JP5374812B2 - INK FOR RECORDING, INK CARTRIDGE, INK RECORDED MATERIAL, INKJET RECORDING DEVICE AND INKJET RECORDING METHOD - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide recording ink having high color-development, picture quality and reliability and suitable for inkjet recording, and an ink cartridge, ink recorded matter, inkjet recording apparatus and inkjet recording method to use the recording ink. <P>SOLUTION: The recording ink at least contains a coloring agent, a water-dispersible resin, a wetting agent, a surfactant and water. The total solid content of the coloring agent and the water-dispersible resin in the recording ink is 10-30 mass%, the ratio of the solid content (B) of the coloring agent in the recording ink to the solid content (C) of the water-dispersible resin in the recording ink (B/C) is 0.1-1.6, the viscosity of the recording ink is 5-20 mPa s at 25&deg;C, and the surface tension of the recording ink is &le;35 mN/m. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention has good image quality for plain paper, can ensure high color development, image quality, and reliability, and is suitable for ink jet recording, and an ink cartridge and ink using the recording ink The present invention relates to a recorded matter, an ink jet recording apparatus, and an ink jet recording method.

Inkjet recording apparatuses are known as image recording apparatuses such as printers, facsimiles, and copying machines. An ink jet recording apparatus performs recording by ejecting ink from a recording head onto a recording medium such as paper. The image forming process is simple, and the apparatus is easy to simplify. High-definition images can be recorded at high speed, running costs are low, noise is low, and color images can be easily recorded using multi-colored inks. doing.
The ink used for such ink-jet recording has water as a main component, and contains a coloring agent, a wetting agent such as glycerin, a penetrating agent that controls penetrability to recording paper, a surfactant, and other additives. The contained water-based ink is generally used for home and office applications.

  In general, inkjet recording using water-based ink is fixed by liquid ink penetrating into the recording medium. Therefore, the ink-jet dedicated paper has functions of improving absorption characteristics, fixing colored components on paper, and protecting colored components. Has been developed. However, inkjet paper is expensive because it undergoes a multi-stage coating process after paper making, and recyclability is inferior to plain paper because it uses a lot of processing chemicals. Therefore, it is desired to obtain sufficient image quality on plain paper.

  Such plain paper is inferior in ink absorptivity to inkjet special paper and does not assist ink performance like special paper, so (1) occurrence of feathering, (2) occurrence of bleeding, (3) density (4) Color developability, (5) Water resistance, (6) Light resistance, (7) Gas resistance, (8) Fixability, (9) Back of ink There are problems such as the occurrence of omission, and solving these problems is an important issue for inkjet recording on plain paper.

In recent years, pigments have been increasingly used in inkjet inks because of improved dispersibility and finer particle size. To improve the dispersibility of pigments, not only pigment dispersion using surfactants and water-soluble resins as in the past, but also hydrophilicity is imparted by surface modifications such as oxidation treatment, sulfonation treatment, and graft polymerization treatment on the pigment surface. In order to improve the self-dispersion stability of the pigment. By using such a pigment, the above (5), (6), and (7) can be improved, but the density and color developability are inferior to those of the dye, and further, ejection stability, long-term storage, It is inferior to dye ink in terms of reliability such as redispersibility. Therefore, when a pigment is used as a colorant, it is a problem to improve the ink density, color developability, and reliability.
In order to solve these problems, for example, an ink for ink jet recording using an emulsion of colored polymer particles, particularly polyester-based or vinyl-based polymer particles has been proposed (for example, see Patent Document 1). This proposal also includes an ink containing a colorant-encapsulating resin dispersion in which a colorant is insoluble in water and encapsulated in a dispersible resin. In addition, when a color organic pigment is used as a colorant, it is known that a conventionally known ink formulation is superior in image density and color reproducibility on plain paper to a pigment ink using a water-soluble dispersant.

  Conventionally, a technique for controlling the penetration of ink into paper has been studied in order to reduce feathering and bleeding, increase print density and color developability, and suppress back-through. Among commercially available inkjet inks, there are super-penetrating inks in which the surface tension of the ink is adjusted to be lower than 35 mN / m to increase the permeability to paper. Such an ink is highly effective in reducing bleeding and has a good drying property on plain paper printing, but has the disadvantages that feathering is likely to occur, the printing density is low, and the character quality is liable to deteriorate. On the other hand, a slow penetrating ink that allows the surface tension of the ink to be adjusted higher than 35 mN / m and slows the permeation into the paper to keep the ink on the surface of the print surface has been put on the market, lowering the feathering, improving the print density, Highly effective in improving color development and reducing back-through. However, the slow-penetration ink has decreased permeability to paper, and as a result, the drying property after printing on plain paper is remarkably deteriorated, and the fixing property is deteriorated, and bleeding between colors is caused when the number of colors is increased.

In addition, a technique has been developed that suppresses bleeding between colors and ensures image quality by using an ink set in which the slow penetrating ink and the super penetrating ink are combined. However, when performing double-sided printing using this ink set, it is necessary to wait for the ink to dry after printing, leading to a deterioration in productivity of double-sided printing. In order to improve the drying property of the ink, an ink jet recording apparatus having a device that heats the paper surface with a heater before and after printing and accelerates the drying of the ink has been proposed and put on the market (Patent Documents 2 and 3). , Patent Document 4, Patent Document 5, and Patent Document 6).
In these proposals, since there is a heating means, the inkjet recording apparatus is increased in size and complexity, and there is a problem that the advantages of the inkjet method are lost, such as wasting energy for heating.

In addition to the above, the inkjet ink has been studied in a direction that combines reliability improvement and image quality improvement. Many inkjet inks are designed in such a way as to suppress the increase in viscosity as much as possible in order to prevent clogging of the nozzles of the head. For example, in Patent Document 7, the viscosity change when the ink is concentrated twice is within 10 times, and the change in particle size is within 3 times to prevent the aggregation of the pigment from suppressing the spread of the ink, so-called white It is said that it can prevent omission. However, it is difficult to form high quality on plain paper with this ink. Further, Patent Document 8 proposes an ink in which a residue after evaporation of a volatile component in the ink is a liquid, and the viscosity is within 10 times the initial viscosity. However, although this ink is a dye ink and has high reliability, the image quality on plain paper is still inferior. Patent Document 9 discloses an ink having an ink viscosity of 600 times or less of that before evaporation when water is evaporated in an environment of 60 ° C. However, this ink is also a dye ink, and adding a water-soluble polymer balances the reliability of the ink with the durability of the image quality, but there remains a problem with water resistance. Further, in Patent Document 10, an ink having a viscosity of 5 to 15 mPa · s is necessary to ensure high image quality, and the initial evaporation rate is adjusted and the viscosity is adjusted to ensure reliability. It has been proposed to add specific compounds as viscosity modifiers for this purpose. However, this proposal does not describe anything about the stability of the particle size of the pigment to be used, and there is reliability after leaving for 24 hours. In this case, the ink prescription is inferior in reliability.
As described above, in order to ensure high-speed and high-quality printing quality, it is necessary to use a high-viscosity ink, but there is a problem that it is difficult to ensure reliability with a high-viscosity ink. .

  For the purpose of improving image quality, for example, Patent Document 11 and Patent Document 12 propose a method of adding a water-insoluble resin to pigment ink. In Patent Document 13, the ratio of pigment to resin emulsion is in the range of 1: 0.1 to 1: 1, and the average particle size of the coloring component is 0.3 to 1.2 μm in plain paper. Techniques for obtaining high image quality have been proposed. Thus, in the ink added with the resin emulsion, bleeding can be suppressed and feathering can be suppressed, but the image density is insufficient and the reliability as an inkjet ink cannot be said to be sufficient. Patent Document 14 discloses an ink having a minimum film forming temperature of 40 ° C. or higher for an ink to which a water-insoluble resin is added, and Patent Document 15 discloses an ink having a particle size of an added emulsion of 50 nm or less. However, there is room for improvement in reliability, and the image quality obtained is not sufficient. Patent Document 16 discloses that printing unevenness is improved by an ink containing a pigment, a saccharide or a derivative thereof, a polyol compound having 5 or more hydroxyl groups, and a resin emulsion. However, this ink has low penetrability with respect to plain paper, and has problems such as occurrence of feathering and bleeding between colors, deterioration of fixing property, and slow drying time. Patent Document 17 discloses an ink having a solid content of 1.0 to 16% by mass comprising a water-dispersible resin and a self-dispersing pigment, and describes an improvement in image quality on plain paper. Water resistance is improved compared to dye inks, but image retention performance for marker pens often used for plain paper is not sufficient.

  Further, when the pigment dispersion and the resin emulsion are added to the ink, the solid content increases and the ink viscosity also increases. Therefore, for example, Patent Document 18 proposes an ink formulation in which a viscosity increase is small even when the solid content is increased by adding a resin that forms a micelle aggregate to the ink. However, the proposed ink has insufficient permeability on plain paper, and there is a problem in the recording image quality as in the above-mentioned Patent Document 16.

In addition, the permeability to paper is explained by capillary absorption represented by the Lucas-Washburn equation. However, the higher the viscosity, the better the permeability if the surface tension and the contact angle between the paper and the ink are not lowered. I can't. For example, in Patent Document 19 and Patent Document 20, when polyhydric alcohol alkyl ether is used for high solid content ink to improve permeability, it is sufficient that the solid content increases and the viscosity increases. The penetrability cannot be obtained and the image quality is deteriorated.
Further, it is known that silicone surfactants and fluorosurfactants improve the permeability even with a small amount. For example, Patent Document 21 and Patent Document 22 propose inkjet inks to which a fluorosurfactant is added. Patent Documents 23 and 24 propose inks containing a pigment dispersion and a fluorosurfactant. Patent Document 25 proposes an ink having a viscosity of 5 mPa · s or more, which contains a fluorosurfactant and a polymer emulsion in which polymer fine particles contain a water-insoluble or hardly water-soluble coloring material. However, even in these proposals, it is difficult to obtain a preferable hue at a high pigment concentration, and it is difficult to say that a self-dispersing pigment has sufficient water resistance and fixing properties.

  Therefore, with respect to the problems in inkjet recording on plain paper, water-dispersible colorants can be used to improve water resistance, light resistance, and gas resistance, and high penetration and high viscosity inks can be used to improve image density. Various attempts have been made to reduce the ink see-through and improve the image quality with reduced feathering and bleeding, but no satisfactory performance has yet been provided, and there is also a problem with color development. What is left is the current situation.

JP 2000-191972 A JP 55-69464 A JP 55-84670 A JP 58-72460 A Japanese Patent Laid-Open No. 62-130863 JP-A-62-130864 JP 2002-337449 A JP 2000-95983 A Japanese Patent Laid-Open No. 9-111166 JP 2001-262025 A JP 55-157668 A Japanese Examined Patent Publication No. 62-1426 JP-A-4-332774 Japanese Patent No. 2867491 JP-A-4-18462 Japanese Patent No. 3088588 JP 2004-35718 A JP 2004-99800 A JP 2004-155867 A JP 2004-203903 A Japanese Patent No. 2675001 Japanese Patent No. 2667401 JP-A-4-21478 JP 2003-277658 A JP 2003-226827 A

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention increases the solid content of the colorant and water-dispersible resin in the recording ink and optimizes the solid content of the water-dispersible resin with respect to the colorant to ensure permeability. Therefore, a recording ink suitable for ink jet recording, an ink cartridge, an ink recorded matter, an ink jet recording apparatus, and an ink jet recording method using the recording ink, which can ensure high color developability, image quality, and reliability. The purpose is to provide.

Means for solving the problems are as follows. That is,
<1> A recording ink containing at least a colorant, a water-dispersible resin, a wetting agent, a surfactant, and water,
The total content of the colorant and the water-dispersible resin in the recording ink is 10 to 30% by mass in solid content,
The ratio (B / C) of the solid content (B) in the recording ink of the colorant to the solid content (C) in the recording ink of the water-dispersible resin is 0.1 to 1. The recording ink has a viscosity of 5 to 20 mPa · s at 25 ° C. and a surface tension of the recording ink of 35 mN / m or less.
<2> The recording ink according to <1>, wherein the colorant is a water-dispersible colorant containing a pigment.
<3> The water dispersible colorant is a pigment having at least one hydrophilic group on the surface and exhibiting at least one of water dispersibility and water solubility in the absence of the dispersant. Recording ink.
<4> The recording ink according to <2>, wherein the water-dispersible colorant is a polymer emulsion in which polymer fine particles contain a colorant that is insoluble or hardly soluble in water.
<5> The recording ink according to <2>, wherein the water-dispersible colorant is a pigment dispersed with any of a surfactant and a water-soluble polymer compound having a mass average molecular weight of 50,000 or less.
<6> The recording ink according to any one of <1> to <5>, wherein the wetting agent is a polyhydric alcohol having an equilibrium water content of 25% by mass or more in an environment of 20 ° C. and 60% RH. is there.
<7> The recording ink according to <6>, wherein the polyhydric alcohol is glycerin, and the content of the glycerin is 60% by mass or less of the whole wetting agent.
<8> The surfactant contains at least one selected from silicone surfactants and fluorine surfactants, and the total content of the surfactant in the recording ink is 0.01 to 5% by mass. The recording ink according to any one of <1> to <7>.
<9> The fluorosurfactant has a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. The recording ink according to <8>, which is at least one selected from polyoxyalkylene ether polymer compounds.
<10> The recording ink according to any one of <1> to <9>, which is at least one selected from cyan ink, magenta ink, yellow ink, and black ink.
<11> An ink cartridge comprising the recording ink according to any one of <1> to <10> contained in a container.
<12> An ink jet comprising at least an ink flying step of applying an stimulus to the recording ink according to any one of <1> to <10> and causing the recording ink to fly to form an image. It is a recording method.
<13> The inkjet recording method according to <12>, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.
<14> Any one of <12> to <13>, wherein the size of a droplet ejected from the nozzle is 2 to 40 pl, the velocity of the droplet is 6 to 20 m / s, the frequency is 1 kHz or more, and the resolution is 300 dpi or more. The inkjet recording method described in 1.
<15> Inkjet comprising at least ink flying means for forming an image by applying a stimulus to the recording ink according to any one of <1> to <10> and causing the recording ink to fly. It is a recording device.
<16> The inkjet recording apparatus according to <15>, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.
<17> The inkjet recording according to any one of <15> to <16>, further including a sub tank for supplying ink on the nozzle head, wherein the sub tank is replenished with ink from an ink cartridge through a supply tube. Device.
<18> An ink recorded matter comprising an image formed using the recording ink according to any one of <1> to <10> on a recording medium.
<19> The ink recording material according to <18>, wherein the recording medium has a Steecht sizing degree of 3 seconds or more.

The recording ink of the present invention contains at least a colorant, a water-dispersible resin, a wetting agent, a surfactant, and water, and the total content of the colorant and the water-dispersible resin in the recording ink. However, when the solid content is 10 to 30% by mass, the character quality can be improved. Further, the ratio (B / C) of the solid content (B) in the recording ink of the colorant to the solid content (C) in the recording ink of the water-dispersible resin is 0.1 to By setting the value to 1.6, an effect of improving the fixing property and improving the coloring property can be obtained.
The recording ink of the present invention has an effect of improving the printing density and character quality by setting the viscosity at 25 ° C. to 5 mPa · s or more, and further suppresses the ink viscosity to 20 mPa · s or less. Thus, the discharge property can be ensured.
Moreover, since the recording ink of the present invention can obtain sufficient permeability even in the high viscosity ink as described above by setting the surface tension to 35 mN / m or less, a high drying speed can be obtained. . Preferably, when a fluorosurfactant is used, the drying speed is further improved, and even if it is a high-viscosity ink, a drying property comparable to that of a low-viscosity ink can be obtained.
Further, the recording ink of the present invention preferably uses a polyhydric alcohol having an equilibrium water content of 25% by mass or more as a wetting agent in an environment of 20 ° C. and 60% RH, thereby reducing the water evaporation rate of the ink. The effect of improving the ink ejection reliability can be obtained. In this case, when glycerin is used as the polyhydric alcohol and the content of the glycerin is 50% by mass or less of the whole wetting agent, an effect of improving the print density and reducing the show-through is obtained.

  The ink cartridge of the present invention comprises the recording ink of the present invention contained in a container. The ink cartridge is suitably used for a printer using an ink jet recording method. When recording is performed using the ink contained in the ink cartridge, the saturation is remarkably improved, the color developability is excellent, the ejection stability is high, and a high-quality image can be formed.

  The ink jet recording apparatus of the present invention comprises at least ink flying means for forming an image by applying energy to the recording ink of the present invention and causing the recording ink to fly. In the ink jet recording apparatus, the ink flying means applies energy to the recording ink of the present invention and causes the recording ink to fly to form an image. As a result, it is excellent in image quality, drying speed, and high-speed printing on plain paper, has excellent ejection stability from nozzles, and has high image quality with high quality close to that of electrophotography and high drying characteristics. Image recording is possible.

  The ink jet recording method of the present invention comprises at least an ink flying step of forming an image by applying energy to the recording ink of the present invention and causing the recording ink to fly. In the ink jet recording method, in the ink flying step, energy is applied to the recording ink of the present invention, and the recording ink is ejected to form an image. As a result, it is excellent in image quality, drying speed, and high-speed printing on plain paper, has excellent ejection stability from nozzles, and has high image quality with high quality close to that of electrophotography and high drying characteristics. Image recording is possible.

  The ink recorded matter of the present invention has an image formed on the recording medium using the recording ink of the present invention. In the ink recorded matter, the saturation is remarkably improved, the color developability is excellent, and a high-quality image is held on the recording medium.

  According to the present invention, conventional problems can be solved, the solid content of the colorant and the water-dispersible resin in the recording ink is increased, and the solid content of the water-dispersible resin is increased with respect to the coloring material. By optimizing and ensuring penetrability, it is possible to ensure high color developability, image quality, and reliability, recording ink suitable for inkjet recording, and an ink cartridge and ink recording using the recording ink Product, an ink jet recording apparatus, and an ink jet recording method can be provided.

(Ink for recording)
The recording ink of the present invention contains at least a colorant, a water-dispersible resin, a wetting agent, a surfactant, and water, and further contains other components as necessary.

  In the present invention, by increasing the total solid content of the colorant and the water-dispersible resin contained in the recording ink, a sharp increase in viscosity is caused in the drying process after ink landing on the paper surface, and the coloring material component is A large amount of solid content is retained on the surface of the paper, resulting in an improvement in image density, an improvement in color development, and a suppression of show-through. Therefore, the total content of the colorant and the water-dispersible resin in the recording ink is 10 to 30% by mass in solid content, and preferably 15 to 25% by mass. When the total content is less than 10% by mass, it may not be possible to keep a large amount of solid content on the recording medium, and the image density and color developability may be inferior. In this case, the drying property is likely to be poor due to high drying performance.

  Further, when compared with the same amount of colorant, if only the colorant concentration is increased, the colorants strongly aggregate after fixing on the paper surface by inkjet, and the hue is greatly changed. As the ratio of the water-insoluble resin to the colorant is increased, aggregation between the colorants is suppressed, and the color developability of the colorant may be improved. In addition, as the ratio of the water-insoluble resin to the colorant increases, the fixability of the colorant to paper also improves. Therefore, the ratio (B / C) of the solid content (B) in the recording ink of the colorant to the solid content (C) in the recording ink of the water-dispersible resin is 0.1 to 1.6, preferably 0.1 to 1.3, and more preferably 0.3 to 1.0. If the ratio (B / C) is less than 0.1, sufficient color developability may not be obtained. If the ratio (B / C) exceeds 1.6, the fixability of the colorant is inferior, and the colorant is dried after recording. It may not be possible to suppress aggregation between each other.

Here, the solid content of the colorant and the water-dispersible resin can be measured, for example, by separating only the colorant and the water-dispersible resin from the ink. As a separation method, for example, by performing ink for 24 hours at 500,000 G or more with a centrifugal separator, the solid content in the ink is settled, and solid-liquid separation becomes possible. Depending on the type of colorant and the type of water-dispersible resin, solid-liquid separation can be performed by salting out or agglomeration with a solvent, and the solid content after separation is sufficiently dried and used for measurement.
Moreover, when the pigment is used as the colorant, the ratio of the colorant to the water-dispersible resin can be measured by evaluating the mass reduction rate by thermal mass spectrometry. At the time of measurement, in order to suppress the combustion of the resin and the pigment, the temperature is increased to 500 ° C. at 10 ° C./min in an inert gas atmosphere, and the mass change is measured. Since the solid after the solid-liquid separation also contains a slight amount of moisture and wetting agent components, the mass at 200 ° C. at which the components are almost eliminated is defined as the total solid mass, and many resin components are thermally decomposed and volatilized. The mass at 0 ° C. is defined as the mass of the pigment, and the ratio of the pigment to the resin can be obtained from the mass of the pigment / (total mass of solid content−mass of pigment).
In addition, in the case of pigments with low heat resistance such as some azo pigments, it is difficult to measure the pigment content because the pigment is thermally decomposed up to 500 ° C., but the resin component is dissolved in a solvent to form a solid It is possible to determine the pigment content by solvent extraction of the content. By obtaining the pigment fraction in the solid from the mass before and after extraction and obtaining the total mass of the solid content from the thermal mass analysis, the solid content mass of the pigment can be calculated as sample mass × pigment fraction.
In addition, when the molecular structure of the colorant is clear, NMR is used for pigments and dyes, and fluorescent X-ray analysis is used for inorganic pigments, metal-containing organic pigments, and metal-containing dyes contained in heavy metal atoms and molecular skeletons. It is possible to quantify the solid content of the colorant.

The viscosity of the recording ink at 25 ° C. is 5 to 20 mPa · s, and preferably 10 to 20 mPa · s. When the viscosity is less than 5 mPa · s, feathering and bleeding may not be suppressed, and 20 mPa.s may be prevented. If it exceeds s, the ejection characteristics from the nozzle may deteriorate.
Here, the said viscosity can be measured at 25 degreeC, for example using a viscometer (RL-500, the Toki Sangyo Co., Ltd. make).

The surface tension of the recording ink is 35 mN / m or less, preferably 30 mN / m or less. The surface tension is preferably 15 mN / m or more, more preferably 20 mN / m or more. When the surface tension exceeds 35 mN / m, bleeding tends to occur between adjacent colors, and the permeability to paper is slow and the drying time may be slow. Also, if the surface tension is too low, ink wetting on the head nozzle surface becomes too strong, and meniscus formation may become unstable and cause ejection failure.
Here, the surface tension can be measured using, for example, a fully automatic surface tension meter (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

  The recording ink of the present invention is a solid content of the colorant in the recording ink with respect to a total content of the colorant and the water-dispersible resin, and a solid content (C) of the water-dispersible resin in the recording ink. The constituent components are not particularly limited as long as they have characteristics such as the ratio (B / C) of the content (B), viscosity, and surface tension, and can be appropriately selected according to the purpose. It contains a colorant, a water-dispersible resin, a wetting agent, a surfactant, and water, and further contains other components as necessary.

-Colorant-
The colorant is preferably a water-dispersible colorant that is water-dispersible and contains a pigment.
Examples of the water dispersible colorant include (1) a pigment having at least one hydrophilic group on the surface and exhibiting at least one of water dispersibility and water solubility in the absence of the dispersant, and (2) polymer fine particles. A polymer emulsion containing a water-insoluble or poorly water-soluble colorant, (3) a pigment dispersed with a surfactant and a water-soluble polymer compound having a mass average molecular weight of 50,000 or less, and the like. .

The water dispersible colorants (1) to (3) will be described as follows for the sake of convenience.
The above (1) is generally referred to as a self-dispersing pigment, and is mainly made hydrophilic by subjecting carbon black or the like to surface oxidation to disperse the pigment alone in water.
The above (2) is generally referred to as a capsule pigment, and the pigment is coated with a hydrophilic water-insoluble resin, and is made hydrophilic by a resin layer on the pigment surface to disperse the pigment in water. It is.
The above (3) is generally called a surfactant-dispersed pigment or a resin-dispersed pigment, and an interface between the pigment and water is obtained by a compound having a surface-active ability (here, a surfactant or a water-soluble polymer compound). In this way, the pigment is dispersed. The difference from the above (2) is whether or not the resin is dissolved in water, which affects the solvent resistance and color developability of the pigment dispersion.

  Such a water-dispersible colorant has water resistance, light resistance, and gas resistance because the colorant molecules are in an aggregated state (including a crystalline state) or coexist with resin molecules and do not exist as single molecules. When such a colorant is used, the image storage stability can be improved. In particular, a pigment that has been treated so that at least one hydrophilic group is bonded to the pigment surface directly or via another atomic group, and thus becomes dispersible in water without a dispersant, or water insoluble in fine resin particles. Alternatively, when a polymer emulsion containing a sparingly soluble color material is used, the ink viscosity relative to the colorant solid content can be kept low, so that a large amount of water-insoluble resin or wetting agent can be added.

In the above (1), the surface of the pigment is modified so that at least one hydrophilic group is bonded directly or via another atomic group. For this purpose, a specific functional group (a functional group such as a sulfone group or a carboxyl group) is chemically bonded to the surface of the pigment, or a wet process using at least one of hypohalous acid and a salt thereof. A method such as oxidation treatment is used. Among these, a form in which a carboxyl group is bonded to the surface of the pigment and dispersed in water is particularly preferable. In this case, since the pigment is surface-modified and the carboxyl group is bonded, not only the dispersion stability is improved, but also high-quality printing quality is obtained and the water resistance of the recording medium after printing is further improved. .
In addition, because this form of ink has excellent redispersibility after drying, printing is paused for a long period of time, and even when the moisture in the ink near the nozzles of the inkjet head evaporates, it does not cause clogging and can be easily cleaned. Good printing can be performed. Further, this self-dispersing pigment has a particularly large synergistic effect when combined with a surfactant and a penetrating agent, which will be described later, and it is possible to obtain a more reliable and high-quality image.
The volume average particle diameter of the self-dispersing pigment is preferably 0.01 to 0.16 μm in the ink.

In the above (2), the polymer emulsion containing a coloring material is at least one of a polymer fine particle encapsulated with a pigment and a polymer fine particle surface adsorbed with a pigment. In this case, it is not necessary for all the pigments to be encapsulated or adsorbed, and the pigments may be dispersed in the emulsion as long as the effects of the present invention are not impaired.
Examples of the polymer that forms the polymer emulsion include vinyl polymers, polyester polymers, polyurethane polymers, polymers disclosed in JP-A Nos. 2000-53897 and 2001-139849, and the like. Among these, vinyl polymers and polyester polymers are particularly preferable.
The volume average particle diameter of the polymer fine particles (colored fine particles) containing the colorant is preferably 0.01 to 0.16 μm in the ink.

In the above (3), as the surfactant, for example, in the case of an anionic surfactant, polyoxyethylene alkyl ether acetate, polyoxyethylene alkyl ether phosphate, alkyl sulfonate, alkyl benzene sulfonate, oxalate ester Examples thereof include sulfonates, laurates, and polyoxyethylene alkyl ether sulfate salts. Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene naphthyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene polyoxypropylene alkyl ester, polyoxyethylene sorbitan. Examples include fatty acid esters, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl amines, polyoxyethylene alkyl amides, and the like.
Commercially available products can be used as such surfactants. Examples of such commercially available products include Nippon Oil & Fat Co., Ltd., Nikko Chemicals Co., Ltd., Nippon Emulsion Co., Ltd., Nippon Shokubai Co., Ltd., Daiichi Kogyo Seiyaku Co., Ltd. , Toho Chemical Co., Ltd., Kao Co., Ltd., Adeka Co., Ltd., Lion Co., Ltd., Aoki Oil Co., Ltd., Sanyo Chemical Industries Co., Ltd., etc.

Examples of the water-soluble polymer compound having a mass average molecular weight of 50,000 or less include polyacrylic acid, polymethacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid. Alkyl ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid-alkyl acrylate copolymer, styne-methacrylic acid-alkyl acrylate copolymer, styrene- α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid copolymer-acrylic acid alkyl ester copolymer, styrene-maleic acid copolymer, vinylnaphthalene-maleic acid copolymer, acetic acid Vinyl-ethylene copolymer, vinyl acetate-fatty acid vinyl Examples thereof include ethylene copolymers, vinyl acetate-maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers, and the like.
As such a water-soluble polymer compound, an appropriately synthesized product or a commercially available product may be used.
Examples of the commercially available products include Johnson Polymer Co., Ltd., Nagase ChemteX Co., Ltd., Toagosei Co., Ltd., Mitsubishi Rayon Co., Ltd., Sumitomo Seika Co., Ltd., JSR Co., Ltd., Showa Polymer Co., Ltd., Arakawa Chemical Co., Ltd. , Nippon Shokubai Co., Ltd., Nippon Synthetic Chemical Co., Ltd., Kuraray Co., Ltd., etc.

  The colorant is not particularly limited and may be appropriately selected depending on the purpose, but is mainly a pigment, but contains a dye within a range that does not deteriorate the weather resistance for the purpose of color tone adjustment. It doesn't matter.

There is no restriction | limiting in particular as said pigment, According to the objective, it can select suitably, For example, any of an inorganic pigment and an organic pigment may be sufficient.
Examples of the inorganic pigment include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, and carbon black. Among these, carbon black is particularly preferable. In addition, as said carbon black, what was manufactured by well-known methods, such as a contact method, a furnace method, and a thermal method, is mentioned, for example.

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

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

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

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

There is no restriction | limiting in particular as said dye, According to the objective, it can select suitably, For example, an acidic dye, a direct dye, a basic dye, a reactive dye etc. are mentioned.
There is no restriction | limiting in particular as said acidic dye, According to the objective, it can select suitably, What is known as a food dye, etc. are mentioned, for example, C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142; C.I. I. Acid Red 1, 8, 13, 14, 18, 26, 27, 35, 37, 42, 52, 82, 87, 89, 92, 97, 106, 111, 114, 115, 134, 186, 249, 254 289; C.I. I. Acid Blue 9, 29, 45, 92, 249; I. Acid Black 1, 2, 7, 24, 26, 94; I. Food Yellow 2, 3, 4; C.I. I. Food Red 7, 9, 14; C.I. I. Food black 1, 2, etc. are mentioned.

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

  Examples of the basic dye include C.I. I. Basic Yellow 1, 2, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 40, 41, 45, 49, 51, 53, 63, 465, 67 70, 73, 77, 87, 91; C.I. I. Basic Red 2, 12, 13, 14, 15, 18, 22, 23, 24, 27, 29, 35, 36, 38, 39, 46, 49, 51, 52, 54, 59, 68, 69, 70 73, 78, 82, 102, 104, 109, 112; I. Basic Blue 1, 3, 5, 7, 9, 21, 22, 26, 35, 41, 45, 47, 54, 62, 65, 66, 67, 69, 75, 77, 78, 89, 92, 93 105, 117, 120, 122, 124, 129, 137, 141, 147, 155; I. Basic black 2, 8, etc. are mentioned.

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

  There is no restriction | limiting in particular as content in the said recording ink of the said coloring agent, Although it can select suitably according to the objective, 5 mass% or more is preferable and 5-15 mass% is more preferable. If the content is less than 5% by mass, the image density may be low and the image may have no contrast. If the content exceeds 15% by mass, it is difficult to ensure the dispersion stability of the colorant. Such clogging is likely to occur, and reliability may deteriorate.

-Wetting agent-
The wetting agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3- Butanediol, 2,3-butanediol, 1,4-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, tetraethylene glycol, 1,6-hexanediol, 2-methyl- Examples include 2,4-pentanediol, polyethylene glycol, 1,2,4-butanetriol, 1,2,6-hexanetriol, and the like. These may be used individually by 1 type and may use 2 or more types together.
Among these, a polyhydric alcohol having an equilibrium water content of 25% by mass or more in an environment of 20 ° C. and 60% RH is obtained because the effect of reducing the water evaporation rate of ink and improving the ink ejection reliability can be obtained. Among these polyhydric alcohols, glycerin is particularly preferable because it has a high effect of suppressing the aggregation of the colorant and preventing the particle size from increasing, although the viscosity rapidly increases as the water evaporates.
One of the polyhydric alcohols is glycerin, and the content of the glycerin is preferably 60% by mass or less, and more preferably 50% by mass or less of the whole wetting agent.

  As the wetting agent used in combination with the glycerin, 1,3-butanediol is particularly preferable. The 1,3-butanediol, like glycerin, has a high equilibrium moisture content, high reliability, and uniform pixel spreading when the ink lands on the paper, and also keeps the color material on the paper surface. Is also expensive. Glycerin has a high reliability improvement effect, but when added in a large amount, the image quality deteriorates, and the viscosity increase after evaporation of water becomes too large, and the discharge stability may also deteriorate. 1: 5-5: 1 are preferred.

  The content of the wetting agent in the recording ink is preferably 10 to 50% by mass, and more preferably 20 to 35% by mass. When the content is small, the storage stability and ejection stability of the ink are deteriorated, and nozzle clogging is likely to occur. On the other hand, if the amount of the wetting agent is too large, the drying property is deteriorated, bleeding of characters and bleeding of the color boundary occurs, and the image quality is deteriorated.

-Surfactant-
The surfactant is not particularly limited, and can be appropriately selected from surfactants that do not impair dispersion stability, depending on the combination of the type of colorant, the wetting agent, and the water-soluble organic solvent. However, a surfactant having only a carbon chain in the hydrophobic group is insufficient for penetrating a paper having a high solid content and a high viscosity as described above. At least one selected from an agent and a fluorosurfactant is preferred. Among these, a fluorine-based surfactant is particularly preferable.

  Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. And polyoxyalkylene ether polymer compounds. Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain has a low foaming property, and also has a low bioaccumulation property of a fluorine compound that has been regarded as a problem in recent years. preferable.

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

As said fluorosurfactant, what was synthesize | combined suitably may be used and a commercial item may be used.
Examples of the commercially available products include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.), Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited), MegaFuck F-470, F1405 , F-474 (all manufactured by Dainippon Ink & Chemicals, Inc.), Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all manufactured by DuPont) , FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), PF 151N (manufactured by Omninova) and the like. Among these, FT-110, FT-250, and FT-251 manufactured by Neos Co., Ltd. are particularly preferable in terms of remarkably improving good print quality, color developability, and leveling on paper. FT-400S, FT-150, FT-400SW, and OM-nova PF-151N are particularly preferable.
As specific examples of the fluorine-based surfactant, those represented by the following general formula are suitable.

(1) Anionic fluorosurfactant
In the general formula, Rf represents a mixture of fluorine-containing hydrophobic groups represented by the following structural formula. A is —SO ₃ X, —COOX, or —PO ₃ X (where X is a counter anion, specifically, a hydrogen atom, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, , NH ₂ (CH ₂ CH ₂ OH) ₂ , or NH (CH ₂ CH ₂ OH) ₃ ).

In the general formula, Rf ′ represents a fluorine-containing group represented by the following structural formula. X represents the same meaning as described above. n represents an integer of 1 or 2, and m represents 2-n.
However, n represents the integer of 3-10.

However, in the general formula, Rf ′ and X have the same meaning as described above.

However, in the general formula, Rf ′ and X have the same meaning as described above.

(2) Nonionic fluorosurfactant
However, in the said general formula, Rf represents the same meaning as the above. n represents an integer of 5 to 20.

In the general formula, Rf ′ represents the same meaning as described above. n represents an integer of 1 to 40.

(3) Amphoteric fluorosurfactant
However, in the said general formula, Rf represents the same meaning as the above.

(4) Oligomer type fluorosurfactant
In the general formula, Rf ″ represents a fluorine-containing group represented by the following structural formula. N represents an integer of 0 to 10. X represents the same meaning as described above.
However, n represents the integer of 1-4.

Here, Rf ″ represents the same meaning as above. L represents an integer of 0 to 10, m represents an integer of 0 to 10, and n represents an integer of 0 to 10.

The silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, side Examples thereof include polydimethylsiloxane modified at both chain ends, and those having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group are particularly preferable because they exhibit good properties as an aqueous surfactant.
As such a surfactant, an appropriately synthesized product or a commercially available product may be used.
Such commercially available products can be easily obtained from, for example, Big Chemie, Shin-Etsu Silicone, Toray Dow Corning Silicone, etc.

In addition to the fluorine surfactant and the silicone surfactant, anionic surfactants, nonionic surfactants, amphoteric surfactants, acetylene glycol surfactants, and the like can be used.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, oxalate sulfonate, laurate, and polyoxyethylene alkyl ether sulfate salt.
Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene polyoxypropylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, Examples thereof include oxyethylene alkyl phenyl ether, polyoxyethylene alkyl amine, and polyoxyethylene alkyl amide.
Examples of the amphoteric surfactant include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, lauryl dihydroxyethyl betaine, lauryl dimethylamine oxide, myristyl dimethylamine oxide, stearyl dimethylamine oxide, dihydroxyethyl lauryl amine oxide, Polyoxyethylene coconut oil alkyl dimethylamine oxide, dimethyl alkyl (coconut) betaine, dimethyl lauryl betaine, etc. are mentioned.
Examples of such surfactants include commercially available products such as Nikko Chemicals Co., Ltd., Nippon Emulsion Co., Ltd., Nippon Shokubai Co., Ltd., Toho Chemical Co., Ltd., Kao Co., Ltd., Adeka Co., Ltd., Lion Co., Ltd., Aoki Yushi Co., Ltd. It can be easily obtained from Sanyo Chemical Industries, Ltd.
Examples of the acetylene glycol surfactants include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyn-3-ol and the like can be mentioned. Examples of commercially available acetylene glycol surfactants include Surfynol 104, 82, 465, 485, and TG manufactured by Air Products (USA).
The surfactant is not limited to these, and may be used alone or in combination. Even if it is not easily dissolved by itself in the recording liquid, it can be solubilized by mixing and exist stably.

  Among these surfactants, nonionic surfactants represented by the following structural formulas (1) to (5) are preferable.

^{_{R 1 -O- (CH 2 CH 2}} O) h -R 2 ··· structural formula (1)
However, in said structural formula (1), R < ¹ > represents the C6-C14 alkyl group which may be branched, or the C6-C14 perfluoroalkyl group which may be branched. R ² represents a hydrogen atom or an optionally branched alkyl group having 1 to 4 carbon atoms. h represents an integer of 5 to 20.

^{_{R 1 -COO- (CH 2 CH 2}} O) h -R 2 ··· structural formula (2)
However, the in the structural formula (2), R ¹ represents an alkyl group which may be branched having 6 to 14 carbon atoms. R ² represents a hydrogen atom or an optionally branched alkyl group having 1 to 4 carbon atoms. h represents an integer of 5 to 20.

In the Structural formula (3), R ³ represents a hydrocarbon group, for example, such as an alkyl group branched carbon atoms and optionally 6-14. k represents an integer of 5 to 20.

However, the structural formula (4), R ⁴ represents a hydrocarbon group, for example, an alkyl group branched carbon atoms and optionally 6-14. L represents an integer of 5 to 10, and p represents an integer of 5 to 20. The propylene glycol chain and the ethylene glycol chain may be block polymerized or randomly polymerized.

However, in said structural formula (5), q and r represent the integer of 5-20, respectively.

  The content of the surfactant in the recording ink is preferably 0.01 to 5% by mass, and more preferably 0.5 to 2% by mass. When the content is less than 0.01% by mass, the effect of adding the surfactant may be lost. When the content exceeds 5% by mass, the permeability to the recording medium becomes higher than necessary, and the image density is reduced. Decrease or strikethrough may occur.

-Water dispersible resin-
There is no restriction | limiting in particular as said water dispersible resin, Although it can select suitably according to the objective, For example, a condensation type synthetic resin, an addition type synthetic resin, a natural polymer compound, etc. are mentioned.
Examples of the condensed synthetic resin include polyester resins, polyurethane resins, polyepoxy resins, polyamide resins, polyether resins, and silicon resins. 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.
The water-dispersible resin may be used as a homopolymer, may be used as a copolymer and used as a composite resin, and is any of a single-phase structure type, a core-shell type, and a power feed type emulsion. Can also be used.

  As the water-dispersible resin, a resin itself having a hydrophilic group and having a self-dispersibility, a resin itself having no dispersibility and having a dispersibility with a surfactant or a resin having a hydrophilic group can be used. . Among these, an emulsion of resin particles obtained by emulsion and suspension polymerization of an ionomer of a polyester resin or a polyurethane resin or an unsaturated monomer is optimal. In the case of emulsion polymerization of an unsaturated monomer, a resin emulsion is obtained by reacting with water to which an unsaturated monomer, a polymerization initiator, a surfactant, a chain transfer agent, a chelating agent, a pH adjusting agent and the like are added. Therefore, a water-dispersible resin can be easily obtained, and the resin properties can be easily changed, so that desired properties can be easily produced.

  Examples of the unsaturated monomer include unsaturated carboxylic acids, (meth) acrylic acid ester monomers, (meth) acrylic acid amide monomers, aromatic vinyl monomers, vinyl cyanide compounds. A monomer, a vinyl monomer, an allyl compound monomer, an olefin monomer, a diene monomer, an oligomer having an unsaturated carbon, and the like can be used alone or in combination. By combining these monomers, the properties can be flexibly modified, and the properties of the resin can be modified by performing a polymerization reaction or a graft reaction using an oligomer type polymerization initiator.

Examples of the unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid and the like.
Examples of the monofunctional (meth) acrylic acid esters include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, and 2-ethylhexyl methacrylate. Octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, methacryloxyethyl trimethylammonium salt, 3 -Metacry Xylpropyltrimethoxysilane, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, decyl acrylate, Examples include dodecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, dimethylaminoethyl acrylate, and acryloxyethyl trimethyl ammonium salt.
Examples of the polyfunctional (meth) acrylic acid esters include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, and 1,4-butylene. Glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol dimethacrylate, 2,2'-bis (4-methacryloxydiethoxyphenyl) ) Propane, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, polyethyleneglycol Diacrylate, Triethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,9-nonanediol di Acrylate, polypropylene glycol diacrylate, 2,2′-bis (4-acryloxypropyloxyphenyl) propane, 2,2′-bis (4-acryloxydiethoxyphenyl) propane trimethylolpropane triacrylate, trimethylolethanetri Acrylate, tetramethylol methane triacrylate, ditrimethylol tetraacrylate, tetramethylol methane tetraacrylate, pentaerythritol tetraacrylate, dipentaene Sri hexaacrylate, and the like.

Examples of the (meth) acrylic acid amide monomers include acrylamide, methacrylamide, N, N-dimethylacrylamide, methylenebisacrylamide, and 2-acrylamido-2-methylpropanesulfonic acid.
Examples of the aromatic vinyl monomers include styrene, α-methylstyrene, vinyltoluene, 4-t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene, divinylbenzene, and the like.
Examples of the vinylcyan compound monomers include acrylonitrile and methacrylonitrile.
Examples of the allyl compound monomers include allyl sulfonic acid or a salt thereof, allylamine, allyl chloride, diallylamine, diallyldimethylammonium salt and the like.
Examples of the olefin monomers include ethylene and propylene.
Examples of the diene monomers include butadiene and chloroprene.
Examples of the vinyl monomers include vinyl acetate, vinylidene chloride, vinyl chloride, vinyl ether, vinyl ketone, vinyl pyrrolidone, vinyl sulfonic acid or a salt thereof, vinyl trimethoxysilane, and vinyl triethoxysilane.
Examples of the oligomers having unsaturated carbon include styrene oligomers having methacryloyl groups, styrene-acrylonitrile oligomers having methacryloyl groups, methyl methacrylate oligomers having methacryloyl groups, dimethylsiloxane oligomers having methacryloyl groups, and polyesters having acryloyl groups. An oligomer etc. are mentioned.

The water-dispersible resin has a strong alkalinity and strong acidity, and causes molecular breakage such as dispersion breakage and hydrolysis. Therefore, the pH is preferably 4 to 12, particularly from the viewpoint of miscibility with a water-dispersible colorant. As for pH, 6-11 are more preferable, and 7-9 are still more preferable.
The particle size of the water-dispersible resin is related to the viscosity of the dispersion. When the composition is the same, the smaller the particle size, the larger the viscosity at the same solid content. The average particle size of the water-dispersible resin is preferably 50 nm or more so as not to have an excessively high viscosity when converted into an ink. In addition, when the particle size is several tens of microns, it becomes larger than the nozzle opening of the ink jet head and cannot be used. It is known that if particles having a large particle diameter exist in the ink even if they are smaller than the nozzle opening, the ejection property is deteriorated. Therefore, the average particle diameter is more preferably 500 nm or less, and even more preferably 150 nm or less, in order not to inhibit the ink ejection properties.

The water-dispersible resin has a function of fixing the water-dispersed colorant on the paper surface, and is preferably formed into a film at room temperature to improve the fixability of the color material. Therefore, the minimum film-forming temperature (MFT) of the water-dispersible resin is preferably normal temperature or lower, and more preferably 20 ° C. or lower.
Further, when the glass transition temperature of the water-dispersible resin is -40 ° C. or lower, the resin film becomes more viscous and the printed matter is tacky. Therefore, the water-dispersible resin has a glass transition temperature of −30 ° C. or higher. It is preferable.

  The content of the water-dispersible resin in the recording ink is preferably 4 to 27% by mass and more preferably 8 to 20% by mass in terms of solid content.

-Penetration agent-
The penetrant preferably contains at least one polyol compound having a solubility in water at 20 ° C. of 0.2 to 5.0 mass%. Examples of such an aliphatic diol as the polyol compound include 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, and 2,2-diethyl-1. , 3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene -1,2-diol, 2-ethyl-1,3-hexanediol and the like.
Among these, 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol are particularly preferable.
Other penetrants that can be used in combination are not particularly limited as long as they can be dissolved in the ink and adjusted to the desired physical properties, and can be appropriately selected according to the purpose. For example, diethylene glycol monophenyl ether, ethylene Examples thereof include alkyl and aryl ethers of polyhydric alcohols such as glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether and tetraethylene glycol chlorophenyl ether, and lower alcohols such as ethanol.
The content of the penetrant in the recording ink is preferably 0.1 to 4.0% by mass. When the content is less than 0.1% by mass, quick-drying may not be obtained and a blurred image may be obtained. When the content exceeds 4.0% by mass, the dispersion stability of the colorant is impaired, and the nozzle In some cases, clogging is likely to occur, and the permeability to the recording medium is increased more than necessary, resulting in a decrease in image density and back-through.

  The other components are not particularly limited and may be appropriately selected as necessary. For example, a pH adjuster, antiseptic / antifungal agent, chelating reagent, rust inhibitor, antioxidant, ultraviolet absorber, oxygen An absorber, a light stabilizer, etc. are mentioned.

The pH adjuster is not particularly limited as long as it can adjust the pH to a desired value without adversely affecting the recording ink to be prepared, and can be appropriately selected according to the purpose. Examples include alcohol amines, alkali metal hydroxides, ammonium hydroxides, phosphonium hydroxides, and alkali metal carbonates.
Examples of the alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, and the like.
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide.
Examples of the ammonium hydroxide include ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, and the like.
Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, and potassium carbonate.

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

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

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

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

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

  The recording ink of the present invention contains at least a colorant, a water-dispersible resin, a wetting agent, and a surfactant, and further disperses or dissolves other components in an aqueous medium as necessary. It can be manufactured by stirring and mixing as necessary. The dispersion can be performed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, etc., and stirring and mixing are performed by a stirrer using a normal stirring blade, a magnetic stirrer, a high-speed disperser, or the like. be able to.

  The pH of the recording ink of the present invention is not particularly limited and can be appropriately selected according to the purpose, but is preferably 7 to 11. If the pH is too low, there is a high risk of dissolving a metal member that comes into contact with ink, such as a head. If the pH is too high, there is a risk of dissolving a glass member or a resin member. May be high. In addition, when a metal member is used, dissolution tends to proceed minutely even in a weakly acidic region, and problems are likely to occur in the long term. Therefore, a weak alkali region is preferable. Furthermore, since many of the dyes and pigments are anionic, there is an advantage that the alkaline region where ion detachment easily occurs is more easily dissolved or dispersed.

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

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

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

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

Next, the ink cartridge will be described with reference to FIGS. Here, FIG. 4 is a view showing an example of the ink cartridge of the present invention, and FIG. 5 is a view including a case (exterior) of the ink cartridge 200 of FIG.
As shown in FIG. 4, the ink cartridge 200 is filled into the ink bag 241 from the ink inlet 242 and exhausted, and then the ink inlet 242 is closed by fusion. In use, the needle of the apparatus main body is pierced into the ink discharge port 243 made of a rubber member and supplied to the apparatus.
The ink bag 241 is formed of a packaging member such as a non-permeable aluminum laminate film. As shown in FIG. 5, the ink bag 241 is usually housed in a plastic cartridge case 244 and is detachably mounted on various ink jet recording apparatuses.

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

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

-Ink flying process and ink flying means-
The ink flying step is a step of forming an image by applying a stimulus to the recording ink of the present invention and causing the recording ink to fly.
The ink flying means is means for forming an image by applying a stimulus to the recording ink of the present invention and causing the recording ink to fly. The ink flying means is not particularly limited, and examples thereof include various nozzles for ejecting ink.
In the present invention, it is preferable that at least a part of the liquid chamber portion, the fluid resistance portion, the vibration plate, and the nozzle member of the ink jet head is formed of a material containing at least one of silicon and nickel.
The nozzle diameter of the inkjet nozzle is preferably 30 μm or less, and preferably 1 to 20 μm.
In addition, it is preferable that a sub tank for supplying ink is provided on the ink jet head, and the sub tank is replenished with ink from an ink cartridge through a supply tube.

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

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

  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. And a method of discharging and jetting. 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 2 to 40 pl, the ejection speed is preferably 6 to 20 m / s, and the driving frequency is preferably 1 kHz or more. The resolution is preferably 300 dpi or more.
In addition, it is preferable that ink is ejected to either the print area or the non-print area before moisture evaporation near the nozzle exceeds 30%.

  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.

One mode for carrying out the ink jet recording method of the present invention by the ink jet recording apparatus of the present invention will be described with reference to the drawings. The ink jet recording apparatus shown in FIG. 6 stocks an apparatus main body 101, a paper feed tray 102 for loading paper mounted on the apparatus main body 101, and paper on which an image is recorded (formed) mounted on the apparatus main body 101. A paper discharge tray 103 and an ink cartridge loading unit 104. In FIG. 6, reference numeral 111 denotes an upper cover, and 112 denotes a front surface.
On the upper surface of the ink cartridge loading unit 104, an operation unit 105 such as operation keys and a display is arranged. The ink cartridge loading unit 104 has a front cover 115 that can be opened and closed for attaching and detaching the ink cartridge 201.

  In the apparatus main body 101, as shown in FIGS. 7 and 8, a carriage 133 is slid in the main scanning direction by a guide rod 131 and a stay 132, which are guide members horizontally mounted on left and right side plates (not shown). The main scanning motor (not shown) moves and scans in the direction indicated by the arrow in FIG.

The carriage 133 includes a plurality of ink jet recording heads 134 including four ink jet recording heads that eject recording ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). The ejection ports are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing downward.
As the ink jet recording head constituting the recording head 134, a piezoelectric actuator such as a piezoelectric element, a thermal actuator using phase change due to liquid film boiling using an electrothermal transducer such as a heating resistor, a metal phase due to temperature change, etc. A shape memory alloy actuator using a change, an electrostatic actuator using an electrostatic force, or the like as an energy generating means for discharging recording ink can be used.
In addition, the carriage 133 is equipped with a sub tank 135 for each color for supplying ink of each color to the recording head 134. The sub-tank 135 is supplied with and supplemented with the recording ink of the present invention from the ink cartridge 201 of the present invention loaded in the ink cartridge loading section 105 via a recording ink supply tube (not shown).

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

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

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

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

In this ink jet recording apparatus, the paper 142 is separated and fed one by one from the paper feed unit, and the paper 142 fed substantially vertically upward is guided by the guide 145 and between the transport belt 151 and the counter roller 152. It is sandwiched and conveyed. Further, the leading end is guided by the conveying guide 153 and pressed against the conveying belt 151 by the leading end pressure roller 155, and the conveying direction is changed by approximately 90 °.
At this time, the conveyance belt 157 is charged by the charging roller 156, and the sheet 142 is conveyed by being electrostatically attracted to the conveyance belt 151. Therefore, by driving the recording head 134 according to the image signal while moving the carriage 133, ink droplets are ejected onto the stopped paper 142 to record one line, and after the paper 142 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 142 has reached the recording area, the recording operation is terminated and the sheet 142 is discharged onto the discharge tray 103.
When the recording ink remaining amount near end in the sub tank 135 is detected, a required amount of recording ink is supplied from the ink cartridge 201 to the sub tank 135.

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

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

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

(Ink record)
The ink recorded matter recorded by the ink jet recording apparatus and the ink jet recording method of the present invention is the ink recorded matter of the present invention. The ink recorded matter of the present invention has an image recorded on the recording medium using the recording ink of the present invention.
There is no restriction | limiting in particular as said recording medium, According to the objective, it can select suitably, For example, a plain paper, glossy paper, special paper, cloth, a film, an OHP sheet etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, as the recording medium, those having a Steecht sizing degree of 3 seconds or more are particularly preferable.
The ink recorded matter has high image quality, no bleeding, excellent temporal stability, and can be suitably used for various purposes as a material on which various prints or images are recorded.

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

(Production Example 1)
-Preparation of polymer solution A-
After sufficiently replacing the inside of a 1 L flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet tube, reflux tube, and dropping funnel, 11.2 g of styrene, 2.8 g of acrylic acid, 12.0 g of lauryl methacrylate Then, 4.0 g of polyethylene glycol methacrylate, 4.0 g of styrene macromer, and 0.4 g of mercaptoethanol were mixed and heated to 65 ° C. Next, 100.8 g of styrene, 25.2 g of acrylic acid, 108.0 g of lauryl methacrylate, 36.0 g of polyethylene glycol methacrylate, 60.0 g of hydroxylethyl methacrylate, 36.0 g of styrene macromer, 3.6 g of mercaptoethanol, azobismethylvalero A mixed solution of 2.4 g of nitrile and 18 g of methyl ethyl ketone was dropped into the flask over 2.5 hours. After dropping, a mixed solution of 0.8 g of azobismethylvaleronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hours. Next, after aging at 65 ° C. for 1 hour, 0.8 g of azobismethylvaleronitrile was added, and further aging was performed for 1 hour. After completion of the reaction, 364 g of methyl ethyl ketone was added to the flask to prepare 800 g of polymer solution A having a concentration of 50% by mass.

-Preparation of pigment-containing polymer fine particle water dispersion-
Next, 28 g of the obtained polymer solution A, C.I. I. . 42 g of CI Pigment Red 122, 13.6 g of a 1 mol / L potassium hydroxide aqueous solution, 20 g of methyl ethyl ketone, and 13.6 g of ion-exchanged water were sufficiently stirred, and then kneaded using a roll mill. The obtained paste was put into 200 g of pure water and sufficiently stirred, and then the methyl ethyl ketone and water were distilled off using an evaporator, and the magenta polymer fine particles of Production Example 1 containing 15% by mass of pigment and 20% by mass of solid were prepared. An aqueous dispersion was prepared.

(Production Example 2)
-Preparation of surface-treated pigment dispersion-
90 g of carbon black having a CTAB specific surface area of 150 m ² / g and DBP oil absorption of 100 ml / 100 g is added to 3,000 ml of 2.5N sodium sulfate solution, stirred at a temperature of 60 ° C. and a speed of 300 rpm, and reacted for 10 hours. Oxidation treatment was performed. The reaction solution was filtered, and the carbon black separated by filtration was neutralized with a sodium hydroxide solution and subjected to ultrafiltration. The obtained carbon black was washed with water, dried, and dispersed in pure water so as to have a solid content of 20% by mass to prepare a black pigment dispersion of Production Example 2.

(Production Example 3)
-Preparation of pigment surfactant dispersion-
C. I. . Pigment Blue 15: 3 (100 g), polyoxyethylene oleyl ether ammonium sulfate (24.8 g) and pure water (175.2 g) were mixed, dispersed in a wet sand mill, mixed with pure water (414.3 g), and centrifuged. Coarse particles were removed. Thus, a cyan pigment dispersion of Production Example 3 having a pigment content of 14% by mass and a solid content of 17.5% by mass was produced.

(Production Example 4)
-Preparation of polymer fine particle dispersion B-
After thoroughly replacing nitrogen gas in a 1 L flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet tube, reflux tube, and dropping funnel, Latemul S-180 (reactive emulsifier with unsaturated carbon, Kao Corporation) 8.0 g and ion-exchanged water 350 g were added and mixed, and the temperature was raised to 65 ° C. After temperature increase, 3.0 g of reaction initiator t-butyl peroxobenzoate and 1.0 g of sodium isoascorbate were added, and after 5 minutes, 45 g of methyl methacrylate, 160 g of 2-ethylhexyl methacrylate, 5 g of acrylic acid, butyl methacrylate 45 g, 30 g of cyclohexyl methacrylate, 15 g of vinyltriethoxysilane, 8.0 g of Latemule S-180, and 340 g of ion-exchanged water were mixed and added dropwise over 3 hours. Then, after heat aging at 80 ° C. for 2 hours, the mixture was cooled to room temperature and the pH was adjusted to 7-8 with sodium hydroxide. Ethanol was distilled off using an evaporator and the water content was adjusted to prepare 730 g of the polymer dispersion B solution of Production Example 4 having a solid content of 40% by mass.

(Examples 1 to 13, Reference Examples 14 to 16 and Comparative Examples 1 to 12)
Each recording ink was manufactured by the following procedure.
First, a wetting agent, a penetrating agent, a surfactant, and water shown in Tables 1 to 4 were mixed, and stirred for 1 hour to mix uniformly. A water-dispersible resin was added to the obtained mixed liquid and stirred for 1 hour, and a pigment dispersion and an antifoaming agent were added and stirred for 1 hour. This dispersion was subjected to pressure filtration through a cellulose acetate membrane filter having an average pore diameter of 0.8 μm to remove coarse particles and dust, and each recording ink used for evaluation was produced.
For Example 3 and Comparative Example 1, a pigment dispersion, a water-dispersible resin, and glycerin were mixed and concentrated by an evaporator to prepare a concentrated dispersion mixed solution. Separately, a wetting agent, a penetrating agent, a surfactant, and water were mixed and stirred for 1 hour to mix uniformly. The concentrated dispersion mixed solution and the antifoaming agent were added to the obtained mixed solution and stirred for 1 hour. This dispersion was subjected to pressure filtration through a cellulose acetate membrane filter having an average pore diameter of 0.8 μm to remove coarse particles and dust, and each recording ink used for evaluation was produced.

In Tables 1 to 4, abbreviations have the following meanings.
・ Jurimer ET-410: Soap-free acrylic copolymer emulsion (manufactured by Nippon Pure Chemical Co., Ltd., solid content 30% by mass, pH 8.0, glass transition temperature (Tg) 44 ° C.)
Nipol LX430: modified styrene-butadiene copolymer emulsion (manufactured by Nippon Zeon Co., Ltd., solid content 49 mass%, pH 7.0, glass transition temperature (Tg) 12 ° C.)
Polyfox PF-151N: oligomer type nonionic fluorosurfactant (manufactured by OMNOVA, component 50 mass%, butyl carbitol 10 mass%)
・ Zonyl FSO-100, FS-300: polyoxyethylene perfluoroalkyl ether (manufactured by DuPont, component 100 mass%)
-Softanol EP-5035: polyoxyethylene polyoxypropylene branched alkyl ether (manufactured by Nippon Shokubai Co., Ltd., component 100% by mass)
Proxel GXL: Antifungal agent containing 1,2-benzisothiazolin-3-on as a main component (Avicia, 20% by mass, containing dipropylene glycol)
KS508: Self-emulsifying silicone defoaming agent (manufactured by Shin-Etsu Silicone Co., Ltd., 100% by mass)

  Next, various characteristics of the obtained recording inks were evaluated as follows. The results are shown in Tables 5-8.

<Measurement of ink properties>
The viscosity of the ink was measured at 25 ° C. using a viscometer (RL-500, manufactured by Toki Sangyo Co., Ltd.).
The surface tension of the ink was measured at 25 ° C. using a fully automatic surface tension meter (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

<Preparation for printing evaluation>
Using an inkjet printer (IPSIO G707, manufactured by Ricoh Co., Ltd.) in an environment adjusted to a temperature of 23 ° C. and 50% RH, the drive voltage of the piezo element is varied so that the amount of ink discharged is uniform, and the recording medium Was set so that the same amount of ink was attached to the.

<Discharge stability>
200 charts are continuously printed on a solid image of 5% of A4 size paper per color created by Microsoft Word 2000 (manufactured by Microsoft) on Type 6200 (manufactured by NBS Ricoh Co., Ltd.), and each nozzle is ejected after ejection. Evaluated from disturbance. The printing mode used was a driver attached to the printer, in which the “plain paper-standard faster” mode was changed to “no color correction” than the user setting for plain paper.
〔Evaluation criteria〕
○: No discharge disturbance ×: Discharge disturbance or no discharge

<Print density>
A chart with 64 point characters “■” created by Microsoft Word 2000 (manufactured by Microsoft) is printed on Xerox 4024 (manufactured by Fuji Xerox Co., Ltd.), and the “■” portion of the printed surface is measured by X-Rite 938. Judgment was made according to the following evaluation criteria. The print mode used was a driver attached to the printer in which the “plain paper-standard fast” mode was changed to “no color correction” from the user setting for plain paper.
〔Evaluation criteria〕
○: Black 1.15 or more, Color 0.85 or more Δ: Black 1.05 or more and less than 1.15, Color 0.75 or more and less than 0.85 ×: Black less than 1.05, Color 0.75 Is less than

<Betrayal>
The chart was punched out in the same manner as the print density, and the “■” portion on the back surface was measured with X-Rite 938, and the background color of the paper was subtracted to make the determination according to the following evaluation criteria.
〔Evaluation criteria〕
○: Less than 0.05 Δ: 0.05 or more and less than 0.1 ×: 0.1 or more

<Water resistance>
Similar to the print density, the chart was punched onto Type 6200 (manufactured by NBS Ricoh Co., Ltd.), and the “■” portion of the printed surface was dried at 23 ° C. and 50% RH for 24 hours. After being immersed for a minute, it was gently lifted, left to dry, and judged according to the following evaluation criteria.
〔Evaluation criteria〕
○: No color exudation ×: Color exudation

<Abrasion resistance>
A chart with a solid solid image of 3 cm x 3 cm created by Microsoft Word 2000 (manufactured by Microsoft) was ejected onto a glossy glossy paper dedicated to the ricoh gel jet printer (manufactured by NBS Ricoh Co., Ltd.) and 24 ° C at 23 ° C and 50% RH. After drying for 10 hours, JIS L0803 Cotton No. 3 attached to the CM-1 type clock meter with double-sided tape was reciprocated 10 times so that it touches the printed part, and then ink adhesion stain on the cotton cloth was measured with X-Rite 938. The density of the soiled portion obtained by subtracting the background color of the cotton cloth was determined according to the following evaluation criteria.
〔Evaluation criteria〕
○: The density of the dirty part is less than 0.1 ×: The density of the dirty part is 0.1 or more

<Marker resistance>
A chart with character strings using Gothic fonts created with Microsoft Word 2000 (manufactured by Microsoft) is printed on Type 6200 (manufactured by NBS Ricoh Co., Ltd.), and the character string portion of the printed surface is printed 10 minutes after printing. Marker pens were marked with optics (yellow), and ink penetrating with a highlighter pen was checked for the presence or absence of stains according to the following criteria.
〔Evaluation criteria〕
○: No dirt △: There is a slight dirt that can be identified by staring ×: There is dirt

<Text quality>
Charts with character strings of 4 to 20 points created with Microsoft Word 2000 (manufactured by Microsoft) are Type 6200, My Paper, My Recycle Paper 100 (all manufactured by NBS Ricoh Co., Ltd.), Xerox 4024 (Fuji Xerox Co., Ltd.), PB paper (manufactured by Canon), Yamayuri paper (manufactured by Oji Paper Co., Ltd.), 4CC 100 g / m ² (manufactured by STORANSO), Tidal MP (manufactured by HAMMER MILL), and the character string portion of the printed printing surface The degree of ink bleeding was determined according to the following criteria.
〔Evaluation criteria〕
◎: Vivid print without blurring ○: Whisker-like blurring occurs on some paper, but it looks clear if it is not enlarged △: Beard-like blurring occurs on all papers and does not enlarge And the print looks thick ×: Smear can be confirmed without enlargement

<Drying>
A chart was punched out in the same manner as the print density, and the “■” portion of the print surface printed on Type 6200 (manufactured by NBS Ricoh Co., Ltd.) was pressed against the filter paper immediately after printing, and the presence or absence of transfer was determined according to the following criteria.
〔Evaluation criteria〕
○: No transfer stain △: Slight transfer stain ×: Transfer stain

In Table 7, “-” indicates that the ink was not discharged, resulting in nozzle omission and ink discharge bending, and as a result, an evaluable image was not obtained, so measurement was not performed.

In Table 8, “−” indicates that the ink was not discharged, resulting in nozzle omission and ink discharge bending, and as a result, an evaluable image was not obtained, and thus measurement was not performed.

  From the results of Tables 5 to 8, (1) the total content of the colorant and the water-dispersible resin is 10 to 30% by mass in solid content, and (2) the solid content of the water-dispersible resin (C ) The ratio (B / C) of the solid content (B) of the colorant to 0.1) to 1.6, and (3) the viscosity at 25 ° C. is 5 to 20 mPa · s, and (4) The recording inks of Examples 1 to 16 that satisfy all the requirements of the surface tension of 35 mN / m or less do not satisfy at least one of the above requirements (1) to (4). High color development, image quality, and reliability can be secured compared to conventional ink, and high-quality image formation with high color saturation and good color tone is possible not only on dedicated recording paper but also on plain paper. Admitted.

(Experiment 1)
-Effect on color development due to increase in total solid content of colorant and water-dispersible resin-
The pigment-containing polymer fine particle water of Production Example 1 is obtained by mixing 20 parts by mass of 3-methyl-1,3-butanediol, 10 parts by mass of glycerin, 1 part by mass of octanediol, and 0.8 parts by mass of Zonyl FSO-100. A recording ink was prepared by adding the dispersion and the polymer dispersion B of Production Example 4.
The pigment-containing polymer fine particle water dispersion of Production Example 1 was increased as Group A, and the pigment-containing polymer fine particle water dispersion of Production Example 1 was 6.67 parts by mass as Group B. Each increased recording ink was prepared.
Next, settings were made so that the same amount of ink was applied to the recording medium, and a gradation chart was printed on a glossy glossy paper exclusively for the gel jet printer manufactured by Ricoh Co., Ltd. The color of the image was measured with X-Rite 938, and the saturation at the same image density (0.8) was obtained as a result. The relationship between the obtained saturation and the total solid content of the colorant and the water-dispersible resin is shown in FIG.
The saturation is a value obtained by the following formula of CIE (1976) ab chroma (C ^* _ab ) based on JIS Z8729.
_{^{C * ab = [(a *}} ) 2 + (b *) 2] 0.5
From the results shown in FIG. 1, it can be seen that the increase in the solid content due to the increase in the pigment seen in Group A has a marked drop in saturation and is inferior to Group B. It was confirmed that the increase in the solid content by the addition of the water-dispersible resin can suppress the influence on the color development to a lower level than just increasing the pigment.

(Experiment 2)
-Measurement of viscosity increase and particle size change accompanying water evaporation-
Each of the recording inks obtained in Examples 2, 3, and 5 was left in an environment of 50 ° C. and 10% RH, and the ink mass change after being left for a certain time was measured. Further, the particle size and viscosity at that time were measured. The particle size was measured using a particle size distribution measuring device UPA150 manufactured by Microtrack Co., Ltd. at a dilution ratio of 500 times. The results are shown in FIGS.
The water evaporation rate and the viscosity increase rate were calculated from the following formula based on the definitions described in JP-A-2006-77232.
Water evaporation rate (%) = [(initial mass−mass after water evaporation) / initial mass] × 100
Viscosity increase rate = viscosity after water evaporation / initial viscosity From the results of FIGS. 2 and 3, the recording inks obtained in Examples 2, 3, and 5 have a remarkable increase in particle size even at a water evaporation rate of 35%. It was found that ejection reliability is ensured if ejection is performed at a moisture evaporation rate of less than 30%. From this, it was found that the ejection reliability was sufficiently ensured even with an ink in which the sum of the solid content of the water-dispersible colorant and the water-dispersible resin was 10 to 30% by mass of the total amount of the ink. .

The recording ink of the present invention can ensure high color development, image quality, and reliability, and can form high-quality images with high color saturation and good color tone not only on dedicated recording paper but also on plain paper. , Ink cartridges, ink records, ink jet recording apparatuses and ink jet recording methods.
The ink jet recording apparatus and the ink jet recording method of the present invention can be applied to various types of recording by the ink jet recording method, and are particularly suitable for, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, and a printer / fax / copier multifunction machine. Can be applied to.

FIG. 1 is a graph showing the relationship between saturation and ink solid content in Experiment 1. FIG. 2 is a graph showing the relationship between the water evaporation rate and the viscosity increase rate in Experiment 2. FIG. 3 is a graph showing the relationship between the water evaporation rate and the particle size change in Experiment 2. FIG. 4 is a schematic view showing an example of the ink cartridge of the present invention. FIG. 5 is a schematic view including the case of the ink cartridge of FIG. FIG. 6 is a perspective explanatory view showing a state where the cover of the ink cartridge loading portion of the ink jet recording apparatus is opened. FIG. 7 is a schematic configuration diagram illustrating the overall configuration of the ink jet recording apparatus. FIG. 8 is a schematic enlarged view showing an example of the ink jet head of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Frame 20 Flow path plate 30 Nozzle plate 40 Base 50 Multilayer piezoelectric element 60 Vibrating plate 70 Adhesive layer 101 Apparatus main body 102 Paper feed tray 103 Paper discharge tray 104 Ink cartridge loading part 111 Upper cover 112 Front surface 115 Front cover 131 Guide rod 132 Stay 133 Carriage 134 Recording head 135 Sub tank 141 Paper placement unit 142 Paper 144 Separation pad 151 Conveying belt 152 Counter roller 156 Charging roller 157 Conveying roller 158 Densation roller 171 Separating claw 172 Paper ejection roller 173 Paper ejection roller 181 Double-sided paper feed unit 200 Ink cartridge 201 Ink cartridge 241 Ink bag 242 Ink inlet 243 Ink outlet 244 Cartridge exterior

Claims (16)

A recording ink containing at least a colorant, a water-dispersible resin, a wetting agent, a surfactant, and water,
The colorant is (1) a pigment having at least one hydrophilic group on the surface and exhibiting at least one of water dispersibility and water solubility in the absence of a dispersant, and (2) water insoluble in polymer fine particles. A polymer emulsion containing a poorly water-soluble colorant, and (3) a pigment dispersed with any of a surfactant and a water-soluble polymer compound having a mass average molecular weight of 50,000 or less,
The content of glycerin as the wetting agent is 60% by mass or less of the whole wetting agent,
The total content of the colorant and the water-dispersible resin in the recording ink is 10 to 30% by mass in solid content,
The ratio (B / C) of the solid content (B) in the recording ink of the colorant to the solid content (C) in the recording ink of the water-dispersible resin is 0.1 to 1. 6. A recording ink, wherein the recording ink has a viscosity of 5 to 20 mPa · s at 25 ° C. and the surface tension of the recording ink is 35 mN / m or less. 2. The recording ink according to claim 1, wherein the colorant is a pigment having at least one hydrophilic group on the surface and exhibiting at least one of water dispersibility and water solubility in the absence of the dispersant. The ratio (B / C) of the solid content (B) in the colorant recording ink to the solid content (C) in the water-dispersible resin recording ink is 0.4 to 1.6. Item 3. The recording ink according to any one of Items 1 to 2. The ratio (B / C) of the solid content (B) in the colorant recording ink to the solid content (C) in the water-dispersible resin recording ink is 0.6 to 1.6. Item 4. The recording ink according to any one of Items 1 to 3. The surfactant contains at least one selected from silicone surfactants and fluorine surfactants, and the total content of the surfactant in the recording ink is 0.01 to 5% by mass. Item 5. The recording ink according to any one of Items 1 to 4. The fluorosurfactant has a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic compound, a perfluoroalkyl phosphate ester compound, a perfluoroalkyl ethylene oxide adduct, and a polyoxyalkylene having a perfluoroalkyl ether group in the side chain. 6. The recording ink according to claim 5, wherein the recording ink is at least one selected from ether polymer compounds. The recording ink according to claim 1, wherein the recording ink is at least one selected from cyan ink, magenta ink, yellow ink, and black ink. An ink cartridge comprising the recording ink according to claim 1 contained in a container. An ink jet recording method comprising at least an ink flying step of forming an image by applying a stimulus to the recording ink according to claim 1 and causing the recording ink to fly. The inkjet recording method according to claim 9, wherein the stimulus is at least one selected from heat, pressure, vibration, and light. The inkjet recording method according to any one of claims 9 to 10, wherein a droplet discharged from the nozzle has a size of 2 to 40 pl, a droplet speed of 6 to 20 m / s, a frequency of 1 kHz or more, and a resolution of 300 dpi or more. . 8. An ink jet recording apparatus comprising at least ink flying means for applying a stimulus to the recording ink according to claim 1 and causing the recording ink to fly to form an image. The inkjet recording apparatus according to claim 12, wherein the stimulus is at least one selected from heat, pressure, vibration, and light. The ink jet recording apparatus according to claim 12, further comprising a sub tank for supplying ink on the nozzle head, wherein the sub tank is supplemented with ink from an ink cartridge through a supply tube. An ink recorded matter comprising an image formed using the recording ink according to any one of claims 1 to 7 on a recording medium. The ink recorded matter according to claim 15, wherein the recording medium has a Steecht sizing degree of 3 seconds or more.