JP2001302953A - Water-soluble ink and process for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink for ink jet recording allowing no attachment of the ink mist to the nozzle surface when the ink is discharged, i.e., the attachment of the ink discharged from the ink-discharge aperture to the nozzle surface without reaching the recording medium, and also provide a recording process using the ink. SOLUTION: The ink contains from 1 to 20 wt.% polyhydric alcohol alkyl ether, from 1 to 30 wt.% glycols or nitrogen-containing heterocyclic compound and from 0.01 to 0.5 wt.% nonionic acetylene glycol surfactant. The use of the ink may inhibit the attachment of the ink mist to the nozzle surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink useful for an ink jet recording system and an ink jet recording method using the same.

[0002]

2. Description of the Related Art In an ink-jet recording system, ink is supplied to a recording head, and small ink droplets are ejected toward a recording medium by using various ink ejection methods, and flying is controlled to achieve an object on the recording medium. It is intended to perform recording by attaching it to the position of, and has the advantages that high-definition images can be recorded quietly at high speed, and color recording can be easily performed by using multicolor inks. Widely used as recording means. In order to perform high-definition printing, it is necessary to make the dot configuration that forms the printing finer, to reduce the amount of ink droplets attached to the printing medium, and to control the ink flight more accurately Thus, the dot configuration on the recording medium is made fine. As a means for achieving this, the ink discharge ports (hereinafter, referred to as nozzles) of the recording head are made finer and arranged at a high density, thereby reducing the amount of ink to be discharged and increasing the discharge speed of the discharged ink droplets. A method of more accurately controlling the flight of the aircraft has been used.

When ink is ejected from each nozzle,
In addition to the ink droplets adhering to the recording medium, satellite-like minute ink mist separated from the ink droplets is also generated. The flying energy of the ink mist is not enough to reach the recording medium, and is affected by the surrounding atmosphere, electrostatic force, etc., so that the ink mist adheres to the nozzle surface without going to the recording medium. I will. If the amount of ink deposited on the nozzle surface increases as the recording operation continues, a large ink mass will be formed, and this ink mass will spread to the nozzles, preventing ink ejection from each nozzle, Further, dust floating around, dust such as paper dust generated from the recording medium comes into contact with and adheres to the attached ink,
These dusts also hinder ink ejection. If the mass of ink on the nozzle surface becomes larger,
The ink may adhere to the surface of the recording medium and cause deterioration of recording quality or generation of dirt.

As described above, it is possible to prevent the ink mist and dust from adhering to the nozzle surface, thereby preventing the ejection of the ink droplet from becoming unstable or stopping the ejection of the ink droplet, thereby maintaining a normal and stable recording. Means for maintaining ink discharge, ink discharge recovery means, nozzle surface cleaning means,
Means for preventing ink mist from adhering to the nozzle surface are provided.

[0005] Ink discharge maintaining means moves the recording head to a non-recording area and discharges an appropriate amount of ink droplets from a nozzle after a predetermined time has elapsed, thereby refreshing the ink flow path portion and the nozzle portion of the recording head. A method of performing idle discharge (hereinafter referred to as flushing) to prevent nozzle clogging is performed. As one method of flushing, Japanese Patent Application Laid-Open No. 1-40342 discloses a method in which printing is performed after a predetermined time has elapsed during printing. A method has been proposed in which a head is moved to an ink receiver provided in a non-recording area to eject ink from all nozzles.

[0006] A recovery device comprising a suction cap and a suction pump is provided as an ink ejection recovery means. The nozzle surface is covered with the suction cap, and the ink is sucked from the nozzle by the negative pressure of the suction pump. A method of removing the foreign matter from the nozzle by the flow of ink (hereinafter, this method is referred to as suction recovery) has been implemented. As one method of suction recovery, JP-A-62-220342 proposes an ink jet recording apparatus provided with an ink suction passage for cleaning a nozzle surface in addition to suction recovery means.

As a nozzle surface cleaning means, a method of wiping the nozzle surface with a flexible blade to remove ink droplets and dust adhering to the nozzle surface (hereinafter, this operation is referred to as wiping) has been implemented. I have.

As means for preventing ink mist from adhering to the nozzle surface, Japanese Patent Application Laid-Open No. 56-25465 proposes a suction system in which an air suction device is provided near the nozzle of the recording head to suck the ink mist. Japanese Patent Application Laid-Open No. 4-176652 proposes a configuration in which a static eliminator for the nozzle surface is provided on the side opposite to the nozzle surface.

[0009]

Problems to be Solved by the Invention
According to the method disclosed in Japanese Patent Application Laid-Open Publication No. H11-229, since flushing is performed by all nozzles regardless of the presence or absence of ejection failure, the amount of ink used for purposes other than recording is increased by ejecting ink from nozzles where no failure occurs. Also, Japanese Patent Application Laid-Open No.
According to the method disclosed in Japanese Patent Application Publication No. 2000-209, in addition to the ink sucked from the nozzles and the ink flow path portion at the time of ink suction recovery, ink used for purposes other than recording is also suctioned from an ink suction passage provided separately. The amount is increasing. In the flushing or suction recovery operation for preventing the ink droplet ejection state from becoming unstable or for removing a substance that causes ejection failure, the ink is consumed as a means thereof. As a result, so-called wasted ink increases, so that the amount of ink that should be used for performing printing, which is the original purpose of the printing apparatus, is reduced. As a result, there is a problem that the running cost of printing increases.

An air suction device proposed in Japanese Patent Application Laid-Open No. 56-25465 and Japanese Patent Application Laid-Open No. 4-176652 are disclosed.
When the static eliminator proposed in the above publication is installed, there is a problem that the recording device becomes larger and the price increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to improve the composition of an ink for ink jet recording so that the ink mist is prevented from adhering to the nozzle surface. It is an object of the present invention to provide an ink and an ink jet recording method in which the frequency of execution of flushing and suction recovery is reduced by reducing ink ejection failures, the amount of waste ink not used for recording is reduced, and the running cost is not increased. It is still another object of the present invention to provide a small and inexpensive ink jet recording apparatus that eliminates the adhesion of ink mist to the nozzle surface and does not require an air suction device or a static elimination device.

[0012]

The water-soluble ink for ink-jet recording according to the present invention is an ink-jet recording ink containing at least water, a colorant, a wetting agent and a surfactant having a penetrating action. -20% by weight of a polyhydric alcohol alkyl ether and 1-30% by weight of a glycol or a nitrogen-containing heterocyclic compound,
It is characterized by containing 0.01 to 5% by weight of a nonionic acetylene glycol surfactant.

In order to prevent clogging of the nozzles and perform highly stable ejection, a wetting agent for providing a wetting effect for suppressing water evaporation of the ink is added to the ink. The polyhydric alcohol alkyl ether has a surface activity of hydrophilicity by the polyhydric alcohol and hydrophobicity by the alkyl, because the polyhydric alcohol and the alkyl group are linked via an ether bond.
By containing the polyhydric alcohol alkyl ether, the ink is provided with a penetrating effect derived from surface activity in addition to wettability. When the content of the polyhydric alcohol alkyl ether is 1% by weight or less, there is no effect on both wettability and penetrating action, and when the content is 20% by weight or more, the viscosity of the ink becomes 1
At 0 ° C., it becomes too large as 5.0 mPa · s, which is not preferable.

It is not always sufficient to prevent clogging of the ink in the nozzles or to delay the generation of the ink by using only the polyhydric alcohol alkyl ether as the solvent contained as the wetting agent. It also contains cyclic compounds. When the content of the glycols or the nitrogen-containing heterocyclic compound is 1% by weight or less, there is no effect in preventing clogging or delaying the generation, and when the content is 30% by weight or more, the viscosity of the ink is increased, and the water content in the ink component is increased. It is not preferable because the recording speed decreases due to the decrease in the amount, and the recording quality decreases due to the occurrence of bleeding due to the reduction in the drying speed.

The inventors of the present invention have made the composition of the ink into the above-mentioned composition, so that the flying of the ink droplets ejected from the nozzle becomes stable, so that the generation of ink mist is suppressed and the ink adhesion to the nozzle surface is suppressed. Can be eliminated.

As the glycols contained as the wetting agent, glycerin, ethylene glycol, diethylene glycol, polyethylene glycol, hexylene glycol and the like can be mentioned.

Examples of the nitrogen-containing heterocyclic compound contained as a wetting agent include 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, 2-pyrrolidone and the like.

A nonionic acetylene glycol surfactant is contained in the ink as a means for imparting a penetrating effect to the ink for improving the quick drying property in recording. The content of nonionic acetylene glycol surfactant is 0.0
When the amount is less than 1% by weight, the effect of promoting the penetration of the ink into the recording medium is not sufficient. When the amount is more than 5% by weight, the ink ejection state is affected, and it becomes difficult to normally and properly eject the ink.

Particularly preferred examples of the polyhydric alcohol alkyl ether contained in the ink include one or both of diethylene glycol mono-n-butyl ether and triethylene glycol mono-n-butyl ether.

Hexylene glycol is a particularly preferred example of glycols contained in the ink. Hexylene glycol is a solvent having a low volatility and a low surface tension of 27 mN / m, and has an effect of promoting penetration of the ink into a recording medium while maintaining wettability when contained in the ink. give.

A particularly preferred example of the nitrogen-containing heterocyclic compound contained in the ink is 2-pyrrolidone. 2
-Pyrrolidone is particularly excellent among nitrogen-containing heterocyclic compounds in enhancing the storage stability of the ink.

Particularly preferred examples of the nonionic acetylene glycol surfactant contained in the ink include a compound represented by the structural formula (I) or the structural formula (II) singly or as a mixture. It is preferable that the compound represented by the structural formula (I) alone be contained in the ink in an amount of 1 to 5% by weight, and the compound represented by the structural formula (II) alone is contained in the ink in an amount of 0.1 to 3% by weight. It is preferable that the compound of the structural formula (I) and the compound of the structural formula (II) are mixed and contained in the ink.

[0023]

Embedded image

Embedded image This adjusted water-soluble ink is stored in a conventional ink cartridge, and inserted into a conventional inkjet recording apparatus.
Ink jet recording can be performed.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The water-soluble ink for ink-jet recording and the ink-jet recording system of the present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these.

[Schematic Configuration of Inkjet Recording Apparatus] An inkjet recording apparatus using a water-soluble ink according to the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are a schematic view of an ink jet recording apparatus and an exploded perspective view of a recording head of the ink jet recording apparatus, respectively.

In FIG. 1, an ink jet recording apparatus 1
The printhead 10 includes a printhead 10, a platen 11 that transports the print medium 2, and an ink tank 12 that stores ink therein. The ink tank 12 is connected to the printhead 10 through an ink supply tube 13. Is supplied. In addition, a carriage 15 that reciprocates on a carriage shaft 14 is mounted on the inkjet recording apparatus 1,
Since the recording head 10 is mounted on the carriage 15, the recording head 10 reciprocates in a direction orthogonal to the method of transporting the recording medium 2. Further, a pump 16 is mounted on the ink jet recording apparatus 1, and this pump 1
In 6, when the recording head 10 has a defective ink ejection, the ink is sucked through the cap 17 and the waste ink collecting tube 18 and collected in the discharged ink reservoir 19.

When color printing is performed by the ink jet recording apparatus 1, a nozzle group corresponding to each color is formed on the recording head 10, and an ink supply tube 1 is supplied for each color in order to supply ink of each color to the nozzles of each color.
3. The ink tank 12 is formed. In color printing, the desired color recording is obtained by mixing colors of each ink on a recording medium using inks of three colors, cyan, magenta, and yellow, but the color mixing of the inks before the ink adheres to the recording medium. When this occurs, the desired color development on the recording medium cannot be obtained. Therefore, it is necessary to separate the ink tank 12 for supplying the ink from the nozzle for discharging the ink for each color.

In the ink jet recording apparatus 1 configured as described above, the recording head 10 is configured as shown in FIG.
Among the three substrates, an intermediate first substrate 101 is a silicon substrate, and nozzle grooves formed at equal intervals in parallel from one end on the surface of the substrate 101 so as to form a plurality of nozzle holes 104. 111, a recess 112 communicating with each nozzle groove 111, forming a discharge chamber 106 having a bottom wall as a diaphragm 105, and an ink inlet forming an orifice 107 at the rear of the recess 112. And a concave portion 114 that forms a common ink cavity 108 for supplying ink to each discharge chamber 106 is formed.

At the lower part of the vibration plate 105, a concave portion 115 which forms a vibration chamber 109 for mounting an electrode to be described later is formed. Here, the orifice 107
Is mainly composed of three narrow grooves 113 so as to increase the flow path resistance and to maintain the normal operation of the recording head 10 even if one of the narrow grooves 113 is clogged. Note that a common electrode 117 is provided on the first substrate 101.

The lower second substrate 102 bonded to the lower surface of the first substrate 101 is made of borosilicate glass. By bonding the second substrate 102 to the first substrate 1, While forming the vibration chamber 109, individual electrodes 121 having substantially the same shape as the vibration plate 105 are formed at respective positions of the first substrate 101 facing the vibration plate 105. The individual electrode 121 includes a lead 122 and a terminal 12.
3 is provided. Further, an insulating film 124 is formed on the front surface side of the individual electrode 121 except for the terminal portion 123, and the insulating film 124 prevents occurrence of dielectric breakdown and short circuit when the recording head 10 is driven.

As in the second substrate 102, borosilicate glass is used for the upper third substrate 103 bonded to the first substrate 101. By joining the third substrate 103, a nozzle hole 104, a discharge chamber 106, an orifice 107, and an ink cavity 108 are formed.
An ink supply port 131 communicating with the ink cavity 108 is formed in the third substrate 103. The ink supply port 131 is connected to the connection pipe 132 and the ink supply tube 1.
3 (see FIG. 1) and connected to the ink tank 12 (see FIG. 1).

After the substrate 101, the substrate 102, and the substrate 103 are joined to each other in the recording head 10, the surface of the recording head 10 where the nozzle holes 104 for discharging ink are formed is the nozzle surface 110. The number of nozzles is 128 and the nozzle density is 180 dpi (do
t per inch).

In the recording head 10 configured as described above, the driving circuit 162 is connected between the common electrode 117 and the terminal portion 123 of the individual electrode 121 by the wiring 161 to configure the ink jet recording apparatus 1. Here, the ink is supplied from the ink tank 12 to the inside of the first substrate 101 through the ink supply port 131, and fills the ink cavity 108, the discharge chamber 106, and the like. In this state, a drive signal is applied between the common electrode 117 and the individual electrode 121 to generate static electricity between the common electrode 117 and the individual electrode 121, and the diaphragm 105 is bent by the electrostatic force and released. As a result, when the vibration plate 105 is vibrated, the ink in the discharge chamber 106 is discharged as ink droplets from the nozzle holes 104 and is recorded on the recording medium 2.

In the above description, a so-called serial system in which the recording head 10 mounted on the carriage 15 reciprocates in the direction perpendicular to the direction in which the recording medium 2 is conveyed to record and print is described as the ink jet recording apparatus. However, the present invention is not limited to this, and the recording is performed by transporting the recording medium 2 to the position facing the recording medium 2 without moving the recording head 10 disposed over the entire width of the recording medium 2. It is also applicable to a so-called line method for printing. In addition to the method of bending the vibration plate 105 by the above-described electrostatic force, the ink-jet head 8 discharges ink by using the vibration pressure of a piezo element, or grows bubbles in ink by film boiling due to high heat. Then, a method of ejecting ink using the pressure generated by this may be used.

[Ink composition] Each component in the table was weighed with a balance at a mixing ratio shown in Table 1 and mixed, stirred at room temperature for 1 hour to sufficiently dissolve, and then dissolved with a 0.8 micron membrane filter. Filtration was performed to purify the water-soluble ink-jet recording inks of Examples 1 to 4 and Comparative Examples 1 and 2. In addition, if necessary, a fungicide, a preservative, a pH adjuster,
A dye dissolution aid or the like can be included for improving various ink properties, and in this embodiment, a fungicide is added. Each component of the ink shown in Table 1 is shown by weight% of each component with respect to the total amount of the ink.

[0037]

[Table 1]

The water-soluble inks of Examples 1 to 4 and Comparative Examples 1 and 2 have a surface tension of 29.0 to 31.0 mN / m and a surface tension of 25.
The viscosity at a temperature of 2.degree. C. indicates a characteristic in the range of 2.40 to 2.50 mPa.s, and when the same ejection energy is applied when ejecting ink, the weights of the ejected ink droplets become substantially the same. Therefore, comparison of the amount of ink adhered to the nozzle surface due to the generation of ink mist due to ink ejection, the ink clogging property of the nozzle, the quick drying property of recording, the quality of recording, and the like can be appropriately performed based on the characteristics of the ink itself.

[1. Amount Attached to Nozzle Surface] Examples 1-4
Using the water-soluble inks of Comparative Examples 1 and 2, ink was ejected by the above-described ink jet printer under the following recording conditions to perform recording, and the amount of ink mist adhering to the nozzle surface of the recording head was measured under a microscope (magnification). (50 times) and the following criteria were used. Table 2 shows the test results.

Recording conditions Recording dot density: 180 dpi (dot per inch) Ink droplet weight: 25 ng / drop Recording pattern: Alphabetic characters, numbers Recording time: Continuous 5 minutes Environmental temperature: 35 ° C. Recording medium: Normal copy paper Evaluation standard A : No ink is attached to the nozzle surface B: Ink is slightly attached to the nozzle surface C: Ink is extremely attached to the nozzle surface

[0041]

[Table 2]

[2. Short-time clogging] Because not all the nozzles of the print head are always used for printing,
In the nozzles not used for recording, the ink evaporates in a short time due to evaporation of water in the ink in the vicinity of the nozzle and the coagulation of the surfactant in the ink, resulting in poor ink ejection. [1. Amount Attached to Nozzle Surface], using the same recording apparatus under the following recording conditions,
The short-time clogging of the water-soluble ink No. 2 was examined.
The test method is to discharge ink from all the nozzles, wait a certain waiting time, discharge the ink from all the nozzles again after the waiting time has elapsed, and compare the length of time up to the point when ejection failure is observed It is. The judgment was made based on the following criteria. Table 2 shows the test results. Items not described in the recording conditions are described in [1. Amount Attached to Nozzle Surface].

Recording conditions Recording pattern: Vertical ruled line Environmental temperature: 10 ° C., 25 ° C., 40 ° C. Evaluation criteria A: Time until ejection failure occurs 20 seconds or more B: Time until ejection failure occurs 5 Not less than 20 seconds and less than 20 seconds C: time until ejection failure occurs is less than 5 seconds

[3. Long-term clogging]
4 and the water-soluble inks of Comparative Examples 1 and 2 were set in the above-mentioned recording apparatus, and after recording and confirming that the ink was ejected from all nozzles, a cap was attached to the recording head to prevent drying of the ink. The recording device was left in an environment of 40 ° C. and 20% RH for 14 days without performing the above. After 14 days, recording was performed again, and the number of suction recovery operations required until the ejection of all the nozzles became possible was examined and determined based on the following criteria. Table 3 shows the results.

Recording conditions Recording pattern: Vertical ruled line Recording environment temperature: 25 ° C. Evaluation criteria A: Recovery of ejection after one suction cycle B: Recovery of ejection within four suction cycles C: No recovery of ejection after four or more suction cycles

[0046]

[Table 3]

[4. Quick drying of recording] When an undried recording medium that does not sufficiently adhere and penetrate the ink as a liquid to the recording medium is conveyed, the contact portion between the recording medium conveying means and the recording medium is rubbed, and the recording quality is deteriorated. Decrease. In particular, solid recording, which is a pattern in which dots constituting a recording are arranged without gaps in the upper, lower, left and right directions, so that non-recording portions do not occur on the recording medium, the amount of ink adhering per unit area of the recording medium is large, so that rubbing stains are caused. Since it easily occurs, it is used as a comparison for quick drying of recording. Examples 1 to 4 and Comparative Example 1,
The water-soluble ink No. 2 was recorded using the recording apparatus under the following recording conditions, and the state of the recording medium discharged from the recording apparatus was observed to check the quick-drying of the recording. Table 3 shows the results.

Recording conditions Recording pattern: Solid recording pattern Environmental temperature for recording: 10 ° C. Evaluation criteria A: The recording portion is dry when the recording medium is discharged, and there is no rubbing stain below the recording portion of the recording medium. B: The recording part is dry when the recording medium is ejected,
Scratch and dirt have occurred below the recording portion of the recording medium. C: The recording portion has not been dried yet when the recording medium has been discharged, and significant rubbing and dirt has occurred below the recording portion of the recording medium.

[5. Recording quality] The high roundness of the recording dots and the small scattering of the ink means that the flying form of the ink droplets ejected from the nozzles is stable, and the characteristics of adhesion and penetration to the recording medium are for ink jet recording. Indicates that it is suitable for ink. The water-soluble inks of Examples 1 to 4 and Comparative Examples 1 and 2 were recorded using the recording apparatus under the following recording conditions, and the bleeding of the recording and the degree of scattering of the ink on the recording medium were observed. The quality of the recording was checked by using the following criteria. Table 3 shows the results.

Recording conditions Recording pattern: Alphabet, letters Environmental temperature of recording: 10 ° C., 25 ° C., 40 ° C. Recording medium: Two types of register paper (45 kg paper manufactured by Oji Paper Co., Ltd., high quality manufactured by Daishowa Paper Co., Ltd.) Cash register 5
5 kg paper) Two types of plain paper (Xerox P paper manufactured by Fuji Xerox Co., Ltd., neutral recycled copy paper manufactured by KONICA Co., Ltd.) Evaluation criteria A: The roundness of the recording dots is high on all papers, Ink scattering is small and there is no adverse effect on recording quality. B: Recording dots are minutely non-uniform depending on paper, and ink scattering is poor in recording quality. C: Recording dots are non-uniform on any paper. Poor recording quality due to ink splattering

[Results] As can be seen from Table 2, with respect to the amount of ink mist adhering to the nozzle surface, none of the inks of the examples had ink adhering to the nozzle surface.
In No. 2, it can be seen that the adhesion of ink to the nozzle surface is remarkable.
By containing a polyhydric alcohol alkyl ether and glycols or a nitrogen-containing heterocyclic compound and a nonionic acetylene glycol surfactant, ink does not adhere to the nozzle surface, but without containing a polyhydric alcohol alkyl ether. When only glycols or a nitrogen-containing heterocyclic compound and a nonionic acetylene glycol surfactant are used, ink adhesion occurs and the amount of adhesion is remarkably large. If there is no ink adhesion, the number of times of cleaning of the nozzle surface inserted during the recording time may be small, but if the amount of ink adhesion is large, the number of times of cleaning of the nozzle surface must be increased. Will increase.

Regarding the short-time clogging property, the time until the ejection failure occurs is 20 seconds or more for all the inks of the examples, whereas the comparative examples 1 and 2 are almost 20 seconds or less, and some are 5 seconds. It can be seen below that a discharge failure has occurred. Flushing for preventing short-time clogging has almost no effect on the recording time in normal recording if the time until flushing is 20 seconds or longer, but the time until flushing is 20 seconds. In the following, particularly in the case of 5 seconds or less, frequent flushing in printing has an adverse effect of increasing the printing time, and the frequency of flushing increases, so that the amount of waste ink is increased.

As can be seen from Table 3, with respect to the long-term clogging property, all the inks of the embodiment recover from the ejection with one suction, but the comparative example 2 recovers the ejection within four times of the suction recovery. In No. 1, since the ink is not recovered even when the number of suctions is four or more, the ink of the composition of the comparative example requires a larger number of suctions of the ink for the recovery of the ink, and the clogging property for a long time is inferior to that of the ink of the example. . As the number of times of suction required for the ejection recovery increases, the amount of ink used by the suction operation increases, and so-called waste ink used for purposes other than recording also increases.

Regarding the quick drying property of recording, no rubbing stain was generated in any of the inks of the examples, but in Comparative Examples 1 and 2, rubbing dirt was markedly generated. The reason why the inks of the examples have good recording quick-drying properties is that the low surface tension polyhydric alcohol alkyl ether contained in the inks of the examples also imparts the effect of improving the quick-drying properties to the inks.

In all the inks of the embodiment, the recording quality is high because the dot roundness is high and the ink scatters little on paper, whereas the comparative examples 1 and 2 have good recording quality. The recording quality is degraded due to unevenness and scattering of ink.

[0056]

As described above, according to the water-soluble ink of the present invention, the amount of ink mist other than the ink droplets forming the recording adheres to the nozzle surface in the ink ejected from the recording head in the inkjet recording. Characteristics, which can provide excellent clogging properties for a short time, and thus reduce the frequency of flushing as a means for maintaining ink ejection and the frequency of cleaning as a means for recovering ink ejection, and The amount of ink used for maintenance can be reduced. As a result, the amount of ink used for printing can be increased because the amount of waste ink is reduced, and the number of recorded characters can be increased when compared with ink cartridges of the same capacity. Therefore, there is an effect that the running cost of recording can be reduced.

Further, by using the water-soluble recording ink of the present invention for ink jet recording, the frequency of performing the ink discharge maintaining means and the ink discharge recovery means can be reduced, so that the control method of the recording head can be simplified. In addition, the time required for recording can be shortened.

Further, since it is not necessary to take any special measures for preventing the ink mist from adhering to the nozzle surface, there is an effect that the recording apparatus is advantageous in reducing the cost and size.

According to the inkjet recording method using the water-soluble ink for inkjet recording of the present invention, the running cost of recording is reduced, the time required for recording is reduced,
The effect that a small and low-cost device can be provided can be brought about.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an ink jet recording apparatus.

FIG. 2 is an exploded perspective view of a head of the ink jet recording apparatus shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink-jet recording apparatus 2 Recording medium 10 Recording head 11 Platen 12 Ink tank 13 Ink supply tube 14 Carriage shaft 15 Carriage 16 Pump 17 Cap 18 Waste ink collection tube 19 Waste ink storage

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2C056 EA23 EA24 EA25 FA02 FA03 FA04 FA10 FC02 JA13 JC13 JC20 2H086 BA53 BA59 4J039 AE07 BC09 BC10 BC11 BC13 BC50 BC51 BE01 BE22 CA03 EA41 EA46 EA47 GA24

Claims (6)

[Claims] At least water, a coloring agent, a wetting agent,
An ink jet recording ink containing a surfactant having an osmotic action, comprising 1 to 20% by weight of a polyhydric alcohol alkyl ether and 1 to 30% by weight of a glycol or a nitrogen-containing heterocyclic compound; A water-soluble ink for ink-jet recording, comprising from 0.01 to 5% by weight of a nonionic acetylene glycol surfactant. 2. The inkjet recording according to claim 1, wherein one or both of diethylene glycol mono-n-butyl ether and triethylene glycol mono-n-butyl ether are used as the polyhydric alcohol alkyl ether. For water-soluble ink. 3. The water-soluble ink for ink-jet recording according to claim 1, wherein hexylene glycol is used as said glycols. 4. A method according to claim 1, wherein said nitrogen-containing heterocyclic compound is
3. The method according to claim 1, wherein pyrrolidone is used.
The water-soluble ink for inkjet recording according to the above. 5. The nonionic acetylene glycol surfactant according to the following structural formula (I) or (II)
The water-soluble ink for inkjet recording according to any one of claims 1 to 4, wherein the surfactant represented by the formula (1) is used alone or in combination. Embedded image Embedded image 6. An ink-jet recording method, comprising using the water-soluble ink for ink-jet recording according to any one of claims 1 to 5.