JP3259481B2 - Ink tank and manufacturing method thereof - Google Patents

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 holding ink, and more particularly to an ink tank suitable for an ink jet recording apparatus.

[0002]

2. Description of the Related Art An ink jet recording apparatus is an apparatus for recording and writing characters and the like according to recording information on recording paper by discharging ink droplets from fine nozzles. The formation of the ink droplets is performed by rapidly changing the volume of the pressure chamber provided inside the recording head by using an electrostrictive vibrator or an electrothermal conversion element to generate a discharge pressure. Therefore, when air is mixed in the ink supply path such as the pressure chamber, the ejection pressure is not generated satisfactorily, and recording and writing become impossible.

Further, when the ink in the ink tank is consumed and the supply is cut off, recording and writing become impossible. Then, there is a problem that it takes a long time before air enters into the ink supply path to the nozzle and recording / writing becomes possible even when ink is newly supplied.

In order to cope with such a problem, a level detector is provided in the ink tank, or a level detector is provided in a part of the ink supply path so that the supply of the ink is stopped. A configuration for detecting the ink end is used. This prevents a large amount of air from entering the ink supply path at the time of ink end. However, it is not possible to completely prevent air from being mixed into the ink supply path when the ink tank is inserted into and removed from the recording head when the ink tank is replaced.

Therefore, as a proposal for initially suppressing the influence of air mixed in the ink supply path at the time of insertion / removal of the ink tank and the recording head, Japanese Patent Application Publication No. Hei.
No. 1592 is known.
An ink tank containing degassed ink is accommodated in a sealed container having extremely high gas barrier properties under reduced pressure. In this conventional example, immediately after the sealed container is opened, the ink in the ink tank is deaerated ink, and the effect of air mixed into the ink supply path by the deaerated ink is to be initially removed. is there.

[0006] The ink tank has an injection hole for filling the ink and a vent hole for communicating with the atmosphere so that air flows in in response to the decrease due to the use of the ink. The ink filled in the ink tank leaks from the injection hole or the air hole due to factors such as the attitude of the ink tank during transportation and the environmental temperature. In particular, when the ink tank is packed under reduced pressure, this phenomenon becomes more remarkable as the pressure is increased. For this purpose, a method has been proposed in which the degree of vacuum at the time of vacuum packaging is reduced to a lower vacuum state than when ink is filled, as described in JP-A-4-12834.

In order to prevent the leakage of the ink, there is conventionally known one disclosed in Japanese Patent Publication No. 54-31897. The vent has a filter, such as polytetrafluoroethylene, with innumerable narrow through passages that allow the passage of air but prevent the flow of liquid. In addition, as disclosed in Japanese Patent Application Laid-Open No. 60-245560 and U.S. Pat. No. 4,771,295, an ink tank having a space is known.

[0008]

However, in the conventional example, as the pressure reduction increases, the degree of deaeration of the ink is maintained and the reliability can be ensured. Leaks easily. In addition, if packaging under reduced pressure after applying an impact such as dropping, the ink leaks with a slight reduction in pressure, resulting in poor workability. If the temperature further changes, the ink leaks due to the expansion of the gas in the ink. If the filling amount is reduced to reduce the filling efficiency to prevent ink leakage, the ink tank becomes large.

In the conventional example shown to prevent leakage, ink does not leak under atmospheric pressure, but if the package is packaged under reduced pressure to ensure sufficient reliability, the ink will seep out of the sealing member. come. This is because the gas permeability of the sealing member is too high, that is, the filter has countless small holes in the sealing member.

If a member having no gas permeation is used for the sealing member, there is no ink leakage, but it will not be degassed again at the time of decompression packaging. There is a problem that the process must be performed in a short time under atmospheric pressure or in a short time, and when ink is decomposed and gas is generated, it is saturated again.

Further, a space is provided in the ink tank,
Even if the lid shape is devised to prevent leakage, the gas in the ink expands and leaks in a high-temperature environment, and it is difficult to completely prevent this, and in addition, the ink tank becomes large. is there.

Accordingly, the present invention is to solve such a problem, and an object of the present invention is to provide an inexpensive, highly reliable and compact ink jet recording apparatus.

[0013]

Ink tank of the present invention, in order to solve the problem] is an ink tank for supplying ink to the recording head, the ink tank includes a communicating portion communicating with an ink reservoir, the recording head and the ink reservoir, a communicating hole bored as if communication with the atmosphere, the water vapor permeability for sealing the communicating hole is not more than ^{2000g / m 2 · 24h · atm} , and gas permeability
A sealing member of 100 cc / m ² · 24 h · atm or more, and is sealed in an airtight container under reduced pressure so as to maintain a space near the communication hole.

Further, the method of manufacturing an ink tank according to the present invention comprises the steps of: providing an ink reservoir, a communication portion communicating the ink reservoir with the recording head, a plurality of communication holes formed so as to communicate with the atmosphere, A method for manufacturing an ink tank, comprising: a sealing member for sealing a hole; Step of depressurizing the ink reservoir through the communication hole B. B. supplying ink from the communication hole to the ink tank and filling the ink tank; Water vapor permeability of not more than ^{2000g / m 2 · 24h · atm} , and a step of gas permeability of the sealing member is 100cc / m ² · 24h · atm or more, sealed at atmospheric pressure in the communication hole D. A step of placing the ink tank in a non-permeable container, providing a space between the communication hole and the closed container, reducing the pressure in the container, and sealingly packing the container.

[0015]

According to the above construction of the present invention, the condition of the sealing member that does not leak ink and allows gas permeation under reduced pressure is found, and a space is provided between the ink tank and the sealed container to reduce the pressure. The ink is degassed again, so that the degassed ink can be supplied to the recording device in a very reliable state at the beginning of use of the ink tank, so that the ink enters the ink supply path when the ink tank is replaced. Eliminate problems caused by air. In addition, since the ink does not leak at the time of vacuum packing, transportation, or storage, the vacuum packing can be performed without impairing the ink filling property. Further, since the ink is filled and sealed under atmospheric pressure and then packaged under reduced pressure, the process is simplified. As described above, it is possible to provide a small, inexpensive inkjet recording apparatus with high reliability.

[0016]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a main cross-sectional view for explaining an embodiment of the ink jet recording apparatus of the present invention, and FIG. 2 is an exploded perspective view of a main part of an ink tank used in the ink jet recording apparatus of the present invention. FIG. 3 is a perspective view of a main part. FIG. 4 is a block diagram for explaining the ink end detection circuit.

As shown in FIG. 3, a carriage 2 reciprocates in a direction indicated by an arrow B on a guide shaft 2a along a platen 1 which is a recording sheet conveying means which rotates in a direction indicated by an arrow A to convey the recording sheet. The recording head 3 is integrally provided near the platen 1. Above the recording head 3, there is provided an ink tank 7 which contains an ink reservoir 6 and contains therein a foam 6a made of a porous member such as polyurethane foam. As shown in FIG. 2, in this embodiment, the ink tank 7 is divided into three rooms 6Y, 6M, and 6C, and three ink reservoirs 6 are provided. Each of these rooms is filled with yellow, cyan, and magenta color inks. However, if the type and number of inks change in design, the number of rooms in the ink tank 7 is divided into a necessary number. It is also possible to change the volume of each room according to the amount of ink consumed.

As shown in FIGS. 1 and 2, the ink tank 7 is provided with a communication hole 9 for communicating with the outside of the lid 8 of the ink tank 7, and a trapezoidal projection 10 is formed on the bottom of the ink tank 7 to make close contact with the foam 6. Have been. An ink chamber 1 for taking out and holding ink in the foam 6 downward from the center of the projection 10
1 is formed. An end of the ink chamber 11 is sealed by a blind plug 12 made of an elastic member such as rubber. The ink impregnated in the ink tank 7 is supplied to the recording head 3 by inserting the hollow needle 5, which is a communication member communicating with the recording head 3, through the blind plug 12 through the filter chamber 4. It is configured. The ink chamber 1
1 is in a closed chamber state by the blind plug 12 and the foam 6. At least one of the communication holes 9 is sealed by a sealable member 21 that can be opened until immediately before use, and is opened immediately before use to become a ventilation hole 9a. However, in this embodiment, a plurality of communication holes 9 are provided, but there is no problem in obtaining a desired effect even if only one communication hole 9 is provided. In order to open the package, a sufficiently long sealing member 21 is used as shown in FIG. 2, and the end is pulled off to open the package. Furthermore, if the end is joined to the packaging bag 25 shown in FIG. 6, it is always opened when it is taken out of the packaging bag 25, so that the user can surely open it without any problem such as forgetting to open it. FIG.
The lever 30 for attaching the ink tank may be provided with a projection 31 as shown in FIG. However, as long as the sealing member 21 can be opened, it is not necessary to open the sealing member 21 using a special device.

In the ink tank of the present invention, a sealing member 22 is provided in the other communication hole 9 which is not opened. All the sealing members 21 and 22 have a water vapor transmission rate of 2000 g / m ² · 24 h · atm or less, and at least one gas transmission rate of 100 cc / m ² · 24 h · a
Use tm or more. The gas permeability is obtained by measuring the air permeability at 23 ± 2 ° C. by taking over the method A of the gas permeability test method for plastic films and sheets of JIS (Japanese Industrial Standards) K7126. The water vapor transmission rate is A under the conditions of 40 ± 0.5 ° C. relative humidity difference (90 ± 2)% RH in the water vapor transmission rate test method (instrument measurement method) of plastic film and sheet of JIS (Japanese Industrial Standard) K7129. It was measured by taking over the law. Reason for the water vapor permeability using the following 2000g / m ² · 24h · atm is in so as to prevent leakage of ink during ^{transportation, 100cc / m 2 · 24h ·} a
The reason for using a material of tm or more is that the ink is degassed again after decompression packaging described later. Water vapor permeability of 2000
When the gas permeability in g / m ² · 24h · atm experimented with cellulose triacetate having a thickness of 13μm is 20000cc / m ² · 24h · atm in the sealing member, the ink without ink leak is re It was degassed and the expected effect was obtained. The water vapor permeability of 3g / m ² · 24h · at gas permeability at 100cc / m ² · 24h · atm
When an experiment was conducted using a vinylidene chloride copolymer having a thickness of 25 μm, which is m, for the sealing member, the ink was not leaked again, the ink was degassed again, and the expected effect was obtained.

Here, the sealing member 21 is opened to open the ventilation holes 9a.
Explain the reason for opening. All the sealing members 21 and 22 have a water vapor transmission rate of 2000 g / m ² · 24 h · atm or less. Gas permeability of such materials is greater by about 1,000,000cc / m ² · 24h
・ Atm, and at this gas permeability, the amount of air refilled into the ink tank is smaller than the ink consumption speed of normal printer use, so the pressure inside the ink tank gradually becomes negative as the printer is used. Become. If the negative pressure exceeds a certain value, that is, if a negative pressure exceeding the capillary force of the meniscus of the ink formed in the nozzles of the head is generated in the ink tank, the meniscus is destroyed and the ink droplets are ejected poorly. Therefore, a vent hole 9a for replenishing air in response to ink consumption is required.

If a discharge failure occurs in the recording head 3, the suction pump 15 is operated via the cap 13 and the pipe 14 to suck ink from the recording head 3. As a result, an operation for recovering from a discharge failure is performed.
The sucked ink is sent to a waste ink reservoir 17 through a pipe 16. In the present invention, the waste ink reservoir 17 and the ink tank 7 are separate bodies, and the waste ink reservoir 17 is provided in the main body of the recording apparatus, and is usually not replaced.

In the drawing, reference numerals S1 and S2 denote electrodes for detecting ink end, one of which is provided on the inner wall surface of the ink tank 7 so as to contact the foam 6, and the other electrode S2 is provided with The hollow needle 5 that contacts the ink also serves as an electrode. A rubber O-ring 23 is provided between the electrode S1 and the ink tank 7 to prevent ink from leaking. Then, the reference voltage Vcc is applied to the electrode S1 as shown in FIG. The hollow needle 5 also serving as the other electrode S2 is grounded. Furthermore, the reference voltage Vcc
Is connected to a resistance change amount detection circuit including a differentiating circuit 19 and a comparing circuit 20. Then, an output signal is generated when the resistance change amount exceeds a certain level.

A print command signal for ejecting ink droplets to be applied to the print head 3 is transmitted by an FPC (Flexible Print Circuit) which is a flexible signal transmitting means.
t) transmitted by 18. A signal line for detecting the ink end is integrally formed on the FPC 18, and the electrode S
1, S2. In addition, instead of the FPC 18 as a signal transmission means, an FFC (Flexible FPC) is used.
It is needless to say that a “lat table” or the like may be used. Needless to say, instead of one FPC, two FPCs may be used.

Next, a method of manufacturing and packaging the ink tank used in this embodiment will be described with reference to FIGS. FIG.
Is a packaging bag made of an aluminum laminated film having extremely high gas barrier properties.

First, a method of filling the ink tank 7 with ink is performed by supplying the ink after the ink tank 7 is depressurized. A desired degree of vacuum can be used when the degree of vacuum used for filling is 0.4 atm or less, but 0.2 atm or less is desirable in consideration of the amount of filled ink and the filling time.
At this time, the ink is decompressed and becomes deaerated ink. As described in Japanese Patent Application Laid-Open No. 60-245560, the method of filling the porous member with ink under this reduced pressure is a method with a very high ink filling effect.

Next, the communication hole 9 is sealed with the sealing members 21 and 22 under the atmospheric pressure. It is sufficient that this operation and the process leading to this operation can be performed under reduced pressure. However, the ink tank 7 filled with the ink is left under atmospheric pressure to saturate the ink, and the ink is sealed under atmospheric pressure. also, since at least one sealing member has a gas permeability of ^{100cc / m 2 · 24h · atm} ,
After decompression packaging in the next step, the ink is degassed again. As a sealing method, a method using welding or an adhesive can be used, but welding is more preferable in order to prevent leakage of the ink. When an adhesive is used, it is necessary to satisfy characteristics such as adhesive force for preventing leakage, releasability, and being not violated by ink. Since the sealing members 21 and 22 are films that transmit air at the molecular level, it is easy to select a material by controlling the gas permeability and the water vapor permeability by using a resin to control the gas permeability and the water vapor permeability. For example, a polystyrene resin is used for the ink tank 7, and a gas permeability of the sealing member 22 is about 2500 cc / m ^2.
A 24 μm polystyrene resin 40 μm film is welded to the openable / closable sealing member 21 using a three-layer laminated film of 100 cc / m ² ≦ 24 h ・ atm or less polystyrene resin 30 μm, polyethylene resin 20 μm and polyethylene terephthalate resin 12 μm. When sealing was carried out, the expected effects were obtained in terms of gas permeability, water vapor permeability, bonding strength, peelability, and strength.

Next, as shown in FIG. 7, the ink tank 7 and the spacer 28 are placed in a packaging bag 25, and the pressure is reduced. Space 2 between ink tank 7 and packaging bag 25
There are nine. Since the degree of vacuum in this space is higher than that in the ink tank 7, the ink is degassed again through a sealing member having a gas permeability of 100 cc / m ² · 24 h · atm or more. Further, even if the ink is decomposed during transportation or storage of the ink tank 7 to generate gas such as nitrogen or oxygen, the gas is degassed. Spacer 2
If a member such as corrugated cardboard or urethane foam that allows air to permeate and has a space inside is used, the space in the member serves as the space 29 even if the spacer 28 is in close contact with the communication hole 9. . Therefore, the shape of the spacer 28 can be simplified, and the manufacture and assembly of the spacer 28 become easy. If the degree of vacuum at the time of vacuum packaging is 0.6 atm or less, the closer to the vacuum, the better. Next, it is stored in a packing box 27 (not shown). In this state, the sealing portion 26 of the packaging bag 25 is located between the sealing portion 26 and the packaging box 27 and also serves as a cushioning material.
Therefore, it is not necessary to use a special buffer member.

Here, the relationship between the degree of vacuum at the time of vacuum packaging and the amount of nitrogen after the storage period in the vacuum packaging state will be described. There are gases other than nitrogen in the atmosphere, but the amount of nitrogen is the largest, so that the amount of nitrogen can be controlled.

According to the experiment, as shown in Table 1, by controlling the degree of vacuum at the time of hermetic sealing, the degree of deaeration of the ink in the ink tank 7 immediately after opening the package can be controlled.

[0031]

[Table 1]

The amount of nitrogen in Table 1 is shown as a percentage of the amount of nitrogen dissolved in the ink with respect to the saturation value.
In the case of the ink used in this embodiment, the saturation value is 10 to 1
It was about 1 ppm. Next, how the degree of deaeration of the ink in the ink tank 7 changes at the time of manufacturing and after opening will be described with reference to the amount of nitrogen in the ink. According to the experiment, as shown in FIG. 8, the period up to b in the figure is a period from immediately after the ink is filled until the ink is left under atmospheric pressure and packed under reduced pressure.
The period from immediately after the ink is filled to the period a is about 3 days.
The ink in the ink tank 7 is gradually degassed through the sealing member 22 or 21 having a large gas permeability until the period c after the packaging under reduced pressure. According to the experiment, the relationship between the time required to reach a certain amount of nitrogen after decompression packaging and the gas permeability when the communication hole 9 of 0.00001 m ² is sealed with a sealing member is shown in Table 2 according to the experiment.
The ink in the ink tank is degassed again in a shorter period as the gas permeability increases.

[0033]

[Table 2]

When a sealing member having a gas permeability of 100 cc / m ² · 24 h · atm or less is used, the period of re-evacuation becomes longer, and if the transportation period and the storage period are taken into consideration, sufficient deaeration is required during use. There is a practical problem because it is not possible to do so. In the case of using a sealing member having a short transportation period and a small gas permeability, it is possible to degas again by shortening the time that the resin is left under atmospheric pressure until it is sealed with the sealing members 21 and 22 after filling. The time required for use is short, and sufficient reliability can be ensured during use. Alternatively, when sealing with the sealing members 21 and 22, the sealing may be performed in an environment with a degree of vacuum even if only slightly. In this case, since the pressure difference between the inside of the ink tank 7 and the space 29 is reduced, there is an effect that even if the bonding strength of the sealing members 21 and 22 is small, the sealing members 21 and 22 are not separated.

In the figure, the period from c to d is the storage period in the packaged state. The experiment assumed two years. Then, the nitrogen amount sequentially increases from the time point d in the figure after opening. The amount of nitrogen in the ink reaches a substantially saturated state shown in e in FIG. However, according to experiments, it was found that the effect of degassing can be expected for about 2 to 4 weeks after opening d in the figure (f in the figure). Thereafter, the ink becomes completely saturated, and the effect of deaeration of the ink desired in the present invention is lost.

Here, the effect of ink degassing will be described. When inserting and removing the ink tank 7 with respect to the hollow needle 5, the amount of air mixed in from the hollow needle 5 is usually very small. According to an experiment, when the ink inlet diameter of the hollow needle 5 was about 0.8 mm in diameter, the amount of air to be mixed was at most about 0.4 cubic mm of the meniscus. The air once mixed flows toward the recording head 3, reaches a filter 4a (not shown) in the filter chamber 4, and is trapped. This trapped air is filtered 4
Since the coarseness of a is very fine, it does not easily pass through the filter 4a. According to the experiment, the diameter of the filter 4a is 4 mm, and the space width in the filter chamber 4 is 0.3 to 0.5 mm.
When the number of times the ink tank 7 is inserted and removed is about 10 to
Even if the recording is performed 0 times, the air is filtered by the filter 4a.
Did not pass through. If air of such a degree is mixed, degassed ink can be obviously supplied to the recording head 3 during the period up to e in FIG. , Hollow needle 5
The more air mixed into the ink does not cause a problem. However, in actual use, a case where the ink tank 7 is left detached from the hollow needle 5 is sufficiently possible. In this case, a large amount of air is mixed. When a large amount of air is mixed, the mixed air blocks the filter 4a and hinders the passage of ink. As a result, the recording head 3
Causes ejection failure. In this case, the suction pump 15 is operated to perform the recovery operation of the ejection failure, but it was also found by experiments that there is a large difference in the recoverability depending on the degree of deaeration of the ink. In the case of the ink up to about 2 to 4 weeks after opening shown by f in FIG.
There is no inconvenience in removing by suction with 5. However, after this period, the amount of air in the ink became completely saturated, and furthermore, became supersaturated, and it was confirmed that fine bubbles were generated from the filter 4a to the recording head 3 when passing through the filter 4a together with the air. If the microbubbles are present in the pressure chamber of the recording head 3, a discharge failure occurs.

As described above, it is possible to eliminate the problem that the air mixed at the time of replacing the ink tank 7 causes a discharge failure due to the effect of deaeration of the ink.
Also, in the recovery operation performed when a large amount of air accumulates in the filter chamber 4, the recovery operation can be terminated satisfactorily due to the effect of ink degassing. If the amount of air in the filter chamber 4 is equal to or less than a certain amount, the air and the ink together
8, there is no problem at the time of the recovery operation even if the ink is in a saturated state after e in FIG.

[0038]

According to the present invention, since the ink in the ink tank does not leak, it is possible to pack the ink in the ink tank under reduced pressure without impairing the filling property of the ink. The gas passes through the sealing member provided in the communication hole of the ink tank, and the ink is degassed again because a space with a high degree of vacuum exists between the ink tank and the packaging container. Thus, the degassed ink can be supplied to the recording apparatus at the beginning of use of the ink tank, and the problem caused by air entering the ink supply path when the ink tank is replaced can be eliminated. Further, it is easy to open the sealing member for sealing the ink tank. As described above, there is an effect that an extremely reliable, small-sized and inexpensive inkjet recording apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a main cross-sectional view for explaining one embodiment of an ink jet recording apparatus of the present invention.

FIG. 2 is an exploded perspective view of a main part of an ink tank used in the ink jet recording apparatus of the present invention.

FIG. 3 is a perspective view of a main part of the ink jet recording apparatus of the present invention.

FIG. 4 is a block diagram illustrating an ink end detection circuit.

FIG. 5 is a perspective view of a main part of the inkjet recording apparatus of the present invention.

FIG. 6 is a perspective view illustrating an ink tank packaged under reduced pressure.

FIG. 7 is a cross-sectional view for explaining the inside of the reduced-pressure packaging container.

FIG. 8 is a diagram showing the relationship between the amount of nitrogen permeation and time.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Platen 2 ... Carriage 3 ... Recording head 4 ... Filter chamber 5 ... Hollow needle 7 ... Ink tank 9 ... Communication hole 9a ... ··· Vent hole 13 ··· Cap 15 ··· Suction pump 17 ··· Waste ink reservoir 19 ··· Differentiator circuit 20 ··· Comparative circuit 21 ··· Openable sealing member 22 sealing member 25 packaging bag 26 sealing portion 28 spacer 29 space S1 electrode S2 electrode

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-270001 (JP, A) JP-A-4-144755 (JP, A) JP-A-2-214665 (JP, A) 81742 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 2/175

Claims (10)

(57) [Claims] 1. An ink tank for supplying ink to a recording head, wherein the ink tank has an ink reservoir and a front of the ink reservoir.
Serial and communication portion for communicating the recording head, and the atmosphere and communicating with it as drilled the communication hole, the water vapor permeability for sealing the communicating hole is not more than ^{2000g / m 2 · 24h · atm} , and gas permeability Is 100c
An ink tank having a sealing member of c / m ² · 24 h · atm or more, and hermetically sealed in an airtight container under reduced pressure so as to maintain a space near the communication hole. 2. A plurality of communication holes, wherein all of the communication holes are sealed by a sealing member having a water vapor permeability of 2000 g / m ² · 24 h · atm or less, and at least one of the communication holes has a water vapor permeability. 100c but not more than ^{2000g / m 2 · 24h · atm} , and gas permeability
^2. The ink tank according to claim 1, wherein the ink tank is sealed with a sealing member of c / m ² · 24 h · atm or more. 3. A process according to claim 1 or 2 ink tank, wherein the at least one of the sealing member is a openable. 4. The ink tank according to any one of claims 1 to 3, characterized in that said sealing member is made of resin. 5. The ink tank according to claim 3, wherein the sealable member that can be opened is opened by peeling. 6. The ink tank according to claim 5, wherein a part of the sealable member that can be opened is joined to the airtight container. 7. The device according to claim 3, wherein the openable sealing member is made of a member that can be broken by a projection.
The described ink tank. 8. The ink tank according to claim 1, wherein the space is formed by a spacer. 9. The ink tank is formed so as to be capable of storing a plurality of color inks, has the communication holes corresponding to the respective colors, and seals the communication holes of the respective colors with one sealing member. any one of claims 1 to 3, characterized in that it is
Item 2. The ink tank according to item 1 . 10. An ink reservoir, a communication portion for communicating the ink reservoir with a recording head, a plurality of communication holes formed so as to communicate with the atmosphere, and a sealing member for sealing the communication hole. A method for manufacturing an ink tank having: Step of depressurizing the ink reservoir through the communication hole B. B. supplying ink from the communication hole to the ink tank and filling the ink tank; Water vapor permeability of not more than ^{2000g / m 2 · 24h · atm} , and a step of gas permeability of the sealing member is 100cc / m ² · 24h · atm or more, sealed at atmospheric pressure in the communication hole D. A method for manufacturing an ink tank, comprising the steps of: placing the ink tank in a non-permeable container, providing a space between the communication hole and the closed container, depressurizing the inside of the container, and sealingly packing the container.