JP2020124895A - Device for discharging liquid - Google Patents

Abstract

To provide a device for discharging liquid that enables easy access to a liquid discharge head when manually performing cleaning while suppressing the enlargement of the device.SOLUTION: A device for discharging liquid includes: a holding member 15 that holds a recording medium; a liquid discharge head that discharges liquid to the recording medium held by the holding member 15; a carriage 10 that is mounted with the liquid discharge head and can move in a main scanning direction; a maintenance unit 18 for performing the maintenance of the liquid discharge head; and an input receiving portion that receives a standby instruction for manually cleaning the liquid discharge head. The maintenance unit 18 is disposed on one end side in the main scanning direction. On the other end side with respect to the one end side where the maintenance unit 18 is disposed, the standby area 40 where the liquid discharge head stands by is provided. When the input receiving portion receives the standby instruction, the carriage 10 is moved so as to dispose the liquid discharge head in the standby area 40.SELECTED DRAWING: Figure 5

Description

The present invention relates to a device for ejecting a liquid.

Ink jet printers have advantages such as low noise, low running cost, and easy color printing, and are widely used in general households as digital signal output devices.

In recent years, not only for home use but also for non-permeable media such as coated paper, non-absorbent media such as plastic film, and fabrics such as woven fabrics and knitted fabrics, image quality comparable to that of conventional analog printing has been achieved by the inkjet recording method. It is required to be acquired.

For example, in the flexible packaging field, small lots of printing jobs and a wide variety of products are rapidly advancing, and the demand for variable printing is also increasing. For flexible packaging films such as polyolefin-based, polyester-based, polyamide-based, etc. A corresponding inkjet recording system is desired.

In addition, the market size in the so-called DTG (Direct to Garment) field, in which printing is directly performed on clothing such as T-shirts, is expanding year by year. In recent years, demand for not only conventional cotton and cotton/polyester mixed spinning media but also sportswear has rapidly increased, and compatibility with polyester media is required. Such a trend is recognized not only in the DTG field but also in the entire textile printing field. Even in an ink jet printing machine equipped with a winding/winding mechanism, color is produced on fabrics made of various materials such as cotton and polyester. The demand for an inkjet recording system capable of forming an image excellent in durability and various fastnesses is increasing more and more.

Patent Document 1 discloses a platen movement type apparatus that mainly prints on a cloth such as a T-shirt as a print medium. However, such a liquid discharge head is regularly manually cleaned by a user. There is a need.
When cleaning the liquid ejection head in the platen movement type inkjet recording apparatus, it is necessary to move the carriage equipped with the liquid ejection head from the home position so that the user can access the liquid ejection head.

However, if the liquid ejection head is large, the number of heads included is large, or if the platen is large, the liquid ejection head may overlap with the platen at the moved position, making access difficult. On the other hand, if an attempt is made to secure the clearance of each member in order to simplify maintenance, the size of the device will increase.

Therefore, it is an object of the present invention to provide an apparatus that ejects a liquid that is easily accessible to a liquid ejection head when performing manual cleaning while suppressing an increase in the size of the apparatus.

In order to solve the above problems, a device for ejecting a liquid of the present invention includes a holding member for holding a recording medium, a liquid ejection head for ejecting a liquid on the recording medium held by the holding member, and the liquid ejection. A carriage that mounts a head and is movable in the main scanning direction, a maintenance unit that performs maintenance of the liquid ejection head, and an input reception unit that receives a movement instruction of the carriage when performing manual cleaning of the liquid ejection head. The maintenance unit is arranged at one end side in the movement area of the carriage, and has a standby area on the other end side with respect to the one end side where the maintenance unit is arranged, in which the liquid ejection head is on standby. When the receiving unit receives the movement instruction, the carriage is moved so that the liquid ejection head is arranged in the standby area.

According to the present invention, it is possible to provide a device for ejecting a liquid that is easily accessible to a liquid ejection head when performing manual cleaning while suppressing an increase in the size of the device.

FIG. 3A is a schematic plan view and FIG. 2B is a schematic cross-sectional view showing a state during capping of a liquid ejection head of an apparatus that ejects liquid. FIG. 9 is a schematic plan view of a conventional example of a device that ejects liquid when cleaning a liquid ejection head. FIG. 11 is a schematic sectional view (front view) when cleaning a liquid ejection head in a conventional example of a device that ejects liquid. FIG. 9 is a schematic plan view of the device for ejecting liquid according to the present embodiment, when the liquid ejection head is cleaned. It is a cross-sectional schematic diagram (front view) at the time of cleaning the liquid ejection head of the device which ejects the liquid according to the present embodiment. FIG. 6 is an explanatory diagram of a space formed around a carriage in a standby area in FIG. 5.

Hereinafter, a device for ejecting a liquid according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be modified within the scope of those skilled in the art, and any mode Also, as long as the action and effect of the present invention are exhibited, it is included in the scope of the present invention.

FIG. 1 shows an example of a device for ejecting a liquid. FIG. 1 shows a state when the liquid ejection head is capped.
FIG. 1A is a plan view seen from the upper surface. In FIG. 1B, a recording medium (for example, a T-shirt) is conveyed in the depth direction (or front direction) of the recording medium, and FIG. 1B is a cross section in a direction perpendicular to the conveying direction of the recording medium. It is a schematic diagram.

In FIG. 1A, a carriage 10, a liquid ejection head 1 including a first head 11 and a second head 12, an exhaust unit 14, a holding unit (platen) 15, a platen moving table 17, and a maintenance unit 18, and The operation unit 30 is illustrated.
In FIG. 1B, the carriage 10, the liquid ejection head 1, the carriage scanning rail 13, the exhaust unit 14, the holding unit (platen) 15, the support member 16, the platen moving table 17, and the maintenance unit 18 are illustrated.

The liquid ejection head 1 includes a first head 11 and a second head 12. In the example of this embodiment, the first head 11 is a head that ejects the pretreatment liquid, and the second head is a head that ejects ink. Hereinafter, when the first head 11 and the second head 12 are described without distinction, they are simply referred to as "liquid ejection head 1". In each embodiment, the “head” means the liquid ejection head 1 and also the first head 11 and the second head 12, respectively.

The holding unit (hereinafter, also referred to as “platen”) 15 is a member that holds the recording medium, and the size and the like can be changed as appropriate.
The recording medium is not limited to the one used as a general recording medium (for example, plain paper, glossy paper, special paper, etc.), wallpaper, flooring, building materials such as tiles, cloths for clothing such as T-shirts, Textiles, leather and the like can be used as appropriate. Further, ceramics, glass, metal or the like can be used by adjusting the configuration of the path for conveying the recording medium.
Also, good image formation can be achieved by using a non-permeable substrate. The non-permeable base material is a base material having a surface with 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. , Bristow method refers to a substrate 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, a polycarbonate film can be preferably used.

The platen 15 is supported by the support member 16.
The platen moving table 17 is a mechanism for moving the platen 15, and moves the platen 15 in the vertical direction (the direction of the arrow indicated by B in the drawing), and also in the recording medium conveyance direction.

As illustrated, the platen 15 moves along the platen moving rail 19, and moves in the direction of the arrow indicated by C in the figure. Since the recording medium is held and moved on the platen 15, the moving direction of the platen 15 and the conveying direction of the recording medium coincide with each other.
Further, as shown in the drawing, the second head 12 is arranged on the downstream side of the first head 11 in the recording medium conveyance direction.

The platen 15 moves in the direction of the arrow indicated by C in the drawing, and the liquid is ejected from the head while the carriage 10 scans in the main scanning direction (direction A in the drawing) near the carriage 10. At this time, the pretreatment liquid is ejected from the first head 11 toward the recording medium first, and then the ink is ejected from the second head 12 toward the recording medium.

The maintenance unit 18 is a mechanism for maintaining the head, and includes a cap, a suction pump, an idle discharge receiver, and the like.
The maintenance unit 18 is arranged on one end side in the movement area of the carriage 10.

The carriage 10 is a housing in which the liquid ejection head 1 is mounted, and in addition to the liquid ejection head 1, the carriage 10 includes an encoder sensor (not shown), a moving belt, a lifting mechanism, and the like.
The carriage scanning rail 13 is a rail for moving the carriage 10 in a direction perpendicular to the conveyance direction of the recording medium.

The moving direction of the carriage 10 (that is, the direction perpendicular to the transport direction of the recording medium) may also be referred to as the main scanning direction, and the main scanning direction is indicated by the arrow A in the figure. Further, the conveyance direction of the recording medium may be referred to as a sub-scanning direction, and the main scanning direction and the sub-scanning direction are orthogonal to each other.

The exhaust unit 14 is a mechanism for exhausting the gas of the device body 22 to the outside of the device body 22. For example, it may have a fan and comprises a fan connected to a motor.

2 and 3 are diagrams showing a state of cleaning a liquid ejection head in a conventional example of an apparatus for ejecting liquid, FIG. 2 is a schematic plan view, and FIG. 3 is a schematic sectional view (front view).
In the figure, the portion D where the liquid ejection head is likely to collect dirt is indicated by a symbol D. It should be noted that dirt is likely to be accumulated at the position of the symbol D because the wiping direction of the nozzle surface of the head is the main scanning direction, and unwiping is likely to occur at the end of the head (or the lower surface of the carriage) in the main scanning direction. There is one.

When manually cleaning the liquid ejection head 1, when a not-shown input reception unit (for example, a part of a control device that controls the movement of the carriage) receives a movement instruction of the carriage 10, a conventional liquid ejection device Then, the carriage 10 is moved in the direction away from the maintenance unit 18, and the liquid ejection head 1 is made to stand by at a position near the maintenance unit 18 shown in the figure. In the conventional technique, the liquid ejection head 1 is generally made to stand by at a position near the illustrated maintenance unit 18 in consideration of, for example, the time required to move the carriage and noise.

The movement instruction received by the input receiving unit may be input by the user from the operation unit 30 or may be issued by the device at a time when maintenance is required. However, this is the same in the embodiment.
As shown in FIGS. 2 and 3, in the conventional standby position, since the distance between the carriage 10 and the side surface of the maintenance unit 18 is short and close to each other, there is a space for inserting a hand when manually cleaning the liquid ejection head 1. It is limited, and in particular, it is difficult to access the portion D where dirt easily accumulates.

FIG. 4 and FIG. 5 are views showing a state when cleaning the liquid ejection head of the device for ejecting liquid according to the present invention, FIG. 4 is a schematic plan view, and FIG. 5 is a schematic sectional view (front view).
In the figure, the portion D where the liquid ejection head is likely to collect dirt is indicated by a symbol D.

The liquid ejecting apparatus according to the present embodiment includes a holding portion (platen) 15 that holds a recording medium, and a liquid ejecting head 1 (first head 11, that ejects liquid onto the recording medium held by the holding member 15). The second head 12), the carriage 10 on which the liquid ejection head 1 is mounted and movable in the main scanning direction, the maintenance unit 18 for maintaining the liquid ejection head 1, and the manual cleaning of the liquid ejection head 1. The maintenance unit 18 is disposed on one end side in the main scanning direction, and the liquid ejection head 1 is disposed on the other end side with respect to the one end side on which the maintenance unit 18 is disposed. Has a waiting area 40 for waiting, and when the input receiving unit receives a movement instruction, the carriage 10 is moved so that the liquid ejection head 1 is arranged in the waiting area 40. Note that the "other end side" refers to at least an area opposite to the side where the maintenance unit 18 is arranged with respect to the center of the carriage movement area in the main scanning direction, and is not limited to the end portion in the main scanning direction. ..

When cleaning the liquid ejection head 1, the device for ejecting a liquid according to the present embodiment, when an input reception unit (not shown) (for example, a part of a control device for controlling the movement of the carriage) receives a movement instruction, Although the liquid discharge head 1 moves the carriage 10 in the direction away from the maintenance unit 18 as in the conventional example, the carriage 10 separates from the maintenance unit 18 in the device for ejecting liquid according to the present embodiment. It moves to the standby area 40 provided on the opposite side from the one end side provided with.

As shown in FIG. 5, the standby area 40 is an area that does not overlap the holding member 15 in the vertical direction when viewed in the recording medium conveyance direction.
That is, in the apparatus for ejecting the liquid according to the present embodiment, when the input receiving unit receives the standby instruction, the carriage 10 is placed at a position that does not overlap with the holding member 15 in the direction perpendicular to the holding member 15 when viewed from the conveyance direction of the recording medium. To move.
Specifically, the device for ejecting liquid according to the present embodiment is arranged at a position where the liquid ejection surface of the liquid ejection head 1 does not face the holding surface 15a of the holding member when the input receiving unit receives the standby instruction. The carriage 10 is moved so that

With such a configuration, the apparatus for ejecting the liquid according to the present embodiment can easily access the portion D where dirt is likely to accumulate and can sufficiently perform the cleaning when the liquid ejection head 1 is manually cleaned. Further, by making the excitation force applied to the carriage 10 small after receiving the standby instruction so that the user can move the carriage 10 by touching the carriage 10, the accessibility to the liquid head 1 is further improved. Can be made. Even when the carriage 10 is moved to a position between the maintenance unit 18 and the holding member 15a after receiving the standby instruction as in the prior art, and the exciting force applied to the carriage 10 is reduced, the user can move the carriage 10 to the carriage 10. It is also possible to improve the accessibility to the part D by moving it to the standby position in this embodiment. However, when the user touches the carriage 10, the carriage 10 slightly moves in the height direction, so that the liquid ejection head 10 (and dirt attached to the surface thereof) touches the holding member 15a and the print medium. There is a risk that the carriage 10 may be loosened or a strong force may be applied to the carriage 10 to cause a failure. Therefore, it is desirable that the first destination of the carriage 10 after receiving the standby instruction is the standby area 40 provided on the opposite side to the one end side where the maintenance unit 18 is provided as in the present embodiment.
Further, since the clearance of each member is secured, the liquid ejection head can be easily accessed without increasing the size of the device.

Examples of a method for manually cleaning the liquid ejection head 1 include a method of wiping the liquid ejection surface and the outer peripheral surface with a wiping member.
A known member can be used as the wiping member, and examples thereof include a non-woven fabric. Alternatively, a cleaning liquid may be applied to the wiping member to wipe it.

FIG. 6 is an explanatory diagram of a space formed around the carriage in the standby area in FIG.
The length W1 of the standby region 40 in the main scanning direction is longer than the length W2 of the carriage 10 in the main scanning direction. Therefore, when the carriage 10 is arranged in the standby area 40, a space 41 is formed around the carriage 10.

Further, it is preferable that at least part of the height L1 of the space 41 formed around the carriage 10 arranged in the standby area 40 is higher than the height L2 of the holding surface 15a of the holding member 15. In other words, it is desirable not to arrange an object (rail, control board, wiring, ink tube, etc.) that reduces L1 around the carriage 10 arranged in the standby area 40. In the present embodiment, one end of the standby region 40 in the main scanning direction is a portion obtained by vertically extending the end of the holding member 15, and the other end of the standby region 40 in the main scanning direction is the inner wall surface of the apparatus body. ..
This facilitates access to the liquid ejection head 1 when the user inserts his/her hand and performs a wiping operation during cleaning.

Further, it is preferable that the carriages 10 arranged in the standby area 40 are arranged so that spaces are formed on both sides in the main scanning direction.
This makes it easier for the user to access the liquid ejection head 1 without the obstacles such as the wall surfaces that are close to each other on both sides.

The liquid ejection head 1 included in the liquid ejection apparatus according to the present embodiment includes the first head 11 and the second head 12 as described above, and the first head 11 ejects the pretreatment liquid and the second head. Head 12 ejects ink.
Hereinafter, the ejected pretreatment liquid and ink will be described.

(Pretreatment liquid)
The pretreatment liquid used in the device for ejecting the liquid of the present embodiment is not particularly limited as long as it can be ejected from the head, and can be appropriately selected from known ones, but it contains a polyvalent metal ion. Is preferred. In addition, if necessary, other components such as a resin may be contained.

The polyvalent metal ion can be appropriately selected from known ones, and examples thereof include calcium ion, magnesium ion, and aluminum ion. These may be used alone or in combination of two or more.

The polyvalent metal ion can be contained in the pretreatment liquid by dissolving a water-soluble polyvalent metal salt.
The polyvalent metal salt can be appropriately selected from known ones, and for example, carboxylates (acetic acid, lactic acid, etc.), sulfates, nitrates, chlorides, and thiocyanates are preferable. The polyvalent metal salts may be used alone or in combination of two or more. Among these, carboxylates, sulfates, nitrates, and chlorides having good solubility in water and water-soluble organic solvents are preferable from the viewpoint of image quality such as color developability and bleeding resistance, and ejection reliability.

The content of the polyvalent metal ion in the pretreatment liquid is preferably 30 mmol/L or more and 700 mmol/L or less, and 60 mmol/L or less from the viewpoints of suppression of bleeding and uneven density, color development, fastness and adhesion. L or more and 500 mmol/L or less are more preferable, and 100 mmol/L or more and 400 mmol/L or less are further preferable.

(ink)
Hereinafter, the organic solvent, water, coloring material, resin, additive and the like used in the ink will be described.

<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 polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds.

Specific examples of the water-soluble organic solvent include, for example, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 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- Polyhydric alcohols such as 1,3-pentanediol and petriol, 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 Polyhydric alcohol alkyl ethers such as ethers, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone , Nitrogen-containing heterocyclic compounds such as 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone, formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N- Amides such as dimethylpropionamide and 3-butoxy-N,N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane and thiodiethanol, propylene carbonate and ethylene carbonate. Etc.
It is preferable to use an organic solvent having a boiling point of 250° C. or less because it not only functions as a wetting agent but also obtains good drying properties.

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 glycol ether compounds include polyhydric alcohol alkyls such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Ethers; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

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

<Water>
The content of water 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 or less from the viewpoint of the drying property of the ink and the 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. Also, a mixed crystal may be used.
Examples of pigments that can be used include black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, luster color pigments such as gold and silver, and metallic pigments.

As an inorganic pigment, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method. Can be used.
As the organic pigment, an azo pigment, a polycyclic pigment (for example, a phthalocyanine pigment, a perylene pigment, a perinone pigment, an anthraquinone pigment, a quinacridone pigment, a dioxazine pigment, an indigo pigment, a thioindigo pigment, an isoindolinone pigment, a quinophthalone pigment, etc.) , Dye chelates (for example, basic dye chelates, acid dye chelates, etc.), nitro pigments, nitroso pigments, aniline black, etc. can be used. Among these pigments, those having a good affinity with the solvent are preferably used. In addition, hollow resin particles and hollow inorganic particles can also be used.

Specific examples of the pigment include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, and channel black, or copper and iron (CI pigment black 11) for black. , Metal oxides 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 Green 1, 4, 7, 8, 10, 17, 18, 36, and the like.

The dye is not particularly limited, and an acid dye, a direct dye, a reactive dye, and a basic dye can be used, and 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. Dilectd 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 ink 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 the following.

In order to obtain an ink by dispersing the pigment, 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 to disperse the pigment, and a method of dispersing using a dispersant are used. Method etc. are mentioned.

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) to make the pigment dispersible in water Is mentioned.
Examples of the method of coating the surface of the pigment with a resin to disperse 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-coated pigment. In this case, it is not necessary for all the pigments mixed in the ink to be coated with the resin, and as long as the effect of the present invention is not impaired, uncoated pigments and partially coated pigments are dispersed in the ink. May be.

Examples of the method of dispersing using a dispersant include a method of dispersing using a known low molecular type dispersant or polymer 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.
Takemoto Yushi Co., Ltd.'s RT-100 (nonionic surfactant) and naphthalenesulfonic acid Na formalin condensate can also be suitably used as the dispersant.
The dispersants may be used alone or in combination of two or more.

<Pigment dispersion>
It is possible to obtain an ink by mixing a pigment with a material such as water or an organic solvent. Further, it is also possible to manufacture an ink by mixing a pigment and other materials such as water and a dispersant to form a pigment dispersion, and 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. A dispersion machine may be used for dispersion.
There is no particular limitation on the particle size of the pigment in the pigment dispersion, but since the dispersion stability of the pigment is good and the image quality such as ejection stability and image density is also high, the maximum frequency is 20 nm or more when converted to the maximum number. 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 Microtrack Bell KK).
The content of the pigment in the pigment dispersion is not particularly limited and may be appropriately selected depending on the purpose, but from the viewpoint of obtaining good ejection stability and increasing the image density, it is 0.1 mass. % Or more and 50% by mass or less is preferable, and 0.1% by mass or more and 30% by mass or less is more preferable.
The pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifugal separator or the like, if necessary.

<Resin>
The type of resin contained in the ink is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, and butadiene resin. Examples thereof include resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.
You may use the resin particle which consists of these resins. Ink can be obtained by mixing resin particles in the state of a resin emulsion in which water is used as a dispersion medium with a material such as a coloring material or an organic solvent. As the resin particles, those synthesized appropriately may be used, or commercially available products may be used. These may be used alone or in combination of two or more kinds of resin particles.

The volume average particle diameter of the resin particles is not particularly limited and may be appropriately selected depending on the 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 more and more preferably 10 nm or more and 100 nm or less.
The volume average particle size can be measured using, for example, a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell KK).

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

The particle size of the solid content in the ink is not particularly limited and can be appropriately selected according to the purpose. However, from the viewpoint of improving the image quality such as ejection stability and image density, the maximum number of times converted to the maximum number Is preferably 20 nm or more and 1000 nm or less, more preferably 20 nm or more and 150 nm or less. The solid content includes resin particles and pigment particles. The particle size can be measured using a particle size analyzer (Nanotrack Wave-UT 151, manufactured by Microtrack Bell KK).

<Additive>
If necessary, a surface active agent, a defoaming agent, an antiseptic/antifungal agent, an anticorrosive agent, a pH adjusting agent, etc. may be added to the ink.

<Surfactant>
As the surfactant, any of silicone-based surfactants, fluorine-based surfactants, amphoteric surfactants, nonionic surfactants, and anionic surfactants can be used.

The silicone surfactant is not particularly limited and can be appropriately selected according to the purpose. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and side-chain both-end modified polydimethylsiloxane. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene 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 having a polyalkylene oxide structure introduced into the side chain of the Si moiety of dimethylsiloxane.

Examples of the fluorinated surfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphoric acid ester 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 sulfonate. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salts. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in its side chain include a sulfuric acid ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in its side chain and a perfluoroalkyl ether group in its side chain. Examples thereof include salts of polyoxyalkylene ether polymers. As counter ions of salts in these fluorine-based surfactants, 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) are used. ₃ etc. are mentioned.

Examples of the amphoteric surfactant include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.

Examples of nonionic surfactants include polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan. Examples thereof include fatty acid esters and ethylene oxide adducts of acetylene alcohol.

Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, and salt of polyoxyethylene alkyl ether sulfate.
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. Examples thereof include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and side-modified. Examples thereof include polydimethyl siloxane modified at both chain ends, and a polyether modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group exhibits excellent properties as an aqueous surfactant. preferable.
As such a surfactant, those synthesized appropriately may be used, or commercially available products may be used. Commercially available products can be obtained from, for example, BIC Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Kagaku Co., Ltd.
The above polyether-modified silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyalkylene oxide represented by the general formula (S-1) may be dimethylpolysiloxane. Introduced into the side chain of the Si part of the above.

(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.)

As the above polyether-modified silicone-based surfactant, commercially available products can be used, and examples thereof include KF-618, KF-642, KF-643 (Shin-Etsu Chemical 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.), 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 fluorine-based surfactant include a perfluoroalkyl phosphate ester compound, a perfluoroalkylethylene oxide adduct, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in its side chain. Among these, polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain are preferable because they have a low foaming property, and particularly fluorine-based compounds represented by the general formula (F-1) and the general formula (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.

General formula (F-2)
_{C n F 2n + 1- CH 2} CH (OH) CH 2 -O- (CH 2 CH 2 O) a -Y

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. An integer or CpH _2p+1 and p is an integer of 1 to 19. n is an integer of 1 to 6. a is an integer of 4-14.

A commercial item 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.); 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 and 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 (manufactured by OMNOVA), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.) Among them, good printing quality, especially color developability, penetrability to paper, wettability, and leveling property are remarkably improved, and thus FS-3100, FS-34, FS- manufactured by Chemours. 300, FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by Neos Co., Ltd., Polyfox PF-151N manufactured by Omnova Co., and Unidyne DSN-manufactured by Daikin Industries, Ltd. 403N is particularly preferred.

The content of the surfactant in the ink is appropriately selected depending on the intended purpose without any limitation, but it is 0.001 mass% from the viewpoint of excellent wettability and ejection stability and improving image quality. % Or more and 5 mass% or less is preferable, and 0.05 mass% or more and 5 mass% or less is more preferable.

<Antifoam>
The defoaming agent is not particularly limited, and examples thereof include a silicone defoaming agent, a polyether defoaming agent, and a fatty acid ester defoaming agent. These may be used alone or in combination of two or more. Among these, a silicone-based defoaming agent is preferable because of its excellent foam breaking effect.

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

<Rust preventive>
The rust preventive agent is not particularly limited, and examples thereof include acid sulfite and sodium thiosulfate.

<pH adjuster>
The pH adjuster is not particularly limited as long as it can adjust the pH to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

The physical properties of the ink are not particularly limited and may be appropriately selected depending on the purpose. For example, the viscosity, surface tension, pH and the like are preferably in the following ranges.
The viscosity of the ink at 25° C. is preferably 5 mPa·s or more and 30 mPa·s or less, from the viewpoint that the printing density and character quality are improved and good ejection properties are obtained, and 5 mPa·s or more and 25 mPa·s or less are preferable. More preferable. Here, as the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. The measurement conditions are 25° C., standard cone rotor (1°34′×R24), sample liquid volume 1.2 mL, rotation speed 50 rpm, and 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 preferably 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 the corrosion of the metal member with which the ink comes into contact.

<Post-treatment liquid>
The apparatus for ejecting the liquid according to the present embodiment can be configured to eject the post-treatment liquid on the recording medium. For example, a mode in which a third head that discharges the post-treatment liquid is provided may be adopted.
In that case, the post-treatment liquid is not particularly limited as long as it can form a transparent layer. The post-treatment liquid is obtained by selecting and mixing an organic solvent, water, a resin, a surfactant, an antifoaming agent, a pH adjusting agent, an antiseptic/antifungal agent, an anticorrosive agent, etc., if 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.

1 Liquid Ejection Head 10 Carriage 11 First Liquid Ejection Head 12 Second Liquid Ejection Head 13 Carriage Scanning Rail 14 Exhaust Means 15 Holding Member (Platen)
15a Holding surface 16 Supporting part 17 Holding member moving stand 18 Maintenance unit 19 Platen moving rail 20 Heating means 22 Device body 40 Standby area 41 Space

JP, 2016-112766, A

Claims (6)

A holding member for holding the recording medium,
A liquid ejection head for ejecting a liquid onto the recording medium held by the holding member;
A carriage that is equipped with the liquid ejection head and is movable in the main scanning direction;
A maintenance unit for performing maintenance of the liquid ejection head,
An input receiving unit that receives an instruction to move the carriage when performing manual cleaning of the liquid ejection head;
The maintenance unit is arranged at one end side in the main scanning direction,
On the other end side with respect to the one end side where the maintenance unit is arranged, there is a standby area where the liquid ejection head is on standby,
An apparatus for ejecting liquid, characterized in that, when the input acceptance unit accepts a movement instruction, the carriage is moved so that the liquid ejection head is arranged in the standby area. The apparatus for ejecting liquid according to claim 1, wherein the standby area does not overlap the holding member in the vertical direction when viewed in the transport direction of the recording medium. The carriage is moved such that when the input receiving unit receives a movement instruction, the liquid ejection surface of the liquid ejection head is arranged at a position not facing the holding surface of the holding member. Or a device for ejecting the liquid according to 2. The device for ejecting liquid according to claim 1, wherein the length of the standby region in the main scanning direction is longer than the length of the carriage in the main scanning direction. The space formed around the carriage arranged in the standby area is
The device for ejecting liquid according to claim 1, wherein at least a part of the height is higher than the holding surface of the holding member. 6. The liquid ejecting head comprises a first liquid ejecting head for ejecting a pretreatment liquid onto the recording medium, and a second liquid ejecting head for ejecting ink. A device for ejecting the liquid according to 1.

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