JP2020151850A - Liquid discharge device and wiping method - Google Patents

Abstract

To solve the problem in which: a fixed matter adhering to a nozzle formation surface by drying of liquid is difficult to be removed in a liquid discharge device using a conventional wiping member.SOLUTION: A liquid discharge device includes: a liquid discharge head which discharges liquid from a nozzle: and a wiping member which wipes a nozzle formation surface of the liquid discharge head. The liquid contains two or more kinds of alcohol. The wiping member is composed of at least two layers. Porosity of the first layer in contact with the nozzle formation surface is smaller than that of at least one layer other than the first layer. Thickness of the first layer is thinner than the total of thickness of layers other than the first layer.SELECTED DRAWING: Figure 3

Description

The present invention relates to a liquid discharge device and a wiping method.

In a liquid ejection device represented by an inkjet printer, problems such as ejection defects occur due to foreign matter on the nozzle forming surface, so it is necessary to regularly clean the liquid ejection device. As a wiping member used for cleaning the nozzle-forming surface, a method of cleaning by combining a sheet-shaped wiping member typified by a non-woven fabric or a woven cloth is already known.

In Patent Document 1, the dispersion liquid adhering to the nozzle forming surface is wiped by relatively moving the liquid injection head for injecting the dispersion liquid in which the solid particles are dispersed in the liquid from the nozzle and the wiping member. A wiper device that is wiped with is disclosed. This wiping member has a first layer on the nozzle forming surface side and a second layer on the side opposite to the nozzle forming surface with respect to the first layer. The first layer guides droplets, which are dispersion media of the dispersion liquid, adhering to the nozzle forming surface to the second layer by capillarity, and has voids capable of capturing and accommodating the dispersoid of the dispersion liquid. The second layer also absorbs the dispersion medium.

However, the conventional liquid discharge device using the wiping member has a problem that it is difficult to remove the adhered matter that the liquid dries on the nozzle forming surface.

The invention according to claim 1 includes a liquid discharge head that discharges a liquid from a nozzle and a wiping member that wipes the nozzle-forming surface of the liquid discharge head, and the liquid contains a polyether-modified silicone compound. The wiping member is composed of at least two layers, and the void ratio of the first layer in contact with the nozzle forming surface is smaller than the void ratio of at least one layer other than the first layer, and the first layer The thickness of the eyes is a liquid discharge device thinner than the total thickness of the layers other than the first layer.

The liquid discharge device of the present invention has an excellent effect that the liquid is dried on the nozzle forming surface and the adhered matter can be easily removed.

FIG. 1 is a diagram schematically showing an example of an image forming apparatus incorporating a wiping apparatus. FIG. 2 is a diagram schematically showing an example of a nozzle forming surface of a liquid discharge head. FIG. 3 is a diagram schematically showing an example of a wiping device. FIG. 4 is a diagram schematically showing an example of a cross section of a sheet-shaped wiping member.

Hereinafter, an embodiment of the present invention will be described.

<< Liquid discharge device, wiping method >>
The liquid discharge device of the present embodiment includes a liquid, a liquid discharge head that discharges a liquid from a nozzle, a wiping device, and the like. The wiping device has a wiping member and, if necessary, has other means such as a cleaning liquid used at the time of wiping. Further, the wiping method executed by the liquid discharge device having the wiping device includes a wiping step and, if necessary, another step such as a cleaning liquid applying step. The wiping device wipes the nozzle-forming surface by bringing the wiping member into contact with the nozzle-forming surface of the liquid discharge head that discharges the liquid from the nozzle. In addition, in this embodiment, "wiping" means that the wiping member and the liquid discharge head are relatively moved while being in contact with the wiping member and the nozzle forming surface. By wiping the nozzle-forming surface with the wiping member, for example, the adhered matter that the liquid has dried and adhered to on the nozzle-forming surface can be removed from the nozzle-forming surface. Further, for example, it can be removed from the nozzle forming surface by absorbing the excess liquid overflowing from the nozzle.

First, the liquid discharge device and the wiping device will be described with reference to FIGS. 1 to 3 by taking as an example an image forming device which is an example of a liquid discharge device incorporating a wiping device. The image forming apparatus is an apparatus for ejecting ink as an example of a liquid. FIG. 1 is a diagram schematically showing an example of an image forming apparatus incorporating a wiping apparatus. FIG. 2 is a diagram schematically showing an example of a nozzle forming surface of a liquid discharge head. FIG. 3 is a diagram schematically showing an example of a wiping device.

The image forming apparatus shown in FIG. 1 is a serial type liquid discharging apparatus. The image forming apparatus movably holds the carriage 3 by the main guide member 1 and the slave guide members horizontally laid on the left and right side plates. Then, the carriage 3 is reciprocated in the main scanning direction (carriage moving direction) by the main scanning motor 5 via the timing belt 8 bridged between the drive pulley 6 and the driven pulley 7. The carriage 3 is equipped with recording heads 4a and 4b (referred to as "recording head 4" when not distinguished), which are examples of liquid discharge heads. The recording head 4 ejects ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K), for example. Further, the recording head 4 is mounted by arranging a nozzle array composed of a plurality of nozzles in the sub-scanning direction orthogonal to the main scanning direction and directing the droplet ejection direction downward.

As shown in FIG. 2, the recording head 4 has two nozzle rows Na and Nb in which a plurality of nozzles 4n are arranged on the nozzle forming surface 41. As the liquid discharge head constituting the recording head 4, for example, a thermal actuator that utilizes a phase change due to boiling of a liquid film using a piezoelectric actuator such as a piezoelectric element or an electric heat conversion element such as a heat generating resistor can be used. ..

Further, the image forming apparatus shown in FIG. 1 includes a transport belt 12 which is a transport means for electrostatically adsorbing the paper and transporting the paper at a position facing the recording head 4 in order to transport the paper 10. The transport belt 12 is an endless belt and is hung between the transport roller 13 and the tension roller 14. Then, the transport belt 12 orbits in the sub-scanning direction by rotationally driving the transport roller 13 via the timing belt 17 and the timing pulley 18 by the sub-scanning motor 16. The transport belt 12 is charged (charged) by a charging roller while moving around.

Further, on one side of the carriage 3 in the main scanning direction, a maintenance / recovery mechanism 20 for maintaining / recovering the recording head 4 is arranged on the side of the transport belt 12, and on the other side, the recording head 4 is arranged on the side of the transport belt 12. Empty discharge receivers 21 that perform empty discharge from the air are arranged. The maintenance / recovery mechanism 20 includes, for example, a cap member 20a that caps the nozzle forming surface (the surface on which the nozzle is formed) of the recording head 4, a mechanism 20b that wipes the nozzle forming surface, and an empty discharge that ejects droplets that do not contribute to image formation. It is composed of receivers and the like.

Further, the image forming apparatus stretches an encoder scale 23 forming a predetermined pattern between both side plates along the main scanning direction of the carriage 3. Further, the carriage 3 is provided with an encoder sensor 24 made of a transmissive photo sensor that reads the pattern of the encoder scale 23. These encoder scales 23 and encoder sensors 24 constitute a linear encoder (main scanning encoder) that detects the movement of the carriage 3.

Further, a cord wheel 25 is attached to the shaft of the transport roller 13, and an encoder sensor 26 composed of a transmissive photo sensor for detecting a pattern formed on the cord wheel 25 is also provided. These cord wheels 25 and an encoder sensor 26 constitute a rotary encoder (secondary scanning encoder) that detects the movement amount and movement position of the transfer belt 12.

In the image forming apparatus configured in this way, the paper 10 is fed onto the charged transport belt 12 and is attracted to the paper, and the paper 10 is transported in the sub-scanning direction by the orbital movement of the transport belt 12. Therefore, by driving the recording head 4 in response to the image signal while moving the carriage 3 in the main scanning direction, ink droplets are ejected onto the stopped paper 10 to record one line. Then, after the predetermined amount of the paper 10 is conveyed, the next line is recorded. When the recording end signal or the signal that the rear end of the paper 10 reaches the recording area is received, the recording operation is ended and the paper 10 is discharged to the paper ejection tray.

When cleaning the recording head 4, the carriage 3 is moved to the maintenance / recovery mechanism 20 while waiting for printing (recording), and the maintenance / recovery mechanism 20 performs cleaning. Further, the recording head 4 may not move, and the maintenance / recovery mechanism 20 may move to clean the head. The recording head 4 shown in FIG. 1 has two nozzle rows Na and Nb in which a plurality of nozzles 4n are arranged as shown in FIG. One nozzle row Na of the recording head 4a ejects black (K) droplets, and the other nozzle row Nb ejects cyan (C) droplets. One nozzle row Na of the recording head 4b ejects magenta (M) droplets, and the other nozzle row Nb ejects yellow (Y) droplets.

The maintenance / recovery mechanism 20b that wipes the nozzle-forming surface is an example of the wiping device, and as shown in FIG. 3, the sheet-shaped wiping member 320 and the sending roller 410 that feeds out the sheet-shaped wiping member 320, which are examples of the wiping members. The cleaning droplet lowering device 430, which is an example of the cleaning liquid applying means for executing the cleaning liquid applying step of applying the cleaning liquid to the sent out sheet-shaped wiping member 320, and the sheet-shaped wiping member 320 to which the cleaning liquid is applied are pressed against the nozzle forming surface. It has a pressing roller 400, which is an example of the pressing means, and a winding roller 420 for collecting the sheet-shaped wiping member 320 used for wiping. The cleaning liquid is supplied from a cleaning liquid storage container that stores the cleaning liquid via a cleaning liquid supply tube provided with a pump for supplying the cleaning liquid on the way. The mechanism 20b for wiping the nozzle forming surface may include a rubber blade or the like for wiping the nozzle forming surface in addition to the sheet-shaped wiping member 320. Further, the pressing roller 400 can adjust the pressing force by adjusting the distance between the cleaning portion and the nozzle forming surface by using a spring. The pressing member is not limited to the roller, and may be a fixed resin or rubber member. When a rubber blade or the like is provided, a mechanism for bringing the rubber blade or the like into contact with the sheet-shaped wiping member 320 may be provided so that the sheet-shaped wiping member 320 has a cleaning function for the rubber blade or the like. Further, from the viewpoint of miniaturization, the sheet-shaped wiping member is preferably stored in a rolled state as shown in FIG. 3, but is not limited to this, and is stored in a folded state. There may be. Further, the cleaning liquid applying means may be a means other than the cleaning droplet lowering device, and examples thereof include a cleaning liquid applying roller for applying the cleaning liquid with a roller, a cleaning liquid applying spray for applying the cleaning liquid with a spray, and the like. Further, the cleaning liquid applying step executed by the cleaning liquid applying means is not particularly limited as long as it is a step in which the cleaning liquid can be applied to the nozzle forming surface, and the cleaning liquid is indirectly applied via the cleaning liquid applying means as in the above embodiment. In addition to the step of applying the cleaning liquid, a step of directly applying the cleaning liquid to the nozzle forming surface may be used, but a step of indirectly applying the cleaning liquid via the cleaning liquid applying means is preferable. The wiping device does not have to have the cleaning droplet lowering device 430.

In the present embodiment, as an example of the wiping process, after applying a certain amount of cleaning liquid to the wiping member, the maintenance / recovery mechanism 20b and the recording head 4 move relatively while the wiping member is pressed against the nozzle forming surface to move the nozzle. It is preferable that the step of wiping off the foreign matter 500 adhering to the forming surface is executed. The foreign matter 500 adhering to the nozzle forming surface includes mist ink generated when ink is ejected from the nozzle, ink adhering when ink is sucked from the nozzle for cleaning or the like, mist ink, and ink adhering to the cap member. Examples include fixed ink dried on the nozzle surface and paper dust generated from the printed matter. In the present embodiment, the foreign matter 500 is wiped after the cleaning liquid is applied to the wiping member that does not contain the cleaning liquid. However, by using the wiping member that contains the cleaning liquid in advance, the cleaning liquid applying means may not be used. .. Further, the place where the cleaning liquid is applied may be other than the wiping member, and may be applied directly to the nozzle forming surface. That is, when the term "cleaning liquid applied to the nozzle forming surface" is mentioned, it means the cleaning liquid of all aspects applied to the nozzle forming surface as a result, for example, the cleaning liquid directly applied to the nozzle forming surface. Examples thereof include a cleaning liquid indirectly applied to the nozzle forming surface via a wiping member containing a cleaning liquid, and a cleaning liquid indirectly applied to the nozzle forming surface via a wiping member containing a cleaning liquid is preferable. Further, if it is assumed that the ink is dried and stuck on the nozzle forming surface due to the standby state for a long time, it can be removed by wiping the nozzle forming surface a plurality of times with a wiping member containing a cleaning liquid. It is preferably configured. In addition to the step of wiping the nozzle-forming surface with the cleaning liquid, there may be an additional step of wiping the nozzle-forming surface without using the cleaning liquid. Further, the step may be a step of wiping the nozzle forming surface without using a cleaning liquid.

<Wipe member>
Next, the wiping member will be described with reference to FIG. FIG. 4 is a diagram schematically showing an example of a cross section of a sheet-shaped wiping member. The wiping member 700 shown in FIG. 4 is, for example, a two-layer non-woven fabric having a first layer 710 having a surface in contact with the nozzle forming surface for wiping the nozzle forming surface of the liquid discharge head, and a nozzle forming. It has a second layer 720 (a layer other than the first layer) having a back surface that does not come into contact with the surface. In addition to this, for example, a three-layer structure in which a film is lined for the purpose of preventing show-through of absorbed ink and improving the strength of a wiping member, or a multi-layer structure in which a plurality of absorption layers having different absorbency are provided in the second and subsequent layers. And so on. That is, the wiping member may be composed of at least two layers and may have at least one layer other than the first layer.

Examples of the material constituting the wiping member include a woven cloth, a knitted cloth, and a porous body in addition to the non-woven fabric. In particular, it is preferable to use a non-woven fabric in which the thickness and porosity are relatively easy to control and various types of fibers can be easily blended. Examples of fiber materials such as non-woven fabrics, woven fabrics, and knitted fabrics include cotton, linen, silk, pulp, nylon, vinylon, polyester, polypropylene, polyethylene, rayon, cupra, acrylic, and polylactic acid. Not only a non-woven fabric composed of one type of fiber, but also a non-woven fabric in which a plurality of types of fibers are mixed may be used. Examples of the porous body include polyurethane, polyolefin, PVA and the like. As an example of a method for manufacturing a wiping member, a case where the wiping member is a non-woven fabric will be described. Examples of the method for forming the non-woven fabric include wet, dry, spunbond, melt blown, and flash spinning methods. In addition, examples of the method for bonding the non-woven fabric include methods such as spunlace, needle punch, thermal bond, and chemical bond. The spunlace method is a manufacturing method in which a jet water stream is jetted onto the deposited fibers, and the fibers are entangled with each other by the pressure to be bonded in a sheet shape. The needle punching method is a manufacturing method in which the deposited fibers are mechanically entwined with each other by piercing the deposited fibers with a needle having a protrusion called a barb several tens of times or more to form a non-woven fabric.

Further, since the porosity of the first layer is smaller than the porosity of at least one layer other than the first layer, the scraping property with respect to the fixed ink is improved, and the wiping property of the fixed ink is improved. Here, the porosity is calculated as follows.
In the case of a sheet-shaped non-woven fabric or the like, the above-mentioned "true density" is the true density of the fibers forming the sheet, and the "apparent density" is the "weighting" from the basis weight and thickness of the sheet-shaped material. Amount ÷ thickness] can be calculated.

The wiping member has a thin thickness and a small porosity, so that the sticking ink can be easily scraped off. However, when the thickness is thin and the porosity is small, it becomes difficult to retain liquid components such as ink and cleaning liquid, and as a result, the cleaning property becomes insufficient with a single layer. Therefore, it is preferable to provide a layer capable of retaining the liquid component in a layer other than the first layer. Further, as described above, by making the porosity of the first layer smaller than the porosity of at least one layer other than the first layer between the layers of the wiping member, the sticking ink wiping property is improved. Further, by making the porosity of the first layer smaller than the porosity of all the layers other than the first layer, the adhesive wiping property is further improved. Further, the thickness of the first layer is thinner than the total thickness of the layers other than the first layer. As a result, the adhesive wiping property is further improved.

The porosity of the first layer is preferably 0.60 or more and 0.85 or less, and more preferably 0.75 or more and 0.80 or less. When the porosity of the first layer is 0.60 or more and 0.85 or less, the wiping property of the fixed ink can be improved, and the wiping member does not form a film that does not allow the liquid to permeate, and is transparent. Can be improved.
Further, the porosity of at least one layer other than the first layer is preferably 0.80 or more and 0.99 or less. When the porosity of the layers other than the first layer is within the above range, the absorbability of the liquid can be improved. By combining these first layers and layers other than the first layer, it is possible to achieve both the scraping property of the fixed ink and the absorption property of the liquid, and to improve the wiping property. The porosity of all layers other than the first layer is preferably within the above range.

The thickness of the wiping member is preferably 0.1 mm or more and 3.0 mm or less, and more preferably 0.2 mm or more and 0.7 mm or less. When the thickness of the wiping member is 0.1 mm or more, the saturated water absorption amount of the liquid per predetermined area of the wiping member becomes sufficient, and the ink to be wiped can be sufficiently absorbed. Further, when the thickness of the wiping member is 3.0 mm or less, the liquid component of the ink is suitably moved from the first layer to the layer other than the first layer, and the liquid component is transferred to the layer other than the first layer. The effect of being able to absorb the water is not impaired, and the device can be miniaturized.

<Liquid>
Ink will be described as an example of the liquid mounted on the liquid ejection device. The liquid is not limited to the ink applied to the recording medium, for example, a pretreatment liquid applied to the recording medium before ink ejection, a posttreatment liquid applied to the ink ejection surface of the recording medium after ink ejection, and the like. It may be.
The liquid contains a polyether-modified silicone compound, and if necessary, contains an organic solvent, water, a coloring material, a resin, a surfactant, an antifoaming agent, an antiseptic / anticorrosive material, an anticorrosive material, a pH adjuster, and the like. Is preferable.
It is preferable that the ink as an example of the liquid is filled in the ink container which is an example of the liquid container and mounted on the liquid ejection device.

-Polyether-modified silicone compound-
The liquid contains a polyether-modified silicone compound. By containing the polyether-modified silicone compound, the adhered matter that the liquid has dried and adhered to on the nozzle forming surface can be easily removed, and the discharge stability of the liquid is improved.

The hydrophobic value of the polyether-modified silicone compound represented by the following mathematical formula (1) is preferably 0.40 or more and 1.50 or less, and more preferably 0.40 or more and 1.20 or less.
In the formula (1), A represents an integrated value of the polyether-modified silicone compound at 0 ppm to 0.3 ppm in a 1H-NMR spectrum using tetramethylsilane (TMS) as a reference material. Further, B represents an integral value of the polyether-modified silicone compound at 3.5 ppm to 4.0 ppm in a 1H-NMR spectrum using tetramethylsilane (TMS) as a reference material. The integrated value does not include the integrated value of the peaks of tetramethylsilane (TMS), which is a reference substance, and the spinning side band of TMS. In addition, 1H-NMR was measured using "JEOL JNM-A400FT NMR SYSTEM" manufactured by JEOL Ltd., with a sample concentration of 1% by mass, deuterated chloroform (CDCl3) as a solvent, and 128 integrations at room temperature. However, if the solubility of the sample is insufficient, use a solvent that can ensure solubility in the order of DMSO, DMF-d7, THF-d8, acetone-d6, methanol-d4, heavy water, and hexane-d14. I decided to. The hydrophobic value is a value rounded to the third decimal place.

Here, the integrated value of 3.5 ppm to 4.0 ppm in the 1H-NMR spectrum corresponds to the number of hydrogen atoms in the hydrophilic portion such as polyoxyethylene or polyoxypropylene in the polyether-modified silicone compound, and corresponds to 0 ppm to 0.3 ppm. The integrated value of corresponds to the number of hydrogen atoms of the alkyl group (hydrophobic moiety) bonded to the Si element in the polyether-modified silicone compound. By setting the hydrophobic value, which is the ratio (A / B) of the integrated value of 0 ppm to 0.3 ppm to the integrated value of 3.5 ppm to 4.0 ppm, to 0.40 or more, the hydrophobic portion in the polyether-modified silicone compound is set. The proportion increases. As a result, the polyether-modified silicone compound is easily adsorbed on the resin or the like having a hydrophobic surface in the liquid, the surface of the resin or the like is made hydrophilic, and the nozzle forming surface (ink-repellent layer) of the liquid discharge head having a hydrophobic surface. ) Can be prevented from sticking to the resin or the like.
On the other hand, by setting the hydrophobic value, which is the ratio (A / B) of the integrated value of 0 ppm to 0.3 ppm to the integrated value of 3.5 ppm to 4.0 ppm, to 1.50 or less, the content of the polyether-modified silicone compound can be reduced. The proportion of hydrophilic sites increases. As a result, the surface can be made hydrophilic with respect to the resin or the like on which the polyether-modified silicone compound is adsorbed in the liquid, and the resin or the like on the nozzle forming surface (ink-repellent layer) of the liquid discharge head whose surface is hydrophobic. Can be suppressed from sticking.

The polyether-modified silicone compound preferably has a polyoxyalkylene group which is an adduct of ethylene oxide and propylene oxide in the side chain of dimethylpolysiloxane. Further, as the polyether-modified silicone compound, a commercially available product can be used. Examples of the commercially available product include DOWN CORNING TORAY L-7604 (manufactured by Toray Dow Corning Co., Ltd., hydrophobic value: 0.47) and KF-353 (Shin-Etsu). Manufactured by Chemical Industry Co., Ltd., hydrophobic value: 1.03) and the like.

From the viewpoint of discharge stability, the content of the polyether-modified silicone compound in the liquid is preferably 0.05% by mass or more and 3.0% by mass or less, and 1.0% by mass or more and 3.0% by mass or more, based on the total amount of the liquid. % Or less is more preferable.

-Resin-
The liquid may contain a resin. The type of resin contained in the liquid is not particularly limited and may be appropriately selected depending on the intended purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene. Examples thereof include based resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.

Resin particles made of these resins may be used. It is possible to obtain a liquid such as ink by mixing resin particles with a material such as a coloring material or an organic solvent in the state of a resin emulsion in which water is dispersed as a dispersion medium. As the resin particles, those synthesized as appropriate may be used, or commercially available products may be used. Further, these may be used alone or in combination of two or more kinds of resin particles.

The resin can be mixed with a material such as an organic solvent to obtain a liquid such as ink in the state of a resin emulsion in which water is dispersed as a dispersion medium. As the resin, a synthetic resin may be used, or a commercially available product may be used.

The volume average particle diameter of the resin particles is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good fixability and high image hardness, 10 nm or more and 1,000 nm or less are preferable. More than 200 nm is more preferable, and 10 nm or more and 100 nm or less is particularly preferable.
The volume average particle size can be measured using, for example, a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

The content of the resin is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of fixability and storage stability of the liquid, 1% by mass or more and 30% by mass or less with respect to the total amount of the liquid. Is preferable, and 5% by mass or more and 20% by mass or less is more preferable.

The mass ratio (resin / polyether-modified silicone compound) between the content of the resin in the liquid and the content of the polyether-modified silicone compound in the liquid is preferably 1.60 or more and 800.00 or less. It is more preferably 60 or more and 10.00 or less, and further preferably 2.60 or more and 8.00 or less.

-Organic solvent-
The organic solvent that can be used for the liquid is not particularly limited, but a water-soluble organic solvent can be used. Examples thereof include ethers such as polyhydric alcohols, polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds.
Specific examples of polyhydric alcohols include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol , 2,4-Pentanediol, 1,5-Pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, Glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl- Examples thereof include 1,3-pentanediol and petriol.
Examples of polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether.
Examples of polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-butyrolactone. Can be mentioned.
Examples of the amides include formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide and the like.
Examples of amines include monoethanolamine, diethanolamine, triethylamine and the like.
Examples of sulfur-containing compounds include dimethyl sulfoxide, sulfolane, thiodiethanol and the like.
Examples of other organic solvents include propylene carbonate and ethylene carbonate.
It is preferable to use an organic solvent having a boiling point of 250 ° C. or lower because it not only functions as a wetting agent but also has good drying properties.

As the organic solvent, a polyol compound having 8 or more carbon atoms and a glycol ether compound are also preferably used. Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.
Specific examples of the glycol ether compound include polyvalent alcohol alkyls such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Ethers: Polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether can be mentioned.

The polyol compound having 8 or more carbon atoms and the glycol ether compound can improve the permeability of the liquid when paper is used as the recording medium.

The content of the organic solvent in the liquid is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of the drying property and discharge reliability of the liquid, 10% by mass or more and 60% by mass with respect to the total amount of the liquid. % Or less is preferable, and 20% by mass or more and 60% by mass or less is more preferable.

-Water-
The content of water in the liquid is not particularly limited and may be appropriately selected depending on the intended purpose, but from the viewpoint of drying property and discharge reliability of the liquid, it is 10% by mass or more and 90% by mass or less with respect to the total amount of the liquid. Is preferable, and 20% by mass or more and 60% by mass or less is more preferable.

-Color material-
The coloring material is not particularly limited, and pigments and dyes can be used. As the pigment, an inorganic pigment or an organic pigment can be used. These may be used alone or in combination of two or more. Further, a mixed crystal may be used as the pigment.

As the pigment, for example, black pigment, yellow pigment, magenta pigment, cyan pigment, white pigment, green pigment, orange pigment, glossy color pigment such as gold or silver, metallic pigment and the like can be used.
Inorganic pigments include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, as well as carbon black produced by known methods such as the contact method, furnace method, and thermal method. Can be used.
Examples of organic pigments include azo pigments and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.). , Dye chelate (for example, basic dye type chelate, acidic dye type chelate, etc.), nitro pigment, nitroso pigment, aniline black and the like can be used. Among these pigments, those having a good affinity with a solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.

As a specific example of the pigment, for black, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11) , Metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).
Further, for color, C.I. I. Pigment Yellow 1,3,12,13,14,17,24,34,35,37,42 (yellow iron oxide), 53,55,74,81,83,95,97,98,100,101,104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium Red), 112, 114, 122 (Quinacridone Magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, C.I. I. Pigment Violet 1 (Rhodamine Lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3, 15: 4 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment Greens 1, 4, 7, 8, 10, 17, 18, 36, etc.

The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used, and one type may be used alone or two or more types may be used in combination.
As a dye, for example, C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52,80,82,249,254,289, C.I. I. Acid Blue 9,45,249, C.I. I. Acid Black 1,2,24,94, C.I. I. Food Black 1, 2, C.I. I. Direct Yellow 1,12,24,33,50,55,58,86,132,142,144,173, C.I. I. Direct Red 1,4,9,80,81,225,227, C.I. I. Direct Blue 1,2,15,71,86,87,98,165,199,202, C.I. I. Dylekdo Black 19,38,51,71,154,168,171,195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive Black 3, 4, 35 can be mentioned.

The content of the coloring material in the liquid is preferably 0.1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass, from the viewpoint of improving the image density, good fixing property and ejection stability. It is as follows.

As a method of dispersing the pigment to obtain a liquid such as ink, a method of introducing a hydrophilic functional group into the pigment to obtain a self-dispersing pigment, a method of coating the surface of the pigment with a resin and dispersing it, and a dispersant are used. There is a method of dispersing the ink.
As a method of introducing a hydrophilic functional group into a pigment to obtain a self-dispersing pigment, for example, a method of adding a functional group such as a sulfone group or a carboxyl group to a pigment (for example, carbon) so that the pigment can be dispersed in water. Can be mentioned.
Examples of the method of coating the surface of the pigment with a resin and dispersing the pigment include a method of encapsulating the pigment in microcapsules so that the pigment can be dispersed in water. This can be rephrased as a resin coating pigment. In this case, all the pigments to be blended in the liquid need not be coated with the resin, and the uncoated pigments and the partially coated pigments are dispersed in the liquid as long as the effects of the present invention are not impaired. May be.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low molecular weight dispersant and a high molecular weight dispersant represented by a surfactant. As the dispersant, for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant and the like can be used depending on the pigment. As the dispersant, RT-100 (nonionic surfactant) manufactured by Takemoto Oil & Fat Co., Ltd. and a naphthalene sulfonate Na formalin condensate can also be preferably used as the dispersant. One type of dispersant may be used alone, or two or more types may be used in combination.

--Pigment dispersion ---
It is possible to obtain a liquid such as ink by mixing a material such as resin, water, or an organic solvent with a pigment, but a resin is obtained by mixing a pigment with water or a dispersant to form a pigment dispersion. It is also possible to produce a liquid such as ink by mixing materials such as water and an organic solvent. The pigment dispersion is obtained by mixing and dispersing water, a pigment, a pigment dispersant, and other components as necessary, and adjusting the particle size. It is preferable to use a disperser for dispersion.
The particle size of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency is 20 nm or more in terms of the maximum number because the dispersion stability of the pigment is good and the image quality such as ejection stability and image density is also high. It is preferably 500 nm or less, more preferably 20 nm or more and 150 nm or less. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).
The content of the pigment in the pigment dispersion is not particularly limited and can be appropriately selected depending on the intended purpose, but is 0.1% by mass from the viewpoint of obtaining good ejection stability and increasing the image density. It is preferably 50% by mass or more, and more preferably 0.1% by mass or more and 30% by mass or less.
It is preferable to degas the pigment dispersion by filtering the coarse particles with a filter, a centrifuge, or the like, if necessary.
The particle size of the solid content in the liquid is not particularly limited and may be appropriately selected depending on the intended purpose. From the viewpoint of improving image quality such as ejection stability and image density, the maximum frequency of the particle size of the solid content in the liquid is preferably 20 nm or more and 1000 nm or less, and more preferably 20 nm or more and 150 nm or less in terms of the maximum number. The solid content includes resin particles, pigment particles, and the like. The particle size can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

<Additives>
If necessary, a surfactant, an antifoaming agent, an antiseptic / antifungal agent, a rust preventive, a pH adjuster, or the like may be added to the liquid.

-Surfactant-
As the surfactant, any of a silicone-based surfactant, a fluorine-based surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant can be used.
The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Of these, those that do not decompose even at high pH are preferable. Examples of the silicone-based surfactant include side-chain modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, one-ended modified polydimethylsiloxane, and side-chain double-ended modified polydimethylsiloxane. Those having a polyoxyethylene group and a polyoxyethylene polyoxypropylene group as the modifying group are particularly preferable because they exhibit good properties as an aqueous surfactant. Further, as the silicone-based surfactant, a polyether-modified silicone-based surfactant can also be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the Si portion side chain of dimethylsiloxane.
The fluorine-based surfactant has, for example, a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. A polyoxyalkylene ether polymer compound is particularly preferable because it has a low foaming property. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonic acid salt. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a poly having a perfluoroalkyl ether group in the side chain. Examples thereof include salts of oxyalkylene ether polymers. The counter ions of the salts in these fluorine-based surfactants are Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH). _3rd grade can be mentioned.
Examples of the amphoteric surfactant include laurylaminopropionate, lauryldimethylbetaine, stearyldimethylbetaine, and lauryldihydroxyethylbetaine.
Examples of the nonionic surfactant include polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, and polyoxyethylene sorbitan. Examples thereof include ethylene oxide adducts of fatty acid esters and acetylene alcohols.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, polyoxyethylene alkyl ether sulfate salt and the like.
These may be used alone or in combination of two or more.

The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain-modified polydimethylsiloxane, double-ended polydimethylsiloxane, one-ended modified polydimethylsiloxane, side chain. Examples thereof include both-terminal modified polydimethylsiloxane, and a polyether-modified silicone-based surfactant having a polyoxyethylene group and a polyoxyethylene polyoxypropylene group as modifying groups is particularly preferable because it exhibits good properties as an aqueous surfactant. ..
As such a surfactant, an appropriately synthesized one may be used, or a commercially available product may be used. As commercially available products, for example, they can be obtained from Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Chemical Co., Ltd., and the like.
The above-mentioned polyether-modified silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the polyalkylene oxide structure represented by the general formula (S-1) is dimethylpoly. Examples thereof include those introduced into the Si part side chain of siloxane.
(However, in the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R'represents an alkyl group.)
Commercially available products can be used as the above-mentioned polyether-modified silicone-based surfactant, for example, KF-618, KF-642, KF-643 (Shinetsu Chemical Industry Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Big Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.) and the like can be mentioned.

As the fluorine-based surfactant, a compound having 2 to 16 carbon atoms substituted with fluorine is preferable, and a compound having 4 to 16 carbon atoms substituted with fluorine is more preferable.
Examples of the fluorine-based surfactant include a perfluoroalkyl phosphate compound, a perfluoroalkylethylene oxide adduct, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain. Among these, polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain are preferable because they have low foaming property, and are particularly fluorine-based compounds represented by the general formulas (F-1) and (F-2). Surfactants are preferred.
In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10, and n is preferably an integer of 0 to 40 in order to impart water solubility.
In the compound represented by the above general formula (F-2), Y is H or CmF _{2m + 1} and m is an integer of 1 to 6, or CH ₂ CH (OH) CH _2- CmF _{2m + 1} and m is 4 to 6. It is an integer, or CpH _{2p + 1} and p is an integer of 1-19. n is an integer of 1-6. a is an integer of 4 to 14.
Commercially available products may be used as the above-mentioned fluorine-based surfactant. Examples of this commercially available product include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Full Lard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Ltd.); Megafuck F-470, F -1405, F-474 (all manufactured by Daikin Industries, Ltd.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by The Chemours Company); FT-110, FT-250, FT-251, FT-400S, FT-150, FT- 400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omniova), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.) Among these, FS-3100, FS-34, FS-300 manufactured by The Chemours Company, FT-110, FT-250, FT-251, FT-400S, FT-150 manufactured by Neos Co., Ltd. FT-400SW, Polyfox PF-151N manufactured by Omninova, and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferable.

The content of the surfactant in the liquid is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.001% by mass or more and 5% by mass or less, and 0.05% by mass or more and 5% by mass. % Or less is more preferable.

-Defoamer-
The defoaming agent is not particularly limited, and examples thereof include a silicone-based defoaming agent, a polyether-based defoaming agent, and a fatty acid ester-based defoaming agent. These may be used alone or in combination of two or more. Among these, a silicone-based defoaming agent is preferable because it has an excellent defoaming effect.

-Preservatives and fungicides-
The antiseptic and antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

-Rust inhibitor-
The rust preventive is not particularly limited, and examples thereof include acidic sulfites and sodium thiosulfate.

-PH regulator-
The pH adjusting agent is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

-Physical properties of liquid-
The physical properties of the liquid are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the viscosity, surface tension, pH and the like are preferably in the following ranges.
The viscosity of the liquid at 25 ° C. is preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa · s or less, from the viewpoint of improving the print density and character quality and obtaining good ejection properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. As the measurement conditions, it is possible to measure at 25 ° C. with a standard cone rotor (1 ° 34'x R24), a sample liquid volume of 1.2 mL, a rotation speed of 50 rpm, and 3 minutes.
The surface tension of the liquid is preferably 35 mN / m or less, more preferably 32 mN / m or less at 25 ° C. from the viewpoint that the liquid is preferably leveled on the recording medium and the drying time of the liquid is shortened.
The pH of the liquid is preferably 7 to 12, more preferably 8 to 11, from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

<Cleaning liquid>
The cleaning liquid that may be mounted on the wiping device preferably contains an organic solvent, water, a surfactant, an antifoaming agent, an antiseptic / antifungal material, an anticorrosive material, a pH adjuster, and the like. By directly or indirectly applying the cleaning liquid to the nozzle-forming surface and then wiping with the wiping member, the viscosity of the adhered matter formed on the nozzle-forming surface is reduced and removal becomes easy. It is preferable that the cleaning liquid is filled in the cleaning liquid storage container and mounted on the wiping device.
The organic solvent, water, surfactant, defoaming agent, antiseptic / antifungal material, rust preventive material, and pH adjuster that can be contained in the cleaning liquid can be used in the same manner as the liquids such as the above inks. The description will be omitted.

<Recording medium>
The recording medium to which the liquid is applied is not particularly limited, and plain paper, glossy paper, special paper, cloth, or the like can be used, but good image formation is possible even if a non-permeable base material is used.
The non-permeable base material is a base material having a surface having low water permeability and low absorbability, and includes a material that does not open to the outside even if there are many cavities inside, and more quantitatively, A substrate having a water absorption of 10 mL / m ² or less from the start of contact to 30 msec ^1/2 in the Bristow method.
As the non-permeable base material, for example, a plastic film such as a vinyl chloride resin film, a polyethylene terephthalate (PET) film, polypropylene, polyethylene, or a polycarbonate film can be preferably used.
Recording media are not limited to those used as general recording media, but wallpaper, flooring materials, etc.
Building materials such as tiles, cloths for clothing such as T-shirts, textiles, leather and the like can be appropriately used. Further, ceramics, glass, metal, or the like can be used by adjusting the configuration of the path for transporting the recording medium.

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

<Ink adjustment>
-Adjustment of black pigment dispersion-
Carbon black manufactured by Tokai Carbon Co., Ltd .: 100 g of Seast SP (SRF-LS) is added to 3000 mL of a 2.5 N (specified) sodium hypochlorite solution, stirred at a temperature of 60 ° C. and a speed of 300 rpm, and reacted for 10 hours. Oxidation treatment was carried out to obtain a pigment having a carboxylic acid group on the surface of carbon black. This reaction solution was filtered, and the filtered carbon black was neutralized with a sodium hydroxide solution, and ultrafiltration was performed. Next, ultrafiltration with a dialysis membrane was performed using the obtained pigment dispersion and ion-exchanged water, and further ultrasonic dispersion was performed to concentrate the pigment solid content to 20%, which is a black pigment having a volume average particle size of 100 nm. A dispersion was obtained.

-Adjustment of urethane resin emulsion-
As the urethane resin emulsion, Takelac W-6110 (manufactured by Mitsui Chemicals, Inc., D50 particle size: 30 nm, Tg: -10 ° C.) was used.

-Adjustment of acrylic resin emulsion-
As the acrylic resin emulsion, Movinyl 6969D (Nippon Synthetic Chemistry, D50 particle size: 100 nm) was used.

-Preparation of polyether-modified silicone compounds-
KF-353 (manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the polyether-modified silicone compound.

-Adjustment of black ink-
The black ink was prepared by mixing and stirring with the formulation as shown in Table 1 below and filtering with a 0.5 μm polypropylene filter. The following surfactants and antiseptic and antifungal agents were used. In addition, the numerical value of each prescription in Table 1 represents mass%. Further, "-" in Table 1 indicates that the addition amount of the corresponding formulation is 0%.
-FS-300 (Fluorine-based surfactant, manufactured by DuPont)
・ Proxel LV (manufactured by Lonza Japan)

<Manufacturing of wiping member>
A sheet-shaped non-woven fabric made of the materials shown in Table 2 below was prepared and bonded as the first layer and the second layer to prepare a wiping member.

(Examples 1 to 11, Comparative Examples 1 to 3)
The produced black ink and the wiping member were combined as shown in Table 2 below, and the wiping property evaluation and the ejection stability evaluation were performed as follows.

[Wipeability evaluation]
0.1 ml of the prepared ink shown in Table 1 was dropped on a nozzle plate of an inkjet head (trade name: MH5440, manufactured by Ricoh Co., Ltd.) and left to stand for 15 hours to prepare a nozzle plate to which the ink was fixed. Next, 20 μl / cm ² of a cleaning solution having the following composition was applied to the wiping member shown in Table 2, and then the surface of the nozzle plate was wiped with the wiping member. The conditions for wiping were a pressing force of 3 N and a wiping speed of 50 mm / s.
-Composition of cleaning solution-
-3-Methoxy-3-methyl-1-butanol (manufactured by Kuraray Co., Ltd.): 20% by mass
-Polyether-modified silicone surfactant (trade name: WET270, manufactured by Evonik Degussa Japan Co., Ltd.): 1% by mass
・ Ion-exchanged water: remaining amount

Next, the nozzle plate after wiping was visually observed, and the number of wiping times from which the fixed ink was removed was determined according to the following evaluation criteria. The evaluation is preferably C or higher. The results are shown in Table 2.
〔Evaluation criteria〕
A: Adhesive ink on the nozzle plate was removed by wiping 5 times or less B: Adhesive ink on the nozzle plate was removed by wiping 6 times or more and 7 times or less C: Wiping 8 times or more and 10 times or less Sticky ink on the nozzle plate was removed D: Sticky ink remained even after wiping 10 times

[Discharge stability evaluation]
An inkjet printer (trade name: IPSio GXe3300, manufactured by Ricoh Co., Ltd.) was filled with the prepared inks shown in Table 1. Next, the inkjet printer is placed in a constant temperature and humidity chamber, the environment inside the tank is set to a temperature of 32 ° C. and a humidity of 30% RH, and after printing 20 sheets of the following print pattern charts in succession, printing is not performed for 20 minutes. This state was repeated 50 times, and a total of 1,000 sheets were printed. Then, the vicinity of the nozzle was observed with a microscope, and the presence or absence of adhered substances was judged according to the following evaluation criteria. The print pattern is a chart in which the print area occupies 5% of the total area of the paper surface, and is printed with 100% duty. The printing conditions were set so that the recording density was 300 dpi and one-pass printing was performed. The evaluation is preferably B or higher. The results are shown in Table 2.
〔Evaluation criteria〕
A: No sticking material near the nozzle B: Sticking material near the nozzle C: Sticking material at the position covering the nozzle

3 Carriage 4, 4a, 4b Recording head 4n Nozzle 20 Maintenance / recovery mechanism 20b Nozzle forming surface wiping mechanism 41 Nozzle forming surface 320 Sheet-like wiping member 400 Pushing roller 410 Feeding roller 420 Winding roller 430 Cleaning droplet lowering device 500 Foreign matter

Japanese Unexamined Patent Publication No. 2014-188900

Claims (10)

A liquid discharge head that discharges liquid from the nozzle,
It has a wiping member for wiping the nozzle forming surface of the liquid discharge head.
The liquid contains a polyether-modified silicone compound and contains
The wiping member is composed of at least two layers.
The porosity of the first layer in contact with the nozzle forming surface is smaller than the porosity of at least one layer other than the first layer.
A liquid discharge device in which the thickness of the first layer is thinner than the total thickness of layers other than the first layer. The liquid discharge device according to claim 1, wherein the porosity of the first layer is 0.60 or more and 0.85 or less. The liquid discharge device according to claim 1 or 2, wherein the porosity of the first layer is 0.75 or more and 0.80 or less. The liquid discharge device according to any one of claims 1 to 3, wherein the porosity of at least one layer other than the first layer is 0.80 or more and 0.99 or less. The liquid discharge device according to any one of claims 1 to 4, wherein the first layer is made of a non-woven fabric. The liquid discharge device according to any one of claims 1 to 5, wherein the thickness of the wiping member is 0.1 mm or more and 3.0 mm or less. The liquid discharge device according to any one of claims 1 to 6, wherein the hydrophobic value of the polyether-modified silicone compound represented by the following mathematical formula (1) is 0.40 or more and 1.50 or less.
(However, in the above formula (1), A represents an integrated value of the polyether-modified silicone compound at 0 ppm to 0.3 ppm in a 1H-NMR spectrum using tetramethylsilane (TMS) as a reference material. , Represents the integrated value of the polyether-modified silicone compound at 3.5 ppm to 4.0 ppm in a 1H-NMR spectrum using tetramethylsilane (TMS) as a reference material.) The item according to any one of claims 1 to 7, wherein the content of the polyether-modified silicone compound in the liquid is 0.05% by mass or more and 3.0% by mass or less with respect to the total amount of the liquid. Liquid discharge device. The liquid contains a resin and
The mass ratio (resin / polyether-modified silicone compound) of the content of the resin in the liquid and the content of the polyether-modified silicone compound in the liquid is 2.60 or more and 10.00 or less. The liquid discharge device according to any one of claims 1 to 8. A wiping method including a wiping step of wiping the nozzle-forming surface of a liquid discharge head that discharges liquid from a nozzle with a wiping member.
The liquid contains a polyether-modified silicone compound and contains
The wiping member is composed of at least two layers.
The porosity of the first layer in contact with the nozzle forming surface is smaller than the porosity of at least one layer other than the first layer.
A wiping method in which the thickness of the first layer is thinner than the total thickness of the layers other than the first layer.