JP2023109508A - Gas barrier laminate and method for manufacturing the same, container for liquid, and liquid-containing container - Google Patents

Abstract

To provide a gas barrier laminate which is excellent in gas barrier property has sufficient gas barrier property even when vibration is applied thereto at the time of conveyance and a method for manufacturing the same, a container for a liquid, and a liquid-containing container.SOLUTION: A method for manufacturing a gas barrier laminate having a laminated structure having a paper base material including a ruled line part, an adhesive resin layer and a gas barrier layer including a vapor-deposited layer in this order includes the steps of: providing the ruled line part on the paper base material; extruding a resin composition forming an adhesive resin layer between the paper base material including the ruled line part and the gas barrier layer, sandwiching the paper base material and the gas barrier layer by a nip roll and a cooling roll, and thereby bonding the paper base material and the gas barrier layer, wherein a Shore D hardness of the nip roll is 60 degrees or more and 80 degrees or less.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present disclosure relates to a gas barrier laminate, a method for manufacturing the same, a liquid container, and a liquid-filled container.

2. Description of the Related Art Conventionally, in the field of packaging materials, liquid paper containers mainly made of paper have been used. Patent Document 1 discloses a package comprising a paper substrate, a barrier layer made of a substrate film provided with an inorganic oxide vapor deposition film, an adhesive resin layer having a specific thickness, and a heat-sealable resin layer. Disclosed is a liquid paper container formed by cartoning the material.

Japanese Patent Application Laid-Open No. 2001-171649

Contents (drinks, etc.) contained in a paper container may be degraded by oxygen or the like. Therefore, such liquid paper containers are required to have excellent gas barrier properties so that the contents can be stored for a long period of time.

By the way, the packaging material constituting the paper container for liquid is provided with a ruled line portion so as to facilitate folding. The ruled line portion is generally provided by pressing the packaging material. However, the present inventors' studies revealed that cracks tend to occur in the vapor-deposited layer because force is applied to the vapor-deposited layer when the packaging material is pressed, and the gas barrier properties tend to deteriorate.

In addition, packaging materials are required to have little deterioration in gas barrier properties even when vibrations are applied during transportation or the like.

The present disclosure provides a gas barrier laminate that has excellent gas barrier properties and has sufficient gas barrier properties even when vibration is applied during transportation, a method for producing the same, a liquid container, and a liquid-filled container.

A method for manufacturing a gas barrier laminate according to one aspect of the present disclosure is a gas barrier having a laminated structure comprising a paper substrate provided with ruled lines, an adhesive resin layer, and a gas barrier layer including a vapor deposition layer in this order. A method for producing a laminate, comprising: providing a ruled line on a paper substrate; extruding a resin composition for forming an adhesive resin layer between the paper substrate provided with the ruled portion and the gas barrier layer; a step of laminating the paper base material and the gas barrier layer by sandwiching the paper base material and the gas barrier layer between a nip roll and a cooling roll, wherein the nip rolls have a Shore D hardness of 60 degrees or more and 80 degrees or less.

The gas barrier laminate obtained by the above-described manufacturing method has excellent gas barrier properties, and has sufficient gas barrier properties even when vibration is applied during transportation. The inventors of the present invention presume that the reason why such an effect is exhibited is as follows. That is, in the method for producing a gas barrier laminate described above, the ruled line portion is provided on the paper substrate in the absence of the vapor deposition layer. Therefore, cracks in the deposited layer due to the provision of the ruled line portion do not occur. Further, the nip roll has a Shore D hardness of 60 degrees or more and 80 degrees or less, so that the gas barrier layer can be bonded along the ruled line. Therefore, gaps are less likely to occur between the paper substrate and the gas barrier layer at both ends of the ruled line. Since the voids are less likely to occur, peeling due to the voids is suppressed even when force is applied from the outside. As a result, the obtained gas barrier laminate has excellent gas barrier properties, and has sufficient gas barrier properties even when vibration is applied during transportation.

A gas barrier laminate according to another aspect of the present disclosure has a laminate structure comprising, in this order, a paper substrate provided with ruled lines, an adhesive resin layer, and a gas barrier layer including a vapor deposition layer, The adhesive resin layer has a first surface including ridges derived from the ruled lines and a second surface including grooves derived from the ruled lines, and between the adhesive resin layer and the gas barrier layer, A gap is formed along the ridge, and the length from the end of the ridge to the end of the gap is 2.0 mm or less in a cross section perpendicular to the extending direction of the ridge.

A gas barrier laminate according to still another aspect of the present disclosure has a laminate structure comprising a paper substrate provided with ruled lines, an adhesive resin layer, and a gas barrier layer including a vapor deposition layer in this order. , the paper substrate has a first surface including ridges derived from the ruled lines, and a second surface including grooves derived from the ruled lines, and between the paper substrate and the adhesive resin layer , a gap is formed along the ridge, and the length from the end of the ridge to the end of the gap is 2.0 mm or less in a cross section perpendicular to the extending direction of the ridge.

In one aspect, the oxygen permeability values A1 and A2 of the gas barrier layered product, each measured in a circular area of 50 cm ² in area, satisfy the following conditions.
A1/A2≤2.0
[wherein A1 is a circular area with a ruled line passing through the center of the circular area, and A2 is a circular area with no ruled line. ]

A liquid container according to still another aspect of the present disclosure is configured by the gas barrier laminate described above. This container has excellent gas barrier properties, and has sufficient gas barrier properties even when vibration is applied during transportation.

A liquid-filled container according to still another aspect of the present disclosure includes the above container and a liquid contained in the above container. This liquid-filled container can sufficiently suppress deterioration of contents over a long period of time.

According to the present disclosure, a gas barrier laminate having excellent gas barrier properties and having sufficient gas barrier properties even when vibration is applied during transportation, a method for producing the same, a liquid container, and a liquid-filled container are provided.

FIG. 1 is a cross-sectional view schematically showing a gas barrier laminate according to one embodiment of the present disclosure. FIG. 2 is a cross-sectional view schematically showing a gas barrier laminate according to another embodiment of the present disclosure. FIG. 3 is a process diagram showing an example of a method for manufacturing a gas barrier laminate according to an embodiment of the present disclosure. FIG. 4 is a schematic diagram showing part of a lamination apparatus that can be used in the method for manufacturing a gas barrier laminate according to an embodiment of the present disclosure. FIG. 5 is a perspective view schematically showing a container according to one embodiment of the present disclosure; FIG. FIG. 6 is a plan view of a blank sheet forming a container according to one embodiment of the present disclosure;

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment.

[Gas barrier laminate]
<First Embodiment>
A gas barrier laminate (hereinafter also simply referred to as "laminate") according to the first embodiment will be described below. FIG. 1 is a cross-sectional view schematically showing a laminate according to this embodiment. As shown in FIG. 1, the laminate 30 according to this embodiment includes a protective layer 1, a paper base material 2, an adhesive resin layer 3, a gas barrier layer 4, and a sealant layer 5 in this order. It has a laminated structure. The gas barrier layer 4 consists of a vapor deposition layer 4a and a film substrate 4b. The paper base material 2 is provided with a ruled line portion 11 . The adhesive resin layer 3 has a first surface including the ridge line portion a1 derived from the ruled line portion 11 and a second surface including the groove portion a2 derived from the ruled line portion. A gap 12 is formed along the ridge line a1 between the adhesive resin layer 3 and the deposited layer 4a. In the gap 12, the adhesive resin layer 3 and the deposited layer 4a are not in contact with each other. Each configuration of the laminate 30 will be described.

(protective layer)
The material of the protective layer 1 may be polyethylene resin, for example. Since the protective layer 1 is made of polyethylene resin, the obtained container is excellent in recyclability. Polyethylene resins are preferably medium-density polyethylene and high-density polyethylene, since they have high physical strength and the resulting container has even more excellent gas barrier properties. The density of such a polyethylene resin is preferably 0.920 g/cm ³ to 0.950 g/cm ³ , more preferably 0.925 g/cm ³ to 0.945 g/cm ³ .

The thickness of the protective layer 1 is preferably from 10 to 30 μm, more preferably from 15 to 20 μm, since the obtained container has a more excellent gas barrier property.

(Paper substrate)
As the paper substrate 2, for example, paper having shapeability, bending resistance, rigidity, stiffness, strength, and the like can be used. As such paper, for example, strong sizing bleached or unbleached paper, pure white roll paper, kraft paper, cardboard and processed paper can be used.

The basis weight of the paper base material 2 is preferably 80 to 600 g/m ² , more preferably 200 to 450 g/m ² , since the obtained container has better gas barrier properties.

The ruled line portion 11 is a portion where the paper base material 2 has unevenness as a line (region) that is made easier to bend by, for example, recessing the paper base material 2 .

The width L1 of the ruled line portion 11 may be 1 mm or more, 2 mm or more, or 3 mm or more, or may be 4 mm or less, 3 mm or less, or 2 mm or less. The width L1 of the ruled line portion 11 can be measured with a glass scale.

Desired printed patterns such as characters, figures, patterns and symbols can be arbitrarily formed on the paper substrate 2 by a normal printing method.

(Adhesive resin layer)
Examples of materials for the adhesive resin layer 3 include polyolefin resins, acid-modified polyolefin resins, ionomers, and ethylene/methacrylic acid copolymer resins.

Polyolefin-based resins include, for example, polyethylene-based resins, polypropylene-based resins, and cyclic olefin-based resins. Polyolefin-based resins may be used singly or in combination of two or more.

Polyethylene-based resins include low-density polyethylene, high-density polyethylene, copolymer resins of polyethylene and polyvinyl acetate, and acid anhydride-modified polyethylene represented by terpolymers such as ethylene/ethyl acrylate/maleic anhydride. and epoxy compound-modified polyethylene such as ethylene-glycidyl methacrylate copolymer. From the viewpoint of adhesiveness between the paper substrate 2 and the gas barrier layer 4, the polyethylene-based resin is preferably low-density polyethylene. Low density polyethylene includes linear low density polyethylene and branched low density polyethylene, preferably branched low density polyethylene. The branched low-density polyethylene is preferably obtained by high-pressure radical polymerization, more preferably by homopolymerizing ethylene by high-pressure radical polymerization. Polyethylene-based resins may be used singly or in combination of two or more.

The density of the low-density polyethylene is preferably 0.900 g/cm ³ to 0.935 g/cm ³ , more preferably 0.915 g/cm ³ to 0.930 g/cm ³ . When the density is within the above range, the low-density polyethylene has appropriate rigidity, so that the adhesive resin layer 3 has improved film formability and extrusion suitability.

The melting point of the polyethylene resin is preferably 80 to 130°C, more preferably 100 to 120°C. If the melting point is within this range, coextrusion workability and compatibility are improved.

Polypropylene-based resins include, for example, propylene homopolymers, propylene/α-olefin random copolymers, acid anhydride-modified polypropylenes represented by terpolymers such as propylene/ethyl acrylate/maleic anhydride, and Epoxy compound-modified polypropylene such as propylene/glycidyl methacrylate copolymer can be used. Examples of propylene/α-olefin random copolymers include propylene-ethylene copolymers, propylene-butene-1 copolymers and propylene-ethylene-butene-1 copolymers. The polypropylene-based resin may be synthesized using a metallocene catalyst. The polypropylene-based resin is preferably a propylene-α-olefin random copolymer, more preferably a propylene/α-olefin random copolymer polymerized using a metallocene catalyst. Polypropylene-based resins may be used singly or in combination of two or more.

The melting point of the polypropylene resin is preferably 120 to 165°C, more preferably 125 to 160°C. If the melting point is within this range, coextrusion workability and compatibility are improved.

Cyclic olefin resins include, for example, cycloolefin polymers (COP), cycloolefin copolymers (COC), vinyl alicyclic hydrocarbon polymers, and cyclic conjugated diene polymers.

The melt flow rate (MFR) of the polyolefin resin may be 3 g/10 minutes or more, 8 g/10 minutes or more, or 20 g/10 minutes or more, and may be 30 g/10 minutes or less, 25 g/10 minutes or less, or 20 g/10 minutes. /10 minutes or less. Melt flow rate means a value measured under conditions of a temperature of 230° C. and a load of 2.16 kg according to the method described in JIS K7210-1:2014.

In the adhesive resin layer 3, as other components other than the above, if necessary, an antifogging agent, an antistatic agent, a heat stabilizer, a nucleating agent, an antioxidant, a lubricant, an antiblocking agent, a release agent, Ultraviolet absorbers, colorants, light stabilizers, crystal nucleating agents, plasticizers, slip agents such as fatty acid amides, dyes, pigments, mold release agents, flame retardants, etc. may be added within a range that does not impair the purpose of the present disclosure. can.

The thickness of the adhesive resin layer 3 is, for example, preferably 5 to 40 μm, more preferably 10 to 30 μm.

The height H1 of the ridge line a1 of the adhesive resin layer 3 may be 0.2 mm or more, 0.3 mm or more, or 0.4 mm or more, and may be 2.0 mm or less, 1.5 mm or less, or 1.0 mm. It may be below. The height H1 of the ridge line portion a1 is measured by a laser ruled line height measuring machine.

(evaporation layer)
By including the vapor deposition layer 4a, the laminate 30 has sufficient gas barrier properties and is excellent in recyclability as compared with a laminate including aluminum foil instead of the vapor deposition layer. The deposited layer 4a is a layer deposited with silicon oxide (SiO _x ). Thereby, the laminated body 30 becomes excellent in water resistance. The thickness of the deposited layer 4a may be appropriately set depending on the intended use, but is preferably 10 to 300 nm, more preferably 30 to 100 nm. When the thickness of the vapor deposition layer 4a is 10 nm or more, the continuity of the vapor deposition layer 4a can be easily made sufficient, and when the thickness is 300 nm or less, the occurrence of curling and cracking can be sufficiently suppressed, and sufficient gas barrier performance and flexibility can be obtained. easy to achieve.

The deposited layer 4a may be a layer deposited with an inorganic oxide other than silicon oxide (SiO _x ) or a metal. The deposited layer 4a may be obtained by, for example, depositing aluminum, or may contain aluminum oxide (AlO _x ).

(Film substrate)
Examples of materials for the film substrate 4b include polyolefin films, polyethylene terephthalate films, and nylon films. The film substrate 4b is preferably a polyolefin film. By using the polyolefin film, it becomes possible to recycle the adhesive resin layer 3 and the sealant layer 5 as an olefin plastic material. Polyolefin films include, for example, polypropylene films and polyethylene films.

The thickness of the film substrate 4b is preferably 3 to 50 μm, more preferably 9 to 20 μm, from the viewpoint of ease of processing such as lamination.

(sealant layer)
The material of the sealant layer 5 is the same as that of the adhesive resin layer 3 .

The thickness of the sealant layer 5 is not particularly limited, but it is preferably 20 to 100 μm in consideration of suitability as a packaging material and workability when laminating another film or forming the vapor deposition layer 4a.

In a cross section perpendicular to the extending direction of the ridge line a1 (the direction from the front side to the back side of the paper surface of FIG. 1), the length L2 from the end e1 of the ridge line a1 to the end e2 of the gap 12 is 0.1 mm or more. , 0.2 mm or more, or 0.5 mm or more, and may be 2.0 mm or less, 1.0 mm or less, less than 1.0 mm, or 0.8 mm or less. Length L2 means a value measured as follows. That is, arbitrary 10 points of the ruled line portion 11 of the laminate 30 are selected. At each of the ten selected points, the length from the end e1 of the ridge line a1 to the end e2 of the gap 12 (where the paper substrate 2 is uneven) is measured using a glass scale. Let the average value of the obtained measured values be the length L2.

It is preferable that the values A1 and A2 of the oxygen permeability of the circular area of 50 cm ² in the laminate 30 to be measured satisfy the following conditions.
A1/A2≤2.0
[wherein A1 is a circular area with a ruled line passing through the center of the circular area, and A2 is a circular area with no ruled line. ]

A1/A2 is more preferably 1.8 or less, even more preferably 1.2 or less. Moreover, A1/A2 is 1.0 or more. Oxygen permeability means a value measured using an oxygen permeability measuring device under the conditions of a temperature of 30° C. and a relative humidity of 70%.

<Second embodiment>
A gas barrier laminate (hereinafter also simply referred to as "laminate") according to the second embodiment will be described below. Points that are not described below are the same as those of the gas barrier laminate according to the first embodiment unless mismatching occurs. FIG. 2 is a cross-sectional view schematically showing a laminate according to the second embodiment. As shown in FIG. 2, the laminate 40 according to this embodiment includes a protective layer 1, a paper base material 2, an adhesive resin layer 3, a gas barrier layer 4, and a sealant layer 5 in this order. It has a laminated structure. The gas barrier layer 4 consists of a vapor deposition layer 4a and a film substrate 4b. The paper base material 2 is provided with a ruled line portion 11 . The paper base material 2 has a first surface including the edge line portion a1 derived from the ruled line portion 11 and a second surface including the groove portion a2 derived from the ruled line portion. Between the paper substrate 2 and the adhesive resin layer 3, a gap 12 is formed along the ridge line a1. The paper substrate 2 and the adhesive resin layer 3 are not in contact with each other in the space 12 .

The numerical range and measuring method of the height H1 of the ridgeline a1 of the paper substrate 2 may be the same as those of the height H1 of the laminate 30 .

In the cross section orthogonal to the extending direction of the ridge line a1, the numerical range and measurement method of the length L2 from the terminal end e1 of the ridge line a1 to the terminal end e2 of the gap 12 are the same as those for the length L2 in the laminate 30. you can

Although the gas barrier laminates according to the first embodiment and the second embodiment have been described above in detail, the present invention is not limited to the above embodiments. For example, in the laminate 30 or the laminate 40, the stacking order of the film substrate 4b and the deposition layer 4a may be changed.

[Method for producing gas barrier laminate]
<First Embodiment>
A method for manufacturing the laminate 30 according to one embodiment will be described below. FIG. 3 is a process chart showing an example of the method for manufacturing the gas barrier laminate according to this embodiment. As shown in (a) to (d) of FIG. 3, the manufacturing method according to the present embodiment includes the following steps.
(a) A step of forming a protective layer 1 on one surface of a paper substrate 2 by extrusion lamination to obtain a first laminate 10 (Fig. 3(a)).
(b) A step of providing a ruled line portion 11 in the first laminate 10 to obtain a second laminate 15 (FIG. 3(b)).
(c) A step of preparing a third laminate 20 including the gas barrier layer 4 and the sealant layer 5 (FIG. 3(c)).
(d) The paper base material 2 of the second laminate 15 and the gas barrier layer 4 of the third laminate 20 are opposed to each other, and the second laminate 15 is positioned below the third laminate 20 in the vertical direction. The second laminate 15 and the third laminate 20 are sent out to the paper substrate 2 and the resin composition that forms the adhesive resin layer 3 between the gas barrier layer 4, and the second laminate 15 and the third laminate are extruded. A step of sandwiching the laminate 20 between nip rolls and cooling rolls to bond the paper substrate 2 and the gas barrier layer 4 together to obtain a laminate 30 (FIG. 3(d)).

[(a) step]
In this step, the first laminate 10 is obtained by forming the protective layer 1 on one surface of the paper substrate 2 by extrusion lamination. The method of forming the protective layer 1 is not limited to extrusion lamination. Other methods include, for example, a T-die extrusion method, a co-extrusion lamination method, an inflation method, and a co-extrusion inflation method.

[(b) step]
In this step, the ruled line portion 11 is provided in the first laminate to obtain the second laminate 15 . The first laminate is provided with a ruled line portion 11 so as to be concave when viewed from the protective layer 1 side.

A method for providing the ruled line portion 11 in the first laminate includes, for example, ruled line processing using a punching machine.

[(c) step]
In this step, the third laminate 20 including the gas barrier layer 4 and the sealant layer 5 is prepared. A method of obtaining the third laminate 20 includes, for example, a method of forming the sealant layer 5 by extrusion lamination on the surface of the film substrate 4b of the gas barrier film including the deposition layer 4a and the film substrate 4b.

From the viewpoint of oxygen gas barrier performance and film uniformity, the deposited layer 4a is preferably formed on the surface of the film substrate 4b by a vacuum film forming means. Film formation means include known methods such as a vacuum deposition method, a sputtering method, and a chemical vapor deposition method (CVD method), but the vacuum deposition method is preferred because of its high film formation speed and high productivity. Among vacuum evaporation methods, electron beam heating is particularly effective because the film formation speed can be easily controlled by adjusting the irradiation area and electron beam current, and the temperature of the evaporation material can be raised and lowered in a short period of time. be.

The method of forming the sealant layer 5 is not limited to extrusion lamination. Other methods include, for example, a T-die extrusion method, a co-extrusion lamination method, an inflation method, a dry lamination method, and a co-extrusion inflation method.

[(d) step]
In this step, the paper substrate 2 and the gas barrier layer 4 are bonded together with the resin composition forming the adhesive resin layer 3 to obtain the laminate 30 . FIG. 4 is a schematic diagram showing a part of a lamination apparatus 100 that can be used in the method for manufacturing a gas barrier laminate according to this embodiment. As shown in FIG. 4, the second stack 15 and the third stack 20 are delivered. A molten resin composition is extruded from the extruder 103 between the paper substrate 2 side of the second laminate 15 and the vapor deposition layer 4a side of the third laminate 20 . The second laminate 15 and the third laminate 20 are sandwiched between the nip roll 105 and the cooling roll 107 . The nip roll 105 is arranged on the second laminate 15 side, and the cooling roll 107 is arranged on the third laminate 20 side. The laminate 30 is obtained by bonding the second laminate 15 and the third laminate 20 together. Since the second laminated body 15 is positioned below the third laminated body 20 in the vertical direction, a gap is formed between the adhesive resin layer 3 and the deposition layer 4a.

The Shore D hardness of the nip roll is preferably 80 degrees or less, more preferably 70 degrees or less, and 65 degrees or less, because the deterioration of the gas barrier property is further suppressed when vibration is applied during transportation. It is even more preferable to have The nip roll may have a Shore D hardness of 50 degrees or more, 55 degrees or more, or 60 degrees or more. The Shore D hardness of the nip roll is measured with a Shore hardness tester.

<Second embodiment>
A method for manufacturing the laminate 40 according to this embodiment will be described below. The manufacturing method according to this embodiment includes steps (a) to (c) as in the first embodiment, but differs in that it includes the following step (e) instead of step (d).

(e) The paper substrate 2 of the second laminate 15 and the gas barrier layer 4 of the third laminate 20 face each other, and the second laminate 15 is vertically above the third laminate 20. Then, the paper base material 2 of the second laminate 15 and the gas barrier layer 4 of the third laminate 20 are coated with a resin composition that forms the adhesive resin layer 3. a step of obtaining a laminated body 40 by bonding;

Since the second laminate 15 is vertically above the third laminate 20 , a gap is formed between the paper substrate 2 and the adhesive resin layer 3 . The pressure for bonding the second laminate 15 and the third laminate 20 and the Shore D hardness of the nip rolls may be the same as in the step (d).

Although the method for manufacturing the gas barrier laminate according to one embodiment has been described above in detail, the method for manufacturing the gas barrier laminate is not limited to the above embodiment. For example, the paper base material 2 may form the ruled line part 11 before forming the protective layer 1 .

Also, the sealant layer 5 may be formed on the surface provided with the vapor deposition layer 4a of the gas barrier film. The third laminate 20 may not have the sealant layer 5 . In that case, the method for manufacturing the gas barrier laminate further comprises the step of forming the sealant layer 5 on the surface of the film substrate 4b on which the vapor deposition layer 4a is not provided after the step (d) or step (e). good too. Each layer constituting the laminate 30 or 40 may be subjected to pretreatment such as corona treatment and plasma treatment before lamination.

[container]
The container (paper container) according to the present embodiment will be described below. The container 50 shown in FIG. 5 is a gable top type container. The container 50 includes a rectangular tube-shaped container main body 52 having an upper portion 52 a provided with an opening 51 , a side surface 52 b and a bottom portion 52 c , and a cap 55 closing the opening 51 . The container main body 52 has the protective layer 1 of the laminate 30 as the outermost layer and the sealant layer 5 as the innermost layer. The container main body 52 has portions (bent portions B1 and B2) where the laminate 30 is bent. The bent portion B1 is a portion where the laminated body 30 is valley-folded when viewed from the innermost layer side, while the bent portion B2 is a portion where the laminated body 30 is mountain-folded when viewed from the innermost layer side. The bent portions B<b>1 and B<b>2 are bent along the ruled line portion 11 of the laminate 30 .

For example, the container 50 can fill and package various foods and drinks, chemicals such as adhesives and pressure-sensitive adhesives, cosmetics, sundries such as medicines, and various other articles. Since the container 50 has excellent gas barrier properties, it can be used as a package for filling and packaging juices such as alcoholic beverages, milk and fruit juice beverages, mineral water, liquid seasonings such as soy sauce and sauces, and liquid foods such as curry, stew and soup. It is particularly suitable for use as a container for liquids.

The container 50 is produced by folding each part of the blank sheet 70 shown in FIG. A blank sheet 70 shown in FIG. 6 is obtained by punching out the laminate 30 .

The blank sheet 70 includes top panels T1 to T4 and roof panels G1 to G4 that form the upper part of the container, side panels S1 to S4 that form the sides, bottom panels B1 to B4 that form the bottom, and a margin panel B5. , S5, G5 and T5. Roof panel G3 comprises an opening 51 . Roof panels G2 and G3 form a gable roof, and roof panels 1G and 4G form a folded roof. Roof panels 1G and 4G are provided with oblique ruled lines 11. As shown in FIG.

In order to form the container 50 from the blank sheet 70, first, the margin panels B5, S5, G5 and T5, the bottom panel B4, the side panel S4, the roof panel G4 and the top panel T4 are heat-sealed and attached to the cylinder. into flat folding cartons. The bottom panels B1-B4 are then folded to form the bottom and filled with contents. The top of the filled carton is folded and finally the top panel is heat sealed to seal.

The container 50 is composed of the laminate 30 having excellent gas barrier properties. Therefore, deterioration of the contents can be sufficiently suppressed for a long period of time. Moreover, since the container 50 can suppress deterioration of the contents, it also contributes to reduction of food loss. A liquid-filled container is obtained by storing a liquid in the container of the container 50 .

Although the container according to the present embodiment has been described in detail above, the container according to the present invention is not limited to the above embodiment. For example, the shape of the container is not limited to the shape of the container 50, and may be a brick type, a substantially octagonal prism shape, or a triangular pyramid shape. The container may consist of a laminate 40 .

EXAMPLES The present disclosure will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples.

[Production of gas barrier laminate]
(Example 1)
A laminate according to this example was obtained through the following steps. Specifically, a first laminate was obtained by forming a protective layer (material: polyethylene-based resin, thickness: 20 μm) on one surface of a paper substrate (basis weight: 200 g/m ² ). A ruled line portion (ruled line width: 1.5 mm) was provided on the first laminate by forming a ruled line using a punching machine to obtain a second laminate. The first laminate was provided with ruled lines so as to be concave when viewed from the side of the paper base on which the protective layer was provided.

On the other hand, a gas barrier film was prepared by forming a vapor deposition layer ( _AlOx vapor deposition layer, thickness: 50 nm) on one surface of a film substrate (material: polyethylene terephthalate resin, thickness: 12 μm). A sealant layer (thickness: 60 μm) was formed by extruding a polyethylene-based resin on the surface of the film substrate opposite to the surface on which the vapor deposition layer was formed, to obtain a third laminate.

Then, the second laminate and the third laminate were laminated together by extrusion lamination to obtain a gas barrier laminate (packaging material). Specifically, a polyethylene resin (melt flow rate: 8.4 g/10 minutes) that forms an adhesive resin layer is placed between the vapor deposition layer of the third laminate and the paper substrate of the second laminate. It was extruded in the molten state. Next, the second and third laminates were sandwiched between nip rolls (Shore D hardness: 60 degrees) and cooling rolls. At this time, the second and third laminates were arranged such that the second laminate was vertically lower than the third laminate. As a result, a gas barrier laminate (packaging material) was obtained in which the second laminate and the third laminate were bonded together by the adhesive resin layer. The thickness of the adhesive resin layer was 30 μm. At both ends of the ruled line portion of the gas barrier laminate, void portions were formed in which the adhesive resin layer and the gas barrier layer were not in contact with each other. The melt flow rate of polyethylene resin was measured according to JIS K7210:1999. The Shore D hardness of the nip roll was measured according to JIS Z2246:2000.

(Comparative example 1)
A protective layer (material: polyethylene resin, thickness: 20 μm) was formed on one surface of a paper substrate (basis weight: 200 g/m ² ) to obtain a second laminate containing the paper substrate. A third laminate was obtained in the same manner as in Example 1.

Next, in the same manner as in Example 1, the second laminate and the third laminate were laminated by extrusion lamination to obtain a laminate. A ruled line portion (ruled line width: 1.5 mm) was provided on the laminate by using a punching machine to form a ruled line, thereby obtaining a gas barrier laminate. The laminate was provided with ruled lines so as to be concave when viewed from the side of the paper substrate on which the protective layer was provided. No voids were found at both ends of the ruled line of the gas barrier laminate.

(Comparative example 2)
A gas barrier laminate was obtained in the same manner as in Example 1 except that a nip roll (Shore D hardness: 90 degrees) was used instead of the nip roll (Shore D hardness: 60 degrees).

[Container manufacturing]
The gas barrier laminate obtained in each example and comparative example was boxed into a gable-top container (capacity: 250 ml). Heat sealing was performed by blowing hot air at 450° C. to the gas barrier laminate.

[Conveyance test]
Regarding the containers obtained in each example and comparative example, according to JIS Z0200: 1999, "Level 1 (extremely long transportation distance (2500 km or more) or transportation infrastructure under poor conditions" in "8.4 Vibration test" It is expected that there will be

[Measurement of oxygen permeability]
Using an oxygen permeability measuring device (manufactured by Mocon, trade name: "OX-TRAN 2/22"), the measurement was carried out under conditions of a temperature of 30°C and a relative humidity of 70%. The measurement was performed on the gas barrier laminate, the container immediately after box making, and the container after the transportation test under 1 atmospheric pressure (oxygen partial pressure: about 0.2 atmospheric pressure). As for the gas barrier laminate, the oxygen permeability values A1 and A2 were measured for a circular area with an area of 50 cm ² . In A1, the circular area has a ruled line passing through the center of the circular area, and in A2, the circular area does not have a ruled line. Also, A1/A2 was calculated. Table 1 shows the results.

[Measurement of length of void]
The length from the end of the ridgeline to the end of the gap was measured in a cross section perpendicular to the extending direction of the ridgeline of the gas barrier laminate obtained in the example. Specifically, 10 arbitrary points of the ruled line portion of the gas barrier laminate were selected. The length from the end of the ridge line to the end of the gap was measured at each of the ten selected points using a glass scale. The average value of the obtained measured values was taken as the length from the end of the ridge to the end of the gap. Table 1 shows the results.

DESCRIPTION OF SYMBOLS 2... Paper base material 3... Adhesive resin layer 4... Gas barrier layer 4a... Vapor-deposited layer 11... Ruled line part 12... Void part 30, 40... Laminated body 50... Container a1... Ridge part, a2 ... Grooves, e1, e2 ... Ends.

Claims (6)

A method for producing a gas barrier laminate having a laminated structure comprising, in this order, a paper substrate provided with ruled lines, an adhesive resin layer, and a gas barrier layer including a vapor deposition layer, comprising:
A step of providing a ruled line portion on the paper base material;
Extruding a resin composition that forms the adhesive resin layer between the paper substrate provided with the ruled line portion and the gas barrier layer, and sandwiching the paper substrate and the gas barrier layer between a nip roll and a cooling roll. a step of bonding the paper base material and the gas barrier layer together;
with
A method for producing a gas barrier laminate, wherein the nip roll has a Shore D hardness of 60 degrees or more and 80 degrees or less. Having a laminated structure comprising a paper substrate provided with ruled lines, an adhesive resin layer, and a gas barrier layer including a vapor deposition layer in this order,
The adhesive resin layer has a first surface including ridges derived from the ruled lines and a second surface including grooves derived from the ruled lines,
A gap is formed along the ridge between the adhesive resin layer and the gas barrier layer,
A gas barrier laminate, wherein the length from the end of the ridge to the end of the gap is 2.0 mm or less in a cross section perpendicular to the extending direction of the ridge. Having a laminated structure comprising a paper substrate provided with ruled lines, an adhesive resin layer, and a gas barrier layer including a vapor deposition layer in this order,
The paper base material has a first surface including ridges derived from the ruled lines and a second surface including grooves derived from the ruled lines,
A gap is formed along the ridgeline between the paper substrate and the adhesive resin layer,
A gas barrier laminate, wherein the length from the end of the ridge to the end of the gap is 2.0 mm or less in a cross section perpendicular to the extending direction of the ridge. 4. The gas barrier laminate according to claim 2 or 3, wherein the oxygen permeability values A1 and A2 of a circular area of 50 cm ^<2> in the gas barrier laminate satisfy the following conditions.
A1/A2≤2.0
[wherein A1 is the circular area having the ruled line passing through the center of the circular area, and A2 is the circular area not having the ruled line. ] A liquid container comprising the gas barrier laminate according to any one of claims 2 to 4. A container containing liquid, comprising: the container for liquid according to claim 5; and a liquid contained in the container.

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