JP2005336285A - Water-based ink, and ink cartridge, ink-recorded matter, inkjet recording apparatus and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-based ink, or the like, which is suitable for inkjet recording and exhibits excellent recording properties particularly on plain paper. <P>SOLUTION: The water-based ink comprises (A) a colorant, (B) at least one compound selected from among diethylene glycol mono-n-butyl ether, diethylene glycol mono-isobutyl ether, triethylene glycol mono-n-butyl ether and triethylene glycol mono-isobutyl ether, and (C) a surfactant selected from among polyoxyethylene alkyl ether sulfates and polyoxyethylene alkylphenyl ether sulfates. Preferably, the polyol compound is either 2,2,4-trimethyl-1,3-pentanediol or 2-ethyl-1,3-hexanediol. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is suitable for inkjet recording such as an on-demand method such as a piezo method and a thermal method, a continuous jet method such as a charge control method, and the like. The present invention relates to an ink cartridge, an ink record, an ink jet recording apparatus, and an ink jet recording method using water-based ink.

An ink jet recording apparatus that discharges liquid ink from a nozzle or the like and records on a recording medium such as paper, cloth, or film is small and inexpensive, and has advantages such as quietness. Widely used in the workplace.
In recent years, many full-color inkjet printers that can perform full-color recording as well as black single-color inkjet printers that can obtain good print quality on plain paper such as report paper, copy paper, and recycled paper are commercially available. The full-color ink jet printer is also required to have high quality when printed on plain paper, particularly high image quality (no image blur) and high color development.
Therefore, as a method for preventing bleeding of an image, for example, ink using glycol ethers as a wetting agent (see Patent Document 1), ink using a water-soluble organic solvent (see Patent Document 2), and dye dissolution acceleration An ink using an agent (see Patent Document 3) has been proposed.

  In addition, image fastness is also required, and an ink has been proposed in which a pigment is used instead of a dye as a coloring material and the bleeding of the image is improved using glycol ethers (see Patent Document 4). However, pigment ink is inferior in storage stability compared to dye ink, and there is a problem that pigment particles aggregate due to long-term storage.

  Further, as a method for modifying the pigment particle surface in order to improve the dispersion stability of the pigment particles, for example, a method of azo coupling a substituent containing a water-solubilizing group to carbon black (see Patent Document 5), A method of polymerizing a water-soluble monomer or the like on the surface of carbon black (see Patent Document 6), a method of oxidizing carbon black (see Patent Document 7), and the like have been proposed. In addition, an ink has been proposed in which image bleeding is improved by using a combination of a surface-modified pigment and a glycol ether (see Patent Document 8). Further, an aqueous recording ink composed of a water-soluble dye, water, and benzyl ether having a specific structure has been proposed (see Patent Document 9). However, these inks have a problem of safety, and oily substances, poorly water-soluble, slightly soluble solvents, benzyl ether, and the like are separated depending on the environmental temperature, resulting in poor stability.

  In addition, an ink containing a pigment and a liquid medium and containing 60% by mass or more of water and 0.2 to 30% by mass of an alkylene glycol having 7 to 10 carbon atoms has been proposed (Patent Document). 10). Examples of the alkylene glycol having 7 to 10 carbon atoms include 1,7-heptanediol, 2,6-heptanediol, 2,4-dimethyl-2,4-pentanediol, and 3-ethyl-1,3-pentane. Diols, and the like. By including these compounds in the ink, we can improve ink bleeding, drying and penetrability on plain paper, provide a balance between bleeding and penetrability, and provide highly reliable ink for preventing clogging. It is supposed to be possible. However, when these compounds are added, there is a problem that ink permeability is insufficiently improved, drying property is low, and bleeding is likely to occur depending on the paper type.

  An ink containing an aliphatic diol compound having a specific structure having at least 6 carbon atoms and having a solubility of 4.5 parts by mass in 100 parts by mass of water at 25 ° C. has been proposed (Patent Document 11). reference). Examples of the aliphatic diol compound include 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, and 2,2-diethyl-1,3-propanediol. 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene-1,2- Diol, and the like. However, the ink to which the aliphatic diol compound is added does not have sufficient permeability, and there is a problem that color bleeding and feathering occur.

  In such a situation, the applicant of the present application has previously proposed a water-based ink containing 2-ethyl-1,3-hexanediol and a recording method using the same for the purpose of enhancing permeability (Patent Document). 12). According to this proposal, by adding 2-ethyl-1,3-hexanediol, an aqueous ink composition that satisfies various properties as an inkjet ink, has excellent permeability and drying properties, and has improved image quality degradation. And a recording method capable of forming a good image using the ink composition.

By the way, due to the rapid progress of technology in recent years, the output speed of ink jet printers is increasing, and it is predicted that the speed will be further increased in the future. Under such circumstances, the ink is required to dry immediately without causing color bleeding even after printing and without rubbing fingers after output.
In general, highly dry inks have the disadvantages of improving the penetrability into paper and decreasing the image density and increasing the back-through density when the colorant penetrates in the thickness direction of the paper. . In particular, it is clear that double-sided printing is indispensable from the viewpoint of the development of inkjet printers and paper consumption as an environmental problem. It has been.

  Thus, even today, the ink jet ink satisfies various properties as an inkjet ink, has excellent permeability and drying regardless of the colorant type and paper type, and has improved image quality and back-through. The desire still exists.

  In recent years, in fields such as barcode printing and postmark printing such as mail, a system that can read recorded information by infrared rays or ultraviolet rays while being normally invisible has been put into practical use. From the viewpoint of environmental pollution, the ink used for these has been studied to be water-based, and in order to cope with the high-speed processing essential for such a system, an ink that is water-based but highly permeable is used. is necessary.

  However, in order to cope with high-speed processing, the ink is prevented from drying and sticking in the vicinity of the nozzle, and even when the viscosity is increased, the ink does not adhere to the nozzle surface and is fluid, clogged, jetting direction There is a need to develop an ink that is less bent and can reduce the number of times it is cleaned and returned as much as possible.

  In addition, the inkjet system has a problem related to the generation of bubbles. Since surfactants are usually added to inkjet inks, air bubbles are easily trapped when ink is filled into the cartridge, when the cartridge is attached to the head, when the ink is sucked after mounting, or during printing or when printing is suspended. This may cause ejection failure.

  For this reason, for the purpose of preventing bubble generation or entrainment, for example, an ink has been proposed in which the stability of bubbles after 5 minutes is 0 mm (the stability of bubbles after 1 minute is less than 5 mm) based on JIS K3362. (See Patent Document 13). According to this proposal, it is said that ejection stability can be ensured, but it is limited to containing a lower alkyl alcohol having 5 or less carbon atoms, is not versatile, and this ink formulation has low permeability. There is a problem that the image quality at the time of high-speed printing is inferior.

  In addition, an ink having a low foaming while maintaining high permeability by using a specific acetylene glycol surfactant has been proposed (see Patent Document 14). Depending on the type of the colorant, this surfactant may cause hydrophobic interaction with the colorant, so that the drying speed does not improve.In addition, pigments such as carbon black tend to aggregate and clog the nozzle. There is a problem that generation of ink and bending of the ink ejection direction are likely to occur.

As a method for improving the drying rate without adding a surfactant, for example, an ink containing a dye and a water-soluble glycol ether has been proposed (see Patent Document 15). An ink composition comprising a pigment, a glycol ether such as diethylene glycol mono-n-butyl ether, and water has been proposed (see Patent Document 16).
However, in any of the proposals, in order to improve the drying speed, it is necessary to add a large amount of glycol ethers, and there is a problem that the odor and safety of the ink are inferior.

  Further, Patent Document 17 describes that a defoaming effect can be obtained in a carbon black ink containing a specific glycol solvent, but the ink of this prescription has insufficient permeability and improves image quality. There's a problem. Similarly, although the ink of the prescription described in Patent Document 18 has an antifoaming effect, it does not contain a surfactant or the like, so that there is a problem that the permeability to paper is slow and the image quality is not good.

  Therefore, conventional water-based inks and ink jet printers do not necessarily have sufficiently improved ejection stability, particularly ejection failure due to bubble entrainment during printing or when printing is suspended. Under the present circumstances, it is strongly desired to develop a water-based ink and related technology that can maintain reliability with a simple recovery mechanism, have high image quality, and have no nozzle clogging.

Japanese Patent Publication No.2-2907 Japanese Patent Publication No. 1-15542 JP-B-2-3837 Japanese Patent No. 3102304 Japanese National Patent Publication No. 10-510862 JP-A-8-81646 JP-A-8-3498 Japanese Patent Laid-Open No. 10-95941 Japanese Patent Laid-Open No. 2-138374 Japanese Patent No. 2894568 Japanese Patent No. 2714482 JP-A-6-157959 Japanese Patent Publication No. 7-26049 JP 2000-144026 A JP-A-8-1173739 Japanese Patent Laid-Open No. 10-95941 JP 7-331142 A JP-A-9-31380

  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 uses a water-based ink that can significantly improve color saturation, has excellent color developability, has high ejection stability, and can form a high-quality image, and the water-based ink. An object of the present invention is to provide an ink cartridge, an ink record, an ink jet recording apparatus, and an ink jet recording method.

Means for solving the problems are as follows. That is,
<1> (A) a colorant and (B) at least one selected from diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether and triethylene glycol mono-iso-butyl ether A water-based ink comprising a seed compound and a surfactant selected from (C) polyoxyethylene alkyl ether sulfate and polyoxyethylene alkyl phenyl ether sulfate. The water-based ink described in <1> is selected from (B) diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether, and triethylene glycol mono-iso-butyl ether. By containing at least one compound and a surfactant selected from (C) polyoxyethylene alkyl ether sulfate and polyoxyethylene alkyl phenyl ether sulfate, the penetrability regardless of the colorant or paper type, The image quality has been improved, such as excellent drying and less bleeding, and also prevents clogging and ejection direction bending, which have been a major issue with high-speed inkjet printing, from drying and sticking near the nozzles. Even if the viscosity is increased, the nozzle surface Wear without has fluidity, clog, it is possible to obtain an ink unbent jetting direction, the aqueous ink can be provided which can reduce as much as possible the number of times for cleaning restored.
<2> The water-based ink according to <1>, wherein the content of the component (B) compound in the water-based ink is 0.1 to 10% by mass. In the water-based ink described in <4>, by setting the content of the polyol compound as the component (B) to 0.1 to 10% by mass, the penetration property is high, the image quality is excellent, and phase separation is caused. Therefore, a stable ink can be provided.

<3> The surfactant of component (C) is the water-based ink according to any one of <1> to <2> represented by the following general formula (1).
^{_{R 4 -O- (C 2 H 4}} O) n SO 3 -M ··· formula (1)
However, In the general formula (2), ^{R 4} represents a hydrocarbon group. M represents one selected from alkali metal ions, quaternary ammonium, quaternary phosphonium, and alkanolamine. n is an integer of 4 to 21.
<4> The water-based ink according to any one of <1> to <3>, wherein a content of the surfactant (C) in the water-based ink is 0.01 to 4% by mass.

<5> The water-based ink according to any one of <1> to <4>, wherein the colorant of the component (A) is a pigment. In the water-based ink described in <5>, by using a pigment as the colorant of the component (A), it is possible to provide an excellent ink with high image density and low show-through while having high penetration characteristics. it can.
<6> The water-based ink according to <5>, wherein the pigment has an average particle diameter of 10 to 200 nm. In the water-based ink according to <6>, by setting the average particle diameter of the pigment to 10 to 200 nm, the dispersion stability is excellent, and thus the storage stability and the ejection stability in the inkjet recording method are excellent, and the image It is possible to provide an excellent ink with little showthrough.
<7> The water-based ink according to any one of <5> to <6>, wherein the pigment exhibits at least one of water dispersibility and water solubility in the presence of a dispersant.
<8> The water-based ink according to <7>, wherein the dispersant has a carboxyl group on the surface.
<9> The water-based ink according to any one of <5> to <6>, wherein the pigment has at least one hydrophilic group and exhibits at least one of water dispersibility and water solubility in the absence of a dispersant. It is. In the water-based ink described in <9>, an ink having extremely high storage stability and reliability can be provided by using a pigment in which the surface of the pigment is modified and a hydrophilic group is bonded.
<10> The water-based ink according to <9>, wherein the hydrophilic group is at least one selected from a carboxyl group, a sulfone group, a carbonyl group, and a hydroxyl group. In the water-based ink according to <10>, by using a surface-modified pigment in which the hydrophilic group bonded to the pigment is a carboxyl group, a sulfone group, a carbonyl group or a hydroxyl group, the image density can be further increased. It is possible to provide an ink that forms an extremely high-quality image with a low strikethrough density and with less bleeding.

<11> The water-based ink according to any one of <1> to <10>, which contains an antifoaming agent, and the antifoaming agent is a silicone-based antifoaming agent.
<12> The water-based ink according to <11>, wherein the silicone-based antifoaming agent is either a self-emulsifying type or an emulsion type.
In the water-based ink according to any one of <11> and <12>, by including a silicone-based antifoaming agent, a problem with conventional ink-jet water-based inks and ink-jet printers, It is difficult to cause ejection failure due to entrainment of air bubbles during filling, when the cartridge is attached to the head, after ink suction after mounting, during printing, or when printing is stopped, and it is reliable with a simple recovery mechanism when ejection failure occurs Ink jet ink with high image quality and no nozzle clogging can be provided. Furthermore, by using a self-emulsifying type or an emulsion type, it is possible to provide an ink-jet ink that is more desirable for ensuring reliability when used in an aqueous system.

<13> A water-soluble organic solvent, wherein the water-soluble organic solvent is at least one selected from glycerin, ethylene glycol, diethylene glycol, 1,3-butanediol, triethylene glycol, and 2-pyrrolidone < The water-based ink according to any one of <1> to <12>. In the water-based ink described in <13>, by containing a predetermined water-soluble organic solvent, when used in an inkjet recording apparatus, occurrence of clogging due to water evaporation in the vicinity of the nozzle is prevented in advance. By acting as a dissolution aid for the polyol compound or polyoxyethylene alkyl ether sulfate surfactant, it is possible to provide an ink with further improved storage stability and further improved ink jetting stability.
<14> The water-based ink according to any one of <1> to <13>, which is at least one selected from cyan ink, magenta ink, yellow ink, and black ink.

<15> An ink cartridge comprising the water-based ink according to any one of <1> to <14> contained in a container.
<16> An ink jet recording apparatus comprising at least ink flying means for applying a stimulus to the water-based ink according to any one of <1> to <14> and causing the water-based ink to fly to form an image. It is. In the ink jet recording apparatus according to <16>, an ink cartridge containing an ink that has such a high penetrability, high reliability, safety, and excellent image characteristics, and a recording including the ink cartridge are provided. A device can be provided.
<17> An inkjet recording method comprising at least an ink flying step of forming an image by applying a stimulus to the water-based ink according to any one of <1> to <14> and causing the water-based ink to fly. It is. In the ink jet recording method described in <17>, since ink that does not cause phase separation and does not cause aggregation or thickening is used, an image is recorded on a recording medium by ejecting and flying as droplets from a fine ejection port. Suitable for the recording method to be formed. In particular, the method of forming an image by applying thermal energy is particularly suitable because the wettability to a thermal element is improved, and a recording method excellent in ejection stability and frequency stability can be provided.
<18> An ink recorded matter comprising an image formed using the water-based ink according to any one of <1> to <14> on a recording medium. The ink recorded matter described in <18> can provide a method for recording a high-quality image at a very high speed and a printed image formed product by utilizing the high permeability of the ink of the present invention. .

The water-based ink of the present invention is selected from (A) a colorant and (B) diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether and triethylene glycol mono-iso-butyl ether. And (C) a surfactant selected from polyoxyethylene alkyl ether sulfate and polyoxyethylene alkyl phenyl ether sulfate. The compound of the component (B) is easily adsorbed on the surface in an ink containing water as a main component, and has a relatively low molecular weight as compared with a so-called surfactant, so that the adsorption rate to the surface is remarkably high. That is, the surface tension of the liquid can be rapidly reduced like the surfactant by adsorbing the compound of the component (B) on the surface. However, since the compound of the component (B) has a small difference between hydrophilicity and hydrophobicity as compared with the surfactant, in order to obtain high permeability only with the component (B), it must be added in a large amount. There wasn't. At this time, the ink to which a large amount of the component (B) compound was added was not preferable because of problems such as safety, phase separation, adsorption and aggregation on the colorant, and in some cases odor. On the other hand, the surfactant of component (C) is also known to lower the surface tension and improve the permeability, but the adsorption rate to the surface is not always high due to the size or shape of the surfactant molecule. As a result, sufficient permeability could not be obtained.
Therefore, in the present invention, when the compound of the component (B) and the surfactant of the component (C) are used in combination, extremely high penetration characteristics can be obtained with a very small amount of use due to their synergistic effect. Furthermore, with respect to clogging and jet direction bending, which have been a major issue as the speed of ink jets increases, ink can be produced by using the compound (B) and the surfactant (C) in combination. The number of times that the ink is dried and fixed in the vicinity to prevent the ink from sticking to the nozzle surface even when the viscosity is increased, fluidity, clogging, and no jet direction bending, and cleaning and return. Can be reduced as much as possible.

  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 ink stored in the ink cartridge, the saturation is remarkably improved, the color developability is excellent, the ejection stability is high, and the image quality with little bleeding is obtained.

  The ink jet recording apparatus of the present invention has at least ink flying means for forming 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 form an image. As a result, the saturation is remarkably improved, the color developability is excellent, the ejection stability is high, and a high-quality image can be formed.

  The ink jet recording method of the present invention includes at least an ink flying step of forming 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 step, energy is applied to the recording ink of the present invention, and the recording ink is ejected to form an image. As a result, the saturation is remarkably improved, the color developability is excellent, the ejection stability is high, and a high-quality image can be formed.

  The inkjet recorded matter of the present invention comprises an image formed on the recording medium using the recording ink of the present invention. In the ink jet recorded matter, a high image quality with less bleeding is retained on the recording medium.

  According to the present invention, water-based inks that can solve various problems in the prior art, can achieve a significant improvement in saturation, excellent color developability, high ejection stability, and high-quality image formation, and In addition, an ink cartridge, an ink record, an ink jet recording apparatus, and an ink jet recording method using the water-based ink can be provided.

(Water-based ink)
The water-based ink of the present invention is selected from (A) a colorant and (B) diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether and triethylene glycol mono-iso-butyl ether. And (C) a surfactant selected from polyoxyethylene alkyl ether sulfates and polyoxyethylene alkyl phenyl ether sulfates, and other components as necessary. It contains.

  The content of the compound (B) in the water-based ink is preferably 0.1 to 8% by mass, and more preferably 0.5 to 5% by mass. When the content is less than 0.1% by mass, improvement in permeability and jetting stability in ink jet may be insufficient. When the content exceeds 8% by mass, the ink does not dissolve stably in the ink. Problems may occur in the storage stability of the ink and the ejection stability in the ink jet.

-(C) Surfactant selected from polyoxyethylene alkyl ether sulfate and polyoxyethylene alkyl phenyl ether sulfate-
As the surfactant (C), for example, those represented by the following general formula (1) are suitable.
^{_{R 4 -O- (C 2 H 4}} O) n SO 3 -M ··· formula (1)
In the general formula (1), R ⁴ represents a hydrocarbon group, and is preferably an alkyl group having 8 to 22 carbon atoms or an alkylphenyl group.
M represents any one selected from alkali metal ions, quaternary ammonium, quaternary phosphonium, and alkanolamine, and quaternary ammonium is preferable. n is an integer of 4 to 21.

As the polyoxyethylene alkyl ether sulfate surfactant as the component (C), the following are suitable.
Formula _{(1-1): C 8 H 17} O (C 2 H 4 O) SO 3 NH 4
Formula _{(1-2): C 10 H 21} O (C 2 H 4 O) 4 SO 3 Na
Formula _{(1-3): C 18 H 37} O (C 2 H 4 O) 18 SO 3 - (CH 3) 3 C 2 H 4 OH
Formula _{(1-4): C 22 H 45} O (C 2 H 4 O) 21 SO 3 NH 4
Formula _{(1-5): CH 3 - (} CH 2) 7 -CH = CH (CH 2) 7 -CH 2 -O (C 2 H 4 O) 8 SO 3 NH 4
Formula _{(1-6): CH 3 - (} CH 2) 7 -CH = CH (CH 2) 7 -CH 2 -O (C 2 H 4 O) 12 SO 3 (C 2 H 4 OH) 4
Formula _{(1-7): CH 3 - (} CH 2) 7 -CH = CH (CH 2) 7 -CH 2 -O (C 2 H 4 O) 18 SO 3 NH 4

As the polyoxyethylene alkylphenyl ether sulfate surfactant as the component (C), the following are suitable.
Formula _{(1-8): C 2 H 5} -C 6 H 5 -O (C 2 H 4 O) 4 SO 3 NH 4
Formula _{(1-9): C 5 H 11} -C 6 H 5 -O (C 2 H 4 O) 6 SO 3 NC 4 H 12
Equation _{(1-10): C 9 H 19} -C 6 H 5 -O (C 2 H 4 O) 4 SO 3 NH 4
Equation _{(1-11): C 9 H 19} -C 6 H 5 -O (C 2 H 4 O) 6 SO 3 NH 4
Equation _{(1-12): C 9 H 19} -C 6 H 5 -O (C 2 H 4 O) 9 SO 3 Na
Equation _{(1-13): C 12 H 25} -C 6 H 5 -O (C 2 H 4 O) 18 SO 3 N- (C 2 H 4 OH) 3 H
Equation _{(1-14): C 9 H 19} -C 6 H 5 -O (C 2 H 4 O) 21 SO 3 NH 4

  These may be used individually by 1 type and may use 2 or more types together. As the surfactant for the component (C), a commercially available product may be used. Examples of the commercially available product include Hightenol N-07, Hightenol N-08, Hightenol N-17, and Hightenol NE-05. , Hightenol NE-15, Hightenol NF-13, Hightenol 08E, Hightenol 12, Hightenol 18E (all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and the like can be used. You may combine 2 or more types.

  The content of the surfactant (C) in the aqueous ink is preferably 0.01 to 4% by mass, more preferably 0.1 to 2% by mass. When the content is less than 0.01% by mass, the improvement in permeability may be insufficient. When the content exceeds 4% by mass, the ink does not dissolve stably or the viscosity is high even when dissolved. Therefore, there may be a problem in the storage stability of the ink and the ejection stability in the ink jet.

  According to the present invention, together with the surfactant as the component (C), diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether and triethylene glycol mono as the component (B). -By containing at least one compound selected from iso-butyl ether, it is possible to obtain an aqueous ink that has extremely high permeability and is stable without separation in the liquid and is highly safe. In addition, by adding the compound of the component (B) and the surfactant of the component (C), recording is performed by applying thermal energy to the ink and ejecting the ink as droplets from fine holes. In a recording method such as a thermal method, wettability to a thermal element is improved, and ejection stability and frequency stability can be obtained even with a small addition amount, and a highly safe ink can be provided.

-(A) Colorant-
There is no restriction | limiting in particular as a coloring agent of said (A) component, According to the objective, it can select suitably from well-known things, For example, a pigment, dye, etc. are mentioned.
These may be used individually by 1 type and may use 2 or more types together. Among these, a pigment is preferable in that light resistance and water resistance can be imparted to the recorded image.

There is no restriction | limiting in particular as said pigment, According to the objective, it can select suitably, For example, any of an inorganic pigment and an organic pigment may be sufficient.
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 pigment 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, C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 219, C.I. I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, and the like.

Of these pigments, those having good affinity with water are preferably used.
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.

Since the pigment is not dissolved in the ink and dispersed as particles compared to the dye, it is difficult for the ink to penetrate deep into the paper even if the ink has the same penetration characteristics. It is possible to obtain a small and good image quality.
There is no restriction | limiting in particular in the average particle diameter of the said pigment, According to the objective, it can select suitably, For example, 10-200 nm is preferable with the value of 50% of volume accumulation percentage, and 20-150 nm is more preferable. If the average particle size is less than 10 nm, the pigment as the colorant may penetrate deep into the paper, resulting in a low image density and a large amount of back-through, and dispersion stability in the ink. In some cases, the image density may be lowered during printing. When the thickness exceeds 200 nm, the fixing property of the image is inferior, the dispersion stability is poor, and the particle size becomes large due to aggregation during long-term storage. Clogging or the like may easily occur.
Here, the average particle diameter is, for example, the amount of change in the frequency (light frequency) of light (backscattered light) returning from the particle when the particle performing Brownian motion in the ink is irradiated with laser light. The particle diameter can be measured by a dynamic light scattering method (Doppler scattered light analysis) or the like.

When the pigment is used as the colorant of the component (A), the pigment is not particularly limited and may be appropriately selected depending on the purpose. For example, the pigment has at least one hydrophilic group, Self-dispersing pigments that exhibit at least one of water dispersibility and water solubility in the absence of a dispersant are preferred.
In this case, the self-dispersing pigment has the hydrophilic group (carboxyl group, sulfone group, etc.) on the surface and the surface is modified, so that it can be dispersed in water even in the absence of a dispersant. It is excellent in dispersibility and dispersion stability in water-based ink, and the water-based ink containing the self-dispersing pigment is excellent in storage stability, discharge stability (for example, intermittent discharge stability) and the like after drying. Because of excellent redispersibility, clogging does not occur even if the ink in the vicinity of the nozzles of the head evaporates after printing is stopped for a long time. This is advantageous in that printing or an image can be obtained and the water resistance of the recorded matter after recording can be further improved.

The hydrophilic group is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a polar group or atomic group having a strong interaction with water, and specifically, —SO _{3 H, -SO 3 M, -OSO} 3 H, -OSO 3 M, -COOM, -COOH, -NR 3 X, -NH 2, -OH, -CN, and the like (provided that the R is Represents an alkyl group, M represents an alkali metal or —NH ₄ , and X represents a halogen atom). Among these, a sulfone group (—SO ₃ H) and a carboxyl group (—COOH) are preferable in terms of dispersion stability and water resistance of an image after printing.

The self-dispersing pigment may be obtained by chemically bonding the hydrophilic group (for example, sulfone group, carboxyl group, etc.) to the surface of the pigment, and using at least one of hypohalous acid and a salt thereof as the pigment. It can be produced by a wet oxidation method or the like.
The self-dispersing pigment may be used in combination with the surfactant, the penetrating agent, and the like from the standpoint of excellent intermittent discharge stability due to a synergistic effect and the ability to record high-quality printing or images.

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, 120, 132, 142, 144, 86; 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, 465, 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.

  As the dye, acid dyes and direct dyes can be preferably used, and excellent effects can be obtained in terms of improvement in the dissolution stability of the ink of the present invention, color tone, water resistance, and light resistance.

  There is no restriction | limiting in particular as content in the said water-based ink of the coloring agent of the said (A) component, According to the objective, it can select suitably, 0.5-25 mass% is preferable, and 2-15 mass% is preferable. More preferred. If the content is less than 0.5% by mass, the image density may be low and the image may have no contrast. If the content exceeds 25% by mass, it is difficult to ensure the dispersion stability of the colorant. The nozzles and the like are easily clogged, and the reliability may be deteriorated.

  The colorant is preferably water-dispersible or water-soluble in the presence of a dispersant, in other words, water-dispersible or water-soluble in the presence of the dispersant. In this case, the dispersant can improve the dispersibility of the colorant in the water-based ink, and can provide a high-quality print or image, thereby further improving the water resistance of the recorded matter after recording. This is advantageous in that it can effectively prevent the back-through and the like.

  The dispersant is not particularly limited, and preferably includes a dispersant used at the time of preparing a pigment dispersion, for example, polyacrylic acid, polymethacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic. Acid ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid-acrylic acid alkyl ester copolymer, stin-methacrylic acid -Acrylic acid alkyl ester copolymer, Styrene-α-methylstyrene-acrylic acid copolymer, Styrene-α-methylstyrene-acrylic acid copolymer-Acrylic acid alkyl ester copolymer, Styrene-maleic acid copolymer , Vinyl naphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer Examples thereof include vinyl acetate, fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic acid copolymer, and the like.

  These may be used individually by 1 type and may use 2 or more types together. Among these, those having a carboxyl group on the surface are preferable. In this case, since the dissociation constant of the carboxyl group is small compared to other acid groups, after the colorant adheres to the recording medium, the pH of the water-based ink decreases, or the calcium present near the surface of the recording medium. The solubility of the dispersant itself does not decrease due to interaction with polyvalent metal ions such as the above, and the dispersant and the pigment do not aggregate. Even when printing or forming an image on a recording medium, it is advantageous in that a sufficient drying speed can be obtained and there is little show-through.

There is no restriction | limiting in particular as a weight average molecular weight (Mw) of the said dispersing agent, According to the objective, it can select suitably, For example, 3,000-50,000 are preferable and 5,000-30,000 are more. Preferably, 7,000 to 15,000 are particularly preferable.
When the weight average molecular weight (Mw) of the dispersant is less than 3,000, the dispersion stability may not be sufficient, and when it exceeds 50,000, the viscosity of the dispersant itself increases to discharge the aqueous ink. Stability may deteriorate.

There is no restriction | limiting in particular as mass ratio (colorant: dispersant) of the said colorant and the said dispersing agent, According to the objective, it can select suitably, For example, 1: 0.06 to 1: 3 are preferable. 1: 0.125 to 1: 3 is more preferable.
If the amount of the dispersant in the mass ratio is too small, the dispersion effect may not be sufficient, and if it is too large, the viscosity of the water-based ink may be increased.

  The dispersant in the ink preferably has a carboxyl group bonded thereto. When a carboxyl group is bonded to the dispersant, not only the dispersion stability is improved, but also high-quality print quality is obtained, and the water resistance of the recording medium after printing is further improved. Furthermore, the effect of preventing the above-described back-through can be obtained. In particular, when a pigment dispersed with a dispersant having a carboxyl group bonded thereto, the compound of the component (B) and the surfactant of the component (C) are used in combination, a relatively large size such as plain paper Even when printing is performed on a recording medium having a high degree, a sufficient drying speed can be obtained, and the effect that there is little show-through can be obtained. This is because the dissociation constant of carboxylic acid is small compared to other acid groups, so that after the pigment adheres to the recording medium, the pH value of the ink decreases, or the polyvalent metal such as calcium present near the surface of the recording medium. It is presumed that the solubility of the dispersant itself decreases due to interaction with ions and the like, and the dispersant itself and the pigment aggregate.

  Another more preferable form includes a form in which the pigment in the ink is surface-modified and the carboxyl group, sulfone group, carbonyl group or hydroxyl group is directly bonded to the pigment and dispersed in water. As a method of making this form, the surface of the pigment particle is subjected to surface modification treatment such as acid treatment, base treatment, coupling agent treatment, polymer graft treatment, plasma treatment or oxidation or reduction treatment. Self-dispersible pigments having a sulfone group, a carbonyl group or a hydroxyl group can be produced. By performing such a surface treatment, the hydrophilic group for water becomes more contained than a normal pigment, and self-dispersion becomes possible. Among these treatment methods, a method of coupling and bonding a diazonium salt having a hydrophilic group capable of various chemical modifications to the pigment particle surface is preferable. This manufacturing method can be carried out by the method described in JP-T-10-510862.

  As the self-dispersible pigment of the present invention, a commercially available self-dispersible pigment can be used as it is. Examples of such commercially available pigments include black pigments such as CAB-O-JET-200, CAB-O-JET-300, IJX-55 (above, manufactured by Cabot Specialty Chemicals, Inc.), Microjet Black. CW-1 (manufactured by Orient Chemical Co., Ltd.), and the like, CAB-O-JET-250C as a cyan pigment, CAB-O-JET-260M as a magenta pigment, and CAB-O-JET-270Y as a yellow pigment. (Above, Cabot Specialty Chemicals, Inc.).

  In this case, since the surface of the pigment is modified and a carboxyl group, a sulfone group, a carbonyl group or a hydroxyl group is bonded, not only the dispersion stability is improved, but also high-quality print quality is achieved by the same action as described above. As a result, the water resistance of the recording medium after printing is further improved. Also, this form of ink has excellent redispersibility after drying, so printing is suspended for a long period of time, and clogging is less likely to occur when ink near the nozzles of the inkjet head evaporates. Good printing can be performed. Among these, a type in which a carboxyl group is bonded is more preferable from the viewpoint of improving the water resistance of the recording medium after printing and preventing the back-through.

  Also, it can be applied to barcode printing and postmark printing using invisible ink, which has been rapidly spreading in recent years. In this case, an infrared absorber or an ultraviolet absorber that does not absorb in the visible region but absorbs infrared rays or ultraviolet rays is added to the ink instead of a normal dye or pigment.

-Antifoaming agent-
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 antifoamer, a fatty acid ester 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 at the point which is excellent in the bubble-breaking effect.

  Examples of the silicone-based antifoaming agent include an oil-type silicone-based antifoaming agent, a compound-type silicone-based antifoaming agent, a self-emulsifying silicone-based antifoaming agent, an emulsion-type silicone-based antifoaming agent, and a modified silicone-based antifoaming agent. , Etc. 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 include fatty acid ester-modified silicone antifoaming agents and alkylene oxide-modified silicone antifoaming agents. Among these, the self-emulsifying silicone-based antifoaming agent and the emulsion-type silicone-based antifoaming agent are preferable in consideration of use in the aqueous ink that is an aqueous medium.

  Commercially available products may be used as the antifoaming agent. Examples of the commercially available products include silicone-based antifoaming agents (KS508, KS531, KM72, KM85, etc.) manufactured by Shin-Etsu Chemical Co., Ltd., Toray Dow Silicone defoaming agent (Q2-3183A, SH5510, etc.) manufactured by Corning Co., Ltd., Silicone defoaming agent (SAG30, etc.) manufactured by Nihon Unicar Co., Ltd., Antifoaming agent (Adeka) manufactured by Asahi Denka Kogyo Co., Ltd. Nate series).

There is no restriction | limiting in particular as content in the said water-based ink of the said antifoamer, According to the objective, it can select suitably, For example, 0.001-3 mass% is preferable, 0.005-0.5 mass % Is more preferable.
When the antifoaming agent is contained in the water-based ink, it is particularly excellent in storage stability and ejection stability over time, and when the content is less than 0.001% by mass, the content effect is not sufficient. If it exceeds 3% by mass, clogging is likely to occur, and the reliability of the water-based ink may be deteriorated.

-Wetting agent (water-soluble organic solvent)-
The aqueous ink of the present invention contains 5 to 50% by weight of a wetting agent for the purpose of preventing clogging due to drying of the ink and further improving the dissolution stability of the ink. Even when water in the ink evaporates, clogging is not likely to occur, and normal printing can be performed. Even if clogging occurs, normal printing can be restored by a simple cleaning operation.

As the wetting agent, a low-volatile water-soluble organic solvent is preferable. The low-volatile water-soluble organic solvent acts as a dissolution aid for the component (A) and the component (B) in the aqueous ink of the present invention, thereby further improving the storage stability and jetting stability of the ink. Can do.
Examples of the low-volatile water-soluble organic solvent include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 1,6-hexanediol, glycerin, 1,2,6-hexanetriol, Polyhydric alcohols such as 1,2,4-butanetriol, 1,2,3-butanetriol, and petriol; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether Polyhydric alcohol alkyl ethers such as ter, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether Nitrogen-containing heterocyclic compounds such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone; formamide, N -Amides such as methylformamide, N, N-dimethylformamide; monoethanolamine, diethanolamine, triethanolamine, monoethylamine, di Ethylamine, amines such as triethylamine; dimethyl sulfoxide, sulfolane, thiodiethanol, sulfur-containing compounds such as thiodiglycol; propylene carbonate, ethylene carbonate. These solvents are used alone or in combination with water.

  Among these, from the viewpoint of excellent compatibility with the surfactant of the component (C) and the compound of the component (B), for example, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol. , Dipropylene glycol, tripropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, tetraethylene glycol, 1,6-hexanediol, 2- Methyl-2,4-pentanediol, polyethylene glycol, 1,2,4-butanetriol, 1,2,6-hexanetriol, thiodiglycol, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl -2-pyrrolidone, 1,3-dimethyl-2-imida Rijinon is preferable. Among these, glycerin, ethylene glycol, diethylene glycol, 1,3-butanediol, triethylene glycol, and 2-pyrrolidone are particularly preferable from the viewpoints of safety and price.

  When the 2-pyrrolidone is added to the ink, an excellent effect is obtained in improving the image density and preventing the back-through. This is because by containing 2-pyrrolidone, the ink easily spreads and spreads on the paper surface, and the penetration in the thickness direction of the paper is relatively suppressed, so that the colorant tends to stay near the paper surface. It is estimated that.

  5-50 mass% is preferable and, as for the addition amount of the said low-volatile water-soluble organic solvent, 8-30 mass% is more preferable. When the added amount is less than 5% by mass, the effect of suppressing water evaporation in the ink is insufficient, and the surfactant of the component (C) and the compound of the component (B) in the ink are contained. Depending on the amount, the effect as a solubilizing agent may be insufficient, resulting in problems such as impaired storage stability and ejection stability of the ink. On the other hand, if it exceeds 50% by mass, the jetting stability in the ink jet due to the increase in viscosity may be inferior, and the cockling of the image area after printing may be deteriorated.

-Surfactant-
The surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include amphoteric surfactants, anionic surfactants, cationic surfactants, and nonionic surfactants. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together. In order to obtain high image quality with the inkjet recording method, it is important to adjust the wettability of the ink with respect to the members constituting the inkjet head. As described above, a surfactant may be further added to the ink of the present invention in order to adjust wettability.

Examples of the amphoteric surfactant include alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine, N-alkyl-N, N-dimethylammonium betaine, and the like.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.
Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, and the like. Is mentioned. Acetylene glycol surfactants are 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl. An acetylene glycol type such as -1-hexyn-3-ol (for example, Surfynol 104, 82, 465, 485 or TG from Air Products (USA)) can be used. TG indicates good print quality. The surfactants can be used alone or in admixture of two or more. It is desirable to add ink so as to have desired physical properties.
Examples of the cationic surfactant include alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt type surfactants such as imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, And quaternary ammonium salt surfactants such as pyridinium salts, alkylisoquinolinium salts, and benzethonium chloride.

  As the surfactant, a fluorine-containing surfactant may be used. The fluorine-containing surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Anionic having a fluoroalkyl group A surfactant, a cationic surfactant having a fluoroalkyl group, and the like are suitable.

Examples of the anionic surfactant having a fluoroalkyl group include a fluoroalkylcarboxylic acid having 2 to 10 carbon atoms or a metal salt thereof, disodium perfluorooctanesulfonylglutamate, 3- [omega-fluoroalkyl (C _6- C ₁₁₎ oxy] -1-alkyl _(C 3 _{~C 4)} sulfonate, sodium 3- [omega - fluoroalkanoyl _{(C 6 ~C} 8) -N- ethylamino] -1-sodium sulfonic acid, fluoroalkyl _(C 11 ~C ₂₀₎ carboxylic acids or metal salts thereof, perfluoroalkyl carboxylic acids _(C 7 _{~C 13)} or metal salts thereof, perfluoroalkyl _(C 4 _{~C 12)} sulfonic acid or metal salts thereof, perfluoroalkyl Octanesulfonic acid diethanolamide, N-propyl-N- (2-hydride Kishiechiru) perfluorooctane sulfonamide, perfluoroalkyl _(C 6 _{-C 10)} sulfonamide propyl trimethyl ammonium salts, perfluoroalkyl _{(C 6} -C 10)-N-ethylsulfonyl glycine salts, monoperfluoroalkyl _{(C 6} -C ₁₆₎ ethyl phosphoric acid ester, and the like.
Examples of commercially available anionic surfactants having a fluoroalkyl group include Surflon S-111, S-112, S-113 (manufactured by Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-29 (manufactured by Sumitomo 3M Co., Ltd.), Unidyne DS-101, DS-102, (manufactured by Taikin Kogyo Co., Ltd.), Megafac F-l0, F-l20, F-113, F-191, F-812, F- 833 (manufactured by Dainippon Ink Co., Ltd.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), Footage F-100, F150 (Manufactured by Neos).

Examples of the cationic surfactant having a fluoroalkyl group include aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, and aliphatics such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts. Quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, and the like can be given.
Examples of commercially available cationic surfactants having a fluoroalkyl group include Surflon S-121 (manufactured by Asahi Glass Co., Ltd.), Florard FC-135 (manufactured by Sumitomo 3M Co., Ltd.), Unidyne DS-202 (manufactured by Daikin Industries), Megafac F-150, F-824 (manufactured by Dainippon Ink, Inc.), Xtop EF-132 (manufactured by Tochem Products), and Fategent F-300 (manufactured by Neos) are listed.

  It is also possible to use a water-soluble surfactant as a pigment dispersant. In this case, the increase in the ink viscosity with respect to the amount used is smaller than when the polymer dispersant is used, and it is easy to obtain a pigment ink having good ejection characteristics when used in the ink jet recording method.

-Other ingredients-
The other components are not particularly limited and may be appropriately selected as necessary. For example, resin emulsion, saccharides, sodium alginate, antiseptic / antifungal agent, pH adjuster, rust preventive agent, chelating reagent, oxidation agent Examples thereof include an inhibitor, an ultraviolet absorber, an oxygen absorber, and a light stabilizer.

The resin emulsion has the property of thickening and agglomerating, has the effect of suppressing the penetration of the coloring component in the paper depth direction, and further promoting the fixing to the recording medium. In addition, depending on the type of resin emulsion, a film is formed on the recording medium, which has the effect of improving the scratch resistance of the printed matter.
The resin emulsion means an emulsion in which the continuous phase is water and the dispersed phase is the following resin component. Examples of the resin component in the dispersed phase include acrylic resins, vinyl acetate resins, styrene-butadiene resins, vinyl chloride resins, acrylic-styrene resins, butadiene resins, and styrene resins. This resin is preferably a polymer having both a hydrophilic part and a hydrophobic part. The particle size of these resin components is not particularly limited as long as an emulsion is formed, but is preferably about 150 nm or less, more preferably about 5 to 100 nm.
These resin emulsions can be obtained by mixing resin particles in water, optionally with a surfactant.
Commercially available products may be used as the resin emulsion. Examples of the commercially available products include Microgel E-1002, E-5002 (styrene-acrylic resin emulsion, manufactured by Nippon Paint Co., Ltd.), Boncoat 4001 ( Acrylic resin emulsion, manufactured by Dainippon Ink & Chemicals, Inc., Boncoat 5454 (styrene-acrylic resin emulsion, manufactured by Dainippon Ink & Chemicals, Inc.), SAE-1014 (styrene-acrylic resin emulsion, manufactured by Nippon Zeon Co., Ltd.) Product), Cybinol SK-200 (acrylic resin emulsion, manufactured by Seiden Chemical Co., Ltd.), and the like.
The content of the resin emulsion is preferably 0.1 to 40% by mass, more preferably 1 to 25% by mass of the resin component of the ink.

Examples of the saccharide include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), and polysaccharides, such as glucose, mannose, fructose, ribose, xylose, arabinose, galactose, maltose, cellobiose, lactose, Preferable examples include sucrose, trehalose, maltotriose and the like. Here, the polysaccharide means a saccharide in a broad sense, and includes a substance that exists widely in nature, such as α-cyclodextrin and cellulose.
The derivatives of these saccharides are represented by the reducing sugars of the saccharides described above (for example, sugar alcohol (general formula: HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)). ), Oxidized sugars (for example, aldonic acid, uronic acid, etc.), amino acids, thioic acids, etc. Among these, sugar alcohols are particularly preferred, and specific examples include maltitol, sorbit and the like.
The content of the saccharide in the ink is preferably 0.1 to 40% by mass, and more preferably 0.5 to 30% by mass.

  The sodium alginate is a substance contained only in brown algae, and is a hydrophilic polymer electrolyte that exists mainly as a cell membrane or intercellular substance. Chemically, it is a polymer of D-Mannuronic acid [M] that bonds β-1,4 and L-Guluronic acid [G] that bonds α-1,4. There are effects such as thickening action, stabilizing action, dispersing action, gelling action, film forming action and the like. When added to an inkjet ink, single color bleeding (feathering) and bleeding between different colors (color bleeding) can be improved by viscosity change due to pH, precipitation by salts, and gelation with polyvalent cations.

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

As the pH adjuster, any substance can be used as long as it can adjust the pH to a desired value without adversely affecting the ink to be prepared.
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 hydroxides. , Quaternary phosphonium hydroxides, alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, and the like.

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

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

Examples of the antioxidant include phenol-based antioxidants (including hindered phenol-based antioxidants), amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.
Examples of the phenol-based antioxidant (including hindered phenol-based antioxidant) 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-butylphenol) L) 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 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, 1,1,3-tris (2-methyl-4-hydroxy-5-te rt-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. Examples include '-thiodipropionate, 2-mercaptobenzimidazole, and dilauryl sulfide.
Examples of the phosphorus antioxidant include triphenyl phosphite, octadecyl phosphite, triisodecyl phosphite, trilauryl trithiophosphite, trinonylphenyl phosphite, and the like.

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-based ultraviolet absorber include phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, and the like.
Examples of cyanoacrylate ultraviolet absorbers include ethyl-2-cyano-3,3′-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate, and butyl-2-cyano-3. -Methyl-3- (p-methoxyphenyl) acrylate and the like.
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-octyl ferrate) -2-ethylhexylamine nickel (II), 2,2'-thiobis (4-tert-octyl ferrate) triethanolamine nickel (II), and the like.

Although there is no restriction | limiting in particular as a physical property of the water-based ink of this invention, For example, it is preferable that surface tension, a viscosity, electrical conductivity, pH, etc. are the following ranges.
The surface tension is preferably 25 to 55 mN / m at 20 ° C. If the surface tension is less than 25 mN / m, bleeding on the paper becomes noticeable and stable jetting may not be obtained. If the surface tension exceeds 55 mN / m, ink permeation to the paper is sufficiently caused. However, the drying time may be prolonged.

  The viscosity is preferably 2 to 20 mPa · s at 25 ° C., more preferably 3 to 10 mPa · s. If the viscosity is less than 2 mPa · s, bleeding may occur in the image, and if it exceeds 20 mPa · s, it may be difficult to ensure ejection stability.

For example, the conductivity is preferably 0.5 S / m or less, and more preferably 0.005 to 0.4 S / m.
As said pH, 7-11 are preferable, for example.

  There is no restriction | limiting in particular as coloring of the water-based 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 formed. When recording is performed using an ink set in which all colors are combined, a full color image is formed. be able to.

The ink of the present invention is particularly preferably used in an ink jet recording method in which a water-based ink is ejected and ejected as droplets from a fine ejection port to form a color image on a recording medium. Examples of the ink include water-based pens, water-based markers, and water-based ballpoint pens. Needless to say, it can be used as ink for general writing instruments, recorders, and pen plotters. Further, the ink of the present invention is not limited to the above applications.
When used in the inkjet recording method, it is necessary to adjust the ink viscosity to a desired value. In general, the viscosity of the ink is preferably 20 mPa · s or less, although it depends on the ejection force of the head. When the pressure is higher than 20 mPa · s, sufficient ejection cannot be performed by inkjet, and a problem of image failure often occurs.

  As a method suitable for recording using the ink of the present invention, there is a method of forming an image on a recording medium by applying thermal energy corresponding to a recording signal to the ink and generating droplets by the thermal energy. Can be mentioned.

  The ink of the present invention has a high quality image with high permeability and no bleeding, and discharge stability, in particular, it is difficult to cause a discharge failure due to bubble entrainment during printing or printing pause, and when a discharge failure occurs. In addition, since an ink that can maintain reliability can be obtained with a simple recovery mechanism, it can be applied to a high-speed recording process that has been difficult in general. That is, in a recording method for forming an image on a recording medium by ejecting and ejecting a plurality of ink droplets from the same or different ejection ports so that at least a part of the pixel area overlaps on the recording medium, the overlapping is performed on the recording medium. It is possible to shorten the difference between the ejection times of the two ink droplets that cause the ink droplets, so that very high speed recording is possible. In recent years, the technology related to inkjet printers has made remarkable progress and the printing speed has improved, but in order to maintain a certain level of high image quality, dots in adjacent positional relations have not been formed continuously. The other ink was not landed until it soaked into the paper. That is, it can be said that high-quality printing is achieved while sacrificing the printing speed by a method called multi-pass printing. Since the ink of the present invention exhibits very high penetrating characteristics, it has become possible to perform high-quality printing in a single pass that could not be achieved conventionally. Furthermore, high-quality printing can be achieved without sacrificing printing speed even in color printing of four or more colors by the line head.

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

  The water-based ink of the present invention can be suitably used in various fields, and can be suitably used in an image forming apparatus (printer or the like) based on an ink jet recording method. The water-based ink is heated at 50 to 200 ° C. and can be used for a printer or the like having a function of accelerating print fixing, and is particularly suitable for the following ink cartridge, ink recorded matter, ink jet recording apparatus and ink jet recording method of the present invention. It can be preferably used.

(ink cartridge)
The ink cartridge of the present invention contains the water-based 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 shows an external perspective view of the ink cartridge before loading into the recording apparatus, and FIG. 2 shows a front sectional view of the ink cartridge.
As shown in FIG. 2, the ink cartridge 7 includes an ink absorber 42 that absorbs ink of a desired color in a cartridge main body 41. The cartridge body 41 is formed by adhering or welding the upper lid member 44 to the upper opening of the case 43 having a wide opening at the upper portion, and is made of, for example, a resin molded product. The ink absorber 42 is made of a porous material such as a urethane foam, and after being compressed and inserted into the cartridge body 41, the ink is absorbed.

  An ink supply port 45 for supplying ink to the recording head 6 is formed at the bottom of the case 43 of the cartridge body 41, and a seal ring 46 is fitted on the inner peripheral surface of the ink supply port 45. The upper lid member 44 has an air opening 47 formed therein. In the cartridge main body 41, the case 43 is compressed and deformed by the pressure applied to the wide side wall when the ink supply port 45 is closed and when the cartridge is handled during loading or transportation, or during vacuum packaging. In order to prevent internal ink from leaking, a cap member 50 is attached.

Further, as shown in FIG. 1, the atmosphere opening 47 is sealed by sticking a film-like sealing member 55 having an oxygen permeability of 100 ml / m ² or more to the upper lid member 44. In this way, by sealing the air opening 47 with the sealing member 55 having an oxygen permeability of 100 ml / m ² or more, the ink cartridge 7 is packaged under reduced pressure using a packaging member such as a non-permeable aluminum laminate film. Thus, even when the gas is dissolved in the ink due to the atmosphere in the space A (see FIG. 2) generated between the ink absorber 42 and the cartridge main body 41 when the ink is filled, the ink is passed through the seal member 55. The air inside is discharged into a space between the packaging body outside the cartridge main body 41 having a high degree of vacuum, and the degree of deaeration of the ink is improved.

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

(Inkjet recording apparatus and inkjet recording method)
The ink jet recording apparatus of the present invention includes at least ink flying means, and further includes other means appropriately selected as necessary, for example, stimulus generation means, control means, and the like.
The inkjet recording method of the present invention includes at least an ink flying process, and further includes other processes appropriately selected as necessary, for example, a stimulus generation process, a control process, and the like.
The ink jet recording method of the present invention can be preferably carried out by the ink jet recording apparatus of the present invention, and the ink flying step can be suitably carried out by the ink flying means. 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 forming an image by applying a stimulus to the aqueous ink of the present invention and causing the aqueous ink to fly.
The ink flying means is means for forming an image by applying a stimulus to the aqueous ink of the present invention and causing the aqueous ink to fly. The ink flying means is not particularly limited, and examples thereof include various nozzles for ejecting ink.

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

  Examples of the stimulus generating means include a 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 change 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, electrostatic actuators that use electrostatic force, etc. It is done.

  The flying mode of the water-based ink is not particularly limited and varies depending on the type of the stimulus. For example, when the stimulus is “heat”, the water-based ink in the recording head corresponds to the recording signal. A method in which thermal energy is applied using, for example, a thermal head, bubbles are generated in the aqueous ink by the thermal energy, and the aqueous ink is ejected and ejected as droplets from the nozzle holes of the recording head by the pressure of the bubbles. , Etc. Further, when the stimulus is “pressure”, for example, by applying a voltage to a piezoelectric element bonded to a position called a pressure chamber in an ink flow path in the recording head, the piezoelectric element bends and the volume of the pressure chamber is increased. And a method of ejecting and ejecting the water-based ink as droplets from the nozzle holes of the recording head.

  The size of the droplet of the water-based ink to be ejected is preferably 3 to 40 pl, for example, and the speed of ejection and ejection is preferably 5 to 20 m / s, and the driving frequency thereof. Is preferably 1 kHz or more, and the resolution is preferably 300 dpi or more.

  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.

  Next, the aqueous ink of the present invention is accommodated in an ink cartridge with reference to the drawings, and the ink cartridge is mounted on an ink jet printer, and ejected and ejected as droplets from fine ejection ports to form an image on a recording medium. A method will be described.

FIG. 3 is a schematic front view of a mechanism part of a serial type ink jet recording apparatus on which an ink cartridge having an ink containing part containing the ink of the present invention is mounted.
The mechanism portion of this ink jet recording apparatus lays the main support guide rod 3 and the sub support guide rod 4 between the side plates 1 and 2 on both sides in a substantially horizontal positional relationship, and the main support guide rod 3 and the sub support guide. The carriage 4 is supported by the rod 4 so as to be slidable in the main scanning direction.

The carriage unit 5 has four heads 6 for ejecting yellow (Y) ink, magenta (M) ink, cyan (C) ink, and black (Bk) ink, respectively, and an ejection surface (nozzle surface) 6a. The four ink cartridges 7y, 7m, 7c, and 7k, which are ink supply bodies for each color, are mounted downward and are supplied to the four heads 6 on the upper side of the heads 6 of the carriage unit 5. Is installed in a replaceable manner.
The carriage unit 5 is connected to a timing belt 11 stretched between a drive pulley (drive timing pulley) 9 and a driven pulley (idler pulley) 10 that are rotated by the main scan motor 8, and the main scan motor 8 is connected to the carriage unit 5. By controlling the driving, the carriage 5, that is, the four heads 6 are moved in the main scanning direction.

  Further, the sub-frames 13 and 14 are erected on the bottom plate 12 connecting the side plates 1 and 2, and a conveyance roller 15 for feeding the paper 16 in the sub-scanning direction orthogonal to the main scanning direction is provided between the sub-frames 13 and 14. Holds freely. A sub-scanning motor 17 is disposed on the side of the sub-frame 14, and a gear 18 and a transport roller 15 fixed to the rotation shaft of the sub-scanning motor 17 in order to transmit the rotation of the sub-scanning motor 17 to the transport roller 15. And a gear 19 fixed to the shaft.

  Further, a reliability maintenance / recovery mechanism (hereinafter referred to as “subsystem”) 21 of the head 6 is disposed between the side plate 1 and the subframe 12. The sub-system 21 holds four cap means 22 for capping the ejection surface of each head 6 by a holder 23, and this holder 23 is held by a link member 24 so as to be swingable so that the carriage unit 5 can move in the main scanning direction. When the carriage unit 5 comes into contact with the engaging portion 25 provided on the holder 23 by the movement of the holder 23, the holder 23 is lifted up according to the movement of the carriage unit 5 and the ejection surface 6a of the inkjet head 6 is capped by the cap means 22, As the carriage unit 5 moves to the printing region side, the holder 23 is lifted down as the carriage unit 5 moves, so that the cap means 22 moves away from the ejection surface 6 a of the inkjet head 6.

The cap means 22 is connected to the suction pump 27 via the suction tube 26, forms an atmosphere opening port, and communicates with the atmosphere via the atmosphere opening tube and the atmosphere opening valve. The suction pump 27 discharges the sucked waste liquid to a waste liquid storage tank (not shown) through a drain tube or the like.
Further, on the side of the holder 23, a wiper blade 28, which is a wiping means made of an elastic member such as a fiber member, a foam member, or rubber, for wiping the discharge surface 6a of the inkjet head 6 is attached to a blade arm 29. Reference numeral 29 is pivotally supported so that it can be swung by rotation of a cam that is rotated by a driving means (not shown).

Next, FIG. 4 shows an example of the configuration of a recording cartridge (recording unit) provided with an ink containing portion containing the ink of the present invention and a head portion for ejecting ink droplets. The recording unit will be described below.
The recording unit 30 is of a serial type, and the main part is composed of a head 6, an ink tank 33 that stores ink supplied to the head 6, and a lid member 34 that seals the inside of the ink tank 33. The
A number of nozzles 32 for ejecting ink are formed in the head 6 of the recording unit 30. The ink is guided from the ink tank 33 to a common liquid chamber (not shown) via an ink supply pipe (not shown), and the nozzles according to an electric signal from the recording apparatus main body input from the electrode 31. 32 is discharged. Such a type of recording unit 30 has a structure suitable for a head of a type that can be manufactured at low cost, a so-called thermal type or bubble type head that uses thermal energy as a driving power source. Since the ink of the present invention uses an ink having excellent permeability in a recording method such as bubble or thermal method, the wettability to a thermal element is improved, ejection stability and frequency stability are obtained, and safety is achieved. It is highly suitable and very suitable.

  Here, the serial type ink jet recording apparatus has been described. However, the ink of the present invention is accumulated by recording the nozzles in an arbitrary arrangement such as a staggered pattern at a density equal to or about a fraction of the target image resolution. The present invention can also be applied to a recording apparatus having a so-called line head arranged more than the width of the medium.

  In addition, although it demonstrated in the example applied to the serial type (shuttle type) inkjet recording device which a carriage scans, it can apply similarly to the line type inkjet recording device provided with the line type head.

  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.

(Recorded material)
The recorded matter recorded by the ink jet recording apparatus and the ink jet recording method of the present invention is the recorded matter of the present invention. The recorded matter of the present invention has an image formed on the recording medium using the water-based 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 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.

(Example 1)
-Preparation of ink set-
An ink set of Example 1 was prepared by combining BK ink, C ink, M ink, and Y ink having the following formulation.

<Preparation of BK ink (black ink)>
C. I. Direct Black 168 4.0% by mass, glycerin 16% by mass, surfactant of the following formula (1-6) 4.2% by mass, diethylene glycol mono-n-butyl ether 2% by mass, silicone-based antifoaming agent KM73E (emulsion) Type, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5% by mass, and ion-exchanged water The remaining amount was sufficiently stirred at room temperature, and then adjusted with lithium hydroxide 5% by mass aqueous solution so that the pH was 8.0. did. Then, it filtered with the membrane filter with an average hole diameter of 0.2 micrometer. Thus, BK ink was produced.
<Formula (1-6)>
_{CH 3 - (CH 2) 7} -CH = CH (CH 2) 7 -CH 2 -O (C 2 H 4 O) 12 SO 3 (C 2 H 4 OH) 4

<Preparation of C ink (cyan ink)>
C. I. Direct Blue 199 3.5% by mass, 1,3-butanediol 4% by mass, glycerin 10% by mass, surfactant of the following formula (1-11) 0.1% by mass, diethylene glycol mono-iso-butyl ether 5% by mass %, Silicone-based antifoaming agent KS508 (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03% by mass, and the remaining amount of ion-exchanged water are sufficiently stirred at room temperature, so that the pH becomes 8.0. Was adjusted with a 5% by weight aqueous solution of lithium hydroxide. Then, it filtered with the membrane filter with an average hole diameter of 0.2 micrometer. C ink was produced by the above.
<Formula (1-11)>
_{C 9 H 19 -C 6 H 5} -O (C 2 H 4 O) 6 SO 3 NH 4

<Preparation of M ink (magenta ink)>
C. I. Direct Red 227 3.2% by mass, thiodiglycol 7% by mass, surfactant of the following formula (1-2) 1.0% by mass, triethylene glycol mono-n-butyl ether 4% by mass, silicone-based defoaming Agent SAG30 (emulsion type, manufactured by Nihon Unicar Co., Ltd.) 0.03% by mass, and ion-exchanged water The remaining amount of lithium hydroxide is 5% by mass so that the pH becomes 8.0 after sufficiently stirring at room temperature. Adjusted. Then, it filtered with the membrane filter with an average hole diameter of 0.2 micrometer. M ink was produced by the above.
<Formula (1-2)>
C ₁₀ H ₂₁ O (C ₂ H ₄ O) ₄ SO ₃ Na

<Preparation of Y ink (yellow ink)>
C. I. Direct Yellow 142 4.0% by mass, ethylene glycol 15% by mass, glycerin 6% by mass, surfactant of the following formula (1-4) 0.5% by mass, triethylene glycol mono-iso-butyl ether 3% by mass, Silicone-based antifoaming agent KS537 (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03% by mass, and ion-exchanged water After sufficiently stirring the remaining amount at room temperature, water is used so that the pH becomes 8.0. It adjusted with the lithium oxide 5 mass% aqueous solution. Then, it filtered with the membrane filter with an average hole diameter of 0.2 micrometer. In this way, Y ink was produced.
<Formula (1-4)>
C ₂₂ H ₄₅ O (C ₂ H ₄ O) ₂₁ SO ₃ NH ₄

(Example 2)
-Preparation of ink set-
An ink set of Example 2 was prepared by combining BK ink, C ink, M ink, and Y ink having the following formulation.

<Preparation of BK ink (black ink)>
Sulfonic acid group-bonded carbon black dispersion (solid content 18% by mass, average particle size 104 nm) 30.6% by mass, triethylene glycol 5% by mass, ethylene glycol 14% by mass, surface activity of the following formula (1-5) 0.5% by weight of the agent, 4% by weight of triethylene glycol mono-iso-butyl ether, and 5% by weight of lithium hydroxide so that the remaining amount of ion-exchanged water is sufficiently stirred at room temperature so that the pH is 8.0. Adjusted with aqueous solution. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. Thus, BK ink was prepared.
<Formula (1-5)>
_{CH 3 - (CH 2) 7} -CH = CH (CH 2) 7 -CH 2 -O (C 2 H 4 O) 8 SO 3 NH 4

<Preparation of C ink (cyan ink)>
-Preparation of pigment dispersion-
C. I. Pigment Blue 15: 3 (average particle size 87 nm) 15% by mass, styrene-acrylate-methacrylic acid diethanolamine salt copolymer 3% by mass, and ion-exchanged water were dispersed using a bead mill to prepare a pigment dispersion. .

-Preparation of ink formulation-
30% by mass of the pigment dispersion, 16% by mass of diethylene glycol, 0.8% by mass of a surfactant of the following formula (1-2), 0.1% by mass of diethylene glycol mono-iso-butyl ether, ethylene glycol mono-n-butyl ether 2 .5% by mass, silicone-based antifoaming agent KS537 (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03% by mass, and the remaining amount of ion-exchanged water were mixed and stirred, so that the pH was 8 It adjusted with the lithium 5 mass% aqueous solution. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. C ink was prepared by the above.
<Formula (1-2)>
C ₁₀ H ₂₁ O (C ₂ H ₄ O) ₄ SO ₃ Na

<Preparation of M ink (magenta ink)>
-Preparation of pigment dispersion-
C. I. Pigment Red 122 (average particle size 32 nm) 15% by mass, styrene-acrylate-methacrylic acid diethanolamine salt copolymer 3% by mass, and the remaining amount of ion-exchanged water were dispersed using a bead mill to prepare a pigment dispersion.

-Preparation of ink formulation-
26.7% by mass of the pigment dispersion, 14% by mass of diethylene glycol, 1.5% by mass of a surfactant represented by the following formula (1-14), 2.5% by mass of diethylene glycol mono-iso-butyl ether, silicone-based antifoaming agent SAG30 (Emulsion type, manufactured by Nippon Unicar Co., Ltd.) 0.03% by mass and the remaining amount of ion-exchanged water were mixed and stirred, and then adjusted with a 5% by mass aqueous solution of lithium hydroxide so that the pH was 8. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. M ink was prepared by the above.
<Formula (1-14)>
_{C 9 H 19 -C 6 H 5} -O (C 2 H 4 O) 21 SO 3 NH 4

<Preparation of Y ink (yellow ink)>
-Preparation of pigment dispersion-
C. I. Pigment Yellow 74 (average particle diameter 174 nm) 15% by mass, naphthalenesulfonate formalin condensate 3% by mass, and the remaining amount of ion-exchanged water were dispersed using a bead mill to prepare a pigment dispersion.

-Preparation of ink formulation-
23.3% by mass of the pigment dispersion, 15% by mass of diethylene glycol, 10% by mass of glycerin, 0.5% by mass of a surfactant of the following formula (1-4), 5% by mass of triethylene glycol mono-n-butyl ether, silicone System antifoaming agent KS531 (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.005% by mass, and the remaining amount of ion-exchanged water are mixed and stirred, and then a lithium hydroxide 5% by mass aqueous solution is added so that the pH becomes 8. Adjusted. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. In this way, Y ink was prepared.
<Formula (1-4)>
C ₂₂ H ₄₅ O (C ₂ H ₄ O) ₂₁ SO ₃ NH ₄

(Example 3)
-Preparation of ink set-
An ink set of Example 3 was prepared by combining BK ink, C ink, M ink, and Y ink having the following formulation.

<Preparation of BK ink (black ink)>
Carboxyl group-bonded carbon black dispersion (solid content 16.4% by mass, average particle size 123 nm) 30.5% by mass, 2-pyrrolidone 2% by mass, glycerin 18% by mass, surface activity of the following formula (1-7) 1.0% by mass of agent, 3.5% by mass of triethylene glycol mono-n-butyl ether, 0.03% by mass of silicone-based antifoaming agent KS537 (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.), remaining amount of ion-exchanged water Was sufficiently stirred at room temperature, and then adjusted with a 5% by weight aqueous solution of sodium hydroxide so that the pH was 8.5. Then, it filtered with the membrane filter with an average hole diameter of 1.2 micrometers. Thus, BK ink was prepared.
<Formula (1-7)>
_{CH 3 - (CH 2) 7} -CH = CH (CH 2) 7 -CH 2 -O (C 2 H 4 O) 18 SO 3 NH 4

<Preparation of C ink (cyan ink)>
Sulfonic acid group-bonded cyan pigment (CAB-O-JET-250C, solid content 10% by mass, Cabot Specialty Chemicals Inc.) 40.0% by mass, 1,3-butanediol 14% by mass, ethylene glycol 4 % By mass, surfactant of the following formula (1-5) 1.5% by mass, diethylene glycol mono-n-butyl ether 12% by mass, silicone-based antifoaming agent SAG30 (emulsion type, manufactured by Nihon Unicar Co., Ltd.) 0.03 mass %, Ion-exchanged water The remaining amount was sufficiently stirred at room temperature, and then adjusted with a 5% by weight aqueous solution of sodium hydroxide so that the pH was 8.5. Then, it filtered with the membrane filter with an average hole diameter of 1.2 micrometers. C ink was prepared by the above.
<Formula (1-5)>
_{CH 3 - (CH 2) 7} -CH = CH (CH 2) 7 -CH 2 -O (C 2 H 4 O) 8 SO 3 NH 4

<Preparation of M ink (magenta ink)>
Sulfonic acid group-bonded magenta pigment (CAB-O-JET-260M, solid content 10% by mass, manufactured by Cabot Specialty Chemicals Inc.) 40.0% by mass, 1,3-butanediol 10% by mass, glycerin 7% by mass %, Surfactant of the following formula (1-7) 0.6% by mass, surfactant of the following formula (1-6) 0.6% by mass, diethylene glycol mono-iso-butyl ether 4.5% by mass, silicone type Defoaming agent KS531 (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03% by mass, and ion-exchanged water The remaining amount of sodium hydroxide was sufficiently stirred at room temperature so that the pH was 8.5. It adjusted with 5 mass% aqueous solution. Then, it filtered with the membrane filter with an average hole diameter of 1.2 micrometers. M ink was prepared by the above.
<Formula (1-7)>
_{CH 3 - (CH 2) 7} -CH = CH (CH 2) 7 -CH 2 -O (C 2 H 4 O) 18 SO 3 NH 4
<Formula (1-6)>
_{CH 3 - (CH 2) 7} -CH = CH (CH 2) 7 -CH 2 -O (C 2 H 4 O) 12 SO 3 (C 2 H 4 OH) 4

<Preparation of Y ink (yellow ink)>
Sulfonic acid group-bonded cyan pigment (CAB-O-JET-270Y, solid content 10% by mass, Cabot Specialty Chemicals Inc.) 40.0% by mass, 1,3-butanediol 12% by mass, diethylene glycol 3% by mass %, Surfactant of the following formula (1-10) 4% by mass, diethylene glycol mono-n-butyl ether 3% by mass, triethylene glycol mono-iso-butyl ether 0.1% by mass, silicone antifoaming agent KS508 (self-emulsifying Type, Shin-Etsu Chemical Co., Ltd.) 3% by mass, and the remaining amount of ion-exchanged water were sufficiently stirred at room temperature, and then adjusted with a 5% by mass aqueous solution of sodium hydroxide so that the pH was 8.5. Then, it filtered with the membrane filter with an average hole diameter of 1.2 micrometers. In this way, Y ink was prepared.
<Formula (1-10)>
_{C 9 H 19 -C 6 H 5} -O (C 2 H 4 O) 4 SO 3 NH 4

(Comparative Example 1)
-Preparation of ink set-
In the ink set of Example 1, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether, and triethylene glycol mono added to the BK, C, M, and Y inks, respectively. -An ink set of Comparative Example 1 was prepared in the same manner as Example 1 except that the iso-butyl ether was removed and the silicone antifoaming agent was removed from the M and Y inks.

(Comparative Example 2)
-Preparation of ink set-
An ink set of Comparative Example 2 was prepared by combining BK ink, C ink, M ink, and Y ink having the following formulation.

<Preparation of BK ink (black ink)>
Sulfonic acid group-bonded carbon black dispersion (solid content 18% by mass, average particle size 104 nm) 30.6% by mass, triethylene glycol 5% by mass, ethylene glycol 14% by mass, ethylene oxide-propylene oxide-ethylene oxide type (Brulonic type) ) Surfactant (HLB = 8, molecular weight = about 2500) 0.5% by mass, triethylene glycol mono-iso-butyl ether 4% by mass, and ion-exchanged water It adjusted with lithium hydroxide 5 mass% aqueous solution so that it might be set to 8.0. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. Thus, BK ink was prepared.

<Preparation of C ink (cyan ink)>
-Preparation of pigment dispersion-
C. I. Pigment Blue 15: 3 (average particle size 87 nm) 15% by mass, styrene-acrylate-methacrylic acid diethanolamine salt copolymer 3% by mass, and ion-exchanged water were dispersed using a bead mill to prepare a pigment dispersion. .

-Preparation of ink formulation-
30% by mass of the pigment dispersion, 16% by mass of diethylene glycol, 0.8% by mass of ethylene oxide adduct of nonylphenol (HLB = 10, manufactured by San Nopco), 0.1% by mass of diethylene glycol mono-iso-butyl ether, ethylene glycol mono- After mixing and stirring n-butyl ether 2.5% by mass, silicone-based antifoaming agent KS537 (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.), and the remaining amount of ion-exchanged water, the pH becomes 8. Thus, it adjusted with the lithium hydroxide 5 mass% aqueous solution. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. C ink was prepared by the above.

<Preparation of M ink (magenta ink)>
-Preparation of pigment dispersion-
C. I. Pigment Red 122 (average particle size 32 nm) 15% by mass, styrene-acrylate-methacrylic acid diethanolamine salt copolymer 3% by mass, and the remaining amount of ion-exchanged water were dispersed using a bead mill to prepare a pigment dispersion.

-Preparation of ink formulation-
26.7% by mass of the pigment dispersion, 14% by mass of diethylene glycol, 1.5% by mass of Surfynol 104 acetylene glycol surfactant (manufactured by Nissin Chemical), 2.5% by mass of diethylene glycol mono-iso-butyl ether, After mixing and stirring the silicone-based antifoaming agent SAG30 (emulsion type, manufactured by Nihon Unicar Co., Ltd.) 0.03% by mass and the remaining amount of ion-exchanged water, a lithium hydroxide 5% by mass aqueous solution is used so that the pH becomes 8. It was adjusted. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. M ink was prepared by the above.

<Preparation of Y ink (yellow ink)>
-Preparation of pigment dispersion-
C. I. Pigment Yellow 74 (average particle diameter 174 nm) 15% by mass, naphthalenesulfonate formalin condensate 3% by mass, and the remaining amount of ion-exchanged water were dispersed using a bead mill to prepare a pigment dispersion.

-Preparation of ink formulation-
After mixing and stirring the pigment dispersion 23.3% by mass, diethylene glycol 15% by mass, glycerin 10% by mass, triethylene glycol mono-n-butyl ether 5% by mass, and the remaining amount of ion-exchanged water, the pH was adjusted to 8. Was adjusted with a 5% by weight aqueous solution of lithium hydroxide. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. In this way, Y ink was prepared.

(Comparative Example 3)
-Preparation of ink set-
In the ink set of Example 3, the above formula (1-7), the above formula (1-5), the above formula (1-7), and the above formula (1) added to the BK, C, M, and Y inks, respectively. 1-6) and the surfactant of the above formula (1-10), and further diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether and triethylene glycol mono-iso- An ink set of Comparative Example 3 was prepared in the same manner as in Example 3 except that butyl ether was removed and a silicone-based antifoaming agent was further removed.

  Next, for each of the inks of the obtained Examples and Comparative Examples, the image sharpness, the image drying property, the back-through, the scratching property, the image filling, the storage property, the initial filling property, and The recoverability was evaluated. The results are shown in Table 1.

<Image clarity>
Inkjet printer EM-900 (manufactured by Seiko Epson Corporation) changed the drive voltage, frequency, and pulse width of the head, and printed on each of the following recording media (1) to (3). The printing conditions were Mj 35 pl, Vj 20 m / sec, frequency 1 kHz, recording density 360 dpi, and one-pass printing. As the print pattern, a general document image including a solid at 100% duty, a character, and a two-color overlapping portion boundary of each ink was printed.
After printing and drying, two-color overlap boundary blur, image blur, color tone, and image density are comprehensively examined visually and using a reflective color spectrocolorimeter (manufactured by X-Rite). Judged.
〔recoding media〕
(1) My paper (NBS Ricoh Co., Ltd.)
(2) Paper source S and recycled paper (manufactured by NBS Ricoh Co., Ltd.)
(3) Xerox 4024 paper (Fuji Xerox Office Supply Co., Ltd.)
[Criteria]
A: All papers are clearly printed.
○: Some paper (recycled paper) has bleeding.
Δ: Bleeding occurs on all papers.
X: The blur has occurred so that the outline of the character and the boundary between the two color overlapping portions are not clear.

<Dryness of image>
After printing a solid image on each of the recording media of (1) to (3) above, press the filter paper against the obtained image with a pressure of 0.1 kgf / cm ² and measure the time until the ink does not transfer to the filter paper. Evaluation was made according to the following criteria.
〔Evaluation criteria〕
○: Any paper was dried in less than 3 seconds.
Δ: All papers were dried in 3 to 20 seconds.
X: Any paper dried in more than 20 seconds.

<Back-through>
A solid image on a recording medium (Xerox 4024 paper, manufactured by Fuji Xerox Office Supply Co., Ltd.) so that the density of each ink color measured with a reflective color spectrophotometric densitometer (manufactured by X-Rite) is 1.0. Formed. This image was visually observed from the back and evaluated according to the following criteria.
〔Evaluation criteria〕
X: The colorant of the solid image is missing to the back surface, and is a level that cannot be used for double-sided printing.
Δ: The colorant of the solid image does not escape to the back side, but the boundary between the solid image and the white background is somewhat unclear, and it is at a level that does not hinder even if used for double-sided printing.
○: The boundary between the solid image and the white background is almost unclear, and it is at a level that does not hinder the use of the double-sided printing.
A: The boundary between the solid image and the white background is completely unclear, and it is a level that does not cause any trouble even when used for double-sided printing.

<Abrasion>
An image formed with each ink on a recording medium (Xerox 4024 paper, manufactured by Fuji Xerox Office Supply Co., Ltd.) is rubbed with a finger, cloth, eraser, and marking pen 30 seconds after printing, and the state after the rub is visually observed. Observed and evaluated according to the following criteria.
〔Evaluation criteria〕
○: No change in image due to abrasion.
X: Image change due to rubbing occurred.

<Embedding image>
A solid image after drying formed with each ink on a recording medium (Xerox 4024 paper, manufactured by Fuji Xerox Office Supply Co., Ltd.) was observed and evaluated according to the following criteria.
〔Evaluation criteria〕
A: The recording medium is uniformly colored with ink even when it is enlarged and observed.
○: The recording medium is uniformly colored with ink as long as visually observed.
X: The recording medium is colored non-uniformly so that the background can be seen visually.

<Preservability>
If each ink is set in an ink jet printer (IPSiO JET 300, manufactured by Ricoh Co., Ltd.) and left at 60 ° C. for 7 days, then it can be restored by one cleaning operation of a conventionally known ink jet printer. If it is possible to recover after 5 times, Δ is indicated.

<Initial fillability>
Each ink is degassed and filled into a cartridge. After being loaded into an ink jet printer (IPSiO JET 300, manufactured by Ricoh Co., Ltd.), an initial filling operation is performed, and then a nozzle check pattern is printed. evaluated.
〔Evaluation criteria〕
○: The initial filling operation performed until the nozzle omission disappeared could be filled once.
X: The initial filling operation performed until nozzle omission disappeared was required twice or more.

<Recovery test>
Using an ink jet printer (IPSiO JET 300, manufactured by Ricoh Co., Ltd.) filled with each ink, a solid image was printed for each color, and when a nozzle missing occurred, recovery operation was performed, and 20 A4 size sheets for each color Printing was performed on a recording medium (Xerox 4024 paper, manufactured by Fuji Xerox Office Supply Co., Ltd.). The mass of the cartridge before and after printing was measured, and the amount of ink used (g) was calculated. In addition, the number of recovery operations performed during printing was measured.

  The water-based ink of the present invention is particularly preferably used in an ink jet recording method in which a water-based ink is ejected and ejected as droplets from a fine ejection port to form a color image on a recording medium. Can be widely used as ink for general writing instruments, recorders, and pen plotters.

FIG. 1 is an external perspective view showing an example of an ink cartridge before being loaded into the recording apparatus of the present invention. FIG. 2 is a front sectional view of the ink cartridge of FIG. FIG. 3 is a schematic front view showing an example of a serial type ink jet recording apparatus equipped with an ink cartridge containing ink to which the present invention is applied. FIG. 4 is an external perspective view showing an example of a recording unit integrated with the recording head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Side plate 2 Side plate 3 Main support guide rod 4 Sub support guide rod 5 Carriage unit 6 Head 6a Discharge surface (nozzle surface)
7 Ink Cartridge 7y Ink Cartridge 7m Ink Cartridge 7c Ink Cartridge 7k Ink Cartridge 8 Main Scanning Motor 9 Drive Pulley (Drive Timing Pulley)
10 Driven pulley (idler pulley)
DESCRIPTION OF SYMBOLS 11 Timing belt 12 Bottom plate 13 Sub frame 14 Sub frame 15 Conveyance roller 16 Paper 17 Sub scanning motor 18 Gear 19 Gear 21 Sub system 22 Cap means 23 Holder 24 Link member 25 Engagement part 26 Suction tube 27 Suction pump 28 Wiper blade 29 Blade Arm 30 Recording unit 31 Electrode 32 Nozzle 33 Ink tank 41 Cartridge body 42 Ink absorber 43 Case 44 Upper lid member 45 Ink supply port 46 Seal ring 47 Atmospheric release port 50 Cap member 55 Seal member A Space

Claims (18)

  (A) a colorant and (B) at least one compound selected from diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol mono-n-butyl ether and triethylene glycol mono-iso-butyl ether And (C) a surfactant selected from polyoxyethylene alkyl ether sulfate and polyoxyethylene alkyl phenyl ether sulfate.   The water-based ink according to claim 1, wherein the content of the component (B) compound in the water-based ink is 0.1 to 10% by mass. The water-based ink according to claim 1, wherein the surfactant as the component (C) is represented by the following general formula (1).
^{_{R 4 -O- (C 2 H 4}} O) n SO 3 -M ··· formula (1)
However, In the general formula (2), ^{R 4} represents a hydrocarbon group. M represents one selected from alkali metal ions, quaternary ammonium, quaternary phosphonium, and alkanolamine. n is an integer of 4 to 21.   The water-based ink according to any one of claims 1 to 3, wherein a content of the surfactant (C) in the water-based ink is 0.01 to 4% by mass.   The water-based ink according to claim 1, wherein the colorant as the component (A) is a pigment.   The aqueous ink according to claim 5, wherein the pigment has an average particle diameter of 10 to 200 nm.   The aqueous ink according to claim 5, wherein the pigment exhibits at least one of water dispersibility and water solubility in the presence of a dispersant.   The water-based ink according to claim 7, wherein the dispersant has a carboxyl group on the surface.   The aqueous ink according to any one of claims 5 to 6, wherein the pigment has at least one hydrophilic group and exhibits at least one of water dispersibility and water solubility in the absence of a dispersant.   The aqueous ink according to claim 9, wherein the hydrophilic group is at least one selected from a carboxyl group, a sulfone group, a carbonyl group, and a hydroxyl group.   The water-based ink according to claim 1, comprising an antifoaming agent, wherein the antifoaming agent is a silicone-based antifoaming agent.   The water-based ink according to claim 11, wherein the silicone-based antifoaming agent is either a self-emulsifying type or an emulsion type.   A water-soluble organic solvent is contained, and the water-soluble organic solvent is at least one selected from glycerin, ethylene glycol, diethylene glycol, 1,3-butanediol, triethylene glycol, and 2-pyrrolidone. The water-based ink according to any one of the above.   The water-based ink according to claim 1, which is at least one selected from cyan ink, magenta ink, yellow ink, and black ink.   An ink cartridge comprising the water-based ink according to claim 1 contained in a container.   15. An ink jet recording apparatus comprising at least ink flying means for forming an image by applying a stimulus to the water-based ink according to claim 1 and causing the water-based ink to fly.   15. An ink jet recording method comprising at least an ink flying step of forming an image by applying a stimulus to the water-based ink according to claim 1 and causing the water-based ink to fly. An ink recorded matter comprising an image formed using the water-based ink according to any one of claims 1 to 14 on a recording medium.

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