JP2000063719A - Ink composition for ink jet recording and recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition for ink jet recording, capable of realizing brilliant printing even on plain paper and capable of ensuring quick dryability, in an ink jet recording method for printing a recording medium with a reactive solution and the ink composition, and to provide a method for recording. SOLUTION: An ink composition for ink jet recording comprises at least a pigment, polymer particles, an aqueous organic solvent, and water, and adopts a polyvalent metal salt as a reactant of a reaction solution. Therein, when the 0.1 wt.% aqueous dispersion of the polymer particles is mixed with an aqueous solution containing the polyvalent metal salt, aggregates comprising the added polyvalent metal salt and the polymer particles in a (polyvalent metal salt/polymer particle) weight ratio of <=50 are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition for ink jet recording and a recording method, and in particular, an ink composition and a reaction liquid containing at least a pigment, polymer fine particles, a water-soluble organic solvent, and water, and the above ink composition. The present invention relates to an inkjet recording method in which printing is performed by attaching the ink.

<Background Art> An ink jet recording method is
This is a printing method in which droplets of the ink composition are ejected and deposited on a recording medium such as paper to perform printing. This method is characterized in that it is possible to print a high-resolution, high-quality image at high speed with a relatively inexpensive device. In general, an ink composition used for ink jet recording contains water as a main component and a coloring component and a wetting agent such as glycerin for the purpose of preventing clogging.

On the other hand, as an ink jet recording method, recently, a method of applying a polyvalent metal salt solution to a recording medium and then applying an ink composition containing a dye having at least one carboxyl group has been proposed ( For example, JP-A-5-202328). In this way,
It is said that an insoluble complex is formed from a polyvalent metal ion and a dye, and the presence of this complex makes it possible to obtain a high-quality image having water resistance and no color bleed.

Further, a color ink containing at least a surfactant or a penetrating solvent which imparts penetrability and a salt, and a black ink which thickens or aggregates by the action of the salt are used in combination to obtain an image. It has also been proposed that a high-quality color image having high density and no color bleed can be obtained (JP-A-6-10673).
No. 5). That is, an inkjet recording method has been proposed in which a good image can be obtained by printing two liquids of a first liquid containing a salt and an ink composition.

In addition to the above, an ink jet recording method for printing two liquids has been proposed (for example, Japanese Patent Laid-Open No. Hei 3-
240557 and Japanese Patent Laid-Open No. 3-240558).

Further, in JP-A-3-157464, a pigment,
It comprises a polymer dispersant, an aqueous medium and an acetylene glycol-based penetrant, the aqueous medium comprises a non-volatile organic solvent and a lower alcohol, and the addition amount in the ink is 0.5% by weight to
Ink compositions in the range of 1% by weight have been proposed.
However, although this ink composition is excellent in quick-drying property,
When printing on plain paper, bleeding occurs.

An object of the present invention is to provide an ink jet recording ink composition and a recording method which can realize sharp printing without bleeding even on plain paper in an ink jet recording method using a two-component liquid and is excellent in quick-drying. And

[0008]

SUMMARY OF THE INVENTION The present inventors have proposed a recording method in which a first liquid containing a polyvalent metal salt and an ink composition containing at least a pigment, polymer fine particles, a water-soluble organic solvent, and water are applied. It has been found that high printing quality and quick-drying printing can be achieved on plain paper when the coagulation reactivity between salt and polymer particles is high. The present invention is based on such findings.

A reaction liquid containing a polyvalent metal salt and a colorant,
In an inkjet recording method of forming an image by adhering an ink composition containing at least polymer fine particles, a water-soluble organic solvent, and water to a recording medium, when the colorant is a pigment, the reaction liquid and the ink composition described above are used. When and are contacted not only with high-quality paper but also with the surfaces of recording media such as plain paper and recycled paper, the polymer fine particles and pigments in the ink composition come into contact with polyvalent metal ions in the reaction liquid, and Since the dispersed state is destroyed and the pigment and the fine polymer particles are rapidly aggregated, the pigment is suppressed from penetrating into a recording medium such as paper and remains near the surface of the recording medium. At this time, the water and the water-soluble organic solvent in the reaction liquid and the ink composition permeate into the recording medium such as paper, and after reduction, the polymer fine particles are united and fused at room temperature to include the pigment. It is considered to form a film.

At this time, the faster the reaction rate of the aggregation reaction of the polymer fine particles with the polyvalent metal ion is, the faster the separation of the water and the aqueous organic solvent from the reaction liquid and the ink composition from the pigment and the polymer fine particles, and the quick drying property. Is expected to improve.

Therefore, the image obtained by using the above reaction liquid and ink composition is a high-quality image with no bleeding, high color density, and little printing unevenness, and also quick drying property, abrasion resistance, and water resistance. And excellent fixability with a recording medium such as paper. Further, in a color image, there is also an advantage that non-uniform color mixing in a boundary region of different colors, that is, color bleeding can be effectively prevented.

However, the explanation of this mechanism is given for explaining the effect when the polymer fine particles are used, and the present invention is not construed as being limited to this mechanism.

[0013]

DETAILED DESCRIPTION OF THE INVENTION <Ink Composition> The ink composition of the present invention contains at least a pigment, polymer fine particles, an aqueous organic solvent, and water, and the polymer fine particles present dispersed in the ink are polyvalent metal salts. It has a high cohesiveness with respect to. That is, the polymer fine particles that can be contained in the ink composition of the present invention include the polyvalent metal salt and the polymer fine particles added when the 0.1% by weight aqueous dispersion of the polymer fine particles and the polyvalent metal salt aqueous solution are mixed. Weight ratio (polyvalent metal salt /
It is characterized in that aggregates can be formed when the fine polymer particles are 50 or less. The polymer fine particles that can be used in the present invention are a mixed solution in which a 0.1% by weight aqueous dispersion of the polymer fine particles and a polyvalent metal salt-containing transparent aqueous solution are mixed at a weight ratio of polyvalent metal salt / polymer fine particles = 50. Of 700
The time required for the absorbance at nm to become 1/2 of the absorbance of 0.1% by weight polymer fine particles aqueous dispersion at the same wavelength is 60
It can also have the characteristic of being less than a second. The properties of the above polymer fine particles can be determined by the following test methods.

The cohesiveness of the fine polymer particles with respect to the polyvalent metal ion is determined by mixing a 0.1 wt% aqueous dispersion of the fine polymer particles with a polyvalent metal-containing aqueous solution prepared in advance to a constant concentration to obtain a polyvalent metal in the mixed solution. It can be determined whether or not aggregates are formed under the condition that the weight ratio of salt / polymer particles is 50 or less.

The reaction rate of the agglutination reaction can be determined by the change with time of the absorbance of a 0.1% by weight aqueous dispersion of polymer particles. That is, when the polymer fine particles and the polyvalent metal-containing aqueous solution are mixed, the faster the agglutination reaction between the polyvalent metal ions and the polymer fine particles, the faster the change in absorbance. Since the change in the absorbance of the polymer particles does not clearly appear in the low wavelength region, the agglutination reaction rate of the polyvalent metal ion and the polymer particles can be found by examining the change with time of the absorbance of the polymer particles in the high wavelength region. The characteristics can be clarified.

According to a preferred embodiment of the present invention, the fine polymer particles contained in the ink composition are preferably contained in the range of 0.1 to 40% by weight, more preferably 1 to 25% by weight. preferable.

The polymer fine particles contained in the ink composition used in the present invention can be obtained by emulsion polymerization of the following monomers alone or with two or more kinds of monomers in the presence of a polymerization catalyst and an emulsifier. As the monomer component constituting the polymer particles, acrylic acid esters, methacrylic acid esters, aromatic vinyl monomers, vinyl esters generally used in emulsion polymerization,
Vinyl cyan compounds, halogenated compounds, olefins,
Dienes, crosslinkable monomers having two or more polymerizable double bonds, further acrylamides for the purpose of imparting stability, hydroxyl group-containing compounds and the like can be exemplified, and usually these are used alone. Alternatively, two or more species may be mixed and used.

Further, it is particularly desirable that the polymer fine particles used in the present invention have a film-forming ability, and it is preferable that the resin emulsion having such polymer fine particles as dispersed particles has a film forming property. The fine polymer particles that can be used in the ink composition of the present invention preferably have a minimum film formation temperature of 30 ° C. or lower. The polymer composition of the fine particles is not particularly limited, but it is necessary to select the unsaturated vinyl monomer in the obtained polymer fine particles in consideration of the above points. The initiator, the surfactant, the molecular weight modifier, and the neutralizing agent used in the above emulsion polymerization are not particularly limited and may be used according to a conventional method.

The pigment used in the present invention may be an inorganic pigment or an organic pigment without any particular limitation. As the inorganic pigment, it is possible to use, in addition to titanium oxide and iron oxide, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method.
The organic pigments include azo dyes (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc.), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, A thioindigo pigment, an isoindolinone pigment, a quinofuraron pigment, etc.), a dye chelate (for example, a basic dye type chelate, an acid dye type chelate, etc.), a nitro pigment, a nitroso pigment, and aniline black can be used.

According to a preferred embodiment of the present invention, these pigments are preferably added to the ink as a pigment dispersion obtained by dispersing them in an aqueous medium with a dispersant. As a preferable dispersant, a dispersant which is commonly used for preparing a pigment dispersion liquid, for example, a polymer dispersant or a surfactant can be used. It will be apparent to those skilled in the art that the dispersant and the surfactant contained in this pigment dispersion will also function as the surfactant of the ink composition described later.

The amount of pigment added to the ink is 0.5 to 25.
It is preferably about wt%, more preferably 2 to 15 wt%
It is a degree.

According to a preferred embodiment of the present invention, the ink composition preferably contains sugar. Examples of saccharides include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinol, galactose, aldonic acid, glucicyl. , Maltose, cellobiose, lactose, sucrose, trehalose, maltotriose and the like. Here, the term "polysaccharide" means a sugar in a broad sense, and is meant to include substances widely existing in nature such as alginic acid, α-cyclodextrin, and cellulose.

The derivatives of these sugars include reducing sugars of the above-mentioned sugars (for example, sugar alcohol (general formula HO
CH ₂ (CHOH) _n CH ₂ OH (where n is an integer of 2 to 5)
), Oxidized sugar (eg, aldonic acid, uronic acid, etc.), amino acid, thiosugar and the like. Sugar alcohol is particularly preferable, and specific examples include maltitol,
Examples include sorbit.

The content of these sugars is from 0.1 to 0.1 of the ink.
A range of 40% by weight, preferably 0.5 to 30% by weight is suitable.

According to a preferred embodiment of the present invention, the ink composition used in the present invention preferably contains a low boiling point organic solvent. Examples of the low boiling point organic solvent include methanol, ethanol, n-propyl alcohol, is
o-propyl alcohol, n-butanol, sec-butanol, ter-butanol, iso-butanol,
Examples thereof include n-pentanol. A monohydric alcohol is particularly preferable.

According to a preferred embodiment of the present invention, the ink used in the present invention preferably further contains a high boiling point organic solvent.

Preferred examples of the high boiling point organic solvent include ethylene glycol, polyethylene glycol, glycerin, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, triethylene glycol, Polyhydric alcohols such as trimethylolethane and trimethylolpropane, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether,
Alkyl ethers of polyhydric alcohols such as diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monoethyl ether, triethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, urea, 2-pyrrolidone, Examples include N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine and the like.

The amount of the high boiling point organic solvent added is preferably 0.5 to 40% by weight of the ink, more preferably 2 to
It is in the range of 20% by weight. The addition amount of the low boiling point organic solvent is preferably 0.5 to 10% by weight of the ink, and more preferably 1.5 to 6% by weight.

In addition, a pH adjusting agent, a preservative, an antifungal agent and the like may be added, if necessary.

<Inkjet Recording Method> The inkjet recording method according to the present invention basically prints the ink composition immediately after selectively depositing the reaction liquid on the recording medium only at the places where the ink composition is deposited. Although it includes a step, it may include a step of first depositing the ink composition, and immediately after that, selectively printing the reaction liquid only on the place where the ink composition is deposited.

Further, according to the present invention, there is provided an ink jet recording method in which the reaction agent of the reaction liquid is a polyvalent metal salt and the ink composition is the above-mentioned ink composition. With the inkjet recording method according to the present invention, high color density,
It realizes printing with less bleeding and unevenness, and also has the advantage of effectively preventing uneven color mixing in the boundary area of different colors, that is, color bleeding in color images, and quick-drying on plain paper. Can be secured.

<Reaction Liquid> The reaction liquid used in the present invention contains a reaction agent which forms an aggregate upon contact with the ink composition. It is considered that the agglomerates are formed by the contact of the reactant with the pigment in the ink composition and the fine polymer particles. In the present invention, it is most preferable to use a polyvalent metal salt as such a reaction agent. The polyvalent metal salt as a reaction agent includes a salt soluble in water, which is composed of a polyvalent metal ion having a valence of 2 or more and an anion binding to these polyvalent metal ions. Specific examples of polyvalent metal ions include Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Zn ²⁺ and Ba ^2+.
And divalent metal ions such as Al ³⁺ , Fe ³⁺ , and Cr ³⁺ . As anions, Cl ⁻ , N
Examples include O ₃ ⁻ , I ⁻ , Br ⁻ , ClO ₃ ^−, CH ₃ COO ^{−, and the} like.

In particular, the metal salt composed of Ca ²⁺ or Mg ²⁺ gives favorable results from the two viewpoints of the pH of the reaction solution and the quality of the printed matter obtained.

The concentration of these polyvalent metal salts in the ink composition may be appropriately determined within a range where printing quality and the effect of preventing clogging can be obtained, but it is preferably about 0.1 to 40% by weight, and It is preferably about 5 to 25% by weight.

In a preferred embodiment of the present invention, the polyvalent metal salt comprises a polyvalent metal ion having a valence of 2 or more and a nitrate ion or a carboxylate ion which binds to these polyvalent metal ions and is soluble in water. It is preferable that it is

Here, the carboxylate ion is preferably derived from a saturated fatty acid monocarboxylic acid having 1 to 6 carbon atoms or a carbocyclic monocarboxylic acid having 7 to 11 carbon atoms. Preferred examples of the saturated aliphatic monocarboxylic acid having 1 to 6 carbon atoms include formic acid, acetic acid, propionic acid, butyric acid,
Examples include isobutyric acid, valeric acid, isovaleric acid, pivalic acid and hexanoic acid. Formic acid and acetic acid are particularly preferable.

The hydrogen atom on the saturated aliphatic hydrocarbon group of this monocarboxylic acid may be substituted with a hydroxyl group, and a preferable example of such a carboxylic acid is lactic acid.

Further, preferred examples of the carbocyclic monocarboxylic acid having 6 to 10 carbon atoms include benzoic acid and naphthoic acid, and more preferred is benzoic acid.

According to a preferred embodiment of the present invention, the reaction liquid contains a polyol in addition to the polyvalent metal salt. Specific preferred examples of the polyol include polyhydric alcohols,
For example, glycerin, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, trimethylolethane,
Trimethylolpropane 1,5-pentanediol, 1,4
-Butanediol and the like can be mentioned. According to a preferred embodiment of the present invention, the amount of this polyol added to the reaction solution is preferably 10% by weight or more, more preferably about 10 to 30% by weight.

According to a preferred embodiment of the present invention, the reaction liquid used in the present invention preferably contains sugar. Specific examples of sugars include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid. , Gluciseal, sorbit, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like.

These polyols and sugars may be added alone or as a mixture of two or more.

According to a preferred embodiment of the present invention, the reaction liquid contains a wetting agent composed of a high boiling point organic solvent. The high boiling point organic solvent prevents the reaction solution from drying, thereby preventing clogging of the head.

As a preferred example of the high boiling point organic solvent, although it partially overlaps with the above-mentioned polyol, ethylene glycol,
Diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-
Polyhydric alcohols such as hexanetriol, thioglycol, hexylene glycol, glycerin, trimethylolethane and trimethylolpropane; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether, Alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether, triethylene glycol monoethyl ether and triethylene glycol monobutyl ether,
Urea, 2-pyrrolidone, N-methyl-2-pyrrolidone,
1,3-dimethyl-2-imidazolidinone, triethanolamine and the like can be mentioned.

The amount of the high-boiling organic solvent added is not particularly limited, but is preferably about 0.5 to 40% by weight, more preferably about 2 to 20% by weight.

According to a preferred embodiment of the present invention, the reaction liquid contains triethanolamine for pH adjustment.
When triethanolamine is added, its addition amount is preferably about 0.1 to 2.0 weight.

Further, the reaction liquid may be colored by adding the color coloring agent described in the section of the ink composition to be described later to have the function of the ink composition.

[0047]

The present invention will be described in detail below with reference to the following examples, but the present invention is not limited thereto.

<Resin Emulsion 1> 200 ml of distilled water and 0.6 g of sodium dodecylbenzenesulfonate were charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping device, a thermometer and a nitrogen inlet tube, and the mixture was placed in a nitrogen atmosphere. Warm to 70 ° C. with stirring and add 2 g of ammonium persulfate. On the other hand, 40 g of butyl acrylate, 54 g of styrene, 5 g of acrylamide, 1 g of acrylic acid, and 0.15 g of t-dodecyl mercaptan are mixed and dissolved, and this is dropped into the reaction vessel. Furthermore, after reacting at 70 ° C. for 6 hours, it was cooled to room temperature, ammonia water was added as a neutralizing agent to adjust the pH, and the mixture was filtered through a 10 μm filter to obtain a resin emulsion in which the target polymer particles were dispersed in water. To get

The minimum film forming temperature of the obtained resin emulsion was measured by the following method. The minimum film formation temperature measuring device was set, and when the temperature gradient on the aluminum sample plate reached equilibrium, the resin emulsion of the sample was thinly spread and dried. When the sample plate is observed after the completion of drying, a transparent continuous film is formed in the region above the minimum film formation temperature, but it becomes a white powder in the region below the minimum film formation temperature. The temperature at this boundary was measured as the minimum film formation temperature. As a result of measurement by this method, the resin emulsion 1 was formed into a film at 25 to 30 ° C. (Minimum film forming temperature) <Resin emulsion 2> Distilled water 2 in a reaction vessel equipped with a stirrer, a reflux condenser, a dropping device, a thermometer, and a nitrogen introduction tube.
00 ml, sodium dodecylbenzene sulfonate
Charge 6 g, warm to 70 ° C. with stirring in a nitrogen atmosphere, and add 2 g of ammonium persulfate. On the other hand, 40 g of butyl acrylate, 50 g of styrene, 5 g of acrylamide, 5 g of acrylic acid, and 0.15 g of t-dodecyl mercaptan are mixed and dissolved, and this is dropped into the reaction vessel. Further, after reacting at 70 ° C. for 6 hours, it is cooled to room temperature, and ammonia water is added as a neutralizing agent to add p.
After adjusting H, the mixture is filtered through a 10 μm filter to obtain a resin emulsion in which desired polymer fine particles are dispersed in water.

The minimum film forming temperature of the resin emulsion 2 was measured by the above method, and the film was formed at 25 to 30 ° C. (Minimum film forming temperature) <Reaction liquid> The components described below were mixed to prepare a reaction liquid.

<Reaction liquid 1> Magnesium nitrate hexahydrate 25.6 wt% (weight of magnesium nitrate 14.8 wt%) Triethylene glycol monobutyl ether 10 wt% Glycerin 10 wt% Ion-exchanged water Remaining amount <Reaction liquid 2> Magnesium nitrate・ Hexahydrate 34.6 wt% (weight of magnesium nitrate 20 wt%) Triethylene glycol monobutyl ether 10 wt% Glycerin 10 wt% Ion-exchanged water Remaining amount <Evaluation of cohesiveness of resin emulsion> Resin emulsion 1 and resin emulsion 2 0. A 1% by weight aqueous dispersion (0.1% by weight in terms of resin component) was prepared, 4 g of this aqueous dispersion was sampled, and then 1 part of the reaction solution 1 was added to this aqueous dispersion.
Then, the presence or absence of aggregates is visually confirmed (polyvalent metal salt / resin emulsion = 37).

A: Aggregates were generated. NG: No aggregate was generated.

<Change in Absorbance with Time> Resin Emulsion 1
And the absorbance of a 0.1% by weight aqueous dispersion of Resin Emulsion 2 by a spectrophotometer (U-3300 manufactured by Hitachi Ltd.)
Measure the absorbance at m. Next, 4 g of 0.1% by weight aqueous dispersion of resin emulsion 1 and resin emulsion 2 was sampled in a quartz cell for measuring absorbance, and then 1 g of reaction solution 2 was added to the quartz cell and the reaction solution was added. The time-dependent change of the absorbance at 700 nm is measured (polyvalent metal salt / resin emulsion = 50) with the time taken as zero.

In the measurement of the absorbance, the time until the absorbance of the mixed solution at 700 nm becomes 1/2 of the absorbance of the 0.1% by weight aqueous dispersions of the resin emulsion 1 and the resin emulsion 2 is obtained and evaluated according to the following criteria. A: Absorbance becomes 1/2 within 60 seconds. B: The time when the absorbance becomes 1/2 is 60 seconds or more.

The evaluation results of the resin emulsion are as follows.

[0056]

[Table 1]

The following ink composition and reaction liquid were prepared by a conventional method. That is, the ink composition was prepared by dispersing the pigment of the colorant component together with the dispersant component, adding the other components and mixing, and filtering with a 10 μm filter to obtain an ink composition.

<Ink Composition><Ink1> Carbon Black MA7 5 wt% Liquid Medium Styrene-Acrylic Copolymer / Ammonium Salt 1.5 wt% (Molecular Weight 7,000, Resin Component 38 wt%: Dispersant) Resin Emulsion 1 5 wt% ( Resin component 30%) Glycerin 10 wt% Ion-exchanged water Remaining ink 2 Carbon black Raven 1080 5 wt% Liquid medium Styrene-acrylic copolymer / ammonium salt 1.5 wt% (molecular weight 7,000, resin component 38 wt%: dispersant) Resin emulsion 2 3 wt% (Resin component 30%) Maltitol 7 wt% Glycerin 10 wt% Ink replacement water Remaining amount <Evaluation 1><Printbleed> Inkjet printer MJ-700
V2C (manufactured by Seiko Epson Corp.)
Printing was performed on two papers, 4024 3R 721 (manufactured by Xerox Co., Ltd.) and Xerox R (manufactured by Xerox Co., Ltd., recycled paper). For printing, dots were printed after printing the reaction solution at 100% duty.

The circularity of dots formed by the ink composition is 4π.
When defined as S / L ² (where S is the dot area and L is the dot perimeter), the roundness was evaluated as follows. A: Both papers have a circularity of 1 to 0.9. B: Roundness of 0.9 or more on either or both papers
0.8. NG: Roundness is less than 0.8 on either or both papers.

<Evaluation 2><Evaluation of quick drying property> Inkjet printer MJ-700
Using V2C (Seiko Epson Corporation), Xerox
A solid pattern was printed on 4024 3R 721 (manufactured by Xerox Co., Ltd.) and the quick-drying property was evaluated. Printing reaction liquid 100
After printing with% duty, print a solid pattern with Inks 1-2, place the same paper as the paper used for printing on the printed part, apply a load of 250 g / cm ² from above, and see if there is any offset to the paper. And measure the time until there is no set-off on the paper. A: The time when set-off disappeared is less than 60 seconds. B: The time until the set-off disappears is 60 or more and less than 90 seconds. NG: It takes 90 seconds or more to eliminate the set-off.

The reaction liquid weight was 20 ng / dot and the ink weight was 40 ng / dot.

[0062]

[Table 2]

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C056 FC01                 4J039 AB01 AD02 AD05 AD06 AD10                       AD11 AD12 BA17 BA30 BC09                       BC13 BC19 BC31 BC35 BC37                       BC50 BC51 BC54 BE12 BE22                       BE33 CA06 EA01 EA46 GA24

Claims (8)

[Claims] 1. An ink composition for ink jet recording containing at least a pigment, polymer fine particles, a water-soluble organic solvent, and water, wherein the polymer fine particles are a 0.1% by weight aqueous dispersion of the polymer fine particles and a polyvalent metal salt. An ink composition for inkjet recording, which forms an aggregate when the weight ratio of the polyvalent metal salt to the polymer fine particles (polyvalent metal salt / polymer fine particles) is 50 or less when mixed with the contained aqueous solution. 2. An ink composition for inkjet recording containing at least a pigment, polymer fine particles, a water-soluble organic solvent, and water, wherein the polymer fine particles are a 0.1% by weight aqueous dispersion of the polymer fine particles and a polyvalent metal salt. When mixed with the contained aqueous solution, the weight ratio of polyvalent metal salt / polymer fine particles = 5
An ink jet characterized in that the time required for the absorbance at 700 nm of the mixed solution mixed with 0 to become 1/2 of the absorbance at 0.1% by weight of the polymer fine particle aqueous dispersion at the same wavelength is 60 seconds or less. Recording ink composition. 3. The ink composition for inkjet recording according to claim 1, wherein the fine polymer particles are made of a polymer having a film-forming ability. 4. The ink composition for ink jet recording according to claim 1, wherein the aqueous resin emulsion containing the polymer fine particles as dispersed particles has a minimum film forming temperature of 30 ° C. or lower. 5. The ink composition for ink jet recording according to claim 1, wherein the polymer fine particles have a hydrophilic group. 6. The ink composition for ink jet recording according to claim 6, wherein the polymer fine particles have a carboxyl group. 7. The ink composition for inkjet recording according to claim 1, wherein the polymer fine particles are used in the form of a resin emulsion containing water as a dispersion medium. 8. An inkjet recording method for printing by adhering a reaction liquid containing a reaction agent and an ink composition to a recording medium, wherein the reaction agent of the reaction liquid is a polyvalent metal salt, An ink jet recording method, wherein the ink composition is the ink composition according to any one of claims 1 to 7.