Soft bag composite file

Abstract

To provide a soft bag composite file that is hard to tear even when storing heavy items such as books.SOLUTION: Provided is a soft bag composite file which includes a cover having a first welded portion and containing a polypropylene (PP)-based resin, and a soft bag having a second welded portion welded to the cover along the first welded portion. The soft bag has a first surface and a second surface opposite the first surface, the first surface being welded to the cover, and the soft bag has an outer layer containing an ethylene-α-olefin copolymer resin or a modified polypropylene resin, and an inner layer laminated to the second surface and containing a polyethylene (PE)-based resin.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a flexible pouch composite file. [Background technology]

[0002] Patent document 1 discloses a storage holder for clear files that can securely hold clear files for long periods of time and allows clear files to be attached and detached without damaging the base material of the double-sided adhesive tape. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-42473 Summary of the Invention [Problem to be solved by the invention]

[0004] The clear file used in the clear file storage holder disclosed in Patent Document 1 is made of a typical polypropylene sheet and is used to store several documents. When a relatively heavy object such as a book is stored in such a clear file, the gravity of the heavy object can cause the adhesive between the clear file and the holder to separate, causing the clear file to fall out of the holder. This gravity can also cause the clear file to tear.

[0005] On the other hand, when storing thick items such as books, it is preferable to use, for example, a soft bag with a zipper rather than a clear file. If such a soft bag is made of a polypropylene sheet, there is a possibility that it will tear due to the gravity of the book, as mentioned above. On the other hand, if the soft bag is made of a polyethylene sheet, which has better tear strength than polypropylene, the possibility of it being torn due to the gravity of the book is reduced. However, if a polyethylene soft bag is attached to, for example, a polypropylene holder, the attachment strength is weak, and there is a possibility that the soft bag will fall off.

[0006] An object of the present disclosure is to provide a composite file with soft bags in which the soft bags are difficult to tear and fall off even when heavy items such as books are stored inside. [Means for solving the problem]

[0007] The present disclosure provides: a cover having a first welded portion and including a polypropylene (PP) resin; a flexible bag having a second welded portion welded to the cover along the first welded portion; A soft bag composite file comprising: The flexible bag is an outer layer having a first surface and a second surface opposite to the first surface, the first surface being welded to the cover, the outer layer containing an ethylene-α-olefin copolymer resin or a modified polypropylene resin; an inner layer laminated on the second surface and containing a polyethylene (PE) resin; A soft bag composite file is provided.

[0008] According to the flexible bag composite file disclosed herein, even if a heavy object is stored in the flexible bag, the flexible bag has an inner layer containing PE-based resin, which has a higher tear strength than PP-based resin, making it less likely to tear due to gravity. Furthermore, because the outer layer of the flexible bag contains ethylene-α-olefin copolymer resin or modified polypropylene resin, which has excellent welding properties with PP-based resin, the flexible bag is less likely to fall off the cover. This makes it possible to continue using the flexible bag composite file for long periods of time without compromising its functionality as a file, even when heavy objects are stored in it. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a soft bag composite file according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the flexible bag composite file according to the present embodiment. [Figure 3] FIG. 2 is a plan view of the inner cover according to the embodiment. [Figure 4] FIG. 2 is a plan view of the flexible bag according to the embodiment. [Figure 5] 3 is a cross-sectional view of the flexible bag composite file according to the first embodiment taken along the cross section VV of FIG. 2. FIG. [Figure 6] FIG. 6 is a cross-sectional view similar to FIG. 5 of the composite file with a soft bag according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0011] [First embodiment] Fig. 1 shows a perspective view of a flexible bag composite file 1 according to a first embodiment. The flexible bag composite file 1 is used to store documents such as paper documents and / or books. Fig. 1 shows the flexible bag composite file 1 in an open state.

[0012] As shown in Figure 1, the flexible bag composite file 1 has a sheet-like cover 10 and a sheet-like flexible bag 20 sandwiched between the cover 10. The cover 10 has an outer cover 11 that forms the outermost part of the flexible bag composite file 1, and an inner cover 12 that is positioned between the outer cover 11 and the flexible bag 20. The outer cover 11 has a substantially rectangular shape. When the outer cover 11 is folded along a fold line 11a that connects the midpoints of the two long sides, the outer cover 11 is divided into a first outer cover 13 and a second outer cover 14.

[0013] The first outer cover 13 and the second outer cover 14 have the same shape. A sheet-like pocket cover 15 is welded to each of the covers 13, 14. A space large enough to store several documents is formed between each of the covers 13, 14 and the pocket cover 15. In this embodiment, the pocket cover 15 is formed by folding the outer cover 11 along a portion of the long side shown in FIG. 1, and is welded to each of the covers 13, 14 at the short side portions of the outer cover 11. The pocket cover 15 may be welded to the long side portions and the short side portions of the outer cover 11.

[0014] The inner cover 12 has the same shape as the first outer cover 13 and the second outer cover 14. The inner cover 12 is welded to the first outer cover 13 at the fold line 11a of the outer cover 11 while sandwiching the flexible bag 20 between the first outer cover 13. A pocket cover 15 may be welded to the inner cover 12.

[0015] Figure 2 shows a plan view of the flexible bag composite file 1 when it is open, with the flexible bag 20 sandwiched between the inner cover 12 and the first outer cover 13. For ease of explanation, part of the second outer cover 14 and the pocket cover 15 are omitted from Figure 2. In Figure 2, the inner cover 12 is located at the front side in the direction perpendicular to the paper surface, and the first outer cover 13 is located at the back side, with the flexible bag 20 located between the two covers 12, 13. Here, the up-down direction in Figure 2 is referred to as the up-down direction of the flexible bag composite file 1, and the direction perpendicular to the up-down direction on the paper surface is referred to as the left-right direction of the flexible bag composite file 1.

[0016] The flexible bag 20 is welded between the inner cover 12 and the first outer cover 13 so that the left side of the flexible bag 20 (referred to as the second welded portion 20b, see FIG. 4) is aligned with the left sides of the inner cover 12 and the first outer cover 13 (referred to as the first welded portion 12b, see FIG. 3). This welding can be performed by, for example, heat welding or ultrasonic welding. Each of the welded portions 20b, 12b extends in the vertical direction. The welded region 30 formed by this welding is provided along the welded portions 20b, 12b of the two covers 12, 13 and the flexible bag 20. In FIG. 2, the welded region 30 has a plurality of rectangular welded portions 30a arranged side by side in the vertical direction. The welded portions 30a may have any shape, such as a triangle, a circle, or an ellipse.

[0017] The flexible bag 20 is disposed vertically inward relative to the two covers 12, 13. That is, the flexible bag 20 is disposed so that the upper end of the second welded portion 20b is below the upper end of the first welded portion 12b and the lower end of the second welded portion 20b is above the lower end of the first welded portion 12b. Due to this arrangement, the welded region 30 has an upper reserve portion 31 and a lower reserve portion 32 at its upper and lower ends, respectively, to which the flexible bag 20 is not welded. That is, at the upper reserve portion 31 and the lower reserve portion 32, the first welded portion 12b of the inner cover 12 and the first welded portion 12b of the first outer cover 13 are welded to each other.

[0018] By providing such upper and / or lower retaining portions 31 and / or 32, the second welded portion 20b of the flexible bag 20 is surrounded by the first welded portions 12b of the two covers 12, 13. In other words, the second welded portion 20b is not exposed in the vertical direction. With this configuration, even if the flexible bag 20 is pulled in a direction perpendicular to the sheet surface, the two covers 12, 13 are firmly welded at the upper and lower retaining portions 31 and 32, so it will not easily come off the covers 12, 13.

[0019] The length L1 of the upper retainer 31 and the length L2 of the lower retainer 32 may be the same or different. Each of the upper retainer 31 and the lower retainer 32 preferably has at least one welded portion 30a. In this embodiment, the lengths L1 and L2 are both approximately 1 cm.

[0020] Next, the cover 10 used in the flexible bag composite file 1 of this embodiment will be described using the inner cover 12 as an example. The structure, materials, and manufacturing method of the inner cover 12 described below are the same as those of the first outer cover 13 and the second outer cover 14.

[0021] 3 shows a plan view of the inner cover 12 of this embodiment. The inner cover 12 is a substantially rectangular sheet composed of a first top edge 12a, a first bottom edge 12d, and left and right first side edges 12b, 12c. The left first side edge 12b is the aforementioned first welded portion 12b, and the right first side edge 12c is referred to as the first non-welded portion 12c.

[0022] The inner cover 12 contains a polypropylene (PP) resin. The PP resin may include any PP resin that can be melted with PP resin, such as a homopolymer in which propylene is homopolymerized, a random polymer copolymerized with other petroleum-derived monomers or biomass-derived monomers, and a block polymer.

[0023] Furthermore, in order to improve the physical properties of the inner cover 12, such as impact strength, an optional olefin-based resin may be added in addition to the PP-based resin. The olefin-based resin may be a petroleum-derived olefin-based resin or a biomass-derived olefin-based resin. Examples of the olefin-based resin include high-density polyethylene resin, medium-density polyethylene resin, low-density polyethylene resin, linear low-density polyethylene resin, polypropylene resin, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-octene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid alkyl ester copolymer, and ethylene-vinyl chloride copolymer. However, low-density polyethylene resin or linear low-density polyethylene resin is preferred. Furthermore, two or more of the above olefin-based resins may be used in combination.

[0024] Furthermore, an antistatic agent may be added to the PP-based resin to prevent static buildup on the inner cover 12. Examples of antistatic agents include polymeric antistatic agents such as polyetheresteramide, polyetherester, polystyrene sulfonic acid, quaternary ammonium salt metal acrylate polymer, and ionomer resin; low-molecular-weight antistatic agents such as alkylamide and glycerin fatty acid ester derivatives, surfactants, sulfonic acid derivatives, and mixtures thereof; and ionic or nonionic antistatic agents. When an antistatic agent is added, the mass ratio of the antistatic agent to the PP-based resin is preferably 0.1% or less, more preferably 0.01% or less, and even more preferably 0.003% or less.

[0025] Furthermore, antioxidants such as phenolic antioxidants or aromatic amine antioxidants may be added to the PP resin to prevent oxidation, ultraviolet absorbers such as salicylic acid esters, benzophenones, benzotriazoles, and cyanoacrylates to prevent deterioration due to ultraviolet light, and / or hindered amine light stabilizers may be added to the PP resin.Furthermore, impact modifiers, anti-fogging agents, flame retardants, colorants, fillers, biomass recycled materials, etc. may also be added to the PP resin.

[0026] Any design or text may be printed on the inner cover 12 of the present embodiment, and in this case, the inner cover 12 may be subjected to a corona treatment to improve printability. Such printing may include offset printing, silk printing, foil stamping, and the like.

[0027] The thickness of the inner cover 12 is preferably 0.1 mm to 1.0 mm to ensure sufficient fixation by welding. Furthermore, depending on the application of the soft bag composite file, the inner cover 12 may be transparent, translucent, or opaque. When transparency is required, it is preferable to set the thickness of the inner cover 12 so that the haze value of the inner cover 12 is 35% or less. In this case, the thickness of the inner cover 12 is 0.15 mm to 0.5 mm.

[0028] The inner cover 12 of this embodiment is manufactured by forming a PP resin containing the above-mentioned additives and the like into a sheet by extrusion molding, and then punching it out by Thomson processing or the like.

[0029] Next, the flexible bag 20 used in the flexible bag composite file 1 of this embodiment will be described.

[0030] 4 shows a plan view of the flexible bag 20 of this embodiment. The flexible bag 20 is a substantially rectangular sheet-like bag composed of a second top edge 20a, a second bottom edge 20d, and left and right second side edges 20b, 20c. The left second side edge 20b is the second welded portion 20b described above, and the right second side edge 20c is referred to as the second non-welded portion 20c.

[0031] A space is defined inside the flexible bag 20 for storing documents and other items. The flexible bag 20 has an opening / closing means 21 that allows access to the space. The opening / closing means 21 has an opening / closing portion 21b provided along part of the second non-welded portion 20c, and a slider 21a that opens and closes the opening / closing portion 21b by sliding it up and down. The opening / closing means 21 is a plastic zipper that is commonly used for resin-based flexible bags.

[0032] FIG. 5 shows the flexible bag composite file 1 according to the first embodiment along cross section VV of FIG. 2. In FIG. 5, the area surrounded by a dotted line indicates the welded region 30. The flexible bag 20 according to the first embodiment includes an outer layer 201 having a first surface 201a and a second surface 201b opposite the first surface 201a, and an inner layer 202 having a third surface 202a and a fourth surface 202b opposite the third surface 202a. The first surface 201a of the outer layer 201 is the outermost surface of the flexible bag 20 and is welded to the inner cover 12 and the first outer cover 13. The inner layer 202 is laminated on the second surface 201b of the outer layer 201. The third surface 202a of the inner layer 202 is in contact with the second surface 201b. The fourth surface 202b of the inner layer 202 is the innermost surface of the flexible bag 20.

[0033] The outer layer 201 contains an ethylene-α-olefin copolymer resin or a modified polypropylene resin, which does not delaminate with the resins constituting other layers during multilayer molding and has excellent adhesion to a PP-based resin cover. Examples of ethylene-α-olefin copolymer resins include ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-octene-1 copolymer, and ethylene-vinyl acetate copolymer. Ethylene-α-olefin copolymer resins containing two or more of these copolymers may also be used for the outer layer 201. An example of a modified polypropylene resin is polypropylene graft-modified with maleic anhydride. Ethylene-α-olefin copolymer resins and modified polypropylene resins have excellent printing properties, making it easy to print desired designs or text on sheets made of these resins. The outer layer 201 may also contain antioxidants and additives, as with the inner cover 12.

[0034] The inner layer 202 contains a polyethylene (PE)-based resin, which has higher tear strength and flexibility than a PP-based resin. Examples of PE-based resins include high-density polyethylene resin, medium-density polyethylene resin, low-density polyethylene resin, and linear low-density polyethylene resin. These resins may be petroleum-derived or biomass-derived resins. From the viewpoints of strength and pinhole resistance, it is preferable to use linear low-density polyethylene resin. Furthermore, two or more of these resins may be used in combination. PE-based resins are also suitable for forming the opening / closing portion 21b. In addition to the above resins, the inner layer 202 may contain a polyolefin-based resin other than the PE-based resin to improve elongation or strength.

[0035] The thickness of the flexible bag 20, i.e., the total thickness of one outer layer 201 and one inner layer 202, can be set taking into consideration the required strength of the flexible bag and the bulkiness of the flexible bag composite file. If the flexible bag 20 is too thick, the bulkiness will increase, which may reduce the space on the storage shelf for storing the flexible bag composite file. If the flexible bag 20 is too thin, the flexible bag 20 may tear when a heavy object such as a book is stored in the flexible bag 20, or the welding to the covers 12, 13 may be insufficient, causing the flexible bag 20 to fall off. The thickness of the flexible bag 20 is preferably set in the range of 60 μm to 600 μm, more preferably 100 μm to 200 μm.

[0036] The thickness of each of the outer layer 201 and the inner layer 202 is set appropriately within the above-mentioned range of the thickness of the flexible bag 20. If the thickness of the outer layer 201 is too thin compared to the thickness of the inner layer 202, the welding strength between the outer layer 201 and the covers 12, 13 will decrease. From this perspective, the thickness ratio of the inner layer 202 to the outer layer 201 is set to at least 100:10, preferably 100:20 or more.

[0037] On the other hand, if the thickness of the inner layer 202 is too thin compared to the thickness of the outer layer 201, the tear strength of the flexible bag 20 may decrease, or the function of the opening / closing means 21 may be impaired. From this perspective, the thickness ratio of the inner layer 202 to the outer layer 201 is set to 100:100 or less, preferably between 100:100 and 100:50.

[0038] Therefore, from the above two viewpoints, it is preferable that the thickness ratio of the outer layer 201 to the inner layer 202 is set within the range of 100:10 to 100:100.

[0039] The sheet constituting the flexible bag 20 of this embodiment is not particularly limited, but can be obtained by forming the resins constituting the outer layer 201 and the inner layer 202, which have been melted in an extruder, into a sheet by inflation molding or sheet molding, forming a two-layer structure by lamination, and cutting to a predetermined size. The resulting sheet is then folded in half along the second welded portion 20b, and the opposing second top edges 20a and second bottom edges 20d are welded together by this folding. Furthermore, the flexible bag 20 is manufactured by providing opening and closing means 21 by fastening the second non-welded portion 20c.

[0040] The composite file with a flexible bag 1 according to the first embodiment has the following advantages.

[0041] (1) The soft bag composite file 1 is Covers 12, 13 have a first welding portion 12b and contain polypropylene (PP) resin; a soft bag (20) having a second welding portion (20b) welded to the covers (12, 13) along the first welding portion (12b); A soft bag composite file 1 comprising: The flexible bag 20 is an outer layer (201) having a first surface (201a) and a second surface (201b) opposite to the first surface (201a), the first surface (201a) being welded to the covers (12, 13), the outer layer (201) containing an ethylene-α-olefin copolymer resin or a modified polypropylene resin; an inner layer 202 laminated on the second surface 201b and containing a polyethylene (PE) resin; It has.

[0042] As a result, the flexible bag 20 has an inner layer 202 containing PE-based resin, which has higher tear strength than PP-based resin, so that the flexible bag 20 is less likely to tear even when a heavy object is stored in the flexible bag 20. Also, because the flexible bag 20 has an outer layer 201 containing ethylene-α-olefin copolymer resin or modified polypropylene resin that can be welded to the covers 12, 13, which contain PP-based resin, the flexible bag 20 and the covers 12, 13 are more firmly welded together. As a result, even when a heavy object such as a book is stored in the flexible bag 20, the flexible bag 20 will not easily fall off the covers 12, 13, particularly in the sheet surface direction of the flexible bag 20.

[0043] (2) The thickness ratio of the inner layer 202 to the outer layer 201 is in the range of 100:10 to 100:100. As a result, it is possible to suitably set the welding strength between the flexible bag 20 and the covers 12, 13 and the tear strength of the flexible bag 20. Furthermore, it is easy to provide the flexible bag 20 with a plastic zipper opening and closing means.

[0044] (3) The soft bag 20 is sandwiched between the covers 12 and 13. In the position of the flexible bag composite file 1 in which the first welded portion 12b and the second welded portion 20b are aligned vertically, The upper end of the second welded portion 20b of the flexible bag 20 is located below the upper end of the first welded portion 12b of the covers 12 and 13, and / or The lower end of the second welded portion 20b of the flexible bag 20 is located above the lower ends of the first welded portions 12b of the covers 12 and 13.

[0045] With this configuration, the flexible bag 20 is sandwiched between the covers 12 and 13, and the retaining portions 31 and 32 are provided on the upper and / or lower sides of the flexible bag 20. As a result, the flexible bag 20 does not easily fall off the covers 12 and 13 even when pulled in a direction perpendicular to the sheet surface.

[0046] [Second embodiment] Next, a composite file with a flexible bag 2 according to a second embodiment will be described with reference to Fig. 6. Only the configuration different from the first embodiment will be described below.

[0047] 6 shows a cross-sectional view similar to FIG. 5 of a flexible bag composite file 2 according to a second embodiment. In FIG. 6, the flexible bag 20 has an additional layer 203 laminated on the fourth surface 202b of the inner layer 202, i.e., on the inside of the inner layer 202.

[0048] The additional layer 203 has the same configuration as the outer layer 201. That is, like the outer layer 201, the additional layer 203 contains an ethylene-α-olefin copolymer resin or a modified polypropylene resin, which have excellent printing properties, and has the same thickness as the outer layer 201.

[0049] The thickness of the flexible bag 20 of the second embodiment is set to be the same as the thickness of the flexible bag 20 of the first embodiment. The thickness ratio of the outer layer 201, the inner layer 202, and the additional layer 203 is set in the range of 10:100:10 to 100:100:100.

[0050] For example, if an arbitrary design is printed on the outermost surface of the flexible bag 20 (i.e., the first surface 201a of the outer layer 201), the printed design is likely to peel off because this surface is easily touched by human hands. On the other hand, if an arbitrary design is printed on the innermost surface of the flexible bag 20 (i.e., the inner surface of the additional layer 203), the printed design is unlikely to peel off because this surface is unlikely to be touched by human hands. Note that, when the innermost surface of the flexible bag 20 is the inner surface (i.e., the fourth surface) of the inner layer 202 containing a PE-based resin as in the first embodiment, it is difficult to print an arbitrary design because the printing characteristics of the PE-based resin are inferior to those of an ethylene-α-olefin copolymer resin or a modified polypropylene resin.

[0051] According to the soft bag composite file 2 of the second embodiment, The inner layer 202 has a third surface 202a on the outer layer 201 side and a fourth surface 202b on the opposite side to the third surface 202a, The flexible bag 20 further has an additional layer 203 laminated on the fourth surface 202b and including an ethylene-α-olefin copolymer resin or a modified polypropylene resin.

[0052] As a result, the innermost layer of the flexible bag 20 is made of the additional layer 203 containing an ethylene-α-olefin copolymer resin or a modified polypropylene resin, which have superior printing properties compared to PE-based resins, and therefore any design can be easily printed on the innermost layer of the flexible bag 20. By printing on the innermost layer of the flexible bag 20, the printed design is less likely to peel off. [Example]

[0053] Next, specific examples of the present disclosure will be described together with comparative examples. As shown in Table 1, Examples 1-6 and Comparative Examples 1-3 were prepared, and the welding strength of the flexible bag against pulling in the sheet surface direction and pulling in the direction perpendicular to the sheet surface was evaluated. First, the configurations of Examples 1-6 and Comparative Examples 1-3 will be described.

[0054] [Examples 1-3] Examples 1 to 3 were produced by sandwiching a flexible bag having only an outer layer of ethylene-α-olefin copolymer resin and an inner layer of PE resin between an inner cover made of PP resin and a first outer cover, and welding along the first and second welds. In Example 1, the length of the upper back portion was 2 cm. In Example 2, the length of the upper back portion was 1 cm. In Example 3, no upper back portion was provided.

[0055] [Example 4] Example 4 was produced by welding an inner cover made of PP resin and a flexible bag having an outer layer made of ethylene-α-olefin copolymer resin and an inner layer made of PE resin only along the first and second welded parts. In Example 4, no upper retaining part was provided.

[0056] [Example 5] A flexible bag having an outer layer of ethylene-α-olefin copolymer resin, an inner layer of PE resin, and an additional layer of ethylene-α-olefin copolymer resin was sandwiched between an inner cover of PP resin and a first outer cover, and the bags were welded along the first and second welds to produce Example 5. In Example 5, the length of the upper retaining portion was 1 cm.

[0057] [Example 6] An inner cover made of PP resin and a flexible bag having an outer layer made of ethylene-α-olefin copolymer resin, an inner layer made of PE resin, and an additional layer made of ethylene-α-olefin copolymer resin were welded together along the first and second welds to produce Example 6. In Example 6, no upper retaining portion was provided.

[0058] The thickness of each element in Examples 1-6 above is as follows: First outer cover: 200 μm Inner cover: 200 μm Outer layer: 20μm Inner layer: 100 μm Additional layer: 20μm

[0059] [Comparative Example 1] An inner cover made of PP resin and a soft bag made of a single layer of PE resin were welded together along the first and second welds to produce Comparative Example 1. In Comparative Example 1, no upper recess was provided.

[0060] Comparative Example 2 A soft bag made of a single layer of PE resin was sandwiched between an inner cover made of PP resin and a first outer cover, and the bags were welded along the first and second welded sections to produce Comparative Example 2. In Comparative Example 2, the length of the upper retaining portion was set to 2 cm.

[0061] Comparative Example 3 A soft bag made of a single layer of PE resin was sandwiched between an inner cover made of PP resin and a first outer cover, and the bags were welded along the first and second welded portions to produce Comparative Example 3. In Comparative Example 3, no upper recess was provided.

[0062] The thickness of each element in the above Comparative Examples 1-3 is as follows: First outer cover: 200 μm Inner cover: 200 μm PE resin single layer: 120 μm In producing Examples 1-6 and Comparative Examples 1-3, the flexible bags were heated to approximately 180°C in a heat sealer and pressed for 1 to 5 seconds to be sealed. Lines 2 to 6 of Table 1 show the configurations of Examples 1-6 and Comparative Examples 1-3. The numerical values ​​listed below each line indicate the thickness of the cover or each layer, or the length of the upper retaining portion.

[0063] Next, the evaluation test method will be described.

[0064] [Seat surface direction strength evaluation test] A book measuring 11 cm wide, 15 cm high, and 1.5 cm thick was placed in the flexible bag. The second top and bottom edges of the first outer cover (and inner cover) were grasped and the bag was shaken 50 times vertically with an amplitude of approximately 10 cm. The flexible bag was then checked for peeling from the welded area. A rating of ⊚ was given for a flexible bag that was not peeled from any of the welded areas and was completely attached to the welded areas. A rating of ◯ was given for a flexible bag that was not peeled from any of the welded areas and only partially peeled from the welded areas. A rating of × was given for a flexible bag that was not peeled from any of the welded areas and only partially peeled from the welded areas. This evaluation was a sensory evaluation to evaluate the weld strength of the flexible bag against pulling in the sheet surface direction, i.e., the resistance of the flexible bag to falling off in the sheet surface direction.

[0065] [Sheet surface vertical direction strength evaluation test] A book measuring 11 cm wide, 15 cm high, and 1.5 cm thick was placed in a flexible bag. With the second unwelded portion of the flexible bag positioned vertically downward and horizontal, and the second unwelded portion of the first outer cover (and inner cover) positioned vertically upward and horizontal, the second unwelded portion of the first outer cover (and inner cover) was grasped and shaken up and down 50 times with an amplitude of approximately 10 cm. It was then confirmed whether the flexible bag had peeled away from the welded area. The criteria for judging ◎, ○, and × were the same as those for the sheet surface direction strength evaluation test. This evaluation was a sensory evaluation to evaluate the weld strength against pulling in a direction perpendicular to the sheet surface of the flexible bag, i.e., the resistance of the flexible bag to falling off in a direction perpendicular to the sheet surface.

[0066] The evaluation results of the sheet surface direction strength evaluation test and the sheet surface perpendicular direction strength evaluation test are shown in the 7th and 8th lines of Table 1. In Table 1, the sheet surface direction strength evaluation test is referred to as the surface direction, and the sheet surface perpendicular direction strength evaluation test is referred to as the perpendicular direction.

[0067] [Table 1]

[0068] Examples 1-2 and 5, in which a soft bag having an outer layer of ethylene-α-olefin copolymer resin and an inner layer (and / or additional layer) of PE-based resin is sandwiched between the inner cover and the first outer cover and which has a recessed portion 1 to 2 cm long, performed well in all tests.

[0069] Example 3-4, in which a flexible bag having an outer layer of ethylene-α-olefin copolymer resin and an inner layer (and / or additional layer) of PE resin was sandwiched between the inner cover and the first outer cover and no retaining portion was provided, performed well in the in-plane test. Furthermore, in the perpendicular test, it was confirmed that the flexible bag had peeled slightly from the welded portion.

[0070] Example 6, in which the soft bag was not sandwiched between the inner cover and the first outer cover, had the same results as Examples 3-4.

[0071] In Comparative Examples 1-3, it was confirmed that the flexible bag was completely peeled from the welded portion in the test in the planar direction. In Comparative Examples 1 and 3, it was confirmed that the flexible bag was completely peeled from the welded portion in the test in the perpendicular direction as well. In Comparative Example 2, it was confirmed that the flexible bag was slightly peeled from the welded portion in the test in the perpendicular direction.

[0072] From the above results, it was found that good welding strength against tensile strength in the planar direction can be obtained by using a soft bag having an outer layer of ethylene-α-olefin copolymer resin and an inner layer of PE resin, and that good welding strength against tensile strength in the vertical direction can be obtained by sandwiching the soft bag with a cover and providing a recess.

[0073] The composite soft-bag file according to the present disclosure is not limited to the configuration of the above embodiment, and various modifications are possible.

[0074] The flexible bag composite file 1 of this embodiment is sandwiched between the inner cover 12 and the first outer cover 13, but it may also be sandwiched between the first outer cover 13 and the second outer cover 14. In that case, the flexible bag composite file does not need to have an inner cover.

[0075] The welded portions 12b, 20b are provided along the fold line 11a of the outer cover 11, but may be provided at a position offset to the left or right of the fold line 11a. Furthermore, the welded portions 12b, 20b do not have to be linear, and may be, for example, curved.

[0076] [Note] The flexible bag composite file according to the present disclosure provides the following features.

[0077] [Aspect 1] a cover having a first welded portion and including a polypropylene (PP) resin; a flexible bag having a second welded portion welded to the cover along the first welded portion; A soft bag composite file comprising: The flexible bag is an outer layer having a first surface and a second surface opposite to the first surface, the first surface being welded to the cover, the outer layer containing an ethylene-α-olefin copolymer resin or a modified polypropylene resin; an inner layer laminated on the second surface and containing a polyethylene (PE) resin; A soft bag composite file having:

[0078] [Aspect 2] The thickness ratio of the inner layer to the outer layer is in the range of 100:10 to 100:100. A flexible bag composite file according to embodiment 1.

[0079] [Aspect 3] the inner layer has a third surface on the outer layer side and a fourth surface opposite the third surface, the flexible bag further has an additional layer laminated on the fourth surface and including an ethylene-α-olefin copolymer resin or a modified polypropylene resin; A flexible bag composite file according to aspect 1 or 2.

[0080] [Aspect 4] The soft bag is sandwiched between the covers, In the orientation of the soft bag composite file in which the first welded portion and the second welded portion are aligned vertically, an upper end of the second welded portion of the soft bag is located below an upper end of the first welded portion of the cover; and / or a lower end of the second welded portion of the soft bag is located above a lower end of the first welded portion of the cover; The flexible bag composite file according to any one of aspects 1 to 3. [Explanation of symbols]

[0081] 1, 2: Soft bag composite file 10:Cover 11: Outer cover 12: Inner cover 12b: 1st weld part 13: First outer cover 14: Second outer cover 15: Pocket cover 20: Soft bag 20b: 2nd weld part 201: Outer layer 201a: 1st surface 201b: 2nd surface 202: Inner layer 202a: Third surface 202b: 4th surface 203: Additional layer 21: Opening and closing means 30: Welding area 31: Upper retaining part 32: Lower backing

Claims

1. a cover having a first welded portion and including a polypropylene (PP) resin; a flexible bag having a second welded portion welded to the cover along the first welded portion; A soft bag composite file comprising: The flexible bag is an outer layer having a first surface and a second surface opposite to the first surface, the first surface being welded to the cover, the outer layer containing an ethylene-α-olefin copolymer resin or a modified polypropylene resin; an inner layer laminated on the second surface and containing a polyethylene (PE) resin; A soft bag composite file having:

2. The thickness ratio of the inner layer to the outer layer is in the range of 100:10 to 100:

100.

2. The flexible composite file according to claim 1.

3. the inner layer has a third surface on the outer layer side and a fourth surface opposite the third surface, the flexible bag further has an additional layer laminated on the fourth surface and containing an ethylene-α-olefin copolymer resin or a modified polypropylene resin; 2. The flexible composite file according to claim 1.

4. The soft bag is sandwiched between the covers, In the orientation of the flexible bag composite file in which the first welded portion and the second welded portion are aligned in the vertical direction, an upper end of the second welded portion of the soft bag is located below an upper end of the first welded portion of the cover; and / or a lower end of the second welded portion of the soft bag is located above a lower end of the first welded portion of the cover; The flexible composite file according to any one of claims 1 to 3.

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