JP2005320509A - Recording ink, ink cartridge, ink record, inkjet recorder and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain recording ink that has extremely improved chroma, excellent color development, high discharge stability and forms high-quality images. <P>SOLUTION: The recording ink is useful for inkjet recording in which dye ink is replaced with pigment ink by the same head and used, has ≥5 mPa s viscosities of the dye ink and the pigment ink at 25°C and ≤3 mPa s difference in viscosity between the dye ink and the pigment ink. The recording ink is used in an inkjet recorder having a head with a plurality of nozzle rows, a subtank for supplying a liquid to the head, a negative pressure generating means for generating negative pressure in the subtank, an atmospheric air releasing means for releasing atmospheric air in the subtank and a detection means for detecting presence of ink by difference of electric resistance, has ≥5 mPa s viscosity at 25°C and ≤40 mN/m surface tension at 25°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recording ink suitably used for ink jet recording, and an ink cartridge, an ink recorded matter, an ink jet recording apparatus, and an ink jet recording method using the recording ink.

  Ink jet printers based on the ink jet recording method are rapidly spreading in recent years because they can print on plain paper, are easy to color, are small and inexpensive, and have low running costs. In general, recording inks used in ink jet recording systems have recording image storability such as color tone to achieve high image quality, image density, and bleeding, and colorant dissolution stability to achieve reliability. Characteristics such as water resistance and light resistance for ensuring, such as quick drying of ink for achieving high speed, are required, and various proposals for satisfying these characteristics have been made. For example, Patent Document 1 proposes a pigment ink having a relatively high viscosity. In particular, when this ink is printed on plain paper at a high speed, the occurrence of feathering and color bleeding is small, and a high-quality image with a good color tone can be obtained.

  However, this proposed pigment ink has relatively good gloss on glossy paper when viewed as a pigment ink, but has the disadvantage that gloss on glossy paper is still inferior to that of dye ink. Therefore, it is required to perform printing with dye ink as necessary, and it is desired to perform printing by appropriately replacing pigment ink and dye ink.

  When printing with dye ink and pigment ink exchanged as appropriate with the same head, dye ink is a solution, while pigment ink is a dispersion, and its characteristics differ greatly. It is unclear whether an ink set having such characteristics is preferable.

In addition, since the dye has a limit in saturation solubility and affects the back-through, it is not always easy to produce a high-viscosity dye ink at the same level as the pigment ink. Further, when printing the dye ink by replacing it with the pigment ink as needed, the settling of the colorant must be prevented. For this reason, Patent Document 2 proposes a dye ink that can be replaced with a pigment ink having a regulated pH.
However, in this proposal, there is no disclosure or suggestion about the viscosity of the dye ink, the surface tension is high from the viewpoint of the material, and the image quality is not sufficient.

In recent years, inkjet recording apparatuses capable of printing high-viscosity pigment inks have been developed (for example, Ricoh Ipushio G707 and Ricoh Ipushio G505, both manufactured by Ricoh Co., Ltd.).
Although it is known to print pigment inks using these ink jet recording devices, there is no disclosure or suggestion of printing dye inks using this device, supplying ink stably, Details regarding dye inks that can be printed have not been studied.

  Dye inks are excellent in water solubility, but unlike disperse pigment inks, there is a limit to water solubility, so if the concentration of dye ink is high, it will crystallize once evaporated and dried, and firmly fixed. May end up. In particular, if the dye ink is firmly fixed to the empty discharge receiver that receives the empty discharge, which is an operation for discharging the dirt in the nozzle after wiping once to clean the head dirt, it is not easy to remove the dirt. Absent.

  Therefore, dye inks, unlike pigment inks, are limited in the saturation solubility of dyes and have a greater penetration than pigment inks, so there are limitations on the selection of materials that increase viscosity, and development of high-viscosity dye inks Is still not progressing and its rapid development is desired.

JP 2003-96345 A JP 2002-60665 A

This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, according to the present invention, first, an optimum combination of ink physical properties used for ink-jet recording in which dye ink and pigment ink are appropriately exchanged with the same head is obtained, and a remarkable improvement in saturation is achieved. Recording ink that has excellent color developability, high ejection stability, and high-quality image formation, and an ink cartridge, an ink recorded matter, an ink jet recording apparatus, and an ink jet recording method using the recording ink The purpose is to provide.
Secondly, the present invention provides a head having a plurality of nozzle rows, a sub tank for supplying liquid to the head, a negative pressure generating means for generating a negative pressure in the sub tank, and the sub tank is opened to the atmosphere. Recording ink comprising a high-viscosity dye ink for use in an ink jet recording apparatus having an atmosphere opening means for detecting and a detecting means for detecting the presence or absence of ink by a difference in electric resistance, and an ink recorded matter using the recording ink And an ink cartridge.

Means for solving the problems are as follows. That is,
<1> Used for inkjet recording in which dye ink and pigment ink are exchanged with the same head, and the viscosity of the dye ink and pigment ink at 25 ° C. is 5 mPa · s or more, and the dye ink and the pigment ink And a viscosity difference of 3 mPa · s or less.
<2> The pigment ink contains at least water, a pigment, a wetting agent, a polyol compound having 8 to 11 carbon atoms and a glycol ether compound, and a surfactant, and has a viscosity at 25 ° C. of 5 mPa · s. The recording ink according to <1> above, wherein the surface tension at 25 ° C. is 40 mN / m or less.
<3> The above <2>, wherein the pigment is at least one selected from polymer fine particles containing at least one of a water-insoluble colorant and a poorly water-soluble colorant, and carbon black having at least one hydrophilic group on the surface. The recording ink described in 1.
<4> A head having a plurality of nozzle rows, a sub-tank that stores liquid supplied from a liquid storage tank and supplies the liquid to the head, and negative pressure generating means for generating negative pressure in the sub-tank And a recording ink for use in an ink jet recording apparatus having an atmosphere opening means for releasing the inside of the sub-tank to the atmosphere and a detecting means for detecting the presence or absence of ink based on a difference in electric resistance. A recording ink characterized by being a dye ink having a viscosity at 25 ° C. of 5 mPa · s or more and a surface tension at 25 ° C. of 40 mN / m or less.
<5> The recording ink according to <4>, wherein the ink jet recording apparatus includes a scraping unit that scrapes off the ink fixed to the idle discharge receiver.
<6> The dye ink contains at least water, a dye, a wetting agent, a thickening agent, and any one of a polyol compound having 8 to 11 carbon atoms and a glycol ether compound, and has a viscosity at 25 ° C. of 5 mPa · The recording ink according to any one of <1> to <5>, which is s or more and has a surface tension at 25 ° C. of 40 mN / m or less.
<7> Wetting agent is glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylolpropane, 1.1. 1. The recording ink according to <6>, which is at least one selected from 1-tris (hydroxymethyl) propane and trimethylolethane.
<8> The recording ink according to any one of <6> to <7>, wherein the content of the wetting agent in the dye ink is 35 to 50% by mass.
<9> The recording ink according to any one of <6> to <8>, wherein the thickening agent is at least one of a surfactant and an alginic acid compound.
<10> The recording ink according to <9>, wherein the surfactant is at least one selected from an anionic surfactant and a nonionic surfactant.
<11> The recording ink according to any one of <9> to <10>, wherein the content of the surfactant in the dye ink is 7% by mass or more.
<12> The recording ink according to any one of <6> to <11>, wherein the content of the dye in the dye ink is 4% by mass or more.
<13> The recording ink according to any one of <6> to <12>, wherein the dye ink contains an antifoaming agent, and the antifoaming agent is a silicone-based antifoaming agent.
<14> The recording ink according to <13>, wherein the silicone-based antifoaming agent is either a self-emulsifying type or an emulsion type.
<15> The recording ink according to any one of <1> to <14>, wherein the dye ink and the pigment ink are at least one selected from cyan ink, magenta ink, yellow ink, and black ink.
<16> An ink cartridge comprising the recording ink according to any one of <1> to <15> contained in a container.
<17> The ink cartridge according to <16>, wherein the amount of ink stored is 15 g or more.
<18> An ink jet comprising at least an ink flying unit that applies a stimulus to the recording ink according to any one of <1> to <15>, and causes the recording ink to fly to form an image. It is a recording device.
<19> The inkjet recording apparatus according to <18>, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.
<20> The ink jet recording apparatus according to any one of <18> to <19>, wherein the ink flying unit is used by exchanging the dye ink and the pigment ink with the same head.
<21> The above items <18> to <19>, wherein the ink flying means includes a head having a plurality of nozzle rows and a sub-tank that stores liquid supplied from a liquid storage tank and supplies liquid to the head. An inkjet recording apparatus according to any one of the above.
<22> A negative pressure generating means for the sub tank to generate a negative pressure in the sub tank, an atmospheric release means for releasing the inside of the sub tank to the atmosphere, and a detecting means for detecting the presence or absence of ink by a difference in electrical resistance It is an inkjet recording device as described in said <21> which has.
<23> The inkjet recording apparatus according to any one of <18> to <22>, further including a scraping unit that scrapes off the ink fixed to the idle discharge receiver.
<24> The ink jet recording apparatus according to <23>, wherein the scraping means is either a wiper or a cutter.
<25> An ink jet comprising at least an ink flying step of forming an image by applying a stimulus to the recording ink according to any one of <1> to <15> and causing the recording ink to fly. It is a recording method.
<26> The inkjet recording method according to <25>, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.
<27> The inkjet recording method according to any one of <25> to <26>, wherein the dye ink and the pigment ink are exchanged with the same head in the ink flying process.
<28> An ink recorded matter comprising an image formed using the recording ink according to any one of <1> to <15> on a recording medium.

In the first embodiment, the recording ink of the present invention is used for ink jet recording in which the dye ink and the pigment ink are exchanged with the same head, and the ink viscosity of the dye ink and the pigment ink at 25 ° C. is 5 mPa · s or more. In addition, since the difference in viscosity between the dye ink and the pigment ink is 3 mPa · s or less, the saturation is remarkably improved, the color developability is excellent, the ejection stability is high, and the quality is high. Image formation is possible.
In this case, the pigment ink contains at least water, a pigment, a wetting agent, one of a polyol compound having 8 to 11 carbon atoms and a glycol ether compound, and a surfactant, and has a viscosity at 25 ° C. of 5 mPa · s or more and a surface tension at 25 ° C. of 40 mN / m or less are used. As a result, an image without blurring and without blur is obtained. The dye ink contains at least water, a dye, a wetting agent, a thickening agent, and any one of a polyol compound having 8 to 11 carbon atoms and a glycol ether compound, and has a viscosity at 25 ° C. of 5 mPa · A material having a surface tension at 25 ° C. of 40 mN / m or less is used. As a result, a dye ink that dries quickly after printing, bleeds and bleeds, gives glossiness even on glossy paper, and has excellent jetting stability.

  In the second embodiment, the recording ink of the present invention includes a head having a plurality of nozzle rows, a subtank that stores liquid supplied from a liquid storage tank and supplies the liquid to the head, and a negative in the subtank. For recording used in an ink jet recording apparatus having a negative pressure generating means for generating pressure, an air releasing means for releasing the inside of the sub tank to the atmosphere, and a detecting means for detecting the presence or absence of ink by a difference in electrical resistance The ink for recording is a dye ink having a viscosity at 25 ° C. of 5 mPa · s or more and a surface tension at 25 ° C. of 40 mN / m or less. As a result, even when using high-viscosity dye ink, it dries quickly after printing, bleeds, has little bleed, and gives glossiness even on glossy paper, and has excellent jetting stability and forms high-quality images. it can.

  The ink cartridge of the present invention comprises the recording ink according to the first and second aspects 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 has at least ink flying means for forming an image by applying energy to the recording ink according to the first aspect of the present invention and causing the recording ink to fly. In the ink jet recording apparatus of the present invention, 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, when the dye and the pigment are exchanged in a timely manner, the saturation is remarkably improved, the color developability is excellent, the ejection stability is high, and a high-quality image can be formed. Further, it is preferable to add an antifoaming agent to the dye ink. As a result, the presence / absence of ink can be stably detected by the sub tank provided with means for detecting the presence / absence of ink based on the difference in electrical resistance. Further, even when the dye ink is fixed by the empty discharge receiver, it is preferable to provide a wiper or a cutter-type scraping mechanism at the empty discharge receiver. As a result, the fixed dye ink can be scraped off efficiently.

  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 according to the first aspect of the present invention and causing the recording ink to fly. In the ink jet recording method of the present invention, 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, when the dye and the pigment are exchanged in a timely manner, 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 recorded matter of the present invention has an image formed on a recording medium using the recording ink according to the first and second aspects of the present invention. In the ink recorded matter of the present invention, the saturation is remarkably improved, the color developability is excellent, and a high-quality image is held on the recording medium.

  In the present specification, “same head” means that at least the same head is used in the same ink jet recording apparatus, and dye ink and pigment ink are used as appropriate. However, a part of the ink jet recording apparatus includes a case where a separate one is used. For example, the cartridge includes a case where a dye ink and a pigment ink are exclusively used. It also includes the case where only the pigment ink is printed and then the cartridge is refilled with dye ink and printed (including the case where cleaning is performed at the time of replacement). In short, “same head” means to include all cases where the pigment ink and the dye ink are mixed even in a small amount in the ink passage (including the portion where the waste liquid is accumulated) in the ink jet recording apparatus. .

According to the present invention, various problems in the prior art can be solved, and in an ink jet recording in which the dye ink and the pigment ink are appropriately exchanged with the same head, a remarkable improvement in color saturation is achieved, the color developability is excellent, and the ejection stability is improved. Recording ink that is capable of forming a high-quality and high-quality image, and an ink cartridge, an ink recording, an ink jet recording apparatus, and an ink jet recording method using the recording ink can be provided.
Further, according to the present invention, a head having a plurality of nozzle rows, a sub tank for supplying liquid to the head, a negative pressure generating means for generating a negative pressure in the sub tank, and the sub tank are opened to the atmosphere. The recording ink comprising a high-viscosity dye ink used in an ink jet recording apparatus having an air release means and a detection means for detecting the presence or absence of ink by a difference in electrical resistance quickly dries, blots, and bleeds after printing. The glossy paper can be obtained with a small amount of glossy paper. Further, the jetting stability is excellent, and a high-quality image can be obtained.

(Ink for recording)
In the first embodiment, the recording ink of the present invention is used for ink jet recording in which the dye ink and the pigment ink are exchanged with the same head, and the viscosity of the dye ink and the pigment ink at 25 ° C. is 5 mPa · s or more. And the difference in viscosity between the dye ink and the pigment ink is 3 mPa · s or less.

In the second embodiment, the recording ink of the present invention includes a head having a plurality of nozzle rows, a subtank that stores liquid supplied from a liquid storage tank and supplies the liquid to the head, and a negative in the subtank. For recording used in an ink jet recording apparatus having a negative pressure generating means for generating pressure, an air releasing means for releasing the inside of the sub tank to the atmosphere, and a detecting means for detecting the presence or absence of ink by a difference in electrical resistance The ink for recording is a dye ink having a viscosity at 25 ° C. of 5 mPa · s or more and a surface tension at 25 ° C. of 40 mN / m or less.
In this case, it is preferable that the ink jet recording apparatus has a scraping unit that scrapes off the fixed ink on the idle discharge receiver, and an aspect in which the scraping unit is either a wiper or a cutter is preferable.
Here, the dye ink according to the second embodiment of the present invention may be the same as the dye ink in the recording ink according to the first embodiment.

The viscosity of the dye ink and the pigment ink at 25 ° C. is 5 mPa · s or more, and preferably 8 mPa · s or more. When the viscosity is less than 5 mPa · s, the image density on plain paper is low.
In the first embodiment, the viscosity difference between the dye ink and the pigment ink is 3 mPa · s or less, and more preferably 1 mPa · s or less. If the viscosity difference exceeds 3 mPa · s, stable particle formation becomes difficult under the same conditions. The viscosity of the dye ink may be higher or lower than the viscosity of the pigment ink. When the viscosity of the dye ink is higher than the viscosity of the pigment ink, the viscosity difference is (dye ink viscosity−pigment ink viscosity). It is represented by On the other hand, when the viscosity of the pigment ink is higher than the viscosity of the dye ink, the viscosity difference is represented by (pigment ink viscosity-dye ink viscosity).
Here, the viscosity can be measured by, for example, a conical plate type rotational viscometer.

The surface tension of the pigment ink and dye ink at 25 ° C. is preferably 40 mN / m or less, and more preferably 35 mN / m or less. When the surface tension exceeds 40 mN / m, if the surface tension is high, the drying speed of images on plain paper is slow, and feathering and set-off tend to occur. In addition, there is a drawback in that the ink in the ink discharge portion is difficult to flow, and is easily retained in the discharge portion, and difficult to flow to the waste liquid tank.
Here, the surface tension can be measured by, for example, a platinum plate method using a surface tension measuring device (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

When printing using the pigment ink, the ink viscosity at 25 ° C. is 5 mPa · s or more and 25 ° C. at 25 ° C. in order to obtain high image density and high-speed drying ink even if plain paper is used. The surface tension is preferably 40 mN / m or less.
Printing was performed in place of the dye ink using a piezo-type experimental apparatus that stably ejected pigment ink having such physical properties (for example, a viscosity of 8 mPa · s at 25 ° C.). Conventional ink-jet dye inks usually have a viscosity of 5 mPa · s or less. Therefore, when a dye ink having a viscosity of 3 mPa · s was prepared and printed with the same head instead of the pigment ink, the particle formation became unstable. In particular, when several droplets are experimentally ejected at high speed and are combined into a single droplet before adhering to paper and deposited as a large particle size droplet, with a dye ink having a viscosity of 3 mPa · s, Did not unite, resulting in dot disturbance.

  Using a waveform that stably ejects a pigment ink having a viscosity of 5 mPa · s and printing a dye ink having a viscosity of 3 mPa · s at 25 ° C., the small droplets coalesce in flight and become large droplets. As a result, it was possible to print stably. On the other hand, even when a waveform was used to stably eject pigment ink having a viscosity of 8 mPa · s and a dye ink having a viscosity of 5 mPa · s was printed, stable printing could be performed. As described above, when the difference in viscosity between the pigment ink and the dye ink is 4 to 5 mPa · s or more, it is difficult to stably jet the dye ink and the pigment ink with the same head.

  Also, in terms of image quality, when a dye ink having a viscosity of 8 mPa · s and a viscosity of 3 mPa · s is printed with a viscosity of 8 mPa · s, the amount of droplets is too large. It became an image. In the case of a dye ink, the plain paper inevitably has a back-through (an image can be confirmed from the back side) compared to the pigment ink. Therefore, in order to reduce the breakthrough, it is necessary to increase the viscosity of the dye ink to a certain level of 5 mPa · s or more (however, depending on the material that increases the viscosity). It is considered that when the viscosity of the dye ink is increased, the amount of see-through is reduced both by the reduction of the amount of droplets and by the solidification on the surface after adhesion to the paper surface.

The dye ink having a low surface tension with a surface tension at 25 ° C. of 40 mN / m or less is used as the dye ink if the surface tension is adjusted to 40 mN / m or less, so that it can rapidly penetrate most recording media. This is based on the fact that drying is possible. In addition, by setting the surface tension of the dye ink to 40 mN / m or less, the wetness of the dye ink to the head member is improved, and the frequency response even with a high viscosity ink of 5 mPa · s (25 ° C.) or more. And the discharge stability is remarkably improved.
In this case, in particular, the pigment ink to be used as needed is highly viscous, and it is a major problem that the pigment ink settles and solidifies in the discharge receiving portion during idle discharge. In order to solve this problem, it is effective to use a dye ink having a low surface tension that is easy to flow so that precipitation does not occur when the dye ink is replaced.
Further, if the viscosity of the dye ink is a high viscosity ink of 5 mPa · s or more, the amount of water in the ink is reduced, the water evaporation rate is increased, the speed at which the dye aggregates on the paper surface increases, and bleeding (feathering) occurs. There is also an effect that it decreases.

<Dye ink>
As described above, the dye ink is not particularly limited as long as the viscosity at 25 ° C. is 5 mPa · s or more and the surface tension at 25 ° C. is 40 mN / m or less, and may be appropriately selected according to the purpose. For example, it contains at least water, a dye, a wetting agent, a thickening agent, and one of a polyol compound and a glycol ether compound having 8 to 11 carbon atoms. Contains ingredients.

-Dye-
Examples of the dye include acid dyes, direct dyes, basic dyes, and reactive dyes.
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.

  The direct dye is not particularly limited and may be appropriately selected depending on the intended purpose. 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.

  There is no restriction | limiting in particular as said basic dye, According to the objective, it can select suitably, For example, C.I. I. Basic Yellow 1, 2, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 40, 41, 45, 49, 51, 53, 63, 65, 67 70, 73, 77, 87, 91; C.I. I. Basic Red 2, 12, 13, 14, 15, 18, 22, 23, 24, 27, 29, 35, 36, 38, 39, 46, 49, 51, 52, 54, 59, 68, 69, 70 73, 78, 82, 102, 104, 109, 112; I. Basic Blue 1, 3, 5, 7, 9, 21, 22, 26, 35, 41, 45, 47, 54, 62, 65, 66, 67, 69, 75, 77, 78, 89, 92, 93 105, 117, 120, 122, 124, 129, 137, 141, 147, 155; I. Basic black 2, 8, etc. are mentioned.

  There is no restriction | limiting in particular as said reactive dye, According to the objective, it can select suitably, For example, 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, acidic dyes and direct dyes can be particularly preferably used, and excellent effects can be obtained in terms of improvement in ink dissolution stability, color tone, water resistance, and light resistance.
The content of the dye in the dye ink is preferably 4% by mass or more, and more preferably 4 to 15% by mass. When the content is less than 4% by mass, the image density tends to be lowered, and the intended high viscosity dye ink may be difficult to obtain.

-Wetting agent (high boiling water-soluble organic solvent)-
The wetting agent (high-boiling water-soluble organic solvent) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexane Preferable examples include at least one selected from diol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylolpropane, 1.1.1-tris (hydroxymethyl) propane, and trimethylolethane. Among these, when glycerin and other wetting agents other than the glycerin are used in combination, a highly viscous ink can be achieved.

  The content of the high-boiling water-soluble organic solvent in the dye ink is preferably 35 to 50% by mass when increasing the amount of wetting agent to increase the viscosity (see FIG. 13). However, this does not apply when the viscosity is increased with a thickening agent. When the content is less than 35% by mass, it is difficult to obtain the target high-viscosity dye ink, the jetting may become unstable, and the effect of increasing the viscosity in the image (high image density) is obtained. In some cases, if it exceeds 50 mass%, on the contrary, there may be a lot of see-through with plain paper.

-High viscosity agent-
Examples of the thickening agent include a surfactant having a molecular weight of about 300 to 1,000, a resin or emulsion having a molecular weight of 1000 or more, a compound having a water-soluble part such as an ethylene oxide chain or a carboxyl group, and a water-soluble increase in an alginate compound. And compounds having a sticky effect. In the present specification, a surfactant, alginic acid, resin, emulsion and the like are used for the purpose of increasing the viscosity of the dye, and may be referred to as “high viscosity agent”.

  As the surfactant, for example, an anionic surfactant or a nonionic surfactant is preferable, and those represented by the following general formulas (1) to (6) are preferable.

^{_{R 1 -O- (CH 2 CH 2}} O) h CH 2 COOM ··· formula (1)
However, in said general formula (1), R < ¹ > represents an alkyl group and the C6-C14 alkyl group which may be branched is suitable. h represents an integer of 3 to 12. M represents one selected from alkali metal ions, quaternary ammonium, quaternary phosphonium, and alkanolamine.

ただし、前記一般式（２）中、Ｒ^２は、アルキル基を表し、炭素数５〜１６の分岐したアルキル基を表す。Ｍは、アルカリ金属イオン、第４級アンモニウム、第４級ホスホニウム、及びアルカノールアミンから選択されるいずれかを表す。

In the general formula (2), ^{R 2} represents an alkyl group, a branched alkyl group having 5 to 16 carbon atoms. M represents one selected from alkali metal ions, quaternary ammonium, quaternary phosphonium, and alkanolamine.

ただし、前記一般式（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 general 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.

^{_{R 4 - (OCH 2 CH 2}} ) j OH ··· formula (4)
In the general formula (4), R ⁴ represents a hydrocarbon group, for example, branched 6-14 carbon atoms which may be an alkyl group, and the like. j represents an integer of 3 to 20.

ただし、前記一般式（５）及び（５’）中、Ｒ^６は、炭化水素基を表し、例えば、炭素数６〜１４のアルキル基を表す。Ｌ、ｍ、ｎ、及びｐは、１〜２０の整数を表す。

In the general formula (5) and (5 '), ^{R 6} represents a hydrocarbon group, for example, an alkyl group having 6 to 14 carbon atoms. L, m, n, and p represent an integer of 1-20.

ただし、前記一般式（６）中、ｑ及びｒは、０〜４０の整数を表す。

However, in said general formula (6), q and r represent the integer of 0-40.

When the amount of the wetting agent is not so much and is a normal amount (about 15 to 30% by mass), the content of the surfactant in the dye ink is preferably 7% by mass or more for increasing the viscosity of the dye ink (FIG. 14). And FIG. 15). If the content is less than 7% by mass, the desired viscosity cannot be obtained. Further, in the case of a surfactant, there is an advantage that if the amount of the surfactant is increased to increase the viscosity for printing, the show-through is reduced.
The effect similar to that of the surfactant can also be obtained by adding a polymer water-soluble resin having a water-soluble part such as a carboxyl group or an ethylene oxide group.

  Examples of the alginic acid compound include alginic acid or a salt thereof. Alginic acid is β- (1 → 4) -D-mannuronic acid (hereinafter sometimes abbreviated as “M”), α- (1 → 4) -L-glucuronic acid (hereinafter abbreviated as “G”). A linear polysaccharide consisting of two types of uronic acid (1) M block consisting only of MM bonds, (2) G block consisting only of GG bonds, (3) M and G is a block heteropolymer in which three types of blocks, which are randomly arranged with random arrangement, coexist, and the M / G ratio varies depending on the species of alga, season, and part of the alga.

The carboxyl groups (—COO) possessed by the M and G units are easily ion-exchanged and can be easily ion-exchanged with various cations.
That is, the physical properties of the alginic acid vary significantly depending on the type of cation paired with the carboxyl group (—COO) in an aqueous system. Examples of the cation include sodium ion, potassium ion, calcium ion, aluminum ion, ammonium ion and the like, and high viscosity and gelation occur due to the influence of these cations. Utilizing this feature, it is used as a thickener, gelling agent, emulsion stabilizer, film-forming agent, shape-retaining agent, flocculant and the like.
Examples of the alginates include potassium salts, sodium salts, and ammonium salts. Among these, sodium salts are preferable.
The high molecular weight alginic acid is abundantly contained between cells of brown algae such as kombu, macombu, wakame, hinoki, arame and kajime. Therefore, high molecular weight alginic acid can be obtained by using a method in which brown algae are washed with, for example, dilute sulfuric acid, extracted with a sodium carbonate solution, and precipitated with sulfuric acid.
Commercially available products can be used as the alginic acid, and examples thereof include ultra-low viscosity alginic acid manufactured by Kibun Food Chemifa Corporation.
When the viscosity of the dye ink is increased by increasing the alginic acid compound, the content of the alginic acid compound is preferably 4% by mass or less, and more preferably 1 to 3% by mass.

-Polyol compound or glycol ether compound having 8 to 11 carbon atoms-
Examples of the polyol compound having 8 to 11 carbon atoms include 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and the like.
Examples of the glycol ether compound include polyhydric alcohol alkyls such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Examples of ethers include polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
The addition amount of the polyol compound or glycol ether compound having 8 to 11 carbon atoms is preferably 0.1 to 10.0% by mass with respect to the total mass of the recording ink.

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

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

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

There is no restriction | limiting in particular as content in the said dye ink of the said antifoamer, According to the objective, it can select suitably, For example, 0.001-3 mass% is preferable, 0.05-0.5 mass % Is more preferable.
When the antifoaming agent is contained in the dye ink, it is particularly excellent in storage stability and ejection stability over time, and when the content is less than 0.001% by mass, the content effect is not sufficient. If it exceeds 3% by mass, clogging is likely to occur, and the reliability of the dye ink may deteriorate.

<Pigment ink>
As described above, the pigment ink is not particularly limited as long as the viscosity at 25 ° C. is 5 mPa · s or more and the surface tension at 25 ° C. is 40 mN / m or less, and may be appropriately selected according to the purpose. For example, it contains at least water, a pigment, a wetting agent, one of a polyol compound having 8 to 11 carbon atoms and a glycol ether compound, and a surfactant, and further contains other components as necessary. It contains.

-Pigment-
The pigment is preferably at least one selected from polymer fine particles containing at least one of a water-insoluble colorant and a poorly water-soluble colorant, and carbon black having at least one hydrophilic group on the surface.
In this case, it is not necessary for all of the color material blended in the pigment ink to be encapsulated or adsorbed in the polymer fine particles, and the color material is dispersed in the emulsion as long as the object and effect of the present invention are not impaired. May be. The color material is not particularly limited as long as it is water-insoluble or hardly water-soluble and can be adsorbed by the polymer, and can be appropriately selected according to the purpose.
Here, in the present specification, “water-insoluble or poorly water-soluble” means that the coloring material does not dissolve 10 parts by mass or more with respect to 100 parts by mass of water at 20 ° C. Further, “dissolve” means that separation or sedimentation of the coloring material is not observed in the surface layer or the lower layer of the aqueous solution visually.

  As the polymer that forms the polymer emulsion, for example, vinyl polymers, polyester polymers, polyurethane polymers, and the like can be used. Particularly preferred polymers are vinyl polymers and polyester polymers, and specific examples thereof include those disclosed in JP-A Nos. 2000-53897 and 2001-139849.

  Examples of the color material include carbon black as a black pigment. Examples of the color pigment include phthalocyanine blue, phthalocyanine green, quinacridone, anthraquinone, diazo, monoazo, pyrantrone, pyrylene, heterocyclic yellow, (thio) indigoid, and the like. Examples of the phthalocyanine blue include copper phthalocyanine blue or a derivative thereof (Pigment Blue 15). Examples of the quinacridone include Pigment Orange 48, Pigment Orange 49, Pigment Red 122, Pigment Red 192, Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209, Pigment Violet 19 and Pigment Violet 42. . Examples of the anthraquinone include pigment red 43, pigment red 194 (perinone red), pigment red 216 (brominated pyrantron red), and pigment red 226 (pyrantron red). Examples of the pyrerin include Pigment Red 123 (Bell Million), Pigment Red 149 (Scarlet), Pigment Red 179 (Maroon), Pigment Red 190 (Red), Pigment Violet, Pigment Red 189 (Yellow Shade Red), and Pigment Red. 224 and the like. Examples of the (thio) indigoid include Pigment Red 86, Pigment Red 87, Pigment Red 88, Pigment Red 181, Pigment Red 198, Pigment Violet 36, and Pigment Violet 38. Examples of the heterocyclic yellow include pigment yellow 117 and pigment yellow 138. Other suitable coloring pigments are described in, for example, The Color Index, Third Edition (The SOCIETY Of Dyer and Colorists, 1982).

  In the black pigment ink, a color pigment that can be stably dispersed without using a dispersant in which at least one hydrophilic group is bonded to the surface of carbon black directly or through another atomic group is suitably used. Use. As a result, unlike the conventional ink, a dispersing agent for dispersing the carbon black becomes unnecessary. As the carbon black used in the present invention, those having ionicity are preferable, and those having an anionic charge and those charged in a cationic form are suitable.

Examples of the anionic hydrophilic group, for _{example, -COOM, -SO 3 M, -PO} 3 HM, -PO 3 M 2, -SO 2 NH 2, -SO 2 NHCOR ( although, M in the formula is hydrogen R represents an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent. ) And the like. Among these, it is preferable to use those in which —COOM and —SO ₃ M are bonded to the surface of the color pigment.

  Further, “M” in the hydrophilic group includes, for example, lithium, sodium, potassium and the like as an alkali metal. Examples of the organic ammonium include mono to trimethyl ammonium, mono to triethyl ammonium, and mono to trimethanol ammonium. As a method of obtaining the anionically charged color pigment, as a method of introducing —COONa to the color pigment surface, for example, a method of oxidizing the color pigment with sodium hypochlorite, a method of sulfonation, a diazonium salt The method of making it react is mentioned.

-Wetting agent-
There is no restriction | limiting in particular as said wetting agent, According to the objective, it can select suitably, For example, the thing similar to the said dye ink can be used.
The amount of the wetting agent added to the pigment ink is preferably 5 to 50% by mass, more preferably 8 to 30% by mass.

-Polyol compound or glycol ether compound having 8 to 11 carbon atoms-
As any of the polyol compound having 8 to 11 carbon atoms and the glycol ether compound, those similar to the dye ink can be used.

-Surfactant-
The surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include amphoteric surfactants, anionic surfactants, cationic surfactants, and nonionic surfactants. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together.

Examples of the amphoteric surfactant include alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine, N-alkyl-N, N-dimethylammonium betaine, and the like.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.
Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, and the like. Is mentioned. As the nonionic surfactant, an acetylene glycol surfactant can also be used. Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3, An acetylene glycol type such as 5-dimethyl-1-hexyn-3-ol (for example, Surfynol 104, 82, 465, 485, or TG from Air Products (USA)) can be used. In particular, Surfinol 465, 104 and TG show good print quality.
Examples of the cationic surfactant include alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt type surfactants such as imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, And quaternary ammonium salt surfactants such as pyridinium salts, alkylisoquinolinium salts, and benzethonium chloride.

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

  The pigment ink may contain an antifoaming agent, and the same antifoaming agent as that of the dye ink can be used.

-Other ingredients-
The dye ink and pigment ink are not particularly limited as other components, and can be appropriately selected as necessary. For example, antiseptic / antifungal agents, pH adjusters, rust inhibitors, antioxidants, An ultraviolet absorber, an oxygen absorber, a light stabilizer, etc. are mentioned.

  The antiseptic / antifungal agent is not particularly limited and may be appropriately selected as necessary. Examples thereof include sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, pentachloro Phenol sodium, etc. are mentioned, and among these, 1,2-benzisothiazolin-3-one is particularly preferably used.

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. Among these, 2-amino-2-ethyl-1,3-propanediol is particularly preferably used. This pH adjuster is water-soluble and dissolves uniformly when added to the recording ink, and has no adverse effect on the colorant that is dispersed and dissolved. In addition to the function as a pH adjuster, in the ink jet recording apparatus of the present invention, at least part of the liquid chamber portion, fluid resistance portion, diaphragm, and nozzle member of the ink jet head is formed of a material containing silicon or nickel. In this case, the elution prevention effect is very high, and it brings about a remarkable effect on the long-term reliability of the ink jet recording apparatus using the ink containing 2-amino-2-ethyl-1,3-propanediol. is there. In addition, it has been found that it is very effective in improving ink ejection stability.

  The rust inhibitor is not particularly limited and may be appropriately selected as necessary. Examples thereof include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium. Nitrite and the like.

There is no restriction | limiting in particular as said antioxidant, It can select suitably as needed, For example, a phenolic antioxidant (a hindered phenolic antioxidant is included), an amine antioxidant, sulfur type | system | group Antioxidants, phosphorus antioxidants, and the like can be mentioned.
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- [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxypheni2,4,6-tris ( 3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakisl) 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 ultraviolet absorber include nickel bis (octylphenyl) sulfide, 2,2′-thiobis (4-tert-octylferrate) -n-butylamine nickel (II), 2,2′-thiobis. (4-tert-octyl ferrate) -2-ethylhexylamine nickel (II), 2,2′-thiobis (4-tert-octyl ferrate) triethanolamine nickel (II), and the like.

  The pH of the recording ink of the present invention is preferably 8 to 11 for the pigment ink. When the pH is less than 8, dispersion may become unstable, and when the pH is more than 11, the liquid contact property may be deteriorated. The dye ink preferably has a pH of 7 to 11. When the pH is less than 7, dispersion of the pigment ink may become unstable when mixed with the pigment ink, and when the pH exceeds 11, the liquid contact property may be deteriorated.

  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 according to the first embodiment of the present invention is used for ink jet recording in which dye ink and pigment ink are appropriately exchanged in the same head, and the ink jet head as the ink flying means includes ink in the ink flow path. A so-called piezo-type device that uses a piezoelectric element as pressure generating means to pressurize the ink and deforms a diaphragm that forms the wall surface of the ink flow path to change the volume of the ink flow path to eject ink droplets (Japanese Patent Laid-Open No. Hei 2- 51734), or a so-called thermal type that generates bubbles by heating ink in the ink flow path using a heating resistor (see Japanese Patent Application Laid-Open No. 61-59911), or a wall surface of the ink flow path The volume of the ink flow path is changed by deforming the diaphragm with electrostatic force generated between the diaphragm and the electrode. Therefore, it can be used favorably in a printer equipped with any ink jet head such as an electrostatic type that discharges ink droplets (see JP-A-6-71882).

  The recording ink according to the first embodiment and the second embodiment 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) by an ink jet recording method. The recording paper and the recording ink are heated at 50 to 200 ° C. before or after printing or can be used for a printer having a function of accelerating print fixing. The following ink cartridge and ink recording of the present invention can be used. Can be used particularly favorably in products, inkjet recording apparatuses, and inkjet recording methods.

(ink cartridge)
The ink cartridge of the present invention contains the recording ink according to the first and second aspects of the present invention in a container, and further has 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.
The amount of ink contained in the ink cartridge is preferably 15 g or more. When the amount is less than 15 g, when the number of printed sheets is large as in the ink jet recording apparatus of the present invention, the cartridge replacement frequency increases, and the object and the function and effect may not be achieved. Further, according to the ink jet recording apparatus of the present invention, even when such a large-capacity ink tank is used, the liquid contact is poor due to storage and air leakage occurs and bubbles are not generated.

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 10 is filled into the ink bag 41 from the ink inlet 42 and exhausted, and then the ink inlet 42 is closed by fusion. When in use, the needle of the apparatus main body is inserted into the ink discharge port 43 made of a rubber member and supplied to the apparatus.
The ink bag 41 is formed of a packaging member such as a non-permeable aluminum laminate film. As shown in FIG. 2, the ink bag 41 is usually accommodated in a plastic cartridge case 44 and can be detachably attached to various ink jet recording apparatuses.

(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, etc. It is preferable that the pigment ink is used as appropriate.
The ink jet recording method of the present invention includes at least an ink flying step, and further includes other steps appropriately selected as necessary, for example, a stimulus generation step, a control step, and the like. It is preferable to use the appropriate replacement.
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 according to the first embodiment 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 according to the first embodiment of the present invention and causing the recording ink to fly. The ink flying means is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include various ink ejection heads, and particularly a head having a plurality of nozzle rows (ink ejection head) and a liquid. It is preferable to have a sub-tank that contains the liquid supplied from the storage tank and supplies the liquid to the droplet discharge head.
The sub tank includes a negative pressure generating means for generating a negative pressure in the sub tank, an air releasing means for releasing the inside of the sub tank to the atmosphere, and a detecting means for detecting the presence or absence of ink by a difference in electric resistance. What has is preferable.

  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.

  Further, it is preferable to have a scraping means for scraping off the ink fixed to the empty discharge receptacle. As the scraping means, either a wiper or a cutter is preferable.

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

  Here, one aspect of 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 1, a paper feed tray 2 for loading paper mounted on the apparatus main body 1, and paper on which an image is recorded (formed) mounted on the apparatus main body 1. A paper discharge tray 3 and an ink cartridge loading unit 6. On the upper surface of the ink cartridge loading unit 6, an operation unit 7 such as operation keys and a display is arranged. The ink cartridge loading unit 6 has a front cover 8 that can be opened and closed for attaching and detaching the ink cartridge 10.

  As shown in FIGS. 4 and 5, in the apparatus main body 1, the carriage 13 is slid in the main scanning direction by a guide rod 11 and a stay 12 which are guide members 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 13 is provided with a recording head 14 composed of four inkjet 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.
The inkjet recording head constituting the recording head 14 includes a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by liquid film boiling using an electrothermal transducer such as a heating resistor, and a metal phase caused by a temperature change. A shape memory alloy actuator using a change, an electrostatic actuator using an electrostatic force, or the like as an energy generating means for discharging recording ink can be used.
In addition, the carriage 13 is equipped with a sub tank 15 for each color for supplying ink of each color to the recording head 14. The sub-tank 15 is supplied with and supplemented with the recording ink of the present invention from the ink cartridge 10 of the present invention loaded in the ink cartridge loading section 6 via a recording ink supply tube (not shown).

  On the other hand, as a paper feeding unit for feeding the paper 22 stacked on the paper stacking unit (pressure plate) 21 of the paper feeding tray 2, a half-moon roller (feeding) that separates and feeds the paper 22 one by one from the paper stacking unit 21. A separation pad 24 made of a material having a large friction coefficient is provided facing the paper roller 23) and the paper feed roller 23, and the separation pad 24 is urged toward the paper feed roller 23 side.

  As a transport unit for transporting the paper 22 fed from the paper feed unit below the recording head 14, a transport belt 31 for transporting the paper 22 by electrostatic adsorption and a guide 25 from the paper feed unit. The counter roller 32 for transporting the paper 22 fed via the transport belt 31 with the transport belt 31 and the paper 22 fed substantially vertically upward are changed by about 90 ° to be copied on the transport belt 31. A conveying guide 33 and a tip pressure roller 35 urged toward the conveying belt 31 by the pressing member 34, and a charging roller 36 as a charging means for charging the surface of the conveying belt 31. It has been.

  The conveyance belt 31 is an endless belt, is stretched between the conveyance roller 37 and the tension roller 38, and can circulate in the belt conveyance direction. A guide member 77 is disposed on the back side of the conveyance belt 31 so as to correspond to a printing area by the recording head 14. As a paper discharge unit for discharging the paper 22 recorded by the recording head 14, a separation claw 51 for separating the paper 22 from the conveyance belt 31, a paper discharge roller 52, and a paper discharge roller 53 are provided. The paper discharge tray 3 is disposed below the paper discharge roller 52.

  A double-sided paper feeding unit 61 is detachably attached to the back surface of the apparatus main body 1. The double-sided paper feeding unit 61 takes in the paper 22 returned by the reverse rotation of the transport belt 31, reverses it, and feeds it again between the counter roller 32 and the transport belt 31. A manual paper feed unit 62 is provided on the upper surface of the duplex paper feed unit 61.

  In this ink jet recording apparatus, the paper 22 is separated and fed one by one from the paper feed unit, and the paper 22 fed substantially vertically upward is guided by the guide 25 and between the transport belt 31 and the counter roller 32. It is sandwiched and conveyed. Further, the front end is guided by the transport guide 33 and pressed against the transport belt 31 by the front end pressure roller 35, and the transport direction is changed by approximately 90 °.

At this time, the conveyance belt 37 is charged by the charging roller 36, and the sheet 22 is conveyed by being electrostatically attracted to the conveyance belt 31. Therefore, by driving the recording head 14 according to the image signal while moving the carriage 13, ink droplets are ejected onto the stopped paper 22 to record one line, and after the paper 22 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 paper 22 has reached the recording area, the recording operation is finished and the paper 22 is discharged onto the paper discharge tray 3.
Then, when it is detected that the remaining amount of recording ink in the sub tank 15 has decreased, a required amount of recording ink is supplied from the ink cartridge 1 to the sub tank 15.

  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.

Here, the recording head 14 (used to collectively refer to a plurality of heads), for example, as shown in FIG. 6, is a nozzle array 14yn composed of a number of nozzles N that eject yellow (Y) ink droplets and magenta ( M) a droplet discharge head 14 a having a nozzle row 14 mn composed of a number of nozzles N that eject ink droplets of M, a nozzle array 14 cn composed of a number of nozzles N that eject cyan (C) ink droplets, and black (Bk) ) And a head 14b having a nozzle row 14kn composed of a number of nozzles N that eject ink droplets.
In this case, two colors are supplied to one recording head from two different sub tanks, and four colors of YMC and black are printed by two heads of four sub tanks. 4 heads with different colors are prepared for each, and 4 different heads with 2 nozzle rows, 4 heads with 4 nozzle rows, 4 colors YMC and black are printed. Also good. In Examples described later, an inkjet printer (IPSiO G707 manufactured by Ricoh Co., Ltd.) having four heads having two nozzle rows was used.

  As the ink jet head constituting the recording head 14, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change. A shape memory alloy actuator to be used, an electrostatic actuator using an electrostatic force, or the like as an energy generating means for discharging ink can be used. In the embodiments described later, a head using a piezoelectric actuator (piezoelectric element) as energy generating means is mounted.

  Further, the carriage 13 has a sub tank 15 which is a liquid container of each color for supplying each color ink to each nozzle row 14yn, 14mn, 14cn, 14kn of the recording head 14 (if each color is distinguished, the nozzle row The codes 15y, 15m, 15c, and 15k are used correspondingly). The sub-tank 15 uses the main tank (ink cartridge) 10 for each color described above via the ink supply tube 16 (in order to distinguish each color, the symbols 10y, 10m, 10c, and 10k are used corresponding to the nozzle rows. ) Is replenished and supplied. Here, the main tank 10 stores ink of each color of yellow (Y), cyan (C), magenta (M), and black (Bk) corresponding to each color, but the main tank 10 stores black ink. The tank 10k has a larger ink storage capacity than the main tanks 10y, 10m, and 10c that store other color inks.

Next, details of the ink supply device which is a liquid supply device in the recording apparatus will be described with reference to FIGS. 7 is an exploded perspective view of a portion related to the ink supply device, FIG. 8 is a detailed view thereof, and FIG. 9 is a schematic side view of the sub tank.
As described above, the ink supply device is mounted on the carriage 13 and supplies a sub tank 15 which is a liquid container for supplying ink to each recording head 14 (14a, 14b), and the sub tank 15 is supplied with ink via a supply tube 16. And a main tank (ink cartridge) 10 for supply and replenishment.
One sub tank 15 is a flexible film-like member that seals an opening (one surface of the sub tank 15) of the ink storage unit 100 to a container main body (case main body) 101 that forms the ink storage unit 100 that stores ink. (Flexible film-like member) 102 is attached by bonding or welding, and further, the film-like member 102 is biased outwardly between the case main body 101 and the film-like member 102 inside the ink containing portion 100. A spring (spring) 103 which is an elastic member is provided.

Here, the film-like member 102 may have a single layer structure, but as shown in FIG. 10A, a two-layer structure in which different types of first layer 102a and second layer 102b are laminated, for example, polyethylene and A nylon film-like member may be laminated, or a silica vapor deposition layer 102c may be formed on the first layer 102a as shown in FIG. By adopting such a configuration, it is possible to ensure liquid resistance against ink. Moreover, the liquid resistance with respect to the ink accommodated can also be improved by including a silica vapor deposition layer in the film-like member 102.
Moreover, as for the thickness of the film-like member 102, 10-100 micrometers is preferable. If the thickness is less than 10 μm, damage due to deterioration over time may easily occur, and if it exceeds 100 μm, flexibility may be reduced and efficient generation of negative pressure may be difficult.
Furthermore, a bulging portion 102a having a convex shape corresponding to the spring 103 is formed on the film-like member 102, and a reinforcing member 104 is attached to the outer surface thereof. In this manner, by providing the flexible film-like member 102 with the convex portion, the elastic member (here, the spring) 103 can be stably held. In this case, the flexible film-like member 102 can be easily formed with a convex portion by forming a sheet-like film member into a convex shape.

  Further, the case 101 is provided with an ink introduction path portion 111 for replenishing ink in the ink containing portion 100, and a connecting means for connecting the ink introduction path portion 111 and the supply tube 16 connected to the ink cartridge 10. 112 can be detachably mounted. A liquid feed pump as described later is provided between the ink cartridge 10 and the sub tank 15 in order to pressure-feed ink from the ink cartridge 10 to the sub tank 15.

  Further, a connecting member 113 for supplying ink from the ink containing portion 100 to the recording head 14 is attached to the lower portion of the case 101, and an ink supply path 114 of the recording head 14 is formed in the connecting member 113. A filter 115 is interposed between the two.

  An air flow path 121 is formed in the upper part of the case 101 for taking out air from the ink containing portion 100. The air flow path 121 includes an inlet flow path portion 122 having an opening facing the ink containing portion 100 and a flow path portion (referred to as an “orthogonal flow path portion”) 123 following the inlet flow path portion 122. An accumulation portion 126 is continuously formed in a portion that communicates with the atmosphere opening hole 131 provided in the case 101 on the downstream side, and that is further below the atmosphere opening hole 131 in use.

  The atmosphere release hole 131 is provided with an atmosphere release valve mechanism 132 which is an atmosphere release means for switching between the sealed state and the atmosphere release state in the sub tank 15. The atmosphere release valve mechanism 132 is configured by accommodating a valve seat 134, a ball 135 as a valve body, and a spring 136 for urging the ball 135 toward the valve seat 134 in a holder 133.

  The operation of the storage unit 126 will be described. When the apparatus main body is tilted or shaken, there is a high possibility that ink will enter the air flow path 121. Therefore, the ink that has entered from the air flow path 121 can be accumulated in the accumulating portion 126, and even if the ink falls and is intruded during transportation, the ink is placed in the atmosphere opening port 131 and the atmosphere opening valve mechanism 132 that opens and closes the ink. Prevents the atmosphere release valve mechanism 132 from malfunctioning due to intrusion and hardening.

  In addition, two detection electrodes 141 and 142 for detecting that the amount of ink in the sub tank 15 is equal to or less than a predetermined amount (this state is “no ink”) are attached to the upper portion of the case 101. ing. Detecting “no ink” by changing the conduction state between the detection electrodes 141 and 142 in a state where both the detection electrodes 141 and 142 are immersed in ink and in a state where at least one of the detection electrodes 141 and 142 is not immersed in ink Can do.

  As shown in FIGS. 11 and 12, in the non-printing area on one side (or both sides) of the carriage 13 in the scanning direction, a maintenance / recovery mechanism (for maintaining and recovering the nozzle state of the recording head 14) Hereinafter, it is referred to as “subsystem”) 71. FIG. 11 is a top view of the maintenance / recovery mechanism, and FIG. 12 is a schematic explanatory diagram of the maintenance unit. The subsystem 71 includes cap members 72A and 72B for capping each nozzle surface of the recording heads 14a and 14b, a wiper blade 73 for wiping the nozzle surface, and the like. Between the cap member 72 </ b> A and the wiper blade 73, there is provided an idle discharge receiver for empty discharge of ink. This empty discharge receiver is configured such that ink is discharged here and flows to the lower waste liquid tank, and the ink is easily fixed to this portion (discharged portion), so that the fixed ink is automatically scraped off. A wiper is provided. In this case, particularly when a dye ink having a high viscosity is used, it is effective for scraping off the dye ink solidified in the idle ejection portion.

  In addition, it is also effective to provide a cutter-type scraping mechanism when a dye-fixed material is accumulated. In both cases, the pigment inks of Ricoh Yipsio G707 and G505 (manufactured by Ricoh Co., Ltd.) also acted effectively on the dye ink. As described above, particularly in the case of a dye ink having a limited solubility, once it has been fixed, it has been difficult to collapse what has conventionally been accumulated. In addition, when the pigment ink and the dye ink are exchanged and used, the ink jet recording apparatus of the present invention can scrape off the mixed adhering material of the pigment ink and the dye ink.

Next, the maintenance / recovery mechanism 71 according to the ink jet recording apparatus of the present invention will be described.
As shown in FIGS. 11 and 12, first, when the motor 231 rotates in the forward direction, the motor gear 232, the pump gear 234, the intermediate gear 235, the intermediate gear 236, and the intermediate gear 237 rotate, and the tube pump 220 operates to operate the pump. The rightmost (recording region side) cap connected by the tube 219 is sucked. Other gears do not operate because the one-way clutch 237 is disconnected.
When the motor 231 rotates in the reverse direction, the one-way clutch 237 is connected and the motor to the camshaft rotate. The tube pump 220 rotates in the reverse direction but does not operate as a pump.
A carriage lock cam 227, cap cams 222B and 222A, a wiper cam 224, a wiper cleaner cam 228, and a home position sensor cam 241 are attached to the cam shaft 221 so as to rotate integrally.
The carriage lock 215 is biased upward (in the locking direction) by a compression spring (not shown). The carriage lock 215 is moved up and down by the carriage lock arm 217 in contact with the cam surface of the carriage lock cam 227.
The caps 72A and 72B and the cap holder 212A are moved up and down by cap cams 222A and 222B.
The wiper 73 is moved up and down by the wiper cam 228.
The wiper cleaner 218 is biased in a direction away from the wiper 73 by a spring and is moved in the wiper direction by the wiper cleaner cam 218. The wiper 73 descends while being sandwiched between the wiper cleaner 218 and the idle ejection receptacle, whereby the ink of the wiper 73 is scraped into the idle ejection.
A sensor (photo interrupter / not shown) is fixed to the maintenance unit body. When the cap comes to the lowermost end with the home position cam, the HP lever (not shown) is operated to open the sensor (pump). The home position is detected (other than that, the HP lever is not operated and the sensor is normally closed).
When the power is turned on, the caps 72A and 72B and the cap holders 212A and 212B move up and down (the position is not detected until the movement is started), and a predetermined amount is detected after detecting the cap home position (in the middle of ascending). Move to the bottom end. Thereafter, the carriage moves left and right, returns to the cap position after position detection, and is capped.

  The order of operation when the motor reverses is as follows: cap lift (carriage lock almost simultaneously), cap lower (carriage lock almost simultaneously), home position sensor open, wiper lift, wiper cleaner start (press wiper against empty discharge receptacle), Repeat the series of actions to lower the wiper (wipe the wiper with the wiper cleaner) and return to the wiper cleaner.

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

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

(Production Example 1)
-Preparation of high viscosity dye ink by increasing the amount of wetting agent-
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, diethylene glycol (DEG) 36% by mass, glycerin (GLY) 12% by mass, 2-ethyl-1,3-hexanediol 2% by mass, nonionic surface activity 2% by mass of an agent (polyoxyalkylene derivative), 0.2% by mass of a benzisothiazoline antiseptic and fungicide, and the remainder of the water were mixed, and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 1 was produced.

(Production Example 2)
-Preparation of high viscosity dye ink by increasing the amount of wetting agent-
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, 1,3-butanediol (1,3-BD) 30.75% by mass, glycerol 10.25% by mass, 2-ethyl-1,3- Hexanediol (2% by mass), nonionic surfactant (polyoxyalkylene derivative) (2% by mass), benzisothiazoline-based antiseptic / antifungal agent (0.2% by mass), and the remaining water were mixed, and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 2 was produced.

(Production Example 3)
-Preparation of high viscosity dye ink by increasing the amount of wetting agent-
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, 1.1.1-tris (hydroxymethyl) propane (TMP) 31.50% by mass, glycerol 10.50% by mass, 2-ethyl-1, Mix 2% by weight of 3-hexanediol, 2% by weight of nonionic surfactant (polyoxyalkylene derivative), 0.2% by weight of benzisothiazoline antiseptic and fungicide, and the rest of the water, and adjust the pH with lithium hydroxide. did. Thus, the dye ink of Production Example 3 was produced.

(Production Example 4)
-Preparation of high viscosity dye ink by increasing the amount of wetting agent-
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, triethylene glycol (TEG) 35.25% by mass, glycerin 11.75% by mass, 2-ethyl-1,3-hexanediol 2% by mass, nonion 2% by mass of a surfactant (polyoxyalkylene derivative), 0.2% by mass of a benzisothiazoline antiseptic and fungicide, and the remainder of the water were mixed, and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 4 was produced.

(Production Example 5)
-Preparation of high viscosity dye ink by increasing the amount of wetting agent-
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, diethylene glycol (DEG) 36% by mass, glycerin (GLY) 12% by mass, 2-ethyl-1,3-hexanediol 2% by mass, nonionic surface activity Agent (polyoxyalkylene derivative) 2% by mass, benzisothiazoline antiseptic mold agent 0.2% by mass, silicone antifoaming agent KS531 (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03% by mass, and the remainder And the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 5 was produced.

(Production Example 6)
-Preparation of high viscosity dye ink by increasing the amount of wetting agent-
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, 1,3-butanediol (1,3-BD) 30.75% by mass, glycerol 10.25% by mass, 2-ethyl-1,3- Hexanediol 2% by mass, nonionic surfactant (polyoxyalkylene derivative) 2% by mass, benzisothiazoline antiseptic fungicide 0.2% by mass, silicone antifoam KM72F (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03 The mass and the remaining water were mixed and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 6 was produced.

(Production Example 7)
-Preparation of high viscosity dye ink by increasing the amount of wetting agent-
C. I. Direct Blue 199 (solid content: 10.25% by mass) 44% by mass, 1.1.1-tris (hydroxymethyl) propane (TMP) 31.50% by mass, glycerol 10.25% by mass, 2-ethyl-1, 3-hexanediol 2% by mass, nonionic surfactant (polyoxyalkylene derivative) 2% by mass, benzisothiazoline antiseptic fungicide 0.2% by mass, silicone antifoam KS531 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0 0.03 mass and the remainder of water were mixed and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 7 was produced.

(Production Example 8)
-Preparation of high viscosity dye ink by increasing the amount of wetting agent-
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, triethylene glycol (TEG) 35.25% by mass, glycerin 10.25% by mass, 2-ethyl-1,3-hexanediol 2% by mass, nonion -Based surfactant (polyoxyalkylene derivative) 2% by mass, benzisothiazoline-based antiseptic and fungicide 0.2% by mass, silicone antifoam KM72F (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03 mass, and water balance The pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 8 was produced.

  Here, FIG. 13 shows the relationship between the concentration and viscosity of various wetting agents in the cyan dye inks of Production Examples 1 to 4 obtained. From the result of FIG. 13, it is recognized that the viscosity of 5 to 10 mPa · s shows a preferable characteristic as a dye ink, and the total content of the corresponding wetting agent is 35 to 50% by mass. If the content of the wetting agent is too large, even if the viscosity becomes high, there may be an increase in the show-through of the image. On the other hand, if the content is too small, the particle formation may become unstable.

(Production Example 9)
-Preparation of high viscosity dye ink by increasing the amount of wetting agent-
Magenta dye-1 (azo magenta dye) 3.75% by mass, C.I. I. Acid Violet 102 1.25% by mass, diethylene glycol 37.5% by mass, glycerin 12.5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, nonionic surfactant (R- (OCH ₂ CH ₂ ) _{n OH, R = C 13 H} 27, n = 3) 2 % by weight, preservative antifungal agent (sodium sorbate) 0.2 wt%, and mixed with water balance and pH adjusted with lithium hydroxide. Thus, the dye ink of Production Example 9 was produced.

(Production Example 10)
-Preparation of high viscosity dye ink by increasing the amount of wetting agent-
Magenta dye-1 (azo magenta dye) 3.75% by mass, C.I. I. Acid Violet 102 1.25% by mass, diethylene glycol 37.5% by mass, glycerin 12.5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, nonionic surfactant (R- (OCH ₂ CH ₂ ) _n OH, R = C ₁₃ H ₂₇ , n = 3) 2% by mass, antiseptic fungicide (sodium sorbate) 0.2% by mass, silicone antifoaming agent SAG30 (emulsion type, manufactured by Nihon Unicar Co., Ltd.) 03% by mass and the remaining water were mixed and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 10 was produced.

(Production Example 11)
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, diethylene glycol (DEG) 15% by mass, glycerin (GLY) 5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, nonionic surface activity 2% by mass of an agent (polyoxyalkylene derivative), 0.2% by mass of a benzisothiazoline antiseptic and fungicide, and the remainder of the water were mixed, and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 11 was produced.

  About each obtained dye ink of the manufacture examples 1-11, pH, a viscosity, and surface tension were measured as follows. The results are shown in Table 1.

<Measurement of pH>
The pH was measured at 23 ° C. using METER MODEL HM3A (manufactured by Toa Denpa Kogyo Co., Ltd.).

<Measurement of viscosity>
The measurement of the said viscosity was performed at 25 degreeC using the viscosity measuring apparatus (The Toki Sangyo Co., Ltd. make, R500 rotational viscometer). The viscosity was measured using a standard cone (cone angle 1 ° 34 ′, outer diameter R = 24 mm) at an appropriate rotation speed of 40 to 180 rpm.

<Measurement of surface tension>
The surface tension is a static surface tension (25 ° C.) measured using a platinum plate using a surface tension measuring device (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

(Production Example 12)
-Preparation of highly viscous dye ink by increasing the amount of surfactant-
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, diethylene glycol 15% by mass, glycerin 5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, nonionic surfactant (polyoxyalkylene derivative) ) 9.2% by mass, benzisothiazoline-based antiseptic / antifungal agent 0.2% by mass, and the remainder of the water were mixed and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 12 was produced.

(Production Example 13)
-Preparation of highly viscous dye ink by increasing the amount of surfactant-
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, diethylene glycol 15% by mass, glycerin 5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, anionic surfactant (R ¹ -O) _{- (CH 2 CH 2 O)} n CH 2 COOM, R = C 13 H 27, n = 3, M = Na) 11.2 wt%, benzisothiazoline antiseptic fungicide 0.2 wt%, and water balance And the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 13 was produced.

(Production Example 14)
-Preparation of highly viscous dye ink by increasing the amount of surfactant-
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, diethylene glycol 15% by mass, glycerin 5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, nonionic surfactant (polyoxyalkylene derivative) 9.2% by mass, benzisothiazoline-based antiseptic and antifungal agent 0.2% by mass, silicone antifoaming agent KM72F (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03% by mass, and the remainder of the water were mixed. The pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 14 was produced.

(Production Example 15)
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, diethylene glycol 15% by mass, glycerin 5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, anionic surfactant (R ¹ -O) — (CH ₂ CH ₂ O) _n CH ₂ COOM, R ¹ = C ₁₃ H ₂₇ , n = 3, M = Na) 11.2% by mass, benzisothiazoline antiseptic / antifungal agent 0.2% by mass, silicone 0.03% by mass of a foaming agent KS531 (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.) and the remaining water were mixed, and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 15 was produced.

(Production Example 16)
C. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, diethylene glycol 15% by mass, glycerin 5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, nonionic surfactant (polyoxyalkylene derivative) ) 2% by mass, benzisothiazoline-based antiseptic and fungicide 0.2% by mass, and the remaining water were mixed, and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 16 was produced.

  About each obtained dye ink of the manufacture examples 12-16, pH, a viscosity, and surface tension were measured as follows. The results are shown in Table 2.

<Measurement of pH>
The pH was measured at 23 ° C. using METER MODEL HM3A (manufactured by Toa Denpa Kogyo Co., Ltd.).

<Measurement of viscosity>
The measurement of the said viscosity was performed at 25 degreeC using the viscosity measuring apparatus (The Toki Sangyo Co., Ltd. make, R500 rotational viscometer). The viscosity was measured using a standard cone (cone angle 1 ° 34 ′, outer diameter R = 24 mm) at an appropriate rotation speed of 40 to 180 rpm.

<Measurement of surface tension>
The surface tension is a static surface tension (25 ° C.) measured using a platinum plate using a surface tension measuring device (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

Here, the relationship between the content of the nonionic surfactant of Production Example 12 and the viscosity is shown in FIG. FIG. 15 shows the relationship between the content of the anionic surfactant of Production Example 13 and the viscosity. From the results of FIGS. 14 and 15, it is recognized that the viscosity is 5 mPa · s or more when the surfactant content is 7 mass% or more. When the amount of the surfactant is increased to make the dye ink highly viscous, if the viscosity exceeds 5 mPa · s (the surfactant content is 7% by mass or more), even if the surface image density is high, the back side of the image There is an advantage that the gap does not become large.
For example, when printed at the same appropriate amount (about 15 pl per drop), the image density on plain paper is Production Example 12 (Image Density 1.3), Production Example 13 (Image Density 1.27), and Production Example. When the amount of the surfactant was large such as 16 (image density 1.23) and the viscosity was high, the image density was high. The show-through was 0.08, and the image quality was high and feathering was reduced. Of course, since it is a combination of a high-viscosity dye ink having the same viscosity as that of the pigment ink, even if the pigment ink and the dye ink are appropriately replaced, printing can be performed without any problem.
The image density was determined by a reflection type color spectrocolorimetric densitometer (manufactured by X-Rite).
Thus, by setting both the pigment ink and the dye ink to a high viscosity, both can be stably printed even if they are replaced appropriately, and both the pigment ink and the dye ink are advantageous in terms of image. It was.

(Experiment)
-Preparation of highly viscous dye ink by addition of alginic acid-
Cyan dye (CI DBLUE 199, solid content 10.25% by mass) 44% by mass, 1,3-butanediol 15% by mass, glycerin 5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, And 0.2% by mass of a benzisothiazoline preservative, and 0% by mass and 4% by mass of alginic acid, 2% by mass, 5% by mass, and 8% by mass of a nonionic surfactant (polyoxyalkylene derivative) % Was added to adjust the viscosity. The results are shown in FIG.
In addition, as alginic acid, the ratio (D-mannuronic acid / L-guluronic acid) of ultra-low-viscosity alginic acid made from Kibun Food Chemifa Corporation, and D-mannuronic acid and L-guluronic acid is about 0.47. Viscosity [neutralization viscosity of 10% by weight aqueous solution (20 ° C.)] of 5.0 mPa · s or less was used.

When the content of alginic acid exceeds 4% by mass, particles having a large particle size increase and filtration with a filter becomes slow. Therefore, the content of alginic acid is preferably 4% by mass or less. From the results shown in FIG. 16, the viscosity can be adjusted to 5 to 10 mPa · s by combining alginic acid with 2 to 4 mass% and nonionic surfactant 2 to 8 mass%. When these high-viscosity dye inks are used, stable printing with less nozzle omission becomes possible even when the ink is replaced with a high-viscosity pigment ink as appropriate. In particular, when a high viscosity agent such as alginic acid is added, a high image density can be obtained with little show-through and less feathering.
In addition, in FIG. 16, although the example using a cyan dye (CIDBLUE199) is shown, the same result was obtained even if it used the magenta dye or the yellow dye.

(Production Example 17)
-Preparation of highly viscous dye ink by addition of alginic acid-
Cyan dye (CI DBLUE 199, solid content 10.25% by mass) 44% by mass, 1,3-butanediol 15% by mass, glycerin 5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, Benzisothiazoline preservative 0.2% by mass, alginic acid 2% by mass, nonionic surfactant (polyoxyalkylene derivative) 6.5% by mass, and the remaining water were mixed, and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 17 was produced.

(Production Example 18)
-Preparation of highly viscous dye ink by addition of alginic acid-
Cyan dye (CI DBLUE 199, solid content 10.25% by mass) 44% by mass, 1,3-butanediol 15% by mass, glycerin 5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, Benzisothiazoline preservative 0.2% by mass, alginic acid 2% by mass, nonionic surfactant (polyoxyalkylene derivative) 6.5% by mass, silicone antifoam KS531 (self-emulsifying type, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03% by mass and the remaining water were mixed and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 18 was produced.

(Production Example 19)
Cyan dye (CI DBLUE 199, solid content 10.25% by mass) 44% by mass, 1,3-butanediol 15% by mass, glycerin 5% by mass, 2-ethyl-1,3-hexanediol 2% by mass, Benzisothiazoline preservative 0.2% by mass, nonionic surfactant (polyoxyalkylene derivative) 5% by mass, and the remaining water were mixed, and the pH was adjusted with lithium hydroxide. Thus, the dye ink of Production Example 19 was produced.

  About each obtained dye ink of the manufacture examples 17-19, pH, a viscosity, and surface tension were measured as follows. The results are shown in Table 3.

<Measurement of pH>
The pH was measured at 23 ° C. using METER MODEL HM3A (manufactured by Toa Denpa Kogyo Co., Ltd.).

<Measurement of viscosity>
The measurement of the said viscosity was performed at 25 degreeC using the viscosity measuring apparatus (The Toki Sangyo Co., Ltd. make, R500 rotational viscometer). The viscosity was measured using a standard cone (cone angle 1 ° 34 ′, outer diameter R = 24 mm) at an appropriate rotation speed of 40 to 180 rpm.

<Measurement of surface tension>
The surface tension is a static surface tension (25 ° C.) measured using a platinum plate using a surface tension measuring device (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

(Preparation Example 1)
-Preparation of copper phthalocyanine pigment-containing polymer fine particle dispersion-
A blue polymer fine particle dispersion was obtained by reexamining Preparation Example 3 disclosed in JP-A No. 2001-139849.
About the obtained polymer fine particle, the volume average particle diameter (D50%) measured with the particle size distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was 93 nm.

(Preparation Example 2)
-Preparation of dimethylquinacridone pigment-containing polymer fine particle dispersion-
A red-purple polymer fine particle dispersion was prepared in the same manner as in Preparation Example 1, except that the copper phthalocyanine pigment was changed to Pigment Pigment Red 122 in Preparation Example 1.
About the obtained polymer fine particle, the volume average particle diameter (D50%) measured with the particle size distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was 127 nm.

(Preparation Example 3)
-Preparation of monoazo yellow pigment-containing polymer fine particle dispersion-
A yellow polymer fine particle dispersion was prepared in the same manner as in Preparation Example 1 except that the copper phthalocyanine pigment was changed to Pigment Pigment Yellow 74 in Preparation Example 1.
About the obtained polymer microparticles | fine-particles, the volume average particle diameter (D50%) measured with the particle size distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was 76 nm.

(Preparation Example 4)
-Preparation of carbon black dispersion treated with diazo compound-
100 g of carbon black having a surface area of 230 m ² / g and a DBP oil absorption of 70 ml / 100 g and 34 g of p-amino-N-benzoic acid are mixed and dispersed in 750 g of water, and 16 g of nitric acid is added dropwise thereto to 70 Stir at ° C. After 5 minutes, a solution of 11 g of sodium nitrite dissolved in 50 g of water was added, and the mixture was further stirred for 1 hour. The resulting slurry was diluted 10 times and centrifuged to remove coarse particles, the pH was adjusted with diethanolamine to pH 8-9, desalted and concentrated with an ultrafiltration membrane to obtain a carbon black dispersion with a pigment concentration of 15%. Then, it was filtered through a polypropylene 0.5 μm filter to obtain a carbon black dispersion.
About the obtained polymer microparticles | fine-particles, the volume average particle diameter (D50%) measured with the particle size distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was 99 nm.

  Next, using the polymer fine particle dispersion and the carbon black dispersion obtained in Preparation Examples 1 to 4, pigment inks were produced as follows.

(Production Example 20)
-Pigment ink set-
<Preparation of cyan ink>
10% by mass (as a solid content) of phthalocyanine pigment-containing polymer fine particles of Preparation Example 1, 22% by mass of 1,3-butanediol, 9.0% by mass of glycerol, and 2.2% by mass of a nonionic surfactant (polyoxyalkylene derivative) %, 2-ethyl-1,3-hexanediol 1.8% by mass, benzisothiazoline preservative 0.2% by mass, silicone antifoaming agent 0.1% by mass, and ion-exchange water %, After mixing and stirring, the mixture was adjusted with an organic amine pH adjuster so that the pH was 9.5. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. A cyan ink was prepared as described above.
The obtained cyan ink had an ink viscosity at 25 ° C. of 8.05 mPa · s, and a surface tension at 25 ° C. of 29.4 mN / m.
In addition, the measurement of the viscosity was performed at 25 degreeC using the viscosity measuring apparatus (The Toki Sangyo Co., Ltd. make, R500 rotational viscometer).
The surface tension is a static surface tension (25 ° C.) measured using a platinum plate using a surface tension measuring device (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

<Preparation of magenta ink>
1. 10.0% by mass (as solids) of dimethylquinacridone pigment-containing polymer fine particles of Preparation Example 2, 24.0% by mass of triethylene glycol, 8.3% by mass of glycerol, nonionic surfactant (polyoxyalkylene derivative) 0% by mass, 1.5% by mass of 2-ethyl-1,3-hexanediol, 0.07% by mass of preservative (sodium sorbate), 0.05% by mass of silicone-based antifoaming agent, and appropriate amount of ion-exchanged water In addition, the mixture was made 100% by mass and mixed and stirred. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. Thus, a magenta pigment ink was prepared.
The obtained magenta ink had an ink viscosity of 7.95 mPa · s at 25 ° C. and a surface tension of 29.5 mN / m at 25 ° C.

<Preparation of yellow ink>
Monoazo yellow pigment-containing polymer fine particles of Preparation Example 10.0 (mass content), 1,3-butanediol 25.0 mass%, glycerol 8.0 mass%, nonionic surfactant (polyoxyalkylene derivative) ) 1.8% by mass, 2,2,4-trimethyl-1,3-pentanediol 1.8% by mass, preservative (sodium sorbate) 0.05% by mass, silicone-based antifoaming agent 0.1% by mass And an appropriate amount of ion-exchanged water was added to make 100% by mass, and the mixture was stirred. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. Thus, a yellow pigment ink was prepared.
The resulting yellow ink had an ink viscosity of 8.02 mPa · s at 25 ° C. and a surface tension of 29.5 mN / m at 25 ° C.

<Preparation of black ink>
Carbon black dispersion treated with the diazo compound of Preparation Example 4 10.0% by mass (as solid content), 2,5-pentanediol 20.5% by mass, glycerol 7.5% by mass, surfactant (CH ₃ (CH ₂ ) ₁₂ O (CH ₂ CH ₂ O) ₃ CH ₂ COOH) 1.7% by mass, 2,2,4-trimethyl-1,3-pentanediol 2.1% by mass, preservative (sodium sorbate) 0 .2 mass%, silicone antifoaming agent KS531 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.03 mass%, and ion-exchanged water are added in an appropriate amount to 100 mass%. It adjusted with the lithium oxide 5 mass% aqueous solution. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. Thus, a black pigment ink was prepared.
The resulting black ink had an ink viscosity of 8.05 mPa · s at 25 ° C. and a surface tension of 30.2 mN / m at 25 ° C.

  The cyan pigment ink, magenta pigment ink, yellow pigment ink, and black pigment ink of Production Example 20 all have a surface tension at 25 ° C. of 40 mN / m or less and a viscosity at 25 ° C. of approximately 8.05 mPa · s. The paper was excellent in quick-drying property, light resistance and water resistance, and had little bleeding and back-through.

(Examples 1-16 and Comparative Examples 1-3)
Next, as shown in Table 4 below, the dye ink and the pigment ink were separately filled in the cartridges of the inkjet printer (manufactured by Ricoh Co., Ltd., IPSiO G707).

<Evaluation>
With respect to Examples 1 to 16 and Comparative Examples 1 to 3, pigment ink and plain paper (Ricoh type 6200) and glossy paper (Ricoh silky glossy paper) were mixed with the pigment ink by the inkjet printer (manufactured by Ricoh Co., Ltd., IPSiO G707). The dye ink was printed separately from the same head (changing the cartridge each time).
As a result, in Examples 1 to 16, high-quality printing was obtained for both the pigment ink and the dye ink. In addition, the dye ink has more show-through in the plain paper than the pigment ink, and is slightly inferior in light resistance and water resistance, but the glossy paper can give a photographic image having a glossy feeling than the pigment ink.

  In addition, using the inkjet printer (Ricoh Co., Ltd., IPSiO G707), a pigment ink having a viscosity of 8.05 mPa · s in Production Example 20 in a waveform that can be stably printed, in Production Examples 11, 16, and 19. A dye ink having a viscosity of 4 mPa · s or less was printed. In this case, in particular, when several droplets are jetted at a high speed and coalesced into one droplet before adhering to paper and adhered as a large particle size droplet, the viscosity of Production Examples 11, 16, and 19 is 4 mPa · s. In the following dye inks, the droplets did not coalesce, and dot disturbance occurred. Therefore, when dye ink is printed using an ink jet printer capable of printing high-viscosity pigment ink, the viscosity difference between the pigment ink and the dye ink is 3 mPa · s or less in order to stably eject even a special waveform. It is recognized that there is a need to adjust.

  In the inkjet printer (IPSiO G707, manufactured by Ricoh Co., Ltd.), the presence or absence of ink was detected by measuring the electrical resistance with an electrode. Accordingly, the subtank is filled with ink, but the dye inks to which the antifoaming agents of Production Examples 1 to 4, 10, 12 to 13, and 17 are not added often cause false detection. The reason is presumed to be caused by bubbles adhering to the electrode, and the high viscosity of the ink is considered to be a contributing factor. Therefore, as in Production Examples 5 to 9, 14 to 15, and 18, when the dye ink added with the silicone-based antifoaming agent was used, the generation of bubbles was reduced and the number of erroneous electrode detections was also reduced. Further, the addition of an antifoaming agent also reduced nozzle omission due to bubbles.

(Comparative Example 4)
A pigment ink was prepared as follows.
1. 10% by mass (as solids) of phthalocyanine pigment-containing polymer fine particles of Preparation Example 1, 27.75% by mass of 1,3-butanediol, 9.25% by mass of glycerol, nonionic surfactant (polyoxyalkylene derivative) 2% by mass, 1.8% by mass of 2-ethyl-1,3-hexanediol, 0.2% by mass of benzisothiazoline preservative, 0.1% by mass of silicone antifoaming agent, and an appropriate amount of ion-exchanged water were added. After mixing and stirring at 100% by mass, the pH was adjusted to 9.5 with an organic amine pH adjuster. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. Thus, a cyan pigment ink was prepared.
The obtained cyan pigment ink had an ink viscosity of 11.4 mPa · s at 25 ° C. and a surface tension of 24.7 mN / m at 25 ° C.

<Evaluation>
Next, the obtained pigment ink having a viscosity of 11.4 mPa · s and the dye ink of Production Example 2 having a viscosity of 7.76 mPa · s were separately filled in a cartridge of an ink jet printer (manufactured by Ricoh Co., Ltd., IPSiO G707). .
In the waveform that can be stably ejected with the pigment ink of Comparative Example 4, the dye ink of Production Example 2 was replaced and printed on plain paper (Ricoh type 6200). The problem of increasing was caused.

(Comparative Example 5)
A pigment ink was prepared as follows.
1. 10% by mass (as solid content) of phthalocyanine pigment-containing polymer fine particles of Preparation Example 1, 13.5% by mass of 1,3-butanediol, 4.5% by mass of glycerol, nonionic surfactant (polyoxyalkylene derivative) 2% by mass, 1.8% by mass of 2-ethyl-1,3-hexanediol, 0.2% by mass of benzisothiazoline preservative, 0.1% by mass of silicone antifoaming agent, and an appropriate amount of ion-exchanged water were added. After mixing and stirring at 100% by mass, the pH was adjusted to 9.5 with an organic amine pH adjuster. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer. Thus, a cyan pigment ink was prepared.
The obtained cyan ink had an ink viscosity at 25 ° C. of 4.8 mPa · s, and a surface tension at 25 ° C. of 26 mN / m.

In addition, the obtained pigment ink having a viscosity of 4.8 mPa · s and the dye ink having a viscosity of 3 mPa · s of Production Example 11 were separately filled into a cartridge of an ink jet printer (manufactured by Ricoh Co., Ltd., IPSiO G707), respectively, When printing was performed by exchanging ink and dye ink, if the jetting conditions were adjusted to a viscosity of about 4 mPa · s, both inks were stable in jetting, but there was little feathering, which is an advantage of high-viscosity inks. A high-quality image could not be obtained.
Therefore, it was found that it is necessary to use a dye ink having a high viscosity of 5 mPa · s or more at 25 ° C. in order to obtain high image density and high image quality with less feathering even in dye ink. In this case, a dye ink to which a thickening agent such as alginic acid, a surfactant, or a resin is added is particularly preferable. In the case of increasing the viscosity of the dye by increasing the amount of the wetting agent, if the amount of the wetting agent is large, the show-through may be worsened.

(Comparative Example 6)
In Production Example 2, a dye ink of Comparative Example 6 was produced in the same manner as Production Example 2 except that 2-ethyl-1,3-hexanediol and a nonionic surfactant were not added. That is, C.I. I. Direct Blue 199 (solid content 10.25% by mass) 44% by mass, 1,3-butanediol (1,3-BD) 30.75% by mass, glycerin 10.25% by mass, benzisothiazoline-based antiseptic and antifungal agent 0 .2% by mass and the remaining water were mixed and the pH was adjusted with lithium hydroxide.
The resulting dye ink had an ink viscosity at 25 ° C. of 7.15 mPa · s and a surface tension at 25 ° C. of 43.8 mN / m.

<Evaluation>
The obtained dye ink of Comparative Example 6 was filled in a cartridge of an ink jet printer (manufactured by Ricoh Co., Ltd., IPSiO G707) and printed on plain paper (Ricoh Type 6200). Since the ink was high, drying of the ink was slow, and feathering and bleeding occurred.

(Comparative Example 7)
A dye ink of Production Example 11 having a viscosity at 25 ° C. of 5 mPa · s or less and a surface tension at 25 ° C. of 40 mN / m or less is filled in a cartridge of an inkjet printer (manufactured by Ricoh Co., Ltd., IPSiO G707). When printed on plain paper (Ricoh type 6200), the printed waveform adjusted for pigment ink with a viscosity of 8 mPa · s could not be printed stably.

(Comparative Example 8)
The pigment ink of Comparative Example 5 having a viscosity at 25 ° C. of 5 mPa · s or less, and the dye of Production Example 11 having a viscosity at 25 ° C. of 5 mPa · s or less and a surface tension at 25 ° C. of 40 mN / m or less Ink was separately filled in the cartridge of an ink jet printer (manufactured by Ricoh Co., Ltd., IPSiO G707) and printed on plain paper (Ricoh type 6200). Under the jetting conditions adjusted for pigment ink having a viscosity of 5 mPa · s, Although the printing was relatively stable, a high-quality image with less feathering, which is an advantage of the original high viscosity ink, could not be obtained.

  Therefore, from the results of Comparative Examples 6 to 8, it is necessary to use a dye ink having a high viscosity with a viscosity at 25 ° C. of 5 mPa · s or more in order to obtain high image quality with less feathering even in the dye ink. I understood that.

  The recording ink of the present invention is used for ink jet recording in which dye ink and pigment ink are appropriately exchanged with the same head, and is remarkably improved in color saturation, excellent in color development, and high in ejection stability. In addition, high-quality image formation is possible, and the recording ink can be suitably used for an ink cartridge, an ink recording, an ink jet recording apparatus, and an ink jet recording method.

  The recording ink of the present invention includes a head having a plurality of nozzle rows, a sub tank for supplying liquid to the head, a negative pressure generating means for generating a negative pressure in the sub tank, and the inside of the sub tank. A high-viscosity dye ink used for an ink jet recording apparatus having an air release means for releasing the atmosphere and a detection means for detecting the presence or absence of ink based on a difference in electrical resistance, the recording ink comprising an ink cartridge, an ink record The ink jet recording apparatus and the ink jet recording method can be suitably used.

FIG. 1 is a diagram showing an example of the ink cartridge of the present invention. FIG. 2 is a view including a case (exterior) of the ink cartridge of FIG. FIG. 3 is a schematic explanatory view showing an example of the ink jet recording apparatus of the present invention. FIG. 4 is a schematic explanatory view showing an example of the internal structure of the ink jet recording apparatus of FIG. FIG. 5 is a schematic enlarged view showing an example of the inkjet head of the present invention. FIG. 6 is a schematic view showing a nozzle row of the inkjet head of the present invention. FIG. 7 is an exploded perspective view of the liquid supply device in the ink jet recording apparatus of the present invention. FIG. 8 is an enlarged exploded perspective view of FIG. FIG. 9 is a schematic side view of the sub tank. FIG. 10 is a schematic cross-sectional view taken along line AA in FIG. FIG. 11 is a top view of the maintenance unit according to the inkjet printer of the present invention. FIG. 12 is a schematic explanatory diagram of a maintenance unit according to the ink jet printer of the present invention. FIG. 13 is a graph showing the relationship between the wetting agent and the viscosity in the dye ink. FIG. 14 is a graph showing the relationship between the nonionic surfactant and the viscosity in the dye ink. FIG. 15 is a graph showing the relationship between the anionic surfactant and the viscosity in the dye ink. FIG. 16 is a graph showing the relationship between alginic acid and viscosity in dye ink.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Paper feed tray 3 Paper discharge tray 6 Ink cartridge loading part 7 Operation part 8 Front cover 10 Ink cartridge 11 Guide rod 12 Stay 13 Carriage 14 Recording head 15 Sub tank 16 Supply tube 22 Paper 23 Paper feed roller 24 Separation pad 25 Guide 31 Conveying belt 32 Counter roller 33 Conveying guide 34 Holding member 36 Charging roller 37 Conveying roller 38 Tension roller 41 Ink bag 42 Ink inlet 43 Ink outlet 44 Cartridge exterior 71 Maintenance recovery mechanism (subsystem)
DESCRIPTION OF SYMBOLS 100 Ink storage part 101 Case main body 102 Film-like member 103 Spring (spring)
113 connecting member 121 air flow path 126 accumulating part 131 atmosphere release hole 132 atmosphere release valve mechanism 133 holder 134 valve seat 135 ball 136 spring

Claims (28)

  Used for ink jet recording in which dye ink and pigment ink are exchanged with the same head, the viscosity of the dye ink and pigment ink at 25 ° C. is 5 mPa · s or more, and the viscosity of the dye ink and the pigment ink A recording ink having a difference of 3 mPa · s or less.   The pigment ink contains at least water, a pigment, a wetting agent, one of a polyol compound having 8 to 11 carbon atoms and a glycol ether compound, and a surfactant, and has a viscosity at 25 ° C. of 5 mPa · s or more. The recording ink according to claim 1, wherein the surface tension at 25 ° C. is 40 mN / m or less.   The recording according to claim 2, wherein the pigment is at least one selected from polymer fine particles containing at least one of a water-insoluble colorant and a poorly water-soluble colorant, and carbon black having at least one hydrophilic group on the surface. For ink.   A head having a plurality of nozzle rows; a subtank that stores liquid supplied from a liquid storage tank and supplies liquid to the head; a negative pressure generating means for generating a negative pressure in the subtank; A recording ink for use in an ink jet recording apparatus having an air opening means for opening the inside of a sub tank to the atmosphere and a detecting means for detecting the presence or absence of ink based on a difference in electrical resistance. A recording ink having a viscosity at 5 mPa · s or more and a surface tension at 25 ° C. of 40 mN / m or less.   The recording ink according to claim 4, wherein the ink jet recording apparatus has scraping means for scraping off the ink fixed to the idle discharge receiver.   The dye ink contains at least water, a dye, a wetting agent, a thickening agent, and any one of a polyol compound having 8 to 11 carbon atoms and a glycol ether compound, and has a viscosity at 25 ° C. of 5 mPa · s or more. The recording ink according to claim 1, which has a surface tension at 25 ° C. of 40 mN / m or less.   The wetting agent is glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylolpropane, 1.1.1.1. The recording ink according to claim 6, which is at least one selected from tris (hydroxymethyl) propane and trimethylolethane.   The recording ink according to any one of claims 6 to 7, wherein the content of the wetting agent in the dye ink is 35 to 50% by mass.   The recording ink according to claim 6, wherein the thickening agent is at least one of a surfactant and an alginic acid compound.   The recording ink according to claim 9, wherein the surfactant is at least one selected from an anionic surfactant and a nonionic surfactant.   11. The recording ink according to claim 9, wherein the content of the surfactant in the dye ink is 7% by mass or more.   The recording ink according to claim 6, wherein the content of the dye in the dye ink is 4% by mass or more.   The recording ink according to claim 6, wherein the dye ink contains an antifoaming agent, and the antifoaming agent is a silicone-based antifoaming agent.   The recording ink according to claim 13, wherein the silicone-based antifoaming agent is either a self-emulsifying type or an emulsion type.   The recording ink according to claim 1, wherein the dye ink and the pigment ink are at least one selected from cyan ink, magenta ink, yellow ink, and black ink.   16. An ink cartridge comprising the recording ink according to claim 1 contained in a container.   The ink cartridge according to claim 16, wherein the ink capacity is 15 g or more.   16. An ink jet recording apparatus comprising at least ink flying means for 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 apparatus according to claim 18, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.   The ink jet recording apparatus according to any one of claims 18 to 19, wherein the ink flying means uses the dye ink and the pigment ink exchanged by the same head.   The ink jet according to any one of claims 18 to 19, wherein the ink flying means includes a head having a plurality of nozzle rows, and a sub tank for storing the liquid supplied from the liquid storage tank and supplying the liquid to the head. Recording device.   The sub tank has a negative pressure generating means for generating a negative pressure in the sub tank, an air opening means for opening the inside of the sub tank to the atmosphere, and a detecting means for detecting the presence or absence of ink by a difference in electric resistance. The ink jet recording apparatus according to claim 21.   The ink jet recording apparatus according to any one of claims 18 to 22, further comprising scraping means for scraping off the ink fixed to the idle discharge receiver.   The ink jet recording apparatus according to claim 23, wherein the scraping means is one of a wiper and a cutter.   16. 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.   26. The ink jet recording method according to claim 25, wherein the stimulus is at least one selected from heat, pressure, vibration and light.   27. The ink jet recording method according to claim 25, wherein the dye ink and the pigment ink are exchanged with the same head in the ink flying process. An ink recorded matter comprising an image formed using the recording ink according to any one of claims 1 to 15 on a recording medium.

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