JP6521269B2 - Ink composition for inkjet recording and inkjet recording method - Google Patents

Description

  The present invention relates to an ink composition for inkjet recording.

  Conventionally, a so-called inkjet recording method is known in which an image or a character is recorded by minute ink droplets ejected from a nozzle of an inkjet recording head. As an ink composition used for such an inkjet recording method, those containing a coloring material (pigment, dye, etc.), surfactant, water, organic solvent, etc. are widely used.

  Among the components contained in such an ink composition for ink jet recording, the surfactant can improve the permeability and the wetting and spreading property of the ink composition to the recording medium, and can improve the image quality of the image to be recorded. Among such surfactants, acetylene glycol surfactants (for example, acetylene glycol, acetylene glycol derivatives, etc.) are excellent in the function of improving the permeability and wet spreading of the ink composition to the recording medium. Because of their excellent defoaming properties, they have attracted attention.

  For example, Patent Document 1 discloses an ink composition for inkjet recording containing an acetylene glycol surfactant. In Patent Document 1, an ink composition containing two ethylene oxide adducts of acetylene glycol having a specific structure and an HLB value, from the viewpoint of being excellent in the prevention effect of the reduction of the dot diameter while maintaining good dischargeability. Is disclosed.

JP, 2013-18951, A

  When an image is recorded on a recording medium having good ink (moisture) absorbability (for example, plain paper mainly composed of cellulose or the like) using the ink composition described in Patent Document 1 above, the ink is recorded Since the ink easily penetrates into the medium, it has a tendency to obtain an image with good fixability, with good image quality in which the aggregation of ink droplets and the color unevenness of the image are suppressed.

  However, even in the case where an image is recorded on the recycled paper among the normal paper whose ink absorbability is considered to be good, the aggregation of ink droplets on the recording medium, the color unevenness of the image and the like occur and the image quality is improved. It may decrease. The recycled paper contains many inorganic components such as calcium carbonate and kaolin, and hydrophobic components such as stearic acid and resin in addition to cellulose etc. Therefore, hydrophilic regions and hydrophobic regions are formed on the surface. It exists in mixture. Therefore, the problem arises that the penetration speed of the ink differs depending on the location where the ink droplet is attached, which may cause deterioration of the image quality such as aggregation or color unevenness.

  In the case of recording an image on a recording medium having low ink (moisture) absorbability (for example, coated paper such as art paper or coated paper) using the ink composition described in Patent Document 1, the ink composition Is difficult to penetrate into the recording medium, and it becomes difficult to wet and spread on the recording medium, causing aggregation of ink droplets on the recording medium, color unevenness of the image, bleeding (bleeding) of the image, and the like. In some cases, the fixability of the image may be degraded.

  As described above, it is difficult to record an image with good image quality and fixability on various types of recording media having different ink absorbability, using the ink composition of one composition.

  Furthermore, the ink composition of Patent Document 1 not only has low permeability to a recording medium having low ink absorbability, but also has an insufficient penetration speed to a recording medium having good ink absorption. Therefore, time is required to promote the spread and penetration of the ink, and the image recording speed tends to decrease.

  Some aspects according to the present invention solve the above-mentioned problems, and provide an ink composition for ink jet recording capable of recording an image with excellent image quality and fixability at high speed on various types of recording media. To provide.

  The present invention has been made to solve at least a part of the problems described above, and can be realized as the following aspects or application examples.

（一般式（１）において、Ｒ^１およびＲ^２はそれぞれ独立に、炭素数１以上５以下のアルキル基を表す。）

（一般式（２）において、Ｒ^３およびＲ^４はそれぞれ独立に、炭素数１以上５以下のアルキル基を表し、ｍおよびｎはそれぞれ、０．５以上２５以下の正数であり、ｍ＋ｎは、１以上４０以下である。） Application Example 1
One embodiment of the ink composition for inkjet recording according to the present invention comprises water, a coloring material, an acetylene glycol represented by the following general formula (1), and an acetylene glycol represented by the following general formula (2) An ink composition for ink jet recording comprising three or more acetylene glycol surfactants selected from the group consisting of ethylene oxide adducts, wherein the total content of the acetylene glycol surfactants is And 0.1% by mass or more and 3% by mass or less with respect to the total mass of the ink composition.

(In General Formula (1), R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms.)

(In the general formula (2), R ³ and R ⁴ each independently represent an alkyl group having 1 or more and 5 or less carbon atoms, m and n each represent a positive number of 0.5 or more and 25 or less, and m + n is , 1 or more and 40 or less.)

  According to the ink composition for inkjet recording of Application Example 1, an image having excellent image quality and fixing property can be recorded at high speed.

Application Example 2
In Application Example 1,
Among the above-mentioned acetylene glycol surfactants, the HLB value of the first acetylene glycol surfactant is h ₁ , and the HLB value of the second acetylene glycol surfactant is h ₂ , the third
The HLB value of the acetylene glycol surfactant in the case of the h _3, the following formula (A), it is possible to satisfy all the formulas (B) and formula (C).
h ₁ <h ₂ <h ₃ (A)
h ₁ <6 (B)
10 ≦ h ₃ (C)

Application Example 3
In Application Example 1 or Application Example 2,
The acetylene glycol surfactant includes one or more acetylene glycols represented by the general formula (1) and two or more ethylene oxide adducts of acetylene glycols represented by the general formula (2), Can be included.

Application Example 4
In any one of application examples 1 to 3,
The content of each of the three or more acetylene glycol surfactants may be 5% by mass or more and less than 50% by mass with respect to the total content of the acetylene glycol surfactants.

Application Example 5
In Application Example 2,
The ratio of the content of the first acetylene glycol surfactant, the content of the second acetylene glycol surfactant, and the content of the third acetylene glycol surfactant is 3 It can be in the range of 1: 1 to 1: 1: 1.

Application Example 6
In any one of the application examples 1 to 5,
Ink jet recording in which an image is recorded by causing the ink composition ejected from the recording head to adhere to the recording medium while moving the recording head relative to the recording medium at a speed of 0.5 m / sec or more. Can be used in the method.

  Hereinafter, preferred embodiments of the present invention will be described. The embodiment described below is an example of the present invention. Further, the present invention is not limited to the following embodiments, and includes various modifications implemented within the scope of the present invention.

1. Ink Composition An ink composition according to an embodiment of the present invention comprises water, a colorant, an acetylene glycol represented by the following general formula (1), and an acetylene glycol represented by the following general formula (2) An ink composition for ink jet recording comprising three or more acetylene glycol surfactants selected from the group consisting of ethylene oxide adducts, wherein the total content of the acetylene glycol surfactants is And 0.1% by mass or more and 3% by mass or less with respect to the total mass of the ink composition.

  Hereinafter, components included in the ink composition according to the present embodiment and components that may be included will be described.

1.1. Acetylene Glycol-Based Surfactant The ink composition according to the present embodiment is a group consisting of an acetylene glycol represented by the following general formula (1) and an ethylene oxide adduct of an acetylene glycol represented by the following general formula (2) It contains three or more kinds of acetylene glycol surfactants selected from among these. Hereinafter, in the present specification, when referring to “three or more acetylene glycol surfactants”, three or more acetylene glycols selected from the group consisting of the following general formula (1) and the following general formula (2) It refers to the surfactant of the system.

In the general formula (1), R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms may have a linear structure or a branched structure. Specific examples of such alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl and neopentyl And the like. R ¹ and R ² may be the same or different.

In the general formula (2), R ³ and R ⁴ each independently represent an alkyl group having 1 to 5 carbon atoms, m and n each represent a positive number of 0.5 to 25 and m + n is 1 or more and 40 or less. The alkyl group having 1 to 5 carbon atoms may have a linear structure or a branched structure. Specific examples of such alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl and neopentyl And the like. R ³ and R ⁴ may be the same or different. Moreover, m and n represent the addition mole number of ethylene oxide, and m + n needs to be 1 or more and 40 or less, preferably 10 or more and 30 or less, and more preferably 15 or more and 25 or less. When m + n exceeds 40, the static surface tension and the dynamic surface tension increase and the wettability is significantly reduced.

  The inventor uses the ink composition containing three or more kinds of acetylene glycol surfactants having the above-described specific structure to obtain good image quality and fixability on plural types of recording media having different ink absorbability. It has been found that it is possible to exert an excellent effect of being able to record an image having the image at high speed. The mechanism that can exert such an effect is considered to be due to the following reasons.

When a plurality of surfactants having similar structures to one another exist in the ink, the arrangement of each surfactant is disturbed, and it becomes difficult to form a large micelle consisting of one surfactant, so each surfactant is a minute cluster. Will be present as. As a result, the moving speed of the ink composition to the surface of the recording medium is improved, and the wettability and permeability to various recording media are improved. As a result, improvement in image quality and speeding up of recording can be realized. Such a phenomenon becomes more pronounced by the presence of three or more acetylene glycol surfactants having similar structures.

  Further, the penetration speed of the ink composition to the recording medium is calculated from a formula represented by γ · cos θ (where, γ represents the surface tension of the ink composition, and θ represents the contact angle of the ink composition to the recording medium). It is known to be proportional to the value being Here, fluorine-based surfactants and silicone-based surfactants widely used in ink compositions for ink jet recording have a small contact angle θ, but also have low surface tension γ, so the penetration speed of the ink composition I can not expect improvement. On the other hand, since the acetylene glycol surfactant has a small contact angle but has a high surface tension γ, the penetration speed of the ink composition is improved, and the image quality and the fixing property can be improved and the recording speed can be realized. Such an action becomes more pronounced by the presence of three or more types of acetylene glycol surfactants having similar structures to one another.

  The quality of the image quality in the present specification can be judged based on the state of ink droplet aggregation, color unevenness, bleeding, and the like. Here, the aggregation of the ink droplets refers to a phenomenon that occurs when the ink droplets adhering to the recording medium flow before being wet and spread and are combined with other ink droplets. When ink droplet aggregation occurs in this manner, streaks may occur where the portion of the surface of the recording medium that is not covered by the ink droplets is streaky, or color irregularities may occur that may cause local density spots in the image. . In addition, bleeding (also referred to as "bleeding" or "bleeding") means that the outline of an image recorded in a single color blurs and the image becomes unclear, or one adjacent color between different colors is on the other color side It is a state where the image becomes unclear as a result of bleeding and mixing.

  Specific examples of the acetylene glycol represented by the above general formula (1) include 2,5,8,11-tetramethyl-6-dodecin-5,8-diol and 5,8-dimethyl-6-dodecin-5. , 8-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 4,7-dimethyl-5-decyne-4,7-diol, 2,3,6,7- Tetramethyl-4-octin-3,6-diol, 3,6-dimethyl-4-octin-3,6-diol, 3,6-diethyl-4-octin-3,6-diol, 2,5-dimethyl -3-hexyne-2,5-diol and the like. Moreover, a commercial item can be used for the acetylene glycol represented by said General formula (1), For example, Surfynol 82, 104, DF-110 (all the brand names, Nisshin Chemical Industry Co., Ltd. make) etc. are mentioned. Be

  Specific examples of the ethylene oxide adduct of acetylene glycol represented by the above general formula (2) include ethylene oxide adducts of the compounds mentioned in the specific examples of acetylene glycol represented by the above general formula (1) . Moreover, a commercial item can be used for the ethylene oxide adduct of acetylene glycol represented by said General formula (2), For example, Olfin E1004, E1010, E4300, Surfynol 485 (all brand names, Nisshin Kogyo Co., Ltd.) And the like.

  The three or more acetylene glycol surfactants include one or more acetylene glycols represented by the general formula (1) and two ethylene oxide adducts of acetylene glycols represented by the general formula (2). It is preferable to include the above. This tends to further improve the effects of the above-mentioned three or more acetylene glycol surfactants.

The total content of the three or more acetylene glycol surfactants needs to be 0.1% by mass or more and 3% by mass or less, preferably 0.5% by mass, based on the total mass of the ink composition. The content is 2% by mass or less, more preferably 1% by mass or more and 2% by mass or less. When the content of the three or more acetylene glycol surfactants is in the above range, the above-described effects are exhibited more favorably. On the other hand, when the amount is less than 0.1% by mass, the image quality and the fixing property are deteriorated, and when the amount is more than 3% by mass, the image quality (particularly, generation of bleeding) tends to occur.

  The content of each of the three or more acetylene glycol surfactants is preferably 5% by mass or more and less than 50% by mass with respect to the total content of the three or more acetylene glycol surfactants, It is more preferable that it is 10 to 50 mass%. By being in the said numerical range, since the compounding balance of 3 or more types of acetylene glycol-type surfactant becomes favorable, the effect produced by containing 3 or more types of acetylene glycol-type surfactant improves further. .

Among the three or more types of acetylene glycol surfactants contained in the ink composition according to the present embodiment, the HLB value of the first acetylene glycol surfactant is h ₁ and the second acetylene glycol surfactant is When the HLB value is h ₂ and the HLB value of the third acetylene glycol surfactant is h ₃ , it is preferable to satisfy all of the following formulas (A), (B), and (C).

h ₁ <h ₂ <h ₃ (A)
h ₁ <6 ... (B)
10 ≦ h ₃ (C)

  Thus, by using an ink composition containing three or more types of acetylene glycol surfactants having different HLB values, a recording medium having high ink absorbability, a recording medium having low ink absorbability, etc. By using one ink composition, various types of recording media can be used to record an image superior in image quality and fixability at high speed. More specifically, by containing the lipophilic first acetylene glycol, the effect of the wetting and spreading property to the recording medium with low absorbability of the ink is exhibited well, and the hydrophilic third acetylene glycol is contained. Thus, the effect of the wetting and spreading property to the recording medium having high ink absorbability is well exhibited. Further, by containing a second acetylene glycol surfactant having an HLB value between the first acetylene glycol surfactant and the second acetylene glycol surfactant, the first acetylene surfactant is contained. Since the compatibility between the glycol surfactant and the third acetylene glycol surfactant is improved, the dischargeability in high speed printing can be improved. In this manner, the above-described effects produced by containing three or more acetylene glycol surfactants can be obtained.

The three or more acetylene glycol surfactants contained in the ink composition according to the present embodiment have the HLB of the second acetylene glycol surfactant in addition to satisfying the above formulas (A) to (C). The value (h ₂ ) is preferably 7 or more and 12 or less (that is, 7 ≦ h ₂ ≦ 12), and more preferably 8 or more and 12 or less (that is, 8 ≦ h ₂ ≦ 12). As a result, the balance of the HLB values of the three or more acetylene glycol surfactants contained in the ink composition is improved, so that the image quality, the fixability, and the high-speed recording property to various types of recording media are further improved. There is a tendency.

The HLB value (h ₁ ) of the first acetylene glycol surfactant is preferably less than 6 as shown in the above formula (B), but the first acetylene glycol surfactant in the ink is preferably used. From the viewpoint of improving the dispersibility, 1 or more and less than 6 (that is, 1 ≦ h ₁ <6) is more preferable, and 3 or more and less than 6 (that is, 3 ≦ h ₁ <6) is more preferable. .

The HLB value (h ₃ ) of the third acetylene glycol surfactant is preferably 10 or more as shown in the above-mentioned formula (C), but the third acetylene glycol surfactant and other surfactants are also preferred. Or more and 20 or less (that is, 10 ≦ h ₃ ≦ 20) from the viewpoint that the permeability of the ink to a recording medium having high absorbability can be further improved while maintaining good mixing properties with the agent. And 12 or more and 18 or less (that is, 12 ≦ h ₃ ≦ 18).

The HLB value in the present invention is a value for evaluating the hydrophilicity of the compound proposed by Davis et al., And is defined, for example, in the document "JTDavies and EKRideal," Interface Phenomena "2nd ed. Academic Press, New York 1963". A numerical value determined by the law, which is a value calculated by the following equation (i).

HLB value = 7 + .SIGMA. [1] +. SIGMA. [2] (i)
(In formula (i), [1] represents the number of hydrophilic groups, and [2] represents the number of hydrophobic groups.)

The content of the first acetylene glycol surfactant is W ₁ % by mass, the content of the second acetylene glycol surfactant is W ₂ % by mass with respect to the total mass (100% by mass) of the ink composition When the content of the acetylene glycol surfactant of ₃ is W ₃ % by mass, the ratio (W ₁ : W ₂ : W ₃ ) of these is in the range of 3: 1: 1 to 1: 1: 1. Is preferred. By being in the said numerical range, since the compounding balance of 3 or more types of acetylene glycol-type surfactant becomes favorable, the effect produced by containing 3 or more types of acetylene glycol-type surfactant improves further. .

  When three or more acetylene glycol surfactants are added to water to a concentration of 1%, one or more acetylene glycols that do not dissolve transparently are added to water to a concentration of 1%. Containing one or more ethylene oxide adducts of acetylene glycol which do not dissolve in the clear, and one or more ethylene oxide adducts of acetylene glycol which dissolves transparently when added to water to a concentration of 1%. Is preferred. This tends to further improve the effects of the above-mentioned three or more acetylene glycol surfactants.

  The solubility of the acetylene glycol surfactant in water can be judged based on the light transmittance of the mixture of the acetylene glycol surfactant and water, and the liquid mixture having a light transmittance of 90% or more is dissolved in a transparent manner. The mixture with a light transmittance of less than 90% is "not transparently soluble". The mixed solution is prepared by adding an acetylene glycol surfactant to water to a concentration of 1% and mixing and stirring for 10 minutes or more. Also, the light transmittance can be measured using a spectrophotometer, using a 1 cm path length quartz cell. As a spectrophotometer used for this measurement, for example, U-3900 (trade name) manufactured by Hitachi High-Technologies Corporation is mentioned.

1.2. Color Material The ink composition according to the present embodiment contains a color material. As the coloring material, conventionally known dyes, organic or inorganic pigments can be used. Among these, it is preferable to use a pigment from the viewpoint of light resistance.

  Among the pigments, examples of inorganic pigments include carbon black, iron oxide, and titanium oxide. Examples of the organic pigment include quinacridone pigments, quinacridone quinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, ansanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, Examples thereof include ketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments. Further, in the ink composition of the present embodiment, as a coloring material, a bright pigment such as metal particles, metal flakes, inorganic salts and the like may be used.

The content of the coloring material in the ink composition of the present embodiment is not particularly limited, but is preferably 0.01% by mass or more and 25% by mass or less based on the total mass of the ink composition, and more preferably The content is 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 15% by mass or less, and particularly preferably 1% by mass or more and 10% by mass or less.

  The pigment is preferably such that it can be stably dispersed in water for application to the ink composition. As a method thereof, a method of dispersing in a pigment-dispersed resin such as a water-soluble resin and / or a water-dispersible resin (hereinafter, the pigment treated by this method may be referred to as a "resin-dispersed pigment"), a dispersant (Hereinafter, the pigment treated by this method may be referred to as “dispersant dispersed pigment”), a hydrophilic functional group is chemically and physically introduced on the surface of the pigment particle, and the above resin Or the method (Hereinafter, the pigment processed by this method may be called "surface treatment pigment") etc. which make it possible to disperse | distribute and / or melt | dissolve in water, without a dispersing agent are mentioned. The ink composition according to the present embodiment may be any of the resin dispersed pigment, the dispersant dispersed pigment, and the surface treated pigment described above, and may be used in the form of a mixture of a plurality of types according to need.

  Pigment Dispersion Resins Used for Resin Dispersion Pigments: polyvinyl alcohols, polyacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid ester copolymer, styrene -Acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid- Acrylic ester copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, vinyl acetate-maleic acid ester copolymer Combined, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic There may be mentioned lactic acid copolymers and the like and salts thereof. Among these, a copolymer of a monomer having a hydrophobic functional group and a monomer having a hydrophilic functional group, and a polymer comprising a monomer having both a hydrophobic functional group and a hydrophilic functional group are preferable. As a form of a copolymer, any form of a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer can be used. A commercial item can be used for such a pigment dispersion resin, For example, Solsperse 20000, 24000, 32000, 32500, 33500, 34000, 35200, 37500 (all are made by LUBRIZOL company), Disperbyk-161, 162, 163, 164, 166, 180, 190, 191, 192 (all are made by BIC Chemie Japan), FLORENE DOPA-17, 22, 33, G-700 (all are made by Kyoeisha Chemical Co., Ltd.), AZISPAR PB821, PB711 (all are Manufactured by Ajinomoto Co., Ltd., LP4010, LP4050, LP4055, POLYMER 400, 401, 402, 403, 450, 451, 453 (all manufactured by EFKA Chemicals, Inc.), and the like.

  The content ratio of the pigment dispersion resin can be appropriately selected according to the pigment to be dispersed, but is preferably 5 parts by mass or more and 200 parts by mass or less, more preferably 100 parts by mass of the pigment content in the ink composition Is 30 parts by mass or more and 120 parts by mass or less.

1.3. Water The ink composition according to the present embodiment contains water. It is preferable that the water is one which is obtained by removing as much as possible ionic impurities such as pure water or ultrapure water such as ion exchange water, ultrafiltered water, reverse osmosis water, and distilled water. In addition, it is preferable to use water sterilized by ultraviolet irradiation, hydrogen peroxide addition or the like because generation of mold and bacteria can be prevented when the ink is stored for a long time. The content of water can be, for example, 50% by mass or more based on the total mass of the ink composition.

1.4. Other Components The ink composition according to this embodiment includes an organic solvent, a resin, a surfactant other than the acetylene glycol surfactant having the above-described specific structure (hereinafter, also referred to as “other surfactant”), and pH adjustment. Agent, antiseptic and antifungal agent, rust inhibitor, chelating agent, etc. may be contained.

1.4.1. Organic solvent The organic solvent is not particularly limited, and examples thereof include 1,2-alkanediols, polyhydric alcohols, pyrrolidone derivatives, glycol ethers and the like.

  Examples of 1,2-alkanediols include 1,2-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol and the like. . The 1,2-alkanediols enhance the wettability of the ink composition to the recording medium and excel in the function of uniformly wetting. In the case of containing 1,2-alkanediols, the content thereof can be set to 1% by mass or more and 20% by mass or less with respect to the total mass of the ink composition.

  Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, glycerin and the like. Be Polyhydric alcohols have functions such as enhancing the wettability of the ink composition to the recording medium, and enhancing the moisture retention of the nozzles of the recording head. When a polyhydric alcohol is contained, it can be 2% by mass or more and 30% by mass or less with respect to the total mass of the ink composition.

  As pyrrolidone derivatives, for example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-pyrrolidone, N-butyl-2-pyrrolidone, 5-methyl-2-pyrrolidone Etc. Pyrrolidone derivatives can act as good solubilizers for resins. When the pyrrolidone derivative is contained, it can be 0.5% by mass or more and 6% by mass or less with respect to the total mass of the ink composition.

As glycol ethers, for example, ethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monoisohexyl ether, diethylene glycol monohexyl ether, triethylene glycol monobutyl ether, monohexyl ether, diethylene glycol monoisohexyl ether, triethylene Glycol monoisohexyl ether, ethylene glycol monoisoheptyl ether, diethylene glycol monoisoheptyl ether, triethylene glycol monoisoheptyl ether, ethylene glycol monooctyl ether, ethylene glycol monoisooctyl ether, diethylene glycol monoisooctyl ether, triethylene glycol mono Isooku Ether, ethylene glycol mono-2-ethyl hexyl ether, diethylene glycol mono-2-ethyl hexyl ether, triethylene glycol mono-2-ethyl hexyl ether, diethylene glycol mono-2-ethyl pentyl ether, ethylene glycol mono-2-ethyl pentyl ether, ethylene glycol Mono-2-ethyl hexyl ether, diethylene glycol mono-2-ethyl hexyl ether, ethylene glycol mono-2-methyl pentyl ether, diethylene glycol mono-2-methyl pentyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether , Propylene glycol monopropyl ether, dip Propylene glycol monopropyl ether, and tripropylene glycol monomethyl ether, and the like. These can be used individually by 1 type or in mixture of 2 or more types. Glycol ethers can control the wettability of the ink composition to the recording medium, and the like. When containing glycol ethers, it is 0.5% by mass or more and 6% by mass with respect to the total mass of the ink composition
The following can be made.

1.4.2. Resin Resin has the function of improving the fixability of the ink composition. As the resin, acrylic resin, fluorene resin, urethane resin, olefin resin, rosin modified resin, terpene resin, ester resin, amide resin, epoxy resin, vinyl chloride resin, vinyl chloride-vinyl acetate A copolymer, ethylene vinyl acetate type resin, etc. are mentioned. These resins can be used singly or in combination of two or more. As the resin, an emulsion type may be used, or a solution type may be used. When it contains resin, the content can be made into 0.1 mass% or more and 6 mass% or less.

1.4.3. Other Surfactant The ink composition according to the present embodiment may contain another surfactant (a surfactant other than the acetylene glycol surfactant having the above specific structure). Examples of such surfactants include acetylene glycol surfactants, silicone surfactants, and fluoro surfactants which do not fall under the above general formulas (1) and (2).

1.4.4. pH adjuster, antiseptic agent / antifungal agent, rust inhibitor, chelating agent As a pH adjuster, for example, potassium dihydrogen phosphate, disodium hydrogen phosphate, sodium hydroxide, lithium hydroxide, potassium hydroxide, Ammonia, diethanolamine, triethanolamine, triisopropanolamine, potassium carbonate, sodium carbonate, sodium hydrogencarbonate, trishydroxymethylaminomethane (THAM), 4- (2-hydroxyethyl) -1-piperazineethanesulfonic acid (HEPES), Morphorinoethanesulfonic acid (MES), carbamoylmethyliminobisacetic acid (ADA), piperazine-1,4-bis (2-ethanesulfonic acid) (PIPES), N- (2-acetamido) -2-aminoethanesulfonic acid ACES), colamin hydrochloric acid, N, N-bi Good buffers such as (2-hydroxyethyl) -2-aminoethanesulfonic acid (BES), N-tris (hydroxymethyl) methyl-2-aminoethanesulfonic acid (TES), acetamidoglycine, tricine, glycine amide, bicine, etc. Phosphate buffer, Tris buffer and the like can be mentioned.

  Examples of preservatives and fungicides include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazolin-3-one (Zeneca Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL.2, Proxel TN, Proxel LV), 4-chloro-3-methylphenol (Preventol CMK from Bayer, etc.) and the like.

  As an antirust agent, benzotriazole etc. are mentioned, for example.

  Examples of the chelating agent include ethylenediaminetetraacetic acid and salts thereof (ethylenediaminetetraacetic acid dihydrogen disodium salt and the like) and the like.

1.5. Preparation Method of Ink Composition The ink composition according to the present embodiment can be obtained by mixing the above-described components in an arbitrary order and, if necessary, filtering to remove impurities. As a mixing method of each component, a method of sequentially adding materials to a container equipped with a stirring device such as a mechanical stirrer, a magnetic stirrer, etc. and stirring and mixing is suitably used. As a filtration method, centrifugal filtration, filter filtration, etc. can be performed as needed.

1.6. Physical Properties The ink composition according to the present embodiment preferably has a surface tension of 20 mN / m to 40 mN / m at 20 ° C. from the viewpoint of the balance between image quality and reliability as an ink composition for inkjet recording. And 25 mN / m or more and 35 mN / m or less. The surface tension is measured, for example, when the platinum plate is wetted with an ink at 20 ° C. using an automatic surface tension meter CBVP-Z (trade name, manufactured by Kyowa Interface Science Co., Ltd.). It can measure by confirming.

  Further, from the same viewpoint, the viscosity at 20 ° C. of the ink composition according to the present embodiment is 1 m. The viscosity is preferably 5 Pa · s or more and 10 mPa · s or less, and more preferably 2 mPa · s or more and 8 mPa · s or less. In addition, the measurement of viscosity can be performed under an environment of 20 ° C. using, for example, a viscoelasticity tester MCR-300 (trade name, manufactured by Pysica).

2. Ink Set An ink set according to an embodiment of the present invention includes a plurality of ink compositions having different hues, and at least one of the plurality of ink compositions described above is an ink composition (that is, water) And an ink composition containing a coloring material, and an acetylene glycol surfactant having a specific structure of three or more types in a range of 0.1% by mass to 3% by mass.

  The plurality of ink compositions having different hues include, for example, yellow ink, magenta ink, and cyan ink, and black ink may be used.

Yellow ink refers to one that can record an image exhibiting a yellow color when it is attached to a recording medium (for example, “photo paper (gloss)” (trade name) manufactured by Seiko Epson Corp.), and is usually yellow-based. Containing the coloring material of Here, the yellow color refers to a color having a hue angle h of 80 ° to 110 ° defined in the CIELAB color space. The lightness and saturation of the yellow color are preferably 70 to 100 for the lightness L ^* and 55 to 90 for the saturation C ^* . Examples of yellow colorants include, but are not limited to, C.I. I. Pigment yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 150, 151, 153, 153, And yellow pigments such as 154, 155, 167, 172, 180, 185, and 213. These pigments may be used alone or in combination of two or more.

Magenta ink refers to one which can record an image exhibiting a magenta color when it is attached to a recording medium (for example, “photo paper (gloss)” (trade name) manufactured by Seiko Epson Corporation), usually a magenta-based image Containing the coloring material of Here, the magenta color means a color having a hue angle h of 330 ° to 360 ° defined in the CIELAB color space. The lightness and saturation of the magenta color are preferably 40 to 70 for the lightness L ^* and 60 to 100 for the saturation C ^* . Examples of magenta colorants include, but are not limited to, C.I. I. Pigment red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 23, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, 254, 264, C.I. I. Pigment Violet 19, 23, 32, 33, 36, 38, 43, 50, and the like. These pigments may be used alone or in combination of two or more.

The cyan ink is a ink capable of recording an image exhibiting a cyan color when attached to a recording medium (for example, "photo paper (gloss)" (trade name) manufactured by Seiko Epson Corporation), and is generally cyan. Containing the coloring material of Here, the cyan color means a color having a hue angle h of 230 ° to 260 ° defined in the CIELAB color space. The lightness and saturation of cyan are preferably 50 to 85 for lightness L ^* and 40 to 80 for saturation C ^* . Examples of cyan-based colorants include, but are not limited to, C.I. I. Pigment blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 15:34, 16, 18, 22, 22, 25, 60, 65, 66, etc. The pigment of a system is mentioned. These pigments may be used alone or in combination of two or more.

A black ink is one that can record an image exhibiting a black color when it is attached to a recording medium (for example, "photo paper (gloss)" (trade name) manufactured by Seiko Epson Corporation), usually a black-based ink Containing the coloring material of The black color refers to a color having a lightness L ^* of 50 or less and a saturation C ^* of 15 or less as defined in the CIELAB color space. Examples of black colorants include, but are not limited to, black colorants represented by carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, and channel black. Pigments are listed. More specifically, as black-based pigments, for example, No. 4 made by Mitsubishi Chemical. 2300, no. 900, MCF 88, no. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, or No2200B, etc .; Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, or Raven 700 etc. manufactured by Columbia, etc. Regal 400R, Regal 330R, Regal 660R, Mogul L, Monarch 700, Monarch manufactured by Cabot. 800, Monarch 880, Monarch 900, Monarch 1000, Monarch
1100, Monarch 1300, or Monarch 1400, etc .; or Degussa's Color Black FW1, Color Black FW2, Color Black FW2 V, Color Black FW18, Color Black FW200, Color Black S150, Color Black
S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140 U, Special Black
6, Special Black 5, Special Black 4A, Special Black 4 and the like. These pigments may be used alone or in combination of two or more.

  As a more preferable aspect of the ink set which concerns on this embodiment, that whose ink composition mentioned above contained in an ink set is a yellow ink is mentioned. An image recorded using yellow ink is more noticeable in bleeding (particularly bleeding at the boundary with other color inks) than an image recorded using other color inks (cyan, magenta ink, etc.) . Therefore, it is preferable in that the image in which the bleeding is suppressed can be obtained by applying the composition described in the ink composition described above to the yellow ink.

  As a further preferable aspect of the ink set according to the present embodiment, the ink composition described above contained in the ink set is a yellow ink and a black ink. An image recorded using a black ink is likely to be noticeable as in the case of the yellow ink, in particular, the bleed (in particular, the bleed at the boundary with the yellow ink). Therefore, in addition to the yellow ink, it is preferable in that the image in which the bleeding is suppressed can be obtained by applying the composition described in the above-described ink composition to the black ink.

  Note that all of the ink compositions contained in the ink set may be those to which the above-described composition of the ink composition is applied.

3. Ink Jet Recording Method An ink jet recording method according to an embodiment of the present invention discharges ink droplets of the ink composition using the above-described ink composition or ink set, and causes the ink droplets to adhere to a recording medium. The image is recorded with Thereby, the recorded matter on which the image is formed on the recording medium is obtained. In the ink jet recording method according to the present embodiment, since the above-described ink composition is used, an image excellent in image quality and fixability can be recorded at high speed on various recording media.

  The inkjet recording method according to the present embodiment is performed using an inkjet recording apparatus (for example, a known inkjet printer or the like). As such an ink droplet discharge apparatus, any one of a so-called serial type ink jet recording apparatus (printer adopting a serial head as a recording head) and a line type ink jet recording apparatus (printer adopting a line head as a recording head) can be used can do. A recording head is mounted on these types of inkjet recording apparatuses, and ink droplets of the ink composition are given predetermined timing from the nozzles of the recording head while changing the relative positional relationship between the recording medium and the recording head. Then, the ink composition can be deposited on a recording medium by discharging the ink composition in a predetermined volume (mass), and a predetermined image can be recorded.

  Here, the recording speed when recording an image on the recording medium is improved by increasing the relative moving speed of the recording head with respect to the recording medium. The ink composition described above has the property of being excellent in permeability to various recording media and wettability and spreading properties, so the relative moving speed of the recording head relative to the recording medium is 0.5 m / sec or more (preferably 0). Even in the case of a high speed of 5 m / sec or more and 3 m / sec or less), an image excellent in image quality and fixability can be recorded.

  The ink jet recording method can use the serial type or line type ink jet recording apparatus as described above, and as the method, the ink composition is discharged as ink droplets from a fine nozzle and the ink droplets are used as a recording medium It is not particularly limited as long as it can be attached to For example, the ink jet recording method may include an electrostatic suction method, a method of ejecting ink droplets by a pump pressure, a method of using a piezoelectric element, a method of heating and bubbling an ink liquid with a microelectrode and ejecting ink droplets. it can. Among these, a system using a piezoelectric element can be preferably used.

  Since the ink jet recording method according to the present embodiment uses the above-described ink composition or ink set, an image excellent in image quality and fixability can be recorded at high speed on various types of recording media. As such a recording medium, a recording medium with high ink absorbability and a recording medium with low ink absorbability can be mentioned.

  Usually, when ink jet recording is performed on a recording medium having low ink absorbability, a heater or the like is used to record an image of good image quality because the ink composition has low wet spreading property and low permeability. It was necessary to dry the recorded image using a dryer. However, since the ink composition described above is excellent in the ink spreading property and permeability even to a recording medium having low ink absorbability, the drying process using a drying apparatus such as a heater can be omitted. It may be As a result, it is possible to solve the problems such as the increase in size of the apparatus and the increase in power consumption caused by the introduction of the drying apparatus, and the speeding up of image recording accompanying the omission of the drying process.

The recording medium having high ink absorbability is not particularly limited. For example, plain paper such as electrophotographic paper having high permeability of aqueous ink, ink jet paper (ink absorbing layer composed of silica particles or alumina particles, or And inkjet-specific paper provided with an ink absorbing layer composed of a hydrophilic polymer such as polyvinyl alcohol (PVA) or polyvinyl pyrrolidone (PVP).

  Examples of the recording medium having low ink absorbability include, but not particularly limited to, coated paper provided with a coating layer for receiving the ink on the surface, and, for example, general ink having relatively low permeability Printing papers such as art paper, coated paper, matte paper, etc. used for offset printing of

4. EXAMPLES Hereinafter, embodiments of the present invention will be more specifically described by examples, but the embodiments are not limited to only these examples.

4.1. Preparation of Ink Composition Each material shown in Table 1 is placed in a container, stirred and mixed for 2 hours with a magnetic stirrer, and then filtered with a membrane filter with a pore size of 5 μm to remove impurities such as dust and coarse particles. Thus, ink compositions according to the examples and the comparative examples were prepared. In Examples and Comparative Examples, four ink compositions (yellow ink, magenta ink, cyan ink, black ink) in which only the type of coloring material is changed are prepared, and each of the four ink compositions is evaluated. The However, the bleed test was performed using a yellow ink and a black ink.

In addition, the material described except compound name in Table 1 is as follows.
-Surfynol 104 (trade name, manufactured by Nisshin Chemical Industry Co., Ltd., acetylene glycol corresponding to the formula (1), 2,4,7,9-tetramethyl-5-decyne-4,7-diol, HLB value: 4)
-Surfynol 82 (trade name, manufactured by Nisshin Chemical Industries, Ltd., acetylene glycol corresponding to the above (1), HLB value: 4)
・ Orphin E 1004 (trade name, manufactured by Nisshin Chemical Industries, Ltd., ethylene oxide adduct of acetylene glycol corresponding to the above formula (2), HLB value: 8)
・ Orphine E4300 (trade name, manufactured by Nisshin Chemical Industries, Ltd., ethylene oxide adduct of acetylene glycol corresponding to the above formula (2), HLB value: 11)
・ Orphin E1010 (trade name, manufactured by Nisshin Chemical Industry Co., Ltd., ethylene oxide adduct of acetylene glycol corresponding to the above formula (2), 2,4,7,9-tetramethyl-5-decyne-4,7-diol Ethylene oxide adduct of ethylene oxide (mole number of ethylene oxide added: 10), HLB value: 13)
-Surfynol 485 (trade name, manufactured by Nisshin Chemical Industry Co., Ltd., ethylene oxide adduct of acetylene glycol corresponding to the above formula (2), 2,4,7,9-tetramethyl-5-decyne-4,7- Ethylene oxide adduct of diol (ethylene oxide added mole number: 30), HLB value: 17)
Neugen ET-116 B (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polyoxyalkylene alkyl ether, HLB value: 12)
・ BYK-348 (trade name, manufactured by Big Chemie Japan Co., Ltd., silicone surfactant, HLB value: 11)
Pigment (for each ink composition, carbon black (for black ink), CI pigment blue 15: 4 (for cyan ink), CI pigment red 122 (for magenta ink), or CI. Pigment yellow 74 (for yellow ink) was used.)
-Styrene acrylic acid copolymer (trade name "JONCRYL390", manufactured by BASF Japan Ltd., glass transition temperature (Tg): -5 ° C, weight average molecular weight: 200,000 or more)

4.2. Evaluation Tests The following evaluation tests were performed using samples obtained as follows. First, the ink jet printer PX-B510 (manufactured by Seiko Epson Corporation) was modified so that the moving speed of the carriage of the recording head could be adjusted to 0.5 m / s and 0.3 m / s. Thereafter, an ink cartridge filled with the ink composition prepared as described above was mounted on the printer, each ink composition was ejected from the nozzle of the recording head, and an image was recorded on the recording medium. The recorded matter on which the image was thus recorded was used as an evaluation sample.

  Evaluation samples were prepared for each of high speed recording (carriage moving speed 0.5 m / sec) and low speed recording (carriage moving speed 0.3 m / sec). Also, the recording condition of the image was set to an image resolution of 100% duty and 360 × 360 dpi.

The recording media used for producing the evaluation sample are as follows.
-Photo paper for ink jet (trade name "Photo Paper <Glossy", manufactured by Seiko Epson Corporation)
・ Normal paper 1 (brand name "both sides high quality normal paper", Seiko Epson Corporation make)
-Plain paper 2 (trade name "Copy Plus Paper", manufactured by Hammermill)
・ Coated paper (trade name "OK Top Coat +", manufactured by Oji Paper Co., Ltd.)

4.2.1. Coagulation and color unevenness The image quality was evaluated by visually checking the state of image aggregation and color unevenness for the evaluation samples obtained as described above. Evaluation criteria are as follows.
:: occurrence of color unevenness and aggregation not observed at a position 20 cm from the image recording surface ○: occurrence of color unevenness and aggregation at a position 20 cm from the image recording surface Δ: position 100 cm from the image recording surface Occurrence of color unevenness and aggregation are observed. ×: Generation of color unevenness and aggregation is observed at a position of 200 cm from the image recording surface.

4.2.2. Bleed (K-Y inter-color bleed)
In the bleed test, an image pattern in which a yellow ink (Y) and a black ink (K) are adjacent is recorded, and the occurrence of bleeding in the boundary portion of the image recorded by both inks is visually confirmed. The image quality was evaluated. Evaluation criteria are as follows.
:: Bleeding not observed at 20 cm from the image recording surface ○: Bleeding observed at 20 cm from the image recording surface Δ: Bleeding observed at 100 cm from the image recording surface x: Image recording Bleeding is observed 200 cm from the surface

4.2.3. Fixation (abrasion test)
The image fixability of the image was evaluated by rubbing the image of the evaluation sample obtained as described above twice with a finger and visually confirming the degree of image contamination. Evaluation criteria are as follows.
A: No stain on the image was observed 20 cm from the image recording surface. O: A stain on the image was observed 20 cm from the image recording surface. C: A stain on the image 100 cm from the image recording surface. Recognized x: Staining of the image is observed at a position of 200 cm from the image recording surface

4.3. Evaluation results The above evaluation results are shown in Table 2.

As shown in the evaluation results of Table 2, various types of ink compositions containing three or more types of acetylene glycol surfactants having a specific structure and containing 0.1% by mass or more and 3% by mass or less of these surfactants are used. It was shown that an image with excellent image quality and fixability can be obtained for both the low speed recording and the high speed recording with respect to the recording medium of the above.

  On the other hand, since the ink compositions according to Comparative Examples 1 to 11 do not contain three or more acetylene glycol surfactants having a specific structure, the image quality to a coated paper with low ink absorbability and low ink speed during low speed recording There was a tendency that the fixability was lowered, and at the time of high speed recording, the image quality and the fixability to the coated paper were lowered and the fixability to the plain paper was lowered.

  The ink composition according to Comparative Example 12 contains three or more types of acetylene glycol surfactants having a specific structure, but the content is less than 0.1% by mass. Therefore, the effect of the acetylene glycol surfactant having the specific structure was not sufficiently exhibited, and the results of the respective evaluation tests were shown to have the same tendency as the ink composition used in Comparative Example 1 to Comparative Example 11. .

  The ink composition according to Comparative Example 13 contains three or more types of acetylene glycol surfactants having a specific structure, but the content exceeds 3% by mass. When the ink composition according to Comparative Example 13 is used, occurrence of bleed on coated paper becomes remarkable at low speed printing, and occurrence of bleed on coated paper becomes remarkable at high speed printing, as well as aggregation and color. It was shown that the occurrence of unevenness also became remarkable.

  The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the invention includes configurations substantially the same as the configurations described in the embodiments (for example, configurations having the same function, method and result, or configurations having the same purpose and effect). The present invention also includes configurations in which nonessential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that can achieve the same effects as the configurations described in the embodiments, or configurations that can achieve the same purpose. Further, the present invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

Claims (4)

water and,
With pigments,
Three or more acetylene glycol surfactants selected from the group consisting of acetylene glycols represented by the following general formula (1) and ethylene oxide adducts of acetylene glycols represented by the following general formula (2):
An ink composition for inkjet recording containing
The total content of the acetylene glycol surfactant is 0.1 % by mass or more and 3% by mass or less based on the total mass of the ink composition,

(In General Formula (1), R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms.)

(In the general formula (2), R ³ and R ⁴ each independently represent an alkyl group having 1 or more and 5 or less carbon atoms, m and n each represent a positive number of 0.5 or more and 25 or less, and m + n is , 1 or more and 40 or less.)
Among the above acetylene glycol surfactants, the HLB value of the first acetylene glycol surfactant is h ₁ , the HLB value of the second acetylene glycol surfactant is h ₂ , and the third acetylene glycol surfactant is The following formula (A), formula (B) and formula (C) are all satisfied when the HLB value of the agent is h ₃ ,
h ₁ <h ₂ <h ₃ (A)
h ₁ <6 (B)
10 ≦ h ₃ (C)
The ratio of the content of the first acetylene glycol surfactant, the content of the second acetylene glycol surfactant, and the content of the third acetylene glycol surfactant is 3 In the range of 1: 1 to 1: 1: 1,
The ink composition ejected from the recording head is adhered to the recording medium while moving the recording head relative to the plain paper as a recording medium at a speed of 0.5 m / sec or more, and the image is printed. Used for inkjet recording method to record ,
The acetylene glycol surfactant includes one or more acetylene glycols represented by the general formula (1) and two or more ethylene oxide adducts of acetylene glycols represented by the general formula (2), An ink composition comprising: In claim 1,
An ink composition, wherein the total content of the acetylene glycol surfactant is 2.4% by mass or less based on the total mass of the ink composition. In claim 1 or claim 2,
An ink composition, wherein the content of each of the three or more acetylene glycol surfactants is 5% by mass or more and less than 50% by mass with respect to the total content of the acetylene glycol surfactants. The ink composition ejected from the recording head is adhered to the recording medium while moving the recording head relative to the plain paper as the recording medium at a speed of 0.5 m / sec or more to record an image. Inkjet recording method, and
The ink composition is
water and,
With pigments,
Three or more acetylene glycol surfactants selected from the group consisting of acetylene glycols represented by the following general formula (1) and ethylene oxide adducts of acetylene glycols represented by the following general formula (2):
Contains
The total content of the acetylene glycol surfactant is 0.1 % by mass or more and 3% by mass or less based on the total mass of the ink composition,

(In General Formula (1), R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms.)

(In the general formula (2), R ³ and R ⁴ each independently represent an alkyl group having 1 or more and 5 or less carbon atoms, m and n each represent a positive number of 0.5 or more and 25 or less, and m + n is , 1 or more and 40 or less.)
Among the above acetylene glycol surfactants, the HLB value of the first acetylene glycol surfactant is h ₁ , the HLB value of the second acetylene glycol surfactant is h ₂ , and the third acetylene glycol surfactant is The following formula (A), formula (B) and formula (C) are all satisfied when the HLB value of the agent is h ₃ ,
h ₁ <h ₂ <h ₃ (A)
h ₁ <6 (B)
10 ≦ h ₃ (C)
The ratio of the content of the first acetylene glycol surfactant, the content of the second acetylene glycol surfactant, and the content of the third acetylene glycol surfactant is 3 : 1: 1 to 1: 1: Ri 1 of the range near,
The acetylene glycol surfactant includes one or more acetylene glycols represented by the general formula (1) and two or more ethylene oxide adducts of acetylene glycols represented by the general formula (2), including, an inkjet recording method.