JP2002285055A - Recording ink and recording method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording ink excellent in permeability and drying characteristics, and capable of obtaining an image of good quality. SOLUTION: A water base ink for recording comprises a water insoluble colorant, water, a wetting agent, a water soluble organic solvent, 2-ethyl-1,3- hexanediol and an acetylene glycol-based surfactant represented by general formula (1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording ink, particularly a water-based ink suitable for ink-jet printing, that is, a water-based ink which is excellent as a color ink for so-called plain paper, and is used for a water-based writing instrument, a recorder, and a pen plotter. It is also used as an aqueous ink.

[0002]

2. Description of the Related Art In recent years, ink jet printers have become popular because of their advantages such as low noise and low running cost, and color printers capable of printing on plain paper have also been put on the market. However, the color reproducibility of the image, waterfastness, lightfastness,
It is difficult to satisfy all of the dryness of an image, image bleeding, and the reliability of ejection. In particular, in the case of a color printer, even if the image quality is not deteriorated in the single-color printing portion of yellow, magenta, and cyan, the image quality is likely to be deteriorated in a portion where two colors of red, green, and blue are overlapped. In particular, when drying is performed without using a fixing device, since the drying property is improved by increasing the permeability as disclosed in Japanese Patent Application Laid-Open No. 55-29546, the paper greatly bleeds on the paper.

Japanese Patent Publication No. 60-23793 discloses that dialkylsulfosuccinic acid as a surfactant improves drying properties and causes less image deterioration. However, the pixel diameter of paper is significantly different, and the image density also decreases. There is a problem that the active agent is differentiated on the alkali side and the activating effect is lost during storage.

In Japanese Patent Publication No. 58-6752,
A quick-drying ink with less bleeding by improving the permeability by using a surfactant which is an ethylene oxide adduct having an acetylene bond is disclosed.
However, depending on the dye, there is a problem that the drying speed is not improved due to hydrophobic interaction with a direct dye such as DBK168.

Japanese Patent Application Laid-Open No. 56-57862 discloses an ink to which a strongly basic substance is added. Although this ink is effective for rosin-sized acidic paper, it is effective for alkyl ketene dimer. And alkenylsulfosuccinic acid have no effect on paper. In addition, even with acidic paper, there is no effect in the two-color overlapping portion.

JP-A-1-203483 discloses a recording liquid characterized by containing a polyhydric alcohol derivative and pectin. The recording liquid is prepared by adding pectin as a thickening agent and causing bleeding. However, since pectin is nonionic having a hydroxyl group as a hydrophilic group, there is a problem that the ejection stability after printing is stopped is lacking. Japanese Patent Application Laid-Open No. 2-36276 discloses 2-propanol as a component for improving frequency response and fixability, but has problems in safety such as toxicity and flammability.

[0007] Penetration-based pigment ink formulations have not yet been developed, and the only possible formulation is to use Surfynol as the surfactant and butyl ether as the penetrant. However, butyl ether reacts with the pigment dispersant to cause aggregation of the pigment, and surfynol also has an aggregation effect on carbon black of a surface functional group addition type.

[0008]

SUMMARY OF THE INVENTION A first object of the present invention is to provide an aqueous ink which satisfies various characteristics as a recording ink, particularly an ink jet ink, has excellent permeability and drying properties, and has improved image quality deterioration. To provide. A second object of the present invention is to provide a recording method for forming an image satisfactorily using the ink. A third object of the present invention is to provide a recording method, particularly an ink jet recording method, using a high-safety ink that can achieve ejection stability by high-frequency driving with a small amount of addition and is highly safe.

[0009]

Means for Solving the Problems As a result of various studies, the present inventors have found that, in the ink used in a recording method for performing recording by applying thermal energy to the ink and discharging the ink as droplets from micro holes. Without using butyl ether or 2-propanol, instead of a small amount of 2-ethyl-1,3-hexanediol or 2,2,4-trimethyl-1,3-pentanediol and a specific acetylene glycol-based surfactant. It has been found that the use of (i) improves the pigment dispersibility of the ink to prevent aggregation of the pigment, and improves the wettability to a thermal element, thereby obtaining ejection stability and frequency stability. The present invention has been made based on this.

The object of the present invention is achieved by the following (1) to (12).

(1) a colorant that disperses without being dissolved in water;
Water, a wetting agent, a water-soluble organic solvent, and 0.1% to 3.0% by weight of 2-ethyl-1,3-hexanediol based on the total weight of the recording ink;
Acetylene glycol-based surfactant represented by 0.1
An ink for recording, characterized in that the recording ink is contained in an amount of from 3.0% by weight to 3.0% by weight. General formula (1)

Embedded image (Where p and q are numbers from 0 to 40)

(2) a colorant that disperses without being dissolved in water;
Water, a wetting agent, a water-soluble organic solvent, and 0.1 to 2.0% by weight of 2,2,4-trimethyl-1,3-pentanediol based on the total weight of the recording ink; A recording ink comprising 0.1% to 3.0% by weight of an acetylene glycol-based surfactant represented by the formula (1).

(3) The wetting agent is glycerin, and the water-soluble organic solvent is ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol,
Dipropylene glycol, tripropylene glycol,
It is at least one selected from the group consisting of 1,5-pentanediol, tetraethylene glycol and hexylene glycol, and the mixing ratio of both is 10% by weight.
(1) characterized by being in the range of 1 to 1:10.
Or the recording ink according to (2).

(4) The above (1), wherein the wetting agent is glycerin, the water-soluble organic solvent is diethylene glycol, and the mixing ratio of the two is in the range of 4: 1 to 1: 4 by weight. The recording ink according to any one of (1) to (3).

(5) Any one of the above (1) to (4), wherein a mixed solvent of a wetting agent and a water-soluble organic solvent is contained in an amount of 1 to 30% by weight based on the total weight of the recording ink. 3. The recording ink according to item 1.

(6) The recording according to any one of the above (1) to (5), wherein the colorant is a pigment and is contained in an amount of 1% by weight to 10% by weight based on the total weight of the recording ink. For ink.

(7) The colorant is 0.05 μm to 0.16
(1) wherein the particles have a particle diameter of μm.
The recording ink according to any one of (1) to (6).

(8) The recording ink according to any one of (1) to (7), wherein the pigment is dispersed in water by a dispersant.

(9) The dispersant has a molecular weight of 5,000 to 1
The recording ink according to the above (8), which is a polymer dispersant of 000.

(10) At least 1 water-soluble organic solvent
The recording ink according to any one of the above (1) to (9), which is a pyrrolidone derivative of any kind.

(11) The recording ink according to any one of the above (1) to (10), wherein the ink contains a resin emulsion.

(12) A recording method in which ink droplets are ejected from a recording head and the droplets are attached to a recording medium to perform printing, wherein the ink is any one of the above (1) to (11). An ink jet recording method using the ink described in the above.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. Glycerin is preferred as the wetting agent used in the recording ink of the present invention.

Preferred examples of the water-soluble organic solvent include polyols such as ethylene glycol, diethylene glycol, triethylene glycol,
At least one glycol selected from the group consisting of propylene glycol, dipropylene glycol, tripropylene glycol, 1,5-pentanediol, tetraethylene glycol and hexylene glycol is exemplified. Examples of the glycol ether include methyl cellosolve (CH ₃ OC ₂ H ₄ OH), ethyl cellosolve (C ₂ H ₅ OC ₂ H ₄ OH), and butyl cellosolve (C ₄ H _9).
OC ₂ H ₄ OH).

The use of the wetting agent glycerin and the above-mentioned water-soluble organic solvent in a range of 10: 1 to 1:10 by weight% is important in balancing the ink composition in view of the properties of various physical properties. preferable. In particular, when the wetting agent is glycerin and the water-soluble organic solvent is diethylene glycol, it is particularly preferable that the mixing ratio of both is in the range of 4: 1 to 1: 4 by weight%. The mixed solvent (wetting agent (glycerin) + water-soluble organic solvent) is preferably contained in an amount of 1% by weight to 30% by weight based on the total weight of the recording ink.

Although the ink of the present invention uses water as a liquid medium, it is used for the purpose of obtaining desired physical properties of the ink, preventing drying of the ink, and improving dissolution stability. For example, the following water-soluble organic solvents are used. These water-soluble organic solvents may be used as a mixture of two or more. When a pyrrolidone derivative, particularly 2-pyrrolidone, is used as at least one of the water-soluble organic solvents, the image quality is further improved.

Specific examples of these water-soluble organic solvents include:
For example, the following are mentioned.

(A) ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,5-pentanediol, 1,6-hexanediol, glycerol,
Polyhydric alcohols such as 1,2,6-hexanetriol, 1,2,4-butanetriol, 1,2,3-butanetriol and petriol;

(B) polyhydric alcohol alkyl ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether;

(C) polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether;

(D) 2-pyrrolidone, N-methyl-2-
Pyrrolidone, N-hydroxyethyl-2-pyrrolidone,
Nitrogen-containing heterocyclic compounds such as 1,3-dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone;

(E) amides such as formamide, N-methylformamide, N, N-dimethylformamide;

(F) monoethanolamine, diethanolamine, triethanolamine, monoethylamine,
Amines such as diethylamine and triethylamine;

(G) Sulfur-containing compounds such as dimethyl sulfoxide, sulfolane and thiodiethanol;

(H) Propylene carbonate, ethylene carbonate and the like.

Among these water-soluble organic solvents, diethylene glycol, thiodiethanol, polyethylene glycol 200 to 600, triethylene glycol, glycerol, 1,2,6-hexanetriol,
Preferred are 2,4-butanetriol, petriol, 1,5-pentanediol, 2-pyrrolidone and N-methyl-2-pyrrolidone. These have an excellent effect on solubility and prevention of poor jet characteristics due to water evaporation.

In the ink of the present invention, for the purpose of adjusting the surface tension of the ink, for example, diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol other than the above polyol and / or glycol ether may be used. Alkyl and aryl ethers of polyhydric alcohols such as monobutyl ether, propylene glycol monobutyl ether and tetraethylene glycol chlorophenyl ether, anionic surfactants, nonionic surfactants, fluorine surfactants, ethanol, 2-propanol, etc. Although lower alcohols can be used, diethylene glycol monobutyl ether is particularly preferred.

The surface tension in the present invention is an index indicating permeability to paper, and particularly indicates a dynamic surface tension in a short time of 1 second or less after the surface is formed, and a static surface tension measured in a saturation time. And different. The measuring method is disclosed in
Any method can be used as long as it can measure a dynamic surface tension of 1 second or less by a conventionally known method described in Japanese Patent Application Laid-Open No. 237/1993, etc., but in the present invention, it is measured using a Wilhelmy type suspended plate type surface tensiometer. did. The value of surface tension is 50 mJ /
m ² or less, and more preferably 40 mJ / m ² or less, excellent drying properties can be obtained.

The pigment, which is a colorant used in the present invention, is
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 the organic pigment 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) , Dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinoflurone pigments, etc.), dye chelates (for example,
Basic dye type chelates, acid dye type chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used.

According to a preferred embodiment of the present invention, among these pigments, those having good affinity for water are preferably used. The particle size of the pigment is preferably 1 μm or less, more preferably in the range of 0.05 μm to 0.16 μm. The amount of the pigment added as a colorant in the ink is preferably about 0.5 to 25% by weight, more preferably about 1 to 10% by weight, based on the total amount of the ink.

Specific examples of the pigment preferably used in the present invention include the following.

(A) For black, carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black and channel black, or copper and iron (CI Pigment Black 11) And metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).

(B) For colors, C.I. I. Pigment Yellow 1 (Fast Yellow G), 3, 12 (Disazo Yellow AAA), 13, 14, 17, 24, 3
4, 35, 37, 42 (yellow iron oxide), 53, 55, 8
1, 83 (Disazo Yellow HR), 95, 97, 9
8, 100, 101, 104, 408, 109, 11
0, 117, 120, 138, 153, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 5
1, C.I. I. Pigment Red 1, 2, 3, 5, 17,
22 (Brilliant First Scarlet), 23, 3
1, 38, 48: 2 (permanent red 2B (B
a)), 48: 2 (permanent red 2B (C
a)), 48: 3 (permanent red 2B (S
r)), 48: 4 (permanent red 2B (M
n)), 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 6
3: 2, 64: 1, 81 (rhodamine 6G lake), 8
3, 88, 101 (Bengara), 104, 105, 10
6, 108 (cadmium red), 112, 114, 1
22 (quinacridone magenta), 123, 146, 14
9, 166, 168, 170, 172, 177, 17
8, 179, 185, 190, 193, 209, 21
9, C.I. I. Pigment Violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I.
I. Pigment Blue 1, 2, 15 (Phthalocyanine Blue R), 15: 1, 15: 2, 15: 3 (Phthalocyanine Blue E), 16, 17: 1, 56, 60, 63,
C. I. Pigment Green 1, 4, 7, 8, 10, 1
7, 18, 36 and the like.

(C) In addition, the surface of a pigment (for example, carbon) is treated with a resin or the like to make it dispersible in water, or a functional group such as a sulfone group or a carboxyl group is added to the surface of the pigment (for example, carbon). For example, a processed pigment which can be dispersed in water can be used. The pigment may be contained in microcapsules so that the pigment can be dispersed in water.

According to a preferred embodiment of the present invention, the colorant, especially the pigment for black ink, is a pigment dispersant (preferably a polymer dispersant having a molecular weight of 5,000 to 100,000) in an aqueous medium. It is preferably added to the ink as a pigment dispersion obtained by dispersing it in the ink. As a preferable dispersant, a known dispersion used for preparing a conventionally known pigment dispersion can be used.

Examples of the dispersant include the following. Polyacrylic acid, polymethacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer Polymer, styrene-acrylic acid-alkyl acrylate copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acryl Acid copolymer-alkyl acrylate copolymer, styrene-maleic acid copolymer, vinylnaphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate -Maleic ester copolymer, vinyl acetate- Crotonic acid copolymer, vinyl acetate-acrylic acid copolymer and the like.

According to a preferred embodiment of the present invention, these copolymers have a weight average molecular weight of 3,000 to 50,000.
And more preferably 5,000 to 3
000, most preferably 7,000 to 15,000
It is. The addition amount of the dispersant may be appropriately added within a range in which the pigment is stably dispersed and other effects of the present invention are not lost. The dispersant is 1: 0.06 to 1: 3 based on the pigment.
Is more preferable, and more preferably 1: 0.125 to
The range is 1: 3.

The recording ink of the present invention preferably contains 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. Examples of the resin component of the dispersed phase include acrylic resins, vinyl acetate resins, styrene-butadiene resins, vinyl chloride resins, acryl-styrene resins, butadiene resins, and styrene resins.

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 mixing resin particles with water, if necessary, together with a surfactant. For example, an emulsion of an acrylic resin or a styrene-acrylic resin is obtained by adding a (meth) acrylate or styrene, a (meth) acrylate, optionally a (meth) acrylate, and a surfactant to water. It can be obtained by mixing. The mixing ratio of the resin component and the surfactant is usually preferably about 10: 1 to 5: 1. When the amount of the surfactant used is less than the above range, it is difficult to form an emulsion, and when the amount exceeds the above range, the water resistance of the ink tends to decrease and the permeability tends to deteriorate.

The surfactant is not particularly limited. Examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium laurate, and ammonium salt of polyoxyethylene alkyl ether sulfate. As nonionic surfactants,
For example, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide and the like can be mentioned. The surfactants may be used alone or in combination of two or more.

The ratio of the resin as the disperse phase component of the emulsion to water is 60 to 100 parts by weight of the resin.
A suitable range is 400 parts by weight, preferably 100 to 200 parts.

Commercially available resin emulsions include Microgel E-1002, E-5002 (styrene-acrylic resin emulsion, manufactured by Nippon Paint), Boncoat 4001 (acrylic resin emulsion, manufactured by Dainippon Ink and Chemicals, Inc.), Bon coat 5454 (styrene-
Acrylic resin emulsion, manufactured by Dainippon Ink and Chemicals, SAE-1014 (styrene-acrylic resin emulsion, manufactured by Zeon Corporation), Cybinol SK-2
00 (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 2%.
It is in the range of 5% by weight.

The resin emulsion has the property of thickening and aggregating, has the effect of suppressing the penetration of the coloring component, and further promoting the fixation to the recording material. Further, depending on the type of the resin emulsion, a film is formed on the recording material, 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 sugar. Examples of saccharides include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, preferably 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 substances widely existing in nature such as α-cyclodextrin and cellulose.

The derivatives of these saccharides include reducing sugars of the aforementioned saccharides (for example, sugar alcohols (formula H
OCH ₂ (CHOH) nCH ₂ OH (where n represents an integer of 2 to 5). ), Oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, thioacids and the like. In particular, sugar alcohols are preferred, and specific examples include maltitol and sorbitol. The content of these saccharides is suitably in the range of 0.1 to 40% by weight, preferably 0.5 to 30% by weight of the ink composition.

In addition, sodium alginate may be contained. Sodium alginate is a substance contained only in brown algae, and is a hydrophilic polymer electrolyte that mainly exists as a cell membrane or intercellular substance. Chemically, D-Mannuronic acid [M] that binds to β-1,4;
L-Gluronic acid that binds to α-1,4
It is a polymer of [G]. It has a thickening action, a stabilizing action, a dispersing action, a gelling action, a film forming action and the like.

When sodium alginate is added to the ink-jet ink, the color bleed between colors is as follows (1).
(2) It can be improved by the effect of (3).

(1) Change in viscosity due to pH: An aqueous sodium alginate solution starts to change its state at pH 5 or less.
Clearly gels below H4. Further, it becomes unstable at pH 11 or more, and eventually gels. (2) Precipitation by salts: When a monovalent salt is added to an aqueous sodium alginate solution, the viscosity changes, and the precipitate is eventually deposited. In the case of divalent or higher valent metal salts (except for magnesium and mercury), they immediately become insoluble metal salts and precipitate. (3) Gelation with polyvalent cation: When a polyvalent cation excluding magnesium is added to an aqueous sodium alginate solution,
It gels in the form of its metal salt. The order of the affinity with the metal is as follows. Pb> Cu >>Cd>Ba>Sr>Ca> Co = Ni =
When Zn>Mn> Mg M / G ratio is small, Ba>Sr> Cd. Affinity with iron is greater than copper.

In the ink of the present invention, the above-mentioned colorant, water, wetting agent, water-soluble organic solvent, 2-ethyl-1,3-hexanediol, acetylene glycol-based surfactant represented by the general formula (1) are used. In addition to the agent, a conventionally known additive can be added.

(A) As preservatives and fungicides, for example, sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, sodium pentachlorophenol and the like can be used in the present invention.

(B) As the pH adjuster, any substance can be used as long as it can adjust the pH to 7 or more without adversely affecting the ink to be prepared. Examples thereof include amines such as diethanolamine and triethanolamine, hydroxides of alkali metal elements such as lithium hydroxide, sodium hydroxide and potassium hydroxide, ammonium hydroxide, quaternary ammonium hydroxide, and quaternary phosphonium. Hydroxide, lithium carbonate, sodium carbonate,
Examples thereof include carbonates of alkali metals such as potassium carbonate.

(C) Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, and sodium uramildiacetate.

(D) Examples of the rust preventive include acid sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite and the like.

(E) In addition, a water-soluble ultraviolet absorber, a water-soluble infrared absorber, and a surfactant can be added according to the purpose.

[0067]

EXAMPLES Examples and comparative examples of the present invention will be shown below, but the present invention is not limited to these.

Example 1 An ink composition having the following formulation was prepared and adjusted to a pH of 9 with a 10% aqueous solution of lithium hydroxide. Thereafter, the mixture was filtered through a membrane filter having an average pore diameter of 0.8 μm to obtain an ink composition. Dispersant dispersed carbon black 5% by weight (manufactured by Dainichi Seika Kogyo Co., Ltd.) Glycerin 5% by weight Diethylene glycol 15% by weight 2-ethyl-1,3-hexanediol 2% by weight 2-pyrrolidone 2% by weight Surfynol 82 0.8 % By weight (Air Products and Chemicals Inc.) Deionized water

Example 2 An ink composition was obtained in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 9 with sodium hydroxide. Sulfone group-added carbon black 5% by weight (Cabot Specialty Chemicals, Inc.) Glycerin 5% by weight Ethylene glycol 15% by weight 2-ethyl-1,3-hexanediol 3% by weight 2-pyrrolidone 2% by weight Surfynol 104 0.5% by weight (manufactured by Air Products and Chemicals Inc.) Sodium alginate NSPLL 0.15% by weight (manufactured by Kibun Food Chemifa) Ion exchange water

Example 3 An ink composition was obtained in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 9 with lithium hydroxide. Carboxyl group-added carbon black 5% by weight (Cabot Specialty Chemicals, Inc.) Glycerin 5% by weight Propylene glycol 10% by weight 2-ethyl-1,3-hexanediol 1% by weight 2-pyrrolidone 2% by weight Surfynol 440 1% by weight (manufactured by Air Products and Chemicals Inc.) Acrylic resin emulsion Z116 (MFT 7 ° C) 3% by weight (manufactured by Mitsui Chemicals, Inc.)

Example 4 An ink composition was obtained in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 9 with lithium hydroxide. Microcapsule-containing carbon black 5% by weight (manufactured by Dainippon Ink and Chemicals, Inc.) Glycerin 5% by weight Dipropylene glycol 15% by weight 2-ethyl-1,3-hexanediol 2% by weight 2-pyrrolidone 2% by weight Surfynol 465 1.2% by weight (Air Products and Chemicals Inc.) Deionized water

Example 5 An ink composition was obtained in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 9 with sodium hydroxide. Dispersant dispersed carbon black 5% by weight (manufactured by Dainichi Seika Kogyo Co., Ltd.) Glycerin 5% by weight Hexylene glycol 10% by weight 2-ethyl-1,3-hexanediol 1% by weight 2-pyrrolidone 2% by weight Surfynol 485 0 .9% by weight (Air Products and Chemicals Inc.) Deionized water

Example 6 An ink composition was obtained in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 8 with lithium hydroxide. Sulfone group-added carbon black 5% by weight (Cabot Specialty Chemicals, Inc.) Glycerin 5% by weight Triethylene glycol 15% by weight 2-ethyl-1,3-hexanediol 2% by weight 2-pyrrolidone 2% by weight Surfynol 82 1.2% by weight (Air Products and Chemicals Inc.)

Example 7 An ink composition was obtained in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 9 with lithium hydroxide. Carboxyl group-added carbon black 5% by weight (Cabot Specialty Chemicals, Inc.) Glycerin 5% by weight Tetraethylene glycol 20% by weight 2-ethyl-1,3-hexanediol 3% by weight N-methyl-2-pyrrolidone 2% by weight Surfynol 440 0.8% by weight (Air Products and Chemicals Inc.) Deionized water

Example 8 An ink composition was obtained in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 8 with sodium hydroxide. Microcapsule-containing carbon black 5% by weight (Dainippon Ink & Chemicals, Inc.) Glycerin 5% by weight 1,5-pentanediol 10% by weight 2-ethyl-1,3-hexanediol 2% by weight 2-pyrrolidone 2% by weight Surfynol 485 0.8% by weight (Air Products and Chemicals Inc.) Deionized water

Comparative Example 1 In Example 1, 2-ethyl-1,3-hexanediol and Surfynol 82 (Ai
r Products and Chemicals Inc.) was replaced with ethylene glycol monomethyl ether to prepare an ink composition in the same manner.

Comparative Example 2 In Example 2, 2-ethyl-1,3-hexanediol and Surfynol 104
(Air Products and Chemicals Inc.) was replaced with ethylene glycol monoethyl ether to obtain an ink composition in the same manner.

Comparative Example 3 In Example 3, 2-ethyl-1,3-hexanediol and Surfynol 440 were used.
(Air Products and Chemicals Inc.) was replaced with ethylene glycol monobutyl ether to prepare an ink composition in the same manner.

Comparative Example 4 In Example 4, 2-ethyl-1,3-hexanediol and Surfynol 465 were used.
An ink composition was prepared in the same manner except that (Air Products and Chemicals Inc.) was replaced with diethylene glycol monomethyl ether.

Comparative Example 5 In Example 5, 2-ethyl-1,3-hexanediol and Surfynol 485 were used.
An ink composition was prepared in the same manner as above except that (Air Products and Chemicals Inc.) was changed to diethylene glycol monobutyl ether.

Next, the following tests were conducted for the above Examples 1 to 8 and Comparative Examples 1 to 5. Table 1 shows the results.

1) Sharpness of Image Printing was performed on each of the following papers with an ink jet printer MJ-930C (manufactured by Seiko Epson Corporation). The printing pattern was 100% duty for each color ink of yellow, magenta, and cyan, and characters were simultaneously printed for black ink. Ink ejection amount is 0.07μg / do
t and the density were 360 dpi. After drying, bleeding, image bleeding, color tone, and density at the boundary of the two-color overlapped portion were comprehensively examined visually and with a reflection-type color spectrophotometric densitometer (manufactured by X-Rite), and judged according to evaluation criteria. The printing test paper used is shown below. My Paper (NBS Ricoh) Paper Source S / Recycled Paper (NBS Ricoh) PB Paper (Canon) Multi Ace (Fuji Xerox Office Supply) Yamayuri Paper (Honshu Paper / Recycled Paper) LH Paper Xerox 4024 paper (manufactured by Fuji Xerox Office Supply) Neneah Bond paper (manufactured by Kimberly Clark) [Judgment Criteria] ：: Clear printing without bleeding of all paper. ：: Some paper (recycled paper) has whisker-like bleeding. Δ: Whisker-like bleeding occurred on all papers. ×: Blurring has occurred so that the outline of the character is not clear.

2) Drying Property of Image The filter paper was pressed against the printed image under certain conditions, and the time until the ink was not transferred to the filter paper was measured. If any of the papers dried within 10 seconds, it was judged as "good".

3) Storage stability Each ink was placed in a polyethylene container and stored at -20 ° C, 5 ° C,
It was stored at 20 ° C. and 70 ° C. for 3 months under the respective conditions, and the surface tension, viscosity, and the presence or absence of precipitation of the precipitate after storage were examined. No change in physical properties and the like was observed regardless of the conditions of storage.

4) Reliability at the time of printing pause During the operation of the printer having the head, it is checked how much the printing can be resumed even if the printing is paused without capping, cleaning, etc., and how long (seconds) the ejection direction can be. The reliability was evaluated based on the deviation of the ink droplet or the change in the weight of the discharged droplet.

[0086]

[Table 1]

[0087]

According to the present invention, the wettability to the paper surface is improved, and various properties are satisfied as a recording ink, especially an ink jet recording ink, and the ink has excellent permeability and drying property and improved image quality deterioration. An aqueous ink can be provided. Further, according to the present invention, it shows good wettability to both so-called plain paper and inkjet coated paper,
It is possible to provide a recording method capable of forming a color image having a high penetration rate and a small amount of bleeding.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Akiko Konishi 1-3-6 Nakamagome, Ota-ku, Tokyo Stock inside Ricoh Company (72) Inventor Masayuki Kogano 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh F-term (reference) 2C056 EA05 FC02 2H086 BA52 BA53 BA55 BA59 BA62 4J039 AD01 AD02 AD03 AD08 AD09 AD10 AD11 AD14 BA04 BA13 BA37 BC07 BC09 BC12 BC13 BC20 BC31 BC33 BC35 BC36 BC37 BC39 BC50 BC51 BC54 BC55 BC60 BE01 BE12 BE22 BE22 EA15 EA16 EA17 EA19 EA42 EA44 EA47 GA24

Claims (12)

[Claims] 1. A colorant that disperses without dissolving in water, water, a wetting agent, a water-soluble organic solvent, and 0.1% of 2-ethyl-1,3-hexanediol based on the total weight of the recording ink.
% To 3.0% by weight, and 0.1% by weight of an acetylene glycol-based surfactant represented by the following general formula (1).
A recording ink containing 0.1 to 3.0% by weight. General formula (1) (Where p and q are numbers from 0 to 40) 2. A colorant which disperses without being dissolved in water, water, a wetting agent, a water-soluble organic solvent, and 2,2,4-trimethyl-1,3-pentanediol in an amount of 0 to the total weight of the recording ink. 0.1 to 2.0% by weight, and 0.1 to 3.0% by weight of an acetylene glycol-based surfactant represented by the following general formula (1) for recording. ink. General formula (1) (Where p and q are numbers from 0 to 40) 3. The humectant is glycerin, and the water-soluble organic solvent is ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,5.
-At least one selected from the group consisting of pentanediol, tetraethylene glycol and hexylene glycol, and the mixing ratio of both is 10: 1 to 1% by weight.
3. The method according to claim 1, wherein the ratio is in the range of 1:10.
3. The recording ink according to item 1. 4. The method according to claim 1, wherein the humectant is glycerin, the water-soluble organic solvent is diethylene glycol, and the mixing ratio of the two is in the range of 4: 1 to 1: 4 by weight. The recording ink according to any one of the above. 5. The recording according to claim 1, wherein a mixed solvent of a wetting agent and a water-soluble organic solvent is contained in an amount of 1% by weight to 30% by weight based on the total weight of the recording ink. For ink. 6. The recording ink according to claim 1, wherein the colorant is a pigment, and is contained in an amount of 1% by weight to 10% by weight based on the total weight of the recording ink. 7. The colorant has a thickness of 0.05 μm to 0.16 μm.
The recording ink according to any one of claims 1 to 6, wherein the particles have a particle size of: 8. The recording ink according to claim 1, wherein the pigment is dispersed in water by a dispersant. 9. The dispersant has a molecular weight of 5,000 to 10
The recording ink according to claim 8, which is a 000 polymer dispersant. 10. The method according to claim 1, wherein the water-soluble organic solvent is at least one kind of pyrrolidone derivative.
10. The recording ink according to any one of 9. 11. The recording ink according to claim 1, wherein the ink contains a resin emulsion. 12. A recording method in which ink droplets are ejected from a recording head and the droplets are adhered to a recording medium to perform printing, wherein the ink according to claim 1 is used as an ink. An ink jet recording method characterized by being used.