RW by the said method A-1 was 200 second. The drying time was measured in the same manner as in Reference Example 1.

(Example 8)
In Reference Example 2, except that the receiving solution C was used instead of the receiving solution A, P-223RW (non-absorbent substrate) was used instead of OK fine paper, and the ink set 3 was used instead of the ink set 1, Printing was performed in the same manner as in Reference Example 2. In addition, the drying time after applying the receiving solution C to P-223RW by the method A-2 measured in advance was 120 seconds. The drying time was measured in the same manner as in Reference Example 1.

Example 9
In Reference Example 3, except that the receiving solution C was used instead of the receiving solution A, P-223RW (non-absorbent substrate) was used instead of OK fine paper, and the ink set 3 was used instead of the ink set 1, Printing was performed in the same manner as in Reference Example 3. In addition, the drying time after apply | coating the receiving solution C previously measured to P-223RW by the said method A-3 was 120 second. The drying time was measured in the same manner as in Reference Example 1.

( Reference Examples 10-12, Examples 13-18 )
After attaching a receiving solution in Reference Examples 1-3 and Examples 4-9, except for changing the difference in time to print inkjet inks as in Table 3, each Reference Examples 1 to 3 and Example 4 to 9 and printing was carried out in the same manner.

(Comparative Examples 1-9)
In Reference Examples 1 to 3 and Examples 4 to 9 , similar to Reference Examples 1 to 3 and Examples 4 to 9 , except that after receiving the receiving solution, the receiving solution was dried and then inkjet ink was printed. Was printed.

(Examples 19, 21, 22, 24, 25, Reference Examples 20, 23)
Using the ink set 2, printing was performed on the OK topcoat + by the receiving solution and ink adhesion method described in Table 6.

(Examples 26, 28, 29, 30, 32, Reference Examples 27 and 31)
Using ink set 3, printing was performed on P-223RW by the receiving solution and ink adhesion method described in Table 7.

(Comparative Examples 15-18)
Using ink set 3, printing was performed on P-223RW by the receiving solution and ink adhesion method described in Table 7.
In Examples 19, 21, 22, 24-26, 28-30, 32, Reference Examples 20, 23, 27, 31 and Comparative Examples 15-18, the ink was received and the inkjet ink was printed. The maximum time difference was adjusted so as to be shorter than the drying time of the receiving solution measured in advance, and printing was performed.

[Print evaluation]
The printed materials obtained in Examples , Reference Examples and Comparative Examples were evaluated from the following three viewpoints. The results are shown in Tables 3-7.

[Summary of results]
As shown in Examples 4 to 9, 13 to 19, 21 to 22 , 24 to 26, 28 to 30 and 32 , according to the printing method of the present invention, it is possible to remove the non-printing portion from the print portion. A clear image could be obtained without blurring in the print area, blurring of color boundaries, and white spots. In addition, the receiving solutions A to G whose pH was adjusted to 6 to 10 did not corrode the resin and the metal, curled the base material, and were excellent in the storage stability of the receiving solution itself.
Table 3 summarizes the results of Examples and Comparative Examples using an absorbent base material as a recording material. As shown in Comparative Example 10, when ink-jet printing was performed on the absorbent base material without using the receiving solution, the image was unclear particularly due to bleeding from the printed area to the non-printed area or color boundary. Even when the receiving solution was used, Comparative Examples 1 to 3 in which inkjet printing was performed after the receiving solution was dried had insufficient results although these bleedings were improved. In Reference Examples 1 to 3 and Reference Examples 10 to 12 in which ink jet printing was performed before the receiving solution was dried, these bleedings were improved. Among the examples, it was clarified that in Reference Examples 1 to 3 in which inkjet printing was performed without taking much time after the receiving solution was adhered, the occurrence of bleeding and white spots was further suppressed.
Table 4 summarizes the results of Examples and Comparative Examples using low-absorbance substrates as recording materials. Table 5 summarizes the results of Examples and Comparative Examples using a non-absorbent substrate as the recording material. As shown in Comparative Examples 11 and 12, when ink-jet printing was performed on a low-absorbency substrate or a non-absorbent substrate in the receiving solution, significant blurring and white spots occurred and the image became unclear. As shown in Comparative Examples 4 to 6 and Comparative Examples 7 to 9, even when a receiving solution is used, when ink-jet printing is performed after the receiving solution is dried, bleeding and white spots are improved but insufficient. It was a result. In Examples 4 to 9 and Examples 13 to 18 in which ink jet printing was performed before the receiving solution was dried, bleeding and white spots were improved.
In addition, units 19 and 21 and Reference Example 20, Examples 22 and 24 and Reference Example 23, Examples 26 and 28 and Reference Example 27, Examples 30 and 32 and Reference Example 31 were compared. When the coating amount per area (Vp) and the coating amount (Vi) per unit area of the inkjet ink satisfy Vp <Vi, the solid filling was better. This is because when Vp <Vi when the recording material has low absorptivity, the balance between the bleeding suppression effect and the wetting spread improvement effect is good from the viewpoint of the magnitude of the interaction between the receiving solution and the ink. It is guessed that.
In Comparative Examples 15 to 18 using a receiving solution having a pH of 5.0 or less, bleeding and white spots were not sufficiently improved even when inkjet printing was performed before the receiving solution was dried. It was speculated that this was because the metal salt was difficult to interact with the pigment because of its low pH.

Claims (6)

An ink jet recording method in which a receiving solution is attached to a printing surface of a recording material, and an ink jet ink is attached to and printed on a receiving portion of the receiving solution,
The receiving solution contains a divalent or higher metal salt and a solvent, the solvent contains at least water, and the solvent having a boiling point of 280 ° C. or higher is 5 parts by mass or less with respect to 100 parts by mass of the receiving solution. A receiving solution having a pH of 6.0 to 10.0,
The inkjet ink contains a pigment, a resin, a surfactant, and a solvent, and the solvent is an inkjet ink containing at least an aqueous solvent,
An ink jet recording method comprising: attaching the ink jet ink and printing after adhering the receiving solution to a printing surface and before drying the receiving solution.   The application amount (Vp) per unit area of the receiving solution and the application amount (Vi) per unit area of the inkjet ink satisfy a relationship of Vp ≦ Vi on the printing surface of the recording material. The inkjet recording method as described.   The inkjet recording method according to claim 1, wherein the method of attaching the receiving solution is coating by a coater method, and the method of attaching the inkjet ink is printing by an inkjet method.   The inkjet recording method according to claim 1, wherein the method of attaching the receiving solution and the method of attaching the inkjet ink are printing by a serial head inkjet method.   The inkjet recording method according to claim 1 or 2, wherein the method of attaching the receiving solution and the method of attaching the inkjet ink are printing by a line head inkjet method. An ink set in which a receiving solution is attached to a printing surface of a recording material, and the receiving solution and the inkjet ink are used in an inkjet recording method for printing by attaching an inkjet ink to an attachment portion of the receiving solution,
The receiving solution contains a divalent or higher metal salt and a solvent, the solvent contains at least water, and the solvent having a boiling point of 280 ° C. or higher is 5 parts by mass or less with respect to 100 parts by mass of the receiving solution. A receiving solution having a pH of 6.0 to 10.0;
The inkjet ink is an inkjet ink containing a pigment, a resin, a surfactant, and a solvent, wherein the solvent contains at least an aqueous solvent, and the pH of the inkjet ink is 6.0 to 10.0. Ink set for inkjet recording.