JP6175352B2 - Ink jet recording ink, ink container, ink jet recording apparatus, method for producing recorded matter, recorded matter - Google Patents

Description

  The present invention relates to an inkjet recording ink.

  In recent years, as an image forming method, since the process is simple and full color can be easily obtained as compared with other recording methods, there is an advantage that a high-resolution image can be obtained even with an apparatus having a simple configuration. The method has become widespread. The ink jet recording method is a method in which a small amount of ink is ejected by an ink jet recording apparatus and is deposited on a recording medium such as paper, and the application has been expanded to personal and industrial printers and printing.

  Ink jet recording apparatuses mainly use water-based ink using a water-soluble dye as a colorant, but the dye ink has a disadvantage that it is inferior in weather resistance and water resistance. Therefore, in recent years, research on pigment inks using pigments instead of water-soluble dyes has been advanced. However, the pigment ink is still inferior in color development, ink ejection stability, and storage stability to the dye ink. In addition, with the improvement of image quality improvement technology for OA printers, image density equivalent to that of dye ink is required for both pigment ink and plain paper as a recording medium. However, when plain paper is used as a recording medium, the pigment ink has a problem that the pigment density on the paper surface is lowered by penetrating into the paper and the image density is lowered. In order to increase the drying speed of the ink adhering to the recording medium for high-speed printing, a means is taken to accelerate drying by adding a penetrant to the ink and allowing water to penetrate into the recording medium. Not only that, the penetrability of the pigment into the recording medium is increased, and the image density is further lowered.

  Various methods have been proposed for improving the image density. For example, Patent Document 1 discloses a water-based ink for ink-jet recording comprising carbon black or an organic pigment, a polymer, a basic substance, and water as essential components. At this time, the ink comprises a copolymer obtained by polymerizing (meth) acrylic acid and another copolymerizable monoethylenically unsaturated monomer as essential components, and a phosphate group-containing monoethylenically unsaturated monomer. It contains a copolymer obtained by polymerizing a monomer and other copolymerizable monoethylenically unsaturated monomers as essential components. Patent Document 2 discloses an ink used for recording on paper containing a water-soluble polyvalent metal salt. At this time, the ink includes (a) a pigment, (b) a functional group having no surface activity, a molecular weight of 150 or more and 10,000 or less, and having phosphoric acid as a basic skeleton in the molecular structure. And a phosphoric acid-based functional group and a phosphonic acid as a basic skeleton having a phosphorus content ((P content / molecular weight) x 100) of 1.4 or more. It contains at least one compound having a functional group selected from functional groups, and (b) the content (% by mass) of the compound is 1.5% by mass or more and 10.0% by mass based on the total mass of the ink. It is characterized by the following. Further, Patent Document 3 discloses an aqueous colorant dispersion comprising a polymer containing a hydrophobic structural unit and a hydrophilic structural unit, a colorant, and an aqueous liquid medium, and an aqueous ink for inkjet recording including the same. At this time, the polymer containing a hydrophobic structural unit and a hydrophilic structural unit is a hydrophobic structural unit containing a hydrophobic structural unit containing a benzene ring that is not directly bonded to an atom forming the main chain of the polymer. The hydrophilic structural unit includes a hydrophilic structural unit containing an ionic group, and the structural unit different from the hydrophobic structural unit and the hydrophilic structural unit exceeds 15% by mass, and is 90% by mass It is characterized by containing less than.

Patent Document 1 exemplifies the monomer represented by (Formula 5) of the present invention as a phosphoric acid group-containing monoethylenically unsaturated monomer, and (Formula 5), (Formula 6), and (Formula 7) are There is no illustration of the copolymer used or the copolymer using (Formula 5), (Formula 6), and (Formula 8), and the effect on improving pigment dispersion stability is not described.
On the other hand, in Patent Document 2, a copolymer using (Formula 5), (Formula 6), and (Formula 7) in the present invention, or (Formula 5), (Formula 6), and (Formula 8) were used. There is no exemplification of the copolymer, and there is no description on the effect of improving the image density, the effect of reducing the strikethrough, and the improvement of the pigment dispersion stability in plain paper having a low content of the water-soluble polyvalent metal salt.
Further, Patent Document 3 exemplifies (Formula 8) of the present invention as a hydrophobic structural unit of a polymer, but the image density when the monomers of (Formula 5) and (Formula 6) of the present invention are used in combination. The improvement effect is not described.
In the methods of Patent Documents 1, 2, and 3, it is not possible to achieve both high image density, low strikethrough density, and dispersion stabilization of the pigment as the pigment dispersion and ink.

An object of the present invention is to solve the above-described problems and achieve the following objects.
That is, an object of the present invention is to provide an ink for ink jet recording, which can obtain a high image density even on plain paper, has reduced strikethrough, and has good dispersion stability of the pigment dispersion and the pigment as the ink. To do.

  As a result of intensive studies, the present inventors have used a copolymer having a phosphate group and a specific structural unit as a component of the ink for ink-jet recording, so that the ink for ink-jet recording aggregates on the surface of plain paper, As a result of the pigment remaining on the paper surface, a high image density can be obtained even on plain paper, and the present invention has been found out that the dispersion of the pigment as a pigment dispersion and ink is stable.

（式１）中のＲ1は、水素原子またはメチル基を表す。Ｍは、水素原子またはアルカリ金属、有機アンモニウムを表す。ｎ，ｍはそれぞれ０から６の整数を表す（但し、ｎ、ｍの値は同時に０であってはならない）。

（式３）中のＲ2は水素原子またはメチル基を表す。

（式４）中のＲ3は水素原子またはメチル基を表す。 That is, the above-described problem is an ink for inkjet recording having at least water, a water-soluble solvent, a pigment, and a copolymer containing a phosphate group, wherein the copolymer containing a phosphate group is represented by (formula 1). The inkjet recording ink has at least the structural unit represented by (Formula 2) and the structural unit represented by (Formula 3) or (Formula 4).

R1 in (Formula 1) represents a hydrogen atom or a methyl group. M represents a hydrogen atom, an alkali metal, or organic ammonium. n and m each represent an integer of 0 to 6 (provided that the values of n and m must not be 0 at the same time).

R2 in (Formula 3) represents a hydrogen atom or a methyl group.

R3 in (Formula 4) represents a hydrogen atom or a methyl group.

  The ink for ink jet recording of the present invention can obtain a high image density even on plain paper, the back-through is reduced, and the dispersion stability of the pigment dispersion and the pigment as the ink is good.

It is a schematic plan view for demonstrating an example of the ink storage container of this invention. FIG. 2 is a schematic plan view including a case (exterior) of the ink container of the present invention shown in FIG. 1. 1 is a perspective view showing an example of a serial type ink jet recording apparatus of the present invention. FIG. 4 is a partially enlarged sectional view of the ink jet recording apparatus shown in FIG. 3. FIG. 4 is another partially enlarged sectional view of the ink jet recording apparatus shown in FIG. 3.

In the inkjet recording ink of the present invention, the copolymer containing a phosphate group is represented by the structural unit represented by (Formula 1), the structural unit represented by (Formula 2), and (Formula 3) or (Formula 4). It is characterized by having at least a structural unit represented by
The phosphoric acid group of (Formula 1) has hydrophilicity, but has a characteristic of reacting with ions such as calcium ion, magnesium ion, and aluminum ion to make it hydrophobic. Therefore, ink for inkjet recording using a copolymer containing a phosphoric acid group as a pigment dispersant dissolves from the recording medium when the pigment dispersant adsorbed on the pigment is used in a recording medium containing a water-soluble polyvalent metal salt. The pigment agglomerates by reacting with the polyvalent metal ions and making it hydrophobic. As a result, the penetration of the pigment into the paper is suppressed, and a high image density and a low back-through density can be obtained.
However, in PPC plain paper that does not contain water-soluble polyvalent metal salts, the amount of metal ions eluted from the recording medium is small, and the effects of image density improvement and back-through density reduction due to pigment aggregation are insufficient. there were.

  As a method for solving the above problems, a method of increasing the ratio of (formula 1) of a copolymer containing a phosphate group, or a method of increasing the ratio of the hydrophobic structural unit of the pigment dispersant to enhance the adsorption of the dispersant and the pigment. Can be considered. However, if the composition ratio of (Formula 1) is increased, the interaction between phosphoric acid groups becomes stronger, or the pigment dispersibility is lowered or the viscosity increases when the pigment dispersion and the water-soluble organic solvent are mixed. There was found. It has also been found that increasing the proportion of hydrophobic structural units decreases the dispersion stability of the pigment in the pigment dispersion and the ink and increases the viscosity.

In the present invention, the following effects can be obtained by combining the structural unit of (Formula 2), (Formula 3) or (Formula 4) in addition to the structural unit of (Formula 1), and the inclusion of the water-soluble polyvalent metal salt Even on plain paper containing only a low-rate or sparingly soluble metal salt, a high image density and a low back-through density can be obtained. Further, the dispersion stability of the pigment in the pigment dispersion and the ink could be ensured. The effect of each structure of (Formula 2), (Formula 3), or (Formula 4) will be described in detail below.
1. The introduction of (Formula 2) increased the affinity of the copolymer for water, making it difficult to increase the viscosity of the copolymer and the pigment dispersion. Therefore, the introduction amount of (Formula 1) was increased and the reactivity with metal ions could be increased.
2. By introducing (Equation 2), the affinity of the copolymer to the water-soluble solvent is increased, the initial viscosity when made into an ink can be kept low, and the storage stability of the ink can also be improved. It was.
3. By introducing (Formula 3) or (Formula 4), the adsorptive power of the copolymer to the pigment was improved, and the pigment was easily aggregated when the copolymer reacted with metal ions. As a result, the image density was improved and the show-through was reduced.

  An ink jet recording apparatus having an ink ejecting means for recording an image on a recording medium by ejecting the ink for ink jet recording of the present invention from a recording head, and applying ink through the ink ejecting means to eject ink from the recording head. If an image is recorded on a recording medium, high density image formation can be realized. Further, if the ink for ink jet recording of the present invention is accommodated in a container to be an ink container, the ink can be easily attached to and detached from the ink container loading portion provided in the ink jet recording apparatus, and stable ink supply for a long period of time can be achieved. It becomes possible. The ink recorded matter of the present invention has high image quality and excellent stability over time, and can be suitably used for various applications as materials on which various prints or images are recorded.

(Copolymer containing phosphate group)
The copolymer containing a phosphate group used in the present invention is represented by a structural unit represented by (Formula 1), a structural unit represented by (Formula 2), and (Formula 3) or (Formula 4). At least a monomer of (Formula 5), (Formula 6) and (Formula 7) or (Formula 8), which is synthesized as a starting material, and is one of the phosphate groups of the copolymer. Part or all is preferably neutralized with a base selected from alkali metals or organic amines.

（式１）中のＲ1は、水素原子またはメチル基を表す。Ｍは、水素原子またはアルカリ金属、有機アンモニウムを表す。ｎ，ｍはそれぞれ０から６の整数を表す（但し、ｎ、ｍの値は同時に０であってはならない）。

（式３）中のＲ2は水素原子またはメチル基を表す。

（式４）中のＲ3は水素原子またはメチル基を表す。

R1 in (Formula 1) represents a hydrogen atom or a methyl group. M represents a hydrogen atom, an alkali metal, or organic ammonium. n and m each represent an integer of 0 to 6 (provided that the values of n and m must not be 0 at the same time).

R2 in (Formula 3) represents a hydrogen atom or a methyl group.

R3 in (Formula 4) represents a hydrogen atom or a methyl group.

（式５）中のＲ4は、水素原子またはメチル基を表す。ｎ，ｍはそれぞれ０から６の整数を表す（但し、ｎ、ｍの値は同時に０であってはならない）。

（式７）中のＲ5は水素原子またはメチル基を表す。

（式８）中のＲ6は水素原子またはメチル基を表す。

R4 in (Formula 5) represents a hydrogen atom or a methyl group. n and m each represent an integer of 0 to 6 (provided that the values of n and m must not be 0 at the same time).

R5 in (Formula 7) represents a hydrogen atom or a methyl group.

R6 in (Formula 8) represents a hydrogen atom or a methyl group.

For example, a solvent in a flask equipped with a stirrer, a thermometer, a nitrogen introduction tube, a monomer of (Formula 5) and (Formula 6), and a monomer of (Formula 7) or (Formula 8) are mixed with nitrogen in the presence of a polymerization initiator. It is obtained by reacting at a temperature of about 50 to 150 ° C. under gas reflux.
Examples of the method for adding the neutralizing agent include a method in which a copolymer containing a phosphate group obtained by the above production method and a neutralizing agent are mixed in a solution. The copolymer containing phosphoric acid groups is dissolved in an organic solvent or water, and a neutralizing agent is added directly to the solution, or a solution in which the neutralizing agent is dissolved in an organic solvent or water is added and stirred. Thereafter, the solvent is removed to obtain a copolymer in which some or all of the phosphate groups are neutralized.
After completion of the polymerization reaction, the produced copolymer containing a phosphate group can be isolated from the reaction solution by a conventionally known method such as reprecipitation or solvent distillation. In addition, a copolymer containing a phosphate group can be purified by repeating reprecipitation or removing unreacted monomers and low molecular weight components by membrane separation, chromatographic methods, extraction methods, and the like.
Details are described in the Examples.
In the present invention, a copolymer in which some or all of the phosphate groups are neutralized is also referred to as a copolymer containing phosphate groups.

The viscosity of the aqueous solution or aqueous dispersion of the copolymer containing phosphate groups can be adjusted by changing the molecular weight, and the monomer concentration during polymerization, the amount of polymerization initiator, the polymerization temperature, and the polymerization time may be changed.
You may add another monomer component to the copolymer containing the said phosphate group.

Examples of (Formula 5) include monomers of (Formula 5-1) to (Formula 5-5).
Examples of (Formula 7) include monomers of (Formula 7-1) and (Formula 7-2).
Examples of (Formula 8) include monomers of (Formula 8-1) and (Formula 8-2).

As the synthesis method, various known synthesis methods such as solution polymerization, suspension polymerization, bulk polymerization, emulsion polymerization and the like can be used. However, since the polymerization operation and the adjustment of the molecular weight are easy, a radical polymerization initiator is used. The method used is preferred.
As the radical polymerization initiator, those generally used can be used, and specifically, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, peroxyesters, cyano series Azobisisobutyronitrile, azobis (2-methylbutyronitrile), azobis (2,2′-isovaleronitrile), non-cyano dimethyl-2,2′-azobisisobutyrate, and the like. . Organic peroxides and azo compounds that can easily control the molecular weight and have a low decomposition temperature are preferable, and azo compounds are more preferable. As for the usage-amount of a polymerization initiator, 1-10 mass% is preferable with respect to the total mass of a polymerizable monomer.
Moreover, in order to adjust the molecular weight of the copolymer containing a phosphate group, mercaptoacetic acid, mercaptopropionic acid, 2-propanethiol, 2-mercaptoethanol, thiophenol, dodecyl mercaptan, 1-dodecanethiol, thioglycerol, etc. An appropriate amount of chain transfer agent may be added to the polymerization system.
A preferable polymerization temperature is 50 to 150 ° C., and a preferable polymerization time is 3 to 48 hours.

The monomer of (Formula 5-1) shows 2-metaquiloxyethyl acid phosphoate. 2-Methacryloxyethyl acid phosphoate is commercially available under the product name “Light Ester P-1M” from Kyoeisha Chemical Industry Co., Ltd. and “Fosmer M” from Unichemical Corporation.
The monomer of (Formula 5-2) represents 2-acryloyl ethyl acid phosphoate. 2-Acroyloxyethyl acid phosphoate is commercially available from Kyoeisha Chemical Industry Co., Ltd. under the product name “Light Acrylate P-1A”.
The monomer of (Formula 5-3) represents acid phosphoxypolyoxyethylene glycol methacrylate.
The monomer of (Formula 5-4) represents acid phosphoxypolyoxypropylene glycol methacrylate.
The monomer of (Formula 5-5) shows acid phosphoxy poly (oxyethylene oxypropylene) glycol methacrylate.
Monomers of (Formula 5-3) and (Formula 5-4) are commercially available under the product names of Unichemical Corporation Phosmer PE and Phosmer PP. The monomer of (Formula 5-5) is a conventionally known compound described in JP-T-2003-506536, and will be referred to as phosmer PEP for convenience in this case.

Moreover, it is preferable that the phosphate group in the copolymer containing the phosphate group of the present invention is ionized by neutralizing a part or all of it with a base. Bases used for neutralization include alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide, ammonium, mono, di or trimethylamine, mono, di or triethylamine, monoethanolamine, diethanolamine, triethanolamine and methylethanol. Amine, methyldiethanolamine, dimethylethanolamine, choline, aminoethanepropanediol, monopropanolamine, dipropanolamine, tripropanolamine, isopropanolamine, trishydroxymethylaminomethane, aminoethylpropanediol, tetramethylammonium, tetraethylammonium, tetra Organic amines such as butylammonium, monophorin, N-methylmonoformin, N-methyl-2pyrrolidone, 2- Organic amines such as cyclic amines, such as pyrrolidone and the like.
It is preferable that M in (Formula 1) constituting the copolymer containing a phosphate group is a hydrogen atom, a potassium atom, or a sodium atom. When M is a hydrogen atom, a potassium atom or a sodium atom, the image density is improved. This is presumably because the pigment tends to aggregate more easily when the counter ion of the phosphate group is potassium ion or sodium ion during the evaporation of water in the ink.
Moreover, it is preferable that about M of (Formula 1) which comprises the copolymer containing a phosphate group, the ratio of the hydrogen atom with respect to the total number of M in a copolymer is 0%-40%. Storage stability of the pigment dispersion and the ink when the ratio of hydrogen atom to the total number of M in the copolymer is 0% to 40% with respect to M (formula 1) constituting the copolymer containing a phosphate group Will improve. In the dispersion and in the ink, the pigment is kept in a dispersed state by the repulsive force between the negative charges of the phosphate groups. Therefore, it is presumed that when M is a metal atom or an organic amine, the repulsion between pigments becomes stronger and the dispersion is stabilized.

In addition, the ratio of the hydrogen atom with respect to the total number of M in a copolymer can be calculated | required by 100% -neutralization rate (%) using the neutralization rate (%) defined below.
In the present invention, the neutralization rate of the phosphoric acid group in the polymer obtained by the neutralization treatment is defined as the neutralization rate as determined by the following method. The ratio of substitution with metal ions or organic ammonium ions is different.
When the compound represented by formula (5) is monomer 1,
Neutralization rate X (%) = (number of moles of base added x valence of base cation)
÷ (number of moles of monomer 1 contained in polymer × 2) × 100
Number of moles of base added = amount of base added Yg ÷ molecular weight of base Number of moles of monomer 1 contained in polymer
= Charge amount of monomer 1 Zg / Molecular weight of monomer 1 Therefore, the amount of base necessary to obtain the neutralization rate X% is: Base addition amount Yg = Neutralization rate X (%) x (Feed amount of monomer 1 Zg × 2)
X base molecular weight / (base cation valence x 100 x monomer 1 molecular weight)
It becomes.

  The monomer of (Formula 6) shows glycerol methacrylate. Glycerol methacrylate is commercially available from NOF Corporation under the product name “Blemmer GLM”.

The composition ratio of the structural unit (formula 1) of the copolymer containing a phosphate group used in the present invention is preferably 5% by mass to 80% by mass, and 10% by mass to 60% by mass with respect to the copolymer weight. More preferred. When the content is 10% by mass or more, the effect of improving the image density is clearly exhibited, and when the content is 60% by mass or less, the storage stability of the pigment dispersion and the ink is remarkably improved.
Moreover, as for the structural ratio of (Formula 2) structural unit, 10 mass%-35 mass% are preferable with respect to the copolymer mass. When it is 10% by mass or more, the viscosity of the dispersion and the ink becomes low, and when it is 35% by mass or less, the effect of improving the image density is clearly exhibited.
Furthermore, the composition ratio of the (Formula 3) or (Formula 4) structural unit is preferably 10% by mass to 60% by mass, and more preferably 50% by mass to 60% by mass with respect to the mass of the copolymer. When it is 50% by mass or more, the storage stability of the dispersion and the ink is improved, and when it is 60% by mass or less, the effect of improving the image density is clearly exhibited.

  The viscosity (25 ° C.) of a 10% by weight solid content aqueous solution or 10% by weight solid content aqueous dispersion of a copolymer containing phosphate groups is preferably in the range of 3.0 to 35.0 mPa · s. More preferably, it is in the range of 0.0 to 30.0 mPa · s. When it is 4.0 mPa · s or more, the reactivity between the metal ions eluted from the paper and the pigment dispersant 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 further improved.

  The copolymer containing phosphoric acid groups used in the present invention is preferably 0.5% by mass to 10.0% by mass, and 1.0% by mass to 5.0% as a solid content with respect to the total weight of the ink. More preferably, it is mass%. The addition of 0.5% by mass clearly shows the effect of improving the image density, and by making it 10.0% by mass or less, it is possible to suppress the viscosity to a range suitable for discharging ink from the head.

The ink for inkjet recording of the present invention is preferably formed by mixing an aqueous dispersion of a pigment composed of a pigment, water, and a copolymer containing a phosphoric acid group, water, and a water-soluble solvent.
If the copolymer containing a phosphate group used in the present invention is used as a pigment dispersant, the image density on plain paper can be further improved. Furthermore, a further improvement is observed in the storage stability of a solvent-rich ink having a water-soluble solvent of 20% by mass or more.

  When used as a dispersant, the content is preferably 10% by mass to 100% by mass with respect to 100% by mass of the pigment. The most suitable pigment particle diameter within this range is obtained, and the image density, dispersibility, and storage stability are in a good range. Moreover, you may use together the dispersing agent described later with a copolymer in the range which does not impair the said effect.

(water)
As water used in the present invention, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used.
The water content is preferably 20 to 60% by mass with respect to the total amount of ink.

(Water-soluble solvent)
The water-soluble solvent used in the present invention is necessary for improving the ejection stability by providing a moisturizing effect in the ink composition. The content is preferably 10 to 50% by mass with respect to the total amount of ink. When the content is 10% by mass or more, it is difficult for the ink to evaporate water, the ink water evaporation in the ink supply system in the ink jet recording apparatus is suppressed, and ink clogging is less likely to occur. When the content is less than 50% by mass, the ink viscosity can be kept low and a high image density can be obtained even if the content of solids such as pigments and resins is large.

Examples of the water-soluble solvent used in the present invention include, but are not limited to, the following. For example, ethylene glycol, diethylene glycol, 1,3-butanediol, 3-methyl-1,3-butyl glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,5-pentanediol, 1,6-hexanediol, glycerin 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,2,4-butanetriol, 1,2,3 -Polyhydric alcohols such as butanetriol and petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetra Polyhydric alcohol alkyl ethers such as tylene glycol monomethyl ether and propylene glycol monoethyl ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, nitrogen-containing heterocyclic compounds such as ε-caprolactam, γ-butyrolactone, amides such as formamide, N-methylformamide, N, N-dimethylformamide , Amines such as monoethanolamine, diethanolamine, triethylamine, sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, thiodiethanol, propylene carbonate, ethylene carbonate, etc. That.
These water-soluble solvents can be used alone or in combination of two or more. Among these, the inclusion of 1,3-butanediol, diethylene glycol, 2,2,4-trimethyl-1,3-pentanediol, triethylene glycol and / or glycerin is excellent in preventing discharge failure due to moisture evaporation. Effect. In particular, glycerin is preferably included.

(Pigment)
The content of the pigment used in the present invention in the recording ink is preferably 0.1% by mass or more and 20.0% by mass or less. The volume average particle diameter (D50) of the pigment is preferably 150 nm or less.
Here, the volume average particle diameter (D50) of the pigment is measured by a dynamic light scattering method using Microtrac UPA manufactured by Nikkiso Co., Ltd. in an environment of 23 ° C. and 55% RH.
There is no restriction | limiting in particular as these pigments, According to the objective, it can select suitably, For example, any of an inorganic pigment and an organic pigment may be sufficient. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the inorganic pigment include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, bitumen, cadmium red, chrome yellow, metal powder, and carbon black. Among these, carbon black is preferable. In addition, as said carbon black, what was manufactured by well-known methods, such as a contact method, a furnace method, and a thermal method, is mentioned, for example.

Examples of the organic pigment include azo pigments, azomethine pigments, polycyclic pigments, dye chelates, nitro pigments, nitroso pigments, and aniline black. Among these, azo pigments and polycyclic pigments are more preferable.
Examples of the azo pigments include azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments. Examples of the polycyclic pigment include phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, rhodamine B lake pigments, and the like. It is done. Examples of the dye chelates include basic dye chelates and acidic dye chelates.

Examples of black materials include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper, iron (CI pigment black 11), titanium oxide, and the like. And organic pigments such as aniline black (CI Pigment Black 1).
As the carbon black, a furnace method, a carbon black produced by the channel method, primary particle diameter of, 15Nm～40nm, specific surface area by BET ^{method, 50m 2 / g~300m 2 / g} , DBP oil absorption amount 40ml / 100 g to 150 ml / 100 g, those having a volatile content of 0.5% to 10% and a pH value of 2 to 9 are preferred.
A commercially available product can be used as the carbon black. Examples of commercially available products include No. 2300, no. 900, MCF-88, no. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, no. 2200B (all manufactured by Mitsubishi Chemical Corporation); Raven700, 5750, 5250, 5000, 3500, 1255 (all manufactured by Columbia); Regal400R, 330R, 660R, Mogu L, Monarch700, 800, 880, 900, 1000, 1100, 1300, Monarch 1400 (all manufactured by Cabot); Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex 35, U, V, 140U, 140V, Special Black 6, 5, 4A, and 4 (all manufactured by Degussa).

  The pigment that can be used for the yellow ink for color is not particularly limited and can be appropriately selected according to the purpose. 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, and the like.

  The pigment that can be used in the magenta ink for color is not particularly limited and may be appropriately selected depending on the intended purpose. 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 that can be used for the cyan ink for the color is not particularly limited and may be appropriately selected according to the purpose. 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 and the like.

In addition, the pigment contained in each ink used in the present invention may be newly produced for the present invention.
By using Pigment Yellow 74 as the yellow pigment, Pigment Red 122, Pigment Bio Red 19 as the magenta pigment, and Pigment Blue 15: 3 as the cyan pigment, an ink with excellent color tone and light fastness and balanced can be obtained. Can be obtained.
Furthermore, the pigment used in the present invention can be a grafted or encapsulated product coated with a surfactant such as a dispersant or a resin, but the compound of the present invention is used as a dispersant. Is more preferable.
Moreover, you may use together the pigment mentioned above in the range which does not impair an effect.

(Other ingredients)
There is no restriction | limiting in particular as another component used for the composition of the ink for inkjet recording of this invention, It can select suitably as needed. Examples of other components include a dispersant, a pH adjuster, a water-dispersible resin, an antiseptic / antifungal agent, a chelating reagent, a rust inhibitor, an antioxidant, an ultraviolet absorber, an oxygen absorber, and a light stabilizer. Is mentioned.

(Dispersant)
As the dispersant, the copolymer containing a phosphate group of the present invention is preferable, but various surfactants and polymers such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant are used. Also included are types of dispersants. These may be used alone or in combination of two or more.
Examples of the anionic surfactant include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acyl methyl taurate, polyoxyalkyl ether sulfates. Salt, polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester salt, lauryl alcohol sulfate ester salt, alkylphenol type phosphate ester, naphthalenesulfonate formalin condensate, alkyl type phosphate ester, alkylallylsulfone hydrochloride, diethyl Examples include sulfosuccinate, diethylhexyl sulfosuccinate, and dioctyl sulfosuccinate.
Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.

Examples of amphoteric surfactants include, Derivatives and the like.
Examples of nonionic surfactants include the following.
Ether-based interfaces such as polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene alkyl ether, polyoxyallylalkyl alkyl ether Active agent;
Polyoxyethylene oleic acid, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate Ester surfactants such as
2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyn-3-ol Examples thereof include acetylene glycol surfactants.

(PH adjuster)
The pH adjuster is not particularly limited as long as the pH can be adjusted to 8.5 to 11 and preferably 9 to 11 without adversely affecting the ink jet ink to be prepared. For example, alcohol amines, hydroxides of alkali metal elements, ammonium hydroxides, phosphonium hydroxides, alkali metal carbonates, and the like can be used. When the pH is less than 8.5 or more than 11, the amount of the ink jet head or ink supply unit that melts out is large, and problems such as ink deterioration, leakage, and ejection failure may occur. When it is less than 8.5, the ink pH may decrease during storage of the ink, and the polymer fine particles may aggregate due to an increase in the particle diameter.
The pH can be measured by, for example, a pH meter HM-30R (manufactured by TOA-DKK).

  Examples of the alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, and the like. Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of the ammonium hydroxide include ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, and the like. Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, and potassium carbonate.

(Water dispersible resin)
The water-dispersible resin has excellent film-forming properties (image formability), high water repellency, high water resistance, and high weather resistance, and has high water resistance and high image density (high color development). Useful for.
Specific examples of the water-dispersible resin include condensation-type synthetic resins, addition-type synthetic resins, natural polymer compounds, and the like.
Examples of the condensed synthetic resin include polyester resin, polyurethane resin, polyepoxy resin, polyamide resin, polyether resin, poly (meth) acrylic resin, acrylic-silicone resin, and fluorine-based resin. Examples of the addition type synthetic resin include polyolefin resins, polystyrene resins, polyvinyl alcohol resins, polyvinyl ester resins, polyacrylic acid resins, unsaturated carboxylic acid resins, and the like. Examples of the natural polymer compound include celluloses, rosins, and natural rubber.
Among these, polyurethane resin fine particles, acrylic-silicone resin fine particles, and fluorine-based resin fine particles are particularly preferable.

The volume average particle diameter (D50) of the water-dispersible resin is related to the viscosity of the dispersion, and for the same composition, the viscosity at the same solid content increases as the particle diameter decreases. The volume average particle diameter (D50) of the water-dispersible resin is preferably 50 nm or more so that the ink does not have an excessively high viscosity. Further, when the particle size is several tens of μm, it becomes larger than the nozzle opening of the ink jet head and cannot be used. If particles having a large particle diameter are present in the ink even though they are smaller than the nozzle opening, the ejection stability is deteriorated. Therefore, the volume average particle diameter (D50) is more preferably 200 nm or less in order not to disturb the ink ejection stability.
Here, the volume average particle diameter (D50) of the water-dispersible resin is measured by a dynamic light scattering method using Microtrac UPA manufactured by Nikkiso Co., Ltd. in an environment of 23 ° C. and 55% RH.

The water-dispersible resin has a function of fixing the water-dispersed pigment on the paper surface, and is preferably formed into a film at room temperature to improve the fixability of the color material. Therefore, it is preferable that the minimum film-forming temperature (MFT) of the water-dispersible resin is 30 ° C. or less.
Further, when the glass transition temperature of the water-dispersible resin is -40 ° C. or lower, the resin film becomes more viscous and the printed matter is tacky. Therefore, the water-dispersible resin has a glass transition temperature of −30 ° C. or higher. It is preferable. The content of the water-dispersible resin in the inkjet ink is preferably 1 to 15% by mass, more preferably 2 to 7% by mass in terms of solid content.

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

(Chelating reagent)
Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate, and the like.

(Rust inhibitor)
Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

(Antioxidant)
Examples of the antioxidant include phenolic antioxidants (including hindered phenolic antioxidants), amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.

(UV absorber)
Examples of the ultraviolet absorber include a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, a salicylate ultraviolet absorber, a cyanoacrylate ultraviolet absorber, and a nickel complex ultraviolet absorber.

(Inkjet ink manufacturing method)
The ink-jet ink of this embodiment is obtained by dispersing or dissolving water, a water-soluble solvent, a pigment, a copolymer containing a phosphate group, and other components in an aqueous medium as required, and further if necessary. Produced by stirring and mixing.
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 a normal stirring blade, a magnetic stirrer, a high-speed disperser, or the like. be able to.
The ink for inkjet recording of the present invention is preferably formed by mixing an aqueous dispersion of a pigment composed of a pigment, water, and a copolymer containing a phosphoric acid group, water, and a water-soluble solvent.

There is no restriction | limiting in particular as a physical property of the inkjet ink of this invention, According to the objective, it can select suitably, For example, it is preferable that viscosity, surface tension, etc. are the following ranges.
The viscosity of the inkjet ink at 25 ° C. is preferably 3 mPa · s to 20 mPa · s. By setting the ink viscosity to 3 mPa · s or more, the effect of improving the printing density and the character quality can be obtained. On the other hand, by suppressing the ink viscosity to 20 mPa · s or less, it is possible to ensure the discharge performance.
The viscosity can be measured at 25 ° C. using, for example, a viscometer (RL-550, manufactured by Toki Sangyo Co., Ltd.).
The surface tension of the inkjet ink is preferably 40 mN / m or less at 25 ° C. When the surface tension exceeds 40 mN / m, leveling of the ink on the recording medium is difficult to occur and the drying time may be prolonged.

(Ink container)
The ink storage container of the present invention includes an ink storage portion for storing ink, and the ink stored in the ink storage portion is the ink for ink jet recording of the present invention, and further includes other members appropriately selected as necessary. It can also be configured.
The shape, structure, size, and material of the container are not particularly limited and can be appropriately selected according to the purpose. Preferred examples include those having at least an ink bag formed of an aluminum laminate film, a resin film, or the like.

One embodiment of the ink container of the present invention will be described with reference to FIGS. FIG. 1 is a schematic plan view for explaining an example of the ink container of the present invention. FIG. 2 is a schematic plan view including a case (exterior) of the ink container shown in FIG.
As shown in FIG. 1, the ink container 200 is filled into the ink container 241 from the ink inlet 242 and exhausted, and then the ink inlet 242 is closed by fusion. In use, the needle of the apparatus main body is pierced into the ink discharge port 243 made of a rubber member and supplied to the apparatus. The ink container 241 is formed of a packaging member such as an aluminum laminate film that does not have air permeability. As shown in FIG. 2, the ink storage portion 241 is normally stored in a plastic cartridge case 244 and is detachably mounted on various ink jet recording apparatuses.

(Inkjet recording apparatus and inkjet recording method)
The ink jet recording apparatus of the present invention is an ink jet recording apparatus that records information or an image on a recording medium using an ink jet head, and includes at least ink flying means, and other types appropriately selected as necessary. Means, for example, stimulus generation means, control means, and the like.
The ink jet recording method using the ink of the present invention includes at least an ink flying process, and further includes other processes appropriately selected as necessary, for example, a stimulus generation process, a control process, and the like.
The ink jet recording method can be preferably carried out by the ink jet recording apparatus of the present invention, and the ink flying step can be suitably carried out by the ink flying means. Moreover, the said other process can be suitably performed by the said other means.

The ink flying step is a step of forming an image by applying a stimulus to the ink jet recording ink of the present invention and causing the ink jet recording ink to fly.
The ink flying means is means for forming an image by applying a stimulus to the ink jet recording ink of the present invention and causing the ink jet recording ink to fly. The ink flying means is not particularly limited, and examples thereof include various nozzles for ejecting ink.

  The stimulus can be generated, for example, by the stimulus generating means, and the stimulus is not particularly limited and can be appropriately selected according to the purpose, such as heat (temperature), pressure, vibration, light, etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, heat and pressure are preferable. Examples of the stimulus generating means include a superheater, a pressurizer, a piezoelectric element, a vibration generator, an ultrasonic oscillator, and a light. Specifically, a piezoelectric actuator such as a piezoelectric element such as a piezoelectric element, a thermal actuator that uses a phase change due to liquid film boiling using an electrothermal transducer such as a heating resistor, a shape that uses a metal phase change due to a temperature change Memory alloy actuators, electrostatic actuators using electrostatic force, and the like can be mentioned.

There is no particular limitation on the mode of the ink flying, and it varies depending on the type of the stimulus. For example, when the stimulus is “heat”, the thermal energy corresponding to the recording signal is output to the ink in the recording head. For example, using a thermal head or the like, generating bubbles in the ink by the thermal energy, and ejecting and ejecting the ink as droplets from the nozzle holes of the recording head by the pressure of the bubbles. It is done. Further, when the stimulus is “pressure”, for example, by applying a voltage to a piezoelectric element bonded to a position called a pressure chamber in an ink flow path in the recording head, the piezoelectric element bends and the volume of the pressure chamber is increased. And a method of ejecting and ejecting the ink as droplets from the nozzle holes of the recording head.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as sequencers and computers.

Here, an aspect of carrying out the ink jet recording method by the ink jet recording apparatus of the present invention will be described with reference to the drawings.
FIG. 3 is a perspective view showing an example of the ink jet recording apparatus of the present invention.
The ink jet recording apparatus shown in FIG. 3 stocks an apparatus main body 101, a paper feed tray 102 for loading paper loaded on the apparatus main body 101, and paper on which an image is recorded (formed) mounted on the apparatus main body 101. A discharge tray 103 for printing, and an ink container container loading unit 104 that protrudes forward from the front surface 112 and is lower than the upper cover 111 are provided at one end of the front surface 112 of the apparatus main body 101. An operation unit 105 such as operation keys and a display is arranged on the upper surface of the ink container loading unit 104. The ink storage container loading unit 104 has a front cover 115 that can be opened and closed for detaching the ink storage container 200.

As shown in FIGS. 4 and 5 (partially enlarged sectional view of the ink jet recording apparatus shown in FIG. 3), a guide which is a guide member horizontally mounted on left and right side plates (not shown) is provided in the apparatus main body 101. The carriage 133 is slidably held in the main scanning direction by the rod 131 and the stay 132, and is moved and scanned in the direction of the arrow as shown in FIG. 5 by the main scanning motor.
The carriage 133 includes a recording head 134 composed of four inkjet heads that eject ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). They are arranged in a direction crossing the scanning direction and mounted with the ink droplet ejection direction facing downward.

  As an inkjet head constituting the recording head 134, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change due to liquid film boiling using an electrothermal conversion element such as a heating resistor, and a metal phase change due to a temperature change. A shape memory alloy actuator to be used, an electrostatic actuator using an electrostatic force, or the like provided as energy generating means for discharging ink can be used. In addition, the carriage 133 is equipped with a sub tank 135 for each color for supplying ink of each color to the recording head 134. The sub tank 135 is replenished with the ink supplied from the ink container 200 of the present invention loaded in the ink container loading unit 104 via an ink supply tube (not shown).

On the other hand, as a paper feeding unit for feeding the paper 142 stacked on the paper stacking unit (pressure plate) 141 of the paper feeding tray 102, a half-moon roller (feeding) that separates and feeds the paper 142 from the paper stacking unit 141 one by one. A separation pad 144 made of a material having a large coefficient of friction is provided facing the paper roller 143) and the paper feed roller 143, and the separation pad 144 is urged toward the paper feed roller 143 side.
As a transport unit for transporting the paper 142 fed from the paper feed unit below the recording head 134, a transport belt 151 for transporting the paper 142 by electrostatic adsorption and a guide 145 from the paper feed unit. The counter roller 152 for transporting the paper 142 fed via the transport belt 151 with the transport belt 151 and the paper 142 fed substantially vertically upward are changed by approximately 90 ° so as to follow the transport belt 151. For this purpose, a conveyance guide 153 and a tip pressure roller 155 urged toward the conveyance belt 151 by a pressing member 154 are provided.

  In addition, a charging roller 156 that is a charging unit for charging the surface of the conveyance belt 151 is provided. The conveyance belt 151 is an endless belt, is stretched between the conveyance roller 157 and the tension roller 158, and can circulate in the belt conveyance direction. The transport belt 151 includes, for example, a surface layer serving as a sheet adsorbing surface formed of a resin material having a thickness of about 40 μm that is not subjected to resistance control, for example, a copolymer of tetrafluoroethylene and ethylene (ETFE), and the surface layer. It has a back layer (medium resistance layer, earth layer) that is made of the same material and has resistance controlled by carbon. On the back side of the conveyance belt 151, a guide member 161 is arranged corresponding to a printing area by the recording head 134.

  Note that, as a paper discharge unit for discharging the paper 142 recorded by the recording head 134, a separation claw 171 for separating the paper 142 from the conveyance belt 151, a paper discharge roller 172, and a paper discharge roller 173 are provided. The paper discharge tray 103 is disposed below the paper discharge roller 172.

A double-sided paper feeding unit 181 is detachably mounted on the back surface of the apparatus main body 101.
The double-sided paper feeding unit 181 takes in the paper 142 returned by the reverse rotation of the transport belt 151, reverses it, and feeds it again between the counter roller 152 and the transport belt 151. A manual paper feed unit 182 is provided on the upper surface of the duplex paper feed unit 181.

  In this ink jet recording apparatus, the paper 142 is separated and fed one by one from the paper feed unit, and the paper 142 fed substantially vertically upward is guided by the guide 145 and between the transport belt 151 and the counter roller 152. It is sandwiched and conveyed. Further, the leading end is guided by the conveying guide 153 and pressed against the conveying belt 151 by the leading end pressure roller 155, and the conveying direction is changed by approximately 90 °. At this time, the conveying belt 151 is charged by the charging roller 156, and the sheet 142 is electrostatically attracted to the conveying belt 151 and conveyed. Therefore, by driving the recording head 134 according to the image signal while moving the carriage 133, ink droplets are ejected onto the stopped paper 142 to record one line, and after the paper 142 is conveyed by a predetermined amount, Record the next line.

  Upon receiving a recording end signal or a signal that the trailing edge of the sheet 142 has reached the recording area, the recording operation is terminated and the sheet 142 is discharged onto the discharge tray 103. When a near-end remaining amount of ink in the sub tank 135 is detected, a required amount of ink is supplied from the ink container 200 to the sub tank 135.

In this ink jet recording apparatus, when the ink in the ink container 201 of the present invention is used up, the housing of the ink container 200 can be disassembled and only the ink container inside can be replaced. Further, the ink container 200 can supply ink stably even if it is placed vertically and has a front loading configuration. Accordingly, even when the upper portion of the apparatus main body 101 is closed and installed, for example, when stored in a rack, or when an object is placed on the upper surface of the apparatus main body 101, the ink container 200 can be easily exchanged.
In addition, although it demonstrated in the example applied to the serial type (shuttle type) inkjet recording device which a carriage scans, it can apply similarly to the line type inkjet recording device provided with the line type head.
The ink jet recording apparatus of the present invention can be applied to various types of recording by the ink jet recording method, and is particularly preferably applied to, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, a printer / fax / copier multifunction machine, and the like. Can do.

(Recorded material manufacturing method and recorded material)
The method for producing a recorded matter of the present invention includes a step of recording on a recording medium by ejecting ink from an inkjet head, and the ink is the inkjet recording ink of the present invention. It can be manufactured by the ink jet recording apparatus of the present invention.
The recorded matter of the present invention is a recorded matter in which information or an image is recorded on a recording medium using ink, and the ink is the inkjet recording ink of the present invention.
That is, the recorded matter of the present invention has an image recorded with the ink for ink jet recording of the present invention on a recording medium (recording medium).

  The recording medium is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include plain paper, coated paper for printing, glossy paper, special paper, cloth, film, and OHP sheet. It is done. These may be used individually by 1 type and may use 2 or more types together. Among these, at least one of plain paper and coated paper for printing is preferable. The plain paper is advantageous in that it is inexpensive. The coated paper for printing is advantageous in that it provides a smooth glossy image at a relatively low cost as compared with glossy paper. However, although the drying property is poor and it is generally difficult to use for inkjet, the drying property is improved by the ink of the present invention.

  The recorded matter of the present invention has high image quality, no bleeding, excellent temporal stability, and can be suitably used for various purposes as a material on which various prints or images are recorded.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples. “Part” represents “part by mass” unless otherwise specified. “%” Represents “% by mass” unless otherwise specified.

(Measurement of copolymer viscosity)
The viscosity of the 10% by weight aqueous solution or 10% by weight aqueous dispersion of the synthesized copolymer was measured using a rotational viscometer (TV-22 viscometer / cone plate type, manufactured by Toki Sangyo Co., Ltd.). The measurement temperature at this time was 25.0 ° C. Specific operations are shown below. 1.1 mL of a 10% by weight aqueous solution or 10% by weight aqueous dispersion of the copolymer was sampled and placed in a sample cup of a viscometer. After the sample cup was attached to the viscometer body and allowed to stand for 1 minute, the viscometer rotor was rotated and the value after 1 minute was read.

<Method for synthesizing copolymer compound>
A method for synthesizing the copolymer compound is shown below. In addition, about the structural ratio etc. of each copolymer, it described collectively in Table 1.

<Synthesis example of copolymers 1 to 49>
(Synthesis Example 1)
Phosmer M (2-methacryloxyethyl acid phosphoate); 6.0 g, GLM (glycerin methacrylate); 2.0 g, StA (stearyl acrylate); 12.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 15 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 1 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 15.2 mPa · s.

(Synthesis Example 2)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, 1.33 g of azobisisobutyronitrile at 75 ° C. was added, and a polymerization reaction was carried out for 3 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. Thus, a copolymer 2 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 3.8 mPa · s.

(Synthesis Example 3)
Phosmer M (2-methacryloxyethyl acid phosphoate); 1.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 12.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 3 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.1 mPa · s.

(Synthesis Example 4)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 4 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.3 mPa · s.

(Synthesis Example 5)
Phosmer M (2-methacryloxyethyl acid phosphoate); 11.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 2.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, 1.33 g of azobisisobutyronitrile at 75 ° C. was added, and a polymerization reaction was carried out for 3 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 5 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 3.8 mPa · s.

(Synthesis Example 6)
Phosmer M (2-methacryloxyethyl acid phosphoate); 13.0 g, GLM (glycerin methacrylate); 4.0 g, StA (stearyl acrylate); 3.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 6 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.0 mPa · s.

(Synthesis Example 7)
Phosmer M (2-methacryloxyethyl acid phosphoate); 11.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 2.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 7 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.2 mPa · s.

(Synthesis Example 8)
Phosmer M (2-methacryloxyethyl acid phosphoate); 11.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 2.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 48 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 8 in which the phosphate group was neutralized 100% was synthesized. The viscosity of the 10% by mass aqueous dispersion of the obtained copolymer was 32.2 mPa · s.

(Synthesis Example 9)
Phosmer M (2-methacryloxyethyl acid phosphoate); 13.0 g, GLM (glycerin methacrylate); 4.0 g, StA (stearyl acrylate); 3.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 24 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 9 having 100% neutralized phosphate groups was synthesized. The viscosity of the 10% by mass aqueous solution of the obtained copolymer was 28.3 mPa · s.

(Synthesis Example 10)
Phosmer M (2-methacryloxyethyl acid phosphoate); 11.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 2.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 24 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 10 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 28.0 mPa · s.

(Synthesis Example 11)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 48 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. Thus, the copolymer 11 in which the phosphate group was neutralized 100% was synthesized. The viscosity of the 10% by mass aqueous dispersion of the obtained copolymer was 31.1 mPa · s.

(Synthesis Example 12)
Phosmer M (2-methacryloxyethyl acid phosphoate); 1.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 12.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 24 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 12 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 29.5 mPa · s.

(Synthesis Example 13)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 24 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 13 having 100% neutralized phosphate groups was synthesized. The viscosity of the 10% by mass aqueous solution of the obtained copolymer was 28.3 mPa · s.

(Synthesis Example 14)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, sodium hydroxide was added so as to achieve 100% acid neutralization, and the dialysis membrane was purified for 3 days. Further, the solid concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 14 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.1 mPa · s.

(Synthesis Example 15)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, lithium hydroxide was added to achieve 100% acid neutralization, and the dialysis membrane was purified for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 15 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.1 mPa · s.

(Synthesis Example 16)
Phosmer M (2-methacryloxyethyl acid phosphoate); 1.0 g, GLM (glycerin methacrylate); 7.0 g, StA (stearyl acrylate); 12.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, 1.33 g of azobisisobutyronitrile at 75 ° C. was added, and a polymerization reaction was carried out for 3 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 16 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 3.8 mPa · s.

(Synthesis Example 17)
Phosmer M (2-methacryloxyethyl acid phosphoate); 13.0 g, GLM (glycerin methacrylate); 4.0 g, StA (stearyl acrylate); 3.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 48 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 17 having 100% neutralized phosphate groups was synthesized. The viscosity of the 10% by mass aqueous dispersion of the obtained copolymer was 33.3 mPa · s.

(Synthesis Example 18)
Light acrylate P-1A (2-acryloyloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, StM (stearyl methacrylate); 10.0 g, ethanol; 113.0 g in 4 mouths The mixture was stirred in a flask to obtain a uniform solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 18 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 10.5 mPa · s.

Synthesis example of BzA (Synthesis Example 19)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, 1.33 g of azobisisobutyronitrile at 75 ° C. was added, and a polymerization reaction was carried out for 3 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 19 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 3.7 mPa · s.

(Synthesis Example 20)
Phosmer M (2-methacryloxyethyl acid phosphoate); 1.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 12.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. Thus, the copolymer 20 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.2 mPa · s.

(Synthesis Example 21)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 21 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.1 mPa · s.

(Synthesis Example 22)
Phosmer M (2-methacryloxyethyl acid phosphoate); 11.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 2.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, 1.33 g of azobisisobutyronitrile at 75 ° C. was added, and a polymerization reaction was carried out for 3 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 22 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 3.8 mPa · s.

(Synthesis Example 23)
Phosmer M (2-methacryloxyethyl acid phosphoate); 13.0 g, GLM (glycerin methacrylate); 4.0 g, BzA (benzyl acrylate); 3.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 23 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.0 mPa · s.

(Synthesis Example 24)
Phosmer M (2-methacryloxyethyl acid phosphoate); 11.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 2.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 24 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.2 mPa · s.

(Synthesis Example 25)
Phosmer M (2-methacryloxyethyl acid phosphoate); 11.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 2.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 48 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 25 in which the phosphate group was neutralized 100% was synthesized. The viscosity of the 10% by mass aqueous dispersion of the obtained copolymer was 31.9 mPa · s.

(Synthesis Example 26)
Phosmer M (2-methacryloxyethyl acid phosphoate); 13.0 g, GLM (glycerin methacrylate); 4.0 g, BzA (benzyl acrylate); 3.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 24 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 26 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 28.0 mPa · s.

(Synthesis Example 27)
Phosmer M (2-methacryloxyethyl acid phosphoate); 11.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 2.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 24 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 27 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 28.5 mPa · s.

(Synthesis Example 28)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 48 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 28 in which the phosphate group was neutralized 100% was synthesized. The viscosity of the 10% by mass aqueous dispersion of the obtained copolymer was 31.1 mPa · s.

(Synthesis Example 29)
Phosmer M (2-methacryloxyethyl acid phosphoate); 1.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 12.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 24 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 29 in which the phosphate group was neutralized 100% was synthesized. The viscosity of the 10% by mass aqueous solution of the obtained copolymer was 28.3 mPa · s.

(Synthesis Example 30)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 24 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 30 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 28.0 mPa · s.

(Synthesis Example 31)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, sodium hydroxide was added so as to achieve 100% acid neutralization, and the dialysis membrane was purified for 3 days. Further, the solid concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 31 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.2 mPa · s.

(Synthesis Example 32)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, lithium hydroxide was added to achieve 100% acid neutralization, and the dialysis membrane was purified for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. Thus, the copolymer 32 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.1 mPa · s.

(Synthesis Example 33)
Phosmer M (2-methacryloxyethyl acid phosphoate); 3.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, DMEA (dimethylethanolamine) was added to achieve 100% acid neutralization, and the dialysis membrane was purified for 3 days. Further, the solid content concentration was adjusted to 10% by mass. Then, the concentration was adjusted with water. In this way, a copolymer 33 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.2 mPa · s.

(Synthesis Example 34)
Phosmer M (2-methacryloxyethyl acid phosphoate); 1.0 g, GLM (glycerin methacrylate); 7.0 g, BzA (benzyl acrylate); 12.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, 1.33 g of azobisisobutyronitrile at 75 ° C. was added, and a polymerization reaction was carried out for 3 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 34 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 3.6 mPa · s.

(Synthesis Example 35)
Phosmer M (2-methacryloxyethyl acid phosphoate); 13.0 g, GLM (glycerin methacrylate); 4.0 g, BzA (benzyl acrylate); 3.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 50 ° C., and a polymerization reaction was carried out for 48 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 35 in which the phosphate group was neutralized 100% was synthesized. The viscosity of the 10% by mass aqueous solution of the obtained copolymer was 32.0 mPa · s.

(Synthesis Example 36)
Light acrylate P-1A (2-acryloyloxyethyl acid phosphoate); 6.0 g, GLM (glycerin methacrylate); 2.0 g, BzM (benzyl methacrylate); 12.0 g, ethanol; 113.0 g in 4 mouths The mixture was stirred in a flask to obtain a uniform solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 60 ° C., and a polymerization reaction was carried out for 15 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 36 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 11.0 mPa · s.

(Synthesis Example 37)
Phosmer PE (acid phosphoxypolyoxyethylene glycol methacrylate (formula 5-3)); 6.0 g, GLM (glycerin methacrylate); 2.0 g, BzA (benzyl acrylate); 12.0 g, ethanol; The mixture was stirred in a double-necked flask to obtain a uniform solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 60 ° C., and a polymerization reaction was carried out for 15 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 37 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 13.5 mPa · s.

(Synthesis Example 38)
Phosmer PP (acid phosphoxypolyoxypropylene glycol methacrylate (formula 5-4)); 6.0 g, GLM (glycerin methacrylate); 2.0 g, BzA (benzyl acrylate); 12.0 g, ethanol; The mixture was stirred in a double-necked flask to obtain a uniform solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 60 ° C., and a polymerization reaction was carried out for 15 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 38 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 15.7 mPa · s.

(Synthesis Example 39)
Phosmer PEP (acid phosphoxypoly (oxyethyleneoxypropylene) glycol methacrylate (formula 5-5)); 6.0 g, GLM (glycerin methacrylate); 2.0 g, BzA (benzyl acrylate); 12.0 g, ethanol; 113 0.0 g was placed in a four-necked flask and stirred to obtain a uniform solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 60 ° C., and a polymerization reaction was carried out for 15 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 39 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 20.0 mPa · s.

(Synthesis Example 40)
Phosmer M (2-methacryloxyethyl acid phosphoate); 6.0 g, GLM (glycerin methacrylate); 2.0 g, BzA (benzyl acrylate); 12.0 g, ethanol; 113.0 g were placed in a four-necked flask. To a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 60 ° C., and a polymerization reaction was carried out for 15 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 50% acid neutralization, and the dialysis membrane was purified for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 40 having 50% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 10.5 mPa · s.

(Synthesis Example 41) Comparative Synthesis Example 1
Phosmer M (2-methacryloxyethyl acid phosphoate); 6.0 g, StA (stearyl acrylate); 14.0 g, ethanol; 113.0 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 41 having 100% neutralized phosphate groups was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 4.0 mPa · s.

(Synthesis Example 42) Comparative Synthesis Example 2
Phosmer M (2-methacryloxyethyl acid phosphoate); 6.0 g, BzA (benzyl acrylate); 14.0 g, ethanol; 113.0 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 5 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 42 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 6.0 mPa · s.

(Synthesis Example 43) Comparative Synthesis Example 3
GLM (glycerin methacrylate); 6.0 g, StA (stearyl acrylate); 14.0 g, ethanol; 113.0 g were placed in a four-necked flask and stirred to obtain a uniform solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 10 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. The obtained copolymer was purified with a dialysis membrane for 3 days while diluting with water, and the concentration was adjusted with water so that the solid concentration was 10% by mass. In this way, a copolymer 43 was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 10.5 mPa · s.

(Synthesis Example 44) Comparative Synthesis Example 4
GLM (glycerin methacrylate); 6.0 g, BzA (benzyl acrylate); 14.0 g, ethanol; After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 10 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. The obtained copolymer was purified with a dialysis membrane for 3 days while diluting with water, and the concentration was adjusted with water so that the solid concentration was 10% by mass. In this way, a copolymer 44 was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 9.8 mPa · s. Molecular weight 10,000.

(Synthesis Example 45) Comparative Synthesis Example 5
MAA (methacrylic acid); 6.0 g, StA (stearyl acrylate); 14.0 g, ethanol; 113.0 g were placed in a four-necked flask and stirred to obtain a uniform solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 10 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 45 in which acid groups were neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 19.8 mPa · s.

(Synthesis Example 46) Comparative Synthesis Example 6
MAA (methacrylic acid); 6.0 g, BzA (benzyl acrylate); 14.0 g, ethanol; 113.0 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 10 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 46 in which acid groups were neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 20.2 mPa · s.

(Synthesis Example 47) Comparative Synthesis Example 7
Phosmer M (2-methacryloxyethyl acid phosphoate); 6.0 g, MAA (methacrylic acid); 14.0 g, ethanol; 113.0 g were placed in a four-necked flask and stirred to obtain a uniform solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 10 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 47 in which the phosphate group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 11.5 mPa · s.

(Synthesis Example 48) Comparative Synthesis Example 8
Styrene; 10.0 g, GLM (glycerin methacrylate); 10.0 g, ethanol; 113.0 g were placed in a four-necked flask and stirred to obtain a uniform solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 10 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. The obtained copolymer was purified with a dialysis membrane for 3 days while diluting with water, and the concentration was adjusted with water so that the solid concentration was 10% by mass. In this way, a copolymer 48 was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 13.0 mPa · s.

(Synthesis Example 49) Comparative Synthesis Example 9
Styrene; 10.0 g, MAA (methacrylic acid); 14.0 g, ethanol; 113.0 g were placed in a four-necked flask and stirred to obtain a uniform solution. After nitrogen was blown into this solution for 30 minutes, azobisisobutyronitrile; 1.33 g was added at 65 ° C., and a polymerization reaction was carried out for 10 hours. A viscous product obtained by removing the solvent from the polymerization solution with an evaporator was added to acetone to collect a solid. While diluting the obtained copolymer with water, potassium hydroxide was added so as to achieve 100% acid neutralization, and dialysis membrane purification was performed for 3 days. Further, the solid content concentration was 10% by mass. The concentration was adjusted with water. In this way, a copolymer 49 in which the acid group was neutralized 100% was synthesized. The viscosity of a 10% by mass aqueous solution of the obtained copolymer was 12.6 mPa · s.

<Preparation Examples 1 to 58 of Pigment Dispersion>
Each material dispersion was prepared as follows. The formulation of each pigment dispersion is summarized in Table 2.
(Pigment dispersion preparation example 1): Black pigment dispersion 1
A mixture having the following formulation was premixed to prepare a mixed slurry (a). This was circulated and dispersed in a disk type media mill (manufactured by Ashizawa Finetech Co., Ltd., DMR type) using 0.05 mm zirconia beads and a filling rate of 55% at a peripheral speed of 10 m / s and a liquid temperature of 10 ° C. for 3 minutes. Coarse particles were centrifuged with a centrifuge (Model 7700, manufactured by Kubota Corporation) to obtain a pigment dispersion having a pigment concentration of 16% by mass.
Carbon black (NIPEX160, manufactured by degussa, BET specific surface area 150 m ² / g,
(Average primary particle size 20 nm, pH 4.0, DBP oil absorption 620 g / 100 g)
... 160 parts by mass-Copolymer 1 (Synthesis Example 1) ... 40 parts by mass-Distilled water ... 800 parts by mass

(Pigment dispersion preparation example 2): Black pigment dispersion 2
Similar to Pigment Dispersion Preparation Example 1 except that the copolymer 1 (Synthesis Example 1) of Pigment Dispersion Preparation Example 1 was changed from 40 parts by mass to 20 parts by mass and distilled water was changed from 800 parts by mass to 820 parts by mass. Thus, a black pigment dispersion having a pigment concentration of 16% by mass was obtained.

(Pigment dispersion preparation example 3): Black pigment dispersion 3
Same as Pigment Dispersion Preparation Example 1 except that copolymer 1 (Synthesis Example 1) of Pigment Dispersion Preparation Example 1 was changed from 40 parts by weight to 160 parts by weight and distilled water was changed from 800 parts by weight to 680 parts by weight. Thus, a black pigment dispersion having a pigment concentration of 16% by mass was obtained.

(Pigment dispersion preparation example 4): Black pigment dispersion 4
Copolymer 1 (Synthesis Example 1) of Pigment Dispersion Preparation Example 1 is added to a 10% aqueous solution of POE (m = 40) β-naphthyl ether, its mass part is changed from 40 parts by mass to 400 parts by mass, and distilled water is 800 masses. A black pigment dispersion having a pigment concentration of 16% by mass was obtained in the same manner as in Pigment Dispersion Preparation Example 1 except that the amount of the pigment was changed to 440 parts by mass.

(Pigment dispersion preparation example 5): Cyan pigment dispersion 1
The pigment concentration was 16% by mass in the same manner as in Pigment Dispersion Preparation Example 1, except that the carbon black of Pigment Dispersion Preparation Example 1 was changed to Pigment Blue 15: 3 (Dainipei Seika Co., Ltd., Chromofine Blue). A blue pigment dispersion was obtained.

(Pigment Dispersion Preparation Example 6): Magenta pigment dispersion 1
Similar to Pigment Dispersion Preparation Example 1, except that the carbon black of Pigment Dispersion Preparation Example 1 was changed to Pigment Red 122 (manufactured by Clariant, Toner Magenta EO02). A pigment dispersion was obtained.

(Pigment dispersion preparation example 7): Yellow pigment dispersion 1
Yellow having a pigment concentration of 16% by mass in the same manner as in Pigment Dispersion Preparation Example 1, except that the carbon black of Pigment Dispersion Preparation Example 1 was changed to Pigment Yellow 74 (Daiichi Seika Chemical Co., Ltd., First Yellow 531). A pigment dispersion was obtained.

(Pigment dispersion preparation example 8): Black pigment dispersion 5
The pigment concentration was 16% by mass in the same manner as in Pigment Dispersion Preparation Example 1 except that the copolymer 1 (Synthesis Example 1) in Pigment Dispersion Preparation Example 1 was changed to the Copolymer 2 (Synthesis Example 2). A black pigment dispersion was obtained.

(Pigment dispersion preparation example 9): Black pigment dispersion 6
The pigment concentration was 16% by mass in the same manner as in Pigment Dispersion Preparation Example 1 except that the copolymer 1 (Synthesis Example 1) of the Pigment Dispersion Preparation Example 1 was changed to the Copolymer 3 (Synthesis Example 3). A black pigment dispersion was obtained.

(Pigment Dispersion Preparation Example 10) to (Pigment Dispersion Preparation Example 53)
Same as Pigment Dispersion Preparation Example 1 except that Copolymer 1 (Synthesis Example 1) of Pigment Dispersion Preparation Example 1 was changed to Copolymer 4 (Synthesis Example 4) to Copolymer 47 (Synthesis Example 47). Thus, a black pigment dispersion having a pigment concentration of 16% by mass was obtained.

(Pigment dispersion preparation example 54): Black pigment dispersion 52
The pigment concentration was 16% by mass in the same manner as in Pigment Dispersion Preparation Example 1 except that the copolymer 1 (Synthesis Example 1) of Pigment Dispersion Preparation Example 1 was changed to the Copolymer 48 (Synthesis Example 48). A black pigment dispersion was obtained.

(Pigment dispersion preparation example 55): Black pigment dispersion 53
The pigment concentration was 16% by mass in the same manner as in Pigment Dispersion Preparation Example 1 except that the copolymer 1 (Synthesis Example 1) of Pigment Dispersion Preparation Example 1 was changed to the Copolymer 49 (Synthesis Example 49). A black pigment dispersion was obtained.

(Pigment dispersion preparation example 56): Cyan pigment dispersion 2
Carbon black of Pigment Dispersion Preparation Example 1 was changed to Pigment Blue 15: 3 (Chromofine Blue, manufactured by Dainichi Seika Co., Ltd.), and Copolymer 1 (Synthesis Example 1) was changed to Copolymer 49 (Synthesis Example 49). Except for the above, a blue pigment dispersion having a pigment concentration of 16% by mass was obtained in the same manner as in Pigment Dispersion Preparation Example 1.

(Pigment dispersion preparation example 57): Magenta pigment dispersion 2
Pigment Dispersion Example 1 except that the carbon black of Preparation Example 1 was changed to Pigment Red 122 (Clariant, Toner Magenta EO02), and Copolymer 1 (Synthesis Example 1) was changed to Copolymer 49 (Synthesis Example 49). In the same manner as in Dispersion Preparation Example 1, a red-violet pigment dispersion having a pigment concentration of 16% by mass was obtained.

(Pigment Dispersion Preparation Example 58): Yellow Pigment Dispersion 2
Except that the carbon black of Pigment Dispersion Preparation Example 1 was changed to Pigment Yellow 74 (Daiichi Seika Co., Ltd., First Yellow 531) and Copolymer 1 (Synthesis Example 1) was changed to Copolymer 49 (Synthesis Example 49). In the same manner as in Pigment Dispersion Preparation Example 1, a yellow pigment dispersion having a pigment concentration of 16% by mass was obtained.

[Examples 1 to 48, Comparative Examples 1 to 12]
<Preparation of ink for ink jet recording>
Table 3 below shows the configurations of the ink compositions of Examples 1 to 48 and Comparative Examples 1 to 12, respectively. In addition, the numerical value in a table | surface shows the mass%.

<Inkjet ink manufacturing method>
Example 1
The ingredients of the following formulation are mixed and stirred for 1 hour to mix uniformly. This dispersion was subjected to pressure filtration with a polyvinylidene fluoride membrane filter having an average pore size of 5.0 μm to remove coarse particles and dust, thereby producing a recording ink.
Pigment dispersion 1 of pigment dispersion preparation example 1 (pigment concentration: 16% by mass) 50.0 parts by weight-glycerin 10.0 parts by weight- 1,3-butanediol 20.0 parts by weight-pure water 20.0 parts by weight Part

(Examples 2-48, Comparative Examples 1-12)
For the inks of Examples 2 to 48 and Comparative Examples 1 to 12, inks were produced in the same manner as described above according to the following prescription table.

  Below, the evaluation method is shown about the storage stability evaluation of each pigment dispersion and each ink, and the printing evaluation of each ink. The evaluation results are summarized in Table 4.

<Evaluation of storage stability of each pigment dispersion and each ink>
For the measurement of the viscosity of each pigment dispersion and each recording ink in Preparation Examples 1 to 58 and Examples 1 to 48 and Comparative Examples 1 to 12 of the pigment dispersion, a viscometer RE80L manufactured by Toki Sangyo Co., Ltd. was used. The viscosity at 25 ° C. was measured. About the rotation speed at the time of a viscosity measurement, it adjusted so that a torque might become fixed in 40%-80% of range. As an index of the dispersion stability of the pigment as the pigment dispersion and the ink, the initial viscosity after the preparation of the pigment dispersion and the ink was measured and evaluated based on the following criteria.
As for storage stability, after measuring the initial viscosity, each pigment dispersion and the ink are put in a polyethylene container, sealed, and measured after storage at 70 ° C. for 1 week, and the change from the initial viscosity is measured. The rate was evaluated based on the following criteria.

[Evaluation criteria for pigment dispersion]
Initial viscosity A: Initial viscosity value is less than 3 mPa · s B: Initial viscosity value is 3 mPa · s or more and less than 7 mPa · s C: Initial viscosity value is 7 mPa · s or more Storage stability A: Based on initial viscosity The change rate of the viscosity after storage is less than 5% B: The change rate of the viscosity after storage based on the initial viscosity is 5% or more and less than 50% C: The change rate of the viscosity after storage based on the initial viscosity is 50% or more

[Ink evaluation criteria]
Initial viscosity A: Initial viscosity value is less than 9 mPa · s B: Initial viscosity value is 9 mPa · s or more and less than 20 mPa · s C: Initial viscosity value is 20 mPa · s or more Storage stability A: Based on initial viscosity The change rate of the viscosity after storage is less than 5% B: The change rate of the viscosity after storage based on the initial viscosity is 5% or more and less than 50% C: The change rate of the viscosity after storage based on the initial viscosity is 50% or more

<Evaluation of printing of each ink>
Printing evaluation was performed on the recording inks of Examples 1 to 48 and Comparative Examples 1 to 13.
Using an inkjet printer (IPSiO GX3000, manufactured by Ricoh Co., Ltd.), change the drive voltage of the piezo element so that the amount of ink discharged is uniform, and set so that the same amount of ink adheres to the recording material. went.

<< Image density & showthrough >>
Using each ink, a chart containing general symbols of JIS X 0208 (1997), 2223 of 64 points created by Microsoft Word 2003 was printed on My Paper (manufactured by Ricoh), and then X-Rite 938 (X- The symbol portion was color-measured by Rite) to evaluate the image density. The print mode was “plain paper-fast” mode with the driver attached to the printer. The image density of each color was evaluated according to the following criteria. In the evaluation, four measurement locations per color were measured once for each chart, and the average value of the four locations was taken as the measurement result for each color. JIS X 0208 (1997), 2223 is a symbol whose outer shape is a regular square and the entire surface of the symbol is filled with ink.
Further, using X-Rite 938, the image density of the symbol part was measured from the back side of the paper, and the obtained OD value was used as the back-through density and evaluated according to the same criteria as described above.

[Image density (OD value) evaluation criteria]
A: OD value Black 1.25 or more
Yellow 0.80 or more
Magenta 0.95 or higher
Cyan 1.05 or more B: OD value Black 1.15 or more and less than 1.25
Yellow 0.75 or more and less than 0.80
Magenta 0.85 or more and less than 0.95
Cyan 0.95 or more and less than 1.05 C: OD value Black 1.05 or more and less than 1.15
Yellow 0.70 or more and less than 0.75
Magenta 0.75 or more and less than 0.85
Cyan 0.85 or more and less than 0.95 D: OD value Black Less than 1.05
Yellow less than 0.70
Less than magenta 0.75
Cyan less than 0.85

[Evaluation criteria for strikethrough density]
A: OD value Black Less than 0.10
Yellow less than 0.08
Magenta less than 0.09
Cyan Less than 0.10 B: OD value Black 0.10 or more and less than 0.20
Yellow 0.08 or more and less than 0.16
Magenta 0.09 or more and less than 0.18
Cyan 0.10 or more and less than 0.20 C: OD value Black 0.20 or more and less than 0.50
Yellow 0.16 or more and less than 0.40
Magenta 0.18 or more and less than 0.40
Cyan 0.20 or more and less than 0.50 D: OD value Black 0.50 or more
Yellow 0.40 or more
Magenta 0.40 or higher
Cyan 0.50 or more

101 apparatus main body 102 paper feed tray 103 paper discharge tray 104 ink storage container loading unit 105 operation unit 111 upper cover 112 front surface 115 front cover 131 guide rod 132 stay 133 carriage 134 recording head 135 sub tank 141 paper placement unit 142 paper 143 paper supply Roller 144 Separation pad 145 Guide 151 Conveying belt 152 Counter roller 153 Conveying guide 154 Pressing member 155 Tip pressure roller 156 Charging roller 157 Conveying roller 158 Tension roller 161 Guide member 171 Separating claw 172 Discharging roller 173 Discharging roller 181 Double-sided sheet feeding Unit 182 Manual paper feed unit 200 Ink container 241 Ink container 242 Ink inlet 243 Ink outlet 244 Cartridge exterior

JP 2007-153985 A JP 2011-122072 A JP 2009-084494 A

Claims (14)

An ink for inkjet recording having at least water, a water-soluble solvent, a pigment, and a copolymer containing a phosphate group, wherein the copolymer containing the phosphate group is represented by (formula 1); An ink for inkjet recording, comprising at least a structural unit represented by (Formula 2) and a structural unit represented by (Formula 3) or (Formula 4).

R1 in (Formula 1) represents a hydrogen atom or a methyl group. M represents a hydrogen atom, an alkali metal, or organic ammonium. n and m each represent an integer of 0 to 6 (provided that the values of n and m must not be 0 at the same time).

R2 in (Formula 3) represents a hydrogen atom or a methyl group.

R3 in (Formula 4) represents a hydrogen atom or a methyl group.   The ink for inkjet recording according to claim 1, wherein the content of the structural unit of (Formula 1) in the copolymer containing a phosphoric acid group is 10% by mass to 60% by mass.   The viscosity of the 10% by weight solid content aqueous solution or 10% by weight solid content aqueous dispersion of the copolymer containing phosphoric acid groups is 4.0 to 30.0 mPa · s, according to claim 1 or 2. The ink for inkjet recording as described. In an inkjet recording ink having at least water, a water-soluble solvent, a pigment, and a copolymer containing a phosphoric acid group, the copolymer containing the phosphoric acid group is a monomer represented by (formula 5); ) And a monomer represented by (Formula 7) or (Formula 8) at least as starting materials, and a part or all of the phosphate groups of the copolymer are alkali metal or organic An ink for ink jet recording, which is neutralized with a base selected from amines.

R4 in (Formula 5) represents a hydrogen atom or a methyl group. n and m each represent an integer of 0 to 6 (provided that the values of n and m must not be 0 at the same time).

R5 in (Formula 7) represents a hydrogen atom or a methyl group.

R6 in (Formula 8) represents a hydrogen atom or a methyl group.   The ink-jet recording ink is obtained by mixing an aqueous dispersion of a pigment composed of a pigment, water, and a copolymer containing a phosphoric acid group, water, and a water-soluble solvent. Item 4. The inkjet recording ink according to any one of Items 1 to 3.   6. The inkjet according to claim 5, wherein a mass ratio of the pigment and the copolymer containing a phosphate group in the aqueous dispersion of the pigment is pigment / copolymer = 100/10 to 100/100. Recording ink.   7. The inkjet according to claim 1, wherein the structural unit of (Formula 1) constituting the copolymer containing a phosphate group is m = 0 and n = 1. Recording ink.   8. The inkjet according to claim 1, wherein M of (Formula 1) constituting the phosphoric acid group-containing copolymer is a hydrogen atom, a potassium atom, or a sodium atom. Recording ink.   The ratio of hydrogen atoms to the total number of M in the copolymer is 0% to 40% with respect to M of (Formula 1) constituting the copolymer containing a phosphate group. The ink for inkjet recording in any one of 3, 5-8.   The ink for inkjet recording according to any one of claims 1 to 9, wherein the water-soluble solvent contains glycerin.   An ink storage container having an ink storage portion for storing ink, wherein the ink stored in the ink storage portion is the ink for ink jet recording according to any one of claims 1 to 10. Ink container.   An ink jet recording apparatus for recording information or an image on a recording medium using an ink jet head, wherein the ink is the ink for ink jet recording according to any one of claims 1 to 10. Recording device.   It is a manufacturing method of the recorded matter which has the process of discharging ink from an ink-jet head and recording on a recording medium, The ink is the ink for ink-jet recording according to any one of claims 1 to 10. A method for producing recorded material.   A recorded matter in which information or an image is recorded on a recording medium using ink, wherein the ink is the ink for ink jet recording according to any one of claims 1 to 10.

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