Treatment liquid

Abstract

The present invention pertains to: (1) a treatment liquid containing (A) a C9 or more alkanediol in which two hydroxyl groups are bonded to carbon atoms that are not adjacent to each other, (B) one or more compounds selected from among polyvalent metal salts and polyamines, and water; (2) an ink set for inkjet recording, which contains the processing liquid of (1) and an ink containing a coloring material and water; and (3) an inkjet recording method which uses the treatment liquid of (1) and which comprises a step 1 of applying the treatment liquid to a recording medium to obtain a surface-treated recording medium, and a step 2 of applying the treatment liquid to the recording medium to obtain a surface-treated recording medium. And step 2: a step for forming an image on the treated surface of the surface-treated recording medium obtained in step 1 by an inkjet recording method using an ink containing a coloring material and water.

Description

Technical Field

[0001] The present invention relates to a treatment liquid, an ink set for inkjet recording, and an inkjet recording method. Background Art

[0002] The inkjet recording method does not require plate making, is easy to handle variable printing, and has many advantages such as non-contact with the printed material. Therefore, it has been popularized in a wide range of fields such as office use and home use. In recent years, attempts have also been made to expand it to commercial printing and industrial printing uses with very large printing volumes. Regarding the inkjet recording method, printing on recording media of various materials is sought.

[0003] In response to such a demand, a method has been proposed in which a treatment liquid that intentionally aggregates solid components contained in ink such as coloring materials and resins is applied to the recording medium before the ink is attached to the recording medium to form an ink aggregate layer on the recording medium.

[0004] For example, Japanese Patent Application Laid-Open No. 2012-111845 (Patent Document 1) describes a pretreatment liquid for inkjet recording, which contains at least one of a polyamine derivative and a polyamide derivative, at least one of ammonium acetate and ammonium lactate, a water-soluble solvent, a surfactant and water. Regarding the image formed, it is described that the image has excellent concentration and abrasion resistance, and can achieve improved printing quality. Summary of the invention

[0005] The present invention relates to a treatment liquid comprising: an alkanediol (A) having 9 or more carbon atoms in which two hydroxyl groups are bonded to non-adjacent carbon atoms; one or more compounds (B) selected from polyvalent metal salts and polyamines; and water. DETAILED DESCRIPTION

[0006] Generally, when an image is formed by inkjet recording on a recording medium with low permeability such as coated paper without using a treatment liquid, the ink dots do not spread in a perfect circle on the recording medium, the shape of the ink dots is deformed, and the ink dots mix with each other on the recording medium to cause mixed colors, which tends to cause a decrease in the image uniformity of the printed matter. On the other hand, when an image is formed by inkjet recording on a recording medium with high permeability such as plain paper without using a treatment liquid, the ink penetrates into the recording medium, so there is a tendency to be difficult to obtain a high image density.

[0007] On the other hand, when an ink aggregation layer is formed on a recording medium using a treatment liquid, the ink can be fixed on the surface of the ink aggregation layer, thereby improving the image density and color development of the printed matter. However, regarding the technology of Patent Document 1, it was found that when printing on a recording medium with low permeability, the ink dot diffusibility and image uniformity are insufficient.

[0008] The present invention relates to a treatment liquid, an ink set for inkjet recording, and an inkjet recording method that can achieve high printing quality regardless of the permeability of a recording medium.

[0009] The present inventors have discovered that, by using a treatment liquid comprising an alkanediol having 9 or more carbon atoms in which two hydroxyl groups are bonded to non-adjacent carbon atoms, one or more compounds selected from polyvalent metal salts and polyamines, and water, the inventors have discovered that the alkanediol can cause the one or more compounds selected from polyvalent metal salts and polyamines to be precipitated minutely and uniformly on a recording medium, thereby achieving high printing quality regardless of the permeability of the recording medium.

[0010] The present invention relates to the following [1] to [3].

[0011] [1] A treatment liquid comprising an alkanediol (A) having 9 or more carbon atoms in which two hydroxyl groups are bonded to non-adjacent carbon atoms, one or more compounds (B) selected from polyvalent metal salts and polyamines, and water.

[0012] [2] An ink set for inkjet recording, comprising the treatment liquid according to [1] above and an ink containing a coloring material and water.

[0013] [3] An inkjet recording method using the treatment liquid described in [1] above and comprising the following steps 1 and 2,

[0014] Step 1: applying the above-mentioned treatment liquid to a recording medium to obtain a surface-treated recording medium;

[0015] Step 2: A step of forming an image on the treated surface of the surface-treated recording medium obtained in step 1 by inkjet recording using an ink containing a coloring material and water.

[0016] According to the present invention, high printing quality can be obtained regardless of the permeability of the recording medium. Specifically, a processing liquid, an ink set for inkjet recording, and an inkjet recording method can be provided, which can obtain a high-quality printed matter with good ink dot diffusion and excellent image uniformity when using a recording medium with low permeability, and can obtain a printed matter with high image density when using a recording medium with high permeability.

[0017] [Processing liquid]

[0018] The treatment liquid of the present invention contains an alkanediol (A) having 9 or more carbon atoms in which two hydroxyl groups are bonded to non-adjacent carbon atoms (hereinafter also referred to as "alkanediol (A)"), one or more compounds (B) selected from polyvalent metal salts and polyamines (hereinafter also referred to as "compound (B)"), and water.

[0019] In addition, in the present invention, “an alkanediol (A) having 9 or more carbon atoms in which two hydroxyl groups are bonded to non-adjacent carbon atoms, one or more compounds (B) selected from polyvalent metal salts and polyamines, and water” also means “an alkanediol (A) having 9 or more carbon atoms in which two hydroxyl groups are bonded to non-adjacent carbon atoms, one or more compounds (B) selected from polyvalent metal salts and polyamines, and water”.

[0020] The treatment liquid of the present invention is preferably used for treating a recording medium used for inkjet recording in image formation using an inkjet recording method, from the viewpoint of being able to obtain a printed product with high printing quality regardless of the permeability of the recording medium. That is, the treatment liquid of the present invention is preferably used as a pre-treatment liquid for inkjet recording.

[0021] According to the present invention, high printing quality can be obtained regardless of the permeability of the recording medium. The reason for this is not clear, but it is considered as follows.

[0022] Since the alkanediol contained in the treatment liquid of the present invention has 9 or more carbon atoms and two hydroxyl groups are bonded to carbon atoms that are not adjacent to each other, it can be considered that the hydroxyl group has a high degree of freedom in orientation, and when the ink for inkjet recording lands on a recording medium treated with the treatment liquid of the present invention, the hydroxyl group can easily exert its affinity with the ink and can diffuse the ink dots of the ink. In addition, the alkanediol has 9 or more carbon atoms and is highly hydrophobic. Therefore, it can be considered that when the ink for inkjet recording contains a resin component, when the ink landed on a recording medium treated with the treatment liquid of the present invention diffuses, the effect of swelling the resin component in the ink is high, the viscosity of the ink can be promoted, uniform agglomeration can occur, and the deviation of the ink dot diffusion behavior caused by the slight unevenness of the surface state of the recording medium can be suppressed, thereby improving the image homogeneity.

[0023] It is also believed that after the treatment liquid of the present invention is applied to the recording medium, due to the high surface activity effect of the above-mentioned alkanediol, the precipitates of the polyvalent metal salt and / or polyamine are minutely and uniformly present on the recording medium. Therefore, it is believed that when the ink is attached to the low-permeability recording medium treated with the treatment liquid of the present invention by inkjet recording, the aqueous medium contained in the ink is supplied to the recording medium, and the polyvalent metal salt and / or polyamine are uniformly redissolved in the ink dots, so that the aggregation effect can be uniformly exhibited, the deformation and color mixing of the ink dots are suppressed, and the image homogeneity is further improved.

[0024] It can also be considered that: after being imparted to the recording medium, the precipitates of the polyvalent metal salt and / or the polyamine are minutely and uniformly present on the recording medium, and since the aqueous medium contained in the ink is supplied to the recording medium, the polyvalent metal salt and / or the polyamine are rapidly redissolved, causing the ink attached to the recording medium to rapidly increase in viscosity. It can also be considered that: the reduction in image density caused by the penetration of the ink into the interior of the highly permeable recording medium can be suppressed, and a printed material with a high image density can be obtained.

[0025] In the present invention, whether the recording medium has low permeability or high permeability can be determined based on the amount of water absorbed by the recording medium when the contact time between the recording medium and pure water is 100 milliseconds. The amount of water absorbed can be measured using an automatic scanning liquid absorptometer (e.g., KM500win manufactured by Kumagai Riki Kogyo Co., Ltd.) under the conditions of 23° C. and a relative humidity of 50% as the amount of transfer when the contact time between the recording medium and pure water is 100 milliseconds.

[0026] "Low permeability" is a concept that includes low permeability and non-permeability, which means that the water absorption is 0g / m 2 Above 7g / m 2 "High permeability" means that the water absorption is greater than 7g / m 2 .

[0027] <Alkanediol (A)>

[0028] The treatment liquid of the present invention contains an alkanediol (A) having 9 or more carbon atoms in which two hydroxyl groups are bonded to carbon atoms that are not adjacent to each other (alkanediol (A)).

[0029] The treatment liquid of the present invention can control the wettability of ink to low-permeability recording media by containing alkanediol (A). In addition, by showing specific interaction with one or more compounds (B) selected from polyvalent metal salts and polyamines, when using low-permeability recording media, high-quality printed materials with good ink dot diffusibility and excellent image uniformity can be obtained, and when using high-permeability recording media, printed materials with high image density can be obtained.

[0030] In the present invention, the alkanediol (A) may have any of a linear, branched, and cyclic structure.

[0031] From the viewpoint of obtaining a high-quality printed product having good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed product when using a high-permeability recording medium, the number of carbon atoms of the alkanediol (A) is 9 or more and preferably 22 or less, more preferably 18 or less, and even more preferably 12 or less.

[0032] From the viewpoint of obtaining a high-quality printed product having good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed product when using a high-permeability recording medium, the alkanediol (A) is preferably a diol having 9 or more carbon atoms in which two hydroxyl groups are bonded to non-adjacent primary carbon atoms, and more preferably at least one selected from α,ω-alkanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol.

[0033] In the present invention, "α,ω-alkanediol" refers to n H 2n+2 A diol in which the hydrogen atoms bonded to two carbon atoms in a saturated hydrocarbon (alkane) represented by (n is an integer greater than 9) are each replaced by one hydroxyl group, and a diol in which the hydrogen atoms bonded to two primary carbon atoms at the end of a saturated hydrocarbon having a non-branched or branched structure and having 9 or more carbon atoms are each replaced by one hydroxyl group.

[0034] In the present invention, the saturated hydrocarbon chain constituting the α,ω-alkanediol may be either unbranched or branched. The saturated hydrocarbon chain constituting the α,ω-alkanediol is preferably unbranched from the viewpoints that the orientation freedom of the two hydroxyl groups is high, the hydroxyl groups can easily exert affinity with the ink when the ink for inkjet recording lands, the ink dot diffusibility is improved, and the surface active effect is used to improve the image homogeneity.

[0035] That is, in the present invention, the α,ω-alkanediol is preferably a diol in which the hydrogen atoms bonded to the primary carbon atoms at both terminals of a saturated hydrocarbon having an unbranched structure with 9 or more carbon atoms are substituted with one hydroxyl group, that is, a diol in which two hydroxyl groups are bonded to the primary carbon atoms at both terminals of an unbranched divalent saturated hydrocarbon group with 9 or more carbon atoms.

[0036] In the present invention, from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed matter when using a high-permeability recording medium, the number of carbon atoms in the α,ω-alkanediol is 9 or more and preferably 12 or less, more preferably 10 or less, and even more preferably 9.

[0037] As the α,ω-alkanediol, from the viewpoint of obtaining a high-quality printed matter having good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed matter when using a high-permeability recording medium, preferably one or more selected from 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,16-hexadecanediol, 1,18-octadecanediol and 2,4-diethyl-1,5-pentanediol can be mentioned. Among these, from the same viewpoint as described above, the α,ω-alkanediol is more preferably one or more selected from 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,16-hexadecandiol and 1,18-octadecanediol, further preferably one or more selected from 1,9-nonanediol and 1,10-decanediol, and further preferably 1,9-nonanediol.

[0038] Since tricyclo[5.2.1.0(2,6)]decanedimethanol is a mixture of isomers, there are many combinations of configurations of carbon atoms bonded to two hydroxyl groups. Therefore, it can be considered that when the ink for inkjet recording lands, the hydroxyl group can be utilized to exhibit a variety of affinities with the ink, the ink dot diffusibility can be improved, and the surface active effect can be used to improve the image uniformity.

[0039] Among these, the alkanediol (A) is more preferably one or more selected from diols having two hydroxyl groups bonded to primary carbon atoms at both ends of an unbranched divalent saturated hydrocarbon group having 9 or more carbon atoms, and tricyclo[5.2.1.0(2,6)]decanedimethanol, and is further preferably selected from 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, One or more selected from 1,16-hexadecanediol, 1,18-octadecanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol, more preferably one or more selected from 1,9-nonanediol, 1,10-decanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol, and more preferably one or more selected from 1,9-nonanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol.

[0040] <Compound (B)>

[0041] The treatment liquid of the present invention contains one or more compounds (B) selected from the group consisting of polyvalent metal salts and polyamines.

[0042] The treatment liquid of the present invention contains a polyvalent metal salt and / or a polyamine, which can reduce the dispersibility of the dispersed substance present in the ink for inkjet recording, causing the agglomeration of the dispersed substance and the resulting thickening or precipitation. As a result, it is possible to suppress color mixing caused by the combination of ink dots, improve image homogeneity, and obtain high-quality printed materials.

[0043] In the present invention, the dispersoid present in the ink for inkjet recording includes, in addition to ink components such as pigments dispersed in the ink in a solid state, ink components that are dissolved in the ink but whose solubility is impaired when in contact with a recording medium treated with the treatment liquid of the present invention, causing thickening or precipitation. Specific examples of ink components that are dissolved in the ink for inkjet recording but whose solubility is impaired when in contact with a recording medium treated with the treatment liquid of the present invention, causing thickening or precipitation, include dyes, water-soluble resins, and the like.

[0044] The dispersibility or solubility of the dispersed substances present in the ink for inkjet recording decreases when the ink comes into contact with the recording medium treated with the treatment liquid of the present invention. The reason for this is considered to be that when the ink comes into contact with the recording medium treated with the treatment liquid of the present invention, the precipitates of the polyvalent metal salt and / or polyamine present in the recording medium are redissolved in the ink, and the polyvalent metal salt and / or polyamine act in a manner to thin the thickness of the double electric layer, and the double electric layer stabilizes the dispersed substances present in the ink, thereby making it impossible to inhibit the approach of the dispersed substances to each other.

[0045] 〔Polyvalent metal salt〕

[0046] As long as the polyvalent metal salt is composed of the polyvalent metal ion and anion (the counter ion of the polyvalent metal ion) of more than 2 valences, any material can be used. As the polyvalent metal ion of more than 2 valences, the ions of calcium, magnesium, copper, nickel, zinc, barium, aluminum, titanium, strontium, chromium, cobalt, iron, etc. can be listed. Among these, from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusivity and excellent image homogeneity when using a recording medium with low permeability and the viewpoint of improving the image density of the printed matter when using a recording medium with high permeability, the polyvalent metal ion constituting the polyvalent metal salt is preferably a metal ion of 2 or 3 valences, more preferably a metal ion of 2 valences. As a metal ion of 2 valences, the ions of the elements belonging to the 2nd group of the periodic table can be listed, specifically magnesium ions, calcium ions, ferrous iron (II) ions, etc. can be listed. As a metal ion of 3 valences, aluminum ions, iron (III) ions, etc. can be listed. Among these, from the viewpoint of obtaining a high-quality printed product having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed product when using a high-permeability recording medium, the polyvalent metal ions constituting the polyvalent metal salt are more preferably at least one selected from magnesium ions and calcium ions, and more preferably magnesium ions.

[0047] Examples of anions constituting the polyvalent metal salt include inorganic ions and organic ions.

[0048] Examples of the inorganic ions include monovalent anions such as nitrate ions and halide ions, and divalent anions such as sulfate ions.

[0049] Examples of the organic ion include organic acid ions such as carboxylic acid ions.

[0050] Among these, the anion constituting the polyvalent metal salt is preferably an inorganic ion, more preferably one or more selected from nitrate ions and sulfate ions, and still more preferably a nitrate ion.

[0051] From the viewpoint of obtaining a high-quality print having good ink dot diffusion and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed material when using a high-permeability recording medium, the polyvalent metal salt is preferably at least one selected from magnesium nitrate, magnesium sulfate, calcium nitrate and aluminum nitrate, more preferably at least one selected from magnesium nitrate, calcium nitrate and aluminum nitrate, further preferably at least one selected from magnesium nitrate and calcium nitrate, and even more preferably magnesium nitrate.

[0052] The polyvalent metal salt may have water of hydration in the raw material form.

[0053] The polyvalent metal salt may be used alone or in combination of two or more.

[0054] 〔Polyamine〕

[0055] Polyamines are compounds that have multiple amino groups in their molecules.

[0056] The amino group contained in the polyamine may be any of a primary amino group, a secondary amino group, and a tertiary amino group. In addition, the polyamine may be in the form of a salt.

[0057] As the salt of the polyamine, inorganic acid salt or organic acid salt of the polyamine can be cited. As the inorganic acid salt of the polyamine, hydrochloride, sulfate, nitrate, phosphate, etc. can be cited. As the organic acid salt of the polyamine, carboxylate, sulfonate, etc. can be cited. Furthermore, the polyamine can also be a quaternary ammonium salt formed by quaternizing the amino group with a quaternizing agent.

[0058] The polyamine may also be an alkanediamine. From the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability and from the viewpoint of increasing the image density of the printed matter when using a recording medium with high permeability, the alkanediamine is preferably one or more selected from ethylenediamine (1,2-diaminoethane), 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine and 1,8-octamethylenediamine.

[0059] As the polyamine, from the viewpoint of obtaining a high-quality print having both good ink dot diffusion and excellent image uniformity when using a recording medium with low permeability and from the viewpoint of increasing the image density of the printed matter when using a recording medium with high permeability, a polymer having multiple amino groups in the molecule (hereinafter also referred to as "amino group-containing polymer") is preferred.

[0060] The amino group-containing polymer is preferably a polymer containing a structural unit derived from a polymerizable monomer having at least one amino group. The amino group-containing polymer may be in the form of a salt, or may be a quaternary ammonium salt obtained by quaternizing the amino group with a quaternizing agent.

[0061] Preferred examples of the amino group-containing polymer and its salt include at least one selected from polyethyleneimine, polyvinylamine, polyallylamine, polydiallylmethylamine, polydiallylethylamine, dimethylamine / epichlorohydrin copolymer, dimethylamine / ammonia / epichlorohydrin copolymer, and salts thereof.

[0062] The quaternary ammonium salt of the amino group-containing polymer is preferably a diallyl quaternary ammonium salt polymer, and more preferably at least one selected from polydiallyldimethylammonium chloride, polydiallyldiethylammonium chloride, polydiallylmethylethylammonium ethyl sulfate, diallyldimethylammonium chloride / acrylic acid copolymer, diallyldimethylammonium chloride / acrylamide copolymer and diallyldimethylammonium chloride / acrylic acid / acrylamide copolymer can be listed.

[0063] The polyamine is preferably in the form of a salt of the polyamine. From the viewpoint of greatly increasing the density of the salt and reducing the dispersibility or solubility of the dispersoid present in the ink for inkjet recording, obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image homogeneity when using a recording medium with low permeability, and increasing the image density of the printed matter when using a recording medium with high permeability, the salt of the polyamine is more preferably a salt of an amino-containing polymer, further preferably one or more selected from polydiallyldimethylammonium chloride, polydiallylmethylethylammonium ethyl sulfate, dimethylamine / epichlorohydrin copolymer, polyethyleneimine hydrochloride, and polyallylamine hydrochloride, and further preferably one or more selected from polydiallyldimethylammonium chloride and dimethylamine / epichlorohydrin copolymer.

[0064] The average molecular weight of the salt of the amino-containing polymer is preferably 5,000 or more from the viewpoint of increasing the density of the salt and improving the image homogeneity of the printed matter when using a low-permeability recording medium, and is preferably 100,000 or less from the viewpoint of suppressing the viscosity increase of the treatment liquid, uniformly imparting the treatment liquid to the recording medium, and improving the image homogeneity of the printed matter when using a low-permeability recording medium. The average molecular weight of the salt of the amino-containing polymer can be measured by gel permeation chromatography (GPC). In addition, when a commercial product is used as the salt of the amino-containing polymer, the average molecular weight of the salt of the amino-containing polymer can refer to the catalog value of each commercial product.

[0065] Preferred examples of commercially available salts of amino group-containing polymers include "PAS" series manufactured by NITTOBO MEDICAL Co., Ltd. and "UNISENSE" series manufactured by SENKA Corporation.

[0066] The polyamines may be used alone or in combination of two or more.

[0067] In the treatment liquid of the present invention, from the viewpoint of obtaining a high-quality printed product having good dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed product when using a high-permeability recording medium, it is preferred that the treatment liquid contains at least one selected from α,ω-alkanediol having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A) and at least one selected from a polyvalent metal salt and a polyamine as the compound (B), and more preferably contains As the alkanediol (A), at least one selected from α,ω-alkanediol having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol contains a polyvalent metal salt as the compound (B), and more preferably contains as the alkanediol (A), at least one selected from α,ω-alkanediol having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol contains as the alkanediol (A), and at least one selected from magnesium nitrate, calcium nitrate and aluminum nitrate contains as the compound (B), and more preferably contains As the alkanediol (A), one or more of a diol having two hydroxyl groups bonded to each of the primary carbon atoms at both ends of an unbranched divalent saturated hydrocarbon group having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol and one or more polyvalent metal salts selected from magnesium nitrate, calcium nitrate and aluminum nitrate are contained as the compound (B), and more preferably one or more of 1,9-nonanediol, 1,10-decanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol are contained as the alkanediol (A); The compound (B) contains one or more polyvalent metal salts selected from magnesium nitrate and calcium nitrate, and more preferably contains one or more selected from 1,9-nonanediol, 1,10-decanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A) and contains magnesium nitrate as the compound (B). The compound (B) contains one or more selected from 1,9-nonanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A) and contains magnesium nitrate as the compound (B).

[0068] <Water>

[0069] The treatment liquid of the present invention contains water.

[0070] As the water used for the treatment liquid of the present invention, pure water or ion-exchanged water is preferred from the viewpoint of preventing mixing of undesired substances.

[0071] The treatment liquid of the present invention may further contain other components other than the alkanediol (A), such as a water-soluble organic solvent, a pH adjuster, a surfactant, a coloring material, a defoaming agent, a corrosion and fungicide, and a rust inhibitor, as required.

[0072] (Water-soluble organic solvent (C))

[0073] The treatment liquid of the present invention preferably further contains a water-soluble organic solvent (C) other than the alkanediol (A) (hereinafter also referred to as "water-soluble organic solvent (C)") from the viewpoint of making the solubility of the alkanediol (A) in the treatment liquid sufficient, obtaining a high-quality printed product having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium, and increasing the image density of the printed product when using a high-permeability recording medium.

[0074] In addition, the water-soluble organic solvent (C) does not include the alkanediol (A).

[0075] The water-soluble organic solvent (C) is not particularly limited as long as it can keep the alkanediol (A) dissolved in the treatment liquid, and can be appropriately selected according to the purpose.

[0076] Examples of the water-soluble organic solvent (C) include polyols; ethers such as polyol alkyl ethers and polyol aryl ethers; nitrogen-containing heterocyclic compounds; amides; amines; and sulfur-containing compounds.

[0077] Examples of the polyols include ethylene glycol, diethylene glycol, propylene glycol (1,2-propylene glycol), 1,3-propylene glycol, dipropylene glycol (isomer mixture), 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,3-butylene glycol, 3-methyl-1,3-butylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1 ,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol and other diols other than alkanediol (A) such as octanediol.

[0078] Examples of the polyol alkyl ethers include (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether and dipropylene glycol monoethyl ether.

[0079] Examples of the polyol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

[0080] Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and ε-caprolactam.

[0081] Examples of the amides include formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide.

[0082] Examples of the amines include monoethanolamine, diethanolamine, triethanolamine, and triethylamine.

[0083] Examples of the sulfur-containing compounds include dimethyl sulfoxide, sulfolane, and thiodiethanol.

[0084] In addition, examples of water-soluble organic solvents other than those mentioned above include propylene carbonate and ethylene carbonate.

[0085] Among these, from the viewpoint of obtaining a high-quality print having both good ink dot diffusion and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the print when using a high-permeability recording medium, the water-soluble organic solvent (C) is preferably one or more selected from polyols and polyol alkyl ethers, and more preferably a polyol.

[0086] From the same viewpoint as above, the polyol is preferably a diol other than the alkanediol (A), more preferably at least one selected from ethylene glycol, diethylene glycol, propylene glycol (1,2-propylene glycol), 1,3-propylene glycol, dipropylene glycol (isomer mixture), 1,2-butylene glycol, 1,3-butylene glycol and 1,4-butylene glycol, further preferably at least one selected from diethylene glycol, propylene glycol (1,2-propylene glycol) and dipropylene glycol (isomer mixture), and further preferably dipropylene glycol (isomer mixture).

[0087] From the same viewpoint as above, the polyol alkyl ether is preferably a (poly)alkylene glycol monoalkyl ether, more preferably one or more selected from ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether and triethylene glycol monobutyl ether, further preferably one or more selected from diethylene glycol monobutyl ether and triethylene glycol monobutyl ether, and still more preferably triethylene glycol monobutyl ether.

[0088] The water-soluble organic solvent (C) can be used alone or in combination of two or more.

[0089] (pH adjuster)

[0090] The treatment liquid of the present invention may contain a pH adjuster.

[0091] The pH adjuster is a preparation that suppresses pH fluctuations caused by environmental changes and keeps the pH of the treatment liquid constant.

[0092] The pH adjuster can be arbitrarily selected according to the pH of the treatment liquid of the present invention.

[0093] Examples of the pH adjuster used to alkaline the treatment liquid of the present invention include: alkanolamines such as dimethylethanolamine, diethanolamine, triethanolamine, and N-methyldiethanolamine; primary amines, secondary amines, tertiary amines, and quaternary ammonium salts; ammonia water; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, and sodium bicarbonate, etc.

[0094] When the pH adjuster is an alkanolamine, a primary amine, a secondary amine, a tertiary amine, or a quaternary ammonium salt, these amines or quaternary ammonium salts are preferably monovalent.

[0095] Examples of pH adjusters used to acidify the treatment liquid of the present invention include: inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and boric acid; organic acids such as acetic acid, citric acid, succinic acid, tartaric acid, malic acid, fumaric acid, malonic acid, ascorbic acid, and glutamic acid; and acetates of alkali metals such as lithium acetate and sodium acetate.

[0096] The pH adjusters may be used alone or in combination of two or more.

[0097] (Surfactant)

[0098] The treatment liquid of the present invention may contain a surfactant.

[0099] The surfactant is preferably a nonionic surfactant.

[0100] Examples of the nonionic surfactant include polyoxyalkylene alkyl ether surfactants, acetylene glycol surfactants and other acetylene alcohol surfactants, polyol surfactants, fatty acid alkanolamides, silicone surfactants, and fluorine surfactants. Among these, the surfactant is preferably an acetylene alcohol surfactant, and more preferably an acetylene glycol surfactant.

[0101] Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, and ethylene oxide adducts of these glycols.

[0102] As acetylene alcohol surfactants other than acetylene glycol surfactants, for example, 3,5-dimethyl-1-hexyn-3-ol, 2,4-dimethyl-5-hexyn-3-ol and ethylene oxide adducts of these monoalcohols can be cited. The sum of the average number of added moles of ethylene oxide (EO) of the above ethylene oxide adducts is preferably 0 or more, and preferably 20 or less, and more preferably 10 or less.

[0103] Examples of commercially available nonionic surfactants include "Surfynol" series manufactured by Nissin Chemical Industry Co., Ltd. and Air Products & Chemicals Inc., and "ACETYLENOL" series manufactured by Kawaken Fine Chemicals Co., Ltd.

[0104] The surfactant may be used alone or in combination of two or more.

[0105] The treatment liquid of the present invention may contain a coloring material described below within the range that does not impair the effect of the present invention. When the treatment liquid of the present invention contains a coloring material, the coloring material is preferably a pigment and a hydrophobic dye from the viewpoint of water resistance, and preferably a pigment from the viewpoint of high weather resistance.

[0106] (Composition of treatment liquid)

[0107] The content of the alkanediol (A) in the treatment liquid of the present invention is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, further preferably 1% by mass or more, further preferably 3% by mass or more, further preferably 4% by mass or more, further preferably 5% by mass or more, from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability and from the viewpoint of increasing the image density of the printed matter when using a recording medium with high permeability. From the same viewpoint as above, it is preferably 15% by mass or less, more preferably 10% by mass or less, further preferably 9% by mass or less, further preferably 8% by mass or less, further preferably 7% by mass or less.

[0108] The content of the compound (B) in the treatment liquid of the present invention is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, further preferably 10% by mass or more, further preferably 13% by mass or more, further preferably 15% by mass or more, from the viewpoint of obtaining a high-quality printed material having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed material when using a high-permeability recording medium. From the same viewpoint as above, it is preferably 30% by mass or less, more preferably 25% by mass or less, further preferably 23% by mass or less, further preferably 20% by mass or less.

[0109] When the treatment liquid of the present invention contains a polyvalent metal salt as the compound (B), the content of the polyvalent metal salt in the treatment liquid of the present invention is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, further preferably 10% by mass or more, further preferably 13% by mass or more, further preferably 15% by mass or more, from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed matter when using a high-permeability recording medium, and from the viewpoint of the same as above, it is preferably 30% by mass or less, more preferably 25% by mass or less, further preferably 23% by mass or less, further preferably 20% by mass or less.

[0110] When the polyvalent metal salt is used in the form of a hydrate having hydration water as a raw material form, the content of the polyvalent metal salt in the treatment liquid of the present invention means the content of the anhydrous form of the polyvalent metal salt.

[0111] In the case where the treatment liquid of the present invention contains a polyamine as the compound (B), the content of the polyamine in the treatment liquid of the present invention is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, further preferably 10% by mass or more, further preferably 13% by mass or more, further preferably 15% by mass or more, from the viewpoint of obtaining a high-quality print having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability and from the viewpoint of increasing the image density of the printed matter when using a recording medium with high permeability, and from the viewpoint of the same as above, it is preferably 30% by mass or less, more preferably 25% by mass or less, further preferably 23% by mass or less, further preferably 20% by mass or less.

[0112] The water content in the treatment liquid of the present invention is preferably 85% by mass or less, more preferably 80% by mass or less, further preferably 75% by mass or less, further preferably 70% by mass or less, further preferably 65% ​​by mass or less, further preferably 60% by mass or less, further preferably 57% by mass or less, further preferably 55% by mass or less, from the viewpoint of obtaining a printed product with excellent image uniformity when using a recording medium with low permeability and from the viewpoint of increasing the image density of the printed product when using a recording medium with high permeability, and is preferably 15% by mass or more, more preferably 20% by mass or more, further preferably 30% by mass or more, further preferably 35% by mass or more, further preferably 40% by mass or more, further preferably 45% by mass or more, further preferably 50% by mass or more, further preferably 53% by mass or more, from the viewpoint of obtaining a high-quality printed product with good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability.

[0113] When the polyvalent metal salt is used in the form of a hydrate having hydration water as a raw material form, the water content in the treatment liquid of the present invention means an amount including the water content derived from the hydrate of the polyvalent metal salt.

[0114] The mass ratio of the content of the compound (B) to the content of the alkanediol (A) in the treatment liquid of the present invention [compound (B) / alkanediol (A)] is preferably 0.1 or more, more preferably 0.5 or more, further preferably 1 or more, further preferably 2 or more, further preferably 3 or more, from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability and from the viewpoint of increasing the image density of the printed matter when using a recording medium with high permeability. From the same viewpoint as above, it is preferably 20 or less, more preferably 10 or less, further preferably 8 or less, further preferably 6 or less, further preferably 5 or less.

[0115] When the treatment liquid of the present invention contains a polyvalent metal salt as the compound (B), the mass ratio of the content of the polyvalent metal salt to the content of the alkanediol (A) in the treatment liquid of the present invention [polyvalent metal salt / alkanediol (A)] is preferably 0.1 or more, more preferably 0.5 or more, further preferably 1 or more, further preferably 2 or more, further preferably 3 or more, from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed matter when using a high-permeability recording medium, and is preferably 20 or less, more preferably 10 or less, further preferably 8 or less, further preferably 6 or less, further preferably 5 or less from the same viewpoint as above.

[0116] When the treatment liquid of the present invention contains a polyamine as the compound (B), the mass ratio of the content of the polyamine to the content of the alkanediol (A) in the treatment liquid of the present invention [polyamine / alkanediol (A)] is preferably 0.1 or more, more preferably 0.5 or more, further preferably 1 or more, further preferably 2 or more, further preferably 3 or more, from the viewpoint of obtaining a high-quality print having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed matter when using a high-permeability recording medium, and is preferably 20 or less, more preferably 10 or less, further preferably 8 or less, further preferably 6 or less, further preferably 5 or less from the same viewpoint as above.

[0117] The mass ratio of the content of the alkanediol (A) to the content of water in the treatment liquid of the present invention [alkanediol (A) / water] is preferably 0.01 or more, more preferably 0.05 or more, further preferably 0.07 or more, and further preferably 0.09 or more, from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability, and from the viewpoint of increasing the image density of the printed matter when using a recording medium with high permeability. From the same viewpoint as above, it is preferably 1 or less, more preferably 0.5 or less, further preferably 0.3 or less, further preferably 0.2 or less, and further preferably 0.1 or less.

[0118] In the case where the treatment liquid of the present invention further contains a water-soluble organic solvent (C), from the viewpoint of obtaining a high-quality printed material having both good ink dot diffusibility and excellent image homogeneity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed material when using a high-permeability recording medium, the content of the water-soluble organic solvent (C) in the treatment liquid is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, and further preferably 25% by mass or less. In addition, in the treatment liquid of the present invention, when two or more water-soluble organic solvents (C) are used, the total content thereof is used.

[0119] When the treatment liquid of the present invention further contains a water-soluble organic solvent (C), from the viewpoint of obtaining a high-quality printed material having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed material when using a high-permeability recording medium, the content of the alkanediol (A) in the treatment liquid relative to the total content of the alkanediol (A) and the water-soluble organic solvent (C) is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, further preferably 10% by mass or more, further preferably 15% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 35% by mass or less, further preferably 30% by mass or less, and further preferably 25% by mass or less.

[0120] When the treatment liquid of the present invention further contains a water-soluble organic solvent (C), the mass ratio of the water-soluble organic solvent (C) to the alkanediol (A) in the treatment liquid [water-soluble organic solvent (C) / alkanediol (A)] is preferably 0.1 or more, more preferably 0.5 or more, further preferably 1.0 or more, further preferably 2.0 or more, further preferably 3.0 or more, further preferably 4.0 or more, and is preferably 25 or less, more preferably 20 or less, further preferably 10 or less, further preferably 8.0 or less, further preferably 7.0 or less, further preferably 5.0 or less, from the viewpoint of making the solubility of the alkanediol (A) in the treatment liquid sufficient, obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium, and from the viewpoint of increasing the image density of the printed matter when using a high-permeability recording medium.

[0121] When the treatment liquid of the present invention further contains a water-soluble organic solvent (C), from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed matter when using a high-permeability recording medium, the mass ratio of the total content of the alkanediol (A) and the water-soluble organic solvent (C) to the content of water in the treatment liquid [[alkanediol (A) + water-soluble organic solvent (C)] / water] is preferably 0.1 or more, more preferably 0.2 or more, further preferably 0.3 or more, and even more preferably 0.4 or more, and is preferably 1.5 or less, more preferably 1 or less, further preferably 0.7 or less, and even more preferably 0.5 or less.

[0122] The content of the coloring material in the treatment liquid of the present invention is preferably 1 mass % or less, more preferably 0.1 mass % or less, further preferably 0.01 mass % or less, and further preferably 0 mass %, that is, it is further preferred that the treatment liquid of the present invention does not contain a coloring material.

[0123] When the content of the coloring material in the treatment liquid of the present invention is within the above range, when the treatment liquid is used together with an inkjet recording ink for inkjet recording, an image can be formed without affecting the hue of the ink.

[0124] The viscosity of the treatment liquid of the present invention is not particularly limited. From the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed matter when using a high-permeability recording medium, the viscosity of the treatment liquid at 25°C is preferably 1 mPa·s or more, more preferably 3 mPa·s or more, and even more preferably 6 mPa·s or more, and is preferably 100 mPa·s or less, more preferably 80 mPa·s or less, and even more preferably 55 mPa·s or less. In addition, the viscosity of the treatment liquid of the present invention can be measured by the method described in the Examples.

[0125] The pH of the treatment liquid of the present invention at 20°C is preferably 1.5 or more, more preferably 2.0 or more, and even more preferably 2.5 or more, and is preferably 11.0 or less, more preferably 10.5 or less, and even more preferably 10.0 or less. The pH of the treatment liquid of the present invention can be measured by the method described in the Examples.

[0126] (Preparation of treatment solution)

[0127] The treatment liquid of the present invention is prepared by appropriately mixing an alkanediol (A), one or more compounds (B) selected from polyvalent metal salts and polyamines, water, and other components as required. The pH of the treatment liquid can be appropriately adjusted using the pH adjuster.

[0128] [Ink set for inkjet recording]

[0129] <Inkjet Recording Ink>

[0130] Hereinafter, an ink for inkjet recording suitable for a recording medium treated with the treatment liquid of the present invention (hereinafter also referred to as a "surface-treated recording medium") will be described.

[0131] From the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability and from the viewpoint of increasing the image density of the printed matter when using a recording medium with high permeability, the ink for inkjet recording preferably contains a coloring material and water. That is, in the present invention, the treatment liquid can be used together with the ink containing a coloring material and water as an ink set for inkjet recording.

[0132] 〔Coloring materials〕

[0133] As the coloring material used in the inkjet recording ink, any of dyes and pigments can be used. Among these, pigments are preferably used as the coloring material from the viewpoint of having water resistance, light resistance, weather resistance, gas resistance, etc.

[0134] Any of known organic pigments and inorganic pigments can be used as the pigment. The pigment can be used alone or in combination of two or more, or in the form of a mixed crystal.

[0135] Examples of the inorganic pigment include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, etc. In addition, as the inorganic pigment, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can also be used.

[0136] Examples of organic pigments include azo pigments, polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.), dye chelates (e.g., basic dye type chelates, acid dye type chelates, etc.), nitro pigments, nitroso pigments, aniline black, etc.

[0137] As the pigment, hollow particles such as resin hollow particles and inorganic hollow particles can be used. Luster pigments such as gold and silver or metallic pigments can also be used.

[0138] Specific examples of pigments for black ink include: carbon black (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, channel black; metals such as copper, iron (CI Pigment Black 11), titanium oxide; and organic pigments such as aniline black (CI Pigment Black 1).

[0139] Specific examples of pigments for color inks include products of one or more types selected from CI pigment yellow, CI pigment orange, CI pigment red, CI pigment violet, CI pigment blue, and CI pigment green.

[0140] The dye is not particularly limited, and examples thereof include acid dyes, basic dyes, direct dyes, reactive dyes, etc. The dye may be used alone or in combination of two or more.

[0141] Examples of the dye include various types of products selected from CI acid yellow, CI acid red, CI acid blue, CI acid black, CI food black, CI direct yellow, CI direct red, CI direct blue, CI direct black, CI reactive red, and CI reactive black.

[0142] When the inkjet recording ink contains a pigment, the pigment is dispersed in a medium in the ink. As the form of the pigment in the inkjet recording ink, there can be cited a form in which the pigment is dispersed using a resin (hereinafter also referred to as a "pigment dispersion resin") or a surfactant as a dispersant, or a form of a self-dispersible pigment that can be dispersed without using a dispersant. Among these, as the form of the pigment in the inkjet recording ink, a form in which the pigment is dispersed using a pigment dispersion resin is preferred.

[0143] The pigment dispersing resin may be either a water-soluble resin or a water-insoluble resin.

[0144] Here, regarding the "water solubility" and "water insolubility" of the resin, the resin was dried at 105°C for 2 hours, and the constant amount of the resin was dissolved in 100g of water at 25°C until saturation. If the amount of the resin dissolved was greater than 10g, it was judged to be "water soluble", and if it was less than 10g, it was judged to be "water insoluble". In addition, as described later, in the case where the resin has anionic groups, the amount of the resin dissolved is the amount of the resin dissolved when the anionic groups of the resin are 100% neutralized with sodium hydroxide.

[0145] As the form of the pigment in the above-mentioned inkjet recording ink, specifically, from the viewpoint of improving the dispersion stability of the pigment, preferably, there can be listed (a) a form in which a water-soluble resin is adsorbed on the surface of the pigment; (b) a form in which a water-soluble surfactant or a water-dispersible surfactant is adsorbed on the surface of the pigment; (c) a form of a self-dispersible pigment in which a hydrophilic functional group is introduced into the surface of the pigment chemically or physically and the pigment is dispersed without using a pigment dispersing resin and a surfactant; (d) a form in which the pigment is covered with a water-insoluble resin, etc.

[0146] The pigments in the above-mentioned forms (a) to (d) are preferably anionic. As a result, the polyvalent metal ions from the polyvalent metal salt or the ammonium cations from the amino groups of the polyamine contained in the above-mentioned treatment liquid interact electrostatically with the anionic properties of the pigment surface, which can reduce the dispersibility of the pigment present in the ink and cause it to agglomerate. As a result, it can be considered that when using a recording medium with low permeability, a high-quality print with good ink dot diffusion and excellent image uniformity can be obtained, and when using a recording medium with high permeability, the image concentration of the print can be increased. From this point of view, in the form of (a), the above-mentioned water-soluble resin preferably has anionic groups, in the form of (b), the water-soluble surfactant or water-dispersible surfactant preferably has anionic groups, in the form of (c), the hydrophilic functional group introduced into the pigment surface preferably has anionic groups, and in the form of (d), the water-insoluble resin preferably has anionic groups.

[0147] Examples of anionic groups include groups that dissociate to release hydrogen ions, such as carboxyl (-COOM), sulfonic acid (-SO3M), and phosphoric acid (-OPO3M2), or ionic forms thereof (-COO - 、-SO3 - 、-OPO3 2- 、-OPO3 - In the above chemical formula, M represents a hydrogen atom, an alkali metal, ammonium or an organic ammonium.

[0148] Among these, from the viewpoint of reducing the dispersibility of the dispersoid present in the ink by using polyvalent metal ions and / or polyamines and showing a good agglomeration effect, from the viewpoint of obtaining a high-quality print having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium, and from the viewpoint of increasing the image density of the printed matter when using a high-permeability recording medium, the form of the pigment in the above-mentioned inkjet recording ink is preferably one or more forms selected from the form (c) and the form (d), and more preferably the form (d).

[0149] When the form of the pigment in the above-mentioned inkjet recording ink is the form (d), the form in which the pigment is covered with a water-insoluble resin includes a form in which the pigment is encapsulated in the water-insoluble resin, a form in which the pigment is uniformly dispersed in the water-insoluble resin, a form in which the pigment is exposed from the surface of the water-insoluble resin particles, a form in which the water-insoluble resin is adsorbed on the pigment, etc.

[0150] When the form of the pigment in the inkjet recording ink is the form of (d), it is preferably a form in which the pigment is covered with a water-insoluble resin having a cross-linked structure. As a form in which the pigment is covered with a water-insoluble resin having a cross-linked structure, the water-insoluble resin preferably has a structure including constituent components of a polymer and constituent components derived from a cross-linking agent, and the polymer has a two-dimensional structure of a straight chain that may have a branch. For such a cross-linked structure, it can be considered that the polymer having a two-dimensional structure of a straight chain that may have a branch forms a three-dimensional structure through constituent components derived from a cross-linking agent.

[0151] When the inkjet recording ink is in the form of (d), the type of the water-insoluble resin used for dispersing the pigment as the pigment dispersing resin is not particularly limited.

[0152] As specific examples of water-insoluble resins, (meth) acrylic resins, styrene / (meth) acrylic resins, maleic acid resins, styrene / maleic acid resins, polyurethane resins, and polyester resins can be cited. Among these, from the viewpoint of reducing the dispersibility of the dispersed substance present in the ink and easily controlling the aggregation effect by using the polyvalent metal ions from the polyvalent metal salt or the ammonium cations from the amino groups of the polyamine, the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusivity and excellent image homogeneity when using a low-permeability recording medium, and the viewpoint of increasing the image density of the printed matter when using a high-permeability recording medium, the water-insoluble resin is preferably selected from (meth) acrylic resins, styrene / (meth) acrylic resins, polyurethane resins, and polyester resins. At least one, more preferably selected from (meth) acrylic resins and styrene / (meth) acrylic resins.

[0153] In the present specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0154] The water-insoluble resin may be a product synthesized by a known method or a commercially available product. The water-insoluble resin may be used alone or in combination of two or more.

[0155] The number average molecular weight of the pigment dispersion resin is preferably 5,000 or more, more preferably 7,000 or more, and further preferably 10,000 or more, and is preferably 100,000 or less, more preferably 50,000 or less, and further preferably 30,000 or less. The number average molecular weight can be measured by the method described in Examples.

[0156] The acid value of the pigment dispersion resin is preferably 5 mgKOH / g or more, more preferably 50 mgKOH / g or more, further preferably 100 mgKOH / g or more, further preferably 150 mgKOH / g or more, further preferably 200 mgKOH / g or more, and is preferably 800 mgKOH / g or less, more preferably 500 mgKOH / g or less, further preferably 300 mgKOH / g or less.

[0157] The acid value of the pigment dispersion resin can be determined by the method described in Examples, or can be calculated from the mass ratio of constituent monomers.

[0158] 〔Fixing resin〕

[0159] The inkjet recording ink may contain a resin that functions as a fixing aid (hereinafter also referred to as "fixing resin"). The fixing resin in the inkjet recording ink is preferably in the form of a resin not coated with a pigment, and more preferably in the form of resin particles not containing a pigment.

[0160] There is no particular limitation on the fixing resin, and it can be appropriately selected according to the purpose. Specific examples of the fixing resin include polyurethane resins, polyester resins, acrylic resins, vinyl acetate resins, styrene resins, butadiene resins, styrene / butadiene resins, vinyl chloride resins, styrene / acrylic resins, and acrylic silicone resins.

[0161] The ink can be obtained by mixing a resin in the form of particles as a fixing resin with a coloring material, water, an organic solvent, etc. The fixing resin may be a synthetic product or a commercially available product.

[0162] The fixing resin may be used alone or in combination of two or more.

[0163] 〔wax〕

[0164] The inkjet recording ink may contain wax, and preferably contains wax from the viewpoint of obtaining a high-quality print having both good ink dot diffusibility and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the print when using a high-permeability recording medium.

[0165] In this specification, "wax" refers to an organic substance that is solid or semi-solid at room temperature (25°C) and becomes liquid when heated. Here, "wax is semi-solid" means that if a force is applied to the wax, it will deform and flow, but can maintain a certain shape when no force is applied to the wax. In addition, the temperature at which the wax becomes liquid by heating, the so-called melting point of the wax, exists in a temperature range of 45°C or above.

[0166] The wax may be any of natural wax and synthetic wax.

[0167] Examples of the natural wax include petroleum waxes such as paraffin wax and microcrystalline wax; plant waxes such as carnauba wax, candelilla wax and rice wax; and animal waxes such as lanolin and beeswax.

[0168] Examples of synthetic waxes include synthetic hydrocarbon waxes such as polyolefin wax and Fischer-Tropsch wax, silicone waxes, and modified waxes such as paraffin derivatives, montan wax derivatives, and microcrystalline wax derivatives. Among these, polyolefin waxes containing olefin monomers as a main component are preferred.

[0169] The waxes may be used alone or in combination of two or more.

[0170] The inkjet recording ink preferably contains wax as a dispersion (hereinafter also referred to as "wax dispersion").

[0171] The wax dispersion is not particularly limited, and examples thereof include a wax dispersion obtained by emulsifying wax with a known surfactant. As the surfactant, a nonionic surfactant, an anionic surfactant, etc. can be used.

[0172] Examples of the nonionic surfactant include ethylene oxide adducts of higher alcohols and ethylene oxide adducts of alkylated phenols.

[0173] Examples of the anionic surfactant include sulfate ester salts or phosphate ester salts based on ethylene oxide adducts of higher alcohols, and alkylated benzene sulfonates.

[0174] Among these, from the viewpoint of improving ink ejection stability and image fastness of printed materials, the wax dispersion is preferably a nonionic wax dispersion obtained by emulsifying wax with a nonionic surfactant, and more preferably a nonionic polyolefin wax dispersion.

[0175] Preferred examples of commercially available wax dispersions include "HiTEC E" series manufactured by Toho Chemical Industry Co., Ltd., "AQUACER" series manufactured by BYK, "Selosol" series manufactured by Chukyo Yushi Co., Ltd., and "CHEMIPEARL" series manufactured by Mitsui Chemicals, Inc.

[0176] 〔water〕

[0177] The medium of the inkjet recording ink is preferably an aqueous medium. That is, the inkjet recording ink is preferably an aqueous ink containing water.

[0178] Here, "aqueous" means that water occupies the largest proportion on a mass basis in the medium of the inkjet recording ink.

[0179] It can be considered that the medium of the ink for inkjet recording is an aqueous medium, and the aqueous medium contained in the ink is supplied to the recording medium treated with the above-mentioned treatment liquid, so that the polyvalent metal salt and / or polyamine precipitated on the recording medium is redissolved, and when a low-permeability recording medium is used, a high-quality print with good ink dot diffusion and excellent image uniformity can be obtained, and when a high-permeability recording medium is used, the image concentration of the printed material can be increased.

[0180] As the water contained in the ink for inkjet recording, it is preferable to use ion-exchanged water, deionized water or distilled water.

[0181] 〔Water-soluble organic solvent〕

[0182] The ink for inkjet recording may further contain a water-soluble organic solvent as an aqueous medium. Examples of the water-soluble organic solvent contained in the ink include: polyols exemplified as the water-soluble organic solvent (C) used in the above-mentioned treatment liquid; ethers such as polyol alkyl ethers and polyol aryl ethers; nitrogen-containing heterocyclic compounds; amides; amines; sulfur-containing compounds, etc.

[0183] In addition, from an environmental point of view, the water content in the aqueous medium of the ink for inkjet recording is preferably 51% by mass or more, more preferably 55% by mass or more, further preferably 60% by mass or more, and further preferably 65% ​​by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, further preferably 85% by mass or less, and further preferably 80% by mass or less.

[0184] The inkjet recording ink may contain a surfactant, a defoaming agent, an antiseptic and an antifungal agent, a rust preventive, a pH adjuster, and the like, as necessary.

[0185] From the viewpoint of improving the image density of the printed matter, the content of the coloring material in the inkjet recording ink is preferably 2% by mass or more, more preferably 3% by mass or more, and further preferably 4% by mass or more. In addition, from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image homogeneity when using a low-permeability recording medium, it is preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 10% by mass or less.

[0186] When the inkjet recording ink contains a pigment as a coloring material, the content of the pigment in the ink is preferably 2% by mass or more, more preferably 3% by mass or more, and further preferably 4% by mass or more from the viewpoint of increasing the image density of the printed matter. In addition, from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image homogeneity when using a recording medium with low permeability, the content of the pigment in the ink is preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 10% by mass or less.

[0187] When the above-mentioned inkjet recording ink contains a pigment dispersing resin, the content of the pigment dispersing resin in the ink is preferably 2% by mass or more, more preferably 4% by mass or more, and further preferably 6% by mass or more from the viewpoint of the dispersion stability of the pigment and the viewpoint of obtaining a high-quality print having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability, and is preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 10% by mass or less from the viewpoint of increasing the image density of the printed matter.

[0188] When the ink for inkjet recording contains a pigment dispersing resin, the mass ratio of the content of the pigment in the ink to the content of the pigment dispersing resin [pigment / pigment dispersing resin] is preferably 0.30 or more, more preferably 0.50 or more, and further preferably 0.70 or more from the viewpoint of improving the image density of the printed matter, and is preferably 1.00 or less, more preferably 0.90 or less, and further preferably 0.80 or less from the viewpoint of the dispersion stability of the pigment and the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability.

[0189] When the above-mentioned ink for inkjet recording contains a fixing resin, the content of the fixing resin in the ink is preferably 0.5% by mass or more, more preferably 1% by mass or more, and further preferably 1.5% by mass or more, from the viewpoint of obtaining a high-quality printed matter having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability, and is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 3% by mass or less, from the viewpoint of increasing the image density of the printed matter.

[0190] In the case where the ink for inkjet recording contains wax, the content of the wax in the ink is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, further preferably 0.8% by mass or more, and is preferably 7% by mass or less, more preferably 5% by mass or less, further preferably 3% by mass or less, from the viewpoint of obtaining a high-quality print having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability and from the viewpoint of increasing the image density of the print when using a recording medium with high permeability.

[0191] In the case where the ink for inkjet recording contains a water-soluble organic solvent, the content of the water-soluble organic solvent in the ink is preferably 15% by mass or more, more preferably 20% by mass or more, further preferably 25% by mass or more, and is preferably 45% by mass or less, more preferably 40% by mass or less, further preferably 35% by mass or less, from the viewpoint of obtaining a high-quality print having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability and from the viewpoint of increasing the image density of the print when using a recording medium with high permeability.

[0192] From the viewpoint of obtaining high-quality printed materials having both good ink dot diffusibility and excellent image uniformity when using a recording medium with low permeability, and from the viewpoint of increasing the image density of the printed materials when using a recording medium with high permeability, the water content in the above-mentioned inkjet recording ink is preferably 40% by mass or more, more preferably 45% by mass or more, further preferably 50% by mass or more, further preferably 55% by mass or more, and is preferably 75% by mass or less, more preferably 70% by mass or less, and further preferably 65% ​​by mass or less.

[0193] [Inkjet recording method]

[0194] The inkjet recording method of the present invention is a method of forming an image on a treated surface of a surface treated recording medium treated with the above-mentioned treatment liquid by inkjet recording using an inkjet recording ink. The inkjet recording method of the present invention preferably includes the following steps 1 and 2.

[0195] Step 1: applying the above-mentioned treatment liquid to a recording medium to obtain a surface-treated recording medium;

[0196] Step 2: A step of forming an image on the treated surface of the surface-treated recording medium obtained in step 1 by inkjet recording using an inkjet recording ink.

[0197] (Process 1)

[0198] Step 1 is a step of applying the above-mentioned treatment liquid to a recording medium to obtain a surface-treated recording medium.

[0199] In the present invention, as the recording medium used in step 1, either a low-permeability recording medium or a high-permeability recording medium can be used.

[0200] As the low permeability recording medium, low water-absorbent coated paper and non-water-absorbent resin film can be cited. As coated paper, general wax paper, multi-color foam glossy paper, etc. can be cited. As the resin film, it is preferably at least one selected from polyester film, polyvinyl chloride film, polypropylene film and polyethylene film. These resin films can also be used after surface treatment such as corona treatment.

[0201] Examples of high-permeability recording media include highly water-absorbent plain paper.

[0202] In the recording method of the present invention, from the viewpoint of obtaining a high-quality printed product having good dot diffusibility and excellent image uniformity and from the viewpoint of increasing the image density of the printed product when using a recording medium with high permeability, the processing liquid preferably contains one or more selected from α,ω-alkanediols having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and contains one or more selected from polyvalent metal salts and polyamines as the compound (B), and more preferably contains one or more selected from polyvalent metal salts and polyamines as the compound (B). The compound (B) contains at least one selected from α,ω-alkanediol having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and contains a polyvalent metal salt as the compound (B), and more preferably contains at least one selected from α,ω-alkanediol having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and contains at least one polyvalent metal salt selected from magnesium nitrate, calcium nitrate and aluminum nitrate as the compound (B), and more preferably contains at least one selected from The alkanediol (A) comprises at least one of a diol having two hydroxyl groups bonded to the primary carbon atoms at both ends of a non-branched divalent saturated hydrocarbon group having 9 or more 9 hydrides, and tricyclo[5.2.1.0(2,6)]decanedimethanol, and at least one of a polyvalent metal salt selected from magnesium nitrate, calcium nitrate and aluminum nitrate as the compound (B), and more preferably at least one of 1,9-nonanediol, 1,10-decanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and at least one of a polyvalent metal salt selected from magnesium nitrate, calcium nitrate and aluminum nitrate as the compound (B). The compound (B) preferably contains one or more polyvalent metal salts selected from magnesium nitrate and calcium nitrate, and more preferably contains one or more selected from 1,9-nonanediol, 1,10-decanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and contains magnesium nitrate as the compound (B). The compound (B) preferably contains one or more selected from 1,9-nonanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and contains magnesium nitrate as the compound (B).

[0203] There is no particular limitation on the method of applying the treatment liquid to the recording medium, and examples of the method include immersion, coating with a roller, coating with a spray, coating with a brush, and coating by an inkjet recording method.

[0204] Among these, coating with a roller is preferred from the viewpoint of being able to easily and uniformly apply the treatment liquid.

[0205] The coating method using a roller refers to: (i) maintaining the above-mentioned treatment liquid in the gap between the recording medium and the component in contact with the recording medium, moving one of the recording medium and the component in contact with the recording medium, so that the above-mentioned treatment liquid applied to a part of the recording medium spreads throughout the entire recording medium, thereby obtaining a surface-treated recording medium treated with the above-mentioned treatment liquid; or (ii) rotating the recording medium and a component in contact with the recording medium or maintaining a small gap with the recording medium and approaching it, so that the above-mentioned treatment liquid is printed on the recording medium or the recording medium absorbs the above-mentioned treatment liquid maintained in the small gap.

[0206] As specific examples of the roller used for coating with a roller, an offset gravure coater, a gravure coater, a doctor coater, a rod coater, a blade coater, a flexographic coater, and a roll coater can be cited. Among these, one or more selected from a doctor coater, a rod coater, and a roll coater is preferred.

[0207] In addition, from the viewpoint of continuously performing step 1 and step 2, as a device for applying the above-mentioned treatment liquid to the recording medium, it is preferred that the applying unit of the above-mentioned treatment liquid used in step 1 and the applying unit of the inkjet recording ink used in step 2 are integrated. In this case, for example, the applying unit of the above-mentioned treatment liquid such as a roller coater may be incorporated into the inkjet recording device described later.

[0208] The amount of the treatment liquid applied to the recording medium is preferably 0.2 g / m 2 from the viewpoint of obtaining a high-quality printed product having good ink dot diffusion and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the printed product when using a high-permeability recording medium. 2 More preferably 0.5 g / m 2 More preferably, 1 g / m 2 From the same viewpoint as above, preferably 5 g / m 2 Below, more preferably 2g / m 2 Below, more preferably 1.8 g / m 2 the following.

[0209] In process 1, from the viewpoint of obtaining a high-quality print having both good ink dot diffusion and excellent image uniformity when using a low-permeability recording medium and from the viewpoint of increasing the image density of the print when using a high-permeability recording medium, it is preferred to dry the treatment liquid on the recording medium after applying the treatment liquid to the recording medium.

[0210] Examples of the drying method in step 1 include static drying, air blowing drying, heating drying, reduced pressure drying, etc. In the recording method of the present invention, the drying of the present invention does not include supply of active energy rays such as ultraviolet rays or radiation.

[0211] The temperature during drying in step 1 is preferably 100° C. or less, more preferably 90° C. or less, further preferably 80° C. or less, and further preferably 70° C. or less from the viewpoint of suppressing deformation of the recording medium, and is preferably 20° C. or more, more preferably 25° C. or more from the viewpoint of drying in a short time.

[0212] The drying time in step 1 is preferably 0.5 minutes or longer, more preferably 1 minute or longer, and is preferably 30 minutes or shorter, more preferably 20 minutes or shorter, and even more preferably 10 minutes or shorter.

[0213] (Process 2)

[0214] Step 2 is a step of forming an image on the treated surface of the surface-treated recording medium obtained in step 1 by an inkjet recording method using an inkjet recording ink.

[0215] The inkjet recording ink can be loaded into a known inkjet recording device and attached as ink dots to the treated surface of the surface treated recording medium obtained in step 1 to form an image. As the inkjet recording device, any type such as a thermal induction type or a piezoelectric type can be used.

[0216] Regarding the above-mentioned embodiment, the present invention further discloses the following embodiment.

[0217] <1> A treatment liquid comprising (A) an alkanediol having 9 or more carbon atoms in which two hydroxyl groups are bonded to non-adjacent carbon atoms, (B) at least one compound selected from a polyvalent metal salt and a polyamine, and water.

[0218] <2> The treatment liquid according to <1>, wherein the alkanediol (A) has preferably 22 or less carbon atoms, more preferably 18 or less, and even more preferably 12 or less carbon atoms.

[0219] <3> The treatment liquid according to <1> or <2>, wherein the alkanediol (A) is preferably a diol having 9 or more carbon atoms in which two hydroxyl groups are bonded to non-adjacent primary carbon atoms, more preferably at least one selected from α,ω-alkanediol having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol, further preferably at least one selected from a diol having two hydroxyl groups bonded to primary carbon atoms at both ends of a non-branched divalent saturated hydrocarbon group having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol, further preferably at least one selected from One or more selected from 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,16-hexadecandiol, 1,18-octadecanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol, more preferably one or more selected from 1,9-nonanediol, 1,10-decanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol, more preferably one or more selected from 1,9-nonanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol.

[0220] <4> A treatment liquid as described in any one of <1> to <3>, wherein the polyvalent metal ions constituting the polyvalent metal salt are preferably divalent or trivalent metal ions, more preferably divalent metal ions, further preferably at least one selected from magnesium ions and calcium ions, and even more preferably magnesium ions.

[0221] <5> The treatment liquid according to any one of <1> to <4>, wherein the anion constituting the polyvalent metal salt is preferably an inorganic ion, more preferably one or more selected from nitrate ions and sulfate ions, and even more preferably a nitrate ion.

[0222] <6> A treatment liquid as described in any one of <1> to <5>, wherein the polyvalent metal salt is preferably at least one selected from magnesium nitrate, magnesium sulfate, calcium nitrate and aluminum nitrate, more preferably at least one selected from magnesium nitrate, calcium nitrate and aluminum nitrate, further preferably at least one selected from magnesium nitrate and calcium nitrate, and further preferably magnesium nitrate.

[0223] <7> The treatment liquid according to any one of <1> to <6>, wherein the polyamine is a polymer including a structural unit derived from a polymerizable monomer having at least one amino group.

[0224] <8> A treatment liquid as described in any one of <1> to <7>, wherein the polyamine is preferably in the form of a salt, more preferably a salt of an amino-containing polymer, further preferably at least one selected from polydiallyldimethylammonium chloride, polydiallylmethylethylammonium ethyl sulfate, dimethylamine / epichlorohydrin copolymer, polyethyleneimine hydrochloride and polyallylamine hydrochloride, and further preferably at least one selected from polydiallyldimethylammonium chloride and dimethylamine / epichlorohydrin copolymer.

[0225] <9> A treatment liquid as described in any one of <1> to <8>, wherein the treatment liquid preferably contains one or more selected from α,ω-alkanediol having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and contains one or more selected from polyvalent metal salts and polyamines as the compound (B), and more preferably contains one selected from α,ω-alkanediol having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol The above is used as the alkanediol (A), and contains a polyvalent metal salt as the compound (B), and more preferably contains one or more selected from α,ω-alkanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and contains one or more polyvalent metal salts selected from magnesium nitrate, calcium nitrate and aluminum nitrate as the compound (B), and more preferably contains a non-branched divalent saturated hydrocarbon group having 9 or more carbon atoms on the primary carbon atoms at both ends thereof. The compound (B) contains at least one of a diol to which two hydroxyl groups are bonded and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and at least one of a polyvalent metal salt selected from magnesium nitrate, calcium nitrate and aluminum nitrate, more preferably at least one of 1,9-nonanediol, 1,10-decanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and at least one of a polyvalent metal salt selected from magnesium nitrate and calcium nitrate as the compound (B). The present invention further preferably contains one or more polyvalent metal salts as the compound (B), and more preferably contains one or more selected from 1,9-nonanediol, 1,10-decanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and contains magnesium nitrate as the compound (B). It is further preferred that the present invention contains one or more selected from 1,9-nonanediol and tricyclo[5.2.1.0(2,6)]decanedimethanol as the alkanediol (A), and contains magnesium nitrate as the compound (B).

[0226] <10> A treatment liquid as described in any one of <1> to <9>, wherein the content of the alkanediol (A) in the treatment liquid is preferably 0.1 mass % or more, more preferably 0.5 mass % or more, further preferably 1 mass % or more, further preferably 3 mass % or more, further preferably 4 mass % or more, further preferably 5 mass % or more, and preferably 15 mass % or less, more preferably 10 mass % or less, further preferably 9 mass % or less, further preferably 8 mass % or less, further preferably 7 mass % or less.

[0227] <11> A treatment liquid as described in any one of <1> to <10>, wherein the content of the compound (B) in the treatment liquid is preferably 1 mass % or more, more preferably 3 mass % or more, further preferably 5 mass % or more, further preferably 10 mass % or more, further preferably 13 mass % or more, further preferably 15 mass % or more, and from the same viewpoint as above, is preferably 30 mass % or less, more preferably 25 mass % or less, further preferably 23 mass % or less, further preferably 20 mass % or less.

[0228] <12> A treatment liquid as described in any one of <1> to <11>, wherein the water content in the treatment liquid is preferably 85 mass % or less, more preferably 80 mass % or less, further preferably 75 mass % or less, further preferably 70 mass % or less, further preferably 65 mass % or less, further preferably 60 mass % or less, further preferably 57 mass % or less, further preferably 55 mass % or less, and preferably 15 mass % or more, more preferably 20 mass % or more, further preferably 30 mass % or more, further preferably 35 mass % or more, further preferably 40 mass % or more, further preferably 45 mass % or more, further preferably 50 mass % or more, further preferably 53 mass % or more.

[0229] <13> A treatment liquid as described in any one of <1> to <12>, wherein the mass ratio of the content of the compound (B) in the treatment liquid to the content of the alkanediol (A) [compound (B) / alkanediol (A)] is preferably 0.1 or more, more preferably 0.5 or more, further preferably 1 or more, further preferably 2 or more, further preferably 3 or more, and preferably 20 or less, more preferably 10 or less, further preferably 8 or less, further preferably 6 or less, further preferably 5 or less.

[0230] <14> A treatment liquid as described in any one of <1> to <13>, wherein the mass ratio of the content of the alkanediol (A) in the treatment liquid to the content of water [alkanediol (A) / water] is preferably 0.01 or more, more preferably 0.05 or more, further preferably 0.07 or more, further preferably 0.09 or more, and is preferably 1 or less, more preferably 0.5 or less, further preferably 0.3 or less, further preferably 0.2 or less, further preferably 0.1 or less.

[0231] <15> The treatment liquid according to any one of <1> to <14>, further comprising a water-soluble organic solvent (C).

[0232] <16> The treatment liquid according to <15>, wherein the water-soluble organic solvent (C) is preferably at least one selected from polyols and polyol alkyl ethers, and more preferably a polyol.

[0233] <17> A treatment liquid as described in <16>, wherein the polyol is preferably a diol other than an alkanediol (A), more preferably at least one selected from ethylene glycol, diethylene glycol, propylene glycol (1,2-propylene glycol), 1,3-propylene glycol, dipropylene glycol (mixture of isomers), 1,2-butanediol, 1,3-butanediol and 1,4-butanediol, further preferably at least one selected from diethylene glycol, propylene glycol (1,2-propylene glycol) and dipropylene glycol (mixture of isomers), and further preferably dipropylene glycol (mixture of isomers).

[0234] <18> A treatment liquid as described in <16> or <17>, wherein the polyol alkyl ether is preferably a (poly)alkylene glycol monoalkyl ether, more preferably at least one selected from ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether and triethylene glycol monobutyl ether, further preferably at least one selected from diethylene glycol monobutyl ether and triethylene glycol monobutyl ether, and further preferably triethylene glycol monobutyl ether.

[0235] <19> A treatment liquid as described in any one of <15> to <18>, wherein the content of the water-soluble organic solvent (C) in the treatment liquid is preferably 5 mass % or more, more preferably 10 mass % or more, further preferably 15 mass % or more, and is preferably 40 mass % or less, more preferably 30 mass % or less, further preferably 25 mass % or less.

[0236] <20> A treatment liquid as described in any one of <15> to <19>, wherein the mass ratio of the water-soluble organic solvent (C) to the alkanediol (A) in the treatment liquid [water-soluble organic solvent (C) / alkanediol (A)] is preferably 0.1 or more, more preferably 0.5 or more, further preferably 1.0 or more, further preferably 2.0 or more, further preferably 3.0 or more, further preferably 4.0 or more, and preferably 25 or less, more preferably 20 or less, further preferably 10 or less, further preferably 8.0 or less, further preferably 7.0 or less, further preferably 5.0 or less.

[0237] <21> A treatment liquid as described in any one of <15> to <20>, wherein the mass ratio of the total content of the alkanediol (A) and the water-soluble organic solvent (C) in the treatment liquid to the content of water [〔alkanediol (A)+water-soluble organic solvent (C)〕 / water] is preferably not less than 0.1, more preferably not less than 0.2, further preferably not less than 0.3, further preferably not less than 0.4, and is preferably not more than 1.5, more preferably not more than 1, further preferably not more than 0.7, further preferably not more than 0.5.

[0238] <22> The treatment liquid according to any one of <1> to <21>, wherein the content of the coloring material in the treatment liquid is preferably 1 mass % or less, more preferably 0.1 mass % or less, further preferably 0.01 mass % or less, and further preferably 0 mass %.

[0239] <23> The treatment liquid according to any one of <1> to <22>, which is used for treating a recording medium used for inkjet recording.

[0240] <24> An ink set for inkjet recording, comprising the treatment liquid according to any one of <1> to <23>, and an ink containing a coloring material and water.

[0241] <25> An inkjet recording ink assembly as described in <24>, wherein the coloring material is a pigment, and the form of the pigment is preferably selected from one or more forms selected from (c) a self-dispersible pigment in which hydrophilic functional groups are chemically or physically introduced into the surface of the pigment and dispersed without using a pigment dispersing resin and a surfactant; and (d) a form in which the pigment is covered with a water-insoluble resin, and (d) the form in which the pigment is covered with a water-insoluble resin is more preferred.

[0242] <26> An ink set for inkjet recording as described in <25>, wherein the water-insoluble resin is preferably one or more selected from (meth)acrylic resins, styrene / (meth)acrylic resins, polyurethane resins and polyester resins, and more preferably one or more selected from (meth)acrylic resins and styrene / (meth)acrylic resins.

[0243] <27> The ink jet recording ink set according to <24>, wherein the coloring material is a pigment, and the pigment is in a form dispersed in a pigment dispersion resin.

[0244] <28> An ink set for inkjet recording as described in <27>, wherein the acid value of the pigment dispersion resin is preferably 5 mgKOH / g or more, more preferably 50 mgKOH / g or more, further preferably 100 mgKOH / g or more, further preferably 150 mgKOH / g or more, further preferably 200 mgKOH / g or more, and is preferably 800 mgKOH / g or less, more preferably 500 mgKOH / g or less, further preferably 300 mgKOH / g or less.

[0245] <29> The ink jet recording ink set according to any one of <24> to <28>, wherein the ink further contains wax as a dispersion.

[0246] <30> An ink set for inkjet recording as described in any one of <25> to <29>, wherein the content of the pigment in the ink is preferably 2 mass % or more, more preferably 3 mass % or more, further preferably 4 mass % or more, and is preferably 20 mass % or less, more preferably 15 mass % or less, further preferably 10 mass % or less.

[0247] <31> An ink set for inkjet recording as described in any one of <25> to <30>, wherein the mass ratio of the content of the pigment in the ink to the content of the pigment dispersion resin [pigment / pigment dispersion resin] is preferably greater than 0.30, more preferably greater than 0.50, further preferably greater than 0.70, and is preferably less than 1.00, more preferably less than 0.90, further preferably less than 0.80.

[0248] <32> An ink set for inkjet recording as described in any one of <29> to <31>, wherein the content of the wax in the ink is preferably 0.3 mass % or more, more preferably 0.5 mass % or more, further preferably 0.8 mass % or more, and is preferably 7 mass % or less, more preferably 5 mass % or less, further preferably 3 mass % or less.

[0249] <33> An inkjet recording method, comprising using the treatment liquid described in any one of <1> to <23> and comprising the following steps 1 and 2,

[0250] Step 1: applying the treatment liquid to a recording medium to obtain a surface-treated recording medium;

[0251] Step 2: A step of forming an image on the treated surface of the surface-treated recording medium obtained in step 1 by inkjet recording using an ink containing a coloring material and water.

[0252] <34> Use of the treatment liquid according to any one of <1> to <23> for treating a recording medium used for inkjet recording.

[0253] Example

[0254] In the following preparation examples, examples and comparative examples, “parts” means “parts by mass” unless otherwise specified. Various physical properties were measured or calculated by the following methods.

[0255] (1) Number average molecular weight of pigment dispersion resin

[0256] The sample used for the measurement was obtained by mixing 0.1 g of the resin with 10 mL of the following eluent in a glass bottle, stirring at 25° C. for 10 hours with a magnetic stirrer, and filtering with a syringe filter “DISMIC-13HP” (PTFE, 0.2 μm, manufactured by Advantech Co., Ltd.). The measurement conditions are shown below.

[0257] GPC apparatus: “HLC-8320GPC” manufactured by Tosoh Corporation;

[0258] Column: "TSKgel SuperAWM-H", "TSKgel SuperAW3000", "TSKgelguardcolum Super AW-H" manufactured by Tosoh Corporation;

[0259] Eluent: a solution obtained by dissolving phosphoric acid and lithium bromide in N,N-dimethylformamide at concentrations of 60 mmol / L and 50 mmol / L, respectively;

[0260] Flow rate: 0.5 mL / min;

[0261] Standard substances: monodisperse polystyrene kits with known molecular weights, “PStQuick b (F-550, F-80, F-10, F-1, a-1000)” and “PStQuick c (F-288, F-40, F-4, A-5000, A-500)” manufactured by Tosoh Corporation.

[0262] (2) Acid value of pigment dispersion resin

[0263] Regarding the acid value of the pigment dispersion resin, the resin was dissolved in a titration solvent mixed with toluene and acetone (2:1) using a potentiometric automatic titration device (manufactured by Kyoto Electronics Co., Ltd., electric burette, model: APB-610), and titrated using a 0.1N potassium hydroxide / ethanol solution by potentiometric titration, with the inflection point on the titration curve being the end point. The acid value (mgKOH / g) was calculated based on the titration amount up to the end point of the potassium hydroxide solution.

[0264] (3) Solid content concentration of pigment dispersion and wax dispersion

[0265] For 30 mL polypropylene container ( 40mm, height: 30mm) is accurately weighed, and about 10.0g of sodium sulfate (reagent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) which has been constant in a desiccator is measured into the container, and the mass of sodium sulfate is accurately weighed. About 1g of pigment dispersion or wax dispersion is added thereto and mixed, and the mass of the pigment dispersion or wax dispersion is accurately weighed. Next, it is maintained at 105°C for 2 hours to remove volatile components, and after being placed in the desiccator for another 15 minutes, the mass of the entire container is accurately weighed. The mass of the residue of the pigment dispersion or wax dispersion after the volatile components are removed is calculated by subtracting the accurately weighed value of the mass of the container and the accurately weighed value of the mass of sodium sulfate from the accurately weighed value of the mass of the entire container. The mass of the residue of the pigment dispersion or wax dispersion after the volatile components are removed is divided by the accurately weighed value of the mass of the pigment dispersion or wax dispersion before the volatile components are removed, and the solid content concentration is obtained.

[0266] (4) Melting point of wax

[0267] The melting point of the wax is measured using an apparatus based on JIS K 0064. Specifically, the wax dispersion is dried and solidified, and the dried substance is used as a sample. The sample is heated to 200° C. using a differential scanning calorimeter "DSC Q20" (manufactured by TA Instruments Inc.), and then cooled from this temperature to 0° C. at a temperature drop rate of 10° C. / min. Next, the sample is heated at a temperature rise rate of 10° C. / min, and the amount of heat raised to 200° C. is measured. Among the observed melting heat peaks, the temperature of the peak with the largest peak area is taken as the maximum peak temperature of melting, and this peak temperature is taken as the melting point of the wax.

[0268] (5) Average particle size of pigment dispersion

[0269] The particle size was measured by a dynamic light scattering method using a laser particle analysis system "ELS-8000" (manufactured by Otsuka Electronics Co., Ltd.), and was calculated by cumulative analysis.

[0270] The measurement conditions were a temperature of 25°C, an angle of 90° between the incident light and the detector, a cumulative number of 100 times, and the refractive index of water (1.333) was input as the refractive index of the dispersion solvent. The measurement sample used was a sample obtained by metering a pigment dispersion into a spiral tube (manufactured by MARUEMU Corporation, No. 5), adding water so that the solid content concentration became 2×10 -4 Mass % was obtained by stirring at 25° C. for 1 hour using a magnetic stirrer.

[0271] (6) Average particle size of wax dispersion

[0272] The average particle size (average dispersed particle size) of the wax dispersion is measured using a MICROTRAC particle size analyzer "UPA" (manufactured by NIKKISO CO., LTD.).

[0273] (7) Viscosity of the treatment fluid

[0274] The viscosity of the treatment liquid at 25° C. was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., model: TV-25, using a standard conical rotor 1° 34′×R24, and a rotation speed of 50 rpm).

[0275] (8) pH of the treatment solution

[0276] The pH at 20° C. was measured using a tabletop pH meter “F-71” (manufactured by Horiba, Ltd.) using a pH electrode “6337-10D” (manufactured by Horiba, Ltd.).

[0277] Production Example 1-1 (Production of Pigment Dispersed Resin (1))

[0278] 31 parts of acrylic acid (agent manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) and 69 parts of styrene (agent manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) were mixed to prepare a monomer mixed liquid.

[0279] Into a reaction container, 10 parts of methyl ethyl ketone (hereinafter also referred to as "MEK") (a reagent manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), 0.2 parts of a polymerization chain transfer agent (2-mercaptoethanol) (a reagent manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) and 10 mass % of the above-mentioned monomer mixture were added and mixed, and the atmosphere was fully replaced with nitrogen.

[0280] Separately, a mixed solution of the remaining 90% by mass of the above-mentioned monomer mixed solution, 0.13 parts of the above-mentioned polymerization chain transfer agent, 30 parts of MEK, and 1.1 parts of a radical polymerization initiator (2,2'-azobis(2,4-dimethylvaleronitrile), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name "V-65") was added to the dropping funnel, and the temperature of the above-mentioned monomer mixed solution in the reaction container was raised to 65°C while stirring under a nitrogen atmosphere, and the mixed solution in the dropping funnel was added dropwise over 3 hours. After the dropwise addition was completed, the mixture was heated at 65°C for 2 hours, and then a solution prepared by dissolving 0.1 parts of the above-mentioned polymerization initiator in 2 parts of MEK was added, and the mixture was aged at 65°C for 2 hours and at 70°C for 2 hours, and then dried under reduced pressure to obtain an acrylic acid / styrene copolymer (number average molecular weight: 19,000, acid value: 240 mgKOH / g) as a pigment dispersion resin (1) (hereinafter also referred to as "pigment dispersion resin (1)").

[0281] Production Example 2-1 (Production of Cyan Ink 1 for Inkjet Recording)

[0282] 100 parts of the pigment dispersion resin (1) obtained in Production Example 1-1 and 78.6 parts of MEK were mixed, and 41.2 parts of a 5N sodium hydroxide aqueous solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., for volumetric analysis, sodium hydroxide content: 16.9 mass %) were added as a neutralizing agent for neutralization (neutralization degree: 40 mol %). Next, 800 parts of ion exchange water were added, and 100 parts of a cyan pigment (CI Pigment Blue 15:3, manufactured by DIC Corporation, trade name "TGR-SD") were added, and the mixture was stirred for 60 minutes at 20° C. with a dispersing blade rotating at 7,000 rpm to obtain a pigment mixture.

[0283] The obtained pigment mixture was subjected to a dispersion treatment 10 times at a pressure of 200 MPa using a microfluidizer (product name, manufactured by Microfluidics) to obtain a cyan pigment dispersion.

[0284] To the obtained cyan pigment dispersion, 250 parts of ion exchange water was added and stirred, and MEK was completely removed at 60°C under reduced pressure. After further removing a portion of water, 35.7 parts of trimethylolpropane polyglycidyl ether (manufactured by Nagase Chemtex Corporation, trade name "Denacol EX-321", epoxy equivalent: 140) as a crosslinking agent was added and the cover was tightly closed. After heating at 70°C for 5 hours while stirring with a stirrer, the temperature was lowered to room temperature, and ion exchange water was added so that the solid content concentration became 24% by mass. The mixture was filtered using a filter with a pore size of 5 μm (acetylcellulose membrane, outer diameter: 2.5 cm, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to obtain a cyan pigment dispersion (crosslinking rate 60 mol %, average particle size: 102 nm).

[0285] 50 parts of the obtained cyan pigment dispersion, 2.9 parts of a polyethylene wax dispersion (manufactured by Toho Chemical Industry Co., Ltd., trade name "HiTEC E-6500", ion type: nonionic, wax melting point: 140°C, solid content concentration: 35% by mass), 19 parts of propylene glycol (1,2-propylene glycol) (agent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 8 parts of ethylene glycol monobutyl ether (agent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 2,4,7,9-tetramethyl-5-decyne-4,7-diol (manufactured by Air Products and Chemicals Inc., trade name "Surfynol 104”), 0.5 parts of iodine and 0.5 parts of iodine were added, ion exchange water was added to make the total amount 100 parts, and the mixture was filtered using a filter with a pore size of 5 μm (acetyl cellulose membrane, outer diameter: 2.5 cm, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to obtain cyan ink 1 for inkjet recording (solid content concentration: 13% by mass, pigment content: 5% by mass, pigment dispersion resin content: 7% by mass, wax content: 1% by mass).

[0286] Production Example 2-2 (Production of Magenta Ink 2 for Inkjet Recording)

[0287] Inkjet recording magenta ink 2 was obtained in the same manner as in Production Example 2-1 except that a magenta pigment (CI Pigment Red 122, manufactured by DIC Corporation, trade name “FASTOGEN Super Magenta RGT”) was used instead of the cyan pigment.

[0288] Preparation Example 1 (Preparation of Treatment Solution 1)

[0289] The components of the treatment liquid were added to a container equipped with a stirrer in the following blending composition, mixed at 25° C. for 1 hour, and then filtered using a 25 mL needleless syringe (manufactured by TERUMO Corporation) equipped with a filter with a pore size of 5 μm (acetylcellulose membrane, outer diameter: 2.5 cm, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to obtain treatment liquid 1. The viscosity of treatment liquid 1 at 25° C. was 6.7 mPa·s, and the pH at 20° C. was 2.6.

[0290] [Composition of treatment solution 1]

[0291] 1,9-nonanediol (manufactured by Kuraray Co., Ltd.) 5.0 parts

[0292] 34.6 parts of magnesium nitrate hexahydrate (reagent manufactured by Tokyo Chemical Industry Co., Ltd.)

[0293] Dipropylene glycol (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) 20.0 parts

[0294] 40.4 parts of ion exchange water

[0295] Preparation Examples 2 to 13 and Comparative Preparation Examples 1 to 4 (Preparation of Treatment Liquids 2 to 13 and C1 to C4)

[0296] In Preparation Example 1, except that the compounding composition of the treatment liquid was changed according to Table 1, the same operation was carried out to prepare each treatment liquid.

[0297] The components of the treatment liquids used in methods other than Preparation Example 1 are shown below.

[0298] [Alkanediol (A)]

[0299] · Tricyclo[5.2.1.0(2,6)]decanedimethanol (manufactured by OQ Chemicals Corporation)

[0300] ·1,10-Decanediol (manufactured by Toyokoku Oil Co., Ltd.)

[0301] 2,4-Diethyl-1,5-pentanediol (manufactured by KH Neochem Co., Ltd.)

[0302] [Alkanediol (A')]

[0303] 1,2-nonanediol (reagent manufactured by Tokyo Chemical Industry Co., Ltd.)

[0304] 1,2-Decanediol (reagent manufactured by Tokyo Chemical Industry Co., Ltd.)

[0305] 2,2,4-Trimethyl-1,3-pentanediol (reagent manufactured by Tokyo Chemical Industry Co., Ltd.)

[0306] 2-Ethyl-1,3-hexanediol (reagent manufactured by Tokyo Chemical Industry Co., Ltd.)

[0307] [Compound (B)]

[0308] 〔Polyvalent metal salt〕

[0309] Calcium nitrate tetrahydrate (reagent manufactured by Tokyo Chemical Industry Co., Ltd.)

[0310] ·Aluminum nitrate nonahydrate (reagent manufactured by Tokyo Chemical Industry Co., Ltd.)

[0311] 〔Polyamine〕

[0312] PAS-H-1L (aqueous solution of polydiallyldimethylammonium chloride (solid content: 28% by mass), manufactured by NITTOBOMEDICAL Co., Ltd., trade name, weight average molecular weight: 8,500 (catalog value))

[0313] UNISENSE KHE-107L (aqueous solution of a dimethylamine / epichlorohydrin copolymer (solid content 52% by mass), manufactured by SENKA Corporation, trade name, PEG-converted molecular weight measured by GPC: less than 20,000 (catalog value))

[0314] [Water-soluble organic solvent (C)]

[0315] ·Triethylene glycol monobutyl ether (reagent manufactured by Tokyo Chemical Industry Co., Ltd.)

[0316] Example 1

[0317] A wireless bar coater "A-Bar" (manufactured by Mitsui Electric Seiki Co., Ltd., model: OSP-1.5, pitch: 0.08 mm, depth: 4 μm, film thickness: 1.5 μm / wet) was used to coat "OK TOP KOTE+" (manufactured by Oji Paper Co., Ltd., basis weight: 127.9 g / m 2 , water absorption of pure water when contact time is 100m seconds: 4.9g / m 2 ) was evenly coated with the treatment liquid 1, and then allowed to stand for 10 minutes at 25°C and 50% RH to dry, thereby obtaining a low-permeability recording medium with surface treatment. The amount of treatment liquid 1 applied was 1.6±0.3 g / m 2 .

[0318] In the preparation of the surface-treated low-permeability recording medium, a high-permeability recording medium made of high-quality plain paper "NPi Form Next-IJ" (manufactured by Nippon Paper Industries, Ltd., basis weight: 81.4 g / m 2 , water absorption of pure water when contact time is 100m seconds: 9.9g / m 2 ) was used instead of the coated paper, and the coating was performed in the same manner, followed by drying by leaving the coated paper to stand for 10 minutes under an environment of 25° C. and 50% RH, thereby obtaining a surface-treated high-permeability recording medium.

[0319] The obtained surface-treated low-permeability recording medium and the surface-treated high-permeability recording medium were used to form images by inkjet recording using the cyan ink or the magenta ink by the methods shown in the following (1) to (3), and the obtained printed materials were evaluated. The results are shown in Table 1.

[0320] Examples 2 to 13 and Comparative Examples 1 to 4

[0321] A surface-treated low-permeability recording medium and a surface-treated high-permeability recording medium were obtained in the same manner except that the treatment liquids shown in Table 1 were used instead of the treatment liquid 1 in Example 1.

[0322] The obtained surface-treated low-permeability recording medium and the surface-treated high-permeability recording medium were used to form images by inkjet recording using the cyan ink or the magenta ink by the methods shown in the following (1) to (3), and the obtained printed materials were evaluated. The results are shown in Table 1.

[0323] <Evaluation>

[0324] (1) Evaluation of ink dot diffusion

[0325] Using the cyan ink 1 for inkjet recording, an image was produced on a surface-treated low-permeability recording medium by the following inkjet recording method.

[0326] (Printing by inkjet recording method)

[0327] A printing evaluation device (manufactured by Trytech Co., Ltd.) equipped with an inkjet head "KJ4B-HD06MHG-STDV" (manufactured by Kyocera Corporation, piezoelectric type) was filled with cyan ink 1 for inkjet recording in an environment of temperature 25±1°C and relative humidity 30±5%.

[0328] The nozzle voltage is set to 26V, the frequency is set to 20kHz, the amount of ejected liquid is set to 12pL, the nozzle temperature is set to 32°C, the resolution is set to 600dpi, and the negative pressure is set to -4.0kPa. The surface-treated low-permeability recording medium is fixed on the conveying table by reducing the pressure in the same direction as the length direction and the conveying direction of the surface-treated low-permeability recording medium. A printing command is sent to the above-mentioned printing evaluation device to print an image of cyan ink Duty 2%. For the dot diameter, a portable image evaluation system "PIAS (registered trademark) -II" (manufactured by Quality Engineering Associates (QEA)) is used to measure the ink dot diameter under the conditions of a threshold of 50%, a minimum dot diameter of 10μm, and a maximum dot diameter of 100μm. The results are shown in Table 1. The larger the dot diameter, the better the ink dot diffusion and the better the image quality. The evaluation criteria are shown as follows. When the evaluation is C, there is no obstacle in practical use.

[0329] (Evaluation Criteria)

[0330] A: The spot diameter is 60 μm or more;

[0331] B: The spot diameter is 57 μm or more and less than 60 μm;

[0332] C: The spot diameter is 55 μm or more and less than 57 μm;

[0333] D: The spot diameter is less than 55 μm.

[0334] (2) Evaluation of image homogeneity

[0335] Using cyan ink 1 for inkjet recording and magenta ink 2 for inkjet recording, an image was produced on a surface-treated low-permeability recording medium by the following inkjet recording method.

[0336] (Printing by inkjet recording method)

[0337] In an environment of temperature 25±1° C. and relative humidity 30±5%, a printing evaluation device (manufactured by Trytech Co., Ltd.) equipped with an inkjet head “KJ4B-HD06MHG-STDV” (manufactured by Kyocera Corporation, piezoelectric type) was filled with cyan ink 1 for inkjet recording and magenta ink 2 for inkjet recording.

[0338] The nozzle voltage was set to 26V, the frequency was set to 20kHz, the ejection liquid volume was set to 12pL, the nozzle temperature was set to 32°C, the resolution was set to 600dpi, and the negative pressure was set to -4.0kPa. The surface-treated low-permeability recording medium was fixed on the conveying table by reducing the pressure in the same direction as the length direction and the conveying direction of the surface-treated low-permeability recording medium. A printing command was sent to the above-mentioned printing evaluation device to print an image with a cyan ink and a magenta ink with a duty of 60% each and a total duty of 120%. The image homogeneity of the portion where the image was printed was measured using a portable image evaluation system "PIAS (registered trademark)-II" (manufactured by Quality Engineering Associates (QEA)). * Graininess value. The results are shown in Table 1. * The smaller the Graininess value, the more the color mixing of ink dots can be suppressed, and the better the image quality. The evaluation criteria are shown below. When the evaluation is C, there is no problem in practical use.

[0339] (Evaluation Criteria)

[0340] A: L * Graininess value is less than 1.5;

[0341] B:L * Graininess value is greater than 1.5 and less than 2.1;

[0342] C:L * Graininess value is greater than 2.1 and less than 2.5;

[0343] D:L * The Graininess value is 2.5 or above.

[0344] (3) Evaluation of image density

[0345] Using the cyan ink 1 for inkjet recording, an image was produced on a surface-treated high-permeability recording medium by the following inkjet recording method.

[0346] (Printing by inkjet recording method)

[0347] A printing evaluation device (manufactured by Trytech Co., Ltd.) equipped with an inkjet head "KJ4B-HD06MHG-STDV" (manufactured by Kyocera Corporation, piezoelectric type) was filled with cyan ink 1 for inkjet recording in an environment of temperature 25±1°C and relative humidity 30±5%.

[0348] The nozzle voltage is set to 26V, the frequency is set to 20kHz, the amount of ejected liquid is set to 12pL, the nozzle temperature is set to 32°C, the resolution is set to 600dpi, and the negative pressure is set to -4.0kPa. The surface-treated high-permeability recording medium is fixed on the conveying table by reducing pressure in the same direction as the length direction and the conveying direction of the surface-treated high-permeability recording medium. A printing command is sent to the above-mentioned printing evaluation device, and an image with a duty of 100% is printed and placed for 1 day. Then, the image density of any 5 parts is measured using the spectral density colorimeter "X-Rite eXact" (manufactured by X-rite) under the conditions of light source D50, viewing angle 2°, CIE color system, and filter T. The average value of the image density of the 5 parts is calculated as the image density of the printed product. The results are shown in Table 1. The higher the image density value, the better the image density. The evaluation criteria are shown as follows. When the evaluation is C, there is no obstacle in practical use.

[0349] (Evaluation Criteria)

[0350] A: Image density is 1.18 or more;

[0351] B: The image density is 1.13 or more and less than 1.18; C: The image density is 1.08 or more and less than 1.13; D: The image density is less than 1.08.

[0352]

[0353] According to Table 1, Examples 1 to 13 can obtain high-quality prints with good ink dot diffusion and image uniformity when printing using a low-permeability recording medium, compared with Comparative Examples 1 to 3. It can also be seen that Examples 1 to 13 can obtain high-quality prints with good ink dot diffusion and image uniformity when printing using a low-permeability recording medium, and can obtain prints with high image density when printing using a high-permeability recording medium, compared with Comparative Example 4.

Claims

1. A treatment liquid, wherein The present invention comprises: an alkanediol (A) having 9 or more carbon atoms in which two hydroxyl groups are bonded to non-adjacent carbon atoms; one or more compounds (B) selected from polyvalent metal salts and polyamines; and water.

2. The treatment liquid according to claim 1, wherein The polyvalent metal ions constituting the polyvalent metal salt are divalent metal ions.

3. The treatment liquid according to claim 1 or 2, wherein The polyamine is a polymer including a structural unit derived from a polymerizable monomer having at least one amino group.

4. The treatment liquid according to any one of claims 1 to 3, wherein The alkanediol (A) is at least one selected from α,ω-alkanediol having 9 or more carbon atoms and tricyclo[5.2.1.0(2,6)]decanedimethanol.

5. The treatment liquid according to any one of claims 1 to 4, wherein The content of the alkanediol (A) in the treatment liquid is 0.1 mass % or more and 15 mass % or less.

6. The treatment liquid according to any one of claims 1 to 5, wherein The mass ratio of the content of the compound (B) to the content of the alkanediol (A) in the treatment liquid is 0.1 to 20 in terms of compound (B) / alkanediol (A).

7. The treatment liquid according to any one of claims 1 to 6, wherein The mass ratio of the content of the alkanediol (A) to the content of water in the treatment liquid is 0.01 or more and 1 or less in terms of alkanediol (A) / water.

8. The treatment liquid according to any one of claims 1 to 7, wherein It also contains a water-soluble organic solvent (C).

9. The treatment liquid according to any one of claims 1 to 8, wherein The content of the coloring material in the treatment liquid is 1% by mass or less.

10. The treatment liquid according to any one of claims 1 to 9, wherein The treatment liquid is used for treatment of a recording medium used for inkjet recording.

11. An ink set for inkjet recording, wherein: The invention comprises the treatment liquid according to any one of claims 1 to 10 and an ink containing a coloring material and water.

12. The ink set for inkjet recording according to claim 11, wherein The coloring material is a pigment, and the pigment is in a form dispersed by a pigment dispersion resin.

13. The ink set for inkjet recording according to claim 12, wherein The acid value of the pigment dispersion resin is 100 mgKOH / g or more and 800 mgKOH / g or less.

14. An inkjet recording method, wherein: Using the treatment liquid according to any one of claims 1 to 10, and comprising the following steps 1 and 2: Step 1: applying the treatment liquid to a recording medium to obtain a surface-treated recording medium; Step 2: A step of forming an image on the treated surface of the surface-treated recording medium obtained in step 1 by inkjet recording using an ink containing a coloring material and water.

15. Use of the treatment liquid according to any one of claims 1 to 10 for treating a recording medium used for inkjet recording.

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