JP2019171744A - Image formation apparatus - Google Patents

Abstract

Provided is an image forming apparatus capable of efficiently wiping a fixed ink formed on a nozzle forming surface of an inkjet head by using a wiping member even if an ink containing a large amount of resin is used. An image forming apparatus includes: a discharge device that discharges an ink composition from a nozzle; and a wiping member that wipes off the ink composition that adheres to a nozzle forming surface of the discharge device. , The wiping member includes at least two layers each having a gap, the thickness of the first layer 610 from the side in contact with the nozzle forming surface is t1, and the thickness of 620 other than the first layer is 620. Where t1 <t2 is satisfied when the sum of the above is t2, and the porosity of the first layer is at least smaller than the porosity of one layer other than the first layer. [Selection diagram] FIG.

Description

  The present invention relates to an image forming apparatus.

Inkjet printers have advantages such as low noise, low running cost, and easy color printing, and are widely used as digital signal output devices.
In recent years, low and non-absorbent recording media such as coated paper and plastic films have been used as printed materials to which ink jet is applied, and inks for that purpose have been developed.

  However, when ink-jet printing is performed on these low / non-absorbent recording media, there is a problem that the ink fixing property is poor because osmotic drying does not occur. In order to cope with these problems, a technique for increasing the resin content in the ink is known.

  Further, in a liquid ejection apparatus typified by an ink jet printer, it is necessary to periodically clean the nozzle formation surface in order to cause problems such as ejection failure due to foreign matters on the nozzle formation surface. In particular, in the ink containing a large amount of resin as described above, foreign matters are likely to be generated on the nozzle forming surface. As a wiping member used for cleaning the nozzle forming surface, a method of cleaning by combining a sheet-like wiping member represented by a nonwoven fabric or a woven fabric is already known.

  Patent Document 1 describes a wiping member for preventing water-repellent film deterioration on a nozzle forming surface. The wiping member includes a first layer that contacts the nozzle formation surface and a second layer that is provided on the opposite side of the nozzle formation surface with respect to the first layer. Thus, the dispersion medium of the droplet on the nozzle forming surface is guided to the second layer by capillary action and absorbed, and the dispersoid is trapped in the voids of the first layer. Thereby, since the dispersoid is not pinched and wiped between the nozzle forming surface and the wiping member, it is possible to prevent deterioration of the water repellent film on the nozzle forming surface.

However, in the cleaning using the conventional wiping member, the wiping property of the fixed ink formed by drying the ink adhering to the nozzle forming surface is poor, and the water repellent film on the nozzle forming surface is increased by increasing the number of wiping or increasing the wiping pressure. There was a problem of deterioration. In particular, in the case of ink containing a large amount of resin for improving the fixability, fixed ink is likely to be generated, and the wiping property is poor.
An object of the present invention is to provide an image forming apparatus capable of efficiently wiping off a fixed ink formed on a nozzle forming surface of an inkjet head using a wiping member even when using an ink containing a large amount of resin. And

The above-mentioned problem can be solved by using the following image forming apparatus (1) according to the present invention as described below.
(1) An image forming apparatus comprising: a discharge device that discharges an ink composition from a nozzle; and a wiping member that wipes the ink composition adhering to a nozzle formation surface of the discharge device.
The ink composition contains 6.0% by mass or more of a resin;
The wiping member comprises at least two layers each having a void;
When the thickness of the first layer from the side in contact with the nozzle forming surface is t1, and the total thickness of the layers other than the first layer is t2, t1 <t2 holds,
The image forming apparatus wherein the porosity of the first layer is at least smaller than the porosity of one layer other than the first layer.

  According to the present invention, there is provided an image forming apparatus capable of improving the fixability to a recording medium and efficiently wiping off the fixed ink formed on the nozzle forming surface of the inkjet head using a wiping member. Can do.

FIG. 1 is a diagram illustrating an example of an image forming apparatus. FIG. 2 is a diagram illustrating an example of the configuration of the nozzle plate wiped by the wiping member. FIG. 3 is a diagram illustrating a schematic configuration of the cleaning unit of the image forming apparatus. FIG. 4 is a diagram schematically showing an example of a cross section of the sheet-like wiping member.

Although the present invention relates to the image forming apparatus described in (1) above, since the following (2) to (9) are included as embodiments of the invention, these embodiments will be described together.
(2) The image forming apparatus according to (1), wherein the ink composition contains 7.5% by mass or more of the resin.
(3) The image forming apparatus according to (1) or (2), wherein the ratio of the resin to the total solid content in the ink composition is 50% by mass or more.
(4) The image forming apparatus according to any one of (1) to (3), wherein the porosity of the first layer of the wiping member is 0.60 or more and 0.85 or less.
(5) The image forming apparatus according to any one of (1) to (4), wherein the porosity of the first layer of the wiping member is 0.75 or more and 0.80 or less.
(6) The image formation according to any one of (1) to (5), wherein a porosity of at least one layer other than the first layer of the wiping member is 0.80 or more and 0.99 or less. apparatus.
(7) The image forming apparatus according to any one of (1) to (6), wherein at least a first layer of the wiping member is made of a nonwoven fabric.
(8) The image forming apparatus according to any one of (1) to (7), wherein the wiping member has a thickness of 0.1 mm to 3 mm.
(9) The image forming apparatus according to any one of (1) to (8), wherein the resin is a polyurethane resin.

The present invention relates to an image forming apparatus having an ink composition (hereinafter also referred to as ink) and a wiping member for wiping a nozzle forming surface of an inkjet head, and has the following characteristics.
-The ink composition contains 6.0% by mass or more of resin.
-Each wiping member should contain at least 2 layers which have a space | gap.
T1 <t2 holds when the thickness of the first layer is t1 from the nozzle forming surface side and the total thickness of the layers other than the first layer is t2.
-The porosity of the first layer is at least smaller than the porosity of one layer other than the first layer.

First, an image forming apparatus using the wiping member of the present invention will be described.
The image forming apparatus of the present invention includes a discharge device that discharges an ink composition from a nozzle, and a wiping member that wipes the ink composition adhering to the nozzle formation surface of the discharge device.
As the ejection device, as an ink ejection head, a piezoelectric element is used as a pressure generating means for pressurizing the ink in the ink flow path, and the diaphragm that forms the wall surface of the ink flow path is deformed to change the volume in the ink flow path So-called piezo type that discharges ink droplets, or so-called thermal type that generates bubbles by heating ink in the ink flow path using a heating resistor, vibration that forms the wall surface of the ink flow path Electrostatic type that discharges ink droplets by changing the volume in the ink flow path by deforming the diaphragm with electrostatic force generated between the diaphragm and the electrode, with the plate and electrode facing each other Any of these ink discharge heads can be mounted.
In the present invention, the ink may be stored in an ink storage container such as an ink cartridge.

FIG. 1 shows an example of the image forming apparatus, which includes a serial type droplet discharge device. The image forming apparatus will be described with reference to FIGS.
A carriage 3 is movably held by a main guide member 1 and a secondary guide member that are horizontally mounted on the left and right side plates. The carriage 3 is reciprocated in the main scanning direction (carriage moving direction) by the main scanning motor 5 via the timing belt 8 spanned between the driving pulley 6 and the driven pulley 7.

  The carriage 3 is mounted with recording heads 4a and 4b (referred to as “recording head 4” when not distinguished), which are liquid ejection heads. For example, the recording head 4 ejects ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). The recording head 4 is mounted with nozzles 4n composed of a plurality of nozzles arranged in the sub-scanning direction orthogonal to the main scanning direction and with the droplet discharge direction facing 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.
As the liquid discharge head constituting the recording head 4, for example, a piezoelectric actuator such as a piezoelectric element, or a thermal actuator that uses a phase change caused by liquid film boiling using an electrothermal transducer such as a heating resistor can be used. .

  On the other hand, in order to transport the paper 10, a transport belt 12, which is transport means for electrostatically attracting the paper and transporting the paper at a position facing the recording head 4, is provided. The transport belt 12 is an endless belt and is stretched between the transport roller 13 and the tension roller 14.

  The transport belt 12 rotates in the sub-scanning direction when the transport roller 13 is rotationally driven by the sub-scanning motor 16 via the timing belt 17 and the timing pulley 18. The conveyor belt 12 is charged (charged) by a charging roller while moving around.

Further, a maintenance / recovery mechanism 20 that performs maintenance / recovery of the recording head 4 on the side of the conveyance belt 12 is arranged on one side of the carriage 3 in the main scanning direction, and the recording head 4 is arranged on the side of the conveyance belt 12 on the other side. The empty discharge receptacles 21 for performing empty discharge are respectively disposed.
The maintenance / recovery mechanism 20 includes, for example, a cap member 20a for capping the nozzle formation surface (surface on which the nozzles are formed) of the recording head 4, a mechanism 20b for wiping the nozzle formation surface, and an idle discharge for discharging droplets that do not contribute to image formation. It consists of a receiver.

  Further, an encoder scale 23 having a predetermined pattern is stretched between both side plates along the main scanning direction of the carriage 3, and the encoder sensor 24 is formed of a transmission type photosensor that reads the pattern of the encoder scale 23 on the carriage 3. Is provided. These encoder scale 23 and encoder sensor 24 constitute a linear encoder (main scanning encoder) that detects the movement of the carriage 3.

  Further, a code wheel 25 is attached to the shaft of the transport roller 13 and an encoder sensor 26 including a transmission type photo sensor for detecting a pattern formed on the code wheel 25 is provided. These code wheel 25 and encoder sensor 26 constitute a rotary encoder (sub-scanning encoder) that detects the amount and position of movement of the conveyor belt 12.

In this image forming apparatus configured as described above, the paper 10 is fed from the paper feed tray onto the charged transport belt 12 and sucked, and the paper 10 is transported in the sub-scanning direction by the circular movement of the transport belt 12. The
Therefore, by driving the recording head 4 according 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 sheet 10 is conveyed by a predetermined amount, the next line is recorded.
Upon receiving a recording end signal or a signal that the trailing edge of the paper 10 has reached the recording area, the recording operation is finished, and the paper 10 is discharged onto a paper discharge tray.

When cleaning the recording head 4, the carriage 3 is moved to the maintenance / recovery mechanism 20 during printing (recording) standby, and the maintenance / recovery mechanism 20 performs cleaning. The recording head 4 may not be moved, and the maintenance / recovery mechanism 20 may be moved 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 discharges black (K) droplets, and the other nozzle row Nb discharges cyan (C) droplets. One nozzle row Na of the recording head 4b discharges magenta (M) droplets, and the other nozzle row Nb discharges yellow (Y) droplets.

  As shown in FIG. 3, the mechanism 20b for wiping the nozzle forming surface mainly presses the sheet-like wiping member 320, the roller 410 for feeding the sheet-like wiping member, and the sent wiping member 320 against the nozzle forming surface. It comprises a pressing roller 400 and a winding roller 420 that collects the wiping member 320 used for wiping. In addition to the sheet-like wiping member, a rubber blade or the like for wiping the nozzle forming surface may be provided. The pressing roller 400 can adjust the pressing force by adjusting the distance between the cleaning unit and the nozzle forming surface using a spring. The pressing member is not limited to a 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-like wiping member may be provided so that the sheet-like wiping member has a cleaning function for the rubber blade or the like.

  After a certain amount of cleaning liquid is applied to the wiping member, the cleaning unit and the head move relative to each other while the wiping member is pressed against the nozzle forming surface, thereby wiping the foreign matter 500 adhering to the nozzle forming surface. Examples of the foreign matter 500 adhering to the nozzle forming surface include mist ink generated when ink is ejected from the nozzle, ink adhering when ink is sucked from the nozzle during cleaning, ink adhering to the mist ink and cap member. Examples thereof include fixed ink dried on the nozzle forming surface and paper dust generated from the substrate. The cleaning liquid may be included in the wiping member in advance. Further, depending on the sequence, the cleaning liquid may be wiped off without being applied. In particular, when it is assumed that the ink is dried and fixed on the nozzle formation surface due to a long-time standby or the like, it is desirable to wipe off the nozzle formation surface multiple times with a sheet-like wiping member containing a cleaning liquid. .

FIG. 4 schematically shows an example of a cross section of the sheet-like wiping member 320.
The sheet-like wiping member 320 shown in FIG. 4 is made of a nonwoven fabric and has a two-layer structure of a first layer 610 and a second layer 620 from the side in contact with the nozzle forming surface. Other than this, for example, a three-layer structure in which a film is lined for the purpose of preventing back-in absorption of absorbed ink and improving the strength of a wiping member, and a multilayer structure in which a plurality of absorption layers having different absorbencies are provided after the second layer, etc. But it ’s okay.

  The wiping member is preferably a wiping absorbing member that includes at least two layers each having a gap and wipes and absorbs ink. As a material constituting the layer having the gap of the wiping member, in addition to a nonwoven fabric, Examples thereof include a knitted fabric and a porous body. In particular, for the first layer, it is preferable to use a nonwoven fabric whose thickness and porosity can be controlled relatively easily. Examples of the fiber material such as nonwoven fabric, woven fabric, and knitted fabric include cotton, hemp, silk, pulp, nylon, vinylon, polyester, polypropylene, polyethylene, rayon, cupra, acrylic, polylactic acid, and the like. Not only the nonwoven fabric which consists of one type of fiber but the nonwoven fabric which mixed multiple types of fiber may be sufficient. Examples of the porous body include polyurethane, polyolefin, PVA and the like. As a method for producing a nonwoven fabric, for example, wet, dry, spunbond, meltblown, flash spinning and the like are used for web formation, and for web bonding, there are methods such as spunlace, thermal bond, chemical bond, needle punch and the like. It is done.

When the thickness of the first layer is t1 from the side in contact with the nozzle formation surface, and the total thickness of the layers other than the first layer is t2, t1 <t2 holds, and the porosity of the first layer is By being 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 fixed ink wiping property is improved. Here, the porosity is calculated as follows.
In the case of a sheet-like nonwoven fabric or the like, the above-mentioned “true density” is the true density of the fibers forming the sheet, and the “apparent density” is calculated from the basis weight and thickness of the sheet-like material. Amount divided by thickness].

  The wiping member for wiping off the fixed ink has a small thickness and a small porosity, so that the scraping property of the fixed ink is high.However, when the thickness is small and the porosity is small, liquid components such as ink and cleaning liquid are removed. As a result, the cleaning property is insufficient with a single layer. Then, an effect is acquired by having the part which can hold | maintain a liquid component in layers other than a 1st layer, and having the relationship of this invention between the layers of a wiping member.

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 and the liquid permeability is good. Can be.
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 liquid absorbability can be improved. By combining these first layer and layers other than the first layer, it is possible to achieve both the scraping property of the fixed ink and the absorbability of the liquid, and to improve the wiping property. It is preferable that at least one layer other than the first layer in which the porosity is 0.80 or more and 0.99 or less is the second layer. The porosity of the first layer is preferably smaller than the porosity of the second layer.

The thickness of the wiping member is preferably from 0.1 mm to 3 mm, more preferably from 0.2 mm to 0.7 mm. When the thickness of the wiping member is 0.1 mm or more, the saturated water absorption amount of the liquid per area of the wiping member becomes sufficient, and the ink to be wiped can be sufficiently absorbed. Further, since the thickness of the wiping member is 3 mm or less, the liquid component of the ink is preferably transferred from the first layer to a layer other than the first layer, and the liquid component is absorbed by the layers other than the first layer. The effect that can be achieved is not impaired, and the apparatus can be miniaturized.
It is preferable that at least the first layer of the wiping member is made of a nonwoven fabric. By using a non-woven fabric, the thickness and porosity can be easily set within a desired numerical range.

<Ink>
Hereinafter, the organic solvent, water, color material, resin, additive, and the like used for the ink will be described.

  The ink composition in the present invention contains 6.0% by mass or more of resin. By adding 6.0% by mass or more of the resin, high adhesion to the recording medium can be obtained.

<Resin>
The type of resin contained in the ink is not particularly limited and can be appropriately selected according to the purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene type Examples thereof include resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.
Resin particles made of these resins may be used. An ink can be obtained by mixing resin particles with a material such as a colorant or an organic solvent in a resin emulsion state in which water is dispersed as a dispersion medium. As a resin particle, what was synthesize | combined suitably may be used and a commercial item may be used. Moreover, these may be used individually by 1 type, or may be used in combination of 2 or more types of resin particles.

A polyurethane resin is preferable as the type of resin contained in the ink.
The polyurethane resin is a reactive product of polyisocyanate and polyol. A characteristic of the polyurethane resin is that it exhibits the performance of a soft segment made of a polyol component having a weak cohesive force and a hard segment made of a urethane bond having a strong cohesive force. The soft segment is soft and resistant to deformation of the base material such as stretching and bending. On the other hand, the hard segment has high adhesion to the substrate and is excellent in wear resistance.

As a kind of polyurethane resin, polyether type urethane resin, polyester type urethane resin, polycarbonate type urethane resin, etc. are mentioned, for example.
There is no restriction | limiting in particular as a kind of urethane resin particle contained in an ink composition, According to the objective, it can select suitably.

  It is possible to obtain a surface treatment composition by mixing resin particles made of these resins with a material such as an organic solvent in a resin emulsion state in which water is used as a dispersion medium. As said resin particle, what was synthesize | combined suitably may be used and a commercial item may be used.

The amount of resin added is preferably 7.5% by mass or more based on the total amount of the ink composition.
When the content is 7.5% by mass or more, the resin sufficiently adheres to the recording medium, and high fixability can be obtained even on a permeable recording medium and a low / non-absorbing recording medium.

  The resin content is preferably 6.0% by mass or more and 30% by mass or less, and more preferably 7.5% by mass or more and 20% by mass or less, based on the total amount of the ink, from the viewpoints of fixability and ink storage stability. preferable.

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

<Organic solvent>
The organic solvent used in the present invention is not particularly limited, and 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 the polyhydric alcohol include, for example, 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-1,3-pentanediol, petriol, and the like.
Examples of the 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, propylene glycol monoethyl ether and the like.
Examples of polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
Examples of nitrogen-containing heterocyclic compounds 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 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, and triethylamine.
Examples of sulfur-containing compounds include dimethyl sulfoxide, sulfolane, thiodiethanol and the like.
Examples of other organic solvents include propylene carbonate and ethylene carbonate.
In addition to functioning as a wetting agent, it is preferable to use an organic solvent having a boiling point of 250 ° C. or lower because good drying properties can be obtained.

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, 2,2,4-trimethyl-1,3-pentanediol, and the like.
Specific examples of the glycol ether compound 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 ethers include polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

  A polyol compound having 8 or more carbon atoms and a glycol ether compound can improve ink permeability when paper is used as a recording medium.

  The content of the organic solvent in the ink is not particularly limited and can be appropriately selected according to the purpose. However, from the viewpoint of ink drying property and ejection reliability, it is preferably 10% by mass or more and 60% by mass or less, 20 mass% or more and 60 mass% or less are more preferable.

<Water>
The water content in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% by mass or more and 90% by mass or less, and 20% by mass from the viewpoint of ink drying property and ejection reliability. % To 60% by mass is more preferable.

<Color material>
The color material is not particularly limited, and pigments and dyes can be used.
An inorganic pigment or an organic pigment can be used as the pigment. These may be used alone or in combination of two or more. A mixed crystal may be used as the pigment.
Examples of pigments that can be used include black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, glossy pigments such as gold and silver, and metallic pigments.
Carbon black produced by known methods such as contact method, furnace method, thermal method in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow as inorganic pigments Can be used.
Organic pigments include azo pigments, polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments). Dye chelates (for example, basic dye type chelates, acidic dye type chelates), nitro pigments, nitroso pigments, aniline black, and the like can be used. Of these pigments, those having good affinity with the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
Specific examples of pigments include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11). And metal pigments such as titanium oxide, and organic pigments such as aniline black (CI Pigment Black 1).
Further, for color use, 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 Green 1, 4, 7, 8, 10, 17, 18, 36, etc.
The dye is not particularly limited, and an acid dye, a direct dye, a reactive dye, and a basic dye can be used. One kind may be used alone, or two or more kinds may be used in combination.
Examples of the dye include 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. Directed 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, and 35 are mentioned.

  The content of the color material in the ink is preferably 15% by mass or less from the viewpoint of good fixability and ejection stability. More preferably, it is 10 mass% or less. The color material content of 0% by mass means that it can be used as a clear ink that does not contain a color material.

As a method of obtaining an ink by dispersing a pigment, a method of introducing a hydrophilic functional group into the pigment to form a self-dispersing pigment, a method of coating and dispersing the surface of the pigment with a resin, and a dispersing agent are used. Method, etc.
As a method of introducing a hydrophilic functional group into a pigment to obtain a self-dispersing pigment, for example, a method of making it dispersible in water by adding a functional group such as a sulfone group or a carboxyl group to the pigment (for example, carbon) Is mentioned.
As a method for coating the surface of the pigment with a resin and dispersing it, a method in which the pigment is included in microcapsules and dispersible in water can be mentioned. This can be paraphrased as a resin-coated pigment. In this case, it is not necessary that all pigments blended in the ink are coated with a resin, and within a range where the effects of the present invention are not impaired, uncoated pigments and partially coated pigments are dispersed in the ink. It may be.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular type dispersant or high-molecular type dispersant represented by a surfactant.
As the dispersant, for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, or the like can be used depending on the pigment.
As the dispersant, RT-100 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and Naphthalenesulfonic acid Na formalin condensate can also be suitably used as the dispersant.
A dispersing agent may be used individually by 1 type, or may use 2 or more types together.

<Pigment dispersion>
An ink can be obtained by mixing a material such as water or an organic solvent with a pigment. Further, it is also possible to produce an ink by mixing a pigment, other water, a dispersant, and the like into a pigment dispersion and mixing a material such as water or 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. For dispersion, a disperser is preferably used.
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 maximum number because the pigment dispersion stability is good and the image quality such as ejection stability and image density is also high. 500 nm or less is preferable and 20 nm or more and 150 nm or less are more preferable. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).
The content of the pigment in the pigment dispersion is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good ejection stability and increasing the image density, 0.1% by mass The content is preferably 50% by mass or less and more preferably 0.1% by mass or more and 30% by mass or less.
The pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifugal separator or the like, if necessary.

  The particle size of the solid content in the ink is not particularly limited and can be appropriately selected depending on the 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 ink 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 inhibitor, a pH adjuster, and the like may be added to the ink.

<Surfactant>
As the surfactant, any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants and anionic surfactants can be used.
There is no restriction | limiting in particular in silicone type surfactant, According to the objective, it can select suitably. Among them, those that do not decompose even at high pH are preferable. Examples of the silicone surfactant include side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, and side chain both terminal modified polydimethylsiloxane. Those having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group are particularly preferred because they exhibit good properties as an aqueous surfactant. Moreover, a polyether modified silicone surfactant can also be used as a silicone surfactant, for example, the compound etc. which introduce | transduced the polyalkylene oxide structure into the Si part side chain of dimethylsiloxane are mentioned.
Examples of the fluorosurfactant include 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. Polyoxyalkylene ether polymer compounds are particularly preferred because of their low foaming properties. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonate. Examples of the perfluoroalkyl carboxylic acid compound include perfluoroalkyl carboxylic acid and perfluoroalkyl carboxylate. 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 polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain. Examples thereof include salts of oxyalkylene ether polymers. As counter ions of salts in these fluorosurfactants, 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) ₃ etc. are mentioned.
Examples of amphoteric surfactants include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Nonionic surfactants include, for example, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan Examples include fatty acid esters and ethylene oxide adducts of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.
These may be used alone or in combination of two or more.

The silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, side chain Examples thereof include polydimethylsiloxane modified at both ends, and a polyether-modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group is particularly preferable because it exhibits good properties as an aqueous surfactant. .
As such a surfactant, an appropriately synthesized product or a commercially available product may be used. Commercially available products can be obtained from, for example, Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., and Kyoeisha Chemical Co., Ltd.
There is no restriction | limiting in particular as said polyether modified silicone surfactant, According to the objective, it can select suitably, For example, the polyalkylene oxide structure represented by a general formula (S-1) type | formula is dimethylpolyethylene. Examples thereof include those introduced into the side chain of Si part of siloxane.
(However, in the formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R ′ represents an alkyl group.)
A commercial item can be used as said polyether modified silicone type surfactant, For example, KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Japan 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 (Bic Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.), etc. are mentioned.

As the fluorine-based surfactant, a fluorine-substituted compound having 2 to 16 carbon atoms is preferable, and a fluorine-substituted compound having 4 to 16 carbon atoms is more preferable.
Examples of the fluorosurfactant include perfluoroalkyl phosphate compounds, perfluoroalkylethylene oxide adducts, and polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain. Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because of its low foaming property, and in particular, fluorine-based compounds represented by the general formulas (F-1) and (F-2) A surfactant is 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 general formula (F-2), Y is H, or C _m F _{2m + 1} , m is an integer of 1 to 6, or CH ₂ CH (OH) CH ₂ —C _m F _{2m + 1} and m is 4-6 integer, or p in _C p _{H 2p + 1} is 1 to 19 integer. n is an integer of 1-6. a is an integer of 4-14.
A commercial item may be used as said fluorosurfactant. As this commercial item, for example, Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F -1405, F-474 (all manufactured by Dainippon Ink & Chemicals, Inc.); 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 Chemours); 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 (Omnova) Manufactured), Unidyne DSN-403N (produced by Daikin Industries, Ltd.) and the like. Among these, good print quality, particularly color developability, penetrability to paper, wettability, and leveling are significantly improved. FS-3100, FS-34, FS-300 manufactured by Chemours, FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by Neos Co., Ltd. Particularly preferred are Fox PF-151N and Unidyne DSN-403N manufactured by Daikin Industries, Ltd.

  There is no restriction | limiting in particular as content of surfactant in an ink, Although it can select suitably according to the objective, From the point which is excellent in wettability and discharge stability, and image quality improves, it is 0.001 mass. % To 5% by mass is preferable, and 0.05% to 5% by mass is more preferable.

<Antifoaming agent>
There is no restriction | limiting in particular as an antifoamer, For example, a silicone type antifoamer, a polyether type | system | group antifoamer, a fatty-acid ester type | system | group antifoamer etc. are mentioned. These may be used alone or in combination of two or more. Among these, a silicone type antifoaming agent is preferable from the viewpoint of excellent foam breaking effect.

<Antiseptic and antifungal agent>
The antiseptic / antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

<Rust preventive>
There is no restriction | limiting in particular as a rust preventive agent, For example, acidic sulfite, sodium thiosulfate, etc. are mentioned.

<PH adjuster>
The pH adjuster 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.

There is no restriction | limiting in particular as a physical property of an ink, According to the objective, it can select suitably, For example, it is preferable that a viscosity, surface tension, pH, etc. are the following ranges.
The viscosity at 25 ° C. of the ink 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 printing density and character quality and obtaining good discharge properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. Measurement conditions are 25 ° C., standard cone rotor (1 ° 34 ′ × R24), sample liquid amount 1.2 mL, rotation speed 50 rpm, and measurement is possible for 3 minutes.
The surface tension of the ink is preferably 35 mN / m or less and more preferably 32 mN / m or less at 25 ° C. from the viewpoint that the ink is suitably leveled on the recording medium and the drying time of the ink is shortened.
The pH of the ink is preferably 7 to 12 and more preferably 8 to 11 from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

The recording apparatus can include not only a portion that ejects ink but also a device called a pre-processing device or a post-processing device.
As one mode of the pretreatment device and the posttreatment device, as in the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y), a pretreatment liquid and a posttreatment liquid are included. There is a mode in which a liquid container and a liquid discharge head are added, and a pretreatment liquid and a posttreatment liquid are discharged by an ink jet recording method.
As another aspect of the pretreatment apparatus and the posttreatment apparatus, there is an aspect in which, for example, a pretreatment apparatus or a posttreatment apparatus other than the ink jet recording method is provided by a blade coating method, a roll coating method, or a spray coating method.

<Pretreatment liquid>
The pretreatment liquid contains a flocculant, an organic solvent, and water, and may contain a surfactant, an antifoaming agent, a pH adjuster, an antiseptic / antifungal agent, an antirust agent, and the like as necessary.
For organic solvents, surfactants, antifoaming agents, pH adjusters, antiseptic / antifungal agents, and rust preventive agents, the same materials as those used for ink can be used, and other materials used for known processing liquids can be used. .
The type of the flocculant is not particularly limited, and examples thereof include water-soluble cationic polymers, acids, and polyvalent metal salts.

<Post-treatment liquid>
The post-treatment liquid is not particularly limited as long as a transparent layer can be formed. The post-treatment liquid is obtained by selecting and mixing an organic solvent, water, resin, surfactant, antifoaming agent, pH adjuster, antiseptic / antifungal agent, rust inhibitor, and the like as necessary. Further, the post-treatment liquid may be applied to the entire recording area formed on the recording medium, or may be applied only to the area where the ink image is formed.

<Recording medium>
The recording medium is not particularly limited, and plain paper, glossy paper, special paper, cloth, and the like can be used. Good image formation is possible even with a non-permeable substrate.
The non-permeable base material is a base material having a surface with low water permeability and absorbability, and includes materials that do not open to the outside even if there are many cavities inside, more quantitatively, In the Bristow method, it refers to a base material having a water absorption amount of 10 mL / m ² or less from the start of contact to 30 msec ^1/2 .
As the non-permeable substrate, 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.

  The recording medium is not limited to those used as general recording media, and wallpaper, flooring, building materials such as tiles, cloth for clothing such as T-shirts, textiles, leather, and the like can be used as appropriate. Moreover, ceramics, glass, metal, etc. can also be used by adjusting the structure of the path | route which conveys a recording medium.

<Recorded material>
The ink recorded matter of the present invention has an image formed using the ink of the present invention on a recording medium.
Recording can be performed by recording with an inkjet recording apparatus and an inkjet recording method.

The use of the ink of the present invention is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be applied to printed materials, paints, coating materials, foundations and the like. Furthermore, it can be used not only to form two-dimensional characters and images using ink, but also as a three-dimensional modeling material for forming a three-dimensional stereoscopic image (three-dimensional modeled object).
A known three-dimensional modeling apparatus for modeling a three-dimensional model can be used, and is not particularly limited. For example, a three-dimensional modeling apparatus including an ink storage unit, a supply unit, a discharge unit, a drying unit, or the like is used. be able to. The three-dimensional structure includes a three-dimensional structure obtained by repeatedly applying ink. Further, a molded product obtained by processing a structure provided with ink on a substrate such as a recording medium is also included. The molded product is obtained by subjecting a recorded matter or a structure formed in a sheet shape or a film shape to a molding process such as heat stretching or punching, for example, an automobile, OA equipment, It is suitably used for applications in which the surface is molded after decorating, such as meters for electronic devices and cameras, and panels for operation units.

  Further, the terms “image formation”, “recording”, “printing”, “printing”, etc. in the terms of the present invention are all synonymous.

  Recording media, media, and printed materials are all synonymous.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited at all by these Examples.

[Preparation of ink]
<Preparation of pigment dispersion>
25 g of titanium oxide STR-100W (manufactured by Sakai Chemical Industry Co., Ltd.), 5 g of pigment dispersant TEGO Dispers651 (manufactured by Evonik Co., Ltd.) and 70 g of water are mixed and 0 in a bead mill (Research Lab, manufactured by Shinmaru Enterprises Co., Ltd.) .3 mmΦ zirconia beads were dispersed at a filling rate of 60% and 8 m / s for 5 minutes to obtain a white pigment dispersion having a volume average particle diameter of 285 nm.

<Preparation of urethane resin emulsion>
In a reaction vessel into which a stirrer, a reflux condenser, and a thermometer were inserted, 1,500 g of polylite OD-X-2420 (manufactured by DIC Corporation, polyester polyol), 220 g of 2,2-dimethylolpropionic acid (DMPA), and 1,347 g of N-methylpyrrolidone (NMP) was charged in a nitrogen atmosphere and heated to 60 ° C. to dissolve DMPA. Next, 1,445 g of 4,4′-dicyclohexylmethane diisocyanate and 2.6 g of dibutyltin dilaurate (catalyst) are added and heated to 90 ° C., and a urethanization reaction is performed over 5 hours. Obtained. The reaction mixture was cooled to 80 ° C., and 4,340 g was extracted from the mixture in which 149 g of triethylamine was added and mixed, and added to a mixed solution of 5,400 g of water and 15 g of triethylamine with vigorous stirring. Next, 1,500 g of ice was added, and 626 g of a 35% by mass 2-methyl-1,5-pentanediamine aqueous solution was added to carry out a chain extension reaction, and the solvent was distilled off so that the solid content concentration became 30% by mass. The obtained resin emulsion was dispersed with a paint conditioner (manufactured by Red Devil, speed adjustable within the range of 50 to 1,425 rpm) to obtain a urethane resin emulsion having a solid content concentration of 40.0% by mass.

<Adjustment of acrylic resin emulsion>
Boncoat CF-6140 (manufactured by DIC) was used as the acrylic resin emulsion.

<Ink adjustment method>
The ink was prepared by mixing and stirring according to the formulation shown in Table 1 (the unit of the numerical value is% by mass) and filtering through a 0.5 μm polypropylene filter.
The following surfactants were used.
FS-300 (Fluorosurfactant manufactured by DuPont)
Proxel LV (Lonza Japan Co., Ltd.) was used as a preservative.

(Examples 1-32 and Comparative Examples 1-5)
The following evaluation was performed by combining the white ink produced above and the wiping member shown in Table 2 in an image forming apparatus having an ejection device that ejects ink from the nozzle and a wiping member. The wiping member shown in Table 2 includes at least two layers each having a gap, and a sheet-like member was used. The used fiber used in the first layer is a non-woven fabric.

[Evaluation]
<Removability>
Using Ricoh MH5440 as an ink-jet head, 0.1 ml of the white ink prepared above was dropped on the nozzle plate of the head and allowed to stand for 15 hours to produce a nozzle plate to which the ink was fixed.
Using the wiping member and ink shown in Table 2 below, 20 μl / cm ² of a cleaning liquid having the following composition was applied to the wiping member, and then the surface of the nozzle plate was wiped off. The wiping conditions were a pressing force of 3 N and a wiping speed of 50 mm / s.
[Composition of cleaning liquid]
・ 3-Methoxy-3-methyl-1-butanol (Kuraray Co., Ltd.) 20% by mass
-Polyether-modified silicone surfactant (trade name: WET270, manufactured by Evonik Degussa Japan) 1% by mass
・ Ion exchange water remaining

(Evaluation methods)
The nozzle plate after wiping was visually discriminated, and the number of wiping operations in which the fixed ink was removed was evaluated. In the following evaluation criteria, Δ is a practical range, ○ is preferable, and ◎ is more preferable.
(Evaluation criteria)
A: The fixed ink on the nozzle plate was removed by five cleanings.
A: The fixed ink on the nozzle plate was removed by seven cleanings.
Δ: The fixed ink on the nozzle plate was removed by cleaning 10 times or less.
X: Fixed ink remains after 10 cleanings.

<Adhesion>
A test image 100 was obtained by a cross-cut peel test using a cloth adhesive tape (123LW-50, manufactured by Nichiban Co., Ltd.) on a solid image formed on a PVC film recording medium using the white ink shown in Table 2. The number of remaining masses was counted, and “adhesion” to the recording medium was evaluated based on the following evaluation criteria. The above evaluation is within a practical range where Δ or more, ○ is preferable, and ◎ is more preferable.
(Evaluation criteria)
◎: Remaining mass number is 98 or more ○: Remaining mass number is 90 or more and less than 98 Δ: Remaining mass number is 70 or more and less than 90 ×: Remaining mass number is less than 70

From the comparison between the example and the comparative example 1, it is understood that when the resin in the ink is less than 6.0% by mass, the adhesion to the recording medium is deteriorated.
From a comparison between the example, Comparative Example 2, and Comparative Examples 4 to 5, it can be seen that when the porosity of the first layer is larger than the porosity of the second layer, the wiping property of the fixed ink is deteriorated.
From the comparison between the example and the comparative example 3, it can be seen that when the thickness of the first layer is larger than the total thickness other than the first layer, the wiping property of the fixed ink is deteriorated.

DESCRIPTION OF SYMBOLS 1 Main guide member 3 Carriage 4, 4a, 4b Recording head 4n Nozzle 5 Main scanning motor 6 Driving pulley 7 Driven pulley 8 Timing belt 10 Paper 12 Conveying belt 13 Conveying roller 14 Tension roller 16 Sub scanning motor 17 Timing belt 18 Timing pulley 20 Maintenance recovery mechanism 21 Empty discharge receptacle 20a Cap member 20b Mechanism for wiping the nozzle forming surface 23 Encoder scale 24 Encoder sensor 25 Code wheel 26 Encoder sensor 320 Wiping member 400 Pressing roller 410 Roller 420 Take-up roller 500 Foreign material 610 First layer 620 Second layer Na, Nb nozzle row

JP 2014-188900 A

Claims (9)

An image forming apparatus comprising: a discharge device that discharges an ink composition from a nozzle; and a wiping member that wipes the ink composition that adheres to a nozzle formation surface of the discharge device,
The ink composition contains 6.0% by mass or more of a resin;
The wiping member comprises at least two layers each having a void;
When the thickness of the first layer from the side in contact with the nozzle forming surface is t1, and the total thickness of the layers other than the first layer is t2, t1 <t2 holds,
The image forming apparatus wherein the porosity of the first layer is at least smaller than the porosity of one layer other than the first layer.   The image forming apparatus according to claim 1, wherein the ink composition contains 7.5% by mass or more of the resin.   The image forming apparatus according to claim 1, wherein a ratio of the resin to the total solid content in the ink composition is 50% by mass or more.   The image forming apparatus according to claim 1, wherein a porosity of the first layer of the wiping member is 0.60 or more and 0.85 or less.   The image forming apparatus according to claim 1, wherein a porosity of the first layer of the wiping member is 0.75 or more and 0.80 or less.   The image forming apparatus according to claim 1, wherein a porosity of at least one layer other than the first layer of the wiping member is 0.80 or more and 0.99 or less.   The image forming apparatus according to claim 1, wherein at least a first layer of the wiping member is made of a nonwoven fabric.   The image forming apparatus according to claim 1, wherein the wiping member has a thickness of 0.1 mm to 3 mm.   The image forming apparatus according to claim 1, wherein the resin is a polyurethane resin.