JPH09295406A - Ink tank, manufacturing method thereof, and inkjet print cartridge - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide an ink tank which can mount a hydrophobic film such as a porous film of a fluororesin on an air communication port with good and good workability, does not leak ink, and is particularly useful for an inkjet print cartridge or the like. To do. An ink tank having an atmosphere communication port and made of a resin, wherein a resin member (10) is provided on an outer peripheral end of a hydrophobic film (101) that allows air to pass therethrough, such as a porous film of fluororesin.
2) or a hydrophobic membrane unit (10 provided with an elastic member
0) is fixed to the atmosphere communication port portion; an ink tank including the fixing step; and an ink jet print cartridge including the ink tank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tank for storing ink, and more particularly to an ink tank useful for an apparatus for recording by an inkjet method.

[0002]

2. Description of the Related Art In an ink tank or the like of an ink jet print cartridge, it is possible to prevent the ink in the tank from being unable to be taken out due to decompression due to ink consumption, and to prevent the ink from leaking from the nozzle of the cartridge by pressurizing the inside of the tank due to temperature rise. An atmosphere communication port is provided for the purpose of prevention. This atmosphere communication port guides the air of the consumed ink into the tank. FIG. 5 is an external perspective view showing an example of a conventional inkjet cartridge.
This inkjet cartridge is roughly divided into
The head unit 202 includes an ink ejecting unit 205, and an ink tank 203 that supplies ink to the head unit.
As shown in FIG. 5, the currently used ink jet cartridges mainly have a system in which a sponge-like member 204 is inserted to hold ink. Further, in this example, a buffer chamber 210 is provided between the atmosphere communication port 206 and the sponge member 204 to prevent ink leakage.
There is also a device such as making the air passage of the atmosphere communication port rectangular rather than a straight hole.

On the other hand, in recent years, a technique for preventing ink leakage by using a porous film (hydrophobic film) of a fluororesin (manufactured by DuPont, trade name Teflon) has been studied. FIG. 6 is a schematic sectional view showing a welded state of a hydrophobic film in a conventional ink tank. As shown in this figure, by covering the atmosphere communication port 206 of the ink tank 208 with a hydrophobic film 201 that allows air to pass through but does not allow ink to pass due to the hydrophobicity of the fluororesin,
Ink leakage can be prevented. The hydrophobic film 201 is welded to the joint 209 by applying heat or ultrasonic waves from the hydrophobic film side.

[0004]

However, the ink tank having a hydrophobic film as shown in FIG. 6 has a problem in terms of welding. The exterior of the ink tank is generally made of a resin molded product having a melting point of about 250 ° C. such as nonyl (modified PPO) or polypropylene, and the hydrophobic film is generally a fluororesin porous film having a melting point of 400 ° C. or more. Therefore, in the case of heat welding as shown in FIG. 6, it is necessary to apply a temperature higher than the melting point of the fluororesin. However, since excessive heat is applied to the tank itself, the tank may be deformed, or the joint 209 may have a nest even though the hydrophobic film is stretched, and the ink may leak from there. Further, in the case of ultrasonic welding, since ultrasonic waves having a power of the melting point of the fluororesin are applied, the power is too large and the hydrophobic film 201 may be broken from the welded portion, and ink may similarly leak.

Further, as another problem, since the hydrophobic film 302 is a fluororesin film, it is easily warped or torn and is difficult to handle, and it cannot be supplied by an automatic parts feeder, resulting in poor workability.

An object of the present invention is to solve the above-mentioned problems, and an ink tank in which a hydrophobic film such as a fluororesin porous film can be mounted in the atmosphere communication port with good and good workability, and which does not leak ink. , A manufacturing method thereof, and an inkjet print cartridge.

[0007]

SUMMARY OF THE INVENTION The present invention is an ink tank having an atmosphere communication port and at least a peripheral portion of the atmosphere communication port made of a resin, wherein an outer peripheral end portion of a hydrophobic film through which air passes. It is an ink tank characterized in that a hydrophobic film unit provided with a resin member or an elastic member is fixed to the atmosphere communication port portion.

The present invention also includes a method of manufacturing an ink tank including a step of fixing such a hydrophobic film unit to a portion of an atmosphere communication port, and an ink jet print cartridge equipped with such an ink tank.

In the present invention, the hydrophobic film is not directly welded to the ink tank as in the prior art, but the hydrophobic film is unitized in advance by insert molding or the like and the hydrophobic film unit is used for mounting. The hydrophobic film can be mounted satisfactorily and with good workability, and ink leakage can be prevented by any method such as welding the resin member portion of the unit or welding the holding member by sandwiching the unit with the holding member. Furthermore, since the hydrophobic membrane is unitized,
It is easy to handle and can be supplied by an automatic machine such as a parts feeder.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

1A and 1B are views showing an example of a hydrophobic membrane unit used in the present invention, wherein FIG. 1A is a schematic perspective view and FIG. 1B is a schematic sectional view thereof. In the hydrophobic membrane unit 100 shown in this figure, the entire outer peripheral end of the circular hydrophobic membrane 101 is covered with the insert-molded resin member 102, and the resin member 102 itself has a ring shape having a square cross section. Further, a rib 103 for ultrasonic welding is provided in a circular shape on one of the wheel side portions of the resin member 102. Compared with a conventional hydrophobic film unit, this hydrophobic film unit 100 welds a resin member 102 (particularly the rib 103 in this example) and a resin forming at least the peripheral portion of the atmosphere communication port of the ink tank. By doing so, it can be fixed to the atmosphere communication port of the tank. The hydrophobic membrane unit 100 is easier to handle than a conventional hydrophobic membrane alone, can prevent the hydrophobic membrane from warping, and can be supplied by a parts feeder, which enables automatic assembly of an ink tank.

As the hydrophobic film 101, a porous film containing a fluororesin such as Teflon (trade name, manufactured by DuPont) is suitable.
However, the present invention is not limited to this, and any hydrophobic film that allows air to pass therethrough but does not allow ink to pass therethrough can be used. For example, a hydrophobic film such as Microtex manufactured by Nitto Denko can be used.

As the resin member 102, a resin of the same type as the resin forming the region to be joined to the ink tank (that is, the peripheral portion of the atmosphere communication port) is suitable from the viewpoint of heat or ultrasonic welding. Since the exterior of the ink tank is usually made of nonyl (modified PPO), polypropylene or the like, it is preferable to use the same resin material for the resin member 102. Especially, the weldability of nonyl is excellent. However, the present invention is not limited to this, and any resin that can be thermally or ultrasonically welded can be used.

As a method for manufacturing the hydrophobic film unit 100, the hydrophobic film 1 is used because there is no ink leakage from the molding interface.
A method of insert-molding 01 into the resin member 102 is suitable. However, the present invention is not limited to this, and the hydrophobic film 10
If it is possible to provide a resin member for welding on the outer peripheral end of 1, a known integral molding method can be appropriately adopted.

FIG. 2 is a schematic perspective view showing an example of the ink jet print cartridge of the present invention in which the hydrophobic film unit of FIG. 1 is mounted. In this inkjet print cartridge, the ultrasonic welding rib 103 of the hydrophobic film unit 100 is brought into contact with the peripheral portion of the atmosphere communication port (opening of the exterior of the ink tank) of the ink tank 104, and ultrasonic waves of appropriate power are applied. Welded together. In this inkjet print cartridge, the hydrophobic film 1
The inside of the ink tank 104 communicates with the outside through 00, but the ink does not leak because it is blocked by the hydrophobic film 100.

FIG. 3 is a view showing another example of the hydrophobic membrane unit used in the present invention, (a) is a schematic perspective view,
(B) is the typical cross section. In the hydrophobic membrane unit 120 shown in this figure, the entire outer peripheral end of the circular hydrophobic membrane 101 is covered by the elastic member 105 formed by insert molding, and the elastic member 105 itself has a ring shape having an elliptical cross section. The resin of the pressing member, at least the joining region of which is made of resin, sandwiching the hydrophobic membrane unit 120,
The hydrophobic film unit 1 is formed by welding at least the resin forming the peripheral portion of the atmosphere communication port of the ink tank.
20 can be fixed to the atmosphere communication port of the tank. Similar to the example shown in FIG. 1, this example is also superior in terms of easiness of handling, prevention of warpage of the hydrophobic film, and automatic assembly.

As the elastic member 105, a silicone-based elastic material is suitable. However, the present invention is not limited to this, and any elastic material that can be fixed by being appropriately pressed by a pressing member 107 described later can be used, for example, those generally used for materials such as O-rings. ,
Specifically, elastic materials such as nitrile rubber, styrene rubber, silicone rubber, fluororubber, acrylic rubber, butyl rubber, and chloroprene rubber can also be used.

As a method of manufacturing the hydrophobic membrane unit 120, a method of insert-molding the hydrophobic membrane 101 is preferable as in the example using the resin member 102 shown in FIG.
The invention is not limited to this, and a known integral molding method can be appropriately adopted.

FIG. 4 is a schematic sectional view showing a state in which the hydrophobic membrane unit of FIG. 3 is mounted. In this example, the hydrophobic membrane unit 1 is previously provided in the atmosphere communication port 106 of the ink tank 108.
20 is provided with a groove having a depth and a width that can accommodate 20. The hydrophobic film unit 120 is housed therein, and the hydrophobic resin unit 120 is pressed by a ring-shaped resin pressing member 107 having a square cross section from above the elastic film unit 120. The member 105 is pressed appropriately, and the ring side portion of the pressing member 107 and the peripheral portion of the atmosphere communication hole of the ink tank 104 (the opening portion of the exterior of the ink tank) are heat or ultrasonically welded.

The pressing member 107 is not particularly limited as long as at least the joining region is made of resin and the elastic member 105 of the hydrophobic film unit 120 is appropriately pressed while heat or ultrasonic welding is possible. Specifically, the same material as the resin member 102, that is, nonyl (modified PP
O), polypropylene and the like are preferable.

In the example shown in FIG. 4, since the elastic member 105 and the pressing member 107 are used for mounting, there is an original effect that the area of the hole of the pressing member 107 can be easily set freely. . Considering the evaporation of ink,
The area of the hole that communicates with the atmosphere should be as small as possible. On the other hand, in the case of a specific ink tank, it is better to increase the area of the hydrophobic film to some extent in consideration of the attitude difference.
Here, in the example shown in FIG. 4, since the area of the hole of the pressing member 107 can be freely set regardless of the area of the hydrophobic film,
The above requirements can be easily met.

The ink tank of the present invention can prevent the adverse effects of depressurization due to ink consumption and pressurization due to temperature rise, prevent ink leakage, and enable stable and good ink jet printing. It is useful for FIG. 2). Inkjet printing is advantageous in that noise generated during printing can be reduced to a level that can be ignored, high-speed printing is possible, and printing can be performed by fixing it on so-called plain paper without requiring special processing. is there. For example, the inkjet printing methods described in Japanese Patent Laid-Open No. 54-51837 and German Patent Publication No. 2843064 are characterized in that thermal energy is applied to a liquid to obtain a driving force for ink ejection. ing. That is, according to this printing method, the liquid subjected to the action of thermal energy undergoes a state change accompanied by a sharp increase in volume, and the action force generated by the state change causes the liquid to be ejected from the orifice at the tip of the recording head of the printer. As a result, flying droplets are formed, and the droplets adhere to a recording medium such as recording paper for recording. Particularly, according to the ink jet printing method disclosed in German Patent Publication No. 2843064, so-called drop-
Not only is it very effectively applied to the on-demand printing method, but the recording head can also be easily embodied in a line printer type head with high density and multi-orifice, so high-resolution, high-quality images can be produced at high speed. It has a feature that can be obtained in.

The recording head of the printer apparatus applied to the above printing method has an orifice provided for ejecting ink droplets, and thermal energy for ejecting ink droplets communicated with the orifice to turn into liquid. A recording head substrate provided with an ink ejecting portion having a liquid flow having a heat acting portion, which is an acting portion, as a part of the constitution, and an electrothermal converter (heat generating material) as means for generating heat energy. including. The ink tank of the present invention is very useful when used as a tank for supplying ink to such an ink jet recording head, and is particularly useful for an ink jet print cartridge in which a head portion and a tank portion are integrated. .

[0024]

According to the ink tank and the method of manufacturing the same of the present invention described above, it is caused by excessive heating and excessive ultrasonic wave application at the time of mounting a hydrophobic film such as a porous film of fluororesin in the prior art. The tank is not deformed and the joint portion and the hydrophobic film are not damaged, and the hydrophobic film can be mounted on the air communication port with good workability, and ink leakage does not easily occur. Moreover, since the hydrophobic membrane is unitized, it is easy to handle and can be supplied by an automatic machine such as a parts feeder, and the workability of mounting is further improved.

Further, according to the ink jet print cartridge of the present invention, ink leakage is unlikely to occur, and stable and good ink jet printing is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a hydrophobic membrane unit used in the present invention, in which (a) is a schematic perspective view and (b) is a schematic sectional view thereof.

FIG. 2 is a schematic perspective view showing an example of the inkjet print cartridge of the present invention in which the hydrophobic film unit of FIG. 1 is mounted.

3A and 3B are diagrams showing another example of the hydrophobic membrane unit used in the present invention, in which FIG. 3A is a schematic perspective view and FIG. 3B is a schematic sectional view thereof.

FIG. 4 is a schematic cross-sectional view showing a state where the hydrophobic membrane unit of FIG. 3 is mounted.

FIG. 5 is an external perspective view showing an example of a conventional inkjet cartridge.

FIG. 6 is a schematic cross-sectional view showing a welded state of a hydrophobic film in a conventional ink tank.

[Explanation of symbols]

 100 Hydrophobic membrane unit 101 Hydrophobic membrane 102 Resin member formed by insert molding of hydrophobic membrane 103 Ultrasonic welding rib 104 Ink tank 105 Elastic member formed by insert molding of hydrophobic membrane 106 Air communication port 107 Holding member 108 Ink tank 120 Hydrophobic membrane unit

Claims (7)

[Claims] 1. An ink tank having an atmosphere communication port and at least a peripheral portion of the atmosphere communication port made of a resin, wherein a resin member or an elastic member is provided on an outer peripheral end of a hydrophobic film through which air passes. An ink tank characterized in that the hydrophobic membrane unit is fixed to the atmosphere communication port. 2. The ink tank according to claim 1, wherein the hydrophobic film is a porous film containing a fluororesin. 3. The hydrophobic membrane unit is fixed to the atmosphere communication port portion by heat-welding or ultrasonic welding a resin member of the hydrophobic membrane unit and a resin forming at least a peripheral portion of the atmosphere communication port of the ink tank. The ink tank according to claim 1 or 2, wherein 4. The ink tank according to claim 3, wherein the resin constituting the resin member of the hydrophobic film unit and at least the peripheral portion of the atmosphere communication port of the ink tank is modified PPO or polypropylene. 5. A resin of a holding member, at least a bonding region of which is made of resin, and at least an atmosphere communication port of an ink tank, with a hydrophobic film unit having an elastic member provided at an outer peripheral end of a hydrophobic film interposed therebetween. 3. The ink tank according to claim 1, wherein the hydrophobic film unit is fixed to the atmosphere communication port portion by heat welding or ultrasonic welding with a resin forming a peripheral portion of the ink. 6. A method of manufacturing an ink tank having an atmosphere communication port and at least a peripheral portion of the atmosphere communication port made of a resin, wherein a resin member or an elastic member is provided at an outer peripheral end of a hydrophobic film through which air is passed. A method of manufacturing an ink tank, comprising a step of fixing a hydrophobic membrane unit formed by the method to the atmosphere communication port portion. 7. An ink jet print cartridge comprising the ink tank according to any one of claims 1 to 5.