阅读说明：本技术 包装袋 (Packaging bag (WU JI KE LI) ) 是由 冈本大 美尾笃 野村纯平 铃木丰明 于 2018-04-10 设计创作，主要内容包括：本发明提供一种水蒸气透过率低、非吸附性优异的包装袋。更具体而言,本发明涉及一种包装袋,其具有袋主体、接合在袋主体上的倒出口,袋主体通过将至少依次具有基材层、第一中间层、密封层的层叠体作为成型材料,并以密封层为内侧,使相对的密封层彼此贴合,从而呈袋状,将倒出口夹持并接合在相对的密封层之间,第一中间层含有聚乙烯类树脂、改性聚乙烯类树脂,基材层包括以氟类树脂作为成型材料的层。(The invention provides a packaging bag with low water vapor transmission rate and excellent non-absorption. More specifically, the present invention relates to a packaging bag having a bag main body and a pouring port joined to the bag main body, wherein the bag main body is formed into a bag shape by bonding opposing sealant layers to each other with the sealant layers inside by using as a molding material a laminate having at least a base material layer, a first intermediate layer and a sealant layer in this order, and the pouring port is sandwiched and joined between the opposing sealant layers, the first intermediate layer contains a polyethylene resin and a modified polyethylene resin, and the base material layer includes a layer made of a fluorine-based resin as a molding material.)

1. A packaging bag having a bag body and a spout joined to the bag body,

The bag main body is formed into a bag shape by bonding opposing seal layers with the seal layer being an inner side, using a laminate having at least a base material layer, a first intermediate layer, and a seal layer in this order as a molding material,

The spout is clamped and engaged between the opposed sealing layers,

the first intermediate layer contains a polyethylene resin or a modified polyethylene resin,

The substrate layer includes a layer made of a fluorine-based resin as a molding material.

2. The packaging bag according to claim 1, wherein the polyethylene-based resin is linear low density polyethylene.

3. The packaging bag according to claim 1 or 2, wherein the modified polyethylene-based resin is maleic anhydride modified polyethylene.

4. A packaging bag having a bag body and a spout joined to the bag body,

The bag main body is formed into a bag shape by bonding opposing seal layers with the seal layer being an inner side, using a laminate having at least a base material layer, a first intermediate layer, and a seal layer in this order as a molding material,

The spout is clamped and engaged between the opposed sealing layers,

The first intermediate layer contains a polyethylene resin, an elastomer component, and a component having an epoxy group,

The substrate layer includes a layer made of a fluorine-based resin as a molding material.

5. The packaging bag according to claim 4, wherein the component having an epoxy group is a component in which an epoxy group is partially introduced into 1, 2-polybutadiene, and the number average molecular weight is 500 or more and 4,000 or less.

6. The packaging bag according to claim 4 or 5, wherein a styrene-ethylene-butylene-styrene copolymer having a styrene content of 8 mass% or more and 24 mass% or less is contained as the elastomer component.

7. The packaging bag according to any one of claims 1 to 6, wherein the layer of the fluorine-based resin as the molding material has a thickness of 20 μm or more and 60 μm or less.

8. The packaging bag according to any one of claims 1 to 7, wherein the fluorine-based resin is polychlorotrifluoroethylene.

9. the packaging bag according to any one of claims 1 to 8, wherein the sealing layer contains a cycloolefin resin.

10. The packaging bag according to any one of claims 1 to 9, wherein a surface resin layer and a second intermediate layer interposed between the substrate layer and the surface resin layer are provided on an outer surface of the substrate layer.

11. A packaging bag according to any one of claims 1 to 10, wherein the spout contains a cycloolefin resin as a molding material.

12. the packaging bag according to any one of claims 1 to 11, wherein the spout is a two-color molded product, and at least a portion that comes into contact with the content contains a cycloolefin resin.

Technical Field

The present application claims priority benefits based on japanese patent application No. 2017-5-1, filed in japan in 2017, and is incorporated by reference in its entirety in this specification.

The invention relates to a packaging bag.

Background

In order to suppress deterioration of active ingredients of pharmaceuticals, cosmetics, foods and the like, resin films used as packaging materials for these contents are required to have low water vapor permeability. In particular, as a packaging material for products suitable for living bodies such as medicines, a packaging bag using a sealant resin such as polyolefin is used (for example, patent document 1). The packaging bag using the sealant resin such as polyolefin can suppress the water vapor transmission rate to a low level because of the hydrophobicity of the polyolefin.

Disclosure of Invention

Technical problem to be solved by the invention

however, packaging bags using a sealant resin such as polyolefin may adsorb drugs or the like on the sealant resin layer or change the components such as proteins contained in the biomaterial. This is presumably due to the fact that the polyolefin having hydrophobicity is high in lipophilicity at the same time. Therefore, a packaging bag which does not easily adsorb a drug or the like is required.

Further, the packaging bag described in patent document 1 is required to further reduce the water vapor transmission rate in accordance with market demand.

The present invention has been made in view of the above circumstances, and provides a novel packaging bag having a low water vapor transmission rate and excellent non-adsorbability.

Means for solving the problems

In order to solve the above-described problems, one aspect of the present invention provides a packaging bag including a bag main body and a spout joined to the bag main body, wherein the bag main body is formed into a bag shape by bonding opposing sealant layers to each other with the sealant layers inside by using as a molding material a laminate including at least a base layer, a first intermediate layer, and a sealant layer in this order, the spout is sandwiched and joined between the opposing sealant layers, the first intermediate layer includes a polyethylene resin and a modified polyethylene resin, and the base layer includes a layer using a fluorine resin as a molding material.

In one embodiment of the present invention, the following configuration may be adopted: the polyethylene resin is linear low density polyethylene.

In one embodiment of the present invention, the following configuration may be adopted: the modified polyethylene resin is maleic anhydride modified polyethylene.

One aspect of the present invention provides a packaging bag having a bag body and a pouring port joined to the bag body, wherein the bag body is formed into a bag shape by bonding opposing sealant layers to each other with the sealant layers inside by using as a molding material a laminate having at least a base layer, a first intermediate layer, and a sealant layer in this order, the pouring port is sandwiched and joined between the opposing sealant layers, the first intermediate layer contains a polyethylene resin, an elastomer component, and a component having an epoxy group, and the base layer includes a layer using a fluorine resin as a molding material.

In one embodiment of the present invention, the following configuration may be adopted: the component having an epoxy group is a component in which an epoxy group is partially introduced into 1, 2-polybutadiene, and has a number average molecular weight of 500 to 4,000.

In one embodiment of the present invention, the following configuration may be adopted: the elastomer composition contains a styrene-ethylene-butylene-styrene copolymer having a styrene content of 8 to 24 mass% as an elastomer component.

In one embodiment of the present invention, the following configuration may be adopted: the thickness of the layer made of the fluorine-based resin as the molding material is 20 μm or more and 60 μm or less.

In one embodiment of the present invention, the following configuration may be adopted: the fluorine resin is polychlorotrifluoroethylene.

In one embodiment of the present invention, the following configuration may be adopted: the sealant layer contains a cyclic olefin resin.

In one embodiment of the present invention, the following configuration may be adopted: the surface of the substrate layer on the outer side thereof is provided with a surface resin layer and a second intermediate layer sandwiched between the substrate layer and the surface resin layer.

In one embodiment of the present invention, the following configuration may be adopted: the pouring port contains a cycloolefin resin as a molding material.

In one embodiment of the present invention, the following configuration may be adopted: the pouring outlet is a two-color molded article, and at least a portion in contact with the content contains a cycloolefin resin.

Effects of the invention

According to the present invention, a novel packaging bag having a low water vapor transmission rate and excellent non-adsorbability can be provided.

Drawings

Fig. 1 is a plan view of a packaging bag 31 according to a first embodiment of the present invention.

Fig. 2 is a sectional view taken along line II-II of fig. 1.

Fig. 3 is a perspective view showing the periphery of the spout 20.

Fig. 4 is a sectional view of a packaging bag 32 according to a second embodiment of the present invention.

Detailed Description

< packaging bag >

Hereinafter, a packaging bag according to a first embodiment of the present invention will be described with reference to fig. 1 and 2. In these drawings, the size, ratio, and the like of each component are drawn to such an extent that they can be visually recognized on the drawings, and therefore the size, ratio, and the like of each component are appropriately different from the actual size, ratio, and the like.

The packaging bag according to the present embodiment is a packaging bag for containing contents such as drugs, cells, tissues, organs, biological materials, blood, body fluids, enzymes, antibodies, cosmetics, nutritional agents, health agents, cosmetics, and foods. The packaging bag according to the present embodiment is suitable as a packaging bag for storing medicines. Examples of the form of the packaging bag include a three-sided bag, a four-sided bag, a back patch bag, a gusset bag, a stand-up pouch, a post-bag (post), an inner bag for bag-in-box, and a large-sized bag such as a can bag.

The specific form, shape, and the like of the content contained in the packaging bag of the present embodiment are not particularly limited. The contents may be, for example, solids, liquids, gases, powders, granules, mixtures, compositions, dispersions, and the like. Further, when the content is a liquid, the liquid may be an aqueous solution containing a medicament. When the contents are contained in the package bag, the package bag may be filled with an inert gas such as nitrogen gas or a liquid.

Fig. 1 is a plan view of a packaging bag 31 according to a first embodiment. Fig. 2 is a sectional view taken along line II-II of fig. 1. As shown in fig. 1 and 2, the packaging bag 31 includes a bag body 17 and a spout 20 joined to the bag body 17.

The bag main body 17 is formed into a bag shape by bonding two sheets of the laminate 10 to each other using the laminate 10 as a molding material. The spout 20 is sandwiched and joined between the opposed stacks 10.

The packaging bag 31 has a first joining portion 14 for joining the stacked body 10 to the spout 20 and a second joining portion 15 for joining the stacked bodies 10 to each other. The first joining portion 14 is connected to the second joining portion in a plan view, and is provided in a closed loop shape at a peripheral edge portion of the bag main body 17. In addition, a part of the first joining portion 14 and the second joining portion 15 of the packaging bag 31 may have a folded portion in which the laminate 10 is folded into a V-shaped cross section.

The bag body 17 is formed with a space 5 for filling the content 16. In the drawings, the specific state, shape, and the like of the content 16 are not illustrated. Before filling the content 16, the bag body 17 may have a filling opening for filling the content 16 into the space 5.

[ laminate ]

The laminate 10 includes a base layer 11, a first intermediate layer 12, and a sealant layer 13 in this order. In the bag main body 17 shown in fig. 2, two laminated bodies 10 are used, and the seal layers 13 of the respective laminated bodies are opposed to each other and the seal layers 13 are bonded to each other.

(substrate layer)

In the first embodiment, the base material layer 11 is a layer exposed on the outside of the space 5. The base material layer 11 of the present embodiment includes a layer made of a fluorine-based resin as a molding material. When the base layer 11 includes a layer made of a fluorine-based resin as a molding material, the packaging bag is excellent in mechanical strength and optical properties and can be provided with a low water vapor transmission rate.

Examples of the fluorine-based resin 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 them, Polychlorotrifluoroethylene (PCTFE) is preferable. The above resins may be used singly or in combination of two or more.

When the two sheets of laminate 10 are heat-sealed using the sealant layer 13, the sealant layer 13 needs to be heated until the resin contained in the sealant layer 13 melts. In this case, in order to suppress deformation or deterioration of the laminate 10, the heating temperature at the time of heat sealing needs to be lower than the melting temperature of the resin contained in the base material layer 11. Therefore, the kind of the resin contained in the sealing layer 13 is limited by the kind of the resin contained in the base layer 11.

In the laminate 10 of the present embodiment, the material for forming the sealing layer 13 can be selected widely by using, as the fluorine-based resin, a fluorine-based resin having a higher glass transition temperature than a resin conventionally used for the base layer.

In the present embodiment, the thickness of the layer made of the fluorine-based resin as the molding material is preferably 20 μm or more and 60 μm or less. If the thickness of the layer made of the fluorine-based resin as the molding material is 20 μm or more, the water vapor permeability of the packaging bag 31 can be sufficiently reduced. Further, if the thickness of the layer made of the fluorine-based resin as the molding material is 60 μm or less, the production cost can be reduced.

The base layer 11 may have a single-layer structure formed of one layer, or may have a laminated structure of 2 or more layers. The layer that can constitute the base material layer 11 (hereinafter referred to as "other layer") can be appropriately selected. Examples of the other layer include a reinforcing layer, a gas barrier layer, a light-shielding layer, a printing layer, a metal foil, and synthetic paper. The other layer may be made of a fluorine-free resin.

Examples of the reinforcing layer include reinforcing resin layers such as biaxially stretched polyethylene terephthalate (O-PET), biaxially stretched nylon (O-Ny), and biaxially stretched polypropylene (OPP).

the gas barrier layer may be made of, for example, an inorganic substance or a gas barrier resin. The inorganic substance may, for example, be a metal vapor deposited layer or a metal oxide such as alumina. Examples of the gas barrier resin include ethylene-vinyl alcohol copolymer (EVOH), vinylidene chloride, and the like.

The laminate 10 may have a printed layer or a coating layer on the surface 11a of the base material layer 11 opposite to the first intermediate layer 12.

The printing layer can impart visibility or design to the packaging bag 31 by printing ink on the surface (surface 11a) of the base material layer 11.

The coating layer is used to protect the base material layer 11 or other layers such as a print 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 layer.

(first intermediate layer)

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 is preferably any one of a layer containing a polyethylene resin, a modified polyethylene resin, or a layer containing a polyethylene resin, an elastomer component, and an epoxy-containing resin composition.

In the present specification, the first intermediate layer containing the polyethylene resin and the modified polyethylene resin is referred to as an "intermediate layer (1)". The first intermediate layer of the resin composition containing a polyethylene resin, an elastomer component and an epoxy group is referred to as "intermediate layer (2)".

Middle layer (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 preferable.

The modified polyethylene resin contained in the intermediate layer (1) is a polyethylene resin modified with an unsaturated carboxylic acid or a derivative thereof, and the polyethylene resin has an acid functional group such as a carboxyl group or a carboxylic anhydride group. In the present embodiment, a modified polyethylene resin obtained by acid-modifying a polyethylene resin is preferred.

Examples of the acid modification method include 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.

The polyethylene resin material before modification is not limited as long as it contains ethylene as a raw material monomer, and a known polyethylene resin can be suitably used. Specifically, the polyethylene-based resin may include, in addition to the above examples, ethylene/α -olefin copolymers such as ethylene-propylene copolymers, ethylene-1-butene copolymers, ethylene-4-methyl-1-pentene copolymers, ethylene-1-hexene copolymers, and ethylene-1-octene copolymers; ethylene copolymer resins such as ethylene-vinyl acetate copolymers, ethylene- (meth) acrylic acid copolymers, and ethylene- (meth) acrylate copolymers.

The acid functional group-containing monomer is a compound having an ethylenic double bond, a carboxyl group or a carboxylic anhydride group in the same molecule, and examples thereof include various unsaturated monocarboxylic acids, dicarboxylic acids or anhydrides of dicarboxylic acids.

Examples of the acid functional group-containing monomer having a carboxyl group (carboxyl group-containing monomer) 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 (norbornene diacid).

Examples of the acid functional group-containing monomer having a carboxylic anhydride group (carboxylic anhydride group-containing monomer) include unsaturated dicarboxylic anhydride monomers such as maleic anhydride, nadic anhydride, itaconic anhydride, citraconic anhydride and nadic anhydride.

In the components constituting the first intermediate layer 12, these acid functional group-containing monomers may be used singly or in combination of two or more.

Among them, as the acid functional group-containing monomer, acid functional group-containing monomers having an acid anhydride group are preferable, carboxylic acid anhydride group-containing monomers are more preferable, and maleic anhydride is particularly preferable.

When a part of the acid functional group-containing monomer used for acid modification is unreacted, in order to prevent a decrease in adhesive force caused by the unreacted acid functional group-containing monomer, it is preferable to use a substance from which the unreacted acid functional group-containing monomer is removed in advance.

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

In the intermediate layer (1), the lower limit of the ratio of the polyethylene resin to the total mass of the polyethylene resin and the modified polyethylene resin is preferably 10% or more, and more preferably 20% or more, assuming that the total mass of the polyethylene resin and the modified polyethylene resin is 100%. The upper limit of the ratio of the polyethylene resin to the total mass of the polyethylene resin and the modified polyethylene resin is preferably 70% or less, and more preferably 60% or less. For example, the mixing ratio of the polyethylene resin to the modified polyethylene resin may be set to [ polyethylene resin ]: 20:80 to 60: 40.

In the present embodiment, by using a mixture of a polyethylene resin and a modified polyethylene resin for the first intermediate layer 12, the adhesion between the sealant layer 13 and the base layer 11 can be improved. Therefore, the laminate 10 in which interlayer peeling is less likely to occur can be provided.

Middle layer (2)

The intermediate layer (2) contains a resin composition containing a polyethylene resin, an elastomer component, and a component having an epoxy group.

The polyethylene resin contained in the intermediate layer (2) may be the same as the polyethylene resin contained in the intermediate layer (1), or may be a biomass-derived polyethylene resin, a petroleum-derived polyethylene resin, or a mixture of these resins.

The polyethylene resin contained in the intermediate layer (2) is preferably a polyethylene resin polymerized by a metallocene catalyst. Among them, ethylene- α -olefin copolymers such as C4-LLDPE, C6-LLDPE and C8-LLDPE polymerized by a metallocene catalyst, long-chain branched polyethylene and the like are preferable examples.

Polyethylene resins polymerized by metallocene catalysts tend to have narrow molecular weight distributions. Therefore, it is considered that the content of the low molecular weight component which may be a factor inhibiting adhesion is low, and when used as an adhesive, high adhesion is obtained.

The density of the polyethylene resin in the resin composition is preferably 0.890g/cm³Above 0.940g/cm³Hereinafter, more preferably 0.910cm³Above 0.930g/cm³The following.

The content of the polyethylene resin in the resin composition is 55 to 90 parts by mass, preferably 60 to 80 parts by mass.

When the content of the polyethylene resin is not more than the above upper limit, adhesiveness with an elastomer component described later can be exhibited, and adhesiveness can be improved.

Examples of the elastomer component contained in the intermediate layer (2) include styrene elastomers, acrylic elastomers, urethane elastomers, and ester elastomers. The elastomer component does not include a component having an epoxy group, which will be described later.

Among them, styrene-based elastomers are preferable, and examples thereof include a block copolymer having a hard segment made of polystyrene or the like and a soft segment made of polyethylene, polybutadiene, polyisoprene or the like. Examples of the styrene-based polymer that can be used in the styrene-based elastomer include aromatic olefin-aliphatic olefin copolymers such as styrene-butadiene copolymers, styrene-isoprene copolymers, and styrene-ethylene copolymers.

The styrene-based elastomer is preferably a styrene-ethylene-butylene-styrene copolymer (SEBS) in which unsaturated bonds in the molecular chain of a styrene-butylene-styrene copolymer (SBS) are completely hydrogenated.

The styrene content is preferably 8 to 24 mass%, more preferably 10 to 20 mass%.

When the styrene content is not more than the upper limit, curing of the resin can be suppressed, and a decrease in adhesion can be suppressed.

Specific examples of the elastomer component contained in the intermediate layer (2) include dynaron of JSR Corporation, Tuftec H series of Asahi Kasei Corporation, and Kraton gc of Kraton Corporation.

The content of the elastomer component in the intermediate layer (2) is 10 to 45 parts by mass, preferably 20 to 40 parts by mass.

When the content of the elastomer component is not more than the above upper limit, a decrease in tensile strength at the time of forming the pressure-sensitive adhesive layer can be suppressed, and a decrease in adhesive strength can be prevented.

The total amount of the polyethylene resin and the elastomer component in the intermediate layer (2) is 100 parts by mass.

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 epoxidized polybutadiene obtained by partially epoxidizing butadiene. Particularly preferred is a product obtained by partially epoxidizing 1, 2-polybutadiene.

Specific examples of the component having an epoxy group include NIPPON SODA CO., LTD. liquid polybutadiene JP-100 and JP-200, and ADK CIZER BF-1000 from ADEKA CORPORATION.

The number average molecular weight of the component having an epoxy group is preferably 500 to 4,000.

When the number average molecular weight of the component having an epoxy group is not more than the upper limit, the decrease in adhesiveness due to the solid state at room temperature can be suppressed, and the decrease in adhesiveness can be prevented.

The number average molecular weight in the present embodiment is a value in terms of polystyrene measured by GPC (gel permeation chromatography).

In the intermediate layer (2), the content of the component having an epoxy group is 0.1 to 1.5 parts by mass, preferably 0.5 to 1.0 part by mass, based on 100 parts by mass of the total amount of the polyethylene resin and the elastomer component.

By setting the content of the component having an epoxy group to the upper limit or less, low-molecular components in the resin composition, which are factors inhibiting adhesion, can be reduced.

In the intermediate layer (2), the elastomer component and the component having an epoxy group are compatible with each other because they have a common repeating unit. The elastomer component and the component having an epoxy group are preferably a combination of styrene elastomers and acrylic elastomers.

The resin composition of the intermediate layer (2) is obtained by mixing a polyethylene resin, an elastomer component, and a component having an epoxy group in a specific mixing ratio. The epoxy group in the component having an epoxy group in the resin composition of the present embodiment is compatible with the fluorine component of the fluorine-based resin, and has excellent adhesion to the fluorine-based resin. The resin composition of the present embodiment contains a component having an epoxy group, and thus can be bonded to a metal material.

In the intermediate layer (2), a polyethylene resin, an elastomer component, and a component having an epoxy group are mixed at a specific mixing ratio, whereby a so-called sea-island structure can be formed in which the polyethylene resin corresponds to "sea" and the elastomer component corresponds to "island". Further, since the elastomer component is compatible with the component having an epoxy group, the component having an epoxy group can be uniformly dispersed in the resin composition. Thus, the epoxy groups are protected by the polyethylene resin and the elastomer component, and the opening of the epoxy groups by moisture can be suppressed.

By using a mixed material of a polyethylene resin, an elastomer component, and a component having an epoxy group in the first intermediate layer 12, adhesion between the sealing layer 13 and the base layer 11 is improved. Therefore, the laminate 10 in which interlayer peeling is less likely to occur can be provided.

By forming the first intermediate layer 12 using the above-described materials, the packaging bag 31 in which interlayer peeling is less likely to occur at the interface between the base material layer 11 and the first intermediate layer 12 or the interface between the first intermediate layer 12 and the sealant layer 13 can be provided. In addition, since the adhesion failure of the first intermediate layer 12 is suppressed, the occurrence of breakage of the packaging bag 31 due to the adhesion failure can be suppressed.

(sealing layer)

The sealing layer 13 is used when the laminate is bonded by heat sealing or the like to form a bag. The sealing layer 13 is a layer facing the space 5 in the packaging bag 31 and in contact with the content 16.

In the present embodiment, the base material layer 11 includes a layer made of a fluorine-based resin having a high glass transition temperature as a molding material. This enables the sealing layers 13 to be bonded to each other at high temperature by heat sealing or the like. Therefore, a material having a high glass transition temperature can be used as the material for forming the sealing layer 13.

It is known that the higher the glass transition temperature of the material forming the sealing layer 13, the more excellent the non-adsorbability to the content 16. The sealing layer 13 of the present embodiment preferably contains a cycloolefin resin. When the sealing layer 13 contains a cycloolefin resin, a packaging bag excellent in non-adsorbability to the content 16 can be provided.

The cyclic olefin-based resin may, for example, be a Cyclic Olefin Polymer (COP), a Cyclic Olefin Copolymer (COC) or the like. The resin component constituting the sealant layer 13 may be one or two or more kinds of cycloolefin resins, or may be a mixture of the cycloolefin resins and other resins, elastomers, or the like.

Examples of the Cyclic Olefin Polymer (COP) include homopolymers of cyclic olefins, copolymers of two or more cyclic olefins, and hydrogenated products thereof. The cyclic olefin polymer is preferably a non-crystalline polymer, and more preferably a ring-opening polymer of a cyclic olefin formed by a metathesis reaction or the like, or a hydride thereof. The cyclic olefin polymer has a higher proportion of alicyclic structures than the cyclic olefin copolymer and the like, and is excellent in non-adsorption to the content 16.

Examples of the Cyclic Olefin Copolymer (COC) include copolymers of one or two or more cyclic olefins and one or two or more acyclic olefins, and hydrogenated products thereof. The cyclic olefin copolymer is preferably a non-crystalline polymer, and more preferably a copolymer of a cyclic olefin and ethylene or a hydrogenated product thereof.

The cyclic olefin used as a structural monomer of the cyclic olefin-based resin is an unsaturated hydrocarbon (olefin) having at least 1 ring structure. Examples thereof include vinylcycloalkane having cycloalkane having 3 to 20 carbon atoms and derivatives thereof, monocyclic olefin having 3 to 20 carbon atoms and derivatives thereof, and cyclic olefin having norbornene skeleton (norbornene-based monomer).

Examples of the norbornene-based monomer include bicyclo [2.2.1] -2-heptene (norbornene) and a derivative thereof. Examples of the derivative include a compound having a substituent such as an alkyl group, a compound having 2 or more unsaturated bonds such as norbornadiene, and a compound having 3 or more ring structures, 2 of which constitute a norbornene skeleton. Examples of the norbornene-based monomer having 3 or more ring structures include compounds obtained by adding 1 or more molecules of cyclopentadiene to tricyclo [5.2.1.02,6] decene (dihydrodicyclopentadiene) or norbornene or dihydrodicyclopentadiene by a diels-alder reaction (for example, tetracyclododecene, pentacyclopentadecene, hexacyclopentadecene and the like), hydrogenated products of these compounds, isomers having different positions of double bonds, alkyl substituted compounds, and the like.

Examples of the acyclic olefin used as a structural monomer of COC include α -olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene; olefins such as 3-decene and 3-dodecene.

The glass transition temperature of the material forming the sealing layer 13 is preferably 100 ℃ to 170 ℃, and more preferably 105 ℃ to 160 ℃. When the glass transition temperature of the material forming the sealing layer 13 is 100 ℃ or higher, the sealing layer 13 tends to have excellent non-adsorbability to the content 16. Further, when the glass transition temperature of the material forming the sealing layer 13 is 170 ℃ or lower, high temperature is not necessary when laminating the laminate 10, and hence moldability is excellent.

The thickness of the sealing layer 13 is preferably 20 μm or more, and more preferably 30 μm or more. When the thickness of the seal layer 13 is 20 μm or more, the seal layers 13 of the laminate 10 can be bonded to each other by heat sealing or the like, and the laminate 10 can be formed into a bag shape. The thickness of the sealing layer 13 is preferably 60 μm or less, and more preferably 50 μm or less. If the thickness of the sealing layer 13 is 60 μm or less, the production cost can be reduced. The upper limit value and the lower limit value of the thickness of the sealing layer 13 can be arbitrarily combined.

When the sealing layer 13 contains a cycloolefin resin, it is known that the thicker the sealing layer 13 is, the lower the water vapor transmission rate of the packaging bag is. On the other hand, it is known that the thicker the sealing layer 13 is, the more easily the sealing layer 13 is broken, and the drop strength of the packaging bag 31 is reduced. Therefore, the sealing layer 13 is preferably thick in view of reducing the water vapor transmission rate of the packaging bag, and the sealing layer 13 is preferably thin in view of improving the drop strength.

In the present embodiment, the base material layer 11 includes a layer made of a fluorine-based resin having a low water vapor transmission rate as a molding material. Thus, even if the sealant layer 13 is made thin, the water vapor permeability of the packaging bag 31 can be sufficiently reduced as compared with the case where the base material layer is made of a resin other than the fluorine-based resin. That is, the packaging bag 31 having excellent barrier properties against water vapor can be provided. Further, it is known that when the sealing layer 13 is thinned, the sealing layer 13 is less likely to be broken, and the drop strength of the packaging bag 31 is increased. Therefore, by including the layer made of the fluorine-based resin as the molding material in the base material layer, a packaging bag excellent in barrier property against water vapor and handling property can be provided.

The laminated structure of the second bonding portion 15 in which the laminated bodies 10 are bonded to each other is in the order of "substrate layer 11/first interlayer 12/sealant layer 13/first interlayer 12/substrate layer 11". The second joint 15 is formed by melting the resin contained in the sealing layer 13 of the laminate 10.

[ pour spout ]

The spout 20 is clamped and engaged between the opposed sealing layers 13. The spout 20 preferably contains a cycloolefin resin, and preferably contains a cycloolefin resin at least in a portion in contact with the content 16. Examples of the cycloolefin-based resin forming the spout 20 include the same resins as those forming the sealant layer 13. The material forming the spout 20 may be the same as or different from the material forming the sealing layer 13. In the present embodiment, the spout 20 and the sealing layer 13 are preferably formed of the same material.

Fig. 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 formed of a first molded body 21 and a second molded body 22.

The first molded body 21 has a cylindrical shape and has a flow path 23 for taking out the content 16 from the inside. The first molded body 21 has at least a portion housed in the space 5. The first molded article 21 preferably contains a cycloolefin resin or a polyolefin resin as a molding material, and more preferably contains a cycloolefin resin as a molding material. When the first molded article 21 is formed of a cycloolefin resin, a packaging bag having excellent non-adsorbability can be provided.

The second molded body 22 has a cylindrical shape, which is formed on the outer surface 21a of the first molded body 21. Wherein the second molded body 22 is not formed on the outer surface of the portion of the first molded body 21 accommodated in the space 5. The second molded body 22 has a shorter length in the axial direction than the first molded body 21. The second molded body 22 preferably contains a polyolefin-based resin as a molding material.

The polyolefin-based resin may be a single polymer (homopolymer) of one kind of olefin, or may be a copolymer (copolymer) of two or more kinds of olefins. The olefin may, for example, be an acyclic olefin such as ethylene, propylene, 1-butene, 1-hexene, 1-octene or an α -olefin. Specific examples of the polyolefin include polyethylene, polypropylene, and ethylene- α -olefin copolymer.

These polyolefins may be copolymers containing a small amount of non-olefinic vinyl monomers such as vinyl acetate, vinyl chloride, and vinyl alcohol. The source of the olefin can be petroleum-derived olefins, plant-derived olefins, or both.

As the polyolefin-based resin forming the second molded article 22, a polyethylene-based resin is preferable, and Linear Low Density Polyethylene (LLDPE) is more preferable.

when the second molded product 22 is formed of a polyolefin resin, the stacked body 10 forming the bag main body 17 and the spout 20 can be easily joined, and the workability and durability are also excellent.

The laminated structure of the first joining part 14 joining the laminated body 10 to the spout 20 is, in order, the base material layer 11/the first intermediate layer 12/the sealant layer 13/the spout 20/the sealant layer 13/the first intermediate layer 12/the base material layer 11. The first joint 14 is formed by melting the sealing layer 13 of the laminate 10 and the resin contained in the spout 20.

In the first joining portion 14, the stacked body 10 may be joined to the first molded body 21 of the spout 20 or may be joined to the second molded body 22. The first joining portion 14 may include both a portion where the laminate 10 is joined to the first molded body 21 and a portion where the laminate 10 is joined to the second molded body 22.

[ other structures ]

The packaging bag 31 may be provided with a spout, a cock, a label, an opening grip, a handle, and the like. When the fitment is a resin molded product, the same structure as the spout described above can be provided.

< method for producing packaging bag >

The method for manufacturing the packaging bag 31 includes a step of forming the laminate 10 and a step of bonding the laminate 10 and the spout 20.

In the step of forming the laminate 10, the resin as the material of the base material layer 11, the resin as the material of the first intermediate layer 12, and the resin as the material of the sealant layer 13 are melt-extruded at the same time to form the laminate 10. The substrate layer 11, the first intermediate layer 12, and the sealant layer 13 may be laminated by a dry lamination method, an extrusion lamination method, or the like to form the laminate 10.

In the step of joining the stacked body 10 and the spout 20, first, the spout 20 is sandwiched between the stacked bodies 10 in a state where the seal layers 13 of the stacked body 10 are opposed to each other. Next, the stacked body 10 is joined to the spout 20 to form the first joint 14. The stacked bodies 10 are bonded to each other to form the second bonded portion 15. Thereby manufacturing the packing bag 31.

According to the above configuration, a packaging bag having a low water vapor transmission rate and excellent non-adsorbability can be provided.

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 sectional view of a packaging bag according to a second embodiment, which corresponds to fig. 2. The same components as those in the first embodiment are denoted by the same reference numerals in the present embodiment, and detailed description thereof is omitted.

As shown in fig. 4, the packaging bag 32 of the second embodiment includes a bag main body 117 and a spout 20 joined to the bag main body 117. The bag body 117 is formed into a bag shape by bonding two sheets of the laminate 110 to each other using the laminate 110 as a molding material.

The laminate 110 of the second embodiment includes a surface resin layer 111, a second interlayer 112, a base material layer 11, a first interlayer 12, and a sealant layer 13 in this order.

The bag main body 117 shown in fig. 4 is formed by using two laminated bodies 110, and bonding the seal layers 13 to each other by facing the seal layers 13 of the respective laminated bodies to each other.

The second intermediate layer 112 in the second embodiment may contain the same material as that contained in the first intermediate layer 12. The second intermediate layer 112 may comprise the same material as the first intermediate layer 12 or may comprise a different material.

(surface resin layer)

The surface resin layer 111 of the second embodiment is a layer containing a polyolefin resin, a polyethylene resin, a polyimide resin, a polyester resin, or the like. Among them, the surface resin layer 111 preferably contains a polyolefin resin, and more preferably is formed of a polyolefin resin containing a cyclic olefin resin.

The cycloolefin resin may be the same as the material contained in the sealing layer 13. The surface resin layer 111 may be made of the same material as the sealing layer 13 or a different material.

The surface resin layer 111 may have a single-layer structure formed of one layer, or may have a laminated structure of 2 or more layers. On the surface 111a of the surface resin layer 111 opposite to the second intermediate layer 112, for example, a printed layer or a colored resin layer may be provided.

According to the above configuration, in the same manner as in the first embodiment, a packaging bag having a low water vapor transmission rate and excellent non-adsorbability can be provided. In the second embodiment, by selecting the resin of the surface resin layer 111 arbitrarily, the printability of the surface of the packaging bag 32 can be improved, and the smoothness can be improved.

Further, since the laminate 110 used in the second embodiment has a 5-layer structure, the strength of the packaging bag 32 is higher than that of the first embodiment. In the second embodiment, the curl of the laminated body 110 can be suppressed as compared with the first embodiment. In particular, by forming the first intermediate layer 12 and the second intermediate layer 112 from the same material, the surface properties on the inner side and the outer side of the base material layer 11 are the same, and curling of the laminate 110 can be further suppressed. As a result, the laminate 110 is prevented from curling, and the laminate 110 can be easily processed in the manufacturing process of the packaging bag 32.

While the preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to these examples. The various shapes and combinations of the respective constituent members shown in the above examples are just examples, and various modifications can be made in accordance with design requirements and the like within a range not departing from the gist of the present invention.