JP2006213855A - Recording ink, ink cartridge, ink recorded material, inkjet recording apparatus and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording ink which is used for inkjet recording apparatus for carrying out preliminary drying by blowing and having excellent image quality, high speed recording and perfecting recording for a plain paper, and ink cartridge using the recording ink, ink recording material, inkjet recording apparatus and inkjet recording method. <P>SOLUTION: The recording ink is used for the inkjet recording apparatus which is provided with at least a blowing means for carrying out preliminary drying by exposing a recording surface of a recording medium to the wind after recording, and comprises at least a coloring agent, a wetting agent, a surfactant and a penetrant, the ink having the viscosity η of 4-20 mPa s and surface tension γ of 20-36 mN/m, in which the viscosity η (mPa s) at 25°C of the recording ink and the surface tension γ (mN/m) at 25°C of the recording ink satisfy the formula: γ/η≤5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  INDUSTRIAL APPLICABILITY The present invention is used in an ink jet recording apparatus that performs pre-drying by blowing air, and has a recording ink excellent in image quality, high-speed recording, and double-sided recording on plain paper, 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 forming apparatuses such as printers, facsimiles, and copying machines. This inkjet recording apparatus performs recording by ejecting ink from a recording head onto a recording medium such as paper, and can record high-definition images at high speed, with low running costs, low noise, and In addition, there is an advantage that it is easy to record a color image using multi-color inks.

As such an ink for ink jet recording, generally, water, a colorant, a wetting agent such as glycerin added for the purpose of preventing clogging, and a penetrating agent for controlling the permeability to recording paper, In addition, those containing other additives are used.
In the inkjet recording using the water-based ink, liquid ink is fixed by penetrating into the recording medium. Therefore, an inkjet-dedicated paper having improved absorption characteristics, fixing the coloring component on the paper surface, and protecting the coloring component has been developed. ing. However, the inkjet paper is expensive because it undergoes a multi-stage coating process after paper making, and because it uses a large amount of processing chemicals, it is inferior in recyclability compared to plain paper. For this reason, it is desired to obtain sufficient image quality on plain paper.

The plain paper is inferior in ink absorbability to the inkjet special paper and does not assist the ink performance as the special paper. (1) Occurrence of color boundary, (2) Decrease in character quality, (3) Decrease in density, (4) decrease in color developability, (5) decrease in water resistance, (6) decrease in light resistance, (7) decrease in gas resistance, (8) decrease in fixability, (9) cockling There are problems such as the occurrence of curling and (10) the occurrence of ink breakthrough.
Solving these problems is an important issue for inkjet recording on plain paper.

  In recent years, the dispersibility of pigments has been improved and the particle size has been miniaturized, and the number of cases used for ink-jet inks has increased. For example, by using a pigment such as carbon black, the above (5), (6), and (7) can be improved, but the pigment is inferior in density and color development compared to the dye, and the ejection stability. In addition, it is inferior in terms of reliability such as long-term storage and redispersibility. For this reason, when a pigment is used as the colorant, it is a problem to improve the reliability of the ink.

  In order to cope with these problems, many inks for ink jet recording using colored polymer particles, particularly emulsions of polyester polymer particles and vinyl polymer particles have been proposed (Patent Document 1, Patent Document 2, Patent Document). 3, Patent Literature 4, Patent Literature 5, Patent Literature 6, Patent Literature 7, Patent Literature 8, Patent Literature 9, Patent Literature 10, Patent Literature 11, Patent Literature 12, Patent Literature 13, Patent Literature 14, Patent Literature 15, Patent Literature 16, Patent Literature 17, Patent Literature 18, Patent Literature 19, Patent Literature 20, Patent Literature 21, Patent Literature 22, Patent Literature 23, Patent Literature 24, Patent Literature 25, Patent Literature 26, Patent Literature 27, Patent Literature 28, Patent Document 29, and Patent Document 30).

  These prior arts include inks containing a colorant-containing 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, the image density and color reproducibility on plain paper is superior to that of a pigment ink using a water-soluble dispersant in a conventionally known ink formulation. Color development is approaching that of dyes from approaches such as making pigment particles finer. Further, although the reliability is inferior to that of a dye, the sedimentation of the pigment as a change with time is suppressed, and it is possible to increase the color material concentration of the pigment ink.

In addition, as a method for improving image quality by penetrability, a super-penetrating ink formulation has been proposed so far, which is the solution of the above (1). However, in the super-penetrating ink formulation, the characters are blurred, which is not a solution to the above (2).
Further, Patent Document 31 has a proposal that a highly viscous ink (5 to 15 mPa · s) is necessary to ensure high image quality. This proposal can be said to be a solution to the above (1), (2), (3), and (4) when a pigment is used.

Further, as a method for improving the image quality of plain paper, the above-mentioned (1), (2), (8), (9), and (9) with respect to plain paper can be achieved by increasing the drying speed faster without reducing the ink adhesion amount. Attempts have been made to solve the problem 10).
As a method for increasing the drying speed, two methods are conceivable: (a) adding a volatile component to the ink, and (b) providing the printer with a drying mechanism.
In the case of (a), the drying property can be easily improved, but the meniscus of the ink nozzle portion of the head is also easily dried, causing an increase in viscosity and adversely affecting stable ejection. Further, since the volatile component is an organic compound, the printing environment is also deteriorated, and the advantage of using the water-based ink is lost. Moreover, the on-demand ink jet system using a pigment has many problems from the viewpoint of reliability.

In the case of (b), it can be realized by incorporating a heater or the like into the apparatus, but there is a disadvantage that the apparatus becomes complicated. For example, a method of heating a recording medium by heating a platen and conducting heat (see Patent Literature 32, Patent Literature 33, Patent Literature 34, Patent Literature 35, and Patent Literature 36), a method using infrared rays (see Patent Literature 37) A method using a fixing device using a heating roller (see Patent Document 38 and Patent Document 39) has been proposed.
However, the method using the platen does not provide uniform thermal conductivity with the recording medium, the method using the infrared rays requires a large amount of power, and the method using the fixing device requires a large amount of apparatus. It is regarded as a problem. Also, heating before and after printing heats not only the recording medium but also the head surface due to waste heat or radiant heat. Further, the heat applied to the head surface in this way promotes the drying of the meniscus and has the disadvantage of reducing the ejection stability.

Patent Document 40 proposes to suppress the influence on heat by making the head surface a heat reflecting surface. However, in this proposal, there is no description of ink, and it is difficult to say that reliability is sufficient only by making the head surface a heat reflecting surface. An inkjet printer having a thermal fixing mechanism while using such water-based ink has a complicated mechanism and has a problem in reliability, but has advantages such as image quality improvement during high-speed printing and double-sided printing, Several are on the market.
However, an on-demand inkjet printer with a thermal fixing mechanism is a huge device equivalent to or better than an electrophotographic system, and the printing process impairs the advantages of a compact inkjet system. The process leads to a solution to the problem with plain paper, but there is concern about the reliability of the nozzle due to heat near the head.

  Such an ink jet recording apparatus that performs pre-drying that does not require strong heat has not been sufficiently studied, and no ink suitable for such an ink jet recording apparatus has been proposed. Further, although a pre-drying method that can be used easily and with low energy can be considered by air blowing, a recording ink used in an ink jet recording apparatus that performs pre-drying by air blowing and related technology have not yet been provided. Currently.

JP 2000-191972 A JP 2000-191968 A JP 2000-191967 A JP 2000-53900 A JP 2000-53899 A JP 2000-53898 A JP 2000-53897 A JP 2000-44852 A JP 2000-26775 A JP 2000-7963 A JP 2000-7962 A Japanese Patent Laid-Open No. 9-241565 Japanese Patent Laid-Open No. 9-217030 JP-A-9-183932 Japanese Patent Laid-Open No. 9-183931 JP-A-9-286939 JP-A-9-157565 Japanese Patent Laid-Open No. 10-46082 Japanese Patent Laid-Open No. 10-46092 Japanese Patent Laid-Open No. 10-60327 Japanese Patent Laid-Open No. 10-273610 Japanese Patent Laid-Open No. 10-279851 JP-A-10-298462 Japanese Patent Laid-Open No. 10-298467 JP 11-217528 A Japanese Patent Laid-Open No. 10-338829 JP-A-10-316918 Japanese Patent Laid-Open No. 11-256083 JP-A-11-323226 Japanese Patent No. 3065950 JP 2001-262025 A JP 55-69464 A JP 55-84670 A JP 58-72460 A Japanese Patent Laid-Open No. 62-130863 JP-A-62-130864 Japanese Patent Laid-Open No. 57-120447 Japanese Patent Laid-Open No. 3-169644 JP-A-6-184478 Japanese Patent Laid-Open No. 11-123828

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, the present invention is used in an inkjet recording apparatus that performs preliminary drying by blowing air, and is a recording ink excellent in image quality, high-speed recording, and double-sided recording on plain paper, and an ink cartridge using the recording ink. An object of the present invention is to provide an ink recording material, an ink jet recording apparatus, and an ink jet recording method.

Means for solving the problems are as follows. That is,
<1> Used in an ink jet recording apparatus provided with at least air blowing means for applying air to a recording surface of a recording medium after recording to perform preliminary drying, and at least a colorant, a wetting agent, a surfactant, and a penetrating agent. A recording ink containing
A viscosity η (mPa · s) at 25 ° C. of the recording ink and a surface tension γ (mN / m) at 25 ° C. of the recording ink satisfy the following formula, γ / η ≦ 5, and the viscosity: η is 4 to 20 mPa · s, and the surface tension γ is 20 to 36 mN / m.
<2> The colorant is a pigment, the pigment has at least one hydrophilic group on the surface thereof, and exhibits at least one of water dispersion or water solubility in the absence of a dispersant. Recording ink.
<3> The recording ink according to <1>, wherein the colorant is a polymer emulsion in which polymer fine particles contain a colorant that is insoluble or hardly soluble in water.
<4> The recording ink according to any one of <1> to <3>, wherein the content of the colorant in the recording ink is 5 to 15% by mass in solid content concentration.
<5> The above-mentioned <1> to <4>, wherein the wetting agent is at least two kinds of polyhydric alcohols having an equilibrium water content of 25% by mass or more in an environment of a temperature of 20 ° C. and a relative humidity of 60%. The recording ink described.
<6> The recording ink according to <5>, wherein the polyhydric alcohol is glycerin, and the content of the glycerin in the wetting agent is 50% by mass or more.
<7> The recording ink according to any one of <1> to <6>, wherein the content of the wetting agent in the recording ink is 10 to 50% by mass in solid content concentration.
<8> The recording ink according to any one of <1> to <7>, wherein the surfactant is at least one of an anionic surfactant and a nonionic surfactant.
<9> The recording ink according to any one of <1> to <8>, wherein the content of the surfactant in the recording ink is 0.01 to 5% by mass.
<10> The recording ink according to any one of <1> to <9>, wherein the content of the penetrant in the recording ink is 0.1 to 5% by mass.
<11> The recording ink according to any one of <1> to <10>, which is at least one selected from cyan ink, magenta ink, yellow ink, and black ink.
<12> An ink cartridge comprising the recording ink according to any one of <1> to <11> contained in a container.
<13> Ink flying means for recording an image by applying a stimulus to the recording ink according to any one of <1> to <11> and causing the recording ink to fly, and recording on a recording medium after recording An ink jet recording apparatus comprising at least air blowing means for applying air to the surface to pre-dry.
<14> The ink jet recording apparatus according to <13>, wherein the air blowing unit is disposed so as to blow wind in a paper discharge direction of the recording medium and prevent the ink flying unit from being blown.
<15> The inkjet recording apparatus according to any one of <13> to <14>, wherein the blowing unit includes a heater, and the warm air is applied to the recording surface of the recording medium by the operation of the heater.
<16> An ink flying process of recording an image by applying a stimulus to the recording ink according to any one of <1> to <11> and causing the recording ink to fly, and recording on a recording medium after recording An ink jet recording method comprising: at least a blowing step for applying air to the surface and pre-drying.
<17> The inkjet recording method according to <16>, wherein the ink is ejected onto the recording medium before the water evaporation rate in the vicinity of the nozzle exceeds 30%.
<18> The inkjet recording method according to any one of <16> to <17>, wherein the air is blown within 5 seconds after the ink is deposited on the recording medium.
<19> An ink recorded matter comprising an image recorded on a recording medium using the recording ink according to any one of <1> to <11>.

  The recording ink of the present invention is used in an ink jet recording apparatus having at least air blowing means for applying air to the recording surface of a recording medium after recording to pre-dry, and includes at least a colorant, a wetting agent, and a surface activity. And a viscosity η (mPa · s) of the recording ink at 25 ° C. and a surface tension γ (mN / m) of the recording ink at 25 ° C. of the following formula: , Γ / η ≦ 5, the viscosity η is 4 to 20 mPa · s, and the surface tension γ is 20 to 36 mN / m. As a result, a recording ink excellent in image quality, high-speed recording, and double-sided recording performance on plain paper can be 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 stored in the ink cartridge, high image quality with excellent image quality, high-speed recording, and double-sided recording on plain paper can be obtained.

  The ink jet recording apparatus of the present invention has at least ink flying means and air blowing means. 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. The blowing means applies air to the recording surface of the recording medium after recording to perform preliminary drying. As a result, it is possible to form a high-quality image excellent in image quality, high-speed recording, and double-sided recording on plain paper.

  The ink jet recording method of the present invention includes at least an ink flying process and a blowing process. 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. In the air blowing step, air is blown against the recording surface of the recording medium after recording to perform preliminary drying. As a result, it is possible to form a high-quality image excellent in image quality, high-speed recording, and double-sided recording on plain paper.

  The inkjet recorded matter of the present invention comprises an image formed on the recording medium using the recording ink of the present invention. In the ink-jet recorded matter, high image quality with excellent image quality, high-speed recording, and double-sided recording properties with respect to plain paper is maintained on the recording medium.

  According to the present invention, the conventional problems can be solved, and the recording ink is used in an ink jet recording apparatus that performs pre-drying by air blowing, and has excellent image quality, high-speed recording, and double-sided recording properties on plain paper, and the recording Ink cartridges, ink recordings, ink jet recording apparatuses, and ink jet recording methods using the above-described ink can be provided.

(Ink for recording)
The recording ink of the present invention is used in an ink jet recording apparatus having at least air blowing means for applying air to a recording surface of a recording medium after recording to perform preliminary drying. At least a colorant, a wetting agent, a surfactant, And a penetrant and, if necessary, other components.

In the present invention, it is possible to increase the drying speed by blowing air after printing, and to suppress the improvement in image density, cockling, and back-through. Here, the “drying” means not a state in which water is completely lost, but a state in which ink that has lost water to some extent has lost fluidity, is retained on a recording medium, and does not flow as a liquid.
In order to obtain the effect of moisture evaporation by the blowing, the speed at which the ink penetrates into the recording medium (paper) is greatly affected. In the case of the super-penetrating ink, it has penetrated into the paper before being dried by the wind, and the effect on the image quality cannot be obtained. On the other hand, in the case of a slowly penetrating ink, since the penetration into paper is slow, a large amount of liquid is required for drying and a large amount of energy is required. Therefore, the effect can be very small when drying by blowing with a small amount of energy. In order to acquire the effect by ventilation, it is necessary to set permeability to an appropriate range.

ただし、前記数式１中、ｌは浸透深さ、ｒは毛管半径、γはインクの表面張力、θは接触角、ηは粘度、ｔは時間をそれぞれ表す。 Here, in general, the penetration of liquid into paper (recording medium) is explained by capillary absorption according to the Lucas-Washburn equation represented by the following Equation 1. It is considered that the ink-jet ink penetrates into the recording medium in accordance with the Lucas-Washburn equation.

In Equation 1, l is the penetration depth, r is the capillary radius, γ is the surface tension of the ink, θ is the contact angle, η is the viscosity, and t is the time.

In Formula 1, the permeability is composed of time and r relating to the recording medium, θ relating to the ink and the recording medium, γ and η relating to the ink, and γ / η in view of only the ink physical properties. .
Accordingly, the viscosity η (mPa · s) at 25 ° C. in the recording ink and the surface tension γ (mN / m) at 25 ° C. in the recording ink satisfy the following expression, γ / η ≦ 5, and γ / Η ≦ 4 is preferable. The viscosity η is 4 to 20 mPa · s, preferably 7 to 15 mPa · s. The surface tension γ is 20 to 36 mN / m, preferably 25 to 32 mN / m.
When the recording ink satisfies the above relationship, the permeability of the ink can maximize the effect of air blowing.

  Here, the viscosity of the recording ink can be measured at 25 ° C. using, for example, a viscometer (RL-500, manufactured by Toki Sangyo Co., Ltd.). The surface tension can be measured at 25 ° C. 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 contains at least a colorant, a wetting agent, a surfactant, and a penetrating agent in order to exhibit the above desired ink physical properties, and further contains other components as necessary. It contains.
In this case, the colorant may be a pigment that can be dispersed in water without a dispersant due to a treatment in which at least one hydrophilic group is bonded to the pigment surface directly or via another atomic group. It is preferable to use a polymer emulsion in which polymer fine particles contain a colorant that is insoluble or hardly soluble in water.
Further, in order to improve the ejection reliability by reducing the water evaporation rate, the wetting agent is at least 2 polyhydric alcohols having an equilibrium water content of 25% by mass or more in an environment of a temperature of 25 ° C. and a relative humidity of 60%. It is desirable to contain more than seeds. One of the polyhydric alcohols is glycerin, and the content of glycerin is 50% by mass or more of the whole wetting agent, which is a desirable condition for developing the above evaporative properties.
In order to improve the image quality while satisfying these configurations, the colorant is 5 to 15% by mass, the surfactant is 0.01 to 5% by mass, the wetting agent is 10 to 50% by mass, and the penetration is performed. It is preferable to contain 0.1-5 mass% of an agent.
Hereinafter, each component of the recording ink will be described in detail.

-Colorant-
As the colorant, a pigment is mainly used from the viewpoint of weather resistance, but a dye may be contained at the same time for the purpose of adjusting the color tone.

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

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

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

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

The black pigment is preferably carbon black. Carbon black as a black ink is excellent in color tone, excellent in water resistance, light-repelling property, dispersion stability, and inexpensive.
Other pigment pigments (for example, carbon) surface treated with resin, etc., and dispersed in water by adding a functional group such as a sulfone group or a carboxyl group to the surface of the pigment (for example, carbon). 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.

Among these pigments, a preferable form is one that has been surface-modified so that at least one hydrophilic group is bonded to the surface of the pigment directly or through 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.

In addition to the pigment, it is also preferable to use a polymer emulsion in which a pigment is contained in polymer fine particles.
Here, the polymer emulsion containing the pigment is at least one of a polymer fine particle encapsulated with the pigment and a polymer fine particle adsorbed on the surface of the polymer fine particle. In this case, it is not necessary that all the pigments are encapsulated and / 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.

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 can be preferably used.

  There is no restriction | limiting in particular as content in the said recording ink of the said coloring agent, According to the objective, it can select suitably, 5-15 mass% is preferable, and 7-12 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 preferably contains at least two polyhydric alcohols having an equilibrium water content of 25% by mass or more under an environment of a temperature of 20 ° C. and a relative humidity of 60%.
Examples of the wetting agent include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butanediol, 2,3-butanediol, and 1,4-butanediol. 3-methyl-1,3-butanediol, 1,5-pentanediol, tetraethylene glycol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, polyethylene glycol, 1,2,4- Examples include butanetriol and 1,2,6-hexanetriol. Among these, glycerin is particularly preferable because the viscosity rapidly increases with water evaporation, but is highly effective in suppressing aggregation of the colorant and preventing the particle size from becoming large. It is preferable that it is 50 mass% or more.

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 deteriorate, so the mixing ratio thereof is 1 : 5 to 5: 1 is preferable, and 1: 1 to 4: 1 is more preferable.
The content of the wetting agent in the recording ink is preferably 10 to 50% by mass, and more preferably 20 to 40% 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-
There is no restriction | limiting in particular as said surfactant, Although it can select suitably according to the objective, Anionic surfactant and a nonionic surfactant are used suitably. A surfactant that does not impair the dispersion stability is selected depending on the combination of the color material, the wetting agent, and the water-soluble organic solvent.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, oxalate sulfonate, laurate, and polyoxyethylene alkyl ether sulfate.
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, polyoxyethylene Examples thereof include ethylene alkyl phenyl ether, polyoxyethylene alkyl amine, and polyoxyethylene alkyl amide.
Commercially available products can be used as such surfactants, such as Nikko Chemicals Co., Ltd., Nippon Emulsion Co., Ltd., Nippon Shokubai Co., Ltd., Toho Chemical Co., Ltd., Kao Corp., Adeka ( Co., Ltd., Lion Co., Ltd., Aoki Oil & Fat Co., Ltd., Sanyo Kasei Co., Ltd., etc.

The acetylene glycol surfactant is 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl. An acetylene glycol type such as -1-hexyn-3-ol (for example, Surfynol 104, 82, 465, 485, or TG from Air Products (USA)) can be used, and among these, Surfynol 465 can be used. 104, TG are particularly preferred.
In addition, the said surfactant is not limited to these, You may use individually or may mix and use several things. 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 particularly suitable.

^{_{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.

ただし、前記構造式（３）中、Ｒ^３は、炭化水素基を表し、例えば、分岐してもよい炭素数６〜１４のアルキル基などが挙げられる。ｋは５〜２０の整数を表す。

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

ただし、前記構造式（４）中、Ｒ^４は、炭化水素基を表し、例えば、分岐してもよい炭素数６〜１４のアルキル基を表す。Ｌは５〜１０、ｐは５〜２０の整数を表す。プロピレングリコール鎖、及びエチレングリコール鎖は、ブロック重合又はランダム重合していてもよい。

However, the structural formula (4), R ⁴ represents a hydrocarbon group, for example, an alkyl group branched carbon atoms which may be 6 to 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.

ただし、前記構造式（５）中、ｑ及びｒは、５〜２０の整数を表す。

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

  The content of the surfactant in the recording ink is preferably 0.01 to 5.0% by mass, and more preferably 0.5 to 3.0% by mass. When the content is less than 0.01% by mass, the effect of adding a surfactant may be lost. When the content exceeds 5.0% by mass, the permeability to a recording medium becomes higher than necessary, and the image Concentration drop or strikethrough may occur.

-Penetration agent-
The penetrant contains at least one polyol having a solubility in water at 20 ° C. of 0.2 to 5.0 mass%, and other wetting agents can be used as necessary.
Among the polyols, examples of the aliphatic diol 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, 2,2,4-trimethyl-1,3-pentanediol, and 1,2-hexanediol are particularly preferable.

  The other penetrant that can be used in combination is not particularly limited and may be appropriately selected depending on the purpose. For example, diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, Examples include alkyl or aryl ethers of polyhydric alcohols such as diethylene glycol monobutyl ether, propylene glycol monobutyl ether, and tetraethylene glycol chlorophenyl ether; lower alcohols such as ethanol.

  The content of the penetrant in the recording ink is preferably 0.1 to 5% by mass, and more preferably 0.5 to 3% by mass. When the content is less than 0.1% by mass, quick-drying cannot be obtained and a blurred image may be obtained. When the content exceeds 5% by mass, the dispersion stability of the colorant is impaired and the nozzle is clogged. Or the permeability to the recording medium is unnecessarily high, and the image density may be lowered or the back-through may occur.

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

  There is no restriction | limiting in particular as said antifoamer, According to the objective, it can select suitably, For example, a silicone type antifoamer, a polyether antifoamer, a fatty acid ester antifoamer etc. are mentioned suitably. These may be used individually by 1 type and may use 2 or more types together. Among these, a silicone type antifoaming agent is preferable in that it has an excellent foam breaking effect.

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

  Commercially available products may be used as the antifoaming agent, such as silicone-based antifoaming agents (KS508, KS531, KM72, KM85, etc.) manufactured by Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Co., Ltd. silicone antifoam (Q2183A, SH5510, etc.), Nippon Unicar Co., Ltd. silicone antifoam (SAG30 etc.), Asahi Denka Kogyo Co., Ltd. Nate series).

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

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

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

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

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

Examples of the ultraviolet absorber include a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, a salicylate ultraviolet absorber, a cyanoacrylate ultraviolet absorber, and a nickel complex ultraviolet absorber.
Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2,4-dihydroxybenzophenone, and 2-hydroxy-4-methoxybenzophenone. 2,2 ′, 4,4′-tetrahydroxybenzophenone, and the like.
Examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-4′-octoxyphenyl) benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, and the like.
Examples of the salicylate-based ultraviolet absorber include phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, and the like.
Examples of 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 is produced by dispersing or dissolving at least a colorant, a wetting agent, a surfactant, a penetrating agent, and other components as required in an aqueous medium, and further stirring and mixing as necessary. To do. 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.

  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. Therefore, a printer equipped with any inkjet head such as an electrostatic type (see Japanese Patent Application Laid-Open No. 6-71882) that discharges ink droplets by changing the volume in the ink flow path. Can also be used well.

  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, at least an ink bag formed of an aluminum laminate film, a resin film, or the like Preferred examples include those possessed.

Next, the ink cartridge will be described with reference to FIGS. Here, FIG. 1 is a view showing an example of the ink cartridge of the present invention, and FIG. 2 is a view including a case (exterior) of the ink cartridge of FIG.
As shown in FIG. 1, the ink cartridge 200 is filled into the ink bag 241 from the ink inlet 242 and exhausted, and then the ink inlet 242 is closed by fusion. In use, the needle of the apparatus main body is pierced into the ink discharge port 243 made of a rubber member and supplied to the apparatus.
The ink bag 241 is formed of a packaging member such as a non-permeable aluminum laminate film. As shown in FIG. 2, the ink bag 241 is usually housed in a plastic cartridge case 244 and is detachably mounted on various ink jet recording apparatuses.

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

(Inkjet recording apparatus and inkjet recording method)
The ink jet recording apparatus of the present invention includes at least ink flying means and air blowing 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 an air blowing 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, the ink flying step can be suitably carried out by the ink flying means, and the air blowing step is suitably carried out by the air blowing means. It can be carried out. 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.

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

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

  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 recording ink droplets to be ejected preferably have a size of, for example, 3 to 40 pl, a discharge ejection speed of 6 to 20 m / s, and a driving frequency thereof. 1 kHz or more is preferable, and the resolution is preferably 300 dpi or more.

-Air blowing process and air blowing means-
The air blowing process is a process of pre-drying by applying air to the recording surface of the recording medium after recording.
The air blowing process is performed by the air blowing means. The air blowing means is arranged so as to blow wind in the paper discharge direction of the recording medium and not to hit the ink flying means, so that the landing position deviation at the time of ink flying due to wind is prevented. This is preferable in that the ink drying is not promoted and the discharge characteristics are not deteriorated.
The air blowing means includes a heater, and it is preferable to apply hot air to the recording surface of the recording medium by operating the heater from the viewpoint of increasing the drying efficiency.

In the air blowing process, it is preferable that ink be ejected onto the recording medium before the water evaporation rate near the nozzle exceeds 30%. As described above, a more stable and high-quality image formation can be performed by using a recording method in which ink is ejected to a printing or non-printing area before moisture evaporation near the nozzle exceeds 30%.
In the air blowing process, it is preferable from the viewpoint of improving the image quality that the air blowing is performed within 5 seconds after the ink adheres to the recording medium because the feathering in the ink absorption process can be suppressed.

  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.

  In addition, the inkjet recording apparatus includes a plurality of pressurized liquid chambers, a nozzle having a hole diameter of 35 μm or less communicating with the pressurized liquid chamber, an ink supply path, a vibration plate, and a recording head including electromechanical conversion means for displacing the vibration plate; By using a recording apparatus in which a plurality of ink droplets are continuously ejected and merged to form a large droplet before landing on a recording medium, ejection stability can be ensured even for ink with high viscosity.

  One mode for carrying out the ink jet recording method of the present invention by the ink jet recording apparatus of the present invention will be described with reference to the drawings. The ink jet recording apparatus shown in FIG. 3 stocks an apparatus main body 101, a paper feed tray 102 for loading paper loaded 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. On the upper surface of the ink cartridge loading unit 104, an operation unit 105 such as operation keys and a display is arranged. The ink cartridge loading unit 104 has a front cover 115 that can be opened and closed for attaching and detaching the ink cartridge 201.

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

The carriage 133 includes a plurality of ink jet recording heads 134 including four ink jet recording heads that eject recording ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). The ejection ports are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing downward.
As the ink jet recording head constituting the recording head 134, a piezoelectric actuator such as a piezoelectric element, a thermal actuator using phase change due to liquid film boiling using an electrothermal transducer such as a heating resistor, a metal phase due to temperature change, etc. A shape memory alloy actuator using a change, an electrostatic actuator using an electrostatic force, or the like 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 the recording ink of the present invention from the ink cartridge 1 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 103, a half-moon roller (feeding) is separately fed from the paper stacking unit 141 one by one. A separation pad 144 made of a material having a large friction coefficient is provided opposite to the paper roller 143) and the paper feed roller 43, 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. For this purpose, a conveyance guide 153 and a tip pressure roller 155 urged toward the conveyance belt 151 by a pressing member 154 are provided. In addition, a charging roller 156 that is a charging unit for charging the surface of the conveyance belt 151 is provided.

  The conveyance belt 151 is an endless belt, is stretched between the conveyance roller 157 and the tension roller 158, and can circulate in the belt conveyance direction. The transport belt 151 includes, for example, a surface layer serving as a sheet 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 1 to the sub tank 135.

  In this ink jet recording apparatus, when the recording ink in the ink cartridge 1 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, the ink cartridge 1 can be replaced even when the upper portion of the apparatus main body 101 is closed, for example, when stored in a rack, or when an object is placed on the upper surface of the apparatus main body 101. Can be easily 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 recorded matter recorded by the ink jet recording apparatus and the ink jet recording method of the present invention is the ink recorded matter of the present invention. The ink recorded matter of the present invention has an image formed on the recording medium using the recording ink of the present invention.
There is no restriction | limiting in particular as said recording medium, According to the objective, it can select suitably, For example, a plain paper, glossy paper, special paper, cloth, a film, an OHP sheet etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
The recorded matter has high image quality, no bleeding, excellent temporal stability, and can be suitably used for various purposes as a material on which various prints or images are recorded.

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

(Synthesis Example 1)
-Synthesis of polymer solution-
The inside of a 1 L flask equipped with a mechanical stirrer, a thermometer, a nitrogen gas introduction tube, a reflux tube, and a dropping funnel was sufficiently substituted with nitrogen gas. Into this flask, 11.2 g of styrene, 2.8 g of acrylic acid, 12.0 g of lauryl methacrylate, 4.0 g of polyethylene glycol methacrylate, 4.0 g of styrene macromer, and 0.4 g of mercaptoethanol were mixed and mixed at 65 ° C. The temperature was raised to.
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 completion of the dropwise addition, 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. 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 synthesize 800 g of a polymer solution having a solid concentration of 50% by mass.

(Preparation Example 1)
-Preparation of pigment-containing polymer fine particle aqueous dispersion A-
28 g of the polymer solution; I. 26 g of CI Pigment Blue 15: 3, 13.6 g of a 1 mol / L aqueous potassium hydroxide 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 methyl ethyl ketone and water were distilled off using an evaporator to prepare an aqueous dispersion A of cyan polymer fine particles.

(Preparation Example 2)
-Preparation of pigment-containing polymer fine particle water dispersion B-
In Preparation Example 1, pigment C.I. I. Pigment Blue 15: 3 to C.I. I. A water dispersion B of magenta polymer fine particles was prepared in the same manner as in Preparation Example 1, except that the pigment red 122 was used.

(Preparation Example 3)
-Preparation of pigment-containing polymer fine particle water dispersion C-
In Preparation Example 1, pigment C.I. I. Pigment Blue 15: 3 to C.I. I. An aqueous dispersion C of yellow polymer fine particles was prepared in the same manner as in Preparation Example 1, except that the pigment yellow 74 was used.

(Examples 1-9 and Comparative Examples 1-5)
-Preparation of recording ink-
First, wetting agents, penetrants, surfactants, and water having the compositions shown in Tables 1 and 2 were stirred and mixed uniformly for 1 hour. To this mixed solution, the pigment dispersion of any one of Preparation Examples 1 to 3 and carbon black dispersion (CAB-O-JET300, manufactured by Cabot Corporation) and an antifoaming agent were added and stirred for 1 hour.
Next, the obtained dispersion was subjected to pressure filtration with a cellulose acetate membrane filter having an average pore size of 0.8 μm to remove coarse particles and dust, thereby preparing each recording ink.

＊：表面に少なくとも１種の親水基が直接又は他の原子団を介して結合するような処理が施されたカーボンブラック

*: Carbon black that has been treated so that at least one hydrophilic group is bonded to the surface directly or through another atomic group.

  Next, with respect to each of the recording inks obtained in Examples and Comparative Examples, the viscosity, surface tension, the effect of improving the image density by blowing, the occurrence of cockling, and the offset resistance were evaluated as follows. The results are shown in Tables 3 and 4.

<Measurement of viscosity>
The viscosity of each ink was measured at 25 ° C. using a viscometer (RL-500, manufactured by Toki Sangyo Co., Ltd.).

<Measurement of surface tension>
The surface tension of each ink was measured at 25 ° C. using a fully automatic surface tension meter (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

  Next, an air blowing unit as shown in FIG. 6 was attached to the paper discharge unit of an inkjet printer (IPSIO G707, manufactured by Ricoh Co., Ltd.) for modification. That is, the duct 1 is installed so that the recording medium 3 discharged after printing can be blown from the top toward the discharge direction so that the airflow does not hit the head nozzle surface. The air source used a heat gun 2 capable of adjusting the temperature, and the air temperature from the duct 1 was measured with a mercury thermometer. In FIG. 6, 6 is a heater, 5 is a propeller, and 4 is a motor.

<Measurement of image density>
Using the modified inkjet printer, the chart was created with Microsoft Word 2000, and the printing mode was set to “No normal color” in the “Plain paper-Standard fast” mode than the user setting of plain paper with the driver attached to the printer. A modified mode was used. The image density was measured with X-Rite 938 (manufactured by X-Rite) for 64 point characters “■” created with Word 2000.
-Evaluation of the effect of air blowing-
The effect of blowing was determined based on the following criteria as to whether or not the image density was improved as compared with the case of not blowing.
〔Evaluation criteria〕
A: Image density was improved by blowing air.
○: Image density was improved by warm air (40 ° C.).
Δ: Image density was improved by warm air (60 ° C.).
X: Image density is not improved.

<Occurrence of cockling>
To check the occurrence of cockling, a Microsoft Word 2000 was used to create a chart in which the entire image was filled with a solid image, and evaluation was performed according to the following criteria based on the degree of paper curl after output.
〔Evaluation criteria〕
○: There is no problem in the subsequent paper discharge.
X: Both ends roll up and interfere with paper discharge.

<Offset resistance>
Confirmation of the offset resistance was made according to the following criteria based on the presence or absence of image transfer onto the filter paper by applying filter paper to the image immediately after printing and pressing it with a fingertip.
〔Evaluation criteria〕
○: No transfer ×: Transfer

  The recording ink of the present invention is used in an inkjet recording apparatus that performs preliminary drying by blowing air, and is excellent in image quality, high-speed recording, and double-sided recording properties with respect to plain paper. Therefore, the recording ink is particularly preferably used in an ink jet recording method in which an image is formed on a recording medium by ejecting and flying the recording ink as droplets from a fine ejection port. It can be widely used as ink for writing instruments, recorders, and pen plotters.

FIG. 1 is a schematic view showing an example of the ink cartridge of the present invention. FIG. 2 is a schematic view including a case (exterior) of the ink cartridge of FIG. FIG. 3 is a perspective explanatory view showing a state where the cover of the ink cartridge loading unit of the ink jet recording apparatus is opened. FIG. 4 is a schematic configuration diagram illustrating the overall configuration of the inkjet recording apparatus. FIG. 5 is a schematic enlarged view showing an example of the ink jet head of the present invention. FIG. 6 is a schematic diagram illustrating an example of an ink jet recording apparatus provided with a blowing unit used in the examples.

Explanation of symbols

1 Duct 2 Heat Gun 3 Recording Medium 4 Motor (Heat Gun)
5 Propeller (heat gun)
6 Heater (heat gun)
DESCRIPTION OF SYMBOLS 101 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 mounting part 142 Paper 144 Separation pad 151 Conveying belt 152 Counter roller 156 Charging roller 157 Conveyance roller 158 Densation roller 171 Separation claw 172 Paper discharge roller 173 Paper discharge roller 181 Double-sided paper feed unit 201 Ink cartridge 241 Ink bag 242 Ink inlet 243 Ink outlet 244 Cartridge exterior

Claims (19)

Used in an inkjet recording apparatus having at least air blowing means for applying air to the recording surface of the recording medium after recording to pre-dry, and contains at least a colorant, a wetting agent, a surfactant, and a penetrating agent. Recording ink,
A viscosity η (mPa · s) at 25 ° C. of the recording ink and a surface tension γ (mN / m) at 25 ° C. of the recording ink satisfy the following formula, γ / η ≦ 5, and the viscosity: A recording ink, wherein η is 4 to 20 mPa · s and the surface tension γ is 20 to 36 mN / m.   2. The recording ink according to claim 1, wherein the colorant is a pigment, the pigment has at least one hydrophilic group on the surface thereof, and exhibits at least one of water dispersion and water solubility in the absence of the dispersant. .   The recording ink according to claim 1, wherein the colorant is a polymer emulsion in which polymer fine particles contain a colorant that is insoluble or hardly soluble in water.   The recording ink according to any one of claims 1 to 3, wherein the content of the colorant in the recording ink is 5 to 15% by mass in solid content concentration.   The recording ink according to any one of claims 1 to 4, wherein the wetting agent is at least two kinds of polyhydric alcohols having an equilibrium water content of 25% by mass or more in an environment of a temperature of 20 ° C and a relative humidity of 60%.   6. The recording ink according to claim 5, wherein the polyhydric alcohol is glycerin, and the content of the glycerin in the wetting agent is 50% by mass or more.   7. The recording ink according to claim 1, wherein the content of the wetting agent in the recording ink is 10 to 50% by mass in terms of solid concentration.   The recording ink according to claim 1, wherein the surfactant is at least one of an anionic surfactant and a nonionic surfactant.   The recording ink according to any one of claims 1 to 8, wherein the content of the surfactant in the recording ink is 0.01 to 5% by mass.   The recording ink according to claim 1, wherein the content of the penetrant in the recording ink is 0.1 to 5% by mass.   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.   12. An ink cartridge comprising the recording ink according to claim 1 contained in a container.   An ink flying means for recording an image by applying a stimulus to the recording ink according to any one of claims 1 to 11 and flying the recording ink, and blowing air on a recording surface of the recording medium after recording. An ink jet recording apparatus comprising at least air blowing means for preliminary drying.   The ink jet recording apparatus according to claim 13, wherein the air blowing unit is disposed so as to blow air in a paper discharge direction of the recording medium and not to blow the ink flying unit.   The ink jet recording apparatus according to any one of claims 13 to 14, wherein the blowing means includes a heater, and hot air is applied to the recording surface of the recording medium by the operation of the heater.   An ink flying step of applying a stimulus to the recording ink according to any one of claims 1 to 11 and causing the recording ink to fly to record an image, and blowing wind on a recording surface of the recording medium after recording. An ink jet recording method comprising at least a blowing step for pre-drying.   The ink jet recording method according to claim 16, wherein ink is ejected onto a recording medium before the water evaporation rate in the vicinity of the nozzle exceeds 30%.   18. The ink jet recording method according to claim 16, wherein the air is blown within 5 seconds after the ink is deposited on the recording medium. An ink recorded matter comprising an image recorded using the recording ink according to any one of claims 1 to 11 on a recording medium.

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