Liquid paper container

Abstract

To provide a paper container for liquid which can prevent delamination.SOLUTION: There is provided a paper container for liquid 1 that is formed of a blank plate 10 in which an outer surface adhesive layer 52 having thermoplasticity, a paper-made paper base material layer 54, a first barrier layer 62 formed of a metallic foil, and a thermoplastic sealant layer 73 are layered in this order from the outer surface side, wherein a second barrier layer 72 formed of an ethylene-vinyl alcohol copolymer resin is provided adjacent to the outer surface side of the sealant layer 73.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a liquid-containing paper container for storing liquid. [Background technology]

[0002] A conventional liquid paper container used to package beverages, detergents, etc. is disclosed in Patent Document 1. This liquid paper container is formed by folding a blank sheet, which has a polyethylene layer laminated on the outer surface of a paper layer and a barrier layer, a contents-resistant layer, and a sealant layer laminated on the inner surface in that order. The barrier layer is made of aluminum foil and blocks oxygen and water vapor. The contents-resistant layer contains nylon and prevents alkaline contents from penetrating the barrier layer if a crack occurs in the sealant layer. This prevents corrosion of the aluminum foil by alkaline contents. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 08-11860 (pages 2-7, Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional liquid-discharging paper containers described above, the nylon-containing content-resistant layer and the sealant layer are bonded together using a dry laminating adhesive or extrusion resin, which has the problem of alkaline or acidic contents degrading the anchor coating agent underlying the dry laminating adhesive or extrusion resin, resulting in delamination.

[0005] An object of the present invention is to provide a liquid paper container that can prevent delamination. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a paper container for liquids formed from a blank plate laminated with, from the outer surface side, a thermoplastic outer adhesive layer, a paper base layer made of paper, a first barrier layer made of metal foil, and a thermoplastic sealant layer, wherein a second barrier layer made of ethylene-vinyl alcohol copolymer resin is provided adjacent to the outer surface side of the sealant layer.

[0007] The present invention is also characterized in that, in the liquid-storing paper container having the above-mentioned configuration, a barrier substrate layer is laminated on the inner surface side of the first barrier layer, and a dry lamination adhesive is arranged between the barrier substrate layer and the second barrier layer.

[0008] The present invention is also characterized in that in the liquid-holding paper container having the above-mentioned configuration, a thermoplastic resin layer is provided on the outer surface side of the second barrier layer, and the barrier substrate layer and the thermoplastic resin layer are bonded together by the dry laminate adhesive.

[0009] Furthermore, the present invention is characterized in that in the liquid-containing paper container having the above-mentioned configuration, a barrier substrate layer is laminated on the inner surface side of the first barrier layer, and a thermoplastic interlayer adhesive layer is arranged between the barrier substrate layer provided with an anchor coating agent and the second barrier layer.

[0010] Furthermore, the present invention is characterized in that in the liquid-containing paper container having the above-described configuration, a thermoplastic resin layer is provided on the outer surface side of the second barrier layer, and the barrier substrate layer and the thermoplastic resin layer are bonded together by the interlayer adhesive layer.

[0011] Furthermore, the present invention is characterized in that in the liquid-sealing paper container having the above-mentioned configuration, a thermoplastic interlayer adhesive layer is disposed adjacent to the inner surface side of the first barrier layer.

[0012] The present invention is also characterized in that, in the liquid paper container of the above configuration, a thermoplastic resin layer is provided on the outer surface side of the second barrier layer, and the first barrier layer and the thermoplastic resin layer are bonded together by the interlayer adhesive layer. [Effects of the Invention]

[0013] According to the present invention, a paper container for storing liquids has a first barrier layer made of metal foil and a second barrier layer made of ethylene-vinyl alcohol copolymer resin adjacent to the outer surface of a thermoplastic sealant layer. This prevents the contents from penetrating to the outer surface, even in the case of highly alkaline or acidic contents. This prevents delamination of the liquid-carton container due to the contents. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view of a liquid container according to a first embodiment of the present invention; [Figure 2] FIG. 1 is a plan view showing a blank plate of a liquid-containing paper container according to a first embodiment of the present invention; [Figure 3] FIG. 1 is a cross-sectional view showing the layer structure of a blank plate of a liquid-repellent paper container according to a first embodiment of the present invention. [Figure 4] 10 is a cross-sectional view showing the layer structure of a blank plate of a liquid-repellent paper container according to a second embodiment of the present invention. [Figure 5] 10 is a cross-sectional view showing the layer structure of a blank plate of a liquid-repellent paper container according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] First Embodiment Embodiments of the present invention will be described below with reference to the drawings. Fig. 1 is a perspective view of a liquid-filled paper container of a first embodiment. The liquid-filled paper container 1 is configured as a Goebel-top type and is filled with liquid contents such as alcoholic beverages (sake, wine, shochu, etc.), beverages (coffee, dairy drinks, juice, tea, etc.), seasonings (dressing, etc.), hygiene products (shampoo, conditioner, etc.), cleaning agents (detergent, bleach, etc.), etc. The liquid-filled paper container 1 is particularly suitable for filling with contents with a high or low pH.

[0016] The liquid-storing paper container 1 comprises a main body 2 and a pouring member 3. The main body 2 is formed by bending a blank plate 10 (see Figure 2) having a paper base layer 54 (see Figure 3) into a box shape. The main body 2 has a cylindrical body 5 whose bottom is closed by a bottom portion 6, and whose top is closed by a sloped roof portion 7. The pouring member 3 is made of a resin molded product, forms a pouring outlet for the contents, and is opened and closed by a cap 3a.

[0017] 2 shows a plan view of the blank plate 10 with the main body 2 of the liquid-filled paper container 1 unfolded. The blank plate 10 has fold lines 9 at predetermined positions, and a rectangular back plate 11, side plates 12, front plate 13, side plates 14, and adhesive strips 15 are arranged in one direction in this order.

[0018] A ceiling rear panel 31 is connected to the upper end of the rear panel 11, and a bottom panel 21 is connected to the lower end. A ceiling side panel 32 is connected to the upper end of the side panel 12, and a bottom panel 22 is connected to the lower end. A ceiling front panel 33 is connected to the upper end of the front panel 13, and a bottom panel 23 is connected to the lower end. A ceiling side panel 34 is connected to the upper end of the side panel 14, and a bottom panel 24 is connected to the lower end. A glue tab 35 is connected to the upper end of the glue tab 15, and a glue tab 25 is connected to the lower end. An insertion hole 33a is provided in the ceiling front panel 33 for attaching the spouting member 3 (see Figure 1).

[0019] The upper end surfaces of the front ceiling panel 33 and the rear ceiling panel 31 are horizontal. The upper end surfaces 32d and 34d of the side ceiling panels 32 and 34 are convex surfaces that slope from both ends toward the center.

[0020] The blank plate 10 is formed into a cylindrical shape by folding along the fold line 9 and thermally bonding with the adhesive tabs 15, 25, and 35. That is, the adhesive tab 15 connected to the side plate 14 at one end is thermally bonded to the back plate 11 at the other end, thereby forming a cylindrical body portion 5 (see FIG. 1) that is closed in the circumferential direction.

[0021] The adhesive strip 25 connected to the bottom panel 24 at one end is thermally bonded to the bottom panel 21 at the other end, so that the bottom portion 6 (see FIG. 1) is formed in a state where the lower end is open and closed in the circumferential direction. The adhesive strip 35 connected to the ceiling side panel 34 at one end is thermally bonded to the ceiling back panel 31 at the other end, so that the sloped roof portion 7 (see FIG. 1) is formed in a state where the upper end is open and closed in the circumferential direction.

[0022] The bottom portion 6 is formed by folding the bottom plates 21 to 24 along the folding lines 9 and then thermally bonding them to the bottom of the body portion 5 in a closed state.

[0023] The spout 3 inserted into the insertion hole 33a is thermally bonded to the periphery of the insertion hole 33a in the front ceiling panel 33 of the sloping roof portion 7. Then, the front ceiling panel 33, the back ceiling panel 31, the side ceiling panel 32, and the side ceiling panel 34 are folded along the folding lines 9 and thermally bonded at predetermined locations. As a result, the sloping roof portion 7 is fixed to the top surface of the body portion 5 while covering it.

[0024] 3 is a cross-sectional view showing the layer structure of the blank plate 10. The blank plate 10 is formed by laminating, from the outer surface side, an outer adhesive layer 52, a paper substrate layer 54, an interlayer adhesive layer 61, a first barrier layer 62, a barrier substrate layer 64, a thermoplastic resin layer 71, a second barrier layer 72, and a sealant layer 73.

[0025] Anchor coating agents 53, 55 such as imine-based, urethane-based, or acrylic-based are printed on the outer and inner surfaces of the paper substrate layer 54. Dry laminating adhesives 63, 65 such as epoxy-based or acrylic-based are disposed between the first barrier layer 62 and the barrier substrate layer 64, and between the barrier substrate layer 64 and the thermoplastic resin layer 71, respectively.

[0026] The paper substrate layer 54 has a basis weight of, for example, 130 to 450 g / m 2The outer adhesive layer 52 is made of a thermoplastic resin and constitutes a thermal adhesive layer that thermally bonds the outer surface of the blank board 10. The outer adhesive layer 52 is made of, for example, polyethylene (PE) or low-density polyethylene (LDPE) with a thickness of 15 to 35 μm. By using the EC (Extrusion Coating) method, the outer adhesive layer 52 is extruded and laminated onto an anchor coating agent 53 provided on the paper base layer 54. This forms a coated paper 50 in which the surface of the paper base layer 54 is covered with resin.

[0027] The outer surface of the outer adhesive layer 52 is corona treated and a printing layer 51 is formed in place by gravure printing or offset printing.

[0028] The anchor coating agents 53 and 55 may be omitted and the surface of the paper substrate layer 54 may be subjected to a corona treatment.

[0029] The interlayer adhesive layer 61 is made of a thermoplastic resin, for example, ethylene-acrylic acid resin (EAA), ethylene-methacrylic acid copolymer resin (EMAA), etc., with a thickness of 15 to 35 μm. The interlayer adhesive layer 61 bonds the barrier film 60, which will be described later, onto the paper base layer 54.

[0030] The first barrier layer 62 is made of metal foil and has gas barrier properties to prevent oxygen, water vapor, etc. from entering the liquid-carton container 1. For example, aluminum foil with a thickness of 6 to 9 μm can be used as the first barrier layer 62. Ethylene-acrylic acid resin and ethylene-methacrylic acid copolymer resin have excellent adhesive properties with aluminum foil. Therefore, the interlayer adhesive layer 61 made of ethylene-acrylic acid resin or ethylene-methacrylic acid copolymer resin can reliably bond the coated paper 50 and the barrier film 60.

[0031] The first barrier layer 62 is dry laminated to a barrier substrate layer 64 using a dry laminating adhesive 63 to form a barrier film 60. The barrier substrate layer 64 is formed, for example, from a polyethylene terephthalate (PET) film with a thickness of 9 to 15 μm. An interlayer adhesive layer 61 is extruded onto the first barrier layer 62 of the barrier film 60, bonding the coated paper 50 and the barrier film 60 together.

[0032] The second barrier layer 72 is made of ethylene-vinyl alcohol copolymer resin (EVOH) and has a thickness of, for example, 2 to 12 μm. The ethylene-vinyl alcohol copolymer resin prevents penetration of liquids, particularly alkalis with high pH and acids with low pH.

[0033] The sealant layer 73 is made of a thermoplastic resin, and is formed, for example, from low density polyethylene (LDPE) having a thickness of 15 to 80 μm, linear low density polyethylene (LLDPE) polymerized using a metallocene catalyst, or the like.

[0034] The thermoplastic resin layer 71 is made of the same thermoplastic resin as the sealant layer 73, and is formed of, for example, low-density polyethylene (LDPE) with a thickness of 15 to 80 μm.

[0035] The thermoplastic resin layer 71, the second barrier layer 72, and the sealant layer 73 are laminated by the EC method to form the sealant film 70. The sealant film 70 is dry laminated to the barrier film 60 with a dry lamination adhesive 65.

[0036] Curling of the sealant film 70 can be suppressed by providing the thermoplastic resin layer 71 and the sealant layer 73 on both sides of the second barrier layer 72. The sealant film 70 may be formed without the thermoplastic resin layer 71. Alternatively, an anchor coating agent may be provided on the barrier film 60, and the second barrier layer 72 and the sealant layer 73 may be laminated in that order by extrusion.

[0037] The blank plate 10 having the above-described configuration is folded and the opposing sealant layers 73 at predetermined locations, the opposing outer adhesive layers 52 at predetermined locations, and the opposing sealant layers 73 and outer adhesive layers 52 are thermally bonded to each other to form the liquid paper container 1.

[0038] When a crack occurs in the sealant layer 73 on the inner surface of the liquid-holding paper container 1, the second barrier layer 72 can prevent the contents from penetrating to the outer surface. Therefore, even if the contents are highly alkaline or acidic, the contents do not reach the dry laminating adhesive 65, preventing deterioration of the dry laminating adhesive 65. Therefore, delamination due to deterioration of the dry laminating adhesive 65 can be prevented.

[0039] This embodiment has a first barrier layer 62 made of metal foil, and a second barrier layer 72 made of ethylene-vinyl alcohol copolymer resin adjacent to the outer surface of a thermoplastic sealant layer 73. This prevents the contents from penetrating to the outer surface, even in the case of highly alkaline or acidic contents, due to the second barrier layer 72. This prevents delamination of the liquid-storing paper container 1 due to the contents.

[0040] Furthermore, a barrier substrate layer 64 is laminated on the inner surface side of the first barrier layer 62, and a dry laminating adhesive 65 is disposed between the barrier substrate layer 64 and the second barrier layer 72. Therefore, the film including the barrier substrate layer 64 (barrier film 60) and the film including the second barrier layer 72 (sealant film 70) are bonded together by the dry laminating adhesive 65. This makes it possible to easily realize a liquid-storing paper container 1 in which the second barrier layer 72 is disposed on the inner surface side of the first barrier layer 62.

[0041] In addition, a thermoplastic resin layer 71 is provided on the outer surface side of the second barrier layer 72, and the barrier substrate layer 64 and the thermoplastic resin layer 71 are bonded together with a dry lamination adhesive 65. This makes it possible to prevent curling of the sealant film 70, which is a laminate of the thermoplastic resin layer 71, the second barrier layer 72, and the sealant layer 73.

[0042] Second Embodiment Next, Figure 4 shows a cross-sectional view showing the layer structure of the blank plate 10 of the liquid-storing paper container 1 of the second embodiment. For ease of explanation, the same parts as those in Figure 3 above are given the same reference numerals. This embodiment differs from the first embodiment in the method of adhering the barrier film 60 and the sealant film 70. Other parts are the same as those in the first embodiment.

[0043] The barrier film 60 including the first barrier layer 62 has an anchor coating agent 66 disposed on the inner barrier substrate layer 64, and an interlayer adhesive layer 67 formed of a thermoplastic resin is extruded. The barrier film 60 and the sealant film 70 are bonded together by the interlayer adhesive layer 67.

[0044] The interlayer adhesive layer 67 is formed of, for example, polyethylene (PE), low-density polyethylene (LDPE), etc., having a thickness of 10 to 40 μm. A thermoplastic resin different from these may be provided between the interlayer adhesive layer 67 and the thermoplastic resin layer 71.

[0045] The sealant film 70 may be formed without the thermoplastic resin layer 71. Alternatively, the second barrier layer 72 and the sealant layer 73 may be laminated in this order by extrusion onto the anchor coating agent 66 provided on the barrier film 60.

[0046] According to this embodiment, as in the first embodiment, the second barrier layer 72 prevents the contents from penetrating to the outer surface side. This prevents deterioration of the anchor coating agent 66 and prevents delamination of the liquid-storing paper container 1 due to the contents.

[0047] Furthermore, a barrier substrate layer 64 is laminated on the inner surface side of the first barrier layer 62, and a thermoplastic interlayer adhesive layer 67 is arranged between the barrier substrate layer 64 and the second barrier layer 72. Therefore, the film including the barrier substrate layer 64 (barrier film 60) and the film including the second barrier layer 72 (sealant film 70) are bonded together by the interlayer adhesive layer 67. This makes it possible to easily realize a liquid-storing paper container 1 in which the second barrier layer 72 is arranged on the inner surface side of the first barrier layer 62.

[0048] In addition, a thermoplastic resin layer 71 is provided on the outer surface side of the second barrier layer 72, and the barrier substrate layer 64 and the thermoplastic resin layer 71 are bonded together by an interlayer adhesive layer 67. This makes it possible to prevent curling of the sealant film 70, which is a laminate of the thermoplastic resin layer 71, the second barrier layer 72, and the sealant layer 73.

[0049] <Third embodiment> Next, Figure 5 shows a cross-sectional view showing the layer structure of the blank plate 10 of the liquid-storing paper container 1 of the third embodiment. For ease of explanation, the same parts as those in Figure 4 above are given the same reference numerals. This embodiment differs from the second embodiment in the arrangement of the barrier film 60. Other parts are the same as those in the second embodiment.

[0050] The barrier film 60 has a first barrier layer 62 disposed on its inner surface, and is bonded to the sealant film 70 via an interlayer adhesive layer 67 made of a thermoplastic resin. The interlayer adhesive layer 67 is formed, for example, from ethylene-acrylic acid resin (EAA), ethylene-methacrylic acid copolymer resin (EMAA), or the like, with a thickness of 15 to 30 μm. Because the interlayer adhesive layer 67, which has high adhesion to metal foil, is adjacent to the first barrier layer 62, the anchor coating agent 66 (see FIG. 4) on the barrier film 60 can be omitted.

[0051] The sealant film 70 may be formed without the thermoplastic resin layer 71. Alternatively, the interlayer adhesive layer 67, the second barrier layer 72, and the sealant layer 73 may be laminated on the barrier film 60 by extrusion in this order.

[0052] According to this embodiment, as in the first and second embodiments, the second barrier layer 72 prevents the contents from penetrating to the outer surface side. This prevents delamination between the first barrier layer 62 and the interlayer adhesive layer 67 due to the contents accumulating in the minute irregularities on the outer surface of the interlayer adhesive layer 67.

[0053] In addition, a thermoplastic interlayer adhesive layer 67 is disposed adjacent to the inner surface side of the first barrier layer 62. Therefore, a liquid-storing paper container 1 in which the second barrier layer 72 is disposed on the inner surface side of the first barrier layer 62 can be easily realized.

[0054] In addition, a thermoplastic resin layer 71 is provided on the outer surface side of the second barrier layer 72, and the first barrier layer 62 and the thermoplastic resin layer 71 are bonded together by an interlayer adhesive layer 67. This makes it possible to prevent curling of the sealant film 70, which is a laminate of the thermoplastic resin layer 71, the second barrier layer 72, and the sealant layer 73.

[0055] In the first to third embodiments, the liquid-storing paper container 1 is of a Gabel-top type, but it may also be a flat liquid-storing paper container of a rectangular parallelepiped shape.

[0056] Examples formed for evaluating the liquid-storing paper container 1 of each embodiment will be described below. [Example]

[0057] In Example 1, a three-sided sealed pouch with inner dimensions of 200 mm x 200 mm was formed using a blank plate having the same layer structure as the blank plate 10 of the liquid-storing paper container 1 of the first embodiment shown in Figure 3. The layers of Example 1 are as follows. Outer adhesive layer 52: 20 μm thick polyethylene (PE) Paper base layer 54: basis weight 400g / m 2 Interlayer adhesive layer 61: 20 μm thick ethylene-methacrylic acid copolymer resin (EMAA) First barrier layer 62: Aluminum foil with a thickness of 7 μm Barrier substrate layer 64: 12 μm thick polyethylene terephthalate (PET) Thermoplastic resin layer 71: 25 μm thick low-density polyethylene (LDPE) Second barrier layer 72: ethylene-vinyl alcohol copolymer resin (EVOH) with a thickness of 6 μm, Sealant layer 73: 25 μm thick linear low-density polyethylene (LLDPE) [Example]

[0058] In Example 2, a three-sided sealed pouch similar to that of Example 1 was formed using a blank plate having the same layer structure as the blank plate 10 of the liquid-storing paper container 1 of the second embodiment shown in Figure 4. The layers of Example 2 are as follows. Outer adhesive layer 52: 20 μm thick polyethylene (PE) Paper base layer 54: basis weight 400g / m 2 Interlayer adhesive layer 61: 20 μm thick ethylene-methacrylic acid copolymer resin (EMAA) First barrier layer 62: Aluminum foil with a thickness of 7 μm Barrier substrate layer 64: 12 μm thick polyethylene terephthalate (PET) Interlayer adhesive layer 67: 20 μm thick polyethylene (PE) Thermoplastic resin layer 71: 25 μm thick low-density polyethylene (LDPE) Second barrier layer 72: ethylene-vinyl alcohol copolymer resin (EVOH) with a thickness of 6 μm, Sealant layer 73: 20 μm thick linear low-density polyethylene (LLDPE) [Example]

[0059] In Example 3, a three-sided sealed pouch similar to that of Example 1 was formed using a blank plate having the same layer structure as the blank plate 10 of the liquid paper container 1 of the third embodiment shown in Figure 5. The layers of Example 3 are as follows. Outer adhesive layer 52: 20 μm thick polyethylene (PE) Paper base layer 54: basis weight 400g / m 2 Interlayer adhesive layer 61: 20 μm thick ethylene-methacrylic acid copolymer resin (EMAA) Barrier substrate layer 64: 12 μm thick polyethylene terephthalate (PET) First barrier layer 62: Aluminum foil with a thickness of 7 μm Interlayer adhesive layer 67: 20 μm thick ethylene-methacrylic acid copolymer resin (EMAA) Thermoplastic resin layer 71: 25 μm thick low-density polyethylene (LDPE) Second barrier layer 72: ethylene-vinyl alcohol copolymer resin (EVOH) with a thickness of 6 μm, Sealant layer 73: 25 μm thick linear low-density polyethylene (LLDPE)

[0060] [Comparative Example 1] For comparison, comparative examples were also prepared. In comparative example 1, the sealant film 70 of example 1 was replaced with a linear low-density polyethylene (LLDPE) having a thickness of 40 μm.

[0061] Comparative Example 2 In Comparative Example 2, instead of the sealant film 70 of Example 2, a linear low-density polyethylene (LLDPE) having a thickness of 60 μm was used.

[0062] Comparative Example 3 In Comparative Example 3, the sealant film 70 of Example 3 was replaced with a linear low-density polyethylene (LLDPE) having a thickness of 40 μm.

[0063] The liquid paper containers 1 of each of the above examples and comparative examples were evaluated for delamination. Each three-sided sealed pouch was filled with 200 mL of concentrated detergent with a pH of 3.0 or 11.0, and left at 40°C for up to 24 weeks, after which the occurrence of delamination was periodically checked. Ten containers were tested for each example and comparative example.

[0064] The evaluation results for contents with a pH of 3.0 are shown in Table 1, and the evaluation results for contents with a pH of 11.0 are shown in Table 2. In Tables 1 and 2, cases in which no delamination occurred in any of the three-side sealed pouches are indicated by "○", and cases in which delamination occurred in one or more three-side sealed pouches are indicated by "×".

[0065] [Table 1]

[0066] [Table 2]

[0067] As is clear from Tables 1 and 2, by providing the second barrier layer 72, it is possible to prevent delamination of the liquid-storing paper container 1. [Industrial Applicability]

[0068] The present invention can be used for liquid paper containers. [Explanation of symbols]

[0069] 1 Liquid paper container 2 Main body 3. Dispensing member 3a Cap 5. Torso 6 Bottom part 7 Sloped roof 9 Fold lines 10 Blank Board 11 Back plate 12, 14 Side plate 13 Front plate 15, 25, 35 Glue allowance piece 21~24 Bottom plate 31 Ceiling back panel 32, 34 Ceiling side panels 32d, 34d top surface 33 Ceiling front plate 33a Insertion hole 50 coated paper 51 Printing layer 52 External adhesive layer 53, 55, 66 Anchor Coat Agent 54 Paper base layer 60 Barrier Film 61, 67 Interlayer adhesive layer 62 First barrier layer 63, 65 Dry laminating adhesive 64 Barrier substrate layer 70 Sealant Film 71 Thermoplastic resin layer 72 Second Barrier Layer 73 Sealant Layer

Claims

1. A liquid paper container formed by a blank plate having laminated thereon, in order from the outer surface side, a thermoplastic outer surface adhesive layer, a paper base layer made of paper, a barrier film, an interlayer adhesive layer, and a sealant film, The barrier film includes a barrier substrate layer and a first barrier layer made of a metal foil, The sealant film includes a second barrier layer made of an ethylene-vinyl alcohol copolymer resin, a thermoplastic resin layer disposed on the outer surface side of the second barrier layer, and a thermoplastic sealant layer disposed on the inner surface side of the second barrier layer, the interlayer adhesive layer is formed of a thermoplastic resin disposed between an inner surface of the barrier film and the thermoplastic resin layer constituting an outer surface of the sealant film, The barrier film and the sealant film are bonded together by the interlayer adhesive layer.

2. The barrier film comprises the first barrier layer provided on the outer surface of the barrier substrate layer, and an anchor coat layer provided on the inner surface of the barrier substrate layer, 2. The liquid paper container according to claim 1, wherein the interlayer adhesive layer is disposed between the anchor coat layer of the barrier film and the thermoplastic resin layer of the sealant film, and is formed of polyethylene (PE) or low-density polyethylene (LDPE) having a thickness of 10 to 40 μm.

3. The barrier film comprises the first barrier layer provided on the inner surface of the barrier substrate layer, 2. The liquid paper container according to claim 1, wherein the interlayer adhesive layer is disposed between the first barrier layer of the barrier film and the thermoplastic resin layer of the sealant film, and is formed from ethylene acrylic acid resin (EAA) or ethylene methacrylic acid copolymer resin (EMAA) having a thickness of 15 to 30 μm.

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