JP2641675B2 - Ink storage container for ink jet head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ink jet recording to be printed recording ink on a recording medium by supplying to the ink jet head
The present invention relates to an ink container for an ink jet head of an apparatus .

[0002]

2. Description of the Related Art An ink tank used in an ink jet recording apparatus can satisfactorily supply ink corresponding to the amount of ink ejected from a recording head during recording.
During non-printing, it is required that there is no leakage of ink from the ejection ports.

When the ink tank is of a replaceable type, it is required that the ink tank is smoothly attached and detached, there is no ink leakage at that time, and the ink is reliably supplied to the recording head.

[0004] As a conventional ink tank for an ink jet recording apparatus, first, an ink bag filled with ink is mounted below a recording head position, and ink is supplied to the recording head by drawing an ink supply tube. There is a method. In this method, a negative head pressure is generated due to a difference in height between the tank and the recording head, and a stable ink meniscus is maintained at the ink discharge port.
However, the supply system itself becomes very large,
Not only is it difficult to reduce the size of the apparatus, but also the amount of ink consumed by the recovery pump is increased due to evaporation of the ink in the tube, and there is also a problem of waste ink treatment and an increase in running cost.

[0005] As another ink tank used in a conventional ink jet recording apparatus, there is one disclosed in JP-A-63-63242. This is an ink jet recording cartridge having a plurality of ink ejection orifices in which a foaming agent (absorber) is arranged in an ink tank. In order to maintain a stable ink meniscus in the ink ejection section of the recording head, the ink is used. The tank is filled with an absorbent such as polyurethane foam as a foam material, and the ink is held by the capillary force of the absorbent. In this case, almost all of the ink tank needs an absorber,
Since the internal negative pressure is generated by holding the ink a little less than the maximum amount of ink that the absorber can hold, the recording head and ink tank may be exposed to mechanical shocks such as vibrations or heat such as temperature changes. Even when a mechanical impact is applied, there is no leakage of ink from the discharge section of the recording head or the air communication section of the ink tank. However, in the conventional method in which the absorber is completely filled in the tank, the amount of ink that can be held with respect to the volume of the ink tank (ink holding ratio) is small, and the amount of ink remaining unused is increased, resulting in poor ink use efficiency. There was a problem. Further, considering that the ink tank is to be scanned with the recording head facing the recording paper, there has been a problem in miniaturizing the recording apparatus main body and reducing the running cost.

[0006] Therefore, there is a demand for an ink having a high use efficiency, and there has been proposed a type which does not use an absorber in an ink tank.

Japanese Patent Application Laid-Open No. 56-067269 discloses a system using an ink bag urged by a spring in an ink tank. Although this spring bag method is excellent in that the internal negative pressure in the ink supply unit is stably generated by using a spring force, there are restrictions on a spring shape for obtaining a predetermined internal negative pressure and an ink tank. However, there is a problem that the process of fixing the bag is slightly complicated, the manufacturing cost is high, and the ink holding ratio is small in a thin ink tank.

Recently, there has been proposed a type in which the absorber is not completely filled in the ink tank but is partially filled with the absorber. This improves the ink use efficiency by improving the ink holding ratio by providing a portion not filled with the porous member.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet apparatus which uses a negative pressure generating member and has a high ink use efficiency.
An object of the present invention is to provide a head ink container .

Further, the present invention relates to a method for recording during distribution and ink jet recording.
In the use condition of the apparatus , the ink jet head and the ink
Even if the thermal impact such as mechanical shock or temperature changes, such as vibration in the storage container is granted, no leakage of ink,
An object of the present invention is to realize a more reliable ink container for an ink jet head .

[0011]

Means for Solving the Problems The present inventors have conducted various studies to achieve the above object, and as a result, completed the present invention. That is, the first invention has a large
To supply ink to the air communication part and the ink jet head
And a negative pressure generating member housed inside.
The negative pressure generating member storage chamber communicates with the negative pressure generating member storage chamber.
Communication through a road, and substantially except for the communication passage.
And an ink storage chamber that is hermetically sealed.
An ink container for the ink container, wherein
Part containing at least one nonionic surfactant
Ink jet head, which is filled with ink
The present invention relates to an ink storage container for storage . In the above invention , the nonionic surfactant is an ethylene oxide adduct of a higher alcohol represented by the following general formula [1],
An ethylene oxide adduct of an alkylphenol represented by the following general formula [2], an ethylene oxide-propylene oxide copolymer represented by the following general formula [3] and an acetylene glycol represented by the following general formula [4]: Surfactants selected from ethylene oxide adducts

[0012]

Embedded image (R is an alkyl group)

[0013]

Embedded image (R is an alkyl group)

[0014]

Embedded image (R is hydrogen or an alkyl group)

[0015]

Embedded image (M and n are integers), and the content of the nonionic surfactant is 0.1.
In the range of 1 to 20% by weight;
Is in the range of 6 <m + n <14.

Further, in the first invention , it is preferable that the ink
A storage container is integrally formed with the ink jet head , or the ink storage container is configured as the ink jet head.
And that it can be separated and exchanged .

Furthermore, the ink tank cartridge
And the recording head can be separated and exchanged.
No.

According to a second aspect of the present invention, there is provided an atmosphere communication section communicating with the atmosphere.
And ink for supplying ink to the ink jet head
Negative pressure generator with a supply section and a negative pressure generating member housed inside
The raw member storage chamber and the negative pressure generation member storage chamber
And is substantially sealed except for the communication passage.
An ink storage chamber having an ink storage chamber;
Ink container, and a non-ink container inside the ink container.
Ink containing at least one surfactant
From the ink storage chamber to the ink storage chamber.
The even flow out of at least 30% or more of the ink volume
It is characterized in that it can be absorbed in the negative pressure generating member storage chamber
The present invention relates to an ink container for an ink jet head .

Further, in the second invention, the ink
The method includes forming a storage container integrally with the ink ejection head , or configuring the ink storage container so as to be separately replaceable with the ink ejection head .

Further, the nonionic surfactant includes an ethylene oxide adduct of a higher alcohol represented by the following general formula [1], an ethylene oxide adduct of an alkylphenol represented by the following general formula [2], A surfactant selected from an ethylene oxide-propylene oxide copolymer represented by the general formula [3] and an ethylene oxide adduct of acetylene glycol represented by the following general formula [4]

[0021]

Embedded image (R is an alkyl group)

[0022]

Embedded image (R is an alkyl group)

[0023]

Embedded image (R is hydrogen or an alkyl group)

[0024]

Embedded image And the content of the nonionic surfactant is 0.1.
In the range of 1 to 20% by weight .

Further, m and n of the above compound are 6 <m + n
<14 .

Furthermore, including Rukoto provided air communicating portion, the ink chamber of the last portion communicating with the supply section ink chamber.

According to a third aspect of the present invention, there is provided an atmosphere communication section communicating with the atmosphere.
And ink for supplying ink to the ink jet head
Negative pressure generator with a supply section and a negative pressure generating member housed inside
The raw member storage chamber and the negative pressure generation member storage chamber
And is substantially sealed except for the communication passage.
It has a certain ink storage chamber, an ink jet result in ink stable supply period in consumption period in the negative pressure curve of the ink
An ink storage container for a head , wherein the ink storage container
Ink jet ink that contains at least one non-ionic surfactant in the interior of the is characterized in that it is filled
The present invention relates to an ink container for a head .

In the third aspect of the present invention, the ink storage device
Configuring the container to be separable exchanged with the ink jet head, or the ink jet heads of said ink container
Comprising configuring the separation interchangeably de.

According to the present invention, there is provided an ink tank comprising an ink chamber filled with an ink absorber and an ink chamber not filled with one or a plurality of absorbers communicating with the ink chamber. By adding an ionic surfactant, it has become possible to realize an ink-jet ink cartridge having a high ink holding ratio that can maintain stable ejection and reliably prevent ink leakage. Further, according to the present invention, the recording head and the ink tank can be configured to be separable, and an ink-jet ink cartridge which is economical and environmentally friendly can be obtained.

Hereinafter, the present invention will be described with reference to the drawings.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a schematic perspective view showing a part of the ink tank of the first embodiment in a cutaway manner, and FIG. 2 is a schematic sectional view of the first embodiment.

As shown in FIGS. 1 and 2, the ink cartridge body 1 of this embodiment has two ink chambers (a,
b) communicating with the bottom at the bottom, filling one ink chamber a with an ink absorber with adjusted capillary force, and having an ink supply unit 2 and an atmosphere communication unit 3 for connecting to an ink jet recording head; Has become.

The positions of the air communication unit 3 and the ink supply unit 2 are not particularly limited to this, and even if the positional relationship is as shown in FIG. 2B, as shown in FIG. The ink supply section may be on the bottom.

FIG. 3 is a cross-sectional view showing a state in which the recording head, the ink tank, and the carriage of the ink jet recording apparatus of the present invention are connected. The recording head 10 according to the present embodiment is of a bubble jet type that performs recording using an electrothermal converter that generates thermal energy for causing ink to cause film boiling according to an electric signal. In FIG. 3, all of the main components of the recording head 10 are formed by laminating or bonding on the head base plate 11 by using a positioning projection (not shown) provided on the head base plate 11 as a positioning reference. Here, the in-plane vertical direction of FIG.
And the projection. Further, in the vertical direction in the cross-sectional view of FIG. 3, a part of the protrusion projects so as to cover the head positioning portion 104, and is positioned by the cutout portion (not shown) of the protrusion and the head positioning portion 104. The heater board 13 is S
An electric heat converter (discharge heater) arranged in a plurality of rows on an i-substrate and electric wiring of Al or the like for supplying electric power to the electric heat converter are formed by a film forming technique. Flexible board (hereinafter referred to as "head PCB") having a wiring in which a pad for receiving a signal is disposed at an end.
The wires 105 are connected to each other by wire bonding so as to correspond to the respective wires. Forming a common liquid chamber and a plurality of discharge ports for introducing ink from the replacement ink tank 1 and supplying the ink to the ink flow path through partition walls and flow paths for partitioning the plurality of ink flow paths corresponding to the discharge heaters; Top plate 12 integrally molded with orifice made of polysulfone
Is pressed against the heater board 13 by a spring (not shown), and is press-fixed and sealed using a sealant to form an ink discharge portion. The flow path 15 coupled and sealed to the groove top plate 12 is:
In this embodiment, the head PCB 13 and the head base plate 1
1 and penetrates to the opposite side of the head base plate 11 and is fixed to the head base plate 11 by a penetrating portion. Further, a filter 8 is provided at an end of the flow path 15 on the side connected to the ink tank 1 to prevent dust or unwanted bubbles from flowing into the discharge section. The replacement ink tank is coupled to the recording head 10 by the engagement guide 5 and the pressurizing means 103, and is mechanically coupled when the ink absorber of the ink supply unit 2 comes into contact with the filter 8 provided at the tip of the flow path 15. Is made. After coupling, the print head suction recovery pump 5015 of the printing apparatus main body
The ink is combined by forcibly supplying and filling the recording head 10 with ink from the replacement ink tank 1 using a method such as the above.

In this embodiment, the recording head 10 and the replacement ink tank 1 are connected when the pressure means is engaged, and the recording head 10 and the carriage HC are mechanically and electrically connected in the same direction. Therefore, the positioning between the pad on the head PCB 105 and the head drive electrode 102 is also reliably performed.

In this embodiment, the ring seal 9 is formed of a somewhat thick elastic ring so that the joint portion with the outer wall of the replacement ink tank can be made wider so as to allow backlash of the ink supply unit 2.

As described above, in the present embodiment, the replacement ink tank 1 and the recording head 10 are sufficiently coupled to each other and then the replacement ink tank is urged, so that the positioning of the carriage, the recording head and the recording head is simplified. In addition, the recording head and the replacement ink tank are easily connected outside the main body and then mounted on the carriage, so that the replacement operation can be facilitated. Further, in the present embodiment, since the electrical connection between the carriage (printing apparatus main body) and the printhead is made at the same time, the operability when replacing the printhead and the replacement ink tank is good, It is also possible to increase the degree of freedom in the configuration for making the connection of the recording head and the connection with the replacement ink tank more reliable by using a separate connector connection method or the like.

Here, in order to explain the arrangement and operation of the recording head in the ink jet recording apparatus of this embodiment, the operation of the recording apparatus will be briefly described with reference to FIG. 4 which is a perspective view. In FIG. 4, the recording medium P is guided upward from the bottom of the paper using a platen roller 5000, and the platen 5 is moved by a paper pressing plate 5002 in the carriage movement direction.
000. The carriage HC is supported and engaged by a lead screw 5005 which operates as a drive source by inserting a carriage drive pin into its spiral groove 5004 and rotates by itself, and a slider 5003 arranged in parallel with the lead screw, thereby causing a platen roller. 50
00 reciprocates right and left along the recording surface of the recording medium P guided upward. The rotation of the lead screw 5005 is controlled via the drive transmission gears 5011 and 5009 in conjunction with the forward / reverse rotation of the drive motor. Reference numerals 5007 and 5008 denote home position detecting means for confirming the presence of the lever 5006 of the carriage HC in this area by photocouplers and switching the rotation direction of the motor 5013. The image recording signal is sent to the recording head 10 in a timely manner with respect to the movement of the carriage HC on which the recording head is mounted, and performs recording by discharging ink droplets at predetermined positions. Reference numeral 5016 denotes a member that supports a cap member 5022 that caps the front surface of the recording head 10. Reference numeral 5015 denotes suction means that suctions the inside of the cap, and performs suction recovery of the recording head through an opening 5023 in the cap. 5017 is a cleaning blade.
Reference numeral 019 denotes a member which enables the blade to move in the front-rear direction, and these members are supported by the main body support plate 5018. It is needless to say that the suction means, the blade, and the like need not be in this form, and well-known ones can be applied. Reference numeral 5012 denotes a lever for determining the timing of the suction recovery operation. The lever 5012 moves with the movement of the cam 5020 engaging with the carriage, and the driving force from the driving motor is controlled by known transmission means such as clutch switching. Is done. These recovery means are configured such that when the carriage HC comes to the home position side area, desired processing can be performed at predetermined positions at the corresponding positions by the action of the lead screw 5005.

Hereinafter, the present invention will be described in more detail.

FIG. 5 shows the initial state of the ink chambers a and b sufficiently filled with ink, and FIG. 6 shows the ink that can be supplied to the ink chamber a and 1/5 of the ink chamber b from the initial state.
This is a state in which about ink has been consumed. In FIG. 6, the ink of the compressed ink absorber is maintained at a height where the water head pressure from the ejection part of the recording head, the pressure reduction in the ink chamber b, and the capillary force in the compressed ink absorber are balanced. When the ink is supplied from the ink supply unit, the amount of ink in the ink chamber a does not decrease and the ink in the ink chamber b is consumed. That is, while the ink distribution in the ink chamber a does not change and the internal pressure is maintained in an equilibrium state, the ink corresponding to the ink supply is consumed from the ink chamber b and the air corresponding to the ink is supplied into the ink chamber b. The ink is introduced from the atmosphere communication portion via the ink chamber a. At this time, in the communicating portion between the ink chambers a and b, the ink and the atmosphere are exchanged (gas-liquid exchange), and a portion of the meniscus formed in the compressed ink absorber of the ink chamber a closes to the ink chamber b. The ink chamber b
Atmosphere is introduced into the ink chamber b until the pressure of the ink balances with the meniscus holding force of the compressed ink absorber. That is, the internal pressure of the ink supply unit is maintained at a predetermined value by the capillary force of the compressed ink absorber in the ink chamber a. At this time, by pressing the flow path 15 of the recording head into the ink supply unit 2 and pressing the filter 8 against the absorber, the compression ratio of the absorber near the ink supply unit is partially increased, and the ink supply unit More ink may be distributed to facilitate gas-liquid exchange near the ink chamber wall. Further, as shown in FIG. 7, a rib 4 or the like may be provided between the ink chamber wall and the compressed ink absorber in the ink chamber a to make it easier for air from the air communication portion to pass.

FIG. 8 shows how the internal pressure in the ink supply section of the replacement ink tank of this embodiment changes according to the ink supply amount (consumption amount). In the initial state, a small amount of ink is present in the ink chamber a, and an internal pressure is generated due to the capillary force of the compressed ink absorber. However, as the ink in the ink chamber a decreases as the ink is supplied, the compressed ink absorber becomes smaller. The internal pressure generated by the capillary force gradually increases in accordance with the compressibility distribution (pore distribution) of. When the ink is further consumed, the ink distribution in the ink chamber a is stabilized, the ink in the ink chamber b is consumed, and the atmosphere is introduced into the ink chamber b as described above, and thereafter, the ink is substantially constant. Is maintained (a stable ink supply period). When the ink is further consumed and all the ink in the ink chamber b is consumed, the ink in the ink chamber a starts to be consumed again, and the internal pressure changes. When the internal pressure of the ink supply unit becomes larger than a predetermined negative value, replacement of the ink tank or replacement integrally with the recording head is required.

FIG. 9 illustrates the function of the compression absorber as a buffer absorber. In the state shown in FIG. 6, the ink chamber b expands due to the expansion of the air in the ink chamber b due to a decrease in atmospheric pressure or an increase in temperature. Of the ink has flowed out toward the ink chamber a. In this embodiment, the ink flowing out into the ink chamber a is held by the compression absorber. Regarding the relationship between the ink absorption amount of the compression absorber and the ink chamber, from the viewpoint of preventing the ink leakage at the time of the above-described pressure reduction or temperature change, the amount of the ink flowing out from the ink chamber b under the worst condition, Considering the amount of ink held in the ink chamber a when the ink is supplied from the chamber b, the ink chamber a
The maximum amount of ink absorption may be determined, and the ink chamber a may have at least a volume for accommodating the corresponding compression absorber. FIG. 10 shows the initial space volume of the ink chamber b before decompression and the value of 0.1.
The relationship with the ink outflow amount when the pressure was reduced to 7 atm is shown in the solid line graph. The case where the maximum pressure reduction condition of the atmospheric pressure is 0.5 atm is shown by the dashed line in FIG. Ink chamber b
The worst-case estimation of the amount of ink spilled from
When the maximum decompression condition of the atmospheric pressure is set to 0.7 atm, the amount of ink flowing out from the ink chamber b becomes the maximum when 30% of the ink in the volume VB of the ink chamber b remains in the ink chamber b. If the ink below the lower end of the ink chamber wall is also absorbed by the compression absorber of the ink chamber a, then all the ink (30% of VB) remaining in the ink chamber b leaks out. good. When the worst condition of the atmospheric pressure is 0.5 atm, 50% of the ink in the ink chamber b flows out. In other words, the air in the ink chamber b that expands under reduced pressure becomes larger as the remaining ink amount is smaller, and a larger amount of ink is pushed out, but does not flow out more than the ink amount in the ink chamber b. Therefore, assuming a pressure of 0.7 atm, if the remaining ink becomes 30% or less, the amount of the remaining ink becomes smaller than the amount of expansion of the air, so that the amount of ink flowing out into the ink chamber a decreases, and 30% of the volume (50% at 0.5 atm) is the maximum leaked ink amount. The above phenomenon is the same even when the temperature of the ink tank changes, but even when the temperature rises by about 50 deg, the outflow amount is smaller than that at the time of the above-described pressure reduction.

It is considered that the design of the ink buffer should be performed in consideration of the maximum amount of leaked ink. However, the effect of the ink buffer depends not only on its capacity but also on the ink composition. Was obtained.

First, a case where an ink having the following composition is used as a comparative example will be described.

Comparative Composition Dye 4 parts Glycerin 7.5 parts Thiodiglycol 7.5 parts Urea 7.5 parts Pure water 73.5 parts As shown in FIG. 11, ink chamber b due to reduced atmospheric pressure or increased temperature. When the ink in the ink chamber b is pushed out toward the ink chamber a due to the expansion of the air inside the chamber, the ink is not absorbed by the absorber and travels along the gap between the tank wall and the ink chamber wall and the absorber to communicate with the atmosphere. This causes a problem that ink leaks out of the apparatus.

As inks for ink jet recording apparatuses, those to which a surfactant is added have been proposed. This type of ink has a very fast fixability to plain paper such as copy paper and bond paper, and in color recording, even if ink recording areas of different colors are adjacent to each other, an improper mixture of colors (bleeding at the boundary or (Bleed) and uniform coloring (less color unevenness). One composition example is shown below.

Working Composition Dye 4 parts Glycerin 7.5 parts Thiodiglycol 7.5 parts Acetylene glycol EO adduct (m + n = 10) 5 parts Urea 7.5 parts Pure water 68.5 parts EO: ethylene oxide When ink is used, as shown in FIG. 9, when the ink in the ink chamber b is pushed out toward the ink chamber a due to expansion of air in the ink chamber b due to a decrease in atmospheric pressure or an increase in air temperature, the ink chamber The ink was not absorbed by the absorber a and leaked out of the ink cartridge.

As described above, when the ink is supplied from the ink chamber b, the gas-liquid interface of the ink in the ink chamber a is caused by the water head pressure from the discharge portion of the recording head, the pressure reduction in the ink chamber b, and the pressure. The capillary force of the compressed ink absorber is maintained at a balanced height. Assuming that the average ink height at the gas-liquid interface of the ink chamber a at this time is H, if there is an outflow of ink from the ink chamber b due to a decrease in atmospheric pressure or an increase in temperature, the gas-liquid The ink height at the interface must be able to be absorbed and held higher by h. As an example in this embodiment, the total height of the ink chamber is 3
cm, and the volume of the ink chambers a and b was 6 cc.
In the initial stage of the ink chamber b, all 6 cc of the ink chamber was filled with ink, and the ink chamber a contained a compression absorber (polyurethane foam), and was initially filled with 4 cc of ink (total ink amount 10 cc). The porosity of the absorber is 9
When the ink is filled in all the voids of the absorber, the ink chamber a can be filled with nearly 6 cc of ink. First, in this ink tank, an ink chamber a
The ink in the ink chamber b starts to be consumed after a while, and the gas-liquid interface of the ink chamber a is reduced by the water head pressure from the discharge part of the recording head, the decompression in the ink chamber b, and its compression. The capillary force of the ink absorber is maintained at a height that is balanced. Since the height of the gas-liquid interface at this time was about 1.5 cm on average, the ink amount in the ink chamber a was about 3 cc if almost all the voids of the absorber were filled with ink. it is conceivable that. Here, when the maximum decompression condition of the atmospheric pressure is set to 0.7 atm, 1.8 cc, which is about 30% of the volume of the ink chamber b, may flow out. Therefore, about 3 cc + 1.8 cc (in the ink chamber a). (Ink liquid level is about 2.4 cm).
Further, when the maximum pressure reduction condition is 0.5 atm, 3 cc, which is about 50% of the volume of the ink chamber b, may flow out. 3cm) It must be able to absorb and hold. That is, the ink chamber a needs to be able to fill and hold at least the volume of the absorber itself, the amount of ink originally in the ink chamber a, and the amount of ink flowing out of the ink chamber b. Therefore, the inner volume of the ink chamber a greatly changes depending on the estimation of the amount of ink flowing out from the ink chamber b.

The ink holding height H of the porous absorber is generally considered to be expressed by a capillary force formula. The surface tension of the ink is γ, the contact angle between the ink and the ink absorber is θ, the density of the ink is θ. Is ρ, g is the gravitational acceleration, and r is the average pore radius of the ink absorber, and H = 2γcos θ / ρgr.

In order to increase the ink holding height H so that more ink can be absorbed and held,
It is considered that the surface tension of the ink should be increased, or the contact angle θ between the ink and the ink absorber should be reduced (cos θ should be increased).

To increase the surface tension of the ink,
The ink of the comparative composition has a surface tension of about 50 dyn / cm, which is a class of ink having a high surface tension. However, as described above, the ink was not well absorbed by the absorber. Reducing the contact angle θ between the ink and the ink absorber means that the ink is very easily wetted by the absorber,
Generally, surfactants are used as penetrants.

In the case of the ink of the working composition, the surface tension was as small as about 30 dyn / cm due to the addition of the surfactant. However, it is considered that the wettability between the absorber and the ink was improved and the permeability was extremely improved. Can be Thus, it can be said that it is more effective to improve the ink leakage than the surface tension.

In order to compare the permeability of the ink, the compressed ink (polyurethane foam) was immersed in the ink of the comparative composition and the ink of the working composition, and the height at which the ink was absorbed was measured. Several meters
m, which hardly absorbed the ink,
The ink of the working composition showed an overwhelming difference in absorbency of 2 cm or more. As long as the ink contains a surfactant as in the embodiment and has good permeability, the ink can be sufficiently absorbed even if there is an outflow of the ink from the ink chamber b due to a decrease in atmospheric pressure or an increase in temperature. Recognize.

Examples of the penetrant include anionic surfactants such as aerosol OT type, sodium dodecylbenzenesulfonate, and sodium lauryl sulfate; ethylene oxide adducts of higher alcohols represented by the following general formula [1]; Ethylene oxide adduct of alkylphenol represented by formula [2], ethylene oxide-propylene oxide copolymer represented by the following general formula [3], ethylene oxide addition of acetylene glycol represented by the following general formula [4] Nonionic surfactants such as materials are excellent.

However, the above-mentioned anionic surfactant has a large foaming power, is inconvenient to handle, and has image characteristics such as boundary bleeding, color uniformity and feathering, which are higher than those of the anionic surfactant. In the present invention, a nonionic surfactant represented by the following general formula was used because the nonionic surfactant was better.

Here, n is preferably 6 to 14 in the general formulas [1] and [2]. R preferably has 5 to 26 carbon atoms. In general formulas [3] and [4], m + n
Is preferably 6 to 14.

[0058]

Embedded image (R is an alkyl group)

[0059]

Embedded image (R is an alkyl group)

[0060]

Embedded image (R is hydrogen or an alkyl group)

[0061]

Embedded image (M and n are integers) Among the ethylene oxide-type nonionic surfactants described above, ethylene oxide adduct of acetylene glycol has an absorptivity to an ink absorber, an image characteristic on a recording medium, and a discharge from a recording head. A very good balance in characteristics and the like is preferable. Further, hydrophilicity and permeability of this compound are controlled by the number m + n of ethylene oxide to be added. When m + n is less than 6, the permeability is good, but the water solubility is poor and the solubility in ink is not good. Conversely, if the number of added ethylene oxides is too large, the hydrophilicity becomes too large and the penetrating power becomes small. If m + n is greater than 14, the permeability is reduced, and the increased amount of addition is not effective, but rather adversely affects the ejection characteristics. Thus, this compound has an ethylene oxide addition number of 6 to 14.
Preferably between

The addition amount of these nonionic surfactants is preferably 0.1 to 20% by weight. If it is less than 0.1%, the image characteristics and permeability are not sufficient, and if it is more than 20%, no further effect can be obtained.
This is because the ink is disadvantageous for reliability and the like.

Further, one or more of these nonionic surfactants may be used in combination.

In addition, the ink component generally contains a dye as a recording agent, a low-volatile organic solvent such as a polyhydric alcohol for preventing clogging, foam stability, and fixability on a recording medium. An intended organic solvent such as an alcohol is added as necessary.

Examples of the water-soluble organic solvent forming the ink of the present invention include polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1, 2, 6-hexane. Alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as triol, hexylene glycol, diethylene glycol; glycerin; ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether, etc. Lower alkyl ethers of polyhydric alcohols: methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol Coal, sec-butyl alcohol, te
alcohols such as rt-butyl alcohol, isobutyl alcohol, benzyl alcohol, cyclohexanol;
Amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; N-methyl-2-pyrrolidone;
Examples include nitrogen-containing cyclic compounds such as pyrrolidone and 1,3-dimethyl-2-imidazolidinone. These water-soluble organic solvents can be contained in an amount that does not deteriorate image characteristics and ejection reliability. It is preferably a polyhydric alcohol or an alkyl ether of a polyhydric alcohol, and the content thereof is preferably from 1 to 30% by weight.

At this time, the amount of pure water in the ink used in the present invention is preferably between 50 and 90% by weight.

The dye used in the present invention is a direct dye,
Examples include acid dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, and the like. The content of these dyes is determined depending on the type of the liquid medium component, the characteristics required for the ink, the ejection amount of the recording head, and the like. It is in the range of 15% by weight, preferably 1 to 7% by weight.

In addition, it was found that the addition of thiodiglycol or urea (or a derivative thereof) to the ink significantly improved the ejection characteristics and the effect of preventing clogging (fixation). It is considered that these additions improve the solubility of the dye in the ink. The content of thiodiglycol or urea (or a derivative thereof) is preferably 1 to 30.
% By weight, and can be added as needed.

The main components of the ink of the present invention are as described above, and in addition, viscosity modifiers such as polyvinyl alcohol, celluloses, and water-soluble resins;
A pH adjuster such as triethanolamine and a buffer, a fungicide, and the like can be added as necessary within a range not to hinder the object of the present invention.

In order to prepare an ink used in an ink jet recording apparatus of the type which charges the ink, a specific resistance adjusting agent such as an inorganic salt such as lithium chloride, ammonium chloride and sodium chloride is added.

By arranging the position of the ink supply section of the ink chamber a on the bottom surface of the ink chamber a as shown in FIG. 2C, the height of the gas-liquid interface of the ink chamber a during the stable ink supply period is increased. Even if the value is reduced, the ink does not run out, and the size of the tank can be reduced by increasing the buffer volume.

FIGS. 12 and 13 show modified examples of the present embodiment, in which two ink chambers c and d are further provided so as to communicate with the ink chamber b. In this modification, ink is consumed in the order of the ink chamber b, the ink chamber c, and the ink chamber d. The reason why the ink chamber is divided into four in this modification is to prevent ink leakage under the reduced pressure environment and the temperature change described in the above embodiment. For example, in the state shown in FIG. When the air in the ink chamber c expands, the air expansion in the ink chamber b is released from the air communication portion through the ink chamber a, and the air expansion in the ink chamber c is transferred to the ink chamber b and the ink chamber a. Is solved by the outflow. That is, the ink chamber a has a function as a buffer chamber, and the ink holding capacity of the compressed ink absorber in the ink chamber a may be set in consideration of leakage from one ink chamber. Become. In this case, it is needless to say that it is more effective to use an ink having a very good permeability (wetting property) such as the working composition.

In this embodiment, a single-color recording apparatus having one recording head has been described. However, a plurality of recording heads capable of ejecting inks of different colors, for example, four of Bk, C, M, and Y
It can be applied to a color ink jet recording device with a head, and can also be applied to a recording head that can eject multiple colors of ink with one recording head, in which case the means for regulating the coupling position and direction of the exchange tank May be added.

In this embodiment, an example in which the ink tank is replaced has been described. However, the present invention is applied to a printhead / ink tank integrated replacement system in which a printhead and an ink tank filled with a predetermined amount of ink are integrally formed. It is also possible.

The present invention brings about an excellent effect particularly in a recording head and a recording apparatus of a bubble jet system among ink jet recording systems.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, liquid (ink)
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling, to the electrothermal transducer disposed corresponding to the sheet or the liquid path in which is held, This is effective because thermal energy is generated in the electrothermal transducer, and the film is boiled on the heat-acting surface of the recording head. As a result, bubbles in the liquid (ink) can be formed in one-to-one correspondence with the drive signal. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. Examples of the drive signal in the form of a pulse include those described in U.S. Pat.
Suitable are those described in US Pat. No. 45,262. If the conditions described in U.S. Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,558,333 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 459600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication (Kokai) No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing pressure waves of thermal energy. The present invention is also effective as a configuration based on JP-A-59-138461 which discloses a configuration corresponding to a discharge unit.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, a combination of a plurality of recording heads as disclosed in the above specification is used. Either a configuration that satisfies the length or a configuration as one integrally formed recording head may be used, but the present invention can more effectively exert the above-described effects.

In addition, the print head is replaceable with a print head of a replaceable chip type, which can be electrically connected to the main body of the apparatus or supplied with ink from the main body of the apparatus, or is integrated with the print head itself. The present invention is also effective when a cartridge-type recording head provided in a fixed manner is used.

It is preferable to add recovery means for the print head, preliminary auxiliary means, and the like provided as components of the printing apparatus of the present invention since the effects of the present invention can be further stabilized. To be more specific, a capping unit, a cleaning unit, a pressure or suction unit, a preheating unit using an electrothermal converter, another heating element, or a combination thereof, for the recording head. ,
Performing a preliminary ejection mode in which ejection is performed separately from printing is also effective for performing stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be a single recording head or a combination of plural recording heads. The present invention is also very effective for an apparatus provided with at least one of full colors by color mixture.

<Second Embodiment> The function of the ink tank in the second embodiment will be described with reference to FIG. The replacement ink tank 1 partitions the inner surface into four ink chambers (a to d), communicates at the bottom, and adjusts the capillary force to the ink chamber a of the ink supply unit and the communication between the ink chambers. 2 with almost no gap, and the air communication part 3
Is an improved ink cartridge of the divided ink chamber type in which a buffer absorber for preventing leakage of ink is packed in the ink chamber d.

The state of the ink in FIG.
This is a state in which about half of the ink in the ink chamber c has been consumed from the initial state where b and c are sufficiently filled. When ink is further consumed, the ink in the ink chamber c is depleted of ink.
As shown in FIG. 5, the supply of the ink in the ink chamber b starts.
When the ink is further consumed from the state of FIG. 15 and the ink in the ink chamber b is exhausted, the supply of the ink held in the ink absorber in the ink chamber a filled with the ink absorber is started, and When the ink is almost exhausted,
Replace the replacement ink tank. FIG. 16 illustrates the principle of ink supply and the generation of ink internal pressure in the second embodiment. The ink chamber on the left side in FIG. 16 almost consumes ink,
It is in an atmospheric pressure state because it is communicated with the atmosphere communication part by the action of the communication part between the ink chambers. When ink is supplied from the ink supply unit to the recording head through the ink chamber communication unit, the ink at atmospheric pressure is compressed through the ink absorber that has been compressed and has increased capillary force in the ink chamber communication unit. Ink flows out and is supplied from the ink chamber adjacent to the chamber. The ink chamber where the ink was consumed is depressurized by that amount, and the meniscus formed in the ink absorber compressed between the ink chambers was partially broken, and the depressurized pressure of the ink chamber was compressed. Atmosphere is introduced into the ink chamber being consumed so as to balance the meniscus holding power of the ink absorber. That is, the internal pressure of the ink supply unit is maintained at a predetermined value by the capillary force of the compressed ink absorber in the communication part between the ink chambers. FIG. 17 shows how the internal pressure in the ink supply section of the replacement ink tank of the second embodiment changes according to the ink supply amount (consumption amount). In the initial state, the internal pressure is generated by the capillary force of the buffer absorber or the ink absorber, but the compressed ink absorber (compressed) in the communication portion between the ink chamber d and the ink chamber c with the supply of ink. The internal pressure is generated by the capillary force of the section (2), and as described above, the internal pressure is maintained substantially constant while the ink is supplied from the ink chamber c. When the ink is further consumed, the ink in the ink chamber b starts to be consumed, but when the ink chamber is switched, the internal pressure of the ink supply unit slightly fluctuates. This is considered to be related to the fact that the ink is continuously supplied and the internal pressure is measured, and the state where both the ink chambers c and b are depressurized temporarily occurs. It was confirmed that the function was not a major problem. Ink chamber b
When the ink is stably consumed, the internal pressure is stabilized again. When the ink in the ink chamber b is consumed, the ink in the ink chamber a is supplied (consumed) next.
According to the study by the present inventor, good printing was performed without any problem in the printing characteristics during the stable ink supply period shown in FIG.

FIG. 18 illustrates the function of the buffer absorber. FIG. 18 shows a state in which the ink in the ink chamber c overflows due to the expansion of the air in the ink chamber c due to a decrease in atmospheric pressure or a rise in temperature from the state of FIG. Is shown. In the present embodiment, the ink overflowing into the ink chamber d is held by the buffer absorber. However, when the pressure is 0.7 atm, the buffer is taken into consideration in consideration of leakage of the ink amount of 30% of the volume of the ink chamber c at the maximum. What is necessary is just to determine the ink absorption capacity of the absorber. When the atmospheric pressure recovers to the level before the pressure reduction (returns to 1 atm), the ink leaked to the ink chamber d and held in the buffer absorber returns to the ink chamber c again. The above phenomenon is the same even when the temperature of the ink tank changes, but even if the temperature rises by about 50 deg, the amount of leakage is smaller than when the pressure is reduced.

However, as a result of earnest studies, it was obtained that the effect of the ink buffer greatly depends on the ink composition.

First, a case where inks having the following compositions are used as comparative examples will be described.

Comparative composition Dye 3 parts Diethylene glycol 5 parts Thiodiglycol 5 parts Ethyl alcohol 3 parts Pure water 84 parts In this case, ink chamber b is expanded due to expansion of air in ink chamber b due to reduced atmospheric pressure or increased temperature. When the ink is pushed out toward the ink chamber a, there occurs a problem that the ink leaks from the atmosphere communication part 3 and the ink supply part 2 through the gap between the tank wall and the ink chamber wall and the absorber.

As inks for ink jet recording apparatuses, those to which a surfactant is added have been proposed. This type of ink has a very fast fixability to plain paper such as copy paper and bond paper, and in color recording, even if ink recording areas of different colors are adjacent to each other, an improper mixture of colors (bleeding at the boundary or (Bleed) and uniform coloring (less color unevenness). One composition example is shown below.

Example composition Dye 3 parts Glycerin 5 parts Thiodiglycol 5 parts Ethylene oxide-fluoropropylene oxide copolymer 3 parts Urea 5 parts Pure water 79 parts When this type of ink is used, the atmospheric pressure is reduced or the temperature is increased. When the ink in the ink chamber b is pushed out toward the ink chamber a due to expansion of the air in the ink chamber b due to, for example, the ink in the ink chamber a is not absorbed by the absorber in the ink chamber a and leaks out of the ink cartridge. Was.

[0090]

As described above, a negative pressure generating member including a negative pressure generating member (ink absorbing member, etc.) with adjusted capillary force is generated.
It has a member storage chamber (supply section ink chamber, etc.) and one or more ink storage chambers communicating therewith for storing ink.
In the ink jet head for an ink container which, by filling the ink containing a nonionic surfactant,
Ink-jet recording device during recording and non-recording
Thus, there was no ink leakage due to the change in environmental conditions , and an ink container for an ink jet head with high ink use efficiency was realized.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of an ink tank according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of the first embodiment.

FIG. 3 is a cross-sectional view illustrating a state in which a recording head and a replacement ink tank are mounted on a carriage according to the first embodiment of the present invention.

FIG. 4 is a perspective view of an example of an ink jet recording apparatus to which the present invention can be applied.

FIG. 5 is a diagram illustrating an initial state of an ink tank.

FIG. 6 is an explanatory diagram of ink consumption.

FIG. 7 is a modification of the first embodiment.

FIG. 8 is an explanatory diagram of an internal pressure of an ink supply unit according to the first embodiment.

FIG. 9 is an explanatory diagram of an ink buffer function.

FIG. 10 is a diagram illustrating the relationship between the amount of ink flowing out during pressure reduction.

FIG. 11 is a diagram showing a state of ink leakage at the time of pressure reduction.

FIG. 12 is a modification of the first embodiment.

FIG. 13 is a modification of the first embodiment.

FIG. 14 is a cross-sectional view illustrating a state in which a recording head and a replacement ink tank according to a second embodiment are mounted on a carriage.

FIG. 15 is an explanatory diagram of ink consumption in the second embodiment.

FIG. 16 is a diagram illustrating the principle of exchanging ink with the atmosphere.

FIG. 17 is an explanatory diagram of an ink supply unit internal pressure according to the second embodiment.

FIG. 18 is an explanatory diagram of an ink buffer function according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink tank cartridge main body 2 Ink supply part 3 Air communication part a, b Ink chamber

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiromitsu Hirabayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shinichi Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Norifumi Koitabashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yuji Akiyama 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shigetasu Nagoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masaya Uezuki 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo Inside Canon Inc. (72 ) Inventor Miyuki Matsubara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Fumihiro Goto 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 Within Canon Inc. (56) References JP-A-61-22952 (JP, A) JP-A-50-843111 (JP, A) JP-A-2-55184 (JP, A) JP-A-Heisei 4- 156339 (JP, A) Japanese Utility Model Showa 56-171271 (JP, U)

Claims (15)

(57) [Claims] An ink jet communication device, comprising: an air communication portion communicating with the atmosphere;
And an ink supply unit for supplying ink to the ejection head.
Negative pressure generating member storage chamber containing a negative pressure generating member inside
And communicate with the negative pressure generating member storage chamber via a communication passage.
An ink storage chamber which is substantially sealed except for the communication passage;
And an ink storage container for an ink jet head having:
Te, less the non-ionic surfactant to the inside of the ink container
It is characterized by being filled with at least one kind of ink
And an ink container for an ink jet head . 2. The nonionic surfactant includes an ethylene oxide adduct of a higher alcohol represented by the following general formula [1], an ethylene oxide adduct of an alkyl phenol represented by the following general formula [2], 2. The ink according to claim 1, wherein the ink is selected from an ethylene oxide-propylene oxide copolymer represented by the general formula [3] and an ethylene oxide adduct of acetylene glycol represented by the following general formula [4]. Injection head ink
Storage container . Embedded image Embedded image Embedded image Embedded image 3. The method according to claim 1, wherein the content of the nonionic surfactant is in the range of 0.1 to 20% by weight .
Ink storage container for ink jet head . 4. The compound wherein m and n are 6 <m + n <14.
The ink jet head according to claim 2 or 3, wherein
Ink storage container . Wherein said ink jet f the ink container
5. An integral structure with the pad.
The ink storage for an ink jet head according to any one of the above items.
Container . Wherein said ink jet f the ink container
Claims, characterized in head and separation interchangeably by being configured
5. The ink jet head according to any one of 1 to 4,
Storage container . 7. An ink jet communication device, comprising: an atmosphere communication portion communicating with the atmosphere;
And an ink supply unit for supplying ink to the ejection head.
Negative pressure generating member storage chamber containing a negative pressure generating member inside
And communicate with the negative pressure generating member storage chamber via a communication passage.
The ink storage chamber is substantive sealed except for communication passage
And an ink storage container for an ink jet head having:
Te, less the non-ionic surfactant to the inside of the ink container
Kutomo one containing ink is filled, even if at least 30% or more of the ink of the ink storage chamber volume from the ink storage chamber flows out said negative pressure generating member Osamu
The ink jet head, which can be absorbed in the delivery room
Ink storage container . 8. The nonionic surfactant includes an ethylene oxide adduct of a higher alcohol represented by the following general formula [1], an ethylene oxide adduct of an alkylphenol represented by the following general formula [2], The ink according to claim 7, wherein the ink is selected from an ethylene oxide-propylene oxide copolymer represented by the general formula [3] and an ethylene oxide adduct of acetylene glycol represented by the following general formula [4]. Ink head ink collection
Container . Embedded image Embedded image Embedded image Embedded image 9. The ink according to claim 8, wherein the content of the nonionic surfactant is in the range of 0.1 to 20% by weight.
Ink storage container for ejection head . 10. The compound wherein m and n are 6 <m + n <1.
The ink jet head according to claim 8 , wherein the range is 4.
Ink storage container . 11. The method according to claim 11, wherein the ink container is ejected with the ink.
Claim 7, characterized in that the head and integrally formed
11. The ink for an ink jet head according to any one of 10.
Storage container . 12. The method according to claim 12, wherein the ink container is ejected from the ink container.
Claims characterized by being configured to be separable and replaceable with the head
Item 10. For an ink jet head according to any one of items 7 to 10,
Ink storage container . 13. An ink jet printer, comprising: an air communication portion communicating with the atmosphere;
An ink supply unit for supplying ink to the ejection head;
Negative pressure generating member storage with a negative pressure generating member stored inside
And communicates with the negative pressure generating member storage chamber through a communication passage.
An ink storage chamber which is substantially sealed except for the communication passage;
And an ink container for an ink jet head that provides a stable ink supply period in a negative pressure curve within an ink consumption period, wherein at least one nonionic surfactant is contained inside the ink container. ink jet head for an ink container which ink is characterized in that it is filled. 14. The method according to claim 14, wherein the ink container is ejected with the ink.
14. The apparatus according to claim 13, wherein the head is integrally formed.
An ink container for an ink jet head as described in the above . 15. The method according to claim 15, wherein the ink container is ejected from the ink container.
Claims characterized by being configured to be separable and replaceable with the head
Item 14. An ink container for an ink jet head according to Item 13 .