JP5721048B2 - Treatment liquid, set of treatment liquid and ink, and ink jet recording apparatus and ink jet recording method using the treatment liquid - Google Patents

Description

  The present invention relates to a treatment liquid for suppressing curling, a set of the treatment liquid and an ink, an ink jet recording apparatus provided with a treatment liquid applying means for applying the treatment liquid, and an ink jet recording method including a step of applying the treatment liquid. About.

  Ink jet recording methods have been rapidly spreading in recent years because they can record color images on plain paper and have low running costs. However, this method has a problem that depending on the combination of the ink and the recording medium, an image defect typified by character bleeding (hereinafter referred to as feathering) is likely to occur, and the image quality is greatly deteriorated. Therefore, attempts have been made to suppress feathering by suppressing ink permeability, but in this case, the drying property of the ink deteriorates, and when touching the recorded matter, the ink is attached to the hand and the image is stained. is there.

  In addition, when recording a color image by the ink jet recording method, inks of different colors are stacked one after another, so that the color ink spreads and mixes at the color boundary portion (hereinafter referred to as color bleed), the image There is also a problem that the quality is greatly reduced. With respect to this problem, attempts have been made to suppress color bleeding by increasing the permeability of the ink. In this case, however, the colorant enters the inside of the recording medium, resulting in a reduction in image density (hereinafter referred to as a recording medium). (Also referred to as a recording medium), there is a problem that the ink oozes out to the back side and duplex printing cannot be performed satisfactorily.

In order to solve these problems at the same time and improve the image quality, an image forming method using a processing liquid and ink has been proposed.
For example, a method for forming a colored portion on a recording medium using a liquid composition in which fine particles having a surface charged with a reverse polarity with respect to water-based ink are dispersed (see Patent Document 1), for example, image formation In order to improve the abrasion resistance of the product, a method of printing by attaching the ink composition and the first liquid containing polymer fine particles to a recording medium (see Patent Document 2), for example, cationic high A method of improving image density and improving smear fixing properties by combining a molecular compound and an organic acid (see Patent Document 3), for example, by applying a high-viscosity processing solution containing a cationic polymer compound. Has been proposed (see Patent Document 4).

  In recent years, since the printing speed of the ink jet apparatus is rapidly increasing, drying on paper, curling and cockling have become major problems. As such measures, for example, a method of providing a step of correcting warping of the recording medium by applying heat or pressure to the recording medium (see Patent Document 5), containing a water-soluble organic solvent with high moisture retention A method of increasing the amount (see Patent Document 6), a method of drying immediately after ink printing (Patent Document 7), and applying a treatment liquid containing a crosslinkable material to the recording medium to increase the rigidity of the recording medium. The method (patent document 8) is taken.

  However, these known vague broadly known technical concepts do not suggest a treatment liquid having a specific and specific configuration particularly suitable for inkjet printing using pigment ink on plain paper having no coating layer. There are problems such as large power consumption and insufficient curl suppression effect.

  An object of the present invention is to provide an ink jet processing liquid and an ink jet recording apparatus capable of forming a high-quality image and excellent in curling suppression and capable of outputting at high speed, paying attention to the above-described problems. For the purpose.

As a result of intensive studies in order to solve the above problems, the present inventors have found that the above problems can be solved by using the following treatment agent, and have reached the present invention.
That is, the present invention is as follows.
(1) In a treatment liquid used in an ink jet recording method comprising a step of applying a treatment liquid to a recording medium, and a step of forming an image by discharging ink containing a coloring material onto the recording medium.
The treatment liquid contains at least a water-soluble flocculant, a surfactant, a water-soluble organic solvent, water,
The water-soluble organic solvent contained in the treatment liquid is 40% by mass or more based on the total amount of the treatment liquid,
A water-soluble organic solvent having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80%, containing 15% by mass or more based on the total amount of the treatment liquid;
A water-soluble organic solvent having an equilibrium water content of 6% by mass to less than 20% by mass at a temperature of 23 ° C. and a humidity of 80%, containing 40% by mass or more of the entire water-soluble organic solvent,
The water-soluble organic solvent having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% is a polyhydric alcohol having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80%,
The water-soluble organic solvent having an equilibrium water content of 6 mass% or more and less than 20 mass% when the temperature is 23 ° C. and 80% humidity is 6 mass% or more and less than 20 mass% when the temperature is 23 ° C. and the humidity is 80%. A treatment liquid characterized by being a polyhydric alcohol alkyl ether .
(2) As a water-soluble organic solvent having an equilibrium water content of 6% by mass or more and less than 20% by mass at 23 ° C. and 80% humidity, isobutyl diglycol, tripropylene glycol monomethyl ether, 2- (2-isopropyloxyethoxy) ) The treatment liquid according to (1) above, comprising any of ethanol.
(3) The water-soluble organic solvent having an equilibrium water content of 30% by mass or more at the temperature of 23 ° C. and the humidity of 80% includes any one of 1,3-butanediol, triethylene glycol, and glycerin. The processing liquid according to (1) or (2).
(4) The treatment liquid according to any one of (1) to (3), wherein the treatment liquid is used in an ink jet recording method provided with a step of drying a recording medium before the step of applying the treatment liquid.
(5) The processing liquid according to (4), wherein the drying step is performed by heating means, warm air, hot air, blower means for applying dry air, or a combination of these.
(6) The water-soluble flocculant contained in the treatment liquid contains a polyvalent metal salt, a water-soluble organic acid, or an ammonium salt of a water-soluble organic acid. The processing liquid in any one.
(7) The treatment liquid and ink set according to any one of (1) to (6), wherein the ink contains a polymer emulsion in which a pigment is contained in polymer fine particles or a self-dispersing pigment. A set of treatment liquid and ink.
(8) In an ink jet recording apparatus having means for applying a treatment liquid to a recording medium and means for forming an image by ejecting ink containing a coloring material onto the recording medium, the treatment liquid (1 ) To (6), and the means for applying the treatment liquid is impregnated by impregnating the rotating body with the processing liquid and bringing the impregnated rotating body into contact with the recording medium. An ink jet recording apparatus characterized by the above.
(9) In an inkjet recording method comprising a step of applying a treatment liquid to a recording medium and a step of forming an image by ejecting ink containing a coloring material onto the recording medium, the treatment liquid (1) (6) An inkjet recording method using the treatment liquid according to any one of (6).

  The treatment liquid according to the present invention is a treatment liquid used in an ink jet recording method including a step of applying a treatment liquid to a recording medium and a step of forming an image by ejecting ink containing a coloring material onto the recording medium. The treatment liquid contains at least a water-soluble flocculant, a surfactant, a water-soluble organic solvent, and water, and the equilibrium water content when the water-soluble organic solvent is at a temperature of 23 ° C. and a humidity of 80% with respect to the total amount of the treatment liquid. 30% by mass or more of the water-soluble organic solvent A 15% by mass or more, and when the temperature is 23 ° C. and the humidity is 80%, the water-soluble organic solvent B having an equilibrium water content of 6% by mass or more and less than 20% by mass When the total amount of the water-soluble organic solvent is 40% by mass or more with respect to the total amount of the treatment liquid, the curl suppressing effect is excellent.

As a water-soluble organic solvent having an equilibrium water content of 6% by mass or more and less than 20% by mass at a temperature of 23 ° C. and a humidity of 80% contained in the treatment liquid, isobutyl diglycol, tripropylene glycol monomethyl ether, 2- (2- By containing any of (isopropyloxyethoxy) ethanol, curling suppression effect is particularly excellent.
As a water-soluble organic solvent having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% contained in the treatment liquid, any one of 1,3-butanediol, triethylene glycol, and glycerin is contained. In particular, it is excellent in curling suppression effect.
By providing a step of drying the paper before the step of treating the treatment liquid, the image quality and curl suppression effect are excellent.
The drying step is particularly effective in improving the image quality and curling suppression effect by using heating means, warm air, hot air, air blowing means for applying dry air, or a combination of these.
Since the water-soluble flocculant contained in the processing liquid contains a polyvalent metal salt, a water-soluble organic acid, or an ammonium salt of a water-soluble organic acid, the effect of improving the image quality is particularly excellent.
Particularly preferably, the water-soluble flocculant contains both a water-soluble organic acid or an ammonium salt of the water-soluble organic acid, so that both the image quality improvement effect and the fixing property can be achieved.
The ink used at the same time as the treatment liquid contains a polymer emulsion in which a pigment is contained in polymer fine particles, or a self-dispersing pigment, thereby improving the image quality improvement effect.
The means for applying the processing liquid is means for applying the processing liquid by impregnating the rotating body with the processing liquid and bringing the impregnated rotating body into contact with the recording medium, so that the processing liquid can be uniformly applied. Become.

  As will be apparent from the following detailed and specific description, according to the present invention, conventional problems can be solved, and the plain paper has excellent image quality such as image density and saturation, as well as offset and fixing properties. In addition, it is possible to form an excellent high-quality image and to provide an inkjet processing liquid capable of high-speed output excellent in curling suppression effect, a set of the processing liquid and ink, an inkjet recording apparatus, and an inkjet recording method. Become.

It is the schematic of an example of the inkjet recording device of this invention.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.
<< Processing liquid >>
The treatment liquid of the present invention contains at least a water-soluble flocculant, a surfactant, a water-soluble organic solvent and water, and the equilibrium water content when the water-soluble organic solvent is at a temperature of 23 ° C. and a humidity of 80% is 30% by mass or more. Solvent B having an equilibrium water content of 6% by mass or more and 20% by mass or less at a temperature of 23 ° C. and a humidity of 80% is 40% by mass or more of the total amount of the water-soluble organic solvent. And the total amount of the water-soluble organic solvent is 40% by mass or more based on the total amount of the treatment liquid.

<Water-soluble flocculant>
Examples of the water-soluble flocculant used in the present invention include water-soluble organic acids, ammonium salt compounds of water-soluble organic acids, water-soluble metal salt compounds, and water-soluble cationic polymers.
When the treatment liquid to which the water-soluble flocculant is added comes into contact with the inkjet ink on the recording medium, the anionic pigment is aggregated and fixed on the recording medium by the salting out effect or the acid precipitation effect. To improve feathering and color bleeding.

  The water-soluble organic acid compound is preferably a water-soluble aliphatic organic acid compound, and examples of the water-soluble aliphatic organic acid compound include lactic acid (pKa: 3.83), malic acid (pKa: 3.4), Citric acid (pKa: 3.13), tartaric acid (pKa: 2.93), succinic acid (pKa: 1.04), malonic acid (pKa: 2.05), succinic acid (pKa: 4.21), adipic acid (PKa: 4.42), acetic acid (pKa: 4.76), propionic acid (pKa: 4.87), butyric acid (pKa: 4.82), valeric acid (pKa: 4.82), gluconic acid (pKa : 2.2), pyruvic acid (pKa: 2.49), fumaric acid (pKa: 3.02).

  The ammonium salt of the water-soluble organic acid is preferably an ammonium salt of a water-soluble aliphatic organic acid. Examples of the water-soluble aliphatic organic acid ammonium salt include ammonium acetate, ammonium lactate, ammonium propionate, and ammonium butanenate. Can be mentioned.

Examples of the water-soluble metal salt compound include a water-soluble polyvalent metal salt compound and a water-soluble monovalent alkali metal salt compound. Examples of the water-soluble polyvalent metal salt compound include magnesium sulfate, aluminum sulfate, manganese sulfate, Nickel sulfate, iron (II) sulfate, copper (II) sulfate, zinc sulfate, iron (II) nitrate, iron (III) nitrate, cobalt nitrate, strontium nitrate, copper (II) nitrate, nickel (II) nitrate, lead nitrate (II), manganese nitrate (II), calcium nitrate, nickel chloride (II), calcium chloride, tin chloride (II), strontium chloride, barium chloride, magnesium chloride. Examples of the water-soluble monovalent alkali metal salt compound include sodium sulfate, potassium sulfate, lithium sulfate, sodium hydrogen sulfate, potassium hydrogen sulfate, sodium nitrate, potassium nitrate, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, Examples include sodium chloride and potassium chloride.
As the water-soluble metal salt compound, a water-soluble polyvalent metal salt is preferable.

  The water-soluble cationic polymer is preferably a quaternary ammonium salt type cationic polymer compound, for example, a dialkylallyl ammonium chloride polymer, a dialkylaminoethyl (meth) acrylate quaternary ammonium salt polymer, a modified polyvinyl alcohol dialkylammonium. Salt polymer, dialkyl diallylammonium salt polymer, and other cationic polymer compounds include cationic epichlorohydrin condensate, cationic special modified polyamine compound, cationic polyamide polyamine compound, cationic urea-formalin resin compound , Cationic polyacrylamide compounds, cationic alkyl ketene dimers, cationic dicyandiamide compounds, cationic dicyandiamide-formalin condensation compounds, cation Sex dicyandiamide - polyamine condensate compound, cationic polyvinyl formamide compounds, cationic polyvinyl pyridine compounds, cationic polyalkylene polyamine compounds, cationic epoxy polyamide compounds.

［式中、Ｒはメチル基又はエチル基を示し、Ｘ^-はハロゲンイオン示す。
また、ｎは整数を示す。］ Particularly preferred are compounds having the following structure.

[Wherein, R represents a methyl group or an ethyl group, and X ⁻ represents a halogen ion.
N represents an integer. ]

［式中、Ｘ^-はハロゲンイオン、硝酸イオン、亜硝酸イオン及び酢酸イオンのいずれかの陰イオンを示し、Ｒ₃は、ＨまたはＣＨ₃、Ｒ₄、Ｒ₅、Ｒ₆はＨ又はアルキル基を示す。
また、ｎは整数を示し、ｍは1〜３の整数を示す。］

[Wherein, X ⁻ represents an anion selected from a halogen ion, a nitrate ion, a nitrite ion, and an acetate ion, and R ₃ represents H or CH ₃ , R ₄ , R ₅ , R ₆ represents H or an alkyl group. Indicates.
N represents an integer, and m represents an integer of 1 to 3. ]

［式中、Ｒはメチル基又はエチル基を示し、Ｘ^-はハロゲンイオン、硝酸イオン、亜硝酸イオン及び酢酸イオンのいずれかの陰イオンを示す。
また、ｎは整数を示す。］

[Wherein, R represents a methyl group or an ethyl group, and X ⁻ represents an anion of any one of a halogen ion, a nitrate ion, a nitrite ion, and an acetate ion.
N represents an integer. ]

  The cationic polymer compound aggregates the color material and the water-dispersible resin in the ink to leave the color material on the surface of the plain paper, thereby improving the image density and image blur.

The water-soluble flocculant is preferably a water-soluble organic acid, an ammonium salt of a water-soluble organic acid, or a polyvalent metal salt, and particularly preferably a water-soluble organic acid or an ammonium salt of a water-soluble organic acid.
The amount of the water-soluble flocculant added is preferably from 0.1 to 30% by mass, more preferably from 1 to 20% by mass, based on the entire treatment liquid as an active ingredient. If it is larger than 30% by mass, the water-soluble organic acid compound may be precipitated without being sufficiently dissolved, and if it is smaller than 0.1% by mass, the effect of improving the image density may be reduced.

<Surfactant>
The surfactant used in the treatment liquid is preferably at least one selected from silicone surfactants and fluorine surfactants. These surfactants can be used alone or in combination of two or more.

As the fluorine-based surfactant used in the treatment liquid,
For example, Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullrad FC-93, FC- 95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431, FC-4430 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F-1405, F -474, F-444 (all manufactured by Dainippon Ink & Chemicals, Inc.); Zonyl FS-300, FSN, FSN-100, FSO (all manufactured by DuPont); F-top EF-351, EF-352, EF -801, EF-802 (both manufactured by Gemco) and the like. Among these, Zonyl FS-300, FSN, FSN-100, and FSO (all manufactured by DuPont) which are favorable in terms of reliability and color development are particularly suitable.
Examples of the silicone surfactant include modified silicones KF-351A, KF-353A, KF354L, KF355A, KF-615A, KF-640, KF-642, KF-643, KF-6011 (all Shin-Etsu Chemical Co., Ltd.) Silicone FZ-77, FZ-2104, FZ-2105, L-7604 (all manufactured by Toray Dow Corning) and the like. Among these, KF-355A, KF-640, KF-642, and KF-643 (all of which are manufactured by Shin-Etsu Kogyo Co., Ltd.) are particularly suitable for improving reliability and color development.
The content of the surfactant in the treatment liquid is preferably 0.01 to 3.0% by mass, and more preferably 0.5 to 2% by mass. If the content is less than 0.01% by mass, the effect of adding a surfactant may be lost, and if it exceeds 3.0% by mass, there may be a problem in storage stability.

<Water-soluble organic solvent>
Examples of the water-soluble organic solvent used in the present invention include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, Examples include propylene carbonate and ethylene carbonate. The water-soluble organic solvent of the present invention imparts fluidity to the treatment liquid by the water-soluble organic solvent retaining a large amount of moisture even when the moisture of the treatment liquid evaporates and reaches an equilibrium state.

As the water-soluble organic solvent, a water-soluble organic solvent having a high equilibrium water content is used, so that the water-soluble organic solvent retains a large amount of water even when the water in the treatment liquid evaporates and reaches an equilibrium state. , Extreme viscosity increase can be suppressed.
In the present invention, the water-soluble organic solvent having a high equilibrium water content refers to a water-soluble organic solvent having an equilibrium water content in an environment of a temperature of 23 ° C. and a humidity of 80% of 30% by mass or more, preferably 40% by mass or more. (Hereinafter referred to as water-soluble organic solvent A). By using such a water-soluble organic solvent A, the water-soluble organic solvent A retains a large amount of water and prevents an increase in viscosity even when the water evaporates and reaches a water balance in the standing state. it can. Equilibrium water content means that a mixture of water-soluble organic solvent and water is opened to air at a constant temperature and humidity, and the evaporation of water in the solution and the absorption of water in the ink into the ink are in an equilibrium state. Says the amount of water when it becomes. Specifically, the equilibrium water content is determined by using a saturated aqueous solution of potassium chloride, keeping the temperature and humidity in the desiccator at 23 ± 1 ° C. and 80 ± 3%, and weighing 1 g of each water-soluble organic solvent in the desiccator. The petri dish can be stored for a period until the mass change disappears, and can be obtained by the following formula.

  Examples of the water-soluble organic solvent A suitably used in the present invention include polyhydric alcohols having an equilibrium water content in an environment of a temperature of 23 ° C. and a humidity of 80% of 30% by mass or more. Specific examples of the water-soluble organic solvent A include 1,2,3-butanetriol (bp 175 ° C./33 hPa, the equilibrium water content 38% by mass), 1,2,4-butane triol (bp 190-191 ° C. / 24 hPa, the equilibrium water content 41% by mass), glycerin (bp 290 ° C., the equilibrium water content 50% by mass), diglycerin (bp 270 ° C./20 hPa, the equilibrium water content 38% by mass), triethylene glycol (bp 285 ° C., The equilibrium water content 39% by mass), tetraethylene glycol (bp 324-330 ° C., the equilibrium water content 37% by mass), diethylene glycol (bp 245 ° C., the equilibrium water content 43% by mass), 1,3-butanediol (bp 203- 204 degreeC, the said equilibrium water content 35 mass%) etc. are mentioned. Among these, glycerin, 1,3-butanediol, and triethylene glycol are particularly preferably used because they can reduce the viscosity when containing water.

  In the present invention, in addition to the water-soluble organic solvent A having a high equilibrium water content, a water-soluble organic solvent having a low equilibrium water content and having an equilibrium water content of 6% by mass to less than 20% by mass at a temperature of 23 ° C. and a humidity of 80% ( Hereinafter, it is necessary to use a water-soluble organic solvent B) together. By using such a water-soluble organic solvent B in combination, the penetration of the treatment liquid can be promoted.

When the processing liquid is applied to the recording medium, the solvent A having a high equilibrium water content in the processing liquid stays on the surface of the recording medium together with the flocculant, and the water-soluble organic solvent B having a low equilibrium water content rapidly has a low water content. It penetrates to the back of the paper. When the ink is subjected to a printing process in a state where a water-soluble organic solvent that can be arbitrarily mixed with water penetrates into the paper, the treatment liquid assists the penetration of the ink and thus has an excellent effect of curling suppression.
Examples of such a water-soluble organic solvent B include isobutyl diglycol (bp 220 ° C., the equilibrium water content 10% by mass), tripropylene glycol monomethyl ether (bp 242 ° C., the equilibrium water content 13% by mass), 2- ( 2-Isopropyloxyethoxy) ethanol (bp 207 ° C., equilibrium water content 18% by mass), isopropyl glycol (bp 142 ° C., equilibrium water content 15% by mass), diethyl diglycol (bp 189 ° C., equilibrium water content 10% by mass) Propylpropylene glycol (bp 150 ° C., the equilibrium water content 17% by mass), dibutyl diglycol (bp 189 ° C., the equilibrium water content 12% by mass), butyl propylene bricol (bp 170 ° C., the equilibrium water content 6% by mass), Methyl propylene glycol acetate (bp1 6 ° C., the equilibrium water content 8 wt%), and the like.

In addition to the water-soluble organic solvents A and B, the equilibrium water content is 20% by mass or more and less than 30% by mass, or the equilibrium water content at a lower temperature of 23 ° C. and 80% humidity is less than 6% by mass. A water-soluble solvent can be used, but if the water content in these solvents becomes too high, the effect of assisting the penetration of the ink will be reduced, and if the water content in the solvent becomes too low, it will be compatible with the ink. The solubility becomes poor and the effect of assisting ink penetration is lost.
Therefore, the content of the water-soluble organic solvent in the treatment liquid is 40% by mass or more from the curling suppression effect, and the water-soluble organic solvent A in the water-soluble organic solvent is 15% by mass or more with respect to the total amount of the treatment liquid. It is necessary that the water-soluble organic solvent B is contained in an amount of 40% by mass or more of the entire water-soluble organic solvent.

  Specific examples of the water-soluble organic solvent C that can be used in addition to the water-soluble organic solvents A and B include, for example, tributyl citrate (bp ° C., 4% by mass of the equilibrium water content), propylpropylene diglycol (bp 220 ° C.). , The equilibrium water content 5 mass%), butyl propylene diglycol (bp 212) ° C., the equilibrium water content 3 mass%), triethylene glycol dimethyl ether (bp 216 ° C., the equilibrium water content 20 mass%), 2-methyl-1, 3-butanediol (bp 203 ° C., the equilibrium water content is 23% by mass) and the like.

In addition, the following organic solvents can be used.
Dipropylene glycol (bp 232 ° C.), 1,5-pentanediol (bp 242 ° C.), propylene glycol (bp 187 ° C.), 2-methyl-2,4-pentanediol (bp 197 ° C.), ethylene glycol (bp 196-198 ° C.), Tripropylene glycol (bp 267 ° C.), hexylene glycol (bp 197 ° C.), polyethylene glycol (viscous liquid to solid), polypropylene glycol (bp 187 ° C.), 1,6-hexanediol (bp 253-260 ° C.), 1, 2, Examples include 6-hexanetriol (bp 178 ° C.), trimethylol ethane (solid, mp 199-201 ° C.), trimethylol propane (solid, mp 61 ° C.), and the like.

Examples of the polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether (bp 135 ° C.), ethylene glycol monobutyl ether (bp 171 ° C.), diethylene glycol monomethyl ether (bp 194 ° C.), diethylene glycol monoethyl ether (bp 197 ° C.), and diethylene glycol monoethyl ether. Examples include butyl ether (bp 231 ° C.), ethylene glycol mono-2-ethylhexyl ether (bp 229 ° C.), propylene glycol monoethyl ether (bp 132 ° C.), and the like.
Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether (bp 237 ° C.) and ethylene glycol monobenzyl ether.

Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone (bp 250 ° C., mp 25.5 ° C., 47-48% by mass), N-methyl-2-pyrrolidone (bp 202 ° C.), 1,3-dimethyl-2- Examples include imidazolidinone (bp 226 ° C.), ε-caprolactam (bp 270 ° C.), γ-butyrolactone (bp 204-205 ° C.), and the like.
Examples of the amides include formamide (bp 210 ° C.), N-methylformamide (bp 199-201 ° C.), N, N-dimethylformamide (bp 153 ° C.), N, N-diethylformamide (bp 176-177 ° C.), and the like. Can be mentioned.
Examples of the amines include monoethanolamine (bp 170 ° C), diethanolamine (bp268 ° C), triethanolamine (bp360 ° C), N, N-dimethylmonoethanolamine (bp139 ° C), N-methyldiethanolamine (bp243 ° C). ), N-methylethanolamine (bp159 ° C.), N-phenylethanolamine (bp282-287 ° C), 3-aminopropyldiethylamine (bp169 ° C), and the like.
Examples of the sulfur-containing compounds include dimethyl sulfoxide (bp 139 ° C.), sulfolane (bp 285 ° C.), thiodiglycol (bp 282 ° C.), and the like.

Other solid water-soluble organic solvents are preferably saccharides.
Examples of the saccharide include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), polysaccharides, and the like. Specific examples include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like. Here, the polysaccharide means a saccharide in a broad sense, and is used to include a substance that exists widely in nature such as α-cyclodextrin and cellulose. The derivatives of these saccharides are represented by the reducing sugars of the saccharides described above (for example, sugar alcohol (general formula: HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)). ), Oxidized sugars (for example, aldonic acid, uronic acid, etc.), amino acids, thioic acids, etc. Among these, sugar alcohols are preferable, and specific examples include maltitol, sorbit, and the like.

The content of the water-soluble organic solvent in the treatment liquid is 40% by mass or more from the curling suppressing effect. If it is less than 40% by mass, the curl suppressing effect may not be achieved. More preferably, it is 40-80 mass%.
As content of the water-soluble organic solvent B, 40-70 mass% is preferable with respect to the water-soluble organic solvent whole quantity, More preferably, it is 40-60 mass%. When the content of the water-soluble organic solvent B is less than 40% by mass with respect to the total amount of the water-soluble organic solvent, curling suppression effect cannot be obtained, and when it exceeds 70% by mass, the permeability of the treatment liquid becomes too high. Ink aggregation effects may not be possible.

―Other ingredients―
The treatment liquid of the present invention preferably contains at least one non-wetting agent polyol compound or glycol ether compound having 8 to 11 carbon atoms as a penetrant. These preferably have a solubility of between 0.2 and 5.0% by weight in water at 25 ° C. Among these, 2-ethyl-1,3-hexanediol [solubility: 4.2% (25 ° C.)], 2,2,4-trimethyl-1,3-pentanediol [solubility: 2.0% (25 ° C)] is particularly preferred.

  Examples of other non-wetting agent polyol compounds include aliphatic diols such as 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 2,2- Diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene-1,2-diol and the like.

  Other penetrants that can be used in combination are not particularly limited as long as they can be dissolved in the treatment liquid and can be prepared to have desired physical properties, and can be appropriately selected according to the purpose. For example, diethylene glycol monophenyl ether, Alkyl and aryl ethers of polyhydric alcohols such as ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, tetraethylene glycol chlorophenyl ether, lower alcohols such as ethanol, Etc.

  The content of the penetrant in the treatment liquid is preferably 0.1 to 5.0% by mass. When the content is less than 0.1% by mass, the effect of infiltrating the ink-jet ink may be lost. When the content exceeds 5.0% by mass, it is separated from the solvent due to low solubility in the solvent. The effect of improving the permeability may be saturated.

  If necessary, the treatment liquid of the present invention may contain preservatives, rust preventives and the like used in ink jet inks described later.

<Inkjet ink>
The ink-jet ink used in the present invention contains a water-dispersible colorant, a water-soluble organic solvent, a surfactant, a penetrating agent, and water, which are color materials.

-Water dispersible colorant-
In the inkjet ink, a pigment is mainly used as a water-dispersible colorant from the viewpoint of weather resistance, but a dye may be contained within a range in which the weather resistance is not deteriorated for the purpose of adjusting the color tone. There is no restriction | limiting in particular as said pigment, According to the objective, it can select suitably, For example, the inorganic pigment, organic pigment, etc. for black or color are mentioned. These may be used individually by 1 type and may use 2 or more types together.

  Inorganic pigments include titanium oxide and iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, as well as carbon produced by known methods such as the contact method, furnace method, and thermal method. Black can be used.

  Organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (eg, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines). Pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (for example, basic dye type chelates, acidic dye type chelates), nitro pigments, nitroso pigments, aniline black, and the like can be used. Of these pigments, those having good affinity with water are particularly preferably used.

  Specific examples of pigments that are more preferably used in the above-mentioned pigments include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron. (CI pigment black 11), metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).

  Further, for color use, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 408, 109, 110, 117, 120, 128, 138, 150, 151, 153, 183, C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 219, C.I. I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15, 15: 1, 15: 2, 15: 3 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, and the like.

The following first and second forms are particularly preferable when the colorant is a pigment.
1) In the first embodiment, the colorant contains a polymer emulsion (an aqueous dispersion of polymer fine particles containing a coloring material) in which a polymer fine particle contains a water-insoluble or poorly water-soluble coloring material.
2) In the second embodiment, the colorant has a surface having at least one hydrophilic group and exhibits water dispersibility in the absence of a dispersant (hereinafter, referred to as “self-dispersible pigment”). ).
In the present invention, in the case of the second embodiment, it is preferable that the following water-dispersible resin is included.

As the water-dispersible colorant of the first form, it is preferable to use a polymer emulsion in which a pigment is contained in polymer fine particles in addition to the pigment. The polymer emulsion in which the pigment is contained in the polymer fine particles is one in which the pigment is encapsulated in the polymer fine particles, or the pigment is adsorbed on the surface of the polymer fine particles. In this case, it is not necessary that all the pigments are encapsulated or adsorbed, and the pigments may be dispersed in the emulsion as long as the effects of the present invention are not impaired. Examples of the polymer forming the polymer emulsion (polymer in the polymer fine particles) include vinyl polymers, polyester polymers, polyurethane polymers, and the like. Particularly preferably used polymers are vinyl polymers and polyester polymers. Polymers disclosed in 2000-53897 and JP 2001-139849 can be used.
Further, the ink containing the aqueous dispersion of polymer fine particles containing the color material of the first form is less susceptible to light scattering than the case where the pigment particles are present alone, and thus has excellent color reproducibility, and the polymer Since the fine particles act as a binder, the image-formed product is also excellent in scratch resistance. The volume average particle size (D ₅₀ ) of the aqueous dispersion of polymer fine particles containing the coloring material is preferably 0.01 to 0.20 μm in the ink.

  The self-dispersing pigment of the second form is a surface modified so that at least one hydrophilic group is bonded to the surface of the pigment directly or via another atomic group. In the surface modification, a specific functional group (a functional group such as a sulfone group or a carboxyl group) is chemically bonded to the surface of the pigment, or at least one of hypohalous acid and a salt thereof is used. A method such as wet oxidation is used. Among these, a form in which a carboxyl group is bonded to the surface of the pigment and dispersed in water is particularly preferable. Since the pigment is thus surface-modified and the carboxyl group is bonded, not only the dispersion stability is improved, but also high-quality print quality is obtained and the water resistance of the recording medium after printing is further improved. improves.

In addition, since the ink containing the self-dispersing pigment of the second form is excellent in redispersibility after drying, clogging does not occur even when printing is stopped for a long time and ink moisture near the inkjet head nozzle evaporates. Good printing can be easily performed with a simple cleaning operation. The volume average particle diameter (D ₅₀ ) of the self-dispersing pigment is preferably 0.01 to 0.20 μm in the ink.

For example, as the self-dispersing carbon black, those having ionicity are preferable, and those having an anionic charge are preferable.
Examples of the anionic hydrophilic group include —COOM, —SO ₃ M, —PO ₃ HM, —PO ₃ M ₂ , —SO ₂ NH ₂ , —SO ₂ NHCOR (where M is an alkali metal, ammonium or And R represents an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent. Among these, it is preferable to use those in which —COOM and —SO ₃ M are bonded to the surface of the color pigment.

  Further, “M” in the hydrophilic group includes, for example, lithium, sodium, potassium and the like as an alkali metal. Examples of the organic ammonium include mono to trimethyl ammonium, mono to triethyl ammonium, and mono to trimethanol ammonium. As a method of obtaining the anionically charged color pigment, as a method of introducing —COONa to the color pigment surface, for example, a method of oxidizing the color pigment with sodium hypochlorite, a method of sulfonation, a diazonium salt The method of making it react is mentioned.

The hydrophilic group may be bonded to the surface of carbon black via another atomic group. Examples of other atomic groups include an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent. Specific examples of the case where the hydrophilic group is bonded to the surface of carbon black through another atomic group include, for example, —C ₂ H ₄ COOM (where M represents an alkali metal or quaternary ammonium). ), -PhSO ₃ M (wherein Ph represents a phenyl group, M represents an alkali metal or quaternary ammonium).

  The content of the colorant in the inkjet ink is preferably 2 to 15% by mass and more preferably 3 to 12% by mass in terms of solid content. If the content is less than 2% by mass, the color developability and image density of the ink may be lowered, and if it exceeds 15% by mass, the ink may be thickened and the dischargeability may be deteriorated. There is not preferable.

―Water-soluble organic solvent―
As the water-soluble organic solvent used in the inkjet ink, a water-soluble organic solvent used in the treatment liquid is preferably used. In particular, a water-soluble organic solvent A having a high equilibrium water content is preferably used. The mass ratio of the water-dispersible colorant to the water-soluble organic solvent in the inkjet ink affects the ink ejection stability from the head. For example, when the solid content of the water-dispersible colorant is high but the blending amount of the water-soluble organic solvent is small, water evaporation near the ink meniscus of the nozzle may progress and cause ejection failure. The content of the water-soluble organic solvent in the inkjet ink is preferably 20 to 50% by mass, and more preferably 20 to 45% by mass. When the content is less than 20% by mass, there is a possibility that the ejection stability is lowered or the waste ink is fixed by the maintenance device of the ink jet recording apparatus. On the other hand, if it exceeds 50% by mass, the dryness on the paper surface is inferior and the character quality on plain paper may be lowered.

―Surfactant―
The surfactant used in the inkjet ink is preferably an anionic surfactant having a low surface tension, low penetrability, and high leveling property without losing dispersion stability depending on the type of the colorant or the combination of the water-soluble organic solvent. At least one selected from surfactants, nonionic surfactants, silicone surfactants and fluorosurfactants is preferred. Among these, silicone surfactants and fluorine surfactants are particularly preferable. These surfactants can be used alone or in combination of two or more.
As the surfactant used in the inkjet ink, the surfactant used in the treatment liquid is preferably used.

  The content of the surfactant in the inkjet ink is preferably 0.01 to 3.0% by mass, and more preferably 0.5 to 2% by mass. When the content is less than 0.01% by mass, the effect of adding a surfactant may be lost. When the content exceeds 3.0% by mass, the permeability to a recording medium becomes higher than necessary. There may be a decrease in the image density or a show-through.

―Penetration agent―
As the penetrant used in the inkjet ink, a penetrant used in the treatment liquid is preferably used. The content of the penetrant in the ink-jet ink is preferably 0.1 to 4.0% by mass. When the content is less than 0.1% by mass, quick-drying may not be obtained and a blurred image may be obtained. When the content exceeds 4.0% by mass, the dispersion stability of the colorant is impaired, and the nozzle In some cases, the image density is lowered or the back-through occurs, such as being easily clogged or having an unnecessarily high permeability to the recording medium.

―Water-dispersible resin―
The water-dispersible resin has excellent film-forming properties (image formability), high water repellency, high water resistance, and high weather resistance, and has high water resistance and high image density (high color development). Useful for. For example, a condensation synthetic resin, an addition synthetic resin, a natural polymer compound, and the like can be given.
Examples of the condensed synthetic resin include polyester resin, polyurethane resin, polyepoxy resin, polyamide resin, polyether resin, poly (meth) acrylic resin, acrylic-silicone resin, and fluorine-based resin.
Examples of the addition type synthetic resin include polyolefin resins, polystyrene resins, polyvinyl alcohol resins, polyvinyl ester resins, polyacrylic acid resins, unsaturated carboxylic acid resins, and the like.
Examples of the natural polymer compound include celluloses, rosins, and natural rubber.
Among these, polyurethane resin fine particles, acrylic-silicone resin fine particles, and fluorine-based resin fine particles are particularly preferable. Moreover, it is not a problem to use two or more kinds of the water-dispersible resins in combination.

As the fluorine resin fine particles, fluorine resin fine particles having a fluoroolefin unit are preferable, and among these, fluorine-containing vinyl ether resin fine particles composed of a fluoroolefin unit and a vinyl ether unit are particularly preferable.
As the fluoroolefin unit is not particularly limited and may be appropriately selected depending on the purpose, for example, _{-CF 2 CF 2 -, - CF} 2 CF (CF 3) -, - CF 2 CFCl- like It is done.
There is no restriction | limiting in particular as said vinyl ether unit, Although it can select suitably according to the objective, For example, the compound etc. which are represented with following Structural formula are mentioned.

As the fluorine-containing vinyl ether resin fine particles composed of the fluoroolefin unit and the vinyl ether unit, an alternating copolymer obtained by alternately copolymerizing the fluoroolefin unit and the vinyl ether unit is preferable.
As such fluorine-based resin fine particles, those appropriately synthesized may be used, or commercially available products may be used. Examples of the commercially available products include Fluorate FEM-500, FEM-600, Dickguard F-52S, F-90, F-90M, F-90N, and Aquafuran TE-5A manufactured by Dainippon Ink & Chemicals, Inc .; Asahi Glass Co., Ltd. Lumiflon FE4300, FE4500, FE4400, Asahi Guard AG-7105, AG-950, AG-7600, AG-7000, AG-1100, etc. are mentioned.
The water-dispersible resin may be used as a homopolymer, may be used as a copolymer and used as a composite resin, and any of a single-phase structure type, a core-shell type, and a power feed type emulsion Can be used.

  As the water-dispersible resin, a resin itself having a hydrophilic group and having a self-dispersibility, and a resin itself having no dispersibility and imparted with a surfactant or a resin having a hydrophilic group can be used. . Among these, an emulsion of resin particles obtained by emulsion and suspension polymerization of an ionomer of a polyester resin or a polyurethane resin or an unsaturated monomer is optimal. In the case of emulsion polymerization of an unsaturated monomer, the resin emulsion is reacted with water to which an unsaturated monomer, a polymerization initiator, a surfactant, a chain transfer agent, a chelating agent, and a pH adjusting agent are added. Therefore, a water-dispersible resin can be easily obtained, and the desired properties can be easily produced because the resin configuration can be easily changed.

  Examples of the unsaturated monomer include unsaturated carboxylic acids, monofunctional or polyfunctional (meth) acrylic acid ester monomers, (meth) acrylic acid amide monomers, and aromatic vinyl monomers. , Vinyl cyano compound monomers, vinyl monomers, allyl compound monomers, olefin monomers, diene monomers, oligomers having unsaturated carbon, etc., alone or in combination Can do. By combining these monomers, the properties can be flexibly modified, and the properties of the resin can be modified by performing a polymerization reaction or a graft reaction using an oligomer type polymerization initiator.

Examples of the unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid and the like.
Examples of the monofunctional (meth) acrylic acid ester monomers include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2 -Ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, methacryloxyethyltrimethylammonium Salt, 3-me Acryloxypropyltrimethoxysilane, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, decyl acrylate , Dodecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, dimethylaminoethyl acrylate, acryloxyethyl trimethyl ammonium salt, and the like.

  Examples of the polyfunctional (meth) acrylic acid ester monomers include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1, 4-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol dimethacrylate, 2,2′-bis (4-methacryloxy) Diethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, polyethylene Glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,9-nonanediol di Acrylate, polypropylene glycol diacrylate, 2,2′-bis (4-acryloxypropyloxyphenyl) propane, 2,2′-bis (4-acryloxydiethoxyphenyl) propane trimethylolpropane triacrylate, trimethylolethanetri Acrylate, tetramethylol methane triacrylate, ditrimethylol tetraacrylate, tetramethylol methane tetraacrylate, pentaerythritol tetraacrylate, Pentaerythritol hexaacrylate, and the like.

Examples of the (meth) acrylic acid amide monomers include acrylamide, methacrylamide, N, N-dimethylacrylamide, methylenebisacrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and the like.
Examples of the aromatic vinyl monomers include styrene, α-methylstyrene, vinyltoluene, 4-t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene, divinylbenzene, and the like.
Examples of the vinyl cyano compound monomers include acrylonitrile and methacrylonitrile.
Examples of the vinyl monomers include vinyl acetate, vinylidene chloride, vinyl chloride, vinyl ether, vinyl ketone, vinyl pyrrolidone, vinyl sulfonic acid or salts thereof, vinyl trimethoxysilane, vinyl triethoxysilane, and the like.
Examples of the allyl compound monomers include allyl sulfonic acid salt thereof, allylamine, allyl chloride, diallylamine, diallyldimethylammonium salt, and the like.
Examples of the olefin monomers include ethylene and propylene.
Examples of the diene monomers include butadiene and chloroprene.
Examples of the oligomers having unsaturated carbon include styrene oligomers having methacryloyl groups, styrene-acrylonitrile oligomers having methacryloyl groups, methyl methacrylate oligomers having methacryloyl groups, dimethylsiloxane oligomers having methacryloyl groups, and polyesters having acryloyl groups. An oligomer etc. are mentioned.

  The water-dispersible resin has a strong alkalinity and strong acidity, and causes molecular breakage such as dispersion breakage and hydrolysis. Therefore, the pH is preferably 4 to 12, particularly from the viewpoint of miscibility with a water-dispersible colorant. As for pH, 6-11 are more preferable, and 7-9 are still more preferable.

The average particle diameter (D ₅₀ ) of the water-dispersible resin is related to the viscosity of the dispersion. When the composition is the same, the viscosity at the same solid content increases as the particle diameter decreases. The average particle diameter (D ₅₀ ) of the water-dispersible resin is preferably 50 nm or more so that the viscosity does not become excessively high when converted into an ink. Further, when the particle size is several tens of μm, it becomes larger than the nozzle opening of the ink jet head and cannot be used. If particles having a large particle diameter are present in the ink even if they are smaller than the nozzle opening, the discharge property is deteriorated. Therefore, the average particle diameter (D ₅₀ ) is preferably 200 nm or less, and more preferably 150 nm or less, in order not to inhibit the ink discharge properties.

The water-dispersible resin has a function of fixing the water-dispersed colorant on the paper surface, and is preferably formed into a film at room temperature to improve the fixability of the color material. Therefore, it is preferable that the minimum film-forming temperature (MFT) of the water-dispersible resin is 30 ° C. or less. Further, when the glass transition temperature of the water-dispersible resin is -40 ° C. or lower, the resin film becomes more viscous and the printed matter is tacky. Therefore, the water-dispersible resin has a glass transition temperature of −30 ° C. or higher. It is preferable.
The content of the water-dispersible resin in the inkjet ink is preferably 1 to 15% by mass, more preferably 2 to 7% by mass in terms of solid content.

  Here, the solid content of the inkjet ink can be measured, for example, by a method of separating only the water-dispersible colorant and the water-dispersible resin component from the inkjet ink. Further, when a pigment is used as the water-dispersible colorant, the ratio of the colorant to the water-dispersible resin can be measured by evaluating the mass reduction rate by thermal mass spectrometry. In addition, when the molecular structure of the water-dispersible colorant is clear, the solid content of the colorant can be quantified using NMR for pigments and dyes, and the inorganic pigment contained in the heavy metal atom, molecular skeleton, For the metal-containing organic pigment and the metal-containing dye, the solid content of the colorant can be quantified by using fluorescent X-ray analysis.

―Other ingredients―
The other components are not particularly limited and may be appropriately selected as necessary. For example, a pH adjuster, antiseptic / antifungal agent, chelating reagent, rust inhibitor, antioxidant, ultraviolet absorber, oxygen An absorber, a light stabilizer, etc. are mentioned.

  The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 to 11 without adversely affecting the ink jet ink to be prepared, and can be appropriately selected according to the purpose. Examples include alcohol amines, alkali metal hydroxides, ammonium hydroxides, phosphonium hydroxides, alkali metal carbonates, and the like. If the pH is less than 7 or more than 11, the amount of the ink jet head or ink supply unit that melts out is large, and problems such as ink deterioration, leakage, and ejection failure may occur.

Examples of the alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, and the like.
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide.
Examples of the ammonium hydroxide include ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, and the like.
Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, and potassium carbonate.

  Examples of the antiseptic / antifungal agent include sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1-oxide sodium, sodium benzoate, sodium pentachlorophenol, and the like.

Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate, and the like.
Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

Examples of the antioxidant include phenolic antioxidants (including hindered phenolic antioxidants), amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.
Examples of the ultraviolet absorber include a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, a salicylate ultraviolet absorber, a cyanoacrylate ultraviolet absorber, and a nickel complex ultraviolet absorber.

―Inkjet ink manufacturing process―
The ink-jet ink is prepared by dispersing or dissolving a water-dispersible colorant, a water-soluble organic solvent, a surfactant, a penetrating agent and water, and other components in an aqueous medium as necessary, and stirring as necessary. Produced by mixing. The stirring and mixing can be performed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, and the like. Can be done.

―Inkjet ink properties―
There is no restriction | limiting in particular as a physical property of the said inkjet ink, According to the objective, it can select suitably, For example, it is preferable that a viscosity, surface tension, etc. are the following ranges.
The viscosity of the inkjet ink at 25 ° C. is preferably 5 to 20 mPa · s. By setting the ink viscosity to 5 mPa · s or more, the effect of improving the printing density and the character quality can be obtained. On the other hand, by suppressing the ink viscosity to 20 mPa · s or less, it is possible to ensure the discharge performance. Here, the said viscosity can be measured at 25 degreeC, for example using a viscometer (RE-550L, Toki Sangyo Co., Ltd. make).

  The static surface tension of the inkjet ink is preferably 20 to 35 mN / m at 25 ° C., more preferably 20 to 30 mN / m or less. When the ink jet ink has a static surface tension of 20 to 35 mN / m, it is highly effective in reducing bleeding by increasing the permeability, and the drying property on plain paper is improved. By being easily wetted with the treatment layer, the color developability is good and white spots are also improved. When the surface tension exceeds 35 mN / m, leveling of the ink on the recording material is difficult to occur and the drying time may be prolonged.

  There is no restriction | limiting in particular as coloring of the said inkjet ink, According to the objective, it can select suitably, Yellow, magenta, cyan, black etc. are mentioned. When recording is performed using an ink set in which two or more of these colorings are used in combination, a multicolor image can be formed. When recording is performed using an ink set in which all colors are combined, a full color image is formed. be able to.

  The ink-jet ink uses an piezoelectric head as a pressure generating means for pressurizing ink in the ink flow path as an ink-jet head, and deforms a diaphragm that forms the wall surface of the ink flow path to change the volume in the ink flow path. A so-called piezo type that discharges ink droplets (refer to Japanese Patent Laid-Open No. 2-51734), or a so-called thermal type that generates bubbles by heating ink in an ink flow path using a heating resistor ( JP, 61-59911, A), the diaphragm which forms the wall surface of an ink channel, and an electrode are arranged opposite, and a diaphragm is deformed by the electrostatic force generated between a diaphragm and an electrode, Mounted with any ink jet head such as an electrostatic type (see JP-A-6-71882) that discharges ink droplets by changing the volume of the ink flow path It can also be successfully used in that printer.

  The ink-jet ink can be used, for example, in a printer having a function of promoting printing and fixing by heating a recording medium and the ink-jet ink at 50 to 200 ° C. at the time of printing or before and after printing.

<Recording media>
As the recording medium, plain paper having no coating layer is preferably used, and plain paper having a sizing degree of 10 S or more and an air permeability of 5 to 50 S, which is generally used as a copy sheet, is preferred.

<Inkjet recording method>
The ink jet recording method of the present invention comprises a treatment step of applying the treatment liquid of the present invention to a recording medium, and applying the stimulus to the ink jet ink, and applying the ink jet ink to the recording medium coated with the treatment liquid. And an ink flying step of flying to form an image.

―Processing process―
The treatment step may be any coating method that uniformly coats the treatment liquid on the surface of the recording medium, and is not particularly limited. Examples of such coating methods include blade coating, gravure coating, gravure offset coating, bar coating, roll coating, knife coating, air knife coating, comma coating, U comma coating, and AKKU coating. Method, smoothing coating method, micro gravure coating method, reverse roll coating method, 4 to 5 roll coating method, dip coating method, curtain coating method, slide coating method, die coating method and the like. In particular, a means for applying the treatment by impregnating the rotating body with the processing liquid and bringing the impregnated rotating body into contact with the recording medium makes it possible to uniformly apply the processing liquid.
Wet adhesion amount to the recording medium of the processing solution in said processing step is preferably intended to achieve the range of ^{0.1g / m 2 ~30.0g / m 2} , more preferably 0.2 to 10 0.0 g / m ² . If the adhesion amount is less than 0.1 g / m ² , the image quality (image density, saturation, color bleed, character bleeding and white spot) may hardly be improved, and the amount exceeds 30.0 g / m ² . The texture of plain paper may be impaired, and curling may occur.

―Ink flight process―
The ink flying step in the ink jet recording method of the present invention includes applying an stimulus (energy) to the ink jet ink and causing the ink jet ink to fly onto the recording medium coated with the treatment liquid, thereby forming an image on the recording medium. Is a step of forming. As the method for forming the image on the recording medium by flying the ink-jet ink on the recording medium in the ink flying step, any known ink-jet recording method can be applied. Examples of such a method include an ink jet recording method in which a head is scanned, and an ink jet recording method in which an image is recorded on a single sheet of recording medium by using a lined head.

  In the ink flying process, there is no particular limitation on the driving method of the recording head, which is an ink flying means, a piezoelectric element actuator using PZT, a method of applying thermal energy, an on demand using an actuator using electrostatic force, etc. A recording head can be used, and recording can be performed with a continuous ejection type charge control type head. In the method of applying thermal energy, it is difficult to freely control the ejection of droplets, and there is a tendency for variations in the image due to the type of recording media to be large. By adding to the above, these problems are solved, and stable high image quality can be obtained regardless of the type of recording medium.

―Recording media drying process―
In the ink jet recording method of the present invention, it is preferable to provide a step of drying the recording medium before the step of applying the treatment liquid.
The recording medium drying step is not particularly limited as long as it is a method for evaporating moisture in the recording medium. Such a drying process of the recording medium can be easily performed by a known heating means such as a heater, a blowing means for applying hot air, hot air, dry air, or a combination of these. The drying process may be performed while the recording medium is being transported, or the cassette before being transported may be dehumidified and dried to transport the dried recording medium.

-apparatus-
An apparatus for applying a treatment liquid to a recording medium after drying the recording medium of the present invention and forming an image with the inkjet ink will be described with reference to a specific example of FIG. The apparatus shown in FIG. 1 is a type of recording apparatus that scans an inkjet recording head to form an image.
In the ink jet recording apparatus of FIG. 1, the recording medium 6 is sent out by a paper feed roller 7 at a paper feed section (dashed line A in FIG. 1) and heated to 100 ° C. or more at a drying section (dashed line B in FIG. 1). After being heated and dried by the heated roller 8 and the pressure roller 9, the treatment liquid 1 is uniformly and thinly applied to the recording medium 6 by the applying roller 4 and the counter roller 5 at the application portion (broken line portion C in FIG. 1). Is done. The processing liquid 1 is pumped up by the pumping roller 3 and is uniformly applied to the applying roller 4 by the film thickness control roller 2. The recording medium 6 to which the treatment liquid 1 is applied is sent to a recording scanning portion (dashed line D) where the inkjet recording head 20 is located. Since the length of the paper path from the coating portion (dashed line portion C in FIG. 1) to the recording scan start portion (FIG. 1D) is set to be longer than the length in the feed direction of the recording medium, the recording medium becomes the recording scan start portion. When it reaches, the application of the treatment liquid can be completely completed. In this case, the treatment liquid can be applied before the ink jet recording head 20 starts printing and the recording medium 6 is transported, so that the transport speed of the recording medium 6 can be continuously applied. , Uniform application without unevenness is possible.

Completion of application can be detected, for example, by providing a known recording medium detection means (not shown) in the vicinity of the outlet of the treatment liquid application apparatus. This detection means is not necessarily required. Information on the length of the recording medium is input to the controller in advance, and the number of rotations of the motor is controlled, so that the feed amount of the recording medium conveyance roller can be adjusted. A system configuration corresponding to the length may be adopted.
The recording medium 6 to which the processing liquid 1 is applied is transported to the recording scanning position again before the processing liquid is dried and solidified. In this case, the recording medium 6 is transported in time with the ink jet recording head 20. Is done.
The drying unit (broken line B in FIG. 1) uses a heating roller as an example, but it is replaced with the above-mentioned known heating means, blowing means for applying hot air, hot air, dry air, or a combination of these. May be. Furthermore, it is also effective to dry the paper by lowering the humidity in the paper feeding unit (broken line A in FIG. 1).

  It is preferable that the recording media are dried and applied in a continuous manner at a constant linear velocity of 10 to 1000 mm / s. For this reason, in this example of the apparatus, using a single-sheet recording medium, and looking at a single-sheet recording medium, a process of applying a treatment liquid after drying the recording medium is set as a set. After finishing the sheet processing, the process of recording an image by the ink jet recording method is started.

  As is apparent from the recording medium conveyance process in this apparatus, after the treatment liquid is applied, the recording medium to which the treatment liquid is applied is used for recording such as rollers, rollers, and guides in order to form an image. In many cases, it is necessary to transport the recording medium by means of contact with the medium. In such a case, if the processing liquid applied to the recording medium is transferred to the recording medium conveyance member, the conveyance function may be impaired, dirt may accumulate, and image quality may deteriorate. Cause the problem of end. In order to prevent this problem, measures such as making the guide into corrugated plates, rolling rollers into a spur shape, or using a water-repellent material on the surface of the roller are alleviated from the device side. Can do.

  However, it is desirable that the treatment liquid applied to the recording medium is absorbed into the recording medium as quickly as possible and apparently dried. In order to achieve this object, it is effective to set the surface tension of the treatment liquid to 40 mN / m or less so that the liquid quickly penetrates into the recording medium. “Dry solidification” after application of the treatment liquid does not mean that the treatment liquid is absorbed into the recording medium as described above, and apparently becomes dry. It means that it evaporates and cannot solidify and solidifies. By using the recording apparatus in which the processing liquid application apparatus and the image recording apparatus are combined as described above, the processing liquid according to the present invention is absorbed by the recording medium and apparently dried. Even in such a case, ink jet recording can be performed in a state where the processing liquid is not solidified, and the image quality can be remarkably improved even when the amount of the processing liquid applied is extremely small.

  In order to control the operation of the apparatus shown in FIG. 1, upon receiving a print command from a host machine such as a personal computer, the heating roller heating, processing liquid application / image forming apparatus performs head cleaning work and processing liquid coating work. Start at the same time, and start recording when all preparations are complete. Processing liquid coating, head cleaning, ejection check operation and image data processing / image data transfer are processed in parallel, so that even when processing liquid coating work is performed, image recording is performed without substantially reducing the throughput of the printing recording apparatus. Is possible.

Examples of the present invention will be described below, but the present invention is not limited to these examples.
Examples 1-80, Comparative Examples 1-55
(Preparation Example 1)
<Preparation of treatment liquid>
Each treatment solution was manufactured according to the following procedure. First, the materials shown in Tables 1 to 8 below are mixed and stirred for 1 hour to mix uniformly. This treatment liquid was subjected to pressure filtration with a polyvinylidene fluoride membrane filter having an average pore size of 5.0 μm to remove coarse particles and dust, thereby producing treatment liquid examples 1 to 74.

The abbreviations in Tables 1 to 8 have the following meanings.
* Calcium nitrate: Calcium nitrate tetrahydrate, Wako Pure Chemical Industries, purity 98.5%
* Lactic acid: manufactured by Tokyo Chemical Industry, purity of 85% or more * Ammonium lactate: manufactured by Musashino Chemical Laboratory, purity 66%
* Ammonium acetate: Wako Pure Chemical Industries, purity 95%
* Charol DC902C:
Cationic polymer (dimethyldiallylammonium chloride homopolymer),
Daiichi Kogyo Seiyaku, molecular weight 9000, active ingredient 51.5%
* Polyfix 301:
Cationic polymer (polyamide, epichlorohydrin polymer),
Showa Polymer, molecular weight 3000, active ingredient 30%
* Araffix 255LOX:
Cationic polymer (epichlorohydrin polymer), active ingredient 25%
* DK-856: Cationic polymer (polyamine resin), 50% active ingredient
* DK-6830:
Cationic polymer (polyamide, epichlorohydrin polymer), 55% active ingredient
* Zonyl FS-300:
Polyoxyethylene perfluoroalkyl ether (manufactured by Dupont, 40% by mass of active ingredient)
* Mega Fuck F-444:
Perfluoroalkyl compound (made by DIC, active ingredient 99% or more)
* Silicone FZ2105: Silicone (Toray Dow Corning, active ingredient 99% or more)
* Softanol EP-7025:
Polyoxyalkylene alkyl ether (manufactured by Nippon Shokubai Co., Ltd., component 100% by mass)
* Proxel GXL:
Antifungal agent based on 1,2-benzisothiazolin-3-one (manufactured by Avicia, 20% by mass, containing dipropylene glycol)

(Preparation Example 2)
<Preparation of pigment-containing polymer fine particle dispersion>
-Preparation of polymer solution A-
After sufficiently replacing the inside of a 1 L flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet tube, reflux tube, and dropping funnel, 11.2 g of styrene, 2.8 g of acrylic acid, 12.0 g of lauryl methacrylate Then, 4.0 g of polyethylene glycol methacrylate, 4.0 g of styrene macromer, and 0.4 g of mercaptoethanol were mixed and heated to 65 ° C.
Next, 100.8 g of styrene, 25.2 g of acrylic acid, 108.0 g of lauryl methacrylate, 36.0 g of polyethylene glycol methacrylate, 60.0 g of hydroxylethyl methacrylate, 36.0 g of styrene macromer, 3.6 g of mercaptoethanol, azobismethylvalero A mixed solution of 2.4 g of nitrile and 18 g of methyl ethyl ketone was dropped into the flask over 2.5 hours. After dropping, a mixed solution of 0.8 g of azobismethylvaleronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hours. After aging at 65 ° C. for 1 hour, 0.8 g of azobismethylvaleronitrile was added and further aging was performed for 1 hour. After completion of the reaction, 364 g of methyl ethyl ketone was added to the flask to obtain 800 g of a polymer solution A having a concentration of 50% by mass.

-Preparation of pigment-containing polymer fine particle dispersion-
28 g of the polymer solution A, 42 g of the coloring material shown in Table 9, 13.6 g of a 1 mol / L potassium hydroxide aqueous solution, 20 g of methyl ethyl ketone, and 13.6 g of ion-exchanged water were sufficiently stirred and then kneaded using a roll mill. did. The obtained paste was put into 200 g of pure water and stirred sufficiently, and then methyl ethyl ketone and water were distilled off using an evaporator, and this dispersion was further removed with polyvinylidene fluoride having an average pore size of 5.0 μm to remove coarse particles. By pressure filtration with a membrane filter, a pigment-containing polymer fine particle dispersion having a pigment content of 15% by mass and a solid content of 20% by mass was obtained. The average particle diameter (D ₅₀ ) of the polymer fine particles in the obtained pigment-containing polymer fine particle dispersion was measured and is shown in Table 9. The measurement of the average particle diameter (D ₅₀₎ particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., NANOTRAC UPA-EX150) was used.

(Preparation Example 3)
<Preparation of inkjet ink>
Each inkjet ink was produced according to the following procedure. First, a water-soluble organic solvent (wetting agent), a penetrating agent, a surfactant, an antifungal agent, and water shown in Table 10 below are mixed and stirred uniformly for 1 hour. Depending on the mixed solution, a water-dispersible resin is added and stirred for 1 hour, and a pigment dispersion, an antifoaming agent, and a pH adjuster are added and stirred for 1 hour. This dispersion was subjected to pressure filtration with a polyvinylidene fluoride membrane filter having an average pore size of 5.0 μm to remove coarse particles and dust, and ink jet inks of Ink Preparation Examples 1 to 8 were produced.

Abbreviations and the like in Table 10 represent the following meanings.
* Magenta pigment-containing polymer fine particle dispersion (Table 9)
* Cyan pigment-containing polymer fine particle dispersion (Table 9)
* Yellow pigment-containing polymer fine particle dispersion (Table 9)
* Black pigment-containing polymer fine particle dispersion (Table 9)
* CAB-O-JET 260:
Made by CABOT, pigment solid content 11%, magenta self-dispersing pigment,
The average particle diameter (D ₅₀₎ 125 nm
* CAB-O-JET 250:
Made by CABOT, pigment solid content 11%, cyan self-dispersing pigment,
The average particle diameter (D ₅₀₎ 110 nm
* CAB-O-JET 270:
Made by CABOT, pigment solid content 11%, yellow self-dispersing pigment,
The average particle diameter (D ₅₀₎ 170 nm
* CAB-O-JET 300:
Made by CABOT, pigment solid content 15%, black self-dispersing pigment,
The average particle diameter (D ₅₀₎ 130 nm
* Fluoropolymer emulsion:
Asahi Glass Co., Ltd., Lumiflon FE4500, solid content 52% by mass,
Average particle size 136 nm, minimum film-forming temperature (MFT) = 28 ° C.
* Acrylic-silicone resin emulsion:
Showa Polymer Co., Ltd., Polysol ROY6312, solid content 40% by mass,
Average particle diameter 171 nm, minimum film-forming temperature (MFT) = 20 ° C.
* KF-640: polyether-modified silicone surfactant
(Shin-Etsu Chemical Co., Ltd., 100% by mass of ingredients)
* Softanol EP-7025: Polyoxyalkylene alkyl ether
(Nippon Shokubai Co., Ltd., 100 mass% component)
* Proxel GXL:
Antifungal agent based on 1,2-benzisothiazolin-3-one (manufactured by Avicia, 20% by mass, containing dipropylene glycol)
* KM-72F:
Self-emulsifying silicone defoamer (Shin-Etsu Silicone Co., Ltd., 100% by mass)

<Drying process>
Drying step (1): With the recording medium taken out of the packing paper, leave it in a desiccator kept at 23 ° C. ± 1.0 ° C. and 20% RH for 1 day or more, and apply the treatment liquid or use a printer Removed immediately before printing.
Drying process (2): Dry with a dryer (Praget PJ-208A 100V-1000W (manufactured by Ishizaki Electric Manufacturing Co., Ltd.) for 5 seconds on each side and apply treatment liquid immediately after drying or print with a printer Went.
Drying step (3): As a heat drying method, an apparatus as shown by broken line B in FIG.
A heating roller having a heat-resistant silicone thin film layer on a plated iron material and a roller having the same configuration as the heating roller were used as a pressure roller. A halogen lamp is provided inside the cylinder of the heating roller, and roller heating is performed by an inner surface heating method. A driving motor is connected to the heating roller by a gear. The heating roller can be driven by arbitrarily changing the rotation speed. When the paper is manually introduced between the heating roller and the pressure roller, the paper is heated and dried.
The heating roller was heated to 120 ° C., and immediately after passing through the recording medium at a conveying speed of 200 mm / sec, the treatment liquid was applied or printed by a printer.

<Coating process>
In the coating process, an apparatus such as a coating part indicated by a broken line C in FIG.
As a coating roller, a roller made of SUS304 material having a diameter of 12 mm was used as a roller in which a coated iron material having a diameter of 22 mm was coated with chloroprene rubber having a thickness of 3 mm and a rubber hardness of 50 degrees. The lengths of the rollers in the longitudinal direction are all 300 mm. The coating liquid storage tank is disposed so that the distance between the lower end of the coating roller and the bottom of the storage container is 2 mm. A driving motor is connected to the application roller by a gear. The application roller can be driven with arbitrarily changing the rotation speed. When the paper is manually introduced between the application roller and the counter roller, the application liquid is applied to the lower surface side of the paper.
By arbitrarily changing the conveying speed, the coating liquid was applied so that the coating amount of the processing liquid became constant.

<Image formation>
In an environment adjusted to a temperature of 23 ± 0.5 ° C. and 50 ± 5% RH, after performing the drying process on the recording medium under the conditions shown in Tables 11 to 14, immediately after the application process, Immediately after the treatment liquid was applied to the printing surface, printing was performed using an ink jet printer (IPSiO GX5000, manufactured by Ricoh Co., Ltd.). The printer was set such that the drive voltage of the piezo element was varied so that the amount of ink discharged was uniform, and the same amount of ink was applied to the recording medium.

Details of the recording media used in Examples and Comparative Examples are shown.
* My_paper: Ricoh Co., Ltd. (fine paper) basis weight 69.6 g / m ² , size 23.2 seconds, air permeability 21 seconds

<Curl evaluation>
Set to the limit of the printing range created with Microsoft Word2000 ■ When a solid chart is ejected onto a recording medium and placed on a flat surface with the printing surface facing down within 5 seconds after printing, the flat surface of the 4 smears of the recording medium The height was measured and judged according to the following evaluation criteria. The print mode was printed with the driver attached to the printer in the "plain paper-standard fast" mode and color matching off. Evaluation was based on the worst of each color as a criterion.
[Color specification for "■" part]
Black: (R) 0, (G) 0, (B) 0
Yellow: (R) 255, (G) 255, (B) 0
Magenta: (R) 255, (G) 0, (B) 255
Cyan: (R) 0, (G) 0, (B) 255
〔Evaluation criteria〕
◎: Less than 20 mm ○: 20 mm or more and less than 30 mm △: 30 mm or more and less than 40 mm ×: 40 mm or more

<Image density>
A chart with 64 point characters “■” created by Microsoft Word 2000 was printed on a recording medium, and the “■” portion of the printed surface was measured with X-Rite 938, and judged according to the following evaluation criteria. The print mode was printed with “plain paper-standard fast” mode color matching off with the driver attached to the printer.
[Color specification for "■" part]
Black: (R) 0, (G) 0, (B) 0
Yellow: (R) 255, (G) 255, (B) 0
Magenta: (R) 255, (G) 0, (B) 255
Cyan: (R) 0, (G) 0, (B) 255

〔Evaluation criteria〕
: Black: 1.3 or more Yellow: 0.85 or more Magenta: 1.05 or more Cyan: 1.1 or more ○: Black: 1.2 or more and less than 1.3 Yellow: 0.8 or more and less than 0.85 Magenta: 1.0 to less than 1.05 Cyan: 1.0 to less than 1.1 Δ: Black: 1.15 to less than 1.2 Yellow: 0.75 to less than 0.8 Magenta: 0.95 to less than 1.0 Cyan: 0.95 or more and less than 1.0 X: Black: less than 1.15 Yellow: less than 0.75 Magenta: less than 0.95 Cyan: less than 0.95

<Image saturation>
Similar to the image density, a chart was printed on a recording medium, and the “■” portion of the printed surface was measured by X-Rite 938, and judged according to the following evaluation criteria. The print mode was printed with “plain paper-standard fast” mode color matching off with the driver attached to the printer.
The ratio of the saturation value of the standard color (Japan color ver. 2) to the measured saturation value (Yellow: 91.34, Magenta: 74.55, Cyan: 62.82) was calculated, and the following evaluation was performed. Judgment was made according to criteria.
〔Evaluation criteria〕
◎: 0.85 or more ○: 0.8 or more and less than 0.85 △: 0.75 or more and less than 0.8 ×: Less than 0.75

<Offset>
As with image density, a chart is printed on a recording medium, and a polyethylene cylindrical roller with a diameter of 40 mm is applied to the “■” portion of 40 mm length on the printing surface within 5 seconds after printing, and the strength is 5N. The portion where the ink was re-transferred from the cylindrical roller to the recording medium was measured by X-Rite 938, and judged according to the following evaluation criteria. The print mode was printed with “plain paper-standard clean” mode color matching off with a driver attached to the printer.
〔Evaluation criteria〕
◎: Less than 0.1 ○: 0.1 or more and less than 0.15 Δ: 0.15 or more and less than 0.2 ×: 0.2 or more

<Fixability>
A chart with a 3cm x 3cm mono black solid image created by Microsoft Word 2000 was ejected onto a recording medium and dried at a temperature of 23 ± 1 ° C and a humidity of 50 ± 10% for 24 hours. -1 type clock meter attached with double-sided tape JIS L 0803 Cotton 3 was reciprocated 5 times so that it touches the printed part, and then the ink adhesion stain on the cotton cloth was measured with X-Rite 938. By subtracting, the density of the soiled part was determined according to the following evaluation criteria.
〔Evaluation criteria〕
◎: Less than 0.05 ○: 0.05 or more and less than 0.1 Δ: 0.1 or more and less than 0.2 ×: 0.2 or more

<Storage stability>
The treatment liquid of Preparation Example 1 was prepared in the same manner as when the image was evaluated, and was left in a constant temperature bath at 70 ° C. for 2 weeks, and the viscosity change rate of the treatment liquid before and after being left in the constant temperature bath was measured. The viscosity of the treatment liquid was measured in the same manner as the ink viscosity.
◎: Viscosity change less than 5% ○: Viscosity change 5% or more and less than 10% △: Viscosity change 10% or more and less than 20% ×: Viscosity change 20% or more The results are shown in Tables 15 to 18, but the evaluation is based on evaluation criteria. Based on each color, it was evaluated. Therefore, each image quality result describes the judgment with the highest evaluation in the result. In the case of the same number of evaluation judgments, the better one is described in the result.

  The treatment liquid of the present invention can be applied to various types of recording by the ink jet recording method, and can be particularly suitably applied to, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, a printer / fax / copier multifunction machine, and the like. it can.

DESCRIPTION OF SYMBOLS 1 Processing liquid 2 Film thickness control roller 3 Pumping roller 4 Giving roller 5 Counter roller 6 Recording medium 7 Feeding roller 8 Heating roller 9 Pressure roller 10-15 Recording medium feed roller 16 Conveying belt 17 Recording medium 20 Recording head

JP 2001-199151 A WO00 / 06390 pamphlet JP 2007-276387 A JP 2004-155868 A Japanese Patent No. 4487475 JP 2005-297549 A Japanese Patent Laid-Open No. 06-239013 JP-A-11-002973

Claims (9)

In a treatment liquid used in an inkjet recording method, the method includes a step of applying a treatment liquid to a recording medium, and a step of forming an image by discharging ink containing a coloring material onto the recording medium.
The treatment liquid contains at least a water-soluble flocculant, a surfactant, a water-soluble organic solvent, water,
The water-soluble organic solvent contained in the treatment liquid is 40% by mass or more based on the total amount of the treatment liquid,
A water-soluble organic solvent having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80%, containing 15% by mass or more based on the total amount of the treatment liquid;
A water-soluble organic solvent having an equilibrium water content of 6% by mass to less than 20% by mass at a temperature of 23 ° C. and a humidity of 80%, containing 40% by mass or more of the entire water-soluble organic solvent,
The water-soluble organic solvent having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% is a polyhydric alcohol having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80%,
The water-soluble organic solvent having an equilibrium water content of 6 mass% or more and less than 20 mass% when the temperature is 23 ° C. and 80% humidity is 6 mass% or more and less than 20 mass% when the temperature is 23 ° C. and the humidity is 80%. A treatment liquid, characterized by being a polyhydric alcohol alkyl ether .   As the water-soluble organic solvent having an equilibrium water content of 6% by mass or more and less than 20% by mass at a temperature of 23 ° C. and a humidity of 80%, isobutyl diglycol, tripropylene glycol monomethyl ether, 2- (2-isopropyloxyethoxy) ethanol The processing liquid according to claim 1, comprising any of them.   2. The water-soluble organic solvent having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% includes any one of 1,3-butanediol, triethylene glycol, and glycerin. Or the processing liquid of Claim 2.   The processing liquid according to any one of claims 1 to 3, wherein the processing liquid is used in an ink jet recording method provided with a step of drying a recording medium before the step of applying the processing liquid.   5. The treatment liquid according to claim 4, wherein the drying step is performed by a heating unit, warm air, hot air, a blowing unit that applies dry air, or a combination thereof.   The water-soluble flocculant contained in the treatment liquid contains a polyvalent metal salt, a water-soluble organic acid, or an ammonium salt of a water-soluble organic acid. Treatment liquid.   A set of the treatment liquid and the ink according to any one of claims 1 to 6, wherein the ink contains a polymer emulsion in which a pigment is contained in polymer fine particles or a self-dispersing pigment. Set of treatment liquid and ink.   In an ink jet recording apparatus having means for applying a processing liquid to a recording medium and means for forming an image by ejecting ink containing a coloring material onto the recording medium, the processing liquid is defined as the processing liquid. 6. The means for applying the processing liquid using the processing liquid according to claim 6 is means for applying the processing liquid by impregnating the rotating body with the processing liquid and bringing the impregnated rotating body into contact with the recording medium. An ink jet recording apparatus.   In an ink jet recording method comprising a step of applying a treatment liquid to a recording medium and a step of forming an image by ejecting ink containing a coloring material onto the recording medium, the treatment liquid is defined as claims 1 to 6. An ink jet recording method comprising using the treatment liquid according to any one of the above.

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