Laminate and packaging bag including same

Abstract

Provided is a laminate that can reduce the environmental load. [Solution] The laminate comprises at least a first substrate layer, a second substrate layer, and a sealant layer, in this order. The laminate further comprises a metal-deposited layer located between the first substrate layer and the second substrate layer or between the second substrate layer and the sealant layer. The second substrate layer contains polyethylene terephthalate with biomass-derived ethylene glycol as the diol unit and fossil fuel-derived terephthalic acid as the dicarboxylic acid unit.

Description

[Technical field]

[0001] The present invention relates to a laminate including at least a first base material layer, a second base material layer, and a sealant layer in this order, and further to a packaging bag including the laminate. [Background technology]

[0002] Bags made of soft packaging materials such as PET and nylon are used to store fluid contents such as liquids and powders, and solid contents such as sweets. Such bags are constructed by heat-welding a front film and a back film facing each other to form a seal part, as described in Patent Document 1, for example. In this case, the storage part for storing the contents is defined as a space surrounded by the film and the seal part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-254997 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, with the growing demand for the creation of a recycling-oriented society, there is a desire to move away from fossil fuels in the materials field, just as there is in the energy field. For example, it is desirable to reduce the amount of fossil fuels used by using raw materials derived from biomass in the production of laminates.

[0005] An object of the present invention is to provide a packaging bag and a laminate that can effectively solve such problems. [Means for solving the problem]

[0006] The present invention is a laminate comprising at least a first substrate layer, a second substrate layer, and a sealant layer in this order, the laminate further comprising a metal vapor deposition layer located between the first substrate layer and the second substrate layer, or between the second substrate layer and the sealant layer, the second substrate layer comprising polyethylene terephthalate having biomass-derived ethylene glycol as a diol unit and fossil fuel-derived terephthalic acid as a dicarboxylic acid unit. Effect of the Invention

[0007] According to the present invention, it is possible to provide a laminate capable of reducing the environmental load. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to the present invention. [Diagram 2] FIG. 1 is a schematic cross-sectional view showing an example of a laminate according to the present invention. [Diagram 3] 1 is a schematic front view showing an example of a packaging bag according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Laminate> The laminate according to the present invention comprises at least a first substrate layer, a second substrate layer, and a sealant layer in this order, and further comprises a metal vapor deposition layer located between the first substrate layer and the second substrate layer, or between the second substrate layer and the sealant layer. The laminate may further comprise an adhesive layer, a printed layer, or other layers. When the laminate comprises two or more adhesive layers or other layers, each layer may have the same composition or different compositions.

[0010] The laminate according to the present invention will be described with reference to the drawings. Examples of schematic cross-sectional views of the laminate according to the present invention are shown in Figs. 1 and 2.

[0011] 1 includes, in this order, a first base material layer 11, a printed layer 15, an adhesive layer 16, a metal vapor deposition layer 14, a second base material layer 12, an adhesive layer 17, and a sealant layer 13. In a packaging bag including the laminate 10, the sealant layer 13 is located on the innermost surface.

[0012] 2 includes, in this order, a first base material layer 11, a printed layer 15, an adhesive layer 16, a second base material layer 12, a metal vapor deposition layer 14, an adhesive layer 17, and a sealant layer 13. In a packaging bag including the laminate 10, the sealant layer 13 is located on the innermost surface.

[0013] Each layer constituting the laminate will now be described.

[0014] [Base material layer] The laminate according to the present invention includes at least a first base material layer and a second base material layer located closer to the inner surface of the laminate than the first base material layer. By including at least two base material layers, the strength and hand-tearability of a packaging bag made from the laminate can be improved.

[0015] [First base layer] (First Configuration of First Base Material Layer)

[0016] The first base layer according to the first configuration is a resin layer containing, for example, polyolefin such as polypropylene, etc. The first base layer is preferably stretched, and more preferably biaxially stretched.

[0017] When the first base layer is made of a biaxially oriented polypropylene film, the biaxially oriented polypropylene film has a great advantage in that it is excellent in moisture resistance, water resistance, chemical resistance, tensile strength, bending strength, etc., and is particularly inexpensive. The thickness of the first base layer in the first configuration is, for example, 10 μm or more and 40 μm or less.

[0018] (Second Configuration of First Base Material Layer) The first base layer according to the second configuration is a resin layer containing polyethylene terephthalate. The first base layer is preferably stretched, and more preferably biaxially stretched.

[0019] The polyethylene terephthalate used in the first substrate layer may be derived from biomass or fossil fuel. By using fossil fuel-derived polyethylene terephthalate in the first substrate layer, the adhesion with the metal deposition layer can be improved. In addition, the first substrate layer may contain both biomass-derived polyethylene terephthalate and fossil fuel-derived polyethylene terephthalate. By using biomass-derived polyethylene terephthalate in at least a part of the first substrate layer, the biomass degree of the entire laminate can be improved.

[0020] When the first base layer is a stretched polyethylene terephthalate film, the stretched polyethylene terephthalate film used for the first base 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, and in the TD direction of preferably 150 MPa or more and 300 MPa or less, more preferably 150 MPa or more and 300 MPa or less, and a tensile elongation in the MD direction of preferably 50% or more and 250% or less, more preferably 70% or more and 200% or less, and in the TD direction of preferably 50% or more and 250% or less, more preferably 60% or more and 200% or less. The tensile strength and tensile elongation can be measured in accordance with JIS K 7127.

[0021] The first base layer according to the second configuration has a thickness of preferably 5 μm to 40 μm, more preferably 8 μm to 25 μm. If the thickness of the first base layer is within the above range, it is easy to mold and can be suitably used as a packaging material.

[0022] (Third configuration of first base material layer) The first base layer according to the third configuration is a resin layer containing polyamide such as nylon, etc. The first base layer is preferably stretched, and more preferably biaxially stretched.

[0023] Examples of polyamide include nylon 6, nylon 6,6, nylon 9, nylon 11, nylon 12, nylon 6 / 66, nylon 66 / 610, nylon MXD6, etc. By using a polyamide for the first base material layer, the strength required for the packaging bag can be improved.

[0024] When the first base layer is a stretched nylon film, the nylon film used for the first base layer has a tensile strength in the MD direction of preferably 150 MPa or more and 350 MPa or less, more preferably 200 MPa or more and 300 MPa or less, and a tensile elongation in the MD direction of preferably 50% or more and 200% or less, more preferably 70% or more and 150% or less, and a tensile elongation in the TD direction of preferably 30% or more and 200% or less, more preferably 50% or more and 150% or less.

[0025] The first base layer according to the third configuration has a thickness of preferably 5 μm to 40 μm, more preferably 8 μm to 25 μm. If the thickness of the first base layer is within the above range, it is easy to mold and can be suitably used as a packaging material.

[0026] [Second base layer] The second substrate layer contains biomass-derived polyethylene terephthalate (hereinafter also referred to as PET). Biomass-derived PET is PET that contains biomass-derived ethylene glycol as a diol unit and fossil fuel-derived terephthalic acid as a dicarboxylic acid unit. The second substrate layer may further contain fossil fuel-derived PET that contains fossil fuel-derived ethylene glycol as a diol unit and fossil fuel-derived terephthalic acid as a dicarboxylic acid unit. It is sufficient that the second substrate layer as a whole achieves the following biomass degree. In the present invention, the second substrate layer contains biomass-derived PET, which can reduce the amount of fossil fuel-derived PET compared to conventional methods, thereby reducing the environmental load.

[0027] In the present invention, the "biomass degree" (carbon concentration derived from biomass) is a value measured by measuring the amount of carbon derived from biomass by radiocarbon (C14) measurement. Carbon dioxide in the atmosphere contains a certain proportion of C14 (105.5 pMC), and it is known that the C14 content in plants that grow by absorbing carbon dioxide from the atmosphere, such as corn, is also about 105.5 pMC. It is also known that fossil fuels contain very little C14. Therefore, the proportion of carbon derived from biomass can be calculated by measuring the proportion of C14 in the total carbon atoms in PET. In the present invention, the C14 content in PET is calculated as P C14 The content of carbon derived from biomass, P bio It can be calculated as follows: P bio (%)=P C14 / 105.5×100

[0028] PET is a polymer of ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms in a molar ratio of 1:1. If only biomass-derived ethylene glycol is used, the content of biomass-derived carbon in PET is P biois 20%. In the present invention, the content of biomass-derived carbon measured by radioactive carbon (C14) is preferably 10% to 20% and may be 10% to 19% relative to the total carbon in the biomass-derived PET. When the content of biomass-derived carbon in the biomass-derived PET is 10% or more, it is suitable as a carbon offset material. In addition, the content of biomass-derived carbon in the fossil fuel-derived PET produced using ethylene glycol derived from fossil fuel and dicarboxylic acid derived from fossil fuel is 0%, and the biomass degree of the fossil fuel-derived PET is 0%.

[0029] In the present invention, the biomass ratio of the second base layer is 5% or more, preferably 10% or more, and more preferably 15% or more. If the biomass ratio of the second base layer is 5% or more, the amount of PET derived from fossil fuels can be reduced compared to conventional methods, thereby reducing the environmental burden.

[0030] When the second base layer is a stretched PET film, the PET film used for the second base layer has a tensile strength in the MD direction of preferably 150 MPa to 300 MPa, more preferably 200 MPa to 300 MPa, and in the TD direction of preferably 150 MPa to 300 MPa, more preferably 150 MPa to 300 MPa, and a tensile elongation in the MD direction of preferably 50% to 250%, more preferably 70% to 200%, and in the TD direction of preferably 50% to 250%, more preferably 60% to 200%. The tensile strength and tensile elongation can be measured in accordance with JIS K 7127.

[0031] The second base layer preferably has a thickness of 5 μm to 40 μm, more preferably 8 μm to 25 μm. If the thickness of the second base layer is within the above range, it is easy to mold and can be suitably used as a packaging material.

[0032] [Sealant layer] The sealant layer is the innermost layer when the package is made. is a layer formed of a thermoplastic resin that can be fused to each other by heat. The sealant layer may contain a resin material derived from a fossil fuel or may contain a resin material derived from a biomass.

[0033] The resin material forming the sealant layer is not particularly limited as long as it is a resin that can be fused to each other by heat, and specific examples thereof include low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), ethylene-α-olefin copolymers polymerized using a metallocene catalyst, random or block copolymers of ethylene and polypropylene, polypropylene, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), and the like. ), ethylene-methyl methacrylate copolymer (EMMA), ionomer resin, heat-sealable ethylene-vinyl alcohol resin, or polyolefin resin such as methylpentene resin, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, polyethylene, polypropylene or cyclic olefin copolymer, acid-modified polyolefin resin obtained by modifying polyolefin resin with unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, polyvinyl acetate resin, poly(meth)acrylic resin, polyvinyl chloride resin, and others. These may be used alone or as a mixture of two or more kinds. The sealant layer can be used as a film or sheet of the above-mentioned resin, or as a coating film thereof.

[0034] When polyethylene is used as the resin material forming the sealant layer, in addition to ethylene obtained from fossil fuels, polymerized ethylene derived from biomass may be used as the raw material. Specific examples of biomass-derived ethylene include those described in JP 2012-251006 A. By using polyethylene obtained by polymerizing ethylene derived from biomass as the material constituting the sealant layer, it is possible to form a layer made of a carbon-neutral material, and by using it in combination with the base layer, it is possible to further reduce the amount of fossil fuel used and reduce the environmental load.

[0035] As the biomass-derived ethylene, commercially available products may be used; for example, a sugarcane-derived linear low-density polyethylene resin "C4LL-LL118 (d=0.916, MFR=1.0 g / 10 min)" manufactured by Braskem, or a sugarcane-derived low-density polyethylene resin "SBC118 (d=0.918, MFR=8.1 g / 10 min)" manufactured by Braskem, can be used.

[0036] In this embodiment, the sealant layer is one layer, but two or more sealant layers may be provided. When the sealant layer has two or more layers, each layer may have the same composition or different compositions. For example, the sealant layer may be composed of three layers, a first layer, a second layer, and a third layer, laminated in order, and the first layer and the third layer may be made of a resin material derived from fossil fuels, and the second layer may be made of a resin material containing a resin material derived from biomass. When the sealant layer is composed of two or more layers, they can be laminated using a co-extrusion method.

[0037] The thickness of the sealant layer is preferably from 10 to 80 μm, and more preferably from 20 to 50 μm.

[0038] [Metal deposition layer] Next, the metal deposition layer will be described.

[0039] The metal vapor deposition layer is a layer made of a metal vapor deposition film that can be formed by a conventionally known method. By providing a metal vapor deposition layer, it is possible to impart or improve gas barrier properties that prevent the transmission of oxygen gas, water vapor, and the like. Furthermore, by including a metal vapor deposition layer in the laminate, in addition to the above-mentioned gas barrier properties, it is possible to impart or improve light blocking properties that prevent the transmission of visible light, ultraviolet rays, and the like. Furthermore, it is possible to impart metallic luster to the packaging bag, thereby improving the design. The laminate may have two or more metal vapor deposition layers. When two or more metal vapor deposition layers are provided, each may have the same composition or different compositions.

[0040] Examples of the metal deposition film that can be used include aluminum (Al), magnesium (Mg), tin (Sn), sodium (Na), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), gold (Au), chromium (Cr), etc. In particular, for packaging bags, it is preferable to have an aluminum deposition film.

[0041] The thickness of the metal vapor deposition film varies depending on the type of metal used, but it is desirable to select any thickness within the range of, for example, 50 Å to 2000 Å, preferably 100 Å to 1000 Å. More specifically, in the case of an aluminum vapor deposition film, the thickness is desirably 50 Å to 600 Å, more preferably 100 Å to 450 Å.

[0042] The metal vapor deposition film can be formed on the second base layer by the following formation methods: Examples of the formation method of the metal vapor deposition film include physical vapor deposition methods (PVD methods) such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition methods (CVD methods) such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.

[0043] [Print layer] The printing layer is a layer that forms any desired printed pattern such as letters, numbers, pictures, figures, symbols, patterns, etc., for decoration, display of contents, display of expiration date, display of manufacturer, seller, etc., and for imparting aesthetics. The printing layer can be provided as necessary, for example, between the first substrate layer and the metal deposition layer. The printing layer may be provided on the entire surface of the first substrate layer, or may be provided on a part of it. The printing layer can be formed using a conventionally known pigment or dye, and the method of forming the printing layer is not particularly limited.

[0044] The printing 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, and even more preferably 1 μm or more and 3 μm or less.

[0045] [Adhesive layer] The adhesive layer is a layer that is provided when any two layers are to be bonded together, and can be provided, for example, between a first base material layer and a second base material layer, or between a second base material layer and a sealant layer.

[0046] The adhesive layer can be formed by a conventional method, for example, a dry lamination method. When two layers are bonded by the dry lamination method, the adhesive layer is formed by applying an adhesive to the surface of the layer to be laminated and drying it. The adhesive to be applied can be, for example, a one-component or two-component cured or non-cured type vinyl, (meth)acrylic, polyamide, polyester, polyether, polyurethane, epoxy, rubber, or other solvent-based, water-based, or emulsion-type adhesive. A two-component cured adhesive can be a cured product of a polyol and an isocyanate compound. The above-mentioned lamination adhesive can be applied by, for example, a direct gravure roll coating method, a gravure roll coating method, a kiss coating method, a reverse roll coating method, a Fountain method, a transfer roll coating method, or other methods.

[0047] <Method of manufacturing laminate> The method for producing the laminate according to the present invention is not particularly limited, and it can be produced by a conventionally known method such as a dry lamination method.

[0048] The laminate according to the present invention can be subjected to secondary processing for the purpose of imparting surface functions such as chemical functions, electrical functions, magnetic functions, mechanical functions, friction / wear / lubrication functions, optical functions, thermal functions, and biocompatibility. Examples of secondary processing include embossing, painting, adhesion, printing, metallizing (plating, etc.), machining, and surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.). In addition, the laminate according to the present invention can be subjected to lamination (dry lamination and extrusion lamination), bag making, and other post-treatment processes to manufacture molded products.

[0049] <Packaging bag> The packaging bag according to the present invention can be suitably used, for example, when storing a drip bag for coffee powder or the like. For such packaging bags, for example, the laminate described above is used, and the laminate is folded in two or three, or two sheets of the laminate are prepared, and the surface of the sealant layer of the front laminate is overlapped with the surface of the sealant layer of the back laminate so as to face each other, and the peripheral edge is heat-sealed by, for example, a side seal type, a two-sided seal type, a three-sided seal type, a four-sided seal type, an envelope seal type, a grooving seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a square bottom seal type, or the like, to produce packaging bags of various shapes. Also, a gusset-type packaging bag can be produced by inserting a folded laminate between the front laminate and the back laminate and heat-sealing the laminate. All of the laminates constituting the packaging bag do not have to be the laminate described above according to the present invention. In other words, at least a portion of the laminate constituting the packaging bag may be a laminate having a first base layer containing biomass-derived PET, and the other portion of the laminate constituting the packaging bag may be a laminate including a second base layer made of fossil fuel-derived PET.

[0050] In the above, the heat sealing can be performed by a known method such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, etc.

[0051] The packaging bag according to the present invention will be described with reference to the drawings. An example of a schematic front view of a four-sided bag according to the present invention is shown in Fig. 3.

[0052] 3, the sealant layers of wall films 31, 31' using the laminate are arranged facing each other, and the three edges of the outer periphery except the upper edge are heat-sealed to form a peripheral seal 32. After filling the contents 33 from the upper opening, the upper edge is heat-sealed to form an upper end seal 34 after degassing, for example, to obtain a four-sided bag 30 with the contents 33 sealed therein. Note that in the above example, an example of constructing the four-sided bag 30 using two wall films has been described, but a packaging bag may also be constructed using a single film. EXAMPLES

[0053] Next, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the description of the following examples as long as it does not depart from the gist of the present invention.

[0054] [Example] As the first base layer, a biaxially oriented polypropylene film (P2161, manufactured by Toyobo Co., Ltd., thickness 20 μm) was prepared as described in the first configuration above. Next, a printed layer was formed by gravure printing on the surface of the biaxially oriented polypropylene film that was to be located on the inner side when constructing a packaging bag. In this way, a biaxially oriented polypropylene film with a printed layer formed on the inner side was obtained.

[0055] In addition, a biaxially stretched biomass-derived PET film (biomass content: 13%, thickness: 12 μm) was prepared as the second substrate layer, which was made using terephthalic acid derived from fossil fuels and ethylene glycol (biomass polyester) derived from biomass. Next, a 450 Å thick aluminum vapor deposition film was formed as a metal vapor deposition layer on the surface of the biomass-derived PET film that would be located on the inner side when constructing a packaging bag. In this way, a biomass-derived PET film with a metal vapor deposition layer formed on the outer side was obtained.

[0056] In addition, a non-oriented linear low-density polyethylene film (manufactured by Mitsui Chemicals Tocello, Inc., TUX (registered trademark) MCS, thickness 25 μm) was prepared as a sealant layer.

[0057] Next, a biaxially oriented polypropylene film, a biomass-derived PET film, and a non-oriented linear low-density polyethylene film were laminated in this order by a dry lamination method to produce a laminate 10 shown in Figure 1. The layer structure of this laminate 10 is expressed as follows. OPP / Mark / DL / Vapour-deposited layer / Bio-PET / DL / LL The " / " indicates the boundary between layers. The leftmost layer is the layer that constitutes the outer surface of the laminate, and the rightmost layer is the layer that constitutes the inner surface of the laminate. "OPP" means biaxially oriented polypropylene film. "Print" means print layer. "DL" means adhesive layer containing adhesive. "Bio-PET" means PET film derived from biomass. "LL" means unoriented linear low density polyethylene film.

[0058] The adhesive layer between the biaxially stretched polypropylene film and the biomass-derived PET film contains a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., base agent: RU-40, hardener: H-4). The adhesive layer between the biomass-derived PET film and the unstretched linear low-density polyethylene film contains a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., base agent: RU-40, hardener: H-4).

[0059] [Comparative Example] A laminate was produced in the same manner as in the example, except that a biaxially stretched PET film (biomass content: 0%, Toyobo, E5100, thickness 12 μm) made from fossil fuel-derived terephthalic acid and fossil fuel-derived ethylene glycol was used as the second base layer. The layer structure of the laminate is expressed as follows. OPP / mark / DL / evaporated layer / fossil PET / DL / LL "Fossil PET" refers to PET film derived from fossil fuels.

[0060] <Manufacturing packaging bags> The laminate obtained in the example was used as a wall film, the sealant layers were arranged facing each other, and the periphery and upper end were heat sealed to produce the four-sided bag shown in Figure 3. In the same manner, the laminate obtained in the comparative example was used to produce the four-sided bag shown in Figure 3.

[0061] <Hand tearability test> The four-sided bag obtained above was cut to check its hand-tearability. (Evaluation Criteria) ○: Cutting was possible without applying excessive force. ×: It was not possible to cut without applying excessive force.

[0062] The results of the above performance evaluation tests are shown in Table 1. [Table 1]

[0063] As a result, all of the packaging bags made from the laminates obtained in the Examples and Comparative Examples had good hand-tearability. Therefore, packaging bags similar to those made from fossil fuels could be obtained from biomass-derived products that can reduce environmental impact.

[0064] (Other Aspects) In a laminate according to another aspect of the present invention, the laminate may further comprise a printed layer located between the first substrate layer and the metal vapor deposition layer, or between the first substrate layer and the second substrate layer.

[0065] In the laminate according to another aspect of the present invention, the metal vapor deposition layer may be made of a vapor-deposited film of aluminum.

[0066] Another aspect of the present invention is a packaging bag comprising the above-described laminate. [Explanation of symbols]

[0067] 10 Laminate 11 First base layer 12 Second base layer 13 Sealant layer 14 Metal deposited layer 15 Printing layer 30 packaging bags

Claims

1. A laminate including at least a first base material layer, a second base material layer, and a sealant layer in this order, The laminate further includes a metal vapor deposition layer located between the first base layer and the second base layer, or between the second base layer and the sealant layer; The first base layer is a biaxially oriented polypropylene film having a thickness of 10 μm or more and 40 μm or less, the second base layer contains polyethylene terephthalate having ethylene glycol derived from biomass as a diol unit and terephthalic acid derived from fossil fuel as a dicarboxylic acid unit, The thickness of the sealant layer is 20 μm or more and 50 μm or less, the sealant layer includes a first layer, a second layer, and a third layer in this order; the first layer comprises fossil fuel derived polyethylene; The second layer comprises biomass-derived polyethylene.

2. The laminate according to claim 1 , further comprising a printed layer located between the first substrate layer and the metal vapor deposition layer or between the first substrate layer and the second substrate layer.

3. The laminate according to claim 1 or 2, wherein the metal vapor deposition layer is made of a vapor-deposited film of aluminum.

4. A packaging bag comprising the laminate according to any one of claims 1 to 3.

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