Barrier laminate, packaging container provided with barrier laminate
The barrier laminate with a stretched polypropylene film and a high-melting-point surface resin layer addresses delamination issues, enhancing gas barrier properties and recyclability in packaging containers.
Patent Information
- Application Number
- JP2025052450
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2019-09-30
- Filing Date
- 2025-03-26
- Publication Date
- 2025-06-24
- Estimated Expiration
- 2040-09-29
AI Technical Summary
Conventional polyester films used in packaging containers do not achieve satisfactory gas barrier properties when a vapor deposition film is applied to stretched polypropylene films, and there is a delamination issue that compromises the gas barrier performance.
A barrier laminate is developed with a stretched polypropylene film as the base, featuring a surface resin layer with a melting point of 180°C or higher, an adhesive resin layer, and a polypropylene resin layer, along with a vapor deposition film composed of inorganic oxide, which includes a stretching treatment to enhance adhesion and gas barrier properties.
The laminate achieves improved adhesion and gas barrier properties, allowing for high lamination strength and recyclability, while maintaining the mechanical properties of the packaging container.
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Figure 2025094241000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a barrier laminate and a packaging container including the barrier laminate.
Background Art
[0002] Conventionally, a film made of polyester such as polyethylene terephthalate (hereinafter also referred to as a polyester film) is excellent in mechanical properties, chemical stability, heat resistance, and transparency, and is inexpensive, so it is used as a base material or an intermediate layer constituting a laminate used for manufacturing a packaging container.
[0003] Depending on the contents filled in the packaging container, the packaging container is required to have gas barrier properties such as high oxygen barrier properties and water vapor barrier properties. In order to meet this requirement, it is widely practiced to form a vapor deposition film containing alumina, silica, etc. on the surface of the polyester film (Patent Document 1).
[0004] By the way, in recent years, a search for a resin material to replace the polyester film has been conducted, and it has been studied to apply a material in which a vapor deposition film is formed on the surface of a polyolefin film, particularly a polypropylene film, as an intermediate layer.
Prior Art Documents
Patent Documents
[0005]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0006] The inventors of the present invention were considering using a stretched polypropylene film (hereinafter also referred to as a stretched polypropylene film) instead of a conventional polyester film. However, they found a new problem that even if a vapor deposition film is formed on the surface of the stretched polypropylene film, satisfactory gas barrier properties cannot be obtained.
[0007] As the inventors further investigated, they found that in a packaging container using a barrier laminate provided with a vapor deposition film on the stretched polypropylene film, there is a peculiar phenomenon not seen in a conventional barrier laminate using a polyester film, that is, delamination occurs between the stretched polypropylene film and the vapor deposition film. They obtained the knowledge that this phenomenon makes the gas barrier properties insufficient.
[0008] Then, the inventors found that by providing a surface resin layer containing a resin material having a melting point of 180°C or higher on the surface of the stretched polypropylene film, the adhesion of the vapor deposition film formed on the surface resin layer is improved, and the gas barrier properties are also improved.
[0009] In addition, the inventors also found that by providing a coat layer containing a resin material having a polar group on the surface of the stretched polypropylene film, the adhesion of the vapor deposition film formed on the coat layer is improved, and the gas barrier properties are also improved.
[0010] The present invention has been made based on such findings, and the problem to be solved is to provide a barrier laminate having an intermediate layer excellent in adhesion to a vapor deposition film and extremely high gas barrier properties.
[0011] Another problem to be solved by the present invention is to provide a packaging container including the barrier laminate.
Means for Solving the Problems
[0012] The barrier laminate of the present invention includes a base material, an adhesive layer, a vapor deposition film, an intermediate layer, and a sealant layer. The intermediate layer includes at least a surface resin layer, an adhesive resin layer, and a polypropylene resin layer in this order. The surface resin layer contains a resin material having a melting point of 180 °C or higher. The resin material is one or more resin materials selected from polyvinyl alcohol, nylon 6, nylon 6,6, and MXD nylon. The adhesive resin layer contains one or more selected from polyethers, polyesters, silicone resins, epoxy resins, vinyl resins, phenolic resins, polyolefins, and acid-modified polyolefins. The barrier laminate includes the vapor deposition film on the surface resin layer. The barrier laminate further includes a barrier coat layer between the adhesive layer and the vapor deposition film. The vapor deposition film is composed of an inorganic oxide. The surface resin layer, the adhesive resin layer, and the polypropylene resin layer are characterized by being subjected to a stretching treatment.
[0013] In one embodiment, the polypropylene resin layer, the base material, and the sealant layer are made of the same material, and the same material is polypropylene.
[0014] In one embodiment, the adhesive layer is an adhesive layer containing a cured product of a composition containing a polyester polyol and an isocyanate compound.
[0015] In one embodiment, the melting point of the resin material is 265 °C or lower.
[0016] In one embodiment, the difference between the melting point of the resin material and the melting point of the polypropylene contained in the polypropylene resin layer is 20 to 80 °C.
[0017] In one embodiment, the resin material is polyamide.
[0018] In one embodiment, the ratio of the thickness of the surface resin layer to the total thickness of the intermediate layer is 1% or more and 10% or less.
[0019] In one embodiment, the intermediate layer is a coextruded film.
[0020] In one embodiment, the barrier laminate of the present invention is used for packaging container applications.
[0021] The packaging container of the present invention is characterized by comprising the above-described barrier laminate.
Advantages of the Invention
[0022] According to the present invention, it is possible to provide a barrier laminate having an intermediate layer excellent in adhesion between layers with a vapor deposition film and having a high lamination strength, and capable of producing a packaging container having an extremely high gas barrier property. Further, according to the present invention, it is possible to provide a packaging container comprising the barrier laminate.
Brief Description of the Drawings
[0023]
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Mode for Carrying Out the Invention
[0024] (Barrier laminate in the first aspect) As shown in FIG. 1, the barrier laminate 10 of the present invention includes a base material 11, an adhesive layer 12, a vapor deposition film 13, an intermediate layer 14, and a sealant layer 15, and the intermediate layer 14 includes at least a surface resin layer 16 and a polypropylene resin layer 17. In one embodiment, as shown in FIG. 2, the barrier laminate 10 of the present invention further includes a barrier coat layer 18 between the adhesive layer 12 and the vapor deposition film 13. In one embodiment, as shown in FIG. 3, the intermediate layer 14 includes an adhesive resin layer 19 between the surface resin layer 16 and the polypropylene resin layer 17. In one embodiment, as shown in FIG. 4, the barrier laminate 10 includes a base material 11, an adhesive layer 12, a barrier coat layer 18, a vapor deposition film 13, an intermediate layer 14, and a sealant layer 15 in this order. The intermediate layer 14 includes at least a surface resin layer 16 and a polypropylene resin layer 17, and the adhesive resin layer 19 is provided between the surface resin layer 16 and the polypropylene resin layer 17.
[0025] In the barrier laminate in the first aspect, the laminate strength between the intermediate layer and the vapor deposition film is preferably 3 N or more, more preferably 4 N or more, and still more preferably 5.5 N or more in a width of 15 mm. The upper limit of the laminate strength of the barrier laminate in the first aspect may be 20 N or less. The method for measuring the lamination strength of the barrier laminate will be described in the examples described later.
[0026] Conventionally, a laminate composed of a substrate, an intermediate layer, and a sealant layer made of different resin materials has been used for manufacturing packaging containers. However, after collecting used packaging containers, it is difficult to separate each layer composed of different resin materials, so there is a current situation where it is not actively recycled. By configuring the substrate, the polypropylene resin layer provided in the intermediate layer, and the sealant layer with the same material, there is no need to separate each layer, and the recyclability can be improved. By configuring the substrate and the sealant with the same material as the polypropylene resin layer provided in the intermediate layer, that is, polypropylene, there is no need to separate the recovered packaging container layer by layer, and the recyclability can be improved.
[0027] When the substrate and the sealant layer are made of polypropylene, the content of polypropylene in the total amount of resin materials contained in the barrier laminate of the present invention is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more. Thereby, the recyclability of the packaging container manufactured using the barrier laminate of the present invention can be further improved.
[0028] Hereinafter, each layer included in the barrier laminate of the present invention will be described.
[0029] (Substrate) The substrate contains a resin material, and examples thereof include polyolefin, vinyl resin, (meth)acrylic resin, cellulose resin, polyamide, polyimide, polyester, ionomer resin, and the like. From the viewpoint of the recyclability of the barrier laminate of the present invention, the substrate is preferably composed of the same material as the polypropylene resin layer provided in the intermediate layer, that is, polypropylene. Moreover, by configuring the base material with polypropylene, the oil resistance of the packaging container produced using the barrier laminate can be improved.
[0030] Within the range that does not impair the characteristics of the present invention, the base material can contain additives, such as crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.
[0031] The base material may have a single-layer structure or a multilayer structure. Also, the base material may or may not be subjected to a stretching treatment. However, from the viewpoints of the heat resistance and strength of the barrier laminate, it is preferably subjected to a stretching treatment.
[0032] The thickness of the base material is preferably 10 μm or more and 50 μm or less, and more preferably 20 μm or more and 40 μm or less. By setting the thickness of the base material to 10 μm or more, the strength and heat resistance of the barrier laminate of the present invention can be improved. Also, by setting the thickness of the base material to 50 μm or less, the film-forming property and processability of the barrier laminate of the present invention can be further improved.
[0033] The base material may have a printing layer on its surface, and the image formed on the printing layer is not particularly limited and can represent characters, patterns, symbols, and combinations thereof. The formation of the printing layer on the base material can be performed using biomass-derived ink. Thereby, the environmental load can be reduced. The method for forming the printing layer is not particularly limited, and examples include conventionally known printing methods such as the gravure printing method, offset printing method, and flexographic printing method.
[0034] (Adhesive layer) The barrier laminate of the present invention includes an adhesive layer between the base material and the vapor deposition film.
[0035] The subsequent layer contains at least one type of adhesive, which may be a one-component curable type, a two-component curable type, or a non-curable type adhesive. Also, the adhesive may be a solventless type adhesive or a solvent-based adhesive, but from the perspective of environmental load, a solventless type adhesive can be preferably used. Examples of the solventless type adhesive include polyether-based adhesives, polyester-based adhesives, silicone-based adhesives, epoxy-based adhesives, and urethane-based adhesives. Among these, a two-component curable type urethane-based adhesive can be preferably used. Examples of the solvent-based adhesive include rubber-based adhesives, vinyl-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and olefin-based adhesives.
[0036] Also, the adhesive layer is preferably an adhesive layer containing a cured product of a composition containing a polyester polyol and an isocyanate compound. By configuring the adhesive layer in this way, the oxygen barrier property and water vapor barrier property of the barrier laminate of the present invention can be further improved. Also, usually, when applying a laminate having a vapor deposition film to a packaging container, a bending load is applied to the laminate by a molding machine or the like, so there is a risk of cracks or the like occurring in the vapor deposition film. By using a gas barrier organic adhesive, the bending load resistance of the barrier laminate of the present invention can be improved, and a decrease in the oxygen barrier property and water vapor barrier property can be suppressed.
[0037] The glass transition temperature of the cured product of the composition containing a polyester polyol and an isocyanate compound is preferably -30°C or higher and 80°C or lower, more preferably 0°C or higher and 70°C or lower, and even more preferably 25°C or higher and 70°C or lower. Thereby, the oxygen barrier property, water vapor barrier property, and laminate strength of the barrier laminate can be further improved. In this specification, Tg is a value obtained by differential scanning calorimetry (DSC) in accordance with JIS K 7121:2012.
[0038] The polyester polyol has two or more hydroxyl groups in one molecule as a functional group. Further, the isocyanate compound has two or more isocyanate groups in one molecule as a functional group. The polyester polyol has, as a main skeleton, for example, a polyester structure or a polyester polyurethane structure.
[0039] As a specific example of the composition (adhesive) containing the polyester polyol and the isocyanate compound, the series of PASLIM sold by DIC Corporation can be used.
[0040] The composition containing the polyester polyol and the isocyanate compound may further contain a phosphate ester, a plate-like inorganic compound, a coupling agent, cyclodextrin and / or its derivative, etc.
[0041] As the polyester polyol having two or more hydroxyl groups in one molecule as a functional group, for example, the following [First Example] to [Third Example] can be used. [First Example] A polyester polyol obtained by polycondensing an ortho-oriented polyvalent carboxylic acid or its anhydride and a polyhydric alcohol. [Second Example] A polyester polyol having a glycerol skeleton. [Third Example] A polyester polyol having an isocyanuric ring. Hereinafter, each polyester polyol will be described.
[0042] The polyester polyol according to the first example is a polycondensate obtained by polycondensing a polyvalent carboxylic acid component containing at least one or more of phthalic acid and its anhydride and a polyhydric alcohol component. In particular, a polyester polyol in which the content of phthalic acid and its anhydride in the total polyvalent carboxylic acid components is 70 to 100% by mass is preferable.
[0043] The polyester polyol according to the first example requires phthalic acid and its anhydride as the polycarboxylic acid component, but other polycarboxylic acid components may be copolymerized within a range that does not impair the effects of the present embodiment. Examples of other polycarboxylic acid components include aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid, unsaturated bond-containing polycarboxylic acids such as maleic anhydride, maleic acid, and fumaric acid, alicyclic polycarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, anhydrides of these dicarboxylic acids, and ester-forming derivatives of these dicarboxylic acids, and polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid, and isophthalic acid are preferred. Note that two or more of the above other polycarboxylic acids may be used.
[0044] Examples of the polyhydric alcohol component include aliphatic polyhydric alcohols and aromatic polyhydric alcohols. Examples of the aliphatic polyhydric alcohol include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, cyclohexanedimethanol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. Examples of the aromatic polyhydric alcohol include hydroquinone, resorcinol, catechol, naphthalenediol, biphenol, bisphenol A, bisphenol F, tetramethylbiphenol, ethylene oxide adducts thereof, and hydrogenated aliphatic compounds thereof. In one embodiment, the polyhydric alcohol component includes at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol.
[0045] Examples of the polyester polyol according to the second example include a polyester polyol having a glycerol skeleton represented by the general formula (1).
Chemical formula
Chemical formula
[0046] In the formula (2), n represents an integer of 1 to 5, X represents an arylene group selected from the group consisting of a 1,2-phenylene group which may have a substituent, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, and Y represents an alkylene group having 2 to 6 carbon atoms). However, at least one of R1, R2, and R3 represents a group represented by the general formula (2).
[0047] In the general formula (1), at least one of R1, R2, and R3 needs to be a group represented by the general formula (2). Among them, it is preferable that all of R1, R2, and R3 are groups represented by the general formula (2).
[0048] Further, a mixture may be formed by any two or more compounds among a compound in which any one of R1, R2, and R3 is a group represented by the general formula (2), a compound in which any two of R1, R2, and R3 are groups represented by the general formula (2), and a compound in which all of R1, R2, and R3 are groups represented by the general formula (2).
[0049] X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, and may have a substituent. When X is substituted by a substituent, it may be substituted by one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.
[0050] In the general formula (2), Y represents an alkylene group having 2 to 6 carbon atoms such as an ethylene group, a propylene group, a butylene group, a neopentylene group, a 1,5-pentylene group, a 3-methyl-1,5-pentylene group, a 1,6-hexylene group, a methylpentylene group, and a dimethylbutylene group. Among them, a propylene group and an ethylene group are preferred, and an ethylene group is most preferred.
[0051] The polyester resin compound having a glycerol skeleton represented by the general formula (1) can be synthesized by reacting glycerol, an aromatic polyvalent carboxylic acid having a carboxylic acid substituted at the ortho position or its anhydride, and a polyhydric alcohol component as essential components.
[0052] Examples of the aromatic polycarboxylic acid or its anhydride in which a carboxylic acid is substituted at the ortho position include phthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracene dicarboxylic acid or its anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.
[0053] Examples of the polyhydric alcohol component include alkylene diols having 2 to 6 carbon atoms. For example, diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol can be exemplified.
[0054] The polyester polyol according to the third example is a polyester polyol having an isocyanurate ring represented by the following general formula (3). [Chemical formula] In general formula (3), R1, R2, and R3 each independently represent "-(CH2)n1-OH (where n1 represents an integer of 2 to 4)" or the structure of general formula (4). [Chemical formula]
[0055] In the general formula (4), n2 represents an integer of 2 to 4, n3 represents an integer of 1 to 5, X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, and may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms). However, at least one of R1, R2, and R3 is a group represented by the general formula (4).
[0056] In the general formula (3), the alkylene group represented by -(CH2)n1- may be linear or branched. n1 is preferably 2 or 3, and most preferably 2.
[0057] In the general formula (4), n2 represents an integer of 2 to 4, and n3 represents an integer of 1 to 5. X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, and may have a substituent.
[0058] When X is substituted by a substituent, it may be substituted by one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group. The substituent of X is preferably a hydroxyl group, a cyano group, a nitro group, an amino group, a phthalimide group, a carbamoyl group, an N-ethylcarbamoyl group, and a phenyl group, and most preferably a hydroxyl group, a phenoxy group, a cyano group, a nitro group, a phthalimide group, and a phenyl group.
[0059] In general formula (4), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, a propylene group, a butylene group, a neopentylene group, a 1,5-pentylene group, a 3-methyl-1,5-pentylene group, a 1,6-hexylene group, a methylpentylene group, and a dimethylbutylene group. Among them, the propylene group and the ethylene group are preferable, and the ethylene group is most preferable.
[0060] In general formula (3), at least one of R1, R2, and R3 is a group represented by general formula (4). Among them, it is preferable that all of R1, R2, and R3 are groups represented by general formula (4).
[0061] Further, a compound in which any one of R1, R2, and R3 is a group represented by general formula (4), a compound in which any two of R1, R2, and R3 are groups represented by general formula (4), and a compound in which all of R1, R2, and R3 are groups represented by general formula (4) may be a mixture of any two or more compounds.
[0062] The polyester polyol having an isocyanurate ring represented by general formula (3) can be synthesized by reacting a triol having an isocyanurate ring, an aromatic polyvalent carboxylic acid in which a carboxylic acid is substituted at the ortho position or its anhydride, and a polyhydric alcohol component as essential components.
[0063] Examples of the triol having an isocyanurate ring include alkylene oxide adducts of isocyanuric acid such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid.
[0064] In addition, examples of the aromatic polyvalent carboxylic acid or its anhydride in which a carboxylic acid is substituted at the ortho position include phthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracene dicarboxylic acid or its anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring.
[0065] Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.
[0066] In addition, examples of the polyhydric alcohol component include alkylene diols having 2 to 6 carbon atoms. For example, diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol can be mentioned. Among them, a polyester polyol compound having an isocyanurate ring, which uses 1,3,5-tris(2-hydroxyethyl)isocyanuric acid or 1,3,5-tris(2-hydroxypropyl)isocyanuric acid as the triol compound having an isocyanurate ring, phthalic anhydride as the aromatic polyvalent carboxylic acid or its anhydride in which a carboxylic acid is substituted at the ortho position, and ethylene glycol as the polyhydric alcohol, is particularly preferable in terms of oxygen barrier properties and adhesiveness.
[0067] The isocyanurate ring is highly polar and trifunctional, can increase the polarity of the whole system, and can increase the crosslinking density. From such a viewpoint, it is preferable to contain the isocyanurate ring in an amount of 5% by mass or more based on the total solid content of the adhesive resin.
[0068] The isocyanate compound has two or more isocyanate groups in the molecule. Also, the isocyanate compound may be aromatic, aliphatic, a low-molecular compound, or a high-molecular compound. Furthermore, the isocyanate compound may be a blocked isocyanate compound obtained by addition reaction of a known isocyanate blocking agent by a known and commonly used appropriate method. Among them, from the viewpoints of adhesiveness and retort resistance, a polyisocyanate compound having three or more isocyanate groups is preferable, and from the viewpoints of oxygen barrier property and water vapor barrier property, it is preferably aromatic.
[0069] Specific examples of the isocyanate compound include, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, metaxylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds, and adducts, burettes, and allophanates obtained by reacting these isocyanate compounds with a low-molecular active hydrogen compound or its alkylene oxide adduct, or a high-molecular active hydrogen compound. Examples of the low-molecular active hydrogen compound include ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bis(hydroxyethyl)benzene, 1,4-bis(hydroxyethyl)benzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and metaxylylene diamine. Examples of the molecular active hydrogen compound include various polyester resins, polyether polyols, and high-molecular active hydrogen compounds of polyamides.
[0070] The cured product of the composition containing a polyester polyol and an isocyanate compound can contain a phosphate-modified compound, for example, a compound represented by the following general formula (5) or (6).
Chemical formula
Chemical formula
[0071] More specifically, phosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate, etc. can be mentioned, and one or more of these can be used.
[0072] The content of the phosphate-modified compound in the adhesive layer containing a polyester polyol and an isocyanate compound is preferably 0.005% by mass or more and 10% by mass or less, and more preferably 0.01% by mass or more and 1% by mass or less. By setting the content of the phosphate-modified compound to 0.005% by mass or more, the oxygen barrier property and the water vapor barrier property can be improved. Further, by setting the content of the phosphate-modified compound to 10% by mass or less, the adhesiveness of the adhesive layer can be improved.
[0073] The adhesive layer containing a polyester polyol and an isocyanate compound may contain a plate-like inorganic compound, whereby the oxygen barrier property, the water vapor barrier property, and the adhesiveness of the adhesive layer can be improved. Further, the flexural load resistance of the barrier laminate of the present invention can be improved. Examples of the plate-like inorganic compound include kaolinite-serpentine group clay minerals (halloysite, kaolinite, endellite, dickite, nacrite, antigorite, chrysotile, etc.) and pyrophyllite-talc group (pyrophyllite, talc, kerolite, etc.).
[0074] Examples of the coupling agent include silane-based coupling agents, titanium-based coupling agents, and aluminum-based coupling agents represented by the following general formula (7). These coupling agents may be used alone or in combination of two or more.
Chemical formula
[0075] Examples of silane coupling agents include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxytrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-triethoxysilyl-N-(1,3-dimethyl-butylidene).
[0076] In addition, examples of the titanium-based coupling agent include isopropyltriisostearoyl titanate, isopropyltri(N-aminoethyl-aminoethyl) titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropyltris(dioctyl pyrophosphate) titanate, tetraoctylbis(didodecyl phosphite) titanate, tetraoctylbis(ditridecyl phosphite) titanate, bis(dioctyl pyrophosphate) oxyacetate titanate, bis(dioctyl pyrophosphate) ethylene titanate, isopropyltrioctainol titanate, isopropyldimethacrylisostearoyl titanate, isopropylisostearoyldiacryl titanate, diisostearoylethylene titanate, isopropyltri(dioctyl phosphate) titanate, isopropyltricumylphenyl titanate, and dicumylphenyloxyacetate titanate, etc.
[0077] In addition, specific examples of the aluminum-based coupling agent include, for example, acetoalkoxyaluminum diisopropylate, diisopropoxyaluminum ethylacetoacetate, diisopropoxyaluminum monomethacrylate, isopropoxyaluminum alkylacetoacetate mono(dioctyl phosphate), aluminum-2-ethylhexanoate oxide trimer, aluminum stearate oxide trimer, and alkylacetoacetate aluminum oxide trimer, etc.
[0078] The adhesive layer composed of the composition containing the polyester polyol and the isocyanate compound can contain cyclodextrin and / or its derivative, whereby the adhesiveness of the adhesive layer can be improved. Also, the flexural load resistance can be further improved. Specifically, for example, those obtained by substituting the hydrogen atom of the hydroxyl group of the glucose unit of cyclodextrin such as cyclodextrin, alkylated cyclodextrin, acetylated cyclodextrin, and hydroxyalkylated cyclodextrin with other functional groups can be used. Also, branched cyclic dextrin can be used. Further, the cyclodextrin skeleton in cyclodextrin and cyclodextrin derivatives may be any of α-cyclodextrin composed of 6 glucose units, β-cyclodextrin composed of 7 glucose units, and γ-cyclodextrin composed of 8 glucose units. These compounds may be used alone or in combination of two or more. Also, hereinafter, these cyclodextrins and / or their derivatives may be collectively referred to as dextrin compounds.
[0079] From the viewpoints of compatibility and dispersibility in the adhesive layer containing polyester polyol and isocyanate compound, it is preferable to use cyclodextrin derivatives as the cyclodextrin compound. From the viewpoint of the polarity of the above various resins, the degree of substitution is preferably in the range of 0.1 or more and 14 or less per glucose, and more preferably in the range of 0.3 or more and 8 or less per glucose.
[0080] Examples of alkylated cyclodextrin include methyl-α-cyclodextrin, methyl-β-cyclodextrin, and methyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.
[0081] Examples of acetylated cyclodextrin include monoacetyl-α-cyclodextrin, monoacetyl-β-cyclodextrin, and monoacetyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.
[0082] Examples of the hydroxyalkylated cyclodextrin include hydroxypropyl-α-cyclodextrin, hydroxypropyl-β-cyclodextrin, and hydroxypropyl-γ-cyclodextrin. These compounds may be used alone or in combination of two or more.
[0083] The thickness of the adhesive layer is preferably 0.5 μm or more and 6 μm or less, more preferably 0.8 μm or more and 5 μm or less, and even more preferably 1 μm or more and 4.5 μm or less. By setting the thickness of the adhesive layer to 0.5 μm or more, the adhesiveness of the adhesive layer can be improved. Further, when the adhesive layer is an adhesive layer containing a cured product of a composition containing a polyester polyol and an isocyanate compound, the flexural load resistance can be improved. By setting the thickness of the adhesive layer to 6 μm or less, the processability of the barrier laminate can be improved. Further, the recyclability of a packaging container produced using a laminate including a substrate and a sealant layer made of polypropylene can be improved.
[0084] The adhesive layer can be formed, for example, by coating and drying on a vapor deposition film or the like by a conventionally known method such as a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a fountain method, and a transfer roll coating method.
[0085] (Vapor deposition film) The barrier laminate of the present invention includes a vapor deposition film composed of an inorganic oxide on a surface resin layer. Thereby, the gas barrier property of the barrier laminate, specifically, the oxygen barrier property and the water vapor barrier property can be improved. Further, the mass reduction of the content filled in the packaging container produced using the barrier laminate of the present invention can be suppressed.
[0086] Examples of the inorganic oxide include aluminum oxide (alumina), silicon oxide (silica), magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide, silicon carbide oxide (carbon-containing silicon oxide), and the like. Among the above, silica, silicon carbide oxide, and alumina are preferred. In addition, silica is particularly preferred because an aging treatment after the formation of the vapor deposition film is not required.
[0087] The thickness of the vapor deposition film is preferably 1 nm or more and 150 nm or less, more preferably 5 nm or more and 60 nm or less, and even more preferably 10 nm or more and 40 nm or less. By setting the thickness of the vapor deposition film to 1 nm or more, the oxygen barrier property and water vapor barrier property of the laminate can be further improved. In addition, by setting the thickness of the vapor deposition film to 150 nm or less, the generation of cracks in the vapor deposition film can be prevented. Further, the recyclability of a packaging container produced using a laminate including a substrate made of polypropylene and a sealant layer can be improved.
[0088] The formation of the vapor deposition film can be performed using a conventionally known method, for example, physical vapor deposition methods (Physical Vapor Deposition method, PVD method) such as vacuum evaporation method, sputtering method, and ion plating method, and chemical vapor deposition methods (Chemical Vapor Deposition method, CVD method) such as plasma chemical vapor deposition method, thermal chemical vapor deposition method, and photo chemical vapor deposition method.
[0089] The vapor deposition film may be a single layer formed by one vapor deposition step or a multilayer formed by a plurality of vapor deposition steps. In the case of a multilayer, each layer may be made of the same material or different materials. Further, each layer may be formed by the same method or different methods.
[0090] As an apparatus used for a method of forming a vapor deposition film by PVD method, a vacuum film forming apparatus with plasma assist can be used. An embodiment of a method for forming a vapor deposition film using a vacuum film forming apparatus with plasma assist will be described below. In one embodiment, as shown in FIGS. 5 and 6, the vacuum film forming apparatus includes a vacuum chamber A, an unwinding section B, a film forming drum C, a winding section D, a conveying roll E, an evaporation source F, a reaction gas supply section G, a deposition prevention box H, a vapor deposition material I, and a plasma gun J. Note that FIG. 5 is a schematic cross-sectional view of the vacuum film forming apparatus in the XZ plane direction, and FIG. 6 is a schematic cross-sectional view of the vacuum film forming apparatus in the XY plane direction. As shown in FIG. 4, an intermediate layer 14 wound around the film forming drum C is disposed in the upper part of the vacuum chamber A with its surface resin layer facing downward, and a deposition prevention box H electrically grounded is disposed below the film forming drum C in the vacuum chamber A. The evaporation source F is disposed on the bottom surface of the deposition prevention box H. The film forming drum C is disposed in the vacuum chamber A such that the surface resin layer of the intermediate layer 10 wound around the film forming drum C is positioned at a position facing the upper surface of the evaporation source F with a certain interval therebetween. In addition, conveying rolls E are disposed between the unwinding section B and the film forming drum C, and between the film forming drum C and the winding section D. Note that the vacuum chamber is connected to a vacuum pump (not shown). The evaporation source F is for holding the vapor deposition material I and includes a heating device (not shown). The reaction gas supply section G is a part for supplying a reaction gas (such as oxygen, nitrogen, helium, argon, and a mixed gas thereof) that reacts with the evaporated vapor deposition material. The vapor deposition material I heated and evaporated from the evaporation source F is irradiated onto the surface resin layer of the intermediate layer 14, and at the same time, plasma is irradiated from the plasma gun J onto the surface resin layer, and a vapor deposition film is formed. Details of this forming method are disclosed in Japanese Patent Application Laid-Open No. 2011-214089.
[0091] As a plasma generator used in the plasma chemical vapor deposition method, generators such as high-frequency plasma, pulse-wave plasma, and microwave plasma can be used. Also, a device having two or more film-forming chambers may be used. The device preferably includes a vacuum pump and can maintain each film-forming chamber in a vacuum state. The degree of vacuum in each film-forming chamber is preferably from 1×10~1×10 -6 Pa. An embodiment of a method for forming a vapor-deposited film using a plasma generator will be described below. First, the intermediate layer is fed into the film-forming chamber and conveyed onto the cooling / electrode drum at a predetermined speed via an auxiliary roll. Next, a mixed gas composition containing a film-forming monomer gas containing an inorganic oxide, oxygen gas, and an inert gas, etc. is supplied from a gas supply device into the film-forming chamber, plasma is generated by glow discharge on the surface resin layer, irradiated with this, and a vapor-deposited film containing an inorganic oxide is formed on the surface resin layer. Details of this forming method are disclosed in Japanese Patent Application Laid-Open No. 2012-076292.
[0092] FIG. 7 is a schematic configuration diagram showing a plasma chemical vapor deposition apparatus used in the CVD method.
[0093] In one embodiment, as shown in FIG. 7, the plasma chemical vapor deposition apparatus unwinds the intermediate layer 14 from the unwinding section B1 disposed in the vacuum chamber A1, and further conveys the intermediate layer 14 at a predetermined speed onto the circumferential surface of the cooling / electrode drum C1 via the conveying roll E1. Oxygen, nitrogen, helium, argon, and a mixed gas thereof are supplied from G1 for the reaction gas supply, and a monomer gas for film formation and the like are supplied from the raw material gas supply section I1. While adjusting the vapor deposition mixed gas composition composed of these, the vapor deposition mixed gas composition is introduced into the vacuum chamber A1 through the raw material supply nozzle H1, and plasma is generated by the glow discharge plasma F1 on the surface resin layer of the intermediate layer 14 conveyed onto the circumferential surface of the above-mentioned cooling / electrode drum C1, and this is irradiated to form a vapor deposition film. At that time, a predetermined power is applied to the cooling / electrode drum C1 from the power source K1 disposed outside the vacuum chamber A1, and a magnet J1 is disposed in the vicinity of the cooling / electrode drum C1 to promote the generation of plasma. Next, after the vapor deposition film is formed on the intermediate layer 14, it is wound up by the winding section D1 via the conveying roll E1 at a predetermined winding speed. In the figure, L1 represents a vacuum pump.
[0094] As an apparatus used for the method of forming a vapor deposition film, a continuous vapor deposition film forming apparatus including a plasma pretreatment chamber and a film forming chamber can be used. One embodiment of the method for forming a vapor deposition film using this apparatus is described below. First, in the plasma pretreatment chamber, the surface resin layer provided in the intermediate layer is irradiated with plasma from the plasma supply nozzle. Next, in the film forming chamber, a vapor deposition film is formed on the plasma-treated surface resin layer. Details of this forming method are disclosed in the pamphlet of International Publication WO2019 / 087960.
[0095] It is preferable that the surface of the vapor deposition film is subjected to the above surface treatment. Thereby, the adhesion with an adjacent layer can be improved.
[0096] In the barrier laminate of the present invention, the vapor deposition film is preferably a vapor deposition film formed by CVD method, and more preferably a carbon-containing silicon oxide vapor deposition film formed by CVD method. Thereby, even when the barrier laminate is bent, a decrease in gas barrier property can be suppressed.
[0097] The carbon-containing silicon oxide vapor deposition film contains silicon, oxygen, and carbon. In the carbon-containing silicon oxide vapor deposition film, the ratio C of carbon is preferably 3% or more and 50% or less, more preferably 5% or more and 40% or less, and even more preferably 10% or more and 35% or less with respect to 100% in total of the three elements of silicon, oxygen, and carbon. In the carbon-containing silicon oxide vapor deposition film, by setting the ratio C of carbon within the above range, even when the barrier laminate is bent, a decrease in gas barrier property can be suppressed. In this specification, the ratio of each element is on a molar basis.
[0098] In one embodiment of the carbon-containing silicon oxide vapor deposition film, the ratio Si of silicon is preferably 1% or more and 45% or less, more preferably 3% or more and 38% or less, and even more preferably 8% or more and 33% or less with respect to 100% in total of the three elements of silicon, oxygen, and carbon. The ratio O of oxygen is preferably 10% or more and 70% or less, more preferably 20% or more and 65% or less, and even more preferably 25% or more and 60% or less with respect to 100% in total of the three elements of silicon, oxygen, and carbon. In the carbon-containing silicon oxide vapor deposition film, by setting the ratio Si of silicon and the ratio O of oxygen within the above ranges, even when the barrier laminate is bent, a decrease in gas barrier property can be more suppressed.
[0099] In one embodiment of the carbon-containing silicon oxide vapor deposition film, the ratio O of oxygen is preferably higher than the ratio C of carbon, and the ratio Si of silicon is preferably lower than the ratio C of carbon. The ratio O of oxygen is preferably higher than the ratio Si of silicon, that is, it is preferable that each ratio decreases in the order of ratio O, ratio C, and ratio Si. Thereby, even when the barrier laminate is bent, a decrease in gas barrier property can be more suppressed.
[0100] In the silicon oxide vapor deposition film containing carbon, the ratios C, Si, and O can be measured by narrow scan analysis under the following measurement conditions using X-ray photoelectron spectroscopy (XPS). (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectrum acquisition conditions Incident X-ray: MgKα (monochromatic X-ray, hν = 1253.6 eV) X-ray output: 150 W (10 kV·15 mA) X-ray scanning area (measurement region): approximately 6 mmφ Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ion species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) Etch range: 10 mmφ Ion sputtering is carried out for 30 seconds, and the spectrum is collected
[0101] (Intermediate layer) The intermediate layer includes at least a surface resin layer and a polypropylene resin layer. Further, the intermediate layer can include an adhesive resin layer between the polypropylene resin layer and the surface resin layer. In the present invention, the surface resin layer and the polypropylene resin layer constituting the intermediate layer (when including an adhesive resin layer, the surface resin layer, the polypropylene resin layer, and the adhesive resin layer) are subjected to a stretching treatment, and the stretching treatment may be uniaxial stretching or biaxial stretching. The stretching ratio in the longitudinal direction (MD direction) and the transverse direction (TD direction) of the intermediate layer is preferably 2 times or more and 15 times or less, and more preferably 5 times or more and 13 times or less. By setting the stretching ratio to 2 times or more, the strength and heat resistance of the intermediate layer can be further improved. Also, the printability on the intermediate layer can be improved. Also, from the viewpoint of the breaking limit of the intermediate layer, the stretching ratio is preferably 15 times or less. In addition, when the polypropylene resin layer included in the intermediate layer is made heat-sealable to form a packaging container (e.g., a tube, etc.) produced by pasting envelopes, the draw ratio is preferably 2 times or more and 10 times or less, and more preferably 2.5 times or more and 7 times or less.
[0102] In one embodiment, it is preferable to perform a stretching process so that the tensile strength in the longitudinal direction (MD direction) of the intermediate layer is greater than the tensile strength in the transverse direction (TD direction). By adopting such a configuration, it is possible to impart high tear ease in one direction to the packaging container produced from the barrier laminate of the present invention. The tensile strength in the longitudinal direction (MD direction) of the intermediate layer is preferably 1.05 times or more, more preferably 1.10 times or more, and even more preferably 1.2 times or more greater than the tensile strength in the transverse direction (TD direction). The tensile strength in the longitudinal direction (MD direction) can be, for example, 200 MPa or more and 300 MPa or less. In this specification, the tensile strength is measured in accordance with JIS K7127:1999. As the measuring instrument, a tensile tester STA-1150 manufactured by Orientec Co., Ltd. can be used. As the test piece, a rectangular film with a width of 15 mm and a length of 150 mm cut out from the intermediate layer can be used. The interval at the start of measurement between a pair of chucks holding the test piece is 100 mm, and the drawing speed is 300 mm / min. In the present application, unless otherwise specified, the environment during the measurement of the tensile strength is a temperature of 23°C and a relative humidity of 50%.
[0103] In addition, the surface resin layer included in the intermediate layer may be subjected to a surface treatment. Thereby, the adhesion with an adjacent layer can be improved. The method of the surface treatment is not particularly limited, and examples thereof include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, glow discharge treatment, and chemical treatments such as oxidation treatment using chemical agents.
[0104] (Surface resin layer) The intermediate layer is provided with a surface protective layer containing a resin material having a melting point of 180°C or higher (hereinafter also referred to as a high melting point resin material) on a polypropylene resin layer, and a vapor deposition film having high adhesion can be formed on the surface resin layer, and the gas barrier property can be improved. In addition, as will be described later, a packaging container produced using the barrier laminate provided with the surface resin layer has high laminate strength.
[0105] The melting point of the high melting point resin material is more preferably 185°C or higher, further preferably 190°C or higher, and particularly preferably 205°C or higher. By setting the melting point of the high melting point resin material to 185°C or higher, the adhesion of the vapor deposition film can be further improved, and the gas barrier property can be further improved. In addition, the laminate strength of the packaging container can be further improved. From the viewpoint of the film-forming property of the intermediate layer, the melting point of the high melting point resin material is preferably 265°C or lower, more preferably 260°C or lower, and further preferably 250°C or lower. In this specification, the melting point can be measured in accordance with JIS K7121:2012 (Method for Measuring the Transition Temperature of Plastics). Specifically, using a differential scanning calorimetry (DSC) apparatus, a DSC curve can be measured at a heating rate of 10°C / min to obtain the melting point.
[0106] The difference between the melting point of the high melting point resin material contained in the surface resin layer and the melting point of polypropylene contained in the polypropylene resin layer is preferably 20 to 80°C, and more preferably 20 to 60°C. When the difference between the melting point of the high melting point resin material contained in the surface resin layer and the melting point of polypropylene contained in the polypropylene resin layer is 20°C or higher, the adhesion of the vapor deposition film can be further improved, and the gas barrier property can be further improved. In addition, the laminate strength of the packaging container can be further improved. Moreover, by setting the difference between the melting point of the high melting point resin material contained in the intermediate layer and the melting point of the polypropylene contained in the polypropylene resin layer to 80°C or less, the film-forming property of the intermediate layer can be further improved.
[0107] The high melting point resin material preferably has a polar group. In the present invention, the polar group refers to a group containing one or more heteroatoms, and examples thereof include an ester group, an epoxy group, a hydroxyl group, an amino group, an amide group, a carboxyl group, a carbonyl group, a carboxylic anhydride group, a sulfone group, a thiol group, and a halogen group. Among these, from the viewpoints of the gas barrier property and the laminate strength of the packaging container, a hydroxyl group, an ester group, an amino group, an amide group, a carboxyl group, and a carbonyl group are preferable, and an amide group is more preferable.
[0108] The high melting point resin material can be used without particular limitation as long as its melting point is 180°C or higher, and examples thereof include vinyl resin, polyamide, polyimide, polyester, (meth)acrylic resin, cellulose resin, polyolefin resin, and ionomer resin.
[0109] In the present invention, a resin material having a melting point of 180°C or higher and having a polar group is particularly preferable, and polyamides such as ethylene vinyl alcohol copolymer, polyvinyl alcohol, polyester, nylon 6, nylon 6,6, MXD nylon, and amorphous nylon are preferable, and nylon 6 is particularly preferable. By using such a resin material, the adhesion of the vapor deposition film formed on the surface resin layer can be significantly improved, and its gas barrier property can be effectively improved.
[0110] In one embodiment, the high melting point resin material is more preferably an ethylene vinyl alcohol copolymer. By using an ethylene vinyl alcohol copolymer as the high melting point resin material, a decrease in the gas barrier property can be suppressed even when the barrier laminate is bent.
[0111] In one embodiment, the high melting point resin material is preferably polyamide. By using polyamide as the high melting point resin material, it is possible to suppress a decrease in gas barrier properties even when the barrier laminate is bent, and it is possible to suppress a decrease in gas barrier properties even when heating such as heat sealing is performed when producing a packaging product using the barrier laminate. The high melting point resin material is more preferably nylon 6.
[0112] The content of the high melting point resin material in the surface resin layer is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.
[0113] Within a range not impairing the characteristics of the present invention, the surface resin layer may contain a resin material other than the high melting point resin material. Also, within a range not impairing the characteristics of the present invention, the surface resin layer can contain additives, for example, crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.
[0114] The ratio of the thickness of the surface resin layer to the total thickness of the intermediate layer is preferably 1% or more and 10% or less, and more preferably 1% or more and 5% or less. By setting the ratio of the thickness of the surface resin layer to the total thickness of the intermediate layer to 1% or more, the adhesion of the vapor deposition film can be further improved, and the gas barrier properties can be further improved. Also, the laminate strength of the packaging container can be further improved. Also, by setting the ratio of the thickness of the surface resin layer to the total thickness of the intermediate layer to 10% or less, the film-forming property and processing suitability of the intermediate layer can be further improved. Also, the recyclability of a packaging container produced using a laminate including a base material and a sealant layer made of polypropylene can be improved.
[0115] The thickness of the surface resin layer is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 4 μm or less. By setting the thickness of the surface resin layer to 0.1 μm or more, the adhesion of the vapor deposition film can be further improved, and the gas barrier property can be further improved. In addition, the laminate strength of the packaging container can be further improved. Also, by setting the thickness of the surface resin layer to 5 μm or less, the film-forming property and processing suitability of the intermediate layer material can be further improved. In addition, the recyclability of a packaging container produced using a laminate including a base material and a sealant layer composed of polypropylene can be improved.
[0116] (Polypropylene resin layer) The polypropylene resin layer may be composed of polypropylene and may have a single-layer structure or a multilayer structure. By providing the intermediate layer with a layer composed of polypropylene, it becomes possible to improve the oil resistance of a packaging container produced using the barrier laminate including the intermediate layer.
[0117] The polypropylene contained in the polypropylene resin layer may be any of a homopolymer, a random copolymer, and a block copolymer. A polypropylene homopolymer is a polymer of only propylene, a polypropylene random copolymer is a random copolymer of propylene and another α-olefin other than propylene (for example, ethylene, butene-1, 4-methyl-1-pentene, etc.), and a polypropylene block copolymer is a copolymer having a polymer block composed of propylene and a polymer block composed of another α-olefin other than the above-mentioned propylene. Among these polypropylenes, from the viewpoint of transparency, it is preferable to use a homopolymer or a random copolymer. When emphasizing the rigidity and heat resistance of the packaging bag, it is preferable to use a homopolymer, and when emphasizing impact resistance, etc., it is preferable to use a random copolymer. Also, polypropylene derived from biomass or polypropylene that has been mechanically recycled or chemically recycled can be used.
[0118] The content of polypropylene in the polypropylene resin layer is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.
[0119] Within the range not impairing the characteristics of the present invention, the polypropylene resin layer may contain a resin material other than polypropylene. Examples thereof include polyolefins such as polyethylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamide resins, polyesters, and ionomer resins. Also, within the range not impairing the characteristics of the present invention, the polypropylene resin layer can contain additives. Examples thereof include crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.
[0120] The thickness of the polypropylene resin layer is preferably 10 μm or more and 50 μm or less, and more preferably 10 μm or more and 40 μm or less. By setting the thickness of the polypropylene resin layer to 10 μm or more, the strength and heat resistance of the intermediate layer can be further improved. Also, by setting the thickness of the polypropylene resin layer to 50 μm or less, the film-forming property and processing suitability of the intermediate layer can be further improved.
[0121] (Adhesive resin layer) In one embodiment, the intermediate layer can include an adhesive resin layer between the polypropylene resin layer and the surface resin layer, thereby improving the adhesion between these layers.
[0122] The adhesive resin layer can be formed by using an adhesive resin such as polyether, polyester, silicone resin, epoxy resin, polyurethane, vinyl resin, phenol resin, polyolefin, and acid-modified polyolefin. Among the above, from the viewpoint of the recyclability of a packaging container produced using a laminate comprising a base material and a sealant layer made of polypropylene, polyolefins and acid-modified products thereof are preferred, and polypropylene and acid-modified products thereof are particularly preferred. As the adhesive polypropylene, commercially available products can be used. For example, those of the Admer series manufactured by Mitsui Chemicals, Inc. can be used.
[0123] The thickness of the adhesive resin layer is not particularly limited, but can be, for example, 1 μm or more and 15 μm or less. By setting the thickness of the adhesive resin layer to 1 μm or more, the adhesion between the polypropylene resin layer and the surface resin layer can be further improved. By setting the thickness of the adhesive layer to 15 μm or less, the processability of the intermediate layer can be improved.
[0124] In one embodiment, the intermediate layer is a coextruded film, which can be produced by forming a film using the T-die method, the inflation method, or the like, and then stretching the film after forming it into a laminated film. By forming a film by the inflation method, stretching of the laminated film can be performed simultaneously.
[0125] (Sealant layer) In one embodiment, the sealant layer contains a resin material that can be fused to each other by heat. Examples of the resin material that can be fused to each other by heat include polyolefins such as polyethylene, polypropylene, polybutene, methylpentene polymer, and cyclic olefin copolymer. Specifically, low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear (linear) low-density polyethylene (LLDPE), ethylene-α-olefin copolymer polymerized using a metallocene catalyst, and ethylene-propylene copolymer such as random or block copolymer of ethylene and propylene can be mentioned. Examples of resin materials that can be fused to each other by heat include, for example, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), ionomer resin, heat-sealable ethylene-vinyl alcohol resin, acid-modified polyolefin obtained by modifying polyolefin with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, and itaconic acid, polyesters such as polyethylene terephthalate (PET), polyvinyl acetate-based resins, poly(meth)acrylic-based resins, polyvinyl chloride-based resins, and the like. Among the above-described resin materials, from the viewpoint of the recyclability of the packaging container produced using the barrier laminate of the present invention, the sealant layer is preferably composed of polypropylene. In addition, by forming the sealant layer from polypropylene, the oil resistance of the packaging container produced using the barrier laminate can be improved.
[0126] The sealant layer can contain a heat-seal modifier. Thereby, the heat-sealability can be improved. The heat-seal modifier is not particularly limited as long as it has excellent compatibility with the resin material constituting the heat-seal layer, for example, polypropylene. Examples thereof include olefin copolymers. In addition, within a range that does not impair the characteristics of the present invention, the sealant layer can contain the above-described additives.
[0127] The sealant layer may have a single-layer structure or a multilayer structure. In addition, the sealant layer may or may not be subjected to a stretching treatment.
[0128] The thickness of the sealant layer is preferably 15 μm or more and 100 μm or less, and more preferably 20 μm or more and 70 μm or less. By setting the thickness of the sealant layer to 15 μm or more, the lamination strength of the packaging container provided with the barrier laminate of the present invention can be further improved. Also, by setting the thickness of the sealant layer to 100 μm or less, the processability of the barrier laminate of the present invention can be further improved.
[0129] In one embodiment, the sealant layer can be formed by laminating a film made of the above resin material via the intermediate layer and the adhesive layer. Also, in another embodiment, the sealant layer can be formed by applying and drying a heat-sealing agent containing the above resin material onto the intermediate layer.
[0130] (Barrier coating layer) The barrier laminate of the present invention can further include a barrier coating layer between the adhesive layer and the vapor deposition film. Thereby, the oxygen barrier property and the water vapor barrier property of the barrier laminate can be improved.
[0131] In one embodiment, the barrier coating layer contains gas barrier resins such as ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVA), polyacrylonitrile, nylon 6, nylon 6,6, and polymetaxylylene adipamide (MXD6), polyesters, polyurethanes, and (meth)acrylic resins. Among these, polyvinyl alcohol is preferred from the viewpoints of oxygen barrier property and water vapor barrier property. Also, by incorporating polyvinyl alcohol into the barrier coating layer, the occurrence of cracks in the vapor deposition film can be effectively prevented.
[0132] The content of the gas barrier resin in the barrier coating layer is preferably 50% by mass or more and 95% by mass or less, and more preferably 75% by mass or more and 90% by mass or less. By setting the content of the gas barrier resin in the barrier coating layer to 50% by mass or more, the oxygen barrier property and the water vapor barrier property can be further improved.
[0133] The barrier coat layer can contain the above additive as long as the properties of the present invention are not impaired.
[0134] The thickness of the barrier coat layer is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 5 μm or less. By setting the thickness of the barrier coat layer to 0.01 μm or more, the oxygen barrier property and water vapor barrier property of the barrier laminate can be further improved. By setting the thickness of the barrier coat layer to 10 μm or less, the processability of the barrier laminate can be improved. Further, the recyclability of a packaging container produced using a laminate including a base material and a sealant layer made of polypropylene can be improved.
[0135] The barrier coat layer can be formed by dissolving or dispersing the above gas barrier resin in water or an appropriate solvent, followed by coating and drying. Also, the barrier coat layer can be formed by coating and drying a commercially available barrier coating agent.
[0136] In another embodiment, the barrier coat layer is a gas barrier coating film containing at least one resin composition such as a hydrolyzate of a metal alkoxide or a hydrolytic condensate of a metal alkoxide obtained by polycondensing a mixture of a metal alkoxide and a water-soluble polymer by a sol-gel method in the presence of a sol-gel method catalyst, water, an organic solvent, etc. By providing such a barrier coat layer on the vapor deposition film, generation of cracks in the vapor deposition film can be effectively prevented.
[0137] In one embodiment, the metal alkoxide is represented by the following general formula. R 1 n M(OR 2 ) m (However, in the formula, R 1 , R 2Each represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents the valence of M.)
[0138] As the metal atom M, for example, silicon, zirconium, titanium, aluminum, etc. can be used. Also, R 1 and R 2 Examples of the organic group represented by include alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group and i-butyl group.
[0139] Examples of the metal alkoxide satisfying the above general formula include tetramethoxysilane (Si(OCH3)4), tetraethoxysilane (Si(OC2H5)4), tetrapropoxysilane (Si(OC3H7)4), tetrabutoxysilane (Si(OC4H9)4), etc.
[0140] Also, it is preferable to use a silane coupling agent together with the above metal alkoxide. As the silane coupling agent, known organoalkoxysilanes containing organic reactive groups can be used, and in particular, organoalkoxysilanes having an epoxy group are preferable. Examples of the organoalkoxysilane having an epoxy group include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc.
[0141] Two or more kinds of the above silane coupling agents may be used, and the silane coupling agent is preferably used in the range of about 1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the above metal alkoxide.
[0142] As the water-soluble polymer, polyvinyl alcohol and ethylene-vinyl alcohol copolymer are preferable, and from the viewpoints of oxygen barrier property, water vapor barrier property, water resistance and weather resistance, it is preferable to use them in combination.
[0143] The content of the water-soluble polymer in the gas barrier coating film is preferably 5 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the metal alkoxide. By setting the content of the water-soluble polymer in the gas barrier coating film to 5 parts by mass or more with respect to 100 parts by mass of the metal alkoxide, the oxygen barrier property and water vapor barrier property of the barrier laminate can be further improved. Further, by setting the content of the water-soluble polymer in the gas barrier coating film to 500 parts by mass or less with respect to 100 parts by mass of the metal alkoxide, the film-forming property of the gas barrier coating film can be improved.
[0144] In the gas barrier coating film, the ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) is preferably 4.5 or less on a mass basis, more preferably 1.0 or more and 4.5 or less, and still more preferably 1.7 or more and 3.5 or less. By setting the ratio of the metal alkoxide to the water-soluble polymer to 4.5 or less, it is possible to suppress a decrease in the gas barrier property even when the barrier laminate is bent. By setting the ratio of the metal alkoxide to the water-soluble polymer to 1.0 or more, it is possible to suppress a decrease in the gas barrier property even when heating such as heat sealing is performed when producing a packaging product using the barrier laminate. Note that the above ratio is a solid content ratio.
[0145] The surface of the gas barrier coating film preferably has a ratio of silicon atoms to carbon atoms (Si / C) measured by X-ray photoelectron spectroscopy (XPS) of 1.60 or less, more preferably 0.50 or more and 1.60 or less, and still more preferably 0.90 or more and 1.35 or less. By setting the ratio of silicon atoms to carbon atoms to 1.60 or less, it is possible to suppress a decrease in gas barrier properties even when the barrier laminate is bent. By setting the ratio of silicon atoms to carbon atoms to 0.50 or more, it is possible to suppress a decrease in gas barrier properties even when heating such as heat sealing is performed when producing a packaging product using the barrier laminate. The above range of the ratio of silicon atoms to carbon atoms can be achieved by appropriately adjusting the ratio of the metal alkoxide to the water-soluble polymer. In this specification, the ratio of silicon atoms to carbon atoms is on a molar basis.
[0146] The ratio of silicon atoms to carbon atoms by X-ray photoelectron spectroscopy (XPS) can be measured by narrow scan analysis under the following measurement conditions. (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectrum acquisition conditions Incident X-ray: MgKα (monochromatic X-ray, hν = 1253.6 eV) X-ray output: 150 W (10 kV·15 mA) X-ray scanning area (measurement region): approximately 6 mmφ Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ion species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) etch range: 10 mmφ Ion sputtering is performed for 30 seconds + 30 seconds + 60 seconds (total 120 seconds), and the spectrum is acquired.
[0147] The thickness of the gas barrier coating film is preferably 0.01 μm or more and 100 μm or less, and more preferably 0.1 μm or more and 50 μm or less. Thereby, while maintaining recyclability, the oxygen barrier property and the water vapor barrier property can be further improved. By setting the thickness of the gas barrier coating film to 0.01 μm or more, the oxygen barrier property and water vapor barrier property of the barrier laminate can be improved. Further, the generation of cracks in the vapor deposition film can be prevented. By setting the thickness of the gas barrier coating film to 100 μm or less, the recyclability of a packaging container produced using a laminate of the barrier laminate of the present invention and a sealant layer made of polypropylene can be improved.
[0148] The gas barrier coating film can be formed by applying a composition containing the above materials by means of conventionally known means such as roll coating using a gravure roll coater, spray coating, spin coating, dipping, brush, bar coating, applicator, etc., and subjecting the composition to polycondensation by the sol-gel method. As the sol-gel method catalyst, an acid or an amine-based compound is suitable. As the amine-based compound, a tertiary amine that is substantially insoluble in water and soluble in an organic solvent is suitable. Examples thereof include N,N-dimethylbenzylamine, tripropylamine, tributylamine, tripentylamine, etc. Among these, N,N-dimethylbenzylamine is preferable. The sol-gel method catalyst is preferably used in the range of 0.01 part by mass or more and 1.0 part by mass or less per 100 parts by mass of the metal alkoxide, and more preferably in the range of 0.03 part by mass or more and 0.3 part by mass or less. By setting the usage amount of the sol-gel method catalyst to 0.01 part by mass or more per 100 parts by mass of the metal alkoxide, the catalytic effect can be improved. Further, by setting the usage amount of the sol-gel method catalyst to 1.0 part by mass or less per 100 parts by mass of the metal alkoxide, the thickness of the formed gas barrier coating film can be made uniform.
[0149] The above composition may further contain an acid. The acid is used as a catalyst for the sol-gel method, mainly as a catalyst for hydrolysis of metal alkoxides, silane coupling agents, etc. Examples of the acid include mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid, and organic acids such as acetic acid and tartaric acid. The amount of the acid used is preferably 0.001 mol or more and 0.05 mol or less with respect to the total molar amount of the alkoxide moiety (e.g., silicate moiety) of the metal alkoxide and the silane coupling agent. By setting the amount of the acid used to 0.001 mol or more with respect to the total molar amount of the alkoxide moiety (e.g., silicate moiety) of the metal alkoxide and the silane coupling agent, the catalytic effect can be improved. Further, by setting the amount of the acid used to 0.05 mol or less with respect to the total molar amount of the alkoxide moiety (e.g., silicate moiety) of the metal alkoxide and the silane coupling agent, the thickness of the gas barrier coating film to be formed can be made uniform.
[0150] Further, the composition preferably contains water in a proportion of preferably 0.1 mol or more and 100 mol or less, more preferably 0.8 mol or more and 2 mol or less, per 1 mol of the total molar amount of the metal alkoxide. By setting the water content to 0.1 mol or more per 1 mol of the total molar amount of the metal alkoxide, the oxygen barrier property and the water vapor barrier property of the barrier laminate of the present invention can be improved. Further, by setting the water content to 100 mol or less per 1 mol of the total molar amount of the alkoxide, the hydrolysis reaction can be carried out promptly.
[0151] Further, the composition may contain an organic solvent. Examples of the organic solvent that can be used include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butanol.
[0152] Hereinafter, an embodiment of a method for forming a gas barrier coating film will be described below. First, a metal alkoxide, a water-soluble polymer, a sol-gel method catalyst, water, an organic solvent, and, if necessary, a silane coupling agent, etc. are mixed to prepare a composition. In the composition, a polycondensation reaction gradually proceeds. Next, the composition is applied and dried on the vapor deposition film by the above-described conventionally known method. By this drying, the polycondensation reaction of the metal alkoxide and the water-soluble polymer (and also the silane coupling agent if the composition contains a silane coupling agent) further proceeds, and a layer of the composite polymer is formed. Finally, the composition can be heated at a temperature of, for example, 20 to 250°C, preferably 50 to 220°C, for 1 second to 10 minutes to form a gas barrier coating film.
[0153] A printing layer may be formed on the surface of the barrier coat layer. The method for forming the printing layer and the like are as described above.
[0154] (Barrier laminate in the second aspect) As shown in FIG. 8, the barrier laminate 20 of the present invention includes a base material 21, an adhesive layer 22, a vapor deposition film 23, an intermediate layer 24, and a sealant layer 25, and the intermediate layer 24 includes a coat layer 26 and a polypropylene resin layer 27. In one embodiment, as shown in FIG. 9, the barrier laminate 20 of the present invention further includes a barrier coat layer 28 between the adhesive layer 22 and the vapor deposition film 23.
[0155] In the barrier laminate in the second aspect, the lamination strength between the intermediate layer and the vapor deposition film is preferably 3 N or more, more preferably 4 N or more, and still more preferably 5.5 N or more in a width of 15 mm. The upper limit of the lamination strength of the barrier laminate in the second aspect may be 20 N or less. Note that the method for measuring the lamination strength of the barrier laminate will be described in the examples described later.
[0156] Similar to the first aspect, it is preferable that the base material and the sealant base material are made of the same material as the polypropylene resin layer included in the intermediate layer, that is, polypropylene. Thereby, the recyclability of the packaging container produced using the barrier laminate of the present invention can be improved.
[0157] When the base material and the sealant layer are made of polypropylene, the content of polypropylene in the total amount of the resin materials contained in the barrier laminate of the present invention is preferably 80% by mass or more, and more preferably 95% by mass or more. Thereby, the recyclability of the packaging container produced using the barrier laminate of the present invention can be further improved.
[0158] Hereinafter, the intermediate layer included in the barrier laminate of the present invention will be described. Note that, since the layers other than the intermediate layer included in the barrier laminate in the second aspect are the same as those in the barrier laminate in the first aspect, the description thereof is omitted here.
[0159] (Intermediate layer) The intermediate layer includes a surface coat layer and a polypropylene resin layer.
[0160] (Surface coat layer) The intermediate layer includes a surface coat layer containing a resin material having a polar group on the polypropylene resin layer, and a vapor deposition film having high adhesiveness can be formed on the surface coat layer, thereby improving the gas barrier property. Also, as will be described later, the packaging container produced using the barrier laminate including the surface coat layer has high laminate strength.
[0161] The surface coat layer contains a resin material having a polar group. In the present invention, the polar group refers to a group containing one or more heteroatoms. Examples thereof include an ester group, an epoxy group, a hydroxyl group, an amino group, an amide group, a carboxyl group, a carbonyl group, a carboxylic anhydride group, a sulfone group, a thiol group, and a halogen group. Among these, from the viewpoint of the laminability of the packaging container, a carboxyl group, a carbonyl group, an ester group, a hydroxyl group, and an amino group are preferable, and a carboxyl group and a hydroxyl group are more preferable.
[0162] Examples of the resin material having a polar group include ethylene vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVA), polyester, polyethyleneimine, a hydroxyl group-containing (meth)acrylic resin, polyamide such as nylon 6, nylon 6,6, MXD nylon, and amorphous nylon, and polyurethane. Polyamide, a hydroxyl group-containing (meth)acrylic resin, ethylene vinyl alcohol copolymer, and polyvinyl alcohol are particularly preferred. By using such a resin material, the adhesion of the vapor deposition film formed on the surface coat layer can be significantly improved, and its gas barrier property can be effectively enhanced.
[0163] In the present invention, the surface coat layer can be formed using an aqueous emulsion or a solvent-based emulsion. Specific examples of the aqueous emulsion include polyamide-based emulsions, polyethylene-based emulsions, polyurethane-based emulsions, etc. Specific examples of the solvent-based emulsion include polyester-based emulsions.
[0164] The content of the resin material having a polar group in the surface coat layer is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more.
[0165] Within a range not impairing the characteristics of the present invention, the surface coat layer may contain a resin material other than the resin material having a polar group. Also, within a range not impairing the characteristics of the present invention, the surface coat layer can contain additives, for example, crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.
[0166] The ratio of the thickness of the surface coat layer to the total thickness of the intermediate layer is preferably 0.08% or more and 20% or less, more preferably 0.2% or more and 20% or less, still more preferably 1% or more and 20% or less, and even more preferably 3% or more and 10% or less. By setting the ratio of the thickness of the surface coating layer to the total thickness of the intermediate layer to 0.08% or more, the adhesion of the vapor deposition film can be further improved, and the gas barrier property can be further improved. Also, the lamination strength of the packaging container can be further improved. Also, by setting the ratio of the thickness of the surface coating layer to the total thickness of the intermediate layer to 20% or less, the processability of the intermediate layer can be further improved. Also, the recyclability of a packaging container produced using a laminate including a base material and a sealant layer made of polypropylene can be improved.
[0167] The thickness of the surface coating layer is preferably 0.02 μm or more and 10 μm or less, more preferably 0.05 μm or more and 10 μm or less, still more preferably 0.1 μm or more and 10 μm or less, and even more preferably 0.2 μm or more and 5 μm or less. By setting the thickness of the surface coating layer to 0.02 μm or more, the adhesion of the vapor deposition film can be further improved, and the gas barrier property can be further improved. Also, the lamination strength of the packaging container can be further improved. Also, by setting the thickness of the surface coating layer to 10 μm or less, the processability of the intermediate layer can be further improved. Also, the recyclability of a packaging container produced using a laminate including a base material and a sealant layer made of polypropylene can be improved.
[0168] (Polypropylene resin layer) The polypropylene resin layer may be composed of polypropylene and may have a single-layer structure or a multilayer structure. By providing that the intermediate layer includes a layer made of polypropylene, it becomes possible to improve the oil resistance of a packaging container produced using the barrier laminate including the intermediate layer.
[0169] The polypropylene resin layer is a film that has been subjected to a stretching treatment, and the stretching treatment may be uniaxial stretching or biaxial stretching. The draw ratio of the polypropylene resin layer in the longitudinal direction (MD direction) and the transverse direction (TD direction) is preferably 2 times or more and 15 times or less, and more preferably 5 times or more and 13 times or less. By setting the draw ratio to 2 times or more, the strength and heat resistance of the polypropylene resin layer can be further improved. In addition, the printability on the polypropylene resin layer can be improved. Also, from the viewpoint of the breaking limit of the polypropylene resin layer, the draw ratio is preferably 15 times or less.
[0170] The polypropylene contained in the polypropylene resin layer may be any of a homopolymer, a random copolymer, and a block copolymer. A polypropylene homopolymer is a polymer of only propylene, a polypropylene random copolymer is a random copolymer of propylene and other α-olefins other than propylene (for example, ethylene, butene-1, 4-methyl-1-pentene, etc.), and a polypropylene block copolymer is a copolymer having a polymer block composed of propylene and a polymer block composed of other α-olefins other than the above-mentioned propylene. Among these polypropylenes, from the viewpoint of transparency, it is preferable to use a homopolymer or a random copolymer. When emphasizing the rigidity and heat resistance of the packaging bag, it is preferable to use a homopolymer, and when emphasizing impact resistance, etc., it is preferable to use a random copolymer. In addition, polypropylene derived from biomass, or polypropylene that has been mechanically recycled or chemically recycled can also be used.
[0171] The content of polypropylene in the polypropylene resin layer is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.
[0172] Within the range that does not impair the characteristics of the present invention, the polypropylene resin layer may contain a resin material other than polypropylene. For example, polyolefins such as polyethylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamide resins, polyesters, and ionomer resins can be mentioned. Also, within the range that does not impair the characteristics of the present invention, the polypropylene resin layer can contain additives. For example, crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins can be mentioned.
[0173] The thickness of the polypropylene resin layer is preferably 10 μm or more and 50 μm or less, and more preferably 10 μm or more and 40 μm or less. By setting the thickness of the polypropylene resin layer to 10 μm or more, the strength and heat resistance of the intermediate layer can be further improved. Also, by setting the thickness of the polypropylene resin layer to 50 μm or less, the film-forming property and processing suitability of the intermediate layer can be further improved.
[0174] Also, the polypropylene resin layer may be surface-treated. Thereby, the adhesion with the surface coat layer can be improved. The method of surface treatment is not particularly limited. For example, physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, glow discharge treatment, and chemical treatments such as oxidation treatment using chemical agents can be mentioned.
[0175] The intermediate layer can be manufactured offline. Specifically, a resin composition containing polypropylene is formed into a resin film using a T-die method or an inflation method, etc., and after stretching, a coating liquid for coat formation is applied onto the resin film and dried to produce it. In addition, the intermediate layer can also be manufactured inline. Specifically, a resin composition containing polypropylene is formed into a resin film by using a T-die method or an inflation method, etc., and after stretching in the longitudinal direction (MD direction), a coating liquid for forming a coat is applied on the resin film, dried, and then stretched in the transverse direction (TD direction) to produce it. Note that stretching in the transverse direction may be performed first.
[0176] (Packaging container) The packaging container of the present invention is characterized by comprising the above-described barrier laminate. Examples of the packaging container include a packaging product (packaging bag), a lid material, and a laminated tube, etc.
[0177] Examples of the packaging bag include various forms of packaging bags such as a standing pouch type, a side seal type, a two-side seal type, a three-side seal type, a four-side seal type, an envelope sticker seal type, a clamshell sticker seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a square bottom seal type, and a gusset type.
[0178] As shown in FIG. 10, the packaging container of the present invention is a packaging bag 30 in which two barrier laminates are bonded together (the hatched portion is a heat-sealed portion). When the tensile strength of the intermediate layer in the longitudinal direction (MD direction) is made larger than the tensile strength in the transverse direction (TD direction), it is preferable to produce the packaging bag so that the longitudinal direction (MD direction) of the intermediate layer corresponds to the transverse direction of the packaging bag 30 and the transverse direction (TD direction) of the intermediate layer corresponds to the longitudinal direction of the packaging bag 30. By adopting such a configuration, tearing of the packaging container in the transverse direction becomes extremely easy. The same applies to the packaging containers exemplified below.
[0179] As shown in FIG. 11, the packaging container of the present invention is a standing pouch 40. FIG. 11 is a diagram schematically showing an example of the configuration of a standing pouch. As shown in FIG. 11, the standing pouch 40 is composed of a body portion (side sheet) 41 and a bottom portion (bottom sheet) 42. At least one of the side sheet 41 and the bottom sheet 42 included in the standing pouch 40 is constituted by the barrier laminate of the present invention.
[0180] In one embodiment, the body portion 41 included in the standing pouch 40 can be formed by bag-making such that the sealant layer included in the barrier laminate of the present invention becomes the innermost layer. In another embodiment, for the side sheet 41, two barrier laminates of the present invention are prepared, and these are overlapped with the sealant layers facing each other. From both ends of the overlapped barrier laminates, two V-shaped folded laminates with the sealant layer on the outside are inserted, and it can be formed by heat-sealing. According to such a manufacturing method, a stand pouch having a body portion with side gussets can be obtained.
[0181] Also, in one embodiment, the bottom sheet 42 included in the standing pouch 40 can be formed by inserting the barrier laminate of the present invention between the bag-made side sheets and heat-sealing. More specifically, the barrier laminate is folded in a V-shape so that the sealant layer is on the outside, inserted between the bag-made side sheets, and can be formed by heat-sealing.
[0182] Also, as shown in FIG. 10, the packaging container may be provided with an easy-opening means 51. Examples of the easy-opening means 51 include, as shown in FIG. 10, a notch portion 52 that serves as a starting point for tearing, and a half-cut line 53 formed by laser processing, a cutter, or the like as a path for tearing.
[0183] Also, as shown in FIG. 11, the packaging container may be provided with a steam venting mechanism 60. The steam venting mechanism 60 is configured to communicate the inside and outside of the packaging container when the steam pressure inside the packaging container reaches a predetermined value or more, release the steam, and suppress the steam from escaping at locations other than the steam venting mechanism 60. The steam venting mechanism 50 includes a steam venting seal portion 60a that protrudes from the side seal portion toward the inside of the packaging container, and a non-sealed portion 60b that is isolated from the content storage portion by the steam venting seal portion 60a. The non-sealed portion 60b communicates with the outside of the packaging container. By heating a packaging container filled with contents and having its opening heat-sealed using a microwave oven or the like, the internal pressure increases and the steam seal portion 60a peels off. The steam passes through the steam seal 60a peeling location and the non-sealed portion 60b and escapes to the outside of the packaging container.
[0184] As a heat-sealing method, for example, known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high-frequency sealing, and ultrasonic sealing can be used.
[0185] The contents filled in the packaging container are not particularly limited, and the contents may be liquid, powder, or gel. Also, they may be food or non-food.
[0186] (Other embodiments) In other embodiments, the barrier laminate of the present invention includes a base material, an adhesive layer, a vapor deposition film, an intermediate layer, and a sealant layer. The intermediate layer includes at least a surface resin layer and a polypropylene resin layer. The surface resin layer contains a resin material having a melting point of 180°C or higher. The vapor deposition film is composed of an inorganic oxide. It is characterized in that the surface resin layer and the polypropylene resin layer are subjected to a stretching treatment. In one embodiment, the polypropylene resin layer, the base material, and the sealant layer are made of the same material, and the same material is polypropylene. In one embodiment, the adhesive layer is an adhesive layer containing a cured product of a composition containing a polyester polyol and an isocyanate compound. In one embodiment, the melting point of the resin material is 265°C or lower. In one embodiment, the difference between the melting point of the resin material and the melting point of the polypropylene contained in the polypropylene resin layer is 20 to 80°C. In one embodiment, the resin material has a polar group. In one embodiment, the resin material is one or more resin materials selected from ethylene vinyl alcohol copolymer, polyvinyl alcohol, nylon 6, nylon 6,6, MXD nylon, and amorphous nylon. In one embodiment, the resin material is polyamide. In one embodiment, the resin material is ethylene vinyl alcohol. In one embodiment, the ratio of the thickness of the surface resin layer to the total thickness of the intermediate layer is 1% or more and 10% or less. In one embodiment, the intermediate layer is a coextruded film.
[0187] In another aspect, the barrier laminate of the present invention includes a substrate, an adhesive layer, a vapor deposition film, an intermediate layer, and a sealant layer. The intermediate layer includes a surface coat layer and a polypropylene resin layer. The polypropylene resin layer is subjected to a stretching treatment. And the surface coat layer contains a resin material having a polar group. The vapor deposition film is composed of an inorganic oxide. In one embodiment, the polypropylene resin layer, the substrate, and the sealant layer are made of the same material, and the same material is polypropylene. In one embodiment, the adhesive layer is an adhesive layer containing a cured product of a composition of polyester polyol and isocyanate compound. In one embodiment, the ratio of the thickness of the surface coat layer to the total thickness of the intermediate layer is 0.08% or more and 20% or less. In one embodiment, the thickness of the surface coat layer is 0.02 μm or more and 10 μm or less. In one embodiment, the resin material is one or more resin materials selected from ethylene vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVA), polyester, polyethyleneimine, hydroxyl group-containing (meth)acrylic resin, nylon 6, nylon 6,6, MXD nylon, amorphous nylon, and polyurethane. In one embodiment, the surface coat layer is a layer formed using an aqueous emulsion or a solvent-based emulsion. In one embodiment, the barrier laminate of the present invention further includes a barrier coat layer between the adhesive layer and the vapor deposition film. In one embodiment, the barrier laminate of the present invention is used for packaging container applications.
[0188] The packaging container according to another aspect of the present invention is characterized by including the above-described barrier laminate.
Examples
[0189] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples.
[0190] Example 1-1 Polyamide (manufactured by Ube Industries, Ltd., polyamide 6, melting point: 220°C), an adhesive resin (manufactured by Mitsui Chemicals, Inc., Admer QF500, maleic anhydride-modified polypropylene), and polypropylene (manufactured by Japan Polypropylene Corporation, Novatec FL203D, melting point: 160°C) were co-extruded and then sequentially stretched 5 times in the longitudinal direction (MD direction) and 10 times in the transverse direction (TD direction) using a twin-screw stretching device to prepare an intermediate layer having a thickness of 21 μm and including a surface resin layer (19.6 μm) made of polyamide, an adhesive resin layer (1 μm) made of an adhesive resin, and a polypropylene resin layer (0.4 μm) made of polypropylene. The ratio of the thickness of the surface resin layer made of polyamide to the layer thickness of the intermediate layer was 2%.
[0191] On the surface resin layer of the intermediate layer produced as described above, using a low-temperature plasma chemical vapor deposition apparatus, which is a real machine, by Roll to Roll, while applying tension to the intermediate layer, a carbon-containing silicon oxide vapor deposition film with a thickness of 12 nm was formed (CVD method). The vapor deposition film formation conditions were as follows. (Formation conditions) · Hexamethyldisiloxane: oxygen gas: helium = 1:10:10 (unit: slm) · Cooling · Electrode drum supply power: 22 kw · Line speed: 100 m / min
[0192] In the carbon-containing silicon oxide vapor deposition film, the ratio C of carbon, the ratio Si of silicon, and the ratio O of oxygen were 32.7%, 29.8%, and 37.5% respectively with respect to the total of 100% of the three elements of silicon, oxygen, and carbon. The ratio of each element was measured by narrow scan analysis under the following measurement conditions by X-ray photoelectron spectroscopy (XPS). (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectrum collection conditions Incident X-ray: MgKα (monochromatic X-ray, hν = 1253.6 eV) X-ray output: 150 W (10 kV · 15 mA) X-ray scanning area (measurement region): approximately 6 mmφ Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ion species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) etch range: 10 mmφ Ion sputtering was carried out for 30 seconds, and the spectrum was collected.
[0193] 385 g of water, 67 g of isopropyl alcohol, and 9.1 g of 0.5 N hydrochloric acid were mixed to obtain a solution with a pH of 2.2. To this solution, 175 g of tetraethoxysilane as a metal alkoxide and 9.2 g of glycidoxypropyltrimethoxysilane as a silane coupling agent were mixed while cooling to 10°C to obtain Solution A. 14.7 g of polyvinyl alcohol with a saponification degree of 99% or more and a polymerization degree of 2400, 324 g of water, and 17 g of isopropyl alcohol were mixed as a water-soluble polymer to obtain Solution B. Solution A and Solution B were mixed so that the mass ratio was 6.5:3.5 to obtain a barrier coating agent.
[0194] The barrier coating agent was spin-coated on the vapor deposition film formed on the intermediate layer and heat-treated in an oven at 80°C for 60 seconds to form a barrier coating layer with a thickness of 300 nm.
[0195] An adhesive layer with a thickness of 3 μm was formed on the barrier coating layer formed as described above with an adhesive (manufactured by DIC Corporation, trade name: PASLIM VM001 / VM102CP (mixing ratio 1:1)) containing polyester polyol and isocyanate compound. Through this adhesive layer, a stretched polypropylene film with a thickness of 20 μm (manufactured by Mitsui Chemicals Toagosei Co., Ltd., U1) was laminated as a base material.
[0196] An adhesive layer with a thickness of 1 μm was formed on the polypropylene resin layer of the intermediate layer with a polyurethane adhesive (manufactured by Mitsui Chemicals, Inc., Take lac A - 969V / Takenate A - 5 (mixing ratio 3 / 1)). Through this adhesive layer, an unstretched polypropylene film with a thickness of 30 μm (manufactured by Mitsui Chemicals Toagosei Co., Ltd., CP S) was laminated as a sealant layer to obtain the barrier laminate of the present invention. The content of polypropylene in the barrier laminate was 92% by mass.
[0197] Example 1-2 A barrier laminate was produced in the same manner as in Example 1-1, except that the sealant layer was changed to a heat-sealable biaxially stretched polypropylene film (manufactured by Toyo Corporation, P6181) with a thickness of 30 μm. The content of polypropylene in the barrier laminate was 9% by mass.
[0198] Example 1-3 A barrier laminate of the present invention was obtained in the same manner as in Example 1-1, except that a polypropylene-based heat-sealing material (manufactured by Unitika Ltd., Arrow Base DA1010N) was applied and dried on the polypropylene resin layer of the intermediate layer to form a sealant layer with a thickness of 3 μm. The content of polypropylene in the barrier laminate was 82% by mass.
[0199] Example 1-4 A barrier laminate was produced in the same manner as in Example 1-1, except that the polyamide used for producing the intermediate layer was changed to polyvinyl alcohol (manufactured by Nippon Gohsei-Bopar Co., Ltd., Bopar JC-33, melting point: 200 °C) and the surface resin layer was formed.
[0200] Example 2-1 On the corona-treated surface of a biaxially stretched polypropylene film (manufactured by Mitsui Chemicals Toagosei Co., Ltd., ME-1) with a thickness of 20 μm and one surface corona-treated, a solution for forming a surface coat layer having the following composition was applied and dried to form a surface coat layer with a thickness of 0.5 μm, and an intermediate layer was produced. (Composition of the coating liquid for forming the surface coat layer) · Polyvinyl alcohol 5% by mass (manufactured by Nippon Gohsei-Bopar Co., Ltd., VC-10, degree of polymerization 1000, saponification degree 99.3 mol% or more) · Water 90% by mass · Isopropanol (IPA) 5% by mass
[0201] A barrier laminate was produced in the same manner as in Example 1-1, except that the intermediate layer produced in Example 1-1 was changed to the intermediate layer produced as described above. The content of polypropylene in the barrier laminate was 93% by mass.
[0202] Example 2-2 A barrier laminate was produced in the same manner as in Example 2-1, except that the composition of the coating liquid for forming the surface coat layer was changed as follows. The content of polypropylene in the barrier laminate was 93% by mass. (Coating liquid composition for forming the surface coat layer) · EVOH 75% by mass (Manufactured by Nippon Shiema Co., Ltd., Eversorb #10) · Water 12.5% by mass · 1-Propanol 12.5% by mass
[0203] Comparative Example 1-1 After extruding the above polypropylene (manufactured by Japan Polypropylene Corporation, Novatec FL203D, melting point: 160°C), it was sequentially stretched 5 times in the longitudinal direction (MD direction) and 10 times in the transverse direction (TD direction) by a biaxial stretching device to produce a propylene film with a thickness of 20 μm. A barrier laminate was produced in the same manner as in Example 1-1, except that the intermediate layer in Example 1-1 was changed to the polypropylene film produced as described above.
[0204] <<Gas barrier property evaluation>> The barrier laminates obtained in the above Examples and Comparative Examples were cut out to obtain test pieces. Using these test pieces, the oxygen permeability (cc / m 2 ·day·atm) and water vapor permeability (g / m 2 ·day) were measured by the following method, and the results were summarized in Table 1.
[0205] [Oxygen permeability] Using an oxygen permeability measuring device (manufactured by MOCON, OX-TRAN2 / 20), the test piece was set so that the base material side was the oxygen supply side, and the oxygen permeability in an environment of 23°C and a relative humidity of 90% RH was measured in accordance with JIS K 7126. [Water vapor permeability] Using a water vapor permeability measuring device (PERMATRAN-w 3 / 33 manufactured by MOCON), the sample was set so that the substrate side of the test piece was the water vapor supply side, and in accordance with JIS K 7129, the water vapor permeability at 40 °C and a relative humidity of 90% RH was measured.
[0206] <<Lamination Strength Test>> Samples obtained by cutting the barrier laminates obtained in the above Examples and Comparative Examples into strips with a width of 15 mm were used with a tensile testing machine (Tensilon universal material testing machine manufactured by Orientec Co., Ltd.) in accordance with JIS K6854-2, and the lamination strength (N / 15 mm) was measured using a 90° peel (T-peel method) at a peel rate of 50 mm / min. Specifically, first, the barrier laminate was cut out, and as shown in FIG. 12, a strip-shaped test piece 70 was prepared by peeling the substrate side 71 and the sealant layer side 72 by 15 mm in the long side direction. Then, as shown in FIG. 13, the already peeled portions of the substrate side 71 and the sealant layer side 72 were respectively gripped by the gripping tools 73 of the measuring instrument. The gripping tools 73 were pulled in opposite directions at a speed of 50 mm / min in a direction orthogonal to the plane direction of the portion where the substrate side 71 and the sealant layer side 72 were still laminated, and the average value of the tensile stress in the stable region (see FIG. 14) was measured. The interval S between the gripping tools 73 at the start of pulling was set to 30 mm, and the interval S between the gripping tools 73 at the end of pulling was set to 60 mm. FIG. 14 is a diagram showing the change in tensile stress with respect to the interval S between the gripping tools 73. As shown in FIG. 14, the change in tensile stress with respect to the interval S passes through the first region and enters the second region (stable region) where the change rate is smaller than that of the first region. For 5 test pieces 70, the average value of the tensile stress in the stable region was measured, and this average value was taken as the lamination strength. The environment during measurement was a temperature of 23 °C and a relative humidity of 50%. The measurement results are summarized in Table 1.
[0207]
Table 1
[0208] Reference Example 1-1 Polyamide (manufactured by Ube Industries, Ltd., polyamide 6, melting point: 220°C), an adhesive resin (manufactured by Mitsui Chemicals, Inc., Admer QF500, maleic anhydride-modified polypropylene), and polypropylene (manufactured by Japan Polypropylene Corporation, Novatec FL203D, melting point: 160°C) were co-extruded and then successively stretched 5 times in the longitudinal direction (MD direction) and 10 times in the transverse direction (TD direction) using a twin-screw stretching device to produce a 21-μm-thick substrate comprising a surface resin layer (19.6 μm) made of polyamide, an adhesive resin layer (1 μm) made of an adhesive resin, and a polypropylene resin layer (0.4 μm) made of polypropylene. The ratio of the thickness of the surface resin layer made of polyamide to the layer thickness of the substrate was 2%.
[0209] A 12-nm-thick carbon-containing silicon oxide vapor deposition film was formed on the surface resin layer of the substrate produced as described above by Roll to Roll using a low-temperature plasma chemical vapor deposition apparatus, which is an actual machine, while applying tension to the substrate (CVD method). The vapor deposition film formation conditions were as follows. (Formation conditions) · Hexamethyldisiloxane: oxygen gas: helium = 1:10:10 (unit: slm) · Cooling · Electrode drum supply power: 22 kw · Line speed: 100 m / min
[0210] In the carbon-containing silicon oxide vapor deposition film, the ratio C of carbon, the ratio Si of silicon, and the ratio O of oxygen were 32.7%, 29.8%, and 37.5%, respectively, with respect to the total of 100% of the three elements of silicon, oxygen, and carbon. The ratio of each element was measured by narrow scan analysis under the following measurement conditions using X-ray photoelectron spectroscopy (XPS). (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectrum acquisition conditions Incident X-ray: MgKα (monochromatic X-ray, hν = 1253.6 eV) X-ray output: 150 W (10 kV·15 mA) X-ray scanning area (measurement region): approximately 6 mm φ Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ion species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) etch range: 10 mm φ Ion sputtering time: performed for 30 seconds and the spectrum was collected
[0211] A barrier coat layer was formed on the vapor deposition film such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 5.1 on a mass basis.
[0212] The ratio of the Si element and the C element present on the surface of the barrier coat layer was measured. The measurement was performed by narrow scan analysis under the following measurement conditions using X-ray photoelectron spectroscopy (XPS). In the following reference examples as well, the ratio of the Si element and the C element present on the surface of the barrier coat layer was measured in the same manner. (Measurement conditions) Equipment used: "ESCA-3400" (manufactured by Kratos) [1] Spectrum collection conditions Incident X-ray: MgKα (monochromatic X-ray, hν = 1253.6 eV) X-ray output: 150 W (10 kV · 15 mA) X-ray scanning area (measurement region): approximately 6 mm φ Photoelectron capture angle: 90 degrees [2] Ion sputtering conditions Ion species: Ar + Acceleration voltage: 0.2 (kV) Emission current: 20 (mA) etch range: 10 mm φ Ion sputtering time: performed for 30 seconds + 30 seconds + 60 seconds (total 120 seconds) and the spectrum was collected
[0213] Next, an unstretched polypropylene film with a thickness of 60 μm (manufactured by Toyobo Co., Ltd., P1128) was dry laminated onto the barrier coat layer with a two-component curable polyurethane-based adhesive to form a sealant layer, thereby obtaining a barrier laminate.
[0214] Reference Example 1-2 A barrier laminate was produced in the same manner as in Reference Example 1-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 4.1 on a mass basis.
[0215] Reference Example 1-3 A barrier laminate was produced in the same manner as in Reference Example 1-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 3.3 on a mass basis.
[0216] Reference Example 1-4 A barrier laminate was produced in the same manner as in Reference Example 1-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 2.7 on a mass basis.
[0217] Reference Example 1-5 A barrier laminate was produced in the same manner as in Reference Example 1-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.9 on a mass basis.
[0218] Reference Example 1-6 A barrier laminate was produced in the same manner as in Reference Example 1-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.5 on a mass basis.
[0219] Reference Example 2-1 A barrier laminate was produced in the same manner as in Reference Example 1-1, except that the formation of the vapor deposition film was changed as follows. Using a continuous vapor deposition film forming apparatus provided with a pretreatment section and a film forming section separated from each other by disposing an oxygen plasma pretreatment apparatus, which is an actual machine, on the surface resin layer, in the pretreatment section, while applying tension to the substrate by Roll to Roll, plasma was introduced from a plasma supply nozzle under the following conditions to perform oxygen plasma pretreatment, and in the continuously conveyed film forming section, a reactive resistance heating method was used as a heating means for the vacuum vapor deposition method on the oxygen plasma treated surface to form an aluminum oxide (alumina) vapor deposition film with a thickness of 12 nm (PVD method). (Forming conditions) (Oxygen plasma pretreatment conditions) · Plasma intensity: 200 W·sec / m 2 · Plasma forming gas ratio: oxygen:argon = 2:1 · Applied voltage between pretreatment drum - plasma supply nozzle: 340 V (Film forming conditions) · Conveying speed: 400 m / min · Oxygen gas supply amount: 20000 sccm
[0220] Reference Example 2-2 A barrier laminate was produced in the same manner as in Reference Example 2-1, except that a barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 4.1 on a mass basis.
[0221] Reference Example 2-3 A barrier laminate was produced in the same manner as in Reference Example 2-1, except that a barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 3.3 on a mass basis.
[0222] Reference Example 2-4 A barrier laminate was produced in the same manner as in Reference Example 2-1, except that a barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 2.7 on a mass basis.
[0223] Reference Example 2-5 A barrier laminate was produced in the same manner as in Reference Example 2-1, except that a barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.9 on a mass basis.
[0224] Reference Example 2-6 A barrier laminate was produced in the same manner as in Reference Example 2-1, except that a barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.5 on a mass basis.
[0225] Reference Example 3-1 A barrier laminate was produced in the same manner as in Reference Example 1-1, except that polyamide was changed to ethylene vinyl alcohol (Eval F171B, manufactured by Kuraray Co., Ltd., melting point: 183°C) and a surface resin layer was formed.
[0226] Reference Example 3-2 A barrier laminate was produced in the same manner as in Reference Example 3-1, except that a barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 4.1 on a mass basis.
[0227] Reference Example 3-3 A barrier laminate was produced in the same manner as in Reference Example 3-1, except that a barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 3.3 on a mass basis.
[0228] Reference Example 3-4 A barrier laminate was produced in the same manner as in Reference Example 3-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 2.7 on a mass basis.
[0229] Reference Example 3-5 A barrier laminate was produced in the same manner as in Reference Example 3-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.9 on a mass basis.
[0230] Reference Example 3-6 A barrier laminate was produced in the same manner as in Reference Example 3-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.5 on a mass basis.
[0231] Reference Example 4-1 A barrier laminate was produced in the same manner as in Reference Example 2-1, except that the polyamide was changed to ethylene vinyl alcohol (Eval F171B, manufactured by Kuraray Co., Ltd., melting point: 183°C) and the surface resin layer was formed.
[0232] Reference Example 4-2 A barrier laminate was produced in the same manner as in Reference Example 4-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 4.1 on a mass basis.
[0233] Reference Example 4-3 A barrier laminate was produced in the same manner as in Reference Example 4-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 3.3 on a mass basis.
[0234] Reference Example 4-4 A barrier laminate was produced in the same manner as in Reference Example 4-1, except that a barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 2.7 on a mass basis.
[0235] Reference Example 4-5 A barrier laminate was produced in the same manner as in Reference Example 4-1, except that a barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.9 on a mass basis.
[0236] Reference Example 4-6 A barrier laminate was produced in the same manner as in Reference Example 4-1, except that a barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.5 on a mass basis.
[0237] Reference Example 5-1 A coating liquid for forming a surface coat layer prepared as follows was applied to the corona-treated surface of a biaxially oriented polypropylene film (ME-1, manufactured by Mitsui Chemicals Toagosei Co., Ltd.) with a thickness of 20 μm and one surface corona-treated, and dried to form a surface coat layer with a thickness of 0.5 μm, thereby producing a substrate.
[0238] A hydroxyl group-containing (meth)acrylic resin (number average molecular weight 25,000, glass transition temperature 99 °C, hydroxyl value 80 mgKOH / g) was diluted with a mixed solvent of methyl ketone and ethyl acetate (mixing ratio 1:1) until the solid content concentration reached 10% by mass to prepare a main agent. An ethyl acetate solution containing tolylene diisocyanate (solid content 75% by mass) was added as a curing agent to the main agent to obtain a coating liquid for forming a surface coat layer. The amount of the curing agent used was 10 parts by mass with respect to 100 parts by mass of the main agent.
[0239] On the surface coating layer of the substrate produced as described above, using a low-temperature plasma chemical vapor deposition apparatus, which is a real machine, by Roll to Roll, while applying tension to the substrate, a carbon-containing silicon oxide vapor deposition film with a thickness of 12 nm was formed (CVD method). The vapor deposition film formation conditions were as follows. (Formation conditions) · Hexamethyldisiloxane: oxygen gas: helium = 1:10:10 (unit: slm) · Cooling · Electrode drum supply power: 22 kw · Line speed: 100 m / min
[0240] Next, a barrier coating layer was formed on the vapor deposition film such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 5.1 on a mass basis.
[0241] Next, an unstretched polypropylene film with a thickness of 60 μm (manufactured by Toyobo Co., Ltd., P1128) was dry laminated on the barrier coating layer with a two-component curable polyurethane-based adhesive to form a sealant layer, and a barrier laminate was obtained.
[0242] Reference Example 5-2 A barrier laminate was produced in the same manner as in Reference Example 5-1, except that a barrier coating layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 4.1 on a mass basis.
[0243] Reference Example 5-3 A barrier laminate was produced in the same manner as in Reference Example 5-1, except that a barrier coating layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 3.3 on a mass basis.
[0244] Reference Example 5-4 A barrier laminate was produced in the same manner as in Reference Example 5-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 2.7 on a mass basis.
[0245] Reference Example 5-5 A barrier laminate was produced in the same manner as in Reference Example 5-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.9 on a mass basis.
[0246] Reference Example 5-6 A barrier laminate was produced in the same manner as in Reference Example 5-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.5 on a mass basis.
[0247] Reference Example 6-1 A second barrier laminate was produced in the same manner as in Reference Example 5-1, except that the formation of the vapor deposition film was changed as follows. On the surface coat layer, using an induction heating type vacuum film forming apparatus equipped with a plasma gun, which is an actual machine, a 20 nm thick silicon oxide (silica) vapor deposition film was formed by Roll to Roll while applying tension to the multilayer substrate (PVD method). The vapor deposition film forming conditions were as follows. (Forming conditions) (Plasma irradiation conditions) · Line speed: 30 m / min · Degree of vacuum: 1.7×10 -2 Pa · Output: 5.7 kw · Acceleration voltage: 151 V · Ar gas flow rate: 7.5 sccm (Film forming conditions) · Vapor deposition material: SiO · Reaction gas: O2 · Reaction gas flow rate: 100 sccm
[0248] Reference Example 6-2 A barrier laminate was produced in the same manner as in Reference Example 6-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 4.1 on a mass basis.
[0249] Reference Example 6-3 A barrier laminate was produced in the same manner as in Reference Example 6-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 3.3 on a mass basis.
[0250] Reference Example 6-4 A barrier laminate was produced in the same manner as in Reference Example 6-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 2.7 on a mass basis.
[0251] Reference Example 6-5 A barrier laminate was produced in the same manner as in Reference Example 6-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.9 on a mass basis.
[0252] Reference Example 6-6 A barrier laminate was produced in the same manner as in Reference Example 6-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.5 on a mass basis.
[0253] Reference Example 7-1 A barrier laminate was produced in the same manner as in Reference Example 5-1, except that the formation of the vapor deposition film was changed as follows.
[0254] Using a continuous vapor deposition film forming apparatus that includes a pretreatment section where an oxygen plasma pretreatment apparatus, which is an actual machine, is placed on the surface coating layer, and a film forming section separated therefrom, in the pretreatment section, while applying tension to a multilayer substrate by Roll to Roll, plasma is introduced from a plasma supply nozzle under the following conditions to perform oxygen plasma pretreatment. In the continuously conveyed film forming section, on the oxygen plasma-treated surface, a reactive resistance heating method is used as the heating means of the vacuum evaporation method under the following conditions to form an aluminum oxide (alumina) vapor deposition film with a thickness of 12 nm (PVD method). (Forming conditions) (Oxygen plasma pretreatment conditions) · Plasma intensity: 200 W·sec / m 2 · Plasma formation gas ratio: oxygen:argon = 2:1 · Applied voltage between pretreatment drum - plasma supply nozzle: 340 V (Film forming conditions) · Conveying speed: 400 m / min · Oxygen gas supply amount: 20000 sccm
[0255] Reference Example 7-2 A barrier laminate was produced in the same manner as in Reference Example 7-1, except that a barrier coating layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 4.1 on a mass basis.
[0256] Reference Example 7-3 A barrier laminate was produced in the same manner as in Reference Example 7-1, except that a barrier coating layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 3.3 on a mass basis.
[0257] Reference Example 7-4 A barrier laminate was produced in the same manner as in Reference Example 7-1, except that a barrier coating layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 2.7 on a mass basis.
[0258] Reference Example 7-5 A barrier laminate was produced in the same manner as in Reference Example 7-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.9 on a mass basis.
[0259] Reference Example 7-6 A barrier laminate was produced in the same manner as in Reference Example 7-1, except that the barrier coat layer was formed such that the solid content ratio of the metal alkoxide to the water-soluble polymer (metal alkoxide / water-soluble polymer) was 1.5 on a mass basis.
[0260] <<Gas barrier property evaluation (after lamination)>> The barrier laminate obtained in the above reference example was cut out to obtain test pieces. Using these test pieces, in the same manner as above, the oxygen permeability (cc / m 2 ·day·atm) and the water vapor permeability (g / m 2 ·day) were measured. The results are summarized in Tables 2 to 8. In Tables 2 to 8, the units of the oxygen permeability and the vapor permeability are omitted.
[0261] <<Gas barrier property evaluation (after gelboflex test)>> Using the barrier laminate obtained in the above reference example, a tubular bag was produced. Using this bag, a gelboflex test conforming to ASTM F392 was repeated 10 times. Thereafter, the barrier laminate was cut out from the bag to obtain test pieces. Using these test pieces, in the same manner as above, the oxygen permeability (cc / m 2 ·day·atm) and the water vapor permeability (g / m 2 ·day) were measured. The results are summarized in Tables 2 to 8. In Tables 2 to 8, the units of the oxygen permeability and the vapor permeability are omitted.
[0262]
Table 2
[0263]
Table 3
[0264]
Table 4
[0265]
Table 5
[0266]
Table 6
[0267]
Table 7
[0268]
Table 8
Explanation of Symbols
[0269] 10: Barrier laminate, 11: Substrate, 12: Adhesive layer, 13: Vapor deposition film, 14: Intermediate layer, 15: Sealant layer, 16: Surface resin layer, 17: Polypropylene resin layer, 18: Barrier coat layer, 19: Adhesive resin layer, 20: Barrier laminate, 21: Substrate, 22: Adhesive layer, 23: Vapor deposition film, 24: Intermediate layer, 25: Sealant layer, 26: Surface coat layer, 27: Polypropylene resin layer, 28: Barrier coat layer, 30: Packaging bag, 40: Standing pouch, 41: Body part (side sheet), 42: Bottom part (bottom sheet), 51: Easy opening means, 52: Notch part, 53: Half cut line, 60: Vapor venting mechanism, 60a: Vapor seal part, 60b: Non-seal part, 70: Test piece, 71: Substrate side, 72: Sealant layer side, 73: Gripping tool, A: Vacuum container, B: Unwinding part, C: Film forming drum, D: Winding part, E: Conveyor roll, F: Evaporation source, G: Reaction gas supply part, H: Anti-deposition box, I: Vapor deposition material, J: Plasma gun, A1: Vacuum container, B1: Unwinding part, C1: Cooling / electrode drum, D1: Winding part, E1: Conveyor roll, F1: Glow discharge plasma, G1: Reaction gas supply part, H1: Raw material supply nozzle, I1: Raw material gas supply part, J1: Magnet, K1: Power supply, L1: Vacuum pump
Claims
1. A barrier laminate comprising a substrate, an adhesive layer, a vapor-deposited film, an intermediate layer, and a sealant layer, the intermediate layer includes at least a surface resin layer, an adhesive resin layer, and a polypropylene resin layer in this order; The surface resin layer contains a resin material having a melting point of 180° C. or more, the resin material is one or more resin materials selected from polyvinyl alcohol, nylon 6, nylon 6,6, and MXD nylon; the adhesive resin layer contains one or more selected from polyether, polyester, silicone resin, epoxy resin, vinyl resin, phenol resin, polyolefin, and acid-modified polyolefin, the barrier laminate has the vapor-deposited film on the surface resin layer, the barrier laminate further includes a barrier coat layer between the adhesive layer and the vapor-deposited film, the deposited film is made of an inorganic oxide, 13. A barrier laminate, comprising: said surface resin layer, said adhesive resin layer and said polypropylene resin layer, each of which has been subjected to a stretching treatment.
2. the polypropylene resin layer, the base material, and the sealant layer are made of the same material; 2. The barrier laminate according to claim 1, wherein the same material is polypropylene.
3. 3. The barrier laminate according to claim 1, wherein the adhesive layer is an adhesive layer containing a cured product of a composition containing a polyester polyol and an isocyanate compound.
4. 4. The barrier laminate according to claim 1, wherein the resin material has a melting point of 265° C. or lower.
5. 5. The barrier laminate according to claim 1, wherein a difference between a melting point of the resin material and a melting point of the polypropylene contained in the polypropylene resin layer is 20 to 80° C.
6. The barrier laminate according to any one of claims 1 to 5, wherein the resin material is a polyamide.
7. 7. The barrier laminate according to claim 1, wherein a ratio of a thickness of the surface resin layer to a total thickness of the intermediate layer is 1% or more and 10% or less.
8. The barrier laminate according to any one of claims 1 to 7, wherein the intermediate layer is a co-extruded film.
9. The barrier laminate according to any one of claims 1 to 8, which is used for a packaging container.
10. A packaging container comprising the barrier laminate according to any one of claims 1 to 9.
Citation Information
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