JP2013194119A - Ink for inkjet recording, ink cartridge, inkjet recording method, inkjet recording apparatus and ink recorded matter - Google Patents

Abstract

Ink jet recording ink having good ink storage stability, high image density on plain paper, good ink ejection stability and ejection recovery, ink cartridge, recording apparatus and ink using the same Provide records.
SOLUTION: Water, a wetting agent, a colorant, a styrene monomer, a dialkylaminoethyl methacrylate monomer, the following general formula (3) [in the general formula (3), R ₂ is an alkyl having 1 to 4 carbon atoms. Indicates a group. k represents the number of repeating units and represents an integer of 1 to 100. Ink jet recording ink is formed by containing at least polymer fine particles composed of a copolymer with a macromonomer represented by the formula:

[Selection] Figure 11

Description

  The present invention relates to an ink for ink jet recording, an ink cartridge, an ink jet recording method, an ink jet recording apparatus, and an ink recorded matter.

In recent years, as an image forming method, since the process is simple and full color can be easily obtained as compared with other recording methods, there is an advantage that a high-resolution image can be obtained even with an apparatus having a simple configuration. The method has become widespread. The ink jet recording system is a system in which a small amount of ink is ejected by an ink jet recording apparatus and adhered to a recording medium such as paper, and an image has been expanded to personal and industrial printers and printing.
Ink jet recording apparatuses mainly use water-based ink using a water-soluble dye as a colorant, but the dye ink has a disadvantage that it is inferior in weather resistance and water resistance. Therefore, in recent years, research on pigment inks using pigments instead of water-soluble dyes has been advanced. However, the pigment ink is still inferior in color development, ink ejection stability, and storage stability to the dye ink. In addition, with the improvement of image quality improvement technology for OA printers, image density equivalent to that of dye ink is required for both pigment ink and plain paper as a recording medium. However, when plain paper is used as a recording medium, the pigment ink has a problem that the pigment density on the paper surface is lowered by penetrating into the paper and the image density is lowered. In order to increase the drying speed of the ink adhering to the recording medium for high-speed printing, a means is taken to accelerate drying by adding a penetrant to the ink and allowing water to penetrate into the recording medium. Not only that, the penetrability of the pigment into the recording medium is increased, and the image density is further lowered.

Various methods have been proposed for improving the image density. For example, the rate of increase in viscosity (mPa · s /%) due to ink water evaporation is 5.0 or less until the water evaporation amount is 30% by mass relative to the total ink mass, and the water evaporation amount is 30 to 45 mass. Ink has been proposed that has a viscosity increase rate of more than 50 in% (see Patent Document 1). According to this proposed ink, when the ink lands on plain paper and the moisture evaporates, the viscosity rapidly increases, so that the penetration of the pigment into the paper is suppressed even when printing at high speed, indicating a high image density. ing.
On the other hand, in an ink jet printer, an ink containing polymer gel microspheres (pH-responsive resin) that swells when the solvent shifts to the acidic side (proton concentration becomes acidic) has been proposed (see Patent Document 2). ). In other words, when ink reaches the surface of plain paper, it is supplied with protons from the paper and the pH of the ink shifts from the alkaline side to the acidic side to swell the pH-responsive resin, thereby increasing the viscosity of the ink. It is said that the image density can be improved by suppressing the permeation of the pigment into the paper.

As described above, when the method disclosed in Patent Document 1 is used to improve the image density, the viscosity of the ink rapidly increases when the water content of the ink evaporates. It has been found that there is a problem that the ink ejection stability is lowered due to the thickening, and the ink is fixed around the nozzle.
On the other hand, when the method of Patent Document 2 is used, even if moisture evaporates in the nozzles of the ink jet recording apparatus, the viscosity does not increase and the ink ejection stability does not decrease, and the pH shifts from the alkaline side to the acidic side. The image density can be improved by this, but it has been found that the viscosity change accompanying the ink pH fluctuation when the ink lands on the paper surface is insufficient, so that sufficient image density cannot be obtained and further improvement is required. .

An object of the present invention is to solve the above-described problems and achieve the following objects.
That is, according to the present invention, when the ink lands on the paper surface (recording medium), the viscosity change accompanying the pH fluctuation of the ink is large and a high image density is obtained. The storage stability of the ink and the ejection of the ink from the recording head are obtained. An object of the present invention is to provide an ink for ink jet recording having good stability and ejection recovery, and an ink cartridge, an ink jet recording apparatus, an ink jet recording method, and an ink recorded matter using the ink.

As a result of intensive studies, the present inventors have found that a copolymer synthesized from a hydrophobic monomer having a specific structural unit, a pH-sensitive monomer having a specific structural unit, and a hydrophilic macromonomer having a specific structural unit Ink jet recording ink lands on a recording medium such as plain paper by using polymer fine particles (hereinafter sometimes referred to as “pH-responsive resin fine particles”) as a composition of the ink for ink jet recording. In this case, the particle diameter of the polymer fine particles is increased in response to the change in pH of the ink (change to the acidic side), and the penetration of the ink into the paper is suppressed to obtain a high image density. Invented.
That is, the above problem is an ink for ink jet recording comprising at least water, a wetting agent, a colorant, and polymer fine particles,
The polymer fine particle comprises a copolymer of a monomer represented by the following formula (1), a monomer represented by the following general formula (2), and a macromonomer represented by the following general formula (3). This is solved by an ink for ink jet recording.

[In General Formula (2), R ₁ represents an alkyl group having 1 to 4 carbon atoms. ]

[In General Formula (3), R ₂ represents an alkyl group having 1 to 4 carbon atoms. k represents the number of repeating units and represents an integer of 1 to 100. ]

Further, the above-mentioned problem is solved by an ink cartridge comprising the ink for ink jet recording according to any one of claims 1 to 3 contained in a container.
Further, the above-described problem is an ink that records an image on a recording medium by applying a stimulus to the ink for ink jet recording according to any one of claims 1 to 3 through an ink flying unit and flying the ink from a recording head. It is solved by an ink jet recording method characterized by including at least a flying step.
The above-described problem is solved by an ink jet recording apparatus comprising ink jetting means for jetting the ink jet recording ink according to any one of claims 1 to 3 from a recording head to record an image on a recording medium. Is done.
Further, the above-mentioned problem is solved by an ink recorded matter characterized in that an image recorded by the ink for ink jet recording according to any one of claims 1 to 3 is provided on a recording medium.
In the present invention, the monomer represented by (1) is a “hydrophobic monomer”, the monomer represented by the general formula (2) is “pH sensitive monomer”, and the macro is represented by the general formula (3). The monomer is sometimes referred to as a “hydrophilic macromonomer”. The polymer fine particles may be referred to as “pH-responsive polymer fine particles”.

The inkjet recording ink of the present invention is a co-polymerization of the monomer represented by the formula (1), the monomer represented by the general formula (2), and the macromonomer represented by the general formula (3). Since it contains polymer fine particles composed of coalescence, when the ink for ink jet recording lands on a recording medium such as plain paper, the polymer fine particles respond in response to a change in pH (decrease in pH value: change to the acidic side). The particle diameter is increased, and the penetration of the ink into the paper is suppressed, so that a high image density can be obtained. In addition, the storage stability of the ink is good, and the ejection stability and ejection recovery performance of the ink from the recording head are also good.
An ink jet recording apparatus having an ink ejecting means for recording an image on a recording medium by ejecting the ink for ink jet recording of the present invention from a recording head, and applying ink through the ink ejecting means to eject ink from the recording head. If an image is recorded on a recording medium, there is no ink ejection defect, and high density image formation can be realized with stable ink ejection characteristics. In addition, if the ink for ink jet recording of the present invention is accommodated in a container to form an ink cartridge, it can be easily attached to and detached from the ink cartridge loading portion provided in the ink jet recording apparatus, and stable ink supply can be performed for a long time. Become. The ink recorded matter of the present invention has high image quality, no bleeding, excellent stability with time, and can be suitably used for various purposes as materials on which various prints or images are recorded.

It is a schematic diagram for demonstrating the production | generation process of the polymer fine particle used for the ink for inkjet recording of this invention. It is the schematic plan view seen from the nozzle surface which shows an example (2 head type) of the recording head arrange | positioned at the inkjet recording device of this invention. It is the schematic plan view seen from the nozzle surface which shows another example (4 head type) of the recording head arrange | positioned at the inkjet recording device of this invention. FIG. 3 is a perspective explanatory view seen from the front side showing an example of an ink jet recording apparatus of the present invention having a maintenance / recovery device. It is a schematic block diagram explaining the whole structure of the mechanism part of the inkjet recording device shown in FIG. It is principal part plane explanatory drawing of the mechanism part of the inkjet recording device shown in FIG. It is principal part top explanatory drawing of the subsystem 91 containing the maintenance recovery apparatus in the inkjet recording device of this invention. It is a typical schematic block diagram of the subsystem shown in FIG. FIG. 8 is an explanatory diagram on the right side of the subsystem shown in FIG. 7. It is side surface explanatory drawing of the holding | maintenance raising / lowering mechanism part of the cap. It is a figure which shows the relationship between the average particle diameter of polymer microparticles | fine-particles obtained by the synthesis example 1, the synthesis example 2, the comparative synthesis example 1, and the comparative synthesis example 2, and pH.

As described above, the ink for ink jet recording in the present invention is an ink for ink jet recording comprising at least water, a wetting agent, a colorant, and polymer fine particles,
The polymer fine particle comprises a copolymer of a monomer represented by the following formula (1), a monomer represented by the following general formula (2), and a macromonomer represented by the following general formula (3). It is characterized by this.

[In General Formula (2), R ₁ represents an alkyl group having 1 to 4 carbon atoms. ]

[In General Formula (3), R ₂ represents an alkyl group having 1 to 4 carbon atoms. k represents the number of repeating units and represents an integer of 1 to 100. ]

Here, R ₁ in the general formula (2) is preferably a lower alkyl group such as a methyl group having 1 to 4 carbon atoms, an ethyl group, a propyl group, or a butyl group, and more preferably a methyl group or an ethyl group. By using a group in which R ₁ is an alkyl group having 1 to 4 carbon atoms, it is possible to exert a function of swelling the hydrophobic polymer when the pH required as the “pH sensitive monomer” is shifted to the acidic side. .
In the general formula (3), R ₂ is preferably a lower alkyl group such as a methyl group having 1 to 4 carbon atoms, an ethyl group, a propyl group, or a butyl group, and more preferably a methyl group or an ethyl group. By using a compound in which R ₂ is an alkyl group having 1 to 4 carbon atoms, a function of dispersing polymer fine particles required as a “hydrophilic macromonomer” in ink can be exhibited.

That is, the inkjet recording ink of the present invention contains at least water, a wetting agent, a colorant, and polymer fine particles, and the pH-responsive polymer fine particles have a structure represented by the formula (1). A unit (hydrophobic monomer), a structural unit represented by the general formula (2) (pH sensitive monomer), and a structural unit represented by the general formula (3) (hydrophilic macromonomer) are copolymerized. Thus, the hydrophobic polymer and the pH sensitive polymer serve as the core of the polymer fine particle, and the polymer chain of the hydrophilic macromonomer is localized on the surface of the polymer fine particle core.
The ink-jet ink of the present invention is kept alkaline in the ink cartridge or in the recording apparatus with a liquidity of about pH 8-11, and in that environment, the pH-responsive polymer fine particles in the ink are dispersed. The viscosity of is low. Therefore, the discharge stability is excellent.
However, when ink lands on plain paper having a pH of 4 to 7 on the paper surface, the ink is supplied with protons from the paper and the liquidity is shifted to the acidic side. Accordingly, the hydrophobic polymer becomes hydrophilic due to the pH-sensitive polymer in the core part of the pH-responsive polymer fine particles, so that the core part swells and the particle diameter increases. The particle diameter of the polymer fine particles increases in response to a so-called pH change (pH value decrease: change to the acidic side). In other words, the ink that has landed on the plain paper thickens as the particle size of the polymer fine particles increases, and remains on the paper surface. As a result, the colorant concentration on the paper surface increases and the image density increases.
For example, the particle diameter of the polymer gel microspheres in the prior art (Japanese Patent No. 3155318) is about 150 nm at pH 9 and is changed to about 380 nm at pH 5, whereas the particle size of the polymer gel microspheres is high in the present invention. The particle size of the molecular fine particles is not limited in response to a change in pH (decrease in pH value: change to the acidic side), but for example, a pH of about 9 to about 150 to 190 nm is 590 at pH 5. It changes to about 660 nm and becomes large. Therefore, since the volume change of the polymer fine particles contained in the ink with respect to the pH change when the ink landed on the paper surface is larger in the present invention, the viscosity change when the ink of the present invention landed on the paper surface is large, and the pigment It is possible to obtain a high image density by staying on the paper surface.
Thus, the inkjet ink of the present invention is excellent in storage stability and ejection stability, and a high image density can be obtained even on plain paper.
Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.

<Ink for inkjet recording>
The ink for ink jet recording of the present embodiment (hereinafter sometimes referred to as “ink”) contains at least water, a wetting agent, a colorant and polymer fine particles, and further contains other components as necessary. It consists of As described above, the ink for ink jet recording of the present invention has a high image density because the particle diameter increases when the polymer fine particles land on a recording medium such as plain paper, and the penetration of the ink into the paper is suppressed. Can be obtained.
Hereinafter, the components constituting the ink jet recording ink of the present invention will be described in more detail.

<Water>
As water used in the present invention, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used. The water content is preferably 10% by mass to 80% by mass with respect to the total amount of ink.

<Polymer fine particles>
The polymer fine particles (pH-responsive polymer fine particles) used in the present invention are high in response to a change in pH (change to the acidic side) when ink for ink jet recording lands on a recording medium such as plain paper. It has the characteristic that the particle diameter of molecular fine particles becomes large. By this function, it is possible to obtain a high image density by suppressing the penetration of the ink into the paper.
The hydrophobic monomer represented by the formula (1) used as the ink composition of the present invention, the pH sensitive monomer represented by the general formula (2), and the hydrophilicity represented by the general formula (3). A schematic diagram of FIG. 1 shows a production process of polymer fine particles composed of a copolymer with a macromonomer.

With reference to the schematic diagram of FIG. 1, the production process of polymer fine particles will be described.
FIG. 1 shows a radical copolymerizable group at a terminal synthesized from styrene [formula (1)] as a hydrophobic monomer, dimethylaminoethyl methacrylate [formula (2)] as a pH sensitive monomer and vinylbenzyltrimethylammonium chloride. This is an example in which a cationic hydrophilic macromonomer [formula (3)] is used as a raw material.
A cationic hydrophilic macromonomer having a radical polymerizable group at the terminal (1 in the figure) is composed of a vinylbenzyltrimethylammonium chloride unit (1a in the figure) and a vinylbenzyl group (1b in the figure).
First, the cationic hydrophilic macromonomer (1), a styrene monomer (2 in the figure) and dimethylaminoethyl methacrylate (3 in the figure) are mixed (step A in the figure), and the styrene monomer and dimethyl are mixed. When aminoethyl methacrylate is polymerized, copolymerization of styrene monomer and dimethylaminoethyl methacrylate (step B in the figure) partially occurs, but copolymerization with vinylbenzyl group (1b) (step C in the figure) Happens at the same time. As a result of the copolymerization, a polymer having a structure as if the cationic macromonomer is grafted to the styrene and dimethylaminoethyl methacrylate copolymer is obtained. Since the reaction is carried out in a polar medium, the hydrophobic styrene unit selectively accumulates (localizes) on the inside and the cationic macromonomer (1) on the outside (step D in the figure). When the polymerization is completed in this way, polymer fine particles (6 in the figure) in which the cationic polymer chain (5 in the figure) is located on the surface of the core part (4 in the figure) of the styrene / dimethylaminoethyl methacrylate unit. ) Is obtained (step E in the figure).
As described above, since the paper surface pH of plain paper is generally 4-7, when ink for ink jet recording lands on the plain paper, protons are donated to make the ink acidic. Therefore, the polymer fine particles having the above structure are in a storage state or in a dispersed state in the ink in the recording apparatus, but after landing on plain paper, the pH of the ink changes to the acidic side, so that the core part of the polymer fine particles It is considered that the hydrophobic polymer is made hydrophilic by the pH-sensitive polymer, so that the core portion swells and the particle diameter increases. In other words, in response to a change in pH (decrease in pH value: change to the acidic side), the particle size of the polymer fine particles increases, so that the particles stay on the paper surface, and the colorant concentration on the paper surface increases and the image density increases. .

The structural unit (hydrophobic monomer) represented by the formula (1) constituting the polymer fine particles of the present invention, the structural unit represented by the general formula (2), and the structure represented by the general formula (3) The ratio of the unit (hydrophilic macromonomer) is not particularly limited, but from the viewpoint of pH responsiveness, the structural unit represented by (Formula 1), the structural unit represented by (Formula 2), and (Formula 3) The ratio of the repeating unit constituting the polymer chain localized on the surface of the polymer fine particle among the structural units represented by 0.5-3 / 0.5-3 are more preferable.
The number k of repeating units in the general formula (3) represents an integer of 1 to 100, but more preferably has a peak at about 70 to 90 in the molecular weight distribution. When the number k of repeating units exceeds 100, the dispersibility of the polymer fine particles in the ink tends to decrease.

  The polymer fine particles used in the present invention are preferably added in an amount of 0.05 to 2.0 mass% as a solid content with respect to the total amount of ink. If the amount is less than 0.05% by mass, an increase in particle diameter due to a sufficient pH response may not be obtained, and the colorant in the ink may permeate the recording medium. In some cases, the polymer fine particles are aggregated, and the viscosity of the ink becomes high, making it difficult to obtain the viscosity of the ink that can be ejected by the ink jet recording apparatus.

  The volume average particle diameter (abbreviated as “average particle diameter”) of the polymer fine particles of the present invention is preferably pH 8.5 or more and 10 to 300 nm. If the average particle size is less than 10 nm, the viscosity of the polymer fine particles themselves becomes too high, and it becomes difficult to obtain the viscosity of ink that can be ejected by the ink jet recording apparatus. When the average particle diameter exceeds 300 nm, particles may be clogged in the nozzle of the ink jet recording apparatus, resulting in ejection failure. The average particle diameter here is measured by a dynamic light scattering method (for example, manufactured by Malvern: Zetasizer Nano ZS), and means a 50% average particle diameter (D50).

<Wetting agent>
The wetting agent used in the present invention is necessary for improving ejection stability by providing a moisturizing effect in the ink composition. The content is preferably 10 to 50% by mass with respect to the total amount of ink. If the content is less than 10% by mass, the ink easily evaporates, and thickened ink may be clogged due to evaporation of the ink in the ink supply system in the inkjet recording apparatus. If the content is more than 50% by mass, clogging of thickened ink is less likely to occur in the ink jet recording apparatus, but it is necessary to reduce the amount of solids such as pigments and resins in order to make the ink have a desired viscosity. In this case, the image density of the recorded matter may be lowered.
In the ink of the present invention, at least two kinds of polyhydric alcohols having an equilibrium water content in an environment of a temperature of 23 ° C. and a relative humidity of 80 are 40% by mass or more, for example, a wetting agent having a high boiling point and viscosity as described below. It is preferable to contain A and a wetting agent B having a relatively low boiling point and viscosity.

Examples of the wetting agent A having a boiling point exceeding 250 ° C. at normal pressure in the polyhydric alcohol include 1,2,3-butanetriol, 1,2,4-butanetriol (bp190-191 ° C./24 hPa), glycerin. (bp 290 ° C.), diglycerin (bp 270 ° C./20 hPa), triethylene glycol (bp 285 ° C.), tetraethylene glycol (bp 324-330 ° C.) and the like. On the other hand, examples of the wetting agent B having a boiling point of 140 to 250 ° C. include diethylene glycol (bp 245 ° C.) and 1,3-butanediol (bp 203-204 ° C.). These wetting agent A and wetting agent B are hygroscopic materials having an equilibrium water content of 40% by mass or more in an environment of a temperature of 23 ° C. and a relative humidity of 80%. Evaporation is relatively high. When the combination of the wetting agent A and the wetting agent B is used, the amount ratio [B] / [A] (mass ratio) between the wetting agent A and the wetting agent B is the amount of the remaining wetting agent C and the penetrant. Since it depends on the type and amount of other additives and the like, it cannot be generally stated, but, for example, a range of 10/90 to 90/10 is preferable.
The equilibrium moisture content in the present invention is a petri dish in which a saturated aqueous potassium chloride solution is used and the temperature and humidity in the desiccator is maintained at 23 ± 1 ° C. and relative humidity 80 ± 3%, and 1 g of each water-soluble organic solvent is weighed in the desiccator. Is stored, and the amount of saturated water is determined.
Saturated water content (%) = (water content absorbed in organic solvent / organic solvent) × 100

  In addition to the above-mentioned wetting agent A and wetting agent B, the recording ink of the present invention may be used in place of or in addition to the wetting agent A and wetting agent B as necessary. The remaining wetting agent C can be used in combination. Examples of the wetting agent C include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, Examples thereof include ethylene carbonate and other wetting agents.

  Examples of the polyhydric alcohols include dipropylene glycol (bp 232 ° C.), 1,5-pentanediol (bp 242 ° C.), 3-methyl-1,3-butane diol (bp 203 ° C.), propylene glycol (bp 187 ° C.) 2-methyl-2,4-pentanediol (bp197 ° C), ethylene glycol (bp196-198 ° C), tripropylene glycol (bp267 ° C), hexylene glycol (bp197 ° C), polyethylene glycol (viscous liquid to solid) , Polypropylene glycol (bp 187 ° C), 1,6-hexanediol (bp253-260 ° C), 1,2,6-hexanetriol (bp 178 ° C), trimethylolethane (solid, mp199-201 ° C), trimethylolpropane ( Solid, mp 61 ° C.).

  Examples of the polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether (bp 135 ° C.), ethylene glycol monobutyl ether (bp 171 ° C.), diethylene glycol monomethyl ether (bp 194 ° C.), diethylene glycol monobutyl ether (bp 231 ° C.), ethylene glycol mono -2-ethylhexyl ether (bp 229 ° C.), propylene glycol monoethyl ether (bp 132 ° C.), and the like.

Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether (bp 237 ° C.) and ethylene glycol monobenzyl ether.
Examples of the nitrogen-containing heterocyclic compound include N-methyl-2-pyrrolidone (bp 202 ° C.), 1,3-dimethyl-2-imidazolidinone (bp 226 ° C.), ε-caprolactam (bp 270 ° C.), γ-butyrolactone. (bp204-205 ° C).

  Examples of the amides include formamide (bp 210 ° C), N-methylformamide (bp199-201 ° C), N, N-dimethylformamide (bp153 ° C), N, N-diethylformamide (bp176-177 ° C) and the like. Can be mentioned.

  Examples of the amines include monoethanolamine (bp 170 ° C), diethanolamine (bp268 ° C), triethanolamine (bp360 ° C), N, N-dimethylmonoethanolamine (139 ° C), N-methyldiethanolamine (bp243 ° C). ), N-methylethanolamine (bp 159 ° C), N-phenylethanolamine (bp282-287 ° C), 3-aminopropyldiethylamine (bp169 ° C), and the like.

  Examples of the sulfur-containing compounds include dimethyl sulfoxide (bp 139 ° C.), sulfolane (bp 285 ° C.), thiodiglycol (bp 282 ° C.), and the like.

Other solid wetting agents are preferably sugars. Examples of the saccharide include monosaccharide, disaccharide, oligosaccharide (including trisaccharide and tetrasaccharide), polysaccharide and the like. Specifically, glucose, mannose, fructose, ribose, xylose, arabinose, galactose, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose and the like can be mentioned. Here, the polysaccharide means a saccharide in a broad sense and is used to include substances widely existing 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) nCH 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 preferred, and specific examples include maltitol, sorbit and the like.

<Colorant>
A pigment is used as the colorant in the present invention. There is no limitation in particular as a pigment, According to the objective, it can select suitably, Any of an inorganic pigment and an organic pigment may be sufficient. Moreover, these pigments may be used individually by 1 type, and may mix and use multiple types. For example, the following pigments are preferably used.
Examples of organic pigments include azo, phthalocyanine, anthraquinone, quinacridone, dioxazine, indigo, thioindigo, perylene, isoindolenone, aniline black, azomethine, rhodamine B lake pigment, and carbon black. It is done.
Examples of inorganic pigments include iron oxide, titanium oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, bitumen, cadmium red, chrome yellow, and metal powder.

The carbon black used in the black pigment ink is carbon black produced by the furnace method and the channel method, the primary particle size is 15 to 40 millimicrons, the specific surface area by the BET method is 50 to 300 m ² / g, The DBP oil absorption is preferably 40 to 150 ml / 100 g, the volatile content is 0.5 to 10%, and the pH value is 2 to 9.

  A commercially available product can be used as the carbon black. Examples of commercially available products include No. 2300, no. 900, MCF-88, no. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, no. 2200B (above, manufactured by Mitsubishi Chemical Corporation), Raven700, 5750, 5250, 5000, 3500, 1255 (above, manufactured by Columbia), Regal400R, 330R, 660R, MoguL, Monarch700, 800, 880, 900, 1000, 1100, 1300 , Monarch 1400 (manufactured by Cabot Corporation), Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex 35, U, V, 140U, 140V, Special Black 6, 5, 4A, 4 ( As mentioned above, although Degussa Co., Ltd.) etc. are mentioned, it is not limited to these.

Specific examples of color pigments are listed below.
Examples of pigments that can be used for yellow ink include C.I. I. Pigment Yellow 1 (Fast Yellow G), 2, 3, 12 (Disazo Yellow AAA), 13, 14, 16, 17, 20, 23, 24, 34, 35, 37, 42 (Yellow Iron Oxide), 53, 55 73, 74, 75, 81, 83 (disazo yellow HR), 86, 93, 95, 97, 98, 100, 101, 104, 108, 109, 110, 114, 117, 120, 125, 128, 129, 137, 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 180, 185, and the like, but are not limited thereto.

  Examples of pigments that can be used in magenta ink include C.I. I. Pigment Red 1, 2, 3, 5, 7, 9, 12, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48: 1 (Permanent Red 2B (Ba)), 48: 2 (Permanent Red 2B) (Ca)), 48: 3 (permanent red 2B (Sr)), 48: 4 (permanent red 2B (Mn)), 49: 1, 52: 2, 53: 1, 57: 1 (brilliant carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81 (Rhodamine 6G rake), 83, 88, 92, 97, 101 (Bengara), 104, 105, 106, 108 (Cadmium red), 112, 114, 122 (dimethylquinacridone), 123, 146, 149, 166, 168, 170, 172, 175, 176, 178, 179, 180 184, 185, 190, 192, 193, 202, 209, 215, 216, 217, 219, 220, 223, 226, 227, 228, 238, 240, 254, 255, 272, etc. It is not something that can be done.

  Examples of pigments that can be used for cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15 (copper phthalocyanine blue R), 15: 1, 15: 2, 15: 3 (phthalocyanine blue G), 15: 4, 15: 6 (phthalocyanine blue E), 16, 17: 1, 2, 56, 60, 63, 64, bat blue 4, bat blue 60, and the like, but are not limited thereto.

  For neutral colors, red, green and blue are C.I. I. Pigment red 177, 194, 224, C.I. I. Pigment orange 16, 36, 43, 51, 55, 59, 61, 71, C.I. I. Pigment violet 3, 19, 23, 29, 30, 37, 40, 50, C.I. I. Pigment green 7, 36, and the like.

There is no restriction | limiting in particular in the average particle diameter of the said pigment, According to the objective, it can select suitably, 10 nm-150 nm are preferable, 20 nm-100 nm are more preferable, 30 nm-80 nm are still more preferable. When the average particle diameter exceeds 150 nm, not only the saturation of the printed image is lowered, but also thickening aggregation during ink storage and clogging of the nozzle during printing are likely to occur. On the other hand, when the average particle size of the pigment is less than 10 nm, not only the light resistance is lowered but also the storage stability tends to be deteriorated.
The average particle diameter of the pigment is, for example, a sample diluted with pure water so that the pigment concentration (mass concentration) in the measurement sample is 0.01% by mass using Microtrac UPA-150 manufactured by Nikkiso Co., Ltd. Used, particle refractive index 1.51, particle density 1.4 g / cm ³ , solvent parameter means 50% average particle diameter (D50) measured at 23 ° C. using parameters of pure water.

[Resin coated pigment]
As the pigment used in the present invention, a resin-coated pigment can also be used. The resin-coated pigment can be provided with dispersibility by being coated with a resin having a hydrophilic group and encapsulated.
As a method for coating a water-insoluble pigment with an organic polymer and microencapsulating, all conventionally known methods can be used. Conventionally known methods include chemical production methods, physical production methods, physicochemical methods, mechanical production methods, and the like. Specifically, there are the following methods.
(A) Interfacial polymerization method (a method in which two kinds of monomers or two kinds of reactants are separately dissolved in a dispersed phase and a continuous phase, and both substances are reacted at the interface between them to form a wall film)
(B) In-situ polymerization method (a method in which a liquid or gaseous monomer and catalyst, or two reactive substances are supplied from either one of the continuous phase core particles to cause a reaction to form a wall film)
(C) In-liquid cured coating method (a method of forming a wall film by insolubilizing droplets of a polymer solution containing core material particles in a liquid with a curing agent)
(D) Coacervation (phase separation) method (a method in which a polymer dispersion in which core material particles are dispersed is separated into a coacervate (concentrated phase) and a dilute phase having a high polymer concentration to form a wall film) (E) In-liquid drying method (preparing a liquid in which a core material is dispersed in a solution of a wall membrane material, placing the dispersion in a liquid in which the continuous phase of this dispersion is not miscible to form a composite emulsion, Method of forming a wall film by gradually removing the dissolved medium)
(F) Melt-dispersed cooling method (using a wall film material that melts into a liquid state and solidifies at room temperature when heated, this material is heated and liquefied, core material particles are dispersed therein, and are cooled to fine particles. A method of forming a wall film)
(G) Air suspension coating method (powder core material particles are suspended in the air by a fluidized bed, and the wall membrane material coating solution is sprayed and mixed while suspended in an air stream to form a wall membrane. Method)
(H) Spray drying method (a method of spraying the encapsulated stock solution and bringing it into contact with hot air to evaporate and dry the volatile matter to form a wall film)
(I) Acid precipitation method (by neutralizing at least part of the anionic group of the organic polymer compound containing an anionic group with a basic compound to provide solubility in water in an aqueous medium together with a coloring material) After kneading, neutralize or acidify with an acidic compound, deposit organic compounds and fix them on the colorant, then neutralize and disperse)
(J) Phase inversion emulsification method (a mixture containing an anionic organic polymer having dispersibility in water and a colorant is used as an organic solvent phase, and water is added to the organic solvent phase, or water And the like).

  Examples of organic polymers (resins) used as the material constituting the microcapsule wall membrane material include polyamide, polyurethane, polyester, polyurea, epoxy resin, polycarbonate, urea resin, melamine resin, phenol resin, and polysaccharide. , Gelatin, gum arabic, dextran, casein, protein, natural rubber, carboxypolymethylene, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, cellulose, ethyl cellulose, methyl cellulose, nitrocellulose, hydroxyethyl cellulose, acetic acid Cellulose, polyethylene, polystyrene, (meth) acrylic acid polymer or copolymer, (meth) acrylic acid ester polymer or copolymer, (meth) acrylic acid (Meth) acrylic acid ester copolymer, styrene- (meth) acrylic acid copolymer, styrene-maleic acid copolymer, sodium alginate, fatty acid, paraffin, beeswax, water wax, hardened beef tallow, carnauba wax, albumin, etc. .

  Among these, organic polymers having an anionic group such as a carboxylic acid group or a sulfonic acid group can be used. Nonionic organic polymers include, for example, polyvinyl alcohol, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, methoxypolyethylene glycol monomethacrylate or their (co) polymers, and 2-oxazoline cationic ring-opening polymers. Is mentioned. In particular, a completely saponified product of polyvinyl alcohol is particularly preferable because it has low water solubility and is easily dissolved in hot water but difficult to dissolve in cold water.

  The amount of the organic polymer constituting the wall film material of the microcapsule is 10% by mass or more and 90% by mass or less with respect to the water-insoluble colorant such as an organic pigment or carbon black. By setting the amount of the organic polymer within the above range, the content of the organic polymer in the capsule is relatively low so that the pigment develops due to the organic polymer covering the pigment surface. Can be suppressed. When the amount of the organic polymer is less than 10% by mass, it becomes difficult to exert the effect of encapsulation. Conversely, when the amount exceeds 90% by mass, the color developability of the pigment is significantly reduced. In consideration of other characteristics, the amount of the organic polymer is preferably in the range of 20 to 70% by mass with respect to the water-insoluble colorant.

  That is, since a part of the color material is exposed without being substantially covered, it is possible to suppress a decrease in color developability, and conversely, a part of the color material is not substantially exposed without being exposed. Since it is coated, it is possible to simultaneously exhibit the effect that the pigment is coated. The number average molecular weight of the organic polymers used in the present invention is preferably 2000 or more from the viewpoint of capsule production. Here, “substantially exposed” means not the partial exposure associated with defects such as pinholes and cracks, but a state where it is intentionally exposed.

  Furthermore, if an organic pigment or self-dispersing carbon black, which is a self-dispersing pigment, is used as a colorant, the dispersibility of the pigment is improved even if the content of the organic polymer in the capsule is relatively low. In addition, since sufficient storage stability of the ink can be secured, it is more preferable for the present invention.

  It is preferable to select an organic polymer suitable for the microencapsulation method. For example, in the case of interfacial polymerization, polyester, polyamide, polyurethane, polyvinyl pyrrolidone, epoxy resin and the like are suitable. In the case of using the in-situ polymerization method, a polymer or copolymer of (meth) acrylic acid ester, (meth) acrylic acid- (meth) acrylic acid ester copolymer, styrene- (meth) acrylic acid copolymer, Polyvinyl chloride, polyvinylidene chloride, polyamide and the like are suitable. In the case of the liquid curing method, sodium alginate, polyvinyl alcohol, gelatin, albumin, epoxy resin and the like are suitable. In the case of the coacervation method, gelatin, celluloses, casein and the like are suitable. In addition, in order to obtain a fine and uniform microencapsulated pigment, it is possible to use all conventionally known encapsulation methods other than those described above.

  When the phase inversion method or the acid precipitation method is selected as the microencapsulation method, anionic organic polymers are used as the organic polymers constituting the wall membrane material of the microcapsules. The phase inversion method is a combination of an anionic organic polymer having self-dispersibility or solubility in water and a composite or composite of carbon black, or carbon black, a curing agent, and an anionic organic polymer. In this method, the mixture is used as an organic solvent phase, and water is added to the organic solvent phase, or the organic solvent phase is added to water and microencapsulated while self-dispersing (phase inversion emulsification). Here, the carbon black includes self-dispersing carbon black. In the above phase inversion method, there is no problem even if the organic solvent phase is mixed with a recording liquid vehicle or additives. In particular, it is more preferable to mix a liquid medium of a recording liquid because a dispersion liquid for recording liquid can be directly produced.

  On the other hand, in the acid precipitation method, a part or all of the anionic group of the anionic group-containing organic polymer is neutralized with a basic compound, and is kneaded with a coloring material such as carbon black in an aqueous medium and acidic. A water-containing cake obtained by a process comprising a step of precipitating an anionic group-containing organic polymer by neutralizing or acidifying with a compound and adhering it to a pigment is obtained by using a basic compound to form an anionic group. This is a method of microencapsulation by neutralizing a part or all of it. By doing in this way, the aqueous dispersion containing the anionic microencapsulated pigment which is fine and contains many pigments can be manufactured.

  Examples of the solvent used for microencapsulation as described above include alkyl alcohols such as methanol, ethanol, propanol and butanol; aromatic hydrocarbons such as benzol, toluol and xylol; methyl acetate Esters such as ethyl acetate and butyl acetate; Chlorinated hydrocarbons such as chloroform and ethylene dichloride; Ketones such as acetone and methyl isobutyl ketone; Ethers such as tetrahydrofuran and dioxane; Cellosolves such as methyl cellosolve and butyl cellosolve Etc. The microcapsules prepared by the above method are once separated from these solvents by centrifugation or filtration, and then stirred and redispersed with water and the necessary solvent, and used for the intended present invention. A recording liquid that can be used is obtained. The average particle diameter of the encapsulated pigment obtained by the above method is preferably 50 nm to 180 nm.

<Other ingredients>
There is no restriction | limiting in particular as another component used for the composition of the ink for inkjet recording of this invention, It can select suitably as needed. Examples of other components include dispersants, penetrants, water-dispersible resins, and other additives (such as antifoaming agents, pH adjusters, antiseptic / antifungal agents, rust preventives, antioxidants, and UV absorbers). Is mentioned.

(Dispersant)
The carbon black and color pigment used as the colorant can be used as an inkjet recording liquid by dispersing them in an aqueous medium using a surfactant. As a surfactant for dispersing such a pigment, a normal water-soluble resin or a water-soluble surfactant can be used. Specific examples of the water-soluble surfactant that can be used as a dispersant in the present invention are generally classified into nonionic, anionic and amphoteric, and are appropriately selected and used according to the pigment type or ink formulation.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene myristyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and polyoxyethylene. Polyoxyethylene alkyl phenyl ethers such as octyl phenyl ether and polyoxyethylene nonyl phenyl ether, polyoxyethylene-α-naphthyl ether, polyoxyethylene-β-naphthyl ether, polyoxyethylene monostyryl phenyl ether, polyoxyethylene distyryl Phenyl ether, polyoxyethylene alkyl naphthyl ether, polyoxyethylene monostyryl naphthyl ether, polyoxy And ciethylene distyryl naphthyl ether. In addition, surfactants such as polyoxyethylene polyoxypropylene block copolymers in which a part of polyoxyethylene of these surfactants is replaced with polyoxypropylene, and aromatic rings such as polyoxyethylene alkylphenyl ether A surfactant obtained by condensing a compound with formalin or the like can also be used.
The nonionic surfactant has an HLB of preferably 12 to 19.5, more preferably 13 to 19. If the HLB is less than 12, there is a tendency for the dispersion stability to deteriorate due to poor conformity of the surfactant to the dispersion medium. If the HLB exceeds 19.5, the surfactant becomes difficult to adsorb to the pigment, so that the dispersion stability is also reduced. There is a tendency to deteriorate.

  Examples of the anionic surfactant include polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene monostyryl phenyl ether sulfate, polyoxyethylene distyryl phenyl ether sulfate, and polyoxyethylene. Alkyl ether phosphate, polyoxyethylene alkyl phenyl ether phosphate, polyoxyethylene monostyryl phenyl ether phosphate, polyoxyethylene distyryl phenyl ether phosphate, polyoxyethylene alkyl ether carboxylate, polyoxyethylene Alkylphenyl ether carboxylate, polyoxyethylene monostyryl phenyl ether carboxylate, polyoxyethylene distyryl phenyl ether carboxylate, Talensulfonate formalin condensate, melanin sulfonate formalin condensate, dialkylsulfosuccinate ester salt, sulfosuccinate alkyl disalt, polyoxyethylene alkylsulfosuccinate disalt, alkylsulfoacetate, α-olefin sulfonate, alkylbenzene Examples include sulfonates, alkylnaphthalene sulfonates, alkyl sulfonates, N-acyl amino acid salts, acylated peptides, soaps, and the like.

(Penetration agent)
By adding a penetrant to the ink, the surface tension is reduced, and the penetration of the ink droplets onto the recording medium such as paper increases after the ink droplets have landed, thereby reducing feathering and color bleeding. it can. Surfactants are mainly used as penetrants, and are classified into nonionic, anionic and amphoteric depending on the polarity of the hydrophilic group. Further, it is classified into fluorine type, silicone type, acetylene type, etc. according to the structure of the hydrophobic group. The range of the appropriate surface tension of the penetrant in the present invention is 20 to 35 mN / m.

Nonionic surfactants include, for example, polyols, glycol ethers, polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylphenyl ethers, Examples include polyoxyethylene alkylamine, polyoxyethylene alkylamide, acetylene glycol and the like.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate, and the like.

  Fluorosurfactants include perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkyl phosphates, perfluoroalkyl ethylene oxide adducts, perfluoroalkyl betaines, perfluoroalkylamine oxide compounds, etc. Can be mentioned. Generally speaking, commercially available fluorine compounds include Surflon S-111, S-112, S-113, S121, S131, S132, S-141, S-144, S-145 (manufactured by Asahi Glass Co., Ltd.), Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431, FC-4430 (manufactured by Sumitomo 3M), MegaFuck F-470, F -1405, F474 (manufactured by DIC), Zonyl FS-300, FSN, FSN-100, FSO, FSO-100 (manufactured by DuPont), F-top EF-351, 352, 801, 802 (manufactured by Gemco), FT -250, 251 (manufactured by Neos), PF-151N, PF-136A, PF-156A (manufactured by OMNOVA), and the like. Among these, FSO, FSO-100, FSN, FSN-100, and FS-300 manufactured by Dupont are preferable because they can provide good print quality and storage stability.

  Examples of the silicone surfactant include polyether-modified silicone compounds. Polyether-modified silicone compounds are side-chain type (pendant type) with a polyether group introduced into the side chain of polysiloxy acid, one-end type with a polyether group introduced into one end of polysiloxane, and both-end type introduced into both ends (ABA type), polysiloxane side-chain end-type with polysiloxane introduced on both side chain and both ends, polysiloxane (A) with polyether group introduced and unintroduced polysiloxane (B) repeated It can be classified into a bonded ABn type, a branched type in which a polyether group is introduced at the end of a branched polysiloxane, and the like. Although there is no particular limitation in the present invention, a side chain type (pendant type) having a structure in which a polyether group is introduced into the side chain of polysiloxane is preferred.

  As commercially available products, KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-618, KF-6011, KF-6015, KF- 6004 (manufactured by Shin-Etsu Chemical Co., Ltd.), SF-3771, SF-8427, SF-8428, SH-3749, SH-8400, FZ-2101, FZ-2104, FZ-2118, FZ-2203, FZ-2207, L -7604 (manufactured by Dow Corning Toray), BYK-345, BYK-346, BYK-348 (manufactured by Big Chemie Japan), and the like.

  As acetylene glycol surfactants, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5 -Acetylene glycol type | system | groups, such as a dimethyl- 1-hexyn-3-ol, etc. are mentioned. For example, Surfynol 104, 82, 465, 485, TG (manufactured by Air Products) can be used.

When the surfactant is added to the ink as a penetrating agent, the addition amount is preferably 0.05 to 5% by mass, more preferably 0.1 to 3% by mass.
In the ink of the present invention, two or more surfactants may be used in combination. In order to improve the permeability, a polyol having 8 to 11 carbon atoms such as 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol may be used in combination.

  Specific examples of water-soluble resins include styrene, styrene derivatives, vinyl naphthalene derivatives, aliphatic alcohol esters of α, β-ethylenically unsaturated carboxylic acids, acrylic acid, acrylic acid derivatives, maleic acid, maleic acid derivatives, itacon. Examples thereof include block copolymers consisting of at least two monomers selected from acids, itaconic acid derivatives, fumaric acid, fumaric acid derivatives, etc., random copolymers, or salts thereof. These water-soluble resins are alkali-soluble resins that are soluble in an aqueous solution in which a base is dissolved. Among these, a resin having a mass average molecular weight of 3000 to 20000 is used as a dispersion when used in an inkjet recording liquid. It is particularly preferred because of the advantages that it can be reduced in viscosity and can be easily dispersed.

(Water dispersible resin)
In the present invention, each color ink may contain a water-dispersible resin (resin emulsion) as necessary. Addition of water-dispersible resin is excellent in film-forming property (image forming property), and has high water repellency, high water resistance, and high weather resistance for high water resistance and high image density (high color development) image recording. Useful. Specific examples of the water-dispersible resin include condensation-type synthetic resins, addition-type synthetic resins, natural polymer compounds, and the like.
Examples of the condensed synthetic resin include polyester resin, polyurethane resin, polyepoxy resin, polyamide resin, polyether resin, poly (meth) acrylic resin, acrylic-silicone resin, and fluorine-based resin.
Examples of the addition type synthetic resin include polyolefin resins, polystyrene resins, polyvinyl alcohol resins, polyvinyl ester resins, polyacrylic acid resins, unsaturated carboxylic acid resins, and the like.
Examples of the natural polymer compound include celluloses, rosins, and natural rubber.
Among these, polyurethane resin fine particles, acrylic-silicone resin fine particles, and fluorine-based resin fine particles are particularly preferable.

(Other additives)
Each color ink may further contain an antifoaming agent, a pH adjuster, an antiseptic / antifungal agent, a rust inhibitor, an antioxidant, an ultraviolet absorber, and the like as necessary.

[Defoamer]
Although it does not specifically limit as an antifoamer, A silicone type antifoamer, a polyether type | system | group antifoamer, a fatty-acid ester type | system | group antifoamer etc. are mentioned, You may use 2 or more types together. Among these, a silicone-based antifoaming agent is preferable because it has an excellent foam breaking effect.

[PH adjuster]
The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 or more, but is not limited to amines such as diethanolamine and triethanolamine, and alkali metal such as lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of the hydroxide include alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate; ammonium hydroxide, quaternary ammonium hydroxide, and quaternary phosphonium hydroxide.

[Antiseptic and antifungal agent]
The antiseptic / antifungal agent is not particularly limited, but 1,2-benzisothiazolin-3-one, sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, sodium pentachlorophenol, etc. Is mentioned.

[Rust preventive]
The rust inhibitor is not particularly limited, and examples thereof include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

〔Antioxidant〕
The antioxidant is not particularly limited, and examples thereof include phenolic antioxidants (including hindered phenolic antioxidants), amine antioxidants, sulfur antioxidants, phosphorus antioxidants, and the like. .

[Ultraviolet absorber]
The ultraviolet absorber is not particularly limited, and examples thereof include oxybenzone, phenyl salicylate, and paraaminobenzoic acid ester.

[Physical properties of ink]
There is no restriction | limiting in particular as a physical property of the liquid composition of this invention, According to the objective, it can select suitably, For example, it is preferable that surface tension, pH, etc. are the following ranges.
The surface tension is preferably 20 mN / m to 40 mN / m at 25 ° C. If the surface tension is less than 20 mN / m, bleeding on the recording medium becomes remarkable and stable jetting may not be obtained. If the surface tension exceeds 40 mN / m, ink penetration into the recording medium is sufficient. However, the drying time may be prolonged. As said pH, 7-10 are preferable, for example.

<Inkjet recording apparatus and inkjet recording method>
The ink jet recording apparatus of the present invention is characterized by having ink ejecting means for recording an image on a recording medium by ejecting the ink for ink jet recording of the present invention from a recording head. That is, the ink jet recording apparatus of the present invention includes at least a recording head and a maintenance / recovery device, and further includes other means such as a stimulus generating means and a control means as necessary.
The ink jet recording method of the present invention includes at least an ink flying process of applying a stimulus to the ink jet recording ink of the present invention via an ink flying means and causing the ink to fly from a recording head to record an image on a recording medium. It is characterized by this. That is, the ink jet recording method of the present invention includes at least an ink flying process and further includes other processes appropriately selected as necessary, for example, a stimulus generation process, a control process, and the like.
Hereinafter, the details of the ink jet recording method of the present invention will be described through the description of the ink jet recording apparatus of the present invention.

The ink jet recording apparatus records an image by applying a stimulus to each ink of the present invention via an ink flying means and ejecting the ink from the nozzle of the recording head. 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, and a light. For example, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, a shape memory alloy actuator that uses a metal phase change caused by a temperature change, an electrostatic force Examples include electrostatic actuators to be used.

There are no particular restrictions on the manner in which the recording ink flies, and it varies depending on the type of the stimulus. For example, when the stimulus is “heat”, a recording signal is output to the recording ink in the recording head. Corresponding thermal energy is applied using, for example, a thermal head, bubbles are generated in the recording ink by the thermal energy, and the recording ink is formed into droplets from the nozzle holes of the recording head by the pressure of the bubbles. For example, a discharge injection method may be used. 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 the recording ink is ejected and ejected as droplets from the nozzle holes of the recording head.
The size of the recording ink droplets to be ejected is preferably 3 to 40 pl, for example, and the ejection jet speed is preferably 5 to 20 m / s, and the driving thereof. The frequency is preferably 1 kHz or more, and the resolution is preferably 300 dpi or more.

  The recording head preferably includes a number of nozzles, and has either a head unit or a recording unit that discharges ink in the ink set into ink droplets by the action of energy. Further, the recording head includes a liquid chamber portion, a fluid resistance portion, a diaphragm, and a nozzle member, and at least a part of the recording head is made of a material containing any one of silicone and nickel. Preferably it is formed. The nozzle diameter of the recording head is preferably 30 μm or less, and more preferably 1 to 20 μm.

  The ink jet recording apparatus of the present invention preferably has a sub tank for supplying ink onto the recording head, and the sub tank is replenished with ink from an ink cartridge through a supply tube.

  The maintenance recovery device covers at least one suction cover means (suction cap) that covers the recording head and communicates with the suction force generation means, and at least one suction cover means that covers the recording head and does not communicate with the suction force generation means Non-suction cover means (moisturizing cap) is provided, and other means are provided as necessary. Thus, by providing the suction cap and the moisture retention cap, the amount of ink consumed for the maintenance operation for ensuring reliability is less than the configuration in which all caps are suction caps, and the time required for the maintenance operation, Ink waste can be prevented. The maintenance / recovery device is not particularly limited and may be appropriately selected depending on the intended purpose. For example, those described in JP-A-2005-170035 may be used.

The ink jet recording apparatus of the present invention preferably has a reversing unit that can perform double-sided printing by reversing the recording surface of the recording medium. Examples of the reversing means include a conveyance belt having electrostatic force, a means for holding a recording medium by air suction, and a combination of a conveyance roller and a spur. It is preferable to have an endless conveying belt and conveying means for conveying the surface of the conveying belt while charging and holding the recording medium. In this case, it is particularly preferable to charge the conveying belt by applying an AC bias of ± 1.2 kV to ± 2.6 kV to the charging roller.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as sequencers and computers.

Here, FIG. 2 and FIG. 3 are schematic plan views as seen from the nozzle surface showing an example of a recording head provided in the ink jet recording apparatus of the present invention. FIG. 2 shows a two-head type composed of a first head and a second head. FIG. 3 shows a four-head type including a first head, a second head, a third head, and a fourth head.
In the two-head type, either the first head or the second head is covered with a suction cover means (suction cap) communicating with the suction force generation means, and the other is not suctioned with no communication with the suction force generation means It is covered with a covering means (moisturizing cap). In the example of FIG. 2, the first head is covered with a suction cap, and the second head is covered with a moisture retention cap.
In the four-head type shown in FIG. 3, at least one of the first to fourth heads is covered with a suction cover means (suction cap) that communicates with the suction force generation means, and the other heads communicate with the suction force generation means. It is covered with non-suction cover means (moisturizing cap) that is not. In the example of FIG. 3, the first head is covered with a suction cap, and the second, third, and fourth heads are covered with a moisture retention cap.
In the two-head type shown in FIG. 2, when full-color printing is performed, yellow (Y), cyan (C), magenta (M), and black (Bk) inks are applied to a total of four nozzle rows. Each needs to be filled.

Here, an example of the ink jet recording apparatus of the present invention having the maintenance / recovery apparatus will be described with reference to FIG. FIG. 4 is an explanatory perspective view of the ink jet recording apparatus as viewed from the front side.
The ink jet recording apparatus shown in FIG. 4 includes an apparatus main body 1, a paper feed tray 2 for loading paper mounted on the apparatus main body 1, and a sheet (recording medium) mounted on the apparatus main body 1 on which an image is recorded (formed). ) And a cartridge loading portion 6 that protrudes forward from the front surface 4 and is lower than the upper surface 5 on one end side of the front surface 4 of the apparatus main body 1. An operation unit 7 such as an operation key or a display is arranged on the upper surface of the cartridge loading unit 6. A main tank (hereinafter referred to as “ink cartridge”) 10 that is a liquid storage tank as a liquid replenishing unit is replaceably mounted on the cartridge loading unit 6, and has a front cover 8 that can be opened and closed. .
Here, the ink cartridge is formed by containing the ink for ink jet recording of the present invention in a container, and may further comprise other members appropriately selected as necessary. The shape, structure, size, and material of the container are not particularly limited and can be appropriately selected according to the purpose. Preferred examples include those having at least an ink bag formed of an aluminum laminate film, a resin film, or the like.
For example, the ink cartridge is filled in an ink bag from an ink injection port (not shown) and exhausted, and then the ink injection port is closed by fusion. In use, the needle of the apparatus main body is pierced into an ink discharge port made of a rubber member and supplied to the apparatus. The ink bag is formed of a packaging member such as a non-permeable aluminum laminate film. The ink bag is usually housed in a plastic cartridge case and is detachably mounted on various ink jet recording apparatuses.

Next, the mechanism part of the ink jet recording apparatus of FIG. 4 will be described with reference to FIGS. FIG. 5 is a schematic configuration diagram for explaining the overall configuration of the mechanism unit, and FIG.
A carriage 33 is slidably held in the main scanning direction by a guide rod 31 and a stay 32 that are horizontally mounted on the left and right side plates 21A and 21B constituting the frame 21, and a main scanning motor (not shown) in FIG. It moves and scans in the carriage scanning direction (main scanning direction).
In the carriage 33, a plurality of recording heads 34, which are ink jet heads that are droplet ejection heads for ejecting ink droplets (ink droplets), are arranged in a direction crossing a plurality of nozzles with the main scanning direction, The ink droplet is ejected in the downward direction.
Here, the recording head 34 includes, for example, a recording head 34y that discharges yellow (Y) droplets, a recording head 34m that discharges magenta (M) droplets, and a recording head that discharges cyan (C) droplets. 34c, and a recording head 34k that discharges black (Bk) droplets. The “recording head 34” does not distinguish between colors. The head configuration is not limited to these examples, and it may be configured using one or a plurality of recording heads having one or a plurality of nozzle rows that eject droplets of one or a plurality of colors. .
The droplet discharge head constituting the recording head 34 includes a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by liquid film boiling using an electrothermal transducer such as a heating resistor, and a metal phase caused by a temperature change. A shape memory alloy actuator using a change, an electrostatic actuator using an electrostatic force, or the like provided as energy generating means for discharging droplets can be used.

Also, the carriage 33 is equipped with sub-tanks 35y, 35m, 35c, and 35k for each color for supplying ink of each color to each recording head 34 (referred to as “sub-tank 35” when colors are not distinguished). Ink is supplied to the sub tank 35 from the ink cartridges 10 of the respective colors (referred to as “ink cartridges 10y, 10m, 10c, 10k” when different colors are distinguished) through the ink supply tubes 37 of the respective colors. I am doing so.
Here, the ink cartridge 10 is accommodated in the cartridge loading unit 6 as shown in FIG. The cartridge loading unit 6 is provided with a supply pump unit 23 for feeding ink in the ink cartridge 10. Further, the ink supply tube 37 from the ink cartridge loading unit 6 to the sub tank 35 is fixed and held by the main body side holder 25 on the rear plate 21C constituting the frame 21 in the middle of rolling. Further, it is fixed on the carriage 33 by the fixing rib 26.
5 and 6, reference numeral 22 denotes a flexible cable, and reference numeral 36 denotes an ink supply tube (sub tank connecting portion).

On the other hand, as a paper feeding unit for feeding the papers 42 stacked on the paper stacking unit (bottom plate) 41 of the paper feed tray 2, a half-moon roller (feeding) that separates and feeds the papers 42 one by one from the paper stacking unit 41. The sheet roller 43 and the sheet feeding roller 43 are opposed to each other, and a separation pad 44 made of a material having a large friction coefficient is provided. The separation pad 44 is urged toward the sheet feeding roller 43 side.
As a transport unit for transporting the paper 42 fed from the paper feed unit on the lower side of the recording head 34, a transport belt 51 for transporting the paper 42 by electrostatic adsorption, and a paper feed unit The counter roller 52 for transporting the paper 42 fed through the guide 45 while sandwiching it between the transport belt 51 and the paper 42 fed substantially vertically upward are changed by approximately 90 ° and copied onto the transport belt 51. A conveying guide 53 for adjusting the pressure and a tip pressing roller 55 urged toward the conveying belt 51 by a pressing member 54. In addition, a charging roller 56 that is a charging unit for charging the surface of the conveyance belt 51 is provided.

Here, the conveyance belt 51 is an endless belt, and is configured to be looped around the conveyance roller 57 and the tension roller 58 in the belt conveyance direction of FIG. The charging roller 56 is disposed so as to contact the surface layer of the conveyor belt 51 and rotate following the rotation of the conveyor belt 51, and applies 2.5N to both ends of the shaft as pressure.
In addition, a guide member 61 is disposed on the back side of the conveyor belt 51 so as to correspond to a printing area by the recording head 54. The upper surface of the guide member 61 protrudes closer to the recording head 34 than the tangent line of the two rollers (the conveyance roller 57 and the tension roller 58) that support the conveyance belt 51. As a result, the conveyance belt 51 is pushed up and guided by the upper surface of the guide member 61 in the printing region, so that highly accurate flatness is maintained.

  Further, as a paper discharge unit for discharging the paper 42 recorded by the recording head 34, a separation claw 71 for separating the paper 42 from the transport belt 51, a paper discharge roller 72, and a paper discharge roller 73 are provided. A paper discharge tray 3 is provided below the paper discharge roller 72. Here, the height from between the paper discharge roller 72 and the paper discharge roller 73 to the paper discharge tray 3 is increased to some extent in order to increase the amount that can be stored in the paper discharge tray 3.

  A double-sided paper feeding unit 81 is detachably attached to the back surface of the apparatus body 1. The double-sided paper feed unit 81 takes in the paper 42 returned by the reverse rotation of the transport belt 51, reverses it, and feeds it again between the counter roller 52 and the transport belt 51. A manual paper feed unit 82 is provided on the upper surface of the duplex paper feed unit 81.

  Further, as shown in FIG. 6, in a non-printing area on one side of the carriage 33 in the scanning direction, a maintenance / recovery device (hereinafter referred to as “sub-system”) for maintaining and recovering the nozzle state of the recording head 34. 91 is also provided. The sub-system 91 includes cap members (hereinafter also referred to as “caps”) 92a to 92d for capping each nozzle surface of the recording head 34 (referred to as “caps 92” when not distinguished). A wiper blade 93 that is a blade member for wiping the nozzle surface, and an empty space that receives a droplet when performing an empty discharge that discharges a droplet that does not contribute to recording in order to discharge the thickened ink. A wiper cleaner 95 (see FIG. 8), which is formed integrally with the discharge receiver 94 and the idle discharge receiver 94 and removes ink adhering to the wiper blade 93, and the wiper blade 93 when the wiper blade 93 is cleaned. A cleaner roller 96 that constitutes a cleaner means to be pressed against the wiper cleaner 95 side is provided. .

In addition, as shown in FIG. 6, in the non-printing area on the other side in the scanning direction of the carriage 33, idle ejection is performed to eject liquid droplets that do not contribute to recording in order to discharge ink that has been thickened during recording or the like. An empty discharge receiver 98 for receiving the droplets is disposed, and the empty discharge receiver 98 is provided with an opening 99 and the like along the nozzle row direction of the recording head 34.
In the ink jet recording apparatus configured as described above, the sheets 42 are separated and fed one by one from the sheet feeding tray 2, and the sheet 42 fed substantially vertically upward is guided by the guide 45, and the transport belt 51 and the counter roller 52, the leading end is guided by the conveying guide 53 and pressed against the conveying belt 51 by the leading end pressing roller 55, and the conveying direction is changed by about 90 °.

  At this time, a positive output and a negative output are alternately repeated from the high voltage power source to the charging roller 56 by a control circuit (not shown), that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 51 alternates, that is, In the sub-scanning direction, which is the circumferential direction, plus and minus are alternately charged in a band shape with a predetermined width. When the sheet 42 is fed onto the conveyance belt 51 charged alternately with plus and minus, the sheet 42 is electrostatically attracted to the conveyance belt 51, and the sheet 42 is moved in the sub-scanning direction by the circular movement of the conveyance belt 51. Be transported. Therefore, by driving the recording head 34 according to the image signal while moving the carriage 33, ink droplets are ejected onto the stopped paper 42 to record one line, and after the paper 42 is conveyed by a predetermined amount, the next Record the line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 42 has reached the recording area, the recording operation is finished and the paper 42 is discharged onto the paper discharge tray 3.

  Further, during printing (recording) standby, the carriage 33 is moved to the subsystem 91 side, the recording head 34 is capped by the cap member 92, and the nozzles are kept in a wet state to prevent ejection failure due to ink drying. . Further, a recovery operation is performed in which ink is sucked from the nozzles (referred to as “nozzle suction” or “head suction”) while the recording head 34 is capped by the cap member 92 and the thickened ink and bubbles are discharged. In addition, an idle ejection operation for ejecting ink not related to recording is performed before the start of recording or during recording. As a result, the stable ejection performance of the recording head 34 is maintained.

  Next, an outline of the configuration of the subsystem 91 including the maintenance / recovery device in the ink jet recording apparatus of the present invention will be described with reference to FIGS. 7 is an explanatory plan view of the main part of the system, FIG. 8 is a schematic schematic diagram of the system, and FIG. 9 is an explanatory diagram on the right side of FIG.

  A frame (maintenance device frame) 111 of the subsystem 91 includes two cap holders 112A and 112B as a cap holding mechanism, a wiper blade 93 as a wiping member including an elastic body as a cleaning means, and a carriage lock 115. Are held up and down (movable up and down). An empty discharge receiver 94 is disposed between the wiper blade 93 and the cap holder 112 </ b> A, and the wiper blade 93 is a cleaning member for the empty discharge receiver 94 from the outside of the frame 111 in order to clean the wiper blade 93. A wiper cleaner 118 that is a cleaner means including a cleaner roller 96 that is a cleaning member to be pressed against the wiper cleaner 95 side is swingably held.

The cap holders 112A and 112B (referred to as “cap holder 112” when not distinguished from each other) hold two caps 92a and 92b and caps 92c and 92d for capping the nozzle surfaces of the two recording heads 34, respectively. .
Here, a tubing pump (suction pump) 120 as a suction means is connected to the cap 92a held by the cap holder 112A closest to the printing area via a flexible tube 119, and the other caps 92b, 92c, 92d does not connect the tubing pump 120. That is, only the cap 92a is used as a suction (recovery) and moisturizing cap (hereinafter also referred to as “suction cap”), and the other caps 92b, 92c, 92d are all used as mere moisturizing caps. Therefore, when performing the recovery operation of the recording head 34, the recording head 34 that performs the recovery operation is selectively moved to a position where it can be capped by the suction cap 92a.

  A cam shaft 121 rotatably supported by the frame 111 is disposed below the cap holders 112A and 112B. Cap cams 122A and 122B for raising and lowering the cap holders 112A and 112B are disposed on the cam shaft 121. A wiper cam 124 for raising and lowering the wiper blade 93, a carriage lock cam 125 for raising and lowering the carriage lock 115 via the carriage lock arm 117, and an empty liquid droplet that is idlely discharged in the idle discharge receiver 94. A roller 126 as a rotating body, which is a discharge landing member, and a cleaner cam 128 for swinging the wiper cleaner 118 are provided.

  Here, the cap 92 is moved up and down by the cap cams 122A and 122B. The wiper blade 93 is moved up and down by the wiper cam 124, and the wiper cleaner 118 is advanced when the wiper blade 124 is lowered. Ink adhering to 93 is scraped off into the empty ejection receiver 94.

The carriage lock 115 is urged upward (in the lock direction) by a compression spring (not shown), and is raised and lowered via a carriage lock arm 117 driven by a carriage lock cam 125.
In order to rotationally drive the tubing pump 120 and the camshaft 121, the motor gear 132 provided on the motor shaft 131a rotates with the motor 131 and the pump gear 133 provided on the pump shaft 120a of the tubing pump 120 is meshed. An intermediate gear 136 with a one-way clutch 137 is engaged with an intermediate gear 134 integral with 133 via an intermediate gear 135, and the intermediate gear 138 coaxial with the intermediate gear 136 is fixed to the camshaft 121 via the intermediate gear 139. The cam gear 140 is engaged. An intermediate shaft 141 that is a rotation shaft of the intermediate gears 136 and 138 with the clutch 137 is rotatably held by the frame 111.

The cam shaft 121 is provided with a home position sensor cam 142 for detecting the home position. When the cap 92 comes to the lowermost end by a home position sensor (not shown) provided in the subsystem 91, a home position lever is provided. (Not shown) is activated, the sensor is opened, and the home position of the motor 131 (other than the pump 120) is detected. Note that when the power is turned on, the position moves up and down (up and down) regardless of the position of the cap 92 (cap holder 112), the position is not detected until the movement starts, and the position is determined after detecting the home position of the cap 92 (on the way up). To the bottom end. Thereafter, the carriage moves left and right, returns to the cap position after position detection, and the recording head 34 is capped.
Reference numeral 142 denotes a home position sensor cam.

Next, details of the holding mechanism and the lifting mechanism (vertical movement mechanism) of the cap 92 will be described with reference to FIG. FIG. 10 is an explanatory side view of the cap holding lifting mechanism.
The cap holder 112A, which is a cap holding mechanism, includes a holder 151 that holds the cap 92a and the cap 92b (sometimes collectively referred to as “cap 92A”) so as to be movable up and down, a bottom surface of the holder 151, and a bottom portion of the cap 92A. And a slider 152 that holds the holder 151 movably in the front-rear direction (the direction in which the nozzles of the recording head 34 are arranged).

The cap 92A is inserted into the guide groove 150 (not shown) of the holder 151 so that the guide pins 150a provided at both ends can be moved up and down, and the guide shaft 150b provided on the bottom surface is inserted into the holder 151 so as to be movable up and down. It is mounted so that it can move up and down. The springs 152, 152 interposed between the cap 92A and the cap holder 151 urge the caps 92a, 92b upward (in the direction of pressing toward the nozzle surface when capping).
The slider 153 is configured such that the guide pins 154 and 155 provided at the front and rear ends are slidably fitted in guide grooves 156 formed in the frame 111 so that the slider 153, the holder 151, and the cap 92A can be moved up and down.

Then, the cam pin 157 provided on the lower surface of the slider 153 is fitted in a cam groove (not shown) of the cap cam 122A, and the slider 153 is rotated by the rotation of the cap cam 122A that is synchronized with the rotation of the cam shaft 121 to which the rotation of the motor 131 is transmitted. The holder 151 and the cap 92A move up and down.
Further, the slider 153 and the holder 151 are inserted into the suction cap 92a, and the tube 119 is wound around and connected from below the center position of the cap in the short direction of the cap 92a.

  Note that the cap holder 112B for holding the caps 92c and 92d (which may be collectively referred to as “cap 92B”) and the configuration for moving the cap holder 112B up and down are the same as described above, and thus the description thereof is omitted. However, the tube 119 is not connected to the caps 92c and 92d. Thus, by driving the motor 131 which is one drive source, the cam shaft 121 which is one shaft rotates, and the cams 122A and 122B fixed to the cam shaft 121 are rotated by the rotation of the cam shaft 121. The cap 92A and the cap 92B move up and down.

  The ink jet recording apparatus and the ink jet recording method of the present invention can be applied to various types of recording by the ink jet recording method, and are particularly suitable for, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, and a printer / fax / copier multifunction machine. Can be applied to.

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

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

<Synthesis example of polymer fine particles>
Below, the synthesis example of the polymer fine particle used for this invention is shown.
In addition, the weight average molecular weight of the polymer in the synthesis example was measured according to the following method.
Shimadzu CTO-20A for the column thermostat, Shimadzu RID-10A for the detector, Shimadzu LC-20AD for the eluent flow path pump, Shimadzu DGU-20A for the degasser, autosampler Was measured by GPC method using SIL-20A manufactured by Shimadzu Corporation. The column used was a Tosoh water-based SEC column TSKgelG3000PWXL (exclusion limit molecular weight 2 × 10 ⁵ ), TSKgelG5000PWXL (exclusion limit molecular weight 2.5 × 10 ⁶ ), and TSKgelG6000PWXL (exclusion limit molecular weight 5 × 10 ⁷ ). The sample was prepared to a concentration of 2 g / 100 ml with an eluent and used for measurement. As an eluent, an aqueous solution adjusted to 0.5 mol / liter each of acetic acid and sodium acetate was used. The column temperature was 40 ° C. and the flow rate was 1.0 ml / min. A calibration curve was determined using nine types of polyethylene glycols having molecular weights of 1065, 5050, 24000, 50000, 107000, 140000, 250,000, 540000, and 920000 as standard samples, and the weight average molecular weight of the polymer was determined based on the calibration curve. .
The particle diameter of the pH-responsive polymer particles according to the present invention was measured by a dynamic light scattering method (Malvern: Zetasizer Nano ZS).
The pH at the time of measuring the particle diameter of the pH-responsive polymer fine particles according to the present invention was adjusted with a 0.2% dispersion with hydrochloric acid or sodium hydroxide.

[Synthesis of pH-responsive polymer fine particle dispersion with VBTMAC polymer chain accumulated on the surface]
(Synthesis Example 1)
(A) Synthesis of VBTMAC polymer In a reaction vessel equipped with a stirrer, reflux condenser, two dropping funnels, a nitrogen gas inlet tube and a thermometer, 463.5 g of water was charged and heated to a temperature of 80 ° C. The temperature rose. Under a nitrogen stream, a mixed solution of 500 g (1.89 mol) of an 80 wt% aqueous solution of vinylbenzyltrimethylammonium chloride (VBTMAC) and 20.3 g (0.22 mol) of mercaptoacetic acid and a 5 wt% aqueous solution of potassium persulfate 16. 2 g (0.003 mol) was added dropwise simultaneously over 2 hours. After completion of dropping, the mixture was kept at 80 ° C. for 3 hours to obtain a VBTMAC polymer solution having a carboxyl group at the end (solid content concentration 41.9% by mass). After completion of the reaction, the VBTMAC polymer was purified by reprecipitation with acetone several times. The obtained polymer had a weight average molecular weight of 14,000 and a number average molecular weight of 7,000 determined by GPC (liquid chromatography).

(B) Introduction of radical polymerizable group to VBTMAC polymer terminal Next, in the reaction vessel equipped with a stirrer, a reflux condenser and a thermometer, the VBTMAC polymer solution (solid content concentration 41.9% by mass). 700.0 g [0.15 mol as a mercaptoacetic acid unit (determined from the previous preparation)] was added, 280.0 g of ethanol was added, 16.7 g (0.20 mol) of a 48 mass% aqueous solution of sodium hydroxide, tetrabutyl 13.0 g (0.04 mol) of ammonium bromide and 30.2 g (0.20 mol) of p-chloromethylstyrene were added and reacted at 30 ° C. for 72 hours to obtain a terminal vinylbenzyl group-containing VBTMAC polymer solution (solid content). A concentration of 32.2% by mass) was obtained. After completion of the reaction, reprecipitation was performed with acetone to purify the terminal vinylbenzyl group-containing VBTMAC polymer. As a result of ¹ H-NMR measurement, it was found that the introduction rate of vinylbenzyl group at the terminal was almost 100%. The number average molecular weight of the polymer containing a terminal vinylbenzyl group VBTMAC measured by GPC (liquid chromatography) was 7,100.

(C) Synthesis of pH-responsive polymer fine particle dispersion in which VBTMAC polymer chains are accumulated on the surface Next, the above-mentioned terminal vinylbenzyl is placed in a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas introduction tube and a thermometer. 338.1 g of group-containing VBTMAC polymer solution [0.43 mol as VBTMAC repeating unit (determined from the previous preparation)], DMAEMA 67.0 g (0.43 mol), styrene 44.4 g (0.43 mol), water 468 .8 g was charged, the pH was adjusted with hydrochloric acid, and the temperature was raised to 60 ° C. Under a nitrogen stream, 81.1 g (0.015 mol) of a 5% by mass aqueous solution of potassium persulfate was added and copolymerized for 6 hours to obtain a milky white dispersion (solid content concentration 24.4% by mass).
The average particle diameter at pH 9 of the pH-responsive polymer fine particles thus obtained was 180 nm, and the average particle diameter at pH 5 was 660 nm.

[Synthesis of pH-responsive polymer fine particle dispersion with VBTBAC polymer chains accumulated on the surface]
(Synthesis Example 2)
(A) Synthesis of VBTBAC polymer In a reaction vessel equipped with a stirrer, reflux condenser, two dropping funnels, a nitrogen gas inlet tube and a thermometer, 463.5 g of water was charged and heated to a temperature of 80 ° C. The temperature rose. In a nitrogen stream, a mixed solution of 438 g (1.89 mol) of an 80% by weight aqueous solution of vinylbenzyltributylammonium chloride (VBTBAC) and 20.3 g (0.22 mol) of mercaptoacetic acid and a 5% by weight aqueous solution of potassium persulfate16. 2 g (0.003 mol) was added dropwise simultaneously over 2 hours. After completion of the dropping, the mixture was kept at 80 ° C. for 3 hours to obtain a VBTBAC polymer solution having a carboxyl group at the terminal (solid content concentration: 37.8% by mass). After completion of the reaction, the VBTEAC polymer was purified by reprecipitation with acetone several times. The obtained polymer had a weight average molecular weight of 12,000 and a number average molecular weight of 5,500 as determined from GPC (liquid chromatography).

(B) Introduction of radical polymerizable group to VBTBAC polymer terminal Next, in the reaction vessel equipped with a stirrer, reflux condenser and thermometer, the above VBTBAC polymer solution (solid content concentration 37.8% by mass) 850.0 g [0.15 mol as a mercaptoacetic acid unit (determined from the previous preparation)] was added, 280.0 g of ethanol was added, 16.7 g (0.20 mol) of a 48% by weight aqueous solution of sodium hydroxide, tetrabutyl Ammonium bromide (13.0 g, 0.04 mol) and p-chloromethylstyrene (30.2 g, 0.20 mol) were added and reacted at 30 ° C. for 72 hours to give a terminal vinylbenzyl group-containing VBTBAC polymer solution (solid content). A concentration of 29.3 mass%) was obtained. After the completion of the reaction, reprecipitation with acetone was performed to purify the terminal vinylbenzyl group-containing VBTBAC polymer. As a result of ¹ H-NMR measurement, it was found that the introduction rate of vinylbenzyl group at the terminal was almost 100%. Further, the number average molecular weight of the polymer containing a terminal vinylbenzyl group VBTBAC measured by GPC (liquid chromatography) was 5,900.

(C) Synthesis of pH-responsive polymer fine particle dispersion in which VBTBAC polymer chains are accumulated on the surface Next, the above-mentioned terminal vinylbenzyl is placed in a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen gas inlet tube and a thermometer. 558.9 g of a group-containing VBTBAC polymer solution [0.43 mol (determined from the previous charge) as a VBTBAC repeating unit], 103.8 g (0.43 mol) of DMABMA, 44.4 g (0.43 mol) of styrene, and water 468 .8 g was charged, the pH was adjusted with hydrochloric acid, and the temperature was raised to 60 ° C. Under a nitrogen stream, 81.1 g (0.015 mol) of a 5% by weight aqueous solution of potassium persulfate was added and copolymerized for 6 hours to obtain a milky white dispersion (solid content concentration 23.9% by weight). The average particle diameter at pH 9 of the obtained pH-responsive polymer fine particles was 155 nm, and the average particle diameter at pH 5 was 590 nm.

(Comparative Synthesis Example 1)
In the synthesis of the pH-responsive polymer fine particle dispersion of Synthesis Example 1, 338.1 g of a terminal vinylbenzyl group-containing VBTMAC polymer solution, 67.0 g (0.43 mol) of DMAEMA (dimethylaminoethyl methacrylate), and 44.styrene. In the same manner as in Synthesis Example 1, 4 g (0.43 mol) and 468.8 g of water were converted into 684.2 g of a VBTMAC polymer solution containing a terminal vinylbenzyl group, 67.9 g (0.65 mol) of styrene, and 319.0 g of water. Reaction was performed to obtain a milky white dispersion (solid content concentration: 22.5% by mass). The average particle size at pH 9 of the obtained pH-responsive polymer fine particles was 120 nm, and the average particle size at pH 5 was 120 nm.

(Comparative Synthesis Example 2)
Similar to Example 1 described in Japanese Patent No. 3155318, gel fine particles obtained by crosslinking dimethylaminomethacrylate with N, N-methylenebisacrylamide were synthesized by the method of Ogura et al. . The average particle size at pH 9 of the synthesized gel fine particles was 150 nm, and the average particle size at pH 5 was 380 nm.

<Measuring method of average particle size>
About the said average particle diameter, using the microtrack UPA-150 by Nikkiso Co., Ltd., and using the sample diluted with the pure water so that the solid content concentration (mass concentration) in a measurement sample may be 0.01 mass%. It was measured. The average particle diameter here means a 50% average particle diameter (D50).

  FIG. 11 shows the relationship between the average particle size and pH of the polymer fine particles obtained in Synthesis Example 1, Synthesis Example 2, Comparative Synthesis Example 1, and Comparative Synthesis Example 2.

From this result, the pH-responsive polymer fine particles of the present invention have a pH of 8.5 or more and an average particle size of 100 to 300 nm, and the average particle size becomes very large as the pH is lowered. In the prior art, for example, in Comparative Synthesis Example 2, the particle diameter when the pH is high is small and the average particle diameter gradually increases as the pH decreases, but in the present invention, the pH is higher than that of Comparative Synthesis Example 2. It can be seen that the particle size when the particle size is high is approximately the same, the pH value at which the particle size increases is high, and the particle size to be saturated is also large. It can also be seen that, in the case of Comparative Synthesis Example 1 lacking the pH-sensitive monomer [general formula (2)], which is a constituent material necessary for the present invention, the particle diameter does not change even if the pH changes.
As characteristics of the pH-responsive polymer fine particles in the present invention, the average particle diameter (D50) is 100 to 300 nm in the pH range of 8 to 9, and the average particle diameter (D50) is 450 to 450 in the pH range of 4 to 6. It is preferable that it is 800 nm.

<Preparation example of pigment dispersion>
Each material dispersion was prepared as follows.
(Preparation Preparation Example 1): Black surfactant-dispersed pigment A black surfactant-dispersed pigment was prepared by the following formulation (1) with reference to Example 1 of JP-A-2009-114286.
A mixture of the following formulation (1) was premixed to prepare a mixed slurry (a). This was circulated and dispersed in a disk type media mill (manufactured by Ashizawa Finetech Co., Ltd., DMR type) using 0.05 mm zirconia beads and a filling rate of 55% at a peripheral speed of 10 m / s and a liquid temperature of 10 ° C. for 3 minutes. Coarse particles were centrifuged with a centrifugal separator (Model 7700, manufactured by Kubota Corporation) to obtain a surfactant-dispersed pigment dispersion having a pigment concentration of 13% by mass.
Formula (1)
・ Carbon black (NIPEX160, manufactured by degussa,
BET specific surface area 150 m ² / g, average primary particle size 20 nm, pH 4.0,
DBP oil absorption 620 g / 100 g) ... 175 parts by mass-Naphthalene sulfonate sodium formalin condensate (Pionine A-45-PN, Naphthalene sulfonate dimer, trimer, manufactured by Takemoto Yushi Co., Ltd.)
And tetramer total content = 50% by mass) 175 parts by mass Distilled water 650 parts by mass

(Preparation Example 2): Cyan Resin-Coated Pigment Dispersion The same procedure as in Preparation Example 1 except that the carbon black pigment of Preparation Example 1 was changed to a copper phthalocyanine pigment (CI Pigment Cyan 15: 3). A blue resin-coated pigment dispersion having a concentration of 13% by mass was obtained.
The average particle size (D50%) measured by a particle size distribution measuring device (Microtrac UPA, manufactured by Nikkiso Co., Ltd.) of the obtained polymer fine particles was 93 nm.

(Preparation Example 3): Yellow surfactant-dispersed pigment The pigment concentration was the same as in Preparation Example 1, except that the carbon black pigment of Preparation Example 1 was changed to Pigment Yellow 138 (LIONOGEN YELLOW 1010 manufactured by Toyo Ink Co., Ltd.). A yellow surfactant-dispersed pigment dispersion of 13% by mass was obtained. The average particle size (D50%) of the obtained yellow pigment dispersion measured with a particle size distribution measuring device (Microtrac UPA, manufactured by Nikkiso Co., Ltd.) was 70 nm.

(Preparation Example 4): Magenta resin-coated pigment A supplementary preparation was made as described below with reference to Synthesis Example 1, Adjustment Example 5, and Adjustment Example 8 described in JP-A-2009-155425.
First, in preparing a polymer solution, the inside of a 1 L flask equipped with a mechanical stirrer, a thermometer, a nitrogen gas introduction tube, a reflux tube and a dropping funnel was sufficiently substituted with nitrogen gas, and then 11.2 g of styrene, 2 acrylic acids .8 g, 12.0 g of lauryl methacrylate, 4.0 g of polyethylene glycol methacrylate, 4.0 g of styrene macromer (manufactured by Toa Gosei Co., Ltd., trade name: AS-6) and 0.4 g of mercaptoethanol were added and the temperature was raised to 65 ° C. Warm up. Next, styrene 100.8 g acrylic acid 25.2 g, lauryl methacrylate 108.0 g polyethylene glycol methacrylate 36.0, hydroxyethyl methacrylate 60.0 g, styrene macromer 36.0 g, mercaptoethanol 3.6 g, azobisdimethylvaleronitrile 2 A mixed solution of 0.4 g and 18 g of methyl ethyl ketone was dropped into the flask over 2.5 hours.
After completion of dropping, a mixed solution of 0.8 g of azobisdimethylvaleronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hours. After aging at 65 ° C. for 1 hour, 0.8 g of azobisdimethylvaleronitrile was added and further aged for 1 hour. After completion of the reaction, 364 g of methyl ethyl ketone was added to the flask to obtain 800 g of a polymer solution having a concentration of 50% by mass. Next, a part of the polymer solution was dried and measured by gel permeation chromatography (standard: polystyrene, solvent: tetrahydrofuran). The weight average molecular weight was 15000.
28 g of the obtained polymer solution, 26 g of CI Pigment Red 122, 13.6 g of 1 mol / L potassium hydroxide solution, 20 g of methyl ethyl ketone, and 30 g of ion-exchanged water were sufficiently stirred. Thereafter, the mixture was kneaded 20 times using a three-roll mill (manufactured by Noritake Company, trade name: NR-84A). After putting the obtained paste into 200 g of ion-exchanged water and stirring sufficiently, the methyl ethyl ketone and a part of the water are distilled off using an evaporator, and the content of pigment becomes 13% by mass. Type pigment dispersion (magenta resin-coated pigment) was obtained.

[Examples 1-14, Comparative Examples 1-12]
<Preparation of ink for ink jet recording>
Tables 1 and 2 below show the configurations of the ink compositions of Examples 1 to 14, and Tables 3 and 4 below show the configurations of the ink compositions of Comparative Examples 1 to 12, respectively. In addition, the numerical value in a table | surface shows the mass%.
Each ink jet recording ink (recording ink) was manufactured according to the following procedure.
First, the materials shown in Tables 1 to 4 below are mixed and stirred for 1 hour to mix uniformly. This dispersion was subjected to pressure filtration with a polyvinylidene fluoride membrane filter having an average pore size of 5.0 μm to remove coarse particles and dust, thereby producing a recording ink.
Note that the annotations * 1 to * 7 in Tables 1 to 4 have the following meanings.
* 1: KM-9036: manufactured by Toyo Ink Co., Ltd., self-dispersing pigment dispersion; pigment concentration is 13 mass%.
* 2: NANOCRYL-S KPX-02-014: manufactured by Toyochem Co., Ltd., solid content: 40.0% by mass.
* 3: Takelac W 5661: manufactured by Mitsui Chemicals, solid content: 35.0% by mass
* 4: Zonyl FS-300: Polyoxyethylene perfluoroalkyl ether, manufactured by Dupon, 40% by mass
* 5: Unidyne DSN-403N: perfluoroalkyl polyethylene oxide addition reaction product, manufactured by Daikin Industries, Ltd. * 6: KF-643: polyether-modified silicone compound, manufactured by Shin-Etsu Chemical Co., Ltd., 100% by mass
* 7: Proxel GXL: Preservative based on 1,2-benzisothiazolin-3-one, manufactured by Arch Chemicals, 20% by mass; containing dipropylene glycol.

Next, the recording inks of Examples 1 to 14 and Comparative Examples 1 to 12 were evaluated by the following evaluation method. The results are shown in Table 5 below.
In addition, the main points of Examples 1-14 and Comparative Examples 1-12 are shown below.
In Examples 1 to 5, the carbon number (R ₁ ) of the alkyl group of the general formula (2) of claim 1 is 1 and the carbon number of the alkyl group (R ₂ ) of the general formula (3) is 1. In Examples 6 to 10, when the carbon number (R ₁ ) of the alkyl group of the general formula (2) in claim 1 is 4 and the carbon number of the alkyl group of the general formula (3) is 4, Examples 11 to 14 are When the addition amount of the pH-responsive polymer fine particles of the present invention is changed Comparative Examples 1 to 5 are the cases of the resin of Comparative Synthesis Example 1 (those lacking the pH-sensitive monomer [general formula (2)]) Comparative Example 6 to 10 are cases where gel fine particles described in Japanese Patent No. 3155318 are used (Comparative Synthesis Example 2)
When Comparative Examples 11 to 12 do not contain polymer fine particles

<Evaluation of storage stability of each ink>
To measure the viscosity of each recording ink in Examples 1 to 14 and Comparative Examples 1 to 12, a viscometer RE80L manufactured by Toki Sangyo Co., Ltd. was used, and the viscosity at 25 ° C. was measured at 50 or 100 revolutions. .
For storage stability, after measuring the initial viscosity, the ink is put in a polyethylene container, sealed, and measured after storage at 70 ° C. for 1 week, and the following standard is determined according to the rate of change from the initial viscosity. And evaluated.
〔Evaluation criteria〕
○: Change rate of the viscosity after storage based on the initial viscosity is less than 5% Δ: Change rate of the viscosity after storage based on the initial viscosity is 5% or more and less than 50% ×: Viscosity after storage based on the initial viscosity Change rate of 50% or more

[Evaluation of printing of each ink]
Printing evaluation of the inks of Examples 1 to 14 and Comparative Examples 1 to 12 shown in Tables 1 to 4 was performed.
Evaluation of “image density” was performed using an inkjet printer (IPSiO GX3000 manufactured by Ricoh Co., Ltd.) in an environment adjusted to MM environment (25 ± 0.5 ° C., 50 ± 5% RH). The drive voltage of the piezo element was varied so that the ink would become smaller, and the setting was made so that the same amount of ink was attached to the recording material. Only the evaluation of “ejection recovery property” was performed in the HL environment (32 ± 0.5 ° C., 15 ± 5% RH).
Each evaluation item and its evaluation method are shown below.

<Image density>
A chart created using Microsoft Word 2003 with a black 64 point character “■” written on it has a basis weight of 69.6 g / m ² , a sizing degree of 23.2 seconds, and an air permeability of 21.0 seconds. Printing was performed on high-quality paper My Paper (manufactured by Ricoh Co., Ltd.), the color “■” was measured using X-Rite 938, and the image density was evaluated. At this time, the printing mode is set to “plain paper—standard, fast” with a driver attached to the printer. The determination of the image density of each color was performed based on the following criteria.
〔Evaluation criteria〕
A: OD value Black 1.20 or more Yellow 0.75 or more
Magenta 0.90 or more Cyan 1.00 or more.
○: OD value Black 1.10 or more and less than 1.20 Yellow 0.70 or more and less than 0.75
Magenta 0.80 or more and less than 0.90 Cyan 0.90 or more and less than 1.00.
Δ: OD value Black 1.00 or more and less than 1.10 Yellow 0.65 or more and less than 0.70
Magenta 0.70 or more and less than 0.80 Cyan 0.80 or more and less than 0.90.
×: OD value Black Less than 1.00 Yellow less than 0.65
Magenta less than 0.70 Cyan less than 0.80.

<Discharge recovery>
Each ink of Examples 1 to 14 shown in Table 1 and Table 2, and Comparative Examples 1 to 12 shown in Table 3 and Table 4 was filled in the ink jet printer, respectively, and the HL environment (32 ± 0.5 ° C., 15 ± 5 % RH) for 3 hours, a nozzle check pattern was printed, and it was confirmed that there were no ejection defects such as missing dots and flying curves. Then, it was left as it was for 6 days. After completion of standing, a nozzle check pattern with a solid print part is applied to high-quality paper Mypaper (made by Ricoh Co., Ltd.) with a basis weight of 69.6 g / m ² , a sizing degree of 23.2 seconds, and an air permeability of 21.0 seconds. Sheets were printed and the presence or absence of missing dots or flying curves was confirmed. When there were missing ink dots or flying bends in the nozzle check pattern, the printer nozzle was cleaned as a return to normal printing, and the total number was evaluated. From the total number of times obtained, the ejection recovery property of each ink was evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
A: Cleaning 0 times or 1 time.
○: Cleaning is performed 2 times or more and less than 5 times.
X: Cleaning 5 times or more.

<Discharge stability>
The inks of Examples 1 to 14 shown in Tables 1 and 2 and Comparative Examples 1 to 12 shown in Table 3 and Table 4 were filled in the inkjet printer, and the areas and shapes of black, cyan, magenta, and yellow were the same. 100 sheets of a chart including a solid and a line pattern were continuously printed on my paper. During printing, when there were missing ink dots or flying curves on the chart, the printer nozzle was cleaned as a return to normal printing, and the total number of times was evaluated. From the total number of times obtained, the ejection stability of each ink set was evaluated according to the following evaluation criteria.
Here, Ricoh (high quality paper) [basis weight 69.6 g / m ² , sizing degree 23.2 seconds, air permeability 21.0 seconds] was used as my paper.
〔Evaluation criteria〕
A: One cleaning.
○: Cleaning is performed 2 times or more and less than 5 times.
X: Cleaning 5 times or more.

From the evaluation results, the hydrophobic monomer represented by the formula (1), the pH sensitive monomer represented by the general formula (2), and the hydrophilic macromonomer represented by the general formula (3). In the ink of the present invention containing polymer fine particles composed of a copolymer as an ink composition, each of the color inks is excellent in image density, ink storage stability, ink ejection stability, and ejection recovery properties. No problematic properties are seen. In the case of Comparative Examples 1 to 12, at least one of image density, ink storage stability, ink ejection stability, and ejection recovery characteristics includes characteristics that cannot be put into practical use.
In addition, even if the upper and lower limits [Example 12 (lower limit), Example 13 (upper limit)] of the preferable range of the content of the polymer fine particles of the present invention are found, the same effects as those of Examples 1 to 10 are obtained. Note that the image density tends to be slightly inferior in Example 11 (less than the lower limit) in which the content of the polymer fine particles is less than the preferred range.

  That is, the present invention has good ink storage stability, good drying properties, high image density on plain paper and coated paper for printing, and good ink ejection stability from the recording head. In addition, since the discharge recovery is excellent and the ink is not fixed around the nozzle, it can be applied to various recordings by the ink jet recording method. The ink recorded matter of the present invention has high image quality, no bleeding, excellent stability over time, and can be suitably used for various purposes as materials on which various prints or images are recorded. As the recording apparatus using the ink jet recording method, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, a printer / fax / copier multifunction machine, and the like can be applied.

(Figure 1)
1 Cationic hydrophilic macromonomer having a radical polymerizable group at its terminal 1a Vinylbenzyltrimethylammonium chloride unit 1b Vinylbenzyl group 2 Styrene monomer 3 Dimethylaminoethyl methacrylate 4 Core part 5 Cationic polymer chain 6 Polymer fine particles (Fig. 4, 5, 6)
DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Paper feed tray 3 Paper discharge tray 4 Front surface 5 Upper surface 6 Ink cartridge loading part 7 Operation part 8 Front cover 10 Main tank (
ink cartridge)
10k Black (Bk) ink cartridge 10y Yellow (Y) ink cartridge 10m Magenta (M) ink cartridge 10c Cyan (C) ink cartridge 21 Frame 21A Side plate 21B Side plate 21C Rear plate 22 Flexible cable 23 Supply pump unit 25 Main body Side holder 26 Fixing rib 31 Guide rod 32 Stay 33 Carriage 34 Recording head 34k Recording head 34c that discharges black (Bk) droplets Recording head 34m that discharges cyan (C) droplets Magenta (M) droplets Recording head 34y for discharging Recording head 35 for discharging yellow (Y) droplets Sub tank 35k Sub tank 35y for supplying black (Bk) ink Sub tank 35m for supplying yellow (Y) ink Ink subtank 36 ink supply tube for supplying the sub-tank 35c cyan ink (C) for supplying the (M) (sub-tank connecting portion)
37 Ink supply tube 41 Paper stacking part (bottom plate)
42 paper 43 half moon roller (paper roller)
44 Separating Pad 45 Guide 51 Conveying Belt 52 Counter Roller 53 Conveying Guide 54 Pressing Member 55 Tip Pressure Roller 56 Charging Roller 57 Conveying Roller 58 Tension Roller 61 Guide Member 71 Separation Claw 72 Paper Discharge Roller 73 Paper Discharge Roller 81 Double-sided Paper Feed Unit 82 Manual paper feed unit 91 Maintenance / recovery device (FIGS. 7, 8, 9, and 10)
91 Subsystem including maintenance device 92 Cap members 92a, 92b, 92c, 92d Cap 93 Wiper blade 94 Empty discharge receiver 95 Wiper cleaner 96 Cleaner roller 98 Empty discharge receiver 99 Opening 111 Frame 112 112A, 112B Cap holder 115 Carriage lock 117 Carriage Lock arm 118 Wiper liner 119 Tube 120 Tubing pump 120a Pump shaft 121 Cam shaft 122, 122A, 122B Cap cam 124 Wiper cam 125 Carriage lock cam 126 Roller 128 Cleaner cam 131 Motor 131a Motor shaft 132 Motor gear 133 Pump gear 134 Intermediate gear 135 Intermediate gear 136 Intermediate gear 137 Clutch 138 Intermediate gear 139 Intermediate gear 140 Cam gear 14 Cam 150a intermediate shaft 142 home position sensor guide pin 150b guide shaft 151 holder 152 a spring 153 the slider 154 guide pin 155 guide pin 156 guide groove 157 cam pin

JP 2006-16412 A Japanese Patent No. 3155318

Claims (7)

An inkjet recording ink comprising at least water, a wetting agent, a colorant, and polymer fine particles,
The polymer fine particle comprises a copolymer of a monomer represented by the following formula (1), a monomer represented by the following general formula (2), and a macromonomer represented by the following general formula (3). Ink for ink jet recording characterized by the above-mentioned.
[In General Formula (2), R ₁ represents an alkyl group having 1 to 4 carbon atoms. ]
[In General Formula (3), R ₂ represents an alkyl group having 1 to 4 carbon atoms. k represents the number of repeating units and represents an integer of 1 to 100. ] The ink for inkjet recording according to claim 1, wherein R ₁ in the general formula (2) is a methyl group or an ethyl group. The ink for inkjet recording according to claim 1 or 2, wherein R ₂ in the general formula (3) is a methyl group or an ethyl group.   An ink cartridge comprising the ink-jet recording ink according to claim 1 contained in a container.   4. The ink jet recording step according to claim 1, further comprising: an ink jetting step of applying a stimulus to the ink jet recording ink according to claim 1 through an ink jetting unit and jetting the ink from a recording head to record an image on a recording medium. An inkjet recording method characterized by the above.   An ink jet recording apparatus comprising ink jetting means for recording an image on a recording medium by causing the ink jet recording ink according to claim 1 to fly from a recording head.   An ink recorded matter comprising an image recorded with the ink for ink jet recording according to any one of claims 1 to 3 on a recording medium.