JP2003112436A - Method and apparatus for electrostatic ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high image-quality, stable, and high productivity ink jet recorder without any crosstalk. SOLUTION: In an electrostatic ink jet recording method of recording onto a recording medium transferred opposite to an opening part of a discharge head by supplying an ink liquid to the discharge head via an ink path from an ink tank which stores the ink liquid and discharging the ink liquid from the opening part of the discharge head by an electrostatic means, a non flexible porous body set to at least either the discharge head or the ink path is utilized to supply the ink to the discharge head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording method for recording on a recording medium by ejecting an ink liquid by using electrostatic means, and more specifically, an ink liquid using a non-flexible porous material. The present invention relates to an inkjet recording method and apparatus for ejecting ink.

[0002]

2. Description of the Related Art The ink jet recording system has been widely put into practical use because it does not require a developing process or the like and the ejection head is small in size, so that the recording device can be easily miniaturized. As a conventional inkjet recording system,
There are a piezo element that deforms according to an electric signal and a flexible plate, and a heating resistor that generates heat according to an electric signal.

In an ink jet recording system using a piezo element or a heating resistor as an ejecting means, the ejection frequency is affected by the speed at which the nozzle or the ink liquid chamber is refilled with the ink liquid after ejecting the ink liquid. It is important to reduce the flow resistance of the ink liquid flow path that supplies the ink liquid. For that purpose, it is effective to increase the cross-sectional area of the flow path, but with that, crosstalk due to pressure interference with the adjacent channel occurs, and waviness of the liquid surface due to vibration when scanning the ejection head, When ejecting the ink, the pressure wave generated from the piezo element or the heating resistor is not effectively transmitted to the nozzle, and the ejection property of the ink droplet is deteriorated. Therefore, the flow path resistance is increased by complicating the flow path shape, while the ink liquid contains a large amount of water-based or organic solvent containing a dye or pigment as a coloring material, and the ink liquid has a low viscosity and a low coloring material concentration. By using the liquid, the refilling speed of the ink liquid is increased. Therefore, image bleeding occurs on the recording medium, and it is difficult to form a high-quality / high-resolution image, and it takes time to dry the image forming unit, and it is difficult to improve productivity. Furthermore, it is difficult to remove bubbles in the ink liquid in the complicated ink liquid flow path, which easily causes image defects and
It is difficult to make an inexpensive nozzle multi.

On the other hand, Japanese Patent Publication No. 6-6375 discloses an ink jet device which uses a piezo element which deforms in response to an electric signal in a shear mode. In this device, the partition wall of the ink liquid chamber is composed of a piezo element, and since the volume change of the ink liquid chamber due to the displacement of the partition wall is larger than the ink liquid volume in the ink liquid chamber, a strong pressure wave is generated even with low driving energy, Even if a complicated ink liquid supply path is not required, the pressure wave required for ejecting ink droplets is sufficiently transmitted to the nozzle section, bubbles in the ink liquid flow path are easily degassed, and the structure is simple It is characterized by being very easy and inexpensive to convert. However, it is still difficult to completely prevent the crosstalk due to the pressure interference to the adjacent channel, and although the driving is performed by shifting the driving timing of the adjacent channel, the drawing frequency is lowered.

Japanese Unexamined Patent Publication No. 7-148925 discloses a droplet discharge device using a sintered metal as a porous material for an ink liquid supply layer. Here, the sintered metal has a function of preventing crosstalk with an adjacent channel and achieving both stable holding of the ink liquid and refilling speed of the ink liquid. Further, it is possible to use an ink liquid having the same head shape and a relatively wide range of viscosities, and it also has an effect of filtering the ink liquid. However, the sintered metal is apt to seal the pores due to the adherence of the ink liquid, and as a result, the refilling speed of the ink liquid is reduced due to long-term use, or the ink droplets cannot be ejected after being left for a long time. This causes a more severe problem in the pigment-dispersed ink liquid, and it is conceivable that the driving energy is increased depending on the sealing state of the porous body, but this shortens the life of the device and makes the driver expensive. Will be.

[0006]

DISCLOSURE OF THE INVENTION In the present invention, as a result of earnest studies, a porous body having a low surface tension in an electrostatic ink jet in which an ink liquid is discharged from an opening by an electrostatic means to record on a recording medium. When used, it was found that the consumed ink liquid was quickly refilled, and the porous body was not sealed even during long-term use, and stable ink droplet ejection was possible. It was made paying attention to the fact that the above-mentioned problems of the inkjet can be solved. In particular, the effect of the present invention is effectively obtained when an ink liquid in which solid colored particles are dispersed at least at room temperature, such as a pigment ink liquid, is used as the ink liquid, or when a high-concentration ink liquid is used. . According to the present invention, it is an object of the present invention to provide an ink jet recording apparatus having a high image quality, a stable operation, and a high speed drivability, in an ink jet recording apparatus that draws by ejecting an ink liquid onto a recording medium.

[0007]

In order to achieve the above object, an ink jet recording method according to a first aspect of the present invention provides an ink liquid from an ink tank storing the ink liquid to an ejection head via an ink passage. In an electrostatic ink jet recording method for supplying and discharging an ink liquid from an opening portion of the ejection head by an electrostatic means to perform recording on a recording medium that is conveyed facing the opening portion of the ejection head, The non-flexible porous body provided in at least one of the ejection head and the ink passage is used for supplying ink to the ejection head. According to another aspect of the invention of an ink jet recording apparatus, an ejection head having an opening for ejecting the ink liquid holding the ink liquid therein, an ink tank for storing the ink liquid, the ink tank and the ejection head. An ink passage for communicating the ink liquid to the ejection head, an ink liquid ejecting means for ejecting the ink liquid from the opening portion using an electrostatic means, and a recording medium facing the opening portion of the ejection head. An electrostatic ink jet recording apparatus having a recording medium conveying device for conveying the recording medium, characterized in that at least one of the ejection head and the ink passage has a non-flexible porous body. According to a third aspect of the present invention, in the ink jet recording apparatus according to the second aspect, the non-flexible porous body is 50 dyne / cm (50 mN / m) to 15 d.
It is characterized by having a surface tension of yne / cm (15 mN / m). In the invention according to claim 4, the surface tension is more preferably 40 dyne / cm (40 mN /
m) to 17 dyne / cm (17 mN / m). In addition, the present invention provides the ink jet recording according to any one of claims 2 to 4, wherein, as the ink liquid for the apparatus, solid particles are dispersed at least at room temperature and the specific electric conductivity is 10 ^-9 S / cm or more. It is also characterized by using a conductive ink having

As described above, according to the present invention, the ink liquid is supplied from the ink tank for storing the ink liquid to the ejection head through the ink liquid supply portion, and the ink liquid is ejected by the ink liquid ejection means using electrostatic means. To use an inflexible porous material having a low surface tension in an inkjet recording method and apparatus for performing recording by ejecting an ink liquid from an opening of an ejection head by applying an electric signal based on an image data signal. As a result, it is possible to provide an inkjet recording method and apparatus with high image quality and high productivity, which can increase the speed of re-supply of the ink liquid consumed by ejection and can be stably driven even after long-term use.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic configuration example of a drawing device including a control unit, an ink supply unit, and a head separation / contact mechanism of the drawing device, and FIGS. 2 and 3 explain an inkjet recording device included in the drawing device of FIG. It is for. In FIG. 1, 10 is a drawing drum, 20 is an inkjet recording device, 30 is an encoder, and 21 is an image data calculation control unit. Inkjet recording device 20
Then, in response to the image data sent from the image data calculation control unit 21, the electrostatic ink is formed on the print medium by the electrostatic field formed between the ejection head 22 and the drawing drum 10 to draw the drawn image. To form. The image data arithmetic control unit 21 receives image data from an image scanner, a magnetic disk device, an image data transmission device, etc., performs color separation, and divides the decomposed data into an appropriate number of pixels and gradations. Calculate and send the signal to the ejection head. Furthermore, in order to convert the conductive ink image into halftone dots by using the ink jet ejection head 22 of the ink jet recording apparatus 20 as necessary, the halftone dot area ratio is calculated, and the head contact / separation device 31 and the head are used. The sub-scanning unit 32 is instructed to control the movement of the inkjet ejection head 22, and also to control the ejection timing of the conductive ink and, if necessary, the print medium operation timing.

The ink jet recording apparatus 20 comprises an ejection head 22, an ink supply section 24, an ink passage 201 which connects the ejection head 22 and the ink supply section 24, a head separation / contact device 31, and a head sub-scanning means 32. The ink supply unit 24 includes an ink tank 25 and an ink supply device 26.
The ink tank 25 may include a stirring means 27 and an ink temperature management means 28. The ink may be circulated in the head, and in this case, the ink supply unit 24 also has a recovery circulation function. The stirring means 27 suppresses precipitation / aggregation of solid components of the ink. As the stirring means, a rotary blade, an ultrasonic vibrator, and a circulation pump can be used.
Alternatively, they are used in combination. The ink temperature management unit 28 changes the physical properties of the ink due to changes in the surrounding temperature,
The dots are arranged so that a high-quality image can be stably formed without changing the dot diameter. Ink temperature management means 2
As 8, a heating element such as a heater or a Peltier element or a cooling element is arranged in an ink tank together with a stirring means so as to keep the temperature distribution in the tank constant, and is controlled by a temperature sensor such as a thermostat. Known methods can be used. The ink temperature in the ink tank is preferably 15 ° C. or higher and 60 ° C. or lower, more preferably 20 ° C. or higher and 50 ° C. or lower. Further, the stirring means for keeping the temperature distribution in the tank constant may be shared with the stirring means for the purpose of suppressing precipitation / aggregation of the solid component of the ink. In the above electrostatic ink jet recording apparatus, according to the present invention, a non-flexible porous layer is provided in the ink passage 201 which connects the ink supply unit 24 (ink tank 25) and the ejection head 22 to supply the ink liquid to the ejection head 22. Body 12
5 is provided. The capillarity of the non-flexible porous body 125 has an effect of preventing waving of the liquid surface due to the movement of the ejection head, and at the same time refilling the ink liquid into the slit after the ink droplet is ejected. Physical properties and the like of the non-flexible porous body 125 will be described later.

The above is an example in which the inflexible porous body 125 is provided in the ink passage 201.
In addition to the above, it is also effective to provide it in the ejection head 22. 2 and 3 and subsequent figures show the latter example.
Next, an application example of the ejection head 22 will be described with reference to FIGS.
To explain. 2 and 3 show an example of the ejection head provided in the inkjet recording apparatus 20. The ejection head 22 has a slit sandwiched between an upper unit 221 and a lower unit 222 made of an insulating base material, the tip thereof is an ejection slit 22a, and an ejection electrode 22b is arranged in the slit. The ink 23 supplied from the ink supply unit 24 (FIG. 1) is in a state where the slit is filled. According to the present invention, a non-flexible porous body 125 is provided in the middle of a slit communicating from the ink supply unit 24 to the ejection slit 22a at the tip. This is effective in that the capillary phenomenon of the non-flexible porous body 125 allows quick refilling of the ink liquid into the slit after the ink droplet is ejected. As the insulating base material for the upper unit 221 and the lower unit 222, for example, plastic, glass, ceramics or the like can be applied. The ejection electrode 22b is formed by vacuum-depositing, sputtering, or electroless plating a conductive material such as aluminum, nickel, chromium, gold, or platinum on the lower unit 222 made of an insulating base material, and applying a photoresist on this. Is applied, the photoresist is exposed through a mask having a predetermined electrode pattern, and the photoresist is developed to form a photoresist pattern of the ejection electrode 22b. Then, the photoresist is etched or mechanically removed. It is formed by a known method such as a combination method.

In the ejection head 22, a voltage is applied to the ejection electrode 22b according to a digital signal of image pattern information. As shown in FIG. 2, the drawing drum 10 serving as a counter electrode is installed so as to face the ejection electrode 22b, and the print medium 9 is provided on the drawing drum 10. By applying a voltage, a circuit is formed between the ejection electrode 22b and the drawing drum 10 serving as the counter electrode, and the conductive ink 23 is ejected from the ejection slit 22a of the ejection head 22 on the drawing drum 10 serving as the counter electrode. An image is formed on the print medium provided in the. The width of the ejection electrode 22b is preferably as thin as possible in order to form a high quality image. The specific value varies depending on conditions such as applied voltage and ink physical properties, but is usually 5 to 100 μm.
Used in the range of the tip width of m. For example, the tip is 20 μm
The discharge electrode 22b having a width is used, the distance between the discharge electrode 22b and the drawing drum 10 serving as a counter electrode is 1.0 mm, and a voltage of 3 KV is applied between these electrodes for 0.1 msec.
Dots of 0 μm can be formed on the print medium 9.

The inflexible porous material used here is
Explain. The non-flexible porous body did not have flexibility
Therefore, it has a feature that accurate processing is easy. this
Such a preferable characteristic in processing is the bending elastic modulus of the porous body.
But 0.5 × 10²kg / cm ²The above is preferable, and more
Preferably 1 × 10²kg / cm²That is all. Like this
Examples of non-flexible porous materials include metals and hard plastics.
Ceramics, glass sintered bodies or foams, etc.
There are properties of the porous body and its applied technology (supervised by Takeuchi,
Published by Fuji Techno System, 1999)
Those that have been used are preferably used. Capillary size
If it is within the range that causes the tube phenomenon and reflects the pressure wave
Well, the average pore size is preferably 0.1 μm to 50 μm.
It is 0 μm, more preferably 1 to 100 μm. Flat hole
If the average size is within this range, refill the ink liquid holding chamber.
Fills quickly and prevents waving of the liquid surface when the discharge head moves.
Can be stopped. The porosity of the porous body is 40%.
~ 97% is preferred, more preferably 50% to 95%
is there. If the porosity is within this range, the ink
Refilling the holding chamber quickly and the liquid level when the discharge head moves
Can be prevented from waving. Furthermore, a non-flexible porous material is preferable.
The surface tension is preferably 40 dyne / cm (mN / m) or less.
Has a force, and more preferably has a surface tension of 35 dyne / c
It is not more than m (mN / m). Within this surface tension range
Confirms that the aging of the porous body is effectively prevented.
Was done. The cause is the low energy surface of the porous body.
Therefore, it is presumed that it is difficult for the ink liquid to adhere. Shi
However, the present invention is not limited to this presumed cause.
If it meets this purpose, the non-flexible porous
Coating and coating materials with low surface energy compounds.
Surface treatment by known methods such as pulling treatment, or
Low surface energy materials such as raw or silicon-containing resin
It is also preferably used.

Further, FIGS. 4 and 5 are schematic views for explaining examples of other ejection heads. FIG. 4 is a diagram showing a configuration of a line scanning multi-channel inkjet head according to the present invention, showing a cross section of ejection electrodes corresponding to recording dots. In the figure, the conductive ink 100 is non-flexible arranged between the head substrate 102 and the ejection electrode substrate 103 from a circulation mechanism 111 including a pump and an ink channel, through an ink supply channel 112 formed in the head block 101. The ink is supplied toward the porous body 125 and is recovered by the ink circulation mechanism 111 through the ink recovery channel 113 also formed in the head block 101. The ejection electrode substrate 103 is composed of an insulating substrate 104 having a through hole 107, and an ejection electrode 109 formed around the through hole 107 on the recording medium side.

On the other hand, a convex ink guide 108 is arranged on the head substrate 102 at a substantially central position of the through hole 107. The convex ink guides 108 are made of an insulating material such as plastic resin or ceramics, are arranged at the same row intervals and pitches so that the centers thereof are the same as the through holes 107, and are held on the head substrate 102 by a predetermined method. There is. Each of the convex ink guides 108 has a shape in which the tip of a flat plate having a constant thickness is cut out in a triangular shape or a trapezoidal shape, and the tip end portion becomes the ink droplet flying position 110. Each convex ink guide 108 may have a slit-shaped groove formed from the tip thereof, and the capillary phenomenon of the slit allows the ink to be smoothly supplied to the ink droplet flying position 110.
The recording frequency can be improved. Further, any surface of the ink guide may have conductivity if necessary, and in that case, the conductive portion is electrically floated so that the ink can be effectively applied by applying a small voltage to the ejection electrode. An electric field can be formed at the flight position. Each convex ink guide 1
Reference numeral 08 projects substantially perpendicularly from each through hole in the ink droplet flying direction by a predetermined distance. A recording medium 121, which is a recording paper, faces the tip of the convex ink guide 108.
And a counter electrode 122 also serving as a platen for guiding the recording medium 121 is arranged on the back surface of the recording medium 121 opposite to the head substrate 102.

Next, a specific structural example of the discharge electrode substrate 103 will be described with reference to FIG. 5 is a view of the ejection electrode substrate 103 of FIG. 4 viewed from the recording medium 121 side of FIG. 4, in which a plurality of ejection electrodes are arranged in an array in two rows in the main scanning direction, and the center of each ejection electrode is arranged. Through-holes 107 are formed in the through holes 107, and individual ejection electrodes 109 are formed around the through-holes 107. In this embodiment, the ejection electrode 10
The inner diameter of 9 is provided slightly larger than the diameter of the through hole 107, but it may be the same as the diameter of the through hole 107. Here, the insulating substrate 104 is made of polyimide having a thickness of about 25 μm to 200 μm, The discharge electrode 109 is 10 μm
The through hole 107 has an inner diameter of about 150 μmφ to about 250 μmφ and is made of a copper foil having a thickness of about 100 μm.

Next, the recording operation of the ink jet recording apparatus according to this embodiment will be described. At the time of recording, the ink 100 supplied from the ink circulation mechanism 111 shown in FIG. 4 via the ink supply channel 112 is supplied from the through hole 107 to the ink flying position 110 at the tip of the convex ink guide 108, and part of it is The ink is collected in the ink circulation mechanism 111 via the ink recovery channel 113. Here, a voltage of, for example, 1.5 kV is constantly applied as a bias to the ejection electrode 109 from the bias voltage source 123, to which the signal voltage source 124 is applied.
As a signal voltage corresponding to the image signal from, for example, a pulse voltage of 500 V is superimposed and applied at the time of ON. on the other hand,
The counter electrode 122 provided on the back surface of the recording medium 121 is
As shown in the figure, the ground voltage is set to 0V. Depending on the case, the recording medium 121 side may be charged to, for example, −1.5 kV and used as a bias voltage. In this case, an insulating layer is provided on the surface of the counter electrode 122, and the recording medium is charged effectively by a corona charger, a scorotron charger, a solid ion generator, or the like.
Now, when the discharge voltage 109 is in the ON state (the state where 500 V is applied) and a total voltage of 2 kV in which the pulse voltage of 500 V is superimposed on the bias DC 1.5 kV is applied, the ink droplet flying position at the tip of the convex ink guide 108. An ink droplet 115 is ejected from 110, is pulled toward the counter electrode 122, and is ejected toward the recording medium 121 to form an image. Inflexible porous body 125 used here
Since it is the same as the above, the description is omitted. In addition, in order to precisely control the flight of the ink droplets after flight and improve the landing accuracy on the recording medium, an intermediate electrode is provided between the ejection electrode and the recording medium, or a guard electrode for suppressing electric field interference between the ejection electrodes. However, it is needless to say that the present invention can be suitably used in this embodiment as well. As shown in the present embodiment, the action of the inflexible porous body 125 can prevent the influence of the change in the internal pressure of the ink due to the movement of the inkjet head, and the ink liquid can be supplied to the through hole 107 after the ink droplet is ejected. Achieved quickly. Therefore, the flight of the ink droplet 115 is stabilized, and a good image with stable density can be recorded on the recording medium 121 at high speed.

6 to 8 are schematic views for explaining another example of the discharge head according to the present invention. FIG. 6 shows the configuration of an ink jet recording apparatus using a line scanning head according to another embodiment of the present invention, and FIG. 7 shows the main part thereof. In FIG. 6, the ejection head is composed of a head substrate 200 having individual nozzles 220 arranged in an array on an insulating substrate 210, and an ink recovery substrate 230 provided thereon. The insulating substrate 210 has a peak (PEEK-Poly EtherE).
A resin having excellent workability such as ther ketone) or ceramics whose surface is insulation-coated is used. A groove 211 for holding the individual nozzle 220 is formed on the upper surface of the insulating substrate 210. The individual nozzle 220 is made of a metal material, has a V-shaped groove in the longitudinal direction, and has a tapered tip, as shown in FIG. 7. Specifically, as shown in FIG. 8, the distal end has a quadrangular pyramid shape with one side cut off, and the V groove is formed up to a substantially central position of the individual nozzle 220. The individual nozzle 220 can also be formed by processing an insulating material into a similar shape and forming a conductive layer on the inner wall of the V-shaped groove by plating or vapor deposition. Further, in the ones shown in FIGS. 6 to 8, the tip of the individual nozzle 220 is formed to have a sharp shape, but the tip of the individual nozzle 220 may be formed with a minute roundness. Ink recovery substrate 2
30 is made of the same material as the insulating substrate 210,
A groove corresponding to the individual nozzle 220 is formed in the inclined portion. This groove serves as an ink recovery channel 231. In addition, the head substrate 200 and the ink recovery substrate 230
When bonded to each other, a space corresponding to the depth of the V-shaped groove of the head substrate 200 is formed to form the ink supply channel 220, and the non-flexible porous body 125 is disposed in this. Since the non-flexible porous body 125 used here is the same as that described above, description thereof will be omitted. The groove for collecting ink has a rectangular cross section, but the shape is not limited as long as it has a depression. An ink circulation mechanism 240 including a pump and an ink flow path is connected to the ejection head to optimize the flow of the ink 250. An opposing drum 261 that holds the recording medium 260 on the surface is installed in front of the ejection head, and also serves as a platen.

Next, the operation of the ink jet recording apparatus according to this embodiment will be described. Ink circulation mechanism 24
The ink 250 supplied from 0 reaches the tip of the head through the non-flexible porous body 125 arranged in the ink supply path 221. Since the ink supply path 221 is formed by a V-shaped groove, surface tension based on a capillary action acts on the ink 250 at the groove bottom, so that the ink 250 is surely at the tip 222 of the individual nozzle at the ink flying position.
Is supplied to. When the amount of the supplied ink reaches such a level as to fill the V-shaped groove, the excess ink 250 flows into the recovery flow path 231 through the groove formed in the ink recovery substrate 230. In the head substrate 200, the insulating substrate 210
Similarly, since the groove of the ink recovery substrate 230 exerts a strong surface tension on the ink due to the capillary phenomenon, the ink can be reliably recovered. In this way, by constantly circulating the excess ink, the individual nozzles 22
It is possible to always optimize the amount of ink at the zero tip. When the inkjet recording apparatus starts the recording operation, the individual nozzles 2
A voltage of, for example, DC 1.5 kV is constantly applied to 20 as a bias from the bias voltage source 270, and a pulse voltage of, for example, 500 V is superposed on the signal 20 as a signal voltage corresponding to the image signal from the signal voltage source 271. On the other hand, the counter electrode 261 provided on the back surface of the recording medium 260
Is set to the ground potential 0V as shown in FIG. now,
Any one of the individual nozzles 220 is turned on (a state where 500 V is applied), and when a voltage of 2 kV in which a pulse voltage of 500 V is superimposed on the bias DC of 1.5 kV is applied, it is turned on. The ink droplet 251 is ejected from the ink droplet ejection position 222 at the tip of the individual nozzle 220, is pulled toward the counter electrode 261, and is ejected toward the recording medium 260 to form an image point. As described above, in the present embodiment, the effect of the inflexible porous body 125 can prevent the influence of the change in the ink internal pressure due to the movement of the inkjet head, and the ink liquid can be supplied to the individual nozzles 220 after the ink droplets are ejected. Achieved quickly. Therefore, the flight of the ink droplet 251 is stabilized, and a good image with stable density can be recorded on the recording medium 260 at high speed.

Next, the recording medium used in the present invention will be described. As the recording medium, paper, plastic film, metal foil, cloth, or a composite thereof can be used, and those having various sizes and thicknesses are used depending on the application. Further, it is also possible to carry out plate making by using a printing original plate as a recording medium. As a printing plate,
Examples include metal plates such as aluminum and chrome-plated steel plates. Particularly, an aluminum plate having excellent surface water retention and abrasion resistance by graining or anodizing treatment is preferable. As a cheaper plate material, a plate material provided with an image receiving layer on a water-resistant support such as paper to which water resistance is imparted, a plastic film, or a paper laminated with plastic can be used. The film thickness of this plate material is appropriately in the range of 100 to 300 μm,
The thickness of the image receiving layer provided therein is preferably in the range of 5 to 30 μm. As the image receiving layer, a hydrophilic layer composed of an inorganic pigment and a binder, or a layer which can be rendered hydrophilic by a desensitizing treatment can be used.

The conductive ink used in the present invention will be described below. The conductive ink used in the present invention has an intrinsic electric conductivity of 10 ⁻⁹ S / cm or more. As the ink, if the electrical conductivity is within the above range and the requirements of color reproducibility, fastness, and safety are satisfied depending on the application, either water-based ink or organic solvent-based ink should be used. Is possible. As the water-based ink, it is possible to use ordinary inks for inkjet printers. For these, for example, the Electrophotographic Society of Japan, Vol. 24, No. 4
No. 78 (1985), "Imaging part2,
Latest Hardcopy Printer Technology "Photo Industry Publishing (19
1999), Journal of the Printing Society of Japan, Vol. 36, No. 4, p. 237 (1
999) and the like. In addition, the solvent-based ink preferably uses a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon as a non-aqueous solvent, and a halogen-substituted product of these hydrocarbons. There is. For example, hexane, heptane, octane,
Isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, cyclohexane, cyclooctane, cyclodecane, benzene, toluene, xylene, mesitylene, isoper C, isoper E, isoper G, isoper H, isoper L (Isoper; product of Exxon company Name), Shelsol 70, Shelsol 71 (Shellsol; trade name of Shell Oil Co.), Amsco OMS, Amsco 460 solvent (Amsco; trade name of Spirits Co., Ltd.), silicone oil and the like, which are used alone or in combination. By setting the electric conductivity of the solvent to be used within the above range, the ink ejection property becomes good even when a low-voltage driver is used, and good image formation can be performed. The particles dispersed in the solvent of the water-based or organic solvent-based ink are preferably colored, and in that case, the coloring material itself may be dispersed as dispersed particles in a non-aqueous solvent, or fixed. It may be contained in dispersed resin particles for improving the property. When it is contained, a pigment or the like is generally coated with a resin material of dispersed resin particles to obtain resin-coated particles, and a dye or the like is generally pigmented by dispersing resin particles into colored particles. is there. Any conventionally used pigments and dyes can be used as the coloring material. As a pigment,
What is generally used in the technical field of printing can be used regardless of whether it is an inorganic pigment or an organic pigment. Specifically, for example, carbon black, cadmium red, molybdenum red, chrome yellow, cadmium yellow, titanium yellow, chromium oxide, viridian, cobalt green, ultramarine blue, Prussian blue, cobalt blue, azo pigment, phthalocyanine pigment. , Quinacridone pigments, isoindolinone pigments, dioxazine pigments, slene pigments, perylene pigments, perinone pigments, thioindigo pigments, quinophthalone pigments, metal complex pigments, etc. Can be used without. As the dye, azo dye, metal complex dye, naphthol dye, anthraquinone dye, indigo dye, carbonium dye, quinone imine dye, xanthene dye, aniline dye, quinoline dye, nitro dye, nitroso dye, benzoquinone dye, naphthoquinone dye, phthalocyanine dye, Metal phthalocyanine dyes and the like are preferred. These pigments and dyes may be used alone or may be used in an appropriate combination, but are preferably contained in the range of 0.5 to 5 mass% with respect to the entire ink. The conductive ink used in the present invention preferably contains dispersed resin particles for improving the fixability of an image after printing, in addition to the colored particles. The resin particles to be dispersed in the above solvent may be resin particles which are solid at room temperature and have a good affinity with the solvent, but the glass transition point thereof is −5 ° C. or higher.
A resin (P) having a temperature of 110 ° C or a softening point of 33 ° C to 140 ° C is preferable, and a glass transition point of 10 ° is more preferable.
C-100 ° C or softening point 38 ° C-120 ° C, more preferably glass transition point 15 ° C-80 ° C.
C or the softening point is 38 ° C to 100 ° C. By using a resin having such a glass transition point or softening point, the affinity between the surface of the recording medium and the resin particles is increased,
Further, since the resin particles are strongly bonded to each other on the recording medium, the adhesion between the image portion and the recording medium surface is improved. The mass average molecular weight Mw of the resin (P) is 1 × 10 ³ to 1 × 10 ^6.
And preferably 5 × 10 ³ to 8 × 10 ⁵ , and more preferably 1 × 10 ^{4 to} 5 × 10 ⁵ . Specific examples of such a resin (P) include olefin polymers and copolymers (for example, polyethylene, polypropylene, polyisobutylene, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, ethylene-methacrylate copolymer). , Ethylene-methacrylic acid copolymers, etc.), vinyl chloride polymers and copolymers (for example, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, etc.), vinylidene chloride copolymers, vinyl alkanoate polymers and copolymers. Polymers, allyl alkanoate polymers and copolymers, polymers and copolymers of styrene and its derivatives (for example, butadiene-styrene copolymers, isoprene-styrene copolymers, styrene-methacrylate copolymers, styrene-acrylates) Copolymer, etc.), acrylonitrile copolymer, methacrylo Tolyl copolymers, alkyl vinyl ether copolymers, acrylic acid ester polymers and copolymers, methacrylic acid ester polymers and copolymers, itaconic acid diester polymers and copolymers, maleic anhydride copolymers, acrylamide copolymers Polymer, methacrylamide copolymer, phenol resin, alkyd resin, polycarbonate resin, ketone resin, polyester resin, silicone resin,
Amide resin, hydroxyl group- and carboxyl group-modified polyester resin, butyral resin, polyvinyl acetal resin, urethane resin, rosin resin, hydrogenated rosin resin, petroleum resin, hydrogenated petroleum resin, maleic acid resin, terpene resin, hydrogenated terpene resin, Coumarone-indene resin, cyclized rubber-methacrylic acid ester copolymer, cyclized rubber-acrylic acid ester copolymer, copolymer containing a nitrogen atom-free heterocycle (e.g., furan ring, tetrahydrofuran Ring, thiophene ring,
Dioxane ring, dioxofuran ring, lactone ring, benzofuran ring, benzothiophene ring, 1,3-dioxetane ring, etc.), epoxy resin and the like.

The total content of dispersed colored particles and resin particles in the conductive ink of the present invention is preferably 0.5 to 30% by mass of the total ink. Within this range, a sufficient print image density can be obtained and stable ink ejection can be obtained. The average particle size of these particles including the colored particles dispersed in the non-aqueous solvent of the present invention and further the resin particles is preferably 0.05 μm to 5 μm. The range is more preferably 0.1 μm to 1.5 μm. This particle size is CAPA-500 (trade name of Horiba, Ltd.)
It was obtained by.

The particle-dispersed ink used in the present invention can be produced by a conventionally known mechanical grinding method or polymerization granulation method. As the mechanical pulverization method, if necessary, a coloring agent is added and mixed with the resin, melted and kneaded, and then directly pulverized by a conventionally known pulverizer to obtain fine particles, and a dispersion polymer is used in combination, and further wet dispersion is performed. Machine (eg ball mill
A paint shaker, Keddy mill, Dynomill, etc.), a colorant and a dispersion-aiding polymer (or a coating polymer) are kneaded in advance to form a kneaded product, which is then pulverized, and then a dispersion polymer is allowed to coexist for dispersion. Can be mentioned. Specifically, a method for producing a paint or a liquid developer for electrostatography can be used. For example, a method for producing a paint or a liquid developer for electrophotography, which is translated by Kenji Ueki, "Paint Flow and Pigment Dispersion," Kyoritsu Publishing (197
1 year), "Solomon, Chemistry of paint", (Paint a
nd Surface Coating Theory
and Practice], Yuji Harazaki "Coating Engineering" Asakura Shoten (1971), Yuji Harazaki "Basic Science of Coating" Maki Shoten (1977) and the like.

There is also a method of producing colored particles by coloring resin particles granulated by polymerization granulation by dyeing. As the polymerization granulation method, a conventionally known non-aqueous dispersion polymerization method can be mentioned, and specifically, “Latest Technology of Ultrafine Particle Polymer” by Soichi Muroi, Chapter 2, CMC Publishing (1991), edited by Koichi Nakamura. Development and Practical Use of Recent Electrophotographic Development System and Toner Material ", Chapter 3 (Nihon Kagaku Information Co., Ltd., 1985), K.K. E. J. Barrett "Dispersi
on Polymerization in Orga
nic Media "(John Wiley 197
5 years) and the like.

Usually, a dispersing polymer is used together to stabilize the dispersed particles in a solvent. The dispersion polymer contains a solvent-soluble repeating unit as a main component, and has an average molecular weight of 1 × 10 ³ to 1 × 1 in terms of mass average molecular weight Mw.
0 ⁶ is preferable, and more preferably 5 × 10 ^{3 to} 5 × 10.
It is in the range of ⁵ . If the ink is oil based,
As a preferred soluble repeating unit of the dispersion polymer,
The polymerization component represented by the following general formula (I) may be mentioned.

[0026]

[Chemical 1]

In the general formula (I), X ₁ is --COO.
Represents-, -OCO- or -O-. R has 10 carbon atoms
To 32 alkyl groups or alkenyl groups, preferably C10 to C22 alkyl groups or alkenyl groups, which may be linear or branched and are preferably unsubstituted, but have a substituent. You may have. Specifically, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosanyl group, docosanyl group, decenyl group, dodecenyl group, tridecenyl group, hexadecenyl group, octadecenyl group, linolel group and the like can be mentioned. . a ₁ and a ₂ may be the same or different from each other, and preferably a hydrogen atom, a halogen atom (eg, chlorine atom, bromine atom, etc.), a cyano group,
An alkyl group having 1 to 3 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, etc.), -COO-Z ₁ or -CH ₂ C
OO-Z ₁ [Z ₁ has 22 carbon atoms which may be substituted.
Represents the following hydrocarbon groups (for example, alkyl groups, alkenyl groups, aralkyl groups, alicyclic groups, aryl groups, etc.)]
Represents Z ₁ specifically represents a hydrocarbon group, and as a preferable hydrocarbon group, an optionally substituted alkyl group having 1 to 22 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, Heptyl group, hexyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group,
Tetradecyl group, hexadecyl group, octadecyl group, eicosanyl group, docosanyl group, 2-chloroethyl group, 2
-Promoethyl group, 2-cyanoethyl group, 2-methoxycarbonylethyl group, 2-methoxyethyl group, 3-promopropyl group, etc.), an alkenyl group having 4 to 18 carbon atoms which may be substituted (for example, 2-methyl- 1-propenyl group, 2-butenyl group, 2-pentenyl group, 3-methyl-
2-pentenyl group, 1-pentenyl group, 1-hexenyl group, 2-hexenyl group, 4-methyl-2-hexenyl group, decenyl group, dodecenyl group, tridecenyl group, hexadecenyl group, octadecenyl group, linolel group, etc.), carbon Aralkyl groups which may be substituted of formulas 7 to 12 (for example, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, chlorobenzyl group, promobenzyl group, methylbenzyl group, ethyl Benzyl group, methoxybenzyl group, dimethylbenzyl group, dimethoxybenzyl group, etc.), alicyclic group having 5 to 8 carbon atoms which may be substituted (eg, cyclohexyl group, 2
-Cyclohexylethyl group, 2-cyclopentylethyl group, etc.), and optionally substituted aromatic group having 6 to 12 carbon atoms (eg, phenyl group, naphthyl group, tolyl group, xylyl group, propylphenyl group, butyl) Phenyl group, octylphenyl group, dodecylphenyl group, methoxyphenyl group, ethoxyphenyl group, butoxyphenyl group, decyloxyphenyl group, chlorophenyl group, dichlorophenyl group, bromophenyl group, cyanophenyl group, acetylphenyl group, methoxycarbonylphenyl group , Ethoxycarbonylphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group, dodecyloylamidophenyl group and the like).

In addition to the repeating unit represented by formula (I), the dispersing polymer may contain another repeating unit as a copolymerization component. Other copolymerization components include
Any compound may be used as long as it is composed of a monomer copolymerizable with the monomer corresponding to the repeating unit of the general formula (I). The content of the polymer component represented by formula (I) in the dispersion polymer is preferably 50% by mass or more, more preferably 60% by mass or more. Specific examples of these dispersion polymers. Examples include the dispersion stabilizing resin (Q-1) used in the examples, and a commercially available product (Sorprene 1205, manufactured by Asahi Kasei Co., Ltd.) can also be used. The dispersion polymer is preferably added in advance during the polymerization when the resin (P) particles are produced as an emulsion (latex) or the like. The addition amount of the dispersion polymer is about 1 to 50 mass% with respect to the resin (P) for particles. Examples of preferred dispersed resin particles and particles of the present invention,
Preferred are positively or negatively charged electrophoretic particles. It is possible to impart an electroscopic property to these particles by appropriately utilizing the technique of a developer for wet electrostatic photography. Specifically, "Recent Developments and Practical Uses of Electrophotographic Development Systems and Toner Materials" pp. 139 to 148, and "Basics and Applications of Electrophotography" edited by The Institute of Electrophotography, pp. 497 to 505 (Corona Publishing Co., Ltd., 1988). Annual), Yuji Harasaki "Electronic Photography" 16 (N
o. 2), p. 44 (1977), etc., and the use of the electrophotographic material and other additives. Specifically, for example, British Patent Nos. 893429 and 9340.
38, U.S. Pat. Nos. 3,900,421 and 4,060,693.
89, JP-A-60-179751, and JP-A-60-185.
No. 963, JP-A-2-13965 and the like. The charge control agent as described above is preferably 0.001 to 1.0 part by mass with respect to 1000 parts by mass of a dispersion medium which is a carrier liquid. If desired, various additives may be added, and the total amount of these additives is controlled by the electric conductivity of the ink. That is, the electrical conductivity of the ink is 10 ⁻⁹ S /
If it is lower than cm, it becomes difficult to obtain a continuous tone image of high quality, so it is necessary to control the addition amount of each additive within this limit.

[0029]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. First, a production example of the resin particles for ink (PL-1) will be described.

Production Example 1 Production of Resin Particles (PL-1) A mixed solution of 10 g of a dispersion stabilizing resin (Q-1) having the following structure, 100 g of vinyl acetate and 384 g of Isopar H was added at a temperature of 70 ° C. with stirring under a nitrogen stream. Warmed. 0.8 g of 2,2'-azobis (isovaleronitrile) (abbreviation AIVN) was added as a polymerization initiator, and the reaction was carried out for 3 hours. Twenty minutes after the addition of the initiator, white turbidity occurred and the reaction temperature rose to 88 ° C. Further, 0.5 g of this initiator was added and after reacting for 2 hours, the temperature was raised to 100 ° C. and stirred for 2 hours to distill off unreacted vinyl acetate. After cooling, it was passed through a nylon cloth of 200 mesh, and the obtained white dispersion was a latex having a polymerization rate of 90% and an average particle size of 0.23 μm and good monodispersity. The particle size was measured by CAPA-500 (manufactured by Horiba, Ltd.).

[0031]

[Chemical 2]

A part of the white dispersion was subjected to a centrifuge (rotation speed 1 × 10 ⁴ rpm, rotation time 60 minutes) to collect and dry the precipitated resin particle component. The weight average molecular weight of the resin particles (Mw: polystyrene-converted GPC value) is 2
× 10 ⁵ , glass transition point (Tg) was 38 ℃.

Example 1 First, an oily conductive ink was prepared. <Oil Conductive Ink (IK-1)> 10 g of dodecyl methacrylate / acrylic acid copolymer (copolymerization ratio; 95/5 weight ratio), nigrosine 10 g, and shell sol 71
Was placed in a paint shaker (manufactured by Toyo Seiki Co., Ltd.) together with glass beads and dispersed for 4 hours to obtain a fine dispersion of nigrosine.

30 g of resin particles (PL-1) of Production Example 1 of ink resin particles (as solid content), 20 g of the above nigrosine dispersion, and FOC-1400 (Nissan Chemical Co., Ltd.).
(Trade name, tetradecyl alcohol) 15 g, and octadecene-half-maleic acid octadecylamide copolymer 0.08
A black oil-based ink was prepared by diluting g to 1 liter of Isopar G. Electrical conductivity is 2.5 × 10
It was ^-9 S / cm.

Next, the head shown in FIG. 2 was set in the ink jet recording apparatus of the drawing apparatus of the printing apparatus shown in FIG. 1, and 2 liters of the conductive ink prepared as described above was filled in the ink tank. Here, a 100-dpi, 128-channel head of the type shown in FIG. 2 was used as the ejection head. As the inflexible porous body 125, foamed nickel metal (manufactured by Mitsubishi Materials Corp.) was used as it was.
A throw-in heater and a stirring blade were provided in the ink tank as an ink temperature control means, the ink temperature was set to 30 ° C., and the temperature was controlled by a thermostat while rotating the stirring blade at 30 rpm. Here, the stirring blade was also used as a stirring means for preventing sedimentation and aggregation. In addition, a part of the ink flow path is made transparent, an LED light emitting element and a light detecting element are arranged with the ink flow path sandwiched therebetween, and an output signal from the LED diluting solution (isopar G) or concentrated ink (solid content of the above IK-1 ink). The concentration was controlled by adding the one whose concentration was adjusted to double. A roll-shaped slightly coated paper as a print medium was provided on the opposing drum and conveyed. After removing dust from the surface of the print medium by suction with an air pump, bring the ejection head close to the print medium to the drawing position, transmit the image data to be printed to the image data calculation control unit, and convey the print medium by rotating the opposing drum. While doing so, the conductive ink was discharged from the full line multi-channel head to form an image. At this time, the tip width of the ejection electrode of the inkjet head was 10 μm, and the distance between the head and the print medium was kept at 1 mm by the output from the optical gap detection device. A voltage of 2.5 KV is constantly applied as a bias voltage, a pulse voltage of 500 V is further superimposed when performing ejection, and the pulse voltage is 256 steps in the range of 0.2 ms to 0.05 ms. While changing the dot area by changing
Drawing was performed at a drive frequency of kHz. No drawing defects due to dust were observed, and no image deterioration due to changes in dot diameter due to changes in outside temperature or increase in printing time was observed, and good printing was possible.

Further, the image was strengthened by heating with a xenon flash fixing device (manufactured by USHIO INC., Emission intensity 200 J / pulse). After the printing was completed, the inkjet recording device was retracted by 50 mm from the position close to the drawing drum in order to protect the inkjet head.

The printed matter obtained was an extremely clear image with no flying, blurring, or blurring in the printed image. A drawing test was carried out for one month, but no image deterioration due to crosstalk or deterioration with time was observed, and a high-definition image was stably obtained.

<Embodiment 2> 50 dp of the type shown in FIG.
Four i384-channel multi-channel heads were used, and the heads were arranged so that the ejection portions were arranged in the direction perpendicular to the axial direction of the drum. As ink, black ink IK-1
And cyan ink IK-2 prepared in the same manner as IK-1 ink except that nigrosine used as a colorant for IK-1 ink was replaced with phthalocyanine blue.
CI Pigment Red 57: 1 was used instead of nigrosine used as the colorant of the ink, and magenta ink IK-3 prepared in the same manner as the IK-1 ink and nigrosine used as the colorant of the IK-1 ink were CI. Pigment Yellow 14 except that four color inks of yellow ink IK-4 prepared in the same manner as IK-1 ink are used.
Four heads each were filled. Here, a pump is used, and an ink reservoir is provided between this pump and the ink inflow path of the ejection head, and between the ink recovery path of the ejection head and the ink tank. A heater and the above-mentioned pump were used as means, the ink temperature was set to 35 ° C., and the temperature was controlled by a thermostat. Here the circulation pump is settling
It was also used as a stirring means for preventing aggregation. Further, an electric conductivity measuring device is arranged in the ink flow path, and the output signal controls the concentration of the ink by diluting the ink or introducing the concentrated ink. After removing dust on the surface of the printing medium with a nylon rotating brush, the image data to be printed is transmitted to the image data calculation control unit, the head is moved in the drum axis direction for main scanning, and the drawing drum is rotated. While performing sub-scanning while drawing at a driving frequency of 10 kHz, ink was ejected onto the roll-shaped fine coated paper to form an image. Porous ceramics (cordierite manufactured by Nippon Insulators Co., Ltd.) was used as the porous body. The drawn image had no bleeding and was subjected to a drawing test for one month. No crosstalk or image deterioration due to deterioration with time was observed, and a high-definition image was stably obtained.

<Embodiment 3> 100d of the type shown in FIG.
By using four pi256 channel multi-channel heads, the discharge part is arranged in parallel with the axis of the opposing drum, the main scanning is performed by the rotation of the opposing drum, and the head is sequentially moved in the axial direction of the drum for each rotation. 9 on coated paper
An image of 00 dpi was drawn to obtain a clear and high-quality full-color printed matter. Sintered stainless steel (Mo
A drawing test was performed in the same manner as in Example 2 except that a silane coupling agent (micron grade manufactured by tt Metallurgical) whose surface tension was reduced by a silane coupling agent (manufactured by Shin-Etsu Silicone Co., Ltd.) was used. Here, the surface tension of the sintered stainless steel after the treatment is 38 dyne / cm (mN /
m). The drawn image was free from bleeding and was subjected to a drawing test for 3 months. No crosstalk or image deterioration due to deterioration with time was observed, and a high-definition image was stably obtained.

<Example 4> As the ink, a commercially available water-based ink was used. Electrical conductivity with 4-color 10 ^- 6 It was on the order of S / cm. Here, a 50 dpi, 384-channel multi-channel head of the type shown in FIG. 4 was used as the discharge head, and a non-flexible porous body made of foamed polyimide was formed and shaped and used.
The surface tension of the created polyimide is 35 dyne / cm.
(MN / m). A drawing test was performed on 10,000 A4 sheets at a driving frequency of 15 kHz. No crosstalk or image deterioration due to deterioration with time was observed in the drawn image, and a high-definition image was stably obtained.

<Example 5> A drawing test was performed in the same manner as in Example 4 except that a sintered metal (Celmet manufactured by Sumitomo Electric Industries, Ltd.) was used as a porous body by coating it by immersing it in a fluorine-containing resin solution. I went. The surface tension of the sintered metal after the treatment was 23 dyne / cm (mN / m). The drawn image has no bleed, and A4 size 2000
A drawing test was performed on 0 sheets, but no image deterioration due to crosstalk or deterioration with time was observed, and a high-definition image was stably obtained.

<Example 6> As a porous body, a PTFE membrane filter (T300 manufactured by Advantech Co., Ltd.) was used.
A drawing test was conducted in the same manner as in Example 2 except that A) was processed and used. Here, the surface tension of the filter is 21 dy.
It was ne / cm (mN / m). The drawn image has no blur, and a drawing test was performed on 10,000 A4 sheets.
No image deterioration due to crosstalk or deterioration over time was observed, and high-definition images were stably obtained.

Example 7 As a non-flexible porous material, a glass fiber filter paper (Whatman GF / D) was used to reduce the surface tension in the same manner as in Example 1 and then processed into a shape. The surface tension of the glass fiber filter paper after the treatment is 30 dyne /
It was cm (mN / m). A drawing test was conducted in the same manner as in Example 3. A drawing test was carried out for 6 months. No crosstalk or image deterioration due to deterioration with time was observed in the drawn image, and a high-definition image was stably obtained.

[0044]

According to the present invention, a non-flexible porous body having a low surface tension is disposed in at least one of the ink passage for supplying the ink liquid to the ejection head or the ejection head, so that there is no crosstalk and a high degree. It is possible to obtain a stable and highly productive inkjet recording device with high image quality.

[Brief description of drawings]

FIG. 1 is a schematic configuration example of a drawing device including a control unit, an ink supply unit, and a head separation / contact mechanism of the drawing device of the electrostatic ink jet recording apparatus of the present invention.

FIG. 2 is a diagram illustrating an inkjet recording device included in the drawing device of FIG.

3 is a diagram for explaining an enlarged cross section of the inkjet recording apparatus of FIG.

FIG. 4 is a diagram showing a configuration of a line scanning multi-channel inkjet head which is another ejection head.

5 is a view of the ejection electrode substrate 103 of FIG. 4 viewed from the recording medium side.

FIG. 6 is a diagram showing a configuration of an inkjet recording apparatus using a line scanning head according to another embodiment of the present invention.

7 is a perspective view showing a main part of the ejection head of FIG.

FIG. 8 is a diagram of the individual nozzles of FIG. 7 viewed from the recording medium side.

[Explanation of symbols]

10 Opposing (drawing) drum 20 Inkjet recording device 201 ink passage 21 Image data calculation controller 22 Discharge head 221 Upper unit 222 Lower unit 22a discharge slit 22b Discharge electrode 23 Oil-based ink 24 Ink supply section 25 ink tanks 26 Ink supply device 27 stirring means 28 Ink temperature control means 30 encoder 31 Head contact / separation device 32 head sub-scanning means 33 First Insulating Base Material 34 Second insulating base material 35 Slope of second insulating base material 36 Upper surface of second insulating base material 37 Ink flow path 38 Ink collection path 39 backing 40 grooves 41 head body 42, 42 'Meniscus regulated version 43 ink groove 44 partition 45, 45 'discharge part 46 partitions 47 Partition tip 50, 50 'support member 51, 51 groove 52 partition 53 Upper end 54 rectangle 55 Top of partition 56 Guide protrusion 100 conductive ink 101 head block 102 head substrate 103 ejection electrode substrate 104 insulating substrate 107 through hole 108 Convex ink guide 109 ejection electrode 110 ink droplet flight position 111 Ink circulation mechanism 112 ink supply flow path 113 ink recovery channel 115 ink drops 121 recording medium 122 counter electrode 123 Bias voltage source 125 Non-flexible porous material 200 head substrate 210 insulating substrate 211 groove 220 individual nozzles 221 ink supply path 230 Ink recovery substrate 240 Ink circulation mechanism 250 ink 251 ink drops 260 recording medium 261 Opposing drum (opposing electrode) 270 bias voltage source 271 Signal voltage source

Claims (4)

[Claims] 1. An ink tank for storing ink liquid supplies the ink liquid to an ejection head through an ink passage, and the electrostatic liquid is used to eject the ink liquid from an opening of the ejection head. In an electrostatic ink jet recording method for recording on a recording medium conveyed facing an opening, a non-flexible porous body provided in at least one of the ejection head or the ink passage is connected to the ejection head. An inkjet recording method characterized by being used for supplying ink. 2. An ejection head having an opening for ejecting the ink liquid holding the ink liquid therein, an ink tank for storing the ink liquid, and the ejection head for communicating the ink tank with the ejection head. An ink passage for supplying the ink liquid to the ink, an ink liquid ejecting means for ejecting the ink liquid from the opening portion using an electrostatic means, and a recording medium conveying device for conveying the recording medium facing the opening portion of the ejection head. An electrostatic ink jet recording apparatus having: a non-flexible porous body in at least one of the ejection head and the ink passage. 3. The non-flexible porous body is 50 dyne
/ Cm (50 mN / m) to 15 dyne / cm (15 m
3. A surface tension of N / m).
The inkjet recording device described. 4. The surface tension is more preferably 40d.
yne / cm (40mN / m) ~ 17dyne / cm
The ink jet recording apparatus according to claim 3, wherein the ink jet recording apparatus is (17 mN / m).