JPH11115303A - Ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain images of which the printing quality is favorable, and also, of which is line width is wide by specifying the application interval for an ink composition and a reaction liquid. SOLUTION: A recording head 1 moves in a direction shown by arrow A. During the movement, an ink composition is discharged from a nozzle surface 1c, and a band-form ink composition adhering region 32 is formed on a recording medium 7. Then, the recording medium 7 is carried by a specified amount in a paper feeding direction shown by arrow B. During the period, the recording head 1 moves in the opposite direction from the arrow A, and returns to a location at the left end of the recording medium 7. Then, a reaction liquid is printed in the region where the ink composition has already adhered, and a printing region 31 is formed. By making the application interval for the ink composition and the reaction liquid 5 ms or higher and 500 ms or lower, favorable results can be obtained both in the printing quality and the line width.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording method, and more particularly, to an ink jet recording method for printing by attaching an ink composition and a reaction liquid to a recording medium.

BACKGROUND ART [0002] Ink jet recording methods include:
This is a printing method in which small droplets of the ink composition fly and adhere to a recording medium such as paper to perform printing. This method has a feature that high-resolution and high-quality images can be printed at a high speed with a relatively inexpensive device. In general, an ink composition used for ink jet recording contains water as a main component, and further contains 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, a method has recently been proposed in which a polyvalent metal salt solution is applied to a recording medium and then an ink composition containing a dye having at least one carboxyl group is applied ( For example, JP-A-5-202328). In this method,
It is stated that an insoluble complex is formed from the polyvalent metal ion and the dye, and the presence of this complex makes it possible to obtain a high-quality image having water resistance and no color bleed.

[0004] Further, by using a color ink containing at least a surfactant or a penetrating solvent for imparting permeability and a salt, and a black ink which thickens or aggregates by the action of the salt, an image is formed. It has been proposed that a high-quality color image having a high density and no color bleed can be obtained (Japanese Patent Laid-Open No. 6-10673).
No. 5). That is, an ink jet 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, an ink jet recording method for printing two liquids has been proposed (for example, see Japanese Patent Application Laid-Open No.
240557, JP-A-3-240558).

In Japanese Patent Application Laid-Open No. 7-195823, the reaction liquid is applied first, and the application interval between the reaction liquid and the ink composition is adjusted to the minimum necessary for adjusting the condition of the recording medium after the application of the reaction liquid. The position of the print head is determined so that the time is limited. However, in this method, the expression of the application interval between the reaction liquid and the ink composition is very abstract, and only the printing at the tip of the reaction liquid is considered.

Accordingly, in the present invention, in order to solve the above-mentioned problems, in a printing method in which an ink composition is first applied and then a reaction liquid is applied, the application interval is set to 5 ms or more and 500 ms or less. An object is to obtain an image having good printing quality and a wide line width.

[0008]

SUMMARY OF THE INVENTION The present inventors have proposed an ink jet recording method in which an ink composition is printed first and a reaction liquid is selectively applied only to a place where the ink composition is applied. The application interval is 5 ms or more and 5
It has been found that by setting the time to 00 ms or less, it is possible to obtain an image having good print quality and a wide line width.

Accordingly, an object of the present invention is to provide a method for obtaining an image having a good and wide line width in an ink jet recording method for printing two liquids.

The ink jet recording method according to the present invention is an ink jet recording method for performing printing by applying a reaction liquid containing a reactant after applying the ink composition to a recording medium, wherein printing is performed. Surface tension is 35m
N / m or less, and the surface tension of the ink composition is 40
An ink composition having an mN / m or more and 55 mN / m or less is used, and an application interval between the ink composition and the reaction liquid is made 5 ms or more and 500 ms or less.

[0011]

DETAILED DESCRIPTION OF THE INVENTION

[Ink Jet Recording Method] The ink jet recording method according to the present invention comprises a step of applying a reaction liquid after selectively depositing an ink composition on a recording medium only at a place where the reaction liquid is applied. . In the present invention, the surface tension of the reaction solution is 35 mN / m or less, and the surface tension of the ink composition is 40 mN / m or more and 55 mN / m.
m or less, and the application interval between the ink composition and the reaction liquid is set to 5 ms or more and 500 ms or less.

If the reaction liquid is applied immediately after the application of the ink composition, the ink composition is mixed with the reaction liquid on the paper before the ink has completely penetrated into the recording medium, and the ink permeability increases. Although the line width increases in the process of entering the inside, bleeding is likely to occur.

On the other hand, if the interval between the application of the ink composition and the reaction liquid is too long, the reaction liquid is applied after the ink has completely penetrated into the paper, and the bleeding and the line width are limited by the permeability of the ink alone. Since the ink composition of the present invention does not have such a high permeability, printing with small bleeding but a small line width is achieved.

Therefore, in the present invention, by setting the coating interval between the ink composition and the reaction liquid to be 5 ms or more and 500 ms or less, it is possible to obtain good results in both print quality and line width. .

The ink jet recording method according to the present invention comprises:
It has the advantage of realizing printing with high color density and less blurring and unevenness, and furthermore, in a color image, non-uniform color mixing in a boundary region between different colors, that is, color bleeding can be effectively prevented. [Reaction liquid] The reaction liquid according to the present invention has a surface tension of 35.
mN / m or less. According to a preferred embodiment of the present invention, this surface tension may be achieved by the addition of a penetrant. Examples of penetrants usable in the present invention include cationic surfactants, anionic surfactants, nonionic surfactants, various surfactants such as amphoteric surfactants, methanol, ethanol, iso-propyl alcohol and the like. Alcohols, ethylene glycol monomethyl ether,
And lower alkyl ethers of polyhydric alcohols such as diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monobutyl ether, and dipropylene glycol monobutyl ether.

[0016] The reaction liquid used in the present invention contains a reaction agent which forms an aggregate when it comes into contact with the ink composition. It is considered that the aggregate is formed by the reaction between the reactant and the colorant component in the ink composition. As will be described further below, the present invention may include a resin emulsion and / or an inorganic oxide colloid, and according to a preferred embodiment of the present invention, the reactant dissolves the resin emulsion and the inorganic oxide colloid. It is preferably one that disrupts the dispersed state.

The reactant used in the present invention is not limited as long as it has the above properties. Preferred specific examples thereof include polyvalent metal salts, polyallylamine and derivatives thereof.

The polyvalent metal salt as a reactant is composed of a polyvalent metal ion having two or more valences and an anion bonded to these polyvalent metal ions, and includes salts soluble in water. Specific examples of polyvalent metal ions include Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg
Divalent metal ions such as ²⁺ , Zn ²⁺ , Ba ²⁺ Al ³⁺ , Fe ³⁺ , Cr ³⁺
And other trivalent metal ions. Examples of the anion include Cl ⁻ , NO ₃ ⁻ , I ⁻ , Br ⁻ , ClO ₃ ⁻ and CH ₃ COO ⁻ .

In particular, a 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 in which the effect of preventing printing quality and clogging can be obtained, but is preferably about 0.1 to 40% by weight, more preferably about 0.1 to 40% by weight. It is about 5 to 25% by weight.

In a preferred embodiment of the present invention, the polyvalent metal salt is composed of a divalent or higher polyvalent metal ion and a nitrate ion or a carboxylate ion bound to the polyvalent metal ion, and is soluble in water. It is preferred that

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,
Isobutyric acid, valeric acid, isovaleric acid, pivalic acid, hexanoic acid and the like. Particularly, formic acid and acetic acid are preferable.

A hydrogen atom on the saturated aliphatic hydrocarbon group of the monocarboxylic acid may be substituted with a hydroxyl group, and a preferred 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, more preferably benzoic acid.

Further, polyallylamine and polyallylamine derivatives as reactants are cationic polymers which are soluble in water and are positively charged in water. For example, the following formulas (I), (II), and (III) are mentioned.

[0026]

Embedded image

[0027] (wherein, X ^- is chloride, bromide, iodide, nitrate, phosphate ion, sulfate ion, represents the acetate ion) polymer or diallyl allylamine and diallylamine were copolymerized in addition to these Copolymers of methyl ammonium chloride and sulfur dioxide can also be used.

The content of these polyallylamine and / or polyallylamine derivative is 0.5% of the ink composition.
Preferably it is about 10% by weight.

According to a preferred embodiment of the present invention, the reaction solution contains a polyol in addition to the polyvalent metal salt. Here, this polyol has a vapor pressure at 20 ° C. of 0.01.
mmHg or less, and the addition amount thereof is 1 or more, preferably 1.0 to 5.0 in weight ratio to the polyvalent metal salt.
It is set to 0. Further, according to a preferred embodiment of the present invention, the amount of the polyol added to the reaction solution is preferably 10% by weight or more, more preferably 10 to 30% by weight.
It is about.

Preferred specific examples of the polyol include polyhydric alcohols such as glycerin, diethylene glycol, triethylene glycol, 1,5-pentanediol, and 1,4-butanediol. further,
Preferred specific examples of polyols include sugars such as monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides)
And polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucosyl, sorbitol, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose and the like.

Even if these polyols are added alone,
It may be added as a mixture of two or more. When it is added as a mixture of two or more, the amount added is 1 or more by weight in total with respect to the polyvalent metal salt.

According to a preferred embodiment of the present invention, the reaction solution contains a wetting agent comprising a high-boiling organic solvent. The high boiling point organic solvent prevents clogging of the head by preventing the reaction solution from drying. Preferred examples of the high-boiling organic solvent, although partially overlap with the polyol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,
2,6-hexanetriol, thioglycol, hexyleneglycol, glycerin, trimethylolethane,
Polyhydric alcohols such as trimethylolpropane; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol Alkyl ethers of polyhydric alcohols such as monobutyl ether, urea, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone,
Triethanolamine and the like.

The amount of the high-boiling organic solvent to be 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 solution contains a low-boiling organic solvent. Preferred examples of the low-boiling organic solvent include methanol, ethanol, n-propyl alcohol, iso-isopropyl alcohol, n-butanol, sec-butanol, tert-butanol, iso-butanol, n-pentanol and the like. Particularly, a monohydric alcohol is preferable. The low-boiling organic solvent has the effect of shortening the drying time of the ink. The addition amount of the low boiling point organic solvent is preferably 0.5 to 10% by weight, more preferably
It is in the range of 1.5-6% by weight.

According to a preferred embodiment of the present invention, the reaction solution contains triethanolamine for pH adjustment.
When triethanolamine is added, the amount added is preferably about 0 to 2.0 weight.

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

[Ink composition] The ink composition used in the present invention has a surface tension of 40 mN / m to 55 m.
N / m or less.

According to a preferred embodiment of the present invention, this surface tension may be realized by adding a penetrant. Specific examples that can be used include those similar to the penetrant used for the reaction solution.

The ink composition used in the present invention contains at least a colorant and water.

The colorant contained in the ink composition used in the present invention preferably reacts with the above-mentioned reactant to form an aggregate. The colorant may be either a dye or a pigment, but is preferably a pigment.

The dyes include direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes,
Various dyes usually used for inkjet recording, such as a soluble vat dye and a reactive disperse dye, can be used.

As the pigment, inorganic pigments and organic pigments can be used without any particular limitation. As the inorganic pigment, in addition to titanium oxide and iron oxide, carbon black produced by a known method such as a contact method, a furnace method, and a thermal method can be used. Examples of organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelated azo pigments, etc.), and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines) Pigments, thioindigo pigments,
An isoindolinone pigment, a quinoflurone pigment, 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 in an aqueous medium with a dispersant or a surfactant. As a preferred dispersant, a dispersant commonly used for preparing a pigment dispersion, for example, a polymer dispersant can be used. It will be apparent to those skilled in the art that the dispersant and surfactant contained in this pigment dispersion will also function as the dispersant and surfactant of the ink composition.

The amount of the pigment added to the ink is preferably about 0.5 to 25% by weight, more preferably about 2 to 15% by weight.

According to a preferred embodiment of the present invention, the ink composition preferably comprises a resin emulsion. Here, the resin emulsion means an emulsion in which the continuous phase is water and the dispersed phase is the following resin component.
As the resin component of the dispersed phase, acrylic resin, vinyl acetate resin, styrene-butadiene resin, vinyl chloride resin, acrylic-styrene resin, butadiene resin,
Examples include a styrene resin, a crosslinked acrylic resin, a crosslinked styrene resin, a benzoguanamine resin, a phenol resin, a silicone resin, and an epoxy resin.

According to a preferred embodiment of the present invention, the resin is preferably a polymer having both a hydrophilic part and a hydrophobic part. Further, the particle size of these resin components is not particularly limited as long as an emulsion is formed.
Or less, more preferably about 5 to 100 nm.

These resin emulsions can be obtained by emulsion polymerization of a resin monomer in water together with a surfactant, if necessary. For example, an emulsion of an acrylic resin or a styrene-acrylic resin can be obtained by emulsion polymerization of (meth) acrylic acid ester or (meth) acrylic acid ester and styrene together with a surfactant in water.
The mixing ratio of the resin component and the surfactant is usually 10: 1.
It is preferable to set it to about 5: 1. When the amount of the surfactant used is in the above range, better water resistance and permeability of the ink can be obtained.

Preferred examples of the surfactant include anionic surfactants (eg, sodium dodecylbenzenesulfonate, sodium laurate, ammonium salts of polyoxyethylene alkyl ether sulfate, etc.), nonionic surfactants (eg, , Polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkylamines, polyoxyethylene alkylamides, and the like. These can be used in combination. In addition, acetylene glycol (olefin Y, and Surfynol 82, 104, 440, 465, and 485 (all of them)
Air Products and Chemicals Inc.)) can also be used.

The proportion of the resin and water as the disperse phase component is suitably in the range of 60 to 400 parts by weight of water, preferably 100 to 200 parts by weight, per 100 parts by weight of the resin.

As such a resin emulsion, known resin emulsions can be used. For example, JP-B-62-1426, JP-A-3-56573, JP-A-3-79678, and JP-A-3-160068. And the resin emulsion described in JP-A-4-18462 can be used as it is.

It is also possible to use a commercially available resin emulsion, for example, Microgel E-100.
2, E-5002 (styrene-acrylic resin emulsion, manufactured by Nippon Paint Co., Ltd.), Boncoat 4001
(Acrylic resin emulsion, manufactured by Dainippon Ink and Chemicals, Inc.) Boncoat 5454 (styrene-acrylic resin emulsion, manufactured by Dainippon Ink and Chemicals, Inc.) SAE-1014 (styrene-acrylic resin emulsion, manufactured by Zeon Corporation) ), Cybinol SK
-200 (acrylic resin emulsion, manufactured by Seiden Chemical Co., Ltd.).

The ink used in the present invention preferably contains a resin emulsion so that the resin component is 0.1 to 40% by weight of the ink, more preferably 1 to 25%.
% By weight.

The resin emulsion has an effect of suppressing the penetration of the coloring component and promoting the fixation to the recording medium by interacting with a reactant, in particular, a polyvalent metal ion or polyallylamine or a derivative of polyallylamine. Further, depending on the type of the resin emulsion, a film is formed on the recording medium, which has the effect of improving the abrasion resistance of the printed matter.

According to a preferred embodiment of the present invention, the ink composition preferably contains a thermoplastic resin in the form of a resin emulsion. Here, a thermoplastic resin has a softening temperature of 5
The temperature is from 0 to 250C, preferably from 60 to 200C.

Further, it is preferable that these resins form a film having strong water resistance and abrasion resistance when heated and cooled to a temperature higher than the softening or melting temperature.

Specific examples of the water-insoluble thermoplastic resin include polyacrylic acid, polymethacrylic acid, polymethacrylate, polyethylacrylic acid, styrene-
Butadiene copolymer, polybutadiene, acrylonitrile-butadiene copolymer, chloroprene copolymer, fluororesin, fluororesin, vinylidene fluoride, polyolefin resin, cellulose, styrene-acrylic acid copolymer,
Styrene-methacrylic acid copolymer, polystyrene, styrene-acrylamide copolymer, polyisobutyl acrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl acetal, polyamide, rosin resin, polyethylene, polycarbonate, vinylidene chloride resin, cellulose resin, Examples include, but are not limited to, vinyl acetate resins, ethylene-vinyl acetate copolymers, vinyl acetate-acrylic copolymers, vinyl chloride resins, polyurethanes, and rosinesters.

Specific examples of the low molecular weight thermoplastic resin include animal and plant waxes such as polyethylene wax, montan wax, alcohol wax, synthetic oxidized wax, α-olefin-maleic anhydride copolymer, carnauba wax, lanolin, and paraffin. Wax, microcrystalline wax and the like.

Further, the ink composition used in the present invention may contain an inorganic oxide colloid. Preferred examples of the inorganic oxide colloid include colloidal silica,
Alumina colloid is mentioned. These are generally colloidal solutions in which ultrafine particles such as SiO ₂ and Al ₂ O ₃ are dispersed in water or an organic solvent. As a commercially available inorganic oxide colloid, the dispersion medium is water, methanol, 2-propanol, n-propanol, etc., and SiO ₂ , Al
Generally, particles such as ₂ O ₃ have a particle size of 5 to 100 nm. In many cases, the pH of the inorganic oxide colloid solution is adjusted not to the neutral region but to acidic or alkaline. This is because the stable dispersion region of the inorganic oxide colloid exists on the acidic side or the alkaline side, and when added to the ink composition, the pH of the stable dispersion region of the inorganic oxide colloid and the pH of the ink are adjusted. It is necessary to add in consideration.

It is preferable to add the inorganic oxide colloid in the ink composition in an amount of 0.1 to 15% by weight, and two or more kinds can be added.

According to a preferred embodiment of the present invention, the ink composition preferably contains an alginic acid derivative. Preferred examples of the alginic acid derivative include alkali metal alginates (eg, sodium salts and potassium salts), organic alginates (eg, triethanolamine salts), and ammonium alginates.

The amount of the alginic acid derivative added to the ink composition is preferably about 0.01 to 1% by weight, more preferably about 0.05 to 0.5% by weight.

The reason why a good image can be obtained by adding an alginic acid derivative cannot be determined, but the polyvalent metal salt present in the reaction solution reacts with the alginic acid derivative in the ink composition to change the dispersion state of the colorant. It is considered that this is because the fixation of the colorant to the recording medium is promoted.

According to a preferred embodiment of the present invention, the ink composition preferably contains an organic solvent. This organic solvent is preferably a low-boiling organic solvent, and preferred examples thereof include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, sec-butanol, tert-butanol, iso-butanol, n-pentanol, and the like. Particularly, a monohydric alcohol is preferable. The low-boiling organic solvent has the effect of shortening the drying time of the ink.

According to a preferred embodiment of the present invention, the ink composition used in the present invention preferably further contains a wetting agent comprising a high-boiling organic solvent. Preferred examples of the high-boiling organic solvent include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, glycerin, and triglyceride. Polyhydric alcohols such as methylolethane and trimethylolpropane; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, Triethylene glycol monobutyl ether Alkyl ethers of polyhydric alcohols,
Urea, 2-pyrrolidone, N-methyl-2-pyrrolidone,
1,3-dimethyl-2-imidazolidinone, triethanolamine and the like.

The wetting agent may be added in an amount of 0.5 to 0.5 of the ink.
It is preferably about 40% by weight, more preferably in the range of 2 to 20% by weight. The amount of the low-boiling organic solvent added is preferably about 0.5 to 10% by weight of the ink, more preferably 1.5 to 6% by weight.

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

The derivatives of these saccharides include reducing sugars of the aforementioned saccharides (for example, sugar alcohols (general formula HO)
CH ₂ (CHOH) _n CH ₂ OH (where n is an integer of 2 to 5), oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, and thiosugars. In particular, sugar alcohols are preferred, and specific examples include maltitol and sorbitol.

The content of these saccharides is 0.1 to 4 of the ink.
A suitable range is 0% by weight, preferably 0.5 to 30% by weight.

In addition, if necessary, a pH adjuster, a preservative, a fungicide, and the like may be added.

[Ink Jet Recording Apparatus] An ink jet recording apparatus for carrying out the ink jet recording method according to the present invention will be described below with reference to the drawings.

The ink jet recording apparatus shown in FIG. 1 is an embodiment in which an ink composition and a reaction liquid are stored in a tank, and the ink composition and the reaction liquid are supplied to a recording head via an ink tube. That is, the recording head 1 and the ink tank 2 are connected by the ink tube 3. Here, the inside of the ink tank 2 is partitioned, and the ink composition,
In some cases, a room for a plurality of color ink compositions and a room for a reaction liquid are provided.

The recording head 1 is moved along a carriage 4 by a timing belt 6 driven by a motor 5. On the other hand, the paper 7 as a recording medium is placed at a position facing the recording head 1 by the platen 8 and the guide 9.
In this embodiment, a cap 10 is provided. A suction pump 11 is connected to the cap 10 to perform a so-called cleaning operation. The sucked ink composition is stored in a waste ink tank 13 via a tube 12.

FIG. 2 is an enlarged view of the nozzle surface of the recording head 1. The portion indicated by 1b is the nozzle surface of the reaction liquid, and the nozzle 21 for discharging the reaction liquid is provided in the vertical direction. On the other hand, the portion indicated by 1c is the nozzle surface of the ink composition, and from the nozzles 22, 23, 24, and 25, the yellow ink composition, the magenta ink composition, the cyan ink composition, and the black ink composition are respectively provided. Discharged.

Further, an ink jet recording method using the recording head shown in FIG. 2 will be described with reference to FIG. The recording head 1 moves in the direction of arrow A. During that move,
The ink composition is ejected from the nozzle surface 1c, and the recording medium 7
A band-shaped ink composition adhering region 32 is formed thereon. Next, the recording medium 7 is transported by a predetermined amount in the paper feed direction arrow B. During that time, the recording head 1 moves in the direction opposite to the arrow A in the figure, and returns to the position on the left end of the recording medium 7. Then, the reaction liquid is printed on the area where the ink composition has already adhered, and the printing area 3 is printed.
Form one.

Further, as shown in FIG. 4, in the recording head 1, all the nozzles can be arranged in the horizontal direction. In the figure, reference numeral 41 denotes a reaction liquid discharge nozzle from which nozzles 42, 43, 44, and 45 discharge a yellow ink composition, a magenta ink composition, a cyan ink composition, and a black ink composition, respectively.
In the recording head of such an embodiment, the interval between the application of the ink composition and the reaction liquid can be made shorter than in the case where the recording head shown in FIG. 2 is used. Can be adjusted by the nozzle interval and the moving speed of the carriage, so that the control of the application interval is easier.

Further, in some ink jet recording apparatuses, replenishment of the ink composition is performed by replacing a cartridge which is an ink tank. This ink tank may be integrated with the recording head.

FIG. 5 shows a preferred example of an ink jet recording apparatus using such an ink tank. Figure 1 in the figure
The same members as those of the above-mentioned apparatus are denoted by the same reference numerals. In the embodiment of FIG. 5, the recording heads 1a and 1b
Are integrated with the ink tanks 2a and 2b. The recording head 1a or 1b discharges the ink composition and the reaction liquid, respectively. The printing method may be basically the same as that of the apparatus shown in FIG. And in this aspect,
Recording head 1a, ink tank 2a and recording head 1a
The ink tank 2b moves on the carriage 4 together.

FIG. 6 shows a preferred example of an ink jet recording apparatus further provided with a heater for heating a printed recording medium. 6 is similar to that shown in FIG. 1 except that a heater 14 is provided. The heater 14 may be a heater that contacts a recording medium and heats the recording medium, or may be a heater that irradiates infrared rays or the like or blows hot air without contacting the recording medium.

Regarding the adhesion of the reaction liquid to the recording medium, either a method of selectively adhering the reaction liquid only to the place where the ink composition is applied or a method of adhering the reaction liquid to the entire surface of the paper. Good. The former is economical because it can minimize the consumption of the reaction liquid, but requires a certain degree of precision in the position where both the reaction liquid and the ink composition are attached. On the other hand, in the latter, the requirement for the accuracy of the adhesion position of the reaction liquid and the ink composition is eased compared to the former, but a large amount of the reaction liquid is attached to the entire paper surface,
During drying, the paper easily curls. In the present invention, in order to obtain sharp print quality with little bleeding and to reduce the curl of the paper, a method of selectively depositing the reaction liquid only at the place where the ink composition is deposited is used.

[0080]

The present invention will be described in more detail with reference to the following examples, but it should not be construed that the invention is limited thereto.

The following ink composition and reaction liquid were prepared according to a conventional method. That is, the ink composition was obtained by dispersing a colorant component together with a dispersant component, adding and mixing other components, and filtering an insoluble component having a size equal to or larger than a predetermined size to obtain an ink composition.

(Ink 1) Carbon black MA7 5 wt% Liquid medium Styrene-acrylic copolymer / ammonium salt 1.5 wt% (Molecular weight 7000, resin component 38 wt%: dispersant) Almatex Z116 5 wt% (Mitsui Toatsu Chemical ( Co., Ltd., resin emulsion, resin component 50%) Snowtex S 1.5 wt% (Nissan Chemical Co., Ltd., colloidal silica SiO ₂ content 30)
wt%) Maltitol 3.5 wt% Glycerin 10 wt% 2-Pyrrolidone 2 wt% Ion exchange water Remaining (ink 2) Carbon black Raven1080 5 wt% Liquid medium Styrene-acrylic copolymer / ammonium salt 1.5 wt% (Molecular weight 7000, resin Component 38 wt%: dispersant) Almatex Z116 3 wt% (Mitsui Toatsu Chemical Co., Ltd., resin emulsion, resin component 5)
0%) Maltitol 7 wt% Glycerin 10 wt% 2-Pyrrolidone 2 wt% Ink exchange water Remaining (ink 3) Carbon black MA7 5 wt% Liquid medium Styrene-acrylic copolymer / ammonium salt 1.5 wt% (Molecular weight 7000, resin component 38 wt%: dispersant) Snowtex S 1.5 wt% (manufactured by Nissan Chemical Industries, Ltd., colloidal silica SiO ₂ content 30)
wt%) Maltitol 3.5 wt% Glycerin 10 wt% 2-Pyrrolidone 2 wt% Hytenol 325D 0.4 wt% (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., sodium salt of polyoxyethylene alkyl ether sulfate) Liquid 1) Magnesium nitrate hexahydrate 25 wt% triethylene glycol monobutyl ether 10 wt% glycerin 10 wt% ion exchange water Remaining amount (reaction liquid 2) polyallylamine 3 wt% triethylene glycol monobutyl ether 10 wt% glycerin 15 wt% ion exchange water residue Amount The above components were mixed to prepare a reaction solution.

Table 1 below shows the surface tensions of the above-mentioned reaction liquid and ink composition.

[0084]

[Table 1]

[Print Evaluation Test] Inkjet printer MJ-810C (trade name: Seiko Epson Corporation)
Xerox 4024 3R 721 (Xerox Co., Ltd.)
2) Xerox R (manufactured by Xerox Co., Ltd., re-papermaking). In printing, the reaction liquid was ejected from a head that ejects yellow ink, and the ink composition was ejected from a head that ejected black ink, and printing was performed so that the ink composition was applied first.

(Evaluation Criteria) When the roundness of a dot by the ink composition is defined as 4πS / L ² (where S is the dot area and L is the circumference of the dot), the printing quality is as follows: Was evaluated as follows. That is, the roundness was A: 1 to 0.9 in both papers B: 0.9 to 0.8 in either or both papers NG: Less than 0.8 in either or both papers The results were as shown in Tables 2 to 5.

The weight of the ink and the reaction liquid was 0.0
Constant at 4 μg / dot, 360 dpi × 360 dpi
The line width when printing with i was measured. The line width measurement was performed using the two evaluation sheets described above, and the average values are shown in Tables 2 to 5.

[0088]

[Table 2]

[0089]

[Table 3]

[0090]

[Table 4]

[0091]

[Table 5]

[0092]

As described above, according to the present invention, a good image having a large line width can be obtained in an ink jet recording method for printing on a recording medium using a reaction liquid and an ink composition. become.

[Brief description of the drawings]

FIG. 1 is a view showing an ink jet recording apparatus preferably used for carrying out an ink jet recording method according to the present invention. In this embodiment, a recording head and an ink tank are independent, and an ink composition and a reaction liquid are ink. It is supplied to the recording head by a tube.

FIG. 2 is an enlarged view of a nozzle surface of a recording head, where 1b is a nozzle surface of a reaction liquid and 1c is a nozzle surface of an ink composition.

FIG. 3 is a diagram illustrating an ink jet recording method using the recording head of FIG. In the figure, reference numeral 31 denotes a reaction liquid adhering area, and reference numeral 32 denotes a printing area where the ink composition is printed on the reaction liquid adhering thereto.

FIG. 4 is a diagram showing another embodiment of a recording head preferably used for carrying out the ink jet recording method according to the present invention, in which all ejection nozzles are arranged in a horizontal direction.

FIG. 5 is a view showing an ink jet recording apparatus preferably used for carrying out the ink jet recording method according to the present invention. In this embodiment, a recording head and an ink tank are integrated.

FIG. 6 is a view showing an ink jet recording apparatus preferably used for carrying out the ink jet recording method according to the present invention. In this embodiment, a heater for heating a recording medium after printing is provided.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording head 2 Ink tank 3 Ink tube 14 Heater 21 Reaction liquid discharge nozzle 22, 23, 24, 25 Ink composition discharge nozzle 31 Reaction liquid adhesion area 32 Printing area

Claims (7)

[Claims] 1. An ink jet recording method for printing by applying a reaction liquid containing a reactant after applying an ink composition to a recording medium, wherein an interval between application of the ink composition and the reaction liquid is 5 ms. More than 500
Inkjet recording method with ms or less. 2. The ink-jet printer according to claim 1, wherein the ink composition comprises a colorant and water, and the reaction liquid contacts the ink composition to form an aggregate. Recording method. 3. The reaction liquid has a surface tension of 35 mN / m or less, and the ink composition has a surface tension of 40 mN / m.
3. The ink jet recording method according to claim 1, wherein the value is from N / m to 55 mN / m. 4. The ink jet recording method according to claim 1, wherein the reactant is a polyvalent metal salt, or polyallylamine or a derivative thereof. 5. The ink-jet recording method according to claim 1, wherein the ink composition contains a pigment as a colorant. 6. The ink jet recording method according to claim 1, wherein the ink composition comprises a resin emulsion and / or an inorganic oxide colloid. 7. The ink jet recording method according to claim 1, wherein the inorganic oxide colloid is colloidal silica.