JP5200718B2 - Liquid paper container and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid paper container suitable for packaging sake, shochu, wine, and the like, and a method for producing the same.

  Conventionally, liquid paper containers are used for packaging sake, shochu, wine, milk, juice and the like. In such a liquid paper container, a barrier layer such as an aluminum foil layer or an aluminum vapor deposition layer is interposed in a laminated body forming the paper container in order to prevent oxidative deterioration of the contents (for example, Patent Document 1). See).

JP 2006-321495 A

However, in a liquid paper container using such a laminate, although a high barrier property is obtained, the paper base material layer and the barrier layer are easily bonded because the paper base material layer and the barrier layer are firmly bonded. There was a problem that it could not be peeled off and the recycling efficiency was low.
Accordingly, the present invention has been made in view of the above circumstances, and liquid paper with high recycling efficiency capable of peeling the paper base material layer and the barrier layer after use while maintaining the performance as a liquid paper container. The purpose is to provide a container.

The first invention for achieving the purpose of, and an outermost layer made of olefin resin, and a paper substrate layer, an acrylic acid - alkyl acrylate - alkyl copolymer or acrylic acid methacrylic acid - alkyl acrylate - and adhesion control layer of styrene copolymer, ethylene - - methacrylic acid alkyl acrylate copolymers, ethylene - ethyl acrylate copolymer, ethylene - methacrylic acid copolymer, ethylene - methyl methacrylate copolymer or ethylene methacrylic acid - an adhesive resin layer having a maleic acid copolymer, a barrier layer containing aluminum, and wherein the resin film layer, that the innermost layer made of olefin resin formed by Seihako the laminate are sequentially stacked Liquid paper container.
The surface of the side in contact with the adhesion control layer of contact Chakujushi layer it is preferable to ozone treatment.

The second invention is a laminate in which an outermost layer made of an olefin resin, a paper base layer, an adhesion adjusting layer, an adhesive resin layer, a barrier layer containing aluminum, a resin film layer, and an innermost layer made of an olefin resin are sequentially laminated. A method for producing a liquid paper container by boxing a body, wherein an acrylic acid-alkyl acrylate-alkyl methacrylate copolymer or acrylic is provided on a paper base material layer side of a paper base material layer on which an outermost layer is laminated. After applying an aqueous composition in which an acid-alkyl acrylate-alkyl methacrylate-styrene copolymer is dissolved to form an adhesion adjusting layer, the adhesion adjusting layer, a resin film layer on which a barrier layer is laminated, during, ethylene - acrylic acid copolymer, ethylene - ethyl acrylate copolymer, ethylene - methacrylic acid copolymer, ethylene - methyl methacrylate copolymer or d Len - a method of manufacturing a liquid packaging cartons, characterized in that the resin material constituting the adhesive resin layer made of maleic acid copolymer is melt-extruded comprising the step of sandwich laminate. In this manufacturing method, sandwich lamination may be performed while ozone is sprayed onto the melt-extruded resin material.

  According to the present invention, it is possible to provide a highly recyclable liquid paper container capable of peeling the paper base material layer and the barrier layer after use while maintaining the performance as a liquid paper container.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view of a laminate for forming a liquid paper container according to an embodiment. As shown in FIG. 1, the laminate in the present embodiment includes an outermost layer 1 made of an olefin resin, a paper base layer 2, an adhesion adjusting layer 3, an adhesive resin layer 4, a barrier layer 5 containing aluminum, and a resin film. The layer 6 and the innermost layer 7 made of an olefin resin are laminated in this order. The laminate according to the present embodiment weakened the adhesive strength of the adhesive resin layer 4 to the paper base material layer 2 by interposing the adhesion adjusting layer 3 between the paper base material layer 2 and the adhesive resin layer 4. It is characterized by (inhibited). By adopting such a stacking order, delamination does not occur when the laminated body is processed into a paper container and when the processed paper container is used, and after use, the paper base material layer 2 can be used with human power. The side and the barrier layer 5 side can be separated.

  Examples of the olefin resin constituting the outermost layer 1 and the innermost layer 7 in the present invention include polypropylene, medium density polyethylene, high density polyethylene, high pressure method low density polyethylene, Ziegler low density polyethylene, and linear polyethylene. From the viewpoint of low-temperature sealing properties, transparency, and processability, it is preferable to use high-pressure low-density polyethylene as the olefin resin. The thickness of the outermost layer 1 is preferably 5 μm to 50 μm. The innermost layer 7 preferably has a thickness of 10 μm to 100 μm. In the outermost layer 1 and the innermost layer 7, an antioxidant, an ultraviolet absorber, an antistatic agent, an antiblocking agent, a flame retardant, a dye, a pigment, and the like are appropriately added as long as the effects of the present invention are not impaired. May be.

  The adhesive resin layer 4 in the present invention is mainly composed of an acid-modified resin material such as ethylene and methacrylic acid. Specific examples of such a resin material include an ethylene-acrylic acid copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-methacrylic acid copolymer, an ethylene-methyl methacrylate copolymer, or an ethylene-maleic acid copolymer. A polymer etc. are mentioned. Among these materials, an ethylene-acrylic acid copolymer, in which strong adhesion to aluminum of the barrier layer 5 is obtained, is excellent in workability, and is relatively inexpensive among these materials, Ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer and ethylene-maleic acid copolymer are preferred. The thickness of the adhesive resin layer 4 is preferably 5 μm to 80 μm.

  The adhesion adjusting layer 3 in the present invention is a layer that plays a role of inhibiting the strong adhesion of the adhesive resin layer 4 to the paper base material layer 2. The adhesion adjusting layer 3 has good adhesion to the paper base material layer 2 and adhesion to the adhesive resin layer 4 is somewhat lower than the adhesive strength between the adhesive resin layer 4 and the paper base material layer 2. Specific examples thereof include acrylic acid-alkyl acrylate-alkyl methacrylate copolymer, acrylic acid-alkyl acrylate-alkyl methacrylate-styrene copolymer, and the like. It is done. Among these materials, the above-described ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-methacrylic acid copolymer (EMAA) are used as the material constituting the adhesive resin layer 4. ), Ethylene-methyl methacrylate copolymer (EMMA) or ethylene-maleic acid copolymer, acrylic acid-alkyl acrylate-alkyl methacrylate copolymer and acrylic acid-alkyl acrylate-methacrylic acid Alkyl-styrene copolymers are preferred. It is preferable that the carbon number of the alkyl group of the alkyl (meth) acrylate which comprises these copolymers is 4-8.

As the paper base material constituting the paper base material layer 2 in the present invention, known paper such as paperboard such as coated ball, card paper, ivory paper, and Manila ball, milk carton base paper, cup base paper, kraft paper, and high-quality paper is used. Can be used. The basis weight of the paper substrate may be suitably determined depending on the form of paper container, it is ^{usually, 100g / m 2 ~500g / m} 2.
Further, before laminating the outermost layer 1 or the adhesion adjusting layer 3 on the paper base material layer 2, the surface of the paper base material to be the paper base material layer 2 is subjected to corona discharge treatment, flame treatment, ozone treatment, anchor coating agent treatment. Etc. may be applied. By performing these treatments, the adhesive strength between the layers can be improved. The corona discharge treatment can be performed by using a known corona discharge treatment device and passing the paper substrate through the generated corona atmosphere. The frame processing can be performed by using a known frame processing device and burning the surface of the paper substrate with fire. The ozone treatment can be performed by passing a paper substrate through a generated ozone atmosphere using a known ozone treatment device. The anchor coating agent treatment can be performed by applying a known aqueous anchor coating agent to the surface of the paper substrate by gravure printing or the like.

  The resin film layer 6 in the present invention is made of a resin material having physical strength that can withstand the heat of hot air blown to the laminate during box making and can withstand physical stress from the outside. Specific examples of such materials include polyethylene terephthalate and nylon. The thickness of the resin film layer 6 is preferably 5 μm to 30 μm.

The barrier layer 5 in the present invention is mainly composed of a material containing aluminum having a property of not allowing water vapor, water, gas and the like to permeate. A specific example of such a material is an aluminum foil, but instead of the aluminum foil, an aluminum deposited film formed on the resin film layer 6 by vacuum deposition or sputtering may be used.
When an aluminum foil is used as the barrier layer 5, it is preferably laminated on the resin film layer 6 using a laminating adhesive such as a urethane adhesive, a vinyl adhesive, an acrylic adhesive, or an epoxy adhesive. The thickness of the aluminum foil is preferably 3 μm to 20 μm. The coating amount of the adhesive may be appropriately set so that the thickness of the adhesive is 0.1g / m ² ~5g / m ² as a dry film. Moreover, when using an aluminum vapor deposition film as the barrier layer 5, it is preferable to form an aluminum vapor deposition film on the resin film layer 6 by which the anchor coating agent process was carried out. The thickness of the aluminum vapor deposition film is preferably 100 to 1000 mm.

The adhesive strength between the adhesion adjusting layer 3 and the adhesive resin layer 4 in the laminate configured as described above is preferably 0.2 N / 15 mm width to 1.5 N / 15 mm width, and 0.5 N / More preferably, the width is 15 mm to 1 N / 15 mm. When the adhesive strength is less than 0.2 N / 15 mm width, delamination may occur when the laminate is processed into a paper container and when the processed paper container is used, and the adhesive strength is 1. If the width exceeds 5 N / 15 mm, peeling may occur from the inside of the paper base material during recycling, which may reduce the recycling efficiency. In addition, the measurement of adhesive strength first cuts out a laminated body to 100 mm with a width of 15 mm to make a test piece, peels the paper base material layer 2 and the adhesive resin layer 4 from one of the cut out test pieces to 50 mm, and uses a tensile tester. Chuck each chuck. The distance between chucks is 100 mm. And it peels in the direction of 180 degree | times at a tension speed of 50 mm / min in 25 degreeC atmosphere, and measures a maximum load. The measurement is performed 5 times, and the arithmetic average is defined as the adhesive strength between the adhesion adjusting layer 3 and the adhesive resin layer 4.
The adhesive strength defined in this way is to change the combination of materials used for the adhesive resin layer 4 and the adhesion adjustment layer 3 or to ozone-treat the surface of the adhesive resin layer 4 on the side in contact with the adhesion adjustment layer 3. Can be appropriately increased or decreased. The ozone treatment can be performed by spraying ozone generated using a known ozone treatment device on the surface of a resin material such as EMAA constituting the adhesive resin layer 4.

Below, the manufacturing method of the liquid paper container which concerns on this Embodiment is demonstrated.
The laminated body in this Embodiment can be manufactured by a well-known method in the packaging material field | area using the above-mentioned material. Specifically, the outermost layer 1 is formed by extrusion coating an olefin-based resin on one surface of the paper base material layer 2, and then the adhesion adjusting layer 3 is formed on the other surface of the paper base material layer 2. An adhesive composition layer 3 is formed by applying a water-based composition in which a resin material to be dissolved is formed, and the adhesive resin layer 4 is interposed between the adhesion adjustment layer 3 and the resin film layer 6 on which the barrier layer 5 is formed. It can be manufactured by melt-extrusion of the constituting resin material and sandwich lamination, and finally applying an anchor coating agent on the resin film layer 6 and then extrusion-coating the olefin resin to form the innermost layer 7. . In addition, it is preferable that water, isopropyl alcohol, etc. contain as an aqueous solvent in the aqueous composition used here, and the above-mentioned copolymer contains 5 mass%-20 mass% as solid content. When the resin solid content is less than 5% by mass, it may be difficult to form the adhesion adjusting layer 3 having an appropriate film thickness. On the other hand, when the resin solid content exceeds 20% by mass, the fluidity of the aqueous composition is increased. May be difficult to apply. The coating amount of the aqueous composition may be appropriately set so that the adhesion control layer 3 becomes 0.25g / m ² ~1.5g / m ² by dry weight. As a method for applying the aqueous composition, known gravure printing, planographic printing, letterpress printing, screen printing, and the like can be used. Among these, it is preferable to employ gravure printing because the coating amount is stable and productivity is high.

In addition, in the production of the laminate described above, adhesion between the paper base material layer 2 and the adhesive resin layer 4 is performed by sandwich lamination while spraying ozone onto the resin material constituting the melt-extruded adhesive resin layer 4. The strength can be increased. Ozone concentration at this time is preferably from ^{10g / Nm 3 ~20g / Nm 3} , also, the air volume is desirably 2.5 g / time to 4.0 g / time.

  The obtained laminate can be boxed to produce liquid paper containers of various shapes such as a gable top type and a brick type. Specifically, first, a blank sheet is obtained by punching the laminate into a predetermined shape and simultaneously providing ruled lines at necessary places. Next, the resin material constituting the innermost layer 7 or the outermost layer 1 is melted by a frame seal or a hot air seal, and the body portion is bonded to obtain a cylindrical sleeve. Subsequently, the cylindrical sleeve can be manufactured by a known method of supplying the cylindrical sleeve to a filling machine, forming a bottom part on the filling machine, filling the liquid, and sealing the top part.

  The liquid paper container according to the present invention is in a liquid state ranging from foods such as alcohol such as sake, shochu and wine, milk beverages such as milk, soft drinks such as orange juice and tea to chemical products such as car wax, shampoo and detergent. It can be suitably used for the packaging of general items.

[Example 1]
Using a two-component curable urethane-based adhesive, a polyethylene terephthalate film (resin film layer) having a thickness of 12 μm and an aluminum foil (barrier layer) having a thickness of 6 μm were laminated by a dry lamination method to produce a laminate film. On the other hand, a high-pressure low-density polyethylene (outermost layer) having a thickness of 22 μm is laminated on one surface of a paperboard (paper base material layer) having a basis weight of 400 g / m ² by an extrusion lamination method, and acrylic acid is applied on the other surface of the paperboard. -Dry weight of an aqueous composition (solid content 10% by mass) containing an alkyl acrylate-alkyl methacrylate copolymer (4 to 8 carbon atoms of the alkyl group of the alkyl (meth) acrylate constituting the copolymer) in dried and coated to a 1.0 g / m ^2, acrylic acid - to form a layer (adhesive adjusting layer) consisting of alkyl methacrylate copolymers - alkyl acrylate. Subsequently, the surface of the paperboard on which the layer made of an acrylic acid-alkyl acrylate-alkyl methacrylate copolymer was formed was opposed to the aluminum foil surface of the previously produced laminate film, and a 20 μm thick ethylene- A methacrylic acid copolymer (adhesive resin layer) was melt extruded at 295 ° C. and sandwich-laminated. Finally, a two-component curable urethane anchor coating agent is applied on a polyethylene terephthalate film, and then a high-pressure low-density polyethylene (innermost layer) having a thickness of 60 μm is laminated by an extrusion lamination method. A laminate having a layer structure of paperboard / acrylic acid-alkyl acrylate-alkyl methacrylate copolymer / ethylene-methacrylic acid copolymer / aluminum foil / polyethylene terephthalate film / high pressure method low density polyethylene was obtained.
The obtained laminate is punched into a predetermined shape, and at the same time, ruled lines are provided at necessary portions to form a blank sheet, and then the barrel portion is bonded by a frame seal to form a cylindrical sleeve, and this cylindrical sleeve is supplied to a filling machine. After forming the bottom part on the filling machine, 35% alcohol aqueous solution was filled, and the top part was sealed to produce the gable top type paper container of Example 1.

[Example 2]
During sandwich lamination, the surface of the paperboard on which the layer of acrylic acid-alkyl acrylate-alkyl methacrylate copolymer is formed is treated in-line with ozone (ozone concentration 15 g / Nm ³ , air volume 2.5 g / hour). In the same manner as in Example 1, except that the laminate film was opposed to the aluminum foil surface and an ethylene-methacrylic acid copolymer (adhesive resin layer) having a thickness of 20 μm was melt extruded at 295 ° C. Obtained.
The obtained laminate is punched into a predetermined shape, and at the same time, ruled lines are provided at necessary portions to form a blank sheet, and then the barrel portion is bonded by a frame seal to form a cylindrical sleeve, and this cylindrical sleeve is supplied to a filling machine. After forming the bottom part on the filling machine, 35% alcohol aqueous solution was filled, and the top part was sealed to prepare a gable top type paper container of Example 2.

[Example 3]
Instead of an aqueous composition containing an acrylic acid-alkyl acrylate-alkyl methacrylate copolymer, an acrylic acid-alkyl acrylate-alkyl methacrylate-styrene copolymer ((meth) acrylic acid constituting the copolymer) The same procedure as in Example 1 was conducted except that an aqueous composition (solid content: 10% by mass) containing an alkyl group having 4 to 8 carbon atoms was applied so that the dry weight was 0.5 g / m ^2. A laminate was obtained.
The obtained laminate is punched into a predetermined shape, and at the same time, ruled lines are provided at necessary portions to form a blank sheet, and then the barrel portion is bonded by a frame seal to form a cylindrical sleeve, and this cylindrical sleeve is supplied to a filling machine. After forming the bottom part on the filling machine, 35% alcohol aqueous solution was filled, and the top part was sealed to prepare the gable top type paper container of Example 3.

[Example 4]
During sandwich lamination, the surface of the paperboard on which the layer made of acrylic acid-alkyl acrylate-alkyl methacrylate-styrene copolymer is formed is treated in-line with ozone (ozone concentration 15 g / Nm ³ , air volume 2.5 g / hour). In the same manner as in Example 3, except that the laminate is opposed to the aluminum foil surface of the laminate film and an ethylene-methacrylic acid copolymer (adhesive resin layer) having a thickness of 20 μm is melt-extruded at 295 ° C. therebetween. Got the body.
The obtained laminate is punched into a predetermined shape, and at the same time, ruled lines are provided at necessary portions to form a blank sheet, and then the barrel portion is bonded by a frame seal to form a cylindrical sleeve, and this cylindrical sleeve is supplied to a filling machine. After forming the bottom part on the filling machine, 35% alcohol aqueous solution was filled, and the top part was sealed to produce the gable top type paper container of Example 4.

[Example 5]
A laminate was obtained in the same manner as in Example 1 except that instead of the laminate film, a polyethylene terephthalate film (aluminum deposition film thickness of 500 mm, polyethylene terephthalate film thickness of 12 μm) on which aluminum was deposited was used.
The obtained laminate is punched into a predetermined shape, and at the same time, ruled lines are provided at necessary portions to form a blank sheet, and then the barrel portion is bonded by a frame seal to form a cylindrical sleeve, and this cylindrical sleeve is supplied to a filling machine. After forming the bottom part on the filling machine, 35% alcohol aqueous solution was filled, and the top part was sealed to prepare the gable top type paper container of Example 5.

[Example 6]
A laminate was obtained in the same manner as in Example 2, except that a polyethylene terephthalate film (aluminum deposition film thickness of 500 mm, polyethylene terephthalate film thickness of 12 μm) on which aluminum was deposited was used instead of the laminate film.
The obtained laminate is punched into a predetermined shape, and at the same time, ruled lines are provided at necessary portions to form a blank sheet, and then the barrel portion is bonded by a frame seal to form a cylindrical sleeve, and this cylindrical sleeve is supplied to a filling machine. After forming the bottom part on the filling machine, 35% alcohol aqueous solution was filled, and the top part was sealed to prepare the gable top type paper container of Example 6.

[Example 7]
A laminate was obtained in the same manner as in Example 3, except that a polyethylene terephthalate film (aluminum deposition film thickness 500 mm, polyethylene terephthalate film thickness 12 μm) on which aluminum was deposited was used instead of the laminate film.
The obtained laminate is punched into a predetermined shape, and at the same time, ruled lines are provided at necessary portions to form a blank sheet, and then the barrel portion is bonded by a frame seal to form a cylindrical sleeve, and this cylindrical sleeve is supplied to a filling machine. After forming the bottom part on the filling machine, 35% alcohol aqueous solution was filled, and the top part was sealed to prepare a gable top type paper container of Example 7.

[Example 8]
A laminate was obtained in the same manner as in Example 4 except that a polyethylene terephthalate film (aluminum deposition film thickness 500 mm, polyethylene terephthalate film thickness 12 μm) on which aluminum was deposited was used instead of the laminate film.
The obtained laminate is punched into a predetermined shape, and at the same time, ruled lines are provided at necessary portions to form a blank sheet, and then the barrel portion is bonded by a frame seal to form a cylindrical sleeve, and this cylindrical sleeve is supplied to a filling machine. After forming the bottom part on the filling machine, 35% alcohol aqueous solution was filled, and the top part was sealed to prepare a gable top type paper container of Example 8.

[Comparative Example 1]
A laminate was obtained in the same manner as in Example 1 except that a layer (adhesion adjusting layer) composed of an acrylic acid-alkyl acrylate-alkyl methacrylate copolymer was not formed.
The obtained laminate is punched into a predetermined shape, and at the same time, ruled lines are provided at necessary portions to form a blank sheet, and then the barrel portion is bonded by a frame seal to form a cylindrical sleeve, and this cylindrical sleeve is supplied to a filling machine. After forming the bottom part on the filling machine, 35% alcohol aqueous solution was filled, and the top part was sealed to prepare a gable top type paper container of Comparative Example 1.

[Comparative Example 2]
A laminate was obtained in the same manner as in Example 5 except that a layer (adhesion adjusting layer) composed of an acrylic acid-alkyl acrylate-alkyl methacrylate copolymer was not formed.
The obtained laminate is punched into a predetermined shape, and at the same time, ruled lines are provided at necessary portions to form a blank sheet, and then the barrel portion is bonded by a frame seal to form a cylindrical sleeve, and this cylindrical sleeve is supplied to a filling machine. After forming the bottom part on the filling machine, 35% alcohol aqueous solution was filled, and the top part was sealed to prepare a gable top type paper container of Comparative Example 2.

<Measurement of adhesive strength>
The adhesive strength of the laminate before filling with 35% alcohol aqueous solution was measured. Specifically, each of the laminates was prepared in the same manner as in Examples 1 to 8 and Comparative Examples 1 and 2, and a test piece having a width of 15 mm and a length of 100 mm was cut out therefrom, and the measurement object was measured from one end of the cut out test piece. 50 mm was peeled off and chucked on both chucks of a Tensilon tensile tester. In a 25 ° C. atmosphere, the film was peeled in the 180 ° direction at a pulling rate of 50 mm / min, and the maximum load was measured. The measurement was performed 5 times, and the results are shown in Table 1 with the arithmetic average as the adhesive strength.

<Evaluation of processability>
It was confirmed whether there was any inconvenience when processing the laminate into a paper container. Specifically, laminates were respectively produced in the same manner as in Examples 1 to 8 and Comparative Examples 1 and 2, and sleeve-like cartons were produced using these laminates. When any laminate was used, no occurrence of wrinkles or floats was observed in the processing step.

<Durability evaluation>
After storing the gable top type paper containers prepared in Examples 1 to 8 and Comparative Examples 1 and 2 at 50 ° C. for 1.5 months (corresponding to 1 year at room temperature), the paper containers were disassembled and described above. The adhesive strength was measured by the same method as the measurement of the adhesive strength. The results are shown in Table 2.

<Evaluation of pinhole resistance>
The temperature at which the top and bottom portions of the paper container were sealed in the filling machine was changed, and the temperature until pinholes were generated was measured. The results are shown in Table 3.

  From the above, the paper containers of Examples 1 to 8 have the same performance (processing suitability, durability and pinhole resistance) as those of Comparative Examples 1 and 2, and the paper base layer after use. The side and the barrier layer side can be easily separated, and it can be said that the recycling efficiency is high.

It is a schematic cross section of the laminated body for forming the liquid paper container which concerns on embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Outermost layer which consists of olefin resin, 2 Paper base material layer, 3 Adhesion adjustment layer, 4 Adhesive resin layer, 5 Barrier layer containing aluminum, 6 Resin film layer, 7 Innermost layer.

Claims (4)

And an outermost layer made of olefin resin, and a paper substrate layer, an acrylic acid - and adhesion control layer of styrene copolymer - alkyl acrylate - alkyl methacrylate copolymer or acrylic acid - alkyl acrylate - alkyl methacrylate , ethylene - acrylic acid copolymer, ethylene - ethyl acrylate copolymer, ethylene - methacrylic acid copolymer, ethylene - methyl methacrylate copolymer or ethylene - and consists maleic acid copolymer adhesive resin layer, an aluminum a barrier layer comprising a resin film layer and a liquid packaging cartons, characterized in that the innermost layer made of olefin resin formed by Seihako the laminate which are sequentially stacked. The liquid paper container according to claim 1 , wherein a surface of the adhesive resin layer on a side in contact with the adhesion adjusting layer is subjected to ozone treatment. Form a laminate in which the outermost layer made of olefin resin, the paper base layer, the adhesion adjusting layer, the adhesive resin layer, the barrier layer containing aluminum, the resin film layer, and the innermost layer made of olefin resin are sequentially laminated. A liquid paper container manufacturing method comprising:
Acrylic acid-alkyl acrylate-alkyl methacrylate copolymer or acrylic acid-alkyl acrylate-alkyl methacrylate-styrene copolymer is dissolved on the paper base layer side of the paper base layer on which the outermost layer is laminated. After forming an adhesion adjusting layer by applying an aqueous composition, an ethylene-acrylic acid copolymer, ethylene-ethyl acrylate is interposed between the adhesion adjusting layer and the resin film layer on which the barrier layer is laminated. Including a step of melt-extruding a resin material constituting an adhesive resin layer made of a copolymer, an ethylene-methacrylic acid copolymer, an ethylene-methyl methacrylate copolymer, or an ethylene-maleic acid copolymer and sandwiching the laminate. A method for manufacturing a liquid paper container. 4. The method for producing a liquid paper container according to claim 3 , wherein sandwich lamination is performed while spraying ozone onto the melt-extruded resin material.

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