JP6043658B2 - Ink for ink jet recording, ink cartridge using the ink, ink jet recording apparatus, ink jet recording method, and ink recorded matter - Google Patents

Description

  The present invention relates to an ink for ink jet recording (hereinafter sometimes simply referred to as “ink”), an ink cartridge, an ink jet recording apparatus, an ink jet recording method, and an ink recorded matter using the 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.
Inkjet recording method is a method of causing a small amount of ink to fly with pressure generated using bubbles generated by heat, piezo or static electricity, and to adhere to a recording medium such as paper, and to dry quickly, or recording medium In this method, an image is formed by penetrating into the printer, and its application has been expanded to personal and industrial printers and printing.

In the ink jet recording apparatus, a water-based ink using a water-soluble dye as a pigment is mainly used. However, the dye ink has a defect 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 recent years, demand for industrial applications has been increasing, and high-speed printing is desired. Ink jet printers equipped with line heads have been proposed along with high-speed printing. 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. In addition to this, 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, an ink used for recording on paper containing a water-soluble polyvalent metal salt has been proposed (see Patent Document 1). This proposed ink has (a) a pigment, (b) a functional group having no surface active ability, a molecular weight of 150 to 10,000, and having phosphoric acid as a basic skeleton in the molecular structure. It contains at least one compound having a phosphorus content ((P content / molecular weight) × 100) of 1.4 or more derived from a functional group selected from functional groups having phosphonic acid as a basic skeleton, (b ) The content (% by mass) of the compound is 1.5% by mass or more and 10.0% by mass or less based on the total mass of the ink.

  However, in the proposed method, the image density is not sufficiently improved on plain paper having a low content of water-soluble polyvalent metal salt. In addition, when a compound having a functional group selected from a functional group having a basic skeleton of phosphoric acid and a functional group having a basic skeleton of phosphonic acid is used, the image density is improved, but the dispersion of the pigment in the ink is unstable. There is a problem of becoming.

  Therefore, it is desired to provide an ink for inkjet recording that can achieve both high image density on plain paper and improvement in storage stability and ejection stability of 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 on plain paper and has good ink storage stability and ejection stability.

The ink for ink jet recording of the present invention as a means for solving the above-mentioned problems comprises water, a water-soluble solvent, a pigment, and a copolymer containing a phosphate group,
The copolymer containing a phosphoric acid group includes a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), the following general formula (3), and the following general formula ( 4) at least.
In the general formula (1), R ¹ represents a hydrogen atom or a methyl group. M ⁺ represents one of an alkali metal ion, an organic amine ion and a hydrogen ion, more than half of M ^{+ in} the copolymer is either an alkali metal ion or an organic amine ion, and the rest are hydrogen ions. .
However, In the general formula (2), R ² represents a hydrogen atom or a methyl group.
In the general formula (3), R ³ represents a hydrogen atom or a methyl group.
In the general formula (4), R ⁴ represents a hydrogen atom or a methyl group.

  According to the present invention, it is possible to solve the above-described conventional problems, achieve the above-described object, obtain a high image density on plain paper, and provide an ink for ink jet recording having good ink storage stability and ejection stability. Can be provided.

FIG. 1 is a schematic diagram illustrating an example of an ink cartridge. FIG. 2 is a schematic view including the case of the ink cartridge of FIG. FIG. 3 is a perspective view showing an example of an ink jet recording apparatus. FIG. 4 is a diagram illustrating an example of an ink jet recording apparatus. FIG. 5 is a schematic enlarged view showing an example of an ink jet head of the ink jet recording apparatus.

(Inkjet recording ink)
The ink for inkjet recording of the present invention contains water, a water-soluble solvent, a pigment, and a copolymer containing a phosphate group, and further contains other components as necessary.

As the copolymer containing a phosphate group, a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), the following general formula (3) and the following general formula And at least a structural unit represented by any one of (4).
In the general formula (1), R ¹ represents a hydrogen atom or a methyl group. M ⁺ represents one of an alkali metal ion, an organic amine ion and a hydrogen ion, more than half of M ^{+ in} the copolymer is either an alkali metal ion or an organic amine ion, and the rest are hydrogen ions. .
However, In the general formula (2), R ² represents a hydrogen atom or a methyl group.
In the general formula (3), R ³ represents a hydrogen atom or a methyl group.
In the general formula (4), R ⁴ represents a hydrogen atom or a methyl group.

The phosphate group contained in the structural unit represented by the general formula (1) exhibits hydrophilicity, but has a characteristic of exhibiting hydrophobicity by binding to a polyvalent metal ion (particularly calcium ion). Therefore, ink for inkjet recording using a copolymer containing a phosphate group as a pigment dispersant is eluted from the recording medium into the ink when an image is formed on the recording medium containing a water-soluble polyvalent metal salt. The phosphate group contained in the structural unit represented by the general formula (1) is hydrophobized by the polyvalent metal ion, and the pigment stays on the surface of the paper by agglomerating the pigment, thereby improving the image density. To do.
However, in the case of PPC plain paper, the contained polyvalent metal salt is generally poorly water-soluble calcium carbonate, and the amount of calcium ions eluted into the ink is small. Therefore, a sufficient image density cannot be obtained on plain paper only by including the structural unit represented by the general formula (1).
As one method for solving the above problem, it is conceivable to increase the ratio of the structural unit represented by the general formula (1) in the copolymer containing a phosphate group. However, if the ratio of the structural unit represented by the general formula (1) is increased, the interaction between the phosphate groups becomes stronger, or the copolymer containing the phosphate groups is gelled. There is a problem of causing a decline in sex. Therefore, the constituent ratio of the conventional copolymer containing phosphate groups has to be less than 20% by mass.

In the present invention, the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), and any one of the general formula (3) and the general formula (4). By combining with the structural unit represented, the affinity for the pigment is improved, the aggregation effect involving the pigment is improved, and the storage stability is improved even with an ink having a high water-soluble solvent content. In addition, the gelation of the copolymer is less likely to occur, the ratio of the structural unit represented by the general formula (1) can be increased, and the reactivity with polyvalent metal ions (especially calcium ions) can be increased. It can be improved. The structural unit represented by either the general formula (3) or the general formula (4) is particularly good in affinity with the pigment, and is used in combination with the structural unit represented by the general formula (2). Thus, the effect of improving the affinity for the pigment and suppressing the gelation of the copolymer containing a phosphate group can be obtained.
The ink for inkjet recording of the present invention is further divided into the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2), and the general formula (3) and the general formula (4). ), It is possible to obtain a high image density even on general plain paper with few water-soluble polyvalent metal salts by using a copolymer containing a phosphate group containing a structural unit represented by any one of Storage stability and ejection stability can be improved.

<Copolymer containing phosphate group>
The copolymer containing a phosphate group includes a structural unit represented by the general formula (1), a structural unit represented by the general formula (2), the general formula (3), and the general formula (4). At least a structural unit represented by any of the above, and further includes other structural units as necessary.

The copolymer containing a phosphoric acid group reacts with polyvalent metal ions (particularly calcium ions) contained in plain paper when ink jet recording ink lands on a recording medium such as plain paper, and aggregates. It is what has. By this function, it is possible to obtain a high image density by suppressing the penetration of the ink into the paper.
In the present invention, the copolymer containing a phosphoric acid group can be used as a pigment dispersant or additive. In particular, by using it as a pigment dispersant, an ink having a higher image density and storage stability. Can be provided.

In the general formula (1), R ¹ represents either a hydrogen atom or a methyl group.
Examples of the alkali metal in the M ⁺ alkali metal ion in the general formula (1) include lithium, sodium, and potassium.
Examples of the organic amine in the M ⁺ organic amine ion in the general formula (1) include alkylamines such as mono-, di- or trimethylamine, mono-, di- or triethylamine; ethanolamine, diethanolamine, triethanolamine, methylethanol Alcohols such as amine, methyldiethanolamine, dimethylethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, isopropanolamine, trishydroxymethylaminomethane, 2-amino-2-ethyl-1,3-propanediol (AEPD) Amines; cyclic amines such as choline, morpholine, N-methylmonoformin, N-methyl-2-pyrrolidone, 2-pyrrolidone, tetramethylammonium, tetraethylammonium, And organic ammonium such as tetrabutylammonium.
Among these, ethanolamine and dimethylethanolamine are preferable from the viewpoints of storage stability and ejection stability of the ink.
As M ⁺ , half or more are preferably alkali metal ions or organic amine ions, and the rest are preferably hydrogen ions (protons). The neutralization rate of the copolymer containing a phosphate group is preferably 50% or more. ), Image density, storage stability, and ejection stability, all (neutralization rate is 100%) are particularly preferably alkali metal ions or organic amine ions.
When the neutralization rate is less than 50%, the dispersion of the pigment becomes unstable, and the initial viscosity of the pigment dispersion may increase or the storage stability may decrease.
The neutralization rate is a neutralizing agent for the charged amount of the structural unit (monomer represented by the following general formula (5)) represented by the general formula (1) at the time of synthesizing the copolymer containing a phosphate group. It can obtain | require from the ratio of the addition amount of.

The copolymer containing a phosphate group includes a structural unit represented by the general formula (1), a structural unit represented by the general formula (2), the general formula (3), and the general formula (4). In addition to the structural unit represented by any of the above, structural units derived from other monomers can be included.
There is no restriction | limiting in particular as said other monomer, According to the objective, it can select suitably, For example, a polymerizable hydrophobic monomer, a polymerizable hydrophilic monomer, etc. are mentioned.

  The polymerizable hydrophobic monomer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aromatics such as styrene, α-methylstyrene, 4-t-butylstyrene, and 4-chloromethylstyrene. Unsaturated ethylene monomer having an aromatic ring; methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, dimethyl maleate, dimethyl itaconate, dimethyl fumarate, lauryl (meth) acrylate (C12), tridecyl (meth) acrylate (C13), tetradecyl (meth) acrylate (C14), pentadecyl (meth) acrylate (C15), hexadecyl (meth) acrylate (C16), heptadecyl (meth) acrylate (C17), nonadecyl (meth) acrylate (C19), (meth) acrylic acid ray Alkyl (meth) acrylates such as syl (C20), heicosyl (meth) acrylate (C21), docosyl (meth) acrylate (C22); 1-heptene, 3,3-dimethyl-1-pentene, 4,4 -Dimethyl-1-pentene, 3-methyl-1-hexene, 4-methyl-1-hexene, 5-methyl-1-hexene, 1-octene, 3,3-dimethyl-1-hexene, 3,4-dimethyl -1-hexene, 4,4-dimethyl-1-hexene, 1-nonene, 3,5,5-trimethyl-1-hexene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene , 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicocene, 1-docose, etc. Monomer, and the like. These may be used individually by 1 type and may use 2 or more types together.

  The polymerizable hydrophilic monomer is not particularly limited and may be appropriately selected depending on the purpose. For example, (meth) acrylic acid or a salt thereof, maleic acid or a salt thereof, monomethyl maleate, itaconic acid, Anionic unsaturated ethylene monomers such as monomethyl itaconic acid, fumaric acid, 4-styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid; (meth) acrylic acid-2-hydroxyethyl, diethylene glycol mono (meth) acrylate, Triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide, N-vinylformamide, N-vinylacetamide N- vinylpyrrolidone, acrylamide, N, N- dimethylacrylamide, N-t-butylacrylamide, N- octyl acrylamide, nonionic ethylenically unsaturated monomers such as N-t-octyl acrylamide, and the like. These may be used individually by 1 type and may use 2 or more types together.

  The content of the structural unit represented by the general formula (1) in the copolymer containing a phosphate group is not particularly limited and can be appropriately selected depending on the purpose. 10 mass%-60 mass% are preferable with respect to mass, and 15 mass%-50 mass% are more preferable. When the content is less than 10% by mass, the image density may decrease, and when it exceeds 60% by mass, the storage stability of the pigment dispersion and the ink may decrease.

  The content of the structural unit represented by the general formula (2) in the copolymer containing a phosphate group is not particularly limited and may be appropriately selected depending on the intended purpose. 1 mass%-40 mass% are preferable with respect to mass, and 5 mass%-30 mass% are more preferable.

The copolymer containing a phosphate group includes a monomer represented by the following general formula (5), a monomer represented by the following general formula (6), the following general formula (7), and the following general formula (8). It can synthesize | combine by superposing | polymerizing the monomer represented by either, and another monomer as needed. Next, the obtained copolymer is neutralized with either an alkali metal base or an organic amine base.
In the general formula (5), R ⁵ represents a hydrogen atom or a methyl group.
In the general formula (6), R ⁶ represents a hydrogen atom or a methyl group.
In the general formula (7), R ⁷ represents a hydrogen atom or a methyl group.
In the general formula (8), R ⁸ represents a hydrogen atom or a methyl group.

Examples of the monomer represented by the general formula (5) include 2-methacryloxyethyl acid phosphoate and 2-acryloxyethyl acid phosphoate.
As the 2-methacryloxyethyl acid phosphoate, an appropriately synthesized product or a commercially available product may be used. Examples of the commercially available products are commercially available from Kyoeisha Chemical Industry Co., Ltd. under the product name “Light Ester P-1M” and from Unichemical Co., Ltd. under the product name “Phosmer M”.
As the 2-acryloxyethyl acid phosphoate, an appropriately synthesized product or a commercially available product may be used. As said commercial item, it is marketed with the product name of "light acrylate P-1A" from Kyoeisha Chemical Co., Ltd., for example, and is available.

Examples of the monomer represented by the general formula (6) include 2-methacryloyloxyethyl phosphorylcholine and 2-acryloyloxyethyl phosphorylcholine.
As said 2-methacryloyloxyethyl phosphorylcholine, what was synthesize | combined suitably can be used.
As said 2-acryloyloxyethyl phosphorylcholine, what was synthesize | combined suitably can be used.

  Examples of the monomer represented by the general formula (7) include stearyl methacrylate and stearyl acrylate.

  Examples of the monomer represented by the general formula (8) include benzyl methacrylate and benzyl acrylate.

The polymerization method of the copolymer containing a phosphate group used in the present invention is not particularly limited, and various known synthesis methods such as solution polymerization, suspension polymerization, bulk polymerization, and emulsion polymerization can be used. However, a method using a radical polymerization initiator is preferred because the polymerization operation and the adjustment of the molecular weight are easy.
The radical polymerization initiator is not particularly limited and can be used as long as it is generally used. Specifically, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxydicarbonate, Peroxyesters, cyano azobisisobutyronitrile, azobis (2-methylbutyronitrile), azobis (2,2′-isovaleronitrile), non-cyano dimethyl-2,2′-azobisiso Examples include butyrate.
Among these, organic peroxides and azo compounds having a low molecular weight and easy decomposition are preferable, and azo compounds are particularly preferable.
The amount of the polymerization initiator used is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1% by mass to 10% by mass with respect to the total mass of the polymerizable monomer.
Further, in order to adjust the molecular weight of the copolymer containing a phosphate group, for example, mercaptoacetic acid, mercaptopropionic acid, 2-propanethiol, 2-mercaptoethanol, thiophenol, dodecyl mercaptan, 1-dodecanethiol, thioglycerol A suitable amount of a chain transfer agent such as may be added to the polymerization system.
There is no restriction | limiting in particular in superposition | polymerization temperature, Although it can select suitably according to the objective, 50 to 150 degreeC is preferable. The polymerization time is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3 hours to 48 hours.

The copolymer containing a phosphate group includes a monomer represented by the general formula (5), a monomer represented by the general formula (6), the general formula (7), and the general formula (8). A monomer represented by any one of the above is synthesized at least as a starting material. In addition, you may add another monomer component to the copolymer containing the said phosphate group.
The copolymer containing a phosphoric acid group is, for example, a thermometer, a stirrer, and a nitrogen introduction tube installed in a four-necked flask, a solvent, a monomer represented by the general formula (5), and the general formula (6 ) And a monomer represented by any one of the general formula (7) and the general formula (8), if necessary, adding a polymerization initiator and a chain transfer agent, Polymerization is possible at 0 ° C.

Some or all of the phosphate groups in the copolymer containing phosphate groups are neutralized with a base. The neutralization treatment can also be performed in a state where the pigment and the copolymer are mixed in the production of the ink.
Examples of the base used for the neutralization treatment include alkali metals and organic amines, and specific examples thereof are as described above.

The viscosity of the 10% by mass aqueous solution of the copolymer containing a phosphoric acid group is not particularly limited and may be appropriately selected depending on the intended purpose. It is 2.5 mPa · s to 35.0 mPa · s at 25 ° C. Is preferable, and 4.0 mPa · s to 30.0 mPa · s is more preferable. If the viscosity is less than 2.5 mPa · s, the reactivity between the metal ion eluted from the recording medium such as plain paper and the pigment dispersant may decrease, and the image density may decrease slightly, 35. If it exceeds 0 mPa · s, the dispersion stability of the pigment may decrease, and the storage stability of the pigment dispersion may slightly decrease.
The viscosity can be measured by, for example, a rotational viscometer (TV-22 type viscometer, cone plate type, manufactured by Toki Sangyo Co., Ltd.).

The copolymer containing a phosphoric acid group is not particularly limited and can be widely used in various fields. In an ink for ink jet recording, a chelating agent, a pigment concentration improver, a binder resin for pigment, a viscosity modifier, etc. Can be suitably used as additives, pigment dispersants, and the like.
The content of the ink for inkjet recording when the copolymer containing a phosphate group is used as an additive is not particularly limited and may be appropriately selected depending on the intended purpose. 10 mass% is preferable and 1 mass%-5 mass% are more preferable. When the content is 0.5% by mass or more, the effect of improving the image density clearly appears, and by making it 10% by mass or less, it is possible to keep the viscosity within a range suitable for discharging ink from the head. It becomes.

When the copolymer containing a phosphoric acid group is used as a pigment dispersant, the image density on plain paper can be improved. Furthermore, a further improvement is seen in the storage stability with rich ink in which the content of the water-soluble solvent exceeds 20% by mass.
The content in the inkjet recording ink when the copolymer containing a phosphoric acid group is used as a pigment dispersant is not particularly limited and may be appropriately selected depending on the intended purpose. 1 mass part-100 mass parts is preferable with respect to 5 mass parts-80 mass parts. 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>
The water is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, and distilled water, and ultrapure water. It is done.
The content of the water in the inkjet recording ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 20% by mass to 60% by mass.

<Water-soluble solvent>
The water-soluble solvent has a function of improving ejection stability by providing a moisturizing effect.
The water-soluble solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include ethylene glycol, diethylene glycol, 1,3-butanediol, 3-methyl-1,3-butyl glycol, and 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- Polyhydric alcohols such as trimethyl-1,3-pentanediol, 1,2,4-butanetriol, 1,2,3-butanetriol, petriol, trimethylolpropane, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether , Diethylene glycol monomer Ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, polyethylene alcohol alkyl ethers such as tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone and other nitrogen-containing heterocyclic compounds, formamide, N- Amides such as methylformamide and N, N-dimethylformamide, amines such as monoethanolamine, diethanolamine and triethylamine, dimethyl Sulfoxide, sulfolane, sulfur-containing compounds such as thiodiethanol, propylene carbonate, and the like ethylene carbonate.
These may be used individually by 1 type and may use 2 or more types together. Among these, 1,3-butanediol, 2-pyrrolidone, glycerin, and trimethylolpropane are preferable from the viewpoint of preventing ejection failure due to moisture evaporation.

  There is no restriction | limiting in particular in content in the said inkjet recording ink of the said water-soluble solvent, Although it can select suitably according to the objective, 10 mass%-50 mass% are preferable. If the content is less than 10% by mass, the ink easily evaporates, and thickened ink may be clogged due to evaporation of the ink in the ink supply system in the inkjet recording apparatus. If the content exceeds 50% by mass, clogging of thickened ink is less likely to occur in the ink jet recording apparatus, but it is necessary to reduce the amount of solids such as pigments and resins in order to make the ink have a desired viscosity. In some cases, the image density of the ink recorded matter may decrease.

<Pigment>
There is no restriction | limiting in particular as said pigment, 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 a phthalocyanine pigment, a perylene pigment, a perinone pigment, an anthraquinone pigment, a quinacridone pigment, a dioxazine pigment, an indigo pigment, a thioindigo pigment, an isoindolinone pigment, a quinofullerone pigment, and a rhodamine B lake pigment. 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, the specific surface area by the BET ^{method, 50m 2 / g~300m 2 / g} , DBP oil absorption of 40 mL / 100 g to 150 mL / 100 g, a volatile content of 0.5% to 10%, and a pH of 2 to 9 are preferable.
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); Raven 700, Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255 (all from Columbian Chemicals); Regal 400R, Regal 330R, Regal 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400 (all manufactured by Cabot Corporation); Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18V Color Black FW200, Color Black S150, Color Black S160, Lur Black S170, Printex 35, Printex U, Printex V, Printex 140U, Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4, NIPEX 160 (all manufactured by Evonik Degussa) ), Etc.

  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.
In addition, as a yellow pigment, C.I. I. Pigment Yellow 74, C.I. I. Pigment red 122, C.I. I. Pigment Bio Red 19, C.I. I. By using CI Pigment Blue 15: 3, a well-balanced ink having excellent color tone and light resistance can be obtained.
Furthermore, the pigment used in the present invention may be a grafted or encapsulated product coated with a surfactant or resin such as a dispersant, but the compound of the present invention is used as a dispersant. Is more preferable.
In addition, you may use together the pigment mentioned above in the range which does not impair an effect.
The volume average particle diameter of the pigment is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 150 nm or less.
The volume average particle diameter of the pigment can be 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 in content in the said inkjet recording ink of the said pigment, Although it can select suitably according to the objective, 0.1 mass%-20 mass% are preferable.

A pigment dispersion is preferably used as the pigment.
The pigment dispersion is obtained by mixing water, a pigment, a pigment dispersant, and, if necessary, other components, and then dispersing the mixture with a disperser and adjusting the particle size.
As the pigment dispersant, it is preferable to use the phosphate group-containing copolymer of the present invention. Examples of other usable dispersants include an anionic surfactant, a cationic surfactant, and an amphoteric interface. Examples of the surfactant include various surfactants such as a nonionic surfactant, a naphthalenesulfonic acid Na formalin condensate, and a polymer-type dispersant. 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 taurates, polyoxyalkyl ethers. Sulfate, polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate, lauryl alcohol sulfate, alkylphenol phosphate, naphthalenesulfonate formalin condensate, alkyl phosphate, alkylallylsulfone hydrochloride, Examples include diethyl sulfosuccinate, diethyl hexyl sulfosuccinate, and dioctyl sulfosuccinate.
Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.
Examples of the amphoteric surfactant include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, Examples include imidazoline derivatives.
Examples of the nonionic surfactant include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl ether, Ether type surfactants such as oxyallylalkyl alkyl ethers; polyoxyethylene oleic acid, polyoxyethylene oleic acid ester, polyoxyethylene distearic acid ester, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate Ester surfactants such as polyoxyethylene monooleate and polyoxyethylene stearate; 2,4,7,9-tetramethyl Acetylene glycol surfactants such as lu-5-decyne-4,7-diol, 3,6-dimethyl-4-octyl-3,6-diol, 3,5-dimethyl-1-hexyn-3-ol, Etc.

There is no restriction | limiting in particular in content of the pigment at the time of producing the said pigment dispersion, Although it can select suitably according to the objective, 0.1 mass%-50 mass% are preferable, 0.1 mass%- 30 mass% is more preferable.
The obtained pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifugal separator or the like, if necessary.

<Other ingredients>
The other components are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include an inhibitor, an ultraviolet absorber, an oxygen absorber, and a light stabilizer.

-Penetration agent-
The penetrant preferably contains either a polyol compound having 8 to 11 carbon atoms or a glycol ether compound having 8 to 11 carbon atoms.
The penetrating agent is different from the wetting agent and has a relatively low wetting property than the wetting agent, and thus can be referred to as a “non-wetting agent-based medium”. These non-wetting agent penetrants preferably have a solubility of between 0.2% and 5.0% by weight in water at 25 ° C.
Among these, 2-ethyl-1,3-hexanediol [solubility: 4.2% by mass (25 ° C.)], 2,2,4-trimethyl-1,3-pentanediol [solubility: 2.0% by mass] (25 ° C.)] is particularly preferred.
As other polyol compounds, as aliphatic diols, for example, 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 2,2-diethyl-1, 3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene- 1,2-diol and the like can be mentioned.
Other penetrants that can be used in combination are not particularly limited as long as they can be dissolved in the ink and adjusted to the desired physical properties, and can be appropriately selected according to the purpose. For example, diethylene glycol monophenyl ether, ethylene Glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, alkyl and aryl ethers of polyhydric alcohols such as tetraethylene glycol chlorophenyl ether, lower alcohols such as ethanol, etc. Is mentioned.
There is no restriction | limiting in particular in content in the said ink for inkjet recording of the said penetrant, Although it can select suitably according to the objective, 0.1 mass%-4 mass% are preferable. When the content is less than 0.1% by mass, a fast drying property cannot be obtained and a blurred image may be obtained. In some cases, the permeability to the recording medium (recording medium) becomes unnecessarily high, or the image density is lowered or the back-through occurs.

-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 recording ink to be prepared. Examples thereof include alcohol amines, hydroxides of alkali metal elements, ammonium hydroxides, phosphonium hydroxides, and alkali metal carbonates. If the pH is less than 8.5 or more than 11, the amount of the ink-jet head or ink supply unit that melts 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 preferable.
The volume average particle size of the water-dispersible resin is related to the viscosity of the dispersion. For the same composition, the viscosity at the same solid content increases as the particle size decreases. The volume average particle diameter 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 is more preferably 200 nm or less in order not to inhibit the ink ejection stability.
Here, the volume average particle diameter of the water-dispersible resin is measured by a dynamic light scattering method using a 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 pigment. 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 ink for inkjet recording is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1% by mass to 15% by mass, and 2% by mass to 7% by mass. Is more preferable.

-Antiseptic and fungicide-
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.

-Antirust agent-
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.

<Method for producing ink for inkjet recording>
The inkjet recording ink is prepared 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 stirring and mixing as necessary. Can be manufactured.
The dispersion can be performed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, and the like. be able to.

The viscosity at 25 ° C. of the ink for inkjet recording of the present invention is not particularly limited and can be appropriately selected according to the purpose, but is preferably 3 mPa · s to 20 mPa · s. By setting the viscosity to 3 mPa · s or more, the effect of improving the printing density and character quality can be obtained. On the other hand, by suppressing the viscosity to 20 mPa · s or less, dischargeability can be ensured.
The viscosity can be measured at 25 ° C. using, for example, a viscometer (RL-550, manufactured by Toki Sangyo Co., Ltd.).
There is no restriction | limiting in particular as surface tension of the said ink for inkjet recording, Although it can select suitably according to the objective, 40 mN / m or less is preferable at 25 degreeC. 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 cartridge)
The ink cartridge of the present invention contains the ink-jet recording ink of the present invention in a container, and further includes other members appropriately selected as necessary.
The container is not particularly limited in its shape, structure, size, and material, and can be appropriately selected according to the purpose. For example, the container has at least an ink bag formed of an aluminum laminate film, a resin film, or the like. Are preferable.

One aspect of the ink cartridge 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 cartridge of the present invention. FIG. 2 is a schematic plan view including a case (exterior) of the ink cartridge of FIG.
As shown in FIG. 1, the ink cartridge 200 is filled into the ink bag 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 bag 241 is formed of a packaging member such as a non-permeable aluminum laminate film. As shown in FIG. 2, the ink bag 241 is usually housed 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 includes at least ink flying means, and further includes other means appropriately selected as necessary, for example, stimulus generation means, control means, and the like.
The inkjet recording method 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 of the present invention 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. The other steps can be suitably performed by the other means.

<Ink flying process and ink flying 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. There is no restriction | limiting in particular as said ink flying means, According to the objective, it can select suitably, For example, the various nozzles for ink discharge etc. are mentioned.

The stimulus can be generated by, for example, the stimulus generating means, and the stimulus is not particularly limited and can be appropriately selected according to the purpose. For example, heat (temperature), pressure, vibration, light , Etc. 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 heating device, a pressurizing device, a piezoelectric element, a vibration generating device, an ultrasonic oscillator, a light, and the like. Specifically, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, a shape memory alloy actuator that uses a metal phase change caused by a temperature change, For example, an electrostatic actuator using an electrostatic force may be used.

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 heat corresponding to the recording signal is applied to the ink in the recording head. A method of applying energy using, for example, a thermal head, 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, etc. Can be mentioned. 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 a sequencer and a computer.

Here, one aspect of carrying out the ink jet recording method of the present invention 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 serial type 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 mounted on the apparatus main body 101, and paper on which an image is recorded (formed) mounted on the apparatus main body 101. A paper discharge tray 103 and an ink cartridge loading unit 104 protruding forward from the front surface 112 and lower than the upper cover 111 are provided on one end portion of the front surface 112 of the apparatus main body 101. On the upper surface of the ink cartridge loading unit 104, an operation unit 105 such as operation keys and a display is arranged. The ink cartridge loading unit 104 has a front cover 115 that can be opened and closed for attaching and detaching the ink cartridge 200.

As shown in FIGS. 4 and 5 (partially enlarged cross-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 is provided with a recording head 134 composed of four ink jet recording heads that eject ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). Are arranged in a direction crossing the main scanning direction, and the ink droplet ejection direction is directed downward.
As the ink jet recording head constituting the recording head 134, a piezoelectric actuator such as a piezoelectric element, a thermal actuator using phase change due to liquid film boiling using an electrothermal transducer such as a heating resistor, a metal phase due to temperature change, etc. A shape memory alloy actuator using a change, 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 supplied with the ink from the ink cartridge 200 of the present invention loaded in the ink cartridge loading unit 104 via an ink supply tube (not shown) and is replenished.

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 103, a half-moon roller (feeding) that separates and feeds the paper 142 one by one from the paper stacking unit 141. 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 ° 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 adsorption 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. And a back layer (medium resistance layer, grounding layer) that is controlled by carbon with the same material. 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 conveyance belt 157 is charged by the charging roller 156, and the sheet 142 is conveyed by being electrostatically attracted to the conveyance belt 151. 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 the ink remaining amount near end in the sub tank 135 is detected, a required amount of ink is supplied from the ink cartridge 200 to the sub tank 135.

  In this ink jet recording apparatus, when the ink in the ink cartridge 201 of the present invention is used up, the casing of the ink cartridge 200 can be disassembled and only the ink bag inside can be replaced. Further, the ink cartridge 200 can supply ink stably even when the ink cartridge 200 is installed vertically and has a front loading configuration. Therefore, the ink cartridge 200 is installed even when the upper portion of the apparatus main body 101 is closed, for example, when stored in a rack, or when an object is placed on the upper surface of the apparatus main body 101. 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.

(Ink record)
The ink recorded matter of the present invention has an image recorded with the ink jet recording ink 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 inkjet recording ink of the present invention improves the drying property and can be used.
The ink recorded matter of the present invention has high image quality, no bleeding, excellent stability with time, and can be suitably used for various purposes as materials 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 these examples.

The following abbreviations mean the following compounds.
PMA: 2-methacryloxyethyl acid phosphoate ("Phosmer M", manufactured by Unichemical Co., Ltd.)
PA: 2-acryloylethyl acid phosphoate ("Light acrylate P-1A", manufactured by Kyoeisha Chemical Industry Co., Ltd.)
MPC: 2-methacryloyloxyethyl phosphorylcholine (manufactured by NOF Corporation)
APC: 2-acryloyloxyethyl phosphorylcholine (manufactured by NOF Corporation)
SMA: Stearyl methacrylate ("Light Ester S", manufactured by Kyoeisha Chemical Co., Ltd.)
SA: Stearyl acrylate ("Light acrylate SA", manufactured by Kyoeisha Chemical Industry Co., Ltd.)
BzMA: benzyl methacrylate ("light ester BZ", manufactured by Kyoeisha Chemical Co., Ltd.)
AIBN: Azobisisobutyronitrile

  The viscosity of the copolymer was measured according to the following method. Moreover, the neutralization rate of the copolymer was calculated as follows.

<Measurement of viscosity of copolymer>
The viscosity of a 10% by weight aqueous solution of the synthesized copolymer was measured using a rotational viscometer (TV-22 viscometer, cone plate type, manufactured by Toki Sangyo Co., Ltd.). Specific operations are shown below. 1.1 mL of the copolymer was collected and placed in a viscometer sample cup. At 25 ° C., the sample cup was attached to the viscometer body and allowed to stand for 1 minute, and then the viscometer rotor was rotated to read the value after 1 minute.

<Neutralization rate of copolymer>
The neutralization rate of the copolymer was determined from the ratio of the added amount of the neutralizing agent to the charged amount of the monomer containing a phosphate group at the time of synthesizing the copolymer.

(Synthesis Example 1)
-Synthesis of Copolymer 1-
PMA; 12.00 g, MPC; 4.00 g, SMA; 24.00 g, and ethanol 226.67 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, the solution whose concentration was accurately adjusted to 10% by mass after purification was designated as an aqueous solution of copolymer 1. The viscosity of the aqueous solution of the obtained copolymer 1 was 13.7 mPa · s at 25 ° C.

(Synthesis Example 2)
-Synthesis of Copolymer 2-
PMA; 12.00 g, MPC; 4.00 g, BzMA; 24.00 g, and ethanol 226.67 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, an aqueous solution of the copolymer 2 was prepared by adjusting the concentration accurately to 10% by mass after purification. The viscosity of the aqueous solution of the obtained copolymer 2 was 14.3 mPa · s at 25 ° C.

(Synthesis Example 3)
-Synthesis of Copolymer 3-
PMA; 12.00 g, MPC; 4.00 g, SMA; 24.00 g, and ethanol 226.67 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. The viscosity of the polymer solution removed by the evaporator is diluted with water, neutralized with sodium hydroxide so that the neutralization rate is 50%, and purified by dialysis membrane for 3 days. Then, an aqueous solution of the copolymer 3 was prepared by adjusting the concentration to 10% by mass after purification. The viscosity of the aqueous solution of the obtained copolymer 3 was 10.1 mPa · s at 25 ° C.

(Synthesis Example 4)
-Synthesis of Copolymer 4-
PMA; 12.00 g, APC: 4.00 g, SA: 24.00 g, and ethanol 226.67 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, the solution whose concentration was accurately adjusted to 10% by mass after purification was designated as an aqueous solution of copolymer 4. The viscosity of the aqueous solution of the obtained copolymer 4 was 14.5 mPa · s at 25 ° C.

(Synthesis Example 5)
-Synthesis of Copolymer 5-
PMA; 12.00 g, MPC; 4.00 g, BzMA; 24.00 g, and ethanol 226.67 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. The viscosity of the polymer solution removed by the evaporator was diluted with water and the concentration adjusted to 10% by mass was neutralized with monoethanolamine (EA) so that the neutralization rate would be 100%, and then for 3 days. The aqueous solution of copolymer 5 was obtained by purifying the dialysis membrane and adjusting the concentration to 10% by mass after purification. The viscosity of the aqueous solution of the obtained copolymer 5 was 13.5 mPa · s at 25 ° C.

(Synthesis Example 6)
-Synthesis of copolymer 6-
PA: 12.00 g, MPC: 4.00 g, SMA: 24.00 g, and ethanol 226.67 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, an aqueous solution of the copolymer 6 was obtained by adjusting the concentration accurately to 10% by mass after purification. The viscosity of the aqueous solution of the obtained copolymer 6 was 12.8 mPa · s at 25 ° C.

(Synthesis Example 7)
-Synthesis of Copolymer 7-
PMA; 2.67 g, MPC; 2.67 g, SMA; 8.00 g, and 253.33 g of ethanol were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, the solution whose concentration was accurately adjusted to 10% by mass after purification was used as an aqueous solution of copolymer 7. The viscosity of the aqueous solution of the obtained copolymer 7 was 4.0 mPa · s at 25 ° C.

(Synthesis Example 8)
-Synthesis of Copolymer 8-
PMA; 5.33 g, MPC; 13.33 g, BzMA; 34.66 g, and ethanol 213.33 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, the solution whose concentration was accurately adjusted to 10% by mass after purification was designated as an aqueous solution of copolymer 8. The viscosity of the aqueous solution of the obtained copolymer 8 was 27.2 mPa · s at 25 ° C.

(Synthesis Example 9)
-Synthesis of copolymer 9-
PMA; 8.00 g, MPC: 2.00 g, BzMA; 3.33 g, and ethanol 253.33 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. While diluting the viscous product obtained by removing the solvent of the polymerization solution with an evaporator into water, the concentration adjusted to 10% by mass is neutralized with sodium hydroxide so that the neutralization rate becomes 100%, and purified by dialysis membrane for 3 days. Then, an aqueous solution of the copolymer 9 was prepared by adjusting the concentration accurately to 10% by mass after purification. The viscosity of the aqueous solution of the obtained copolymer 9 was 6.2 mPa · s at 25 ° C.

(Synthesis Example 10)
-Synthesis of copolymer 10-
PMA; 32.00 g, MPC; 5.33 g, SMA; 16.00 g, and 213.33 g of ethanol were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, the solution whose concentration was accurately adjusted to 10% by mass after purification was used as an aqueous solution of the copolymer 10. The viscosity of the aqueous solution of the obtained copolymer 10 was 30.0 mPa · s at 25 ° C.

(Synthesis Example 11)
-Synthesis of copolymer 11-
PMA; 2.13 g, MPC; 2.67 g, BzMA; 5.87 g, and ethanol 256.00 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, the solution whose concentration was accurately adjusted to 10% by mass after purification was used as an aqueous solution of the copolymer 11. The viscosity of the aqueous solution of the obtained copolymer 11 was 3.1 mPa · s at 25 ° C.

(Synthesis Example 12)
-Synthesis of copolymer 12-
PMA; 6.13 g, MPC; 12.26 g, SMA; 42.93 g, and ethanol 205.33 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. While diluting the viscous product obtained by removing the solvent of the polymerization solution with an evaporator into water, the concentration adjusted to 10% by mass is neutralized with sodium hydroxide so that the neutralization rate becomes 100%, and purified by dialysis membrane for 3 days. Then, an aqueous solution of the copolymer 12 was prepared by adjusting the concentration to 10% by mass after purification. The viscosity of the aqueous solution of the obtained copolymer 12 was 31.8 mPa · s at 25 ° C.

(Synthesis Example 13)
-Synthesis of copolymer 13-
PMA; 6.40 g, MPC; 2.13 g, SMA; 2.13 g, and ethanol 256.00 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. While diluting the viscous product obtained by removing the solvent of the polymerization solution with an evaporator into water, the concentration adjusted to 10% by mass is neutralized with sodium hydroxide so that the neutralization rate becomes 100%, and purified by dialysis membrane for 3 days. Then, an aqueous solution of the copolymer 13 was prepared by adjusting the concentration accurately to 10% by mass after purification. The viscosity of the aqueous solution of the obtained copolymer 13 was 3.6 mPa · s at 25 ° C.

(Synthesis Example 14)
-Synthesis of copolymer 14-
PMA; 36.80 g, MPC; 6.13 g, BzMA; 18.4 g, and ethanol 205.33 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, a solution whose concentration was accurately adjusted to 10% by mass after purification was used as an aqueous solution of the copolymer 14. The viscosity of the aqueous solution of the obtained copolymer 14 was 32.7 mPa · s at 25 ° C.

(Synthesis Example 15)
-Synthesis of copolymer 15-
PMA; 1.60 g, MPC; 9.60 g, SMA; 20.80 g, and ethanol 768.00 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 8.00 g was added at 65 ° C. to carry out a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, the solution whose concentration was accurately adjusted to 10% by mass after purification was used as an aqueous solution of copolymer 15. The viscosity of the aqueous solution of the obtained copolymer 15 was 2.6 mPa · s at 25 ° C.

(Synthesis Example 16)
-Synthesis of copolymer 16-
PMA; 3.06 g, MPC; 15.33 g, BzMA; 42.93 g, and ethanol 2.5.33 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, an aqueous solution of the copolymer 16 was prepared by accurately adjusting the concentration to 10% by mass after purification. The viscosity of the aqueous solution of the obtained copolymer 16 was 31.2 mPa · s at 25 ° C.

( Reference Synthesis Example 17)
-Synthesis of Reference Copolymer 17-
PMA: 8.53 g, MPC: 1.06 g, SMA: 1.06 g, and ethanol 256.00 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, an aqueous solution of the reference copolymer 17 was obtained by adjusting the concentration accurately to 10% by mass after purification. The viscosity of the aqueous solution of the obtained reference copolymer 17 was 4.7 mPa · s at 25 ° C.

( Reference Synthesis Example 18)
-Synthesis of Reference Copolymer 18-
PMA; 49.06 g, MPC; 3.06 g, BzMA; 9.20 g, and ethanol 205.33 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, an aqueous solution of the reference copolymer 18 having a concentration adjusted to 10% by mass after purification was used. The viscosity of the aqueous solution of the obtained reference copolymer 18 was 34.7 mPa · s at 25 ° C.

(Synthesis Example 19)
-Synthesis of copolymer 19-
PMA; 12.00 g, MPC; 4.00 g, BzMA; 24.00 g, and ethanol 226.67 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. The diluted solution obtained by removing the solvent of the polymerization solution with an evaporator is diluted with water and neutralized with dimethylethanolamine (DMEA) so that the neutralization rate becomes 100% for 3 days. A solution obtained by purifying the dialysis membrane and adjusting the concentration accurately to 10% by mass after purification was used as an aqueous solution of the copolymer 19. The viscosity of the aqueous solution of the obtained copolymer 19 was 14.2 mPa · s at 25 ° C.

(Comparative Synthesis Example 1)
-Synthesis of Comparative Copolymer 1-
100 g maleic acid, 100 g styrene, 500 g water, and 15 g animmonium persulfate were placed in a four-necked flask and stirred to obtain a uniform solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; Diluted the viscous solution obtained by removing the solvent of the polymerization solution with an evaporator into water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate becomes 100%, and purified the dialysis membrane for 3 days. Then, an aqueous solution of Comparative Copolymer 1 was prepared by adjusting the concentration accurately to 10% by mass after purification. The viscosity of the aqueous solution of the obtained comparative copolymer 1 was 13.5 mPa · s at 25 ° C.

(Comparative Synthesis Example 2)
-Synthesis of Comparative Copolymer 2-
An aqueous solution of comparative copolymer 2 was obtained in the same manner as in the synthesis of comparative copolymer 1 except that the maleic acid and styrene in comparative synthesis example 1 were changed to PMA and styrene. The viscosity of the aqueous solution of the obtained comparative copolymer 2 was 14.4 mPa · s at 25 ° C.

(Comparative Synthesis Example 3)
-Synthesis of Comparative Copolymer 3-
An aqueous solution of comparative copolymer 3 was obtained in the same manner as in the synthesis of comparative copolymer 1 except that maleic acid and styrene in Comparative Synthesis Example 1 were changed to maleic acid and MPC. The viscosity of the aqueous solution of the obtained comparative copolymer 3 was 14.1 mPa · s at 25 ° C.

(Comparative Synthesis Example 4)
-Synthesis of Comparative Copolymer 4-
PMA; 12.00 g, MPC; 4.00 g, SMA; 24.00 g, and ethanol 226.67 g were placed in a four-necked flask and stirred to obtain a homogeneous solution. Nitrogen was blown into this solution for 30 minutes, and then AIBN; 2.67 g was added at 65 ° C. to cause a polymerization reaction for 5 hours or more. Diluted the thickened liquid obtained by removing the solvent of the polymerization solution with an evaporator in water, neutralized 10% by mass with sodium hydroxide so that the neutralization rate is 40%, and purified the dialysis membrane for 3 days. Then, an aqueous solution of the comparative copolymer 4 was prepared by adjusting the concentration accurately to 10% by mass after purification. The viscosity of the aqueous solution of the obtained comparative copolymer 4 was 8.4 mPa · s at 25 ° C.

Next, Tables 1 and 2 show the copolymers of Synthesis Examples 1 to 16, 19, Reference Synthesis Examples 17 to 18, and Comparative Synthesis Examples 1 to 4.

* EA: Monoethanolamine * DMEA: Dimethylethanolamine

(Preparation Example 1 of Pigment Dispersion)
<Preparation of pigment dispersion 1>
After premixing a mixture of the following carbon black pigment, copolymer and pure water in the following formulation (1), a disk type bead mill (Shinmaru Enterprises, KDL type, media: 0.1 mm in diameter) Circulating and dispersing for 10 minutes at a peripheral speed of 10 m / s using a zirconia ball), a black pigment dispersion was obtained.
-Prescription (1)-
Carbon black pigment (NIPEX150, gas black manufactured by Evonik Degussa, Inc., gas black) 20 parts by mass Aqueous solution of copolymer 1 (solid content 10.0% by mass) 75 parts by mass Pure water 5 Parts by mass

(Preparation Example 2 of Pigment Dispersion 2)
-Preparation of pigment dispersion 2-
Pigment Dispersion 2 was obtained in the same manner as Pigment Dispersion Preparation Example 1 except that the carbon black pigment of Preparation Example 1 of Pigment Dispersion was replaced with Pigment Blue 15: 3.

(Preparation Example 3 of Pigment Dispersion)
-Preparation of pigment dispersion 3-
A pigment dispersion 3 was obtained in the same manner as in the pigment dispersion preparation example 1 except that the pigment black 122 was used instead of the carbon black pigment in the pigment dispersion preparation example 1.

(Preparation Example 4 of Pigment Dispersion)
-Preparation of pigment dispersion 4-
Pigment Dispersion 4 was obtained in the same manner as Pigment Dispersion Preparation Example 1 except that the carbon black pigment of Pigment Dispersion Preparation Example 1 was replaced with Pigment Yellow 74.

(Preparation Example 5 of Pigment Dispersion)
-Preparation of pigment dispersion 5-
Pigment Dispersion 5 was obtained in the same manner as Pigment Dispersion Preparation Example 1 except that the aqueous solution of Copolymer 1 of Preparation Example 1 of Pigment Dispersion was replaced with the aqueous solution of Copolymer 2.

(Pigment Dispersion Preparation Example 6)
-Preparation of pigment dispersion 6-
Pigment Dispersion 6 was obtained in the same manner as Pigment Dispersion Preparation 5 except that the carbon black pigment of Pigment Dispersion Preparation 5 was replaced with Pigment Blue 15: 3.

(Preparation Example 7 of Pigment Dispersion)
-Preparation of pigment dispersion 7-
Pigment Dispersion 7 was obtained in the same manner as Pigment Dispersion Preparation Example 5 except that the pigment black 122 was used instead of the carbon black pigment of Pigment Dispersion Preparation Example 5.

(Preparation Example 8 of Pigment Dispersion)
-Preparation of pigment dispersion 8-
A pigment dispersion 8 was obtained in the same manner as in the pigment dispersion preparation example 5 except that the pigment black 74 was used instead of the carbon black pigment in the pigment dispersion preparation example 5.

(Preparation Example 9 for Pigment Dispersion)
-Preparation of pigment dispersion 9-
A pigment dispersion 9 was obtained in the same manner as in Preparation 1 of the pigment dispersion, except that the aqueous solution of the copolymer 1 in Preparation 1 of the pigment dispersion was replaced with the aqueous solution of Copolymer 3.

(Pigment dispersion preparation example 10)
-Preparation of pigment dispersion 10-
A pigment dispersion 10 was obtained in the same manner as in Preparation Example 1 of the pigment dispersion, except that the aqueous solution of the copolymer 1 of Preparation Example 1 of the pigment dispersion was replaced with the aqueous solution of Copolymer 4.

(Preparation Example 11 of Pigment Dispersion)
-Preparation of pigment dispersion 11-
A pigment dispersion 11 was obtained in the same manner as in Preparation 1 of the pigment dispersion, except that the aqueous solution of the copolymer 1 of Preparation Example 1 of the pigment dispersion was replaced with the aqueous solution of Copolymer 5.

(Preparation Example 12 of Pigment Dispersion)
-Preparation of pigment dispersion 12-
A pigment dispersion 12 was obtained in the same manner as in Preparation Example 1 of the pigment dispersion, except that the aqueous solution of the copolymer 1 in Preparation Example 1 of the pigment dispersion was replaced with the aqueous solution of Copolymer 6.

(Preparation Example 13 of Pigment Dispersion)
-Preparation of pigment dispersion 13-
A pigment dispersion 13 was obtained in the same manner as in the pigment dispersion preparation example 12 except that the carbon black pigment in Preparation Example 12 of Pigment Dispersion was replaced with Pigment Blue 15: 3.

(Preparation Example 14 of Pigment Dispersion)
-Preparation of pigment dispersion 14-
Pigment Dispersion 14 was obtained in the same manner as Pigment Dispersion Preparation Example 1 except that the pigment black 122 was used instead of the carbon black pigment of Preparation Example 12 of Pigment Dispersion.

(Preparation Example 15 for Pigment Dispersion)
-Preparation of pigment dispersion 15-
A pigment dispersion 15 was obtained in the same manner as in the pigment dispersion preparation example 12 except that the pigment black 74 was used instead of the carbon black pigment of the pigment dispersion preparation example 12.

(Preparation Examples 16 to 25 and 28 of pigment dispersion)
-Preparation of pigment dispersions 16-25 and 28-
Pigment dispersions 16-25 , similar to pigment dispersion preparation example 1, except that the aqueous solution of compound 1 of Preparation Example 1 of Pigment Dispersion was replaced with the aqueous solutions of Copolymers 7-16 and 19 . And 28 were obtained.
(Reference Pigment Dispersion Preparation Examples 26 to 27)
-Preparation of Reference Pigment Dispersions 26-27-
Reference pigment dispersions 26 to 27 were obtained in the same manner as in Pigment dispersion preparation example 1 except that the aqueous solution of compound 1 in Preparation example 1 of pigment dispersion was replaced with the aqueous solution of reference copolymers 17 to 18. It was.

(Comparative Preparation Example 1)
-Preparation of Comparative Pigment Dispersion 1-
In Preparation Example 1 of Pigment Dispersion, the same procedure as in Preparation Example 1 of Pigment Dispersion was performed except that the aqueous solution of Copolymer 1 in Preparation Example 1 of Pigment Dispersion was replaced with the aqueous solution of Comparative Copolymer 1. A comparative pigment dispersion 1 was obtained.

(Comparative Preparation Example 2)
-Preparation of Comparative Pigment Dispersion 2-
In Preparation Example 3 of Pigment Dispersion, the same procedure as in Preparation Example 3 of Pigment Dispersion was performed, except that the aqueous solution of Copolymer 1 in Preparation Example 3 of Pigment Dispersion was replaced with the aqueous solution of Comparative Copolymer 1. A comparative pigment dispersion 2 was obtained.

(Comparative Preparation Example 3)
-Preparation of Comparative Pigment Dispersion 3-
In Preparation Example 4 of Pigment Dispersion, the same procedure as in Preparation Example 4 of Pigment Dispersion was performed except that the aqueous solution of Copolymer 1 in Preparation Example 4 of Pigment Dispersion was replaced with the aqueous solution of Comparative Copolymer 1. A comparative pigment dispersion 3 was obtained.

(Comparative Preparation Example 4)
-Preparation of comparative pigment dispersion 4-
In Preparation Example 5 of Pigment Dispersion, the same procedure as in Preparation Example 5 of Pigment Dispersion was carried out, except that the aqueous solution of Copolymer 1 in Preparation Example 5 of Pigment Dispersion was replaced with the aqueous solution of Comparative Copolymer 1. A comparative pigment dispersion 4 was obtained.

(Comparative Preparation Example 5)
-Preparation of comparative pigment dispersion 5-
Comparative pigment dispersion 5 was obtained in the same manner as Comparative Preparation Example 1 except that the aqueous solution of Comparative Copolymer 1 of Comparative Preparation Example 1 was replaced with the aqueous solution of Comparative Copolymer 2.

(Comparative Preparation Example 6)
-Preparation of Comparative Pigment Dispersion 6-
Comparative pigment dispersion 6 was obtained in the same manner as Comparative preparation example 1 except that the aqueous solution of comparative copolymer 1 of comparative preparation example 1 was replaced with the aqueous solution of comparative copolymer 3.

(Comparative Preparation Example 7)
-Preparation of Comparative Pigment Dispersion 7-
Comparative pigment dispersion 7 was obtained in the same manner as Comparative preparation example 1 except that the aqueous solution of comparative copolymer 1 of comparative preparation example 1 was replaced with the aqueous solution of comparative copolymer 4.

Example 1
<Preparation of ink for ink jet recording>
The materials having the following formulation were mixed and stirred for 30 minutes to prepare ink for inkjet recording.
-Pigment dispersion 1 of preparation example 1 (pigment concentration 20% by mass) ... 44.4 parts by mass-1,3-butanediol ... 15 parts by mass-Glycerin ... 20 parts by mass-2-ethyl- 1,3-hexanediol ... 1 part by mass-2,2-trimethyl-1,3-pentanediol ... 1 part by mass-Polyoxyethylene perfluoroalkyl ether (FS-300, manufactured by Dupont, component 40 % By mass) ... 2.5 parts by mass Pure water ... 16.1 parts by mass

(Example 2)
−Preparation of ink for ink jet recording−
The materials having the following formulation were mixed and stirred for 30 minutes to prepare ink for inkjet recording.
Pigment dispersion 1 of pigment dispersion 1 (pigment concentration 20% by mass): 44.4 parts by mass 1,3-butanediol: 15 parts by mass Glycerin: 20 parts by mass 2-ethyl-1,3-hexanediol: 1 part by mass 2,2-trimethyl-1,3-pentanediol: 1 part by mass Polyoxyethylene perfluoroalkyl ether (FS-300, Dupont) Manufactured, 40 mass%) ... 2.5 parts by mass Acrylic-silicone resin emulsion (manufactured by Showa Polymer Co., Ltd., Polysol ROY6312) 6 parts by mass Pure water ... 10.1 parts by mass

Example 3
−Preparation of ink for ink jet recording−
The materials having the following formulation were mixed and stirred for 30 minutes to prepare ink for inkjet recording.
Pigment Dispersion 2 of Pigment Dispersion Example 2 (Pigment Concentration 20% by Mass) ... 33.3 parts by mass1,3-butanediol ... 15 parts by massGlycerin ... 20 parts by mass 2-ethyl-1,3-hexanediol: 2 parts by mass Polyoxyethylene perfluoroalkyl ether (FS-300, manufactured by Dupont, 40 mass% component): 2.5 parts by mass Pure water ..27.2 parts by mass

Example 4
−Preparation of ink for ink jet recording−
The materials having the following formulation were mixed and stirred for 30 minutes to prepare ink for inkjet recording.
Pigment Dispersion 3 in Pigment Dispersion Example 3 (Pigment Concentration 20% by Mass) ... 33.3 parts by mass1,3-butanediol ... 15 parts by massGlycerin ... 20 parts by mass 2-ethyl-1,3-hexanediol: 2 parts by mass Polyoxyethylene perfluoroalkyl ether (FS-300, manufactured by Dupont, 40 mass% component): 2.5 parts by mass Pure water ..27.2 parts by mass

(Example 5)
−Preparation of ink for ink jet recording−
The materials having the following formulation were mixed and stirred for 30 minutes to prepare ink for inkjet recording.
Pigment Dispersion 4 of Pigment Dispersion Example 4 (Pigment Concentration 20% by Mass) ... 33.3 parts by mass1,3-butanediol ... 15 parts by massGlycerin ... 20 parts by mass 2-ethyl-1,3-hexanediol: 2 parts by mass Polyoxyethylene perfluoroalkyl ether (FS-300, manufactured by Dupont, 40 mass% component): 2.5 parts by mass Pure water ..27.2 parts by mass

(Examples 6 to 10)
−Preparation of ink for ink jet recording−
Ink-jet recording inks of Examples 6 to 10 were obtained in the same manner as in Examples 1 to 5, except that the pigment dispersions 1 to 4 were replaced with the pigment dispersions 5 to 8 in Examples 1 to 5.

(Examples 11 to 13)
−Preparation of ink for ink jet recording−
Ink recording inks of Examples 11 to 13 were obtained in the same manner as in Example 1 except that the pigment dispersion 1 was replaced with the pigment dispersions 9 to 11 in Example 1.

(Examples 14 to 18)
−Preparation of ink for ink jet recording−
Ink jet recording inks of Examples 14 to 18 were obtained in the same manner as in Examples 1 to 5, except that the pigment dispersions 1 to 4 were replaced with the pigment dispersions 12 to 15 in Examples 1 to 5.

(Examples 19 to 28 and 31)
−Preparation of ink for ink jet recording−
Ink jet recording inks of Examples 19 to 31 were obtained in the same manner as in Example 1 except that the pigment dispersion 1 was replaced with the pigment dispersions 16 to 25 and 28 in Example 1.
(Reference Examples 29-30)
−Preparation of ink for ink jet recording−
Ink jet recording inks of Reference Examples 29 to 30 were obtained in the same manner as in Example 1 except that the pigment dispersion 1 was replaced with the reference pigment dispersions 26 to 27 in Example 1.

(Comparative Example 1)
−Preparation of ink for ink jet recording−
An ink jet recording ink of Comparative Example 1 was obtained in the same manner as in Example 1 except that the pigment dispersion 1 was replaced with the comparative pigment dispersion 1 in Example 1.

(Comparative Example 2)
−Preparation of ink for ink jet recording−
An ink jet recording ink of Comparative Example 2 was obtained in the same manner as in Example 1 except that the pigment dispersion 1 was replaced with the comparative pigment dispersion 2 in Example 3.

(Comparative Example 3)
−Preparation of ink for ink jet recording−
An ink jet recording ink of Comparative Example 3 was obtained in the same manner as in Example 4 except that the pigment dispersion 1 was replaced with the comparative pigment dispersion 3 in Example 4.

(Comparative Example 4)
−Preparation of ink for ink jet recording−
An ink jet recording ink of Comparative Example 4 was obtained in the same manner as in Example 5 except that the pigment dispersion 1 was replaced with the comparative pigment dispersion 4 in Example 5.

(Comparative Example 5)
−Preparation of ink for ink jet recording−
An ink jet recording ink of Comparative Example 5 was obtained in the same manner as in Example 1 except that the pigment dispersion 1 was replaced with the comparative pigment dispersion 5 in Example 1.

(Comparative Example 6)
−Preparation of ink for ink jet recording−
An ink jet recording ink of Comparative Example 6 was obtained in the same manner as in Example 1 except that the pigment dispersion 1 was replaced with the comparative pigment dispersion 6 in Example 1.

(Comparative Example 7)
−Preparation of ink for ink jet recording−
An ink jet recording ink of Comparative Example 7 was obtained in the same manner as in Example 1 except that Pigment Dispersion 1 was replaced with Comparative Pigment Dispersion 7 in Example 1.

Next, it summarizes the content of the comparative example contents of Examples in Table 3-1 Table 3-3, the contents of Examples and Reference Examples in Tables 3-4, and in Table 4.

Next, various characteristics of each of the inkjet recording inks of Examples 1 to 28, 31 , Reference Examples 29 to 30 and Comparative Examples 1 to 7 were evaluated as follows. The results are shown in Tables 5 and 6.

<Image density>
A chart with a 64 point character “■” written in Microsoft Word 2000 (manufactured by Microsoft), filled with each ink prepared in an inkjet printer (IPSiO GX5000, manufactured by Ricoh Co., Ltd.) at 23 ° C. in a 50% RH environment. Was printed on MyPaper (manufactured by Ricoh Co., Ltd.), and the “■” portion of the printed surface was measured with X-Rite 938 to evaluate the image density. At this time, a mode in which the “plain paper-standard fast” mode was changed to “no color correction” from the user setting for plain paper with a driver attached to the printer was used. The determination of the image density of each color was performed based on the following evaluation criteria.
〔Evaluation criteria〕
: Black: 1.25 or more,
Magenta: 1.00 or more,
Cyan: 1.00 or more, or
Yellow: 0.85 or more ○: Black: 1.2 or more,
Magenta: 0.95 or higher
Cyan: 0.95 or more, or
Yellow: 0.8 or more ○ △: Black: 1.15 or more,
Magenta: 0.9 or more,
Cyan: 0.9 or more, or
Yellow: 0.75 or more △: Black: 1.10 or more
Magenta: 0.85 or more,
Cyan: 0.85 or more, or
Yellow: 0.7 or more ×: Black: less than 1.10,
Magenta: less than 0.85,
Cyan: Less than 0.85 or
Yellow: less than 0.70

<Ink storage stability>
Each ink jet recording ink was filled in an ink cartridge and stored at 60 ° C. for 2 weeks, and the change rate of the viscosity after storage with respect to the viscosity before storage was evaluated according to the following criteria. The viscosity of the ink was measured at 25 ° C. using a viscometer RE80L manufactured by Toki Sangyo Co., Ltd.
[Evaluation criteria]
◎: Change rate of viscosity is less than ± 3% ○: Change rate of viscosity is ± 3% or more and less than ± 6% ○ △: Change rate of viscosity is ± 6% or more and less than ± 10% △: Change rate of viscosity is ± 10% or more and less than ± 20% ×: Viscosity change rate is 20% or more

<Ink ejection stability>
Regarding the ejection stability, after printing the printed matter, the ink jet printer was left in a 50 ° C. environment for one month with the recording head capped. Whether or not the discharge state of the printer after being left is restored to the initial discharge state was evaluated according to the following evaluation criteria by the following number of cleaning operations.
[Evaluation criteria]
A: Printing was possible without cleaning.
○: Recovered by 1 to 3 operations.
◯: Recovered by 4 to 5 operations.
Δ: Recovered by 6 to 10 operations.
X: No recovery was observed even after 10 or more operations.

From the results of Table 5 and Table 6, the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), the general formula (3), and the general formula (4). Any of the inkjet recording inks of the present invention containing a copolymer containing a phosphoric acid group containing a structural unit represented by any one of the above is excellent in image density, ink storage stability and ejection stability. Therefore, no problem characteristic was found in practical use.
From the comparison between Examples 1 to 28, 31 and Reference Examples 29 to 30 and Comparative Examples 1 to 7, the ink for inkjet recording of the present invention has high image density, and the storage stability and ejection stability of the ink are equivalent. It turns out that it is above.
Furthermore, the following things were understood from the comparison between Examples.
From the comparison of Examples 1-5 and 6-10, the same effect was recognized even if it was the structural unit represented by either the said General formula (3) and the said General formula (4).
From comparison between Examples 1 and 11 and Comparative Example 7, it was found that the effect was obtained when the neutralization rate of the structural unit represented by the general formula (1) with the neutralized salt was 50% or more.
From the comparison between Examples 1 and 12, it is the same whether R ² and R ³ of the structural unit represented by the general formula (2) and the general formula (3) are either a methyl group or a hydrogen atom. It turns out that an effect is acquired.
From comparison between Examples 1 and 13, it was found that the same effect was obtained regardless of the type of neutralized salt of the structural unit represented by the general formula (1).
From comparison between Examples 1 to 5 and 14 to 18, it was found that the same effect was obtained regardless of whether R ^{1 of the} structural unit represented by the general formula (1) is a methyl group or a hydrogen atom. .
According to Examples 19 to 22, the structural unit represented by the general formula (1), the structural unit represented by the general formula (2), any one of the general formula (3) and the general formula (4) It was found that the same effect can be obtained by changing the ratio with the structural unit represented by.
From comparison between Examples 1 to 22, 31 and 23 to 26, the viscosity of a 10% by mass aqueous solution of a copolymer containing a phosphate group is 4.0 mPa · s to 30.0 mPa · s. It was found that both the storage stability and ejection stability of the ink were excellent.
From comparison between Examples 23 to 26, Examples 27 to 28, and Reference Examples 29 to 30 , the ratio of the structural unit represented by the general formula (1) is 10% by mass to 60% by mass. It was found that the density, ink storage stability, and ejection stability were all excellent.
From Examples 1-5, 6-10, and 14-18, it turned out that it is effective irrespective of the color of a pigment.
Examples 1 and 2, 6 and 7, and 14 and 15 proved to be effective regardless of the ink formulation.

  From the above results, the ink for ink-jet recording of the present invention has a clear image density and excellent ink storage for each color ink due to the aggregation effect due to the reaction with polyvalent metal ions (especially calcium ions) contained in plain paper. It was found that the stability and ejection stability were equal or better. That is, the ink for ink jet recording of the present invention has good ink storage stability and good drying properties, and a high image density can be obtained with plain paper or printing coated paper. Since the stability is good and there is no ink sticking around the nozzle, it can be applied to various recordings by the ink jet recording method. In addition, the ink recorded matter of the present invention has high image quality, no bleeding, excellent temporal stability, and can be suitably used for various applications as a material on which various prints or images are recorded. As the recording apparatus using the ink jet recording method, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, a printer / fax / copier multifunction machine, and the like can be applied.

As an aspect of this invention, it is as follows, for example.
<1> comprising water, a water-soluble solvent, a pigment, and a copolymer containing a phosphate group,
The copolymer containing a phosphoric acid group includes a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), the following general formula (3), and the following general formula ( 4) At least the structural unit represented by any one of 4), It is an ink for inkjet recording characterized by the above-mentioned.
In the general formula (1), R ¹ represents a hydrogen atom or a methyl group. M ⁺ represents one of an alkali metal ion, an organic amine ion and a hydrogen ion, more than half of M ^{+ in} the copolymer is either an alkali metal ion or an organic amine ion, and the rest are hydrogen ions. .
However, In the general formula (2), R ² represents a hydrogen atom or a methyl group.
In the general formula (3), R ³ represents a hydrogen atom or a methyl group.
In the general formula (4), R ⁴ represents a hydrogen atom or a methyl group.
<2> The ink for inkjet recording according to <1>, wherein the content of the structural unit represented by the general formula (1) in the copolymer containing a phosphate group is 10% by mass to 60% by mass. .
<3> The viscosity of an aqueous solution having a solid content of 10% by mass of the copolymer containing a phosphoric acid group is from 2.5 mPa · s to 35.0 mPa · s at 25 ° C. The ink for inkjet recording according to any one of the above.
<4> The copolymer containing a phosphoric acid group includes a monomer represented by the following general formula (5), a monomer represented by the following general formula (6), the following general formula (7), and the following general formula. The ink for inkjet recording according to any one of <1> to <3>, wherein the monomer represented by any one of (8) is polymerized.
In the general formula (5), R ⁵ represents a hydrogen atom or a methyl group.
In the general formula (6), R ⁶ represents a hydrogen atom or a methyl group.
In the general formula (7), R ⁷ represents a hydrogen atom or a methyl group.
In the general formula (8), R ⁸ represents a hydrogen atom or a methyl group.
<5> An ink cartridge comprising the ink for ink jet recording according to any one of <1> to <4> contained in a container.
<6> at least an ink flying step of recording an image by applying a stimulus to the ink for ink jet recording according to any one of <1> to <4> and causing the ink jet recording ink to fly. This is an ink jet recording method.
<7> At least ink jetting means for recording an image by applying a stimulus to the ink for ink jet recording according to any one of <1> to <4> and causing the ink jet recording ink to fly. Inkjet recording apparatus.
<8> An ink recorded matter comprising an image recorded with the ink for ink jet recording according to any one of <1> to <4> on a recording medium.

JP 2011-122072 A

101 Device Main Body 134 Recording Head 142 Paper 200 Ink Cartridge

Claims (8)

Comprising water, a water-soluble solvent, a pigment, and a copolymer containing a phosphate group,
The copolymer containing a phosphoric acid group includes a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), the following general formula (3), and the following general formula ( and a structural unit represented by any one of 4), seen at least contains,
The content rate of the structural unit represented by the said General formula (1) in the copolymer containing the said phosphate group is 10 mass%-60 mass%,
The content rate of the structural unit represented by the said General formula (2) in the copolymer containing the said phosphate group is 1 mass%-40 mass%,
The content of the structural unit represented by any one of the general formula (3) and the general formula (4) in the copolymer containing a phosphoric acid group is 10% by mass to 65% by mass. Ink for ink jet recording.
In the general formula (1), R ¹ represents a hydrogen atom or a methyl group. M ⁺ represents one of an alkali metal ion, an organic amine ion and a hydrogen ion, more than half of M ^{+ in} the copolymer is either an alkali metal ion or an organic amine ion, and the rest are hydrogen ions. .
However, In the general formula (2), R ² represents a hydrogen atom or a methyl group.
In the general formula (3), R ³ represents a hydrogen atom or a methyl group.
In the general formula (4), R 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 represented by the general formula (1) in the copolymer containing the phosphoric acid group is 15% by mass to 50% by mass .   The inkjet according to any one of claims 1 to 2, wherein a viscosity of an aqueous solution having a solid content of 10% by mass of the copolymer containing a phosphate group is 2.5 mPa · s to 35.0 mPa · s at 25 ° C. Recording ink. The copolymer containing the phosphoric acid group includes a monomer represented by the following general formula (5), a monomer represented by the following general formula (6), the following general formula (7), and the following general formula (8). The ink for inkjet recording according to any one of claims 1 to 3, wherein a monomer represented by any one of the above is polymerized.
In the general formula (5), R ⁵ represents a hydrogen atom or a methyl group.
In the general formula (6), R ⁶ represents a hydrogen atom or a methyl group.
In the general formula (7), R ⁷ represents a hydrogen atom or a methyl group.
In the general formula (8), R ⁸ represents a hydrogen atom or a methyl group.   An ink cartridge comprising the ink-jet recording ink according to claim 1 contained in a container.   5. An ink jet recording method comprising at least an ink flying step of recording an image by applying a stimulus to the ink for ink jet recording according to claim 1 and causing the ink for ink jet recording to fly.   5. An ink jet recording apparatus comprising at least ink flying means for recording an image by applying a stimulus to the ink for ink jet recording according to claim 1 and causing the ink for ink jet recording to fly.   An ink recorded matter comprising an image recorded with the ink for ink jet recording according to any one of claims 1 to 4 on a recording medium.