JP6835156B2 - Method for producing polymer - Google Patents

Description

The present invention relates to a polymer, a method for producing a polymer, an ink using the polymer, and an ink container.

Compared to other recording methods, the inkjet recording method has become popular because it has the advantages of a simple process, easy full-color conversion, and the ability to obtain high-resolution images even with a device with a simple configuration. It is expanding from personal to office applications, commercial printing and industrial printing. In such an inkjet recording method, a water-based ink composition using a water-soluble dye as a coloring material is mainly used, but since it has a drawback of being inferior in water resistance and light resistance, it is water-insoluble instead of the water-soluble dye. The development of pigment inks using the above pigments is underway.

In inkjet printing for office use, plain paper is mainly used as a recording medium, and high image density is required. Generally, when a pigment ink is printed on plain paper, the pigment penetrates into the paper without staying on the paper surface, so that the pigment density on the paper surface becomes low and the image density decreases. If the pigment density in the ink is increased, the image density is increased, but the viscosity of the ink is increased and the ejection stability is lowered.

Further, in the fields of commercial printing and industrial printing, there is a need for a technique for stably producing images with higher resolution and sharpness at a higher speed. As the recording medium, plain paper, coated paper, art paper, non-permeable film such as PET film, and the like are used, and high compatibility of ink with the recording medium is required. In the inkjet recording method, in order to prevent paper curl that occurs when printing on plain paper, or when printing on coated paper or art paper, the ink permeability is increased to accelerate drying and prevent beading. There is a method of adding a hydrophilic organic solvent to the water-based ink.

Further, unlike the water-based dye ink prepared by dissolving the dye in water, the water-based pigment ink used in the above-mentioned inkjet recording method and writing instrument needs to stably disperse the pigment insoluble in water in water for a long period of time. Therefore, various pigment dispersants have been developed. For example, Patent Document 1 proposes a graft polymer containing an aromatic ring in the side chain. By using this graft polymer as a pigment dispersant, ink storage stability at 70 ° C. for 3 days is ensured.

When a conventional graft polymer is used as a pigment dispersant, it is insufficient in terms of long-term storage stability.
The present invention has been made in view of the current state of the prior art, and an object of the present invention is to provide a novel polymer effective as a pigment dispersion resin.

The above problem is solved by the invention of the following (1).
(1) A polymer having at least a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2).
In the general formula (1), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (2), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.

According to the present invention, it is possible to provide a novel polymer effective as a pigment dispersion resin for water-based inks.
That is, when the polymer of the present invention is used as a pigment dispersion resin, a pigment dispersion having high dispersibility and long-term stability can be obtained.
Further, when the polymer of the present invention is used for a water-based ink, a high image density can be obtained even when recorded on plain paper, and a water-based ink having excellent storage stability can be obtained.

It is a figure which shows an example of the ink containing container of this invention. It is explanatory drawing including the case (exterior) of the example of the ink container of FIG. It is a chart which shows the IR spectrum of the polymer CP1-1 obtained in Example I-1. It is a chart which shows the IR spectrum of the polymer CP2-1 obtained in Example I-14. It is a chart which shows the IR spectrum of the polymer CP3-1 obtained in Example I-29. It is a chart which shows the IR spectrum of the polymer CP4-1 obtained in Example I-43. It is a chart which shows the IR spectrum of the polymer CP6-1 obtained in Example I-63.

The polymer of the present invention has at least a structural unit represented by the general formula (1) and a structural unit represented by the general formula (2).
In the general formula (1), R ₁ and R ₂ are hydrogen atoms or methyl groups.
n represents a value of 1 to 90.
The structure represented by the general formula (1) of the cellulose that mainly constitutes plain paper and the polymer of the present invention is hydrophilic. Therefore, the structure represented by the general formula (1) is considered to have an affinity for cellulose rather than a hydrophobic solvent. When the polymer of the present invention is used for ink, the polymer of the present invention adsorbed on the pigment during printing is adsorbed on cellulose, and the pigment easily stays on the paper surface. It is considered that having a polyethylene glycol chain in which n is 1 to 90 in the general formula (1) facilitates contact with cellulose and more easily adsorbs to cellulose. As a result, high image density can be exhibited even on plain paper.
In the general formula (1), n represents the average number of moles _{of ethylene oxide (C 2} H _{4 O) added.}
R ₂ is preferably a hydrogen atom from the viewpoint of water solubility.

In the general formula (2), R ₃ is a hydrogen atom or a methyl group, L is an alkylene group having 2 to 18 carbon atoms, preferably an alkylene group having 2 to 16 carbon atoms, and more preferably an alkylene group having 2 to 16 carbon atoms. It is 2 to 12 alkylene groups. The naphthyl group whose one end exists at the end via L in the open end (open end, that is, the pendant structure portion) is a pigment which is a coloring material in water-based ink (hereinafter, also referred to as ink). Due to the π-π stacking of, it has excellent pigment adsorption power.
As can be understood from the description of the above-mentioned "naphthyl group existing at the end via L in the pendant", the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) are It may be the main chain of a polymer having a pendant group such as a terminal naphthyl group or a side chain carboxyl group that hangs down via L, typically. However, of course, it does not exclude the case where a part is included in the side chain.
For example, it is a well-known fact that it is difficult to completely eliminate the secondary radical polymerization reaction that produces a branched structure.
Further, when the polymer of the present invention is used when preparing a pigment dispersion in which a pigment is dispersed in water, a naphthyl group is present at the end of a side chain of the polymer, so that it is easily adsorbed on the pigment surface and becomes a pigment. Because of its high adsorptive power, a highly dispersible and long-term stable dispersion can be obtained.

The molar ratio of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) constituting the polymer of the present invention is the general formula (1) in terms of the ability to adsorb pigments. : (2) = 0.5: 1.0 to 10.0: 1.0, more preferably 0.5: 1.0 to 7.0: 1.0, still more preferably 0.5: 1. .0 to 5.0: 1.0. When the preferable range of the ratio of the structural unit represented by the general formula (1) to the structural unit represented by the general formula (2) is shown by mass ratio, it is 25:75 to 87:13, more preferably 40:60 to. It is 82:18, more preferably 57:43 to 77:23.

The structure of the polymer can be analyzed by using a general analytical method such as NMR or IR.
The molar ratio of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) constituting the polymer is determined by the molar ratio of the monomers used when synthesizing the polymer. be able to. Further, it can be obtained from the polymer by NMR.

In addition to the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2), the polymer of the present invention further comprises a structural unit represented by the following general formula (3). You may have.

In the general formula (3), R ₄ represents a hydrogen atom or a methyl group, and X represents a hydrogen atom or a cation. If X is a cation, the oxygen adjacent to cation O ^- present as. Examples of cations include sodium ion, potassium ion, lithium ion, tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, tetrabutylammonium ion, tetrapentylammonium ion, tetrahexylammonium ion, triethylmethylammonium ion, and tributylmethyl. Ammonium ion, trioctylmethylammonium ion, 2-hydroxyethyltrimethylammonium ion, tris (2-hydroxyethyl) methylammonium ion, propyltrimethylammonium ion, hexyltrimethylammonium ion, octyltrimethylammonium ion, nonyltrimethylammonium ion, decyltrimethyl Ammonium ion, dodecyltrimethylammonium ion, tetradecyltrimethylammonium ion, hexadecyltrimethylammonium ion, octadecyltrimethylammonium ion didodecyldimethylammonium ion, ditetradecyldimethylammonium ion, dihexadecyldimethylammonium ion, dioctadecyldimethylammonium ion, Ethylhexadecyldimethylammonium ion, ammonium ion, dimethylammonium ion, trimethylammonium ion, monoethylammonium ion, diethylammonium ion, triethylammonium ion, monoethanolammonium ion, diethanolammonium ion, triethanolammonium ion, methylethanolammonium ion, Methyldiethanolammonium ion, dimethylethanolammonium ion, monopropanolammonium ion, dipropanolammonium ion, tripropanolammonium ion, isopropanolammonium ion, morpholinium ion, N-methylmorpholinium ion, N-methyl-2-pyrrolidoni Examples thereof include um ion and 2-pyrrolidnium ion.

By having the structural unit represented by the general formula (3), the storage stability is further excellent and the image density can be increased.
The structural unit represented by the general formula (3) is different from the structural unit represented by the general formula (1). From the viewpoint of the strength of pKa, X is cationized and the solvent is formed by replacing the alkaline ion with X. Becomes an anion inside. Therefore, when used as a dispersant, dispersion due to electrical repulsion occurs. The structure represented by the general formula (1) depends on the solvent due to the dispersion of the structural unit represented by the general formula (1) due to steric hindrance and the dispersion of the structural unit represented by the general formula (3) due to the electrical repulsion. Storability is better than when only units are used.
Further, the carboxyl group contained in the structural unit represented by the general formula (3) is neutralized by Ca ions dissolved from the paper after the ink drops and landed, so that the electrical repulsive force is lost. As a result, the pigment particles quickly aggregate after the ink drops land and stay on the paper surface, so that the image density can be increased for the paper containing a large amount of Ca.

The molar ratio of the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3) constituting the polymer of the present invention is the pigment. From the viewpoint of the ability to adsorb, the general formula (1): (2): (3) = 0.3: 1.0: 0.6 to 2.0: 1.0: 3.0 is preferable, and more preferable. 0.6: 1.0: 1.2 to 1.8: 1.0: 2.6, more preferably 0.8: 1.0: 1.5 to 1.5: 1.0: 2.4 Is. When the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3) are expressed by mass ratio, 15:77: 8 to 47: It is preferably 35:18, more preferably 25:62:13 to 45:38:17, and even more preferably 30:56:14 to 42:41:17.

In addition to the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2), the polymer of the present invention further comprises a structural unit represented by the following general formula (7). You may have.
_{R 5} in the general formula (7) represents a hydrogen atom or a methyl group.
The structure of the general formula (7) has a high affinity with the water-soluble organic solvent used for the ink. In the structure of the general formula (1), hydrophilic groups gather together under a hydrophobic ink solvent and the spread is lost, so that the steric hindrance is lowered, and the storage stability in the ink may be slightly inferior to that in water. Therefore, by introducing the structure of the general formula (7) having a more hydrophobic hydrophilic group, it is possible to maintain the spread of the polymer chain even under the ink solvent and improve the storage stability. By introducing this structure, the dispersion of the pigment can be kept stable even when the water in the ink volatilizes and the ratio of the water-soluble organic solvent in the ink is high. As a result, high discharge reliability can be obtained.

The molar ratio of the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (7) constituting the polymer of the present invention is the pigment. From the viewpoint of the ability to adsorb, the general formula (1): (2): (7) = 0.3: 1.0: 0.1 to 4.0: 1.0: 1.5 is preferable, and more preferable. 0.5: 1.0: 0.2 to 3.5: 1.0: 1.0, more preferably 1.0: 1.0: 0.3 to 3.0: 1.0: 0.8 Is. The preferable range of the ratio of the structural unit represented by the general formula (1) to the structural unit represented by the general formula (2) and the structural unit represented by the general formula (7) is expressed by a mass ratio of 16:81. : 3 to 63:24:13, more preferably 24:70: 6 to 62:27:11, and even more preferably 37:56:7 to 60:30:10.

The structure of the polymer can be analyzed by using a general analytical method such as NMR or IR.
Further, the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3) or the general formula (7) constituting the polymer. The molar ratio with the structural unit represented by (1) can be determined from the molar ratio of the monomer used in synthesizing the polymer. Further, it can be obtained from the polymer by NMR.

A polymer having the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) of the present invention, and the structural unit and the general formula represented by the general formula (1). The number average molecular weight and the weight average molecular weight of the polymer having the structural unit represented by (2) and the structural unit represented by the general formula (3) or the structural unit represented by the general formula (7) are: In terms of polystyrene, 500 to 10000 and 1500 to 30000 are preferable, respectively.

In addition to the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2), the polymer of the present invention further comprises a structural unit represented by the following general formula (9). You may have.

In the general formula (9), R ₆ is a hydrogen atom or a methyl group, R ₇ is either —O— or —NH—, and R ₈ is an alkylene group having 5 or less carbon atoms which may have a substituent. R ₉ represents a hydrogen atom or an alkyl group having 5 or less carbon atoms, and a and b are independently 0 or 1, respectively.
R ₈ is preferably an ethylene group, a propylene group or the like, and R ₉ is preferably a hydrogen atom, a methyl group, an ethyl group or the like.
The structural unit represented by the general formula (9) has basicity. The acidic surface modification of the pigment surface and the base of the polymer of the present invention are bonded by acid-base interaction. In addition to π-π stacking, the polymer has an excellent pigment adsorption amount by having an adsorption mechanism by acid-base interaction.

The structure of the polymer can be analyzed by using a general analytical method such as NMR or IR.
Further, the molar ratio of the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (9) constituting the polymer is the polymer. It can be determined by the molar ratio of the monomers used in the synthesis. Further, it can be obtained from the polymer by NMR.

The molar ratio of the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (9) constituting the polymer of the present invention is a pigment. From the viewpoint of the ability to adsorb, the general formula (1): (2): (9) = 0.3: 1.0: 0.05 to 6.0: 1.0: 1.0 is preferable, and more preferable. Is 0.5: 1.0: 0.1 to 6.0: 1.0: 0.8, more preferably 1.0: 1.0: 0.2 to 6.0: 1.0: 0. It is 5.

A 6.5% by mass aqueous solution of a polymer having a structural unit represented by the general formula (1), a structural unit represented by the general formula (2), and a structural unit represented by the general formula (9). The viscosity is preferably in the range of 1.0 to 30.0 mPa · s. When it is 1.0 mPa · s or more, the reactivity of the pigment dispersant with respect to cellulose in paper is further improved, and the effect of improving the image density becomes remarkable. When it is 30.0 mPa · s or less, the dispersion stability of the pigment is further improved, and the storage stability of the pigment dispersion is also further improved. The viscosity is a value measured at 25 ° C., as will be described later.

Examples of the structural unit represented by the general formula (9) in the polymer include the structural unit represented by the following general formula (9-1).
In the general formula (9-1), R ₆ represents a hydrogen atom or a methyl group.

In addition to the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2), the polymer of the present invention further comprises a structural unit represented by the following general formula (11). You may have.
In the general formula (11), R ₁₀ is a hydrogen atom or a methyl group, R ₁₁ is either —O— or —NH—, and R ₁₂ is an alkylene group having 5 or less carbon atoms which may have a substituent. R ₁₃ represents an alkyl group having 5 or less carbon atoms, Y ⁻ represents an anion species, and a and b are independently 0 or 1, respectively.
Here, Y ^- is a counter ion of a quaternary ammonium salt, and various anion species can be used. Specifically, halide ions such as chloride ion, bromide ion, iodide ion, and fluoride ion, Hydroxide ions, carboxylic acid ions, nitrate ions, phosphate ions and sulfate ions can be preferably used.
R ₁₂ is preferably an ethylene group, a propylene group or the like, and R ₁₃ is preferably a methyl group, an ethyl group or the like.

The structural unit represented by the general formula (11) has basicity. The acidic surface modification of the pigment surface and the base of the polymer of the present invention are bonded by acid-base interaction. In addition to π-π stacking, the polymer of the present invention has an excellent pigment adsorption amount because it has an adsorption mechanism by acid-base interaction.
Further, the basicity of the quaternary ammonium salt represented by the general formula (11) is not easily affected by pH and ions, and the acid-base interaction with the pigment surface is stabilized. Therefore, the general formula (11) is used. By having the represented structural unit, excellent pigment adsorptivity can be exhibited. Further, since the water solubility is improved by using the quaternary ammonium salt, the applicability to the water-based ink can be improved.

The structure of the polymer can be analyzed by using a general analytical method such as NMR or IR.
Further, the molar ratio of the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (11) constituting the polymer is the polymer. It can be determined by the molar ratio of the monomers used in the synthesis. Further, it can be obtained from the polymer by NMR.

The molar ratio of the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (11) constituting the polymer of the present invention is the pigment. From the viewpoint of the ability to adsorb, the general formula (1): (2): (11) = 0.3: 1.0: 0.05 to 6.0: 1.0: 1.0 is preferable, and more preferable. 0.5: 1.0: 0.05 to 6.0: 1.0: 0.8, more preferably 1.0: 1.0: 0.05 to 6.0: 1.0: 0.5 Is.

A 6.5% by mass aqueous solution having a solid content of a polymer having a structural unit represented by the general formula (1), a structural unit represented by the general formula (2), and a structural unit represented by the general formula (11). The viscosity is preferably in the range of 1.0 to 30.0 mPa · s. When it is 1.0 mPa · s or more, the reactivity of the pigment dispersant with respect to cellulose in paper is further improved, and the effect of improving the image density becomes remarkable. When it is 30.0 mPa · s or less, the dispersion stability of the pigment is further improved, and the storage stability of the pigment dispersion is also further improved. The viscosity is a value measured at 25 ° C., as will be described later.

In addition to the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2), the polymer of the present invention further comprises a structural unit represented by the following general formula (13). You may have.
_{R 14} in the general formula (13) represents a hydrogen atom or a methyl group.

The structure of the general formula (13) is highly hydrophilic. The structure of the general formula (2) effectively adsorbs to the pigment and improves the storage stability, but when it is added to the polymer in a large amount, the water solubility decreases. Therefore, by adding the general formula (13) having high hydrophilicity to the polymer, it is possible to maintain water solubility even when a large amount of the general formula (2) is added. As a result, the polymer of the present invention can be strongly adsorbed on the pigment, and the storage stability is improved.

The structure of the polymer can be analyzed by using a general analytical method such as NMR or IR.
Further, the molar ratio of the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (13) constituting the polymer is the polymer. It can be determined by the molar ratio of the monomers used in the synthesis. Further, it can be obtained from the polymer by NMR.

The molar ratio of the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (13) constituting the polymer of the present invention is the pigment. From the viewpoint of the ability to adsorb, the general formula (1): (2): (13) = 1.0: 1.0: 0.05 to 5.0: 1.0: 1.0 is preferable, and more preferable. 1.0: 1.0: 0.05 to 4.0: 1.0: 0.7, more preferably 1.0: 1.0: 0.05 to 3.0: 1.0: 0.5 Is.

A 6.5% by mass aqueous solution of a polymer having a structural unit represented by the general formula (1), a structural unit represented by the general formula (2), and a structural unit represented by the general formula (13). The viscosity is preferably in the range of 1.0 to 30.0 mPa · s. When it is 1.0 mPa · s or more, the reactivity of the pigment dispersant with respect to cellulose in paper is further improved, and the effect of improving the image density becomes remarkable. When it is 30.0 mPa · s or less, the dispersion stability of the pigment is further improved, and the storage stability of the pigment dispersion is also further improved. The viscosity is a value measured at 25 ° C., as will be described later.

The polymer of the present invention has a structural unit represented by the general formula (1), a structural unit represented by the general formula (2), a structural unit represented by the general formula (3), and the general formula ( In addition to the structural unit represented by 7), the structural unit represented by the general formula (9), the structural unit represented by the general formula (11), and the structural unit represented by the general formula (13). , Other polymerizable monomers can have repeating units.
The other polymerizable monomer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a polymerizable hydrophobic monomer, a polymerizable hydrophilic monomer and a polymerizable surfactant.
Examples of the polymerizable hydrophobic monomer include unsaturated ethylene monomers having an aromatic ring such as α-methylstyrene, 4-t-butylstyrene, and 4-chloromethylstyrene; methyl (meth) acrylate, (meth). ) Ethyl acrylate, -n-butyl (meth) acrylate, dimethyl maleate, dimethyl itacone, dimethyl fumarate, lauryl (meth) acrylate (C12), tridecyl (meth) acrylate (C13), (meth) Tetradecyl acrylate (C14), pentadecyl (meth) acrylate (C15), hexadecyl (meth) acrylate (C16), heptadecyl (meth) acrylate (C17), nonadecil (meth) acrylate (C19), (meth) Alkyl (meth) acrylates such as eicosyl acrylate (C20), henicosyl (meth) acrylate (C21), docosyl (meth) acrylate (C22); 1-hexene, 3,3-dimethyl-1-pentene, 4 , 4-Dimethyl-1-pentene, 3-methyl-1-hexene, 4-methyl-1-hexene, 5-methyl-1-hexene, 1-octene, 3,3-dimethyl-1-hexene, 3,4 -Dimethyl-1-hexene, 4,4-dimethyl-1-hexene, 1-monomer, 3,5,5-trimethyl-1-hexene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1 -Examples include unsaturated ethylene monomers having an alkyl group such as tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene and 1-dococene. These may be used alone or in combination of two or more.

Examples of the polymerizable hydrophilic monomer include maleic acid or a salt thereof, monomethyl maleate, itacon acid, monomethyl itaconate, fumaric acid, 4-styrene sulfonic acid, 2-acrylamide-2-methylpropane sulfonic acid, or Anionic unsaturated ethylene monomers such as unsaturated ethylene monomers containing phosphoric acid, phosphonic acid, alendronic acid or ethidronic acid; -2-hydroxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol mono (Meta) acrylate, tetraethylene glycol mono (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide, N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone, acrylamide, N, N-dimethylacrylamide , N-t-butylacrylamide, N-octylacrylamide, Nt-octylacrylamide and other nonionic unsaturated ethylene monomers and the like.
The polymerizable hydrophobic monomer and the polymerizable hydrophilic monomer are one or a mixture of two or more, and the structural unit represented by the general formula (1) and the structure represented by the general formula (2). The unit, the structural unit represented by the general formula (3), the structural unit represented by the general formula (7), the structural unit represented by the general formula (9), and the structural unit represented by the general formula (11). 5 to 100% by mass may be used with respect to the total amount of the structural units and the monomers forming the structural units represented by the general formula (13).

The polymerizable surfactant is an anionic or nonionic surfactant having at least one radically polymerizable unsaturated double bond group in the molecule.
Examples of the anionic surfactant, ammonium sulfate base (-SO ₃ ^- NH ₄ ⁺⁾ hydrocarbon compound having a sulfate group and an allyl group (-CH ₂ -CH = CH _2), such as, ammonium sulfate base (-SO ₃ ^- NH ₄ ⁺⁾ sulfate group and methacrylic group, such as _{[-CO-C (CH 3) =} CH 2 ] a hydrocarbon compound having, or ammonium sulfate base (-SO ₃ ^- NH ₄ ⁺⁾ sulfate, such as base and 1 Examples thereof include aromatic hydrocarbon compounds having a −propenyl group (−CH = CH ₂ CH _3). Specific examples thereof include Eleminor JS-20 and RS-300 manufactured by Sanyo Chemical Industries, Ltd., Aqualon KH-10 manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Aqualon KH-1025, Aqualon KH-05, Aqualon HS-10, and Aqualon HS. -1025, Aqualon BC-0515, Aqualon BC-10, Aqualon BC-1025, Aqualon BC-20, Aqualon BC-2020 and the like.

The nonionic surfactant is a hydrocarbon compound or aromatic having a 1-propenyl group (-CH = CH ₂ CH ₃ ) and a polyoxyethylene group [-(C ₂ H _{4 O) n-H].} Hydrocarbon compounds can be mentioned. Specific examples thereof include Aqualon RN-20, Aqualon RN-2025, Aqualon RN-30, and Aqualon RN-50 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., and Latemul PD-104, Latemul PD-420, and Latemul PD manufactured by Kao Corporation. -430, Latemul PD-450 and the like.

The polymerizable surfactant is a structural unit represented by the general formula (1), a structural unit represented by the general formula (2), or a structural unit represented by the general formula (3) by mixing one or more of them. The structural unit represented, the structural unit represented by the general formula (7), the structural unit represented by the general formula (9), the structural unit represented by the general formula (11), and the general formula ( 0.1 to 10% by mass may be used with respect to the total amount of the monomers forming the unit represented by 13).

The polymer having the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) of the present invention is a compound represented by the following general formula (4) and the following general formula ( It is preferable that the compound represented by 5) is at least synthesized as a starting material.
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.

The polymer of the present invention can be obtained, for example, by the reactions represented by the following reaction formulas (1) to (3-1). First, as shown in the reaction formula (1) below, naphthalenecarbonyl chloride (A-1) and an excess amount of a diol compound are condensed in the presence of an acid acceptor such as amine or pyridine to cause a hydroxynaphthalenecarboxylic acid An alkyl ester (A-2) is obtained. Next, as shown in the reaction formula (2) below, the 2-methacryloyloxyethyl isocyanate (A-3) is reacted with the above (A-2) to form a monomer which is a compound represented by the general formula (5). (A-4) is obtained. Then, as shown in the reaction formula (3-1), the monomer (A-4) and the compound represented by the general formula (4) in the presence of the radical polymerization initiator (methoxy) polyethylene glycol (mono) ( By copolymerizing with a meta) acrylate (A-5), the polymer (A-7) of the present invention can be obtained. Here, the weight average molecular weight of the monomer (A-4) is 357 to 596 because L in the general formula (2) is an alkylene group having 2 to 18 carbon atoms and R ₃ is a hydrogen atom or a methyl group. is there.

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3) of the present invention is the following general. It is preferable that the compound represented by the formula (4), the compound represented by the following general formula (5), and the compound represented by the following general formula (6) are at least synthesized as a starting material.
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (6), R ₄ represents a hydrogen atom or a methyl group, and X represents a hydrogen atom or a cation.

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (3) is, for example, the above general formula (1). 2-Methacryloyloxyethyl isocyanate (A-3) and (A-2), as in the synthesis of the polymer having the structural unit represented by) and the structural unit represented by the general formula (2). To obtain a monomer (A-4) which is a compound represented by the general formula (5), and then, as shown in the following reaction formula (3-2), the monomer in the presence of a radical polymerization initiator. (A-4) and the compound represented by the general formula (4) (methoxy) polyethylene glycol (mono) (meth) acrylate (A-5) and the compound represented by the general formula (6) (meth). ) The polymer (A-8) of the present invention can be obtained by copolymerizing with acrylic acid or a salt thereof (A-6).

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (7) of the present invention is the following general. It is preferable that the compound represented by the formula (4), the compound represented by the following general formula (5), and the compound represented by the following general formula (8) are at least synthesized as a starting material.
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (8), R ₅ represents a hydrogen atom or a methyl group.

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (7) is, for example, the general formula. 2-methacryloyloxyethyl isocyanate (A-3) and the above (A-2) are similar to the synthesis of the polymer having the structural unit represented by (1) and the structural unit represented by the general formula (2). ) To obtain the monomer (A-4) which is a compound represented by the general formula (5), and then, as shown in the following reaction formula (3-3), in the presence of a radical polymerization initiator. The monomer (A-4) and the compound represented by the general formula (4) are (methoxy) polyethylene glycol (mono) (meth) acrylate (A-5) and the compound represented by the general formula (8). By copolymerizing with diacetone (meth) acrylamide (A-9), the polymer (A-10) of the present invention can be obtained.

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (9) of the present invention has the following general formula. It is preferable that the compound represented by (4), the compound represented by the following general formula (5), and the compound represented by the following general formula (10) are at least synthesized as a starting material.
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (10), R ₆ is a hydrogen atom or a methyl group, R ₇ is either —O— or —NH—, and R ₈ is an alkylene group having 5 or less carbon atoms which may have a substituent. R ₉ represents a hydrogen atom or an alkyl group having 5 or less carbon atoms, and a and b are independently 0 or 1, respectively.

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (9) is, for example, the general formula. 2-methacryloyloxyethyl isocyanate (A-3) and the above (A-2) are similar to the synthesis of the polymer having the structural unit represented by (1) and the structural unit represented by the general formula (2). ) To obtain a monomer (A-4) which is a compound represented by the general formula (5), and then, as shown in the following reaction formula (3-4), in the presence of a radical polymerization initiator. The monomer (A-4) and the compound represented by the general formula (4) (methoxy) polyethylene glycol (mono) (meth) acrylate (A-5) and the compound represented by the general formula (10) (A). By copolymerizing with -11), the polymer (A-12) of the present invention can be obtained.

When the structural unit represented by the general formula (9) is the structural unit represented by the general formula (9-1), the structural unit represented by the general formula (1) and the general formula (2). ) And the polymer having the structural unit represented by the general formula (9-1) are represented by the compound represented by the following general formula (4) and the following general formula (5). It is preferable that the compound is synthesized by using at least the compound represented by the following general formula (10-1) as a starting material.
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (10-1), R ₆ represents a hydrogen atom or a methyl group.

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (9-1) is, for example, the above-mentioned polymer. 2-methacryloyloxyethyl isocyanate (A-3) and the above (A) are similar to the synthesis of the polymer having the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2). -2) is reacted to obtain a monomer (A-4) which is a compound represented by the general formula (5), and then, as shown in the following reaction formula (3-5), the radical polymerization initiator In the presence of the monomer (A-4) and the compound represented by the general formula (4) (methoxy) polyethylene glycol (mono) (meth) acrylate (A-5) and the general formula (10-1). The polymer (A-14) of the present invention can be obtained by copolymerizing with the compound dimethylamidopropyl (meth) acrylamide (A-13).

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (11) of the present invention has the following general formula. It is preferable that the compound represented by (4), the compound represented by the following general formula (5), and the compound represented by the following general formula (12) are at least synthesized as a starting material.
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (12), R ₁₀ is a hydrogen atom or a methyl group, R ₁₁ is either —O— or —NH—, and R ₁₂ is an alkylene group having 5 or less carbon atoms which may have a substituent. R ₁₃ represents an alkyl group having 5 or less carbon atoms, Y ⁻ represents an anion species, and a and b are independently 0 or 1, respectively.

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (11) is, for example, the general formula. 2-methacryloyloxyethyl isocyanate (A-3) and the above (A-2) are similar to the synthesis of the polymer having the structural unit represented by (1) and the structural unit represented by the general formula (2). ) To obtain a monomer (A-4) which is a compound represented by the general formula (5), and then, as shown in the following reaction formula (3-6), in the presence of a radical polymerization initiator. The monomer (A-4) and the compound represented by the general formula (4) (methoxy) polyethylene glycol (mono) (meth) acrylate (A-5) and the compound represented by the general formula (12) (A). By copolymerizing with -15), the polymer (A-16) of the present invention can be obtained.

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (13) of the present invention has the following general formula. It is preferable that the compound represented by (4), the compound represented by the following general formula (5), and the compound represented by the following general formula (14) are at least synthesized as a starting material.
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (14), R ₁₄ represents a hydrogen atom or a methyl group.

The polymer having the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and the structural unit represented by the general formula (13) is, for example, the general formula. 2-methacryloyloxyethyl isocyanate (A-3) and the above (A-2) are similar to the synthesis of the polymer having the structural unit represented by (1) and the structural unit represented by the general formula (2). ) To obtain a monomer (A-4) which is a compound represented by the general formula (5), and then, as shown in the following reaction formula (3-7), in the presence of a radical polymerization initiator. The monomer (A-4) and the compound represented by the general formula (4) (methoxy) polyethylene glycol (mono) (meth) acrylate (A-5) and the compound represented by the general formula (14) (A). By copolymerizing with -17), the polymer (A-18) of the present invention can be obtained.

The radical polymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. Examples include peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxydicarbonate, peroxyester, cyano-based azobisisobutyronitrile, azobis (2-methylbutyronitrile), Examples thereof include azobis (2,2'-isovaleronitrile) and non-cyano dimethyl-2,2'-azobisisobutyrate. Among these, organic peroxides and azo compounds are preferable, and azo compounds are particularly preferable, because the molecular weight can be easily controlled and the decomposition temperature is low.

The content of the radical polymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 to 10% by mass with respect to the total amount of the polymerizable monomer.

An appropriate amount of the chain transfer agent may be added to adjust the molecular weight of the polymer.
Examples of the chain transfer agent include mercaptoacetic acid, mercaptopropionic acid, 2-propanethiol, 2-mercaptoethanol, thiophenol, dodecyl mercaptan, 1-dodecanethiol, thioglycerol, and the like.
The polymerization temperature is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 50 ° C to 150 ° C, more preferably 60 ° C to 100 ° C. The polymerization time is also not particularly limited and may be appropriately selected depending on the intended purpose, but 3 to 48 hours is preferable.

The ink of the present invention contains water, a coloring material, and a polymer. The polymer is the polymer of the present invention.
The content of the polymer in the ink is not particularly limited when used as a pigment dispersant and can be appropriately selected depending on the intended purpose, but is preferably 10 to 100 parts by mass with respect to 100 parts by mass of the pigment. .. If the content is in this range, a high image density can be obtained. Further, other dispersants may be used in combination as long as the effect of the polymer as a dispersant is not impaired.
Examples of the water include ion-exchanged water, and the water content in the ink is preferably 20 to 60% by mass of the entire ink.
Pigments and dyes can be used as the color material for the ink of the present invention. Pigments are preferable to dyes in terms of their ability to adsorb the polymer to the coloring material, and from the viewpoints of water resistance and light resistance.
Further, the ink of the present invention preferably contains at least one water-soluble organic solvent and / or a surfactant.

The pigment is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include inorganic pigments and organic pigments for black or color. These may be used alone or in combination of two or more.

As the inorganic pigment, for example, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, it is produced by a known method such as a contact method, a furnace method, or a thermal method. Carbon black can be used.
Examples of black pigments include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black and channel black, and metals such as copper and iron (CI pigment black 11). Examples thereof include metal oxides such as titanium oxide and organic pigments such as aniline black (CI pigment black 1).
The carbon black is a carbon black produced by the furnace method or the channel method, having a primary particle size of 15 to 40 nm, a specific surface area of 50 to 300 m ² / g by the BET method, and a DBP oil absorption of 40 to 150 mL / 100 g. Those having a volatile content of 0.5 to 10% and a pH of 2 to 9 are preferable.

Examples of the organic pigment include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc.), polycyclic pigments (eg, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, etc. Dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofuralone pigments, etc.), dye chelate (for example, basic dye type chelates, acidic dye type chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used.
Among these pigments, those having a good affinity for water are particularly preferably used.

Examples of the azo pigment include azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, and the like.
Examples of the polycyclic pigment include phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofuralone pigments, and Rhodamine B lake pigments. Be done.
Examples of the dye chelate include a basic dye type chelate and an acid dye type chelate.

The pigment for yellow is not particularly limited and may be appropriately selected depending on the intended purpose.
An example is C.I. I. Pigment Yellow 1, C.I. I. Pigment Yellow 2, C.I. I. Pigment Yellow 3, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 16, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 73, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 75, C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 95, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 98, C.I. I. Pigment Yellow 114, C.I. I. Pigment Yellow 120, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 129, C.I. I. Pigment Yellow 138, C.I. I. Pigment Yellow 150, C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 154, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 174, C.I. I. Pigment Yellow 180, etc.

The pigment for magenta is not particularly limited and may be appropriately selected depending on the intended purpose.
An example is C.I. I. Pigment Red 5, C.I. I. Pigment Red 7, C.I. I. Pigment Red 12, C.I. I. Pigment Red 48 (Ca), C.I. I. Pigment Red 48 (Mn), C.I. I. Pigment Red 57 (Ca), C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 112, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 146, C.I. I. Pigment Red 168, C.I. I. Pigment Red 176, C.I. I. Pigment Red 184, C.I. I. Pigment Red 185, C.I. I. Pigment Red 202, Pigment Violet 19, and the like.

The pigment for cyan is not particularly limited and may be appropriately selected depending on the intended purpose.
An example is C.I. I. Pigment Blue 1, C.I. I. Pigment Blue 2, C.I. I. Pigment Blue 3, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 15: 4, C.I. I. Pigment Blue 15:34, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 22, C.I. I. Pigment Blue 60, C.I. I. Pigment Blue 63, C.I. I. Pigment Blue 66; C.I. I. Bat Blue 4, C.I. I. Bat Blue 60, etc. can be mentioned.

As a yellow pigment, C.I. I. Pigment Yellow 74, C.I. as a magenta pigment. I. Pigment Red 122, C.I. I. Pigment Violet 19, Cyan pigment C.I. I. By using Pigment Blue 15: 3, it is possible to obtain a well-balanced ink having excellent color tone and light resistance.

Further, as the ink of the present invention, a color material newly produced for the present invention can also be used.
Further, from the viewpoint of color development of the obtained image, a self-dispersing pigment may be used, and an anionic self-dispersing pigment is preferable. The anionic self-dispersing pigment refers to a pigment whose dispersion is stabilized by introducing an anionic functional group directly on the surface of the pigment or via another atomic group.
As the pigment before dispersion stabilization, various conventionally known pigments can be used, for example, as listed in International Publication No. 2009/014242.
The anionic functional group is a functional group in which more than half of hydrogen ions are dissociated at pH 7.0. Specific examples of the anionic functional group include a carboxyl group, a sulfo group, a phosphonic acid group and the like. Of these, a carboxyl group or a phosphonic acid group is preferable from the viewpoint of increasing the optical density of the obtained image.
Examples of the method of introducing an anionic functional group into the surface of the pigment include a method of oxidizing carbon black.
Specific examples of the oxidation treatment method include a method of treating with hypochlorite, ozone water, hydrogen peroxide, chlorite, nitric acid and the like, Japanese Patent No. 3808504, and Japanese Patent Application Laid-Open No. 2009-515007. And a surface treatment method using a diazonium salt as described in Japanese Patent Publication No. 2009-506196.
Examples of commercially available pigments having a hydrophilic functional group introduced on the surface include CW-1, CW-2, and CW-3 (all manufactured by Orient Chemical Industries Co., Ltd.); CAB-O-JET200, CAB- Examples thereof include O-JET300 and CAB-O-JET400 (manufactured by Cabot Corporation).
The content of the pigment in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.5 to 20% by mass, more preferably 1 to 10% by mass.

As the dye, a dye classified into an acid dye, a direct dye, a basic dye, a reactive dye, and an edible dye in the color index can be used.
Specifically, as acid dyes and edible dyes, C.I. I. Acid Black 1, 2, 7, 24, 26, 94, C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Blue 9, 29, 45, 92, 249, C.I. I. Acid Red 1,8,13,14,18,26,27,35,37,42,52,82,87,89,92,97,106,111,114,115,134,186,249,254, 289, C.I. I. Hood Black 1, 2, C.I. I. Hood Yellow 3, 4, C.I. I. Food Red 7, 9, 14, as a direct dye, C.I. I. Direct Black 19, 22, 32, 38, 51, 56, 71, 74, 75, 77, 154, (168), 171 and C.I. I. Direct Yellow 1, 12, 24, 26, 33, 44, 50, 86, 120, 132, 142, 144, C.I. I. Direct Blue 1, 2, 6, 15, 22, 25, 71, 76, 79, 86, 87, 90, 98, 163, 165, 199, 202, C.I. I. Direct Red 1, 4, 9, 13, 17, 20, 28, 31, 39, 80, 81, 83, 89, 225, 227, C.I. I. Direct Orange 26, 29, 62, 102, as a basic dye, C.I. I. Basic Black 2, 8, C.I. I. Basic Yellow 1,2,11,13,14,15,19,21,23,24,25,28,29,32,36,40,41,45,49,51,53,63,64,65, 67, 70, 73, 77, 87, 91, C.I. I. Basic Blue 1,3,5,7,9,21,22,26,35,41,45,47,54,62,65,66,67,69,75,77,78,89,92,93, 105, 117, 120, 122, 124, 129, 137, 141, 147, 155, C.I. I. Basic Red 2,12,13,14,15,18,22,23,24,27,29,35,36,38,39,46,49,51,52,54,59,68,69,70, 73, 78, 82, 102, 104, 109, 112, as reactive dyes, C.I. I. Reactive Black 3, 4, 7, 11, 12, 17, C.I. I. Reactive Yellow 1, 5, 11, 13, 14, 20, 21, 22, 25, 40, 47, 51, 55, 65, 67, C.I. I. Reactive Blue 1, 2, 7, 14, 15, 23, 32, 35, 38, 41, 63, 80, 95, C.I. I. Reactive Red 1, 14, 17, 25, 26, 32, 37, 44, 46, 55, 60, 66, 74, 79, 96, 97 and the like can be mentioned.

The ink of the present invention is water-soluble in order to enhance the permeability to plain paper, coated paper, etc., further suppress the occurrence of beading, and to prevent the ink from drying by utilizing the wetting effect. It is preferable to use an organic solvent.
The water-soluble organic solvent is not particularly limited, and for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-butanediol. , 3-Methyl-1,3-butanediol, trimethylolethane, trimethylolpropane, 1,5-pentanediol, 1,6-hexanediol, hexylene glycol, glycerin, 1,2,3-butanetriol, 1 , 2,4-Butantriol, 1,2,6-hexanetriol, isopropylideneglycerol, petriol and other polyvalent alcohols; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, Polyhydric alcohol alkyl ethers such as diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; 2-pyrrolidone, N- Nitrogen-containing heterocyclic compounds such as methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone; formamide, N-methylformamide, N, N Amids such as −dimethylformamide, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide; monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine, etc. Amines; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, and thiodiethanol; examples thereof include 3-ethyl-3-hydroxymethyloxetane, 3-methyl-3-hydroxymethyloxetane, propylene carbonate, and ethylene carbonate. These may be used alone or in combination of two or more.
Among these, 3-ethyl-3-hydroxymethyloxetane, isopropylideneglycerol, N, N-dimethyl-β-methoxypropionamide, N, N-dimethyl-β-butoxypropionamide, from the viewpoint of curl prevention in plain paper. Is preferable.
Further, diethylene glycol, triethylene glycol, 1,3-butanediol, 2,2,4-trimethyl-1,3-pentanediol and glycerin are excellent in preventing discharge defects due to water evaporation.

Further, as a water-soluble organic solvent having relatively low wettability and permeability, for example, 2-ethyl-1,3-hexanediol [solubility: 4.2% (25 ° C.)], 2,2,4- Examples thereof include trimethyl-1,3-pentanediol [solubility: 2.0% (25 ° C.)].
Examples of water-soluble organic solvents other than the above include 2-ethyl-2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, and 2-methyl-2-propyl as aliphatic diols. -1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene -1,2-diol and the like can be used.

Examples of the water-soluble organic solvent that can be used in combination with the above-mentioned water-soluble organic solvent include diethylene glycol monobutyl ether, propylene glycol monobutyl ether, ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, ethylene glycol monoallyl ether, and tetraethylene glycol chlorophenyl ether. Alcohols and aryl ethers of polyhydric alcohols, lower alcohols such as ethanol, and the like can be appropriately selected and used according to the purpose.

A water-soluble solvent is used to improve the stabilization of ink ejection by imparting a moisturizing effect. The content is preferably 10 to 60% by mass of the total ink. When the content is 10% by mass or more, the water content of the ink is less likely to evaporate, the water evaporation of the ink in the ink supply system in the inkjet recording device is suppressed, and ink clogging or the like is less likely to occur. Further, when the content is 60% by mass or less, the ink viscosity can be suppressed to a low level and a high image density can be obtained even if a large amount of solid content such as pigment or resin is contained.

In the ink of the present invention, it is preferable to use a surfactant in order to enhance the permeability and wettability to plain paper, coated paper and the like, and further suppress the occurrence of beading.
As the surfactant, for example, a fluorine-based surfactant, a silicone-based surfactant, an anionic surfactant, a nonionic surfactant, and a betaine-based surfactant can be used. These surfactants may be used alone or in combination of two or more.
The surface tension of the ink is preferably 40 mN / m or less, more preferably 30 mN / m or less at 25 ° C.
Among these, fluorine-based surfactants and silicone-based surfactants are preferable because the surface tension can be reduced to 30 mN / m or less.

Examples of the fluorine-based surfactant include nonionic fluorine-based surfactants, anionic fluorine-based surfactants, amphoteric fluorine-based surfactants, and oligomer-type fluorine-based surfactants. Further, those having a fluorine-substituted carbon number of 2 to 16 are preferable, and those having a fluorine-substituted carbon number of 4 to 16 are more preferable. When the number of carbon atoms is 2 or more, the effect peculiar to the fluorine-based surfactant can be obtained, and when the number of carbon atoms is 16 or less, problems such as storage stability do not occur.
Examples of the nonionic fluorine-based surfactant include a perfluoroalkyl phosphate ester compound, a perfluoroalkylethylene oxide adduct, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain. Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because it has low foaming property, and is preferably represented by the following general formula (I), the following general formula (II), or the following general formula (III). The represented fluorine-based surfactant is more preferable.
CF ₃ CF ₂ (CF ₂ CF ₂ ) m-CF ₂ CF ₂ (CF ₂ CF ₂ ) nH ・ ・ ・ General formula (I)
(In the formula, m is 0 to 10, n is 0 to 40)
CF ₃ (CF ₂ ) i-CH ₂ CH (OH) CH _2- O- (CH ₂ CH ₂ O) j-H
・ ・ ・ General formula (II)
(In the formula, i and j are 5 to 10)
CF ₃ (CF ₂ ) a−CH ₂ CH (OH) CH ₂ −O− (CH ₂ CH ₂ O) b−CH ₂ CH (OH) CH ₂ − (CF ₂ ) ₅ CF ₃・ ・ ・ General formula ( III)
(In the formula, a and b are 5 to 10)

Examples of the anionic fluorine-based surfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate ester compound, and a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain. Examples include compounds.
Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonic acid salt.
Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt.
Examples of the perfluoroalkyl phosphoric acid ester compound include perfluoroalkyl phosphoric acid ester, salt of perfluoroalkyl phosphoric acid ester, and the like.
Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a polyoxyalkylene ether having a perfluoroalkyl ether group in the side chain. Examples thereof include a sulfate ester salt of a polymer and a salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in a side chain.
The counterions of the salts in these fluorine-based surfactants are Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH). ) ₃ and so on.

Commercially available products of fluorine-based surfactants include, for example, Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all from Asahi Glass Co., Ltd.). (Manufactured by); Furrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Ltd.); Megafuck F-470 , F-1405, F-474 (all manufactured by Dainippon Ink and Chemicals); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all Also manufactured by DuPont); Surfactant FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos), Polyfox PF-136A, PF-156A , PF-151N, PF-154, PF-159 (manufactured by Omniova) and the like.
Among these, FS-300 manufactured by DuPont, FT-110, FT-250, FT-251 and FT- of Neos are significantly improved in good print quality, especially color development and leveling property on paper. 400S, FT-150, FT-400SW, and Polyfox PF-151N manufactured by Omniova are particularly preferable.

The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include side chain modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, single-ended modified polydimethylsiloxane, side chain double-ended modified polydimethylsiloxane, and examples thereof include polyoxyethylene group and polyoxyethylene. A polyether-modified silicone-based surfactant having a polyoxypropylene group is particularly preferable because it exhibits good properties as an aqueous surfactant.
Commercially available silicone-based surfactants can be easily obtained from, for example, Big Chemie, Shin-Etsu Chemical, Toray Dow Corning Silicone, Nippon Emulsion, Kyoei Kagaku, and the like.

Examples of the anionic surfactant include salts of polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, and polyoxyethylene alkyl ether sulfate.
Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl amine, and poly. Examples thereof include oxyethylene alkyl amide.

To the ink of the present invention, as other components, a pH adjuster, an antiseptic / antifungal agent, a rust preventive, an antioxidant, an ultraviolet absorber, an oxygen absorber, a light stabilizer and the like are appropriately added as necessary. can do.
The pH adjuster is not particularly limited as long as it can adjust the pH to 8.5 to 11 without adversely affecting the ink to be blended, and can be appropriately selected depending on the intended purpose. Examples thereof include alcohol amines, alkali metal element hydroxides, ammonium hydroxides, phosphonium hydroxides, alkali metal carbonates, and the like. Examples of the alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, and the like. Examples of the hydroxide of the alkali metal element include lithium hydroxide, sodium hydroxide, potassium hydroxide and the like. Examples of the ammonium hydroxide include ammonium hydroxide and quaternary ammonium hydroxide. Examples of the phosphonium hydroxide include a quaternary phosphonium hydroxide. Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, potassium carbonate and the like.

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

Examples of the rust preventive include acidic sulfites, sodium thiosulfate, ammon thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite, and the like.
Examples of the antioxidant include phenol-based antioxidants (including hindered phenol-based antioxidants), amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.

Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, nickel complex salt-based ultraviolet absorbers, and the like.

The ink of the present invention can be produced, for example, by dispersing or dissolving water, a water-soluble organic solvent, a pigment, the polymer, and if necessary, other components in an aqueous medium, and stirring and mixing them. Further, the polymer may be used as a pigment dispersion resin when producing a pigment dispersion.
The dispersion can be performed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, etc., and stirring and mixing are performed by a stirrer using ordinary stirring blades, a magnetic stirrer, a high-speed disperser, or the like. be able to.

In the production, it is preferable to filter the coarse particles with a filter, a centrifuge, or the like, if necessary, and degas.

The physical characteristics of the ink of the present invention are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the viscosity, surface tension and the like are preferably in the following ranges.
The viscosity of the ink at 25 ° C. is preferably 3 to 20 mPa · s. When the viscosity is 3 mPa · s or more, the effect of improving the print density and the character quality can be obtained. Further, by setting the value to 20 mPa · s or less, the ink ejection property can be ensured.
The viscosity can be measured at 25 ° C. using, for example, a viscometer (RE80L, manufactured by Toki Sangyo Co., Ltd.).

The ink container of the present invention is an ink container provided with an ink accommodating portion for accommodating ink, and the ink contained in the ink accommodating portion is the ink of the present invention. The ink is contained in a container and further has other members appropriately selected as needed.
The container is not particularly limited, and its shape, structure, size, material, etc. can be appropriately selected according to the purpose. For example, at least an ink container formed of an aluminum laminate film, a resin film, or the like is used. Those having, etc. are suitable.

The ink container will be described with reference to FIGS. 1 and 2.
FIG. 1 is a diagram showing an example of an ink container, and FIG. 2 is a diagram including a case (exterior) of the ink container of FIG. The ink container 200 fills the ink container 241 from the ink injection port 242, exhausts the ink, and then closes the ink injection port 242 by fusion.
At the time of use, the needle of the main body of the device is pierced into the ink discharge port 243 made of a rubber member to supply the ink to the device. The ink accommodating portion 241 is formed of a packaging member such as a non-permeable aluminum laminated film. As shown in FIG. 2, the ink accommodating portion 241 is usually accommodated in a plastic accommodating container case 244, and is detachably attached to various inkjet recording devices for use.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In addition, "part" and "%" in an example are "part by mass" and "mass%" unless there is particular notice.
The molecular weight and viscosity of the polymers obtained in Examples and Comparative Examples were determined as follows.

<Measurement of molecular weight of polymer>
It was measured by GPC (Gel Permeation Chromatography) under the following conditions.
・ Equipment: GPC-8020 (manufactured by Tosoh)
-Column: TSK G2000HXL and G4000HXL (manufactured by Tosoh Corporation)
・ Temperature: 40 ℃
-Solvent: THF (tetrahydrofuran)
-Flow flow rate: 1.0 mL / min Inject 1 mL of a polymer with a concentration of 0.5 mass%, and use the molecular weight calibration curve prepared from the monodisperse polystyrene standard sample from the molecular weight distribution of the polymer measured under the above conditions. The number average molecular weight Mn and the weight average molecular weight Mw of the coalescence were calculated.

<Measurement of polymer viscosity>
The viscosity of the 6.5 mass% aqueous solution of the synthesized polymer was measured at 25 ° C. using a rotational viscometer (viscometer RE80L, cone plate type, manufactured by Toki Sangyo Co., Ltd.). The specific operation is shown below. 1.1 mL of a 6.5 mass% aqueous solution of the polymer was collected and placed in a sample cup of a viscometer. After the sample cup was attached to the main body of the viscometer and allowed to stand for 1 minute, the rotor of the viscometer was rotated and the value after 1 minute was read. The rotation speed at the time of viscosity measurement was adjusted so that the torque was constant in the range of 40% to 80%.

[Example I-1: Synthesis of polymer CP1-1]
62.0 g (525 mmol) of 1,6-hexanediol (manufactured by Tokyo Kasei Co., Ltd.) was dissolved in 700 mL of methylene chloride, and 20.7 g (262 mmol) of pyridine was added.
A solution prepared by dissolving 50.0 g (262 mmol) of 2-naphthalenecarbonyl chloride (manufactured by Tokyo Kasei Co., Ltd.) in 100 mL of methylene chloride was added dropwise to this solution with stirring over 2 hours, and then the mixture was stirred at room temperature for 6 hours. .. After washing the obtained reaction solution with water, the organic phase was isolated, dried over magnesium sulfate, and the solvent was distilled off. The residue was purified by silica gel column chromatography using a mixed solvent of methylene chloride / methanol (volume ratio 98/2) as an eluent to obtain 52.5 g of 2-naphthoic acid-2-hydroxyethyl ester.

Next, 42.1 g (155 mmol) of 2-naphthoic acid-2-hydroxyethyl ester was dissolved in 80 mL of dry methyl ethyl ketone and heated to 60 ° C. A solution prepared by dissolving 24.0 g (155 mmol) of 2-methacryloyloxyethyl isocyanate (Kalens MOI, manufactured by Showa Denko KK) in 20 mL of dry methyl ethyl ketone was added dropwise to this solution with stirring over 1 hour, and then at 70 ° C. Was stirred for 12 hours. After cooling to room temperature, the solvent was distilled off. The residue was purified by silica gel column chromatography using a mixed solvent of methylene chloride / methanol (volume ratio 99/1) as an eluent to obtain 57.0 g of the structure represented by the following structural formula (5-1). The monomer M-1 having was obtained.

Next, 5.35 g (18.83 mmol) of polyethylene glycol monomethacrylate (n≈4.5) (manufactured by NOF CORPORATION) and 2.68 g (6.3 mmol) of monomer M-1 were dissolved in 40 mL of dry methyl ethyl ketone. To prepare a monomer solution. After heating 10% of the monomer solution to 75 ° C. under an argon stream, 0.206 g (1.26 mmol) of 2,2'-azoiso (butyronitrile) (manufactured by Tokyo Kasei Co., Ltd.) was dissolved in the remaining monomer solution. Was added dropwise over 1.5 hours, and the mixture was stirred at 75 ° C. for 6 hours. After cooling to room temperature, the obtained reaction solution was dropped into hexane. The precipitated polymer is recovered, dissolved in THF, the solvent is removed using a rotary evaporator, dried under reduced pressure, and 8.00 g of the polymer CP1-1 (weight average molecular weight (Mw): 12500, number average molecular weight). (Mn): 7100) was obtained. FIG. 3 shows the IR spectrum of the obtained polymer.

Next, an aqueous solution of the polymer CP1-1 was prepared for the obtained polymer so that the concentration of the polymer was 10%.

[Example I-2: Synthesis of polymer CP1-2]
A monomer having a structure represented by the following structural formula (5-2) in the same manner as in Example I-1 except that ethylene glycol (manufactured by Tokyo Kasei Co., Ltd.) was used instead of 1,6-hexanediol. M-2 was obtained.

Next, using polyethylene glycol monomethacrylate (n≈4.5) and the obtained monomer M-2, the polymer CP1-2 (weight average molecular weight (Mw): 12000) was used in the same manner as in Example I-1. , Number average molecular weight (Mn): 7000) was obtained, and an aqueous solution of the polymer CP1-2 was prepared in the same manner as in Example I-1. The IR spectrum of the obtained polymer CP1-2 showed the same IR spectrum as that of the polymer CP1-1.

[Example I-3: Synthesis of polymer CP1-3]
It is represented by the following structural formula (5-3) in the same manner as in Example I-1 except that 1,12-dodecanediol (manufactured by Tokyo Kasei Co., Ltd.) is used instead of 1,6-hexanediol. A monomer M-3 having a structure was obtained.

Next, using polyethylene glycol monomethacrylate (n≈4.5) and the obtained monomer M-3, the polymer CP1-3 (weight average molecular weight (Mw): 12800) was used in the same manner as in Example I-1. , Number average molecular weight (Mn): 7200) was obtained, and an aqueous solution of the polymer CP1-3 was prepared in the same manner as in Example I-1. The IR spectrum of the obtained polymer CP1-3 showed the same IR spectrum as that of the polymer CP1-1.

[Example I-4: Synthesis of polymer CP1-4]
It is represented by the following structural formula (5-4) in the same manner as in Example I-1 except that 1,16-hexadecanediol (manufactured by Tokyo Kasei Co., Ltd.) is used instead of 1,6-hexanediol. A monomer M-4 having a structure was obtained.

Next, using polyethylene glycol monomethacrylate (n≈4.5) and the obtained monomer M-4, the polymer CP1-4 (weight average molecular weight (Mw): 13500) was used in the same manner as in Example I-1. , Number average molecular weight (Mn): 7500) was obtained, and an aqueous solution of the polymer CP1-4 was prepared in the same manner as in Example I-1. The IR spectrum of the obtained polymer CP1-4 showed the same IR spectrum as that of the polymer CP1-1.

[Examples I-5 to I-11: Synthesis of polymers CP1-5A to CP1-8]
Polyethylene glycol monoacrylate (n≈4.5) (manufactured by Nichiyu), methoxypolyethylene glycol methacrylate (n≈4) (manufactured by Nichiyu), polyethylene glycol monomethacrylate (n≈2) (manufactured by Nichiyu), Table 1-1 shows polyethylene glycol monomethacrylate (n≈8) (manufactured by Nichiyu Co., Ltd.) or polyethylene glycol monomethacrylate (n≈4.5) and the monomer M-1 synthesized in Example I-1. Polymers CP1-5A to CP1-8 were obtained in the same manner as in Example I-1, except that the combination and the ratio were changed, and the polymers CP1-5A to CP1 were obtained in the same manner as in Example I-1. An aqueous solution of −8 was prepared.
The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polymer are shown in Table 1-1.
The IR spectra of the obtained polymers CP1-5C, CP1-5D, and CP1-6 showed the same IR spectra as the polymer CP1-1.

[Example I-12: Synthesis of polymer CP1-9]
Monomer M- having a structure represented by the following structural formula (5-5) in the same manner as in Example I-1 except that 2-acryloyloxyethyl isocyanate was used instead of 2-methacryloyloxyethyl isocyanate. I got 5.
Next, using polyethylene glycol monomethacrylate (n≈4.5) and the obtained monomer M-5, the polymer CP1-9 (weight average molecular weight (Mw): 12600) was used in the same manner as in Example I-1. , Number average molecular weight (Mn): 7200) was obtained, and an aqueous solution of the polymer CP1-9 was prepared in the same manner as in Example I-1. The IR spectrum of the obtained polymer CP1-9 showed the same IR spectrum as that of the polymer CP1-1.

[Example I-13: Synthesis of polymer CP1-10]
Using 2-hydroxyethyl methacrylate (n = 1) and the monomer M-1 synthesized in Example 1, the polymer CP1-10 (weight average molecular weight (Mw): 11900," in the same manner as in Example I-1. A number average molecular weight (Mn): 6700) was obtained, and an aqueous solution of the polymer CP1-10 was prepared in the same manner as in Example I-1.
The IR spectrum of the obtained polymer CP1-10 showed the same IR spectrum as that of the polymer CP1-1.

[Example I'-1 to I'-9: Synthesis of polymer CP1'-1 to CP1'-9]
The combination of methoxypolyethylene glycol methacrylate (n≈2,4.5, 9, 23, 90) (manufactured by Nichiyu Co., Ltd.) and the monomer M-1 synthesized in Example I-1 are shown in Table 1-2. Polymers CP1'-1 to CP1'-9 were obtained in the same manner as in Example I-1, and polymers CP1'-1 to 1 in the same manner as in Example I-1. An aqueous solution of CP1'-9 was prepared.
The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polymer are shown in Table 1-2.
The IR spectra of the obtained polymers CP1'-1 to CP1'-9 showed the same IR spectra as the polymer CP1-1.

[Example I-14: Synthesis of polymer CP2-1]
2.67 g (9.4 mmol) of polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu Co., Ltd.), 1.36 g (18.8 mmol) of acrylic acid, and 4.02 g (9.4 mmol) of acrylic acid. The monomer M-1 synthesized in Example I-1 was dissolved in 40 mL of dry methyl ethyl ketone to prepare a monomer solution. A solution in which 0.309 g (1.88 mmol) of 2,2'-azoiso (butyronitrile) (manufactured by Tokyo Kasei Co., Ltd.) was dissolved in the remaining monomer solution after heating 10% of the monomer solution to 75 ° C. under an argon stream. Was added dropwise over 1.5 hours, and the mixture was stirred at 75 ° C. for 6 hours. After cooling to room temperature, the obtained reaction solution was dropped into hexane. The supernatant was discarded to obtain a precipitated polymer. The obtained polymer is dissolved in tetrahydrofuran, evaporated, and dried under reduced pressure to obtain 8.00 g of the polymer (weight average molecular weight (Mw): 15200, number average molecular weight (Mn): 8700). It was. FIG. 4 shows the IR spectrum of the obtained polymer.

Next, the obtained polymer was dissolved in an aqueous solution of tetraethylammonium hydroxide so that the concentration of the polymer was 10% and the pH was 8.0 to prepare an aqueous solution of the polymer CP2-1.

[Example I-15: Synthesis of polymer CP2-1']
Using polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu Co., Ltd.), methacrylic acid, and the monomer M-1 synthesized in Example I-1, a polymer (manufactured in the same manner as in Example I-14). A weight average molecular weight (Mw): 15000 and a number average molecular weight (Mn): 8600) were obtained, and an aqueous solution of the polymer CP2-1'was prepared in the same manner as in Example I-14.

[Example I-16: Synthesis of polymer CP2-1]]
Using polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu Co., Ltd.), acrylic acid, and the monomer M-1 synthesized in Example I-1, a polymer (manufactured by Nichiyu Co., Ltd.) in the same manner as in Example I-14. A weight average molecular weight (Mw): 15200 and a number average molecular weight (Mn): 8700) were obtained, and an aqueous solution of the polymer CP2-1 ”was prepared using an aqueous sodium hydroxide solution instead of the aqueous tetraethylammonium hydroxide solution.

[Examples I-17 to I-28: Synthesis of Polymers CP2-2 to CP2-10]
Polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu), polyethylene glycol monoacrylate (n≈4.5) (manufactured by Nichiyu), methoxypolyethylene glycol methacrylate (n≈4) (manufactured by Nichiyu) ), Polyethylene glycol monomethacrylate (n≈2) (manufactured by Nichiyu Co., Ltd.), polyethylene glycol monomethacrylate (n≈8) (manufactured by Nichiyu Co., Ltd.), or 2-hydroxyethyl methacrylate (n = 1), and acrylic acid. In Example I-, except that any of the monomers M-1 to M-5 synthesized in Examples I-1 to I-4 and I-12 was changed to the combinations and ratios shown in Table 2. Polymers CP2-2 to CP2-10 were obtained in the same manner as in Example I-14, and an aqueous solution of the polymer CP2-2 to CP2-10 was prepared in the same manner as in Example I-14.
Table 2 shows the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polymer.
The IR spectra of the obtained polymers CP2-2, CP2-3, CP2-4, CP2-5C, CP2-5D, CP2-6, CP2-7, CP2-9, and CP2-10 are the same as the polymer CP2-1. A similar IR spectrum was shown.

[Example I-29: Synthesis of polymer CP3-1]
4.70 g (16.55 mmol) of polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu Co., Ltd.) and 0.56 g (3.31 mmol) of diacetone acrylamide (DAAM) (manufactured by Tokyo Kasei Co., Ltd.). And 2.83 g (6.62 mmol) of the monomer M-1 synthesized in Example I-1 was dissolved in 40 mL of dry methyl ethyl ketone to prepare a monomer solution. After heating 10% of the monomer solution to 75 ° C. under an argon stream, 0.22 g (1.32 mmol) of 2,2'-azoiso (butyronitrile) (manufactured by Tokyo Kasei Co., Ltd.) was dissolved in the remaining monomer solution. Was added dropwise over 1.5 hours, and the mixture was stirred at 75 ° C. for 6 hours. After cooling to room temperature, the obtained reaction solution was added dropwise to n-hexane. The supernatant was discarded to obtain a precipitated polymer. The obtained polymer is dissolved in tetrahydrofuran, evaporated, and dried under reduced pressure to obtain 8.00 g of the polymer (weight average molecular weight (Mw): 6800, number average molecular weight (Mn): 1900). It was. FIG. 5 shows the IR spectrum of the obtained polymer.

Next, an aqueous solution of the polymer CP3-1 was prepared for the obtained polymer so that the concentration of the polymer was 10%.

[Examples I-30 to I-42: Synthesis of polymers CP3-1'to CP3-10]
Polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu), polyethylene glycol monoacrylate (n≈4.5) (manufactured by Nichiyu), methoxypolyethylene glycol methacrylate (n≈4) (manufactured by Nichiyu) ), Polyethylene glycol monomethacrylate (n≈2) (manufactured by Nichiyu Co., Ltd.), polyethylene glycol monomethacrylate (n≈8) (manufactured by Nichiyu Co., Ltd.), or 2-hydroxyethyl methacrylate (n = 1). Any of the monomers M-1 to M-5 synthesized in I-1 to I-4 and I-12 and diacetone acrylamide (DAAM) or diacetone methacrylicamide (DMAAM) are combined as shown in Table 3. Polymers CP3-1'to CP3-10 were obtained in the same manner as in Example I-29 except that the ratio was changed to and, and polymers CP3-1'to CP3-10 were obtained in the same manner as in Example I-29. Ten aqueous solutions were prepared.
Table 3 shows the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polymer.
The IR spectra of the obtained polymers CP3-2, CP3-3, CP3-4, CP3-5C, CP3-5D, CP3-6, CP3-7, and CP3-10 are the same IR spectra as the polymer CP3-1. showed that.

[Example I-43: Synthesis of polymer CP4-1]
4.40 g (15.49 mmol) of polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu Co., Ltd.) and 0.30 g (1.94 mmol) of dimethylaminopropylacrylamide (DMAPAA) (manufactured by Tokyo Kasei Co., Ltd.) And 3.31 g (7.75 mmol) of the monomer M-1 synthesized in Example I-1 was dissolved in 40 mL of dry methyl ethyl ketone to prepare a monomer solution. After heating 10% of the monomer solution to 75 ° C. under an argon stream, 0.207 g (1.26 mmol) of 2,2'-azoiso (butyronitrile) (manufactured by Tokyo Kasei Co., Ltd.) was dissolved in the remaining monomer solution. Was added dropwise over 1.5 hours, and the mixture was stirred at 75 ° C. for 6 hours. After cooling to room temperature, the obtained reaction solution was dropped into hexane. The supernatant was discarded to obtain a precipitated polymer. The obtained polymer is dissolved in tetrahydrofuran, evaporated, and dried under reduced pressure to obtain 8.00 g of the polymer (viscosity of 6.5% by mass aqueous solution: 2.3 (mPa · s)). It was. FIG. 6 shows the IR spectrum of the obtained polymer.

Next, the obtained polymer was dissolved in ion-exchanged water so that the concentration of the polymer was 6.5% to prepare an aqueous solution of the polymer CP4-1.

[Examples I-44 to I-55: Synthesis of Polymers CP4-1'to CP4-9]
Polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu), polyethylene glycol monoacrylate (n≈4.5) (manufactured by Nichiyu), methoxypolyethylene glycol methacrylate (n≈4) (manufactured by Nichiyu) ), Polyethylene glycol monomethacrylate (n≈2) (manufactured by Nichiyu Co., Ltd.), or polyethylene glycol monomethacrylate (n≈8) (manufactured by Nichiyu Co., Ltd.) and the above Examples I-1 to I-4 and I-12. Table 4 shows any of the monomers M-1 to M-5 synthesized in 1 and dimethylaminopropyl acrylamide (DMAPAA) (manufactured by Tokyo Kasei Co., Ltd.) or dimethylaminopropylmethacrylamide (DMAPMAA) (manufactured by Tokyo Kasei Co., Ltd.). Polymers CP4-1'to CP4-9 were obtained in the same manner as in Example I-43 except that the combination and the ratio were changed, and the polymers CP4-1'were the same as in Example I-43. An aqueous solution of ~ CP4-9 was prepared.
Table 4 shows the viscosities of the obtained polymer in a 6.5% by mass aqueous solution.
The IR spectra of the obtained polymers CP4-2, CP4-3, CP4-4, CP4-5C, CP4-5D, CP4-6, CP4-7, and CP4-9 are the same IR spectra as the polymer CP4-1. showed that.

[Example I-56: Synthesis of polymer CP4-10]
2.27 g (8.0 mmol) of polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu) and 0.06 g (0.50 mmol) of N, N-diethylacrylamide (DEA) (manufactured by Tokyo Chemical Industry). ) And 0.64 g (1.50 mmol) of monomer M-1 were dissolved in 17 mL of dry methyl ethyl ketone to prepare a monomer solution. A solution in which 0.08 g (0.50 mmol) of 2,2'-azoiso (butyronitrile) (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in the remaining monomer solution after heating 10% of the monomer solution to 75 ° C. under an argon stream. Was added dropwise over 1 hour, and the mixture was stirred at 75 ° C. for 6 hours. Then, the reaction solution cooled to room temperature was reprecipitated with hexane 5 times to purify the polymer. After the purification treatment, the polymer was filtered off and dried under reduced pressure to obtain 2.74 g of the polymer (viscosity of 6.5 mass% aqueous solution: 2.7 mPa · s). The IR spectrum of the obtained polymer was similar to that of the polymer CP4-1. Next, the obtained polymer was dissolved in ion-exchanged water so that the concentration of the polymer was 6.5% by mass to prepare an aqueous solution of the polymer CP4-10.

[Examples I-57 to I-61: Synthesis of Polymers CP4-11 to CP4-15]
In Example I-56, instead of N, N-diethylacrylamide (manufactured by Tokyo Chemical Industry), acrylamide monomer (AM) (manufactured by Tokyo Chemical Industry), N, N-dimethylacrylamide (DMA) (Tokyo) shown in Table 4 Kasei Kogyo), N, N-diethylaminoethyl methacrylate (DEAEM) (Tokyo Kasei Kogyo), N, N-dimethylaminoethyl methacrylate (DMAEM) (Tokyo Kasei Kogyo), or N, N-dimethylaminopropyl acrylate (N, N-dimethylaminopropyl acrylate) Polymers CP4-11 to CP4-15 were obtained in the same manner as in Example I-56 except that DMAPA) (manufactured by Sigma Aldrich Japan) was used, and polymers CP4-11-in the same manner as in Example I-56. An aqueous solution of CP4-15 was prepared.
Table 4 shows the viscosities of the obtained polymer in a 6.5% by mass aqueous solution.
The IR spectra of the obtained polymers CP4-11, CP4-12, CP4-13, CP4-14, and CP4-15 showed the same IR spectra as the polymer CP4-1.

[Example I-62: Synthesis of polymer CP5-1]
1.07 g (8.2 mmol) of 2-hydroxyethyl methacrylate (n = 1) (manufactured by Tokyo Chemical Industry) and 0.026 g (0.10 mmol) of about 80% aqueous solution of metachlorocholine chloride (manufactured by Tokyo Chemical Industry). ), And 0.73 g (1.7 mmol) of the monomer M-1 synthesized in Example I-1 was dissolved in a mixed solution of 7 ml of dimethylformamide and 3 ml of ion-exchanged water to prepare a monomer solution. A solution in which 0.08 g (0.50 mmol) of 2,2'-azoiso (butyronitrile) (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in the remaining monomer solution after heating 10% of the monomer solution to 75 ° C. under an argon stream. Was added dropwise over 1 hour, and the mixture was stirred at 75 ° C. for 6 hours. Then, the reaction solution cooled to room temperature was reprecipitated 5 times using a mixed solution of hexane and tetrahydrofuran to purify the polymer. After the purification treatment, the polymer was filtered off and dried under reduced pressure to obtain 1.67 g of the polymer (viscosity of 6.5 mass% aqueous solution: 2.6 mPa · s). The IR spectrum of the obtained polymer was similar to that of the polymer CP4-1. Next, the obtained polymer was dissolved in ion-exchanged water so that the concentration of the polymer was 6.5% by mass to prepare an aqueous solution of the polymer CP5-1.

[Example I-63: Synthesis of polymer CP6-1]
4.82 g (16.95 mmol) of polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu Co., Ltd.) and 0.29 g (3.39 mmol) of N-vinylacetamide (NVA) (manufactured by Showa Denko). And 2.90 g (6.78 mmol) of the monomer M-1 synthesized in Example I-1 was dissolved in 40 mL of dry methyl ethyl ketone to prepare a monomer solution. After heating 10% of the monomer solution to 75 ° C. under an argon stream, 0.223 g (1.36 mmol) of 2,2'-azoiso (butyronitrile) (manufactured by Tokyo Kasei Co., Ltd.) was dissolved in the remaining monomer solution. Was added dropwise over 1.5 hours, and the mixture was stirred at 75 ° C. for 6 hours. After cooling to room temperature, the obtained reaction solution was dropped into hexane. The supernatant was discarded to obtain a precipitated polymer. The obtained polymer is dissolved in tetrahydrofuran, evaporated, dried under reduced pressure, and 8.00 g of the polymer CP6-1 (weight average molecular weight (Mw): 11600, number average molecular weight (Mn): 5800). ) Was obtained. FIG. 7 shows the IR spectrum of the obtained polymer.

Next, the obtained polymer was dissolved in ion-exchanged water so that the concentration of the polymer was 6.5% to prepare an aqueous solution of the polymer CP6-1.

[Examples I-64 to I-76: Synthesis of Polymers CP6-1'to CP6-10]
Polyethylene glycol monomethacrylate (n≈4.5) (manufactured by Nichiyu), polyethylene glycol monoacrylate (n≈4.5) (manufactured by Nichiyu), methoxypolyethylene glycol methacrylate (n≈4) (manufactured by Nichiyu) ), Polyethylene glycol monomethacrylate (n≈2) (manufactured by Nichiyu Co., Ltd.), polyethylene glycol monomethacrylate (n≈8) (manufactured by Nichiyu Co., Ltd.), or 2-hydroxyethyl methacrylate (n = 1). One of the monomers M-1 to M-5 synthesized with I-1 to I-4 and I-12, and N-vinylacetamide (NVA) (manufactured by Showa Denko) or N-vinylformamide (NVF) (Tokyo Kasei Co., Ltd.) In the same manner as in Example I-63, polymers CP6-1'to CP6-10 were obtained in the same manner as in Example I-63, except that the combinations and ratios shown in Table 5 were changed. Then, an aqueous solution of the polymers CP6-1'to CP6-10 was prepared.
Table 5 shows the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the obtained polymer.
The IR spectra of the obtained polymers CP6-2, CP6-3, CP6-4, CP6-5C, CP6-5D, CP6-6, CP6-7, and CP6-10 are the same IR spectra as the polymer CP6-1. showed that.

[Examples II-1 to II-16: Preparation of water-based inks GJ1-1 to GJ1-13]
(Preparation of pigment dispersions PD1-1 to PD1-13)
An aqueous solution of the polymers CP1-1 to CP1-10 prepared in Examples I-1 to I-13, carbon black (NIPEX150, manufactured by Degusa), and pigment blue 15: 3 (manufactured by Dainichi Seika, Chromofine Blue). Cyan pigment), Pigment Red 122 (Toner Magenta EO02 Magenta Pigment manufactured by Clariant), or Pigment Yellow 74 (First Yellow 531 Yellow Pigment manufactured by Dainichi Seika Co., Ltd.) and ion-exchanged water in the ratio shown in Table 6-1. And stirred for 12 hours. The obtained mixture was circulated and dispersed at a peripheral speed of 10 m / s for 1 hour using a disk-type bead mill (manufactured by Simmal Enterprises, KDL type, media: using zirconia balls having a diameter of 0.1 mm), and then the pore diameter was 1. The mixture was filtered through a 2 μm membrane filter, and an adjusted amount of ion-exchanged water was added to obtain pigment dispersions PD1-1 to PD1-13. The numerical values in Table 6-1 represent "parts". The pigment dispersions PD1-1 to PD1-8 and PD1-1 to PD1-13 have a pigment solid content concentration of 16%, and the pigment dispersions PD1-9 to PD1-11 have a pigment solid content concentration of 20%. ..

(Making ink)
Pigment dispersions PD1-1 to PD1-13, 1,3-butanediol, glycerin, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, solid content 40) Mass%) and ion-exchanged water are mixed at the ratios shown in Table 7-1, stirred for 1 hour, filtered through a membrane filter having a pore size of 1.2 μm, and the water-based inks of the present invention GJ1-1 to GJ1-13. Got The numerical values in Table 7-1 represent "parts".

[Comparative Examples 1 to 4: Preparation of Comparative Water Ink RGJ1-1 to RGJ1-4]
6.36 g of polymer RCP1-1 (weight average molecular weight (Mw)) in the same manner except that the monomer M-1 in Example I-1 was replaced with a monomer having a structure represented by the following structural formula (15). : 7500, number average molecular weight (Mn): 2800) was obtained, and an aqueous solution of the polymer RCP1-1 was prepared in the same manner as in Example I-1.

Aqueous solution of polymer RCP1-1, carbon black (NIPEX150, manufactured by Degusa), pigment blue 15: 3 (manufactured by Dainichi Seika, chromofine blue cyan pigment), pigment red 122 (manufactured by Clariant, toner magenta EO02 magenta) Pigment Yellow 74 (manufactured by Dainichi Seika Co., Ltd., First Yellow 531 Yellow Pigment) and ion-exchanged water were added at the ratios shown in Table 6-1 to obtain comparative pigment dispersions RPD1-1 to RPD1-4. It was.
Next, pigment dispersions RPD1-1 to RPD1-4, 1,3-butanediol, glycerin, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, Solid content 40% by mass) and ion-exchanged water were mixed at the ratios shown in Table 7-1, stirred for 1 hour, and then filtered through a membrane filter having a pore size of 1.2 μm to compare the aqueous inks RGJ1-1 to RGJ1-. I got 4.

[Comparative Example 5: Preparation of Comparative Water-based Ink RGJ1-5]
(Synthesis of Comparative Polymer RCP1-2)
Add 80 g of 2-phenoxyethyl methacrylate as a monomer, 3.7 g of 3-mercapto-1-propanol as a chain transfer agent, and 0.3 g of 2,2-azobis (2,4-dimethylvaleronitrile) as an initiator in 160 mL of THF. It was dissolved and heated to 65 ° C. under a nitrogen atmosphere and reacted for 7 hours. The obtained solution was allowed to cool, 80 mg of dibutyl tin dilaurate (IV) and a catalytic amount of hydroquinone were added, and 10.0 g of 2-methacryloyloxyethyl isocyanate was added dropwise. After raising the temperature to 50 ° C. and reacting for 2.5 hours, it was purified by reprecipitation with a mixed solvent of methanol and water, and 71 g of macromonomer MM-1 (weight average molecular weight (Mw): 4000, number average). The molecular weight (Mn) was 1900).
Next, 20 g of methyl ethyl ketone was heated to 75 ° C. under a nitrogen atmosphere, followed by 1.16 g of dimethyl 2,2'-azobisisobutyrate, and 1.8 g of the 9 g macromonomer MM-1, obtained above. A solution of p-styrene sulfonic acid and 49.2 g of methyl methacrylate in 40 g of methyl ethyl ketone was added dropwise over 3 hours. After completion of the dropwise addition, after reacting for another 1 hour, a solution prepared by dissolving 0.2 g of dimethyl 2,2'-azobisisobutyrate in 0.6 g of methyl ethyl ketone was added, the temperature was raised to 80 ° C., and the mixture was heated and stirred for 4 hours. did. Further, a solution prepared by dissolving 0.2 g of dimethyl 2,2'-azobisisobutyrate in 0.6 g of methyl ethyl ketone was added, and the mixture was heated and stirred for 6 hours. After cooling, the obtained reaction solution was dropped into hexane, the precipitated graft polymer was filtered off, and dried to obtain a comparative polymer RCP1-2, which was obtained in the same manner as in Example I-1. An aqueous solution of -2 was prepared.

(Preparation of Comparative Pigment Dispersion RPD1-5 and Comparative Water-based Ink RGJ1-5)
Next, the comparative pigment dispersion RPD1-5 was used in the same manner except that the aqueous solution of the comparative polymer RCP1-2 was used instead of the aqueous solution of the polymer CP1-1 in the preparation of the pigment dispersion of Example II-1. Got
Next, a comparative water-based ink RGJ1-5 was obtained in the same manner except that the comparative pigment dispersion RPD1-5 was used instead of the pigment dispersion PD1-1 in the preparation of the ink of Example II-1.

[Comparative Example 6: Preparation of Comparative Water-based Ink RGJ1-6]
Polymer RCP1-3 was obtained in the same manner except that the polyethylene glycol monomethacrylate in Example I-1 was replaced with poly (ethylene glycol / tetramethylene glycol) -monomethacrylate represented by the following structural formula. An aqueous solution of the polymer RCP1-3 was prepared in the same manner as in I-1.
A comparative pigment dispersion RPD1-6 was obtained in the same manner except that an aqueous solution of the comparative polymer RCP1-3 was used instead of the aqueous solution of the polymer CP1-1 in the preparation of the pigment dispersion of Example II-1. It was.
Next, a comparative water-based ink RGJ1-6 was obtained in the same manner except that the comparative pigment dispersion RPD1-6 was used instead of the pigment dispersion PD1-1 in the preparation of the ink of Example II-1.

The characteristics of the pigment dispersions produced in Examples II-1 to II-16 and Comparative Examples 1 to 6 and the water-based ink were evaluated by the following methods.
A list of the produced pigment dispersions is shown in Table 6-1, a list of the produced water-based inks is shown in Table 7-1, and the evaluation results are shown in Table 8-1.

<Storage stability of pigment dispersion>
Each pigment dispersion was filled in a glass container and stored at 70 ° C. for 2 weeks, and the rate of change in viscosity after storage with respect to the viscosity before storage was calculated from the following formula and evaluated according to the following criteria.
A viscometer (RE80L, manufactured by Toki Sangyo Co., Ltd.) was used to measure the viscosity, and the viscosity at 25 ° C. was measured at 50 rotations.
〔Evaluation criteria〕
AA: Viscosity change rate within ± 3% A: Viscosity change rate exceeds ± 3% and within ± 5% B: Viscosity change rate exceeds ± 5% and within ± 8% C: Viscosity change Rate exceeds ± 8% and within ± 10% D: Viscosity change rate exceeds ± 10% and within ± 30% E: Viscosity change rate exceeds ± 30% (gelled and cannot be evaluated)

<Ink storage stability>
Each ink was filled in an ink container and stored at 70 ° C. for one week, and the rate of change in viscosity after storage with respect to the viscosity before storage was calculated from the following formula and evaluated according to the following criteria.
A viscometer (RE80L, manufactured by Toki Sangyo Co., Ltd.) was used to measure the viscosity, and the viscosity at 25 ° C. was measured at 50 rotations.
〔Evaluation criteria〕
AA: Viscosity change rate within ± 3% A: Viscosity change rate exceeds ± 3% and within ± 5% B: Viscosity change rate exceeds ± 5% and within ± 8% C: Viscosity change Rate exceeds ± 8% and within ± 10% D: Viscosity change rate exceeds ± 10% and within ± 30% E: Viscosity change rate exceeds ± 30% (gelled and cannot be evaluated)

<Image density>
64point JIS X 0208 (1997), 2223 general symbols created by filling each ink in an inkjet printer (Ricoh, IPSiO GX5000) under a 50% RH environment at 23 ° C and using Microsoft Word2000 (Microsoft). The chart on which is described is printed on plain paper 1 (XEROX4200, manufactured by XEROX) and plain paper 2 (MyPaper, manufactured by Ricoh), and the symbol portion on the printed surface is X-Rite938 (manufactured by X-Rite). The color was measured according to the following criteria.
As the print mode, the driver attached to the printer was used to change the "plain paper-standard fast" mode to "no color correction" from the user settings for plain paper.
The above JIS X 0208 (1997), 2223 is a symbol whose outer shape is a regular square and whose entire surface is filled with ink.
〔Evaluation criteria〕
AA: 1.27 or more A: 1.25 or more and less than 1.27 B: 1.20 or more and less than 1.25 C: 1.10 or more and less than 1.20 D: less than 1.10 E: Pigment is gel It cannot be dispersed in the ink and cannot be printed.

Pigment dispersion produced by using the polymer of Examples II-1 to II-16 having the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) of the present invention. The body had excellent storage stability as compared with the pigment dispersion prepared using the polymer of Comparative Examples 1 to 5 which did not have the structural unit represented by the general formula (2). It is considered that this is because the adsorptivity to the pigment is enhanced by the π-π interaction between the naphthyl group of the structural unit represented by the general formula (2) of the polymer and the pigment. Further, the pigment dispersion produced by using the polymer of Comparative Example 6 which does not have the structural unit represented by the general formula (1) was used instead of the structural unit represented by the general formula (1). Due to the low hydrophilicity of the structural unit tetramethylene glycol chain, the pigment could not be well dispersed in water.
In addition, the inks produced using the pigment dispersions of Examples II-1 to II-16 containing the polymer of the present invention are the pigment dispersions of Comparative Examples 1 to 6 containing a polymer different from the present invention. It showed higher storage stability than the ink prepared using the above, and had excellent characteristics in terms of image density.

[Examples II'-1 to II'-12: Preparation of water-based inks GJ1'-1 to GJ1'-12]
(Preparation of pigment dispersion PD1'-1 to PD1'-12)
An aqueous solution of the polymer CP1'-1 to CP1'-9 prepared in Examples I'-1 to I'-9, carbon black (NIPEX150, manufactured by Degusa), and pigment blue 15: 3 (manufactured by Dainichi Seika). , Chromofine Blue Cyan Pigment), Pigment Red 122 (Clariant, Toner Magenta EO02 Magenta Pigment), or Pigment Yellow 74 (Dainichi Seika, First Yellow 531 Yellow Pigment), and ion-exchanged water are shown in Table 6- The mixture was added at the ratio shown in 2 and stirred for 12 hours. The obtained mixture was circulated and dispersed at a peripheral speed of 10 m / s for 1 hour using a disk-type bead mill (manufactured by Simmal Enterprises, KDL type, media: using zirconia balls having a diameter of 0.1 mm), and then the pore diameter was 1. The mixture was filtered through a 2 μm membrane filter, and an adjusted amount of ion-exchanged water was added to obtain a pigment dispersion PD1'-1 to PD1'-12. The numerical values in Table 6-2 represent "parts". The pigment dispersions PD1'-1 to PD1'-6 and PD1'-10 to PD1'-12 have a pigment solid content concentration of 16%, and the pigment dispersions PD1'-7 to PD1'-9 have a pigment solid content. The concentration is 20%.

(Making ink)
Pigment dispersion PD1'-1 to PD1'-12, 3-ethyl-3-hydroxymethyloxetane, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, Solid content 40% by mass) and ion-exchanged water are mixed at the ratios shown in Table 7-2, stirred for 1 hour, and then filtered through a membrane filter having a pore size of 1.2 μm to obtain the aqueous ink GJ1'-1 of the present invention. ~ GJ1'-12 was obtained. The numerical values in Table 7-2 represent "parts".

The characteristics of each pigment dispersion prepared in Examples II'-1 to II'-12 and the water-based ink were evaluated by the same method as in Example II-1.
A list of the prepared pigment dispersions is shown in Table 6-2, a list of the prepared water-based inks is shown in Table 7-2, and the evaluation results are shown in Table 8-2.

It was prepared using the polymer of Examples II'-1 to II'-12 having the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) of the present invention. In the pigment dispersion, the dispersion storage stability was improved as the ethylene glycol chain in the structural unit represented by the general formula (1) became longer. It is considered that this is because the hydrophilic ethylene glycol chain becomes longer and the steric interaction in water becomes larger. In addition, the ink storage stability was improved by increasing the composition ratio of the general formula (2) in the polymer.

[Examples II-17 to II-34: Preparation of water-based inks GJ2-1 to GJ2-13]
(Preparation of pigment dispersions PD2-1 to PD2-13)
An aqueous solution of the polymers CP2-1 to CP2-10 prepared in Examples I-14 to I-28, carbon black (NIPEX150, manufactured by Degusa), pigment blue 15: 3 (manufactured by Dainichi Seika, Chromofine Blue). Pigment Red 122 (Toner Magenta EO02 Magenta Pigment manufactured by Clariant) or Pigment Yellow 74 (First Yellow 531 Yellow Pigment manufactured by Dainichi Seika Co., Ltd.) and ion-exchanged water at the ratios shown in Table 9. Stirred for 12 hours. The obtained mixture was circulated and dispersed at a peripheral speed of 10 m / s for 1 hour using a disk-type bead mill (manufactured by Simmal Enterprises, KDL type, media: using zirconia balls having a diameter of 0.1 mm), and then the pore diameter was 1. The mixture was filtered through a 2 μm membrane filter, and an adjusted amount of ion-exchanged water was added to obtain pigment dispersions PD2-1 to PD2-13. The numerical values in Table 9 represent "parts". The pigment dispersions PD2-1 to PD2-8 and PD2-12 to PD2-13 have a pigment solid content concentration of 16%, and the pigment dispersions PD2-9 to PD2-11 have a pigment solid content concentration of 20%. ..

(Making ink)
Pigment dispersions PD2-1 to PD2-13, 1,3-butanediol, glycerin, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, solid content 40) Mass%) and ion-exchanged water were mixed at the ratios shown in Table 10, stirred for 1 hour, and then filtered through a membrane filter having a pore size of 1.2 μm to obtain the aqueous inks GJ2-1 to GJ2-13 of the present invention. It was. The numerical values in Table 10 represent "parts".

[Comparative Examples 7 to 10: Preparation of Comparative Water-based Inks RGJ2-1 to RGJ2-4]
6.36 g of polymer RCP2-1 (weight average molecular weight (Mw)) in the same manner except that the monomer M-1 in Example I-14 was replaced with a monomer having a structure represented by the following structural formula (15). : 7500, number average molecular weight (Mn): 2800) was obtained, and an aqueous solution of the polymer RCP2-1 was prepared in the same manner as in Example I-14.

Aqueous solution of polymer RCP2-1, carbon black (NIPEX150, manufactured by Degusa), pigment blue 15: 3 (manufactured by Dainichi Seika, chromofine blue cyan pigment), pigment red 122 (manufactured by Clariant, toner magenta EO02 magenta) Pigment Yellow 74 (Fast Yellow 531 Yellow Pigment manufactured by Dainichi Seika Co., Ltd.) and ion-exchanged water were added in the proportions shown in Table 9 to obtain comparative pigment dispersions RPD2-1 to RPD2-4.
Next, the pigment dispersions RPD2-1 to RPD2-4, 1,3-butanediol, glycerin, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, Solid content 40% by mass) and ion-exchanged water are mixed at the ratios shown in Table 10, stirred for 1 hour, and then filtered through a membrane filter having a pore size of 1.2 μm to obtain comparative aqueous inks RGJ2-1 to RGJ2-4. Obtained.

[Comparative Example 11: Preparation of Comparative Water-based Ink RGJ2-5]
The polymer RCP2-2 was obtained in the same manner except that the polyethylene glycol monomethacrylate in Example I-14 was replaced with poly (ethylene glycol / tetramethylene glycol) -monomethacrylate represented by the following structural formula, and Examples were obtained. An aqueous solution of the polymer RCP2-2 was prepared in the same manner as in I-14.
A comparative pigment dispersion RPD2-5 was obtained in the same manner except that an aqueous solution of the comparative polymer RCP2-2 was used instead of the aqueous solution of the polymer CP2-1 in the preparation of the pigment dispersion of Example II-17. It was.
Next, a comparative water-based ink RGJ2-5 was obtained in the same manner except that the comparative pigment dispersion RPD2-5 was used instead of the pigment dispersion PD2-1 in the preparation of the ink of Example II-17.

The characteristics of the pigment dispersions prepared in Examples II-17 to II-34 and Comparative Examples 7 to 11 and the water-based ink were evaluated by the same method as in Example II-1.
Table 9 shows a list of the produced pigment dispersions, Table 10 shows a list of the produced water-based inks, and Table 11 shows the evaluation results.

The structural unit represented by the above general formula (1), the structural unit represented by the general formula (2), and the structure represented by the general formula (3) of Examples II-17 to II-34. The pigment dispersion prepared using the polymer having a unit is compared with the pigment dispersion prepared using the polymer having no structural unit represented by the general formula (2) in Comparative Examples 7 to 10. It had excellent storage stability. It is considered that this is because the adsorptivity to the pigment is enhanced by the π-π interaction between the naphthyl group of the structural unit represented by the general formula (2) of the polymer and the pigment. Further, the pigment dispersion produced by using the polymer having no structural unit represented by the general formula (1) of Comparative Example 11 has a structure used instead of the structural unit represented by the general formula (1). Due to the low hydrophilicity of the unit tetramethylene glycol chain, the pigment could not be well dispersed in water.
In addition, the ink produced by using the dispersion made of the polymer of the present invention of Examples II-17 to II-34 uses the dispersion of Comparative Examples 7 to 11 containing a polymer different from the present invention. It showed higher storage stability than the ink produced in the above, and had excellent characteristics in terms of image density.

[Examples II-35 to II-51; Preparation of water-based inks GJ3-1 to GJ3-13]
(Preparation of pigment dispersions PD3-1 to PD3-13)
An aqueous solution of the polymers CP3-1 to CP3-10 prepared in Examples I-29 to I-42, carbon black (NIPEX150, manufactured by Degusa), pigment blue 15: 3 (manufactured by Dainichi Seika, Chromofine Blue). Pigment Red 122 (Clariant, Toner Magenta EO02 Magenta Pigment), or Pigment Yellow 74 (Dainichi Seika Co., Ltd., First Yellow 531 Yellow Pigment) and ion-exchanged water at the ratio shown in Table 12. Stirred for 12 hours. The obtained mixture was circulated and dispersed at a peripheral speed of 10 m / s for 1 hour using a disk-type bead mill (manufactured by Simmal Enterprises, KDL type, media: using zirconia balls having a diameter of 0.1 mm), and then the pore diameter was 1. The mixture was filtered through a 2 μm membrane filter, and an adjusted amount of ion-exchanged water was added to obtain a pigment dispersion PD3-1 to PD3-13. The numerical values in Table 12 represent "parts". The pigment dispersions PD3-1 to PD3-10 have a pigment solid content concentration of 16%, and the pigment dispersions PD3-11 to PD3-13 have a pigment solid content concentration of 20%.

(Making ink)
Pigment dispersions PD3-1 to PD3-13, 1,3-butanediol, glycerin, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, solid content 40) Mass%) and ion-exchanged water were mixed at the ratios shown in Table 13, stirred for 1 hour, and then filtered through a membrane filter having a pore size of 1.2 μm to obtain the aqueous inks GJ3-1 to GJ3-13 of the present invention. It was. The numerical values in Table 13 represent "parts".

[Comparative Examples 12 to 15; Preparation of Comparative Water-based Inks RGJ3-1 to RGJ3-4]
6.36 g of polymer RCP3-1 (weight average molecular weight (Mw)) in the same manner except that the monomer M-1 in Example I-29 was replaced with a monomer having a structure represented by the following structural formula (15). : 7500, number average molecular weight (Mn): 2800) was obtained, and an aqueous solution of the polymer RCP3-1 was prepared in the same manner as in Example I-29.

Aqueous solution of polymer RCP3-1, carbon black (NIPEX150, manufactured by Degusa), pigment blue 15: 3 (manufactured by Dainichi Seika, chromofine blue cyan pigment), pigment red 122 (manufactured by Clariant, toner magenta EO02 magenta) Pigment Yellow 74 (Fast Yellow 531 Yellow Pigment manufactured by Dainichi Seika Co., Ltd.) and ion-exchanged water were added at the ratios shown in Table 12 to obtain comparative pigment dispersions RPD3-1 to RPD3-4.
Next, pigment dispersions RPD3-1 to RPD3-4, 1,3-butanediol, glycerin, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, Solid content 40% by mass) and ion-exchanged water were mixed at the ratios shown in Table 13, stirred for 1 hour, and then filtered through a membrane filter having a pore size of 1.2 μm to obtain comparative aqueous inks RGJ3-1 to RGJ3-4. Obtained.

[Comparative Example 16; Preparation of Comparative Water-based Ink RGJ3-5]
The polymer RCP3-2 was obtained in the same manner except that the polyethylene glycol monomethacrylate in Example I-29 was replaced with poly (ethylene glycol / tetramethylene glycol) -monomethacrylate represented by the following structural formula, and Examples were obtained. An aqueous solution of the polymer RCP3-2 was prepared in the same manner as in I-29.
A comparative pigment dispersion RPD3-5 was obtained in the same manner except that an aqueous solution of the comparative polymer RCP3-2 was used instead of the aqueous solution of the polymer CP3-1 in the preparation of the pigment dispersion of Example II-35. It was.
Next, a comparative water-based ink RGJ3-5 was obtained in the same manner except that the comparative pigment dispersion RPD3-5 was used instead of the pigment dispersion PD3-1 in the preparation of the ink of Example II-35.

The characteristics of the pigment dispersions prepared in Examples II-35 to 51 and Comparative Examples 12 to 16 and the water-based ink were evaluated by the same method as in Example II-1.
Table 12 shows a list of the produced pigment dispersions, Table 13 shows a list of the produced water-based inks, and Table 14 shows the evaluation results.

The structural unit represented by the above general formula (1), the structural unit represented by the general formula (2), and the structure represented by the general formula (7) of Examples II-35 to II-51. The pigment dispersion prepared using the polymer having a unit is compared with the pigment dispersion prepared using the polymer having no structural unit represented by the general formula (2) in Comparative Examples 12 to 15. It had excellent storage stability. It is considered that this is because the adsorptivity to the pigment is enhanced by the π-π interaction between the naphthyl group of the structural unit represented by the general formula (2) of the polymer and the pigment. Further, the pigment dispersion produced by using the polymer of Comparative Example 16 having no structural unit represented by the general formula (1) was used instead of the structural unit represented by the general formula (1). Due to the low hydrophilicity of the structural unit tetramethylene glycol chain, the pigment could not be well dispersed in water.
In addition, as the ink produced by using the dispersion containing the polymer of the present invention of Examples II-35 to II-51, the dispersion containing the polymer of Comparative Examples 12 to 16 different from the present invention was used. It showed higher storage stability than the ink produced in the above, and had excellent characteristics in terms of image density.

[Examples II-52 to II-73: Preparation of water-based inks GJ4-1 to GJ4-18]
(Preparation of pigment dispersions PD4-1 to PD4-18)
An aqueous solution of the polymers CP4-1 to CP4-15 prepared in Examples I-43 to I-61, carbon black (NIPEX150, manufactured by Degusa), pigment blue 15: 3 (manufactured by Dainichi Seika, Chromofine Blue). Pigment Red 122 (Toner Magenta EO02 Magenta Pigment manufactured by Clariant) or Pigment Yellow 74 (First Yellow 531 Yellow Pigment manufactured by Dainichi Seika Co., Ltd.) and ion-exchanged water at the ratios shown in Table 15. Stirred for 12 hours. The obtained mixture was circulated and dispersed at a peripheral speed of 10 m / s for 1 hour using a disk-type bead mill (manufactured by Simmal Enterprises, KDL type, media: using zirconia balls having a diameter of 0.1 mm), and then the pore diameter was 1. The mixture was filtered through a 2 μm membrane filter, and an adjusted amount of ion-exchanged water was added to obtain pigment dispersions PD4-1 to PD4-18. The numerical values in Table 15 represent "parts". The pigment dispersions PD4-1 to PD4-9 and PD4-13 to PD4-18 have a pigment solid content concentration of 16%, and the pigment dispersions PD4-10 to PD4-12 have a pigment solid content concentration of 20%.

(Making ink)
Pigment dispersions PD4-1 to PD4-18, 1,3-butanediol, glycerin, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, solid content 40) Mass%) and ion-exchanged water were mixed at the ratios shown in Table 16, stirred for 1 hour, and then filtered through a membrane filter having a pore size of 1.2 μm to obtain the water-based inks GJ4-1 to GJ4-18 of the present invention. It was. The numerical values in Table 16 represent "parts".

[Comparative Examples 17 to 20; Preparation of Comparative Water-based Inks RGJ4-1 to RGJ4-4]
6.36 g of polymer RCP4-1 (6.5% by mass aqueous solution) in the same manner except that the monomer M-1 in Example I-43 was replaced with a monomer having a structure represented by the following structural formula (15). (Viscosity of 1.9 (mPa · s)) was obtained, and an aqueous solution of the polymer RCP4-1 was prepared in the same manner as in Example I-43.

Aqueous solution of polymer RCP4-1, carbon black (NIPEX150, manufactured by Degusa), pigment blue 15: 3 (manufactured by Dainichi Seika, chromofine blue cyan pigment), pigment red 122 (manufactured by Clariant, toner magenta EO02 magenta) Pigment Yellow 74 (Fast Yellow 531 Yellow Pigment manufactured by Dainichi Seika Co., Ltd.) and ion-exchanged water were added in the proportions shown in Table 15 to obtain comparative pigment dispersions RPD4-1 to RPD4-4.
Next, pigment dispersions RPD4-1 to RPD4-4, 1,3-butanediol, glycerin, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, Solid content 40% by mass) and ion-exchanged water were mixed at the ratios shown in Table 16, and after stirring for 1 hour, the comparative water-based inks RGJ4-1 to RGJ4-4 were filtered through a membrane filter having a pore size of 1.2 μm. Obtained.

[Comparative Example 21; Preparation of Comparative Water-based Ink RGJ4-5]
The polymer RCP4-2 was obtained in the same manner except that the polyethylene glycol monomethacrylate in Example I-43 was replaced with poly (ethylene glycol / tetramethylene glycol) -monomethacrylate represented by the following structural formula, and Examples were obtained. An aqueous solution of the polymer RCP4-2 was prepared in the same manner as in I-43.
A comparative pigment dispersion RPD4-5 was obtained in the same manner except that an aqueous solution of the comparative polymer RCP4-2 was used instead of the aqueous solution of the polymer CP4-1 in the preparation of the pigment dispersion of Example II-52. It was.
Next, a comparative water-based ink RGJ4-5 was obtained in the same manner except that the comparative pigment dispersion RPD4-5 was used instead of the pigment dispersion PD4-1 in the preparation of the ink of Example II-52.

The characteristics of the pigment dispersions prepared in Examples II-52 to II-73 and Comparative Examples 17 to 21 and the water-based ink were evaluated by the same method as in Example II-1.
Table 15 shows a list of the produced pigment dispersions, Table 16 shows a list of the produced water-based inks, and Table 17 shows the evaluation results.

[Example II-74; Preparation of water-based ink GJ5-1]
(Preparation of pigment dispersion PD5-1)
22.5 g of ion-exchanged water was added to 16.0 g of an aqueous solution of 61.5 g of the polymer CP5-1 prepared in Example I-62 and 16.0 g of carbon black (NIPEX150, manufactured by Degussa), and the mixture was stirred for 12 hours. The obtained mixture was circulated and dispersed for 1 hour at a peripheral speed of 10 m / s using a disk-type bead mill (Symmal Enterprises, KDL type, media: zirconia ball with a diameter of 0.1 mm), and then a pore diameter of 1.2 μm. The mixture was filtered through the membrane filter of the above, and an adjusted amount of ion-exchanged water was added to obtain a pigment dispersion PD5-1 (pigment solid content concentration: 16% by mass).

(Making ink)
45.0 g of pigment dispersion PD5-1, 10.0 g of 1,3-butanediol, 10.0 g of glycerin, 10.0 g of 3-methoxy-N, N-dimethylpropionamide, 1.0 g of zonyl FS -300 (DuPont, fluorine-based surfactant, solid content 40% by mass) and 24.0 g of ion-exchanged water are mixed, stirred for 1 hour, and then filtered through a membrane filter having a pore size of 1.2 μm. The water-based ink GJ5-1 of the present invention was obtained.
The characteristics of the produced pigment dispersion PD5-1 and the water-based ink GJ5-1 were evaluated by the same method as in Example II-1. The evaluation results are shown in Table 17.

The structural unit represented by the above general formula (1), the structural unit represented by the general formula (2), and the structure represented by the general formula (9) of Examples II-52 to II-73. The pigment dispersion prepared using the polymer having a unit is compared with the pigment dispersion prepared using the polymer having no structural unit represented by the general formula (2) in Comparative Examples 17 to 20. It had excellent storage stability. It is considered that this is because the adsorptivity to the pigment is enhanced by the π-π interaction between the naphthyl group of the structural unit represented by the general formula (2) of the polymer and the pigment. Further, the pigment dispersion produced by using the polymer having no structural unit represented by the general formula (1) of Comparative Example 21 has a structure used instead of the structural unit represented by the general formula (1). Due to the low hydrophilicity of the unit tetramethylene glycol chain, the pigment could not be well dispersed in water.
A polymer having a structural unit represented by the above general formula (1), a structural unit represented by the general formula (2), and a structural unit represented by the general formula (11) of the present invention of Example II-74. The pigment dispersion prepared using the above also had excellent storage stability.
In addition, the ink produced by using the dispersion made of the polymer of the present invention of Examples II-52 to II-74 uses the dispersion of Comparative Examples 17 to 21 containing a polymer different from the present invention. It showed higher storage stability than the ink produced in the above, and had excellent characteristics in terms of image density.

[Examples II-75 to II-91: Preparation of water-based inks GJ6-1 to GJ6-13]
(Preparation of pigment dispersions PD6-1 to PD6-13)
An aqueous solution of the polymers CP6-1 to CP6-10 prepared in Examples I-63 to I-76, carbon black (NIPEX150, manufactured by Degusa), pigment blue 15: 3 (manufactured by Dainichi Seika, Chromofine Blue). Pigment Red 122 (Clariant, Toner Magenta EO02 Magenta Pigment), or Pigment Yellow 74 (Dainichi Seika Co., Ltd., First Yellow 531 Yellow Pigment) and ion-exchanged water at the ratios shown in Table 18. Stirred for 12 hours. The obtained mixture was circulated and dispersed at a peripheral speed of 10 m / s for 1 hour using a disk-type bead mill (manufactured by Simmal Enterprises, KDL type, media: using zirconia balls having a diameter of 0.1 mm), and then the pore diameter was 1. The mixture was filtered through a 2 μm membrane filter, and an adjusted amount of ion-exchanged water was added to obtain pigment dispersions PD6-1 to PD6-13. The numerical values in Table 18 represent "parts". The pigment dispersions PD6-1 to PD6-8 and PD6-12 to PD6-13 have a pigment solid content concentration of 16%, and the pigment dispersions PD6-9 to PD6-11 have a pigment solid content concentration of 20%. ..

(Making ink)
Pigment dispersion PD6-1 to PD6-13, 1,3-butanediol, glycerin, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, solid content 40) Mass%) and ion-exchanged water were mixed at the ratios shown in Table 19, stirred for 1 hour, and then filtered through a membrane filter having a pore size of 1.2 μm to obtain the water-based inks GJ6-1 to GJ6-13 of the present invention. It was. The numerical values in Table 19 represent "parts".

[Comparative Examples 22 to 25: Preparation of Comparative Water-based Inks RGJ6-1 to RGJ6-4]
6.36 g of polymer RCP6-1 (weight average molecular weight (Mw)) in the same manner except that the monomer M-1 in Example I-63 was replaced with a monomer having a structure represented by the following structural formula (15). : 11900, number average molecular weight (Mn): 6600) was obtained, and an aqueous solution of the polymer RCP6-1 was prepared in the same manner as in Example I-63.

Aqueous solution of polymer RCP6-1, carbon black (NIPEX150, manufactured by Degusa), pigment blue 15: 3 (manufactured by Dainichi Seika, chromofine blue cyan pigment), pigment red 122 (manufactured by Clariant, toner magenta EO02 magenta) Pigment Yellow 74 (manufactured by Dainichi Seika Co., Ltd., First Yellow 531 Yellow Pigment) and ion-exchanged water were added at the ratios shown in Table 18 to obtain comparative pigment dispersions RPD6-1 to RPD6-4.
Next, pigment dispersions RPD6-1 to RPD6-4, 1,3-butanediol, glycerin, 3-methoxy-N, N-dimethylpropionamide, Zonyl FS-300 (Dupont, fluorine-based surfactant, Solid content 40% by mass) and ion-exchanged water were mixed at the ratios shown in Table 19, stirred for 1 hour, and then filtered through a membrane filter having a pore size of 1.2 μm to obtain comparative aqueous inks RGJ6-1 to RGJ6-4. Obtained.

[Comparative Example 26: Preparation of Comparative Water-based Ink RGJ6-5]
The polymer RCP6-2 was obtained in the same manner except that the polyethylene glycol monomethacrylate in Example I-63 was replaced with poly (ethylene glycol / tetramethylene glycol) -monomethacrylate represented by the following structural formula, and Examples were obtained. An aqueous solution of the polymer RCP6-2 was prepared in the same manner as in I-63.
A comparative pigment dispersion RPD6-5 was obtained in the same manner except that an aqueous solution of the comparative polymer RCP6-2 was used instead of the aqueous solution of the polymer CP6-1 in the preparation of the pigment dispersion of Example II-75. It was.
Next, a comparative water-based ink RGJ6-5 was obtained in the same manner except that the comparative pigment dispersion RPD6-5 was used instead of the pigment dispersion PD6-1 in the preparation of the ink of Example II-75.

The characteristics of the pigment dispersions prepared in Examples II-75 to II-91 and Comparative Examples 22 to 26 and the water-based ink were evaluated by the same method as in Example II-1.
Table 18 shows a list of the produced pigment dispersions, Table 19 shows a list of the produced water-based inks, and Table 20 shows the evaluation results.

The structural unit represented by the above general formula (1), the structural unit represented by the general formula (2), and the structure represented by the general formula (13) of Examples II-75 to II-91. The pigment dispersion prepared using the polymer having a unit is compared with the pigment dispersion prepared using the polymer having no structural unit represented by the general formula (2) in Comparative Examples 22 to 25. It had excellent storage stability. It is considered that this is because the adsorptivity to the pigment is enhanced by the π-π interaction between the naphthyl group of the structural unit represented by the general formula (2) of the polymer and the pigment. Further, the pigment dispersion produced by using the polymer having no structural unit represented by the general formula (1) of Comparative Example 26 has a structure used instead of the structural unit represented by the general formula (1). Due to the low hydrophilicity of the unit tetramethylene glycol chain, the pigment could not be well dispersed in water.
Further, as the ink produced by using the dispersion made of the polymer of the present invention of Examples II-75 to II-91, the dispersion containing the polymer different from the present invention of Comparative Examples 22 to 26 was used. It showed higher storage stability than the ink produced in the above, and had excellent characteristics in terms of image density.

200 Ink container 241 Ink storage 242 Ink inlet 243 Ink outlet 244 Ink container case

Japanese Unexamined Patent Publication No. 2011-105866

Claims (6)

A method for producing a polymer, which comprises polymerizing a compound represented by the following general formula (4) and a compound represented by the following general formula (5).
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms. A method for producing a polymer, which comprises polymerizing a compound represented by the following general formula (4), a compound represented by the following general formula (5), and a compound represented by the following general formula (6).
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (6), R ₄ represents a hydrogen atom or a methyl group, and X represents a hydrogen atom or a cation. A method for producing a polymer, which comprises polymerizing a compound represented by the following general formula (4), a compound represented by the following general formula (5), and a compound represented by the following general formula (8).
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (8), R ₅ represents a hydrogen atom or a methyl group. A method for producing a polymer, which comprises polymerizing a compound represented by the following general formula (4), a compound represented by the following general formula (5), and a compound represented by the following general formula (10).
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (10), R ₆ is a hydrogen atom or a methyl group, R ₇ is either —O— or —NH—, and R ₈ is an alkylene group having 5 or less carbon atoms which may have a substituent. R ₉ represents a hydrogen atom or an alkyl group having 5 or less carbon atoms, and a and b are independently 0 or 1, respectively. A method for producing a polymer, which comprises polymerizing a compound represented by the following general formula (4), a compound represented by the following general formula (5), and a compound represented by the following general formula (12).
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (12), R ₁₀ is a hydrogen atom or a methyl group, R ₁₁ is either —O— or —NH—, and R ₁₂ is an alkylene group having 5 or less carbon atoms which may have a substituent. R ₁₃ represents an alkyl group having 5 or less carbon atoms, Y ⁻ represents an anion species, and a and b are independently 0 or 1, respectively. A method for producing a polymer, which comprises polymerizing a compound represented by the following general formula (4), a compound represented by the following general formula (5), and a compound represented by the following general formula (14).
In the general formula (4), R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents a value of 1 to 90.
In the general formula (5), R ₃ represents a hydrogen atom or a methyl group, and L represents an alkylene group having 2 to 18 carbon atoms.
In the general formula (14), R ₁₄ represents a hydrogen atom or a methyl group.