JP2023028094A - Gas barrier laminate, method for producing the same, container, and raw roll - Google Patents

Abstract

To provide a gas barrier laminate capable of obtaining a container having excellent gas barrier properties, a method for producing the same efficiently, the container, and a raw roll.SOLUTION: A method for producing a gas barrier laminate of the present disclosure includes the steps of: preparing a first raw roll which includes a gas barrier layer and a first adhesion layer provided on a first surface of the gas barrier layer, and is wound with a first laminate in which the first adhesion layer is exposed on a surface; preparing a second raw roll which is wound with a paper base material; and laminating the first laminate and the paper base material while extruding an adhesive resin containing an olefin resin, between the first adhesion layer of the first laminate fed from the first raw roll and the paper base material fed from the second raw roll.SELECTED DRAWING: Figure 3

Description

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

Conventionally, in the field of packaging materials, laminates made mainly of paper have been used. Patent Document 1 discloses a laminated material comprising a paper substrate, an adhesive resin layer having a specific thickness, a specific barrier layer, and a heat-sealable resin layer. Patent Document 2 describes a barrier layer comprising an outermost layer, a paper substrate, an adhesive layer, and a substrate film, and a vapor-deposited film of an inorganic oxide, a gas barrier coating film, and a protective film on one side of the substrate film. and a laminated material in which innermost layers are sequentially laminated.

On the other hand, the paper base material used in the laminated material for paper containers is required to have a certain degree of thickness in order to obtain the self-supporting property and strength of the container. However, a paper substrate having a sufficient thickness cannot obtain sufficient interlaminar adhesive strength when laminated with another substrate via an adhesive layer, and delamination is likely to occur. In particular, when a paper base material is laminated with a gas barrier coating film of a barrier film as in Patent Document 2, there is a problem that sufficient interlaminar adhesive strength cannot be obtained, resulting in insufficient gas barrier properties.

In order to solve such problems, Patent Document 3 discloses that a primer layer, a barrier coat layer, a first vapor deposition layer of inorganic oxide, a substrate film, and a second vapor deposition layer of inorganic oxide are provided in this order, Laminates are disclosed in which the primer layer comprises a barrier film comprising certain polyolefin polymers.

Further, in Patent Document 4, an aluminum foil layer is formed by laminating an outermost layer, a paper base layer, a first adhesive resin layer, a resin film layer, an aluminum foil layer, a second adhesive resin layer and an innermost layer. are laminated in a specific direction.

Japanese Patent Application Laid-Open No. 2001-171649 JP-A-2002-154524 JP 2020-157717 A Japanese Patent Application Laid-Open No. 2010-137880

By the way, such a container (paper container) generally includes a container main body having an upper portion, side surfaces, and a bottom portion, which are made of a packaging material. For example, when the container body has a rectangular tube shape, the container can be obtained by forming ruled lines on the packaging material in advance, bending the packaging material along the ruled lines, and heating and bonding the packaging materials. In addition, when the container main body is cylindrical, the container can be obtained by heating separate members constituting the upper portion, the side surface, and the bottom portion, respectively, and bonding them together. Such a member is obtained by bending the packaging material while heating it so as to obtain a desired shape.

Therefore, if the adhesion between the gas barrier layer and the adhesive resin layer is not sufficient, gaps are likely to occur between the gas barrier layer and the adhesive resin layer during bending. When voids are generated, the paper substrate tends to bend at an acute angle without following the gas barrier layer, and the load applied to the gas barrier layer tends to increase. As a result, cracks and pinholes are generated in the gas barrier layer, and the gas barrier properties of the container are deteriorated.

In particular, when the container body is cylindrical, the packaging material is bent while being heated, so cracks and pinholes are likely to occur in the gas barrier layer.

The laminated materials disclosed in Patent Documents 1 to 3 and the laminate disclosed in Patent Document 4 have room for improvement in terms of adhesion between layers.

By the way, packaging materials are generally made by laminating an outer layer material having a paper substrate and an inner layer material having a gas barrier layer with a resin that forms an adhesive resin layer so that the paper substrate and the gas barrier layer face each other. Manufactured in

Here, in order to improve the adhesion between the gas barrier layer and the adhesive resin layer, it is possible to form an adhesion layer made of a resin that improves the adhesion with the adhesive resin layer on the surface of the gas barrier layer of the inner layer material. Conceivable. However, if, for example, a urethane-based adhesive or an emulsion-type vinyl acetate-based adhesive is used as such a resin, the adhesive layer becomes sticky, so the inner layer material cannot be wound and used as a raw fabric. . Therefore, the adhesion layer must be formed on the surface of the gas barrier layer during the manufacturing process of bonding the outer layer material and the inner layer material together, which makes the manufacturing apparatus large-scale and inefficient.

The present disclosure provides a gas barrier laminate capable of obtaining a container having excellent gas barrier properties, a manufacturing method capable of efficiently manufacturing the same, a container, and a raw sheet.

A method for manufacturing a gas barrier laminate according to one aspect of the present disclosure includes:
A first raw roll is prepared, which includes a gas barrier layer and a first adhesion layer provided on the first surface of the gas barrier layer, and is wound with a first laminated body in which the first adhesion layer is exposed on the surface. process and
A step of preparing a second raw roll around which the paper substrate is wound;
The first laminate while extruding an adhesive resin containing an olefin resin between the first adhesion layer of the first laminate sent out from the first roll and the paper base material sent out from the second roll and a step of laminating the paper base material;
with
The first adhesion layer contains first olefinic copolymer particles having a number average particle size of 1 μm or less,
The first olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or its anhydride, and the content of the structural unit is from 0.01 to 0.01 based on the total amount of the first olefinic copolymer particles. 5% by mass.

A method for manufacturing a gas barrier laminate according to one aspect of the present disclosure can efficiently manufacture a gas barrier laminate having excellent gas barrier properties. Such an effect is presumed to be produced by the following mechanism. That is, the first adhesion layer contains the first olefinic copolymer particles. The first olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or its anhydride, and the content of the structural unit is within the above range, so that the adhesive resin containing the olefinic resin The adhesion of is improved. Moreover, since the number average particle diameter of the first olefinic copolymer particles is 1 μm or less, the first adhesion layer is improved in adhesion to the adhesive resin, while suppressing tackiness. By suppressing the tack of the first adhesion layer, the first laminate in which the first adhesion layer is exposed on the surface can be wound as a raw roll, so that the first laminate and the paper base are laminated. It is not necessary to form the adhesion layer during the manufacturing process. Therefore, according to the method for manufacturing a gas barrier laminate according to one aspect of the present disclosure, it is possible to efficiently manufacture a gas barrier laminate having excellent gas barrier properties.

The first laminate further includes a second adhesion layer provided on the second surface of the gas barrier layer because the resulting gas barrier laminate has even better gas barrier properties, and the second adhesion layer has a number average particle diameter of It contains second olefinic copolymer particles of 1 μm or less, the second olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or its anhydride, and the content of the structural unit is It may be 0.01 to 5% by mass based on the total amount of the biolefin copolymer particles.

The melting point of the first and second olefinic copolymer particles may be 120° C. or higher because the heat resistance of the resulting gas barrier laminate is improved. The gas barrier layer has a film base material containing at least a polypropylene film and a deposited layer containing an inorganic oxide provided on the surface of the film base material, since the resulting gas barrier laminate has excellent recyclability and water resistance. You may have

A gas barrier laminate according to another aspect of the present disclosure includes a paper substrate, an adhesive resin layer containing an olefin resin, and first olefin copolymer particles having a number average particle diameter of 1 μm or less. It has a laminated structure comprising an adhesion layer, a gas barrier layer, and a sealant layer in this order, and the first olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or its anhydride, The content of structural units is 0.01 to 5% by mass based on the total amount of the first olefinic copolymer particles. This gas barrier laminate has excellent gas barrier properties.

As one aspect, the gas barrier laminate further comprises a second adhesion layer between the gas barrier layer and the sealant layer, since the gas barrier laminate is more excellent in gas barrier properties. olefinic copolymer particles, wherein the second olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or its anhydride, and the content of the structural unit is equal to that of the second olefinic copolymer It may be 0.01 to 5% by weight based on the total amount of particles.

The melting point of the first and second olefinic copolymer particles may be 120° C. or higher because the heat resistance of the gas barrier laminate is improved. Since the gas barrier laminate is excellent in recyclability and water resistance, the gas barrier layer consists of a film substrate containing at least a polypropylene film and a deposited layer containing an inorganic oxide provided only on one surface of the film substrate. may have. The vapor deposition layer may have a thickness of 30 nm or more and 300 nm or less, since the gas barrier laminate is more excellent in gas barrier properties.

A container according to still another aspect of the present disclosure is configured by the above gas barrier laminate. This container has excellent gas barrier properties.

A raw fabric according to still another aspect of the present disclosure includes a gas barrier layer and a first adhesion layer provided on the first surface of the gas barrier layer, and the first adhesion layer is exposed on the surface. the body is wrapped. The first adhesion layer contains first olefinic copolymer particles having a number average particle diameter of 1 μm or less, and the first olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or its anhydride. The content of the structural unit is 0.01 to 5% by mass based on the total amount of the first olefinic copolymer particles.

The laminate further includes a second adhesion layer provided on the second surface of the gas barrier layer, the second adhesion layer containing second olefin copolymer particles having a number average particle diameter of 1 μm or less, and the second olefin system copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or its anhydride, and the content of the structural unit is 0.01 to 5% by mass based on the total amount of the second olefinic copolymer particles may be

The melting point of the first and second olefinic copolymer particles may be 120° C. or higher. The gas barrier layer may have a film substrate containing at least a polypropylene film and a deposited layer containing an inorganic oxide provided on the surface of the film substrate.

ADVANTAGE OF THE INVENTION According to this disclosure, the gas-barrier laminated body which can obtain the container which is excellent in gas-barrier property, the manufacturing method which can manufacture it efficiently, a container, and a raw fabric are provided.

FIG. 1 is a cross-sectional view schematically showing one embodiment of the gas barrier laminate according to the present disclosure. FIG. 2 is a cross-sectional view schematically showing one embodiment of the first laminate wound around the first raw fabric. FIG. 3 is a schematic diagram showing an example of a laminating apparatus that can be used in one embodiment of the method for producing a gas barrier laminate according to the present disclosure. FIG. 4 is a perspective view schematically showing one embodiment of a container according to the present disclosure; FIG. FIG. 5 is a perspective view schematically showing another embodiment of the container according to 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]
The gas barrier laminate according to this embodiment will be described below. FIG. 1 is a cross-sectional view schematically showing a gas barrier laminate according to this embodiment. As shown in FIG. 1, the laminate 10 according to the present embodiment includes a paper substrate 1, an adhesive resin layer 3, a first adhesion layer 5a, a gas barrier layer 7, a second adhesion layer 5b, and a sealant. layer 9 in that order. A protective layer 11 is arranged on the surface of the paper substrate 1 opposite to the surface in contact with the adhesive resin layer 3 . The gas barrier layer 7 has a film substrate 7a in contact with the first adhesion layer 5a, a deposited layer 7b, and an overcoat layer 7c in this order. Each configuration of the laminate 10 will be described below.

(Paper substrate)
As the paper substrate 1, 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 1 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.

Desired printed patterns such as characters, figures, patterns and symbols can be arbitrarily formed on the paper substrate 1 by a normal printing method.

(Adhesive resin layer)
The adhesive resin layer 3 contains an olefin resin. Examples of olefinic resins include branched low-density polyethylene, linear low-density polyethylene, polypropylene, copolymers of polyethylene and polyvinyl acetate, and terpolymers such as ethylene/ethyl acrylate/maleic anhydride. and epoxy compound-modified polyolefins such as ethylene-glycidyl methacrylate copolymers and acid anhydride-modified polyolefins represented by. Among these, branched low-density polyethylene, linear low-density polyethylene and polypropylene are preferable because they are easy to clean the extrusion device after processing and are excellent in recyclability. The olefinic resin may be used singly or in combination of two or more.

The content of the olefin resin in the adhesive resin layer 3 may be 80% by mass or more, 90% by mass or more, or 95% by mass or more based on the total amount of the adhesive resin layer 3 .

The thickness of the adhesive resin layer 3 is, for example, preferably 10-40 μm, more preferably 15-25 μm.

(First adhesion layer)
The first adhesion layer 5a contains (A) first olefinic copolymer particles having a number average particle diameter of 1 μm or less (hereinafter also referred to as component (A)), and component (A) is (A1) unsaturated It contains a structural unit derived from a carboxylic acid or its anhydride (hereinafter also referred to as component (A1)), and the content of the structural unit is from 0.01 to 0.01 based on the total amount of the first olefinic copolymer particles. 5% by mass.

The number average particle diameter of the first olefinic copolymer particles may be, for example, 50 nm to 200 nm from the viewpoint of uniform dispersion of the first olefinic copolymer particles and improved film formability. The number average particle size of the first olefinic copolymer particles is a value measured by a dynamic light scattering method using a particle size distribution meter.

The melting point of the first olefinic copolymer particles is preferably 120° C. or higher because the heat resistance of the gas barrier laminate is improved. The melting point of the first olefinic copolymer particles can be measured using a differential scanning calorimeter (DSC).

The first olefinic copolymer particles may have structural units derived from (A2) an olefinic compound (hereinafter also referred to as component (A2)). The first olefinic copolymer particles may have a structural unit derived from (A3) (meth)acrylic acid ester (hereinafter also referred to as component (A3)).

The content of components (A2) and (A3) in the first olefinic copolymer particles may be 95 to 99.99% by mass based on the total amount of the first olefinic copolymer particles. The mass ratio ((A2)/(A3)) between the (A2) component and the (A3) component in the first olefinic copolymer is (A2)/(A3) = 55/45 to 99/1. may

The first adhesion layer 5a may further contain (B) a polyester-based resin (hereinafter also referred to as component (B)). (B) Component may have an anionic group. Examples of anionic groups include carboxyl groups, sulfonic acid groups, sulfate groups and phosphoric acid groups, preferably carboxyl groups and sulfonic acid groups. These anionic groups may be partially salted.

Component (B) may have an anionic group in the range of 20 to 700 (equivalents/10 ⁶ g).

The mass ratio of component (A) to component (B) ((A)/(B)) may be (A)/(B)=90/10 to 20/80.

The total content of the components (A) and (B) in the first adhesion layer 5a is 80% by mass or more, 90% by mass or more, or 95% by mass or more, based on the total amount of the first adhesion layer 5a. good.

(Second adhesion layer)
The second adhesion layer 5b contains second olefinic copolymer particles having a number average particle diameter of 1 μm or less, and the second olefinic copolymer particles have a structural unit derived from an unsaturated carboxylic acid or its anhydride. The content of the structural unit is 0.01 to 5% by mass based on the total amount of the second olefinic copolymer particles.

As the second olefinic copolymer particles, the same particles as the first olefinic copolymer can be used. The second adhesion layer 5b may contain a polyester-based resin like the first adhesion layer 5a. The same polyester-based resin as that contained in the first adhesion layer 5a can be used. The mass ratio and total content of the second olefin copolymer particles and the polyester resin in the second adhesion layer 5b are the mass ratio and total content of the components (A) and (B) in the first adhesion layer 5a. It may be the same as the amount.

(Film substrate)
Examples of materials for the film substrate 7a include polyolefin films, polyethylene terephthalate films, and nylon films. The film substrate 7a is preferably a polyolefin film. By using the polyolefin film, it becomes possible to recycle the olefin plastic material together with the adhesive resin layer 3 . Polyolefin films include, for example, polypropylene films and polyethylene films. The film substrate 7a may be a uniaxially stretched film or a biaxially stretched film.

The thickness of the film substrate 7a is preferably 15 to 30 μm, more preferably 18 to 20 μm, from the viewpoint of ease of processing such as lamination and ease of transportation.

(evaporation layer)
The deposited layer 7b is a layer deposited with silicon oxide (SiO _x ). Thereby, the laminate 10 becomes excellent in water resistance. The thickness of the deposited layer 7b may be appropriately set according to the intended use, but is preferably 10 to 300 nm, more preferably 30 to 300 nm, and even more preferably 30 to 100 nm. When the thickness of the deposition layer 7b is 10 nm or more, the continuity of the deposition layer 7b 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 7b may be a layer deposited with an inorganic oxide other than silicon oxide (SiO _x ) or a metal. The deposited layer 7b may be obtained by, for example, depositing aluminum, or may contain aluminum oxide (AlO _x ).

From the viewpoint of oxygen gas barrier performance and film uniformity, the deposited layer 7b is preferably formed by 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 rate can be easily controlled by adjusting the irradiation area and electron beam current, and the temperature of the vapor deposition material can be raised and lowered in a short period of time. be.

In the laminated body 10, the vapor deposition layer 7b is provided only on one surface of the film substrate 7a. , the adhesion between the sealant layer 9 and the adhesive resin layer 3 can be easily maintained.

(overcoat layer)
Examples of the material of the overcoat layer 7c include polyvinyl alcohol.

The thickness of the overcoat layer 7c may be, for example, 50-400 nm.

As the material of the sealant layer 9, resins generally used for heat seal layers, such as branched low density polyethylene, linear low density polyethylene, polypropylene, and copolymer resins of polyethylene and polyvinyl acetate, can be used.

The melting point of the sealant layer 9 is preferably 130.degree. The melting point of the sealant layer 9 is preferably lower than the melting point of the first adhesion layer 5a because the sealability tends to be improved during heat sealing. The melting points of the sealant layer 9 and the first adhesion layer 5a can be measured using a differential scanning calorimeter (DSC).

The thickness of the sealant layer 9 is preferably 30 to 150 μm, more preferably 50 to 80 μm, because the gas barrier property is further improved.

(protective layer)
The material of the protective layer 11 may be polyethylene resin, for example. Since the protective layer 11 is made of polyethylene resin, the obtained container is excellent in recyclability. The polyethylene resin is preferably medium-density polyethylene or high-density polyethylene, since the polyethylene resin has high physical strength and the resulting container has even more excellent gas barrier properties. The thickness of the protective layer 11 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.

Although the gas barrier laminate according to one embodiment has been described above in detail, the present invention is not limited to the above embodiment. For example, in the laminate 10, the lamination order of the film substrate 7a, the deposition layer 7b, and the overcoat layer 7c may be changed. At least one of the deposited layer 7b and the overcoat layer 7c may not be provided in the laminate 10 . In the laminate 10, the second adhesion layer 5b may not be provided.

[Manufacturing method and original fabric of gas barrier laminate]
A method of manufacturing the gas barrier laminate 10 and the original fabric according to the present embodiment will be described below. The manufacturing method according to this embodiment includes the following steps.
(a) includes a gas barrier layer, a first adhesion layer provided on the first surface of the gas barrier layer, and a second adhesion layer provided on the second surface of the gas barrier layer, and the first adhesion layer is provided on the surface; A step of preparing a first raw roll around which the exposed first laminate is wound.
(b) A step of preparing a second raw roll around which the paper substrate is wound.
(c) A step of forming a protective layer 11 on one surface of the paper substrate sent out from the second raw sheet to obtain a second laminate.
(d) Adhesiveness containing an olefin resin between the first adhesion layer of the first laminate sent out from the first roll and the paper substrate of the second laminate sent out from the second roll A step of obtaining a third laminate by laminating the first laminate and the second laminate while extruding the resin.
(e) A step of forming a sealant layer 9 on the surface of the second adhesion layer of the third laminate to obtain a fourth laminate, and winding the obtained fourth laminate around a third roll.

[(a) step]
FIG. 2 is a cross-sectional view schematically showing the first laminate wound around the first raw fabric according to the present embodiment. The first laminate 30 has a laminate structure including a first adhesion layer 5a, a film substrate 7a, a deposition layer 7b, an overcoat layer 7c, and a second adhesion layer 5b in this order.

From the viewpoint of oxygen gas barrier performance and film uniformity, the vapor deposition layer 7b is preferably formed on the surface of the film substrate 7a 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 rate can be easily controlled by adjusting the irradiation area and electron beam current, and the temperature of the vapor deposition material can be raised and lowered in a short period of time. be.

The overcoat layer 7c can be formed, for example, by wet-coating the deposition layer 7b using a gravure roll.

When the first adhesion layer 5a contains the first olefin copolymer particles and the polyester resin, the first adhesion layer 5a is, for example, an aqueous dispersion of the first olefin copolymer particles and an aqueous dispersion of the polyester resin. A coating film may be formed by coating the first surface f1 of the gas barrier layer 7 with an aqueous dispersion obtained by mixing the gas barrier layer 7 and drying the coating film. As such an aqueous dispersion, those described in JP-A-2004-9504 can be used. Commercially available products of such aqueous dispersions include, for example, SB-5230N, DA-5010 and DC-5010 (manufactured by Unitika Ltd.).

Examples of coating methods for the aqueous dispersion include direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, fonten method and transfer roll coating.

The coating amount of the aqueous dispersion is preferably 0.1 to 10 g/m ² (weight before drying: 0.4 to 40 g/m ^{2 ) after drying, and 1 to 3 g/m 2} (weight before drying: 0.4 to 40 g/m ² ). More preferably, the previous weight: 4-12 g/m ² ).

When the second adhesion layer 5b contains the second olefin copolymer particles and the polyester resin, the second adhesion layer 5b is, for example, an aqueous dispersion of the second olefin copolymer particles and an aqueous dispersion of the polyester resin. Alternatively, the second surface f2 of the gas barrier layer 7 may be coated with an aqueous dispersion obtained by mixing the gas barrier layer 7 to form a coating film, and the coating film may be dried. As such an aqueous dispersion, the same one as that for the first adhesion layer 5a can be used. The method and amount of application of the aqueous dispersion may be the same as those of the first adhesion layer 5a.

[(b) step]
A second raw roll around which the paper substrate 1 is wound is prepared.

[(c) step]
FIG. 3 is a schematic diagram showing a laminating apparatus 100 that can be used in the method for manufacturing a gas barrier laminate according to this embodiment. The laminator 100 is a 3-unit type laminator having three extruders. The steps (c) to (e) will be described below with reference to FIG. The material forming the protective layer 11 is melted and extruded from the extruder 103a onto one surface of the paper base material 1 sent out from the second raw material 101b. The extruded material and the paper substrate 1 are sandwiched between a press roll 105a and a cooling roll 107a. Thereby, a second laminate having the protective layer 11 formed on the surface of the paper substrate 1 is obtained.

The method of forming the protective layer 11 on the surface of the paper substrate 1 is not limited to extrusion lamination. Other methods include, for example, an extrusion lamination method, a T-die extrusion method, a co-extrusion lamination method, an inflation method, and a co-extrusion inflation method.

[(d) step]
An adhesive resin containing an olefin-based resin is extruded from the extruder 103b between the first adhesion layer 5a of the first laminate fed from the first raw fabric and the paper substrate 1 of the second laminate. The first laminate and the second laminate are sandwiched between the press roll 105b and the cooling roll 107b. Thereby, the first laminate and the paper base material of the second laminate are laminated to obtain the third laminate.

[(e) step]
On the surface of the second adhesion layer 5b of the third laminate, the material forming the sealant layer 9 is extruded from the extruder 103c in a molten state. The extruded material and the second adhesion layer 5b are sandwiched between the press roll 105c and the cooling roll 107c. As a result, a fourth laminate is obtained in which the sealant layer 9 is formed on the surface of the second adhesion layer 5b. The third raw fabric 101c is obtained by winding the fourth laminate.

The method of forming the sealant layer 9 on the surface of the second adhesion layer 5b 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.

The method for producing a gas barrier laminate according to the present embodiment can efficiently produce a gas barrier laminate having excellent gas barrier properties. Such an effect is presumed to be produced by the following mechanism. That is, the first and second adhesion layers contain the first and second olefinic copolymer particles. The first and second olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or an anhydride thereof, and the content of the structural unit is 0.5 based on the total amount of the olefinic copolymer particles. When it is 01 to 5% by mass, the adhesion between the first adhesion layer and the adhesive resin containing the olefin resin and the adhesion between the second adhesion layer and the sealant layer 9 are improved. Moreover, since the number average particle diameter of the first olefinic copolymer particles is 1 μm or less, the first adhesion layer is improved in adhesion to the adhesive resin, while suppressing tackiness. By suppressing the tack of the first adhesion layer, the first laminate in which the first adhesion layer is exposed on the surface can be wound as a raw roll, so that the first laminate and the paper base are laminated. It is not necessary to form the adhesion layer during the manufacturing process. Therefore, according to the method for manufacturing a gas barrier laminate according to one aspect of the present disclosure, it is possible to efficiently manufacture a gas barrier laminate having excellent gas barrier properties.

Although the method for manufacturing the gas barrier laminate and the original fabric according to one embodiment have been described above in detail, the present invention is not limited to the above embodiment. For example, the first laminate wound around the first raw fabric may have the sealant layer 9 on the surface of the second adhesion layer 5b opposite to the surface in contact with the overcoat layer 7c. In this case, the method for manufacturing the gas barrier laminate may not include the step (e). In this case, the laminator 100 may be a two-unit type laminator that does not include the extruder 103c, the press roll 105c, and the cooling roll 107c. Moreover, in the first laminated body wound on the first raw fabric 101a, the lamination order of the film substrate 7a, the vapor deposition layer 7b, and the overcoat layer 7c may be changed. At least one of the vapor deposition layer 7b and the overcoat layer 7c may not be provided in the first laminate. The second adhesion layer 5b may not be provided in the first laminate. Each layer constituting the laminate 10 may be subjected to pretreatment such as corona treatment and plasma treatment before lamination.

[container]
<First Embodiment>
A container (paper container) according to the first embodiment will be described below. A container 50 shown in FIG. 4 is produced using the laminate 10 .

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 store dairy products such as sake and milk, juices such as 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 suitably used as a packaging container for filling and packaging.

The container 50 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 11 of the laminate 10 as the outermost layer and the sealant layer 9 as the innermost layer. The container body 52 has portions (bent portions B1 and B2) where the laminate 10 is bent. The bent portion B1 is a portion where the laminated body 10 is valley-folded when viewed from the innermost layer side, while the bent portion B2 is a portion where the laminated body 10 is mountain-folded when viewed from the innermost layer side.

The container 50 is composed of the laminate 10 that can maintain sufficient gas barrier properties even after tension is applied. Therefore, deterioration of the contents can be sufficiently suppressed for a long period of time.

<Second embodiment>
A container (paper container) according to the second embodiment will be described. Points not described below are the same as those of the container according to the first embodiment unless inconsistency occurs. A container 60 shown in FIG. 5 is produced using the laminate 10 .

The container 60 includes a cylindrical container main body 62 having an upper portion 62 a provided with an opening 61 , a side surface 62 b and a bottom portion 62 c , and a seal portion 65 closing the opening 61 . The container main body 62 has the protective layer 11 of the laminate 10 as the outermost layer and the sealant layer 9 as the innermost layer. The side surface 62b is composed of the laminate 10 that is bent while being heated.

The laminated body 10 is composed of a laminated body 10 that can be bent at a low temperature and that can maintain sufficient gas barrier properties even after tension is applied by bending. Therefore, deterioration of the contents can be sufficiently suppressed for a long period of time.

Although the container according to one embodiment has been described above in detail, the present invention is not limited to the above embodiment. For example, the container 50 is provided with the opening 51 in the upper portion 52a, but the opening 51 may not be provided. Moreover, the shape of the container is not limited to the shape of the containers 50 and 60, and may be, for example, a brick type or a triangular pyramid shape.

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.

Materials for forming the adhesion layer, the sealant layer, and the adhesive resin layer were prepared as follows.
Aqueous dispersion A containing olefin copolymer particles: DA-5010 (trade name, manufactured by Unitika Ltd.)
Aqueous dispersion B containing olefin copolymer particles: SB-5230N (trade name, manufactured by Unitika Ltd.)
・Polyethylene-based resin A (manufactured by Prime Polymer Co., Ltd., trade name “Neozex”)
・Ethylene-methacrylic acid copolymer resin A (manufactured by Mitsui Dow Polychemicals Co., Ltd., trade name “EMAA N0908C”)

[Production of laminate]
(Example 1)
A laminate according to this example was obtained through the following steps. That is, a gas barrier film was prepared by forming a vapor deposition layer containing silica as a main component (silica vapor deposition layer, thickness: 50 nm) on one surface of a film substrate (material: polypropylene resin, thickness: 18 μm). Aqueous dispersion A containing olefin copolymer particles was applied to the surface of the gas barrier film on which the vapor deposition layer was formed so that the weight after drying was 0.5 g/m ² to form a coating film. A second adhesion layer was formed by drying the coating film. A sealant layer (thickness: 30 μm) is formed by extruding and laminating low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., trade name “LC600A”) on the surface opposite to the surface in contact with the vapor deposition layer of the second adhesion layer. formed. Aqueous dispersion A containing olefinic copolymer particles was coated on the surface of the film substrate opposite to the surface on which the deposited layer was formed so that the weight after drying was 0.5 g/m ² . to form a coating film. By drying the coating film, a first adhesion layer was formed to obtain a first laminate.

On the other hand, a protective layer (thickness: 20 μm) made of polyethylene-based resin A was formed on one surface of a paper substrate (basis weight: 260 g/m ² ) to obtain a second laminate containing the paper substrate. . A gas barrier laminate (packaging material) was obtained by laminating the first and second laminates with a polyethylene resin A (adhesive resin layer) by extrusion lamination so that the first adhesion layer and the paper substrate faced each other. The thickness of the adhesive resin layer was 15 μm.

(Example 2)
A gas barrier laminate was obtained in the same manner as in Example 1, except that the aqueous dispersion B containing olefin copolymer particles was used in place of the aqueous dispersion A containing olefin copolymer particles.

(Example 3)
A gas barrier film was prepared in the same manner as in Example 1. Plasma treatment was performed on the surface on which the vapor deposition layer of the gas barrier film was formed. A sealant layer (thickness: 30 μm) was formed by extrusion laminating low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., trade name “LC600A”) on the plasma-treated surface. A first adhesion layer was formed in the same manner as in Example 1 on the surface of the film substrate opposite to the surface on which the vapor deposition layer was formed, to obtain a first laminate. A second laminate was obtained in the same manner as in Example 1. In the same manner as in Example 1, the first and second laminates were laminated to obtain a gas barrier laminate.

(Comparative example 1)
A gas barrier film was prepared in the same manner as in Example 1. Plasma treatment was performed on the surface on which the vapor deposition layer of the gas barrier film was formed. A sealant layer (thickness: 30 μm) was formed by extrusion laminating low-density polyethylene (manufactured by Japan Polyethylene Co., Ltd., trade name “LC600A”) on the plasma-treated surface. The surface of the film substrate opposite to the surface on which the vapor deposition layer was formed was subjected to corona treatment to obtain a first laminate. A second laminate was obtained in the same manner as in Example 1. A gas barrier laminate was obtained by laminating the first and second laminates with a polyethylene-based resin A (adhesive resin layer) by extrusion lamination so that the film substrate and the paper substrate faced each other. The thickness of the adhesive resin layer was 15 μm.

(Comparative example 2)
A gas barrier film was prepared in the same manner as in Example 1. A sealant layer (thickness: 30 μm) was formed by extrusion laminating the ethylene-methacrylic acid copolymer resin A on the surface of the gas barrier film on which the vapor deposition layer was formed, to obtain a first laminate. A second laminate was obtained in the same manner as in Example 1. A gas barrier laminate was obtained by laminating the first and second laminates with the ethylene-methacrylic acid copolymer resin A (adhesive resin layer) by extrusion lamination so that the film substrate and the paper substrate faced each other. The thickness of the adhesive resin layer was 15 μm.

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

[Measurement of oxygen permeability]
(Examples 1 to 3 and Comparative Examples 1 and 2)
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 container immediately after box making. Table 1 shows the results. The measured value was expressed as [(cc/pkg·day)].

[Measurement of lamination strength]
The lamination strength between the gas barrier film and the adhesive resin layer was measured for the gas barrier laminate obtained in each example and comparative example. The measurement was performed according to JIS Z-1707. Specifically, the laminate was cut into strips having a width of 15 mm. The adhesive resin layer of the laminate cut into strips was measured using a Tensilon tensile tester (product name "Tensilon RTC-1250", manufactured by Orientec) so that the adhesive resin layer and the gas barrier film were on the opposite side. It was peeled off from the CPP film at a peeling speed of 300 mm/min in the direction (that is, so that the peeling angle was T-shaped), and the strength required for peeling (unit: N/15 mm) was measured as the lamination strength. Table 1 shows the results.

[Presence or absence of floating or peeling]
For the gas barrier laminates obtained in each of the examples and comparative examples, the presence or absence of separation or peeling between layers was visually confirmed. Table 1 shows the results.

DESCRIPTION OF SYMBOLS 1... Paper base material, 3... Adhesive resin layer, 5... Adhesion layer, 7... Gas barrier layer, 9... Sealant layer, 10... Gas barrier laminate, 11... Protective layer, 50 and 60... Container, 100... Lamination apparatus, 101... Raw fabric.

Claims (14)

a first raw roll including a gas barrier layer and a first adhesion layer provided on a first surface of the gas barrier layer and having the first adhesion layer exposed on the surface wound thereon; the process of preparing,
A step of preparing a second raw roll around which the paper substrate is wound;
An adhesive resin containing an olefin-based resin is extruded between the first adhesion layer of the first laminate sent out from the first raw roll and the paper substrate sent out from the second raw roll. while laminating the first laminate and the paper base material;
with
The first adhesion layer contains first olefinic copolymer particles having a number average particle size of 1 μm or less,
The first olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or an anhydride thereof, and the content of the structural unit is 0.5 based on the total amount of the first olefinic copolymer particles. 01 to 5% by mass, a method for producing a gas barrier laminate. The first laminate further includes a second adhesion layer provided on the second surface of the gas barrier layer,
The second adhesion layer contains second olefinic copolymer particles having a number average particle size of 1 μm or less,
The second olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or an anhydride thereof, and the content of the structural unit is 0.5 based on the total amount of the second olefinic copolymer particles. 2. The method for producing a gas barrier laminate according to claim 1, wherein the content is 01 to 5% by mass. 3. The method for producing a gas barrier laminate according to claim 2, wherein both the first and second olefinic copolymer particles have a melting point of 120[deg.] C. or higher. 4. The gas barrier layer according to any one of claims 1 to 3, wherein the gas barrier layer has a film substrate containing at least a polypropylene film, and a deposited layer containing an inorganic oxide provided on the surface of the film substrate. A method for producing a gas barrier laminate. a paper substrate;
an adhesive resin layer containing an olefin resin;
a first adhesion layer containing first olefinic copolymer particles having a number average particle diameter of 1 μm or less;
a gas barrier layer;
a sealant layer;
in this order,
The first olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or an anhydride thereof, and the content of the structural unit is 0.5 based on the total amount of the first olefinic copolymer particles. 01 to 5% by mass of the gas barrier laminate. further comprising a second adhesion layer between the gas barrier layer and the sealant layer;
The second adhesion layer contains second olefinic copolymer particles having a number average particle size of 1 μm or less,
The second olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or an anhydride thereof, and the content of the structural unit is 0.5 based on the total amount of the second olefinic copolymer particles. 6. The gas barrier laminate according to claim 5, wherein the content is 01 to 5% by mass. 7. The gas barrier laminate according to claim 6, wherein both the first and second olefinic copolymer particles have a melting point of 120[deg.] C. or higher. 8. The gas barrier layer according to any one of claims 5 to 7, wherein the gas barrier layer has a film substrate containing at least a polypropylene film, and a deposited layer containing an inorganic oxide provided only on one surface of the film substrate. The gas barrier laminate according to 1. The gas barrier laminate according to claim 8, wherein the vapor deposition layer has a thickness of 30 nm or more and 300 nm or less. A container composed of the gas barrier laminate according to any one of claims 5 to 9. A raw fabric on which a laminate including a gas barrier layer and a first adhesion layer provided on a first surface of the gas barrier layer and having the first adhesion layer exposed on the surface is wound,
The first adhesion layer contains first olefinic copolymer particles having a number average particle size of 1 μm or less,
The first olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or an anhydride thereof, and the content of the structural unit is 0.5 based on the total amount of the first olefinic copolymer particles. 01 to 5% by mass, raw fabric. The laminate further includes a second adhesion layer provided on the second surface of the gas barrier layer,
The second adhesion layer contains second olefinic copolymer particles having a number average particle size of 1 μm or less,
The second olefinic copolymer particles contain a structural unit derived from an unsaturated carboxylic acid or an anhydride thereof, and the content of the structural unit is 0.5 based on the total amount of the second olefinic copolymer particles. The raw fabric according to claim 11, which is 01 to 5% by mass. The raw fabric according to claim 12, wherein both the first and second olefinic copolymer particles have a melting point of 120°C or higher. 14. The gas barrier layer according to any one of claims 11 to 13, wherein the gas barrier layer has a film substrate containing at least a polypropylene film, and a deposited layer containing an inorganic oxide provided on the surface of the film substrate. Original fabric.

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