JP2008230160A - Image forming method and recorded matter - Google Patents

Abstract

[PROBLEMS] To handle environmentally and safely without problems in a general home environment, and to obtain an image having excellent fixability and glossiness in a recorded image on glossy media by an ink composition containing a pigment. Further, there is a demand for an image forming method capable of obtaining a high-quality and clear image with little bleeding, shading unevenness and the like in plain paper and recycled paper.
An image forming method according to the present invention is an image forming method in which a coating liquid is applied to a recorded image, and is insoluble in water on a recorded image recorded with an ink composition comprising at least a coloring component and water. The coating is performed with a coating liquid containing a resin emulsion containing a hardly soluble resin solvent, a humectant, and water.
[Selection figure] None

Description

  The present invention relates to an image forming method using an ink jet recording printer and a recorded matter.

Inkjet printers have recently been commercialized as noiseless, high speed, high resolution non-impact printers. From the viewpoints of odor, safety, etc., water-based inks using water or water-soluble organic solvents are the mainstream as ink solvents used in ink jet recording. Further, water-soluble dyes have been conventionally used as colorants for inks used in ink jet recording, but dyes may be inferior in various properties such as light resistance and water resistance, and therefore, dye-based ink compositions. The recorded matter recorded by the above is inferior in light resistance and water resistance. The water resistance is improved by an ink jet recording medium having an ink absorbing layer, but it is still not sufficient for plain paper and recycled paper.
In contrast, pigments are superior in light resistance and water resistance compared to dyes. In recent years, the use of pigments as colorants in ink compositions for ink jet recording has been studied for the purpose of improving light resistance and water resistance. In the case of a water-based ink using a pigment as a colorant, since the pigment is originally insoluble in water and easily separated (aggregation / precipitation, sedimentation, etc.) from the ink, in order to stably disperse this in water, Various studies have been conducted.

One method of dispersing the pigment in water is to mix and disperse it together with a dispersant such as a dispersible resin. Many conventional dispersion methods (type of pigment used, particle size, type of dispersant used, and Dispersing means, etc.) and ink for ink jet recording have been proposed. Another method is to improve the dispersibility of the pigment by physically or chemically bonding a dispersibility-imparting group to the surface of the pigment particle so that it can be dispersed in water without a dispersant. Dispersed surface-treated pigments (hereinafter sometimes referred to as “surface-treated pigments”) have been proposed.
In the ink using the pigment obtained by the above dispersion method, although the dispersion stability of the pigment in the ink can be ensured, the recorded image on the glossy media such as glossy paper obtained using the pigment is the above-mentioned In some cases, the fixing property and glossiness were inferior to those of other dye inks. The reason why the pigment ink and the dye ink behave differently is as follows. That is, in the dye ink, the dye is dissolved in a molecular form in the ink. When this is attached to the glossy media, the dye molecules penetrate into the ink receiving layer of the glossy media surface layer together with the ink liquid component, so that the glossiness of the glossy media surface layer is maintained. In addition, since the dye molecules penetrate into the medium, there is no problem in fixing the image. In contrast, in the pigment ink, since the pigment is dispersed in the form of particles in the ink, when the ink is attached, the ink liquid component penetrates into the ink receiving layer, but the pigment particles and the like are solid. Minutes are difficult to penetrate and stay near the glossy media surface. For this reason, the recorded image obtained is inferior in fixability, and the image surface is inferior in smoothness, resulting in inferior glossiness. In particular, the above-mentioned surface-treated pigments have a more prominent defect because there are no fixing component and gloss component as they are.

  As a method for improving the above problems, various studies have been made on coating a recorded image obtained with a pigment ink. For example, it has been proposed to spray or apply a protective liquid composed of a low-boiling hydrocarbon solvent and a lipophilic resin dissolved therein (see Patent Document 1). In addition, it has been proposed to spray or apply a protective liquid made of cyclohexane, isohexane, monohydric alcohol, resin, or the like on a recorded image (see Patent Document 2). In addition, it has been proposed to coat a recorded image with an aqueous protective solution containing a resin having an acid value of greater than 110 (see Patent Document 3). Further, it has been proposed to coat a recorded image with a protective liquid containing a resin having a film forming ability by an ink jet recording method (see Patent Document 4).

JP 2002-240446 A JP 2004-175895 A JP 2004-195451 A JP 2005-81754 A

However, the prior art described above has the following problems.
Since the coating liquids according to Patent Document 1 and Patent Document 2 are mainly composed of oil-soluble and volatile solvents, they are difficult to handle in terms of environment and safety, and cannot be used in general home environments. there were.
Further, in the coating liquids according to Patent Document 3 and Patent Document 4, it is necessary to contain a large amount of resin in order to effectively impart a fixing property and gloss to the recorded image. There is a problem that the printer head is likely to be clogged as the coating liquid is dried. In addition, when a water-soluble resin is used as the resin in the coating liquid, the resin adheres to the nozzle surface of the printer head on the nozzle surface of the printer head when this is used in the ink jet recording method, resulting in ejection failure. There was also a problem that it was easy.

  Accordingly, the present invention has been made to solve the above-described problems. That is, the object of the present invention is that it can be handled without problems in terms of environment and safety even in a general home environment, and also has a fixing property and glossiness in a recorded image on a glossy medium by an ink composition containing a pigment. It is an object of the present invention to provide a coating liquid that is excellent in dischargeability and has excellent ejection stability and clogging properties in an ink jet recording method, and an image forming method using the same.

  As a result of intensive studies, the present inventor, as a coating liquid suitable for application to a recorded image recorded on glossy media using an ink composition containing a pigment as a coloring component, and an image forming method using the same The knowledge that the said subject can be solved by setting it as the structure shown below was acquired. The present invention is based on such knowledge. That is,

(1) The image forming method of the present invention is an image forming method in which a coating liquid is applied to a recorded image, and is insoluble or difficult to dissolve in water on a recorded image recorded with an ink composition comprising at least a coloring component and water. The coating is performed with a coating liquid containing a resin emulsion containing a soluble resin solvent, a humectant, and water.
(2) In the image forming method of the present invention, the resin solvent is selected from the group consisting of alcohols, ketones, ethers, esters, nitrogen-containing compounds, and sulfur-containing compounds. It is characterized by.
(3) The image forming method of the present invention is characterized in that the coating liquid and / or ink composition further contains a penetrant.
(4) In the image forming method of the present invention, the coloring component contained in the ink composition is bonded directly or indirectly to at least one of the functional group represented by the following formula or a salt thereof on the surface. It is a surface-treated pigment that has been surface-treated and made dispersible in water without a dispersant.

(5) The image forming method of the present invention is characterized in that the coloring component contained in the ink composition is a dispersion in which a pigment is included in a dispersion polymer and can be dispersed in water.
(6) In the image forming method of the present invention, the dispersion polymer comprises a hydrophobic part and a hydrophilic part, and at least a part of the hydrophilic part contains an unneutralized group that is a part of the hydrophobic part. A neutralized group obtained by adding, wherein the abundance of the neutralized group is in a range of 20% or more and less than 60% in molar ratio to the sum of the unneutralized group and the neutralized group To do.
(7) The image forming method of the present invention is a method of applying a coating liquid to a recorded image by applying the coating liquid to at least a recorded image portion on a recording medium using an inkjet head. Features.
(8) The image forming method of the present invention is characterized in that the recording image to be coated is formed by discharging the ink composition onto a recording medium using an ink jet head.
(9) The recorded matter of the present invention is recorded using the image forming method described above.

  According to the image forming method having the above-described configuration, a clear image excellent in fixing property and glossiness can be obtained even when recording on glossy media using an ink composition using a pigment as a coloring component. In such a configuration, it is not necessary to use an oil-soluble / volatile solvent as a main component of the liquid component in the coating liquid as in the prior art, and therefore it can be handled safely and easily even in a general household environment. Further, since it is not necessary to contain a large amount of resin in the protective liquid (coating liquid), the reliability (ejection stability, clogging characteristics) is excellent when the coating liquid is applied to the ink jet recording system.

Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.
The image forming method of the present invention is an image forming method in which a coating liquid is applied to a recorded image, and is insoluble or hardly soluble in water on a recorded image recorded with an ink composition comprising at least a coloring component and water. The coating is performed with a coating liquid containing a resin emulsion containing a resin solvent, a humectant, and water.
In addition, the resin solvent is selected from the group consisting of alcohols, ketones, ethers, esters, nitrogen-containing compounds, and sulfur-containing compounds. A coating liquid containing such a resin emulsion is excellent in the effect of improving the fixability / glossiness of an image recorded on a glossy medium by the ink composition according to the present invention.

The reason for this is not clear yet, but is estimated as follows. In the image forming method of the present invention, an image is first recorded on a glossy medium with an ink composition. When a pigment is used as the colorant of the ink composition to be used, as described above, in this state, the gloss media surface layer mainly contains solids in the ink composed of pigment particles and the image surface is smooth. In some cases, the glossiness of the image is poor. Conventionally, in order to improve the glossiness, various studies have been made on ink additives and ink components (mainly, the structure of the dispersion polymer to be added, solvent types, and combinations thereof). However, satisfactory results were not obtained.
However, when the coating liquid according to the present invention is applied to at least the image area, the resin emulsion in the coating liquid remains on the surface of the image area as the coating liquid penetrates, and other liquid components are present in the image area. The ink composition penetrates and diffuses into the glossy media receiving layer through the solid content of the ink composition. As the liquid component in the coating liquid coated on the image surface decreases, the resin emulsion softens and dissolves due to the action of the resin solvent contained in the resin emulsion. The resin softened / dissolved material enters between the pigment particles in the image portion printed in advance and the surface of the pigment particles, and then forms a uniform resin film with drying. This resin film is rich in smoothness and uniformly reflects light incident on the image surface, which is considered to improve the glossiness of the image. Further, since this resin film also has an action of firmly bonding between the pigment particles and between the pigment particles and the glossy media, it is considered that the resin film also has an effect of improving the fixability of the image.
The coating liquid and ink composition in the image forming method of the present invention will be described below.

<Coating solution>
In the image forming method of the present invention, in the image forming method of applying a coating liquid to a recorded image, the resin emulsion containing a resin solvent insoluble or hardly soluble in water, a humectant, and water are contained as essential components. Use a coating solution. Below, the component of the coating liquid used for this invention is demonstrated.

[Resin solvent]
The coating liquid according to the present invention must contain a resin solvent that is insoluble or hardly soluble in water. This resin solvent has a feature that it functions as a good softening agent / dissolving agent for the resin emulsion essential for the coating liquid in the present invention, which will be described in detail later. When such a resin solvent is included, as described above, the resin emulsion existing on the surface of the image portion is softened and dissolved, and then a uniform resin film is formed with drying. Since this resin film is rich in smoothness and uniformly reflects light incident on the image surface, it is excellent in the effect of improving the glossiness of the image. Further, this resin film also has an effect of improving the fixability of an image because it exhibits an action of firmly bonding the colorant and the glossy media by the ink composition.

The resin solvent having such an effect is selected from those that are insoluble or hardly soluble in water, and more specifically those having a solubility in water at 25 ° C. of less than 3% by weight. When such a resin solvent is used, since the resin solvent contained in the resin emulsion does not dissolve into the coating liquid, the storage stability of the coating liquid is excellent. In addition, when such a resin solvent is used, adhesion of the resin emulsion to the nozzle surface of the printer head when applied to an ink jet printer can be suppressed, so that there is no clogging or ejection failure and excellent ejection stability. Furthermore, in addition to the above properties, the above-mentioned glossiness and fixing properties are imparted when one or more types are selected from the group consisting of alcohols, ketones, ethers, esters, nitrogen-containing compounds, and sulfur-containing compounds. This is preferable because of its excellent effect.
Here, when a resin solvent having a solubility in water at 25 ° C. of 3% by weight or more is used, a part or all of the resin solvent is eluted from the resin emulsion into the coating solution, and the resin solvent acts by the action of the resin solvent. Some or all of this may dissolve. If so, the dispersibility of the resin emulsion itself is hindered and the storage stability is lacking. In addition, when applied to an ink jet printer, a dissolved resin emulsion may adhere to the nozzle surface of the printer head, which causes problems such as clogging and ejection failure.

More specifically, as the resin solvent exhibiting the above-described effects, as alcohols, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl- 2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, 1-nonanol, 3,5 , 5-trimethyl-1-hexanol, 1-decanol, 2- (benzyloxy) ethanol.
Examples of ethers include dibutyl ether, dihexyl ether, propylene oxide, furan, and 2-methyl furan.
Examples of ketones include 2-hexanone, 2-methyl-4-pentanone, 2-heptanone, 4-heptanone, 2,6-dimethyl-4-heptanone, mesityl oxide, phorone, and isophorone.
Further, as esters, n-propyl formate, n-butyl formate, isobutyl formate, n-amyl formate, n-propyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-amyl acetate, isopentyl acetate, acetic acid sec-hexyl, 2-ethylbutyl acetate, cyclohexyl acetate, benzyl acetate, ethyl propionate, butyl propionate, isopentyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, isopentyl butyrate, isobutyl isobutyrate, ethyl isovalerate, Isopentyl isovalerate, butyl stearate, pentyl stearate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isopentyl benzoate, benzyl benzoate, ethyl abietate, benzyl abietate, dibutyl tartrate, Phosphate, tributyl diethyl carbonate, 2-butoxyethyl acetate.
Examples of nitrogen-containing compounds include 1-nitropropane and 2-nitropropane.
Examples of the sulfur-containing compound include dimethyl sulfide, diethyl sulfide, and thiophene.

  The content of the resin solvent contained in the coating liquid according to the present invention is preferably in the range of 1% by weight to 30% by weight with respect to the resin solid content of the resin emulsion. When the content is 1% by weight or more, the above-described effects (glossiness and fixability imparting) are exhibited. If it is 30% by weight or less, the resin emulsion in the coating solution can be stably dispersed, so that the storage stability can be maintained well, and the adhesion of the resin emulsion to the nozzle surface of the printer head is suppressed, so clogging. And problems such as defective discharge do not occur.

[Humectant]
It is essential that the coating liquid according to the present invention contains a humectant. The humectant used in the present invention is selected from those having low volatility and high water retention ability. By including such a humectant, it is possible to suppress drying of the coating liquid due to water evaporation, and to prevent alteration of the composition of the coating liquid due to long-term standing. For this reason, for example, even when the apparatus has been in an inactive state for a long time after the coating liquid is filled in the printer head, the coating liquid can be prevented from drying and solidifying on the nozzle surface of the printer head, resulting in problems such as clogging. There is no effect.

In detail, the humectant having the above-mentioned characteristics includes glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-propanediol, 1,4- Polyols such as butanediol, 1,5-pentanediol and pentaerythritol, and lactams such as 2-pyrrolidone and N-methyl-2-pyrrolidone can be used.
Furthermore, a water-soluble solid humectant can be used in combination and added for the purpose of assisting the ability of the above materials. Specifically, diols such as 1,6-hexanediol, 1,8-octanediol, 2,2-dimethyl-1,3-propanediol, and 2,2-diethyl-1,3-propanediol, trimethylolethane , Trimethylolpropane, etc., ureas, glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, etc. Examples of saccharides, oligosaccharides and polysaccharides and derivatives of these saccharides include reducing sugars, oxidized sugars, amino acids, thiosaccharides, and the like of the aforementioned sugars. Sugar alcohol is particularly preferable, and specific examples include maltitol and sorbit.

  The amount of the humectant added is preferably in the range of 1% by weight to 50% by weight based on the total amount of the coating liquid by mixing one or more of the specific examples described above. If it is 1 weight% or more, the above-mentioned effect will be exhibited. If it is 50% by weight or less, the viscosity of the coating liquid can be adjusted to a suitable range in the ink jet recording method, and the ejection stability is also good.

  The humectant described above can also be added to the ink composition described below. In that case, similarly to the case where it is included in the coating liquid according to the present invention, it is possible to suppress drying due to water evaporation of the ink composition, and to suppress the alteration of the composition of the ink composition due to long-term standing, This is preferable because drying and solidification on the nozzle surface of the printer head can be suppressed.

[Resin emulsion]
It is essential that the coating liquid in the present invention contains a resin emulsion containing the above-described resin solvent. When the coating liquid containing this is coated on the surface of the image on the glossy media, the resin emulsion is softened / dissolved by the action of the encapsulating resin solvent, and the resin emulsion softening / dissolving material and the colorant in the image and Adhesion with the glossy media surface can improve image fixability. Furthermore, this resin emulsion softening / dissolving material forms a uniform and smooth resin film in such a form that the colorant covers the colorant, so that it also has an effect of forming an image having excellent glossiness on an image on glossy media. .

Examples of the resin constituting the resin emulsion having such characteristics include acrylic resin, methacrylic resin, styrene resin, urethane resin, acrylamide resin, epoxy resin, and the like, and a mixed system of these resins. May be used. Among these resins, more preferred are styrene-acrylic acid copolymers, styrene-acrylic acid-alkyl acrylate copolymers, styrene-maleic acid copolymers, styrene-maleic acid-alkyl acrylates. Examples include ester copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-alkyl acrylate copolymers, styrene-maleic acid-half ester copolymers, and the like. These resins may be synthesized so as to satisfy desired characteristics, or commercially available resins may be used as they are. In order to obtain various characteristics, these may be used alone or in combination.
These resins are required to have both a hydrophobic part and a hydrophilic part as a structure. Here, the hydrophobic portion refers to a repeating unit having an alkyl group, a cycloalkyl group, an aromatic ring, or an unneutralized group. An unneutralized group is a group that can be neutralized by a neutralizing agent, and examples thereof include an acid group and an alkaline group. Specific examples of the unneutralized group include a carboxylic acid group and a sulfonic acid group. Moreover, as a hydrophilic part, the repeating unit which has a hydroxyl group, an amino group, an amide group, and a neutralizing group is shown. The neutralizing group is a group formed by neutralizing an unneutralized group, and is preferably an ionic group. The unneutralized group and the neutralized group are preferably anionic groups, and particularly suitable when the unneutralized group is a carboxylic acid group and the neutralized group is a carboxylic acid anion group (carboxylate group). Can be illustrated. Examples of the carboxylate include lithium carboxylate, sodium carboxylate, potassium carboxylate, and ammonium carboxylate. The hydrophobic part mentioned here has high affinity with the above-mentioned resin solvent, and conversely, the hydrophilic part has low affinity with the resin solvent. Therefore, since the resin constituting the resin emulsion has the above-described structure, the hydrophobic portion can be present inside the resin emulsion and isolated from water, and the resin solvent can be efficiently introduced into the resin emulsion.・ It can be effectively wrapped. Further, it can take a form in which a hydrophilic portion is present on the surface, and can be adapted to water by the action of the hydrophilic portion. Therefore, it becomes a resin emulsion that is stably dispersed in water. Also, after adhering to the recording medium, the resin emulsion softening / dissolving material is efficiently and effectively generated by the action of the encapsulating resin solvent, and the resin emulsion softening / dissolving material and the colorant are bonded together. -It becomes a film and the hydrophobic part can cover the film surface. This film is insoluble in water and does not re-disperse, and is firmly fixed on the recording medium together with the colorant, so that the image fixability and water resistance are improved.

  Such a resin emulsion may be synthesized and used so as to satisfy various characteristics, or a commercially available product may be used. Specifically as a commercial item, mobile 701 (Tg: -19 degreeC), mobile 743 (Tg: 39 degreeC), mobile 745 (Tg: 21 degreeC), mobile 940 (Tg: 1 degreeC), mobile 1930 (Tg: 1 ° C), mobile 664 (Tg: 6 ° C), mobile DM5 (Tg: -3 ° C), mobile 700 (Tg: -2 ° C), mobile 792 (Tg: -2 ° C), mobile DM772 (Tg: 3 ° C) ), Mobile 865 (Tg: 1 ° C), Mobile 870 (Tg: 19 ° C), Mobile 928 (Tg: 5 ° C), Mobile 1750T (Tg: 16 ° C), Mobile 1751 (Tg: 16 ° C), Mobile 1760 ( Tg: 7 ° C), mobile LDM6316 (Tg: 17 ° C), mobile 7200 (Tg: 24 ° C), mobile 727 ( g: 5 ° C), mobile 752 (Tg: 16 ° C), mobile 837 (Tg: 10 ° C), mobile 860 (Tg: 3 ° C), mobile 864 (Tg: 4 ° C), mobile 864M (Tg: 4 ° C) , Mobile DM60 (Tg: 0 ° C.), Mobile DM 765 (Tg: −19 ° C.), Mobile 937 (Tg: −42 ° C.), Mobile 1906 (Tg: −45 ° C.), Mobile LDM 6300 (Tg: 10 ° C.), Mobile 742N (Tg: 37 ° C.), mobile 749E (Tg: 25 ° C.), mobile 752 (Tg: 16 ° C.), mobile 916 (Tg: −5 ° C.), mobile 1700A (Tg: 37 ° C.), mobile 7210 (Tg: 16 ° C), mobile 747 (Tg: 42 ° C), mobile 6520 (Tg: 40 ° C), mobile 7 02 (Tg: −35 ° C.), mobile LDM7010 (Tg: 34 ° C.), mobile VDM7410 (Tg: −4 ° C.), mobile DM 772 (Tg: 3 ° C.), mobile DM 774 (Tg: 10 ° C.), mobile 947 (Tg) : -55 ° C), mobile LDM6481 (Tg: -22 ° C), mobile LDM6880 (Tg: 9 ° C), mobile DM758 (Tg: -60 ° C), mobile DM765 (Tg: -19 ° C), mobile 650 (Tg: −37 ° C.), mobile 760H (Tg: −17 ° C.), mobile 761HG (Tg: −35 ° C.), mobile 763 (Tg: −18 ° C.), mobile 412 (Tg: −62 ° C.), mobile 490 (Tg: −53 ° C.), mobile S-71 (Tg: −53 ° C.), mobile 987 (Tg: -2 ° C), Mobile 1410 (Tg: -8 ° C), Mobile 630 (Tg: 27 ° C), Mobile 620 (Tg: -22 ° C), Mobile 730L (Tg: -13 ° C), Mobile 735 (Tg: 14) ° C), mobile 767 (Tg: 25 ° C), mobile 790 (Tg: 102 ° C), mobile 9000 (Tg: 46 ° C), mobile 880 (Tg: 3 ° C), mobile DM60 (Tg: 3 ° C), mobile 8020 (Tg: −22 ° C.), Mobile 8030 (Tg: 17 ° C.), Mobile 8055 (Tg: 78 ° C.), Mobile 8201 (Tg: 8 ° C.), Mobile 787 (Tg: 14 ° C.), Mobile 710 (Tg: 9) ° C), mobile 718 (Tg: -6 ° C), mobile 776 (Tg: -20 ° C), mobile 952 (Tg:- 8 ° C), Mobile 963A (Tg: -19 ° C), Mobile DM 772 (Tg: 6 ° C), Mobile 975A (Tg: 27 ° C), Mobile 3200 (Tg: -21 ° C), Apletan 760H (Tg: -17 ° C) ), Apletan 2200 (Tg: 19 ° C.), Apretan 2000 (Tg: 19 ° C.), Apretan 3510 (Tg: 0 ° C.), Apretan 3410 (Tg: −32 ° C.) (all trade names, manufactured by Clariant Japan Co., Ltd.) PCL series 0619 (Tg: −4 ° C.), PCL series 0623A (Tg: −6 ° C.), PCL series 0640 (Tg: 55 ° C.), PCL series 0693 (Tg: 20 ° C.), PCL series 0695 (Tg: − 4 ° C), PCL series 0696 (Tg: -12 ° C), PCL series 0850 (Tg: 7) ), PCL series 0890 (Tg: −17 ° C.), SB series 0561 (Tg: −63 ° C.), SB series 0589 (Tg: 0 ° C.), SB series 0602 (Tg: 40 ° C.), SB series 2108 (Tg: -66 ° C), SB series 0533 (Tg: -20 ° C), SB series 0545 (Tg: -31 ° C), SB series 0548 (Tg: -49 ° C), SB series 0568 (Tg: -23 ° C), SB Series 0569 (Tg: -4 ° C), SB series 0573 (Tg: -9 ° C), SB series 0597C (Tg: 28 ° C), AE series AE116 (Tg: 50 ° C), AE series AE119 (Tg: 55 ° C) AE series AE120 (Tg: -10 ° C), AE series AE121 (Tg: 58 ° C), AE series AE125 (Tg : 60 ° C), AE series AE134 (Tg: 48 ° C), AE series AE137 (Tg: 48 ° C), AE series AE140 (Tg: 53 ° C), AE series AE173 (Tg: 60 ° C), AE series AE200 (Tg) : -45 ° C), AE series AE311 (Tg: -50 ° C), AE series AE318 (Tg: 5 ° C), AE series AE337 (Tg: -30 ° C), AE series 343 (Tg: 0 ° C), AE series 362 (Tg: -5 ° C), AE series AE373B (Tg: 10 ° C), AE series AE379A (Tg: 20 ° C), AE series AE513A (Tg: -48 ° C), AE series AE517 (Tg: -48 ° C) AE series AE604 (Tg: 5 ° C), AE series AE610C (Tg: -62 ° C), AE series AE815 (Tg: 5 ° C), AE series AE945 (Tg: -17 ° C), AE series AE950 (Tg: -20 ° C), AE series AE986A (Tg: 2 ° C) (all trade names, manufactured by JSR Corporation) ), Jonkrill 7100 (Tg: −10 ° C.), Jonkrill 390 (Tg: −5 ° C.), Jonkrill 1674 (Tg: −4 ° C.), Jonkrill 711 (Tg: 0 ° C.), Jonkrill 1695 (Tg) : 5 ° C), Joncryl 511 (Tg: 9 ° C), Joncryl 7001 (Tg: 12 ° C), Joncryl 632 (Tg: 12 ° C), Joncryl 741 (Tg: 15 ° C), Joncryl 450 (Tg) : 16 ° C), Joncryl 840 (Tg: 16 ° C), Joncryl 74J (Tg: 22 ° C), PDX-7111B (Tg: 19 ° C), HR -1645 (Tg: 21 ° C.), Jonkrill 734 (Tg: 30 ° C.), Jonkrill 852 (Tg: 31 ° C.), Jonkrill 7600 (Tg: 35 ° C.), Jonkrill 775 (Tg: 37 ° C.), John Krill 537 (Tg: 49 ° C), Jonkrill 1535 (Tg: 50 ° C), PDX-7630A (Tg: 53 ° C), Jonkrill 352 (Tg: 56 ° C), Jonkrill 352D (Tg: 56 ° C), PDX -7145 (Tg: 56 ° C.), Jonkrill 538J (Tg: 66 ° C.) (all trade names, manufactured by BASF Japan Ltd.), and the like.

  These resin emulsions can be used alone or in combination of two or more in the coating solution of the present invention. The addition amount of these resin emulsions may be appropriately determined in consideration of fixing properties, glossiness, etc., but is preferably in the range of 1% by weight to 20% by weight in terms of resin solid content in the coating solution. If it is 1% by weight or more, the above-described effects (fixing property and glossiness imparting) can be exhibited. Moreover, if it is 20 weight% or less, the coating liquid containing this can be prepared in the suitable viscosity range in an inkjet recording method, and discharge stability can be kept favorable.

  When it is necessary to include a neutralizing group as the hydrophilic portion of the resin emulsion described above, a basic compound is required to generate the neutralizing group. Examples of the basic compound include amines and alkali metal salt compounds. Examples of amines include water-soluble volatile amines, alkanolamines, and the like. Specifically, volatile amines substituted with alkyl groups (for example, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine). , Isopropylamine, dipropylamine, diisopropylamine, butylamine, isobutylamine, sec-butylamine, tert-butylamine, dibutylamine, diisobutylamine, pentylamine, etc .; alkanolamines substituted with alkanol groups (eg 2-aminoethanol) , 2- (dimethylamino) ethanol, 2- (diethylamino) ethanol, diethanolamine, N-butylethanolamine, triethanolamine, isopropanolamine Triisopropanolamine, etc.); alkyl and alkyl alkanol amines substituted with alkanol group. Specific examples of the alkali metal salt compound include compounds having lithium, sodium and potassium as the alkali metal, preferably an alkali metal hydroxide salt such as sodium hydroxide, potassium hydroxide and lithium hydroxide, more preferably potassium hydroxide. Can be mentioned. These basic compounds can be added in appropriate amounts in order to ensure stable dispersibility of the resin emulsion.

  The particle size of the resin emulsion used in the coating liquid of the present invention is preferably 500 nm or less, more preferably 300 nm or less, and further preferably an average particle size in the range of 10 nm to 200 nm from the viewpoint of dispersion stability. .

[water]
Water is a coating medium according to the present invention and a medium serving as the center of the ink composition described below. Preferred water is ion-exchanged water, ultrafiltered water, reverse water for the purpose of reducing ionic impurities as much as possible. Pure water such as osmotic water or distilled water, or ultrapure water can be used. Further, when water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, it is preferable because generation of mold and bacteria can be prevented when the coating liquid and the ink composition are stored for a long period of time.

<Ink composition>
The image forming method of the present invention comprises a resin emulsion containing a resin solvent insoluble or hardly soluble in water and a humectant on a recorded image recorded with an ink composition comprising at least a coloring component and water. And coating with a coating solution containing water and water. The constituent elements of the ink composition used in the present invention will be described below.

[Coloring ingredients]
The coloring component essential for the ink composition of the present invention may contain a colorant that is insoluble or hardly soluble in an aqueous medium from the viewpoint of maintaining good weather resistance (water resistance, light resistance, etc.) of the image. preferable. Specific examples thereof include organic pigments, carbon black, oil-soluble dyes, disperse dyes, etc., but organic pigments, carbon blacks, etc. because of good color developability and low precipitation due to low specific gravity. The pigments are particularly preferred. Specific examples of preferred pigments as colorants are given below.

(Pigment)
In the present invention, specific examples of preferable carbon black include No. 2300, 900, MCF88, no. 20B, no. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, No2200B, etc. (all trade names, manufactured by Mitsubishi Chemical Corporation), color black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Pretex 35, U, V, 140U , Special Black 6, 5, 4A, 4, 250, etc. (all trade names, manufactured by Degussa), Conductex SC, Raven 1255, 5750, 5250, 5000, 3500, 1255, 700, etc. (all trade names, Colombia) (Manufactured by Carbon Co., Ltd.), Regar 400R, 330R, 660R, Mogul L, Monarch 700, 800, 880, 900, 1000, 1100, 1300, 1400, Elftex 12, etc. (all trade names, manufactured by Cabot Corporation). In addition, these are description of an example of the carbon black suitable for this invention, and this invention is not limited by these. These carbon blacks may be used singly or as a mixture of two or more.
These carbon blacks are added in an amount of 0.5 to 15% by weight, preferably 1 to 10% by weight, based on the total amount of the ink composition.

Preferred organic pigments in the present invention include quinacridone pigments, quinacridone quinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, ansanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments. And diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments and azo pigments.
Specific examples of the organic pigment used in the ink composition according to the present invention include the following.
Examples of the pigment used in the cyan ink composition include C.I. I. Pigment blue 1, 2, 3, 15: 3, 15: 4, 15:34, 16, 22, 60, etc .; C.I. I. Bat blue 4, 60 and the like, preferably C.I. I. Pigment Blue 15: 3, 15: 4, and one or a mixture of two or more selected from the group consisting of 60. These pigments are contained in an amount of about 0.5 to 15% by weight, preferably about 1 to 10% by weight, based on the total amount of the cyan ink composition.
Examples of the pigment used in the magenta ink composition include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 112, 122, 123, 168, 184, 202, C.I. I. Pigment violet 19 and the like, preferably C.I. I. Pigment red 122, 202, and 209, C.I. I. One or a mixture of two or more selected from the group consisting of pigment violet 19. These pigments are contained in an amount of about 0.5 to 15% by weight, preferably about 1 to 10% by weight, based on the total amount of the magenta ink composition.
Examples of the pigment used in the yellow ink composition include C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14C, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 119, 110, 114, 128, 129, 138, 150, 151, 154, 155, 180, 185, etc., preferably C.I. I. One or a mixture of two or more selected from the group consisting of CI Pigment Yellow 74, 109, 110, 128, and 138. These pigments are contained in an amount of about 0.5 to 15% by weight, preferably about 1 to 10% by weight, based on the total amount of the yellow ink composition.
Examples of the pigment used in the orange ink composition include C.I. I. Pigment Orange 36 or 43, or a mixture thereof. These pigments are contained in an amount of about 0.5 to 15% by weight, preferably about 1 to 10% by weight, based on the total amount of the orange ink composition.
Examples of the pigment used in the green ink composition include C.I. I. Pigment Green 7 or 36 or a mixture thereof. These pigments are contained in an amount of about 0.5 to 15% by weight, preferably about 1 to 10% by weight, based on the total amount of the green ink composition.

  In the ink composition of the present invention, the pigment described above is preferably used as a colorant. As a form for including the pigment as a coloring component in the ink composition, a dispersion made dispersible in water by a dispersion polymer (a polymer having an anionic group) described later, or the following formula on the surface thereof: A surface-treated pigment that is surface-treated so that at least one of the represented functional groups or a salt thereof is bonded directly or indirectly and is dispersible in water without a dispersant is preferred.

  Hereinafter, the dispersion and the surface-treated pigment will be described in detail.

(Dispersion)
As an example, the ink composition according to the present invention includes, as a coloring component, a dispersion in which the above-described pigment can be dispersed in water by a dispersion polymer. The dispersion polymer used in the ink composition of the present invention is insoluble in water by itself, and is soluble in an organic solvent (preferably a water-soluble organic solvent such as acetone or methyl ethyl ketone) used in the method for producing a dispersion described later in Examples. In addition, it is essential that the polymer structure has both a hydrophobic portion and a hydrophilic portion.
Here, the hydrophobic portion refers to a repeating unit having an alkyl group, a cycloalkyl group, an aromatic ring, or an unneutralized group. An unneutralized group is a group that can be neutralized by a neutralizing agent, and examples thereof include an acid group and an alkaline group. Specific examples of the unneutralized group include a carboxylic acid group and a sulfonic acid group. Moreover, as a hydrophilic part, the repeating unit which has a hydroxyl group, an amino group, an amide group, and a neutralizing group is shown. The neutralizing group is a group formed by neutralizing an unneutralized group, and is preferably an ionic group. The unneutralized group and the neutralized group are preferably anionic groups, and particularly suitable when the unneutralized group is a carboxylic acid group and the neutralized group is a carboxylic acid anion group (carboxylate group). Can be illustrated. Examples of the carboxylate include lithium carboxylate, sodium carboxylate, potassium carboxylate, and ammonium carboxylate. When the dispersion polymer has the above-described structure, the hydrophobic polymer can be firmly adsorbed on the hydrophobic surface of the pigment and can include the pigment. Furthermore, since the hydrophilic part is compatible with water, it can be a dispersion that is stably dispersed in water.

The dispersion polymer having an anionic group is obtained by polymerizing, for example, a monomer having an anionic group (hereinafter referred to as an anionic group-containing monomer) and, if necessary, another monomer that can be copolymerized with these monomers in a solvent. Is obtained. Examples of the anionic group-containing monomer include a monomer having a carboxylic acid group and a monomer having a sulfonic acid group.
As the monomer having a carboxylic acid group, an acrylic monomer containing one or two carboxylic acid groups in the repeating unit is preferable. Specific examples of the monomer having a carboxylic acid group include acrylic acid, methacrylic acid, crotonic acid, ethacrylic acid, propylacrylic acid, isopropylacrylic acid, itaconic acid, fumaric acid, maleic acid and the like. Among these, acrylic acid, methacrylic acid, and maleic acid are preferable. Specific examples of the monomer having a sulfonic acid group include styrene sulfonic acid, isoprene sulfonic acid, sulfobutyl methacrylate, and allyl sulfonic acid. Furthermore, after polymerizing the polymer, it is also preferable to sulfonate with a sulfonating agent such as sulfuric acid, fuming sulfuric acid, sulfamic acid and the like.

  Specific examples of other monomers that can be copolymerized with the anionic group-containing monomer include methyl acrylate, ethyl acrylate, isopropyl acrylate, acrylic acid-n-propyl, acrylic acid-n-butyl, and acrylic acid-t-. Butyl, 2-ethylhexyl acrylate, n-octyl acrylate, lauryl acrylate, benzyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, methacrylic acid n-propyl, methacrylic acid n-butyl, (Meth) acrylic esters such as isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, lauryl methacrylate, stearyl methacrylate, tridecyl methacrylate, benzyl methacrylate, etc. ; Steer Addition reaction product of oil fatty acid and (meth) acrylic acid ester monomer having oxirane structure such as addition reaction product of acid and glycidyl methacrylate; oxirane compound containing alkyl group having 3 or more carbon atoms and (meth) acrylic Addition reaction product with acid; styrene monomer such as styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-tert-butylstyrene, etc .; such as benzyl itaconate Itaconic acid esters; maleic acid esters such as dimethyl maleate; fumaric acid esters such as dimethyl fumarate; acrylonitrile, methacrylonitrile, vinyl acetate, isobornyl acrylate, isobornyl methacrylate, aminoethyl acrylate, acrylic acid Aminopropyl, aqua Methylaminoethyl acrylate, methylaminopropyl acrylate, ethylaminoethyl acrylate, ethylaminopropyl acrylate, aminoethylamide acrylate, aminopropylamide acrylate, methylaminoethylamide acrylate, methylaminopropylamide acrylate, Acrylic acid ethylaminoethylamide, acrylic acid ethylaminopropylamide, methacrylic acid amide, aminoethyl methacrylate, aminopropyl methacrylate, methylaminoethyl methacrylate, methylaminopropyl methacrylate, ethylaminoethyl methacrylate, ethylamino methacrylate Propyl, methacrylic acid aminoethylamide, methacrylic acid aminopropylamide, methacrylic acid methylaminoethylamide, methacrylic acid methylaminoamide Pyramide, ethyl aminoethylamide methacrylate, ethyl aminopropyl amide methacrylate, hydroxymethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, hydroxymethyl methacrylate, 2-hydroxyethyl methacrylate, Examples include 2-hydroxypropyl methacrylate, N-methylolacrylamide, and allyl alcohol.

  These dispersion polymers preferably have a weight average molecular weight in the range of 1,000 to 200,000, particularly preferably in the range of 3,000 to 150,000. When the weight average molecular weight of the dispersed polymer is within this range, the function as a pigment coating film or a coating film in the ink composition can be sufficiently exhibited.

  A basic compound is required to neutralize a part of the unneutralized group of the dispersion polymer having an anionic group, and the basic compound is suitable for the resin emulsion contained in the above-described coating liquid of the present invention. Can be used as is.

  In the dispersion used in the ink composition of the present invention, the balance between the hydrophobic portion and the hydrophilic portion of the dispersion polymer described above is important, and the amount of neutralizing groups that are part of the hydrophilic portion is the dispersion. Greatly affects the dispersion stability of the toner, the ejection stability from the printer head, and the image quality of the recorded matter. The ratio is preferably 20% or more and less than 60% in molar ratio with respect to the sum of the unneutralized group which is a part of the hydrophobic part and the neutralized group which is a part of the hydrophilic part in the dispersion polymer. . Within this range, it is possible to obtain an ink composition having higher storage stability and ejection stability, and particularly excellent image quality on plain paper, recycled paper, and the like. When the amount of the neutralizing group is 20% or more, the balance between the hydrophobic portion and the hydrophilic portion becomes good, and the dispersion of the pigment by the dispersion polymer is stabilized, so that the aggregation and sedimentation of the pigment can be prevented. If it is less than 60%, the penetration of ink solids (especially pigment particles) into the paper is suppressed particularly when an image is formed on plain paper, recycled paper, or the like. There is an effect that pigment particles can be present on the surface, and as a result, color developability is improved and a clear recorded image having a high density can be obtained.

  The amount of the anionic group in the dispersion polymer is such that the acid value is about 30 KOHmg / g or more, preferably in the range of about 50 KOHmg / g to 250 KOHmg / g. When the acid value of the dispersion polymer is in such a range, the storage stability of the pigment particles formed into a coating is improved, and the water resistance of the recorded image is good.

  When the dispersion polymer described above is used, a clear recorded image with high color development can be obtained on paper such as plain paper and recycled paper by using the ink composition using the dispersion, and this and the coating liquid described above are used. By using in combination, it is possible to form an image excellent in glossiness and fixability in an image on a glossy medium.

(Surface treatment pigment)
Next, the surface-treated pigment will be described in detail.
As another example of the coloring component, the ink composition in the present invention is surface-treated so that at least one of the functional group represented by the following formula or a salt thereof is bonded directly or indirectly to the surface of the pigment described above. A surface-treated pigment that can be dispersed in water without a dispersant is included as a coloring component.

  In the surface-treated pigment, the functional group or salt thereof bonded to one pigment particle may be one type or two or more types. The type and degree of the functional group bonded or the salt thereof may be appropriately determined in consideration of the dispersion stability in the ink composition, the color density, the drying property on the front surface of the inkjet head, and the like. Further, in the surface-treated pigment contained in the ink composition of the present invention, the functional group or a salt thereof may be present at least on the particle surface, and may be contained inside the particle.

  Various known surface treatment means can be applied as the surface treatment means for bonding the functional group or a salt thereof directly or indirectly to the surface of the pigment particles. For example, means for treating a commercially available oxidized carbon black with ozone or a sodium hypochlorite solution to further oxidize the carbon black to make the surface more hydrophilic (for example, JP-A-7-258578, JP-A-H10-238707). 8-3498, JP-A-10-120958, JP-A-10-195331, JP-A-10-237349), means for treating carbon black with 3-amino-N-alkyl-substituted pyridium bromide ( For example, JP-A-10-195360 and JP-A-10-330665), an organic pigment is dispersed in a solvent in which the organic pigment is insoluble or hardly soluble, and a sulfone group is introduced onto the pigment particle surface by a sulfonating agent. Means (for example, JP-A-8-283596, JP-A-10-110110, JP-A-10-110 No. 11), means for dispersing a organic pigment in a basic solvent that forms a complex with sulfur trioxide, treating the surface of the organic pigment by adding sulfur trioxide, and introducing a sulfone group or a sulfonamino group (For example, JP-A-10-110114), a method of introducing a water-solubilizing functional group and a polymer onto a pigment surface through a phenylene group bonded to carbon black by an azo coupling reaction (for example, JP-A-2000-2000). No. -53902) and the like, but the preparation means for the surface-treated pigment used in the ink composition of the present invention is not limited to these means.

  The surface-treated pigment used in the ink composition of the present invention can introduce (chemically bond) a polymer substance directly or indirectly to the surface of the pigment particles. Introduction of the polymer substance to the pigment surface is realized by an acylation reaction or an ester group nucleophilic substitution reaction. Specific examples of such a high-molecular substance include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and their homologs (polyethylene glycol having 1 to 10 carbon atoms in the alkyl group, polypropylene glycol, and polytetramethylene glycol). Monoalkyl ethers or monoaryl ethers, amines of methoxypolyethylene glycol, polyvinyl alcohol, copolymers of polyvinyl alcohol and polyvinyl acetate, and the like. These polymer materials desirably have at least one amino group or hydroxyl group at the terminal.

  In the surface-treated pigment described above, a basic compound can be used so that at least the functional group present on the particle surface is in the form of a salt. As the basic compound, those suitable for the resin emulsion contained in the above-described coating liquid of the present invention can be used as they are.

  When the surface-treated pigment described above is used in the ink composition according to the present invention and an image is formed on paper such as plain paper or recycled paper, the penetration of pigment particles into the paper is suppressed. There is an effect that pigment particles can be present on the surface, and as a result, the color developability is improved and a high quality and clear recorded image can be obtained. The reason is not clear, but it is presumed as follows. The surface-treated pigment in the present invention has at least one functional group represented by the above formula or a salt thereof bonded to each other in the ink composition, and the electrostatic repulsive force is generated between the pigment particles by ion dissociation. Because it works, it is stably dispersed. When the ink composition adheres to the recording medium, ionic substances in the recording medium, for example, alkaline earth metal ions such as magnesium and calcium, are dissolved in the ink composition, whereby the functional group and the ionic substance Are combined by a salting-out reaction and the pigment particles are aggregated, whereby separation from the liquid component in the ink composition occurs. As a result, the pigment aggregate first settles and adsorbs on the surface of the recording medium, and then the liquid component penetrates and diffuses into the surface and inside of the recording medium. As a result of the presence of the pigment aggregate on the surface of the recording medium in this way, it is considered that a clear image with high color developability can be obtained.

  The particle diameter of the dispersion / surface-treated pigment used as a coloring component suitable for the ink composition in the present invention is preferably 500 nm or less, more preferably 300 nm or less, in terms of dispersion stability. The average particle size is preferably in the range of 10 nm to 150 nm.

  In addition, the ink composition according to the present invention preferably contains a humectant essential for the coating liquid described above. In that case, similarly to the case where it is included in the coating liquid according to the present invention, it is possible to suppress drying due to water evaporation of the ink composition, and to suppress the alteration of the composition of the ink composition due to long-term standing, This is preferable because drying and solidification on the nozzle surface of the printer head can be suppressed.

<Other additives to coating liquid and ink composition>
The coating liquid according to the present invention contains a resin emulsion containing the above-described resin solvent, a humectant, and water as essential components, and the ink composition includes the above-described coloring component (dispersion containing a pigment in a dispersion polymer). Body or surface-treated pigment) and water as essential components. By forming an image using the coating liquid and ink composition having such a configuration, even if recording is performed on glossy media using an ink composition containing a pigment, a clear and excellent fixability and glossiness are obtained. An image can be obtained and is excellent in reliability (ejection stability, clogging characteristics) when the coating liquid is applied to an ink jet recording system. -Various characteristics of each ink composition can be further improved. Hereinafter, the components will be described.

[Penetration agent]
The coating liquid and ink composition according to the present invention preferably further contain a penetrant. By containing a penetrating agent, the coating liquid has improved penetrability on the image recorded by the ink composition, and the resin emulsion softened / dissolved by the resin solvent is effectively, efficiently, and uniformly between the colorant and The surface can be covered. For this reason, it is possible to provide the characteristics of further improving the fixability and glossiness of the image on the glossy medium. Further, the ink composition can increase the permeability to the recording medium, and thus has an effect of improving the drying speed of the recorded image. Furthermore, the irregular flow of ink in the recorded image and the phenomenon of spreading larger than the adhering ink droplets (hereinafter referred to as “bleeding”), irregular image density unevenness (hereinafter referred to as “light / dark unevenness”). As a result, a high quality and clear recorded image can be obtained.

As an example of a penetrant having such an effect, it is preferable to select a glycol monoether derivative of a polyhydric alcohol or 1,2-alkyldiols.
As the glycol monoether derivative of a polyhydric alcohol, a derivative of a polyhydric alcohol in which the alkyl group has 3 or more carbon atoms is particularly preferable. Specifically, ethylene glycol monobutyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-tert-butyl ether Diethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether, diethylene glycol mono-tert-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol mono-tert-butyl ether, propylene glycol mono-n-propyl ether, Propylene glycol mono-iso-propyl ether, propylene glycol mono-n-butyl ether Ether, dipropylene glycol mono -n- butyl ether, dipropylene glycol mono -n- propyl ether, dipropylene glycol monomethyl -iso- propyl ether. The addition amount of the glycol monoether derivative of the polyhydric alcohol is preferably within a range of 15% by weight or less based on the total amount of the coating liquid or the total amount of the ink composition.
As the 1,2-alkyldiols, 1,2-alkyldiols having 4 to 8 carbon atoms such as butanediol, pentanediol, hexanediol, heptanediol, and octanediol are preferable. Among these, 1,2-hexanediol, 1,2-heptanediol, and 1,2-octanediol having 6 to 8 carbon atoms are particularly preferable because of the strong effect of improving permeability described above. These 1,2-alkyldiols are preferably added in an amount of 5% by weight or less based on the total amount of the coating liquid or the total amount of the ink composition.

  Other examples of penetrants include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, 2,2-dimethyl-1-propanol, n-butanol, 2-butanol, tert-butanol, and iso-butanol. Water-soluble ones such as 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-2-butanol, n-pentanol, 2-pentanol, 3-pentanol, tert-pentanol, etc. And monohydric alcohols. The addition amount of these monohydric alcohols is preferably in the range of 10% by weight or less based on the total amount of the coating liquid or the total amount of the ink composition.

  Furthermore, another example of the penetrating agent is an acetylene glycol surfactant or an acetylene alcohol surfactant. Acetylene glycol surfactants and acetylene alcohol surfactants have less foaming properties and superior antifoaming properties compared to other surfactants. Therefore, it is possible to efficiently record a coating or an image without causing defects such as missing dots due to the coating liquid or bubbles of the ink composition. Specific examples of the acetylene glycol surfactant or acetylene alcohol surfactant preferable in the present invention include Surfynol 104, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 104S, 420, 440, 465. , 485, SE, SE-F, 504, 61, DF37, CT111, CT121, CT131, CT136, TG, GA (all are trade names, manufactured by Air Products and Chemicals), Olfin B, Y, P, A, STG SPC, E1004, E1010, PD-001, PD-002W, PD-003, PD-004, EXP. 4001, EXP. 4036, EXP. 4051, AF-103, AF-104, AK-02, SK-14, AE-3 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.), acetylenol E00, E00P, E40, E100 (all trade names, Kawaken Fine Chemical Co., Ltd.). The addition amount of these acetylene glycol surfactants and acetylene alcohol surfactants may be appropriately determined, but is preferably 10% by weight or less based on the total amount of the coating liquid or the total amount of the ink composition.

Another example of the penetrant includes a glycerin ether compound represented by the following formula.

Any glycerin ether compound may be used as long as it has the structure of the above formula, among which 3-methoxy-1,2-propanediol, 3-ethoxy-1,2-propane, among others. Diol, 3-allyloxy-1,2-propanediol, 3- (octadecyloxy) -1,2-propanediol, monoolein, 1,2-dihydroxy-3- (2-methoxyphenoxy) propane, 3-phenoxy It is preferably selected from the group consisting of -1,2-propanediol. The addition amount of these glycerin ether compounds may be appropriately determined so that a desired effect can be exhibited, but is preferably 10% by weight or less based on the total amount of the coating liquid or the total amount of the ink composition according to the present invention.

These penetrants may be used alone or in a mixture of two or more. In particular, when a plurality of penetrants having different structures are used in combination, the same penetrability and color developability can be obtained for various recording medium types exhibiting different penetrance and color developability. It is preferable from the viewpoint.

[Antiseptic / antifungal agent]
The coating liquid and ink composition of the present invention preferably further contain an antiseptic / antifungal agent. If bacteria, wrinkles, etc. occur in the coating liquid or ink composition, they become foreign matters and clog the head nozzles and ink flow paths in the ink jet printer, adversely affecting the ejection of the coating liquid and ink composition. However, by including these antiseptic / antifungal agents, it is possible to more effectively suppress the generation of bacteria, wrinkles and the like even when left for a long period of time.

The antiseptic / antifungal agent used in the present invention is preferably selected from the group consisting of isothiazolone compounds and oxazolidine compounds. Specifically, Proxel XL2, Proxel GXL (trade name, manufactured by Avisia), Denside CSA, NS-500W (trade name, manufactured by Nagase ChemteX Corporation) and the like can be mentioned. The antiseptic / antifungal agent may be used alone or in combination of two or more.

The antiseptic / antifungal agent may be contained in an amount of 2% by weight or less based on the total amount of the coating liquid or the total amount of the ink composition in the present invention. More preferably, it is in the range of 5% by weight.

<Physical properties of coating liquid and ink composition>
The coating liquid and ink composition in the present invention preferably have a pH in the range of 6 to 11 at 25 ° C. More preferably, the pH is in the range of 7-10. When the pH is less than 6, the coating solution in the coating liquid deteriorates in coating properties, that is, the resin emulsion is softened, and the effective and effective coating property of the dissolved material is deteriorated.・ There may be inferior fixing effect. In addition, the ink composition may lack the dispersion stability of the dispersion or the surface-treated pigment, and may have adverse effects such as thickening, granulation, and generation of sediment. On the other hand, when the pH is higher than 11, both the coating liquid and the ink composition have high reactivity with respect to the ink flow path member inside the printer, which may cause deterioration of the member, generation of foreign matters, unstable ejection, and the like. In order to adjust the pH of the coating liquid and the ink composition to the above range, a water-soluble basic compound can be used as necessary.
Specific examples of the basic compound include, in addition to the basic compounds suitable for the resin emulsion described above, carbonates such as potassium hydrogen carbonate (hydrogen), sodium hydrogen carbonate, lithium hydrogen carbonate, and other phosphates. Inorganic alkalis are mentioned, and they can be used.
In addition, salts of alkyl carboxylic acids such as acetate and propionate, organic acids such as hydroxy acid salts such as lactate, glycolate and glycerate, especially alkali metal salts of alkyl carboxylic acids, sodium acetate , Potassium acetate, sodium propionate, potassium propionate and the like. Moreover, organic buffer agents, such as a tris (hydroxymethyl) aminomethane, a tris-hydrochloride, a tris-maleic acid, bis (2-hydroxyethyl) imino tris (hydroxymethyl) methane, are mentioned.

The coating liquid and ink composition of the present invention preferably have a surface tension at 25 ° C. of 40 mN / m or less. More preferably, it is 35 mN / m or less. When the surface tension is within the above range, the wettability with respect to the surface of an ink flow path member generally used in an ink jet printer is improved, and the discharge is easily stabilized. In order to adjust the surface tension within the above range, the above-described penetrant and other surfactants can be used as necessary.

As the surfactant, in addition to the acetylene glycol-based and acetylenic alcohol-based surfactants listed as suitable for the above-mentioned penetrants, general anionic surfactants, cationic surfactants, amphoteric surfactants Can be selected from nonionic surfactants and nonionic surfactants, but nonionic surfactants or anionic surfactants are preferred.
Nonionic surfactants include sorbitan fatty acid ester, glycerin fatty acid ester, decagrin fatty acid ester, polyglycerin fatty acid ester, propylene glycol / pentaerythritol fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene sorbit fatty acid ester, polyoxyethylene glycerin. Fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene / polyoxypropylene / block polymer, polyoxyethylene alkylphenyl ether, polyoxyethylene castor oil / cured castor oil , Polyoxyethylene lanolin / lanolin alcohol, polyoxyethylene alcohol Triethanolamine, fatty acid amides, polyoxyethylene alkylphenyl formaldehyde condensates, fluorine-based surfactants such as polyoxyethylene perfluoroalkyl, and the like.
Anionic surfactants include alkyl sulfates, polyoxyethylene alkyl sulfates, N-acyl amino acids and their salts, N-acyl methyl taurates, dialkyl sulfosuccinates, disodium sulfosuccinate monoesters, N-alkyl sulfosuccinates. Examples include acid monoamides, polyoxyethylene alkyl ether acetates, alkyl sulfocarboxylates, α-olefin sulfonates, alkyl phosphates, and polyoxyethylene alkyl ether phosphates.

  In addition, the viscosity of the coating liquid and ink composition in the present invention is preferably 25 cPs or less at 25 ° C. from the viewpoint of ensuring ejection stability in the ink jet recording apparatus. More preferably, it is 15 cPs or less.

<Method for producing resin emulsion containing resin solvent>
In the coating liquid of the present invention, a resin emulsion containing a resin solvent that is insoluble or hardly soluble in water is essential. Examples of the production method thereof include the following methods.

As an example of the manufacturing method, there is a method in which a resin constituting a resin emulsion and a resin solvent are mixed to form a resin emulsion.
Specifically, the resin constituting the resin emulsion is first dissolved in a water-soluble organic solvent (for example, monohydric alcohols such as ethanol and isopropanol, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran). Dissolve in. The resin solvent which is insoluble or hardly soluble in the water of this invention is added there, and a resin-resin solvent mixed liquid is manufactured. At that time, a combination of a resin type and a resin solvent type that are mixed well is important. Therefore, not only a combination of single species but also a combination of a plurality of resin species and / or a plurality of resin solvent species may be used as necessary. Further, considering the miscibility of the resin and the resin solvent, a plurality of water-soluble organic solvents may be used in combination.
Next, this resin-resin solvent mixed solution is mixed with water to produce an oil-in-water emulsion. The water to be used is water suitably used for the above-described coating liquid and ink composition of the present invention (preferably pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water). Etc.) can be used as they are. Further, a necessary amount of a basic compound for neutralizing unneutralized groups present in the resin can be added as necessary. This basic compound may be added to the resin-resin solvent mixed solution or may be added to water. When added to the resin-resin solvent mixed solution, it is preferable to select one that is mixed and compatible with the water-soluble organic solvent used therein. When mixing the resin-resin solvent mixture and water, (A) when adding the resin-resin solvent mixture in water, (B) adding water to the resin-resin solvent mixture In the case where (C) the resin-resin solvent mixture and water are poured into another container at the same time and mixed together, any of the above methods can be suitably mixed, but particularly in the above (A), while stirring the water It is preferable to use a method in which a resin-resin solvent mixed solution is gradually added dropwise because an emulsion can be efficiently generated.
The emulsion mixture obtained in this way is adjusted to the desired emulsion particle size with a sand mill, jet mill, attritor, homogenizer, etc., if necessary, and then subjected to reduced pressure and heating using ultrafiltration and / or an evaporator, etc. The dispersion of the resin emulsion used for the coating liquid of the present invention can be obtained by removing the total amount of the water-soluble organic solvent.

As another example of the production method, a method of using a resin emulsion dispersion produced in advance or commercially available and encapsulating a resin solvent that is insoluble or hardly soluble in water can be given.
First, a resin solvent is mixed with the resin emulsion dispersion. As a mixing method, (D) when adding a resin solvent in a resin emulsion dispersion, (E) when adding a resin emulsion dispersion in a resin solvent, (F) combining a resin emulsion dispersion and a resin solvent. In the case of simultaneously pouring into another container and mixing, any of the above methods can be suitably mixed, but in the above (D), the resin solvent is gradually added dropwise while stirring the resin emulsion dispersion, This is preferable because the resin solvent can be efficiently contained inside the resin emulsion. At this time, in the case where the combination of the resin constituting the resin emulsion and the resin solvent has a high affinity for both, the resin is mixed inside the resin emulsion particles by stirring with a stirrer or the like and thoroughly mixing by the above method. Although the solvent is well encapsulated, the following method is preferred for more efficient and effective encapsulation.
As an example of a preferable encapsulation method, the resin emulsion-resin solvent mixed solution mixed by any of the methods (D) to (F) is preferably sealed in a container that can be sealed so that the water in the mixed solution does not evaporate. And a method of performing heat treatment. The conditions at this time can be appropriately changed depending on the combination of the resin emulsion and the resin solvent to be used, but it is preferable to heat to a temperature higher than the glass transition temperature of the resin constituting the resin emulsion (hereinafter sometimes referred to as Tg). In such a case, the resin solvent is easily and efficiently taken into the resin emulsion.
Another example of a preferable encapsulation method is a method of adding an auxiliary agent having an affinity for the resin emulsion and the resin solvent when the resin emulsion and the resin solvent are mixed by any of the methods (D) to (F). Is mentioned. As the auxiliary agent, the above-described penetrant and surfactant can be used. Specifically, a small amount of an auxiliary agent is added in advance to the resin emulsion dispersion and / or the resin solvent, and then the resin emulsion dispersion and the resin solvent are mixed. In such a case, the resin solvent is easily and efficiently taken into the resin emulsion. Furthermore, the combination of the heating methods mentioned above is more preferable because it can be processed more efficiently and effectively.

  By using a resin emulsion containing a resin solvent that is insoluble or hardly soluble in water, manufactured by the method described above, it is excellent in storage stability and is an optimal coating solution for imparting glossiness and fixing properties to images. It can be. Further, when these resin emulsions are applied to the coating liquid of the present invention, not only one type but also two or more types may be mixed and used in consideration of the effect of imparting glossiness and fixing property.

<Method for producing dispersion>
Here, the manufacturing method of the dispersion used for the ink composition in the present invention will be described. The dispersion used in the ink composition of the present invention is prepared by dissolving or dispersing a dispersion polymer containing an anionic group in an alkaline water containing an alkaline compound such as an organic amine or an alkali metal salt compound. And are dispersed using a dispersing machine such as a ball mill, a sand mill, an attritor, a roll mill, an agitator mill, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a jet mill, or an ang mill. More preferably, in order to adhere the colorant and the dispersion polymer more firmly and stabilize the dispersion, JP-A-9-151342, JP-A-10-140065, JP-A-11-209672, JP-A-11 -172180, JP-A-10-25440, JP-A-11-43636, or JP-A-2001-247810. The manufacturing methods disclosed in these publications are outlined below.

  Japanese Patent Laid-Open Nos. 2001-247810, 9-151342, and 10-140065 disclose a “phase inversion method” and an “acid precipitation method”.

(A) "Phase inversion method"
In the present invention, the “phase inversion method” basically refers to a self-dispersing (phase inversion emulsification) method in which a mixed melt of a polymer having a self-dispersing ability or a dissolving ability and a colorant is dispersed in water. Say. Here, the mixed melt means a mixed state without dissolving, a mixed state with dissolved, or a state including both of these states.
As one specific example, (1) a solvent-based slurry is prepared by adding a pigment, a neutralizing agent, and a small amount of water to a dispersion polymer precursor (a polymer containing an anionic group as described above) / solvent solution. Step (2) Dispersing the slurry while adding it to a large amount of water to produce a water-based slurry, (3) Removing the solvent used to dissolve the polymer from the water-based slurry and dispersing the water A step of preparing a pigment-containing polymer particle dispersion including a pigment with a functional polymer.

(B) "Acid deposition"
In the present invention, the “acid precipitation method” refers to preparing a water-containing cake composed of a dispersion polymer and a colorant, and neutralizing a part of unneutralized groups contained in the dispersion polymer in the water-containing cake. The method of manufacturing a dispersion by neutralizing with.
When the unneutralized group is an anionic acid group and the neutralizing agent is a basic compound, specifically, for example, (1) a dispersion polymer and a pigment are dispersed in an alkaline aqueous medium, A step of heat-treating the polymer as necessary to gel the polymer, (2) hydrophobizing the dispersion polymer by making the pH neutral or acidic, and strongly fixing the dispersion polymer to the pigment; (3) If necessary, filtering and washing with water to obtain a water-containing cake; and (4) part or all of the anionic group contained in the dispersion polymer in the water-containing cake. And a step of re-dispersing in an aqueous medium, and (5) a step of subjecting the dispersion polymer to gelation by heat treatment as necessary.
More specific production methods of the above “phase inversion method” and “acid precipitation method” are the same as those disclosed in JP-A-9-151342 and JP-A-10-140065. Good.

Furthermore, JP-A-11-209672 and JP-A-11-172180 disclose a method for producing a dispersion. The outline of this production method basically comprises the following production steps.
(1) A polymer having an anionic group or a solution obtained by dissolving it in an organic solvent and a neutral compound are mixed and neutralized. (2) A pigment is mixed into this mixed solution to form a suspension. Later, the pigment is dispersed with a disperser or the like to obtain a pigment dispersion, (3) if necessary, the solvent is distilled off, and (4) a dispersion having an anionic group by adding an acidic compound. Coating the pigment with a dispersion polymer having an anionic group by precipitating the polymer; (5) filtering and washing with water if necessary; and (6) adding a basic compound to add the anionic group. Neutralizing an anionic group of a dispersion polymer having a dispersion in an aqueous medium to obtain an aqueous dispersion.
More specific manufacturing methods of the dispersion shown above may be the same as those disclosed in JP-A-11-209672 and JP-A-11-172180.

<Method for producing surface-treated pigment>
Next, the manufacturing method of the surface treatment pigment used for the ink composition in this invention is demonstrated.
As a method for producing a surface-treated pigment, first, a step of surface-treating the pigment is performed. In this step, the surface treatment of the pigment is performed by mixing the pigment and the surface treatment agent in an aqueous or non-aqueous solvent, or by heating the mixture (introduction of the above-described functional group or salt thereof). To implement. After the surface treatment, the obtained reaction product is repeatedly washed with water, ultrafiltration, reverse osmosis, centrifugation and / or filtration to remove residual unreacted substances, reaction by-products, residual treatment agents, etc. Thus, a surface-treated pigment can be obtained.
In addition, it is desirable that the pigment used in the surface treatment step is pulverized and atomized in advance before introducing the above-described functional group or a salt thereof. As a means for pulverizing the pigment, pulverization media such as zirconia beads, glass beads, and inorganic salts can be used, and wet pulverization or dry pulverization can be used. Examples of the pulverizer include an attritor, a ball mill, and a vibration mill. After the pulverization treatment, it is desirable to remove contaminant components generated from the pulverization media and the pulverizer by washing the pigment, ultrafiltration and the like.
In particular, a pulverization treatment method (salt milling method) combining dry pulverization and an inorganic salt can be easily removed by washing with water because the contaminant component generated from the pulverization medium is a water-soluble inorganic salt.

Here, as an example of a method for producing a surface-treated pigment used in the ink composition of the present invention, an example of a method for producing a surface-treated pigment having a sulfonic acid group or a sulfinic acid group on the surface will be described below in more detail. To do.
First, in the step of surface-treating the pigment, a fine particulate or powdery pigment is placed in an aprotic solvent (for example, N-methyl-2-pyrrolidone or sulfolane) 3 to 200 times the amount of the pigment, The pigment is sized with a sulfonating agent. As the sulfonating agent, for example, sulfonated pyridine salt, sulfamic acid, amidosulfuric acid, fluorosulfuric acid, chlorosulfuric acid, sulfur trioxide, fuming sulfuric acid or sulfuric acid can be used alone or in combination of two or more. . The treatment with the sulfonating agent can be performed under heating (about 60 ° C. to 200 ° C.) and under stirring, and the heating can be performed before or after the addition of the sulfonating agent.
After the sulfonation treatment, the aprotic solvent and the remaining sulfonating agent are removed from the obtained pigment slurry. The removal treatment can be carried out repeatedly by washing with water, ultrafiltration, reverse osmosis, centrifugation, and / or filtration. Moreover, the contaminant component mixed in the above-mentioned sizing and dispersing treatment and sulfonation treatment is also removed together with the aprotic solvent and the sulfonating agent.

The amount of the functional group introduced into the surface-treated pigment used in the ink composition of the present invention is preferably 10 × 10 ⁻⁶ equivalents or more, more preferably 15 × 10 ⁻⁶ equivalents or more per 1 g of pigment particles. If the amount of functional group introduced is less than 5 × 10 ⁻⁶ equivalents per gram of pigment particles, aggregation of dispersed pigment particles and the like occur, and the viscosity or dispersion of the pigment dispersion / ink composition is increased. In some cases, the storage stability of the pigment dispersion or the ink composition may be reduced, such as an increase in the particle size of the pigment particles. For example, when the functional group is a sulfonic acid group or a sulfinic acid group, the pigment aqueous dispersion is treated by an oxygen flask combustion method and absorbed in an aqueous hydrogen peroxide solution. It can be measured by quantifying sulfate ions (divalent) by ion chromatography and converting them to sulfonic acid groups and sulfinic acid groups.

  The zeta potential of the surface-treated pigment particles used in the ink composition of the present invention is a dilution obtained by diluting the surface-treated pigment particles with ion-exchanged water so that the pigment concentration is 0.001 wt% to 0.01 wt%. The absolute value at 20 ° C. and pH 8 to pH 9 when measured as a liquid is preferably 30 mV or more. More preferably, it is 40 mV or more, and an even more preferable absolute value of the zeta potential is 50 mV or more. When the absolute value of the zeta potential of the pigment particles is 20 mV or less, the storage stability of the pigment dispersion or the ink composition is lowered as in the case where the amount of the dispersibility-imparting group introduced is insufficient.

[Method for producing dispersion of surface-treated pigment]
In the ink composition of the present invention, the surface-treated pigment can be used as it is in the ink composition, but it is preferable to use it in the form of a pigment dispersion described below because it is easy to handle.

In the production of the pigment dispersion, first, the surface treatment pigment obtained in the above-described pigment surface treatment step, or the slurry of the surface treatment pigment, the wet cake, etc., has a pigment concentration of about 5 wt% to 50 wt%. Thus, it adds with a neutralizing agent etc. in an aqueous medium (especially ion-exchange water or distilled water) as needed. Subsequently, a surface-treated pigment dispersion can be obtained by dispersing the pigment particles in an aqueous medium by applying an appropriate shearing force using a stirrer or a dispersing device.
In the dispersion step, it is preferable to add a small amount of the above-mentioned penetrating agent or surfactant to disperse. The reason for this is that these penetrants and surfactants have the effect that the pigment particles are easily adapted (wet easily) to the aqueous medium, and the contact resistance between the pigment particles in the aqueous medium and between the pigment and the dispersion medium is reduced. This is because it is effective to increase the dispersion efficiency. As a result, the shearing conditions of the apparatus in the dispersion treatment step can be relaxed (the shear force applied from the apparatus to the pigment dispersion can be reduced), and the time required for the dispersion treatment can be shortened. In such a case, the contamination component (particularly polyvalent metal ions such as Si, Ca, Mg, Fe, Cr, Ni, etc.) due to the dispersion media and the dispersion device is reduced. There is an effect that the dispersion stability and storage stability of the used ink composition are improved. These penetrants and surfactants only need to be mixed with at least the pigment in the dispersion step, and the timing of addition to the pigment may be before the dispersion step or during the dispersion step.
Examples of the apparatus that can be used in the dispersion treatment include a stirrer, paint shaker, ball mill, sand mill, roll mill, speed line mill, homomixer, ultrasonic homogenizer, nanomizer, and microfluidizer.
The neutralizing agent is added in order to dissociate the salt-forming group of the functional group on the surface of the surface-treated pigment, and the above-described water-soluble basic compound can be suitably used.
The pigment surface treatment step and the surface treatment pigment dispersion step described above can be carried out continuously. In particular, when the surface treatment of the pigment is carried out with an aqueous solvent, the reaction solvent in the surface treatment step and the dispersion medium in the dispersion step can be made the same aqueous system, so that it is easy to assemble continuous steps. However, the removal of residual unreacted substances, reaction by-products and the like in the surface treatment step is easier to obtain a pigment dispersion having better final dispersion stability if carried out before the dispersion step. On the other hand, when the solvent in the surface treatment step is a non-aqueous solvent, it may be easier to separate and remove residual unreacted substances from the target surface-treated pigment.

<Example>
The image forming method of the present invention will be described in detail below, but the present invention is not limited to these examples. Prior to this, a coating liquid and an ink composition to be used, and a resin emulsion and a dispersion of a coloring component (dispersion, surface treatment pigment) used in these were prepared by the materials and methods described below.

[Production of resin emulsion]
(1) Resin emulsion 1
A reaction vessel equipped with a stirrer, thermometer, reflux condenser and dropping funnel was replaced with nitrogen gas, and then styrene as a monomer into the reaction vessel; 25 parts by weight, n-dodecyl methacrylate; 30 parts by weight, methoxypolyethylene glycol methacrylate; 20 parts by weight, butyl methacrylate; 15.5 parts by weight, methacrylic acid; 9.3 parts by weight, and methyl ethyl ketone; 100 parts by weight as a water-soluble organic solvent were added and mixed well to prepare a solution.
Separately prepare a similar monomer / methyl ethyl ketone solution in the dropping funnel, and further add 2,2′-azobis (2,4-isomethylvaleronitrile); 0.2 parts by weight to perform nitrogen gas replacement. It was.
Under a nitrogen atmosphere, the polymerization reaction was carried out while adding and dropping the solution in the dropping funnel over 3 hours while heating and holding the reaction vessel at 65 ° C. After completion of the reaction, it was naturally cooled to room temperature. Thereafter, the obtained copolymer solution was purified by repeated filtration, drying under reduced pressure, and dissolution with methyl ethyl ketone to synthesize Resin A having an acid value of 70 KOH mg / g and a weight average molecular weight of 50,000. Using this resin A, the resin A was dissolved in methyl ethyl ketone so that the solid content of the resin A was 50% by weight to obtain a resin A solution. A resin A-resin solvent mixture was prepared by stirring and mixing 10 parts by weight of 2-reseptanol, which is a resin solvent, with 100 parts by weight of this resin A solution.
Ion exchange water prepared in a separate container; 400 parts by weight of potassium hydroxide as a basic compound; 2 parts by weight are added and stirred well to prepare an aqueous solution, and the above resin A-resin is stirred while stirring the aqueous solution. The solvent mixture was mixed dropwise over 1 hour. The obtained dispersion mixture was dispersed with an ultrahigh pressure homogenizer for 3 hours.
Subsequently, this dispersion mixture was transferred into an evaporator, and all of methyl ethyl ketone and a part of water were removed under conditions of reduced pressure and 60 ° C. Thereafter, the resin solid content concentration was adjusted to 40% by weight to obtain a resin emulsion 1 containing a resin solvent. The average particle size of the obtained resin emulsion was 120 nm.

(2) Production of Resin Emulsion 2 Using the resin A solution prepared in (1) Resin Emulsion 1, 100 parts by weight of this is triethanolamine as a basic compound; 55 parts by weight of propylene as a resin solvent. Oxide; 5 parts by weight was added and mixed well with stirring to prepare a resin A-resin solvent mixed solution.
Ion exchange water prepared in a separate container; while stirring 400 parts by weight, the above resin A-resin solvent mixture was added dropwise over 2 hours. The obtained dispersion mixture was dispersed with an attritor for 2 hours.
Subsequently, this dispersion mixture was transferred into an evaporator, and all of methyl ethyl ketone and a part of water were removed under conditions of reduced pressure and 60 ° C. Thereafter, the resin solid content concentration was adjusted to 40% by weight to obtain a resin emulsion 2 containing a resin solvent. The average particle size of the obtained resin emulsion was 150 nm.

(3) Production of Resin Emulsion 3 Commercially available resin emulsion Jonkrill 538 (trade name, manufactured by BASF Japan, resin solid content: 45 wt%, Tg: 66 ° C.); 1,000 parts by weight of resin solvent 4-heptanone, 4.5 parts by weight, was added and mixed well with stirring. And this resin emulsion-resin solvent mixture was put in another container, sealed, and heat-treated in a 70 ° C. environment for 2 days. Thereafter, the mixture was cooled to room temperature and adjusted so that the resin solid content concentration was 40% by weight to obtain a resin emulsion 3 containing a resin solvent. The average particle size of the obtained resin emulsion was 110 nm.

(4) Production of Resin Emulsion 4 Commercially available resin emulsion Jonkrill 538 (trade name, manufactured by BASF Japan Ltd., resin solid content: 45 wt%, Tg: 66 ° C.); 100 parts by weight is a resin solvent 2-butoxyethyl acetate; 13.5 parts by weight, triethylene glycol monobutyl ether as an auxiliary agent; 2 parts by weight were added and well mixed with stirring. And this resin emulsion-resin solvent mixture was put in another container, sealed, and heat-treated in a 70 ° C. environment for 1 day. Thereafter, the mixture was cooled to room temperature and adjusted so that the resin solid content concentration was 40% by weight to obtain a resin emulsion 4 containing a resin solvent. The average particle diameter of the obtained resin emulsion was 160 nm.

(5) Production of resin emulsion 5 In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel, ion exchange water; 900 parts by weight and sodium lauryl sulfate; Was replaced with nitrogen. Further, while maintaining the internal temperature of the container at 70 ° C., 2 parts by weight of potassium persulfate as a polymerization initiator was added and dissolved. Next, ion exchange water; 450 parts by weight, sodium lauryl sulfate; 3 parts by weight, styrene; 435 parts by weight, butyl acrylate; 475 parts by weight, and 2-acryloylamino-2-methylpropanesulfonic acid; 30 parts by weight, diethylene glycol An emulsion prepared by stirring and mixing 4 parts by weight of dimethacrylate was placed in a dropping funnel and dropped into the reaction vessel at a constant rate over 4 hours. After completion of dropping, aging was performed for 3 hours while maintaining the temperature at 70 ° C. After cooling the resulting mixture to room temperature, ion-exchanged water and sodium hydroxide were added so that the resin solid content was 50% by weight and pH 8, and filtered through a membrane filter having a pore size of 1 μm. Tg: 20 ° C. A resin emulsion was obtained.
To 100 parts by weight of this resin emulsion, 1 part by weight of 2-nitropropane as a resin solvent and 1.5 parts by weight of diethyl sulfide were added, and the mixture was stirred and mixed in an environment at 25 ° C. for 4 hours. Thereafter, the resin solid content concentration was adjusted to 40% by weight to obtain a resin emulsion 5 containing a resin solvent. The particle diameter of the obtained resin emulsion was 200 nm.

(6) Production of Resin Emulsion 6 Jonkrill 538 (trade name, manufactured by BASF Japan Ltd., resin solid content: 45 wt%, Tg: 66 ° C.); 1,000 parts by weight of resin solvent 2-butoxyethyl acetate; 3.5 parts by weight were added and mixed well with stirring. And this resin emulsion-resin solvent mixture was put in another container, sealed, and heat-treated in a 70 ° C. environment for 1 day. Thereafter, the mixture was cooled to room temperature and adjusted so that the resin solid content concentration was 40% by weight to obtain a resin emulsion 6 containing a resin solvent. The average particle size of the obtained resin emulsion was 100 nm.

(7) Production of Resin Emulsion Dispersion 7 Jonkrill 538 (trade name, manufactured by BASF Japan Ltd., resin solid content: 45 wt%, Tg: 66 ° C.) which is a commercially available resin emulsion; 4-heptanone, 15 parts by weight, triethylene glycol monobutyl ether as an auxiliary agent; 2 parts by weight were added and well stirred and mixed. And this resin emulsion-resin solvent mixture was put in another container, sealed, and heat-treated in a 70 ° C. environment for 1 day. Thereafter, the mixture was cooled to room temperature and adjusted so that the resin solid content concentration was 40% by weight to obtain a resin emulsion 7 containing a resin solvent. The average particle diameter of the obtained resin emulsion was 300 nm.

(8) Production of Resin Emulsion Dispersion 8 Jonkrill 538 (trade name, manufactured by BASF Japan, resin solid content: 45% by weight, Tg: 66 ° C.), which is a commercially available resin emulsion; N, N-dimethylformamide (13.5 parts by weight) was added, and the mixture was stirred and mixed at room temperature for 3 hours. And it adjusted so that resin solid content concentration might be 40 weight%, and the resin emulsion 8 was obtained. The obtained resin emulsion had an average particle size of 550 nm, and an adhesive was floating on the surface of the dispersion.

<Preparation of coating solution>
Coating solutions were prepared with the compositions shown in Tables 1 and 2. Each coating solution was used for each of the following evaluations after sufficiently stirring and mixing the respective materials and performing pressure filtration at a pressure of ² kg / cm ² using a membrane filter having a pore size of 1 μm.

<Preparation of ink composition>
Hereinafter, the preparation of the ink composition in the invention will be described. First, preparation examples of Dispersion 1 to Dispersion 4 containing the dispersion will be described.

(1) Dispersion 1
MA100 which is carbon black as a pigment (trade name, manufactured by Mitsubishi Chemical Co., Ltd.); 75 g, Jonkrill 611 of a styrene-acrylic acid polymer having a carboxylic acid group as an anionic group as a dispersion polymer (trade name, BASF Japan Ltd.) Manufactured, weight average molecular weight 8,100, acid value 53 KOH mg / g); 25 g, potassium hydroxide as a basic compound; 0.75 g, ultrapure water purified by ion exchange method and reverse osmosis method; Dispersion was performed for 10 hours by a ball mill using zirconia beads. The obtained dispersion liquid was filtered through a membrane filter (trade name, manufactured by Nihon Millipore Limited) having a pore size of about 8 μm to remove coarse particles, and diluted with ultrapure water to a pigment concentration of 15% by weight to prepare dispersion 1. .

(2) Dispersion 2
For dispersion 1, the pigment is an organic pigment such as C.I. I. Dispersion 2 was prepared in the same manner except that it was changed to Pigment Yellow 74 and the addition amount was changed to 75 g.

(3) Dispersion 3
C. which is an organic pigment as a pigment. I. Pigment Blue 15: 4; 75 g, a styrene-acrylic acid polymer Jonkrill 678 having a carboxylic acid group as an anionic group as a dispersion polymer (trade name, manufactured by BASF Japan Ltd., weight average molecular weight 8,500, acid value 215 KOHmg / G); 75 g, potassium hydroxide as a basic compound; 9.4 g, ultrapure water purified by ion exchange and reverse osmosis methods; 250 g were mixed and mixed for 10 hours in a ball mill with zirconia beads. Dispersion was performed. The obtained dispersion stock solution is filtered through a membrane filter having a pore diameter of about 8 μm (trade name, manufactured by Nippon Millipore Limited) to remove coarse particles, diluted with ultrapure water to a pigment concentration of 15% by weight, and C, which is an organic pigment. . I. Dispersion 3 in which Pigment Blue 15: 4 was dispersed with a dispersion polymer was prepared.

(4) Dispersion 4
[Synthesis of dispersion polymer]
1-L beaker was mixed with n-butyl methacrylate; 200 g, n-butyl acrylate; 25 g, styrene; 100 g, 2-hydroxyethyl methacrylate; 75 g, methacrylic acid; 100 g, and tert-butyl peroxyoctoate as a polymerization initiator; 4 g was added to prepare a polymer synthesis mixture.
Next, 500 g of methyl ethyl ketone was placed in a 1 L flask, and the temperature was raised to 75 ° C. with stirring in a nitrogen atmosphere. The above polymer synthesis mixture was added dropwise with stirring over 3 hours. After completion of the dropwise addition, the reaction was further continued at 75 ° C. with stirring for 8 hours. Thereafter, the reaction product was naturally cooled to 25 ° C., and diluted by adding methyl ethyl ketone so that the solid content was 50% by weight. A dispersion polymer A solution having an acid value of 150 KOH mg / g and a weight average molecular weight of 15,000 was prepared.
[Preparation of dispersion]
C. which is an organic pigment as a pigment. I. Pigment Violet 19; 150 g, dispersion polymer A solution described above; 100 g, potassium hydroxide (10% by weight aqueous solution) as a basic compound; 50 g, ultrapure water purified by an ion exchange method and reverse osmosis method; Each was mixed and dispersed in a sand mill (manufactured by Yaskawa Seisakusho) with glass beads (1.7 mm in diameter, 1.5 times the weight of the mixture (weight)) for 2 hours. Thereafter, the glass beads were removed, and the mixture was stirred at room temperature for 20 minutes, and then filtered through a 5 μm membrane filter.
The obtained filtrate was distilled at 80 ° C. under normal pressure to remove all of methyl ethyl ketone and a part of water. Further, 1N hydrochloric acid solution was added dropwise with stirring to coagulate the dispersed polymer layer. This was subjected to suction filtration while washing with water to obtain a water-containing pigment cake. The water-containing cake was gradually added to stirred potassium hydroxide (1 wt% aqueous solution); 422 g, and stirred and mixed to redisperse. Further, ultrapure water was added so that the pigment concentration was 15% by weight to prepare dispersion 4.

Next, a method for producing a surface-treated pigment and preparation examples of dispersion 5 to dispersion 8 containing the same will be described.
[Preparation of surface-treated pigment and preparation of dispersion]
(1) Preparation of surface-treated pigment 1 and preparation of dispersion 5: carbon black MA-7 which is carbon black as a pigment (trade name, manufactured by Mitsubishi Chemical Corporation); 15 parts by weight of sulfolane; 200 parts by weight mixed In an Eiger motor mill M250 type (trade name, manufactured by Eiger Japan Co., Ltd.), the mixture is dispersed for 1 hour under the conditions of a bead filling rate of 70% and a rotational speed of 5,000 rpm. The mixture was heated and heated to 120 ° C. while reducing the pressure to 30 mmHg or less, and after the water contained in the system was distilled off as much as possible, the temperature was controlled at 150 ° C.
Next, sulfur trioxide; 25 parts by weight was added and reacted for 6 hours. After the reaction was completed, the product was washed several times with excess sulfolane, poured into water, and filtered to remove functional groups such as sulfinic acid groups or sulfonic acid groups. A slurry of the surface-treated pigment 1 introduced directly on the carbon black surface was obtained.
The surface-treated pigment 1 (carbon black) prepared above was mixed with 20 parts by weight, triethanolamine as a neutralizing agent; 3 parts by weight, ion-exchanged water; 77 parts by weight, and a paint shaker (using glass beads: filled with beads) Dispersion liquid 5 having a pigment concentration of 20% by weight was prepared by dispersing the pigment until the average particle size (secondary particle size) of the pigment reached 100 nm using a ratio of 60% and a media diameter of 1.7 mm.

(2) Preparation of surface-treated pigment 2 and preparation of dispersion 6: C.I. I. Pigment Blue 15: 3
Organic pigment phthalocyanine blue pigment (CI Pigment Blue 15: 3); 20 parts by weight of quinoline; 500 parts by weight mixed, beads with Eiger Motor Mill M250 (trade name, manufactured by Eiger Japan) Dispersed for 2 hours under conditions of a filling rate of 70% and a rotational speed of 5,000 rpm, the dispersed pigment paste and solvent mixture is transferred to an evaporator, heated to 120 ° C. while reducing the pressure to 30 mmHg or less, and contained in the system After removing water as much as possible, the temperature was controlled at 160 ° C. Next, 20 parts by weight of a sulfonated pyridine complex is added and reacted for 8 hours. After completion of the reaction, the quinoline is washed several times with excess quinoline, poured into water, and filtered to obtain a functional group such as a sulfinic acid group or a sulfonic acid group. A slurry of the surface-treated pigment 2 was obtained, in which was introduced directly onto the surface of the organic pigment.
Surface-treated pigment 2 prepared above (CI Pigment Blue 15: 3); 20 parts by weight, Surfynol 465 (trade name, manufactured by Air Products and Chemicals Co., Ltd.), an acetylene glycol surfactant that is a penetrant; 2 parts by weight, triethanolamine which is a basic compound as a neutralizing agent; 4 parts by weight, ion-exchanged water; 74 parts by weight are mixed, and a paint shaker (using glass beads: bead filling ratio 60%, media diameter 1. 7 mm) was used until the average particle size (secondary particle size) of the pigment was 95 nm, whereby dispersion 6 having a pigment concentration of 20% by weight was prepared.

(3) Preparation of surface-treated pigment 3 and preparation of dispersion 7: C.I. I. Pigment Red 122
Dimethylquinacridone pigment (CI Pigment Red 122), which is an organic pigment, is mixed with 20 parts by weight of quinoline; 500 parts by weight, and filled with beads by Eiger Motor Mill M250 (trade name, manufactured by Eiger Japan). Moisture contained in the system after being dispersed for 2 hours under the conditions of 70% and a rotational speed of 5,000 rpm, the mixture of the pigment paste and the solvent after dispersion is transferred to an evaporator and heated to 120 ° C. while reducing the pressure to 30 mmHg or less. Was distilled off as much as possible, and the temperature was controlled at 160 ° C. Next, 20 parts by weight of a sulfonated pyridine complex as a reactant is added and reacted for 4 hours. After completion of the reaction, the mixture is washed several times with excess quinoline, poured into water, and filtered to obtain a sulfinic acid group or a sulfonic acid group. Thus, a slurry of the surface-treated pigment 3 was obtained, in which the functional group was directly introduced on the surface of the organic pigment.
Surface-treated pigment 3 prepared as described above (CI Pigment Red 122); 20 parts by weight, Surfynol 465 (trade name, manufactured by Air Products and Chemicals), an acetylene glycol surfactant that is a penetrant; 5 weights 3 parts by weight, 10 parts of 1,2-hexanediol as a penetrating agent, 30% aqueous ammonia as a neutral compound as a neutralizing agent; 62 parts by weight of ion-exchanged water; Use: Using a bead filling ratio of 60% and a media diameter of 1.7 mm), the dispersion liquid 7 having a pigment concentration of 20% by weight is dispersed by dispersing until the average particle diameter (secondary particle diameter) of the pigment reaches 100 nm. Prepared.

(4) Preparation of surface-treated pigment 4 and preparation of dispersion 8: C.I. I. Pigment Yellow 128
Condensed azo yellow pigment (CI Pigment Yellow 128) which is an organic pigment as a pigment; 20 parts by weight is mixed with quinoline; 500 parts by weight, and filled with beads with Eiger Motor Mill M250 type (trade name, manufactured by Eiger Japan) The mixture is sized and dispersed for 2 hours under the conditions of a rate of 70% and a rotational speed of 5,000 rpm, and the mixture of the pigment paste and the solvent after the sized dispersion is transferred to an evaporator and heated to 120 ° C. while reducing the pressure to 30 mmHg or less. The water contained therein was distilled off as much as possible, and the temperature was controlled at 160 ° C. Next, 20 parts by weight of a sulfonated pyridine complex as a reactant is added and reacted for 4 hours. After completion of the reaction, the mixture is washed several times with excess quinoline, poured into water, and filtered to obtain a sulfinic acid group or sulfonic acid group. Thus, a slurry of the surface-treated pigment 4 in which a functional group such as was directly introduced on the surface of the organic pigment was obtained.
Surface-treated pigment 4 (CI Pigment Yellow 128) prepared above: 20 parts by weight, Surfynol 104 (trade name, manufactured by Air Products and Chemicals), an acetylene glycol surfactant that is a penetrant; 1 weight Part, triethylene glycol monobutyl ether as penetrant; 10 parts by weight, potassium hydroxide as basic compound as neutralizer; 1 part by weight, ion-exchanged water; 68 parts by weight, and paint shaker (glass beads Use: Using a bead filling ratio of 60% and a media diameter of 1.7 mm), the dispersion 8 having a pigment concentration of 20% by weight is dispersed by dispersing until the average particle diameter (secondary particle diameter) of the pigment reaches 130 nm. Prepared.

Ink compositions were prepared with the compositions shown in Table 3 using the dispersions 1 to 8 obtained by the materials and methods described above. Each ink composition was used for each of the following evaluations after sufficiently stirring and mixing the respective materials and performing pressure filtration at a pressure of ² kg / cm ² using a membrane filter having a pore size of 1 μm.

  Using the coating liquid and ink composition prepared by the materials and methods described above, the following evaluations (recorded product evaluation, printer characteristic evaluation) were performed. Table 4 shows the combination of the coating liquid and the ink composition and the evaluation results at the time of evaluation. However, with respect to Example 11 and Example 12, when performing the evaluation shown below, the four types of ink composition examples shown in Table 4 were combined to produce a full color image in which a single color, a secondary color, and a tertiary color were mixed. Was performed by printing.

<Evaluation of recorded materials>
[Evaluation 1: Evaluation of glossiness on glossy media]
Using the coating liquid examples 1 to 14 and the ink composition examples 1 to 8 prepared as described above, the combinations shown in Table 4 were evaluated. First, ink composition example 1 to ink composition example 8 are mounted on an ink jet printer PX-A650 (trade name, manufactured by Seiko Epson Corporation), and images with varying fill density in increments of 5% from 5% to 100% are used as glossy media. Printed on top. The print setting at this time was “paper type: EPSON photo paper, print quality: clean”. Thereafter, coating liquid example 1 to coating liquid example 14 are mounted on the black cartridge portion of another inkjet printer PX-A650, and using this, on the recorded image printed in ink composition example 1 to ink composition example 8 earlier. An image filled with a coating solution was printed on the surface. The print setting at this time was “paper type: plain paper, print quality: fast”. The gloss of the recorded material thus recorded was evaluated. The glossy media used in this evaluation are (1) glossy paper, (2) photographic paper <gloss>, (Both (1) and (2) are trade names, manufactured by Seiko Epson Corporation), and (3) professional photo paper ( (Product name, manufactured by Canon Inc.), (4) Premium Plus Photo Paper (Gloss) (trade name, manufactured by Hured Packard), (5) Glossy Inkjet Photo Paper (Photolike QP) (Product Name, Konica Minolta Holdings, Inc.) Made by Co., Ltd.). Evaluation was made visually. The evaluation criteria are shown below. The evaluation results are shown in Table 4. The numbers ((1) to (5)) shown for the recording medium types in Table 4 are the same as those attached to the names of the glossy media.
Evaluation A: Glossiness is recognized in all filled images.
Evaluation B: An image with a fill density of 100% is slightly glossy but has no practical problem.
Evaluation C: An image with a fill density of 50% or more lacks gloss.
Evaluation D: All painted images lack gloss.

[Evaluation 2: Evaluation of fixability on glossy media]
Using the coating liquid examples 1 to 14 and the ink composition examples 1 to 8 prepared as described above, the combinations shown in Table 4 were evaluated. First, ink composition example 1 to ink composition example 8 were mounted on an ink jet printer PX-A650 (trade name, manufactured by Seiko Epson Corporation), and 12-point Gothic character printing was performed on each. The print setting at this time was “paper type: EPSON photo paper, print quality: clean”. Thereafter, coating liquid example 1 to coating liquid example 14 are mounted on the black cartridge portion of another inkjet printer PX-A650, and using this, on the recorded image printed in ink composition example 1 to ink composition example 8 earlier. An image filled with a coating solution was printed on the surface. The print setting at this time was “paper type: plain paper, print quality: fast”. Using the recorded matter thus recorded, the fixability was evaluated. The glossy media used in this evaluation was the same as that used in [Evaluation 1: Evaluation of glossiness on glossy media]. Evaluation is carried out by visually observing the deviation or blurring of characters after rubbing with a finger using a recorded material that has been dried at 20 ° C. to 25 ° C./40% RH to 60% RH for 1 hour after printing. It was. The evaluation criteria are shown below. The evaluation results are shown in Table 4. The numbers ((1) to (5)) shown for the recording medium types in Table 4 are the same as those shown in [Evaluation 1: Evaluation of glossiness on glossy media].
Evaluation A: Misalignment and blurring are not recognized.
Evaluation B: A slight deviation is recognized, but there is no practical problem.
Evaluation C: Misalignment or blurring is observed.
Evaluation D: Misalignment and faintness are severe, and characters are difficult to read.

[Evaluation 3: Evaluation of image quality on plain paper / recycled paper]
Using the ink composition examples 1 to 8 prepared above, the ink composition printer PX-A650 (trade name, manufactured by Seiko Epson Corporation) was mounted. Image quality (character quality) when the print setting is “paper type: plain paper, print quality: fast” and 1 to 20 points of Gothic characters are printed in 1 point increments on plain paper and recycled paper. ) Was evaluated. Furthermore, images with different fill densities were printed in 5% increments from 5% to 100% with the same print settings, and the image quality (filled image quality) due to shading unevenness of the recorded matter was evaluated. In this evaluation, as plain paper, (6) Xerox Business Multipurpose 4200 Paper (trade name, manufactured by Xerox Corporation), (7) Xerox P (trade name, manufactured by Fuji Xerox Office Supply Co., Ltd.), (8) Hammill Milly Plus ( (9) Xerox R (trade name, manufactured by Fuji Xerox Office Supply Co., Ltd.) was used as the recycled paper, and the evaluation was made visually. The evaluation criteria are shown below. The evaluation results are shown in Table 4. The numbers ((6) to (9)) shown for the recording medium types in Table 4 are the same as those assigned to the names of the above-mentioned plain paper and recycled paper.

[Character quality]
Evaluation A: No blur is seen in the characters at all points.
Evaluation B: Slight bleeding is observed with characters of 5 points or less (practical level).
Evaluation C: Characters of 5 points or less appear thick due to bleeding.
Evaluation D: Bleeding is remarkable and characters of 5 points or less cannot be distinguished.

[Filled image quality]
Evaluation A: Light and shade unevenness is hardly recognized in all filled images.
Evaluation B: Slight shading unevenness is recognized in an image with a fill density of 100% (practical level).
Evaluation C: Density unevenness is observed in an image having a fill density of 50% or more.
Evaluation D: Light and shade unevenness is observed in all filled images.

<Printer characteristic evaluation>
[Evaluation 4: Clogging evaluation]
Using the coating liquid examples 1 to 14 and the ink composition examples 1 to 8 prepared above, they were mounted on an ink jet printer PX-A650 (trade name, manufactured by Seiko Epson Corporation), respectively. Thereafter, the printer was left in a 60 ° C. environment for one week in a state where the coating liquid example and the ink composition example were filled. After returning the printer to room temperature, premium plus photo paper (gloss) (trade name, manufactured by Hured Packard) is used as a recording medium, and the temperature is 20 ° C / -25 ° C / 40% RH-60% RH. Filled image printing was continuously performed in an environment, and clogging was determined based on the following criteria based on conditions such as missing dots and bent dots. The print setting was “paper type: plain paper, print quality: fast”. The evaluation criteria are shown below. The evaluation results are shown in Table 4.
Evaluation A: Clogging such as bent dots and missing dots does not occur immediately after the start of continuous printing.
Evaluation B: The clogging is eliminated by performing the cleaning operation of the printer within two times.
Evaluation C: The clogging is eliminated by performing the cleaning operation of the printer 3 to 5 times.
Evaluation D: The printer needs to be cleaned six times or more to eliminate clogging, or clogging is not eliminated.

[Evaluation 5: Evaluation of ejection stability]
Using the coating liquid examples 1 to 14 and the ink composition examples 1 to 8 prepared above, they were mounted on an ink jet printer PX-A650 (trade name, manufactured by Seiko Epson Corporation), respectively. Premium plus photo paper (glossy) (trade name, manufactured by Hured Packard) is used as a recording medium, and images with mixed text and fill are continuously displayed in an environment of 20 ° C to 25 ° C / 40% RH to 60% RH. The image was printed and the presence or absence of defects such as bent dots or missing dots in the image was visually measured. The print setting was “paper type: plain paper, print quality: fast”. The evaluation criteria are shown below. The evaluation results are shown in Table 4.
Evaluation A: Even when continuous printing is performed up to 200 sheets, dot bending and dot missing do not occur.
Evaluation B: In continuous printing up to 100 sheets, dot bending and dot missing do not occur.
Evaluation C: In continuous printing up to 100 sheets, dot bending / dot missing occurred but there were less than 10 points.
Evaluation D: At the time of continuous printing up to 100 sheets, 10 or more dots are bent or missing.

表４から明らかなように、本発明における画像形成方法、すなわち記録画像にコート液を施す画像形成方法において、少なくとも水に不溶あるいは難溶である樹脂溶剤を内包している樹脂エマルジョンと保湿剤と水とを含んでなるコート液と、かつ前記記録画像は少なくとも水と着色成分とを含んでなるインク組成物にて記録されたものである画像形成方法による実施例１〜実施例１２では、光沢紙等の光沢メディア上で光沢性・定着性に優れ、普通紙・再生紙上で滲み、濃淡ムラの少ない、高品質で鮮明な記録物を得られた。また、この実施例１〜実施例１２で用いたコート液例１〜コート液例１０、及びインク組成物例１〜インク組成物例８では、プリンタ特性（目詰まり性、吐出安定性）においても良好であった。特に、実施例１１、実施例１２においては、上記評価の他に、人物及び風景の写真画像を用いてフルカラー画像を印刷したが、上記評価と同様に、光沢紙等の光沢メディア上で光沢性・定着性に優れ、普通紙・再生紙上で滲み、濃淡ムラの少ない、高品質で鮮明な記録物が得られた。

As is apparent from Table 4, in the image forming method of the present invention, that is, the image forming method of applying a coating solution to a recorded image, at least a resin emulsion containing a resin solvent that is insoluble or hardly soluble in water and a humectant In Examples 1 to 12 by the image forming method according to Examples 1 to 12, the gloss was a coating liquid containing water, and the recorded image was recorded with an ink composition containing at least water and a coloring component. A high-quality and clear recorded material with excellent glossiness and fixing property on glossy media such as paper, bleeding on plain paper and recycled paper, and less uneven density was obtained. Further, in the coating liquid examples 1 to 10 and the ink composition examples 1 to 8 used in Examples 1 to 12, the printer characteristics (clogging property and ejection stability) are also used. It was good. In particular, in Example 11 and Example 12, in addition to the above evaluation, a full color image was printed using a photograph image of a person and a landscape. However, similar to the above evaluation, glossiness on glossy media such as glossy paper was used. -A high-quality, clear recorded matter having excellent fixing properties, bleeding on plain paper / recycled paper, and less uneven density was obtained.

  On the other hand, in Comparative Example 1, since the coating liquid containing no resin emulsion containing a resin solvent that is insoluble or hardly soluble in water (Coating Liquid Example 11) was used, gloss on glossy media was used. Both sex and fixation were bad. Further, in Comparative Example 2, since a coating liquid (coating liquid example 12) in which a resin emulsion containing a resin solvent that is insoluble or hardly soluble in water is included and a moisturizing agent is not used, printer characteristics (clogging property) , Discharge stability) was poor. In Comparative Example 3, since the coating liquid (Coating Liquid Example 13) to which a resin emulsion not containing a resin solvent insoluble or hardly soluble in water was added was used, glossiness and fixability on the glossy media were improved. Both were bad. In Comparative Example 4, a coating liquid (Coating Liquid Example 14) to which N, N-dimethylformamide, which is soluble in water as a resin solvent (solubility in water at 25 ° C. of 3% by weight or more) was added, was used. Since it was used, a part of the resin emulsion was dissolved in the coating liquid, and as a result, the printer characteristics (clogging property, ejection stability) were poor. In Comparative Example 5, the coating liquid (Coating Liquid Example 15) based on Japanese Patent Application Laid-Open No. 2005-81754 was used. However, the glossiness on the glossy media despite the addition of the water-soluble resin. The coating properties of the coating liquid (clogging and ejection stability) were also poor. Further, in Comparative Example 6 and Comparative Example 7, the coating liquid according to the present invention was not used at the time of image formation, so the image quality on plain paper / recycled paper and the printer characteristics (clogging property, ejection stability) of the ink composition are Although there was no problem, glossiness and fixability on glossy media were both bad.

  As described above, in the image forming method according to the present invention, that is, the image forming method of applying a coating liquid to a recorded image, water is applied onto the recorded image recorded by the ink composition containing at least a coloring component and water. In an image forming method characterized by coating with a coating liquid containing a resin emulsion containing a resin solvent that is insoluble or hardly soluble, a humectant, and water, the coating liquid used is oil-soluble and volatile. Since no solvent is used as the main component of the liquid component, it can be handled without problems in terms of environment and safety even in general household environments, and it can also be used to fix images recorded on glossy media using pigment-containing ink compositions. An image having excellent glossiness can be obtained, and the ink jet recording method is also excellent in ejection stability and clogging. Furthermore, as a dispersant for dispersing a colorant (particularly, a pigment) in a coloring component in the ink composition to be used, the dispersant comprises a hydrophobic part and a hydrophilic part, and at least a part of the hydrophilic part is a part of the hydrophobic part. A neutralizing group obtained by neutralizing an unneutralized group, wherein the amount of neutralizing group is 20% or more and less than 60% in molar ratio to the sum of the unneutralized group and the neutralized group When using a dispersion polymer that is within the above range and / or using a surface-treated pigment, a high-quality and clear image with little bleeding and shading unevenness can be obtained even on plain paper and recycled paper. It also has the effect.

  The present invention should not be considered to be limited to these examples, and various modifications can be made without departing from the gist of the present invention.

Claims (9)

  In an image forming method of applying a coating liquid to a recorded image, a resin containing a resin solvent insoluble or hardly soluble in water on a recorded image recorded by an ink composition comprising at least a coloring component and water An image forming method comprising coating with a coating liquid comprising an emulsion, a humectant, and water.   2. The resin solvent according to claim 1, wherein the resin solvent is one or more selected from the group consisting of alcohols, ketones, ethers, esters, nitrogen-containing compounds, and sulfur-containing compounds. Image forming method.   The image forming method according to claim 1, wherein the coating liquid and / or the ink composition further contains a penetrating agent. The color component contained in the ink composition is surface-treated so that at least one of the functional groups represented by the following formula or a salt thereof is bonded directly or indirectly to the surface of the ink composition, and is dispersed in water without a dispersant. The image forming method according to claim 1, wherein the surface-treated pigment is made possible.

  The image according to any one of claims 1 to 3, wherein the coloring component contained in the ink composition is a dispersion in which a pigment is included in a dispersion polymer and can be dispersed in water. Forming method.   The dispersion polymer is composed of a hydrophobic part and a hydrophilic part, and at least a part of the hydrophilic part is a neutralizing group obtained by neutralizing an unneutralized group which is a part of the hydrophobic part, 6. The image forming method according to claim 5, wherein the abundance of the neutralizing group is in a range of 20% or more and less than 60% in molar ratio with respect to the sum of the unneutralized group and the neutralized group.   7. An image forming method for applying a coating liquid to a recorded image, wherein the coating liquid is applied to at least a recorded image portion on a recording medium by using an ink jet head to apply the coating liquid. The image forming method according to one item.   The recorded image to be coated is formed by discharging the ink composition onto a recording medium using an inkjet head. Image forming method.   A recorded matter recorded using the image forming method according to claim 1.