Ink container

Abstract

To provide an ink container with improved recyclability that does not require separation of each layer of the laminated sheet while maintaining high functionality and high reliability as an ink container, where the technologies described in this specification have the potential of contributing to sustainable society such as decarbonized society / circular society.SOLUTION: An ink container that stores ink to be ejected by an ink ejection apparatus includes an ink storage bag made of a laminated sheet and storing the ink therein, and an ink supply member having an ink supply portion for supplying the ink inside the ink storage bag to the ink ejection apparatus. A resin material constituting the laminated sheet contains 90 mass% or more of polyolefin resin.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an ink container. [Background technology]

[0002] Ink containers have been widely used to supply ink to inkjet recording devices. For example, the ink container disclosed in Patent Document 1 is made of a laminated sheet mainly made of resin and has a flexible bag, and the bag contains ink to be supplied to the inkjet recording device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-065373 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the material of the bag of the ink container is not particularly limited, and the ink container can be formed using a plurality of resin materials such as polyethylene and polyethylene terephthalate (PET), for example. When considering recycling the materials, polyethylene and PET have very different properties, so they must be separated for recycling. However, because the individual sheets are strongly bonded together with adhesives, they cannot be easily separated, and the cost of separating them is high, making recycling the ink container difficult. Therefore, the present disclosure provides an ink container that maintains high functionality and high reliability as an ink container, does not require separation of the layers of the laminated sheet, and has improved recyclability. [Means for solving the problem]

[0005] The present disclosure provides an ink container for storing ink to be ejected by an ink ejection device, The ink container is an ink storage bag made of a laminated sheet and storing the ink therein; an ink supply member having an ink supply portion for supplying the ink inside the ink storage bag to the ink discharge device; and The ink container is characterized in that the resin material constituting the laminate sheet contains 90% by mass or more of polyolefin resin. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to provide an ink container that is highly functional and highly reliable as an ink container, does not require separation of the layers of the laminated sheet, and has improved recyclability. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic perspective view of a liquid ejection device. [Figure 2] 1A and 1B are a schematic perspective view and a schematic cross-sectional view of an ink container according to an embodiment of the present invention; [Figure 3] 3 is a schematic cross-sectional view of a laminated sheet constituting an ink accommodating body according to an embodiment of the present invention; FIG. [Figure 4] 3 is a schematic cross-sectional view of a laminated sheet constituting an ink accommodating body according to an embodiment of the present invention; FIG. [Figure 5] FIG. 2 is a schematic perspective view of an ink accommodating body according to the embodiment. [Figure 6] FIG. 2 is a schematic perspective view of an ink accommodating body according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the present disclosure, expressions such as "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined arbitrarily. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ. Note that when XX is a group, multiple XXs may be selected, and the same applies to YY and ZZ.

[0009] In this disclosure, "polyolefin resin" refers to a resin containing 50% by mass or more of a monomer unit corresponding to an olefin monomer. "Monomer unit" refers to the reacted form of a monomer substance in a polymer. The polyolefin resin may contain a polymer of an olefin monomer, or may contain a copolymer of a monomer mixture containing an olefin monomer. Preferably, the polyolefin resin contains 100% by mass of a polymer or copolymer of an olefin monomer.

[0010] Hereinafter, embodiments for carrying out the technology of the present disclosure will be described with reference to the drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0011] As mentioned above, when an ink storage body is formed using multiple types of resin materials, recycling may be difficult. In the present disclosure, in an ink storage bag made of a laminate sheet that stores ink, the resin material that makes up the laminate sheet contains 90% by mass or more of polyolefin resin. In other words, the resin material contains 90% by mass or more of a polyolefin structure. If the resin material contains 90% by mass or more of polyolefin resin, the resin material can be treated as polyolefin resin when recycling the laminate sheet. Therefore, recycling is possible without separating the resin material, such as by separating the individual layers of the laminate sheet.

[0012] Furthermore, polyolefin resins such as polypropylene have high durability and barrier properties, and are therefore excellent in durability and barrier properties as ink storage bags. As described above, the present disclosure provides an ink container that maintains high functionality and reliability as an ink container, does not require separation of the layers of the laminated sheet, and is therefore highly recyclable. The technology described in this specification can contribute to the realization of a sustainable society, such as a carbon-free, recycling-oriented society.

[0013] A liquid ejection device such as an ink ejection device to which the ink container can be applied will be described below. 1 is a schematic perspective view of a liquid ejection device 100 according to this embodiment. As shown in FIG. 1, the liquid ejection device 100 includes a liquid ejection head 101, a recording sheet 102, a carriage 103, a transport roller 104, a liquid supply unit 105, a liquid supply tube 106, and a recovery unit 107.

[0014] The liquid ejection device 100 repeats reciprocating movement (main scanning) of the liquid ejection head 101 and conveyance (sub-scanning) of a recording medium, that is, a recording sheet 102, at a predetermined pitch. In synchronization with these movements, liquids of multiple colors (for example, ink, etc.) are selectively ejected from the liquid ejection head 101 and landed on the recording medium, that is, the recording sheet 102, thereby forming characters, symbols, images, etc.

[0015] An example of the liquid ejection device 100 is an inkjet printer. The recording medium may be any medium capable of forming an image by impacting ink droplets. For example, recording media of various materials and shapes such as paper, cloth, optical disc label surfaces, plastic sheets, overhead projector sheets, and envelopes can be used.

[0016] The liquid ejection head 101 is slidably supported on two guide rails and is mounted on a carriage 103 that moves back and forth in a straight line along the guide rails by a driving means (not shown) such as a motor.

[0017] A recording sheet 102 onto which the liquid ejected from the liquid ejection portions of the liquid ejection head 101 lands is conveyed by a conveying roller 104, which serves as a conveying means, in a direction that faces the liquid ejection surface of the liquid ejection head 101 and intersects with the direction of movement of the carriage 103. The liquid ejection head 101 has a plurality of nozzle rows, each of which ejects liquid of a different color, as a plurality of liquid ejection portions. A plurality of independent ink containers 1 (see FIG. 2), each having a liquid outlet member for guiding the liquid corresponding to the color of the liquid ejected from the liquid ejection head 101, are attached to a liquid supply unit 105.

[0018] In this embodiment, four ink containers 1 containing cyan (C), magenta (M), yellow (Y), and black (K) ink, respectively, are mounted on the liquid supply unit 105. The four ink containers 1 are the same size, but for example, the ink container 1 for black ink may be larger than the ink containers 1 for the other colors of ink. Furthermore, the liquid ejection head 101 may be mounted on the carriage 103 in an easily detachable manner, or in a fixed arrangement.

[0019] The liquid supply unit 105 and the liquid ejection head 101 are connected by a plurality of liquid supply tubes 106, each corresponding to a different color of liquid. By installing the ink container 1 (see FIG. 2) inside the liquid supply unit 105, it becomes possible to independently supply each color of liquid contained in the ink container 1 to each nozzle row of the liquid ejection head 101. A recovery unit 107 is disposed in a non-printing area, which is within the reciprocating movement range of the liquid ejection head 101 but outside the range through which the recording sheet 102 passes, so as to face the liquid ejection surface of the liquid ejection head 101.

[0020] The dimensions shown in the drawings will now be explained. In this specification, the longitudinal direction of the ink container 1 is called the X direction (length direction), the planar direction perpendicular to the length direction is called the Y direction (width direction), and the direction perpendicular to the X and Y directions is called the Z direction (height direction). With respect to the X direction, the direction toward the side where the ink container 1 is attached to the liquid supply unit 105 is called the +X direction, and the direction opposite to the +X direction is called the -X direction. With respect to the Y direction, the direction toward the left of the side where the ink container 1 is attached to the liquid supply unit 105 is called the -Y direction, and the direction opposite to the -Y direction is called the +Y direction. With respect to the Z direction, the anti-gravity direction is called the +Z direction, and the gravity direction is called the -Z direction (FIG. 1).

[0021] The recovery unit 107 has a cap portion for capping the liquid ejection surface of the liquid ejection head 101, a suction mechanism for forcibly sucking the liquid while the liquid ejection surface is capped, and a cleaning blade for wiping dirt off the liquid ejection surface. The suction operation described above is performed by the recovery unit 107 prior to the recording operation of the liquid ejection device 100. As a result, even if the liquid ejection device 100 is operated after being left unused for a long period of time, the recovery process performed by the recovery unit 107 can remove residual air bubbles in the liquid ejection portion of the liquid ejection head 101 and / or thickened liquid near the ejection orifices. This allows the ejection characteristics of the liquid ejection head 101 to be maintained. As described above, the liquid ejection device 100 has the function of introducing liquid from the ink accommodating body 1 and ejecting the liquid.

[0022] The ink container stores ink to be ejected by the ink ejection device. FIG. 2A shows a schematic perspective view of the ink container. FIG. 2B shows a schematic view of the AA cross section. The ink container 1 is set in the liquid ejection device 100. The ink container has an ink storage bag 2 that stores ink therein and an ink supply member 3 that supplies ink to the ink ejection device. The ink storage bag is made of a laminated sheet, and is formed into a bag shape by joining multiple films containing polyolefin resin, for example. Two laminated sheets may be formed into a bag shape, or one sheet may be folded into a bag shape. The laminated sheet may be formed into a bag shape by, for example, heat welding.

[0023] The resin material constituting the laminate sheet contains 90% by mass or more of polyolefin resin (polyolefin structure). The resin material also includes an adhesive layer that bonds the sheets in the laminate sheet. From the viewpoint of recyclability, the resin material preferably contains 92% by mass or more of polyolefin resin, more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more. There is no particular upper limit, and the resin material may contain 100% by mass of polyolefin resin. The content of polyolefin resin (polyolefin structure) in the resin material is preferably, for example, 90 to 100% by mass, 92 to 100% by mass, 95 to 100% by mass, 98 to 100% by mass, or 99 to 100% by mass.

[0024] Examples of the polyolefin resin include at least one selected from the group consisting of polypropylene resin and polyethylene resin; a copolymer of ethylene and / or propylene with an olefin monomer other than ethylene and propylene; etc. Examples of the olefin monomer other than ethylene and propylene include α-olefins having 3 to 20 carbon atoms (preferably 4 to 20 carbon atoms). The polyolefin resin is preferably a polypropylene resin, and more preferably a polyethylene resin.

[0025] The polyolefin resin is preferably subjected to one or both of a stretching treatment and an electron beam treatment. The polypropylene resin used in the laminate sheet may be at least one selected from the group consisting of unstretched polypropylene, stretched polypropylene, and electron beam-treated polypropylene. The polypropylene resin is preferably at least one selected from the group consisting of stretched polypropylene, electron beam-treated polypropylene, and stretched and electron beam-treated polypropylene.

[0026] The polyethylene resin used in the laminate sheet may be at least one selected from the group consisting of high-density polyethylene, medium-density polyethylene, low-density polyethylene, oriented high-density polyethylene, oriented medium-density polyethylene, oriented low-density polyethylene, electron-beam-treated high-density polyethylene, electron-beam-treated medium-density polyethylene, and electron-beam-treated low-density polyethylene. The polyethylene resin is preferably at least one selected from the group consisting of high-density polyethylene, medium-density polyethylene, oriented high-density polyethylene, oriented medium-density polyethylene, electron-beam-treated high-density polyethylene, electron-beam-treated medium-density polyethylene, oriented and electron-beam-treated high-density polyethylene, and oriented and electron-beam-treated medium-density polyethylene.

[0027] The method for measuring the content of polyolefin resin in the resin material constituting the laminate sheet from the ink container is as follows. The polyolefin resin content can be measured by heating to 600°C using a pyrolysis GC-MS (Agilent Technologies, Inc., GC: 7890B, MS: 5977B). Cut.

[0028] The ink storage bag 2 is formed by molding a laminated sheet into a bag shape. The ink storage bag 2 is formed, for example, by joining laminated sheets together near the outer periphery. The laminated sheets are preferably joined by a method of heating, melting, and pressing, but this is not limiting and they may also be joined using an adhesive or the like. The ink supply member 3 has a connection part 4 at its tip that connects to the ink discharge device. The connection part 4 preferably has a check valve function to prevent the ink supplied to the ink discharge device from flowing backward. Materials that can be used to form the ink supply member 3 include resins such as polyolefin resin, polyester resin, and polyamide resin, as well as metals, inorganic materials, and composite materials thereof. Considering recyclability, it is desirable to form the ink supply member 3 from the same polyolefin resin as the ink storage bag 2. In other words, the ink supply member 3 preferably contains polyolefin resin.

[0029] The layer structure of the laminate sheet is not particularly limited. For example, the laminate sheet has a protective layer and a sealing layer. An adhesive layer may be provided between the protective layer and the sealing layer. A gas barrier layer may also be provided between the protective layer and the sealing layer to provide gas barrier properties. Figure 3 shows an example of a laminate sheet 5 that constitutes the ink storage bag 2. Figure 4 shows another example of a laminate sheet 5 that constitutes the ink storage bag 2 (these are enlarged views of part B in Figure 2B).

[0030] The laminate sheet 5 in Fig. 3 has, in this order, a protective layer 6, a gas barrier layer 9, an adhesive layer 8, and a sealing layer 7. The laminate sheet 5 may have, in this order, a protective layer 6, an adhesive layer 8, a gas barrier layer 9, an adhesive layer 8, and a sealing layer 7. The laminate sheet 5 in Fig. 4 has, in this order, a protective layer 6, a gas barrier layer 9, an adhesive layer 8, an adjustment layer 10, an adhesive layer 8, and a sealing layer 7.

[0031] As shown in FIG. 5, the ink container 1 has an ink supply pipe 11 disposed inside the ink container and connected to an ink supply unit; a spacer member connected to the ink supply pipe 11 and having a liquid inlet for introducing the ink in the ink storage bag 2 into the ink supply section via the ink supply pipe 11; It is preferred that the compound has the following structure:

[0032] It is preferable that the ink supply tube and the spacer member contain 90% by mass or more of polyolefin resin. In this configuration, when the ink container 1 is recycled after the ink has been used up, the constituent materials can be recycled as olefin materials, which significantly improves recyclability. The polyolefin resin in the ink supply tube and the spacer member is preferably the same type as the resin material in the laminate sheet.

[0033] The spacer member preferably has at least two liquid inlets at different positions in the height direction when in a given orientation, which makes it less likely that the ink composition will become uneven. The type and content of the polyolefin resin in the ink supply tube and the spacer member are the same as those of the resin material in the laminate sheet. For example, the content of the polyolefin resin is preferably 90 to 100 mass%, 92 to 100 mass%, 95 to 100 mass%, 98 to 100 mass%, or 99 to 100 mass%. The polyolefin resin is preferably unstretched.

[0034] 6, the ink container 1 preferably has a gripping area 13 at least partially around the outer periphery of the ink storage bag 2, whereby the laminated sheet 5 can be gripped. For example, by providing an unbonded area of ​​the laminated sheet at the end of the ink storage bag formed by bonding the laminated sheets together, In this way, the unbonded region can be used as the gripping region 13. The bonded laminated sheets can be pulled apart by gripping the gripping region 13. This makes it easier to clean the inside of the ink accommodating body 1 after using up the ink.

[0035] The width of the gripping region is preferably 2 mm to 20 mm, and more preferably 5 mm to 10 mm. The presence of such gripping region 13 further improves recyclability. In Figure 6, the width of the gripping region is the length indicated by W.

[0036] (protective layer) The laminate sheet may have a protective layer 6. The protective layer 6 protects the ink container 1 from external impacts and the like. As shown in Figures 3 and 4, the protective layer 6 is preferably disposed as the outermost layer of the ink container bag. The protective layer 6 contains the above-mentioned polyolefin resin. Furthermore, from the viewpoint of further improving durability, it is preferable that the protective layer 6 contains at least one selected from the group consisting of stretched polypropylene, electron beam treated polypropylene, stretched and electron beam treated polypropylene, high density polyethylene, medium density polyethylene, stretched high density polyethylene, stretched medium density polyethylene, electron beam treated high density polyethylene, electron beam treated medium density polyethylene, stretched and electron beam treated high density polyethylene, and stretched and electron beam treated medium density polyethylene.

[0037] The protective layer 6 may contain various additives, such as a crosslinking agent, an antioxidant, an antiblocking agent, an ultraviolet absorber, a lubricant, a light stabilizer, a filler, a reinforcing agent, an antistatic agent, a pigment, and a modifier.

[0038] The polyolefin may be stretched. When stretched, the film may be uniaxially stretched or biaxially stretched. The stretching ratio in the machine direction (MD) is preferably 2 to 10 times, and more preferably 3 to 7 times. By setting the stretching ratio in the machine direction (MD) to 2 times or more, durability can be further improved. From the viewpoint of the breaking limit, the upper limit of the stretching ratio in the machine direction (MD) is preferably 10 times or less.

[0039] The stretch ratio in the transverse direction (TD) is preferably 2 to 10 times, more preferably 3 to 7 times. By stretching the substrate in the transverse direction (TD) at a ratio of 2 or more, durability can be further improved. From the viewpoint of the breaking limit, the upper limit of the stretch ratio in the transverse direction (TD) is preferably 10 times or less. The degree of orientation can be changed by performing a stretching treatment, and the degree of orientation is preferably 60% or more, and more preferably 90% or more.

[0040] The polyolefin may be subjected to electron beam treatment. When electron beam treatment is performed, the dose of the electron beam to be irradiated is preferably in the range of 10 kGy to 2000 kGy, more preferably in the range of 20 kGy to 1000 kGy, and even more preferably in the range of 150 kGy to 500 kGy. The acceleration voltage of the electron beam is preferably in the range of 30 kV to 300 kV, more preferably in the range of 50 kV to 300 kV, and even more preferably in the range of 70 kV to 250 kV. The irradiation energy of the electron beam is preferably in the range of 20 keV to 750 keV, more preferably in the range of 25 keV to 500 keV, and particularly preferably in the range of 30 keV to 200 keV.

[0041] The oxygen concentration in the electron beam irradiation device is preferably 500 ppm or less, more preferably 100 ppm or less. By performing electron beam irradiation under such conditions, it is possible to suppress the generation of ozone and also to prevent radicals generated by electron beam irradiation from entering the atmosphere. This can prevent the catalyst from being deactivated by oxygen in the atmosphere, and such conditions can be achieved, for example, by creating an inert gas (nitrogen, argon, etc.) atmosphere inside the apparatus. Electron beam treatment improves the crosslink density and strengthens the resin, thereby further improving durability. The gel fraction, which is an index for measuring the crosslink density, is preferably 15% or more and 90% or less, and more preferably 20% or more and 80% or less.

[0042] The protective layer satisfies at least one of the following conditions: (1) the degree of orientation of the protective layer is 60% or more, and (2) the gel fraction of the protective layer is 15% or more. It may satisfy both conditions. By satisfying the above degree of orientation and / or gel fraction, the durability of the ink storage body is further improved, and it becomes easier to balance recyclability and durability. The degree of orientation of the protective layer is preferably 60 to 100%, more preferably 90 to 100%. The gel fraction of the protective layer is preferably 15 to 90%, more preferably 20 to 80%, still more preferably 30 to 80%, and even more preferably 40 to 60%.

[0043] The degree of orientation is calculated by X-ray diffraction analysis using the formula: degree of orientation F [%] = (360 - ΣW) / 360 × 100 <W: half-value width>. The means of X-ray diffraction analysis was carried out using Empyrean manufactured by Malvern Panalytical B.V., under the following conditions. (X-ray: Cu-Kα ray / 50 kV / 200 mA, step angle: 0.04°, scan range: 2θ = 5 to 40°)

[0044] The gel fraction is measured by the method of JIS K 6796. Specifically, after precisely weighing the resin layer, it is wrapped with a wire mesh of 120 to 150 mesh and precisely weighed, and the sample wrapped with the wire mesh is immersed in a flask containing xylene. A condenser tube is attached to the flask, and after boiling xylene for 8 hours, the resin layer wrapped with the wire mesh is taken out from the flask and completely dried. The resin layer wrapped with the wire mesh is precisely weighed, and the gel fraction is calculated by the following formula. Gel fraction = (mass of the resin layer after immersion and drying) / (mass of the resin layer before immersion) × 100

[0045] In addition, the protective layer 6 may be surface-treated. Thereby, the adhesion with an adjacent layer can be improved. The method of surface treatment is not particularly limited, and examples include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using various gases, glow discharge treatment, and chemical treatments such as oxidation treatment using chemical agents.

[0046] Printing may be performed on the surface of the protective layer 6, and the image is not particularly limited, and characters, patterns, symbols, and combinations thereof are represented.

[0047] The thickness of the protective layer 6 is preferably 10 μm or more and 150 μm or less, and more preferably 30 μm or more and 100 μm or less. By making the thickness 10 μm or more, durability can be further improved. Furthermore, by making the thickness 150 μm or less, the processability of the laminated sheet can be improved.

[0048] The thickness of each layer in the laminated sheet is measured by embedding the sheet in epoxy resin or the like, cutting the cross section with a microtome (Leica RM2165), and observing the cross section with a metallurgical microscope.

[0049] (Sealing layer) The laminated sheet may include a sealing layer. As shown in Figures 4 and 5, the sealing layer 7 is preferably disposed as the innermost layer of the ink storage bag. The sealing layer can be heat-sealed to form the ink storage bag. For example, the ink storage bag is formed by joining the sealing layers together by heat welding to form a bag. The sealing layer is the layer that comes into direct contact with the ink when the ink is contained in the bag.

[0050] The sealing layer 7 preferably contains the above-mentioned polyolefin resin. The sealing layer 7 preferably contains a polyolefin resin that has not been subjected to stretching treatment or electron beam treatment. The polyethylene is preferably medium-density polyethylene or low-density polyethylene. From the viewpoint of thermal welding, the sealing layer preferably contains at least one selected from the group consisting of unstretched polypropylene, medium-density polyethylene, and low-density polyethylene, and more preferably contains at least one selected from the group consisting of unstretched polypropylene, medium-density polyethylene, and low-density polyethylene.

[0051] When the sealing layers 7 are joined together by heat sealing, it is preferable that the sealing layers 7 have lower heat resistance than the protective layer 6. For example, when polypropylene is used for the protective layer 6, it is preferable that polypropylene that has not been stretched or electron beam treated, or various polyethylenes, be used for the sealing layer 7. When polyethylene is used for the protective layer 6, it is preferable that medium-density polyethylene or low-density polyethylene that has not been stretched or electron beam treated be used for the sealing layer 7. When the sealing layers 7 are bonded together with an adhesive, the sealing layers 7 only need to contain a polyolefin resin.

[0052] The sealing layer 7 may contain various additives, such as a crosslinking agent, an antioxidant, an antiblocking agent, an ultraviolet absorber, a lubricant, a light stabilizer, a filler, a reinforcing agent, an antistatic agent, a pigment, and a modifier.

[0053] The thickness of the sealing layer 7 is preferably 30 μm or more and 200 μm or less, and more preferably 50 μm or more and 150 μm or less. By making the thickness 30 μm or more, the strength can be further improved. Furthermore, by making the thickness 200 μm or less, the processability of the laminate sheet 5 can be improved.

[0054] (adhesive layer) The laminate sheet may include an adhesive layer between layers of the laminate sheet. The laminate sheet bonds the layers of the laminate sheet together. The laminate sheet may include an adhesive layer, for example, between the protective layer 6 and the sealing layer 7. In the case of FIG. 3, the laminate sheet includes an adhesive layer 8 between the gas barrier layer 9 and the sealing layer 7. In the case of FIG. 4, the laminate sheet 5 includes adhesive layers 8 between the gas barrier layer 9 and the adjustment layer 10, and between the adjustment layer 10 and the sealing layer 7.

[0055] The adhesive layer 8 preferably contains a polyolefin resin. The polyolefin resin preferably contains at least one selected from the group consisting of a polypropylene resin and a polyethylene resin. The adhesive layer 8 preferably contains, as at least one copolymerization component selected from the group consisting of a polypropylene resin and a polyethylene resin, a monomer unit corresponding to an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride. By using an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride as copolymerization components of the polyolefin resin in the adhesive layer, the adhesive layer contains a carboxyl group, which increases polarity and improves adhesion. The content of these copolymerization components may be in a range such that the content of polyolefin resin in the resin material constituting the laminate sheet is 90% by mass or more.

[0056] When the adhesive layer 8 contains a polyethylene resin, the polyethylene resin preferably contains, as a copolymerization component, 0.01% by mass to 5% by mass of monomer units corresponding to unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides.When the adhesive layer 8 is a polypropylene resin, the polypropylene resin preferably contains, as a copolymerization component, 0.01 to 5% by mass of monomer units corresponding to unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides.

[0057] When adhesive layer 8 contains polyethylene resin, the content of ethylene component in the polyethylene resin is preferably 50 to 99.9 mass%, more preferably 90 to 99 mass%.When adhesive layer 8 contains polypropylene resin, the content of propylene component in the polypropylene resin is preferably 50 to 99.9 mass%, more preferably 90 to 99 mass%.

[0058] The unsaturated carboxylic acid used as a copolymerization component may be at least one selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, crotonic acid, etc. The unsaturated carboxylic acid anhydride may be an anhydride of the above unsaturated carboxylic acid, such as maleic anhydride or itaconic anhydride.

[0059] The weight average molecular weight of the polyethylene polymer is preferably 20,000 or more and 100,000 or less, and more preferably 25,000 or more and 70,000 or less. The weight average molecular weight of the polypropylene polymer is preferably 5,000 or more and 150,000 or less, and more preferably 20,000 or more and 120,000 or less.

[0060] The adhesive layer 8 may also contain additives such as pigments such as titanium oxide, zinc oxide and carbon black, dyes such as disperse dyes, acid dyes and cationic dyes, antioxidants, lubricants, colorants, stabilizers, wetting agents, thickeners, coagulants, gelling agents, anti-settling agents, softeners, plasticizers, leveling agents, ultraviolet absorbers and flame retardants.

[0061] The thickness of the adhesive layer 8 is preferably 0.05 μm to 1.0 μm, more preferably 0.1 μm to 0.7 μm, and even more preferably 0.1 μm to 0.5 μm. By making the thickness of the adhesive layer 0.05 μm or more, it is possible to further improve the adhesion between the layers and the resistance to contents. Furthermore, by making the thickness of the adhesive layer 1 μm or less, it is possible to prevent poor drying and the like.

[0062] The adhesive layer can be formed by applying and then drying using, for example, gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, or the like.

[0063] (barrier layer) The laminate sheet may include a barrier layer 9. The laminate sheet preferably includes a barrier layer between the layers of the laminate sheet. For example, the laminate sheet includes at least a protective layer, a barrier layer, and a sealing layer in this order. Other layers may be provided between the layers. For example, an adhesive layer may be provided between the barrier layer and the sealing layer. The barrier layer 9 prevents ink components in the ink container 1 from volatilizing and leaking to the outside, and also prevents external gases from penetrating and entering through the laminate sheet 5 of the ink container 1.

[0064] The barrier layer 9 is preferably a metal foil or a vapor-deposited film. The barrier layer 9 is composed of a metal foil such as aluminum; a vapor-deposited film of a metal such as aluminum, or an inorganic oxide such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, or barium oxide. The barrier layer 9 preferably contains at least one selected from the group consisting of aluminum and inorganic oxides. Furthermore, the barrier layer 9 is more preferably an aluminum foil or a vapor-deposited film of at least one selected from the group consisting of aluminum and inorganic oxides. The inorganic oxide is preferably silicon oxide.

[0065] The thickness of the metal foil, such as aluminum foil, is preferably 2 μm or more and 20 μm or less. The thickness of the vapor-deposited film is preferably from 1 nm to 150 nm, more preferably from 5 nm to 60 nm, and even more preferably from 10 nm to 40 nm.

[0066] Although it is difficult to recycle the above metals or inorganic oxides together with resin materials, they are recyclable because they are present in small amounts relative to the total amount of constituent materials. Therefore, although the use of various vapor-deposited films is slightly inferior to the use of aluminum foil in terms of gas barrier properties, the use of fewer materials makes them more recyclable. The barrier layer 9 is preferably disposed at a position other than the outermost or innermost position.

[0067] (adjustment layer) The laminate sheet may include an adjustment layer between the layers of the laminate sheet. The adjustment layer 10 shown in FIG. 4 is used for adjusting strength, etc. The adjustment layer 10 preferably contains at least one selected from the group consisting of polypropylene resin and polyethylene resin, which are polyolefin resins. The adjustment layer 10 preferably contains a polyolefin resin that has been subjected to one or both of a stretching treatment and an electron beam treatment. For example, stretched polypropylene, electron beam treated polypropylene, high density polyethylene, medium density polyethylene, stretched high density polyethylene, medium density polyethylene, low density polyethylene, electron beam treated high density polyethylene, medium density polyethylene, low density polyethylene, etc. are desirable.

[0068] Alternatively, a copolymer of the above-mentioned ethylene and / or propylene with an olefin monomer other than ethylene and propylene may be used. The adjustment layer may also contain a resin other than a polyolefin-based resin, specifically a polyester resin, a polyamide resin, a vinyl resin, a polyurethane resin, or the like. However, the resin material constituting the laminate sheet must contain 90% by mass or more of a polyolefin resin.

[0069] The adjustment layer may contain various additives, such as a crosslinking agent, an antioxidant, an antiblocking agent, an ultraviolet absorber, a lubricant, a light stabilizer, a filler, a reinforcing agent, an antistatic agent, a pigment, and a modifier.

[0070] The polyolefin may be stretched. When stretched, the film may be uniaxially stretched or biaxially stretched. The stretching ratio in the machine direction (MD) is preferably 2 to 10 times, and more preferably 3 to 7 times. By setting the stretching ratio in the machine direction (MD) to 2 times or more, durability can be further improved. From the viewpoint of the breaking limit, the upper limit of the stretching ratio in the machine direction (MD) is preferably 10 times or less.

[0071] The stretch ratio in the transverse direction (TD) is preferably 2 to 10 times, more preferably 3 to 7 times. By stretching the substrate in the transverse direction (TD) at a ratio of 2 or more, durability can be further improved. From the viewpoint of the breaking limit, the upper limit of the stretch ratio in the transverse direction (TD) is preferably 10 times or less.

[0072] The polyolefin may be subjected to electron beam treatment. When electron beam treatment is performed, the dose of the electron beam to be irradiated is preferably in the range of 10 kGy to 2000 kGy, more preferably in the range of 20 kGy to 1000 kGy, and even more preferably in the range of 150 kGy to 500 kGy. The acceleration voltage of the electron beam is preferably in the range of 30 kV to 300 kV, more preferably in the range of 50 kV to 300 kV, and even more preferably in the range of 50 kV to 250 kV. The irradiation energy of the electron beam is preferably in the range of 20 keV to 750 keV, more preferably in the range of 25 keV to 500 keV, and particularly preferably in the range of 30 keV to 200 keV.

[0073] The oxygen concentration in the electron beam irradiation apparatus is preferably 500 ppm or less, more preferably 100 ppm or less. By performing electron beam irradiation under such conditions, it is possible to suppress the generation of ozone and also to prevent the radicals generated by electron beam irradiation from being deactivated by oxygen in the atmosphere. Such conditions can be achieved, for example, by creating an inert gas (nitrogen, argon, etc.) atmosphere inside the apparatus.

[0074] The adjustment layer 10 may also be subjected to a surface treatment, which can improve adhesion to adjacent layers. The method of surface treatment is not particularly limited, and examples include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using various gases, and glow discharge treatment, as well as chemical treatments such as oxidation treatment using chemicals. The surface of the adjustment layer 10 may be printed, and the image is not particularly limited, and may include letters, patterns, symbols, and combinations thereof.

[0075] The thickness of the adjustment layer 10 is preferably 10 μm or more and 100 μm or less, and more preferably 20 μm or more and 50 μm or less. 4 shows an example in which there is one adjustment layer 10, but there may be multiple adjustment layers 10. Also, although the adjustment layer 10 is disposed in the middle of the layers in FIG. 4, the adjustment layer 10 may be disposed on the outermost side of the layers. [Example]

[0076] The present disclosure will be described in more detail below using examples, but the present disclosure is not limited to these examples.

[0077] Table 1 shows the layer structures of the laminate sheets of Examples 1 to 12 and Comparative Examples 1 to 4. In Example 1, a laminated sheet was obtained having the layer structure shown in Figure 3, and further having an adhesive layer between the protective layer and the barrier layer. A 60 μm-thick high-density polyethylene (HDPE film manufactured by Wako Plastics Industry Co., Ltd.) that had been stretched (5 times in both MD and TD) was used as the protective layer 6. The degree of orientation was 95%. The degree of orientation was determined by the procedure described above. The barrier layer 9 was made of aluminum foil with a thickness of 6 μm. The sealing layer 7 was made of low-density polyethylene (LDPE film manufactured by Wahiro Plastics Industry Co., Ltd.) with a thickness of 150 μm. The adhesive layer 8 between each layer was formed by roll coating a polyethylene polymer (SB-1200 manufactured by Unitika) containing 0.01 to 5 mass% of a monomer unit corresponding to an unsaturated carboxylic acid or anhydride thereof, such as (meth)acrylic acid, maleic acid, itaconic acid, fumaric acid, or crotonic acid, to a thickness of 0.5 μm, followed by drying. The layers were bonded together by the adhesive layer to obtain the laminated sheet of this example.

[0078] In Example 2, the protective layer 6 was made of 60 μm thick polypropylene (OPP manufactured by Seiwa Film Group Co., Ltd.) that had been stretched (5 times in both MD and TD). The degree of orientation was 95%. The sealing layer 7 was made of 80 μm thick unstretched polypropylene (CPP manufactured by Seiwa Film Group Co., Ltd.). The adhesive layer 8 between each layer was made of a polypropylene polymer (DA-1010 manufactured by Unitika Co., Ltd.) containing 0.01 to 5 mass % of a monomer unit corresponding to an unsaturated carboxylic acid or an anhydride thereof, such as (meth)acrylic acid, maleic acid, itaconic acid, fumaric acid, or crotonic acid, and formed to a thickness of 0.5 μm. The laminate sheet was otherwise formed in the same manner as in Example 1.

[0079] In Example 3, a laminate sheet having the layer structure shown in Figure 3 was obtained. In Example 3, aluminum was vapor-deposited to a thickness of 30 nm on the protective layer as a barrier layer 9. No adhesive layer was used between the protective layer 6 and the barrier layer 9. The laminate sheet was otherwise formed in the same manner as in Example 2.

[0080] In Example 4, a 30 nm thick silicon oxide film was deposited on the protective layer 6 as a barrier layer 9. Otherwise, a laminated sheet was formed in the same manner as in Example 3.

[0081] In Example 5, a 30 nm thick silicon oxide film was deposited on the protective layer 6 as the barrier layer 9. No adhesive layer was used between the protective layer 6 and the barrier layer 9. A laminate sheet was formed in the same manner as in Example 1 except for the above.

[0082] In Example 6, a 60 μm thick polypropylene sheet that had been subjected to electron beam treatment was used as the protective layer 6. The conditions for the electron beam irradiation were a dose of 200 kGy, an electron beam acceleration voltage of 100 kV, an electron beam irradiation energy of 100 keV, and an oxygen concentration of 80 ppm in the electron beam irradiation device. The gel fraction was 45%. The gel fraction was measured using the method of JIS K 6796. A laminate sheet was formed in the same manner as in Example 4.

[0083] In Example 7, a laminate sheet was formed in the same manner as in Example 4, except that a low-density polyethylene having a thickness of 150 μm was used as the sealing layer 7.

[0084] In Example 8, a polypropylene polymer (DA-1010 manufactured by Unitika) containing 0.01 to 5 mass % of a monomer unit corresponding to an unsaturated carboxylic acid or its anhydride was formed as an adhesive layer 8 to a thickness of 0.5 μm between the protective layer 6 and the barrier layer 9. A laminate sheet was formed in the same manner as in Example 4 except for the above.

[0085] In Example 9, a 60 μm thick polypropylene that had been stretched and then electron beam treated was used as the protective layer 6. That is, the polypropylene of the protective layer in Example 2 was subjected to electron beam treatment in the same manner as in Example 6. A laminate sheet was otherwise formed in the same manner as in Example 4.

[0086] In Example 10, an adjustment layer 10 was provided between the barrier layer 9 and the seal layer 7 via an adhesive layer 8. A stretched polypropylene (OPP manufactured by Seiwa Film Group Co., Ltd.) having a thickness of 30 μm was used as the adjustment layer 10. A laminate sheet was formed in the same manner as in Example 4.

[0087] In Example 11, the layers were the same as in Example 10, but the protective layer 6 and the adjustment layer 10 were made of resin with an orientation degree of 60% (both protective layer and adjustment layer: OPP manufactured by Seiwa Film Group Co., Ltd.).

[0088] Example 12 had the same configuration as Example 11 except for the adjustment layer 10, but a 10 μm thick nylon was placed in the adjustment layer 10. This improved durability compared to Example 11. The polyolefin resin content in the resin material constituting the laminate sheet was 92 mass %, but it was recyclable.

[0089] In Comparative Example 1, a 12 μm thick PET film (E5200 manufactured by Toyobo Co., Ltd.) was used for the protective layer 6. A 3 μm thick polyurethane adhesive (Uprene UXA-307 manufactured by Sanyo Chemical Industries Co., Ltd.) was used for the adhesive layer 8. A 6 μm thick aluminum foil was used for the barrier layer 9. A 25 μm thick nylon film (N2102 manufactured by Toyobo Co., Ltd.) was used for the adjustment layer 10. A 150 μm thick low-density polyethylene film (LDPE film manufactured by Kazuhiro Plastic Industry Co., Ltd.) was used for the seal layer 7.

[0090] In Comparative Example 2, a laminated sheet was formed in the same manner as in Comparative Example 1 except that a 30 nm thick silicon oxide film was vapor-deposited on the protective layer as the barrier layer 9, and no adhesive layer was used between the protective layer and the barrier layer.

[0091] In Comparative Example 3, stretched polypropylene (OPP manufactured by Seiwa Film Group Co., Ltd.) having a thickness of 30 μm was used as the protective layer 6. Furthermore, nylon (N2102 manufactured by Toyobo Co., Ltd.) having a thickness of 25 μm was used as the adjustment layer 10. Furthermore, a polyurethane adhesive (Uprene UXA-307 manufactured by Sanyo Chemical Industries, Ltd.) having a thickness of 3 μm was used as the adhesive layer 8 between the adjustment layer 10 and the seal layer. Otherwise, a laminated sheet was formed in the same manner as in Example 4.

[0092] In Comparative Example 4, a 25 μm thick nylon (N2102 manufactured by Toyobo Co., Ltd.) adjustment layer and a 0.5 μm thick PE adhesive (SB-1200 manufactured by Unitika Co., Ltd.) were added to the configuration of Example 5. The olefin resin ratio was 87 mass %. Comparative Example 4 was rated C for recyclability.

[0093] [Table 1] In the table, A indicates the content (mass %) of polyolefin resin in the resin material that constitutes the laminate sheet.

[0094] Using each of the above laminated sheets, the edges were heat-sealed to form a bag shape, forming an ink storage bag 2. Then, an ink supply member 3 made of high-density polyethylene was attached by heat-sealing to obtain each ink storage body 1. After storing ink in the ink storage body, the following evaluations were carried out. The composition of the evaluation ink was 7% by mass of pigment, 15% by mass of solvent, 1% by mass of surfactant, 6% by mass of amino acid, 3% by mass of inorganic material, and 68% by mass of water.

[0095] <Durability check> As a durability confirmation test, the ink storage body 1 was dropped from a height of 90 cm in six directions to check the damage to the ink storage bag 2. As a result, if the bag was damaged and the ink inside leaked out, it was rated as "C", if the ink storage bag 2 was damaged but the ink did not leak out, it was rated as "B", and if the ink storage bag 2 was not damaged, it was rated as "A".

[0096] When the polypropylene of the protective layer 6 is subjected to both a stretching treatment and an electron beam treatment, or when the adjustment layer 10 is inserted, the durability is further improved.

[0097] <Barrier performance check> As a barrier property confirmation test, the product was stored for two months at 60°C and a relative humidity of 20% or less, and then the amount of evaporation of the internal ink was checked. As a result, if the product was unable to print using the ink ejection device, it was rated as "C," if it was printable but there was a slight change in color in the printed material, it was rated as "B," and if there was no change in color at all, it was rated as "A." In this evaluation, particularly good results were obtained when aluminum foil was used for the barrier layer 9.

[0098] <Recyclability check> To determine whether or not the material could be recycled, the ink container was drained of ink and then cleaned, and then formed into pellets using an extrusion molding machine. As a result, if it could not be pelletized, it was given a "C," if it could be pelletized but the strength was less than 50% of that of virgin material, it was given a "B," and if the strength was 50% or more, it was given an "A."

[0099] Pelletization was not possible in Comparative Examples 1 to 4, but material recycling was possible in all Examples. In particular, when no aluminum foil was used or when the content of polyolefin resin was high, there was little decrease in strength of the material.

[0100] Next, we will explain Example 13. Figure 5 shows an ink container 1 that has two ink supply tubes 11 for drawing out ink evenly, and a spacer member 12 that is connected to the ink supply tubes 11 and has two liquid inlets at different heights within the ink container 1. With this configuration, ink is supplied from the top and bottom of the bag, so even if there are sediment components in the ink, the ink is sucked evenly from above and below, making it less likely that the ink composition will become uneven. In this example, the laminate sheet 5 in the ink accommodating body 1 is the same as in Example 4, and the ink supply tube 11 and spacer member 12 are made of unstretched polypropylene. This significantly improves recyclability when recycling the ink accommodating body 1 after the ink inside has been used up, since all of the constituent materials are made of olefin-based materials.

[0101] 6 shows the structure of the ink accommodating body 1 in Example 14. An unbonded area that allows the laminated sheet to be gripped is provided at least in a part of the outer periphery of the ink storage bag 2, forming a gripping area 13. This is used when the ink inside the ink accommodating body 1 has been used up and the inside of the ink accommodating body 1 is to be cleaned. When removing the laminated sheets 5, the gripping region 13 is gripped and the laminated sheets 5 are pulled apart, making it easier to clean the inside. The width W of the gripping region 13 is preferably 2 mm or more and 20 mm or less, and more preferably 5 mm or more and 10 mm or less. The presence of the gripping region 13 further improves recyclability.

[0102] The present disclosure relates to the following configurations. (Configuration 1) An ink container that stores ink to be ejected by an ink ejection device, The ink container is an ink storage bag made of a laminated sheet and storing the ink therein; an ink supply member having an ink supply portion for supplying the ink inside the ink storage bag to the ink discharge device; and The ink container is characterized in that the resin material constituting the laminated sheet contains 90% by mass or more of polyolefin resin. (Configuration 2) 2. The ink container according to claim 1, wherein the polyolefin resin is a polypropylene resin. (Configuration 3) The ink container according to Configuration 1, wherein the polyolefin resin is a polyethylene resin. (Configuration 4) The laminated sheet has a protective layer, the protective layer is disposed on the outermost layer of the ink storage bag, 4. The ink container according to any one of configurations 1 to 3, wherein the protective layer satisfies at least one of the following: a degree of orientation of the protective layer of 60% or more; and a gel fraction of the protective layer of 15% or more. (Configuration 5) 5. The ink container according to claim 4, wherein the protective layer has a thickness of 10 μm or more and 150 μm or less. (Configuration 6) The laminated sheet comprises a sealing layer, the sealing layer is disposed on the innermost layer of the ink storage bag, the sealing layer comprises at least one selected from the group consisting of unstretched polypropylene, medium density polyethylene, and low density polyethylene; 6. The ink storage body according to any one of configurations 1 to 5, wherein the seal layer is heat-sealed to form the ink storage bag. (Configuration 7) 7. The ink container according to claim 6, wherein the thickness of the sealing layer is 30 μm or more and 200 μm or less. (Configuration 8) the laminated sheet includes an adhesive layer between layers of the laminated sheet; the adhesive layer contains at least one selected from the group consisting of polypropylene resin and polyethylene resin, The ink container according to any one of Aspects 1 to 7, wherein the adhesive layer contains, as at least one copolymerization component selected from the group consisting of the polypropylene resin and the polyethylene resin, a monomer unit corresponding to an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride. (Configuration 9) 9. The ink container according to claim 8, wherein the adhesive layer has a thickness of 0.05 μm or more and 1.0 μm or less. (Invoice 10) the laminated sheet comprises a barrier layer between layers of the laminated sheet; 10. The ink container according to any one of configurations 1 to 9, wherein the barrier layer contains at least one selected from the group consisting of aluminum and inorganic oxides. (Configuration 11) the barrier layer is an aluminum foil or a vapor-deposited film of at least one material selected from the group consisting of aluminum and inorganic oxides; The thickness of the aluminum foil is 2 μm or more and 20 μm or less, 11. The ink container according to claim 10, wherein the thickness of the vapor-deposited film is 1 nm or more and 150 nm or less. (Configuration 12) The laminated sheet includes an adjustment layer between layers of the laminated sheet, 12. The ink container according to any one of configurations 1 to 11, wherein the adjustment layer contains a polyolefin resin that has been subjected to a stretching treatment and / or an electron beam treatment. (Configuration 13) 13. The ink container according to claim 12, wherein the thickness of the adjustment layer is 10 μm or more and 100 μm or less. (Configuration 14) The ink container is an ink supply pipe disposed within the ink container and connected to the ink supply unit; a spacer member connected to the ink supply pipe and having a liquid inlet for introducing the ink in the ink storage bag to the ink supply section through the ink supply pipe; and 14. The ink container according to any one of configurations 1 to 13, wherein the ink supply tube and the spacer member contain 90% by mass or more of polyolefin resin. (Configuration 15) 15. The ink container according to any one of configurations 1 to 14, wherein the ink container has a gripping area on at least a part of the outer periphery of the ink container bag where the laminated sheet can be gripped. (Configuration 16) 16. The ink container according to claim 15, wherein the width of the gripping area is 2 mm or more and 20 mm or less. [Explanation of symbols]

[0103] 1: ink storage body, 2: ink storage bag, 3: ink supply part, 4: connection part, 5: laminated sheet, 6: protective layer, 7: sealing layer, 8: adhesive layer, 9: barrier layer, 10: intermediate layer, 11: ink supply tube; 12: spacer member; 13: gripping region; 100: Liquid ejection device, 101: Liquid ejection head, 102: Recording sheet, 103: Carriage, 104: Conveying roller, 105: Liquid supply unit, 106: Liquid supply tube, 107: Recovery unit

Claims

1. An ink container that stores ink to be ejected by an ink ejection device, The ink container is an ink storage bag made of a laminated sheet and storing the ink therein; an ink supply member having an ink supply portion for supplying the ink inside the ink storage bag to the ink discharge device; and The ink container is characterized in that the resin material constituting the laminated sheet contains 90% by mass or more of a polyolefin resin.

2. 2. The ink container according to claim 1, wherein the polyolefin resin is a polypropylene resin.

3. 2. The ink container according to claim 1, wherein the polyolefin resin is a polyethylene resin.

4. The laminated sheet has a protective layer, the protective layer is disposed on the outermost layer of the ink storage bag, 4. The ink container according to claim 1, wherein the protective layer has at least one of a degree of orientation of 60% or more and a gel fraction of 15% or more.

5. 5. The ink container according to claim 4, wherein the protective layer has a thickness of 10 [mu]m or more and 150 [mu]m or less.

6. The laminated sheet comprises a sealing layer, the sealing layer is disposed on the innermost layer of the ink storage bag, the sealing layer comprises at least one selected from the group consisting of unstretched polypropylene, medium density polyethylene, and low density polyethylene; 4. The ink container according to claim 1, wherein the seal layer is heat-sealed to form the ink storage bag.

7. 7. The ink container according to claim 6, wherein the thickness of the sealing layer is 30 [mu]m or more and 200 [mu]m or less.

8. the laminated sheet includes an adhesive layer between layers of the laminated sheet; the adhesive layer contains at least one selected from the group consisting of polypropylene resin and polyethylene resin, 4. The ink container according to claim 1, wherein the adhesive layer contains, as at least one copolymerization component selected from the group consisting of the polypropylene resin and the polyethylene resin, a monomer unit corresponding to an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride.

9. 9. The ink container according to claim 8, wherein the adhesive layer has a thickness of 0.05 [mu]m or more and 1.0 [mu]m or less.

10. the laminated sheet comprises a barrier layer between layers of the laminated sheet; 4. The ink container according to claim 1, wherein the barrier layer contains at least one selected from the group consisting of aluminum and inorganic oxides.

11. The barrier layer is an aluminum foil or a layer made of aluminum and an inorganic oxide. At least one vapor-deposited film selected from the group consisting of The thickness of the aluminum foil is 2 μm or more and 20 μm or less, 11. The ink container according to claim 10, wherein the thickness of the vapor-deposited film is 1 nm or more and 150 nm or less.

12. The laminated sheet includes an adjustment layer between layers of the laminated sheet, 4. The ink container according to claim 1, wherein the adjustment layer contains a polyolefin resin that has been subjected to one or both of a stretching treatment and an electron beam treatment.

13. 13. The ink accommodating body according to claim 12, wherein the thickness of the adjustment layer is 10 μm or more and 100 μm or less.

14. The ink container is an ink supply pipe disposed within the ink container and connected to the ink supply unit; a spacer member connected to the ink supply pipe and having a liquid inlet for introducing the ink in the ink storage bag to the ink supply section through the ink supply pipe; and 4. The ink container according to claim 1, wherein the ink supply tube and the spacer member contain 90% by mass or more of a polyolefin resin.

15. 4. The ink container according to claim 1, wherein the ink container has a gripping area on at least a part of the outer periphery of the ink storage bag, where the laminated sheet can be gripped.

16. 16. The ink container according to claim 15, wherein the width of the gripping area is 2 mm or more and 20 mm or less.

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