Laminate and packaging bag

Abstract

To provide novel laminates and packaging bags characterized by low water vapor permeability and excellent non-adsorbability.SOLUTION: A laminate 10 has at least a substrate layer 11, a first intermediate layer 12, and a sealant layer 13 in this order. The first intermediate layer 12 bonds the substrate layer 11 to the sealant layer 13. The substrate layer 11 includes a layer based on a fluororesin as a forming material and other layers. The first intermediate layer 12 includes a polyethylene resin, an elastomer component, and a component with epoxy groups.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a laminate and a packaging bag. [Background technology]

[0002] Resin films used as packaging materials for pharmaceuticals, cosmetics, food, etc. are required to have low water vapor permeability in order to prevent deterioration of the active ingredients of these contents. In particular, packaging bags using sealant resins such as polyolefins are used as packaging materials for products that are applied to living organisms, such as pharmaceuticals (for example, Patent Document 1). Packaging bags using sealant resins such as polyolefins can maintain low water vapor permeability due to the hydrophobicity of polyolefins. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-084044 Summary of the Invention [Problem to be solved by the invention]

[0004] However, packaging bags using sealant resins such as polyolefins may adsorb pharmaceuticals and other substances into the sealant resin layer or alter the properties of proteins and other components contained in biomaterials. This is thought to be because polyolefins, which are hydrophobic, are also highly lipophilic. Therefore, there has been a demand for packaging bags that are less likely to adsorb pharmaceuticals and other substances.

[0005] Furthermore, in response to market demands, there has been a demand for packaging bags such as those described in Patent Document 1 to have a further reduced water vapor transmission rate.

[0006] The present invention has been made in view of the above circumstances, and provides a novel packaging bag that has low water vapor permeability and excellent non-adsorption properties. [Means for solving the problem]

[0007] In order to solve the above problems, one aspect of the present invention provides a packaging bag having a bag body and a pouring outlet joined to the bag body, the bag body being formed from a laminate having at least a base material layer, a first intermediate layer, and a sealant layer in this order, and having the sealant layers on the inside and opposing sealant layers bonded together to form a bag shape, the pouring outlet being sandwiched and bonded between the opposing sealant layers, the first intermediate layer comprising a polyethylene resin and a modified polyethylene resin, and the base material layer comprising a layer made of a fluorine-based resin.

[0008] In one embodiment of the present invention, the polyethylene resin may be linear low-density polyethylene.

[0009] In one embodiment of the present invention, the modified polyethylene resin may be maleic anhydride modified polyethylene.

[0010] One aspect of the present invention provides a packaging bag having a bag body and a pouring outlet joined to the bag body, the bag body being formed from a laminate having at least a base material layer, a first intermediate layer, and a sealant layer in this order, and having the sealant layers on the inside and facing each other by bonding them together to form a bag shape, the pouring outlet being sandwiched and joined between the facing sealant layers, the first intermediate layer containing a polyethylene resin, an elastomer component, and a component having an epoxy group, and the base material layer including a layer made of a fluorine-based resin.

[0011] In one embodiment of the present invention, the component having an epoxy group may be 1,2-polybutadiene in which epoxy is partially introduced, and may have a number average molecular weight of 500 or more and 4,000 or less.

[0012] In one embodiment of the present invention, the elastomer component may contain a styrene-ethylene-butylene-styrene copolymer having a styrene content of 8% by mass or more and 24% by mass or less.

[0013] In one aspect of the present invention, the thickness of the layer made of a fluorine-based resin may be 20 μm or more and 60 μm or less.

[0014] In one aspect of the present invention, the fluorine-based resin may be polychlorotrifluoroethylene.

[0015] In one aspect of the present invention, the sealant layer may contain a cyclic olefin resin.

[0016] In one aspect of the present invention, the film may have a configuration in which a surface resin layer is provided on the outer surface of the base material layer, and a second intermediate layer is sandwiched between the base material layer and the surface resin layer.

[0017] In one aspect of the present invention, the pouring outlet may be configured to contain a cyclic olefin resin as a forming material.

[0018] In one aspect of the present invention, the spout may be a two-color molded product, and at least the portion that comes into contact with the contents may contain a cyclic olefin resin. [Effects of the Invention]

[0019] According to one aspect of the present invention, a novel packaging bag is provided that has low water vapor permeability and excellent non-adsorption properties. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 is a plan view of the packaging bag 31 of the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. [Figure 4] FIG. 6 is a cross-sectional view of a packaging bag according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] First Embodiment <Packaging bag> A packaging bag according to a first embodiment of the present invention will be described below with reference to Figures 1 and 2. In all of the following drawings, the dimensions and proportions of each component have been changed as appropriate to make the drawings easier to understand.

[0022] The packaging bag of this embodiment is a packaging bag for containing contents such as pharmaceuticals, cells, tissues, organs, biomaterials, blood, body fluids, enzymes, antibodies, beauty products, nutrients, health supplements, cosmetics, foods, etc. The packaging bag of this embodiment is suitably used as a packaging bag for containing pharmaceuticals. Examples of the form of the packaging bag include three-sided bags, four-sided bags, seamed bags, gusset bags, self-standing bags, pouches, and large bags such as inner bags for bag-in-boxes and inner bags for drums.

[0023] The specific state, shape, etc. of the contents contained in the packaging bag of this embodiment are not particularly limited. The contents may be, for example, a solid, liquid, gas, powder, granules, a mixture, a composition, a dispersion, etc. Furthermore, when the contents are liquid, the liquid may be an aqueous solution containing a drug. When the contents are contained in the packaging bag, an inert gas such as nitrogen or a liquid may be filled.

[0024] Fig. 1 is a plan view of a packaging bag 31 of a first embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. As shown in Figs. 1 and 2, the packaging bag 31 has a bag body 17 and a spout 20 joined to the bag body 17.

[0025] The bag body 17 is formed into a bag shape by bonding two sheets of the laminate 10 together, using the laminate 10 as the forming material. The spout 20 is sandwiched and joined between the opposing laminates 10.

[0026] The packaging bag 31 has a first joint 14 where the laminate 10 and the spout 20 are joined, and a second joint 15 where the laminates 10 are joined together. In a plan view, the first joint 14 and the second joint 15 are continuous and are provided in a closed loop shape on the periphery of the bag body 17. Furthermore, the packaging bag 31 may have folded-back portions at parts of the first joint 14 and the second joint 15 where the laminate 10 is mountain-folded to form a V-shaped cross section.

[0027] The bag body 17 forms a space 5 for filling with the contents 16. Note that the drawings do not show the specific state, shape, etc. of the contents 16. Before filling with the contents 16, the bag body 17 may have a filling opening for filling the contents 16 into the space 5.

[0028] [Laminate] The laminate 10 has, in this order, a base material layer 11, a first intermediate layer 12, and a sealant layer 13. The bag body 17 shown in the figure is made by using two laminates 10, with the sealant layers 13 of each laminate facing each other and bonding the sealant layers 13 together.

[0029] (base material layer) In the first embodiment, the base material layer 11 is a layer exposed to the outside of the space 5. The base material layer 11 of the present embodiment includes a layer made of a fluororesin. When the base material layer 11 includes a layer made of a fluororesin, a packaging bag having excellent mechanical strength and optical properties and low water vapor permeability can be provided.

[0030] Examples of fluorine-based resins include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether (EPA), tetrafluoroethylene-ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and chlorotrifluoroethylene-ethylene copolymer (ECTFE). Among these, polychlorotrifluoroethylene (PCTFE) is preferred. The above-mentioned resins may be used alone or in combination of two or more.

[0031] When two laminates 10 are heat-sealed with the sealant layer 13, it is necessary to heat the sealant layer 13 until the resin contained in the sealant layer 13 melts. At this time, in order to suppress deformation and deterioration of the laminate 10, the heating temperature during heat sealing needs to be lower than the melting temperature of the resin contained in the base layer 11. Therefore, the type of resin contained in the sealant layer 13 is limited depending on the type of resin contained in the base layer 11.

[0032] In the laminate 10 of this embodiment, a fluororesin having a higher glass transition temperature than resins that have been used in base layers up to now is used, thereby widening the options for materials for forming the sealant layer 13.

[0033] In this embodiment, the thickness of the layer made of fluororesin is preferably 20 μm or more and 60 μm or less. When the thickness of the layer made of fluororesin is 20 μm or more, the water vapor transmission rate of the packaging bag 31 can be sufficiently reduced. Furthermore, when the thickness of the layer made of fluororesin is 60 μm or less, production costs can be reduced.

[0034] The base layer 11 may have a single layer structure or a laminate structure of two or more layers. Layers that may constitute the base layer 11 (hereinafter referred to as "other layers") can be selected appropriately. Examples of other layers include a reinforcing layer, a gas barrier layer, a light-shielding layer, a printed layer, metal foil, and synthetic paper. The other layers may be configured not to contain fluorine-based resin.

[0035] Examples of the reinforcing layer include reinforcing resin layers such as biaxially oriented polyethylene terephthalate (O-PET), biaxially oriented nylon (O-Ny), and biaxially oriented polypropylene (OPP). The gas barrier layer can be made of, for example, an inorganic material or a gas barrier resin. Examples of inorganic materials include a metal vapor deposition layer and a metal oxide such as alumina. Examples of gas barrier resins include ethylene-vinyl alcohol copolymer (EVOH) and vinylidene chloride.

[0036] The laminate 10 may have a printed layer or a coated layer on the surface 11 a of the substrate layer 11 opposite to the first intermediate layer 12 .

[0037] The printing layer can impart distinctiveness and design to the packaging bag 31 by printing ink on the surface (surface 11a) of the base material layer 11.

[0038] The coating layer is intended to protect the base material layer 11 or other layers such as a printed layer provided on the base material layer 11. Examples of such a coating layer include a thin resin layer (resin film) and an ultraviolet-curable resin.

[0039] (First middle class) The first intermediate layer 12 bonds the base material layer 11 and the sealant layer 13. The first intermediate layer 12 of the present embodiment preferably contains either a polyethylene resin and a modified polyethylene resin, or a polyethylene resin, an elastomer component, and a resin composition containing an epoxy group.

[0040] In this specification, the first intermediate layer containing the polyethylene resin and the modified polyethylene resin may be referred to as "intermediate layer (1)." Also, the first intermediate layer containing the polyethylene resin, the elastomer component, and the resin composition containing an epoxy group may be referred to as "intermediate layer (2)."

[0041] "Middle Class (1)" Examples of the polyethylene resin contained in the intermediate layer (1) include linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE), and linear low-density polyethylene is preferred.

[0042] The modified polyethylene resin contained in the intermediate layer (1) is a polyethylene resin modified with an unsaturated carboxylic acid or its derivative, and has an acid functional group such as a carboxy group or a carboxylic anhydride group in the polyethylene resin. In this embodiment, a polyethylene resin obtained by acid modification is preferred. The acid modification method includes graft modification in which a polyethylene resin and an acid functional group-containing monomer are melt-kneaded in the presence of a radical polymerization initiator such as an organic peroxide or an aliphatic azo compound.

[0043] The polyethylene resin material before modification is not limited as long as it contains ethylene as a raw material monomer, and known polyethylene resins can be appropriately used. Specific examples of polyethylene resins include the above-mentioned examples, as well as ethylene-α-olefin copolymers such as ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-hexene copolymer, and ethylene-1-octene copolymer; and ethylene copolymer resins such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, and ethylene-(meth)acrylic acid ester copolymer.

[0044] The acid functional group-containing monomer is a compound having an ethylenic double bond and a carboxy group or a carboxylic acid anhydride group in the same molecule, and examples thereof include various unsaturated monocarboxylic acids, dicarboxylic acids, and acid anhydrides of dicarboxylic acids. Examples of acid functional group-containing monomers having a carboxy group (carboxy group-containing monomers) include α,β-unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, maleic acid, nadic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, tetrahydrophthalic acid, and endo-bicyclo[2.2.1]-5-heptene-2,3-dicarboxylic acid (endic acid). Examples of the acid functional group-containing monomer having a carboxylic acid anhydride group (carboxylic acid anhydride group-containing monomer) include unsaturated dicarboxylic acid anhydride monomers such as maleic anhydride, nadic anhydride, itaconic anhydride, citraconic anhydride, and endic anhydride. These acid functional group-containing monomers may be used alone or in combination of two or more types in the components constituting the first intermediate layer 12.

[0045] Of these, as the acid functional group-containing monomer, an acid functional group-containing monomer having an acid anhydride group is preferred, a carboxylic acid anhydride group-containing monomer is more preferred, and maleic anhydride is particularly preferred. When a portion of the acid functional group-containing monomer used for the acid modification remains unreacted, it is preferable to use a resin from which the unreacted acid functional group-containing monomer has been removed in advance in order to prevent a decrease in adhesive strength due to the unreacted acid functional group-containing monomer.

[0046] The modified polyethylene resin contained in the intermediate layer (1) is preferably maleic anhydride modified polyethylene.

[0047] In the intermediate layer (1), when the total mass of the polyethylene resin and the modified polyethylene resin is taken as 100%, the lower limit of the proportion of the polyethylene resin relative to the total mass of the polyethylene resin and the modified polyethylene resin is preferably 10% or more, more preferably 20% or more. The upper limit of the proportion of the polyethylene resin relative to the total mass of the polyethylene resin and the modified polyethylene resin is preferably 70% or less, more preferably 60% or less. For example, the mixing ratio of the polyethylene resin and the modified polyethylene resin can be [polyethylene resin]:[modified polyethylene resin] = 20:80 to 60:40.

[0048] By using a mixed material of polyethylene resin and modified polyethylene resin for the first intermediate layer 12, the adhesion between the sealant layer 13 and the base layer 11 is improved, thereby making it possible to provide a laminate 10 that is less susceptible to delamination.

[0049] "Middle Class (2)" The intermediate layer (2) contains a resin composition containing a polyethylene resin, an elastomer component, and a component having an epoxy group.

[0050] The polyethylene resin contained in the intermediate layer 2 is the same as the polyethylene resin contained in the mixture of the polyethylene resin and the modified polyethylene resin. The polyethylene resin contained in the resin composition may be biomass polyethylene, petroleum-derived polyethylene, or a mixture of both.

[0051] The polyethylene resin contained in the intermediate layer (2) is preferably polyethylene polymerized using a metallocene catalyst. Among these, preferred examples include ethylene-α-olefin copolymers such as C4-LLDPE, C6-LLDPE, and C8-LLDPE polymerized using a metallocene catalyst, and long-chain branched polyethylene. Polyethylene resins polymerized with methacerone catalysts tend to have narrow molecular weight distributions, which means they contain fewer low-molecular-weight components that can inhibit adhesion, and are thought to provide high adhesive properties when used as adhesives.

[0052] The density of the polyethylene resin in the resin composition is 0.890 g / cm 3 More than 0.940g / cm 3 Less than 0.910cm is preferred 3 More than 0.930g / cm 3 The following is more preferred:

[0053] The content of the polyethylene resin in the resin composition is 55 parts by mass or more and 90 parts by mass or less, and preferably 60 parts by mass or more and 80 parts by mass or less. When the content of the polyethylene resin is equal to or less than the upper limit, the adhesiveness with the elastomer component described below is exhibited, and the adhesiveness is increased.

[0054] Examples of the elastomer component contained in the intermediate layer (2) include styrene-based elastomers, acrylic-based elastomers, urethane-based elastomers, ester-based elastomers, etc. However, the elastomer component does not include components having an epoxy group, which will be described later. Among these, styrene-based elastomers are preferred, and examples thereof include block copolymers having a hard segment made of polystyrene or the like and a soft segment made of polyethylene, polybutadiene, polyisoprene, etc. Examples of styrene-based polymers that can be used for the styrene-based elastomer include aromatic olefin-aliphatic olefin copolymers such as styrene-butadiene copolymer, styrene-isoprene copolymer, and styrene-ethylene copolymer.

[0055] The styrene elastomer is preferably a styrene-ethylene-butylene-styrene copolymer (SEBS) obtained by hydrogenating a styrene-butylene-styrene copolymer (SBS) to completely open the unsaturated bonds in the molecule. The styrene content is preferably 8% by mass or more and 24% by mass or less, and more preferably 10% by mass or more and 20% by mass or less. When the styrene content is equal to or less than the upper limit, curing of the resin can be suppressed, and a decrease in adhesiveness can be suppressed.

[0056] Specific examples of the elastomer component contained in the intermediate layer (2) include Dynaron from JSR Corporation, Tuftec H series from Asahi Kasei Chemicals Corporation, and Kraton G Polymer from Kraton Polymers Co., Ltd.

[0057] In the intermediate layer (2), the content of the elastomer component is 10 parts by mass or more and 45 parts by mass or less, and preferably 20 parts by mass or more and 40 parts by mass or less. When the content of the elastomer component is equal to or less than the upper limit, a decrease in tensile strength when the adhesive layer is formed can be suppressed, and a decrease in adhesive strength can be prevented.

[0058] The total amount of the polyethylene resin and the elastomer component is 100 parts by mass.

[0059] The component having an epoxy group contained in the intermediate layer (2) is preferably a component having an epoxy group and a vinyl group. The component having an epoxy group and a vinyl group is preferably a component having a 1,2-vinyl structure, and is preferably an epoxidized polybutadiene obtained by partially epoxidizing butadiene. Partially epoxidized 1,2-polybutadiene is particularly preferred.

[0060] Specific examples of components having an epoxy group include liquid polybutadiene JP-100 and JP-200 from Nippon Soda Co., Ltd. and Adeka Cizer BF-1000 from Adeka Corporation.

[0061] The number average molecular weight of the component having an epoxy group is preferably 500 or more and 4,000 or less. When the number average molecular weight of the component having an epoxy group is equal to or less than the upper limit, it is possible to suppress a decrease in adhesiveness due to the component becoming solid at room temperature, and it is possible to prevent a decrease in adhesiveness. In the present embodiment, the number average molecular weight is a value calculated as polystyrene measured by GPC (gel permeation chromatography).

[0062] In the intermediate layer (2), the content of the component having an epoxy group relative to 100 parts by mass of the total amount of the polyethylene resin and the elastomer component is 0.1 parts by mass or more and 1.5 parts by mass or less, and preferably 0.5 parts by mass or more and 1.0 part by mass or less. When the content of the component having an epoxy group is equal to or less than the upper limit, the amount of low-molecular-weight components in the resin composition that cause adhesion inhibition can be reduced.

[0063] In the intermediate layer 2, the elastomer component and the component having an epoxy group have a common repeating unit and are compatible with each other. The elastomer component and the component having an epoxy group are preferably a combination of styrene-based elastomers or acrylic-based elastomers.

[0064] The resin composition of the intermediate layer (2) is characterized by a mixture of a polyethylene resin, an elastomer component, and an epoxy group-containing component in specific blending ratios. The resin composition of this embodiment has excellent adhesion to fluororesins because the epoxy groups in the epoxy group-containing component are compatible with the fluorine component of the fluororesin. The presence of epoxy groups also enables adhesion to metal materials.

[0065] In the intermediate layer (2), a polyethylene resin, an elastomer component, and an epoxy group-containing component are mixed in specific blending ratios to form a so-called sea-island structure, with the polyethylene resin acting as the "sea" and the elastomer component acting as the "islands." Furthermore, the epoxy group-containing component is compatible with the elastomer component, allowing the epoxy group-containing component to be uniformly dispersed throughout the resin composition. This is thought to protect the epoxy groups between the polyethylene resin and the elastomer component, preventing ring-opening of the epoxy groups due to moisture.

[0066] By using a mixed material of a polyethylene resin, an elastomer component, and a component having an epoxy group for the first intermediate layer 12, the adhesion between the sealant layer 13 and the base layer 11 is improved, thereby making it possible to provide a laminate 10 that is less susceptible to delamination.

[0067] By forming first intermediate layer 12 using the above-mentioned materials, it is possible to provide packaging bag 31 in which delamination is unlikely to occur between base material layer 11 and first intermediate layer 12 or between first intermediate layer 12 and sealant layer 13. Furthermore, by suppressing poor adhesion of first intermediate layer 12, it is possible to suppress cracks in packaging bag 31 caused by such poor adhesion.

[0068] (sealant layer) The sealant layer 13 is used when the laminate 10 is bonded together by heat sealing or the like to form a bag. The sealant layer 13 is a layer that faces the space 5 in the packaging bag 31 and comes into contact with the contents 16.

[0069] In this embodiment, the base layer 11 includes a layer made of a fluorine-based resin having a high glass transition temperature. This allows the sealant layers 13 to be bonded together at high temperatures using heat sealing or the like. Therefore, a material with a high glass transition temperature can be used to form the sealant layer 13.

[0070] It is also known that the higher the glass transition temperature of the material forming sealant layer 13, the better the non-adsorption property to contents 16. In this embodiment, sealant layer 13 preferably contains a cyclic olefin resin. When sealant layer 13 contains a cyclic olefin resin, a packaging bag with excellent non-adsorption property to contents 16 can be provided.

[0071] Examples of cyclic olefin resins include cyclic olefin polymers (COP), cyclic olefin copolymers (COC), etc. The resin component constituting the sealant layer 13 may be one or more types of cyclic olefin resins, or may be a mixture of a cyclic olefin resin with another resin or elastomer, etc.

[0072] Examples of COP include a homopolymer of a cyclic olefin, a copolymer of two or more types of cyclic olefins, or a hydrogenated product thereof. The cyclic olefin polymer is preferably an amorphous polymer, and more preferably a ring-opening polymer of a cyclic olefin obtained by metathesis or the like, or a hydrogenated product thereof. Compared to cyclic olefin copolymers and the like, cyclic olefin polymers contain a higher proportion of alicyclic structures and have excellent non-adsorption properties for the contents 16.

[0073] Examples of COC include copolymers of one or more cyclic olefins and one or more acyclic olefins, or hydrogenated products thereof. The cyclic olefin copolymer is preferably an amorphous polymer, and more preferably a copolymer of a cyclic olefin and ethylene, or a hydrogenated product thereof.

[0074] The cyclic olefin used as a constituent monomer of the cyclic olefin resin is an unsaturated hydrocarbon (olefin) having at least one ring structure. Examples include vinylcycloalkanes having cycloalkanes with 3 to 20 carbon atoms and derivatives thereof, monocycloalkenes having 3 to 20 carbon atoms and derivatives thereof, and cyclic olefins having a norbornene skeleton (norbornene monomers).

[0075] Norbornene-based monomers include bicyclo[2.2.1]-2-heptene (norbornene) and its derivatives. Derivatives include compounds with a substituent such as an alkyl group, compounds with two or more unsaturated bonds such as norbornadiene, and compounds with three or more ring structures, two of which constitute a norbornene skeleton. Norbornene-based monomers with three or more ring structures include tricyclo[5.2.1.0]-2-heptene. 2,6]decene (dihydrodicyclopentadiene), compounds in which one or more molecules of cyclopentadiene are added to norbornene or dihydrodicyclopentadiene by the Diels-Alder reaction (e.g., tetracyclododecene, pentacyclopentadecene, hexacycloheptadecene, etc.), hydrogenated products of these, isomers with different double bond positions, alkyl-substituted products, etc.

[0076] Examples of acyclic olefins used as constituent monomers of COC include α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene, and alkenes such as 3-decene and 3-dodecene.

[0077] The glass transition temperature of the material forming the sealant layer 13 is preferably 100° C. or higher and 170° C. or lower, and more preferably 105° C. or higher and 160° C. or lower. When the glass transition temperature of the material forming the sealant layer 13 is 100° C. or higher, the sealant layer 13 tends to have excellent non-adsorption properties for the contents 16. Furthermore, when the glass transition temperature of the material forming the sealant layer 13 is 170° C. or lower, high temperatures are not required when bonding the laminate 10, and therefore the sealant layer 13 has excellent formability.

[0078] The thickness of the sealant layer 13 is preferably 20 μm or more, and more preferably 30 μm or more. When the thickness of the sealant layer 13 is 20 μm or more, the sealant layers 13 of the laminate 10 can be bonded together by heat sealing or the like to form the laminate 10 into a bag shape. Furthermore, the thickness of the sealant layer 13 is preferably 60 μm or less, and more preferably 50 μm or less. When the thickness of the sealant layer 13 is 60 μm or less, production costs can be reduced. The upper and lower limit values ​​for the thickness of the sealant layer 13 can be combined in any manner.

[0079] When the sealant layer 13 contains a cyclic olefin resin, it is known that the thicker the sealant layer 13, the lower the water vapor permeability of the packaging bag. On the other hand, it is known that the thicker the sealant layer 13, the more likely it is to crack, and the lower the drop strength of the packaging bag 31. Therefore, from the viewpoint of lowering the water vapor permeability of the packaging bag, a thicker sealant layer 13 is preferable, but from the viewpoint of increasing the drop strength, a thinner sealant layer 13 is preferable.

[0080] In this embodiment, the base layer 11 includes a layer made of a fluororesin with a low water vapor permeability. This allows the water vapor permeability of the packaging bag 31 to be sufficiently low even if the sealant layer 13 is made thinner compared to when the base layer is made of a resin other than a fluororesin. In other words, a packaging bag 31 with excellent barrier properties against water vapor can be provided. It is also known that a thinner sealant layer 13 makes the sealant layer 13 less likely to crack, and increases the drop strength of the packaging bag 31. Therefore, by including a layer made of a fluororesin in the base layer, a packaging bag with excellent barrier properties against water vapor and easy handling can be provided.

[0081] The layer structure of the second bonding portion 15 where the laminates 10 are bonded together is in the order of base material layer 11 / first intermediate layer 12 / sealant layer 13 / sealant layer 13 / first intermediate layer 12 / base material layer 11. The second bonding portion 15 is formed by the fusion of the resin contained in the sealant layer 13 of the laminates 10.

[0082] [Pour spout] The spout 20 is sandwiched and joined between the opposing sealant layers 13. The spout 20 preferably contains a cyclic olefin resin, and preferably contains a cyclic olefin resin at least in the portion that comes into contact with the contents 16. Examples of cyclic olefin resins that form the spout 20 include the same cyclic olefin resins that form the sealant layer 13. The material that forms the spout 20 and the material that forms the sealant layer 13 may be the same or different. In this embodiment, the spout 20 and the sealant layer 13 are preferably formed from the same material.

[0083] 3 is a perspective view showing the periphery of the spout 20. As shown in FIG. 3, the spout 20 is a two-color molded product made up of a first molded body 21 and a second molded body 22.

[0084] The first molded body 21 has a cylindrical shape and has a flow path 23 therein for removing the contents 16. The first molded body 21 has at least a portion contained in the space 5. The first molded body 21 preferably contains a cyclic olefin resin or a polyolefin resin as a forming material, and more preferably contains a cyclic olefin resin. When the first molded body 21 is formed from a cyclic olefin resin, a packaging bag with excellent non-adsorbent properties can be provided.

[0085] The second molded body 22 has a cylindrical shape and is formed on the outer peripheral surface 21a of the first molded body 21. However, the second molded body 22 is not formed on the outer peripheral surface of the portion of the first molded body 21 that is to be accommodated in the space 5. The second molded body 22 has a shorter axial length than the first molded body 21. The second molded body 22 preferably contains a polyolefin resin as a forming material.

[0086] The polyolefin resin may be a homopolymer of one type of olefin or a copolymer of two or more types of olefins. Examples of the olefin include acyclic olefins such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, and α-olefins. Specific examples of polyolefins include polyethylene, polypropylene, and ethylene-α-olefin copolymers. These polyolefins may be copolymers containing small amounts of non-olefinic vinyl monomers such as vinyl acetate, vinyl chloride, vinyl alcohol, etc. The olefins may be derived from petroleum-derived olefins, plant-derived olefins, or a combination of both. The polyolefin resin forming the second molded body 22 is preferably a polyethylene resin, and more preferably linear low-density polyethylene (LLDPE).

[0087] When the second molded body 22 is made of a polyolefin resin, the laminate 10 forming the bag body 17 and the spout 20 can be easily joined, and the bag body 17 is easy to handle and has excellent durability.

[0088] The layer structure of first joint 14 where laminate 10 and spout 20 are joined is in the following order: base material layer 11 / first intermediate layer 12 / sealant layer 13 / spout 20 / sealant layer 13 / first intermediate layer 12 / base material layer 11. First joint 14 is formed by fusion of the resin contained in sealant layer 13 of laminate 10 and spout 20.

[0089] At first joint 14, laminate 10 may be joined to first molded body 21 of spout 20, or may be joined to second molded body 22. First joint 14 may include both a portion where laminate 10 and first molded body 21 are joined and a portion where laminate 10 and second molded body 22 are joined.

[0090] [Other configurations] In addition to the spout, the packaging bag 31 may also be provided with accessories such as a pouring port, a cock, a label, an opening tab, a handle, etc. If the accessories are resin molded products, they may have the same structure as the spout described above.

[0091] <Manufacturing method of packaging bags> The method for manufacturing the packaging bag 31 includes a step of forming the laminate 10 and a step of joining the laminate 10 and the spout 20 together.

[0092] In the process of forming the laminate 10, the resin that will be the raw material for the base layer 11, the resin that will be the raw material for the first intermediate layer 12, and the resin that will be the raw material for the sealant layer 13 are simultaneously melt-extruded to form the laminate 10. Alternatively, the base layer 11, the first intermediate layer 12, and the sealant layer 13 can be laminated by a method such as dry lamination or extrusion lamination to form the laminate 10.

[0093] In the step of joining the laminate 10 and the spout 20, first, the sealant layers 13 of the laminates 10 are placed opposite each other, and the spout 20 is sandwiched between the laminates 10. Next, the laminates 10 and the spout 20 are joined to form a first joint 14. The laminates 10 are joined to each other to form a second joint 15. In this way, the packaging bag 31 is manufactured.

[0094] According to the above configuration, a novel packaging bag having low water vapor permeability and excellent non-adsorption properties can be provided.

[0095] Second Embodiment <Packaging bag> A packaging bag according to a second embodiment of the present invention will be described below with reference to Fig. 4. Fig. 4 is a cross-sectional view of the packaging bag according to the second embodiment, and corresponds to Fig. 2. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0096] 4, the packaging bag 32 of the second embodiment has a bag body 117 and a spout 20 joined to the bag body 117. The bag body 117 is formed from a laminate 110 and is formed into a bag shape by bonding two sheets of the laminate 110 together.

[0097] The laminate 110 of the second embodiment has a surface resin layer 111, a second intermediate layer 112, a base material layer 11, a first intermediate layer 12, and a sealant layer 13 in this order.

[0098] The bag body 117 shown in FIG. 4 is made by using two laminates 110, with the sealant layers 13 of the laminates facing each other and pasting the sealant layers 13 together.

[0099] The second intermediate layer 112 in the second embodiment may contain the same material as the material contained in the first intermediate layer 12. The second intermediate layer 112 may contain the same material as the first intermediate layer 12, or may contain a different material.

[0100] (Surface resin layer) The surface resin layer 111 in the second embodiment is a layer made of a polyolefin resin, a polyethylene resin, a polyimide resin, a polyester resin, etc. Among these, the surface resin layer 111 is preferably made of a polyolefin resin, and more preferably made of a polyolefin resin containing a cyclic olefin resin.

[0101] The cyclic olefin resin may be the same material as that contained in the sealant layer 13. The surface resin layer 111 may be the same material as that contained in the sealant layer 13, or may be a different material.

[0102] The surface resin layer 111 may have a single-layer structure consisting of one layer, or may have a laminated structure consisting of two or more layers. A printed layer or a colored resin layer, for example, may be provided on the surface 111a of the surface resin layer 111 opposite to the second intermediate layer 112.

[0103] According to the above configuration, it is possible to provide a novel packaging bag having low water vapor permeability and excellent non-adsorption properties, as in the first embodiment. In the second embodiment, by arbitrarily selecting the resin for the surface resin layer 111, it is possible to improve the printability and slipperiness of the surface of the packaging bag 32.

[0104] Furthermore, since the laminate 110 used in the second embodiment has a five-layer structure, the strength of the packaging bag 32 is higher than in the first embodiment. Furthermore, in the second embodiment, curling of the laminate 110 can be suppressed compared to the first embodiment. In particular, by forming the first intermediate layer 12 and the second intermediate layer 112 from the same material, the properties of the inner and outer surfaces of the base material layer 11 are the same, which further suppresses curling of the laminate 110. As a result of suppressing curling of the laminate 110, the laminate 110 can be easily processed in the manufacturing process of the packaging bag 32.

[0105] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention. [Example]

[0106] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0107] [Examples 1 to 13, Comparative Example 1] A three-layer laminate was produced, consisting of a substrate layer, an intermediate layer, and a sealant layer in that order. The resins used as raw materials for each layer, as shown in Table 1, were separately heated and melt-mixed, and then a multilayer film was formed simultaneously using an extruder capable of simultaneous multilayer extrusion molding, to obtain a three-layer laminate.

[0108] Separately, a five-layer laminate was produced having a surface resin layer, a second intermediate layer, a substrate layer, a first intermediate layer, and a sealant layer in that order. The resins used as raw materials for each layer, as shown in Table 2, were used to form a film in the same manner as for the three-layer laminate, yielding a five-layer laminate. In Tables 1 and 2, the values ​​in brackets [ ] indicate the thickness of each layer.

[0109] In addition to these laminates, a cylindrical spout, the inside of which was made of COP and the outside of which was partly made of polyethylene (PE), was molded by two-color molding. A spout was sandwiched between the laminates, and a first joint between the laminate and the spout and a second joint between the laminates 10 were joined to produce a packaging bag.

[0110] [Table 1]

[0111] [Table 2]

[0112] The following materials were used as raw materials for the base layer, sealant layer, and surface resin layer. COP: Cycloolefin polymer. ZEONOR (registered trademark) 1020R manufactured by Zeon Corporation was used. PE: Linear low-density polyethylene (Nipolon, manufactured by Tosoh Corporation, ρ = 0.930 g / cm 3 , for the inner layer). PCTFE: Polychlorotrifluoroethylene resin. Daikin Industries, Ltd., DF0050-C1 is used. MAH-ETFE: Fluorine-based resin. Asahi Glass Co., Ltd., Fluon LH-8000 (ρ = 1.75 g / cm 3 , Tm = 180 ° C, melt mass flow rate = 4 g / 10 min (test temperature 230 ° C, load 2.16 kgf)).

[0113] Table 3 shows the compositions of intermediate layers 1 to 4. In Table 3, the ratio of each material is expressed as a mass ratio (%).

[0114] [Table 3]

[0115] The materials used in Table 3 were the following commercially available products. Elastomer: Kraton G1657M (styrene content 13% by mass, ρ = 0.90 g / cm), manufactured by Kraton Corporation 3 , Melt mass flow rate = 22 g / 10 min (test temperature 230 °C, load 5 kgf) was used. Epoxidized polybutadiene: Epoxidized 1,2-polybutadiene (ρ=0.99g / cm) manufactured by Adeka Corporation 3 , Mn=1000).

[0116] <Evaluation> The following tests were carried out on each of the packaging bags of Examples 1 to 13 and Comparative Example 1. The results of each test are shown in Table 4.

[0117] [Deterioration of contents] The packaging bags of the Examples and Comparative Examples were filled with 100 mL of 0.05% by mass nitroglycerin injection as the content. These were subjected to high-pressure steam sterilization at 110°C and 0.106 MPa for 40 minutes to obtain packaging bags containing the content. The packaging bags containing the content were stored at 40°C for 3 months, and the content of nitroglycerin injection was visually confirmed. ○: The content of the contents was 95% or more of the filled amount. △: The content of the contents was 80% or more of the filling amount. ×: The content of the contents was less than 80% of the filled amount.

[0118] [Drop strength] 100 packaging bags each of the example and comparative example were prepared and subjected to a drop test under the following conditions. Ambient temperature: 20℃ Drop height: 2.0m

[0119] Based on the above test results, the evaluation was made according to the following criteria. ◎: There were no damaged packaging bags. ○: One packaging bag was damaged. △: Two packaging bags were damaged. ×: Three or more packaging bags were damaged.

[0120] [Table 4]

[0121] As shown in Table 4, the packaging bags of Examples 1 to 13 to which the present invention was applied were able to suppress deterioration of the contents. From this, it is believed that the packaging bags of Examples 1 to 13 were able to suppress adsorption of the contents. The packaging bags of Examples 1 to 13 also had excellent drop strength. On the other hand, deterioration of the contents was confirmed in Comparative Example 1. This is thought to be due to poor adhesion of the intermediate layer in the packaging bag of Comparative Example 1. The packaging bag of Comparative Example 1 also had poor drop strength. [Explanation of symbols]

[0122] 5...space, 10...laminate, 11...base material layer, 11a...surface, 12...first intermediate layer, 13...sealant layer, 111...surface resin layer, 112...second intermediate layer, 16...contents, 17...bag body, 20...pouring outlet, 31, 32...packaging bag

Claims

1. A laminate having at least a base layer, a first intermediate layer, and a sealant layer in this order, the first intermediate layer bonds the base layer and the sealant layer together; the substrate layer includes a layer made of a fluorine-based resin and other layers, the first intermediate layer contains a polyethylene resin, an elastomer component, and a component having an epoxy group, The component having an epoxy group is 1,2-polybutadiene with partially introduced epoxy groups, and has a number average molecular weight of 500 or more and 4,000 or less.

2. A laminate having at least a base layer, a first intermediate layer, and a sealant layer in this order, the first intermediate layer bonds the base layer and the sealant layer together; the substrate layer includes a layer made of a fluorine-based resin and other layers, the first intermediate layer contains a polyethylene resin, an elastomer component, and a component having an epoxy group, The laminate contains, as the elastomer component, a styrene-ethylene-butylene-styrene copolymer having a styrene content of 8% by mass or more and 24% by mass or less.

3. 3. The laminate according to claim 1, wherein the other layer is at least one layer selected from the group consisting of a reinforcing layer, a gas barrier layer, a light-shielding layer, a printed layer, a metal foil, and a synthetic paper.

4. a surface resin layer on a surface of the base material layer opposite to a surface in contact with the first intermediate layer; 4. The laminate according to claim 1, further comprising: a second intermediate layer sandwiched between the substrate layer and the surface resin layer.

5. A packaging bag formed by using the laminate according to any one of claims 1 to 4 as a forming material and bonding opposing sealant layers together with the sealant layers facing each other with the sealant layers facing each other.

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