Liquid filling container

Abstract

There is provided a liquid filling container in which an amount of resin forming a resin container main body is sufficiently reduced, and leakage of liquid as a content is suppressed even when an impact such as dropping is received. A liquid filling container (100) includes: a resin container main body (10) having an opening (12) in an upper portion; a moisture-permeable waterproof sheet (30) covering the opening (12); and a liquefying agent (44) or a liquid (42) filled in the resin container main body (10), and is configured such that a maximum thickness of the resin container main body (10) is 400 µm or less, and when a direction along a longitudinal direction of the opening (12) of the moisture-permeable waterproof sheet (30) is defined as a sheet longitudinal direction (LO), and a direction along a lateral direction of the opening (12) of the moisture-permeable waterproof sheet (30) is defined as a sheet lateral direction (SD), a tensile breaking strength in the sheet longitudinal direction (LO) and the sheet lateral direction (SD) is 40 (N / 25mm) or more, and a tensile elongation at break in the sheet lateral direction (SD) is 60% or more.

Description

Liquid-filled container

[0001] The present invention relates to a liquid-filled container filled with a liquefiable agent or liquid.

[0002] Conventionally, liquid-filled containers have been known that include a resin container body with an opening at the top and a moisture-permeable waterproof sheet covering the opening, with the resin container body filled with a liquid agent or a deliquescent chemical. Examples of the liquid agent or deliquescent chemical that can be filled include fragrances, deodorizers, anti-mold agents, and dehumidifiers. The moisture-permeable waterproof sheet is a sheet that is breathable and moisture-permeable and can inhibit the permeation of liquid. Such liquid-filled containers are placed in any space, such as a room or a storage space such as a closet. Such resin container bodies have the function of releasing fragrance components, deodorizing components, anti-mold components, etc. into the external space through the moisture-permeable waterproof sheet, or absorbing moisture from the external space into the resin container body.

[0003] The liquid-filled containers described above include, for example, a type in which the resin container body is already filled with a liquid drug at the start of use. Another type is a type in which the resin container body is filled with a solid drug, such as a deliquescent drug, at the start of use, and the liquid is stored in the resin container body by exerting an action such as moisture absorption. In either of these types, the liquid-filled container must be designed to reliably retain the liquid inside the resin container body and prevent leakage even when subjected to impact such as being dropped. Therefore, the liquid-filled container is required to have good sealing properties and impact resistance.

[0004] For this reason, the resin container body of conventional liquid-filled containers is generally a box-shaped resin molded product with an opening at the top, manufactured by injection molding synthetic resin, which ensures liquid retention and impact resistance. Furthermore, the opening of the box-shaped resin molded product is covered with a moisture-permeable waterproof sheet that is breathable and moisture-permeable and prevents liquid from passing through, ensuring a tight seal against liquid.

[0005] On the other hand, as part of efforts to combat environmental issues in recent years, resource conservation and waste reduction are being called for, and a reduction in the amount of waste generated from synthetic resin molded products is also being called for, which has led to a demand for a reduction in the amount of resin used in the manufacture of resin molded products.

[0006] In response to this, for example, Patent Document 1 below discloses an attempt to construct a resin container body using a thermoplastic resin sheet. Specifically, Patent Document 1 discloses a type of dehumidifying agent container that includes a resin container body formed from a thermoplastic resin sheet and an inner tray that is supported on the inner surface of the resin container body and has a plurality of holes that divide the interior of the resin container body into upper and lower sections. This dehumidifying agent container is configured to place a granular dehumidifying agent (deliquescent agent) on the inner tray, and to store deliquescent liquid generated from the dehumidifying agent during use by passing it downward through the holes formed in the inner tray.

[0007] JP 2012-143675 A

[0008] However, the desiccant container described in Patent Document 1 requires the resin container body to be rigid enough to support the inner tray carrying the desiccant on its inner surface, which necessitates making the resin container body thick, which is not sufficient in terms of reducing the amount of resin used.

[0009] Therefore, the inventors investigated a liquid-filled container with a thinner resin container body without an inner tray. However, they found that thinning the resin container body resulted in a problem of reduced liquid retention. Conventional resin containers with injection-molded synthetic resin container bodies are sufficiently thick and have excellent impact resistance, allowing them to absorb impacts such as those caused by being dropped while containing a large amount of liquid. Therefore, conventional thick-walled resin container bodies are less likely to experience liquid leakage due to drops and have excellent liquid retention. In contrast, thin-walled resin container bodies constructed with minimal resin content tend to be unable to fully absorb impacts such as those caused by being dropped while filled with liquid, resulting in the impact being transmitted strongly to the liquid inside. The liquid that is transmitted by the impact flows instantaneously inside the resin container body and presses against the moisture-permeable waterproof sheet covering the opening of the resin container body from the inside. This can tear the moisture-permeable waterproof sheet and cause liquid to leak out of the container.

[0010] The present invention has been made in view of the above-mentioned problems, and aims to provide a liquid-filled container in which the amount of resin constituting the resin container body is sufficiently reduced and in which leakage of the liquid contents is suppressed even when subjected to an impact such as being dropped.

[0011] The liquid-filled container of the present invention is a liquid-filled container comprising a resin container body having an opening at the top, a moisture-permeable waterproof sheet covering the opening, and a liquefiable agent or liquid filled in the resin container body, wherein the maximum thickness of the resin container body is 400 μm or less, and when the direction along the longitudinal direction of the opening of the moisture-permeable waterproof sheet is defined as the sheet longitudinal direction and the direction along the short side direction of the opening of the moisture-permeable waterproof sheet is defined as the sheet short side direction, the tensile breaking strength in the sheet longitudinal direction and the sheet short side direction is 40 (N / 25 mm) or more, and the tensile breaking elongation in the sheet short side direction is 60% or more.

[0012] The liquid-filled container of the present invention having the above-mentioned configuration has a thin resin container body with a maximum thickness of 400 μm or less, sufficiently reducing the amount of resin used, and the moisture-permeable waterproof sheet is less likely to tear even when the container is subjected to an impact such as being dropped while filled with liquid, making it less likely for the liquid to leak out. Therefore, the liquid-filled container of the present invention is suitable as a container for storing liquid chemicals such as air fresheners, deodorizers, and anti-mold agents, or chemicals that liquefy after use, such as deliquescent dehumidifiers.

[0013] Figure 5 is a perspective view of a liquid-filled container according to one embodiment of the present invention. Figure 6 is a cross-sectional view of the liquid-filled container shown in Figure 1 along II-II. Figure 7 is a cross-sectional view of a liquid-filled container according to another embodiment of the present invention. Figure 8 is a cross-sectional view of a resin container body according to one embodiment of the present invention. (5A) to (5C) are cross-sectional views showing steps in a method for manufacturing a resin container body according to the present invention.

[0014] An embodiment of the present invention will be described below using FIGS. 1 to 5 (FIGS. 5A to 5C). In all drawings, similar components are designated by the same reference numerals, and redundant explanations will be omitted where appropriate. The drawings used in describing the present invention do not limit the dimensions, dimensional ratios, or shapes of the present invention or the components included therein. FIG. 1 is a perspective view of a liquid-filled container 100 according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of the liquid-filled container 100 shown in FIG. 1 along line II-II. FIG. 3 is a cross-sectional view of a liquid-filled container 100 according to another embodiment of the present invention. FIG. 4 is a cross-sectional view of a resin container body 100 according to one embodiment of the present invention. FIGS. 5A to 5C are cross-sectional views showing steps in a method for manufacturing a resin container body 10 according to the present invention.

[0015] In the following description of liquid-filled containers, unless otherwise specified, the up-down direction refers to the top-to-bottom direction when the liquid-filled container is placed horizontally in its normal usage position. Furthermore, in the context of this invention, a liquid-filled container includes both a container that is already filled with liquid within the resin container body at the start of use and a container that is filled with a solid liquefier at the start of use and in which liquid accumulates within the resin container body over time due to moisture absorption or other reasons. Furthermore, the liquid that can be contained within the resin container body in this invention includes not only liquid substances but also semi-liquid substances such as sols or gels. This is because if the breathable waterproof sheet is damaged by being dropped or otherwise damaged, the damage to the surrounding area if these semi-liquid substances spill out of the container body can be as severe as with a liquid.

[0016] As shown in Figure 1, the liquid-filled container 100 comprises a resin container body 10 having an opening 12 at the top, a moisture-permeable waterproof sheet 30 covering the opening 12, and a liquefiable agent (see reference numeral 44 in Figure 3) or liquid (see reference numeral 42 in Figure 2) filled in the resin container body 10. In the present invention, the maximum thickness of the resin container body 10 is 400 µm or less, and when the direction along the longitudinal direction of the opening 12 of the moisture-permeable waterproof sheet 30 is defined as the sheet longitudinal direction LD and the direction along the transverse direction of the opening 12 of the moisture-permeable waterproof sheet 30 is defined as the sheet transverse direction SD, the resin container body 10 is configured so that the tensile breaking strength (N / 25 mm) in the sheet longitudinal direction LD and the sheet transverse direction SD is 40 (N / 25 mm) or more, and the tensile breaking elongation (%) in the sheet transverse direction SD is 60% or more.

[0017] The inventors of the present invention have conducted extensive research in light of the above-mentioned problems and have come to the following conclusion. Specifically, moisture-permeable waterproof sheets covering the opening of liquid-filled containers are typically thin and microporous to ensure breathability and moisture permeability, and therefore have weaker tensile breaking strength than the resin container body. Therefore, when a liquid-filled container with a thin-walled resin container body is subjected to an impact, such as by being dropped, and the impact is transmitted to the liquid contained therein, the moisture-permeable waterproof sheet breaks due to the pressure of the liquid. Therefore, to prevent damage to the moisture-permeable waterproof sheet upon impact, the inventors attempted to use a moisture-permeable waterproof sheet with high tensile breaking strength. However, they found that even using a moisture-permeable waterproof sheet with improved tensile breaking strength did not fully resolve the above-mentioned problems. Based on this knowledge, further research revealed that the above-mentioned problems can be successfully resolved by using a moisture-permeable waterproof sheet with improved tensile breaking strength and a tensile breaking elongation within specific conditions. This led to the completion of the present invention having the above-mentioned configuration.

[0018] That is, the liquid-filled container 100 of the present invention having the above-described configuration is a container in which the resin container body 10 is thin and uses a small amount of synthetic resin, yet the moisture-permeable waterproof sheet 30 is not easily torn by impact such as being dropped. Therefore, the liquid-filled container 100 is suitable as a container for liquid agents such as air fresheners, deodorizers, and anti-mold agents, or deliquescent dehumidifiers that liquefy upon absorbing moisture.

[0019] In particular, with the recent increase in storage capacity in walk-in closets and other storage spaces, there has been a growing need for large-capacity products, such as air fresheners, deodorizers, dehumidifiers, and anti-mold agents, to be placed in these storage spaces. Such large-capacity liquid-filled containers hold a large amount of liquid inside the container body, which increases the risk of damage to the breathable waterproof sheet when subjected to impacts such as being dropped. In contrast, the liquid-filled container 100 of the present invention is environmentally friendly because it uses a small amount of resin to construct the resin container body 10, and it also has excellent liquid retention properties, with the breathable waterproof sheet 30 being less likely to be damaged when subjected to impacts such as being dropped. The liquid-filled container 100 is described in more detail below.

[0020] (Resin Container Body) As shown in FIGS. 1 and 2 , the liquid-filled container 100 comprises a resin container body 10 and a moisture-permeable waterproof sheet 30. The resin container body 10 has an opening 12 at the top and is capable of containing a liquid 42. In this embodiment, the resin container body 10 has a bottom portion 14 and a side portion 16 extending upward from the outer edge of the bottom portion 14, with the opening 12 provided at the upper end of the side portion 16. In this embodiment, the bottom portion 14 is approximately rectangular, and the resin container body 10 is a rectangular parallelepiped with an open top. The shapes of the bottom portion 14 and the opening 12 are preferably identical or similar, and in this embodiment, they are approximately identical in top view. Therefore, the longitudinal and lateral directions of the opening 12 are parallel or approximately parallel to the longitudinal and lateral directions of the bottom portion 14, respectively. The liquid-filled container 100 of this embodiment, which has a rectangular bottom portion 14 and is an approximately rectangular parallelepiped overall, is a shape that is suitable for easy installation in gaps, etc. The term "approximately rectangular parallelepiped" as used herein includes, for example, a configuration in which the side surface 16 is slightly curved outward due to the weight of the liquid 42, as shown in FIG. 2 . The resin container body 10 in this embodiment has a flange 20 extending from the upper end of the side surface 16. The flange 20 extends from the upper end of the side surface 16 in a direction intersecting the vertical direction, with the upper surface of the flange 20 serving as the adhesive surface for the moisture-permeable waterproof sheet 30. While the flange 20 may have any configuration, it is preferable because it enables the moisture-permeable waterproof sheet 30 to be firmly attached and supported to the resin container body 10. For example, as shown in FIG. 2 , the flange 20 extends approximately horizontally from the upper end of the side surface 16 toward the outside of the container. In a modified example (not shown), the flange 20 may extend toward the interior of the container (i.e., in a direction that does not protrude beyond the resin container body 10 when viewed from above). The flange 20 is provided on at least a portion of the opening 12, and preferably around the entire periphery of the opening.

[0021] In the present invention, the maximum thickness of the resin container body 10 is 400 μm or less. This significantly reduces the amount of resin used compared to conventional methods. For example, considering that typical liquid-filled containers (commercially available products) equipped with conventional injection-molded resin container bodies often have sidewall thicknesses of 600 μm to 1100 μm, it is clear that the amount of resin used in the resin container body 10 of the present invention is sufficiently reduced. In the present invention, the maximum thickness of the resin container body 10 refers to the thickest portion measured at the bottom portion 14 and the side portion 16 of the resin container body 10. Furthermore, by manufacturing the resin container body 10 using a 400 μm-thick resin sheet by plug-assist molding, as described below, the maximum thickness of the resin container body 10 can be reliably reduced to 400 μm or less.

[0022] The configuration of the resin container body 10 will be described in further detail with reference to FIG. 4 . In the resin container body 10, the average thickness T3 of the bottom portion 14 may be 400 μm or less. The average thickness T3 of the bottom portion 14 is not particularly limited, but from the viewpoint of maintaining good shape retention of the liquid-filled container 100, the average thickness is preferably 160 μm or more and 350 μm or less. In the present invention, the average thickness T3 of the bottom portion 14 refers to the thickness of the center portion of the bottom portion 14 of the resin container body 10. Furthermore, in the resin container body 10, the average thickness of the side portion 16 may be 400 μm or less. The average thickness of the side portion 16 is not particularly limited, but from the viewpoint of maintaining adequate strength when filled with liquid, the average thickness T1 of the side portion 16 at a predetermined height is preferably 60 μm or more and 110 μm or less. Here, the average thickness T1 at a predetermined height refers to the average thickness of the side portion 16 at a height position 3 / 8 of the height H1 from the installation surface to the opening 12. The average thickness T1 of the side portion 16 can be determined by measuring the thickness at four randomly selected locations at the predetermined height and arithmetically averaging the measurements. Furthermore, the average thickness T2 of the side portion 16 near the corner R of the rectangular bottom portion 14 is not particularly limited, but is preferably 30 μm or more and 110 μm or less. In particular, when the resin container body 10 is manufactured by plug-assist molding, as described below, the region for measuring the average thickness T2 near the corner R is the part where the resin sheet is most stretched and thinned. It has been clearly confirmed that a liquid-filled container 100 including a resin container body 10 having an average thickness T2 in this region within the above-mentioned range has good liquid retention and is less likely to leak liquid even when subjected to impacts such as being dropped, yet uses a significantly reduced amount of resin.

[0023] The volume of the resin container body 10 can be determined appropriately depending on the intended use of the liquid-filled container 100. From the viewpoint of adaptability to any requirement, from a compact shape to a large capacity, the maximum volume of the liquid-filled container 100 is preferably 300 ml to 2000 ml. In particular, from the viewpoint of being able to effectively adapt to large capacities while reducing the amount of resin used in the resin container body 10, the maximum volume of the liquid-filled container 100 is preferably 800 ml to 2000 ml, and it is more preferable that the weight of the resin container body 10 for a large-capacity liquid-filled container 100 within this range be 2 g to 22 g. Despite this large maximum volume of the resin container body 10, the present invention allows the amount of resin used to constitute the resin container body 10 to be kept sufficiently small, and the moisture-permeable waterproof sheet 30 is resistant to tearing even when dropped while filled with liquid.

[0024] The liquid filling rate or expected filling rate in the liquid-filled container 100 is not particularly limited, but can be, for example, approximately 50% to 90% of the maximum capacity. In the case of a liquid-filled container 100 in which a liquefiable agent is filled in the resin container body 10 at the start of use and liquid is stored in the resin container body 10 due to moisture absorption or the like, the expected filling rate is calculated from the estimated amount of liquid to be stored. The expected filling rate can be adjusted by the amount of liquefiable agent filled in the resin container body 10.

[0025] In the present invention, the resin container body 10 is made of a thermoplastic resin. The thermoplastic resin may be one type of resin or a mixture of two or more types of resins that can be used in general thermoforming, such as polyethylene-based resin, nylon-based resin, polypropylene-based resin, or polystyrene-based resin.

[0026] Although there are no particular limitations on the form of the resin material that constitutes the resin container body 10, it is preferable that the resin container body 10 be constituted by a resin sheet. By using a resin sheet, it is easy to thin the resin container body 10, and by using a resin sheet with an average thickness of 400 μm, the maximum thickness of the formed resin container body 10 can be reliably adjusted to 400 μm or less.

[0027] From the viewpoint of thinning, the resin sheet constituting the resin container body 10 preferably has an average thickness of 400 μm or less, more preferably 360 μm or less, and even more preferably 320 μm or less. From the viewpoint of the shape retention of the resin container body 10 and the strength of the container, the average thickness of the resin sheet is preferably 200 μm or more, more preferably 230 μm or more, and even more preferably 260 μm or more. In the present invention, the average thickness of the resin sheet is obtained by measuring the thickness in the normal direction to the sheet surface at four randomly selected points on the sheet and arithmetically averaging the measured values.

[0028] The resin sheet may be any suitable material for sheet formation by thermal processing, such as a nylon-based resin sheet, a polyethylene-based resin sheet, a polypropylene-based resin sheet, or a polystyrene-based resin sheet. The resin sheet may be a single-layer resin sheet or a laminated resin sheet formed by laminating various resins. Here, the term "nylon-based resin sheet" encompasses both sheets containing only nylon resin as the resin material and sheets containing a mixture of nylon resin and other resins. The same applies to the other resin sheets mentioned above, such as polyethylene-based resin sheets. Among these, from the viewpoint of excellent pinhole resistance, a single-layer nylon-based resin sheet or a laminated resin sheet having a nylon-based resin layer is preferred. Furthermore, from the viewpoint of imparting appropriate flexibility to the resin container body 10 and enhancing impact absorption, a single-layer polyethylene-based resin sheet or a laminated resin sheet having a polyethylene-based resin layer is preferred. A more preferred example of a resin sheet is, for example, a laminated resin sheet having polyethylene-based resin layers on both outermost surfaces and another resin layer between them, which is preferred from the viewpoint of flexibility. Among these, a laminated sheet formed by laminating a polyethylene resin layer / a nylon resin layer / a polyethylene resin layer in this order is more preferred from the viewpoint of combining flexibility and pinhole resistance.

[0029] In the resin container body 10, the bottom surface portion 14 may be made of the same resin material as the side surface portion 16, or may be made of a different resin material. Considering ease of manufacturing and disposal, it is preferable that the bottom surface portion 14 and the side surface portion 16 are made of the same resin material.

[0030] While the method for manufacturing the resin container body 10 using a resin sheet is not particularly limited, a preferred example of manufacturing the resin container body 10 using a single resin sheet 50 will be described below with reference to FIGS. 5A to 5C. FIGS. 5A to 5C are explanatory diagrams illustrating an example of the manufacturing process for the resin container body 10, showing the process of deep-drawing the resin container body 10 into a predetermined shape using a plug for molding assistance (hereinafter also referred to as plug-assisted molding). Each of the drawings in FIGS. 5A to 5C is a vertical cross-sectional view. First, as shown in FIG. 5A, a resin sheet 50, which is a single resin sheet constituting the resin container body 10, is placed on a desired mold 201. The resin sheet 50 is, for example, a sheet-like resin molded product with an average thickness of 400 μm or less. The outer edge of the resin sheet 50 is clamped by a clamp 204, maintaining a horizontally tensed state. When deep-drawing the resin container body 10, instead of using plug-assist molding, the resin sheet 50 can be sucked (vacuum-suctioned) through suction holes 203 provided in the mold 201 and processed into the desired shape along the inner wall surface of the mold 201. However, by performing plug-assist molding, it is easier to obtain a resin container body 10 with a more desirable shape. Although a heating device is not shown in Figures 5A to 5C, the desired resin container body 10 can be easily obtained by appropriately heating and softening the resin sheet 50 before deep-drawing.

[0031] The plug 202 is mated with the molding die 201 in a concave-convex shape. As shown in Fig. 5A, the molding die 201 and the plug 202 are placed opposite each other via the resin sheet 50, and then, as shown in Fig. 5B, they are mated in a concave-convex shape, thereby forming the resin sheet 50 into the resin container body 10 of the desired shape. By using plug-assisted molding in addition to vacuum suction, it is possible to prevent the thickness of the portion corresponding to the bottom surface 14 from becoming too thin during deep drawing.

[0032] 5C , the plug 202 is removed from the mold 201. After that, the outer edge region of the resin sheet 50 is cut away, leaving the portion that will become the flange portion 20, thereby forming the resin container body 10 that includes the flange portion 20 that continues from the upper end of the side surface portion 16.

[0033] While FIG. 1 shows the liquid-filled container 100 with the resin container body 10 filled with a liquid 42, a liquefiable agent may be filled instead of the liquid 42. Furthermore, the resin container body 10 may be in an extended state with the side wall 16 unfolded as shown in FIGS. 1 and 2, or the side wall 16 may be vertically contracted as shown in FIG. 3. In particular, when the resin container body 10 is filled with a liquefiable agent 44, the apparent volume may be reduced by degassing the resin container body 10 while it is filled with the liquefiable agent 44. In this case, a non-breathable lid sheet (not shown) may be provided on the upper surface of the moisture-permeable waterproof sheet 30 to maintain a sealed state and maintain the degassed state until immediately before use. This reduces the bulk of the liquid-filled container 100 before use, improving portability and storage. The resin container body 10 of the present invention is very thin, with a maximum thickness of 400 μm or less, making it easy to contract the side wall 16 by degassing. Furthermore, after the lid sheet is removed and the sealed state is released, as liquid accumulates inside the resin container body 10, the weight of the liquid gradually expands the side portion 16, and the lid sheet is pushed upward, eventually resulting in the state shown in Fig. 2. In other words, as liquid accumulates inside the resin container body 10, the resin container body 10 that has shrunk due to degassing is restored to a shape close to the shape before degassing.

[0034] Furthermore, when measuring the resin container body 10 with the side portion 16 in a contracted state, the average thickness T3 of the bottom portion 14, the average thickness T1 at a predetermined height of the side portion 16, the average thickness T2 at a position near the corner R of the rectangular bottom portion 14, and the volume of the resin container body 10, these are measured with the contracted portion of the side portion 16 stretched.

[0035] (Moisture-Permeable Waterproof Sheet) The moisture-permeable waterproof sheet 30 is a sheet that covers the opening 12 of the resin container body 10, has breathability and moisture permeability, and is capable of suppressing the penetration of liquids. In the present invention, the moisture-permeable waterproof sheet 30 is configured such that, when the direction along the longitudinal direction of the opening 12 of the moisture-permeable waterproof sheet 30 is defined as the sheet longitudinal direction LD and the direction along the transverse direction of the opening 12 of the moisture-permeable waterproof sheet 30 is defined as the sheet transverse direction SD, the tensile breaking strength (N / 25 mm) in the sheet longitudinal direction LD and the sheet transverse direction SD is 40 (N / 25 mm) or more, and the tensile breaking elongation (%) in the sheet transverse direction SD is 60% or more. From the viewpoint of being able to withstand larger impacts, the tensile breaking strength in the sheet longitudinal direction LD and the sheet transverse direction SD is preferably 50 (N / 25 mm) or more, more preferably 80 (N / 25 mm) or more, and even more preferably 100 (N / 25 mm) or more. In this way, by specifying the tensile breaking strength in the sheet longitudinal direction LD and the sheet short direction SD to a certain level or higher, and by ensuring sufficient tensile breaking elongation at least in the sheet short direction SD, the intended object of the present invention is successfully achieved.

[0036] From the viewpoint of better absorbing the shock when dropped and better preventing damage to the moisture-permeable waterproof sheet 30, the tensile breaking elongation (%) in the sheet longitudinal direction LD is also preferably 60% or more, and more preferably 80% or more. The tensile breaking strength and tensile breaking elongation of the moisture-permeable waterproof sheet 30 are measured by reference to the measurement methods in the examples described below.

[0037] The inventors further studied the posture in which a liquid-filled container 100 having a thin-walled resin container body 10 is dropped, and found that when the container is dropped with the bottom portion 14 facing downwards (hereinafter referred to as drop mode 1), when the container is dropped with the long side portion 16a (see Figure 1) facing downwards (hereinafter referred to as drop mode 2), and when the container is dropped with the short side portion 16b (see Figure 1) facing downwards (hereinafter referred to as drop mode 3), drop mode 3 causes the most significant damage to the moisture-permeable waterproof sheet 30. This is thought to be because when the liquid-filled container 100 is dropped onto the floor, drop mode 3 has the smallest contact area between the resin container body 10 and the floor, resulting in poor dispersion of the impact and therefore reduced impact absorption.

[0038] Therefore, from the viewpoint of being able to sufficiently prevent damage to the moisture-permeable waterproof sheet 30 even in the above-mentioned fall mode 3, it is preferable to configure the sheet so that the tensile breaking elongation in the sheet's short direction SD is greater than the tensile breaking elongation in the sheet's longitudinal direction LD.

[0039] The moisture-permeable waterproof sheet 30 is preferably a microporous resin sheet, as long as it is moisture-permeable and waterproof. While the manufacturing method of this microporous resin sheet is not particularly limited, it can be produced, for example, by molding and then stretching a thermoplastic resin sheet containing an inorganic filler. Examples of thermoplastic resins used to form this microporous resin sheet include polyolefins such as polyethylene and polypropylene, as well as polyvinyl chloride, polyester, and polyamide. Commercially available moisture-permeable waterproof films made from this microporous resin sheet include those under the trade name "Cellpore" manufactured by Sumika Sekisui Film Co., Ltd., "NF Sheet" manufactured by Tokuyama Corporation, "Breathlon" manufactured by Nitoms Corporation, and "Excepol" manufactured by Mitsubishi Chemical Corporation. A multilayer sheet may be formed by laminating a nonwoven fabric or other porous film to the microporous resin sheet, provided that the moisture permeability of the microporous resin sheet is not impaired.

[0040] In this embodiment, the outer edge region of the moisture-permeable waterproof sheet 30 is attached and fixed by adhesion to the flange portion 20. Methods for attaching the moisture-permeable waterproof sheet 30 to the flange portion 20 include, but are not limited to, ultrasonic welding, hot plate welding, and high-frequency welding. However, the method for attaching the moisture-permeable waterproof sheet 30 to the resin container body 10 is not particularly limited as long as sufficient adhesion is maintained to prevent liquid leakage.

[0041] (Liquid, Liquefying Agent) The resin container body 10 is filled with a liquid 42, a liquefying agent 44, or a liquid 42 stored due to the liquefying agent 44. The liquid 42 is not particularly limited as long as it is liquid or semi-liquid (gel / sol), and can be appropriately selected depending on the intended use of the liquid-filled container 100. Examples include, but are not limited to, liquid or semi-liquid air fresheners, deodorizers, and anti-mold agents. These liquids 42 pass through the moisture-permeable waterproof sheet 30 and are released to the outside of the resin container body 10 by, for example, evaporating.

[0042] The liquefiable agent 44 may be a solid substance of any shape, such as granules, as long as it is liquefiable and can be appropriately selected depending on the intended use of the liquid-filled container 100. Examples include deliquescent agents that can be used as moisture absorbents. The deliquescent agent broadly includes agents that liquefy by absorbing moisture, and specific examples include deliquescent substances such as calcium chloride, magnesium chloride, lithium chloride, lithium bromide, and potassium acetate. Calcium chloride and magnesium chloride are particularly preferred as deliquescent substances in terms of moisture absorption capacity and cost. The deliquescent agent may be composed of one or more known deliquescent substances. For example, the deliquescent agent may be formulated into granules using one or more of the above-mentioned deliquescent substances, using a drip granulation method, air-cooled granulation method, or the like. For example, if a deliquescent agent is used as the liquefiable agent 44, after the liquid-filled container is first used, it is possible that a portion of the deliquescent agent 44 liquefies, leaving the remainder of the deliquescent agent in the liquid, or that the entire deliquescent agent has been visually confirmed to be liquid. Even in these states, the moisture-absorbing function can be exhibited. Therefore, the present invention does not require an inner tray separating the deliquescent agent from the liquid, as in the dehumidifying agent container disclosed in Patent Document 1. A preferred embodiment of the present invention is a liquid-filled container 100 using a dehumidifying agent 44 containing a deliquescent agent that liquefies upon absorbing moisture. In this embodiment, at the start of use, the resin container body 10 is filled with a solid liquefiable agent 44 containing essentially no liquid 42. After use, the deliquescent agent gradually liquefies due to moisture absorption, increasing the amount of liquid 42 stored in the resin container body 10, until the amount of liquid 42 stored in the resin container body 10 reaches its maximum at the end of use. In this manner, even if a user accidentally drops the liquid-filled container 100 when lifting it up from the installation location or carrying it away to dispose of it after use, it is preferable that damage to the breathable waterproof sheet 30 is suppressed and the liquid 42 inside is prevented from leaking out.

[0043] While the present invention has been described above using the liquid-filled container 100, portions of the liquid-filled container 100 can be modified or any configuration can be added without departing from the spirit of the present invention. For example, the liquid-filled container 100 may be provided with a lid sheet (not shown) that covers the moisture-permeable waterproof sheet 30. The lid sheet may be a non-breathable sheet that covers the opening 12 via the moisture-permeable waterproof sheet 30 before use of the liquid-filled container 100 and is removed when in use. In particular, it is desirable for a liquid-filled container 100 in which a liquefying agent 44 is filled in the resin container body 10 to be provided with a lid sheet to prevent a moisture absorption reaction from occurring until use begins.

[0044] The lid sheet may be transparent or opaque as long as it is moisture-impermeable (gas barrier). Examples of moisture-impermeable sheets include resin-based sheets such as oriented polypropylene (OPP), polyethylene terephthalate (PET), polyvinylidene chloride-coated PET (K-PET), polyvinylidene chloride-coated OPP (K-OPP), silica-deposited PET, and alumina-deposited PET, as well as aluminum sheets. These moisture-impermeable sheets may be used in a single layer or in a composite (laminated) configuration of multiple layers.

[0045] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Table 1 shows the tensile breaking strength (N / 25 mm) and tensile breaking elongation (%) in the widthwise and lengthwise directions of the moisture-permeable waterproof sheets used in each example and comparative example, as well as the results of the example evaluations described below.

[0046] Example 1 A moisture-impermeable multilayer film (thickness 300 μm) consisting of three layers laminated in the order of polyethylene resin / nylon resin / polyethylene resin was set in the mold of a deep-drawing vacuum / pressure molding machine. The multilayer film was then subjected to plug-assist molding while vacuuming to form a rectangular resin container body with a short side of 125 mm, a long side of 190 mm, and a depth of 80 mm, and an opening that was open at the entire top. At this time, a flange portion extending outward from the opening was simultaneously formed. The width dimensions of the flange portion were 15 mm on the short side of the opening and 18 mm on the long side of the opening. The resin container body obtained in this manner had an average bottom thickness T3 of 250 μm, an average thickness T1 at a predetermined height of the side portion of 60 μm, and an average thickness T2 at a position near the corner R of the bottom portion of 110 μm, as shown in FIG. 4. The maximum capacity of the resin container body formed as described above was 1300 ml and the weight was 7 g. The resin container body formed as described above was filled with a deliquescent chemical (355 g of calcium chloride dihydrate). 355 g of calcium chloride dihydrate is the amount of deliquescent chemical capable of absorbing approximately 850 g of water. A moisture-permeable waterproof sheet was then heat-sealed to the upper surface of the flange, yielding the liquid-filled container of Example 1. The moisture-permeable waterproof sheet used was a polyolefin-based microporous membrane to which a sheath-core nonwoven fabric having a core layer made of polyethylene terephthalate and a sheath layer made of polyethylene was bonded on both sides. The sheet exhibited the tensile breaking strength (N / 25 mm) and tensile breaking elongation (%) shown in Table 1.

[0047] (Examples 2, 3 and Comparative Example 1) Liquid-filled containers were prepared in the same manner as in Example 1, except that a moisture-permeable waterproof sheet was used in which the tensile breaking strength and tensile breaking elongation in the short direction of the sheet, and the tensile breaking strength and tensile breaking elongation in the long direction of the sheet were changed to the values ​​shown in Table 1. These were designated Examples 2, 3 and Comparative Example 1, respectively.

[0048] <Method for measuring tensile breaking strength (N / 25 mm) and tensile breaking elongation (%)> The tensile breaking strength of the moisture-permeable waterproof sheet used in each Example and Comparative Example was measured as follows. A test piece measuring 25 mm wide and 80 mm long was cut from a moisture-permeable waterproof sheet. The width direction of the test piece was aligned with the short side of the sheet when used in a liquid-filled container, and the length direction of the test piece was aligned with the longitudinal direction of the sheet when used in a liquid-filled container. Both longitudinal ends of the test piece were held in the holder of a tensile tester, and the test piece was pulled in accordance with JIS K7127:1999 at 25°C, 60% RH, at a pulling rate of 200 mm / min, and with a chuck distance of 50 mm. The tensile breaking strength and tensile breaking elongation were measured when the test piece broke. This measurement was performed five times. The arithmetic mean values ​​for the tensile breaking strength and tensile breaking elongation were calculated from the obtained measurements, and these were taken as the tensile breaking strength (N / 25 mm) and tensile breaking elongation (%) in the longitudinal direction of the sheet. The test was carried out five times in the same manner as above, except that the width direction of the test piece was aligned with the longitudinal direction of the sheet when used in a liquid-filled container, and the length direction of the test piece was aligned with the transverse direction of the sheet when used in a liquid-filled container. The arithmetic mean values ​​were taken as the tensile breaking strength (N / 25 mm) and tensile breaking elongation (%) in the transverse direction of the sheet. The tensile tester used was a Force Tester MCT2105 SPEED CONTROL manufactured by A&D Co., Ltd.

[0049] <Impact Resistance Test (1)> Each of the Examples and Comparative Examples prepared as described above was placed indoors, and the deliquescent chemicals filled in the resin container body were allowed to absorb moisture and liquefy. The resin container body was filled with 800 ml of liquid, which was used as the post-moisture absorption sample. The post-moisture absorption sample was left standing in an environment of 25°C for 24 hours or more, and the impact resistance test (1) was performed in accordance with the drop impact test of JIS S3106:1994. Specifically, the post-moisture absorption sample was dropped from a height of 1 m onto a smooth oak board with its bottom facing downwards, and the post-moisture absorption sample was visually observed for damage and evaluated as follows: ○: No damage or leakage was observed; ×: Damage to the breathable waterproof sheet was observed.

[0050] As shown in Table 1, Comparative Example 1 had a sufficiently high tensile breaking strength in the sheet width direction, but a small tensile breaking elongation, and therefore received a poor evaluation in the impact resistance test (1). On the other hand, all of the Examples in which the tensile breaking strength (N / 25 mm) in both the sheet length direction and the sheet width direction was 40 (N / 25 mm) or more and the tensile breaking elongation (%) in the sheet width direction was 60% or more received a good evaluation in the impact resistance test (1), and it was confirmed that the intended problem of the present invention was solved.

[0051] Impact Resistance Test (2) (Severe Test) A moisture-absorbed sample was prepared in the same manner as in Impact Resistance Test (1), and Impact Resistance Test (2) was conducted under more severe conditions as follows. Specifically, the moisture-absorbed sample was allowed to stand in an environment of 25°C for at least 24 hours, and then dropped from a height of 50 cm onto a smooth oak board with its short side facing downwards. The moisture-absorbed sample was then visually observed for damage. If no damage was confirmed by visual observation after the 50 cm drop test, the drop height was increased by 10 cm, and a similar drop test was conducted. The drop height at which damage and leakage occurred was determined as the damage height, and is shown in Table 1.

[0052] As shown in Table 1, Examples 1 and 2, in which the tensile breaking elongation (%) in the sheet longitudinal direction was 60% or more, showed no breakage when dropped from a height of 50 cm in the impact resistance test (2), confirming superior impact resistance. Furthermore, Example 1, in which the tensile breaking elongation (%) in the sheet transverse direction was greater than the tensile breaking elongation (%) in the sheet longitudinal direction, showed the highest breakage height in the impact resistance test (2), confirming extremely excellent impact resistance.

[0053]

[0054] The present invention as described above encompasses the following technical concepts: (1) A liquid-filled container comprising a resin container body having an opening at an upper portion, a moisture-permeable waterproof sheet covering the opening, and a liquefiable agent or liquid filled in the resin container body, wherein the resin container body has a maximum thickness of 400 μm or less, and wherein, when the direction along the longitudinal direction of the opening of the moisture-permeable waterproof sheet is defined as the sheet longitudinal direction and the direction along the lateral direction of the opening of the moisture-permeable waterproof sheet is defined as the sheet lateral direction, the tensile breaking strength in the sheet longitudinal direction and the sheet lateral direction is 40 (N / 25 mm) or more and the tensile breaking elongation in the sheet lateral direction is 60% or more. (2) The liquid-filled container as described in (1) above, wherein the resin container body is made of a resin sheet. (3) The liquid-filled container as described in (1) or (2) above, wherein the tensile breaking elongation in the sheet longitudinal direction is 60% or more. (4) The liquid-filled container according to any one of (1) to (3) above, wherein the tensile elongation at break in the widthwise direction of the sheet is greater than the tensile elongation at break in the lengthwise direction of the sheet. (5) The liquid-filled container according to any one of (1) to (4) above, wherein the maximum volume of the resin container body is 800 ml or more and 2000 ml or less, and the weight of the resin container body is 2 g or more and 22 g or less. (6) The liquid-filled container according to any one of (1) to (5), wherein the liquefying agent is a dehumidifying agent containing a deliquescent agent that liquefies by absorbing moisture.

[0055] DESCRIPTION OF SYMBOLS 10: Resin container body 12: Opening 14: Bottom surface 16: Side surface 16a: Long side surface 16b: Short side surface 20: Flange 30: Moisture-permeable waterproof sheet 42: Liquid 44: Liquefying agent 50: Resin sheet 100: Liquid-filled container 201: Mold 202: Plug 203: Suction hole 204: Holding body LD: Longitudinal direction of sheet SD: Short side direction of sheet H1, H2: Height T1, T2, T3: Average thickness R: Corner

Claims

1. A liquid-filled container comprising a resin container body having an opening at the upper part, a moisture-permeable and waterproof sheet covering the opening, and a liquefiable agent or liquid filled in the resin container body, wherein the maximum thickness of the resin container body is 400 μm or less. When the direction along the longitudinal direction of the opening of the moisture-permeable and waterproof sheet is defined as the sheet longitudinal direction and the direction along the short-side direction of the opening of the moisture-permeable and waterproof sheet is defined as the sheet short-side direction, the tensile breaking strength in the sheet longitudinal direction and the sheet short-side direction is 40 (N / 25 mm) or more, and the tensile breaking elongation in the sheet short-side direction is 60% or more.

2. The liquid-filled container according to claim 1, wherein the resin container body is constituted by a resin sheet.

3. The liquid-filled container according to claim 1 or 2, wherein the tensile breaking elongation in the sheet longitudinal direction is 60% or more.

4. The liquid-filled container according to any one of claims 1 to 3, wherein the tensile breaking elongation in the sheet short-side direction is greater than the tensile breaking elongation in the sheet longitudinal direction.

5. The liquid-filled container according to any one of claims 1 to 4, wherein the maximum volume of the resin container body is 800 ml or more and 2000 ml or less, and the weight of the resin container body is 2 g or more and 22 g or less.

6. The liquid-filled container according to any one of claims 1 to 5, wherein the liquefiable agent is a dehumidifying agent containing a deliquescent agent that liquefies by absorbing moisture.