JP2017039879A - Copolymer, ink, recorded matter, ink cartridge and recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copolymer excellent in dispersion stability and long-term stability.SOLUTION: The copolymer has a structural unit (1) represented by the specified general formula (1), and a structural unit (2) represented by the specified structural formula (1), and is characterized in that the HLB value calculated by the Griffin method is from 8.8 to 15.1 inclusive.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a copolymer, ink, recorded matter, ink cartridge, and recording apparatus.

  The inkjet recording method is popular because it has the advantages of being simpler than other recording methods, easy to make full color, and capable of obtaining high-resolution images even with a simple configuration. Have been doing. In this ink jet recording method, a small amount of ink is ejected by pressure generated using bubbles generated by heat, piezo or electrostatic, and the ink is attached to a recording medium such as paper and dried quickly (or recording). This is a method of forming an image by penetrating into a medium), and its application has been expanded to personal and industrial printers and printing.

  In such an ink jet recording system, a water-based ink using a water-soluble dye as a colorant is mainly used. However, the dye ink has a defect that it is inferior in weather resistance and water resistance. For this reason, research on pigment inks that use water-insoluble pigments instead of water-soluble dyes is underway, but pigment inks are still inferior in color development and ink storage stability compared to dye inks.

In order to solve such a problem, a dispersion resin is often used in the pigment ink. In order to improve dispersibility and stability, a polymer containing a polyethylene glycol (meth) acrylate monomer and an α, β-ethylenically unsaturated carboxylic acid is disclosed (for example, Patent Document 1).
However, in this method, since the hydrophilic property of the polymer is too high, the dispersion resin is largely diffused in water, and the long-term stability of the dispersion and the ink containing the dispersion is insufficient.

As a countermeasure, an attempt has been made to further improve the stability by adjusting the hydrophilicity / hydrophobicity of the polymer by using a highly hydrophobic monomer such as styrene (Patent Document 2). Thereby, it is thought that the dispersibility and long-term stability as an aqueous dispersion improve.
However, when an organic solvent is added to produce an ink using the dispersion, the polymer has insufficient affinity for the pigment, and there is a concern that the resin may be released from the pigment. Stability is still difficult, and long-term stability as ink becomes poor.

In addition, a method is disclosed in which an aromatic ring functional group is introduced at the end of a polyethylene glycol side chain of a graft polymer containing a polyethylene glycol (meth) acrylate monomer so that the resin is efficiently adsorbed on the pigment surface (patent). Reference 3).
However, even if an aromatic ring functional group is simply introduced at the end of the side chain, if the hydrophilicity / hydrophobicity of the whole resin is not adjusted, it can be said that there remains a problem with respect to the compatibility of the dispersion and ink dispersibility and solvent resistance.

  Then, an object of this invention is to provide the copolymer excellent in dispersion stability and long-term stability.

  In order to solve the above problems, the copolymer of the present invention comprises a structural unit (1) represented by the following general formula (1) and a structural unit (2) represented by the following structural formula (1). And the calculated value of HLB by the Griffin method is 8.8 or more and 15.1 or less.

（式中、Ｒは水素原子又はメチル基であり、Ａは（ＣＨ_２ＣＨ_２Ｏ）ｍ又は（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）ｍで表されるアルキルエーテルであり、Ａｒは芳香環官能基である。また、ｍは任意の整数である。）

Wherein R is a hydrogen atom or a methyl group, A is an alkyl ether represented by (CH ₂ CH ₂ O) m or (CH ₂ CH (CH ₃ ) O) m, and Ar is an aromatic ring functional group. And m is an arbitrary integer.)

  According to the present invention, a copolymer having excellent dispersion stability and long-term stability can be provided.

1 is a perspective view schematically showing an example of a recording apparatus according to the present invention. FIG. 3 is a perspective view schematically showing an example of an ink cartridge according to the present invention.

  Hereinafter, the copolymer, ink, recorded matter, ink cartridge and recording apparatus according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and any aspect is possible. As long as the functions and effects of the present invention are exhibited, the scope of the present invention is included.

(Copolymer)
The copolymer according to the present invention has a structural unit (1) represented by the following general formula (1) and a structural unit (2) represented by the following structural formula (1), and is an HLB by the Griffin method. The calculated value of is 8.8 or more and 15.1 or less.

（式中、Ｒは水素原子又はメチル基であり、Ａは（ＣＨ_２ＣＨ_２Ｏ）ｍ又は（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）ｍで表されるアルキルエーテルであり、Ａｒは芳香環官能基である。また、ｍは任意の整数である。）

Wherein R is a hydrogen atom or a methyl group, A is an alkyl ether represented by (CH ₂ CH ₂ O) m or (CH ₂ CH (CH ₃ ) O) m, and Ar is an aromatic ring functional group. And m is an arbitrary integer.)

By using a copolymer having the above structural unit (1) and the above structural unit (2), when used as a dispersant when producing a pigment dispersion, the dispersibility is good. In addition, since a high dispersion stability is maintained even when an organic solvent is added during ink preparation, a copolymer having excellent long-term stability can be provided. In particular, a copolymer having high dispersion stability and long-term stability when used in water-based inks can be provided.
This is because a side chain having a hydrophilic part having a high affinity for an aqueous medium and an aromatic ring functional group having a high affinity for the pigment can be used efficiently, so that the copolymer adsorbed on the pigment spreads in the dispersion medium. The dispersion stability can be improved because the pigments can be prevented from aggregating due to the steric hindrance of the copolymer, and the aromatic ring functional group can freely move in the dispersion medium to efficiently co-polymerize the pigment. This is presumably because the coalescence can be adsorbed.

  Further, the copolymer according to the present invention is obtained by radical polymerization of a polymerizable material containing a (meth) acrylate monomer represented by the following general formula (2) and a styrene monomer represented by the following structural formula (2). Can be synthesized.

Wherein R is a hydrogen atom or a methyl group, A is an alkyl ether represented by (CH ₂ CH ₂ O) m or (CH ₂ CH (CH ₃ ) O) m, and Ar is an aromatic ring functional group And m is an arbitrary integer.)

  Details will be described below.

<(Meth) acrylate monomer>
As described above, the copolymer of the present invention has the structural unit (1). In this case, for example, the structure having the structural unit (1) can be formed using the (meth) acrylate monomer represented by the general formula (2).

In general formula (1) or general formula (2), by using an alkyl ether as A, dispersion stability can be improved when it is contained in a pigment dispersion or ink. This is because the highly hydrophilic alkyl ether portion is arranged in the side chain, so that it can freely spread into water, thereby increasing the steric hindrance function by the copolymer and preventing aggregation of pigments. Because.
A is not particularly limited as long as it is an alkyl ether group, but from the viewpoint of dispersion stability, (C ₂ H ₄ O) m, (C ₃ H ₆ O) m, (C ₄ H ₈ O) m is preferable, and (CH ₂ CH ₂ O) m or (CH ₂ CH (CH ₃ ) O) m is more preferable. In this case, sufficient hydrophilicity can be obtained, so that the solubility of the copolymer can be prevented and aggregation between the copolymers can be prevented.

  M in the general formulas (1) and (2) is an arbitrary integer and is not particularly limited. However, from the viewpoint of hydrophilicity / hydrophobicity balance and dispersion stability, m is 6 or more and 13 or less. It is preferable that m is 6 or more and 9 or less. When m is 6 or more and 13 or less, the hydrophilicity / hydrophobicity of the copolymer becomes an appropriate level, which leads to improvement in dispersibility and stability.

  Moreover, when an aromatic ring functional group is used for Ar, solvent stability can be improved when it is contained in a pigment dispersion or ink. This is because the aromatic ring functional group can express not only a hydrophobic interaction but also a high adsorption force due to the π-π stacking force on the pigment, so that even when an organic solvent is added, the copolymer is formed from the pigment surface. This is because it becomes difficult to release. On the other hand, when Ar is a copolymer having a terminal other than an aromatic ring functional group, the pigment easily aggregates due to the addition of the solvent, and the desired solvent stability cannot be obtained.

  Ar is not particularly limited as long as it is an aromatic ring functional group, but one or more benzene rings are condensed, and the hydrogen atom of the aromatic ring is substituted with another functional group. Also good. Specific examples include benzene, naphthalene, anthracene, fluorene, phenanthrene, acethefene, and the like. From the viewpoint of hydrophilic / hydrophobic balance and dispersion stability, benzene and naphthalene are particularly preferable.

  The aromatic ring functional group represented by Ar may be introduced into the copolymer using the monomer represented by the general formula (2), and Ar of the general formula (2) has another functional group. When the synthesis is performed using the monomers, aromatic ring functional groups may be introduced before and after the synthesis of the copolymer.

<Physical properties of copolymer>
In the copolymer according to the present invention, the ratio of the structural unit (2) to the total of the structural unit (1) and the structural unit (2) is preferably 20 mol% or more and 30 mol% or less. By making it 20 mol% or more, it becomes suitable hydrophilicity / hydrophobicity, and it can prevent that the adsorptivity to the pigment by the diffusion increase to the water of a copolymer falls. On the other hand, by making it 30 mol% or less, it is possible to prevent a decrease in dispersibility due to the too high hydrophobicity of the copolymer.

  The weight average molecular weight of the copolymer according to the present invention is preferably from 1,000 to 1,000,000, and more preferably from 2,000 to 500,000 from the viewpoints of dispersibility and dispersion stability. Here, the weight average molecular weight of the copolymer is measured under the following conditions by ordinary GPC (gel permeation chromatography).

[Measurement condition]
・ Device: HLC-8220GPC (manufactured by Tosoh Corporation)
Column: TSKgel SuperHZM-Mx3
・ Solvent: THF (tetrahydrofuran)
From the molecular weight distribution of the copolymer measured under the above conditions, the weight average molecular weight is calculated using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample. As the monodisperse polystyrene standard sample, 10 samples in the range of 5.8 × 100 to 7.5 × 1000000 are used.

The use of the copolymer of the present invention is not particularly limited, and can be suitably used for, for example, ink and film. Further, it can be used as a dispersant to be contained in a pigment dispersion used in producing an ink.
When the copolymer of the present invention is used as a dispersant to be contained in a pigment dispersion used at the time of ink production, the content of the copolymer is not particularly limited and can be appropriately selected depending on the purpose. From the standpoint of fixability and storage stability of the ink, it is preferably 1% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less based on the total amount of the ink.

<< HLB value of copolymer >>
Although the hydrophilicity / hydrophobicity balance of the copolymer has a great influence on the dispersibility and stability, the structure of the hydrophilicity / hydrophobicity balance of the copolymer of the present invention is similar to that of the nonionic surfactant. Therefore, it is calculated as an HLB (Hydrophile-Lipophile Balance) value.

In the present invention, the composition is preferably adjusted so that the calculated HLB value of the copolymer by the Griffin method is 8.8 or more and 15.1 or less, and 9.2 or more and 15.1 or less. When the calculated value of HLB by the Griffin method is smaller than 8.8, the hydrophilicity of the copolymer is low, the solubility of the copolymer is deteriorated and the copolymers are aggregated in water, and the dispersibility is low. descend.
On the other hand, when the calculated value of HLB is greater than 15.1, the hydrophilicity of the copolymer is too high, so the diffusion of the copolymer into water is large, but it is released into water, and the pigment aggregates and settles. In addition, the effect of lowering the surface tension of the dispersion medium cannot be obtained so much and the initial dispersibility becomes poor. Therefore, the calculated value of HLB indicating the balance between hydrophilicity and hydrophobicity must be controlled to be in an appropriate region.

  By using a copolymer having a calculated HLB value of 8.8 or more and 15.1 or less by the Griffin method, it shows good dispersibility in the preparation of a pigment dispersion, and an organic solvent is added during preparation of an aqueous ink. It was also found that it becomes a copolymer that maintains high dispersion stability.

For example, HLB can increase the value of HLB by increasing the number of hydrophilic substituents introduced into the copolymer. Examples of the hydrophilic substituent include (CH ₂ CH ₂ O) m and (CH ₂ CH (CH ₃ ) O) m. Further, the HLB value of the copolymer can be lowered by reducing the number of hydrophilic substituents.

In Non-Patent Document 1, in the Griffin method, the HLB value is calculated from the following equation.
HLB = 20 × (formula weight of resin hydrophilic part / molecular weight of resin)
In the present invention, the resin corresponds to a copolymer.

<< Surface tension of copolymer aqueous solution >>
The surface tension of the aqueous solution of the copolymer is an indicator of dispersibility. There is no restriction | limiting in particular as surface tension of copolymer aqueous solution, According to the objective, it can select suitably. For example, the surface tension when a 3.2% by mass aqueous solution of the copolymer is prepared is preferably 35 mN / m or less at 25 ° C., and more preferably 30 mN / m or less.
In the initial process at the time of preparing the pigment dispersion, the aqueous copolymer solution penetrates into the fine gaps of the pigment aggregate. Therefore, the penetration rate of the aqueous copolymer solution into the pigment aggregate is important. The penetration rate is known to be discussed by the Lucas-Washburn theory, but when the surface tension is higher than 35 mN / m, the initial wettability of the aqueous copolymer solution with respect to the pigment decreases, and the desired dispersibility. You may not get.

  The method for measuring the surface tension is not particularly limited and can be appropriately selected from known methods according to the purpose. For example, the surface tension can be measured by the Wilhelmy method. In the present invention, the surface tension of the aqueous copolymer solution is measured under the following conditions.

[Measurement condition]
・ Device: DY-500 (manufactured by Kyowa Interface Science Co., Ltd.)
-Method: Wilhelmy method-Plate material: Platinum-Temperature: 25 ° C

<Synthesis Method of Copolymer>
The copolymer used in the present invention can be synthesized by various polymerization methods, for example, known polymerization methods such as a bulk polymerization method, a liquid polymerization method, a suspension polymerization method, and an emulsion polymerization method. The polymerization reaction can be carried out by a known operation such as batch, semi-continuous or continuous. Although not limited to these polymerization methods, a method using a radical polymerization initiator is preferable because polymerization operation and molecular weight adjustment are easy, and a solution polymerization method in which polymerization is performed in a mixed solvent of an organic solvent and water is more preferable.
The operation for performing radical polymerization by the solution polymerization method is not particularly limited, but the monomer, initiator, chain transfer agent, and solvent may be charged all at once into the polymerization reaction vessel, or a dropping funnel (dropping funnel). You may supply continuously using. Moreover, you may add an initiator during a polymerization reaction as needed.

The solvent used in the solution polymerization method is preferably a polar organic solvent. When the polar organic solvent is miscible with water, it can be used by mixing with water.
Examples of the polar organic solvent include alcohol solvents such as methanol, ethanol, 2-methoxyethanol and 2-ethoxyethanol, ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as tetrahydrofuran, N, N-dimethylformamide, and the like. And amide solvents such as ethyl acetate and esters such as ethyl acetate. Among these, methanol, ethanol, acetone, methyl ethyl ketone, or a mixed solution of these with water is preferable.

  There is no restriction | limiting in particular as said radical polymerization initiator, According to the objective, it can select suitably. For example, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxydicarbonate, peroxyester, cyano-based azobisisobutyronitrile, azobis (2-methylbutyronitrile), azobis (2 , 2′-isovaleronitrile), non-cyano dimethyl-2,2′-azobisisobutyrate, and the like. Among these, organic peroxides and azo compounds are preferable, and azo compounds are particularly preferable from the viewpoint of easy control of molecular weight and low decomposition temperature.

  The amount of the polymerization initiator is preferably 0.001 to 5 mol, more preferably 0.01 to 2 mol, per mol of the monomer composition.

  In the polymerization, a polymerization chain transfer agent may be further added. Specific examples of the polymerization chain transfer agent include mercaptans such as octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-tetradecyl mercaptan and 2-mercaptoethanol; xanthogen disulfides such as dimethylxanthogen disulfide and diisopropylxanthogen disulfide. ; Thiuram disulfides such as tetramethylthiuram disulfide and tetrabutylthiuram disulfide; halogenated hydrocarbons such as carbon tetrachloride and ethylene bromide; hydrocarbons such as pentaphenylethane; acrolein, methacrolein, allyl alcohol, 2- Ethylhexyl thioglycolate, terbinolene, α-terpinene, γ-terpinene, dipentene, α-methylstyrene dimer, 9,10-dihydroanthracene, , 4-dihydronaphthalene, indene, 1,4-cyclohexadiene unsaturated cyclic hydrocarbon compounds of a diene and the like; 2,5-unsaturated heterocyclic compounds dihydrofuran like, and the like. These polymerization chain transfer agents can be used alone or in admixture of two or more.

  Although the polymerization conditions of the monomer composition vary depending on the type of radical polymerization initiator, monomer, solvent, etc. to be used and cannot be determined unconditionally, the polymerization temperature is usually preferably 30 to 100 ° C., more preferably The polymerization time is preferably 1 to 20 hours. The polymerization atmosphere is preferably an inert gas atmosphere such as nitrogen gas.

  After completion of the polymerization reaction, the produced copolymer can be isolated from the reaction solution by a known method such as reprecipitation or solvent distillation. Further, the obtained copolymer can be purified by repeating reprecipitation or removing unreacted monomers by membrane separation, chromatographic method, extraction method or the like.

  In addition, as described above, the copolymer according to the present invention is a polymerizable containing the (meth) acrylate monomer represented by the general formula (2) and the styrene monomer represented by the structural formula (2). It can be synthesized by radical polymerization of the material. Therefore, the present invention is not limited to this, but according to the present invention, polymerization comprising a (meth) acrylate monomer represented by the general formula (2) and a styrene monomer represented by the structural formula (2). Provided is a method for producing a copolymer, which comprises performing radical polymerization of a functional material.

  In this invention, it is not restricted to the manufacturing method of said copolymer. For example, in the (meth) acrylate monomer represented by the general formula (2), after reacting a monomer in which Ar in the formula is not an aromatic ring functional group with the styrene monomer represented by the structural formula (2) Further, a method by a process of introducing an aromatic ring functional group into the Ar site in the general formula (2) may be used.

<Method for identifying copolymer>
The copolymer can be identified using, for example, a ¹ H-NMR spectrum, an IR spectrum, or the like.
The ¹ H-NMR spectrum can be measured using ¹ H-NMR (500 MHz) (manufactured by JEOL) or the like.
The IR spectrum can be measured using FT-IR Spectrum GX (manufactured by PERKIN ELMER).

(ink)
The ink of the present invention contains water, a water-soluble organic solvent, a coloring material, and a copolymer, and further contains other components as necessary. The copolymer has at least the copolymer of the present invention, but may have other copolymers as necessary, or one type may be used alone, or two or more types may be used. You may use together.

  The copolymer of the present invention can be used for ink production by mixing with other components when the ink is produced. Further, it can be used as a dispersant to be contained in a pigment dispersion used in producing an ink. When used as a dispersant, as in the case of ink production, it contains water, a coloring material, and a copolymer, and if necessary, a pigment dispersion containing other components can be obtained. . As water, a color material, and other components used for the pigment dispersion, the same materials as those used for the ink can be used.

<Ink>
Hereinafter, the organic solvent, water, color material, resin, additive, and the like used for the ink will be described.

<Organic solvent>
The organic solvent used in the present invention is not particularly limited, and a water-soluble organic solvent can be used. Examples thereof include ethers such as polyhydric alcohols, polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds.
Specific examples of the water-soluble organic solvent include, for example, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, Glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-he Polyhydric alcohols such as sundiol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, petriol, ethylene glycol mono Polyhydric alcohol alkyl ethers such as ethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monophenyl ether, ethylene glycol mono Polyhydric alcohol aryl ethers such as benzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl- -N-containing heterocyclic compounds such as pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone, formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, Amides such as N-dimethylpropionamide and 3-butoxy-N, N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane and thiodiethanol, propylene carbonate, Examples thereof include ethylene carbonate.
In addition to functioning as a wetting agent, it is preferable to use an organic solvent having a boiling point of 250 ° C. or lower because good drying properties can be obtained.

A polyol compound having 8 or more carbon atoms and a glycol ether compound are also preferably used. Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and the like.
Specific examples of glycol ether compounds include polyhydric alcohol alkyls such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Examples of ethers include polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

  A polyol compound having 8 or more carbon atoms and a glycol ether compound can improve ink permeability when paper is used as a recording medium.

  The content of the organic solvent in the ink is not particularly limited and can be appropriately selected according to the purpose, but is preferably 10% by mass or more and 60% by mass or less from the viewpoint of the drying property and ejection reliability of the ink, 20 mass% or more and 60 mass% or less are more preferable.

<Water>
The water content in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% by mass or more and 90% by mass or less, and 20% by mass from the viewpoint of ink drying property and ejection reliability. % To 60% by mass is more preferable.

<Color material>
The color material is not particularly limited, and pigments and dyes can be used. An inorganic pigment or an organic pigment can be used as the pigment. These may be used alone or in combination of two or more. A mixed crystal may be used.
As the pigment, for example, a black pigment, a yellow pigment, a magenta pigment, a cyan pigment, a white pigment, a green pigment, an orange pigment, a glossy pigment such as gold or silver, a metallic pigment, or the like can be used.
Carbon black produced by known methods such as contact method, furnace method, thermal method in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow as inorganic pigments Can be used.
Organic pigments include azo pigments, polycyclic pigments (eg, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinofullerone pigments). Dye chelates (for example, basic dye type chelates, acidic dye type chelates), nitro pigments, nitroso pigments, aniline black, and the like can be used. Of these pigments, those having good affinity with the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
Specific examples of pigments include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11). And organic pigments such as metals such as titanium oxide and aniline black (CI Pigment Black 1).
Further, for color use, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, C.I. I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3, 15: 4 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment Green 1, 4, 7, 8, 10, 17, 18, 36, etc.
The dye is not particularly limited, and an acid dye, a direct dye, a reactive dye, and a basic dye can be used. One kind may be used alone, or two or more kinds may be used in combination.
Examples of the dye include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52, 80, 82, 249, 254, 289, C.I. I. Acid Blue 9, 45, 249, C.I. I. Acid Black 1, 2, 24, 94, C.I. I. Food Black 1, 2, C.I. I. Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173, C.I. I. Direct Red 1, 4, 9, 80, 81, 225, 227, C.I. I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, C.I. I. Directed Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive black 3, 4, and 35 are mentioned.

  The content of the color material in the ink is preferably 0.1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass from the viewpoints of improvement in image density, good fixability and ejection stability. It is as follows.

In order to disperse the pigment in the ink, a method of introducing a hydrophilic functional group into the pigment to form a self-dispersing pigment, a method of dispersing the pigment surface by coating with a resin, a method of dispersing using a dispersant, Etc.
Examples of a method for introducing a hydrophilic functional group into a pigment to form a self-dispersing pigment include a self-dispersing pigment that can be dispersed in water by adding a functional group such as a sulfone group or a carboxyl group to the pigment (for example, carbon). Can be used.
As a method for coating the surface of the pigment with a resin and dispersing it, a method in which the pigment is included in microcapsules and can be dispersed in water can be used. This can be paraphrased as a resin-coated pigment. In this case, it is not necessary that all pigments blended in the ink are coated with a resin, and within a range where the effects of the present invention are not impaired, uncoated pigments and partially coated pigments are dispersed in the ink. It may be.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular type dispersant or high-molecular type dispersant represented by a surfactant.
As the dispersant, for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, or the like can be used depending on the pigment.
RT-100 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and naphthalenesulfonic acid Na formalin condensate can also be suitably used as a dispersant.
A dispersing agent may be used individually by 1 type, or may use 2 or more types together.

<Pigment dispersion>
An ink can be obtained by mixing a material such as water or an organic solvent with a color material. Further, it is also possible to produce an ink by mixing a pigment, other water, a dispersant, and the like into a pigment dispersion and mixing a material such as water or an organic solvent.
The pigment dispersion is obtained by dispersing water, a pigment, a pigment dispersant, and other components as required, and adjusting the particle size. For dispersion, a disperser is preferably used.
The particle size of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency is 20 nm or more in terms of maximum number because the pigment dispersion stability is good and the image quality such as ejection stability and image density is also high. 500 nm or less is preferable and 20 nm or more and 150 nm or less are more preferable. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).
The content of the pigment in the pigment dispersion is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good ejection stability and increasing the image density, 0.1% by mass. % To 50% by mass is preferable, and 0.1% to 30% by mass is more preferable.
The pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifugal separator or the like, if necessary.

<Additives>
If necessary, a surfactant, an antifoaming agent, an antiseptic / antifungal agent, a rust inhibitor, a pH adjuster, and the like may be added to the ink.

<Surfactant>
As the surfactant, any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants and anionic surfactants can be used.
There is no restriction | limiting in particular in silicone type surfactant, According to the objective, it can select suitably. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, and side chain both terminal modified polydimethylsiloxane. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene group are particularly preferred because they exhibit good properties as an aqueous surfactant. In addition, as the silicone surfactant, a polyether-modified silicone surfactant can be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the side chain of the Si portion of dimethylsiloxane.
Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. Polyoxyalkylene ether polymer compounds are particularly preferred because of their low foaming properties. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylate. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a perfluoroalkyl ether group in the side chain. Examples thereof include salts of polyoxyalkylene ether polymers. As counter ions of salts in these fluorosurfactants, 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 etc. are mentioned.
Examples of amphoteric surfactants include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Nonionic surfactants include, for example, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan Examples include fatty acid esters and ethylene oxide adducts of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.
These may be used alone or in combination of two or more.

The silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, side Since both ends of the chain are modified with polydimethylsiloxane, a polyether-modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group exhibits good properties as an aqueous surfactant. preferable.
As such a surfactant, an appropriately synthesized product or a commercially available product may be used. Commercially available products can be obtained from, for example, Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., and Kyoeisha Chemical Co., Ltd.
The polyether-modified silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a polyalkylene oxide structure represented by the general formula (S-1) is represented by dimethylpolysiloxane. Examples thereof include those introduced into the side chain of Si part of siloxane.

(In the general formula (S-1), m, n, a, and b represent integers. R and R ′ represent an alkyl group and an alkylene group.)
A commercial item can be used as said polyether modified silicone type surfactant, For example, KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Japan Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Bic Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.), etc. are mentioned.

As the fluorine-based surfactant, a fluorine-substituted compound having 2 to 16 carbon atoms is preferable, and a fluorine-substituted compound having 4 to 16 carbon atoms is more preferable.
Examples of the fluorosurfactant include perfluoroalkyl phosphate compounds, perfluoroalkylethylene oxide adducts, and polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain. Among these, polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain are preferred because of their low foaming properties, and are particularly fluorine-based compounds represented by the general formulas (F-1) and (F-2). A surfactant is preferred.

In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10 and n is preferably an integer of 0 to 40 in order to impart water solubility.
_{C n F 2n + 1- CH 2} CH (OH) CH 2 -O- (CH 2 CH 2 O) a -Y Formula (F-2)
In the compound represented by the general formula (F-2), Y is H, or CnF _{2n + 1} , n is an integer of 1 to 6, or CH ₂ CH (OH) CH ₂ —CnF _{2n + 1,} where n is 4 to 6. An integer, or CpH _{2p + 1} , p is an integer of 1-19. a is an integer of 4-14.
A commercial item may be used as said fluorosurfactant. As this commercial item, for example, Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F -1405, F-474 (all manufactured by Dainippon Ink & Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all are corporations) (Manufactured by Male), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (Omnova), Unidyne DSN-403N (produced by Daikin Industries, Ltd.), and the like. Among these, FS-300 manufactured by Du Pont, FT-110, FT-250 manufactured by Neos Co., Ltd., and the like, have excellent print quality, particularly color developability, paper permeability, wettability, and leveling. FT-251, FT-400S, FT-150, FT-400SW, Polyfox PF-151N manufactured by Omninova, and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferable.

  There is no restriction | limiting in particular as content of surfactant in an ink, Although it can select suitably according to the objective, From the point which is excellent in wettability and discharge stability, and image quality improves, it is 0.001 mass. % To 5% by mass is preferable, and 0.05% to 5% by mass is more preferable.

<Antifoaming agent>
There is no restriction | limiting in particular as an antifoamer, For example, a silicone type antifoamer, a polyether type | system | group antifoamer, a fatty-acid ester type | system | group antifoamer etc. are mentioned. These may be used alone or in combination of two or more. Among these, a silicone type antifoaming agent is preferable from the viewpoint of excellent foam breaking effect.

<Antiseptic and antifungal agent>
The antiseptic / antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

<Rust preventive>
There is no restriction | limiting in particular as a rust preventive agent, For example, acidic sulfite, sodium thiosulfate, etc. are mentioned.

<PH adjuster>
The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

There is no restriction | limiting in particular as a physical property of an ink, According to the objective, it can select suitably, For example, it is preferable that a viscosity, surface tension, pH, etc. are the following ranges.
The viscosity at 25 ° C. of the ink is preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa · s or less from the viewpoint of improving the printing density and character quality and obtaining good discharge properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. Measurement conditions are 25 ° C., standard cone rotor (1 ° 34 ′ × R24), sample liquid amount 1.2 mL, rotation speed 50 rpm, and measurement is possible for 3 minutes.
The surface tension of the ink is preferably 35 mN / m or less and more preferably 32 mN / m or less at 25 ° C. from the viewpoint that the ink is suitably leveled on the recording medium and the drying time of the ink is shortened.
The pH of the ink is preferably 7 to 12 and more preferably 8 to 11 from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

<Recording medium>
The recording medium used for recording is not particularly limited, and examples thereof include plain paper, glossy paper, special paper, cloth, film, OHP sheet, and general-purpose printing paper.

<Recorded material>
The ink recorded matter of the present invention has an image formed using the ink of the present invention on a recording medium.
Recording can be performed by recording with an inkjet recording apparatus and an inkjet recording method.

<Recording apparatus and recording method>
The ink of the present invention can be suitably used for various recording apparatuses using an ink jet recording method, such as a printer, a facsimile apparatus, a copying apparatus, a printer / fax / copier complex machine, and a three-dimensional modeling apparatus.
In the present invention, the recording apparatus and the recording method are an apparatus capable of ejecting ink, various treatment liquids, and the like to a recording medium, and a method of performing recording using the apparatus. The recording medium means a medium on which ink or various processing liquids can be temporarily attached.
The recording apparatus can include not only a head portion that ejects ink but also means for feeding, transporting, and discharging a recording medium, and other devices called pre-processing devices and post-processing devices. .
The recording apparatus and the recording method may include a heating unit used in the heating step and a drying unit used in the drying step. The heating means and the drying means include, for example, a means for heating and drying the printing surface and the back surface of the recording medium. Although it does not specifically limit as a heating means and a drying means, For example, a warm air heater and an infrared heater can be used. Heating and drying can be performed before printing, during printing, after printing, and the like.
Further, the recording apparatus and the recording method are not limited to those in which significant images such as characters and figures are visualized by ink. For example, what forms patterns, such as a geometric pattern, etc. includes what forms a three-dimensional image.
Further, the recording apparatus includes both a serial type apparatus that moves the ejection head and a line type apparatus that does not move the ejection head, unless otherwise specified.
Furthermore, this recording apparatus can use not only a desktop type but also a wide recording apparatus that can print on an A0 size recording medium, for example, a continuous paper wound up in a roll shape as a recording medium. Also included are continuous paper printers.
An example of the recording apparatus will be described with reference to FIGS. FIG. 1 is a perspective view of the apparatus. FIG. 2 is an explanatory perspective view of the main tank. An image forming apparatus 400 as an example of a recording apparatus is a serial type image forming apparatus. A mechanism unit 420 is provided in the exterior 401 of the image forming apparatus 400. Each ink storage portion 411 of the main tank 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), yellow (Y) is packaged, for example, an aluminum laminate film It is formed by a member. The ink storage unit 411 is stored in, for example, a plastic container case 414. As a result, the main tank 410 is used as an ink cartridge for each color.
On the other hand, a cartridge holder 404 is provided on the inner side of the opening when the cover 401c of the apparatus main body is opened. A main tank 410 is detachably attached to the cartridge holder 404. Thus, the ink discharge ports 413 of the main tank 410 and the discharge heads 434 for the respective colors communicate with each other via the supply tubes 436 for the respective colors, and ink can be discharged from the discharge heads 434 to the recording medium.

The recording apparatus can include not only a portion that ejects ink but also a device called a pre-processing device or a post-processing device.
As one mode of the pretreatment device and the posttreatment device, as in the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y), a pretreatment liquid and a posttreatment liquid are included. There is a mode in which a liquid container and a liquid discharge head are added, and a pretreatment liquid and a posttreatment liquid are discharged by an ink jet recording method.
As another aspect of the pretreatment apparatus and the posttreatment apparatus, there is an aspect in which, for example, a pretreatment apparatus or a posttreatment apparatus other than the ink jet recording method is provided by a blade coating method, a roll coating method, or a spray coating method.

  The method of using the ink is not limited to the ink jet recording method, and can be widely used. Besides the ink jet recording method, for example, a blade coating method, a gravure coating method, a bar coating method, a roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, a spray coating method and the like can be mentioned.

The use of the ink of the present invention is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be applied to printed materials, paints, coating materials, foundations and the like. Furthermore, it can be used not only to form two-dimensional characters and images using ink, but also as a three-dimensional modeling material for forming a three-dimensional three-dimensional image (three-dimensional modeled object).
A known three-dimensional modeling apparatus for modeling a three-dimensional model can be used, and is not particularly limited. For example, a three-dimensional modeling apparatus including an ink storage unit, a supply unit, a discharge unit, a drying unit, or the like is used. be able to. The three-dimensional structure includes a three-dimensional structure obtained by repeatedly applying ink. Further, a molded product obtained by processing a structure provided with ink on a substrate such as a recording medium is also included. The molded product is obtained by subjecting a recorded material or a structure formed in a sheet shape or a film shape to a molding process such as heat stretching or punching, for example, an automobile, an OA device, an electric -It is suitably used for applications in which surfaces are decorated after decorating, such as meters for electronic devices, cameras, etc., and panels for operation units.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example. “Part” represents “part by mass” unless otherwise specified, and “%” represents “% by mass” unless otherwise specified.

(Synthesis Example 1)
<Synthesis of Copolymer 1>
-Polymerization of (meth) acrylate monomer and styrene monomer-
In a reaction vessel, 20 parts of methyl ethyl ketone, 0.04 part of a polymerization chain transfer agent (2-mercaptoethanol), 9.6 parts of polypropylene glycol monomethacrylate monomer (Blenmer PP-500, Nippon Oil & Fat Co., Ltd.), and styrene monomer 0.4 parts was mixed and nitrogen gas substitution was fully performed to obtain a mixed solution.
Meanwhile, in the dropping funnel, 86.3 parts of the polypropylene glycol monomethacrylate monomer (Blenmer PP-500, Nippon Oil & Fat Co., Ltd.) and 3.7 parts of styrene monomer were charged, and then polymerization chain transfer agent (2-mercaptoethanol) 0 .36 parts by weight, 60 parts by weight of methyl ethyl ketone and 1.2 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) were mixed and sufficiently substituted with nitrogen gas to obtain a mixed solution.
Under a nitrogen atmosphere, the temperature of the mixed solution in the reaction vessel was increased to 65 ° C. while stirring, and the mixed solution in the dropping funnel was gradually dropped into the reaction vessel over 3 hours. After completion of the dropwise addition, the liquid temperature of the mixed solution was maintained at 65 ° C. for 2 hours, and then a solution in which 0.3 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in 5 parts by weight of methyl ethyl ketone was prepared. In addition to the mixed solution, the mixture was further aged at 65 ° C. for 2 hours and at 70 ° C. for 2 hours to obtain a polymer solution. The disappearance of the monomer was confirmed by performing ¹ H-NMR measurement. A portion of the resulting polymer solution was isolated by drying at 105 ° C. under reduced pressure for 2 hours and removing the solvent.

-Introduction of aromatic ring functional groups-
10 parts of the obtained polymer was dissolved again in 100 parts of methyl ethyl ketone, 0.022 part of phosphorus tribromide was added, and the mixture was stirred for 3 hours. After completion of the reaction, the reaction solution was poured into water, extracted with methyl ethyl ketone, and methyl ethyl ketone was added until the methyl ethyl ketone extract was 100 parts. Further, a mixture of 0.010 part of naphthalene and 0.012 part of AlCl ₃ dissolved in 100 parts of methyl ethyl ketone was stirred and heated at reflux temperature, and 100 parts of methyl ethyl ketone extract was added dropwise. The reaction mixture was heated under reflux until the evaporation of hydrogen chloride ceased (5 hours) to distill off the solution. A portion of this solution was dried at 160 ° C. under reduced pressure for 3 hours to remove the solvent, and then the dried product was added to hexane, and copolymer 1 was precipitated and isolated.

The structure of the obtained copolymer is shown in Table 1.
Further, structural analysis of the obtained copolymer 1 by ¹ H-NMR spectrum and IR spectrum revealed that the formula weight of the repeating unit of the copolymer 1 was 5080. Thereby, the HLB value by the Griffin method was calculated from the following formula (the following synthesis examples are also the same).
HLB = 20 × (formula weight of hydrophilic part of copolymer repeating unit / formula weight of copolymer repeating unit)
The formula amount of the hydrophilic part of the repeating unit of the copolymer was 3168.

(Synthesis Example 2)
In the process of “polymerization of (meth) acrylate monomer and styrene monomer” in Synthesis Example 1, the number of parts of the monomer put into the reaction vessel is changed to 9.3 parts of polypropylene glycol monomethacrylate monomer (Blenmer PP-500, NOF Corporation). The styrene monomer was changed to 0.7 parts. Also, the number of parts of the monomer to be placed in the dropping funnel was changed to 83.9 parts of polypropylene glycol monomethacrylate monomer (Blenmer PP-500, Nippon Oil & Fats Co., Ltd.), and the same was performed except that the styrene monomer was changed to 6.1 parts. Thus, a copolymer 2 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 2 was 2772, and the formula amount of the repeating unit of the copolymer 2 was 4575.

(Synthesis Example 3)
In the process of “polymerization of (meth) acrylate monomer and styrene monomer” in Synthesis Example 1, polypropylene glycol monomethacrylate monomer (Blenmer PP-500, Nippon Oil & Fat Co., Ltd.) was changed to polypropylene glycol monoacrylate monomer (Blenmer AP-400, Nippon Oil & Fat Co., Ltd.). Company). The number of parts of the monomer placed in the reaction vessel was changed to 9.5 parts of polypropylene glycol monoacrylate monomer (Blenmer AP-400, Nippon Oil & Fat Co., Ltd.), and the styrene monomer was changed to 0.5 parts. Moreover, it changed similarly that the number of parts of the monomer put into the dropping funnel was changed to 85.9 parts of polypropylene glycol monoacrylate monomer (Blemmer AP-400, Nippon Oil & Fats Co., Ltd.), and the styrene monomer was changed to 4.1 parts. Copolymer 3 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 3 was 2688, and the formula amount of the repeating unit of the copolymer 3 was 4600.

(Synthesis Example 4)
In the synthesis of “(Meth) acrylate monomer and styrene monomer” in Synthesis Example 3, the number of monomers to be placed in the reaction vessel was changed to 9.2 parts of polypropylene glycol monoacrylate monomer (Blemmer AP-400, NOF Corporation). The styrene monomer was changed to 0.8 part. Moreover, it changed similarly that the number of parts of the monomer put into the dropping funnel was changed to 83.2 parts of polypropylene glycol monoacrylate monomer (Blemmer AP-400, Nippon Oil & Fat Co., Ltd.), and styrene monomer was changed to 6.8 parts. Copolymer 4 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 4 was 2352, and the formula amount of the repeating unit of the copolymer 4 was 4155.

(Synthesis Example 5)
In the process of “polymerization of (meth) acrylate monomer and styrene monomer” in Synthesis Example 1, polypropylene glycol monomethacrylate monomer (Blenmer PP-500, Nippon Oil & Fat Co., Ltd.) was changed to polypropylene glycol monoacrylate monomer (Blenmer AP-550, Nippon Oil & Fats Co., Ltd.). Company). The number of parts of the monomer placed in the reaction vessel was changed to 9.7 parts of polypropylene glycol monoacrylate monomer (Blenmer AP-550, Nippon Oil & Fat Co., Ltd.), and the styrene monomer was changed to 0.3 part. Moreover, it changed similarly that the number of parts of the monomer put into the dropping funnel was changed to 87.6 parts of polypropylene glycol monoacrylate monomer (Blenmer AP-550, Nippon Oil & Fats Co., Ltd.), and the styrene monomer was changed to 2.4 parts. Copolymer 5 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 5 was 5824, and the formula amount of the repeating unit of the copolymer 5 was 7736.

(Synthesis Example 6)
In the “polymerization of (meth) acrylate monomer and styrene monomer” process of Synthesis Example 5, the number of monomers to be placed in the reaction vessel was changed to 9.5 parts of polypropylene glycol monoacrylate monomer (Blenmer AP-550, Nippon Oil & Fat Co., Ltd.). The styrene monomer was changed to 0.5 part. Moreover, it changed similarly that the number of parts of the monomer put into the dropping funnel was changed to 85.9 parts of a polypropylene glycol monoacrylate monomer (Blemmer AP-550, Nippon Oil & Fats Co., Ltd.) and the styrene monomer was changed to 4.1 parts. Copolymer 6 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 6 was 5096, and the formula amount of the repeating unit of the copolymer 6 was 6899.

(Synthesis Example 7)
In the process of “polymerization of (meth) acrylate monomer and styrene monomer” in Synthesis Example 1, polypropylene glycol monomethacrylate monomer (Blenmer PP-500, Nippon Oil & Fat Co., Ltd.) was converted to polyethylene glycol monomethacrylate monomer (Blenmer PE-200, Nippon Oil & Fat Co., Ltd.). Company). The number of parts of the monomer placed in the reaction vessel was changed to 9.4 parts of polyethylene glycol monomethacrylate monomer (Blenmer PE-200, Nippon Oil & Fat Co., Ltd.), and the styrene monomer was changed to 0.6 parts. Moreover, it changed similarly that the number of parts of the monomer put into the dropping funnel was changed to 84.9 parts of polyethylene glycol monomethacrylate monomer (Blemmer PE-200, Nippon Oil & Fats Co., Ltd.), and the styrene monomer was changed to 5.1 parts. Copolymer 7 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 7 was 1760, and the formula amount of the repeating unit of the copolymer 7 was 3672.

(Synthesis Example 8)
In the process of Synthesis Example 7, “polymerization of (meth) acrylate monomer and styrene monomer”, the number of parts of the monomer put into the reaction vessel was changed to 9.1 parts of polyethylene glycol monomethacrylate monomer (Blenmer PE-200, Nippon Oil & Fat Co., Ltd.). The styrene monomer was changed to 0.9 part. Moreover, it changed similarly that the number of parts of the monomer put into the dropping funnel was changed to 81.6 parts of polyethylene glycol monomethacrylate monomer (Blemmer PE-200, Nippon Oil & Fats Co., Ltd.) and styrene monomer was changed to 8.4 parts. Copolymer 8 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 8 was 1540, and the formula amount of the repeating unit of the copolymer 8 was 3343.

(Synthesis Example 9)
In the process of “polymerization of (meth) acrylate monomer and styrene monomer” in Synthesis Example 7, the number of monomers to be placed in the reaction vessel was changed to 9.7 parts of polyethylene glycol monomethacrylate monomer (Blenmer PE-200, Nippon Oil & Fat Co., Ltd.). The styrene monomer was changed to 0.3 part. Moreover, it changed similarly that the number of parts of the monomer put into the dropping funnel was changed to 87.7 parts of polyethylene glycol monomethacrylate monomer (Blemmer PE-200, Nippon Oil & Fats Co., Ltd.), and styrene monomer was changed to 2.3 parts. Copolymer 9 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 9 was 1980, and the formula amount of the repeating unit of the copolymer 9 was 4001.

(Synthesis Example 10)
In the process of “polymerization of (meth) acrylate monomer and styrene monomer” in Synthesis Example 7, the number of monomers to be placed in the reaction vessel was changed to 8.6 parts of polyethylene glycol monomethacrylate monomer (Blenmer PE-200, Nippon Oil & Fat Co., Ltd.). The styrene monomer was changed to 1.4 parts. Moreover, it changed similarly that the number of parts of the monomer put into the dropping funnel was changed to 77.6 parts of polyethylene glycol monomethacrylate monomer (Blenmer PE-200, Nippon Oil & Fats Co., Ltd.) and styrene monomer was changed to 12.4 parts. Copolymer 10 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 10 was 1320, and the formula amount of the repeating unit of the copolymer 10 was 3014.

(Synthesis Example 11)
In the same manner as in Synthesis Example 8 except that 0.010 part of naphthalene was changed to 0.006 part of benzene and the reaction time was changed from 5 hours to 7 hours in the process of “introduction of aromatic ring functional group”. 11 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 11 was 1960, and the formula amount of the repeating unit of the copolymer 11 was 3413.

(Synthesis Example 12)
A copolymer was prepared in the same manner as in Synthesis Example 3 except that 0.010 part of naphthalene was changed to 0.006 part of benzene and the reaction time was changed from 5 hours to 7 hours. 12 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 12 was 2352, and the formula amount of the repeating unit of the copolymer 12 was 3805.

(Synthesis Example 13)
A copolymer 13 was obtained in the same manner as in Synthesis Example 9 except that the “introduction of aromatic ring functional group” process was not performed.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 13 was 1980, and the formula amount of the repeating unit of the copolymer 13 was 2858.

(Synthesis Example 14)
A copolymer 14 was obtained in the same manner as in Synthesis Example 10 except that the “introduction of aromatic ring functional group” process was not performed.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 14 was 1320, and the formula amount of the repeating unit of the copolymer 14 was 2252.

(Synthesis Example 15)
In the process of “polymerization of (meth) acrylate monomer and styrene monomer” in Synthesis Example 1, polypropylene glycol monomethacrylate monomer (Blenmer PP-500, Nippon Oil & Fat Co., Ltd.) was converted to polyethylene glycol monoacrylate monomer (Blenmer AP-90, Nippon Oil & Fats Co., Ltd.). Company). The number of parts of the monomer placed in the reaction vessel was changed to 8.1 parts of polyethylene glycol monoacrylate monomer (Blemmer AP-90, Nippon Oil & Fat Co., Ltd.), and the styrene monomer was changed to 1.9 parts. Moreover, it changed similarly that the number of parts of the monomer put into the dropping funnel was changed to 73.1 parts of polyethylene glycol monoacrylate monomer (Blemmer AP-90, Nippon Oil & Fats Co., Ltd.) and the styrene monomer was changed to 16.9 parts. Copolymer 15 was obtained. The copolymer 15 was insoluble in water, and the aqueous solution was cloudy.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 15 was 528, and the formula amount of the repeating unit of the copolymer 15 was 2222.

(Synthesis Example 16)
In the process of “polymerization of (meth) acrylate monomer and styrene monomer” in Synthesis Example 1, polypropylene glycol monomethacrylate monomer (Blenmer PP-500, Nippon Oil & Fat Co., Ltd.) was replaced with methoxypolyethylene glycol monomethacrylate monomer (Blenmer PME-1000, Nippon Oil & Fats). Changed to KK). The number of parts of the monomer placed in the reaction vessel was changed to 9.9 parts of methoxypolyethylene glycol monomethacrylate monomer (Blemmer PME-1000, Nippon Oil & Fat Co., Ltd.), and the styrene monomer was changed to 0.1 part. Further, the number of parts of the monomer placed in the dropping funnel was changed to 89.1 parts of methoxypolyethylene glycol monomethacrylate monomer (Blemmer PME-1000, Nippon Oil & Fats Co., Ltd.), and the same procedure was performed except that the styrene monomer was changed to 0.1 part. Thus, a copolymer 16 was obtained.
The structure of the obtained copolymer is shown in Table 1. Moreover, the formula amount of the hydrophilic part of the repeating unit of the obtained copolymer 16 was 9108, and the formula amount of the repeating unit of the copolymer 16 was 10112.

(Pigment dispersion 1)
After premixing the following mixture, it was circulated and dispersed for 10 minutes at a peripheral speed of 10 m / s with a disk-type bead mill (Shinmaru Enterprises Co., Ltd., KDL type, media: using zirconia balls with a diameter of 0.1 mm), and the pore size was 1 A pigment dispersion 1 was obtained by filtration through a 2 μm membrane filter.
[blend]
Carbon black (NIPEX 160, manufactured by Degussa) 16.0 parts by mass A 10% by weight aqueous solution of copolymer 1 32.0 parts by weight Pure water 52.0 parts by weight

(Pigment dispersion 2)
A pigment dispersion 2 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 2 in the preparation of the pigment dispersion 1.

(Pigment dispersion 3)
A pigment dispersion 3 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 3 in the preparation of the pigment dispersion 1.

(Pigment dispersion 4)
A pigment dispersion 4 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 4 in the preparation of the pigment dispersion 1.

(Pigment dispersion 5)
A pigment dispersion 5 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 5 in the preparation of the pigment dispersion 1.

(Pigment dispersion 6)
A pigment dispersion 6 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 6 in the preparation of the pigment dispersion 1.

(Pigment dispersion 7)
A pigment dispersion 7 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 7 in the preparation of the pigment dispersion 1.

(Pigment dispersion 8)
A pigment dispersion 8 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 8 in the preparation of the pigment dispersion 1.

(Pigment dispersion 9)
A pigment dispersion 9 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 9 in the preparation of the pigment dispersion 1.

(Pigment dispersion 10)
A pigment dispersion 10 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 10 in the preparation of the pigment dispersion 1.

(Pigment dispersion 11)
A pigment dispersion 11 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 11 in the preparation of the pigment dispersion 1.

(Pigment dispersion 12)
A pigment dispersion 12 was produced in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 12 in the production of the pigment dispersion 1.

(Pigment dispersion 13)
A pigment dispersion 13 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 13 in the preparation of the pigment dispersion 1.

(Pigment dispersion 14)
A pigment dispersion 14 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 14 in the preparation of the pigment dispersion 1.

(Pigment dispersion 15)
The pigment dispersion 1 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 15. However, the copolymer was insoluble in water and the pigment was appropriately dispersed. Thus, a pigment dispersion could not be prepared.

(Pigment dispersion 16)
A pigment dispersion 16 was prepared in the same manner as the pigment dispersion 1 except that the copolymer 1 was changed to the copolymer 16 in the preparation of the pigment dispersion 1.

Example 1
The following materials were mixed, stirred for 1.5 hours, and filtered through a membrane filter having a pore size of 1.2 μm to obtain an ink.
[material]
Pigment dispersion 1 (pigment solid content 20% by mass) 40.0 parts by mass 1,3-butanediol (water-soluble organic solvent) 20.0 parts by mass Glycerin (water-soluble organic solvent) 10.0 parts by mass 2-ethyl-1,3-hexanediol (water-soluble organic solvent) 1.0 part by mass ・ 2,2,4-trimethyl-1,3-pentanediol 1.0 part by mass (water-soluble organic solvent)
-Fluorosurfactant 1.0 part by mass (100% solids, manufactured by Daikin Industries, Unidyne DSN-403N)
・ 27.0 parts by mass of distilled water

  The obtained ink was evaluated as follows. The evaluation results are shown in Table 1.

(Example 2)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 2 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Example 3)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 3 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

Example 4
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 4 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Example 5)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 5 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Example 6)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 6 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Example 7)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 7 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Example 8)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 8 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

Example 9
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 9 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Example 10)
Ink was prepared in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 10 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Example 11)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 11 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Example 12)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 12 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Comparative Example 1)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 13 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Comparative Example 2)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 14 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Comparative Example 3)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 15 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

(Comparative Example 4)
Ink was produced in the same manner as in Example 1 except that the pigment dispersion 1 was changed to the pigment dispersion 16 in Example 1, and the same evaluation was performed. The evaluation results are shown in Table 1.

<Ink storage stability>
Each ink was filled in an ink cartridge and stored at 70 ° C. for 2 weeks. The change rate of the viscosity after storage with respect to the viscosity before storage was obtained from the following formula and evaluated according to the following criteria.
Viscosity change rate (%) = (ink viscosity after storage / ink viscosity before storage) × 100
The viscosity was measured using a viscometer (RE500L, manufactured by Toki Sangyo Co., Ltd.), adjusted to 50 or 100 rotations according to the viscosity of the sample, and evaluated based on the following criteria. . C or higher is practical.

[Evaluation criteria]
A: Change rate of viscosity is within ± 5% B: Change rate of viscosity is over ± 5% and within ± 8% C: Change rate of viscosity is over ± 8% and within ± 10% D: Change rate of viscosity is Over ± 10% and within ± 30% E: Viscosity change rate exceeds ± 30% (cannot be evaluated due to gelation)

As is clear from the above description and the results in Table 1, the pigment dispersions using the copolymers of Examples 1 to 12 are excellent in dispersibility, but further exhibit high solvent stability. Excellent long-term stability. Particularly in Examples 1 to 4, since the balance of hydrophilicity / hydrophobicity of the copolymer is appropriately controlled, the long-term stability of the ink is particularly excellent.
On the other hand, in Comparative Examples 1 and 2, since Ar in the general formula (1) is not an aromatic ring functional group, the adsorptivity to the pigment is low and the solvent stability is low. Further, even if Ar in the general formula (1) is an aromatic ring functional group, if the calculated value of HLB (balance of hydrophilicity / hydrophobicity) of the copolymer is not appropriate, the dispersibility is low, and the solvent stability Is not enough. In addition, when the calculated HLB value of the copolymer is lower than an appropriate value, the copolymer becomes insoluble in water as in Comparative Example 3, and the function of the copolymer cannot be obtained.

  As described above, according to the present invention, a copolymer that exhibits good dispersibility in the preparation of a pigment dispersion and maintains high dispersion stability even when an organic solvent is added during preparation of an aqueous ink, and long-term stability Ink, an ink cartridge, and a recording apparatus can be provided.

400 Image forming apparatus 401 Exterior of image forming apparatus 401c Cover of apparatus main body 404 Cartridge holder 410 Main tank 410k, 410c, 410m, 410y For each color of black (K), cyan (C), magenta (M), yellow (Y) Main tank 411 Ink storage section 413 Ink discharge port 414 Storage container case 420 Mechanism section 434 Discharge head 436 Supply tube

JP-A-6-306317 JP 2004-75988 A JP 2011-105866 A

W. C. Griffin, J. Soc. Cosmetic Chem., 5 (4), 249-256 (1954). Table 1 Copolymer Structure

Claims (7)

It has a structural unit (1) represented by the following general formula (1) and a structural unit (2) represented by the following structural formula (1),
A copolymer having a calculated HLB value of 8.8 or more and 15.1 or less by the Griffin method.

Wherein R is a hydrogen atom or a methyl group, A is an alkyl ether represented by (CH ₂ CH ₂ O) m or (CH ₂ CH (CH ₃ ) O) m, and Ar is an aromatic ring functional group. And m is an arbitrary integer.)

  The copolymer according to claim 1, wherein a ratio of the structural unit (2) to a total of the structural unit (1) and the structural unit (2) is 20 mol% or more and 30 mol% or less.   The copolymer according to claim 1 or 2, wherein the m is 6 or more and 13 or less.   An ink comprising water, a water-soluble organic solvent, a coloring material, and a copolymer, wherein the copolymer is the copolymer according to any one of claims 1 to 3.   A recorded matter comprising an image formed using the ink according to claim 4.   An ink cartridge comprising the ink according to claim 4 contained in a container.   A recording apparatus comprising the ink cartridge according to claim 6.

Images