JP2003251823A - Ink tank for inkjet printer and production method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ink tank for an inkjet printer with little concern of deteriorating the printing quality by quickly coping with change of the tank inner pressure accompanied by the ink consumption, capable of restraining ink leakage, introduction of bubbles, or the like. <P>SOLUTION: A movable wall comprises a viscoelastic liquid and a floating body soaked in the viscoelastic liquid. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink tank for an ink jet printer, which contains ink in a free state and supplies the ink in response to a request from a printer head.

[0002]

2. Description of the Related Art An ink jet printer is a printing machine that ejects ink by using heat or vibration to apply the ink to the surface to be printed. It can be easily connected to a personal computer and used as a household printing machine. It has become popular in recent years because it enables accurate color printing. With the spread of small personal computers such as mobile personal computers, printers are also becoming smaller, and there are demands for their portability to be taken into consideration. Therefore, the ink tank that holds the ink is placed in various directions, and the ink does not leak even when the product is transported or when it is carried or vibrated by the user, ensuring the desired print quality during printing. It is necessary to be able to do so.

If ink is ejected, a negative pressure is created in the ink tank unless the volume reduction of the ejected ink is recovered in some form, which adversely affects the subsequent ink ejection. On the other hand, it is known that a vent hole is formed to prevent the negative pressure inside the tank by taking in the outside air, or the volume of the ink tank itself is automatically changed (decreased). If the vent holes are formed, it may become a way for ink to leak, and it is feared that air bubbles may enter the ink due to vibration or shock, which may adversely affect the printing quality. A complicated structure has been adopted in which the ink is made to be difficult to move by being held by an ink absorber such as a focusing body or a sponge, and a valve element which is closed when unnecessary is arranged by using a coil spring or the like.

However, in the case where the ink tank volume is gradually reduced with the content of ink, it is not necessary to form a hole which substantially communicates with a portion where ink is present, so that it is reliable against ink leakage. It can be said that the structure is highly flexible.
For example, the ink is contained in a shrinkable bag having rubber elasticity, or the movable wall is disposed so as to be substantially in contact with the wall surface of the ink tank. The one using the shrinkable bag body is difficult to mount while maintaining the liquid tightness of the bag body in the tank, and the assembly process is complicated in the end.
It was difficult to gradually shrink the remaining ink so that all of the remaining ink would be used. On the other hand, a structure having a movable wall has a relatively simple structure, and is disclosed in JP-A-5-057900 and JP-A-9-029990.
It is disclosed in the publication.

[0005]

However, the one using a movable wall as disclosed in the above publication is one in which a lubricant is arranged between the movable wall and the inner wall of the tank. It is difficult to avoid direct contact between the inner wall surface of the tank and the movable wall without extremely sophisticated dimensional control between the inner wall surface of the tank and the movable wall. Will be. Further, although the above-mentioned lubricant is said to be interposed between the inner wall surface of the tank and the movable wall, it is substantially adhered to the inner wall surface of the tank. It is possible that there will be a shortage, and there will be direct contact between the inner wall of the tank and the movable wall,
There was a concern that a gap would be formed and the ink would leak out.

[0006]

SUMMARY OF THE INVENTION The present invention is an ink jet that accommodates ink in a free state, supplies the ink in response to a request from a printer head, and takes in air corresponding to ink consumption from a ventilation hole. In an ink tank for a printer, a backflow inhibitor composition is arranged in layers in contact with the interface of the ink and the inner peripheral wall of the ink tank, and a portion having an ink discharge port for storing ink in the ink tank and a vent hole are formed. The gist of the present invention is an ink tank for an ink jet printer, which is separated from the above-mentioned portion by a layer of a backflow preventing composition.

[0007]

[Function] The backflow preventive composition maintains the geometrical layered state of the backflow preventive composition not only during use but also during transportation, and promptly responds to changes in tank internal pressure due to ink consumption. As a result, there is little concern that print quality will be impaired, and ink leakage and air bubble mixing can be suppressed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example will be described below with reference to the drawings.
1 and FIG. 2, which is a sectional view taken along the line II ′ of FIG. 1, assume an ink cartridge that is replaceably attached to the printer body (not shown). Fixing means and the like used when connecting to the printer body are omitted. The tank body 1 has a box shape which is an injection molded product of polypropylene resin having low gas permeability and high light transmittance, and the remaining amount of ink is visible. The tank body 1 has an ink discharge port 2 at the bottom for supplying ink to a printer head (not shown).
And a top box 1b having a ventilation hole 3 capable of communicating the inside and outside air. The joint between the bottom box 1a and the top box 1b is formed by a liquid-tight crossover fit or an adhesive. It is necessary that liquid contents etc. do not leak out, such as binding,
In this example, ultrasonic fusion is applied. 20c of ink 4 (specific gravity: 1.06) inside
c, a backflow preventing composition 5 in contact with the interface of the ink 4
0.8 cc is stored (specific gravity: 0.89).

At the ink discharge port 2, coarse particles such as agglomerates and reactants in the ink, a backflow preventive composition, and air bubbles remaining in the ink are connected to the printer head or a communication path to the printer head. A filter 6 that suppresses entry and a valve body 7 that allows ink to be ejected by opening a slit-shaped ink passage 7a according to a request of a printer head.
Is installed. The valve body 7 is an elastic valve made of an elastic material such as silicon rubber, butyl rubber, or ethylene propylene rubber, and is deformed in response to a request such as a suction force from the printer head to open the ink passage 7a having one character slit. You can The filter 6 is a twill weave and is a stainless wire mesh with a thickness of 0.06 mm and 3000 MESH. In addition to this, the flat mesh, twill weave, warp twist plain weave, co-twist weave, plain weave, twill weave, cedar twill weave, etc. can be used for the wire mesh, the thickness is 0.06 mm to 2.00 mm, and the mesh is 1200 MESH. ~ 3500 MESH is preferred. Although not shown, the functions of the filter 6 and the valve body 7 are
It is also possible to provide it by a plate member made of continuous porous polyurethane or polyethylene resin that is thermally compressed so that the skeleton portions are in contact with each other.

The ventilation hole 3 is heat-compressed so that the leakage preventing filter 8 made of a material which is hard to get wet with the anti-reflux agent composition or a material which has been treated and the skeleton parts for adjusting the internal pressure are in contact with each other. A continuous porous sheet 9 made of polyurethane resin is arranged. Leakage prevention filter 8
Is to prevent the backflow preventing composition 5 from leaking to the outside through the vent holes 3 when the vent holes 3 face downward. However, if it is considered that the backflow preventive composition does not substantially leak out due to the relationship between the substantial diameter of the vent hole and the fluidity of the backflow preventive composition, it is not always necessary to install it. The communicating porous sheet 9 is capable of continuously communicating the inside and outside air according to the internal pressure state of the ink tank, and depending on the setting of the opening of the pores of the ink tank, holds the water isobaric pressure of the ink accommodated inside the tank. It can assist in maintaining a negative pressure. However, if the negative pressure in the tank can be easily maintained by adjusting the layer shape stability of the anti-reflux agent composition or the hardness of the gel, it is not always necessary. The member indicated by reference numeral 10 is a stopper for fixing the leak prevention filter 8 and the communicating porous sheet 9 to the ceiling box 1b.

Ink 4 contained in the tank
Uses a dye as a colorant and assumes an aqueous dye ink containing water as a main medium, but a pigment ink or an oil-based ink containing an organic solvent as a main medium can also be used. Since it is desirable that the anti-reflux agent composition be substantially incompatible with the ink, when an oil-based ink is used, an aqueous anti-reflux agent composition using water as a medium can be used. . However, since an aqueous composition has a high gas permeability or is easily dried, a layer of an oil-based backflow / permeation / drying inhibitor composition using an organic solvent as a medium is further formed thereon. Alternatively, a plate-shaped lid member may be arranged between the two.

The inner wall surface of the tank has a contact angle of 50 ° (25 ° C.) with the anti-reflux agent composition 5 so that the anti-reflux agent composition 5 can move smoothly. , A small amount of the anti-reflux agent composition that adheres to and remains on the wall surface as much as possible when the layer of the anti-reflux agent composition moves,
It is set so that no layer break is formed between it and the inner wall surface. This contact angle can be adjusted by blending the anti-reflux agent composition, the material of the tank body, the surface condition of the wall surface, and the like. The contact angle between the backflow preventing composition and the inner wall surface of the tank is preferably 30 ° or more and 120 ° or less. Three
If it is less than 0 °, the backflow preventive composition adheres extremely strongly to the inner wall of the tank, which may hinder the movement of the layer of the backflow preventive composition, and even if it moves, it will adhere to the wall surface. The amount of the anti-reflux agent composition that remains as a result increases, and in order to maintain the anti-reflux effect of the anti-reflux agent composition, a large amount of the anti-reflux agent composition must be arranged, and it is costly in terms of volume. It is uneconomical. Also, 12
If it exceeds 0 °, the inner wall surface of the tank becomes extremely difficult to get wet, the backflow prevention function may not be effectively exerted, and the ink ejection resistance may be too low and ink may be attached to the printer head. There is a concern (a state in which the ink having a backflow preventive composition is slightly more difficult to move may be a force for sucking the ink that cannot be completely discharged from the printer head). When the ink remains on the printer head, there is a concern that uncontrolled unnecessary ink will be used in the next printing, which may affect the printing quality.

Further, in this example, the backflow preventing composition 5
Is Nisseki Polybutene HV-15 (Polybutene, manufactured by Nippon Oil Co., Ltd.) 48.5 parts by weight, Mobil SHF1003
(Poly α-olefin, manufactured by Mobil Chemical Co., Ltd.) 4
8.5 parts by weight, Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 3.0 parts by weight, which is a highly viscous fluid, has a viscosity of 100,000 mPa · s.
(25 ° C, 0.5 rpm), surface tension is 40 mN / m
(25 ° C).

Ink filling is mainly described in FIGS. 3 to 6 as to the method of manufacturing the ink tank of this embodiment. Figure 3 shows the top box 1b
Only the air vent 3 is shown facing downward. As shown in FIG. 4, the top box 3 in this state is filled with the high-viscosity backflow inhibitor composition 5 by the filling nozzle 11 having a plurality of discharge ports 11a having a relatively small diameter. By doing so, the backflow preventive composition can be uniformly covered at once at a wide area in the tank, and the backflow preventive composition is continuously filled, and the backflow is prevented in a state where air such as bubbles is not caught as much as possible. A layer of the agent composition 5 can be formed. FIG. 5 shows a state in which the ink 4 as the content liquid is filled from above the layer of the backflow preventing composition 5. In this state, the open end of the bottom box 1a is covered with the front box 2 and ultrasonically welded (not shown), and the container is closed (FIG. 6). In addition, here
If you dislike applying ultrasonic vibrations due to ultrasonic welding to the ink or the backflow preventive composition, from the viewpoint of ink splattering or from the viewpoint of the interface shape between the ink and the backflow preventive composition, backflow After filling the inhibitor composition and before filling the ink, the bottom box 1a can be ultrasonically welded, and the ink can be filled by inserting a nozzle from the ink discharge port 2 or the like. Even if it does not depend on it, it can also be used for fitting and the use of adhesive. Although not shown, when the bottom box 1a is thereafter subjected to a centrifugal treatment, the ink 1 and the backflow preventive composition layer move in the direction of the bottom box 2, and gas is discharged from the ventilation holes 3 of the top box 1b. Can be removed to obtain the container in the state of FIG.

In the present production method, the anti-reflux agent composition 5
The shape of the nozzle for filling is not limited to that shown in the figure, and may be one having a large diameter.
A nozzle having a small diameter hole may be moved during filling. In any case, care should be taken to prevent the entrapment of air during filling as much as possible.

FIG. 7 shows another example. A small ink chamber 1c is provided in which a partition 12 is arranged in the ink cartridge and is divided into small portions.
Is formed. The small ink chambers 1c communicate with each other in the vicinity of the ink discharge port 2 so that the divided inks merge. Since the partition wall 12 is formed integrally with the top box 1b, the ventilation holes 3 are formed in each small ink chamber due to the ease of manufacturing on the mold, but the space near the ventilation hole is shared. Alternatively, one ventilation hole may be formed. In this case, as shown in FIG. 8, the leak prevention filter 8 and the communicating porous sheet 9 are provided outside the ventilation holes 3a for the small ink chambers 1c.
It is also possible to arrange so as to cover the vent holes of the respective small ink chambers so as to prevent leakage and assist in adjusting the internal pressure.

Also in the case of this example, when filling the ink, the top box 1b is installed so that the ventilation hole 3 is on the lower side in the same manner as in the above example, and the backflow preventive composition 5 and the ink are added. 4 may be filled in this order, and the bottom box 1a may be placed and then centrifuged. The one having a plurality of small ink chambers 1c as in this example is effective for an ink tank for storing a large amount of ink such as an industrial ink cartridge, and a backflow preventive composition even for a small ink tank. It is possible to form a state in which the layer of the article 5 is not easily deformed by impact or pressure change, and it can be said that this is a preferable example for controlling ink ejection and preventing leakage.

FIG. 9 shows another example. This is an example in which the floating body 13 in which most of the front side is immersed is arranged in the layer of the backflow preventing composition 5. The floating body 13 is an injection molded product of polypropylene resin, and its specific gravity is about 0.86. Ink 4 has a specific gravity of 1.06 and backflow preventive composition 5 has a specific gravity of 0.89, but is formed of a polypropylene synthetic resin injection molded product having a specific gravity of 0.86. The floating body 13 is prevented from moving into the ink 4 or coming off from the layer of the backflow preventing composition 5 due to the difference in specific gravity from the backflow preventing composition 5. In the initial state, the volume ratio of the backflow preventing composition 5 and the floating body 13 is 4.9,
The contact area of the floating body 13 with the backflow preventing composition 5 and the initial cross-sectional area of the ink chamber in the portion where the floating body 13 is located are (contact area of the floating body with the backflow preventing composition) / (ink chamber crossing). Area) = 5.2, and the distance between the tip of the floating body 13 and the interface of the ink 4 is set to 3.5 mm.

As shown in FIG. 10, forming the floating body 13 in the shape of a box with a bottom is advantageous in terms of cost because the amount of resin material used can be reduced, and the overall thickness of the body is increased. To minimize the occurrence of sink marks (a phenomenon in which dents are formed on the outer surface due to partial differences in resin shrinkage speed and non-uniformity) during molding, and to manage dimensions. It is preferable because it is easy. In this example, the ratio between the maximum outer diameter of the front end and the maximum outer diameter of the rear end of the floating body 13 (the maximum outer diameter of the front end) / (the maximum outer diameter of the rear end) = 1.0, that is, the side surface is straight and the side wall of the floating body 13 is present. The shape of (1) has as few irregularities and inclination as possible so that the layer of the backflow preventive composition 5 and the floating body 13 can be smoothly moved along with the movement of the interface of the ink 4. The smoothness of the movement of the backflow preventive composition 5 and the floating body 13 accompanying the movement of the interface of the ink 4 is determined by the ratio of the maximum outer diameter of the front end to the maximum outer diameter of the rear end (the maximum outer diameter of the front end) / (the rear end The maximum end outer diameter) is allowed within the range of 0.9 to 1.1.

As is the case with the example shown in FIG. 9, in this example, the floating body 13 substantially forms a portion having a small cross-sectional area in the layer of the backflow preventing composition 5. 11 is a sectional view taken along the line II-II ′ of FIG.
As shown in, the narrow space formed by the inner wall of the ink tank and the floating body 13 greatly suppresses the deformation of the backflow preventing composition 5. That is, the anti-reflux agent composition 5 is, for example, 50 parts by weight of poly α-olefin (Mobil SHF1003, manufactured by Mobil Chemical Co., Ltd.), polybutene (Nisseki Polybutene H).
V-3000, manufactured by Nippon Oil Co., Ltd., is a highly viscous fluid having a composition such as 50 parts by weight, but its flow is extremely slow due to its high viscosity. Therefore, even when a shock or the like is applied, it absorbs the force to some extent and has a role of suppressing rapid movement. However, when it is clamped in a narrow space, the contacting member per unit volume Since the contact area with respect to is large, its adhesiveness and tackiness are easily exhibited, and the impact resistance is also high. However, since it moves sufficiently in response to a slow movement request due to ink ejection, ink ejection is not hindered, and it is sufficient to suppress leakage due to impact.

For example, as shown in FIG. 12 showing a modified example as a view corresponding to FIG. 11, the cross-sectional shape of the outside of the tank has unevenness for being attached to the ink jet printer. Although the inner surface shape may be a shape having no unevenness irrespective of the outer shape of the tank, it is realistic that the shape is uneven due to the influence of the outside. And the inner wall surface of the tank are maintained at 0.3 to 0.5 mm, the outer diameter of the floating body 13 is substantially similar to the inner shape of the tank, and the floating body 13 and the backflow preventive composition 5 are In addition, as the ink 4 decreases, the ink 4 can be moved quickly, and printing defects such as blurring of printing do not occur, and the shape of the backflow preventive composition 5 can be maintained even with respect to shock such as vibration during storage, transportation or printing. Layer state Can be made to suppress can be maintained to one, leakage ink generated in inversion of the backflow preventing agent composition 5 and the ink 4.

The rear end (upper side in the drawing) of the floating body 13 is a contact portion 13a with respect to the top box 1b, and when the air present in the ink 4 should expand in volume due to a temperature rise due to some accident or the like. When the backflow preventing composition 5 and the floating body 13 move rearward, the backflow preventing composition 5 comes into contact with the top surface of the top box 1b to restrict rearward movement. This circumferential abutment substantially limits the backward movement of the backflow preventive composition 5 and the ink 4 further, and the circumferential abutment is formed so as to surround the ventilation hole 3, so that the through-flow is prevented. It is also possible to prevent the ink 4 and the backflow preventing composition 5 from leaking from the pores 3.

13 to 15 show modified examples of contact between the floating body 13 and the top 1b. Each is shown as an enlarged view of a part III in FIG. In each of the modified examples, a protrusion is formed as an abutting portion so that the contact area is minimized. In the example of FIG. 13, a convex portion 13b having a semicircular vertical cross section is formed in an annular shape at the rear end of the floating body 13. 14
In the example, the mountain-shaped protrusion 1d having a substantially triangular vertical section is formed on the tank side, and in the example of FIG. 15, the packing ring 14 made of an elastic material such as rubber is fitted to the floating body 13. In any of the examples, the contact area when contacting is extremely small, it is easy to contact in a circumferential shape, and the contact pressure per unit area at the time of contact is large, so that the ink 4 or the backflow preventive composition is obtained. The object 5 is more surely blocked from leaking out. In particular, in the case of using an elastic material, even if there is a difference in the positional relationship of each member due to variations in molding dimensions, it is possible to absorb the difference and deform it, so that abutting can be performed more reliably. The ink leakage is suppressed.

Even if the floating body 13 is arranged as described above, it can be assembled in the same manner when the ink is filled. The assembly method will be described with reference to FIGS. FIG. 16 shows a state in which only the top box 1b is placed with the ventilation holes 3 facing downward. As shown in FIG. 17, first, the floating body 13 is placed in the top box 1b, and the top surface portion 1e of the top box 1b.
It is arranged along the inward projection 1f standing upright. The state shown in FIG. 18 is the filled state of the antireflux agent composition 5. The high-viscosity backflow preventive agent composition 5 is filled on the floating body 13 by the filling nozzle 11 having a plurality of discharge ports 11 a having a relatively small diameter. By doing so, it is possible to uniformly cover the floating body 13 with the liquid at one time.
By continuously filling the anti-reflux agent composition,
It is possible to prevent air such as bubbles from being trapped as much as possible. FIG. 19 shows a state in which the ink 4 is filled on the backflow preventing composition. In this state, the bottom box 1a is placed over the opening of the top box 1b to close the container (FIG. 20). Although not shown, when the front box 2 is thereafter subjected to centrifugal treatment toward the outside, the ink 4 and the backflow preventive composition 5, and the floating body 13 immersed in the backflow preventive composition 5 is directed toward the bottom box 1a. Then, the air is removed from the ventilation hole 3 of the top box 1b, and the container in the state of FIG. 10 can be obtained.

[0025]

As a test for confirming the effect, various anti-reflux agent compositions are blended, and the shape of the ink tank to be tested by accommodating such anti-reflux agent composition is shown in FIG. 10 was used, and the size of the gap between the floating body and the inner wall surface of the ink tank was variously changed.

Backflow Prevention Composition 1 Nisseki Polybutene HV-100 (Polybutene, manufactured by Nippon Oil Co., Ltd.) 94.3 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 2.7 parts by weight CDIS- 400 (polyethylene glycol diisostearate, Nikko Chemicals Co., Ltd.) 3.0 parts by weight The above components are mixed to obtain a surface tension of 10 mN / m and a viscosity of 10,000.
A backflow preventing composition 1 of 00 mPa · s was obtained.

Backflow Prevention Composition 2 Nisseki Polybutene LV-7 (Polybutene, Nippon Oil Co., Ltd.) 38.6 parts by weight Mobil SHF21 (Poly α-olefin, Mobil Chemical Co., Ltd.) 57.8 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloedir Co., Ltd.) 3.6 parts by weight The above components are mixed to give a surface tension of 73 mN / m and a viscosity of 100 mP.
An anti-reflux agent composition 2 of a · s was obtained.

Backflow Prevention Composition 3 Nisseki Polybutene HV-15 (Polybutene, manufactured by Nippon Oil Co., Ltd.) 48.5 parts by weight Mobil SHF1003 (poly α-olefin, manufactured by Mobil Chemical Co., Ltd.) 48.5 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloedir Co., Ltd.) 3.0 parts by weight The above are mixed to have a surface tension of 40 mN / m and a viscosity of 10,000.
The anti-reflux agent composition 3 was obtained at 0 mPa · s.

Anti-reflux composition 4 Lucant HC-600 (α-olefin, manufactured by Mitsui Petrochemical Co., Ltd.) 93.3 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 3.4 parts by weight CDIS -400 (polyethylene glycol diisostearate, manufactured by Nikko Chemical Co., Ltd.) 3.3 parts by weight The above components are mixed to obtain a surface tension of 10 mN / m and a viscosity of 10,000.
A backflow inhibitor composition 4 of 00 mPa · s was obtained.

Anti-reflux agent composition 5 Mobil SHF41 (poly α-olefin, manufactured by Mobil Chemical Co., Ltd.) 7.8 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 2.2 parts by weight The above are mixed. And surface tension 73mN / m, viscosity 100mP
An anti-reflux agent composition 5 of a · s was obtained.

Anti-reflux agent composition 6 Nisseki Polybutene HV-35 (Polybutene, manufactured by Nippon Oil Co., Ltd.) 96.7 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 3.3 parts by weight Surface tension 40mN / m, viscosity 10000 by mixing
A backflow inhibitor composition 6 of 0 mPa · s was obtained.

Backflow prevention composition 7 Nisseki Polybutene LV-100 (Polybutene, manufactured by Nippon Oil Co., Ltd.) 30.5 parts by weight Mobil SHF1003 (Poly α-olefin, manufactured by Mobile Chemicals Co., Ltd.) 64.5 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aerosil Co., Ltd.) 3.0 parts by weight CDIS-400 (polyethylene glycol diisostearate, manufactured by Nikko Chemicals Co., Ltd.) 2.0 parts by weight Surface tension 40 mN / m, viscosity 10000
A backflow inhibitor composition 7 of 0 mPa · s was obtained.

Anti-reflux agent composition 8 Nisseki Polybutene HV-100 (Polybutene, manufactured by Nippon Oil Co., Ltd.) 94.4 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 2.5 parts by weight CDIS- 400 (polyethylene glycol diisostearate, Nikko Chemicals Co., Ltd.) 3.1 parts by weight The above components are mixed to have a surface tension of 9 mN / m and a viscosity of 100,000.
A backflow preventing composition 8 of 0 mPa · s was obtained.

Anti-reflux agent composition 9 Nisseki Polybutene HV-100 (Polybutene, manufactured by Nippon Oil Co., Ltd.) 94.0 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 3.0 parts by weight CDIS- 400 (polyethylene glycol diisostearate, manufactured by Nikko Chemicals Co., Ltd.) 3.0 parts by weight The above components are mixed to have a surface tension of 10 mN / m and a viscosity of 10200.
A backflow inhibitor composition 9 of 00 mPa · s was obtained.

Backflow prevention composition 10 Mobil SHF21 (poly α-olefin, manufactured by Mobil Chemical Co., Ltd.) 96.5 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 3.5 parts by weight The above are mixed. And surface tension 73mN / m, viscosity 98mPa
The anti-reflux agent composition 10 of * s was obtained.

Anti-reflux agent composition 11 Nisseki Polybutene LV-7 (polybutene, manufactured by Nippon Oil Co., Ltd.) 19.3 parts by weight Mobil SHF21 (poly α-olefin, manufactured by Mobil Chemical Co., Ltd.) 77.1 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloedir Co., Ltd.) 3.6 parts by weight The above components are mixed to obtain a surface tension of 74 mN / m and a viscosity of 100 mP.
An anti-reflux agent composition 11 of a · s was obtained.

Anti-reflux agent composition 12 Lucant HC-600 (α-olefin, manufactured by Mitsui Petrochemical Co., Ltd.) 93.0 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 3.5 parts by weight CDIS -400 (polyethylene glycol diisostearate, Nikko Chemical Co., Ltd.) 3.5 parts by weight The above components are mixed to obtain a surface tension of 8 mN / m and a viscosity of 100,000.
A backflow preventing composition 12 of 0 mPa · s was obtained.

Anti-reflux agent composition 13 Lucant HC-600 (α-olefin, manufactured by Mitsui Petrochemical Co., Ltd.) 93.1 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 3.6 parts by weight CDIS -400 (polyethylene glycol diisostearate, manufactured by Nikko Chemical Co., Ltd.) 3.3 parts by weight The above are mixed to have a surface tension of 10 mN / m and a viscosity of 10300.
A backflow preventing composition 13 of 00 mPa · s was obtained.

Anti-reflux agent composition 14 Mobil SHF41 (α-olefin, manufactured by Mobil Chemical Co., Ltd.) 98.0 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aloezil Co., Ltd.) 2.0 parts by weight The above is mixed. Surface tension 73 mN / m, viscosity 97 mPa
A backflow inhibitor composition 14 of .s was obtained.

Backflow Prevention Composition 15 Nisseki Polybutene LV-25 (Polybutene, manufactured by Nippon Oil Co., Ltd.) 32.0 parts by weight Mobil SHF21 (poly α-olefin, manufactured by Mobil Chemical Co., Ltd.) 66.0 parts by weight Aerosil R972 (fine particle silica, manufactured by Nippon Aerosil Co., Ltd.) 2.0 parts by weight The above components are mixed to obtain a surface tension of 74 mN / m and a viscosity of 100 mP.
An anti-reflux agent composition 15 of a · s was obtained.

Table 1 shows the settings of each example and comparative example.

[0042]

[Table 1]

The test samples of Examples 1-9 and Comparative Examples 1-20 were tested. The results are shown in Tables 2, 3 and 4.

Printing Test The test samples of each Example and Comparative Example were set in a BJF200 (manufactured by Canon Inc.), a printing speed of 70 mm / sec was applied, and 10 cm of a 2.0 mm wide coating was printed, and every 1 cm. The amount of ink discharged was measured, and the presence or absence of blurring was visually confirmed on the print marks. The ink discharge amount was converted into a volume (cc) from the measured value (g) of the change in mass of the printed paper with an ink specific gravity (1.06). Scratch: A state where there is a part without ink in the print mark.

[0045]

[Table 2]

[0046]

[Table 3]

[0047]

[Table 4]

The composition of the ink used in the test is as follows. DUASYN-D. BLACK HEF-SSLIQ 10% aqueous solution (dye, Clariant Japan KK) 30.00 parts by weight ethylene glycol 5.00 parts by weight glycerin 10.00 parts by weight isopropanol 3.00 parts by weight BO-10TX (surfactant, Nikko Chemicals (Manufactured by Co., Ltd.) 0.02 parts by weight Water 50.98 parts by weight

As described above, the ink tank for the ink jet printer of the present invention can smoothly move the floating body due to the consumption of the ink in the container during printing, and stably discharges the content liquid and causes the printing blur in printing. It can be suppressed as much as possible.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example.

FIG. 2 is a sectional view taken along the line I-I ′ of FIG.

FIG. 3 is a vertical sectional view illustrating a manufacturing method.

FIG. 4 is a vertical sectional view for explaining the manufacturing method.

FIG. 5 is a vertical sectional view for explaining the manufacturing method.

FIG. 6 is a vertical sectional view for explaining the manufacturing method.

FIG. 7 is a vertical cross-sectional view showing another example.

FIG. 8 is a vertical sectional view showing a modified example.

FIG. 9 is a vertical cross-sectional view showing another example.

FIG. 10 is a vertical sectional view showing a modified example.

11 is a sectional view taken along the line II-II ′ of FIG.

FIG. 12 is a view corresponding to FIG. 11 showing a modified example.

FIG. 13 is an enlarged vertical cross-sectional view showing a portion corresponding to a portion III in FIG. 10 showing a modified example.

14 is an enlarged vertical cross-sectional view showing a portion corresponding to a portion III in FIG. 10 showing a modified example.

FIG. 15 is an enlarged vertical cross-sectional view showing a portion corresponding to a portion III in FIG. 10 showing a modified example.

FIG. 16 is a vertical sectional view for explaining the manufacturing method.

FIG. 17 is a vertical sectional view for explaining the manufacturing method.

FIG. 18 is a vertical sectional view for explaining the manufacturing method.

FIG. 19 is a vertical sectional view for explaining the manufacturing method.

FIG. 20 is a vertical sectional view for explaining the manufacturing method.

[Explanation of symbols]

1 tank body 1a bottom box 1b roof 1c Small ink room 1d Yamagata protrusion 1e Top part 1f inward protrusion 2 Ink outlet 3 ventilation holes 3a Vent 4 ink 5 Antireflux agent composition 6 filters 7 valve body 7a Ink passage 8 Leakage prevention filter 9 continuous porous sheet 10 stop 11 Filling nozzle 11a outlet 12 partitions 13 Floating body 13a contact part 13b convex part 14 Packing ring

Claims (20)

[Claims] 1. An ink tank for an ink jet printer, which stores ink in a free state, supplies the ink in response to a request from a printer head, and takes in air corresponding to ink consumption from a ventilation hole in the ink tank. The backflow preventive composition is arranged in layers in contact with the interface of the ink tank and the inner peripheral wall of the ink tank, and the backflow is prevented between the portion having the ink discharge port where the ink is stored and the portion where the vent hole is formed in the ink tank. Ink tank for ink jet printers separated by a layer of the agent composition. 2. The ink tank for an ink jet printer according to claim 1, wherein the contact angle of the backflow preventing composition with the inner peripheral wall of the ink tank is 30 degrees or more and 120 degrees or less. 3. The viscosity of the anti-reflux agent composition is 100 mPa · s or more and 1,000,000 mPa · s at 20 ° C.
The ink tank for an ink jet printer according to claim 1 or 2, which is as follows. 4. The surface tension of the anti-reflux agent composition is 20.
The ink tank for an ink jet printer according to any one of claims 1 to 3, which has a temperature of 10 mN / m to 73 mN / m inclusive. 5. The ink jet printer according to claim 1, wherein the ink is a water-based ink containing water, and the backflow preventing composition contains α-olefin and / or polyolefin. Ink tank. 6. The backflow preventive composition layer according to claim 1, wherein partition walls are arranged in the ink tank, and the backflow preventing composition layer is formed in each small ink chamber separated by each partition wall. Ink tank for ink jet printer. 7. An ink in which a plug body is arranged in the vent hole so that, when the vent hole is placed downward, at least the backflow preventive agent is closed to the outside of the container through the vent hole. Ink tank for jet printer. 8. The floating body is arranged by immersing at least a part in the layer of the anti-reflux agent composition.
An ink tank for an ink jet printer according to any one of 1. 9. The volume ratio of the backflow preventing composition to the floating body is 0.4 ≦ (backflow preventing composition) / (floating body) ≦ 1.
The ink tank for an ink jet printer according to claim 8, which is 5. 10. The floating body is lighter than the specific gravity of the anti-reflux agent composition, the specific gravity difference between the floating body and the anti-reflux agent composition is 0.01 or more and 0.1 or less, and the anti-reflux agent composition. The material is lighter than the specific gravity of the ink, and the specific gravity difference between the anti-reflux agent composition and the ink is 0.01 or more and 0.4 or more.
The ink tank for an ink jet printer according to claim 8 or 9, which is as follows. 11. The contact area of the floating body with the anti-reflux agent composition and the cross-sectional area of the ink tank at the portion where the floating body is located are 1 ≦ (contact area of the floating body with the anti-reflux agent composition). ) / (Ink tank cross-sectional area) ≤ 20. The ink tank for an ink jet printer according to any one of claims 8 to 10. 12. The ink tank for an ink jet printer according to claim 8, wherein a gap between the inner peripheral wall of the ink tank and the floating body is 0.01 mm or more and 3 mm or less. . 13. The ink jet according to claim 8, wherein a ratio of the maximum outer diameter of the front end to the maximum outer diameter of the rear end of the floating body is 90% or more and 110% or less. Ink tank for printer. 14. The ink tank for an ink jet printer according to claim 8, wherein the floating body has an inner hole that is opened rearward. 15. The ink tank for an ink jet printer according to claim 8, wherein a barrier that circumferentially abuts on the moving plug when the floating body moves rearward is formed. 16. The ink tank for an ink jet printer according to claim 15, wherein the barrier is formed of a member different from a member having an ink discharge port. 17. The ink tank for an ink jet printer according to claim 15, wherein an annular convex portion is provided at a contact portion of the floating body with respect to the barrier and / or a contact portion of the barrier with respect to the moving plug. 18. The ink tank for an ink jet printer according to claim 17, wherein the annular convex portion is formed of an elastic body. 19. The backflow preventive composition is filled by installing the ventilation hole at a lower side, and then ink is filled on the backflow preventive composition layer, and then the container is closed. Centrifuge with the ink outlet of the ink tank facing outward to move the ink and backflow preventive composition layer to the ink outlet side, and communicate with the ink outlet in the ink tank. The gas intervening between the anti-reflux agent composition and the ink ejection port is discharged from the vent hole while the layer of the anti-reflux agent composition is positioned between the pores. A method for manufacturing an ink tank for an ink jet printer according to claim 18. 20. The ventilation hole is installed at a lower side, the floating body is arranged so as to cover the ventilation hole, the backflow preventing composition is filled on the floating body, and then the backflow preventing agent is filled. After filling the composition layer with ink, the container is closed and subjected to centrifugal treatment in a state where the direction of the ink discharge port of the ink tank is outside, the ink, the layer of the backflow preventing composition, and , Moving the float to the ink discharge port side so that the layer of the backflow preventive composition and the float are located between the ink discharge port and the vent hole in the ink tank,
The method for manufacturing an ink tank for an ink jet printer according to any one of claims 8 to 18, wherein the gas existing between the backflow preventive composition and the ink discharge port is discharged from the vent hole.