JP7296059B2 - Laminate and packaging bag provided with the same - Google Patents

Description

The present invention relates to a laminate comprising at least a substrate layer and a three-layered sealant layer in this order. Furthermore, it is related with the packaging bag provided with this laminated body.

In recent years, along with the increasing demand for building a recycling-based society, the use of biomass has been attracting attention in the field of materials as well as the use of fossil fuels, as is the case with energy. Biomass is an organic compound that is photosynthesised from carbon dioxide and water, and is a so-called carbon-neutral renewable energy that is regenerated into carbon dioxide and water by using it. In recent years, biomass plastics using biomass as raw materials have been rapidly put to practical use, and attempts have been made to produce various resins from biomass raw materials.

As a biomass-derived resin, polylactic acid (PLA), which is produced through lactic acid fermentation, began commercial production first, but its performance as a plastic, including its biodegradability, has fallen behind that of today's general-purpose plastics. Since it is very different from the standard, it has not been widely used due to limitations in product applications and product manufacturing methods. In addition, PLA is subjected to Life Cycle Assessment (LCA) evaluation, and discussions are being made on energy consumption during PLA production and equivalence when replacing general-purpose plastics.

Here, as general-purpose plastics, various types such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, and polyester are used. In particular, polyethylene is molded into films, sheets, bottles, etc., and is used in various applications such as packaging materials, and is used in large quantities all over the world. Therefore, the use of conventional fossil fuel-derived polyethylene imposes a large environmental load. Therefore, it is desired to reduce the consumption of fossil fuels by using biomass-derived raw materials for the production of polyethylene. For example, up to now, a resin film for packaging products using biomass-derived polyethylene has been proposed (see Patent Document 1).

Japanese Unexamined Patent Application Publication No. 2012-251006

The present inventors have developed biomass polyolefins using biomass-derived ethylene as a raw material, along with conventional polyolefins produced using ethylene obtained from fossil fuels (hereinafter sometimes simply referred to as "fossil fuel-derived polyolefins"). (hereinafter sometimes simply referred to as "biomass polyolefin"), we have developed a packaging bag with increased biomass content while keeping costs down. In the process, the present inventors faced a technical problem that the performance as a packaged product may be impaired due to the powder adhering to the surroundings of the packaging bag when the powdery content is taken out. bottom. Therefore, as a result of further studies, the present inventors have found a layer structure of a laminate that can produce a packaging bag having excellent antistatic performance while improving the biomass content, and have completed the present invention. rice field.

Accordingly, an object of the present invention is to provide a laminate having excellent antistatic performance while improving the degree of biomass.

According to a first aspect of the invention,
A laminate comprising at least a substrate layer and a sealant layer in this order,
The laminate has antistatic performance,
The sealant layer has a three-layer structure of an inner layer, an intermediate layer, and an outer layer in order from the base layer side,
an intermediate layer of the sealant layer comprising biomass-derived linear low-density polyethylene;
A laminate is provided in which the thickness of the entire sealant layer is 40 μm or more and 70 μm or less.

In the first aspect of the present invention, it is preferable that the intermediate layer of the sealant layer further contains linear low-density polyethylene derived from fossil fuel.

In the first aspect of the present invention, it is preferred that the inner and outer layers of the sealant layer contain linear low-density polyethylene derived from fossil fuels.

In the first aspect of the present invention, the intermediate layer of the sealant layer preferably has a biomass degree of 50% or more and 95% or less.

In the first aspect of the present invention, the biomass degree of the entire sealant layer is preferably 10% or more and 35% or less.

In the 1st aspect of this invention, it is preferable that the said base material layer contains an antistatic agent.

In the first aspect of the present invention, it is preferable that the laminate further comprises a printed layer between the base material layer and the sealant layer.

In the first aspect of the present invention, it is preferable that the laminate further comprises an adhesive layer between the printed layer and the sealant layer.

A second aspect of the present invention provides a packaging bag comprising the laminate.

The laminate according to the present invention includes at least a substrate layer, and a sealant layer having a three-layer configuration of an inner layer, an intermediate layer, and an outer layer in this order, and the intermediate layer of the sealant layer is made of biomass-derived linear low-density polyethylene. By including and the laminate having antistatic performance, it is possible to manufacture a packaging bag having excellent antistatic performance while improving the degree of biomass.

1 is a schematic cross-sectional view showing an example of a laminate according to the present invention; FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to the present invention; FIG. 1 is a schematic front view showing an example of a standing pouch according to the present invention; FIG.

<Laminate>
The laminate according to the present invention includes at least a substrate layer and a sealant layer in this order, and the sealant layer has a three-layer structure of an inner layer, an intermediate layer, and an outer layer in order from the substrate layer side, and has antistatic performance. It has Because the laminate has antistatic properties, packaging bags manufactured using the laminate prevent powder from adhering to the surroundings of the packaging bag when the contents are taken out even if the contents are powder. can do. The laminate may further include a printing layer, an adhesive layer, other layers, and the like. When the laminate has two or more other layers, each layer may have the same composition or may have a different composition.

A laminate according to the present invention will be described with reference to the drawings. Examples of schematic cross-sectional views of laminates according to the invention are shown in FIGS.
The laminate 10 shown in FIG. 1 includes a substrate layer 11 and a three-layered sealant layer 12 consisting of an inner layer 13, an intermediate layer 14 and an outer layer 15 in this order. In the packaging bag including the laminate 10, the sealant layer 14 is positioned on the content side.
The laminate 20 shown in FIG. 2 includes a base layer 21, a printed layer 26, an adhesive layer 27, and a three-layered sealant layer 22 consisting of an inner layer 23, an intermediate layer 24, and an outer layer 25 in this order. It is. In the packaging bag including the laminate 20, the sealant layer 24 is positioned on the content side.
Each layer constituting the laminate will be described below.

[Base material layer]
The laminate according to the present invention is provided with a base material layer when manufacturing a packaging bag. By imparting antistatic performance to the base material layer, packaging bags manufactured using the laminate suppress adhesion of powder around the packaging bag when the content, which is powder, is taken out. can do.

As a method for imparting antistatic performance to the base material layer, an antistatic agent is included in the base material layer. Antistatic agents are roughly classified into cationic antistatic agents, anionic antistatic agents, amphoteric ionic antistatic agents, and nonionic antistatic agents. Examples of cationic antistatic agents include aliphatic amine salts, quaternary ammonium salts, alkylpyridinium salts and the like. Examples of anionic antistatic agents include fatty acid salts, higher alcohol sulfates, liquid fatty oil sulfates, sulfates of fatty amines and fatty amides, fatty alcohol phosphates, and dibasic fatty acid esters. salts, fatty acid amidesulfonates, alkylsulfonates, alkylarylsulfonates, naphthalenesulfonates of formalin condensation, etc.; Examples include ester ammoniums, phosphate ammoniums, sulfonate ammoniums and the like. Among these, sulfonic acid metal salts having an alkyl group having 8 to 20 carbon atoms are preferable because they have a good balance between effect and economy. Examples of nonionic antistatic agents include ethylene oxide adducts of fatty alcohols, ethylene oxide adducts of fatty acids, and ethylene oxide adducts of alkylphenols. In addition to the above, waxes, paraffins, and silicone compounds can also be used. One or more of these antistatic agents can be used.

As the substrate layer, for example, a polyester such as polyethylene terephthalate, a polyamide such as nylon, or a polyolefin such as polypropylene can be used. From the viewpoint of moldability and durability as a packaging product, a polyethylene terephthalate film can be used. preferable. The polyethylene terephthalate used for the base material layer may be derived from biomass or fossil fuel. The substrate layer may contain both biomass-derived polyethylene terephthalate and fossil fuel-derived polyethylene terephthalate. By using biomass-derived polyethylene terephthalate for at least part of the base material layer, the biomass content of the entire laminate can be improved. The biomass-derived polyethylene terephthalate is polyethylene terephthalate having biomass-derived ethylene glycol as a diol unit and fossil fuel-derived terephthalic acid as a dicarboxylic acid unit.

The method for producing the substrate layer is not particularly limited, but it can be formed using a resin composition containing the antistatic agent and, if necessary, a binder, and the resin composition is formed into a film to form a substrate film. preferably. As one aspect of the method for producing a base film, an example in which the base film is a biaxially stretched polyethylene terephthalate film containing an antistatic agent will be described. A mixture of polyethylene terephthalate resin and metal alkylsulfonate was melt extruded at a resin temperature of 270 to 290°C using an extruder equipped with a coat hanger type T die, and the temperature was adjusted to 10 to 40°C. It is wrapped tightly around a cooling drum and cooled. Subsequently, the obtained unstretched sheet can be biaxially stretched at a temperature of 90 to 140° C. to obtain a base film.

The substrate layer is preferably stretched, more preferably biaxially stretched.
When the substrate layer is a stretched polyethylene terephthalate film, the stretched polyethylene terephthalate film used for the substrate layer has a tensile strength in the MD direction of preferably 150 MPa or more and 300 MPa or less, more preferably 200 MPa or more and 300 MPa or less, in the TD direction, Preferably 150 MPa or more and 300 MPa or less, more preferably 150 MPa or more and 300 MPa or less, and the tensile elongation in the MD direction is preferably 50% or more and 250% or less, more preferably 70% or more and 200% or less, and TD direction is preferably 50% or more and 250% or less, more preferably 60% or more and 200% or less.
When the substrate layer is a stretched nylon film, the stretched nylon film used for the substrate layer has a tensile strength of preferably 150 MPa or more and 350 MPa or less, more preferably 200 MPa or more and 300 MPa or less in the MD direction, and preferably 150 MPa or more and 400 MPa or less, more preferably 200 MPa or more and 350 MPa or less, and the tensile elongation in the MD direction is preferably 50% or more and 200% or less, more preferably 70% or more and 150% or less, and in the TD direction It is preferably 30% or more and 200% or less, more preferably 50% or more and 150% or less.
When the substrate layer is a stretched polypropylene film, the stretched polypropylene film used for the substrate layer has a tensile strength in the MD direction of preferably 50 MPa or more and 250 MPa or less, more preferably 70 MPa or more and 200 MPa or less, in the TD direction, preferably 150 MPa or more and 450 MPa or less, more preferably 200 MPa or more and 400 MPa or less, and the tensile elongation in the MD direction is preferably 100% or more and 300% or less, more preferably 150% or more and 250% or less, and in the TD direction It is preferably 20% or more and 100% or less, more preferably 30% or more and 80% or less.
The above tensile strength and tensile elongation can be measured according to JIS K 7127.

The substrate layer preferably has a thickness of 5 μm or more and 40 μm or less, more preferably 8 μm or more and 25 μm or less. The thickness of the substrate layers may be different or the same. If the thickness of the base material layer is within the above range, molding is easy, and it can be suitably used as a packaging material.

[Antistatic layer]
Instead of imparting antistatic performance to the substrate layer, an antistatic layer containing the antistatic agent may be separately provided on the substrate layer. The antistatic layer is located on the outermost layer when the packaging bag is manufactured. The antistatic layer is not particularly limited as long as it contains the antistatic agent. The method for producing the antistatic layer is not particularly limited, but it can be formed using the same resin composition as the base layer, and it is preferable to form an antistatic film by forming the resin composition.

[Sealant layer]
The laminate according to the present invention is provided with a sealant layer that will be on the content side when manufacturing a packaging bag. The sealant layer has a three-layer structure of an inner layer, an intermediate layer, and an outer layer in order from the substrate layer side.

The middle layer of the sealant layer comprises biomass-derived linear low-density polyethylene (LLDPE), and may further comprise fossil fuel-derived linear low-density polyethylene. By including biomass-derived linear low-density polyethylene in the intermediate layer of the sealant layer, the degree of biomass of the laminate can be increased. In the intermediate layer of the sealant layer, the content of the biomass-derived linear low-density polyethylene is preferably 50% by mass or more and 100% by mass or less, more preferably 60% by mass or more and 90% by mass or less, and fossil fuel The content of the derived linear low-density polyethylene is preferably 0% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 40% by mass or less. If the content of the biomass-derived linear low-density polyethylene in the intermediate layer of the sealant layer is within the above range, the biomass degree of the entire laminate can be increased.

The inner and outer layers of the sealant layer preferably contain conventionally known linear low-density polyethylene derived from fossil fuels, in consideration of sealability, adhesion to the substrate layer, production cost, and the like.

The biomass degree of the intermediate layer of the sealant layer is preferably 50% or more and 95% or less, more preferably 60% or more and 90% or less. In addition, the biomass degree of the entire sealant layer is preferably 10% or more and 35% or less, more preferably 15% or more and 30% or less by mass. If the degree of biomass is within the above range, it is possible to reduce the amount of fossil fuel used while keeping costs down, thereby reducing the burden on the environment. In the present invention, the term “biomass degree” indicates the weight ratio of biomass-derived components.

The "biomass degree" (biomass-derived carbon concentration) is the value of the C14 content obtained by a radioactive carbon (C14) measurement method according to ASTM-D6866. Since carbon dioxide in the atmosphere contains a certain proportion of C14 (105.5 pMC), the C14 content in plants that grow by taking in carbon dioxide in the atmosphere, such as corn, is also about 105.5 pMC. It is known. It is also known that fossil fuels contain almost no C14. Therefore, by measuring the ratio of C14 contained in the total carbon atoms in the intermediate layer of the sealant layer, the ratio of biomass-derived carbon can be calculated. In the present invention, the biomass-derived carbon content Pbio can be obtained as follows, where PC14 is the content of C14 in the intermediate layer of the sealant layer.
Pbio (%) = PC14/105.5 x 100
Note that PMC is an abbreviation for Percent Modern Carbon.

Biomass polyethylene is a monomer polymer containing ethylene derived from biomass. Since biomass-derived ethylene is used as a raw material monomer, the polymerized polyolefin is derived from biomass. The content of biomass-derived ethylene in the raw material monomer does not need to be 100% by mass, and is preferably 50% or more, more preferably 80% or more, for example. Feedstock monomers may include ethylene derived from fossil fuels and may include α-olefin monomers such as butylene, hexene, and octene. Even in such cases, the resulting polymer is called biomass polyethylene. By including an α-olefin, the polymerized polyolefin has an alkyl group as a branched structure, so that it can be made more flexible than a simple linear one.

For example, biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from plant raw materials. Plant raw materials are not particularly limited, and conventionally known plants can be used. For example, corn, sugar cane, beets, and manioc can be mentioned.

In the present invention, biomass-derived fermented ethanol refers to purified ethanol produced by contacting a culture medium containing a carbon source obtained from a plant material with a microorganism that produces ethanol or a product derived from a crushed product thereof. Conventionally known methods such as distillation, membrane separation, and extraction can be applied to purify ethanol from the culture medium. For example, a method of adding benzene, cyclohexane or the like to cause azeotropy or removing water by membrane separation or the like can be mentioned.

Linear low-density polyethylene is obtained by polymerizing ethylene and a small amount of α-olefin by a low-pressure polymerization method (gas phase polymerization method using a Ziegler-Natta catalyst or liquid phase polymerization method using a metallocene catalyst). . Linear low-density polyethylene has many short molecular chains in its molecular chain and is excellent in sealing performance.

Linear low-density polyethylene is less than 0.93 g/cm ³ , preferably 0.91 g/cm ³ or more and less than 0.93 g/cm ³ , more preferably 0.912 g/cm ³ or more and 0.928 g/cm ³ or less More preferably, it has a density of 0.915 g/cm ³ or more and 0.925 g/cm ³ or less. The density of linear low-density polyethylene is a value measured according to the method specified in A method of JIS K7112-1980 after annealing according to JIS K6760-1995. If the linear low-density polyethylene has a density of 0.91 g/cm ³ or more, the rigidity of the sealant layer containing the linear low-density polyethylene can be increased, and it can be suitably used as the inner layer of the packaging bag. Also, if the density of the linear low-density polyethylene is less than 0.93 g/cm ³ , the mechanical strength of the sealant layer can be increased, and it can be suitably used as the inner layer of the packaging bag.

Linear low-density polyethylene is 0.1 g/10 min or more and 10 g/10 min or less, preferably 0.2 g/10 min or more and 9 g/10 min or less, more preferably 1 g/10 min or more and 8.5 g/10 min. It has a melt flow rate (MFR) of: The melt flow rate is a value measured by method A under conditions of a temperature of 190° C. and a load of 21.18 N in the method specified in JIS K7210-1995. If the MFR of the linear low-density polyethylene is 0.1 g/10 minutes or more, the extrusion load during molding can be reduced. Moreover, if the MFR of the linear low-density polyethylene is 10 g/10 minutes or less, the mechanical strength of the sealant layer can be increased.

In the present invention, the biomass polyethylene that is preferably used is a biomass-derived linear low-density polyethylene manufactured by Braskem (trade name: SLL118, density: 0.916 g/cm ³ , MFR: 1.0 g/10 min. , biomass degree 87%), biomass-derived linear low-density polyethylene manufactured by Braskem (trade name: SLL318, density: 0.918 g/cm ³ , MFR: 2.7 g/10 min, biomass degree 87%), Biomass-derived linear low-density polyethylene manufactured by Braskem (trade name: SLH218, density: 0.916 g/cm ³ , MFR: 2.3 g/10 minutes, biomass degree: 87%).

Biomass-derived linear low-density polyethylene is produced using, for example, sugarcane as a raw material. The degree of dispersion of such sugarcane-derived linear low-density polyethylene can be 4 or more and 7 or less. On the other hand, the polydispersity of fossil-derived linear low-density polyethylene is usually 1.5 or more and 3.5 or less.

The thickness of the entire sealant layer is preferably 40 μm or more and 80 μm or less, more preferably 45 μm or more and 70 μm or less. If the thickness of the sealant layer is within the above range, sufficient sealability can be imparted when the packaging bag is produced. In addition, the thickness of the intermediate layer in the sealant layer is preferably 20% or more and 50% or less, more preferably 30% or more and 40% or less, with respect to the thickness of the entire sealant layer. Also, the thickness of the inner layer and the outer layer may be the same or different.

[Print layer]
The printed layer contains letters, numbers, pictures, figures, symbols, patterns, etc. It is a layer that forms any desired printed pattern. The printed layer can be provided as necessary, for example, it can be provided between the base material layer and the sealant layer. The printed layer may be provided on the entire surface of the base material layer, or may be provided on a part thereof. The print layer can be formed using conventionally known pigments and dyes, and the formation method is not particularly limited.

The print layer preferably has a thickness of 0.1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less, still more preferably 1 μm or more and 3 μm or less.

[Adhesion layer]
An adhesion layer is a layer provided when arbitrary two layers are adhered, and can be provided, for example, between a print layer and a sealant layer.

The adhesive layer can be an adhesive layer formed by applying an adhesive to the surface of the layer on the side to be laminated and drying it when two layers are adhered by a dry lamination method. Examples of adhesives include one-component or two-component curing or non-curing vinyl, (meth)acrylic, polyamide, polyester, polyether, polyurethane, epoxy, rubber, and others. A solvent-type, water-based, or emulsion-type adhesive can be used. A cured product of a polyol and an isocyanate compound can be used as the two-liquid curing adhesive. Examples of coating methods for the lamination adhesive include a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fontaine method, a transfer roll coating method, and other methods. .

The adhesive layer may be an adhesive resin layer used when bonding two layers by a sand lamination method. Thermoplastic resins that can be used for the adhesive resin layer include polyethylene-based resins, polypropylene-based resins, cyclic polyolefin-based resins, or copolymer resins, modified resins, or mixtures (including alloys) containing these resins as main components. ) can be used. Polyolefin resins include, for example, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), polypropylene (PP), metallocene catalyst Ethylene-α-olefin copolymer polymerized using ethylene-polypropylene random or block copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene- Ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-maleic acid copolymer, ionomer resin, adhesion between layers In order to improve the above, it is possible to use an acid-modified polyolefin resin obtained by modifying the above polyolefin resin with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, or itaconic acid. can. Further, a resin obtained by graft polymerization or copolymerization of an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or an ester monomer can be used as the polyolefin resin. These materials can be used singly or in combination of two or more. Cyclic polyolefins such as ethylene-propylene copolymers, polymethylpentene, polybutene, and polynorbonene can be used as cyclic polyolefin resins. These resins can be used singly or in combination. As the polyethylene-based resin described above, the biomass content can be further improved by using the above-described biomass-derived ethylene as a monomer unit.

When the adhesive resin layer is laminated by the melt extrusion lamination method, an anchor coat layer formed by applying an anchor coat agent and drying it may be provided on the surface of the layer to be laminated. The anchor coating agent includes any resin having a heat resistance temperature of 135° C. or higher, such as an anchor coating agent made of vinyl-modified resin, epoxy resin, urethane resin, polyester resin, polyethyleneimine, etc. Especially, An anchor coating agent which is a cured product of a polyacrylic or polymethacrylic resin (polyol) having two or more hydroxyl groups and an isocyanate compound as a curing agent can be preferably used. In addition, a silane coupling agent may be used together as an additive, and nitrocellulose may be used together to improve heat resistance.

The number of adhesive layers in the laminate may be one, or two or more may be included. For example, when two adhesive layers are included in a laminate, one adhesive layer may be referred to as an adhesive layer, and the other adhesive layer may be referred to as a second adhesive layer.

The anchor coat layer after drying has a thickness of 0.1 μm or more and 1 μm or less, preferably 0.3 μm or more and 0.5 μm or less. The dried adhesive layer has a thickness of 1 μm or more and 10 μm or less, preferably 2 μm or more and 5 μm or less. The adhesive resin layer preferably has a thickness of 5 μm or more and 50 μm or less, preferably 10 μm or more and 30 μm or less.

[Other layers]
The laminate according to the present invention may further include a thermoplastic resin layer or the like as another layer. The same material as the adhesive resin layer can be used for the thermoplastic resin layer.

The laminate according to the invention may comprise barrier layers as further layers. The barrier layer is provided to extend the storage period of the contents, and includes a metal foil such as aluminum, a vapor deposition layer of a metal such as aluminum, a metal oxide such as aluminum oxide, an inorganic oxide such as silicon oxide, and an ethylene oxide layer. - Resin layers having gas barrier properties such as vinyl alcohol copolymer (EVOH), polyvinylidene chloride resin (PVDC), and aromatic polyamide such as nylon MXD6 can be used. Further, on the vapor deposition layer, the general formula R1nM (OR2) m (wherein R1 and R2 represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n is 0 or more represents an integer, m represents an integer of 1 or more, and n+m represents the valence of M.) and at least one or more alkoxides represented by the above polyvinyl alcohol-based resin and / or A gas barrier coating film obtained from a transparent gas barrier composition which contains an ethylene-vinyl alcohol copolymer and is polycondensed by a sol-gel method in the presence of a sol-gel catalyst, acid, water, and an organic solvent. may be provided.

<Method for manufacturing laminate>
The method for producing the laminate according to the present invention is not particularly limited, and it can be produced using a conventionally known method such as a dry lamination method or a sand lamination method.

The laminate according to the present invention is imparted with chemical functions, electrical functions, magnetic functions, mechanical functions, friction/wear/lubricating functions, optical functions, thermal functions, surface functions such as biocompatibility, and the like. For the purpose, it is also possible to apply secondary processing. Examples of secondary processing include embossing, painting, adhesion, printing, metallizing (plating, etc.), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.). Also, the laminate according to the present invention can be subjected to lamination (dry lamination or extrusion lamination), bag making, and other post-treatments to produce a molded product.

<Packaging bag>
A packaging bag according to the present invention includes the laminate described above. For example, using the above laminate, folding it in two, or preparing two laminates, overlapping the sealant surfaces with each other, and further sealing the peripheral edge thereof, for example, a side seal type , 2-side seal type, 3-side seal type, 4-side seal type, envelope seal type, palm seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, gusset type, etc. By heat-sealing with, various forms of packaging bags can be produced.

In the above, as the heat sealing method, known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, and ultrasonic sealing can be used.

Since the packaging bag has excellent antistatic performance while exhibiting a high degree of biomass, it can be suitably used for sealing powdery materials that may adhere to the surroundings of the packaging bag. Powdery contents include, for example, dry foods such as wheat flour, barley flour, rice flour, potato starch, and seasoning powders, powder detergents, pharmaceutical powders, metal powders, and the like.

A packaging bag according to the present invention will be described with reference to the drawings. An example of a schematic front view of a pouch according to the present invention is shown in FIG.
The pouch 30 shown in FIG. 3 is produced in the form of a standing pouch, in which the sealant layers of the wall films 31, 31' (using the laminate described above) are arranged to face each other, and the wall films 31, 31' are arranged to face each other. The bottom film (which may be the same as or different from the wall film) 32 is folded inward between the lower parts of the bottom film and inserted up to the bottom film folded part 33. It is heat-sealed with a ship bottom-shaped bottom sealing portion 34 including a portion to form a bottom portion. At this time, substantially semicircular notch portions 32a and 32b of the bottom sheet may be provided in the vicinity of both lower ends of the folded bottom film 32 to form the bottom sealing portion 34. FIG. Next, the side edges of the wall films 31, 31' are heat-sealed with the side sealing portions 35a, 35b to form a trunk portion, and the upper end portion is left as a filling port for contents. The upper sealing portion 36 provided at the filling port at the upper end portion is heat-sealed by, for example, degassing sealing after the contents are filled from this portion. In addition, below the upper seal part 36, a zipper tape 37 having a male tape of a zipper tape attached to one wall film and a female tape attached to the other wall film is provided, so that it can be used as a standing pouch with a zipper tape. good. Also, between the upper seal portion 36 and the zipper tape 37, a printed perforation line 38 and notches 39a and 39b at both ends thereof may be provided. In the above example, the standing pouch 30 is configured using two wall films and one bottom film, but one film or two films are used to configure the standing pouch. You may make it

The fastener tape is heat-bonded to the inner surface of one wall film and to the inner surface of the other wall film so as to face the first tape body having the convex male fitting portion thermally bonded to the inner surface of the wall film. and a second tape body having a grooved female fitting portion. When the outer layer of the sealant layer is made of polyethylene, the zipper tape is also preferably made of polyethylene from the viewpoint of heat-bonding the zipper tape to the inner surface of the wall film (the outer layer of the sealant layer). Linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, or high-density polyethylene is preferably used for the zipper tape. It is more preferred to use low density polyethylene.

<Other aspects>
According to a third aspect of the invention,
A laminate comprising at least a substrate layer and a sealant layer in this order,
The laminate has antistatic performance,
The sealant layer has a three-layer structure of an inner layer, an intermediate layer, and an outer layer in order from the base layer side,
A laminate is provided wherein an intermediate layer of the sealant layer comprises biomass-derived linear low density polyethylene.
In the third aspect of the present invention, it is preferable that the intermediate layer of the sealant layer further contains linear low-density polyethylene derived from fossil fuel.
In the third aspect of the present invention, the inner and outer layers of the sealant layer preferably contain linear low-density polyethylene derived from fossil fuels.
In the third aspect of the present invention, the intermediate layer of the sealant layer preferably has a biomass degree of 50% or more and 95% or less.
In the third aspect of the present invention, the biomass degree of the entire sealant layer is preferably 10% or more and 35% or less.
In the third aspect of the present invention, the thickness of the entire sealant layer is preferably 40 µm or more and 80 µm or less.
In the 3rd aspect of this invention, it is preferable that the said base material layer contains an antistatic agent.
In the third aspect of the present invention, it is preferable that the laminate further comprises a printed layer between the base material layer and the sealant layer.
In the third aspect of the present invention, it is preferable that the laminate further comprises an adhesive layer between the printed layer and the sealant layer.
A fourth aspect of the present invention provides a packaging bag comprising the laminate.

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

[Example 1]
<Production of Laminate 1>
An antistatic biaxially stretched polyethylene terephthalate film (thickness: 12 μm, Emblet PTME manufactured by Unitika Ltd.) was prepared as a base layer, and a printed layer was formed on one surface of the polyethylene terephthalate film by gravure printing. In addition, the inner layer is a linear low-density polyethylene resin derived from fossil fuel (density: 0.918 g/cm ³ , MFR: 3.8 g/10 min, biomass degree: 0%), and the intermediate layer is a biomass-derived straight-chain resin. 80 parts by mass of linear low-density polyethylene (LLDPE, manufactured by Braskem, trade name: SLL118, density: 0.916 g/cm ³ , MFR: 1.0 g/10 min, biomass content: 87%) and fossil fuel-derived linear chain A mixed resin (biomass degree 70%) consisting of 20 parts by mass of low-density polyethylene (biomass degree), and a linear low-density polyethylene derived from fossil fuel as an outer layer (density: 0.918 g / cm ³ , MFR: 3.8 g / 10 minutes, Three layers of resin with biomass degree: 0%) are co-extruded to form a film by an inflation method, and a biomass-derived laminated polyethylene film (biomass degree: 23%, thickness: 50 μm, thickness ratio of each layer (inner layer: Intermediate layer:outer layer)=1:1:1) was obtained. Next, the printed layer surface of the antistatic biaxially stretched polyethylene terephthalate film and the inner layer surface of the biomass-derived laminated polyethylene film are bonded together with a two-liquid curing adhesive (manufactured by Mitsui Chemicals, Inc., A-969V/A-5 ) to obtain a laminate 1 in which a substrate layer, a printed layer, an adhesive layer, and a sealant layer (inner layer, intermediate layer, outer layer) are laminated in this order.

[Comparative Example 1]
<Production of laminate 2>
Laminate 2 was obtained in the same manner as in Example 1, except that the antistatic biaxially stretched polyethylene terephthalate film of the base layer was changed to a biaxially stretched polyethylene terephthalate film (thickness 12 μm) containing no antistatic agent. rice field.

<Manufacturing of pouches>
The laminate obtained in Example 1 was used as a wall film and a bottom film, the sealant layers were heat-sealed, and a zipper tape made of linear low-density polyethylene (manufactured by Idemitsu Unitech Co., Ltd., trade name: : LL-217) was attached to prepare a standing pouch with zipper tape shown in FIG. Similarly, using the laminate obtained in Comparative Example 1, a standing pouch shown in FIG. 3 was produced.

<Antistatic performance test>
Each pouch obtained above was filled with flour and heat-sealed to seal. Next, after opening the upper part of these pouches and removing the fitting of the zipper tape, the opening was tilted and the flour was taken out. . As a result, Example 1 was able to reduce the amount of flour adhering to the inner surface of the pouch compared to Comparative Example 1.

REFERENCE SIGNS LIST 10, 20 laminate 11, 21 base layer 12, 22 sealant layer 13, 23 inner layer 14, 24 intermediate layer 15, 25 outer layer 26 printed layer 27 adhesive layer 30 packaging bag 31, 31' wall film 32 bottom film 32a, 32b Bottom film notch portion 33 Bottom film folded portion 34 Bottom sealing portion 35a, 35b Side sealing portion 36 Top sealing portion 37 Zipper tape 38 Cut line 39a, 39b Notch

Claims (8)

A laminate comprising at least a substrate layer and a sealant layer in this order,
The laminate has antistatic performance,
The sealant layer has a three-layer structure of an inner layer, an intermediate layer, and an outer layer in order from the base layer side,
The resin constituting the intermediate layer of the sealant layer is only biomass-derived linear low-density polyethylene and fossil fuel-derived linear low-density polyethylene,
The resin constituting the inner layer of the sealant layer is only fossil fuel-derived linear low-density polyethylene,
A laminate, wherein the thickness of the entire sealant layer is 40 μm or more and 70 μm or less. 2. The laminate of claim 1, wherein an outer layer of the sealant layer comprises linear low density polyethylene derived from fossil fuels. The laminate according to claim 1 or 2, wherein the intermediate layer of the sealant layer has a biomass degree of 50% or more and 95% or less. The laminate according to any one of claims 1 to 3, wherein the biomass degree of the entire sealant layer is 10% or more and 35% or less. The laminate according to any one of claims 1 to 4, wherein the base layer contains an antistatic agent. The laminate according to any one of claims 1 to 5, wherein the laminate further comprises a print layer between the base layer and the sealant layer. 7. The laminate of Claim 6, wherein the laminate further comprises an adhesive layer between the print layer and the sealant layer. A packaging bag comprising the laminate according to any one of claims 1 to 7.

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