JP2008184567A - Recording ink, ink cartridge, inkjet recording method, and inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording ink having penetrativity high enough for high-speed printing and satisfying all of ejection stability, storage stability, and the ability to form a high-quality image even on plain paper and to provide others. <P>SOLUTION: The recording ink comprises a pigment dispersion prepared with the aid a specified anionic surfactant based dispersant, a water-soluble organic solvent, and a stabilizer, wherein the water-soluble organic solvent is at least one member selected from among 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, and 2-methyl-2,4-pentanediol, and the stabilizer contains a specified phosphorylcholine-like group-containing polymer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a recording ink that has excellent printing characteristics on plain paper and good storage stability and is suitable for inkjet recording, and an ink cartridge, an inkjet recording method, and an inkjet recording apparatus using the recording ink. .

  The ink jet recording method has the advantage that the process is simpler than other recording methods, so that full color can be easily obtained, and a high-resolution image can be obtained even with an apparatus having a simple configuration. As inks for ink jet recording, dye-based inks obtained by dissolving various water-soluble dyes in water or a mixed liquid of water and an organic solvent are used. Although this dye-based ink is excellent in color tone clarity, it has the disadvantages that it is inferior in light resistance and water resistance and has a large blur on plain paper. On the other hand, a pigment-based ink in which carbon black or various organic pigments are dispersed in a solvent is superior to the dye-based ink in terms of light resistance and water resistance, and is less liable for plain paper.

  However, the pigment-based ink tends to cause ejection failure due to aggregation or thickening of the pigment as compared with the dye-based ink. There are roughly four types of pigment dispersions that are the raw materials for pigment-based inks: capsule type, self-dispersing type, polymer dispersing type, and surfactant dispersing type. For example, in a capsule-type dispersion as disclosed in Patent Document 1, an organic solvent is indispensable in the production process, which not only adversely affects the environment but also tends to increase the production cost. In addition, the self-dispersing dispersion as disclosed in Patent Document 2 needs to use chemicals such as an oxidant and a diazo coupling agent, and thus has an adverse effect on the environment. Then, the pigment is likely to be dissolved (dyed) by the hydrophilic group introduced into the pigment, and the water resistance of the ink tends to be poor.

  The surfactant-dispersed type can be obtained by simply dispersing after mixing the pigment and the dispersant, and can reduce the production cost because it can be made into fine particles in a short time. There is a tendency that the storage stability of the ink is inferior to that of the dispersion. In recent years, high-density inks have been developed in which the solid content concentration of pigments, resins, etc. in the ink has been increased in order to support high-speed printing on plain paper and improve fixability. Therefore, the storage stability tends to be inferior to that of the conventional pigment ink. Further, there is a problem that even when printing is performed at high speed, there is little color boundary bleeding, and storage stability is inferior when combined with an ink composition that allows ink to permeate quickly, and a practical level of ink cannot be obtained.

  Therefore, as a method for improving the storage stability of the surfactant-dispersed pigment dispersion, a method of using a surfactant and a polymer dispersant or emulsion particles in combination has been proposed (Patent Document 3, Patent). Reference 4 and Patent Document 5). According to these proposals, the storage stability is improved depending on the ink composition, but even these pigment dispersions are water-soluble with good wettability to the recording paper in order to ensure quick drying in high-speed printing on plain paper. When a water-soluble organic solvent or a highly permeable surfactant is added, the storage stability tends to be inferior. In addition, further improvement is required for image quality such as image density and saturation.

  In the case of the polymer dispersion type, a water-soluble polymer containing components such as carboxylic acid and sulfonic acid is generally used as the dispersant. However, these dispersants prevent aggregation of particles by electrostatic repulsion. However, there is a problem that the dispersibility is lowered due to contamination by other ionic substances and fluctuation of pH. When a nonionic polymer is used as a dispersant, it tries to maintain dispersion stability due to the steric repulsion effect of a hydrated nonionic hydrophilic component. To maintain dispersion stability, however, a high concentration of the hydrophilic component is required. There is a problem that water resistance is inferior. Further, as a problem common to the polymer dispersion type, there is a problem that when the distance between particles is close, the polymer chains are entangled and the redispersibility is lowered. Further, as in the case of the surfactant-dispersed type, when a water-soluble organic solvent having good wettability with respect to the recording paper or a highly permeable surfactant is added, the storage stability tends to be inferior.

For example, Patent Document 6 discloses a water-based ink using at least one of an anionic surfactant containing an ethylene oxide group and a nonionic surfactant as a surfactant-type dispersant. The surfactant type dispersant used in this ink has high storage stability as a dispersion, so it is easy to use in terms of stabilizing the quality of the ink, and by using specific components in the penetrant, it can penetrate into plain paper. In terms of quick drying, the compatibility with high-speed printing was good. The decrease was significant. The pigment concentration of this ink is generally in the range of 3% by mass to 6% by mass in the examples. However, if the pigment concentration exceeds 6% by mass in order to improve image density and saturation, the storage stability of the ink The particle diameter increased and the viscosity increased.
Also, in order to further improve the high-speed printability, replacing with a water-soluble organic solvent that can further improve the wettability to paper unlike the disclosed water-soluble organic solvent, the storage stability is extremely lowered, and the ejection The stability was also poor.
This is the storage stability such as increase in particle size and thickening that is seen when a surfactant-dispersed or polymer-dispersed pigment dispersion is combined with a water-soluble organic solvent that can improve wettability to paper. The reason for the decrease in the surfactant is that the surfactant / polymer as a dispersant and the binding force between the polymer particles and the pigment particles are not sufficient, and the interaction with the water-soluble organic solvent whose hydrophilic / lipophilic balance has been shifted to lipophilicity, etc. This is considered to be because the dispersant is desorbed from the surface of the pigment particles.

In order to improve storage stability, for example, Patent Document 7 and Patent Document 8 propose using a polymer containing a phosphorylcholine group as a pigment dispersant. In Patent Document 7, the drying property of the ink is remarkably lowered due to the phosphorylcholine group, the ink is hardly solidified, and the hydrophilicity of the ink composition itself is increased, whereby the nozzle surface is hydrophilized and the nozzle is clogged. Is said to be prevented. However, since the ink of the embodiment of Patent Document 7 has insufficient wettability with respect to plain paper and insufficient penetrability, when printed with a printer capable of high-speed printing, the image density is low and color boundary bleeding is caused. And feathering were not satisfactory levels compared to low-speed printing. In order to improve this and cope with high-speed printing, the ink permeation speed may be increased. However, the permeation speed is proportional to the wettability (γcos θ) and inversely proportional to the viscosity (η) (Lucas). -Washburn equation), V = k (γcos θ / η) is known to be satisfied, and in order to increase γcos θ, the water-soluble organic solvent disclosed in Patent Document 7 is made wettable with plain paper. When replaced with components that can be enhanced, the drying characteristics of ink and color boundary bleeding in high-speed printing can be improved, but when used over a long period (about 6 months or more), nozzle clogging, Fading of printing was recognized, and the physical properties of the ink stored for a long period of time were increased in viscosity and increased in particle diameter compared to the initial stage. In this way, even if parameters such as the blending ratio of the polymer containing phosphorylcholine groups and the presence or absence of copolymerization components are changed within the design range, these characteristics do not improve, so the effect of the phosphorylcholine group-containing polymer is an ink-containing component It was found that there is a strong interaction with.
In addition, since the ink formulation described in Patent Document 7 is inferior in fixing property to plain paper and marker resistance, when a resin emulsion is added, the discharge stability and storage stability tend to deteriorate.

  Patent Document 8 proposes to use a polymer containing a phosphorylcholine group as a pigment dispersant. This proposed ink composition is composed of diethylene glycol having a pigment concentration of 3% by mass and a highly hydrophilic solvent. Even if this ink composition has sufficient storage stability, the image quality when printed on plain paper at high speed is low, and the color boundary bleeding and feathering are at a level that is satisfactory compared to low-speed printing. There wasn't. Therefore, when the water-soluble organic solvent was replaced with a component capable of improving the wettability to plain paper, the ink drying property and color boundary bleeding in high-speed printing tended to improve, but for a long time (about 6 months or more) ), Clogging of the nozzles and faint printing were observed, and the physical properties of the ink stored for a long period of time increased in viscosity as compared to the initial stage, and an increase in particle diameter was also observed.

JP 2001-247800 A Japanese Patent No. 3405817 Japanese Patent No. 3625595 Japanese Patent No. 3390153 JP 2003-96342 A JP 2002-88286 A JP 2001-335724 A JP 2002-249684 A

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, the present invention is a recording ink that has high permeability corresponding to high-speed printing and has both ejection stability, storage stability, and high image quality on plain paper, and uses the recording ink. It is an object of the present invention to provide an ink cartridge, an ink jet recording method, and an ink jet recording apparatus.

Means for solving the problems are as follows. That is,
<1> comprising at least a pigment dispersion, a water-soluble organic solvent, and a stabilizer,
The pigment dispersion is obtained by dispersing a pigment with an anionic surfactant-based dispersant, and the anionic surfactant-based dispersant is at least one selected from the following general formula (1) and the following general formula (2). And
The water-soluble organic solvent is at least one selected from 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol and 2-methyl-2,4-pentanediol. Including
The recording ink is characterized in that the stabilizer contains a phosphorylcholine-like group-containing polymer having at least a structural unit represented by the following general formula (3).
^{_{R 1 O (CH 2 CH 2}} O) k CH 2 COOM 1 ··· formula (1)
^{_{R 2 O (CH 2 CH 2}} O) l SO 3 M 2 ··· formula (2)
In the general formula (1) and (2), ^{R 1} represents an alkyl group having 6 to 14 carbon atoms. R ² represents any of an alkyl group having 4 to 24 carbon atoms, an alkylphenyl group having 4 to 24 carbon atoms, and an alkylallyl group having 4 to 24 carbon atoms. M ¹ and M ² each represent a hydrogen atom, an alkali metal ion, a quaternary ammonium, a quaternary phosphonium, or an alkanolamine. k shows the integer of 3-12. l represents an integer of 4 to 50.
However, in said general formula (3), X shows a bivalent organic residue. Y represents an alkyleneoxy group having 1 to 6 carbon atoms. Z is a hydrogen atom, and R ⁷ —O— (C═O) — (wherein R ⁷ represents an alkyl group having 1 to 10 carbon atoms or a hydroxyalkyl group having 1 to 10 carbon atoms) Represents one of the following. R ³ represents either a hydrogen atom or a methyl group. R ⁴ , R ⁵ , and R ⁶ may be the same as or different from each other, and are any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a hydroxyalkyl group having 1 to 6 carbon atoms. Represents m shows the integer of 0-20. n shows the integer of 1-4.
<2> The recording ink according to <1>, which contains a polyol compound having 8 to 11 carbon atoms.
<3> The <2>, wherein the polyol compound having 8 to 11 carbon atoms includes any of 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol. Recording ink.
<4> The surfactant according to any one of <1> to <3>, which contains a surfactant, and the surfactant contains at least one selected from an anionic surfactant and a nonionic surfactant. It is a recording ink.
<5> The recording ink according to <4>, wherein the surfactant is at least one selected from polyoxyethylene alkyl ethers.
<6> The recording ink according to <4>, wherein the surfactant is at least one selected from fluorine-based surfactants.
<7> The recording ink according to any one of <1> to <6>, further comprising a resin emulsion.
<8> An ink cartridge comprising the recording ink according to any one of <1> to <7> contained in a container.
<9> Inkjet comprising at least an ink flying step of recording an image by applying a stimulus to the recording ink according to any one of <1> to <7> and causing the recording ink to fly. It is a recording method.
<10> The inkjet recording method according to <9>, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.
<11> An ink jet having at least ink flying means for recording an image by applying a stimulus to the recording ink according to any one of <1> to <7> and causing the recording ink to fly. It is a recording device.
<12> The inkjet recording apparatus according to <11>, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.
<13> An ink recorded matter comprising an image formed using the recording ink according to any one of <1> to <7> on a recording medium.

The recording ink of the present invention comprises at least a pigment dispersion, a water-soluble organic solvent, and a stabilizer,
The pigment dispersion is obtained by dispersing a pigment with an anionic surfactant-based dispersant, and the anionic surfactant-based dispersant is at least one selected from the general formula (1) and the general formula (2). Seeds,
The water-soluble organic solvent is at least one selected from 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol and 2-methyl-2,4-pentanediol. Yes,
The stabilizer contains a phosphorylcholine-like group-containing polymer having at least a structural unit represented by the general formula (3).
In the recording ink of the present invention, a pigment dispersion dispersed with at least one anionic surfactant-based dispersant selected from the above general formula (1) and the above general formula (2) is used as the pigment. This pigment dispersion has high storage stability itself, and even when stored for 1 year or more at room temperature, the viscosity and the particle diameter hardly change from the initial stage, which is advantageous in keeping the ink quality constant.
However, the storability of the recording ink containing the pigment dispersion and a specific water-soluble organic solvent effective for increasing the permeation rate is inferior to the storability of the pigment dispersion which is a raw material, and the particle size is small. Increase and increase in viscosity occur.
Moreover, when a phosphorylcholine-like group-containing polymer having at least the structural unit represented by the above general formula (3) is added as a stabilizer, surprisingly, there is little change in ink viscosity and particle diameter during long-term storage, and storage stability The effect which improves property is acquired. As such stabilizers, organic polymer compounds described in JP-A-2003-292838 are known. However, the combination of a pigment dispersion dispersed with at least one anionic surfactant-based dispersant selected from the general formula (1) and the general formula (2) and a conventionally known stabilizer is specified. Ink storage stability in the presence of a water-soluble organic solvent is not sufficient, and a combination of a pigment, a specific dispersant, and a specific stabilizer is stored in the presence of the specific water-soluble organic solvent. It has been found that this results in improved stability.
Although the effect of this stabilizer is not clearly understood, the anionic surfactant dispersant tends to be detached from the pigment particle surface in the presence of a water-soluble organic solvent having high wettability to paper. This is thought to lead to a decrease in storage stability. Therefore, an anionic surfactant dispersion can be obtained by adding a phosphorylcholine-like group-containing polymer having at least the structural unit represented by the general formula (3) as a stabilizer after the micronization (= pigment dispersion step) is completed. It is presumed that the agent prevents the agent from detaching from the pigment particle surface.
Therefore, the recording ink of the present invention has the above-described configuration, so that it has high permeability corresponding to high-speed printing, and has both ejection stability, storage stability, and high image quality on plain paper. Can do.

  The ink cartridge of the present invention comprises the recording ink of the present invention contained in a container. The ink cartridge is suitably used for a printer using an ink jet recording method. When recording is performed using the recording ink contained in the ink cartridge, it has high permeability corresponding to high-speed printing, and has both ejection stability, storage stability, and high image quality on plain paper. High-quality images can be obtained.

  The ink jet recording apparatus of the present invention comprises at least ink flying means for recording an image by applying energy to the recording ink of the present invention and causing the recording ink to fly. In the ink jet recording apparatus, the ink flying means applies energy to the recording ink of the present invention and causes the recording ink to fly to record an image. As a result, it has high penetrability for high-speed printing, has both ejection stability, storage stability, and high image quality on plain paper, and a high-quality image can be obtained.

  The ink jet recording method of the present invention includes at least an ink flying step of recording an image by applying energy to the recording ink of the present invention and causing the recording ink to fly. In the ink jet recording method, in the ink flying process, energy is applied to the recording ink of the present invention, and the recording ink is ejected to record an image. As a result, it has high penetrability for high-speed printing, has both ejection stability, storage stability, and high image quality on plain paper, and a high-quality image can be obtained.

  The ink recorded matter of the present invention has an image formed on the recording medium using the recording ink of the present invention. The ink recorded matter of the present invention has high permeability corresponding to high-speed printing, and has both ejection stability, storage stability, and high image quality with plain paper. In this case, a high-quality image having a good color tone is held on the recording medium.

  According to the present invention, various problems in the past can be solved, and by using a surfactant-dispersed pigment dispersion excellent in manufacturing cost, it has high permeability corresponding to high-speed printing, ejection stability, and storage. It is possible to provide a recording ink having both stability and high image quality on plain paper, an ink cartridge using the recording ink, an ink jet recording method, and an ink jet recording apparatus.

(Ink for recording)
The recording ink of the present invention contains at least a pigment dispersion, a water-soluble organic solvent, and a stabilizer. The polyol compound having 8 to 11 carbon atoms, a surfactant, a resin emulsion, and other if necessary It contains.

-Pigment dispersion-
The pigment dispersion is obtained by dispersing a pigment with an anionic surfactant-based dispersant, and the anionic surfactant-based dispersant is at least one selected from the following general formula (1) and general formula (2). Seed compounds are used.
^{_{R 1 O (CH 2 CH 2}} O) k CH 2 COOM 1 ··· formula (1)
^{_{R 2 O (CH 2 CH 2}} O) l SO 3 M 2 ··· formula (2)
In the general formula (1) and (2), ^{R 1} represents an alkyl group having 6 to 14 carbon atoms. R ² represents any of an alkyl group having 4 to 24 carbon atoms, an alkylphenyl group having 4 to 24 carbon atoms, and an alkylallyl group having 4 to 24 carbon atoms. M ¹ and M ² each represent a hydrogen atom, an alkali metal ion, a quaternary ammonium, a quaternary phosphonium, or an alkanolamine. k shows the integer of 3-12. l represents an integer of 4 to 50.
The alkyl group for R ¹ and R ² may be branched, and examples thereof include a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, and a tetradecyl group.
Examples of the alkali metal in M ¹ and M ² include lithium, sodium, and potassium.

The anionic surfactant-based dispersant is generally used as a pigment dispersant because the hydrophilic group in the molecule is dissociated in water to become an organic anion, and many of them have a strong dispersing action and are not toxic. However, in the compounds of the above general formulas (1) and (2), —COOM ¹ , —SO ₃ M ^{2 and the} like are dissociated in water to act as hydrophilic groups, and oxyethylene is adjacent to these hydrophilic groups. Since it contains a chain, it is easier to attract water molecules, and the dispersion stabilization effect and the redispersion effect are improved. By improving the dispersion stability and redispersibility, the aggregation of the pigment during long-term storage is suppressed, and the ejection stability is ensured even if non-ejection continues for a long time and moisture evaporates to some extent in the nozzle. The nonionic surfactant containing an oxyethylene chain generally has a cloud point, whereas the anionic surfactant dispersants of the general formulas (1) and (2) do not exhibit a cloud point. However, this is considered to contribute to the fact that the action of attracting molecules of oxyethylene chains does not decrease even under temperature changes or long-term storage, and is presumed to be able to maintain a high degree of dispersion stability.
Regarding the oxyethylene chain and alkyl chain lengths of the compounds of the general formulas (1) and (2), both the dispersibility and the redispersibility are affected. May be inferior. In particular, the oxyethylene chain is an essential requirement for ensuring dispersion stability in the present invention, but if the number of repetitions exceeds the upper limit, redispersibility when a penetrant is added may be lowered.

Specific examples of the compounds represented by the general formulas (1) and (2) are shown in free acid form. It is not limited to these. These may be used individually by 1 type and may use 2 or more types together.
Compound _{(1) -1: C 13 H} 27 O (CH 2 CH 2 O) 3 COOH
Compound _{(1) -2: C 10 H} 21 O (CH 2 CH 2 O) 12 COOH
Compound _{(1) -3: C 4 H} 9 C 6 H 4 O (CH 2 CH 2 O) 10 COOH
Compound _{(1) -4: C 3 H} 7 C 6 H 4 O (CH 2 CH 2 O) 12 COOH
Compound _{(1) -5: C 13 H} 27 O (CH 2 CH 2 O) 6 COOH
Compound _{(2) -1: C 8 H} 17 O (CH 2 CH 2 O) 4 SO 3 H
Compound _{(2) -2: C 9 H} 19 C 6 H 4 O (CH 2 CH 2 O) 12 SO 3 H
Compound _{(2) -3: C 2 H} 5 (C 2 H 5) C 12 H 25 C 6 H 4 O (CH 2 CH 2 O) 24 SO 3 H
Compound _{(2) -4: CH 3 (} CH 2) 7 CH = CH (CH 2) 8 O (CH 2 CH 2 O) 8 SO 3 H
Compound _{(2) -5: C 12 H} 25 C 6 H 4 O (CH 2 CH 2 O) 8 SO 3 H

  10 mass parts-100 mass parts are preferable with respect to 100 mass parts of said pigments, and, as for the addition amount of the said anionic surfactant type dispersing agent, 10 mass parts-50 mass parts are more preferable. When the addition amount of the anionic surfactant-based dispersant is less than 10 parts by mass, the storage stability of the pigment dispersion and the ink may be reduced, or dispersion may take an extremely long time. When the amount exceeds 100 parts by mass, the ejection stability tends to decrease when the amount exceeds 100 parts by mass.

In addition to the anionic surfactant-based dispersant, a nonionic surfactant containing an ethylene oxide group may be used in combination with the pigment dispersion ink. In general, the nonionic surfactant containing an ethylene oxide group can be used alone, but it is preferably used in combination with the anionic surfactant of the present invention in order to have a cloud point. When used in combination, the cloud point, which was clear by itself, becomes unclear or disappears, so that the action of attracting the molecules of the oxyethylene chain does not decrease even under temperature changes or long-term storage.
The nonionic surfactant is a nonionic group in which the hydrophilic group in the molecule does not ionize in water. Are known. Among these, since a compound containing an oxyethylene group can arbitrarily design an HLB by changing the proportion of the oxyethylene group in the molecule, a surfactant having a high dispersion effect can be obtained.
Examples of the nonionic surfactant as the dispersant include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene glycol ester, polyoxyethylene polyoxypropylene glycol, and glycerin ester. Polyoxyethylene ether, polyoxyethylene ether of sorbitan ester, polyoxyethylene ether of sorbitol ester, polyoxyethylene fatty acid amide, polyoxyethylene alkylamine and the like.

There is no restriction | limiting in particular as a pigment in the said pigment dispersion, According to the objective, it can select suitably, For example, any of an inorganic pigment and an organic pigment may be sufficient.
Examples of the inorganic pigment include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, 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, polycyclic pigments, dye chelates, nitro pigments, nitroso pigments, and aniline black. Among these, azo pigments and polycyclic pigments are more preferable.
Examples of the azo pigments include azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments.
Examples of the polycyclic pigment include phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinofullerone pigments.
Examples of the dye chelates include basic dye chelates and acidic dye chelates.

There is no restriction | limiting in particular as a color of the said coloring agent, According to the objective, it can select suitably, For example, the thing for black, the thing for color, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
Examples of the black color include carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper, iron (CI pigment black 11), oxidation, and the like. Examples thereof include metals such as titanium, organic pigments such as aniline black (CI Pigment Black 1), and the like.

  Examples of the color are C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide) 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104, 408, 109, 110, 117, 120, 128, 138, 150, 151, 153, 183; I. Pigment orange 5, 13, 16, 17, 36, 43, 51; C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53 : 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 (Cadmium Red) , 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 219; I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38; I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3 (phthalocyanine blue), 16, 17: 1, 56, 60, 63; I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, and the like.

The black pigment is preferably carbon black. Carbon black as a black ink is excellent in color tone, excellent in water resistance, light-repelling property, dispersion stability, and inexpensive.
Other pigment (for example, carbon) surface is treated with resin, etc. to make it dispersible in water, and pigment (for example, carbon) surface is added with a functional group such as sulfone group or carboxyl group and dispersed in water Processed pigments made possible can be used.
Further, the pigment may be included in the microcapsule so that the pigment can be dispersed in water.

In addition, you may contain dye within the range which does not degrade light resistance etc. for the purpose of color tone adjustment. There is no restriction | limiting in particular as said dye, According to the objective, it can select suitably, For example, an acidic dye, a direct dye, a basic dye, a reactive dye etc. are mentioned.
There is no restriction | limiting in particular as said acidic dye, According to the objective, it can select suitably, What is known as a food dye, etc. are mentioned, for example, C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142; C.I. I. Acid Red 1, 8, 13, 14, 18, 26, 27, 35, 37, 42, 52, 82, 87, 89, 92, 97, 106, 111, 114, 115, 134, 186, 249, 254 289; C.I. I. Acid Blue 9, 29, 45, 92, 249; I. Acid Black 1, 2, 7, 24, 26, 94; I. Food Yellow 2, 3, 4; C.I. I. Food Red 7, 9, 14; C.I. I. Food black 1, 2, etc. are mentioned.

  Examples of the direct dye include C.I. I. Direct yellow 1, 12, 24, 26, 33, 44, 50, 86, 120, 132, 142, 144; I. Direct red 1, 4, 9, 13, 17, 20, 28, 31, 39, 80, 81, 83, 89, 225, 227; I. Direct orange 26, 29, 62, 102; I. Direct Blue 1, 2, 6, 15, 22, 25, 71, 76, 79, 86, 87, 90, 98, 163, 165, 199, 202; C.I. I. Direct black 19, 22, 32, 38, 51, 56, 71, 74, 75, 77, 154, 168, 171 and the like.

  Examples of the basic dye include C.I. I. Basic Yellow 1, 2, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 40, 41, 45, 49, 51, 53, 63, 65, 67 70, 73, 77, 87, 91; C.I. I. Basic Red 2, 12, 13, 14, 15, 18, 22, 23, 24, 27, 29, 35, 36, 38, 39, 46, 49, 51, 52, 54, 59, 68, 69, 70 73, 78, 82, 102, 104, 109, 112; I. Basic Blue 1, 3, 5, 7, 9, 21, 22, 26, 35, 41, 45, 47, 54, 62, 65, 66, 67, 69, 75, 77, 78, 89, 92, 93 105, 117, 120, 122, 124, 129, 137, 141, 147, 155; I. Basic black 2, 8, etc. are mentioned.

Examples of the reactive dye include C.I. I. Reactive Black 3, 4, 7, 11, 12, 17; C.I. I. Reactive Yellow 1, 5, 11, 13, 14, 20, 21, 22, 25, 40, 47, 51, 55, 65, 67; C.I. I. Reactive Red 1, 14, 17, 25, 26, 32, 37, 44, 46, 55, 60, 66, 74, 79, 96, 97; C.I. I. Reactive blue 1, 2, 7, 14, 15, 23, 32, 35, 38, 41, 63, 80, 95, and the like.
Among these dyes, acid dyes and direct dyes are particularly preferable.

  The content of the pigment dispersion in the recording ink is not particularly limited and may be appropriately selected depending on the purpose. The solid content is preferably 3% by mass to 15% by mass, and preferably 5% by mass to 12% by mass. Is more preferable. When the content is less than 3% by mass, the image density may be thin and there may be an image having no contrast. When the content exceeds 15% by mass, it is difficult to ensure the dispersion stability of the pigment, such as a nozzle. Clogging is likely to occur, and reliability may be reduced.

  The pigment dispersion is mixed with water, a pigment, and an anionic surfactant-based dispersant, and dispersed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, or an ultrasonic disperser. At this time, the stabilizer may be added and mixed after dispersing the pigment dispersion, and the addition timing may be appropriately changed within the range where the effect of the stabilizer is obtained. From the viewpoint of preventing dropout, it is preferable to add the specific water-soluble organic solvent of the present invention before mixing.

-Stabilizer-
The stabilizer includes a phosphorylcholine-like group-containing polymer having at least a structural unit represented by the following general formula (3).
However, in said general formula (3), X shows a bivalent organic residue. Y represents an alkyleneoxy group having 1 to 6 carbon atoms. Z is a hydrogen atom, and R ⁷ —O— (C═O) — (wherein R ⁷ represents an alkyl group having 1 to 10 carbon atoms or a hydroxyalkyl group having 1 to 10 carbon atoms) Represents one of the following. R ³ represents either a hydrogen atom or a methyl group. R ⁴ , R ⁵ , and R ⁶ may be the same as or different from each other, and are any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a hydroxyalkyl group having 1 to 6 carbon atoms. Represents m shows the integer of 0-20. n shows the integer of 1-4.
Examples of the alkyl group for R ⁴ , R ⁵ , R ⁶ , and R ⁷ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.

  Among these, what uses 2- (methacryloyloxy) ethyl-2 '-(trimethylammonio) ethyl phosphate as a monomer is easily available. Commercially available products of the phosphorylcholine-like group-containing polymer include “Lipidure-HM” (Nippon Yushi Co., Ltd., polymethacryloyloxytyl phosphorylcholine), “Lipidure-PMB” (Nippon Yushi Co., Ltd., 2-methacryloyloxyethylphosphorylcholine). -A butyl methacrylate copolymer) etc. are mentioned. The “Lipidure-HM” is a homopolymer containing a phosphorylcholine-like group, and the “Lipidure-PMB” is a copolymer of a hydrophobic component.

Both the phosphorylcholine-analogous group-containing homopolymer and copolymer have a function as a stabilizer, but there are more preferable combinations depending on the type of anionic surfactant-based dispersant used. In the combination with the compound of the general formula (1), there is no significant difference in the effect as a stabilizer of the homopolymer and the copolymer, but in the combination with the compound of the general formula (2), the combination with the homopolymer Thus, a recording ink having higher storage stability can be obtained.
The weight average molecular weight of the phosphorylcholine-like group-containing polymer is preferably 10,000 to 2,000,000, and more preferably 10,000 to 700,000.
The content of the stabilizer in the recording ink is preferably 0.01% by mass to 5% by mass, and more preferably 0.1% by mass to 1% by mass.

-Water-soluble organic solvent-
Examples of the water-soluble organic solvent include propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, and 3-methyl-1,3-butanediol. 1,5-pentanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 1,2,4-butanetriol, 1,2,6-hexanetriol, and the like. Among these, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, and 2-methyl-2,4-pentanediol are preferable, and 1,3-butanediol and 3-methyl -1,3-butanediol is particularly preferred. Thereby, the penetration speed of the ink can be increased, the spread of the pixels when the ink lands on the paper is made uniform, and the effect of keeping the colorant on the paper surface is also improved.

  The specific water-soluble organic solvent also has a role of a wetting agent that ensures the moisture retention of the ink in addition to the purpose of improving wettability to paper, and there is no particular limitation other than the specific water-soluble organic solvent. It can be appropriately selected depending on the purpose as long as it is easy to bind, has a high viscosity by itself, has a high equilibrium water content, and decreases in the presence of water. For example, polyhydric alcohols Polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, ethylene carbonate and the like. These may be used alone or in combination of two or more.

Examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,3-propanediol, tetraethylene glycol, glycerin, 1,2,3-butanetriol, and petriol. Is mentioned.
Examples of the polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. It is done.
Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
Examples of the nitrogen-containing heterocyclic compound include N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, and ε-caprolactam.
Examples of the amides include formamide, N-methylformamide, N, N-dimethylformamide and the like.
Examples of the amines include monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, and triethylamine.
Examples of the sulfur-containing compounds include dimethyl sulfoxide, sulfolane, thiodiethanol, thiodiglycol, and the like.

Among these, glycerin is particularly preferable because of its high effect of preventing the pigment from agglomerating and preventing the particle size from increasing, although the viscosity rapidly increases with moisture evaporation.
Therefore, at least one water-soluble organic solvent selected from 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol and 2-methyl-2,4-pentanediol is essential. It is a preferred embodiment that it is contained as a component and glycerin is used in combination, and other water-soluble organic solvents can be further used as necessary.
Among these, 1,3-butanediol and 3-methyl-1,3-butanediol have a high equilibrium moisture content and high reliability like glycerin, and the pixel spread when ink lands on paper. The effect of keeping the pigment uniform and further keeping the pigment on the paper surface is also high. Glycerin has a high reliability improvement effect, but when added in a large amount, the image quality deteriorates, and the viscosity increase after evaporation of water becomes too large, and the discharge stability may deteriorate. Butanediol: glycerin) is preferably 1: 4 to 4: 1, more preferably 1: 3 to 3: 1, and still more preferably 1: 1 to 3: 1.

  The content of the water-soluble organic solvent in the recording ink is preferably 10% by mass to 40% by mass, and more preferably 25% by mass to 35% by mass. When the content is less than 10% by mass, the storage stability and ejection stability of the ink are deteriorated and nozzle clogging is likely to occur. When the content exceeds 40% by mass, the drying property is deteriorated. Image blur and color boundary blur occur, and the image quality deteriorates.

-Surfactant-
Examples of the surfactant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant. These may be used individually by 1 type and may use 2 or more types together. Among these, anionic surfactants and nonionic surfactants are particularly preferable.

  Examples of the anionic surfactant include alkyl allyl, alkyl naphthalene sulfonate, alkyl phosphate, alkyl sulfate, alkyl sulfonate, alkyl ether sulfate, alkyl sulfosuccinate, alkyl ester sulfate, alkyl benzene sulfonic acid. Salt, alkyl diphenyl ether disulfonate, alkyl aryl ether phosphate, alkyl aryl ether sulfate, alkyl aryl ether ester sulfate, olefin sulfonate, alkane olefin sulfonate, polyoxyethylene alkyl ether phosphate, polyoxy Ethylene alkyl ether sulfate ester salt, polyoxyethylene alkyl ether acetate salt, ether carboxylate, sulfosuccinate, α-sulfo fatty acid ester, fatty acid salt, Condensates of grade fatty acids and amino acids, such as naphthenic acid salts. Among these, polyoxyethylene alkyl ether acetate is particularly preferable.

Examples of the nonionic surfactant include acetylene glycol surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, and the like. Among these, polyoxyethylene alkyl ether is particularly preferable.
Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, An acetylene glycol surfactant such as 1,5-dimethyl-1-hexyn-3-ol is preferred. Examples of commercially available acetylene glycol surfactants include Surfynol 104, 82, 465, 485, and TG manufactured by Air Products (USA).

Examples of the cationic surfactant include alkylamine salts, dialkylamine salts, aliphatic amine salts, benzalkonium salts, quaternary ammonium salts, alkylpyridinium salts, imidazolinium salts, sulfonium salts, phosphonium salts, and the like. Can be mentioned.
Examples of the amphoteric surfactant include imidazoline derivatives such as imidazolinium betaine, dimethylalkyl lauryl betaine, alkyl glycine, and alkyl di (aminoethyl) glycine.

In order to further improve the image quality, it is more preferable to use either a fluorosurfactant or a silicone surfactant having high penetrating properties. Among these, a fluorosurfactant is particularly preferable. preferable.
Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. And polyoxyalkylene ether polymer compounds. Among these, the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain has a low foaming property, a low bioaccumulation property of a fluorine compound that has been regarded as a problem in recent years, and a high safety. Particularly preferred.

Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like.
Examples of the perfluoroalkyl carboxylic compounds include perfluoroalkyl carboxylic acids and perfluoroalkyl carboxylic acid salts.
Examples of the perfluoroalkyl phosphate compound include perfluoroalkyl phosphate esters, perfluoroalkyl phosphate salts, and the like.
The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain, and a polyoxyalkylene ether having a perfluoroalkyl ether group in the side chain. Examples thereof include a sulfate salt of a polymer and a salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain.
As counter ions of salts in these fluorosurfactants, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH) ₃ etc. are mentioned.
Among these, compounds represented by at least one of the following structural formulas (1) to (2) are preferably exemplified.

_{CF 3 CF 2 (CF 2 CF} 2) j -CH 2 CH 2 O (CH 2 CH 2 O) k H ··· structural formula (1)
However, in said structural formula (1), j represents the integer of 0-10. k represents an integer of 1 to 40.

In the structural formula (2), Rf represents a fluorine-containing group, and a perfluoroalkyl group is particularly preferable.
Examples of the perfluoroalkyl group preferably has a carbon number of 1 to 10, more preferably those of 1 to 3, for _example, -C _{n F 2n-1} (where, n is an integer of 1 to 10) Etc. Examples of the perfluoroalkyl group include —CF ₃ , —CF ₂ CF ₃ , —C ₃ F ₇ , —C ₄ F ₉ , etc. Among these, —CF ₃ , —CF ₂ CF ₃ Is particularly preferred.
m, n, and p each represent an integer, n is preferably 1-4, m is preferably 6-25, and p is preferably 1-4.

As said fluorosurfactant, what was synthesize | combined suitably may be used and a commercial item may be used.
Examples of the commercially available products include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F1405 , F-474 (all manufactured by Dainippon Ink & Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all manufactured by DuPont) FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Corporation); PF-151 N (made by Omninova) etc. are mentioned. Among these, Zonyl FS-300, FSN, FSN-100, and FSO (all manufactured by DuPont) are particularly preferable from the viewpoint of improving reliability and color development.

The silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, side Examples thereof include polydimethylsiloxane modified at both chain ends, and those having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group are particularly preferable because they exhibit good properties as an aqueous surfactant.
There is no restriction | limiting in particular as such surfactant, What was synthesize | combined suitably may be used and a commercial item may be used.
Such commercially available products can be easily obtained from, for example, Big Chemie, Shin-Etsu Silicone, Toray Dow Corning Silicone, etc.

  The content of the surfactant in the recording ink is preferably 0.01% by mass to 5.0% by mass, and more preferably 0.5% by mass to 3% by mass. When the content is less than 0.01% by mass, there is no effect of addition. When the content exceeds 5.0% by mass, the permeability to the recording medium is unnecessarily high, and the image density is lowered or the screen is lost. May occur.

-Polyol compound having 8 to 11 carbon atoms-
By containing the polyol compound having 8 to 11 carbon atoms, it is possible to further improve the wettability of the ink to the paper, and it is extremely effective for improving the drying property in high-speed printing and for pixel formation with a small ink adhesion amount. In addition, there is a merit in terms of image quality improvement that there is little color boundary bleeding and show-through. On the other hand, these polyol compounds are not very soluble in water at 20 ° C. (0.2 mass% or more and less than 5 mass%) and easily wet the pigment surface. However, when the stabilizer of the present invention is used in combination, the storage stability of the ink is good, the ejection stability during long-term use is high, and both image quality and reliability can be achieved.

Examples of the polyol compound having 8 to 11 carbon atoms include 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- Examples include 1,2-diol and 2-ethyl-1,3-hexanediol. Among these, 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol are particularly preferable.
Other penetrants that can be used in combination are not particularly limited as long as they can be dissolved in ink and adjusted to desired physical properties, and can be appropriately selected according to the purpose. Examples thereof include diethylene glycol monophenyl ether and ethylene. Alkyl and aryl ethers of polyhydric alcohols such as glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, tetraethylene glycol chlorophenyl ether; lower alcohols such as ethanol, etc. Is mentioned.

  The content of the penetrant in the recording ink is preferably 0.1% by mass to 4.0% by mass. When the content is less than 0.1% by mass, a fast-drying property cannot be obtained and a blurred image may be obtained. When the content exceeds 4.0% by mass, the dispersion stability of the colorant is impaired, and the nozzle May easily become clogged, or the permeability to the recording medium may be increased more than necessary, resulting in a decrease in image density or show-through.

-Resin emulsion-
A resin emulsion is added to the recording ink in order to improve image fixability. Here, the resin emulsion is obtained by dispersing resin fine particles in water as a continuous phase, and may contain a dispersant such as a surfactant as necessary. The content of resin fine particles as the dispersed phase component (content of resin fine particles in the resin emulsion) is generally preferably about 10% by mass to 70% by mass.
The particle diameter of the resin fine particles is preferably 10 nm to 1,000 nm, more preferably 20 nm to 300 nm in terms of volume average particle diameter, considering use in ink jet recording.
The resin fine particle component of the dispersed phase is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include acrylic resins, vinyl acetate resins, styrene resins, butadiene resins, and styrene-butadiene resins. Examples thereof include resins, vinyl chloride resins, acrylic-styrene resins, acrylic-silicone resins, and the like. Among these, acryl-silicone resin is particularly preferable from the viewpoint of good fixability.

As said resin emulsion, what was synthesize | combined suitably may be used and a commercial item may be used.
Examples of the commercially available products include Microgel E-100, E-2002, E-5002 (styrene-acrylic resin emulsion, manufactured by Nippon Paint Co., Ltd.); Boncoat 5454 (styrene-acrylic resin emulsion, Dainippon) Jonkrill 775 (styrene-acrylic resin emulsion, manufactured by Johnson Polymer Co., Ltd.); SAE1014 (styrene-acrylic resin emulsion, manufactured by Nippon Zeon Co., Ltd.); Cybinol SK-200 (acrylic resin) Emulsion, manufactured by Syden Chemical Co., Ltd.); Primal AC-22, AC-61 (acrylic resin emulsion, manufactured by Rohm and Haas); Nanoacryl SBCX-2821, 3689 (acrylic-silicone resin emulsion, East Ltd. Ink Manufacturing Co., Ltd.); # 3070 (methyl methacrylate polymer resin emulsion, manufactured by Mikuni Color Ltd.); PESRESIN A210 (polyester resin emulsion, Takamatsu Yushi Co., Ltd.), and the like.

  The content of the resin emulsion in the recording ink is preferably 0.1% by mass to 30% by mass in terms of solid content, more preferably 1% by mass to 20% by mass, and still more preferably 5% by mass to 15% by mass.

The water content in the recording ink is preferably 35% by mass or more, and more preferably 45% by mass or more. In this case, the upper limit value is not particularly limited and can be appropriately selected according to the purpose, but is preferably 70% by mass. When the water content is less than 35% by mass, the increase in viscosity at the time of evaporation becomes too large, and the discharge stability may be deteriorated.
Further, the total content of the pigment dispersion and the resin emulsion in the recording ink is preferably 10% by mass to 30% by mass, and more preferably 12% by mass to 18% by mass in terms of solid content. When the total content is less than 10% by mass, the image density becomes low and the fixability may be insufficient. When the total content exceeds 30% by mass, the increase in viscosity at the time of evaporation becomes too large. It may become clogged easily.

  The other components are not particularly limited and may be appropriately selected as necessary. For example, an antifoaming agent, a pH adjuster, an antiseptic / antifungal agent, a rust inhibitor, an antioxidant, an ultraviolet absorber, Examples include oxygen absorbers and light stabilizers.

There is no restriction | limiting in particular as said antifoamer, According to the objective, it can select suitably, For example, a silicone type antifoamer, a polyether type antifoamer, a fatty-acid ester type | system | group antifoamer etc. are mentioned suitably. These may be used individually by 1 type and may use 2 or more types together. Among these, a silicone type antifoaming agent is preferable in that it has an excellent foam breaking effect.
Examples of the silicone-based antifoaming agent include oil-type silicone antifoaming agents, compound-type silicone antifoaming agents, self-emulsifying silicone antifoaming agents, emulsion-type silicone antifoaming agents, and modified silicone antifoaming agents. . Examples of the modified silicone-based antifoaming agent include amino-modified silicone antifoaming agents, carbinol-modified silicone antifoaming agents, methacrylic-modified silicone antifoaming agents, polyether-modified silicone antifoaming agents, alkyl-modified silicone antifoaming agents, and higher grades. Examples thereof include fatty acid ester-modified silicone antifoaming agents and alkylene oxide-modified silicone antifoaming agents. Among these, the self-emulsifying type silicone antifoaming agent and the emulsion type silicone antifoaming agent are preferable in consideration of use in the recording ink which is an aqueous medium.
Commercially available products may be used as the antifoaming agent, such as silicone antifoaming agents (KS508, KS531, KM72, KM85, etc.) manufactured by Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Co., Ltd. Silicone antifoaming agents (Q2-3183A, SH5510, etc.) manufactured by company, silicone antifoaming agents (SAG30, etc.) manufactured by Nihon Unicar Co., Ltd., antifoaming agents (Adecanate series, etc.) manufactured by Asahi Denka Kogyo Co., Ltd., etc. Can be mentioned.
There is no restriction | limiting in particular as content in the said recording ink of the said defoamer, According to the objective, it can select suitably, 0.001 mass%-3 mass% are preferable, 0.05 mass%-0 More preferably, 5% by mass.

  Examples of the antiseptic / antifungal agent include 1,2-benzisothiazolin-3-one, sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, sodium pentachlorophenol, and the like. Can be mentioned.

  The pH adjuster is not particularly limited as long as it can adjust the pH to 7 or more without adversely affecting the ink to be prepared, and any substance can be used according to the purpose. Examples of the pH adjuster include amines such as diethanolamine and triethanolamine, hydroxides of alkali metal elements such as lithium hydroxide, sodium hydroxide and potassium hydroxide; ammonium hydroxide and quaternary ammonium hydroxide. , Quaternary phosphonium hydroxides, alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, and the like.

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

Examples of the antioxidant include phenol-based antioxidants (including hindered phenol-based antioxidants), amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.
Examples of the phenolic antioxidants (including hindered phenolic antioxidants) include butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, stearyl-β- (3,5 -Di-tert-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-Butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) ) Propionyloxy] ethyl] 2,4,8,10-tetrixaspiro [5,5] undecane, 1,1,3-tris (2-methyl-4- Hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane, and the like.
Examples of the amine-based antioxidant include phenyl-β-naphthylamine, α-naphthylamine, N, N′-di-sec-butyl-p-phenylenediamine, phenothiazine, N, N′-diphenyl-p-phenylenediamine. 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butyl-phenol, butylhydroxyanisole, 2,2′-methylenebis ( 4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), tetrakis [methylene -3 (3,5-di-tert-butyl-4-dihydroxyphenyl) propionate] methane, 1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, and the like.
Examples of the sulfur-based antioxidant include dilauryl 3,3′-thiodipropionate, distearyl thiodipropionate, lauryl stearyl thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl β. , β′-thiodipropionate, 2-mercaptobenzimidazole, dilauryl sulfide, and the like.
Examples of the phosphorus antioxidant include triphenyl phosphite, octadecyl phosphite, triisodecyl phosphite, trilauryl trithiophosphite, and trinonylphenyl phosphite.

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.
Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2,4-dihydroxybenzophenone, and 2-hydroxy-4-methoxybenzophenone. 2,2 ′, 4,4′-tetrahydroxybenzophenone, and the like.
Examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-4′-octoxyphenyl) benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, and the like.
Examples of the salicylate UV absorber include phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, and the like.
Examples of the cyanoacrylate ultraviolet absorber include ethyl-2-cyano-3,3′-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate, and butyl-2- And cyano-3-methyl-3- (p-methoxyphenyl) acrylate.
Examples of the nickel complex ultraviolet absorber include nickel bis (octylphenyl) sulfide, 2,2′-thiobis (4-tert-octylferrate) -n-butylamine nickel (II), 2,2′-thiobis. (4-tert-octylferrate) -2-ethylhexylamine nickel (II), 2,2′-thiobis (4-tert-octylferrate) triethanolamine nickel (II), and the like.

  The recording ink of the present invention is prepared by mixing and stirring water, a pigment dispersion, a stabilizer, a specific water-soluble organic solvent, preferably a resin emulsion, a surfactant, a penetrating agent, and other components as necessary. Can be manufactured. The stirring and mixing can be performed with a stirrer using a normal stirring blade, a magnetic stirrer, a high-speed disperser, or the like.

The physical properties of the recording ink of the present invention are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the viscosity, surface tension, pH and the like are preferably in the following ranges.
The viscosity of the recording ink is preferably 20 mPa · s or less, more preferably 15 mPa · s or less at 25 ° C. If the viscosity exceeds 20 mPa · s, it may be difficult to ensure ejection stability.
The dynamic surface tension of the recording ink at 25 ° C. and 10 msec to 100 msec is preferably 20 mN / m to 35 mN / m, and more preferably 25 mN / m to 33 mN / m.
The static surface tension around 1,000 msec at 25 ° C. in the recording ink is preferably 20 mN / m to 35 mN / m, more preferably 22 mN / m to 28 mN / m.
The pH of the recording ink is preferably 7 to 10, for example.

  There is no restriction | limiting in particular as coloring of the recording ink of this invention, According to the objective, it can select suitably, Yellow, magenta, cyan, black etc. are mentioned. When recording is performed using an ink set in which two or more of these colorings are used in combination, a multicolor image can be recorded. When recording is performed using an ink set in which all colors are combined, a full color image is recorded. be able to.

  The recording ink of the present invention uses an piezoelectric head as a pressure generating means for pressurizing ink in an ink flow path as an ink jet head, and deforms a diaphragm that forms the wall surface of the ink flow path to increase the volume in the ink flow path. A so-called piezo type that discharges ink droplets by changing (see Japanese Patent Laid-Open No. 2-51734), or a so-called thermal type that generates bubbles by heating ink in an ink flow path using a heating resistor. (Refer to Japanese Patent Application Laid-Open No. 61-59911), a diaphragm that forms the wall surface of an ink flow path and an electrode are arranged opposite to each other, and the diaphragm is deformed by an electrostatic force generated between the diaphragm and the electrode. Thus, a pre-printer equipped with any ink jet head, such as an electrostatic type that discharges ink droplets by changing the volume of the ink flow path (see Japanese Patent Application Laid-Open No. 6-71882). Can also be used well for printers.

  The recording ink of the present invention can be suitably used in various fields, and can be suitably used in an image recording apparatus (printer or the like) using an ink jet recording method. For example, the recording medium and the recording medium before and after printing can be used. The recording ink is heated at 50 ° C. to 200 ° C., and can be used for a printer or the like having a function of promoting print fixing, and is particularly suitable for the following ink cartridge, ink jet recording apparatus, and ink jet recording method of the present invention. Can be used for

(ink cartridge)
The ink cartridge of the present invention contains the recording ink of the present invention in a container, and further includes other members and the like appropriately selected as necessary.
The container is not particularly limited, and its shape, structure, size, material and the like can be appropriately selected according to the purpose. For example, at least an ink bag formed of an aluminum laminate film, a resin film, or the like Preferred examples include those possessed.

Next, the ink cartridge will be described with reference to FIGS. Here, FIG. 1 is a view showing an example of the ink cartridge of the present invention, and FIG. 2 is a view including a case (exterior) of the ink cartridge 200 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.

  The ink cartridge of the present invention contains the recording ink (ink set) of the present invention and can be used by being detachably attached to various ink jet recording apparatuses, and can be attached to and detached from the ink jet recording apparatus of the present invention described later. It is particularly preferable to install and use it.

(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 ink jet 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. Moreover, the said other process can be suitably performed by the said other means.

-Ink flying process and ink flying means-
The ink flying step is a step of recording an image by applying a stimulus to the recording ink of the present invention and causing the recording ink to fly.

The ink flying means is means for recording an image by applying a stimulus to the recording ink of the present invention and causing the recording ink to fly. The ink flying means is not particularly limited, and examples thereof include various nozzles for ejecting ink.
In the present invention, it is preferable that at least a part of the liquid chamber portion, the fluid resistance portion, the vibration plate, and the nozzle member of the ink jet head is formed of a material containing at least one of silicon and nickel.
The head preferably has a nozzle plate having a water repellent treatment applied to the ink discharge surface, and the water repellent finish is selected from PTFE-Ni eutectoid processing, fluororesin processing, and silicone resin processing. Either is preferred.
Further, the nozzle diameter of the inkjet nozzle is preferably 35 μm or less, more preferably 30 μm or less, and further preferably 15 μm to 25 μm. The printing speed is preferably 8 ppm or more. Thereby, more stable and high-quality image recording can be performed.
Preferably, the ink jet head has a sub tank for supplying ink, and the sub tank is supplemented with ink from an ink cartridge through a supply tube.

  The stimulus can be generated, for example, by the stimulus generating means, and the stimulus is not particularly limited and can be appropriately selected according to the purpose, such as heat (temperature), pressure, vibration, light, etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, heat and pressure are preferable.

  Examples of the stimulus generating means include a heating device, a pressurizing device, a piezoelectric element, a vibration generating device, an ultrasonic oscillator, a light, and the like. Specifically, for example, a piezoelectric actuator such as a piezoelectric element, Examples include thermal actuators that use phase changes due to liquid film boiling using electrothermal transducers such as heating resistors, shape memory alloy actuators that use metal phase changes due to temperature changes, and electrostatic actuators that use electrostatic forces. .

  There are no particular restrictions on the manner in which the recording ink flies, and it varies depending on the type of the stimulus. For example, when the stimulus is “heat”, a recording signal is output to the recording ink in the recording head. Corresponding thermal energy is applied using, for example, a thermal head, bubbles are generated in the recording ink by the thermal energy, and the recording ink is liquidated from the nozzle holes of the recording head by the pressure of the bubbles. For example, a method of discharging and ejecting droplets can be used. 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 is bent, and the pressure chamber For example, a method in which the volume is reduced and the recording ink is ejected and ejected as droplets from the nozzle holes of the recording head.

  The size of the recording ink droplets to be ejected is preferably 2 pl to 40 pl, for example, and the ejection jet speed is preferably 5 m / sec to 20 m / sec, The drive frequency is preferably 1 kHz or higher, and the resolution is preferably 300 dpi or higher.

The ink jet recording apparatus of the present invention preferably has a reversing unit that can perform double-sided printing by reversing the recording surface of the recording medium. Examples of the reversing means include a conveyance belt having electrostatic force, a means for holding a recording medium by air suction, and a combination of a conveyance roller and a spur.
It is preferable to have an endless transport belt and transport means for transporting the surface of the transport belt while charging and holding the recording medium. In this case, it is particularly preferable to charge the conveyor belt by applying an AC bias of ± 1.2 kV to ± 2.6 kV to the charging roller.

  The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as sequencers and computers.

  The inkjet recording apparatus of the present invention includes a plurality of pressurized liquid chambers, nozzles and ink supply passages having a hole diameter of 35 μm or less communicating with the pressurized liquid chambers, a vibration plate, and electromechanical conversion means for displacing the vibration plate. The ink for forming the ink droplets is formed by merging before a plurality of ink droplets are continuously ejected and landed on the recording medium. Ink is preferred. As a result, it is possible to ensure ejection stability even with high viscosity ink.

In this case, the recording ink in the vicinity of the nozzle during printing may have ink discharging means for discharging the recording ink inside the nozzle hole before the specific viscosity change rate expressed by the following formula 1 exceeds 100. preferable.
<Formula 1>
Specific viscosity change rate = {[(η ₁ −η ₀ ) / η ₀ ] × 100} / T
In Equation 1, η ₀ represents the initial viscosity (mPa · s) of the recording ink before performing the evaporation test in an environment of 25 ° C. and 50% RH. η ₁ represents the viscosity (mPa · s) after the elapse of T time when the evaporation test is performed. T represents the elapsed time in the evaporation test.

  The recording ink of the present invention has an ink discharging means for discharging the ink inside the nozzle hole before it because the viscosity suddenly increases after a certain period of time depending on the printing environment. preferable. As the ink discharging means, a method of ejecting ink to a non-printing area is preferable, and the number of scans of a carriage on which the head is mounted is counted, and when the value exceeds a certain threshold (or every predetermined time), A method is employed in which the head is driven to eject a certain amount of ink so that the ink is ejected to the non-printing area. The amount of ink to be discharged to the non-printing area can be set arbitrarily by changing the number of times the head is driven when ejecting the ink and controlling the threshold value. It is preferable to set so that the minimum amount of ink is ejected within a range in which the property can be maintained. With respect to the recording ink of the present invention, it has been confirmed that reliability is ensured when 2,000 to 30,000 pl of ink is discharged per minute per nozzle.

Since the evaporation speed of the recording ink is affected by the temperature and humidity environment, and there is a slight difference between colors, the ink jet recording apparatus of the present invention is provided with a temperature and humidity meter sensor, and the inside of the nozzle hole depends on the color. The amount of ink discharged from the ink can be changed.
In the ink jet recording apparatus of the present invention, it is preferable that the amount of recording ink to be discharged is variable depending on the rate of change in the specific viscosity of the recording ink. The amount of ink discharged from the inside of the nozzle hole can be changed by changing the interval of ink discharge and the number of droplets discharged once.
Further, as an example of providing an ink receiver that receives the discharged recording ink, the ink receiver can be provided outside the belt that conveys the recording medium, as long as the structure of the recording apparatus allows. In this way, when a certain number of scans is exceeded (or every certain time), a certain amount of ink is discharged to the ink receiver provided in the non-printing area, so that ejection stability is further ensured. In addition, an inkjet recording apparatus can be provided.

One mode for 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. 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. In FIG. 3, reference numeral 111 denotes an upper cover, and 112 denotes a front surface.
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 201.

  In the apparatus main body 101, as shown in FIGS. 4 and 5, the carriage 133 is slid in the main scanning direction by guide rods 131 and stays 132 which are horizontally mounted on left and right side plates (not shown). It is held movably and moved and scanned in the direction of the arrow in FIG. 5 by a main scanning motor (not shown).

The carriage 133 includes a plurality of ink jet recording heads 134 including four ink jet recording heads that eject recording ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). The ejection ports are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing 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 recording ink can be used.
Also, 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 and supplemented with the recording ink of the present invention from the ink cartridge 201 of the present invention loaded in the ink cartridge loading section 105 via a recording ink supply tube (not shown).

  On the other hand, as a paper feeding unit for feeding the paper 142 stacked on the paper stacking unit (pressure plate) 141 of the paper feeding tray 102, a half-moon roller (feeding) that separates and feeds the paper 142 from the paper stacking unit 141 one by one. A separation pad 144 made of a material having a large coefficient of friction is provided facing the paper roller 143) and the paper feed roller 143, and the separation pad 144 is urged toward the paper feed roller 143 side.

  As a transport unit for transporting the paper 142 fed from the paper feed unit below the recording head 134, a transport belt 151 for transporting the paper 142 by electrostatic adsorption and a guide 145 from the paper feed unit. The counter roller 152 for transporting the paper 142 fed via the transport belt 151 with the transport belt 151 and the paper 142 fed substantially vertically upward are changed by approximately 90 ° so as to follow the transport belt 151. A conveying guide 153 and a tip pressure roller 155 urged toward the conveying belt 151 by a pressing member 154, and a charging roller 156 as a charging means for charging the surface of the conveying belt 151. It has been.

  The conveyance belt 151 is an endless belt, is stretched between the conveyance roller 157 and the tension roller 158, and can circulate in the belt conveyance direction. The transport belt 151 includes, for example, a surface layer serving as a sheet adsorbing surface formed of a resin material having a thickness of about 40 μm that is not subjected to resistance control, for example, a copolymer of tetrafluoroethylene and ethylene (ETFE), It has a back layer (medium resistance layer, earth layer) that is made of the same material and has resistance controlled by carbon. On the back side of the conveyance belt 151, a guide member 161 is arranged corresponding to a printing area by the recording head 134. Note that, as a paper discharge unit for discharging the paper 142 recorded by the recording head 134, a separation claw 171 for separating the paper 142 from the conveyance belt 151, a paper discharge roller 172, and a paper discharge roller 173 are provided. The paper discharge tray 103 is disposed below the paper discharge roller 172.

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

In this ink jet recording apparatus, the paper 142 is separated and fed one by one from the paper feed unit, and the paper 142 fed substantially vertically upward is guided by the guide 145 and between the transport belt 151 and the counter roller 152. It is sandwiched and conveyed. Further, the leading end is guided by the conveying guide 153 and pressed against the conveying belt 151 by the leading end pressure roller 155, and the conveying direction is changed by approximately 90 °.
At this time, the conveying belt 151 is charged by the charging roller 156, and the sheet 142 is electrostatically attracted to the conveying belt 151 and conveyed. Therefore, by driving the recording head 134 according to the image signal while moving the carriage 133, ink droplets are ejected onto the stopped paper 142 to record one line, and after the paper 142 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 142 has reached the recording area, the recording operation is terminated and the sheet 142 is discharged onto the discharge tray 103.
When the recording ink remaining amount near end in the sub tank 135 is detected, a required amount of recording ink is supplied from the ink cartridge 201 to the sub tank 135.

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

  Here, an example is described in which the present invention is applied to a serial (shuttle type) ink jet recording apparatus that is scanned by a carriage, but the present invention can be similarly applied to a line type ink jet recording apparatus having a line type head.

  Further, the ink jet recording apparatus and the ink jet recording method of the present invention can be applied to various types of recording by the ink jet recording method. For example, the ink jet recording apparatus, the facsimile apparatus, the copying apparatus, the printer / fax / copier multifunction machine, etc. It can be particularly preferably applied.

Hereinafter, an ink jet head to which the present invention is applied will be described.
FIG. 6 is an enlarged view of elements of an ink jet head according to an embodiment of the present invention, and FIG. 7 is an enlarged cross-sectional view of the main part in the channel-to-channel direction of the head.
This ink jet head has a frame 10 formed with an engraving serving as an ink supply port (not shown) and a common liquid chamber 1b, and a communication port 2c communicating with the nozzle 3a and the engraving serving as a fluid resistance portion 2a and a pressurized liquid chamber 2b. The formed flow path plate 20, the nozzle plate forming the nozzle 3 a, the vibration plate 60 having the convex portion 6 a, the diaphragm portion 6 b, and the ink inflow port 6 c, and the vibration plate 60 are bonded via the adhesive layer 70. A laminated piezoelectric element 50 and a base 40 to which the laminated piezoelectric element 50 is fixed are provided.
The base 40 is made of a barium titanate ceramic, and the laminated piezoelectric elements 50 are arranged in two rows and joined.
The laminated piezoelectric element 50 includes a lead zirconate titanate (PZT) piezoelectric layer having a thickness of 10 μm / 1 layer to 50 μm / 1 layer, and an internal electrode layer made of silver / palladium (AgPd) having a thickness of several μm / 1 layer. Are stacked alternately. The internal electrode layer is connected to the external electrode at both ends.
The laminated piezoelectric element 50 is divided onto comb teeth by half-cut dicing, and is used as a drive unit 5f and a support unit 5g (non-drive unit) one by one. The length of the outside of the external electrode is limited by machining such as notches so that it is divided by half-cut dicing, and these become a plurality of individual electrodes. The other is not divided by dicing but is conductive and becomes a common electrode.
The FPC 8 is soldered to the individual electrodes of the drive unit. In addition, the common electrode is provided with an electrode layer at the end of the laminated piezoelectric element, and is wound around and joined to the Gnd electrode of the FPC 8. A driver IC (not shown) is mounted on the FPC 8 to control application of a drive voltage to the drive unit 5f.

The diaphragm 60 is joined to a thin film diaphragm portion 6b, an island-shaped convex portion (island portion) 6a that joins the laminated piezoelectric element 50 that is the driving portion 5f formed at the center portion of the diaphragm portion 6b, and a support portion. A thick film portion including a beam and an opening serving as an ink inflow port 6c are formed by stacking two layers of Ni plating films by electroforming. The diaphragm portion has a thickness of 3 μm and a width of 35 μm (one side).
The island-shaped convex part 6a of the diaphragm 60 and the movable part 5f of the laminated piezoelectric element 50, and the coupling of the diaphragm 60 and the frame 10 are bonded by patterning the adhesive layer 70 including a gap material.

As the flow path plate 20, a silicon single crystal substrate was used, and the engraving to be the fluid resistance portion 2a and the pressurized liquid chamber 2b and the through-hole to be the communication port 2c at the position relative to the nozzle 3a were patterned by an etching method.
The portion left by etching becomes the partition wall 2d of the pressurized liquid chamber 2b. Further, in this head, a portion for narrowing the etching width is provided, and this is used as the fluid resistance portion 2a.
The nozzle plate 30 is formed of a metal material, for example, an Ni plating film formed by an electroforming method, and has a number of nozzles 3a that are fine discharge ports for causing ink droplets to fly. The internal shape (inner shape) of the nozzle 3a is formed in a horn shape (may be a substantially cylindrical shape or a substantially frustum shape). The diameter of the nozzle 3a is 20 μm to 35 μm on the ink droplet outlet side. The nozzle pitch of each row was 150 dpi.
The ink ejection surface (nozzle surface side) of the nozzle plate 30 is provided with a water-repellent treatment layer 3b that has been subjected to a water-repellent surface treatment (not shown). Ink, such as PTFE-Ni eutectoid plating, electrodeposition coating of fluororesin, vapor-deposited fluororesin (for example, fluorinated pitch, etc.), baking after solvent application of silicone resin and fluororesin A water repellent film selected according to the physical properties is provided to stabilize the ink droplet shape and flight characteristics so that high quality image quality can be obtained. Among these, for example, various materials are known as the fluororesin, but a modified perfluoropolyoxetane (manufactured by Daikin Industries, Ltd., trade name: OPTOOL DSX) has a thickness of 30 to 100 mm. Thus, good water repellency can be obtained by vapor deposition.

The frame 10 that forms the engraving that becomes the ink supply port and the common liquid chamber 1b is made by resin molding.
In the ink jet head configured as described above, a driving waveform (pulse voltage of 10V to 50V) is applied to the driving unit 5f in accordance with the recording signal, thereby causing displacement in the stacking direction in the driving unit 5f, and the diaphragm 60. The pressurized liquid chamber 2b is pressurized via the pressure to increase the pressure, and ink droplets are ejected from the nozzle 3a.
Thereafter, the ink pressure in the pressurizing liquid chamber 2b is reduced with the end of ink droplet ejection, and negative pressure is generated in the pressurizing liquid chamber 2b due to the inertia of the ink flow and the discharge process of the drive pulse, and the ink is filled. Move to the process. At this time, the ink supplied from the ink tank flows into the common liquid chamber 1b, passes from the common liquid chamber 1b through the ink inlet 6c, passes through the fluid resistance portion 2a, and is filled into the pressurized liquid chamber 2b.
The fluid resistance portion 2a is effective in damping the residual pressure vibration after ejection, but becomes resistant to refilling (refilling) due to surface tension. By appropriately selecting the fluid resistance portion, it is possible to balance the attenuation of the residual pressure and the refill time, and to shorten the time (drive cycle) until the transition to the next ink droplet ejection operation.

(Ink record)
The ink recorded matter recorded by the ink jet recording apparatus and the ink jet recording method of the present invention is the ink recorded matter of the present invention. The ink recorded matter of the present invention has an image formed on the recording medium using the recording ink of the present invention.
There is no restriction | limiting in particular as said recording medium, According to the objective, it can select suitably, For example, a plain paper, glossy paper, special paper, cloth, a film, an OHP sheet etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
The ink recorded matter has high image quality, no bleeding, excellent temporal stability, and can be suitably used for various purposes as a material on which various prints or images are recorded.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Production Example 1)
-Preparation of pigment dispersion A-
20% by weight of C.I. I. Pigment Black 7, Compound (2) -1 as a dispersing agent: 5% by mass of C ₈ H ₁₇ O (CH ₂ CH ₂ O) ₄ SO ₃ H and water are premixed, and then manufactured by Ashizawa Finetech Co., Ltd. After dispersion for 2 hours using zirconia beads having a diameter of 0.3 μm with a dyno mill, the zirconia beads and the liquid were separated to prepare a pigment dispersion A.

(Production Examples 2 to 15)
-Preparation of pigment dispersions B to O-
In Production Example 1, pigment dispersions B to O of Production Examples 2 to 15 were produced in the same manner as Production Example 1 except that the pigments and dispersants shown in Table 1 were used.

* Compound (1) -1: C ₁₃ H ₂₇ O (CH ₂ CH ₂ O) ₃ COOH
* Compound (1) -2: C ₁₀ H ₂₁ O (CH ₂ CH ₂ O) ₁₂ COOH
* Compound _{(1) -3: C 4 H} 9 C 6 H 4 O (CH 2 CH 2 O) 10 COOH
* Compound _{(1) -4: C 3 H} 7 C 6 H 4 O (CH 2 CH 2 O) 12 COOH
* Compound _{(1) -5: C 13 H} 27 O (CH 2 CH 2 O) 6 COOH
* Compound _{(2) -1: C 8 H} 17 O (CH 2 CH 2 O) 4 SO 3 H
* Compound _{(2) -2: C 9 H} 19 C 6 H 4 O (CH 2 CH 2 O) 12 SO 3 H
* Compound _{(2) -3: C 2 H} 5 (C 2 H 5) C 12 H 25 C 6 H 4 O (CH 2 CH 2 O) 24 SO 3 H
* Compound _{(2) -4: CH 3 (} CH 2) 7 CH = CH (CH 2) 8 O (CH 2 CH 2 O) 8 SO 3 H
* Compound _{(2) -5: C 12 H} 25 C 6 H 4 O (CH 2 CH 2 O) 8 SO 3 H

Stabilizer a and stabilizer b shown in Table 2 below were prepared.

Surfactant α to surfactant γ shown in Table 3 below were prepared.

(Example 1)
-Preparation of black ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore size of 0.8 μm to produce the black ink of Example 1.
-Pigment dispersion A: 40 parts by mass (pigment concentration: 8% by mass)
-Stabilizer a ... 10 parts by mass-3-methyl-1,3-butanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-Surfactant α ... 1 part by mass-Ion exchange Water ... remainder

(Example 2)
-Preparation of cyan ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce the cyan ink of Example 2.
-Pigment dispersion B: 30 parts by mass (pigment concentration: 6% by mass)
Stabilizer a: 5 parts by mass 1,5-pentanediol: 15 parts by mass Glycerin: 15 parts by mass Surfactant α: 0.5 parts by mass Ion exchange water ..Remainder

(Example 3)
-Preparation of magenta ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce the magenta ink of Example 3.
・ Pigment dispersion C: 40 parts by mass (pigment concentration: 8% by mass)
-Stabilizer a ... 10 parts by mass-2-methyl-2,4-pentanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-Surfactant β ... 1 part by mass-Ion exchange Water ... remainder

Example 4
-Preparation of yellow ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce a yellow ink of Example 4.
・ Pigment dispersion D: 30 parts by mass (pigment concentration: 6% by mass)
-Stabilizer a ... 5 parts by mass-1,3-butanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-Surfactant β ... 1 part by mass-Ion exchange water ... The rest

(Example 5)
-Preparation of black ink-
After stirring the following composition, it filtered with the filter with an average hole diameter of 0.8 micrometer, and produced the black ink of Example 5. FIG.
・ Pigment dispersion E: 40 parts by mass (pigment concentration: 8% by mass)
-Stabilizer b ... 10 parts by mass-3-methyl-1,3-butanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-Surfactant α ... 1 part by mass-Ion exchange Water ... remainder

(Example 6)
-Preparation of cyan ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce the cyan ink of Example 6.
・ Pigment dispersion F: 30 parts by mass (pigment concentration: 6% by mass)
-Stabilizer b ... 5 parts by mass-1,5-pentanediol ... 15 parts by mass-Glycerin ... 15 parts by mass-Surfactant α ... 0.5 parts by mass-Ion exchange water- ..Remainder

(Example 7)
-Preparation of magenta ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce a magenta ink of Example 7.
・ Pigment dispersion G: 40 parts by mass (pigment concentration: 8% by mass)
-Stabilizer b ... 10 parts by mass-2-methyl-2,4-pentanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-Surfactant β ... 1 part by mass-Ion exchange Water ... remainder

(Example 8)
-Preparation of yellow ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce the yellow ink of Example 8.
・ Pigment dispersion H: 30 parts by mass (pigment concentration: 6% by mass)
-Stabilizer b ... 5 parts by mass-1,3-butanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-Surfactant β ... 1 part by mass-Ion exchange water ... The rest

Example 9
-Preparation of magenta ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce a magenta ink of Example 9.
・ Pigment dispersion I: 40 parts by mass (pigment concentration: 8% by mass)
-Stabilizer a ... 10 parts by mass-3-methyl-1,3-butanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-2-ethyl-1,3-hexanediol ... 2 parts by mass-Surfactant α-0.5 parts by mass-Ion exchange water-the balance

(Example 10)
-Preparation of magenta ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce the magenta ink of Example 10.
・ Pigment dispersion J: 40 parts by mass (pigment concentration: 8% by mass)
Stabilizer b: 10 parts by mass 1,5-pentanediol: 15 parts by mass Glycerin: 15 parts by mass 2,2,4-trimethyl-1,3-pentanediol (TMPD)・ ・ ・ 2 parts by mass ・ Surfactant β ... 1 part by mass ・ Ion-exchanged water ... remainder

(Example 11)
-Preparation of magenta ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore size of 0.8 μm to produce a magenta ink of Example 11.
・ Pigment dispersion C: 40 parts by mass (pigment concentration: 8% by mass)
-Stabilizer a ... 10 parts by mass-2-methyl-2,4-pentanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-2-ethyl-1,3-hexanediol ... 2 parts by mass ・ Surfactant γ ・ ・ ・ 1 part by mass ・ Ion-exchanged water ・ ・ ・ Balance

(Example 12)
-Preparation of magenta ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce a magenta ink of Example 12.
・ Pigment dispersion K: 40 parts by mass (pigment concentration: 8% by mass)
-Stabilizer b ... 10 parts by mass-1,3-butanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-2,2,4-trimethyl-1,3-pentanediol ... 2 parts by mass ・ Surfactant γ ・ ・ ・ 1 part by mass ・ Ion-exchanged water ・ ・ ・ Balance

(Example 13)
-Preparation of black ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce a black ink of Example 13.
-Pigment dispersion A: 40 parts by mass (pigment concentration: 8% by mass)
-Stabilizer a ... 10 parts by mass-3-methyl-1,3-butanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-2-ethyl-1,3-hexanediol ... 2 parts by mass-Surfactant γ ... 1 part by mass-Acrylic silicone resin emulsion (Toyo Ink Manufacturing Co., Ltd., TOCRYL BCX-9583, solid content 50% by mass) ... 8 parts by mass-Ion exchange water- ..Remainder

(Example 14)
-Preparation of cyan ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce a cyan ink of Example 14.
-Pigment dispersion B: 30 parts by mass (pigment concentration: 6% by mass)
-Stabilizer a ... 5 parts by mass-1,5-pentanediol ... 15 parts by mass-Glycerin ... 15 parts by mass-2,2,4-trimethyl-1,3-pentanediol ... 2 parts by mass-Surfactant γ ... 1 part by mass-Acrylic silicone resin emulsion (Toyo Ink Manufacturing Co., Ltd., TOCRYL BCX-9583, solid content 50% by mass) ... 8 parts by mass-Ion exchange water- ..Remainder

(Example 15)
-Preparation of magenta ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce a magenta ink of Example 15.
・ Pigment dispersion C: 40 parts by mass (pigment concentration: 8% by mass)
-Stabilizer a ... 10 parts by mass-2-methyl-2,4-pentanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-2-ethyl-1,3-hexanediol- -2 parts by mass-Surfactant γ ... 1 part by mass-Acrylic silicone resin emulsion (Toyo Ink Manufacturing Co., Ltd., TOCRYL BCX-9583, solid content 50% by mass) ... 8 parts by mass-Ion-exchanged water ... Remainder

(Example 16)
-Preparation of yellow ink-
First, the following pigment dispersion and stabilizer were mixed and stirred. Next, the remaining components were added and stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce a yellow ink of Example 16.
・ Pigment dispersion L: 30 parts by mass (pigment concentration: 6% by mass)
-Stabilizer a ... 5 parts by mass-1,3-butanediol ... 20 parts by mass-Glycerin ... 10 parts by mass-2,2,4-trimethyl-1,3-pentanediol ... 2 parts by mass-Surfactant γ ... 1 part by mass-Acrylic silicone resin emulsion (Toyo Ink Manufacturing Co., Ltd., TOCRYL BCX-9583, solid content 50% by mass) ... 8 parts by mass-Ion exchange water- ..Remainder

(Comparative Example 1)
-Preparation of magenta ink-
After stirring the following composition, it filtered with the filter with an average hole diameter of 0.8 micrometer, and produced the magenta ink of the comparative example 1.
・ Pigment dispersion C: 40 parts by mass (pigment concentration: 8% by mass)
2-methyl-2,4-pentanediol: 20 parts by mass Glycerin: 10 parts by mass 2-ethyl-1,3-hexanediol: 2 parts by mass Surfactant β: 1 part by mass ・ Ion-exchanged water: remainder

(Comparative Example 2)
-Preparation of magenta ink-
After stirring the following composition, it filtered with the filter with an average hole diameter of 0.8 micrometer, and produced the magenta ink of the comparative example 2.
・ Pigment dispersion K: 20 parts by mass (pigment concentration: 4% by mass)
・ Diethylene glycol: 25 parts by mass ・ Surfactant α: 1 part by mass ・ Ion-exchanged water: Remainder

(Comparative Example 3)
-Preparation of magenta ink-
After stirring the following composition, it filtered with the filter with an average hole diameter of 0.8 micrometer, and produced the magenta ink of the comparative example 3.
・ Pigment dispersion M: 40 parts by mass (pigment concentration: 8% by mass)
・ 3-Methyl-1,3-butanediol: 20 parts by mass ・ Glycerin: 10 parts by mass ・ 2-Ethyl-1,3-hexanediol: 2 parts by mass ・ Surfactant α: 1 part by mass ・ Ion-exchanged water: remainder The ink of Comparative Example 3 uses a 2-methacryloyloxyethyl phosphorylcholine homopolymer described in JP-A No. 2002-249684 as a dispersant, to a high pigment concentration and to paper. The ink is composed of a water-soluble organic solvent having excellent wettability.

(Comparative Example 4)
-Preparation of magenta ink-
The following composition was stirred and then filtered through a filter having an average pore size of 0.8 μm to prepare a magenta ink of Comparative Example 4.
・ Pigment dispersion N: 40 parts by mass (pigment concentration: 8% by mass)
2-methyl-2,4-pentanediol: 20 parts by mass Glycerin: 10 parts by mass 2,2,4-trimethyl-1,3-pentanediol: 2 parts by mass Surfactant β ... 1 part by mass ・ Ion-exchanged water ... remainder The ink of Comparative Example 4 uses a 2-methacryloyloxyethyl phosphorylcholine homopolymer disclosed in JP-A-2002-249684 as a dispersant, and has a high pigment concentration and The ink is composed of a water-soluble organic solvent having excellent wettability to paper.

(Comparative Example 5)
-Preparation of cyan ink-
According to Example 1 of JP 2002-249684 A, 15 g of C.I. I. Pigment Blue 15: 3 was added to a mixture of 50 g of ethylene glycol and 25 g of N-methylpyrrolidone, and after stirring and coarse dispersion, 200 g of stabilizer a in Table 2 (20 g in solid content) and 210 g of pure water Was added and dispersed with an ultrasonic homogenizer, followed by pressure emulsification with a microfluidizer. This liquid was filtered through a membrane filter having an average pore diameter of 0.45 μm to produce a cyan ink of Comparative Example 5.

(Comparative Example 6)
-Preparation of yellow ink-
The following composition was stirred, and then filtered through a filter having an average pore diameter of 0.8 μm to produce a yellow ink of Comparative Example 6.
・ Pigment dispersion O: 40 parts by mass (pigment concentration: 8% by mass)
3-methyl-1,3-butanediol: 20 parts by mass Glycerin: 10 parts by mass 2,2,4-trimethyl-1,3-pentanediol: 2 parts by mass Surfactant β ... 1 part by mass · Ion-exchanged water ... Remainder The ink of Comparative Example 6 is a pigment dispersion-like composition described in Example 3 of JP-A-2001-335724, and has a high pigment concentration and The ink is composed of a water-soluble organic solvent having excellent wettability to paper.

(Comparative Example 7)
-Preparation of yellow ink-
The following composition was stirred and then filtered through a filter having an average pore diameter of 0.8 μm to prepare a yellow ink of Comparative Example 7.
Pigment dispersion O: 16.5 parts by mass (pigment concentration: 3.3% by mass)
Triethylene glycol: 11.5 parts by mass Dipropylene glycol monoethyl ether: 2.4 parts by mass Styrene-maleic acid copolymer (manufactured by San Nopco, SN Dispersant 5027) 3 .5 parts by mass ・ Ion-exchanged water: remaining part The ink of Comparative Example 7 constitutes the ink formulation described in Example 3 of JP-A-2001-335724.

  The obtained recording inks of Examples 1 to 16 and Comparative Examples 1 to 7 were vacuum degassed and then filled into an ink pack for IPSiO G717 manufactured by Ricoh Co., Ltd. to obtain an ink cartridge. Using these, various characteristics were evaluated as follows. The results are shown in Table 5.

<Viscosity change rate before and after storage>
The obtained recording inks of Examples 1 to 16 and Comparative Examples 1 to 7 were stored in a sealed state at 50 ° C. for 30 days, and the rate of change in viscosity before and after storage was calculated. evaluated. The ink viscosity was measured as a viscosity of 25 ° C. using a viscometer (RL-500, manufactured by Toki Sangyo Co., Ltd.).

<Measurement of optical density (OD) of image, blur of characters, blur of color boundary>
An ink cartridge degassed and filled with each recording ink stored at 50 ° C. for 30 days is set in an inkjet printer (IPSiO G717, manufactured by Ricoh Co., Ltd.), and plain paper (Type 6200, Co., Ltd.) in plain paper high-quality mode. A solid image was printed on Ricoh Co., Ltd., and the optical density (OD) of the image was measured with X-Rite 938. The printed images were visually observed for character bleeding and color boundary bleeding and evaluated according to the criteria shown in Table 4 below.

<Evaluation of ejection stability>
A chart with an area ratio of 5% is set in an ink jet printer (IPSiO G717, manufactured by Ricoh Co., Ltd.) by degassing and filling each recording ink stored at 50 ° C. for 30 days in an environment of 30% RH. Was continuously printed, and the number of printed sheets until nozzle omission and ejection bending were visually observed was counted and evaluated according to the criteria shown in Table 4 below. In addition, the head cleaning operation (wiping operation) of the printer was stopped, and the test was carried out by modifying the sequence so as not to start cleaning during continuous printing. Further, the idle ejection operation during printing (head maintenance operation by ink droplet ejection in the non-printing area) was evaluated by a sequence in which 50 droplets of 30 pL were ejected every 30 seconds.

From the results of Table 5, Examples 1 to 16 had high image density, and the use of a phosphorylcholine-like group-containing polymer as a stabilizer resulted in high ink storage stability and high ejection stability.
On the other hand, Comparative Examples 1 to 7 could not achieve both image density, storage stability, and ejection stability. Also, from the comparison between the examples and the comparative examples, the pigment concentration was increased to the paper when the phosphorylcholine-like group-containing polymer was used as a dispersion and when it was used as a stabilizer and combined with a specific dispersant. It was found that the behavior when combined with a water-soluble organic solvent having high wettability is completely different, and the combination of the dispersant and the stabilizer of the present invention is an effective constitution for ensuring image quality and reliability.

The recording ink of the present invention has high permeability corresponding to high-speed printing, and has both ejection stability, storage stability, and high image quality on plain paper. It can be suitably used for an ink jet recording apparatus and an ink jet recording method.
The ink jet recording apparatus and the ink jet recording method of the present invention can be applied to various types of recording by the ink jet recording method, and are particularly suitable for, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, and a printer / fax / copier multifunction machine. Can be applied to.

FIG. 1 is a schematic view showing an example of the ink cartridge of the present invention. FIG. 2 is a schematic view including the case of the ink cartridge of FIG. FIG. 3 is an explanatory perspective view of the ink jet recording apparatus in a state where the cover of the ink cartridge loading unit is opened. FIG. 4 is a schematic configuration diagram illustrating the overall configuration of the ink jet recording apparatus. FIG. 5 is a schematic enlarged view showing an example of the inkjet head of the present invention. FIG. 6 is an element schematic enlarged view showing another example of the ink jet head of the present invention. FIG. 7 is an enlarged schematic cross-sectional view of a main part of the inkjet head of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Frame 20 Flow path plate 30 Nozzle plate 40 Base 50 Laminated piezoelectric element 60 Vibrating plate 70 Adhesive layer 101 Apparatus main body 102 Paper feed tray 103 Paper discharge tray 104 Ink cartridge loading part 111 Upper cover 112 Front surface 115 Front cover 131 Guide rod 132 Stay 133 Carriage 134 Recording Head 135 Subtank 141 Paper Placement Unit 142 Paper 144 Separation Pad 151 Conveying Belt 152 Again Counter Roller 156 Charging Roller 157 Conveyance Roller 158 Densation Roller 171 Separation Claw 172 Paper Discharge Roller 173 Paper Discharge Roller 181 Double-sided Paper Feed Unit 200 Ink cartridge 201 Ink cartridge 241 Ink bag 242 Ink inlet 243 Ink outlet 244 Cartridge exterior

Claims (13)

Comprising at least a pigment dispersion, a water-soluble organic solvent, and a stabilizer,
The pigment dispersion is obtained by dispersing a pigment with an anionic surfactant-based dispersant, and the anionic surfactant-based dispersant is at least one selected from the following general formula (1) and the following general formula (2). And
The water-soluble organic solvent is at least one selected from 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol and 2-methyl-2,4-pentanediol. Including
A recording ink, wherein the stabilizer contains a phosphorylcholine-like group-containing polymer having at least a structural unit represented by the following general formula (3).
^{_{R 1 O (CH 2 CH 2}} O) k CH 2 COOM 1 ··· formula (1)
^{_{R 2 O (CH 2 CH 2}} O) l SO 3 M 2 ··· formula (2)
In the general formula (1) and (2), ^{R 1} represents an alkyl group having 6 to 14 carbon atoms. R ² represents any of an alkyl group having 4 to 24 carbon atoms, an alkylphenyl group having 4 to 24 carbon atoms, and an alkylallyl group having 4 to 24 carbon atoms. M ¹ and M ² each represent a hydrogen atom, an alkali metal ion, a quaternary ammonium, a quaternary phosphonium, or an alkanolamine. k shows the integer of 3-12. l represents an integer of 4 to 50.
However, in said general formula (3), X shows a bivalent organic residue. Y represents an alkyleneoxy group having 1 to 6 carbon atoms. Z is a hydrogen atom, and R ⁷ —O— (C═O) — (wherein R ⁷ represents an alkyl group having 1 to 10 carbon atoms or a hydroxyalkyl group having 1 to 10 carbon atoms) Represents one of the following. R ³ represents either a hydrogen atom or a methyl group. R ⁴ , R ⁵ , and R ⁶ may be the same as or different from each other, and are any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a hydroxyalkyl group having 1 to 6 carbon atoms. Represents m shows the integer of 0-20. n shows the integer of 1-4.   The recording ink according to claim 1, comprising a polyol compound having 8 to 11 carbon atoms.   The recording ink according to claim 2, wherein the polyol compound having 8 to 11 carbon atoms includes any of 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol. .   The recording ink according to any one of claims 1 to 3, further comprising a surfactant, wherein the surfactant contains at least one selected from an anionic surfactant and a nonionic surfactant.   The recording ink according to claim 4, wherein the surfactant is at least one selected from polyoxyethylene alkyl ethers.   The recording ink according to claim 4, wherein the surfactant is at least one selected from fluorine-based surfactants.   The recording ink according to any one of claims 1 to 6, further comprising a resin emulsion.   An ink cartridge comprising the recording ink according to claim 1 contained in a container.   8. An ink jet recording method comprising at least an ink flying step of recording an image by applying a stimulus to the recording ink according to claim 1 and causing the recording ink to fly.   The inkjet recording method according to claim 9, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.   8. An ink jet recording apparatus comprising at least ink flying means for recording an image by applying a stimulus to the recording ink according to claim 1 and causing the recording ink to fly.   The inkjet recording apparatus according to claim 11, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.   An ink recorded matter comprising an image formed using the recording ink according to any one of claims 1 to 7 on a recording medium.