DE69216878T2 - Provide closure member for an ink tank part and recording head with it - Google Patents

Abstract

An adhesive sheet-type sealing member is suitably used for protecting ink-ejecting nozzles or a communication hole of an ink-jet recording head during transportation or storage. The sealing member exhibits a yield point at a load of not more than 1 kgf/cm for a specimen of 10 mm wide at a stress rate of 200 mm/min +/-10% according to JIS-K-7113 and/or exhibits a folding load of not more than 0.10 g/cm for a specimen of 10 mm wide with a free length of 10 mm from the end of a specimen holder measured on the center of an electronic balance placed at a position 5 mm apart from the end of the specimen holder. <IMAGE>

Description

The present invention relates to a thin film member usable for sealing an ink outlet (a discharge outlet or the like) or an air communication hole or for temporarily fixing an object of an ink recording head. The present invention also relates to a recording head to which the thin film member is applied. The thin film according to the present invention is suitably used as a sealing tape.

State of the art

Conventionally, in ink jet devices, clogging of ink nozzles during transportation or trouble in ink ejection are prevented by covering the ink ejection outlet surface with a capping device having an absorbent as described in Japanese Patent Application Laid-Open No. 59-198161.

Recently, cartridge type ink jet recording heads having an integral ink tank have been developed, and hence protective members for protecting the ink ejection outlet surface without using a capping device have been proposed. For example, Japanese Laid-Open Patent Application No. 60-204348 typically discloses a cap-shaped protective member having a ink absorber, and Japanese Patent Application Laid-Open No. 61-125851 discloses a seal tape for protecting the ejection outlet which is basically composed of a vinylidene chloride resin.

However, the conventional cutting devices have a risk of causing ink overflow during transportation of an ink jet recording device due to shock during transportation or other causes and contaminating the inside of the recording device.

This phenomenon has been investigated and it has been newly found that it depends largely on the overall properties of the sealing member itself including its adhesive portion or the connecting portion adhering to the opening rather than on the adhesive strength of the pressure-sensitive adhesive. Further extensive investigation of the properties revealed that the stretching or bending properties of the sealing member in the form of a thin film (e.g., tape) are important for resistance to environmental fluctuations and durability. Accordingly, the present invention is directed to eliminating the use of a cap-shaped protective member by attaching a sealing member to which suitable properties are given for sealing an ink container portion.

A conventional sealing tape, which is composed, for example, of at least a carrier and a layer of pressure-sensitive adhesive coated thereon, is not sufficient for sealing an irregular surface, which results in gradual detachment during a long period of storage and causes ink leakage. It is necessary that the sealing element be able to prevent ink leakage even in the case where the sealed surface has a graded structure, an irregular surface structure or a discontinuous structure, for a long period of time.

SUMMARY OF THE INVENTION

The present invention intends to provide a sealing member which is capable of preventing the leakage of ink from an ink tank during transportation by itself and which enables the storage of an ink jet recording head for a long period of time.

The present invention also intends to provide a seal protection tape for an ink jet recording head which allows immediate start of ink recording without the adverse effect of a substance released from an adhesive portion of the seal member or a remaining adhesive substance after removal of the seal member.

The present invention provides a sealing member comprising a sealing film and a pressure-sensitive adhesive portion for sealing, by means of the pressure-sensitive adhesive portion, a communication hole or a communication portion between the inside and the outside of the recording/container portion in which an ink is held, which is characterized in that the sealing film has a yield point at a stress of not more than 9.81 N/cm (1 kgf/cm) for a sample of 10 mm width at a loading rate of 200 mm/min ± 10% according to JIS-K-7113.

Preferably, the closure member is used to close a graduated surface of the recording/container portion.

Moreover, the present invention provides a recording head having an ink container, an energy generating element for generating energy for ejecting an ink held in the ink container, an ink ejection portion corresponding to the energy generating element, and a sealing member comprising a sealing film and a pressure-sensitive adhesive for sealing the ink ejection portion of the recording head by means of the pressure-sensitive adhesive, which is characterized in that the sealing film has a yield point at a stress of not more than 9.81 N/cm (1 kgf/cm) for a sample of 10 mm width at a loading rate of 200 mm/min ± 10% according to JIS-K-7113.

Furthermore, the present invention provides a sealing member comprising a sealing film and a pressure-sensitive adhesive portion for sealing, by means of the pressure-sensitive adhesive portion, a communication hole or a communication portion between the inside and the outside of the recording/container portion in which an ink is held, which is characterized in that the sealing film has a folding stress of not more than 0.10 g/cm for a sample of 10 mm width with a free length of 10 mm from the end of a sample holder, which is measured at the center of an electronic balance arranged at a position 5 mm apart from the end of the sample holder.

Furthermore, the present invention provides a recording head comprising an ink container, an energy generating element for generating energy for ejecting an ink held in the ink container, and an ink ejection section corresponding to the energy generating element, which is characterized in that the above-defined shutter element is designed as a Sealing member for the ink recording head is used to seal the ink ejection section by means of a pressure sensitive adhesive section.

The sealing member is effective when applied to a portion in which an ink is present in the vicinity, the portion such as an ink ejection portion corresponding to an energy generating element of an ink jet recording head. In such a case, for the purpose of satisfactorily reducing a residual component of the pressure sensitive adhesive, the pressure sensitive adhesive comprises an acrylate ester copolymer crosslinked by an isocyanate, the acrylate ester copolymer being composed of at least 80% of the total weight of an alkyl and/or alkoxyalkyl acrylate ester containing a hydroxy group and an acrylate ester having a side chain of an alkyl or alkoxyalkyl group of 4 to 9 carbons.

In the event that the portion to be closed by means of the closure element is stepped, the previously mentioned folding stress of not more than 0.05 g/cm and not less than 0.01 g/cm enables effective closure.

The shutter member according to the present invention is suitably used for ink jet recording heads to protect the ejection portion thereof and to prevent leakage of ink from the ejection outlet during a long period of storage.

The shutter member according to the present invention is easily peelable even after a long period of storage at the start of ink jet recording, causing no contamination around the ink ejection outlets which enables satisfactory inkjet recording.

Furthermore, the closure element according to the present invention can achieve the above-mentioned objects by itself without using an additional component, namely an additional protective element (for example, a pressing element) to prevent detachment.

BRIEF DESCRIPTION OF THE DRAWINGS

Figs. 1A to 1C are rough perspective views of examples of application of a fastener tape according to the present invention.

Figure 2 is a perspective view of an inkjet cartridge according to the present invention.

Fig. 3 is an exploded perspective view of an ink cartridge according to the present invention.

Fig. 4 is a schematic diagram illustrating a head portion of an ink cartridge according to the present invention.

Fig. 5 is a rough drawing of a lateral side surface of the head section.

Fig. 6 is a drawing for explaining the insertion of a head into the main body of an ink-jet recording apparatus.

Fig. 7 is a perspective view of a recording device provided with a head according to the present invention.

Fig. 8A and Fig. 8B are rough drawings illustrating an example of a fastener tape according to the present invention and a coating process.

Fig. 9 illustrates an air communication hole of a head according to the present invention.

Fig. 10 illustrates a shape of the air communication hole.

Fig. 11 illustrates a packaging state of a cassette according to the present invention.

Fig. 12A to Fig. 12C illustrate a structure of an ink supply section which connects an ink tank of a cartridge according to the present invention to a recording head. Fig. 12A illustrates an ink supply section. Fig. 12B illustrates a shutter ball. Fig. 12C illustrates its installation.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The sealing member according to the present invention yields 10% under a stress of not more than 9.81 N/cm (1 kgf/cm) for a sample of 10 mm width at a loading speed of 200 mm/min 1 according to JIS-K-7113. No suitable criterion for evaluating sealing properties has ever been provided for surfaces such as a discharge outlet of an ink jet recording head. Therefore, the preliminary study was started with a study to establish a criterion for evaluating sealing properties on such a surface, particularly on a surface for a joint portion having an inclined portion and a corner portion. The aforementioned JIS-K-7113 itself is not a standard applicable to a sealing member such as that according to the present invention. However, after extensive studies, according to the present invention, it was decided to evaluate the properties of a thin film having a pressure-sensitive adhesive as a fastener by taking the strain at the yield point for a sample of 10 mm width at a loading rate of 200 mm/min ± 10% as an evaluation criterion. The critical criterion is the strain of 9.81 N/cm (1 kgf/cm) at the yield point. In the case where the measured strain was larger than 9.81 N/cm (1 kgf/cm), the fastener could not provide stable closure of a bonded portion for a long period of time.

When the width of the sample is not 10 mm, the measured stress can be converted into the value for the width of 10 mm to indicate the yield stress in terms of 9.81 N/cm (1 kgf/cm) unit as defined in the present invention.

In addition to the yield point stress mentioned above, another independent evaluation criterion was found to suitably evaluate the properties. The evaluation criterion is that the closure element has a folding stress of not more than 0.10 g/cm for a sample of 10 mm width with a free length of 10 mm from a supported end at a position 1 mm from the supported end and in the middle of an electronic balance. This evaluation was found to be effective for samples having a free length of at least 10 mm. In this evaluation criterion, the value of 0.10 g/cm is the critical criterion. At a folding stress exceeding 0.07 g/cm, considerable peeling occurs, while at a folding stress not exceeding 0.10 g/cm, the sealing member achieves a stable sealing effect for the ink tank for a long period of time.

The pressure-sensitive adhesive contains various known materials. Acrylic materials are preferred, particularly preferred are acrylate ester copolymers crosslinked by means of an isocyanate, wherein the acrylate ester copolymer is composed of at least 80% of the total weight of a hydroxyalkyl acrylate and/or an alkoxyalkyl acrylate and an acrylate ester having a side chain of an alkyl or alkoxyalkyl group of 4 to 9 carbons.

The acrylic monomer for the acrylic pressure-sensitive material includes alkyl ester monomers such as methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, 2-methylbutyl acrylate, 2-ethylbutyl acrylate, 3-methylbutyl acrylate, 1,3-dimethylbutyl acrylate, pentyl acrylate, 3-pentyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, heptyl acrylate, 2-heptyl acrylate, octyl acrylate, 2-octyl acrylate, nonyl acrylate and the like. A variety of alkoxyalkyl ester monomers may also be used. Such a monomer is used in combination with the hydroxy group-containing monomer in a total amount ranging from 50 to 100% by weight, preferably from 50 to 80% by weight.

The polyvalent isocyanate compound includes tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, di(isocyanatomethyl)cyclohexane, dicyclohexylmethane diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, adducts of tolylene diisocyanate and hexamethylene diisocyanate, urethane-modified compounds, allophanate-modified compounds, biuret-modified compounds, isocyanurate-modified compounds, urethane prepolymers (oligomeric compounds having an isocyanate group at each end) and the like.

The cohesive properties of pressure-sensitive adhesives can be adjusted using various methods.

A first method for adjusting the cohesive property of the pressure-sensitive adhesive is copolymerization using a hydroxy group-containing monomer and crosslinking using a polyvalent isocyanate compound. The hydroxy group-containing monomer includes 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, hydroxybutyl methacrylate, polyhydric alcohol acrylate ester, polyhydric alcohol methacrylate ester, ethyl carbitol acrylate ester, methyl triglycol acrylate ester, 2-hydroxyethyl acryloyl phosphate, propoxyethyl acrylate and so on. The hydroxy group-containing monomer is preferably used in an amount ranging from 5 to 25% by weight, and a part or the whole of it is crosslinked by means of a polyvalent isocyanate.

A second method for adjusting the cohesive property of the pressure-sensitive adhesive is to appropriately use a copolymerization component such as a methacrylate monomer, vinyl acetate, styrene, acrylonitrile, acrylamide and methacrylamide. Such a component is preferably used in an amount ranging from 5 to 15% by weight. Among the components, acrylonitrile, acrylamide and methacrylamide are particularly suitable for the ink jet recording head according to the present invention.

A third method for adjusting the cohesive property of the pressure-sensitive adhesive is crosslinking using a crosslinking monomer such as N-methylol acrylamide, N-methylol methacrylamide, diacetone acrylamide and butoxymethyl acrylamide. The crosslinking monomer is preferably used in an amount ranging from 5 to 15% by weight.

To obtain a more suitable pressure-sensitive adhesive, the first method is combined with the second or third method.

The pressure-sensitive adhesive used in the present invention has higher chemical resistance to inkjet ink, emits less organic compounds, contains a smaller amount of polyvalent metals, and has excellent properties for protecting the nozzle surface of the inkjet recording head.

The pressure-sensitive adhesive can be produced by polymerizing the above-mentioned materials into a giant molecule having a weight-average molecular weight of 250,000 to 1,000,000 by a known polymerization process. In the polymerization, it is necessary that the content of lower polymers and residual monomers be as low as possible. Accordingly, for this purpose, the polymerization process and polymerization conditions must be strictly controlled. The lower polymer and residual monomer are preferably removed by reprecipitation. The polymer thus produced is dissolved in a good solvent, and a diisocyanate is added thereto to form a paint. The paint is applied to a carrier film to form a layer of pressure-sensitive adhesive having a dry thickness in the range of 5 µm to 100 µm by a known coating method such as blade coating method, air knife method, roll coating method, brush coating method, Chamblex coating method, bar coating method, gravure coating method and the like, and the applied paint is dried in a conventional manner. After After drying, the film may, if desired, be subjected to an aging treatment for the purpose of stabilizing the properties of the pressure-sensitive adhesive.

The support for the pressure-sensitive adhesive according to the present invention may be made of a material such as paper and plastic films, provided that the fastener tape formed by the combination of the support and the pressure-sensitive adhesive satisfies the above-mentioned criterion of the present invention. Synthetic papers and plastic-made films are suitable in terms of durability and weather resistance. The film material is made of polyethylene terephthalate, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, vinylidene chloride-vinyl chloride copolymers, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymers, tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymers and the like. In view of the fact that the pressure-sensitive adhesive tape is peeled off and discarded before use of the recording head, polyethylene terephthalate, polyethylene and polypropylene, which do not generate harmful gases when burned, are preferable. The thickness of the support when used as a protective sealing tape is preferably in the range of 5 µm to 100 µm, particularly preferably 10 µm to 50 µm, but is not limited thereto. The support may be colored by printing or dip coating. Furthermore, for the purpose of improving the bonding effect with the pressure-sensitive adhesive, the support is preferably physically pretreated by applying a high frequency alternating electric field, ion radiation, electron radiation, corona discharge and the like, or chemically pretreated by applying a coupling agent or the like before applying the pressure-sensitive adhesive.

For better handling, the fastener tape according to the present invention can be coated with the adhesive side on a removable base material, although this does not directly relate to the present invention.

The protective seal tape according to the present invention is to be applied to an ink-repellent surface of the ejection outlet of an ink jet recording head, whereby satisfactory sealing properties are achieved without damaging the tape and the ejection outlet surface. The above-mentioned ink-repellent surface is a surface which has been treated with a treating agent such as a silicone oil, a fluorine-containing low-molecular or high-molecular compound, in particular, KP-801 (trade name, manufactured by Shin-Etsu Silicone K.K.), Defenser (trade name, manufactured by Dainippon Ink and Chemikals, Inc.), CTX-105 and -805 (trade name, manufactured by Asahi Glass Co., Ltd.), Teflon AF (trade name, manufactured by Dupont Co.), etc.

The sealing member may be bonded by any method. However, the sealing member is preferably pressed with a pressure of not more than several kg/cm² so as not to break the surface of the ejection outlet of the ink jet recording head, and the pressing is carried out for a time of several minutes to 10 minutes. Heating in the bonding by pressure is highly desirable.

The ink jet recording to which the present invention is applied will be described below with reference to Figs. 2 to 7.

Fig. 2 is a perspective view of an ink jet cartridge 11 applied to an ink jet recording apparatus according to the present invention. Fig. 3 is an exploded view showing the structure of the ink jet cartridge 11. The following description is mainly based on Fig. 3, and other drawings to which reference is made are indicated by the figure numbers in parentheses.

The ink jet cartridge 11 is constructed in an integral manner of an ink jet unit 13 including an ink jet head 12 having a plurality of ejection outlets 30 formed in a body including a recording head, an electric wiring for the same, tubes, and an ink tank 14 containing the ink. The ink jet cartridge 11 according to this example has a larger ink storage capacity than a conventional one, and has a front portion of the ink unit 13 slightly projecting from the front surface of the ink tank 14. This ink jet cartridge 11 is fixed and held by means of a fitting device and points for electric contact described later, and is detachable from the carriage 16 (see Fig. 6) attached to an ink jet recording device 15, and is replaceable.

First, the structure of the inkjet head 12 is explained.

As shown in Fig. 4, the ink jet head 12 has a plurality of ejection outlets 30 arranged in a row, and an electrothermal transducer 40 is provided in each liquid channel to generate thermal energy by applying voltage. The supply of drive signals to the transducer causes thermal energy to be generated in the electrothermal transducers 40, causing film boiling and forming bubbles in the ink liquid channel. The growth of the bubbles serves to eject the ink droplets from the ejection outlets 30. The respective electrothermal transducers 40 are provided on a heating surface 100 constructed of a silicon base plate and are heated by means of The recessed cover plate 1300 having a partition for partitioning the plurality of ink channels and the common liquid chamber 1301 for temporarily storing the ink, etc., and the orifice plate 400 having an ink inlet 1500 for introducing ink from the ink tank 14 into the common liquid chamber 1301 and a plurality of ejection outlets 30 corresponding to the respective ink flow channels are integrally formed by the film forming technique. The material thereof is preferably polysulfone, but other molding resins such as polyethersulfone, polyphenylene oxide and the like are also applicable.

Second, the construction of the ink jet unit 13 is explained.

The one end portion of the wiring base 200 is connected to the wiring portion of the heating surface 100 of the ink jet head 12, and the other end portion of the wiring base 200 is provided with a plurality of pads 201 corresponding to the respective electrothermal transducers 40 (Fig. 4) for receiving electric signals from the main device. Thereby, the electric signals from the main device are supplied to the respective electrothermal transducers 40.

A metallic support 300, which carries the wiring base plate 200 on the back, serves as the lower plate of the ink jet unit 13. The pressure rod spring 500, which has an M-shape, presses the common liquid chamber 1301 (Fig. 4) by means of the middle portion of the M-shape. The front portion 501 presses a portion of the liquid channels, preferably the area around the discharge outlets 30. The heating surface 100 and the cover plate 1300 are abutted between the compression spring 500 and the carrier 300 by means of the foot portion of the compression spring, which is brought into abutment with the rear side of the carrier 300 through the holes 3121, and are pressure-fastened to one another by the concentrated force of the compression spring 500 and its front portion 501. The carrier 312, 1900, 2000 has holes corresponding to the two fitting projections 1012 of the ink tank 14 and the fitting and heat-melting holding projections 1800 and 1801, and further has on the back side fitting projections 2500 and 2600 corresponding to the carriage 16. The carrier 300 further has a hole 320 through which an ink supply tube 2200 (described later) from the ink tank 14 passes. A wiring base plate 200 is fixed on the carrier 300 using an adhesive.

The hollow portions 2400, 2400 of the carrier 300 are provided in the vicinity of the projections 2500, 2600, respectively. Thus, in the assembled ink jet cartridge 11 (Fig. 2), they are in the front area of the head which is provided on the surrounding three sides with parallel recesses 3000, 3001, thereby preventing undesirable substances such as dust and ink from reaching the projections 2500, 2600. The cover member 800 having parallel recesses 300 forms the outer wall of the ink cartridge 11 and also forms a space with the ink tank 14 for holding the ink jet unit 13, as shown in Fig. 6. In the ink supply element 600, which has parallel recesses 3001 formed therein, the ink introduction tube 1600 connected to the ink supply tube 2000 is fixed in the form of a cantilevered tube next to the ink supply tube 2200. In order to ensure a capillary phenomenon between the fixed side of the ink introduction tube 1600 and the ink supply tube 2200, a sealing pin is inserted into the latter. To connect the ink container 14 and the ink supply tube 2200, a seal 601 is applied. At the end portion of the ink supply tube on the side of the ink tank 14, a filter 700 is provided.

Since the ink supply device 600 is manufactured by molding, it is inexpensive and has positional accuracy, and the production accuracy is kept high. Due to the cantilevered structure of the ink introduction tube 1600, the pressure contact of the ink introduction tube with the ink inlet 1500 is kept stable even in mass production. In this example, the connection state is secured simply by applying a sealing adhesive from the side of the ink supply member 600 in the pressure contact state. The ink supply member 600 is easily attached to the carrier 300 in such a manner that two pins (not shown in the drawing) on the back of the ink supply member 600 are protruded through the holes 1901, 1902 in the carrier 300, respectively, and fused. The small projections formed by fusion are housed in cavities (not shown in the drawing) in the lateral side of the ink tank 14 to which the ink jet unit 13 is attached, so that the position of the ink jet unit 13 is precise.

The construction of the ink tank 14 is described below.

The ink tank 14 is composed of the cartridge main body 1000, the ink absorbing body 900, and the cover member 1100, and is formed by inserting the ink absorbing body 900 into the cartridge main body 1000 from the side opposite to the ink jet unit 13 and then closing it by the cover member 1100.

The ink absorbing body 900 is for storing the ink by soaking and is arranged in the main body of the cartridge 1000. The details will be described later. The ink supply inlet 1200 is for supplying ink into the ink jet unit 13 and also serves as an ink supply inlet for filling ink into the ink absorbing body when assembling the ink jet cartridge 11. The ink container 14 has an air communication hole 1401 for communicating air with the interior, and a liquid repellent material 1400 is arranged inside the air communication hole 1401 for preventing ink from leaking therefrom.

In this example, in order to supply the ink satisfactorily from the ink absorbing body 900, a continuous air space is formed in the ink tank 14 by means of the ribs 2300 in the main body of the cartridge 1000 and the partial ribs 2310, 2320 of the cover member 1100 in the area from the air communication hole 1401 to the corner portion most spaced from the ink supply inlet 1200. Therefore, the ink is supplied from the ink supply inlet 1200 into the ink absorbing body 900 in a relatively satisfactory manner, which is important. This method is extremely effective in practice. The four ribs 2300 are provided on the back of the main body of the cartridge 1000 of the ink container 14 in a direction parallel to the moving direction of the carriage 16 (Fig. 7) to prevent the close contact of the ink absorbing body 900 with the back. The partial ribs 2310, 2320 are arranged at the corresponding positions on extended lines of the ribs 2300 and on the inner surface of the cover member 1100, and are in a divided state different from that of the ribs 2300 so that the air space is increased. The partial ribs 2310, 2320 are distributed on an area not more than half the area of the The ribs allow the ink to be introduced from the furthest corner portion into the ink supply outlet 1200 by capillary force.

The aforementioned structure and arrangement of the ribs are particularly effective in the aforementioned ink container 14 having an ink storage space in the form of a rectangular body having its long side in the side surface. In the case where the rectangular body has its long side along the moving direction of the carriage 16 (Fig. 7), the ink supply from the ink absorbing body can be stabilized by providing the ribs over the entire surface of the cover member 1100. The rectangular shape of the body is suitable for storing as much ink as possible within a limited size of the space. In order to effectively use the stored ink for recording without waste, the ribs playing the aforementioned role are preferably provided in two surface areas adjacent to the corner portion. Further, the inner ribs of the ink container 14 in this example are uniformly distributed in the direction of the thickness of the ink absorbing body 900 in the form of a rectangular solid body. This structure enables the maximum possible use of substantially all of the ink in the ink absorbing body 900 by uniforming the distribution of atmospheric pressure. The distribution of the ribs is based on the following technical idea. When the position of the ink supply inlet 1200 protrudes toward the rectangular upper surface of the rectangular solid body and a circle is drawn with the protruding position as a center with a radius of the length of the long side of the rectangle, it is important to provide the ribs on the surface outside the circle line in order to quickly achieve the atmospheric pressure state. In this case, the position of the air hole in the ink tank is not limited to that according to this example, provided that that the air is introduced into the area with distributed fins.

In this example, the back of the ink cartridge 11 opposite to the ink jet head 12 is made flat to minimize the space required for installation in the apparatus and to maximize the amount of ink contained therein, thereby miniaturizing the apparatus and desirably reducing the frequency of cartridge replacement. Behind the space for installing the ink jet unit 13, a projection of the air hole 1401 is formed, and the inside of the projection portion is left empty to form an atmospheric pressure supply space 1402 for the entire thickness of the ink absorbing body 900. Such a structure provides an excellent ink jet cartridge which has not yet been known. This atmospheric pressure supply space 1402 is much larger than conventional spaces, and the air communication hole 1401 is arranged at a higher position. Thus, when the ink comes out from the ink absorbing body 900, this atmospheric pressure supply space 1402 is adapted to temporarily retain the ink, enabling steady recovery of the ink into the ink absorbing body 900, thus providing an efficient and excellent cartridge.

The structure of the surface of the ink tank 14 to which the ink jet unit 13 is attached is shown in Fig. 5. Two projections 1012 for fittingly engaging with the holes 312 on the carrier 300 are located on a straight line L₁ which is near the center of the ejection outlet of the orifice plate 400 and is parallel to the bottom surface of the ink tank 14 or a base surface of the mount of the carriage 16. The height of the projection 1012 is slightly higher than the thickness of the carrier 300 and fits the carrier 300. On the extension of the Line L₁ in this drawing, there is provided a claw 2100 which engages with an engaging surface 4002 perpendicular to the hook 4001 to fit the carriage 16 as shown in Fig. 5. Consequently, the force for fitting the carriage 16 is applied to the flat surface parallel to the base surface including the line L₁. As will be explained later, such a design relation is effective because the accuracy of fitting of the ink tank 14 itself is almost equal to the accuracy of position fitting of the outlet of the ink jet head 12.

The projections 1800, 1801 of the ink container 14, which correspond to the holes 1900, 2000 in the bracket 300 for fixing it to the side surface of the ink container 14, respectively, are longer than the aforementioned projection 1012, and are used for fixing the bracket 300 by fusion-bonding the portion protruding through the bracket 300. The approximate center of the ink supply inlet 1200 is located on a line L₃ which is perpendicular to the aforementioned line L₁ and passes the projection 1800. Thereby, the connection of the ink supply inlet 1200 to the ink supply tube 2200 is stabilized, and a stress caused by subsidence or an impact applied to the connecting portion is reduced. The line L₂ passes the projection 1801. The lines L₂ and L₃ do not intersect each other. The projections 1800, 1801 also serve to fit the ink jet head 12 relative to the ink tank 14. The curve L₄ indicates the position of the outer wall when the ink supply member 600 is attached. The projections 1800 and 1801 are arranged along the curve L₄, which provides sufficient strength and positioning accuracy against the weight of the structure of the front portion of the ink jet head 12. The front edge 2700 of the ink jet head 12 is inserted into the hole of the front plate 4000 (Fig. 6) of the carriage 16, to meet an abnormality such as an extreme displacement of the ink tank 14. The stopper 2101 which resists sliding of the carriage 16 is provided so as to fit a rod (not shown in the drawing) of the carriage 16, and is a protective member for maintaining the fixed state when the ink jet cartridge 11 comes under the rod to the position in which the cartridge 11 has been fixed and receives a vertical force for displacement from the fixed position.

The ink jet unit 13 is inserted up to the ink tank 14 and then covered by the cover member 800 to close the ink jet unit 13 except for the upper opening portion. However, the ink jet cartridge 11 is attached to the carriage 16 and the lower opening comes close to the carriage 16, thereby forming a substantially four-side closed space. Although the closed space is effective for thermal insulation of heat generated by the ink jet head 12, a slight temperature increase is caused over a long operating time. As a countermeasure against this, in this example, a slit 1700 having a narrower width than the closed space is provided to prevent temperature increase while uniformizing the temperature distribution throughout the ink jet unit 13 regardless of the environment.

After the ink jet cartridge is assembled, the ink is supplied from inside the main body of the cartridge 1000 through the ink supply inlet 1200, the hole 320 in the carrier 300 and an introduction port on the back of the ink supply member 600 to the ink supply member 600, and then flows through an outlet hole, an appropriate supply tube and the ink inlet 1500 in the cover plate 1300 into the common liquid chamber.

The ink supply path is secured by sealing by means of gaskets made of silicone rubber, butyl rubber or the like.

As described above, the ink supply member 600, the cover plate 1300 with the orifice plate 400, and the main body of the cartridge 1000 are each molded as an integral part, which makes the assembly precise and is effective for mass production with high quality. The number of parts is less than that of conventional products, so that the intended great characteristics are surely achieved.

In the assembled ink jet cartridge 11 according to this example, a slit 1701 is provided between the upper surface 603 of the ink supply member 600 and the end portion 4008 of the roof portion having a long and narrow opening 1700 of the ink tank 14 as shown in Fig. 2. Similarly, a slit (not shown in the drawing) is formed between the lower surface 604 of the ink supply member 600 and a head-side end portion 4011 of the thin plate member bonded to the cover member 800 at the lower portion of the ink tank 14. These slits accelerate the heat release from the aforementioned opening 1700, and prevent any direct force from being applied to the ink supply member 600 or the ink jet unit 13 when an unnecessary force is applied to the ink tank 14.

As described above, the construction of the present invention is novel. Not only is each of the construction units effective individually, but their combination is also particularly effective.

The fastening of the inkjet cartridge 11 on the carriage 16 is explained below.

As shown in Fig. 6, the platen roller 5000 guides the recording medium 5200 (e.g., recording paper) from the back of the plane of the drawing to the front thereof. The carriage 16, which moves along the longitudinal direction of the platen roller 5000, is provided on the front side of the carriage 16, namely the platen roller side, with a front plate 4000 (2 mm thick), a holding plate 4003 for electrical connection described later, and a fitting hook 4001 for fixing the ink jet cartridge 11 in a predetermined recording position. The front plate 4000 has two projecting surfaces 4010 for fitting correspondingly to the projections 2500, 2600 of the carrier 300 of the ink jet cartridge 11 and receives a force perpendicular to the projecting surface 4010 after the ink jet cartridge 11 is installed. Therefore, on the platen roller 5000 side of the front plate 4000, a plurality of reinforcing ribs (not shown in the drawing) are provided. These ribs also form head-protecting projection portions which project slightly (about 0.1 mm) from the position L5 of the front surface of the built-in ink jet cartridge 11 toward the platen roller 5000. The holding plate 4003 has a plurality of reinforcing ribs 4004 which are vertically aligned with the paper surface of the drawing. The projection length of these ribs decreases from the front of the rib on the platen roller 5000 side to the rib on the hook 4001 side, whereby the ink jet cartridge 11 is mounted obliquely as shown in the drawing. The holding plate 4003 has a flexible strip 4005 provided with pads 2001 corresponding to the pads 201 of the wiring base 200 of the ink jet cartridge 11, and a rubber pad strip 4007 with reinforcements to provide elasticity for pressing the flexible strip to each of the pads 2011 from the back side. To stabilize the electrical contact between the pads 201 and the pads 2011, the holding plate 4003 has a fitting surface 4006 on the side of the hook 4001, which exerts a force in a direction opposite to the direction of tension of the aforementioned protruding surface 4010 on the ink jet cartridge 11. Between them, the pad contact is established, and the deformation of the reinforcements of the rubber strip 4007 corresponding to the pads 2011 is realized in a defined manner. When the ink jet cartridge 11 is fixed in the recording position, the fitting surface 4006 is in contact with the surface of the wiring base plate 200. Since the pads 201 are symmetrically distributed with respect to the aforementioned line L₁, the rubber pad strip 4007 has uniformly deformed reinforcements, and the contact pressure between the pads 2011 and the pads 201 is stabilized. In this example, the distribution of the pads 201 is in two rows vertically and in two rows laterally.

The hook 4001 has a long slot in which a fixing shaft 4009 is engaged. After the rotational movement in the counterclockwise direction from the position shown in the drawing using the movement space, the ink jet cartridge 11 is fitted by the movement to the left along the longitudinal direction of the platen roller 5000 relative to the carriage 16. The movement of the hook 4001 can be carried out in any way, but is preferably realized by a lever manipulation. In any case, with the rotational movement of the hook 4001, the ink jet cartridge 11 moves toward the side of the platen roller 5000 to the position in which the fitting projections 2500, 2600 can come into contact with the protruding surface 4010 of the front plate 4000. The ink jet cartridge 11 rotates horizontally around the contact area of the projection 2500 during the leftward movement of the hook 4001, with its hook surface at 900 being kept in close contact with the 90º surface of the claw 2100 of the ink jet cartridge 11. with the projection surface 4010, thereby finally causing the contact of the terminal surfaces 201 with the terminal surfaces 2011. When the hook 4001 is to be held in a predetermined position or a fixed position, the full contact of the terminal surfaces 201 with the terminal surfaces 2011, the end face contact of the projections 2500, 2600 with the projection surface 4010, and the end face contact of the hook surface 4002 with the 90° surface of the claw are realized, thereby completing the mounting of the ink jet cartridge 11 on the carriage 16.

The following explains a diagram of the main body of the ink-jet recording apparatus.

An external appearance of an ink jet recording apparatus applicable to the present invention is shown in Fig. 7. A lead screw 5005 having a spiral groove 5004 is driven to rotate in a normal or reverse direction by coupling with a drive motor 5013 via drive force transmitting gears 5011 and 5009. The carriage 16 is engaged with the spiral groove 5004 by a pin (not shown in the drawing) at the mounting portion 5001 (Fig. 6), and is slidably guided by a guide rail 5003 for reciprocating movement in the direction shown by arrow marks a and b. A paper platen 5002 pushes and presses a recording medium 5200 toward the platen roller 5000 regardless of the moving direction of the carriage 16. Photocouplers 5007, 5008 constitute a home position detecting means for confirming that the position of the lever 5006 of the carriage 16 is in the range and for controlling the driving direction etc. of the driving motor 5013. A capping member 5022 for capping the front surface of the ink jet head 12 is held by the holding member 5016 and has a suction means 5015 for restoring the suction of the ink jet head. 12 through an opening 5023 in the cap. The main body support plate 5018 has a support plate 5019. A cleaning blade 5017 slidably supported by the support plate 5019 is driven forward and backward by means of a drive device not shown in the drawing. The shape of the cleaning blade 5017 is not limited to that shown in the drawing, but a variety of known shapes of blades are applicable to the present example. The lever 5012 is provided to start the suction recovery operation, moving with the movement of a cam 5020 engaged with the carriage 16. The movement is caused by the driving force of the drive motor 5013 transmitted by means of a known transmission device such as a gear 5010, a displacement clutch and the like.

The respective capping, cleaning and suction recovery operations are carried out by the action of the lead screw 5005 at the corresponding location when the carriage 16 comes to the home position. Each of the operations is applicable to the present invention if the operations are carried out at a known timing and in a desired manner. The respective constructions are excellent individually or in combination and are preferred in the present invention.

Fig. 1A to Fig. 1C illustrate a partial perspective view of a portion in which a fastener tape composed of a carrier of the fastener member and an adhesive layer is adhered by means of the adhesive layer of the fastener tape to a plurality of discharge outlets (as shown in Fig. 2) and a stepped surface extending in a direction vertical to the arrangement of the outlet from the carrier 300 to the cover member 800. The fastener tape 2 has a portion 1A, to be adhered to the substrate 300 and a portion 1B to be brought into close contact with the discharge outlet surface and to be bonded to the cover member 800. (In this example, the surface itself is also an irregular surface.) As shown in Fig. 1A, the fastener tape is folded back and the adhesive portions are adhered together to form a boss 1C, thereby simplifying the construction of the finger gripping portion and easily forming the same. In Fig. 1B, further, a separate tape of pressure-sensitive adhesive is attached to the fastener tape to attach it more tightly. As shown in Fig. 1C, in the reverse manner, by utilizing the adhesive portion of the fastener tape, a piece of paper or film is used as the finger grip, whereby the cost is lower than that of Fig. 1B.

In any design, it is important to provide sufficient sealing tape effect to prevent ink leakage from the ejection outlet.

The evaluation criterion according to the load at a yield point (or yield stress) is explained with reference to experimental results.

The measurement conditions are explained below for the fastener tape in which the pressure-sensitive adhesive portion serves as the fastener element. The present invention has been accomplished on the basis of the finding that the yield stress shows the overall properties of the fastener material more precisely when measured using a test piece of 10 mm width at a loading rate of 200 mm/min ± 10% in accordance with JIS-K-7113.

example 1

A fastener tape 1 was prepared as explained below. An unstretched polypropylene film of 30 µm thickness was used as a carrier. The area to which the adhesive was to be applied was subjected to corona discharge treatment and the acrylic pressure-sensitive adhesive was applied thereto.

(Composition of pressure sensitive adhesive)

Butyl acrylate 80 parts by weight

Acrylonitrile 10 parts by weight

2-Hydroxyethyl acrylate 10 parts by weight

These substances were polymerized using a benzene peroxide catalyst in a solution in a mixed solvent composed of toluene and butyl acetate (50:50 by volume) at 85°C for 8 hours to obtain a copolymer having a weight-average molecular weight of 300,000. The copolymer was precipitated from ethanol to remove residual monomers and a lower polymer with the aid of the solvent, and then the copolymer was dried. The resulting copolymer was again dissolved in a mixed solvent composed of toluene and ethyl acetate (50:50 by volume), and dicyclohexylmethane diisocyanate was added thereto in an amount of 10.1 g per 100 g of the copolymer to obtain a coating liquid. This coating liquid was coated on the above-mentioned support so as to give a dry thickness of 30 µm, dried by heating at 60 ºC for 10 minutes, and further aged for one week at room temperature. Thus, fastener tape A was prepared.

Example 2

Fastener tape B was prepared in the same manner as fastener tape A except that dicyclohexylmethane diisocyanate was added in an amount of 2.5 g.

Example 3

Fastener tape C was prepared in the same way as fastener tape B, except that the carrier used was an unstretched polypropylene film of 20 µm thickness.

Example 4

Fastener tape D was prepared in the same manner as fastener tape B, except that the carrier used was a polyvinyl chloride film of 30 µm thickness.

Example 5

Fastener tape E was prepared in the same manner as fastener tape B, except that the carrier used was an unstretched polypropylene film of 20 µm thickness containing titanium oxide.

Example 6

Fastener tape I was prepared in the same way as fastener tape A, except that the carrier used was an unstretched polypropylene film of 32 µm thickness.

Example 7

Fastener tape J was manufactured in the same way as fastener tape B, except that the The carrier was an unstretched polypropylene film of 25 µm thickness containing titanium oxide.

Comparison example 1

Fastener tape F was prepared in the same way as fastener tape A, except that the carrier used was an unstretched polypropylene film of 40 µm thickness.

Comparison example 2

Fastener tape G was prepared in the same way as fastener tape B, except that the carrier used was an unstretched polypropylene film of 30 µm thickness containing titanium oxide.

Comparison example 3

Fastener tape H was prepared in the same manner as fastener tape B, except that the carrier used was a polyethylene terephthalate film of 2.5 µm thickness.

Evaluation procedure 1. Adhesive strength (gf/25 mm):

Fastener tapes A to J were tested according to the adhesive strength measurement of JIS-Z-0237.

The test plate used was made of stainless steel (SUS304). The peeling speed was 300 mm/min.

2. Yield stress (N/cm (kgf/cm)):

Fastener tapes A to J were tested according to the above-mentioned JIS-K-7113.

The specimen was 10 mm wide and the loading rate was 200 mm/min.

3. Ink leakage:

An ink jet recording head was used which had 64 nozzles at a nozzle pitch of 16 nozzles per mm. The ink having the following composition was filled into the ink jet recording head and the sealing tapes A to H were applied to seal the nozzle surface.

Ink composition

C.I. Food Black 2 2 parts by weight

Glycerine 10 parts by weight

Urea 5 parts by weight

Isopropyl alcohol 5 parts by weight

Water 78 parts by weight

The ink jet recording heads with the seal tapes applied were placed in a heat cycle tester and subjected to 10 heat cycles; a cycle consisting of -30ºC for 2 hours, room temperature for 2 hours, and 60ºC for 2 hours. After the test, the nozzle surfaces to which the seal tapes were applied were examined. The evaluation results are shown in Table 1, in which the symbol "X" means that ink leaked despite the seal tape, and the symbol "O" means that ink did not leak. Table 1

As shown above, according to the evaluation criterion of yield stress, ink leakage is prevented when the yield stress is not greater than 9.81 N/cm (1.0 kgf/cm).

A further investigation was made particularly with respect to the case where the above-mentioned fastener tape is applied to a stepped surface. As a result, another preferable evaluation criterion was found, according to which a measurement is carried out as shown in Fig. 8A and Fig. 8B and will be described below.

That is, according to the present invention, a property has been found which can be used as an evaluation criterion for peeling a pressure-sensitive adhesive portion from a stepped surface after a long residence time is useful. Fig. 8A and Fig. 8B are rough drawings for explaining the above evaluation criterion. According to the drawings, the holder T2 made of polysulfone holds a sample T3 to be tested. The holder T2 may be made of any material if it is capable of holding the sample T3 without deforming it. In this example, the holder T2 holds the sample T3 by means of the adhesive force at its portion 1D with the pressure-sensitive adhesive. The holder T2 is rotatable at the holding point about the rotation axis T7, and is in a direction parallel to the horizontal plate surface of the electronic balance T5. The moving distance is set to 5 mm. The width of the sample T3 is not limited, but the standard width is 10 mm. The measured value is converted to the standard width in proportion to the width of the sample to enable comparison of the folding stress.

As shown in Fig. 8A, in the measurement, a sample T3 of the fastener member having the pressure-sensitive adhesive portion is adhered to the polysulfone plate T2 such that the free length T4 is 10 mm long. Then, the non-adhesive side (or the support side) of the sample T3 is passed along the plate surface of the electronic balance with the above-mentioned distance set to 5 mm and stopped at the center of the plate. The stress is immediately read, and then the measured stress is converted into the stress per 10 mm when the width of the sample is not 10 mm, and the converted value of the stress per 10 mm shows the folding stress according to the present invention.

The samples of the previously described examples and comparative examples were tested for folding stress. The results are shown in Table 2. Table 2

Further, various samples were prepared and tested. As a result, the samples having a folding stress of 0.1 g/cm did not cause ink leakage immediately after the experiment, but peeled off slightly after several hours. It was found that such samples are practically usable. However, a folding stress of 0.08 g/cm or less is more preferable. Of course, it is desirable that the fastener element simultaneously satisfies the above-mentioned yield stress condition of not more than 9.81 N/cm (1.0 kgf/cm) in addition to the above-mentioned folding stress condition.

The folding stress is preferable as the evaluation criterion in the present invention. The closure element gives an extraordinary effect when it has a Folding stress of not more than 0.10 g/cm of width at the centre of the plate of an electronic balance.

Next, the structure of the connection to air, which is extremely effective in the present invention, is explained.

In short, the ink container has an air communication device for opening its interior to the outside air. The air communication device has a plurality of cells through which the interior communicates with the outside. The opening of the respective cells is smaller in comparison with the size of the cells. The plurality of cells, which are larger in comparison with the openings, are arranged in sequence and communicate through the small openings, so that the leakage of ink is suppressed many times and the leaked ink has to pass through the multiple holding space to get outside. Thus, the effect of preventing the leakage of ink is remarkable in comparison with the conventional ink container. With the aid of the plurality of cells, the evaporation of ink is greatly reduced even if the small spaces are saturated with water vapor at an early stage. In addition, the openings of the cells are shifted in position from one another, so that the ink that has penetrated through vibration or swinging is distributed as finely as possible, whereby the small spaces effectively prevent ink from leaking out.

In another construction of the device in which the plurality of cells are arranged in a crossed direction from the inside to the outside, ink penetrated into them by vibration or swinging can be finely dispersed, thereby effectively preventing ink leakage and advantageously enabling miniaturization of the air communication device.

Although this construction is effective alone, by combining it with the above-mentioned construction, the effect is enhanced in a synergistic manner. Furthermore, if the cells are made progressively larger from the outside to the inside, the buffer space for the given space size is made larger and ink leakage is prevented more effectively.

On the other hand, if there is a member which is continuous on the inner wall near the connecting device, the arrangement of the air connecting device on the inside of the ink container may cause another problem such that the ink may be spread along the member connected to the inner wall. This ink spreading is prevented by the foregoing construction in a more secure manner than by a conventional construction. If this phenomenon can be prevented, the effect of the present invention is reliably ensured for a long period of time. Accordingly, in a preferred construction of the present invention, the end of the opening protrudes relative to the continuous member. In such a case, it is preferable that the end of the opening does not come into contact with the ink absorbing body such as a porous sponge.

Fig. 9 illustrates the construction of the air communication device of a recording cartridge in a perspective manner. The recording cartridge comprises a recording head 2 for ejecting ink droplets in accordance with electric signals, a container 3 for storing a recording liquid to be supplied into the recording head 2, an air communication device 4 for equalizing the internal pressure in the container 3 with the atmospheric pressure, a cap member 5 which forms the air communication opening and a plurality of cells, a porous material 8 for holding the recording liquid ity and a buffer chamber 8 for preventing the leakage of ink caused by the fluctuation of temperature and atmospheric pressure, which corresponds to the aforementioned atmospheric pressure supply space 1402 and separates the air communication device from the porous material 8. Fig. 10 illustrates details of the construction of the air communication device of Fig. 9 by means of a sectional view of the opening portion. As can be understood from these drawings, the air communication device is constructed of an inner opening 43, an inner cell 44, an opening 45 between the cells, an outer cell 42 and an outer opening 41 which communicate with the atmospheric air in this order. In this example, as shown in the drawing, the cap member is fitted into the cylindrical inner wall 11 of the ink container by deforming a projection (such as a burr deformable by pressing to a size of about 0.1 mm) of the cap member to form the air communication device. In another example, a structure which achieves the same object may be attached to the outer wall of the ink container.

The air connection device has a tubular opening facing the inside of the ink tank and has a compartment plate to form two cells when inserted into the cylindrical opening of the tank casing. A hole is provided in the compartment plate to connect the two cells. One of the two cells is opened to the inside of the ink tank and the other cell is opened to the outside atmospheric air. The tubular opening is arranged to face the inside of the ink tank. The respective openings are positioned at the center of gravity of the plane facing the cells. The hole in the compartment plate is also preferably positioned at the center of gravity of the compartment plate. The inner diameter is preferably in the range of 0.5 mm to 1.0 mm. mm. In this example, each of the openings has a diameter of 0.8 mm. The outermost opening 41 preferably has a smaller diameter than the inner openings. In this example, the diameter of 0.7 mm is the most suitable.

Fig. 10 illustrates a sectional diagram of the cap member attached to the ink tank casing. The tubular opening has a protruding portion having a length L (preferably not less than 5 mm).

12A, 12B and 12C are shown to explain an ink recording device having a shutter portion formed by inserting a shutter member into the opening of the ink-containing container, the opening being constructed of a deformable resin material and the shutter member being a ball for closing the opening by pressing and deforming the resin material. By adopting such a structure having an effect of preventing ink evaporation in addition to the structure of the present invention, the advantageous effect of the recording head according to the present invention is further increased. FIG. 12A illustrates a sectional view of the ink supply path in a curved shape having an opening 602B. FIG. 12B illustrates a ball 602A to be pressed in. FIG. 12C illustrates a closed state. In this example, an approximately L-shaped ink supply path (Fig. 12A) is constructed from a fixed side of an ink tube 1600 and an ink supply tube 2200 which are integrally molded from a resin. The opening 602B is an opening for degassing in the integral molding. In this opening, the pressure ball 602A is pressed, which has a diameter slightly larger than the minimum inner diameter of the opening, so that the resin is deformed, to securely close the opening using the ball.

In this example, not only the sealing ball serves to seal the opening, but also the capillary phenomenon between the ink channel 1600 and the ink supply tube 2200 is secured by reducing the sectional area at the bent portion from the ink supply tube 1200 to the ink channel 1600. Thus, the use of a sealing member in a spherical shape provides the advantage of stabilizing the ink flow without disturbing the ink flow.

The examples of the numerical values are shown in detail. As shown in Fig. 12A, the end portion of the ink supply tube 2200 which is pressed into an ink absorbing member in the ink tank to supply ink to the recording head in accordance with ink consumption has an inner diameter of 2.0 mm. The ink channel 1600 has an inner diameter of 1.5 mm with a tolerance of not less than -0.08 mm and not more than -0.05 mm, and has a supply tube of 1.0 mm in inner diameter for supplying ink into a common liquid chamber of the recording head at the other end portion opposite to the ink supply tube 2200. Accordingly, the minimum diameter of the opening is 1.5 mm with a tolerance of not less than -0.08 mm and not more than -0.05 mm, and the front of the opening 6028 is tapered to easily insert a spherical plug member corresponding to 2.2 mm in diameter. The ball 602A to be pressed in as shown in Fig. 12B has a diameter of 1.5 mm ± 0.02 mm and is an inelastic metal ball such as stainless steel, aluminum and iron. When the ball 602A is pressed into the minimum diameter portion, the ink channel 1600 made of a resin is deformed only slightly, and thus the plugged state as shown in Fig. 12C is obtained. The ball itself may be made of a resin. However, the ball is preferably less elastic than the opening portion. In view of the evaporation of ink, a metal ball is preferable. The pressure contact of the metal with a resin provides a relatively stable sealing state for a long period of time regardless of the fluctuation of the ambient conditions. A stainless steel ball is particularly suitable in view of the results of the test of resistance to ink at 80 ºC when stored for two months.

The degree of depression of the ball 602A may be arbitrary, if the closure can be achieved. In this example, the entire ball 602A is disposed behind the surface of the ink supply tube 2200 to avoid the possibility of displacement of the ball by contact with another component and to simplify the manufacturing without causing variations in manufacturing.

The constructions shown in Fig. 9 and Fig. 12A to 12C were applied to the present invention to provide a simplified structure which is excellent in overall functionality and was evaluated in various aspects. As a result, it was found that the structure had the advantages of satisfactorily maintaining the ejection outlet area of the recording head, eliminating inconvenience at the start of recording, preventing ink evaporation, maintaining the recording characteristics during the standstill from sale to use and further standstill, and was excellent in the overall evaluation.

The packaging shown in Fig. 11 is briefly explained. The evaporation is lower by a factor of about 0.6 than with conventional packaging. This increases the printing quantity by the same amount of packaged ink, and the Freedom in the selection of packaging material is increased. Consequently, the thickness of the packaging can be reduced, for example, from 1 mm to 0.6 mm. By reducing the thickness, the material cost can be reduced and productivity can be increased. Moreover, while a layer of aluminum foil is conventionally used on the cover side, the foil can be replaced by a vapor-deposited aluminum layer. Consequently, the production steps are reduced, which reduces costs.

An example of a package with the connection opening is shown below.

(Packaging example)

Packaging material 6002: thickness 0.6 mm

Packaging cover 6003: Outer layer: PET 12 µ

(Layer structure) Aluminium 0.05 µ

Nylon 15 µ

EVA release layer 25 µ

The inkjet cartridge is placed in the packaging described above and further packed in the packaging carton 6001.

As described above, the closure design according to the present invention achieves a simplification of the design and, in combination with other new designs, achieves synergistic effects that are industrially significant.

The protective seal tape as the sealing member of the present invention is capable of providing a to maintain sufficient adhesive strength, and, when applied to the ejection outlet, it is suitable for protecting the ejection outlet and preventing leakage of ink from the ejection outlet during a long storage period.

In addition, the protective seal tape comprising a preferred pressure-sensitive adhesive can be easily peeled off when the ink jet recording head is used after a long period of storage without contaminating the ejection outlet of the ink jet recording head and its surroundings, and the protection is achieved without adversely affecting the ink jet recording.

The above object is achieved by single use of the fastener tape according to the present invention without making use of another protective element (such as a pressing element for preventing detachment of the fastener tape).

Claims (13)

1. A sealing member for sealing a recording head having a recording section for ejecting an ink and a reservoir section for storing the ink, the sealing member comprising a sealing film and a pressure-sensitive adhesive section (1A, 1B) for sealing, by means of the pressure-sensitive adhesive section (1A, 1B), a communication hole (30) between the inside and the outside of the recording/reservoir section in which an ink is held, characterized in that the sealing film exhibits a yield point at a stress of not more than 9.81 N/cm (1 kgf/cm) for a sample of 10 mm width at a loading rate of 200 mm/min ± 10% according to JIS-K-7113. 2. Use of a closure member according to claim 1 to close a stepped surface of a recording/container section. 3. A recording head (12) having an ink tank (1301), an energy generating element (40) for generating energy for ejecting an ink held in the ink tank (1301), an ink ejection section (30) corresponding to the energy generating element (40) and a sealing element (1) having a sealing film and a pressure-sensitive adhesive for sealing the ink ejection section (30) of the recording head by means of the pressure-sensitive adhesive, characterized in that the sealing film exhibits a yield point at a stress of not more than 9.81 N/cm (1 kgf/cm) for a sample of 10 mm width at a loading rate of 200 mm/min ± 10% according to JIS-K-7113. 4. A recording head (12) according to claim 3, wherein the pressure-sensitive adhesive is an acrylate ester copolymer crosslinked by means of an isocyanate, the acrylate ester copolymer being composed of at least 80% of the total weight of an alkyl and/or alkoxyalkyl acrylate ester containing a hydroxy group and an acrylate ester having a side chain of an alkyl or alkoxyalkyl group of 4 to 9 carbons. 5. A recording head (12) according to claim 3 or 4, wherein the energy generating element (40) comprises an electrothermal transducer for generating thermal energy for ejecting the ink. 6. A recording head (12) according to claim 3, wherein the portion to be closed by the closure member has a stepped structure. 7. A sealing member for sealing a recording head having a recording section for ejecting an ink and a reservoir section for storing the ink, the sealing member comprising a sealing film and a pressure-sensitive adhesive section (1A, 1B) for sealing, by means of the pressure-sensitive adhesive section (1A, 1E), a communication hole (30) between the inside and the outside of the recording/reservoir section in which an ink is held, characterized in that the sealing film has a folding stress of not more than 0.10 g/cm for a sample (T3) of 10 mm width with a free length (T4) of 10 mm from the end of a sample holder, measured at the center of an electronic balance (T5) arranged in a position 5 mm from the end of the sample holder (T2). 8. A fastener according to claim 7, wherein the fastener has a yield point at a stress of not more than 9.81 N/cm (1 kgf/cm) for a sample of 10 mm width at a loading rate of 200 mm/min ± 10% according to JIS-K-7113. 9. A recording head (12) comprising an ink tank (1301), an energy generating element (40) for generating energy for ejecting an ink held in the ink tank (1301), and an ink ejection section (30) corresponding to the energy generating element (40), characterized in that the sealing member according to claim 7 or claim 8 is applied as a sealing member for the ink recording head to seal the ink ejection portion (30) by means of a pressure-sensitive adhesive portion. 10. A recording head (12) according to claim 9, wherein the pressure-sensitive adhesive is an acrylate ester copolymer crosslinked by means of an isocyanate, the acrylate ester copolymer being composed of at least 80% of the total weight of an alkyl and/or alkoxyalkyl acrylate ester containing a hydroxy group and an acrylate ester having a side chain of an alkyl or alkoxyalkyl group of 4 to 9 carbons. 11. A recording head (12) according to claim 10, wherein the energy generating element (40) comprises an electrothermal converter for generating thermal energy for ejecting the ink. 12. A recording head (12) according to claim 11, wherein the portion to be closed by the closing member has a stepped structure, and the folding stress is not greater than 0.05 g/cm and not less than 0.01 g/cm. 13. A fastener element according to claim 1 or 7, wherein the pressure-sensitive adhesive is an acrylate ester copolymer crosslinked by means of an isocyanate, the acrylate ester copolymer being composed of at least 80% of the total weight of an alkyl and/or alkoxyalkyl acrylate ester containing a hydroxy group and an acrylate ester having a side chain of an alkyl or alkoxyalkyl group of 4 to 9 carbons.